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The design of a chemical process involves many aspects: from profitability, flexibility and reliability to safety to the environment. While each of these is important, in this work, the focus will be on profitability and the environment. Key to the study of these aspects is the ...
Molecular Thermodynamics for Chemical Process Design
ERIC Educational Resources Information Center
Prausnitz, J. M.
Discusses that aspect of thermodynamics which is particularly important in chemical process design: the calculation of the equilibrium properties of fluid mixtures, especially as required in phase-separation operations. (MLH)
Molecular thermodynamics for chemical process design.
Prausnitz, J M
Chemical process design requires quantitative information on the equilibrium properties of a variety of fluid mixtures. Since the experimental effort needed to provide this information is often prohibitive in cost and time, chemical engineers must utilize rational estimation techniques based on limited experimental data. The basis for such techniques is molecular thermodynamics, a synthesis of classical and statistical thermodynamics, molecular physics, and physical chemistry.
Chemical kinetics and oil shale process design
Burnham, A.K.
Oil shale processes are reviewed with the goal of showing how chemical kinetics influences the design and operation of different processes for different types of oil shale. Reaction kinetics are presented for organic pyrolysis, carbon combustion, carbonate decomposition, and sulfur and nitrogen reactions.
An Integrated Course and Design Project in Chemical Process Design.
ERIC Educational Resources Information Center
Rockstraw, David A.; And Others
Describes a chemical engineering course curriculum on process design, analysis, and simulation. Includes information regarding the sequencing of engineering design classes and the location of the classes within the degree program at New Mexico State University. Details of course content are provided. (DDR)
The design and improvement of chemical processes can be very challenging. The earlier energy conservation, process economics and environmental aspects are incorporated into the process development, the easier and less expensive it is to alter the process design. Process emissio...
Chemical Process Design: An Integrated Teaching Approach.
ERIC Educational Resources Information Center
Debelak, Kenneth A.; Roth, John A.
Reviews a one-semester senior plant design/laboratory course, focusing on course structure, student projects, laboratory assignments, and course evaluation. Includes discussion of laboratory exercises related to process waste water and sludge. (SK)
Designing a chemical process normally includes aspects of economic and environmental disciplines. In this work we describe methods to quickly and easily evaluate the economics and potential environmental impacts of a process, with the hydrodealkylation of toluene as an example. ...
Designing a chemical process normally includes aspects of economic and environmental disciplines. In this work we describe methods to quickly and easily evaluate the conomics and potential environmental impacts of a process, with the hydrodealkylation of toluene as an example. Th...
New Vistas in Chemical Product and Process Design.
Zhang, Lei; Babi, Deenesh K; Gani, Rafiqul
Design of chemicals-based products is broadly classified into those that are process centered and those that are product centered. In this article, the designs of both classes of products are reviewed from a process systems point of view; developments related to the design of the chemical product, its corresponding process, and its integration are highlighted. Although significant advances have been made in the development of systematic model-based techniques for process design (also for optimization, operation, and control), much work is needed to reach the same level for product design. Timeline diagrams illustrating key contributions in product design, process design, and integrated product-process design are presented. The search for novel, innovative, and sustainable solutions must be matched by consideration of issues related to the multidisciplinary nature of problems, the lack of data needed for model development, solution strategies that incorporate multiscale options, and reliability versus predictive power. The need for an integrated model-experiment-based design approach is discussed together with benefits of employing a systematic computer-aided framework with built-in design templates.
Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori
The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.
A Framework to Design and Optimize Chemical Flooding Processes
Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori
The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.
Mojdeh Delshad; Gary A. Pope; Kamy Sepehrnoori
The goal of this proposed research is to provide an efficient and user friendly simulation framework for screening and optimizing chemical/microbial enhanced oil recovery processes. The framework will include (1) a user friendly interface to identify the variables that have the most impact on oil recovery using the concept of experimental design and response surface maps, (2) UTCHEM reservoir simulator to perform the numerical simulations, and (3) an economic model that automatically imports the simulation production data to evaluate the profitability of a particular design. Such a reservoir simulation framework is not currently available to the oil industry. The objectives of Task 1 are to develop three primary modules representing reservoir, chemical, and well data. The modules will be interfaced with an already available experimental design model. The objective of the Task 2 is to incorporate UTCHEM reservoir simulator and the modules with the strategic variables and developing the response surface maps to identify the significant variables from each module. The objective of the Task 3 is to develop the economic model designed specifically for the chemical processes targeted in this proposal and interface the economic model with UTCHEM production output. Task 4 is on the validation of the framework and performing simulations of oil reservoirs to screen, design and optimize the chemical processes.
Incorporating Industrial Ecology into Hierarchical Chemical Process Design: Determining Targets for the Exchange of Waste
The exchange of waste to be used as a recycled feed has long been encouraged by practitioners of industrial ecology. Industrial ecology is a field t...
Portfolio Assessment on Chemical Reactor Analysis and Process Design Courses
ERIC Educational Resources Information Center
Alha, Katariina
Assessment determines what students regard as important: if a teacher wants to change students' learning, he/she should change the methods of assessment. This article describes the use of portfolio assessment on five courses dealing with chemical reactor and process design during the years 1999-2001. Although the use of portfolio was a new…
Prodrugs design based on inter- and intramolecular chemical processes.
Karaman, Rafik
This review provides the reader a concise overview of the majority of prodrug approaches with the emphasis on the modern approaches to prodrug design. The chemical approach catalyzed by metabolic enzymes which is considered as widely used among all other approaches to minimize the undesirable drug physicochemical properties is discussed. Part of this review will shed light on the use of molecular orbital methods such as DFT, semiempirical and ab initio for the design of novel prodrugs. This novel prodrug approach implies prodrug design based on enzyme models that were utilized for mimicking enzyme catalysis. The computational approach exploited for the prodrug design involves molecular orbital and molecular mechanics (DFT, ab initio, and MM2) calculations and correlations between experimental and calculated values of intramolecular processes that were experimentally studied to assign the factors determining the reaction rates in certain processes for better understanding on how enzymes might exert their extraordinary catalysis.
Chemicals and chemical processes are at the heart of most environmental problems. This isn't surprising since chemicals make up all of the products we use in our lives. The common use of cjhemicals makes them of high interest for systems analysis, particularly because of environ...
The design of chemical processes is normally an interactive process of synthesis and analysis. When one also desires or needs to limit the amount of pollution generated by the process the difficulty of the task can increase substantially. In this work, we show how combining hier...
The objective of this cooperative agreement was to postulate a means by which an engineer could routinely include environmental considerations in day-to-day conceptual design problems; a means that could easily integrate with existing design processes, and thus avoid massive retr...
There is an opportunity to minimize the potential environmental impacts (PEIs) of industrial chemical processes by providing process designers with timely data nad models elucidating environmentally favorable design options. The second generation of the Waste Reduction (WAR) algo...
A catalytic reforming process has been studied using hierarchical design and simulation calculations. Aproximations for the fugitive emissions indicate which streams allow the most value to be lost and which have the highest potential environmental impact. One can use tis inform...
A catalytic reforming process has been studied using hierarchical design and simulation calculations. Approximations for the fugitive emissions indicate which streams allow the most value to be lost and which have the highest potential environmental impact. One can use this infor...
Development of Chemical Process Design and Control for Sustainability
This contribution describes a novel process systems engineering framework that couples advanced control with sustainability evaluation and decision making for the optimization of process operations to minimize environmental impacts associated with products, materials, and energy....
The Waste Reduction Decision Support System (WAR DSS) is a Java-based software product providing comprehensive modeling of potential adverse environmental impacts (PEI) predicted to result from newly designed or redesigned chemical manufacturing processes. The purpose of this so...
Development of Chemical Process Design and Control for ...
This contribution describes a novel process systems engineering framework that couples advanced control with sustainability evaluation and decision making for the optimization of process operations to minimize environmental impacts associated with products, materials, and energy. The implemented control strategy combines a biologically inspired method with optimal control concepts for finding more sustainable operating trajectories. The sustainability assessment of process operating points is carried out by using the U.S. E.P.A.'s Gauging Reaction Effectiveness for the ENvironmental Sustainability of Chemistries with a multi-Objective Process Evaluator (GREENSCOPE) tool that provides scores for the selected indicators in the economic, material efficiency, environmental and energy areas. The indicator scores describe process performance on a sustainability measurement scale, effectively determining which operating point is more sustainable if there are more than several steady states for one specific product manufacturing. Through comparisons between a representative benchmark and the optimal steady-states obtained through implementation of the proposed controller, a systematic decision can be made in terms of whether the implementation of the controller is moving the process towards a more sustainable operation. The effectiveness of the proposed framework is illustrated through a case study of a continuous fermentation process for fuel production, whose materi
Xpert Design and Diagnostic's (XDD)potassium permanganate in situ chemical oxidation (ISCO) process was evaluated under the EPA Superfund Innovative Technology Evaluation (SITE) Program at the former MEC Building site located in Hudson, New Hampshire. At this site, both soil and ...
A novel double loop control model design for chemical unstable processes.
Cong, Er-Ding; Hu, Ming-Hui; Tu, Shan-Tung; Xuan, Fu-Zhen; Shao, Hui-He
In this manuscript, based on Smith predictor control scheme for unstable process in industry, an improved double loop control model is proposed for chemical unstable processes. Inner loop is to stabilize integrating the unstable process and transform the original process to first-order plus pure dead-time dynamic stable process. Outer loop is to enhance the performance of set point response. Disturbance controller is designed to enhance the performance of disturbance response. The improved control system is simple with exact physical meaning. The characteristic equation is easy to realize stabilization. Three controllers are separately design in the improved scheme. It is easy to design each controller and good control performance for the respective closed-loop transfer function separately. The robust stability of the proposed control scheme is analyzed. Finally, case studies illustrate that the improved method can give better system performance than existing design methods.
Membrane process designs in the recovery of bio-fuels and bio-chemicals
Leeper, S.A.
In this presentation, the emerging membrane unit operations and process designs that can be used in recovery of fuels and organic chemicals produced via bioconversion are briefly summarized. Product recovery costs are a major barrier to increased use of bioconversion for the production of fuels and chemicals. The integration of developing membrane unit operations into product recovery schemes may reduce process energy requirements and cost. Membrane unit operations that are used or studied in recovery of bio-fuels and organic chemicals include pervaporation (PV), vapor permeation (VPe), reverse osmosis (RO), membrane extraction, and electrodialysis (ED). Although it can be argued that ultrafiltration (UF) is used to purify bio-fuels and bio-chemicals, UF is not included in this survey for two reasons: (1) the primary uses of UF in bioprocessing are to clarify fermentation broth and to retain cells/enzymes in bioreactors and (2) the literature on UF in biotechnology is expansive. Products of bioconversion for which data are compiled include ethanol, acetone, butanol, glycerol, isopropanol, ethyl acetate, fusel oils, acetaldehyde, acetic acid, butyric acid, citric acid, propionic acid, succinic acid, and tartaric acid. 13 refs.
Chemical process hazards analysis
The Office of Worker Health and Safety (EH-5) under the Assistant Secretary for the Environment, Safety and Health of the US Department (DOE) has published two handbooks for use by DOE contractors managing facilities and processes covered by the Occupational Safety and Health Administration (OSHA) Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119), herein referred to as the PSM Rule. The PSM Rule contains an integrated set of chemical process safety management elements designed to prevent chemical releases that can lead to catastrophic fires, explosions, or toxic exposures. The purpose of the two handbooks, ``Process Safety Management for Highly Hazardous Chemicals`` and ``Chemical Process Hazards Analysis,`` is to facilitate implementation of the provisions of the PSM Rule within the DOE. The purpose of this handbook ``Chemical Process Hazards Analysis,`` is to facilitate, within the DOE, the performance of chemical process hazards analyses (PrHAs) as required under the PSM Rule. It provides basic information for the performance of PrHAs, and should not be considered a complete resource on PrHA methods. Likewise, to determine if a facility is covered by the PSM rule, the reader should refer to the handbook, ``Process Safety Management for Highly Hazardous Chemicals`` (DOE- HDBK-1101-96). Promulgation of the PSM Rule has heightened the awareness of chemical safety management issues within the DOE. This handbook is intended for use by DOE facilities and processes covered by the PSM rule to facilitate contractor implementation of the PrHA element of the PSM Rule. However, contractors whose facilities and processes not covered by the PSM Rule may also use this handbook as a basis for conducting process hazards analyses as part of their good management practices. This handbook explains the minimum requirements for PrHAs outlined in the PSM Rule. Nowhere have requirements been added beyond what is specifically required by the rule.
Chemical feedstock from hardwood by organosolv hydrolysis: Computer-aided process design and economic evaluation
NASA Astrophysics Data System (ADS)
Nguyen, X. N.
A two stage catalyzed organosolv plant producing ethanol, furfural, acetic acid, and soluble lignin from wood waste was investigated. The GEMS computer system was used to aid the preliminary design and cost estimation of the proposed wood chemical plant. For a plant processing 1000 ovendry tons of wood per day, a capital investment of $66 million and an operating expense of about $20 million per year were estimated. The capital cost calculated compares favorably with other published estimates. Sensitivity analyses of some key factors in the proposed process disclose that the recovery efficiency of ethanol used in the lignin extraction stage is most important in determining the process economics. Ethanol solvent recovery of about 98% is required. At 95% recovery efficiency, conversion to glucose in the acid hydrolysis step above 90% is necessary for the ethanol selling price to be comparable to the current market price.
Using an On-Line Tool To Investigate Chemical Engineering Seniors' Concept of the Design Process.
ERIC Educational Resources Information Center
Streveler, Ruth A.; Miller, Ronald L.; Boyd, Thomas M.
In this study, multidimensional scaling (MDS) was used to measure how 23 chemical engineering seniors categorized key design terms at the beginning and end of a capstone design course. An on-line method was developed to collect the MDS data. The results suggest that some important design concepts were not well understood, even at the end of the…
The second generation of the Waste Reduction (WAR) Algorithm is constructed as a decision support system (DSS) in the design of chemical manufacturing facilities. The WAR DSS is a software tool that can help reduce the potential environmental impacts (PEIs) of industrial chemical...
Optimizing the lanthanum adsorption process onto chemically modified biomaterials using factorial and response surface design.
Gabor, Andreea; Davidescu, Corneliu Mircea; Negrea, Adina; Ciopec, Mihaela; Grozav, Ion; Negrea, Petru; Duteanu, Narcis
The rare metals' potential to pollute air, water, soil, and especially groundwater has received lot of attention recently. One of the most common rare earth group elements, lanthanum, is used in many industrial branches, and due to its toxicity, it needs to be eliminated from all residual aqueous solutions. The goal of this study was to evaluate the control of the adsorption process for lanthanum removal from aqueous solutions, using cellulose, a known biomaterial with high adsorbent properties, cheap, and environment friendly. The cellulose was chemically modified by functionalization with sodium β-glycerophosphate. The experimental results obtained after factorial design indicate optimum adsorption parameters as pH 6, contact time 60 min, and temperature 298 K, when the equilibrium concentration of lanthanum was 250 mg L(-1), and the experimental adsorption capacity obtained was 31.58 mg g(-1). Further refinement of the optimization of the adsorption process by response surface design indicates that at pH 6 and the initial concentration of 256 mg L(-1), the adsorption capacity has maximum values between 30.87 and 36.73 mg g(-1).
Implementation of an Innovative Teaching Project in a Chemical Process Design Course at the University of Cantabria, Spain
ERIC Educational Resources Information Center
Galan, Berta; Muñoz, Iciar; Viguri, Javier R.
This paper shows the planning, the teaching activities and the evaluation of the learning and teaching process implemented in the Chemical Process Design course at the University of Cantabria, Spain. Educational methods to address the knowledge, skills and attitudes that students who complete the course are expected to acquire are proposed and…
This work describes a method for using spreadsheet analyses of process designs and retrofits to provide simple and quick economic and environmental evaluations simultaneously. The method focuses attention onto those streams and components that have the largest monetary values and...
NASA Technical Reports Server (NTRS)
Beyerle, F. J.
Chemical processes presented in this document include cleaning, pickling, surface finishes, chemical milling, plating, dry film lubricants, and polishing. All types of chemical processes applicable to aluminum, for example, are to be found in the aluminum alloy section. There is a separate section for each category of metallic alloy plus a section for non-metals, such as plastics. The refractories, super-alloys and titanium, are prime candidates for the space shuttle, therefore, the chemical processes applicable to these alloys are contained in individual sections of this manual.
Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide
Mark A. Eiteman
This report describes results toward developing a process to sequester CO{sub 2} centered on the enzyme pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The first phase of this research has focused on strain development and on process development. Progress in strain development has been made in three areas. The gene encoding for alcohol dehydrogenase has been ''knocked out'' of the bacteria, and thereby eliminating the synthesis of the by-product ethanol. The gene for glucokinase has been overexpressed in the production strain with the goal of faster utilization of glucose (and hence CO{sub 2}). Efforts have continued toward integrating pyruvate carboxylase gene (pyc) onto the E. coli chromosome. Progress in process development has come in conducting several dozen fermentation experiments to find a defined medium that would be successful for the growth of the bacteria, while permitting a high rate of CO{sub 2} utilization in a subsequent prolonged production phase. Using this defined medium, the strains that continue to be constructed are being compared for CO{sub 2} utilization, so that we may understand the factors that govern the biological sequestration process.
Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide
Mark Eiteman
This report describes results toward developing a process to sequester CO{sub 2} centered on the enzymes PEP carboxylase and pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The study reports on strain development and process development. In the area of strain development, knockouts in genes which divert carbon from the enzymatic steps involved in CO{sub 2} consumption were completed, and were shown not to affect significantly the rate of CO{sub 2} sequestration and succinic acid generation. Furthermore, the pyc gene encoding for pyruvate carboxylase proved to be unstable when integrated onto the chromosome. In the area of process development, an optimal medium, pH and base counterion were obtained, leading to a sequestration rate as great as 800 mg/Lh. Detailed studies of gas phase composition demonstrated that CO{sub 2} composition has a significant affect on CO{sub 2} sequestration, while the presence of 'toxic' compounds in the gas, including NO{sub 2}, CO and SO{sub 2} did not have a detrimental effect on sequestration. Some results on prolonging the rate of sequestration indicate that enzyme activities decrease with time, suggesting methods to prolong enzyme activity may benefit the overall process.
The INSIDE project integrating inherent SHE in chemical process development and plant design
Rogers, R.L.; Mansfield, D.P.; Malmen, Y.
The concept of {open_quote}Inherently Safer{close_quote} plant has been with us now for many years, but despite its clear potential safety, health, environmental (SHE) and cost benefits, there have been few attempts to systematically consider or apply inherently safer approaches in process development and plant design. This is one of the findings of a pilot study commissioned by the United Kingdom (UK) Health and Safety Executive and carried out by AEA Technology to assess the current status of Inherent Safety in UK Industry. This pilot study has now been expanded into a major industry/CEC Industrial Safety co-sponsored project (The INSIDE Project) which is taking an European wide view on the current status of inherently SHE approaches. It will also develop tools for chemists and engineers to use to identify and evaluate safer options and to optimise processes and plant designs accordingly. This paper summarises the findings of the HSE pilot study and describes the results of Phase 1 of the CEC project which have given a valuable insight into the way SHE issues are addressed throughout the process development and design lifecycle and highlighted ways in which these can be improved to encourage the adoption of inherent SHE approaches. The overall framework being used for tool development is described and the early tool ideas and their underlying principles are also discussed. 19 refs., 1 fig., 4 tabs.
Column flotation: Processes, designs and practices. Process engineering for the chemical, metals and minerals industry, Volume 2
Rubinstein, J.B. . Flotation Equipment and Process Engineering Dept.)
Practically all mined ores of non-ferrous and rare metals and an increasing share of industrial minerals and coal are processed through flotation. This book presents the analysis of a wide range of problems in the process theory of flotation columns, including the first published analysis of models of flotation froths. The experience of pilot tests and commercial applications of column flotation for mineral processing and in waste water treatment circuits are also considered. This is the first book to consider column flotation design and operation experience and to present data on column parameters. Topics include: design of flotation columns; aerators in flotation columns; experimental methods of column aerohydrodynamics investigation; aerohydrodynamic characteristics of flotation columns; experimental investigation of the flotation process in columns; kinetics aspects of column flotation; scaling-up methods for flotation columns; structure and mass transfer in flotation froths; column flotation practice; and column flotation control.
Process Design for the Biocatalysis of Value-Added Chemicals from Carbon Dioxide
Mark A. Eiteman
This report describes results toward developing a process to sequester CO{sub 2} centered on the enzyme pyruvate carboxylase. The process involves the use of bacteria to convert CO{sub 2} and glucose as a co-substrate and generates succinic acid as a commodity chemical product. The phases of research have included strain development and process development. Though we continue to work on one important component of strain development, the research has principally focused on process development. In the previous year we constructed several strains which would serve as templates for the CO{sub 2} sequestration, including the knock-out of genes involved in the formation of undesirable byproducts. This project period the focus has been on the integration of the pyruvate carboxylase gene (pyc) onto the E. coli chromosome. This has proven to be a difficult task because of relatively low expression of the gene and resulting low enzyme activity when only one copy of the gene is present on the chromosome. Several molecular biology techniques have been applied, with some success, to improve the level of protein activity as described herein. Progress in process development has come as a result of conducting numerous fermentation experiments to select optimal conditions for CO{sub 2} sequestration. This process-related research has progressed in four areas. First, we have clarified the range of pH which results in the optimal rate of sequestration. Second, we have determined how the counterion used to control the pH affects the sequestration rate. Third, we have determined how CO{sub 2} gas phase composition impacts sequestration rate. Finally, we have made progress in determining the affect of several potential gaseous impurities on CO{sub 2} sequestration; in particular we have completed a study using NO{sub 2}. Although the results provide significant guidance as to process conditions for CO{sub 2} sequestration and succinate production, in some cases we do not yet understand
Designing for the environment requires consideration of environmental impacts. The Generalized WAR Algorithm is the methodology that allows the user to evaluate the potential environmental impact of the design of a chemical process. In this methodology, chemicals are assigned val...
Fiber-optic sensor design for chemical process and environmental monitoring
NASA Astrophysics Data System (ADS)
Mahendran, R. S.; Wang, L.; Machavaram, V. R.; Pandita, S. D.; Chen, R.; Kukureka, S. N.; Fernando, G. F.
"Curing" is a term that is used to describe the cross-linking reactions in a thermosetting resin system. Advanced fiber-reinforced composites are being used increasingly in a number of industrial sectors including aerospace, marine, sport, automotive and civil engineering. There is a general realization that the processing conditions that are used to manufacture the composite can have a major influence on its hot-wet mechanical properties. This paper is concerned with the design and demonstration of a number of sensor designs for in situ monitoring of the cross-linking reactions of a commercially available thermosetting resin system. Simple fixtures were constructed to enable a pair of cleaved optical fibers with a defined gap between the end-faces to be held in position. The resin system was introduced into this gap and the cure kinetics were followed by transmission infrared spectroscopy. A semi-empirical model was used to describe the cure process using the data obtained at different cure temperatures. The same sensor system was used to detect the ingress of moisture into the cured resin system.
Assessing Chemical Process Sustainability with GREENSCOPE
GREENSCOPE is a sustainability assessment tool used to evaluate and assist in the design of chemical processes. The goal is to minimize resource use, prevent or reduce releases, and increase the economic feasibility of a chemical process.
Design, Fabrication, Processing, and Testing of Micro-Electro-Mechanical Chemical Sensors
3.2.2 Electrostatic Theory. .. .. .. .. ... ... ... .... .. 48 3.2.3 Capacitance . .. .. .. .. ... ... .... ... ... .... 50 3.3 Chemical Transport Theory...available to heat the thin film coating, effecting both an intrinsic conductivity change due to the semiconducting material and an extrinsic change due to...other surface-fabricated MOSFET device, except that the metal gate is replaced by an external reference electrode and is coated with a chemically
Design of a compact ultrahigh vacuum-compatible setup for the analysis of chemical vapor deposition processes
Weiss, Theodor; Nowak, Martin; Zielasek, Volkmar Bäumer, Marcus; Mundloch, Udo; Kohse-Höinghaus, Katharina
Optimizing thin film deposition techniques requires contamination-free transfer from the reactor into an ultrahigh vacuum (UHV) chamber for surface science analysis. A very compact, multifunctional Chemical Vapor Deposition (CVD) reactor for direct attachment to any typical UHV system for thin film analysis was designed and built. Besides compactness, fast, easy, and at the same time ultimately clean sample transfer between reactor and UHV was a major goal. It was achieved by a combination of sample manipulation parts, sample heater, and a shutter mechanism designed to fit all into a NW38 Conflat six-ways cross. The present reactor design is versatile to be employed for all commonly employed variants of CVD, including Atomic Layer Deposition. A demonstration of the functionality of the system is provided. First results of the setup (attached to an Omicron Multiprobe x-ray photoelectron spectroscopy system) on the temperature dependence of Pulsed Spray Evaporation-CVD of Ni films from Ni acetylacetonate as the precursor demonstrate the reactor performance and illustrate the importance of clean sample transfer without breaking vacuum in order to obtain unambiguous results on the quality of CVD-grown thin Ni films. The widely applicable design holds promise for future systematic studies of the fundamental processes during chemical vapor deposition or atomic layer deposition.
Sustainability in the Design, Synthesis and Analysis of Chemical Engineering Processes 1st edition (Preface)
This book preface explains the needs found by the book editors for assembling the state of the art of technical and scientific knowledge relevant to chemical engineering, sustainability, and sustainable uses of wastes and materials management, and to do so in an accessible and c...
Implementation of an innovative teaching project in a Chemical Process Design course at the University of Cantabria, Spain
NASA Astrophysics Data System (ADS)
Galan, Berta; Muñoz, Iciar; Viguri, Javier R.
This paper shows the planning, the teaching activities and the evaluation of the learning and teaching process implemented in the Chemical Process Design course at the University of Cantabria, Spain. Educational methods to address the knowledge, skills and attitudes that students who complete the course are expected to acquire are proposed and discussed. Undergraduate and graduate engineers' perceptions of the methodology used are evaluated by means of a questionnaire. Results of the teaching activities and the strengths and weaknesses of the proposed case study are discussed in relation to the course characteristics. The findings of the empirical evaluation shows that the excessive time students had to dedicate to the case study project and dealing with limited information are the most negative aspects obtained, whereas an increase in the students' self-confidence and the practical application of the methodology are the most positive aspects. Finally, improvements are discussed in order to extend the application of the methodology to other courses offered as part of the chemical engineering degree.
Design, Synthesis, and Chemical Processing of Hierarchical Ceramic Structures for Aerospace Applications
Figure 2. The alkoxides rapidly hydrolyze in moist air or of zirconium hydrous oxides , as shown in Figure 4. The water giving a series of condensed...utanoxanes, but quan- zirconium hydrous- oxide precipitate is converted to ZrO2 titative cleavage of all the alkoxy groups is difficult to thermally and...demonstrated that nanosized powders can be processed to obtain ceramic composites with ultrafine microstructures and high densities. Nanosized powders of
Experiments To Demonstrate Chemical Process Safety Principles.
ERIC Educational Resources Information Center
Dorathy, Brian D.; Mooers, Jamisue A.; Warren, Matthew M.; Mich, Jennifer L.; Murhammer, David W.
Points out the need to educate undergraduate chemical engineering students on chemical process safety and introduces the content of a chemical process safety course offered at the University of Iowa. Presents laboratory experiments demonstrating flammability limits, flash points, electrostatic, runaway reactions, explosions, and relief design.…
Chemical Sensing in Process Analysis.
ERIC Educational Resources Information Center
Hirschfeld, T.; And Others
Discusses: (1) rationale for chemical sensors in process analysis; (2) existing types of process chemical sensors; (3) sensor limitations, considering lessons of chemometrics; (4) trends in process control sensors; and (5) future prospects. (JN)
A Nuclear Reactor and Chemical Processing Design for Production of Molybdenum-99 with Crystalline Uranyl Nitrate Hexahydrate Fuel
NASA Astrophysics Data System (ADS)
Stange, Gary Michael
Medical radioisotopes are used in tens of millions of procedures every year to detect and image a wide variety of maladies and conditions in the human body. The most widely-used diagnostic radioisotope is technetium-99m, a metastable isomer of technetium-99 that is generated by the radioactive decay of molybdenum-99. For a number of reasons, the supply of molybdenum-99 has become unreliable and the techniques used to produce it have become unattractive. This has spurred the investigation of new technologies that avoid the use of highly enriched uranium to produce molybdenum-99 in the United States, where approximately half of the demand originates. The first goal of this research is to develop a critical nuclear reactor design powered by solid, discrete pins of low enriched uranium. Analyses of single-pin heat transfer and whole-core neutronics are performed to determine the required specifications. Molybdenum-99 is produced directly in the fuel of this reactor and then extracted through a series of chemical processing steps. After this extraction, the fuel is left in an aqueous state. The second goal of this research is to describe a process by which the uranium may be recovered from this spent fuel solution and reconstituted into the original fuel form. Fuel recovery is achieved through a crystallization step that generates solid uranyl nitrate hexahydrate while leaving the majority of fission products and transuranic isotopes in solution. This report provides background information on molybdenum-99 production and crystallization chemistry. The previously unknown thermal conductivity of the fuel material is measured. Following this is a description of the modeling and calculations used to develop a reactor concept. The operational characteristics of the reactor core model are analyzed and reported. Uranyl nitrate crystallization experiments have also been conducted, and the results of this work are presented here. Finally, a process flow scheme for uranium
TMTD), N-oxydiethylene-2- benzothiazole sulfenamide (MOR) and N-cyclohexyl- benzothiazole -2-sulfenamide (CBS). The chemical structures of the accelerators...disulfide CBS - N-cyclohexyl- benzothiazole -2-sulfenamide MOR - N-oxydiethylene- benzothiazole -2-sulfenamide AO - Antioxidant SA - Stearic acid 5.5. Results
Evaluation of a no-clean soldering process designed to eliminate the use of ozone depleting chemicals
Iman, R.L.; Armendariz, M.E.; Anderson, D.J. |; Lichtenberg, L.; Van Buren, P.; Paffett, M.T.
The destruction of the Earth`s protective ozone layer is one of today`s largest environmental concerns. Solvent emissions released during the cleaning of printed wiring boards (PWBs) have been identified as a primary contributor to ozone destruction. No-clean soldering (sometimes referred to as self-cleaning) processes represent an ideal solution since they eliminate the need for cleaning after soldering. Elimination of solvent cleaning operations significantly reduces the emissions of ozone depleting chemicals (ODCs), reduces energy consumption, and reduces product costs. Several no-clean soldering processes have been developed over the past few years. The program`s purpose was to evaluate the no-clean soldering process and to determine if hardware produced by the process is acceptable for military applications. That is, determine if the no-clean process produces hardware that is as reliable as that soldered with the existing rosin-based flux solvent cleaning process.
Chemical processing of lunar materials
NASA Technical Reports Server (NTRS)
Criswell, D. R.; Waldron, R. D.
The paper highlights recent work on the general problem of processing lunar materials. The discussion covers lunar source materials, refined products, motivations for using lunar materials, and general considerations for a lunar or space processing plant. Attention is given to chemical processing through various techniques, including electrolysis of molten silicates, carbothermic/silicothermic reduction, carbo-chlorination process, NaOH basic-leach process, and HF acid-leach process. Several options for chemical processing of lunar materials are well within the state of the art of applied chemistry and chemical engineering to begin development based on the extensive knowledge of lunar materials.
Teaching Process Design through Integrated Process Synthesis
ERIC Educational Resources Information Center
Metzger, Matthew J.; Glasser, Benjamin J.; Patel, Bilal; Hildebrandt, Diane; Glasser, David
The design course is an integral part of chemical engineering education. A novel approach to the design course was recently introduced at the University of the Witwatersrand, Johannesburg, South Africa. The course aimed to introduce students to systematic tools and techniques for setting and evaluating performance targets for processes, as well as…
Future integrated design process
NASA Technical Reports Server (NTRS)
Meyer, D. D.
The design process is one of the sources used to produce requirements for a computer system to integrate and manage product design data, program management information, and technical computation and engineering data management activities of the aerospace design process. Design activities were grouped chronologically and explored for activity type, activity interface, data quantity, and data flow. The work was based on analysis of the design process of several typical aerospace products, including both conventional and supersonic airplanes and a hydrofoil design. Activities examined included research, preliminary design, detail design, manufacturing interface, product verification, and product support. The design process was then described in an IPAD environment--the future.
Lyophilization process design space.
Patel, Sajal Manubhai; Pikal, Michael J
The application of key elements of quality by design (QbD), such as risk assessment, process analytical technology, and design space, is discussed widely as it relates to freeze-drying process design and development. However, this commentary focuses on constructing the Design and Control Space, particularly for the primary drying step of the freeze-drying process. Also, practical applications and considerations of claiming a process Design Space under the QbD paradigm have been discussed.
Evaluation of no-clean solder process designed to eliminate the use of ozone-depleting chemicals
Paffett, M.T.; Farr, J.D.; Rogers, Y.C.; Hutchinson, W.B.
This paper summarizes the LANL contributions to a joint Motorola/SNLA/LANL cooperative research and development agreement study on the reliability of an alternative solder process that is intended to reduce or eliminate the use of ozone-depleting chemicals in the manufacture of printed wire boards (PWBs). This process is termed self-cleaning because of the nature of the thermal chemistry associated with the adipic and formic acid components used in place of traditional solder rosin fluxes. Traditional rosin fluxes used in military electronic hardware applications are cleaned (by requirement) using chlorofluorohydrocarbons. The LANL contribution centers around analytical determination of PWB cleanliness after soldering using the self-cleaning method. Results of these analytical determinations involving primarily surface analysis of boards following temperature, temperature and humidity, and long-term storage testing are described with representative data. It is concluded that the self-cleaning process leaves behind levels of solid residue that are visually and analytically observable using most of these surface analysis techniques. The materials compatibility of electronic components soldered using the self-cleaning soldering process is more fully described in the project report issued by SNLA that encompasses the complete project with statistical lifetime and accelerated aging studies. Analytical surface specificity and suggestions for further work are also given.
Process Security in Chemical Engineering Education
ERIC Educational Resources Information Center
Piluso, Cristina; Uygun, Korkut; Huang, Yinlun; Lou, Helen H.
The threats of terrorism have greatly alerted the chemical process industries to assure plant security at all levels: infrastructure-improvement-focused physical security, information-protection-focused cyber security, and design-and-operation-improvement-focused process security. While developing effective plant security methods and technologies…
Chemical input multiplicity facilitates arithmetical processing.
Margulies, David; Melman, Galina; Felder, Clifford E; Arad-Yellin, Rina; Shanzer, Abraham
We describe the design and function of a molecular logic system, by which a combinatorial recognition of the input signals is utilized to efficiently process chemically encoded information. Each chemical input can target simultaneously multiple domains on the same molecular platform, resulting in a unique combination of chemical states, each with its characteristic fluorescence output. Simple alteration of the input reagents changes the emitted logic pattern and enables it to perform different algebraic operations between two bits, solely in the fluorescence mode. This system exhibits parallelism in both its chemical inputs and light outputs.
Estimation of environment-related properties of chemicals for design of sustainable processes: development of group-contribution+ (GC+) property models and uncertainty analysis.
Hukkerikar, Amol Shivajirao; Kalakul, Sawitree; Sarup, Bent; Young, Douglas M; Sin, Gürkan; Gani, Rafiqul
of the developed property models for the estimation of environment-related properties and uncertainties of the estimated property values is highlighted through an illustrative example. The developed property models provide reliable estimates of environment-related properties needed to perform process synthesis, design, and analysis of sustainable chemical processes and allow one to evaluate the effect of uncertainties of estimated property values on the calculated performance of processes giving useful insights into quality and reliability of the design of sustainable processes.
Synthesis and optimization of integrated chemical processes
Barton, Paul I.; Evans, Lawrence B.
This is the final technical report for the project titled ''Synthesis and optimization of integrated chemical processes''. Progress is reported on novel algorithms for the computation of all heteroazeotropic compositions present in complex liquid mixtures; the design of novel flexible azeotropic separation processes using middle vessel batch distillation columns; and theory and algorithms for sensitivity analysis and numerical optimization of hybrid discrete/continuous dynamic systems.
Microcomponent chemical process sheet architecture
Wegeng, R.S.; Drost, M.K.; Call, C.J.; Birmingham, J.G.; McDonald, C.E.; Kurath, D.E.; Friedrich, M.
The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one chemical process unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation. 26 figs.
Microcomponent chemical process sheet architecture
Wegeng, Robert S.; Drost, M. Kevin; Call, Charles J.; Birmingham, Joseph G.; McDonald, Carolyn Evans; Kurath, Dean E.; Friedrich, Michele
The invention is a microcomponent sheet architecture wherein macroscale unit processes are performed by microscale components. The sheet architecture may be a single laminate with a plurality of separate microcomponent sections or the sheet architecture may be a plurality of laminates with one or more microcomponent sections on each laminate. Each microcomponent or plurality of like microcomponents perform at least one chemical process unit operation. A first laminate having a plurality of like first microcomponents is combined with at least a second laminate having a plurality of like second microcomponents thereby combining at least two unit operations to achieve a system operation.
Walsh, Catherine; Millar, T. J.; Nomura, Hideko
We have developed a high-resolution combined physical and chemical model of a protoplanetary disk surrounding a typical T Tauri star. Our aims were to use our model to calculate the chemical structure of disks on small scales (submilliarcsecond in the inner disk for objects at the distance of Taurus, {approx}140 pc) to investigate the various chemical processes thought to be important in disks and to determine potential molecular tracers of each process. Our gas-phase network was extracted from the UMIST Database for Astrochemistry to which we added gas-grain interactions including freezeout and thermal and non-thermal desorption (cosmic-ray-induced desorption, photodesorption, and X-ray desorption), and a grain-surface network. We find that cosmic-ray-induced desorption has the least effect on our disk chemical structure while photodesorption has a significant effect, enhancing the abundances of most gas-phase molecules throughout the disk and affecting the abundances and distribution of HCN, CN, and CS, in particular. In the outer disk, we also see enhancements in the abundances of H{sub 2}O and CO{sub 2}. X-ray desorption is a potentially powerful mechanism in disks, acting to homogenize the fractional abundances of gas-phase species across the depth and increasing the column densities of most molecules, although there remain significant uncertainties in the rates adopted for this process. The addition of grain-surface chemistry enhances the fractional abundances of several small complex organic molecules including CH{sub 3}OH, HCOOCH{sub 3}, and CH{sub 3}OCH{sub 3} to potentially observable values (i.e., a fractional abundance of {approx}>10{sup -11}).
Chemically amplified photoresist: Materials and processes
NASA Astrophysics Data System (ADS)
Pawloski, Adam Richard
Advances in microfabrication technology to construct smaller and faster integrated circuits depend on improving resolution capabilities of patterning thin films of photoresist materials by photolithographic imaging. Positive-tone, chemically amplified photoresists represent one of the most important classes of photoresist materials. These materials function by the generation of a photoacid catalyst from the decomposition of a photoacid generator with exposure that catalyzes chemical reactions that alter the development rate of the exposed resist. Chemical amplification is derived from the fact that a single molecule of photogenerated catalyst may participate in numerous reactions. Photoacid catalyzes the cleavage of acid-labile protecting groups from the backbone of the resin polymer, increasing the dissolution rate of the resist in aqueous base. A pattern is formed in the photoresist film from the difference between dissolution rates of the exposed and unexposed material. The continual improvement of the resolution of chemically amplified resists depends on understanding, controlling, and optimizing the chemical processes that govern pattern formation, namely photoacid generation, resin deprotection, and resist dissolution. To elucidate how the formulation of the resist affects these processes, a systematic methodology was designed, validated and implemented to analyze the materials and processing of chemically amplified photoresist systems. The efficiency of photoacid generation and the concentration of photoacid produced upon exposure were determined for a wide range of resist formulations, processing conditions, and exposure technologies. The chemical structure of photoacid generators and base quenchers were found to affect the processes of acid-base neutralization, resin deprotection, and resist development. The reaction-diffusion process of photoacid to deprotect the resin was identified to depend on the concentration of the photoacid generator. A much
Idaho Chemical Processing Plant safety document ICPP hazardous chemical evaluation
Harwood, B.J.
This report presents the results of a hazardous chemical evaluation performed for the Idaho Chemical Processing Plant (ICPP). ICPP tracks chemicals on a computerized database, Haz Track, that contains roughly 2000 individual chemicals. The database contains information about each chemical, such as its form (solid, liquid, or gas); quantity, either in weight or volume; and its location. The Haz Track database was used as the primary starting point for the chemical evaluation presented in this report. The chemical data and results presented here are not intended to provide limits, but to provide a starting point for nonradiological hazards analysis.
Chemically assisted mechanical refrigeration process
Vobach, A.R.
There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.
Chemically assisted mechanical refrigeration process
Vobach, A.R.
There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.
Chemically assisted mechanical refrigeration process
Vobach, Arnold R.
There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing he evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.
Chemically assisted mechanical refrigeration process
Vobach, Arnold R.
There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.
Experimental design and optimization of leaching process for recovery of valuable chemical elements (U, La, V, Mo, Yb and Th) from low-grade uranium ore.
Zakrzewska-Koltuniewicz, Grażyna; Herdzik-Koniecko, Irena; Cojocaru, Corneliu; Chajduk, Ewelina
The paper deals with experimental design and optimization of leaching process of uranium and associated metals from low-grade, Polish ores. The chemical elements of interest for extraction from the ore were U, La, V, Mo, Yb and Th. Sulphuric acid has been used as leaching reagent. Based on the design of experiments the second-order regression models have been constructed to approximate the leaching efficiency of elements. The graphical illustrations using 3-D surface plots have been employed in order to identify the main, quadratic and interaction effects of the factors. The multi-objective optimization method based on desirability approach has been applied in this study. The optimum condition have been determined as P=5 bar, T=120 °C and t=90 min. Under these optimal conditions, the overall extraction performance is 81.43% (for U), 64.24% (for La), 98.38% (for V), 43.69% (for Yb) and 76.89% (for Mo) and 97.00% (for Th).
Chemical Processing. Resources in Technology.
ERIC Educational Resources Information Center
Technology Teacher, 1991
Reviews major organic and inorganic chemicals, their products, and the sociocultural impact of the chemical industry. Provides the following learning activity components: objectives, list of materials and equipment, procedures, student quiz with answers, and three references. (SK)
Flow Chemistry for Designing Sustainable Chemical Synthesis (journal article)
An efficiently designed continuous flow chemical process can lead to significant advantages in developing a sustainable chemical synthesis or process. These advantages are the direct result of being able to impart a higher degree of control on several key reactor and reaction par...
Metabolic design for cyanobacterial chemical synthesis.
Oliver, John W K; Atsumi, Shota
Photosynthetic chemical production in cyanobacteria is a promising technology for renewable energy, CO2 mitigation, and fossil fuel replacement. Metabolic engineering has enabled a direct biosynthetic process from CO2 fixation to chemical feedstocks and biofuels, without requiring costly production, storage, and breakdown of cellulose or sugars. However, direct production technology is challenged by a need to achieve high-carbon partitioning to products in order to be competitive. This review discusses principles for the design of biosynthetic pathways in cyanobacteria and describes recent advances in relevant genetic tools. This field is at a critical juncture in assessing the strength and feasibility of carbon partitioning. To address this, we have included the stoichiometry of reducing equivalents and carbon conservation for heterologous pathways, and a method for calculating product yields against a theoretical maximum.
[Signal Processing Suite Design
NASA Technical Reports Server (NTRS)
Sahr, John D.; Mir, Hasan; Morabito, Andrew; Grossman, Matthew
Our role in this project was to participate in the design of the signal processing suite to analyze plasma density measurements on board a small constellation (3 or 4) satellites in Low Earth Orbit. As we are new to space craft experiments, one of the challenges was to simply gain understanding of the quantity of data which would flow from the satellites, and possibly to interact with the design teams in generating optimal sampling patterns. For example, as the fleet of satellites were intended to fly through the same volume of space (displaced slightly in time and space), the bulk plasma structure should be common among the spacecraft. Therefore, an optimal, limited bandwidth data downlink would take advantage of this commonality. Also, motivated by techniques in ionospheric radar, we hoped to investigate the possibility of employing aperiodic sampling in order to gain access to a wider spatial spectrum without suffering aliasing in k-space.
Chemical genomics: a challenge for de novo drug design.
Dean, P M
De novo design provides an in silico toolkit for the design of novel small molecular structures to a set of specified structural constraints. With the avalanche of bioinformatics data, de novo design is ideally suited for exploring molecules that could be useful for chemical genomics. The design process involves manipulation of the input, modification of structural constraints, and further processing of the de novo generated molecules using various modular toolkits. The development of a theoretical framework for each of these stages will provide novel practical solutions to the problem of creating compounds with maximal chemical diversity. This short review describes the fundamental problems encountered in the application of novel chemical design technologies to chemical genomics by means of a formal representation. This notation helps to outline and clarify ideas and hypotheses that can then be explored using mathematical algorithms. It is only by developing this rigorous foundation that in silico design can progress in a rational way.
Chemical design of nanocrystal solids.
Kovalenko, Maksym V
This account highlights our recent and present activities dedicated to chemical synthesis and applications of inorganic nanostructures. In particular, we discuss the potential of metal amides as precursors in the synthesis of metallic and semiconductor nanocrystals. We show the importance of surface chemical functionalization for the emergence of collective electronic properties in nanocrystal solids. We also demonstrate a new kind of long-range ordered, crystalline matter comprising colloidal nanocrystals and atomically defined inorganic clusters. Finally, we point the reader's attention to the high potential benefits of size- and shape-tunability of nanocrystals for achieving higher performance of rechargeable Li-ion battery electrodes.
Chemical process safety at fuel cycle facilities
Ayres, D.A.
This NUREG provides broad guidance on chemical safety issues relevant to fuel cycle facilities. It describes an approach acceptable to the NRC staff, with examples that are not exhaustive, for addressing chemical process safety in the safe storage, handling, and processing of licensed nuclear material. It expounds to license holders and applicants a general philosophy of the role of chemical process safety with respect to NRC-licensed materials; sets forth the basic information needed to properly evaluate chemical process safety; and describes plausible methods of identifying and evaluating chemical hazards and assessing the adequacy of the chemical safety of the proposed equipment and facilities. Examples of equipment and methods commonly used to prevent and/or mitigate the consequences of chemical incidents are discussed in this document.
Life cycle costs for chemical process pumps
Urwin, B.; Blong, R.; Jamieson, C.; Erickson, B.
Though construction and startup costs are always a concern, proper investment in equipment and installation will save money down the line. This is particularly important for heavily used items, such as centrifugal pumps, one of the workhouses of the chemical process industries (CPI). By properly sizing and installing a centrifugal pump, the life and efficiency of the pump can be increased. At the same time, maintenance costs can be reduced. When considering a new pump, there are several areas that require attention. The first is the baseplate design. The impeller is another area of concern. The seal chamber, the third area of importance, must be designed for proper heat dissipation and lubrication of seal faces. Lastly, the power end must be considered. Optimum bearing life, effective oil cooling and minimum shaft deflection are all vital. The paper discusses installation costs, operating cost, maintenance cost, seal environment, and extended bearing life.
P2P is a computer-based tool that supports the comparison of process and product alternatives in terms of environmental impacts. This tool provides screening-level information for use in process design and in product LCA. Twenty one impact categories and data for approximately ...
Chemical Processing of Electrons and Holes.
ERIC Educational Resources Information Center
Anderson, Timothy J.
Presents a synopsis of four lectures given in an elective senior-level electronic material processing course to introduce solid state electronics. Provides comparisons of a large scale chemical processing plant and an integrated circuit. (YP)
Virtual design of chemical penetration enhancers for transdermal drug delivery.
Golla, Sharath; Neely, Brian J; Whitebay, Eric; Madihally, Sundar; Robinson, Robert L; Gasem, Khaled A M
Traditional drug design is a laborious and expensive process that often challenges the pharmaceutical industries. As a result, researchers have turned to computational methods for computer-assisted molecular design. Recently, genetic and evolutionary algorithms have emerged as efficient methods in solving combinatorial problems associated with computer-aided molecular design. Further, combining genetic algorithms with quantitative structure-property relationship analyses has proved effective in drug design. In this work, we have integrated a new genetic algorithm and nonlinear quantitative structure-property relationship models to develop a reliable virtual screening algorithm for the generation of potential chemical penetration enhancers. The genetic algorithms-quantitative structure-property relationship algorithm has been implemented successfully to identify potential chemical penetration enhancers for transdermal drug delivery of insulin. Validation of the newly identified chemical penetration enhancer molecular structures was conducted through carefully designed experiments, which elucidated the cytotoxicity and permeability of the chemical penetration enhancers.
Markov Chains and Chemical Processes
ERIC Educational Resources Information Center
Miller, P. J.
Views as important the relating of abstract ideas of modern mathematics now being taught in the schools to situations encountered in the sciences. Describes use of matrices and Markov chains to study first-order processes. (Author/DF)
Analysis of chemical coal cleaning processes. Final report
Not Available
Six chemical coal cleaning processes were examined. Conceptual designs and costs were prepared for these processes and coal preparation facilities, including physical cleaning and size reduction. Transportation of fine coal in agglomerated and unagglomerated forms was also discussed. Chemical cleaning processes were: Pittsburgh Energy Technology Center, Ledgemont, Ames Laboratory, Jet Propulsion Laboratory (two versions), and Guth Process (KVB). Three of the chemical cleaning processes are similar in concept: PETC, Ledgemont, and Ames. Each of these is based on the reaction of sulfur with pressurized oxygen, with the controlling factor being the partial pressure of oxygen in the reactor. All of the processes appear technically feasible. Economic feasibility is less certain. The recovery of process chemicals is vital to the JPL and Guth processes. All of the processes consume significant amounts of energy in the form of electric power and coal. Energy recovery and increased efficiency are potential areas for study in future more detailed designs. The Guth process (formally designed KVB) appears to be the simplest of the systems evaluated. All of the processes require future engineering to better determine methods for scaling laboratory designs/results to commercial-scale operations. A major area for future engineering is to resolve problems related to handling, feeding, and flow control of the fine and often hot coal.
Design of Chemical Stores--Or Not!
ERIC Educational Resources Information Center
Piggott, Andy
When science departments are designed for new builds, or are to be refurbished or moved to other parts of the school, design of preparation areas should be a major feature. It is vital that the brief contains everything that is needed including, in particular, a chemical store. But no matter how well a brief is specified, the people who actually…
Chemical sensing in process analysis.
Hirschfeld, T; Callis, J B; Kowalski, B R
Improvements in process control, which determine production efficiency and product quality, are critically dependent upon on-line process analysis. The technology of the required instrumentation will be substantially expanded by advances in sensing devices. In the future, the hardware will consist of sensor arrays and miniaturized instruments fabricated by microlithography and silicon micromachining. Chemometrics will be extensively used in software to provide error detection, selfcalibration, and correction as well as multivariate data analysis for the determination of anticipated and unanticipated species. A number of examples of monolithically fabricated sensors now exist and more will be forthcoming as the new paradigms and new tools are widely adopted. A trend toward not only on-line but even in-product sensors is becoming discernible.
Microwave-enhanced chemical processes
Varma, Ravi
A process for disposal of toxic wastes including chlorinated hydrocarbons, comprising, establishing a bed of non-metallic particulates having a high dielectric loss factor. Effecting intimate contact of the particulates and the toxic wastes at a temperature in excess of about 400.degree. C. in the presence of microwave radiation for a time sufficient to break the hydrocarbon chlorine bonds and provide detoxification values in excess of 80 and further detoxifying the bed followed by additional disposal of toxic wastes.
Chemical engineering design of CO oxidation catalysts
NASA Technical Reports Server (NTRS)
Herz, Richard K.
How a chemical reaction engineer would approach the challenge of designing a CO oxidation catalyst for pulsed CO2 lasers is described. CO oxidation catalysts have a long history of application, of course, so it is instructive to first consider the special requirements of the laser application and then to compare them to the characteristics of existing processes which utilize CO oxidation catalysts. All CO2 laser applications require a CO oxidation catalyst with the following characteristics: (1) active at stoichiometric ratios of O2 and CO, (2) no inhibition by CO2 or other components of the laser environment, (3) releases no particulates during vibration or thermal cycling, and (4) long lifetime with a stable activity. In all applications, low consumption of power is desirable, a characteristic especially critical in aerospace applications and, thus, catalyst activity at low temperatures is highly desirable. High power lasers with high pulse repetition rates inherently require circulation of the gas mixture and this forced circulation is available for moving gas past the catalyst. Low repetition rate lasers, however, do not inherently require gas circulation, so a catalyst that did not require such circulation would be favorable from the standpoint of minimum power consumption. Lasers designed for atmospheric penetration of their infrared radiation utilize CO2 formed from rare isotopes of oxygen and this application has the additional constraint that normal abundance oxygen isotopes in the catalyst must not exchange with rare isotopes in the gas mixture.
Microwave-enhanced chemical processes
Varma, R.
A process is disclosed for the disposal of toxic wastes including chlorinated hydrocarbons, comprising, establishing a bed of non-metallic particulates having a high dielectric loss factor. Intimate contact of the particulates and the toxic wastes at a temperature in excess of about 400 C in the presence of microwave radiation for a time sufficient breaks the hydrocarbon chlorine bonds. Detoxification values in excess of 80 are provided and further detoxification of the bed is followed by additional disposal of toxic wastes. 1 figure.
Introducing the "Decider" Design Process
ERIC Educational Resources Information Center
Prasa, Anthony R., Jr.; Del Guercio, Ryan
Engineers are faced with solving important problems every day and must follow a step-by-step design process to arrive at solutions. Students who are taught an effective design process to apply to engineering projects begin to see problems as an engineer would, consider all ideas, and arrive at the best solution. Using an effective design process…
Chemical production processes and systems
Holladay, Johnathan E.; Muzatko, Danielle S.; White, James F.; Zacher, Alan H.
Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.
Chemical production processes and systems
Holladay, Johnathan E; Muzatko, Danielle S; White, James F; Zacher, Alan H
Hydrogenolysis systems are provided that can include a reactor housing an Ru-comprising hydrogenolysis catalyst and wherein the contents of the reactor is maintained at a neutral or acidic pH. Reactant reservoirs within the system can include a polyhydric alcohol compound and a base, wherein a weight ratio of the base to the compound is less than 0.05. Systems also include the product reservoir comprising a hydrogenolyzed polyhydric alcohol compound and salts of organic acids, and wherein the moles of base are substantially equivalent to the moles of salts or organic acids. Processes are provided that can include an Ru-comprising catalyst within a mixture having a neutral or acidic pH. A weight ratio of the base to the compound can be between 0.01 and 0.05 during exposing.
Reengineering the Project Design Process
NASA Technical Reports Server (NTRS)
Casani, E.; Metzger, R.
In response to NASA's goal of working faster, better and cheaper, JPL has developed extensive plans to minimize cost, maximize customer and employee satisfaction, and implement small- and moderate-size missions. These plans include improved management structures and processes, enhanced technical design processes, the incorporation of new technology, and the development of more economical space- and ground-system designs. The Laboratory's new Flight Projects Implementation Office has been chartered to oversee these innovations and the reengineering of JPL's project design process, including establishment of the Project Design Center and the Flight System Testbed. Reengineering at JPL implies a cultural change whereby the character of its design process will change from sequential to concurrent and from hierarchical to parallel. The Project Design Center will support missions offering high science return, design to cost, demonstrations of new technology, and rapid development. Its computer-supported environment will foster high-fidelity project life-cycle development and cost estimating.
U-GAS process for chemical manufacture
Dihu, R.; Leppin, D.; Patel, J.G.
The U-GAS coal gasification process and its potential application to the manufacture of two important industrial chemicals, methanol and ammonia, are described. Pilot plant results, the current status of the process, and economic projections for the cost of manufacture of methanol and ammonia are presented.
Process safety management for highly hazardous chemicals
Purpose of this document is to assist US DOE contractors who work with threshold quantities of highly hazardous chemicals (HHCs), flammable liquids or gases, or explosives in successfully implementing the requirements of OSHA Rule for Process Safety Management of Highly Hazardous Chemicals (29 CFR 1910.119). Purpose of this rule is to prevent releases of HHCs that have the potential to cause catastrophic fires, explosions, or toxic exposures.
Chemicals Industry New Process Chemistry Roadmap
The Materials Technology I workshop was held in November 1998 to address future research needs for materials technology that will support the chemical industry. Areas covered included disassembly, recovery, reuse and renewable technology; new materials; and materials measurement and characterization. The Materials Technology II workshop was held in September 1999 and covered additives, modeling and prediction and an additional segment on new materials. Materials Technology Institute (MTI) for the Chemical Process Industries, Inc. and Air Products & Chemicals lead the workshops. The Materials Technology Roadmap presents the results from both workshops.
Process/Equipment Co-Simulation on Syngas Chemical Looping Process
Zeng, Liang; Zhou, Qiang; Fan, Liang-Shih
The chemical looping strategy for fossil energy applications promises to achieve an efficient energy conversion system for electricity, liquid fuels, hydrogen and/or chemicals generation, while economically separate CO{sub 2} by looping reaction design in the process. Chemical looping particle performance, looping reactor engineering, and process design and applications are the key drivers to the success of chemical looping process development. In order to better understand and further scale up the chemical looping process, issues such as cost, time, measurement, safety, and other uncertainties need to be examined. To address these uncertainties, advanced reaction/reactor modeling and process simulation are highly desired and the modeling efforts can accelerate the chemical looping technology development, reduce the pilot-scale facility design time and operating campaigns, as well as reduce the cost and technical risks. The purpose of this work is thus to conduct multiscale modeling and simulations on the key aspects of chemical looping technology, including particle reaction kinetics, reactor design and operation, and process synthesis and optimization.
Circumventing Graphical User Interfaces in Chemical Engineering Plant Design
ERIC Educational Resources Information Center
Romey, Noel; Schwartz, Rachel M.; Behrend, Douglas; Miao, Peter; Cheung, H. Michael; Beitle, Robert
Graphical User Interfaces (GUIs) are pervasive elements of most modern technical software and represent a convenient tool for student instruction. For example, GUIs are used for [chemical] process design software (e.g., CHEMCAD, PRO/II and ASPEN) typically encountered in the senior capstone course. Drag and drop aspects of GUIs are challenging for…
Enhanced membrane bioreactor process without chemical cleaning.
Krause, S; Zimmermann, B; Meyer-Blumenroth, U; Lamparter, W; Siembida, B; Cornel, P
In membrane bioreactors (MBR) for wastewater treatment, the separation of activated sludge and treated water takes place by membrane filtration. Due to the small footprint and superior effluent quality, the number of membrane bioreactors used in wastewater treatment is rapidly increasing. A major challenge in this process is the fouling of the membranes which results in permeability decrease and the demand of chemical cleaning procedures. With the objective of a chemical-free process, the removal of the fouling layer by continuous physical abrasion was investigated. Therefore, particles (granules) were added to the activated sludge in order to realise a continuous abrasion of the fouling layer. During operation for more than 8 months, the membranes showed no decrease in permeability. Fluxes up to 40 L/(m(2) h) were achieved. An online turbidity measurement was installed for the effluent control and showed no change during this test period. For comparison, a reference (standard MBR process without granules) was operated which demonstrated permeability loss at lower fluxes and required chemical cleaning. Altogether with this process an operation at higher fluxes and no use of cleaning chemicals will increase the cost efficiency of the MBR-process.
Fully Integrating the Design Process
T.A. Bjornard; R.S. Bean
The basic approach to designing nuclear facilities in the United States does not currently reflect the routine consideration of proliferation resistance and international safeguards. The fully integrated design process is an approach for bringing consideration of international safeguards and proliferation resistance, together with state safeguards and security, fully into the design process from the very beginning, while integrating them sensibly and synergistically with the other project functions. In view of the recently established GNEP principles agreed to by the United States and at least eighteen other countries, this paper explores such an integrated approach, and its potential to help fulfill the new internationally driven design requirements with improved efficiencies and reduced costs.
A pollution minimization methodology was developed for chemical process design using computer simulation. It is based on a pollution balance that at steady state is used to define a pollution index with units of mass of pollution per mass of products. The pollution balance has be...
A Novel Chemical Nitrate Destruction Process
Dziewinski, J.; Marczak, S.
Nitrates represent one of the most significant pollutant discharged to the Baltic Sea by the Sliiamae hydrometallurgical plant. This article contains a brief overview of the existing nitrate destruction technologies followed by the description of a new process developed by the authors. The new chemical process for nitrate destruction is cost effective and simple to operate. It converts the nitrate to nitrogen gas which goes to the atmosphere.
Design of intelligent controllers for exothermal processes
NASA Astrophysics Data System (ADS)
Nagarajan, Ramachandran; Yaacob, Sazali
Chemical Industries such as resin or soap manufacturing industries have reaction systems which work with at least two chemicals. Mixing of chemicals even at room temperature can create the process of exothermic reaction. This processes produces a sudden increase of heat energy within the mixture. The quantity of heat and the dynamics of heat generation are unknown, unpredictable and time varying. Proper control of heat has to be accomplished in order to achieve a high quality of product. Uncontrolled or poorly controlled heat causes another unusable product and the process may damage materials and systems and even human being may be harmed. Controlling of heat due to exothermic reaction cannot be achieved using conventional control methods such as PID control, identification and control etc. All of the conventional methods require at least approximate mathematical model of the exothermic process. Modeling an exothermal process is yet to be properly conceived. This paper discusses a design methodology for controlling such a process. A pilot plant of a reaction system has been constructed and utilized for designing and incorporating the proposed fuzzy logic based intelligent controller. Both the conventional and then an adaptive form of fuzzy logic control were used in testing the performance. The test results ensure the effectiveness of controllers in controlling exothermic heat.
Total chemical management in photographic processing
Luden, Charles; Schultz, Ronald
The mission of the U. S. Geological Survey's Earth Resources Observation Systems (EROS) Data Center is to produce high-quality photographs of the earth taken from aircraft and Landsat satellite. In order to meet the criteria of producing research-quality photographs, while at the same time meeting strict environmental restrictions, a total photographic chemical management system was installed. This involved a three-part operation consisting of the design of a modern chemical analysis laboratory, the implementation of a chemical regeneration system, and the installation of a waste treatment system, including in-plant pretreatment and outside secondary waste treatment. Over the last ten years the result of this program has yielded high-quality photographs while saving approximately 30,000 per year and meeting all Environmental Protection Agency (EPA) restrictions.
CLEVER: pipeline for designing in silico chemical libraries.
Song, Chun Meng; Bernardo, Paul H; Chai, Christina L L; Tong, Joo Chuan
Advances in virtual screening have created new channels for expediting the process of discovering novel drugs. Of particular relevance and interest are in silico techniques that enable the enumeration of combinatorial chemical libraries, generation of 3D coordinates and assessment of their propensity for drug-likeness. In a bid to provide an integrated pipeline that encompasses the common components functional for designing, managing and analyzing combinatorial chemical libraries, we describe a platform-independent, standalone Java application entitled CLEVER (Chemical Library Editing, Visualizing and Enumerating Resource). CLEVER supports chemical library creation and manipulation, combinatorial chemical library enumeration using user-specified chemical components, chemical format conversion and visualization, as well as chemical compounds analysis and filtration with respect to drug-likeness, lead-likeness and fragment-likeness based on the physicochemical properties computed from the derived molecules. Also provided is an integrated property-based graphing component that visually depicts the diversity, coverage and distribution of selected compound collections. When deployed in conjunction with large-scale virtual screening campaigns, CLEVER can offer insights into what chemical compounds to synthesize, and more importantly, what not to synthesize. The software is available at http://datam.i2r.a-star.edu.sg/clever/.
Chemical computing with reaction-diffusion processes.
Gorecki, J; Gizynski, K; Guzowski, J; Gorecka, J N; Garstecki, P; Gruenert, G; Dittrich, P
Chemical reactions are responsible for information processing in living organisms. It is believed that the basic features of biological computing activity are reflected by a reaction-diffusion medium. We illustrate the ideas of chemical information processing considering the Belousov-Zhabotinsky (BZ) reaction and its photosensitive variant. The computational universality of information processing is demonstrated. For different methods of information coding constructions of the simplest signal processing devices are described. The function performed by a particular device is determined by the geometrical structure of oscillatory (or of excitable) and non-excitable regions of the medium. In a living organism, the brain is created as a self-grown structure of interacting nonlinear elements and reaches its functionality as the result of learning. We discuss whether such a strategy can be adopted for generation of chemical information processing devices. Recent studies have shown that lipid-covered droplets containing solution of reagents of BZ reaction can be transported by a flowing oil. Therefore, structures of droplets can be spontaneously formed at specific non-equilibrium conditions, for example forced by flows in a microfluidic reactor. We describe how to introduce information to a droplet structure, track the information flow inside it and optimize medium evolution to achieve the maximum reliability. Applications of droplet structures for classification tasks are discussed.
Rock fracture processes in chemically reactive environments
NASA Astrophysics Data System (ADS)
Eichhubl, P.
Rock fracture is traditionally viewed as a brittle process involving damage nucleation and growth in a zone ahead of a larger fracture, resulting in fracture propagation once a threshold loading stress is exceeded. It is now increasingly recognized that coupled chemical-mechanical processes influence fracture growth in wide range of subsurface conditions that include igneous, metamorphic, and geothermal systems, and diagenetically reactive sedimentary systems with possible applications to hydrocarbon extraction and CO2 sequestration. Fracture processes aided or driven by chemical change can affect the onset of fracture, fracture shape and branching characteristics, and fracture network geometry, thus influencing mechanical strength and flow properties of rock systems. We are investigating two fundamental modes of chemical-mechanical interactions associated with fracture growth: 1. Fracture propagation may be aided by chemical dissolution or hydration reactions at the fracture tip allowing fracture propagation under subcritical stress loading conditions. We are evaluating effects of environmental conditions on critical (fracture toughness KIc) and subcritical (subcritical index) fracture properties using double torsion fracture mechanics tests on shale and sandstone. Depending on rock composition, the presence of reactive aqueous fluids can increase or decrease KIc and/or subcritical index. 2. Fracture may be concurrent with distributed dissolution-precipitation reactions in the hostrock beyond the immediate vicinity of the fracture tip. Reconstructing the fracture opening history recorded in crack-seal fracture cement of deeply buried sandstone we find that fracture length growth and fracture opening can be decoupled, with a phase of initial length growth followed by a phase of dominant fracture opening. This suggests that mechanical crack-tip failure processes, possibly aided by chemical crack-tip weakening, and distributed
Process simulation and design '94
Not Available
This first-of-a-kind report describes today's process simulation and design technology for specific applications. It includes process names, diagrams, applications, descriptions, objectives, economics, installations, licensors, and a complete list of process submissions. Processes include: alkylation, aromatics extraction, catalytic reforming, cogeneration, dehydration, delayed coking, distillation, energy integration, catalytic cracking, gas sweetening, glycol/methanol injection, hydrocracking, NGL recovery and stabilization, solvent dewaxing, visbreaking. Equipment simulations include: amine plant, ammonia plant, heat exchangers, cooling water network, crude preheat train, crude unit, ethylene furnace, nitrogen rejection unit, refinery, sulfur plant, and VCM furnace. By-product processes include: olefins, polyethylene terephthalate, and styrene.
VCM Process Design: An ABET 2000 Fully Compliant Project
ERIC Educational Resources Information Center
Benyahia, Farid
A long experience in undergraduate vinyl chloride monomer (VCM) process design projects is shared in this paper. The VCM process design is shown to be fully compliant with ABET 2000 criteria by virtue of its abundance in chemical engineering principles, integration of interpersonal and interdisciplinary skills in design, safety, economics, and…
The Process Design Courses at Pennsylvania: Impact of Process Simulators.
ERIC Educational Resources Information Center
Seider, Warren D.
Describes the use and impact of process design simulators in process design courses. Discusses topics covered, texts used, computer design simulations, and how they are integrated into the process survey course as well as in plant design projects. (JM)
Estimation of Environment-Related Properties of Chemicals for Design of Sustainable Processes: Development of Group-Contribution+ (GC+) Property Models and Uncertainty Analysis
The aim of this work is to develop group-contribution+ (GC+) method (combined group-contribution (GC) method and atom connectivity index (CI) method) based property models to provide reliable estimations of environment-related properties of organic chemicals together with uncert...
Human Integration Design Processes (HIDP)
NASA Technical Reports Server (NTRS)
Boyer, Jennifer
The purpose of the Human Integration Design Processes (HIDP) document is to provide human-systems integration design processes, including methodologies and best practices that NASA has used to meet human systems and human rating requirements for developing crewed spacecraft. HIDP content is framed around human-centered design methodologies and processes in support of human-system integration requirements and human rating. NASA-STD-3001, Space Flight Human-System Standard, is a two-volume set of National Aeronautics and Space Administration (NASA) Agency-level standards established by the Office of the Chief Health and Medical Officer, directed at minimizing health and performance risks for flight crews in human space flight programs. Volume 1 of NASA-STD-3001, Crew Health, sets standards for fitness for duty, space flight permissible exposure limits, permissible outcome limits, levels of medical care, medical diagnosis, intervention, treatment and care, and countermeasures. Volume 2 of NASASTD- 3001, Human Factors, Habitability, and Environmental Health, focuses on human physical and cognitive capabilities and limitations and defines standards for spacecraft (including orbiters, habitats, and suits), internal environments, facilities, payloads, and related equipment, hardware, and software with which the crew interfaces during space operations. The NASA Procedural Requirements (NPR) 8705.2B, Human-Rating Requirements for Space Systems, specifies the Agency's human-rating processes, procedures, and requirements. The HIDP was written to share NASA's knowledge of processes directed toward achieving human certification of a spacecraft through implementation of human-systems integration requirements. Although the HIDP speaks directly to implementation of NASA-STD-3001 and NPR 8705.2B requirements, the human-centered design, evaluation, and design processes described in this document can be applied to any set of human-systems requirements and are independent of reference
Bayesian molecular design with a chemical language model.
Ikebata, Hisaki; Hongo, Kenta; Isomura, Tetsu; Maezono, Ryo; Yoshida, Ryo
The aim of computational molecular design is the identification of promising hypothetical molecules with a predefined set of desired properties. We address the issue of accelerating the material discovery with state-of-the-art machine learning techniques. The method involves two different types of prediction; the forward and backward predictions. The objective of the forward prediction is to create a set of machine learning models on various properties of a given molecule. Inverting the trained forward models through Bayes' law, we derive a posterior distribution for the backward prediction, which is conditioned by a desired property requirement. Exploring high-probability regions of the posterior with a sequential Monte Carlo technique, molecules that exhibit the desired properties can computationally be created. One major difficulty in the computational creation of molecules is the exclusion of the occurrence of chemically unfavorable structures. To circumvent this issue, we derive a chemical language model that acquires commonly occurring patterns of chemical fragments through natural language processing of ASCII strings of existing compounds, which follow the SMILES chemical language notation. In the backward prediction, the trained language model is used to refine chemical strings such that the properties of the resulting structures fall within the desired property region while chemically unfavorable structures are successfully removed. The present method is demonstrated through the design of small organic molecules with the property requirements on HOMO-LUMO gap and internal energy. The R package iqspr is available at the CRAN repository.
Bayesian molecular design with a chemical language model
NASA Astrophysics Data System (ADS)
Ikebata, Hisaki; Hongo, Kenta; Isomura, Tetsu; Maezono, Ryo; Yoshida, Ryo
The aim of computational molecular design is the identification of promising hypothetical molecules with a predefined set of desired properties. We address the issue of accelerating the material discovery with state-of-the-art machine learning techniques. The method involves two different types of prediction; the forward and backward predictions. The objective of the forward prediction is to create a set of machine learning models on various properties of a given molecule. Inverting the trained forward models through Bayes' law, we derive a posterior distribution for the backward prediction, which is conditioned by a desired property requirement. Exploring high-probability regions of the posterior with a sequential Monte Carlo technique, molecules that exhibit the desired properties can computationally be created. One major difficulty in the computational creation of molecules is the exclusion of the occurrence of chemically unfavorable structures. To circumvent this issue, we derive a chemical language model that acquires commonly occurring patterns of chemical fragments through natural language processing of ASCII strings of existing compounds, which follow the SMILES chemical language notation. In the backward prediction, the trained language model is used to refine chemical strings such that the properties of the resulting structures fall within the desired property region while chemically unfavorable structures are successfully removed. The present method is demonstrated through the design of small organic molecules with the property requirements on HOMO-LUMO gap and internal energy. The R package iqspr is available at the CRAN repository.
Denitrification as a Model Chemical Process
NASA Astrophysics Data System (ADS)
Grguric, Gordan
Bacterial denitrification in seawater facilities such as aquaria and mariculture systems is a process particularly well suited for illustrating important concepts in chemistry to undergraduates. Students can gain firsthand experience related to these concepts, for example by (i) analyzing and quantifying chemical reactions based on empirical data, (ii) employing stoichiometry and mass balance to determine the amounts of reactants required and products produced in a chemical reaction, and (iii) using acid-base speciation diagrams and other information to quantify the changes in pH and carbonic acid speciation in an aqueous medium. At the Richard Stockton College of New Jersey, we have utilized actual data from several seawater systems to discuss topics such as stoichiometry, mass and charge balance, and limiting reagents. This paper describes denitrification in closed seawater systems and how the process can be used to enhance undergraduate chemistry education. A number of possible student exercises are described that can be used as practical tools to enhance the students' quantitative understanding of chemical reactions.
ESS Cryogenic System Process Design
NASA Astrophysics Data System (ADS)
Arnold, P.; Hees, W.; Jurns, J.; Su, X. T.; Wang, X. L.; Weisend, J. G., II
The European Spallation Source (ESS) is a neutron-scattering facility funded and supported in collaboration with 17 European countries in Lund, Sweden. Cryogenic cooling at ESS is vital particularly for the linear accelerator, the hydrogen target moderators, a test stand for cryomodules, the neutron instruments and their sample environments. The paper will focus on specific process design criteria, design decisions and their motivations for the helium cryoplants and auxiliary equipment. Key issues for all plants and their process concepts are energy efficiency, reliability, smooth turn-down behaviour and flexibility. The accelerator cryoplant (ACCP) and the target moderator cryoplant (TMCP) in particular need to be prepared for a range of refrigeration capacities due to the intrinsic uncertainties regarding heat load definitions. Furthermore the paper addresses questions regarding process arrangement, 2 K cooling methodology, LN2 precooling, helium storage, helium purification and heat recovery.
Discriminative Chemical Patterns: Automatic and Interactive Design.
Bietz, Stefan; Schomburg, Karen T; Hilbig, Matthias; Rarey, Matthias
The classification of molecules with respect to their inhibiting, activating, or toxicological potential constitutes a central aspect in the field of cheminformatics. Often, a discriminative feature is needed to distinguish two different molecule sets. Besides physicochemical properties, substructures and chemical patterns belong to the descriptors most frequently applied for this purpose. As a commonly used example of this descriptor class, SMARTS strings represent a powerful concept for the representation and processing of abstract chemical patterns. While their usage facilitates a convenient way to apply previously derived classification rules on new molecule sets, the manual generation of useful SMARTS patterns remains a complex and time-consuming process. Here, we introduce SMARTSminer, a new algorithm for the automatic derivation of discriminative SMARTS patterns from preclassified molecule sets. Based on a specially adapted subgraph mining algorithm, SMARTSminer identifies structural features that are frequent in only one of the given molecule classes. In comparison to elemental substructures, it also supports the consideration of general and specific SMARTS features. Furthermore, SMARTSminer is integrated into an interactive pattern editor named SMARTSeditor. This allows for an intuitive visualization on the basis of the SMARTSviewer concept as well as interactive adaption and further improvement of the generated patterns. Additionally, a new molecular matching feature provides an immediate feedback on a pattern's matching behavior across the molecule sets. We demonstrate the utility of the SMARTSminer functionality and its integration into the SMARTSeditor software in several different classification scenarios.
Designing Endocrine Disruption Out of the Next Generation of Chemicals.
Schug, T T; Abagyan, R; Blumberg, B; Collins, T J; Crews, D; DeFur, P L; Dickerson, S M; Edwards, T M; Gore, A C; Guillette, L J; Hayes, T; Heindel, J J; Moores, A; Patisaul, H B; Tal, T L; Thayer, K A; Vandenberg, L N; Warner, J; Watson, C S; Saal, F S Vom; Zoeller, R T; O'Brien, K P; Myers, J P
A central goal of green chemistry is to avoid hazard in the design of new chemicals. This objective is best achieved when information about a chemical's potential hazardous effects is obtained as early in the design process as feasible. Endocrine disruption is a type of hazard that to date has been inadequately addressed by both industrial and regulatory science. To aid chemists in avoiding this hazard, we propose an endocrine disruption testing protocol for use by chemists in the design of new chemicals. The Tiered Protocol for Endocrine Disruption (TiPED) has been created under the oversight of a scientific advisory committee composed of leading representatives from both green chemistry and the environmental health sciences. TiPED is conceived as a tool for new chemical design, thus it starts with a chemist theoretically at "the drawing board." It consists of five testing tiers ranging from broad in silico evaluation up through specific cell- and whole organism-based assays. To be effective at detecting endocrine disruption, a testing protocol must be able to measure potential hormone-like or hormone-inhibiting effects of chemicals, as well as the many possible interactions and signaling sequellae such chemicals may have with cell-based receptors. Accordingly, we have designed this protocol to broadly interrogate the endocrine system. The proposed protocol will not detect all possible mechanisms of endocrine disruption, because scientific understanding of these phenomena is advancing rapidly. To ensure that the protocol remains current, we have established a plan for incorporating new assays into the protocol as the science advances. In this paper we present the principles that should guide the science of testing new chemicals for endocrine disruption, as well as principles by which to evaluate individual assays for applicability, and laboratories for reliability. In a 'proof-of-principle' test, we ran 6 endocrine disrupting chemicals (EDCs) that act via
Treatment Process Requirements for Waters Containing Hydraulic Fracturing Chemicals
NASA Astrophysics Data System (ADS)
Stringfellow, W. T.; Camarillo, M. K.; Domen, J. K.; Sandelin, W.; Varadharajan, C.; Cooley, H.; Jordan, P. D.; Heberger, M. G.; Reagan, M. T.; Houseworth, J. E.; Birkholzer, J. T.
A wide variety of chemical additives are used as part of the hydraulic fracturing (HyF) process. There is concern that HyF chemicals will be released into the environment and contaminate drinking water, agricultural water, or other water used for beneficial purposes. There is also interest in using produced water (water extracted from the subsurface during oil and gas production) for irrigation and other beneficial purposes, especially in the arid Southwest US. Reuse of produced water is not speculative: produced water can be low in salts and is being used in California for irrigation after minimal treatment. In this study, we identified chemicals that are used for hydraulic fracturing in California and conducted an analysis to determine if those chemicals would be removed by a variety of technically available treatment processes, including oil/water separation, air stripping, a variety of sorption media, advanced oxidation, biological treatment, and a variety of membrane treatment systems. The approach taken was to establish major physiochemical properties for individual chemicals (log Koc, Henry's constant, biodegradability, etc.), group chemicals by function (e.g corrosion inhibition, biocides), and use those properties to predict the fate of chemical additives in a treatment process. Results from this analysis is interpreted in the context of what is known about existing systems for the treatment of produced water before beneficial reuse, which includes a range of treatment systems from oil/water separators (the most common treatment) to sophisticated treatment trains used for purifying produced water for groundwater recharge. The results show that most HyF chemical additives will not be removed in existing treatment systems, but that more sophisticated treatment trains can be designed to remove additives before beneficial reuse.
Virtual Design of Chemical Penetration Enhancers for Transdermal Drug Delivery
Golla, Sharath; Neely, Brian J.; Whitebay, Eric; Madihally, Sundar; Robinson, Robert L.; Gasem, Khaled A. M.
Traditional drug design is a laborious and expensive process that often challenges the pharmaceutical industries. As a result, researchers have turned to computational methods for computer-assisted molecular design. Recently, genetic and evolutionary algorithms have emerged as efficient methods in solving combinatorial problems associated with computer-aided molecular design. Further, combining genetic algorithms (GAs) with quantitative structure-property relationship (QSPR) analyses has proved effective in drug design. In this work, we have integrated a new genetic algorithm and non-linear QSPR models to develop a reliable virtual screening algorithm for generation of potential chemical penetration enhancers (CPEs). The GA-QSPR algorithm has been implemented successfully to identify potential CPEs for transdermal drug delivery of insulin. Validation of the newly-identified CPE molecular structures was conducted through carefully designed experiments, which elucidated the cytotoxicity and permeability of the CPEs. PMID:22172168
Using GREENSCOPE for Sustainable Process Design: An Educational Opportunity
Increasing sustainability can be approached through the education of those who design, construct, and operate facilities. As chemical engineers learn elements of process systems engineering, they can be introduced to sustainability concepts. The EPA's GREENSCOPE methodology and...
Exergy analysis of a chemical metallurgical process
NASA Astrophysics Data System (ADS)
Morris, D. R.; Steward, F. R.
The concept of available work or exergy is used to develop an expression from which the causes of exergy losses in a chemical reactor are identified. The concept is illustrated by application to a lead blast furnace. The performance of the sinter plant and the lead smelter are assessed by the same procedures. The possibilities of exergy recovery are discussed and a heat pump installation is described. The advantages of the exergy method of process assessment relative to the traditional heat balance are discussed.
GREENSCOPE: A Method for Modeling Chemical Process ...
Current work within the U.S. Environmental Protection Agency's National Risk Management Research Laboratory is focused on the development of a method for modeling chemical process sustainability. The GREENSCOPE methodology, defined for the four bases of Environment, Economics, Efficiency, and Energy, can evaluate processes with over a hundred different indicators. These indicators provide a means for realizing the principles of green chemistry and green engineering in the context of sustainability. Development of the methodology has centered around three focal points. One is a taxonomy of impacts that describe the indicators and provide absolute scales for their evaluation. The setting of best and worst limits for the indicators allows the user to know the status of the process under study in relation to understood values. Thus, existing or imagined processes can be evaluated according to their relative indicator scores, and process modifications can strive towards realizable targets. A second area of focus is in advancing definitions of data needs for the many indicators of the taxonomy. Each of the indicators has specific data that is necessary for their calculation. Values needed and data sources have been identified. These needs can be mapped according to the information source (e.g., input stream, output stream, external data, etc.) for each of the bases. The user can visualize data-indicator relationships on the way to choosing selected ones for evalua
chemical process designers using simulation software generate alternative designs for one process. One criterion for evaluating these designs is their potential for adverse environmental impacts due to waste generated, energy consumed, and possibilities for fugitive emissions. Co...
Designing Endocrine Disruption Out of the Next Generation of Chemicals
Schug, T.T; Abagyan, R.; Blumberg, B.; Collins, T.J.; Crews, D.; DeFur, P.L.; Dickerson, S.M.; Edwards, T.M.; Gore, A.C.; Guillette, L.J.; Hayes, T.; Heindel, J.J.; Moores, A.; Patisaul, H.B.; Tal, T.L.; Thayer, K.A.; Vandenberg, L.N.; Warner, J.; Watson, C.S.; Saal, F.S. vom; Zoeller, R.T.; O'Brien, K.P.; Myers, J.P.
A central goal of green chemistry is to avoid hazard in the design of new chemicals. This objective is best achieved when information about a chemical's potential hazardous effects is obtained as early in the design process as feasible. Endocrine disruption is a type of hazard that to date has been inadequately addressed by both industrial and regulatory science. To aid chemists in avoiding this hazard, we propose an endocrine disruption testing protocol for use by chemists in the design of new chemicals. The Tiered Protocol for Endocrine Disruption (TiPED) has been created under the oversight of a scientific advisory committee composed of leading representatives from both green chemistry and the environmental health sciences. TiPED is conceived as a tool for new chemical design, thus it starts with a chemist theoretically at "the drawing board." It consists of five testing tiers ranging from broad in silico evaluation up through specific cell- and whole organism-based assays. To be effective at detecting endocrine disruption, a testing protocol must be able to measure potential hormone-like or hormone-inhibiting effects of chemicals, as well as the many possible interactions and signaling sequellae such chemicals may have with cell-based receptors. Accordingly, we have designed this protocol to broadly interrogate the endocrine system. The proposed protocol will not detect all possible mechanisms of endocrine disruption, because scientific understanding of these phenomena is advancing rapidly. To ensure that the protocol remains current, we have established a plan for incorporating new assays into the protocol as the science advances. In this paper we present the principles that should guide the science of testing new chemicals for endocrine disruption, as well as principles by which to evaluate individual assays for applicability, and laboratories for reliability. In a 'proof-of-principle' test, we ran 6 endocrine disrupting chemicals (EDCs) that act
The concepts of energy, environment, and cost for process design
Abu-Khader, M.M.; Speight, J.G.
The process industries (specifically, energy and chemicals) are characterized by a variety of reactors and reactions to bring about successful process operations. The design of energy-related and chemical processes and their evolution is a complex process that determines the competitiveness of these industries, as well as their environmental impact. Thus, we have developed an Enviro-Energy Concept designed to facilitate sustainable industrial development. The Complete Onion Model represents a complete methodology for chemical process design and illustrates all of the requirements to achieve the best possible design within the accepted environmental standards. Currently, NOx emissions from industrial processes continue to receive maximum attention, therefore the issue problem of NOx emissions from industrial sources such as power stations and nitric acid plants is considered. The Selective Catalytic Reduction (SCR) is one of the most promising and effective commercial technologies. It is considered the Best Available Control Technology (BACT) for NOx reduction. The solution of NOx emissions problem is either through modifying the chemical process design and/or installing an end-of-pipe technology. The degree of integration between the process design and the installed technology plays a critical role in the capital cost evaluation. Therefore, integrating process units and then optimizing the design has a vital effect on the total cost. Both the environmental regulations and the cost evaluation are the boundary constraints of the optimum solution.
Automation of Design Engineering Processes
NASA Technical Reports Server (NTRS)
Torrey, Glenn; Sawasky, Gerald; Courey, Karim
A method, and a computer program that helps to implement the method, have been developed to automate and systematize the retention and retrieval of all the written records generated during the process of designing a complex engineering system. It cannot be emphasized strongly enough that all the written records as used here is meant to be taken literally: it signifies not only final drawings and final engineering calculations but also such ancillary documents as minutes of meetings, memoranda, requests for design changes, approval and review documents, and reports of tests. One important purpose served by the method is to make the records readily available to all involved users via their computer workstations from one computer archive while eliminating the need for voluminous paper files stored in different places. Another important purpose served by the method is to facilitate the work of engineers who are charged with sustaining the system and were not involved in the original design decisions. The method helps the sustaining engineers to retrieve information that enables them to retrace the reasoning that led to the original design decisions, thereby helping them to understand the system better and to make informed engineering choices pertaining to maintenance and/or modifications of the system. The software used to implement the method is written in Microsoft Access. All of the documents pertaining to the design of a given system are stored in one relational database in such a manner that they can be related to each other via a single tracking number.
Quantification of chemical transport processes from soil to surface runoff
Technology Transfer Automated Retrieval System (TEKTRAN)
Although there is a conceptual understanding on processes governing chemical transport from soil to surface runoff, there are little literature and research results actually quantifying these individual processes. We developed a laboratory flow cell and experimental procedures to quantify chemical ...
Idaho Chemical Processing Plant failure rate database
Alber, T.G.; Hunt, C.R.; Fogarty, S.P.; Wilson, J.R.
This report represents the first major upgrade to the Idaho Chemical Processing Plant (ICPP) Failure Rate Database. This upgrade incorporates additional site-specific and generic data while improving on the previous data reduction techniques. In addition, due to a change in mission at the ICPP, the status of certain equipment items has changed from operating to standby or off-line. A discussion of how this mission change influenced the relevance of failure data also has been included. This report contains two data sources: the ICPP Failure Rate Database and a generic failure rate database. A discussion is presented on the approaches and assumptions used to develop the data in the ICPP Failure Rate Database. The generic database is included along with a short discussion of its application. A brief discussion of future projects recommended to strengthen and lend credibility to the ICPP Failure Rate Database also is included.
Odor processing in multiple chemical sensitivity.
Hillert, Lena; Musabasic, Vildana; Berglund, Hans; Ciumas, Carolina; Savic, Ivanka
Multiple chemical sensitivity (MCS) is characterized by somatic distress upon exposure to odors. As in other idiopathic environmental intolerances, the mechanisms behind the reported hypersensitivity are unknown. Using the advantage of the well-defined trigger (odor), we investigated whether subjects with MCS could have an increased odor-signal response in the odor-processing neuronal circuits. Positron emission tomography (PET) activation studies with several different odorants were carried out in 12 MCS females and 12 female controls. Activation was defined as a significant increase in regional cerebral blood flow (rCBF) during smelling of the respective odorant compared to smelling of odorless air. The study also included online measurements of respiratory frequency and amplitude and heart rate variations by recording of R wave intervals (RR) on the surface electrocardiogram. The MCS subjects activated odor-processing brain regions less than controls, despite the reported, and physiologically indicated (decreased RR interval) distress. In parallel, they showed an odorant-related increase in activation of the anterior cingulate cortex and cuneus-precuneus. Notably, the baseline rCBF was normal. Thus, the abnormal patterns were observed only in response to odor signals. Subjects with MCS process odors differently from controls, however, without signs of neuronal sensitization. One possible explanation for the observed pattern of activation in MCS is a top-down regulation of odor-response via cingulate cortex.
Quantum Chemical Strain Analysis For Mechanochemical Processes.
Stauch, Tim; Dreuw, Andreas
The use of mechanical force to initiate a chemical reaction is an efficient alternative to the conventional sources of activation energy, i.e., heat, light, and electricity. Applications of mechanochemistry in academic and industrial laboratories are diverse, ranging from chemical syntheses in ball mills and ultrasound baths to direct activation of covalent bonds using an atomic force microscope. The vectorial nature of force is advantageous because specific covalent bonds can be preconditioned for rupture by selective stretching. However, the influence of mechanical force on single molecules is still not understood at a fundamental level, which limits the applicability of mechanochemistry. As a result, many chemists still resort to rules of thumb when it comes to conducting mechanochemical syntheses. In this Account, we show that comprehension of mechanochemistry at the molecular level can be tremendously advanced by quantum chemistry, in particular by using quantum chemical force analysis tools. One such tool is the JEDI (Judgement of Energy DIstribution) analysis, which provides a convenient approach to analyze the distribution of strain energy in a mechanically deformed molecule. Based on the harmonic approximation, the strain energy contribution is calculated for each bond length, bond angle and dihedral angle, thus providing a comprehensive picture of how force affects molecules. This Account examines the theoretical foundations of quantum chemical force analysis and provides a critical overview of the performance of the JEDI analysis in various mechanochemical applications. We explain in detail how this analysis tool is to be used to identify the "force-bearing scaffold" of a distorted molecule, which allows both the rationalization and the optimization of diverse mechanochemical processes. More precisely, we show that the inclusion of every bond, bending and torsion of a molecule allows a particularly insightful discussion of the distribution of mechanical
Chemical laser exhaust pipe design research
NASA Astrophysics Data System (ADS)
Sun, Yunqiang; Huang, Zhilong; Chen, Zhiqiang; Ren, Zebin; Guo, Longde
In order to weaken the chemical laser exhaust gas influence of the optical transmission, a vent pipe is advised to emissions gas to the outside of the optical transmission area. Based on a variety of exhaust pipe design, a flow field characteristic of the pipe is carried out by numerical simulation and analysis in detail. The research results show that for uniform deflating exhaust pipe, although the pipeline structure is cyclical and convenient for engineering implementation, but there is a phenomenon of air reflows at the pipeline entrance slit which can be deduced from the numerical simulation results. So, this type of pipeline structure does not guarantee seal. For the design scheme of putting the pipeline contract part at the end of the exhaust pipe, or using the method of local area or tail contraction, numerical simulation results show that backflow phenomenon still exists at the pipeline entrance slit. Preliminary analysis indicates that the contraction of pipe would result in higher static pressure near the wall for the low speed flow field, so as to produce counter pressure gradient at the entrance slit. In order to eliminate backflow phenomenon at the pipe entrance slit, concerned with the pipeline type of radial size increase gradually along the flow, flow field property in the pipe is analyzed in detail by numerical simulation methods. Numerical simulation results indicate that there is not reflow phenomenon at entrance slit of the dilated duct. However the cold air inhaled in the slit which makes the temperature of the channel wall is lower than the center temperature. Therefore, this kind of pipeline structure can not only prevent the leak of the gas, but also reduce the wall temperature. In addition, compared with the straight pipe connection way, dilated pipe structure also has periodic structure, which can facilitate system integration installation.
A pollution reduction methodology for chemical process simulators
Mallick, S.K.; Cabezas, H.; Bare, J.C.; Sikdar, S.K.
A pollution minimization methodology was developed for chemical process design using computer simulation. It is based on a pollution balance that at steady state is used to define a pollution index with units of mass of pollution per mass of products. The pollution balance has been modified by weighing the mass flowrate of each pollutant by its potential environmental impact score. This converts the mass balance into an environmental impact balance. This balance defines an impact index with units of environmental impact per mass of products. The impact index measures the potential environmental effects of process wastes. Three different schemes for chemical ranking were considered: (1) no ranking, (2) simple ranking from 0 to 3, and (3) ranking by a scientifically derived measure of human health and environmental effects. Use of the methodology is illustrated with two examples from the production of (1) methyl ethyl ketone and (2) synthetic ammonia.
Effects of Semiconductor Processing Chemicals on Conductivity of Graphene
Chen, Chung Wei; Ren, F.; Chi, G.C.; Hung, S. C.; Huang, Y. P.; Kim, J.; Kravchenko, Ivan I; Pearton, S. J.
Graphene layers on SiO2/Si substrates were exposed to chemicals or gases commonly used in semiconductor fabrication processes, including solvents (isopropanol, acetone), acids (HCl), bases (ammonium hydroxide), UV ozone, H2O and O2 plasmas. The recovery of the initial graphene properties after these exposures was monitored by measuring both the layer resistance and Raman 2D peak position as a function of time in air or vacuum. Solvents and UV ozone were found to have the least affect while oxygen plasma exposure caused an increase of resistance of more than 3 orders of magnitude. Recovery is accelerated under vacuum but changes can persist for more than 5 hours. Careful design of fabrication schemes involving graphene is necessary to minimize these interactions with common processing chemicals.
Film processing investigation. [improved chemical mixing system
NASA Technical Reports Server (NTRS)
Kelly, J. L.
The present operational chemical mixing system for the Photographic Technology Division is evaluated, and the limitations are defined in terms of meeting the present and programmed chemical supply and delivery requirements. A major redesign of the entire chemical mixing, storage, analysis, and supply system is recommended. Other requirements for immediate and future implementations are presented.
Advanced Chemical Design for Efficient Lignin Bioconversion
Xie, Shangxian; Sun, Qining; Pu, Yunqiao; ...
Here, lignin depolymerization mainly involves redox reactions relying on the effective electron transfer. Even though electron mediators were previously used for delignification of paper pulp, no study has established a bioprocess to fragment and solubilize the lignin with an effective laccase–mediator system, in particular, for subsequent microbial bioconversion. Efficient lignin depolymerization was achieved by screening proper electron mediators with laccase to attain a nearly 6-fold increase of kraft lignin solubility compared to the control kraft lignin without laccase treatment. Chemical analysis suggested the release of a low molecular weight fraction of kraft lignin into the solution phase. Moreover, NMR analysismore » revealed that an efficient enzyme–mediator system can promote the lignin degradation. More importantly, the fundamental mechanisms guided the development of an efficient lignin bioconversion process, where solubilized lignin from laccase–HBT treatment served as a superior substrate for bioconversion by Rhodococcus opacus PD630. The cell growth was increased by 106 fold, and the lipid titer reached 1.02 g/L. Overall, the study has manifested that an efficient enzyme–mediator–microbial system can be exploited to establish a bioprocess to solubilize lignin, cleave lignin linkages, modify the structure, and produce substrates amenable to bioconversion.« less
Advanced chemical design for efficient lignin bioconversion
Xie, Shangxian; Sun, Qining; Pu, Yunqiao; Lin, Furong; Sun, Su; Wang, Xin; Ragauskas, Arthur J.; Yuan, Joshua S.
Here, lignin depolymerization mainly involves redox reactions relying on the effective electron transfer. Even though electron mediators were previously used for delignification of paper pulp, no study has established a bioprocess to fragment and solubilize the lignin with an effective laccase–mediator system, in particular, for subsequent microbial bioconversion. Efficient lignin depolymerization was achieved by screening proper electron mediators with laccase to attain a nearly 6-fold increase of kraft lignin solubility compared to the control kraft lignin without laccase treatment. Chemical analysis suggested the release of a low molecular weight fraction of kraft lignin into the solution phase. Moreover, NMR analysis revealed that an efficient enzyme–mediator system can promote the lignin degradation. More importantly, the fundamental mechanisms guided the development of an efficient lignin bioconversion process, where solubilized lignin from laccase–HBT treatment served as a superior substrate for bioconversion by Rhodococcus opacus PD630. The cell growth was increased by 106 fold, and the lipid titer reached 1.02 g/L. Overall, the study has manifested that an efficient enzyme–mediator–microbial system can be exploited to establish a bioprocess to solubilize lignin, cleave lignin linkages, modify the structure, and produce substrates amenable to bioconversion.
A general theory known as the WAste Reduction (WASR) algorithm has been developed to describe the flow and the generation of potential environmental impact through a chemical process. This theory integrates environmental impact assessment into chemical process design Potential en...
GRP vessels and pipework for the chemical and process industries
Not Available
Plastic can be reinforced by an appreciable number of materials, the most commonly used is glass-fibre. Glass reinforced plastic (GRP) has been used in the chemical and process industries for 25 years. In the course of its use and development, much data has been gathered on the material, its chemistry, mechanical properties, methods of fabrication and moulding, its behaviour in service and the methods and mathematics of the analysis of plant constructed from it. The importance of the material in industry was reflected by the large response to a symposium organised by UMIST, the Institution of Chemical Engineers and the Institution of Mechanical Engineers. Topics considered include GRP piping - a multi-sponsored research project; inspection authority views; failure of attachments to GRP cylinders due to local loads; aspects of GRP service failure in the chemical and process industries; stress corrosion of GRP in relation to design stress and service performance; design of GRP pipe bends in relation to internal pressure tests to destruction; and acoustic emission monitoring: a complementary inspection method for fibre-reinforced plastic components.
Foundations for Excellence in the Chemical Process Industries. Voluntary Industry Standards for Chemical Process Industries Technical Workers.
ERIC Educational Resources Information Center
Hofstader, Robert; Chapman, Kenneth
This document discusses the Voluntary Industry Standards for Chemical Process Industries Technical Workers Project and issues of relevance to the education and employment of chemical laboratory technicians (CLTs) and process technicians (PTs). Section 1 consists of the following background information: overview of the chemical process industries,…
Zamecnik, J.; Koopman, D.
The Defense Waste Processing Facility has experienced significant issues with the stripping and recovery of mercury in the Chemical Processing Cell (CPC). The stripping rate has been inconsistent, often resulting in extended processing times to remove mercury to the required endpoint concentration. The recovery of mercury in the Mercury Water Wash Tank has never been high, and has decreased significantly since the Mercury Water Wash Tank was replaced after the seventh batch of Sludge Batch 5. Since this time, essentially no recovery of mercury has been seen. Pertinent literature was reviewed, previous lab-scale data on mercury stripping and recovery was examined, and new lab-scale CPC Sludge Receipt and Adjustment Tank (SRAT) runs were conducted. For previous lab-scale data, many of the runs with sufficient mercury recovery data were examined to determine what factors affect the stripping and recovery of mercury and to improve closure of the mercury material balance. Ten new lab-scale SRAT runs (HG runs) were performed to examine the effects of acid stoichiometry, sludge solids concentration, antifoam concentration, form of mercury added to simulant, presence of a SRAT heel, operation of the SRAT condenser at higher than prototypic temperature, varying noble metals from none to very high concentrations, and higher agitation rate. Data from simulant runs from SB6, SB7a, glycolic/formic, and the HG tests showed that a significant amount of Hg metal was found on the vessel bottom at the end of tests. Material balance closure improved from 12-71% to 48-93% when this segregated Hg was considered. The amount of Hg segregated as elemental Hg on the vessel bottom was 4-77% of the amount added. The highest recovery of mercury in the offgas system generally correlated with the highest retention of Hg in the slurry. Low retention in the slurry (high segregation on the vessel bottom) resulted in low recovery in the offgas system. High agitation rates appear to result in lower
Electron Beam Applications in Chemical Processing
NASA Astrophysics Data System (ADS)
Martin, D.; Dragusin, M.; Radoiu, M.; Moraru, R.; Oproiu, C.; Cojocaru, G.; Margarit, C.
Our recent results in the field of polymeric materials obtained by electron beam irradiation are presented. Two types of polymeric flocculants and three hydrogels are described. The effects of radiation absorbed dose and chemical composition of the irradiated solutions upon the polymeric materials characteristics are discussed. The required absorbed dose levels to produce the polymeric flocculants are in the range of 0.4 kGy to 1 kGy, and 4 kGy to 12 kGy for hydrogels. Experimental results obtained by testing polymeric flocculants with waste water from food industry are given. Plymeric materials processing was developed on a pilot small scale level with a 0.7 kW and 5.5 MeV linac built in Romania. A new facility for application of combined electron beam and microwave irradiation in the field of polymeric materials preparation is presently under investigation. Preliminary results have demonstrated that some polymeric flocculants characteristics, such as linearity, were improved by using combined electron beam and microwave irradiation. Also, the absorbed dose levels decreases in comparison with those required when only electron beam irradiation was used.
Physical-chemical processes in a protoplanetary cloud
NASA Technical Reports Server (NTRS)
Lavrukhina, Avgusta K.
Physical-chemical processes in a protoplanetary cloud are discussed. The following subject areas are covered: (1) characteristics of the chemical composition of molecular interstellar clouds; (2) properties and physico-chemical process in the genesis of interstellar dust grains; and (3) the isotope composition of volatiles in bodies of the Solar System.
Speleothems as Examples of Chemical Equilibrium Processes.
ERIC Educational Resources Information Center
Wilson, James R.
The chemical formation of speleothems such as stalactites and stalagmites is poorly understood by introductory geology instructors and misrepresented in most textbooks. Although evaporation may be a controlling factor in some caves, it is necessary to consider chemical precipitation as more important in controlling the diagenesis of calcium…
Design Thinking in Elementary Students' Collaborative Lamp Designing Process
ERIC Educational Resources Information Center
Kangas, Kaiju; Seitamaa-Hakkarainen, Pirita; Hakkarainen, Kai
Design and Technology education is potentially a rich environment for successful learning, if the management of the whole design process is emphasised, and students' design thinking is promoted. The aim of the present study was to unfold the collaborative design process of one team of elementary students, in order to understand their multimodal…
ESS Accelerator Cryoplant Process Design
NASA Astrophysics Data System (ADS)
Wang, X. L.; Arnold, P.; Hees, W.; Hildenbeutel, J.; Weisend, J. G., II
The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. The ESS accelerator will deliver protons with 5 MW of power to the target at 2.0 GeV, with a nominal current of 62.5 mA. The superconducting part of the accelerator is about 300 meters long and contains 43 cryomodules. The ESS accelerator cryoplant (ACCP) will provide the cooling for the cryomodules and the cryogenic distribution system that delivers the helium to the cryomodules. The ACCP will cover three cryogenic circuits: Bath cooling for the cavities at 2 K, the thermal shields at around 40 K and the power couplers thermalisation with 4.5 K forced helium cooling. The open competitive bid for the ACCP took place in 2014 with Linde Kryotechnik AG being selected as the vendor. This paper summarizes the progress in the ACCP development and engineering. Current status including final cooling requirements, preliminary process design, system configuration, machine concept and layout, main parameters and features, solution for the acceptance tests, exergy analysis and efficiency is presented.
Optimal design of solidification processes
NASA Technical Reports Server (NTRS)
Dantzig, Jonathan A.; Tortorelli, Daniel A.
An optimal design algorithm is presented for the analysis of general solidification processes, and is demonstrated for the growth of GaAs crystals in a Bridgman furnace. The system is optimal in the sense that the prespecified temperature distribution in the solidifying materials is obtained to maximize product quality. The optimization uses traditional numerical programming techniques which require the evaluation of cost and constraint functions and their sensitivities. The finite element method is incorporated to analyze the crystal solidification problem, evaluate the cost and constraint functions, and compute the sensitivities. These techniques are demonstrated in the crystal growth application by determining an optimal furnace wall temperature distribution to obtain the desired temperature profile in the crystal, and hence to maximize the crystal's quality. Several numerical optimization algorithms are studied to determine the proper convergence criteria, effective 1-D search strategies, appropriate forms of the cost and constraint functions, etc. In particular, we incorporate the conjugate gradient and quasi-Newton methods for unconstrained problems. The efficiency and effectiveness of each algorithm is presented in the example problem.
Enhanced Teaching and Student Learning through a Simulator-Based Course in Chemical Unit Operations Design
ERIC Educational Resources Information Center
Ghasem, Nayef
This paper illustrates a teaching technique used in computer applications in chemical engineering employed for designing various unit operation processes, where the students learn about unit operations by designing them. The aim of the course is not to teach design, but rather to teach the fundamentals and the function of unit operation processes…
Designer cell signal processing circuits for biotechnology.
Bradley, Robert W; Wang, Baojun
Microorganisms are able to respond effectively to diverse signals from their environment and internal metabolism owing to their inherent sophisticated information processing capacity. A central aim of synthetic biology is to control and reprogramme the signal processing pathways within living cells so as to realise repurposed, beneficial applications ranging from disease diagnosis and environmental sensing to chemical bioproduction. To date most examples of synthetic biological signal processing have been built based on digital information flow, though analogue computing is being developed to cope with more complex operations and larger sets of variables. Great progress has been made in expanding the categories of characterised biological components that can be used for cellular signal manipulation, thereby allowing synthetic biologists to more rationally programme increasingly complex behaviours into living cells. Here we present a current overview of the components and strategies that exist for designer cell signal processing and decision making, discuss how these have been implemented in prototype systems for therapeutic, environmental, and industrial biotechnological applications, and examine emerging challenges in this promising field.
Designer cell signal processing circuits for biotechnology
Bradley, Robert W.; Wang, Baojun
Microorganisms are able to respond effectively to diverse signals from their environment and internal metabolism owing to their inherent sophisticated information processing capacity. A central aim of synthetic biology is to control and reprogramme the signal processing pathways within living cells so as to realise repurposed, beneficial applications ranging from disease diagnosis and environmental sensing to chemical bioproduction. To date most examples of synthetic biological signal processing have been built based on digital information flow, though analogue computing is being developed to cope with more complex operations and larger sets of variables. Great progress has been made in expanding the categories of characterised biological components that can be used for cellular signal manipulation, thereby allowing synthetic biologists to more rationally programme increasingly complex behaviours into living cells. Here we present a current overview of the components and strategies that exist for designer cell signal processing and decision making, discuss how these have been implemented in prototype systems for therapeutic, environmental, and industrial biotechnological applications, and examine emerging challenges in this promising field. PMID:25579192
Managing Analysis Models in the Design Process
NASA Technical Reports Server (NTRS)
Briggs, Clark
Design of large, complex space systems depends on significant model-based support for exploration of the design space. Integrated models predict system performance in mission-relevant terms given design descriptions and multiple physics-based numerical models. Both the design activities and the modeling activities warrant explicit process definitions and active process management to protect the project from excessive risk. Software and systems engineering processes have been formalized and similar formal process activities are under development for design engineering and integrated modeling. JPL is establishing a modeling process to define development and application of such system-level models.
Development of the chemical and electrochemical coal cleaning (CECC) process
Yoon, Roe-Hoan; Basilio, C.I.
The Chemical and Electrochemical Coal Cleaning (CECC) process developed at Virginia Polytechnic Institute and State University was studied further in this project. This process offers a new method of physically cleaning both low- and high-rank coals without requiring fine grinding. The CECC process is based on liberating mineral matter from coal by osmotic pressure. The majority of the work was conducted on Middle Wyodak, Pittsburgh No. 8 and Elkhorn No. 3 coals. The coal samples were characterized for a variety of physical and chemical properties. Parametric studies were then conducted to identify the important operating parameters and to establish the optimum conditions. In addition, fundamental mechanisms of the process were studied, including mineral matter liberation, kinetics of mineral matter and pyrite dissolution, ferric ion regeneration schemes and alternative methods of separating the cleaned coal from the liberated mineral matter. The information gathered from the parametric and fundamental studies was used in the design, construction and testing of a bench-scale continuous CECC unit. Using this unit, the ash content of a Middle Wyodak coal was reduced from 6.96 to 1.61% at a 2 lbs/hr throughput. With an Elkhorn No. 3 sample, the ash content was reduced from 9.43 to 1.8%, while the sulfur content was reduced from 1.57 to 0.9%. The mass balance and liberation studies showed that liberation played a more dominant role than the chemical dissolution in removing mineral matter and inorganic sulfur from the different bituminous coals tested. However, the opposite was found to be the case for the Wyodak coal since this coal contained a significant amount of acid-soluble minerals.
Low temperature radio-chemical energy conversion processes
Gomberg, H.J.
This patent describes a radio-chemical method of converting radiated energy into chemical energy form comprising the steps of: (a) establishing a starting chemical compound in the liquid phase that chemically reacts endothermically to radiation and heat energy to produce a gaseous and a solid constituent of the compound, (b) irradiating the compound in its liquid phase free of solvents to chemically release therefrom in response to the radiation the gaseous and solid constituents, (c) physically separating the solid and gaseous phase constituents from the liquid, and (d) chemically processing the constituents to recover therefrom energy stored therein by the irradiation step (b).
Chemical Compound Design Using Nuclear Charge Distributions
Paquette, W. D.; Skoko, J . J .; Beratan, D. N.; Yang, W. T .; Shinde , S.; Johnston, P. A.; Lazo, J . S.; Wipf, P. Computational Design, Synthesis and...Wang, M. L.; Hu, X. Q.; Beratan, D. N.; Yang, W. T . Designing Molecules by Optimizing Potentials. J . Am. Chem. Soc. 2006, 128 (10), 3228–3232. [16...Fann, G. I.; Yanai, T .; Gan, Z.; Beylkin, G. Multiresolution Quantum Chemistry: Basic Theory and Initial Applications. J . Chem. Phys. 2004, 121 (23
Design Expert's Participation in Elementary Students' Collaborative Design Process
ERIC Educational Resources Information Center
Kangas, Kaiju; Seitamaa-Hakkarainen, Pirita; Hakkarainen, Kai
The main goal of the present study was to provide insights into how disciplinary expertise might be infused into Design and Technology classrooms and how authentic processes based on professional design practices might be constructed. We describe elementary students' collaborative lamp designing process, where the leadership was provided by a…
Industrial Scale Synthesis of Carbon Nanotubes Via Fluidized Bed Chemical Vapor Deposition: A Senior Design Project
ERIC Educational Resources Information Center
Smith, York R.; Fuchs, Alan; Meyyappan, M.
Senior year chemical engineering students designed a process to produce 10 000 tonnes per annum of single wall carbon nanotubes (SWNT) and also conducted bench-top experiments to synthesize SWNTs via fluidized bed chemical vapor deposition techniques. This was an excellent pedagogical experience because it related to the type of real world design…
Veers, Paul
The design of offshore wind plants is a relatively new field. The move into U.S. waters will have unique environmental conditions, as well as expectations from the authorities responsible for managing the development. Wind turbines are required to test their assumed design conditions with the site conditions of the plant. There are still some outstanding issues on how we can assure that the design for both the turbine and the foundation are appropriate for the site and will have an acceptable level of risk associated with the particular installation.
Inorganic chemical precipitate formation payload design
NASA Technical Reports Server (NTRS)
Friedrich, Craig
The Get Away Special payload to investigate the formation of inorganic precipitates (G-405) utilizes six transparent chemical reaction chambers to actively mix a dry powder with a liquid solution. At predetermined intervals the progress of the precipitate formation is photographed and stored as data. The precipitate particles will also be subject to post-flight analysis. The various tasks performed during the 14 hour duration of the experiment are initiated and monitored by a custom-built digital controller. The payload is currently scheduled as a backup payload for STS-29 with a possible launch date of January, 1989.
Hierarchical Process Control of Chemical Vapor Infiltration.
convergence artificial neural network and used it to discover improved regions of the CVI processing parameter space; also, the Technology Assessment...identify in situ process sensors of considerable promise and as artificial neural network training pairs.
Boosting Manufacturing through Modular Chemical Process Intensification
Manufacturing USA's Rapid Advancement in Process Intensification Deployment Institute will focus on developing breakthrough technologies to boost domestic energy productivity and energy efficiency by 20 percent in five years through manufacturing processes.
Boosting Manufacturing through Modular Chemical Process Intensification
Manufacturing USA's Rapid Advancement in Process Intensification Deployment Institute will focus on developing breakthrough technologies to boost domestic energy productivity and energy efficiency by 20 percent in five years through manufacturing processes.
Reengineering the JPL Spacecraft Design Process
NASA Technical Reports Server (NTRS)
Briggs, C.
This presentation describes the factors that have emerged in the evolved process of reengineering the unmanned spacecraft design process at the Jet Propulsion Laboratory in Pasadena, California. Topics discussed include: New facilities, new design factors, new system-level tools, complex performance objectives, changing behaviors, design integration, leadership styles, and optimization.
Graphic Design in Libraries: A Conceptual Process
ERIC Educational Resources Information Center
Ruiz, Miguel
Providing successful library services requires efficient and effective communication with users; therefore, it is important that content creators who develop visual materials understand key components of design and, specifically, develop a holistic graphic design process. Graphic design, as a form of visual communication, is the process of…
Stereodynamics: From elementary processes to macroscopic chemical reactions
Kasai, Toshio; Che, Dock-Chil; Tsai, Po-Yu; Lin, King-Chuen; Palazzetti, Federico; Aquilanti, Vincenzo
This paper aims at discussing new facets on stereodynamical behaviors in chemical reactions, i.e. the effects of molecular orientation and alignment on reactive processes. Further topics on macroscopic processes involving deviations from Arrhenius behavior in the temperature dependence of chemical reactions and chirality effects in collisions are also discussed.
Program Prepares Students for Chemical-Processing Careers
ERIC Educational Resources Information Center
Jorgensen, Haley
This article describes a chemical-processing program at Saginaw Career Complex in Saginaw, Michigan. The program is preparing 42 11th- and 12th-graders to work as chemical-processing operators or technicians by the time they graduate from high school. It was developed in partnership with the Saginaw Career Complex--one of 51 centers in the state…
21 CFR 170.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2014 CFR
... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD ADDITIVES General Provisions § 170.19 Pesticide chemicals in processed foods. When...
Project Designed to Educate Public on Chemicals Starts Up.
ERIC Educational Resources Information Center
Baum, Rudy
The Chemical Education for Public Understanding Project is a three-year pilot project designed to provide the public with accurate information on uses and hazards of chemicals, ranging from control of garden pests to types of toxic wastes generated by industry. Discusses project aims and educational materials to be developed. (JN)
A Course in Chemical Engineering Practice: Graduate Plant Design.
ERIC Educational Resources Information Center
Marnell, Paul
Describes a year-long graduate plant design course. The course provides students with an appreciation of the profit motive that drives business activity, the role of the chemical engineer in achieving this goal, and historical and contemporary perspectives on chemical engineering practice. (JN)
Chemical process safety management within the Department of Energy
Piatt, J.A.
Although the Department of Energy (DOE) is not well known for its chemical processing activities, the DOE does have a variety of chemical processes covered under OSHA`s Rule for Process Safety Management of Highly Hazardous Chemicals (the PSM Standard). DOE, like industry, is obligated to comply with the PSM Standard. The shift in the mission of DOE away from defense programs toward environmental restoration and waste management has affected these newly forming process safety management programs within DOE. This paper describes the progress made in implementing effective process safety management programs required by the PSM Standard and discusses some of the trends that have supported efforts to reduce chemical process risks within the DOE. In June of 1994, a survey of chemicals exceeding OSHA PSM or EPA Risk Management Program threshold quantities (TQs) at DOE sites found that there were 22 processes that utilized toxic or reactive chemicals over TQs; there were 13 processes involving flammable gases and liquids over TQs; and explosives manufacturing occurred at 4 sites. Examination of the survey results showed that 12 of the 22 processes involving toxic chemicals involved the use of chlorine for water treatment systems. The processes involving flammable gases and liquids were located at the Strategic Petroleum Reserve and Naval petroleum Reserve sites.
In-design process hotspot repair using pattern matching
NASA Astrophysics Data System (ADS)
Jang, Daehyun; Ha, Naya; Jeon, Junsu; Kang, Jae-Hyun; Paek, Seung Weon; Choi, Hungbok; Kim, Kee Sup; Lai, Ya-Chieh; Hurat, Philippe; Luo, Wilbur
As patterning for advanced processes becomes more challenging, designs must become more process-aware. The conventional approach of running lithography simulation on designs to detect process hotspots is prohibitive in terms of runtime for designers, and also requires the release of highly confidential process information. Therefore, a more practical approach is required to make the In-Design process-aware methodology more affordable in terms of maintenance, confidentiality, and runtime. In this study, a pattern-based approach is chosen for Process Hotspot Repair (PHR) because it accurately captures the manufacturability challenges without releasing sensitive process information. Moreover, the pattern-based approach is fast and well integrated in the design flow. Further, this type of approach is very easy to maintain and extend. Once a new process weak pattern has been discovered (caused by Chemical Mechanical Polishing (CMP), etch, lithography, and other process steps), the pattern library can be quickly and easily updated and released to check and fix subsequent designs. This paper presents the pattern matching flow and discusses its advantages. It explains how a pattern library is created from the process weak patterns found on silicon wafers. The paper also discusses the PHR flow that fixes process hotspots in a design, specifically through the use of pattern matching and routing repair.
Design of Nanomaterial Synthesis by Aerosol Processes
Buesser, Beat; Pratsinis, Sotiris E.
Aerosol synthesis of materials is a vibrant field of particle technology and chemical reaction engineering. Examples include the manufacture of carbon blacks, fumed SiO2, pigmentary TiO2, ZnO vulcanizing catalysts, filamentary Ni, and optical fibers, materials that impact transportation, construction, pharmaceuticals, energy, and communications. Parallel to this, development of novel, scalable aerosol processes has enabled synthesis of new functional nanomaterials (e.g., catalysts, biomaterials, electroceramics) and devices (e.g., gas sensors). This review provides an access point for engineers to the multiscale design of aerosol reactors for the synthesis of nanomaterials using continuum, mesoscale, molecular dynamics, and quantum mechanics models spanning 10 and 15 orders of magnitude in length and time, respectively. Key design features are the rapid chemistry; the high particle concentrations but low volume fractions; the attainment of a self-preserving particle size distribution by coagulation; the ratio of the characteristic times of coagulation and sintering, which controls the extent of particle aggregation; and the narrowing of the aggregate primary particle size distribution by sintering. PMID:22468598
News: Good chemical manufacturing process criteria
This news column covers topics relating to manufacturing criteria, machine to machine technology, novel process windows, green chemistry indices, business resilience, immobilized enzymes, and Bt crops.
Conversion of Lignocellulosic Biomass to Nanocellulose: Structure and Chemical Process
Lee, H. V.; Hamid, S. B. A.; Zain, S. K.
Lignocellulosic biomass is a complex biopolymer that is primary composed of cellulose, hemicellulose, and lignin. The presence of cellulose in biomass is able to depolymerise into nanodimension biomaterial, with exceptional mechanical properties for biocomposites, pharmaceutical carriers, and electronic substrate's application. However, the entangled biomass ultrastructure consists of inherent properties, such as strong lignin layers, low cellulose accessibility to chemicals, and high cellulose crystallinity, which inhibit the digestibility of the biomass for cellulose extraction. This situation offers both challenges and promises for the biomass biorefinery development to utilize the cellulose from lignocellulosic biomass. Thus, multistep biorefinery processes are necessary to ensure the deconstruction of noncellulosic content in lignocellulosic biomass, while maintaining cellulose product for further hydrolysis into nanocellulose material. In this review, we discuss the molecular structure basis for biomass recalcitrance, reengineering process of lignocellulosic biomass into nanocellulose via chemical, and novel catalytic approaches. Furthermore, review on catalyst design to overcome key barriers regarding the natural resistance of biomass will be presented herein. PMID:25247208
NASA System Engineering Design Process
NASA Technical Reports Server (NTRS)
Roman, Jose
This slide presentation reviews NASA's use of systems engineering for the complete life cycle of a project. Systems engineering is a methodical, disciplined approach for the design, realization, technical management, operations, and retirement of a system. Each phase of a NASA project is terminated with a Key decision point (KDP), which is supported by major reviews.
The Architectural and Interior Design Planning Process.
ERIC Educational Resources Information Center
Cohen, Elaine
Explains the planning process in designing effective library facilities and discusses library building requirements that result from electronic information technologies. Highlights include historical structures; Americans with Disabilities Act; resource allocation; electrical power; interior spaces; lighting; design development; the roles of…
Chemical Sensing for Buried Landmines - Fundamental Processes Influencing Trace Chemical Detection
Mine detection dogs have a demonstrated capability to locate hidden objects by trace chemical detection. Because of this capability, demining activities frequently employ mine detection dogs to locate individual buried landmines or for area reduction. The conditions appropriate for use of mine detection dogs are only beginning to emerge through diligent research that combines dog selection/training, the environmental conditions that impact landmine signature chemical vapors, and vapor sensing performance capability and reliability. This report seeks to address the fundamental soil-chemical interactions, driven by local weather history, that influence the availability of chemical for trace chemical detection. The processes evaluated include: landmine chemical emissions to the soil, chemical distribution in soils, chemical degradation in soils, and weather and chemical transport in soils. Simulation modeling is presented as a method to evaluate the complex interdependencies among these various processes and to establish conditions appropriate for trace chemical detection. Results from chemical analyses on soil samples obtained adjacent to landmines are presented and demonstrate the ultra-trace nature of these residues. Lastly, initial measurements of the vapor sensing performance of mine detection dogs demonstrates the extreme sensitivity of dogs in sensing landmine signature chemicals; however, reliability at these ultra-trace vapor concentrations still needs to be determined. Through this compilation, additional work is suggested that will fill in data gaps to improve the utility of trace chemical detection.
Biomimetic design processes in architecture: morphogenetic and evolutionary computational design.
Menges, Achim
Design computation has profound impact on architectural design methods. This paper explains how computational design enables the development of biomimetic design processes specific to architecture, and how they need to be significantly different from established biomimetic processes in engineering disciplines. The paper first explains the fundamental difference between computer-aided and computational design in architecture, as the understanding of this distinction is of critical importance for the research presented. Thereafter, the conceptual relation and possible transfer of principles from natural morphogenesis to design computation are introduced and the related developments of generative, feature-based, constraint-based, process-based and feedback-based computational design methods are presented. This morphogenetic design research is then related to exploratory evolutionary computation, followed by the presentation of two case studies focusing on the exemplary development of spatial envelope morphologies and urban block morphologies.
Genetic algorithm calculations are applied to the design of chemical processes to achieve improvements in environmental and economic performance. By finding the set of Pareto (i.e., non-dominated) solutions one can see how different objectives, such as environmental and economic ...
Profit opportunities for the chemical process industries
NASA Technical Reports Server (NTRS)
Papers given at a seminar designed to assist industry in the utilization of NASA-developed technology are presented. The topics include the following: the Technology Utilization program, NASA patent policy changes, transfer of Hysttl resin technology, nonflammable cellulosic materials development, nonflammable paper technology, circuit board laminates and construction, polymide resins and other polymers, and intumescent coatings.
Computational design of chemically propelled catalytic nanorotors.
Chen, Yanping; Shi, Yunfeng
We designed catalytic nanorotors and investigated the rotational motion and energy conversion efficiency using reactive molecular dynamics in two dimensions. First, a two-arm nanorotor was constructed by decorating a slender beam with catalysts asymmetrically on its two long edges, while fixing the beam center as the rotational axis. Autonomous rotation was observed for the two-arm nanorotor immersing in a fuel environment. Here fuel molecules undergo exothermic combination reaction facilitated by the catalysts. It was found that the angular velocity increases with the catalyst coverage parabolically, while the rotary nanomotor efficiency stays roughly constant. These observations are consistent with a single-collision-momentum-transfer-based propulsion model. Furthermore, multi-arm nanorotors (up to eight arms) were constructed by carving radially distributed arms followed by decorating catalysts. For multi-arm nanorotors, both the angular velocity and the efficiency decrease as the number of arms increases. These behaviors contradict the aforementioned model, which are likely due to the deceleration from secondary collisions between products and the nanorotor arms. Our simulation results show that the optimal design for a nanorotor that maximizes its angular velocity and the motor efficiency is a two-arm nanorotor with nearly full coverage of catalysts.
Water in Biological and Chemical Processes
NASA Astrophysics Data System (ADS)
Bagchi, Biman
Part I. Bulk Water: 1. Uniqueness of water; 2. Anomalies of water; 3. Dynamics of water: molecular motions and hydrogen bond breaking kinetics; 4. Inherent structures of liquid water; 5. pH of water; Part II. Water in Biology: Dynamical View and Function: 6. Biological water; 7. Explicit role of water in biological functions; 8. Hydration of proteins; 9. Can we understand protein hydration layer: lessons from computer simulations; 10. Water in and around DNA and RNA; 11. Role of water in protein-DNA interaction; 12. Water surrounding lipid bilayers; 13. Water in Darwin's world; Part III. Water in Complex Chemical Systems: 14. Hydrophilic effects; 15. Hydrophobic effects; 16. Aqueous binary mixtures: amphiphilic effect; 17. Water in and around micelles, reverse micelles and microemulsions; 18. Water in carbon nanotubes; Part IV. Bulk Water: Advanced Topics: 19. Entropy of water; 20. Freezing of water into ice; 21. Supercritical water; 22. Microscopic approaches to understand water anomalies.
Incorporating Risk Assessment and Inherently Safer Design Practices into Chemical Engineering Education
ERIC Educational Resources Information Center
Seay, Jeffrey R.; Eden, Mario R.
This paper introduces, via case study example, the benefit of including risk assessment methodology and inherently safer design practices into the curriculum for chemical engineering students. This work illustrates how these tools can be applied during the earliest stages of conceptual process design. The impacts of decisions made during…
Total Ship Design Process Modeling
Microsoft Project® or Primavera ®, and perform process simulations that can investigate risk, cost, and schedule trade-offs. Prior efforts to capture...planning in the face of disruption, delay, and late‐changing requirements. ADePT is interfaced with PrimaVera , the AEC industry favorite program
A software for managing chemical processes in a multi-user laboratory
Camino, Fernando E.
Here, we report a software for logging chemical processes in a multi-user laboratory, which implements a work flow designed to reduce hazardous situations associated with the disposal of chemicals in incompatible waste containers. The software allows users to perform only those processes displayed in their list of authorized chemical processes and provides the location and label code of waste containers, among other useful information. The software has been used for six years in the cleanroom of the Center for Functional Nanomaterials at Brookhaven National Laboratory and has been an important factor for the excellent safety record of the Center.
Practicing universal design to actual hand tool design process.
Lin, Kai-Chieh; Wu, Chih-Fu
UD evaluation principles are difficult to implement in product design. This study proposes a methodology for implementing UD in the design process through user participation. The original UD principles and user experience are used to develop the evaluation items. Difference of product types was considered. Factor analysis and Quantification theory type I were used to eliminate considered inappropriate evaluation items and to examine the relationship between evaluation items and product design factors. Product design specifications were established for verification. The results showed that converting user evaluation into crucial design verification factors by the generalized evaluation scale based on product attributes as well as the design factors applications in product design can improve users' UD evaluation. The design process of this study is expected to contribute to user-centered UD application.
A Probablistic Diagram to Guide Chemical Design with ...
Toxicity is a concern with many chemicals currently in commerce, and with new chemicals that are introduced each year. The standard approach to testing chemicals is to run studies in laboratory animals (e.g. rats, mice, dogs), but because of the expense of these studies and concerns for animal welfare, few chemicals besides pharmaceuticals and pesticides are fully tested. Over the last decade there have been significant developments in the field of computational toxicology which combines in vitro tests and computational models. The ultimate goal of this ?field is to test all chemicals in a rapid, cost effective manner with minimal use of animals. One of the simplest measures of toxicity is provided by high-throughput in vitro cytotoxicity assays, which measure the concentration of a chemical that kills particular types of cells. Chemicals that are cytotoxic at low concentrations tend to be more toxic to animals than chemicals that are less cytotoxic. We employed molecular characteristics derived from density functional theory (DFT) and predicted values of log(octanol-water partition coe?fficient) (logP)to construct a design variable space, and built a predictive model for cytotoxicity using a Naive Bayesian algorithm. External evaluation showed that the area under the curve (AUC) for the receiver operating characteristic (ROC) of the model to be 0.81. Using this model, we provide design rules to help synthetic chemists minimize the chance that a newly synthesize
Chemical processing in geothermal nuclear chimney
Krikorian, O.H.
A closed rubble filled nuclear chimney is provided in a subterranean geothermal formation by detonation of a nuclear explosive device therein, with reagent input and product output conduits connecting the chimney cavity with appropriate surface facilities. Such facilities will usually comprise reagent preparation, product recovery and recycle facilities. Proccsses are then conducted in the nuclear chimney which processes are facilitated by temperature, pressure, catalytic and other conditions existent or which are otherwise provided in the nuclear chimney. (auth)
Chemical delivery systems and soft drugs: Retrometabolic approaches of drug design.
Bhardwaj, Yashumati Ratan; Pareek, Ashutosh; Jain, Vivek; Kishore, Dharma
Inclusion of metabolic considerations in the drug design process leads to significant development in the field of chemical drug targeting and the design of safer drugs during past few years which is a part of an approach now designated as Retro metabolic drug design (RMDD). This approach represents systematic methodologies that integrate structure-activity and structure-metabolism relationships and are aimed to design safe, locally active compounds with an improved therapeutic index. It embraces two distinct methods, chemical delivery systems and a soft drug approach. Present review recapitulates an impression of RMDD giving reflections on the chemical delivery system and the soft drug approach and provides a variety of examples to embody its concepts. Successful application of such design principles has already been applied to a number of marketed drugs like esmolol; loteprednol etc., and many other candidates like beta blockers, ACE inhibitors, alkylating agents, antimicrobials etc., are also under investigation.
Process Design Manual for Nitrogen Control.
ERIC Educational Resources Information Center
Parker, Denny S.; And Others
This manual presents theoretical and process design criteria for the implementation of nitrogen control technology in municipal wastewater treatment facilities. Design concepts are emphasized through examination of data from full-scale and pilot installations. Design data are included on biological nitrification and denitrification, breakpoint…
Reinventing The Design Process: Teams and Models
NASA Technical Reports Server (NTRS)
Wall, Stephen D.
The future of space mission designing will be dramatically different from the past. Formerly, performance-driven paradigms emphasized data return with cost and schedule being secondary issues. Now and in the future, costs are capped and schedules fixed-these two variables must be treated as independent in the design process. Accordingly, JPL has redesigned its design process. At the conceptual level, design times have been reduced by properly defining the required design depth, improving the linkages between tools, and managing team dynamics. In implementation-phase design, system requirements will be held in crosscutting models, linked to subsystem design tools through a central database that captures the design and supplies needed configuration management and control. Mission goals will then be captured in timelining software that drives the models, testing their capability to execute the goals. Metrics are used to measure and control both processes and to ensure that design parameters converge through the design process within schedule constraints. This methodology manages margins controlled by acceptable risk levels. Thus, teams can evolve risk tolerance (and cost) as they would any engineering parameter. This new approach allows more design freedom for a longer time, which tends to encourage revolutionary and unexpected improvements in design.
Sustainability Indicators for Chemical Processes: III. Biodiesel Case Study
The chemical industry is one of the most important business sectors, not only economically, but also societally; as it allows humanity to attain higher standards and quality of life. Simultaneously, chemical products and processes can be the origin of potential human health and ...
Chemical, thermal and impact processing of asteroids
NASA Technical Reports Server (NTRS)
Scott, E. R. D.; Taylor, G. J.; Newsom, H. E.; Herbert, F.; Zolensky, M.
The geological effects of impacts, heating, melting, core formation, and aqueous alteration on asteroids are reviewed. A review of possible heat sources appears to favor an important role for electrical induction heating. The effects of each geologic process acting individually and in combination with others, are considered; it is concluded that there is much evidence for impacts during alteration, metamorphism and melting. These interactions vastly increased the geologic diversity of the asteroid belt. Subsequent impacts of cool asteroids did not reduce this diversity. Instead new rock types were created by mixing, brecciation and minor melting.
Solar powered chemical processing method and apparatus
Moore, W.T.
An apparatus and method is disclosed for direct absorption of solar energy by material being processed whereby it is not necessary to first convert the solar energy to sensible heat in an intermediate heat exchange medium or apparatus. The material to be processed is dispersed downwardly in a chamber, or reaction vessel, in the form of small droplets, or particles, of controlled size. Solar energy entering the vessel through an elongated vertically disposed window impinges directly upon the dispersed material and energy that is not absorbed but is scattered by the dispersed material is generally intercepted by surrounding droplets or particles. Energy not so absorbed by the dispersed droplets or particles is absorbed by the vessel walls and is re-radiated to the dispersed droplets or particles. The vessel is sized so as to absorb the energy whereby the energy is re-radiated from the walls at wave lengths essentially absent from the solar spectrum at sea level due to atmospheric attenuation.
Evaluation of Chemical Coating Processes for AXAF
NASA Technical Reports Server (NTRS)
Engelhaupt, Darell; Ramsey, Brian; Mendrek, Mitchell
The need existed at MSFC for the development and fabrication of radioisotope calibration sources of cadmium 109 and iron 55 isotopes. This was in urgent response to the AXA-F program. Several issues persisted in creating manufacturing difficulties for the supplier. In order to meet the MSFC requirements very stringent control needed to be maintained for the coating quality, specific activity and thickness. Due to the difficulties in providing the precisely controlled devices for testing, the delivery of the sources was seriously delayed. It became imperative that these fabrication issues be resolved to avoid further delays in this AXA-F observatory key component. The objectives are: 1) Research and provide expert advice on coating materials and procedures. 2) Research and recommend solutions to problems that have been experienced with the coating process. 3) Provide recommendations on the selection and preparation of substrates. 4) Provide consultation on the actual coating process including the results of the qualification and acceptance test programs. 5) Perform independent tests at UAH or MSFC as necessary.
Modular microcomponents for a flexible chemical process technology
NASA Astrophysics Data System (ADS)
Schwesinger, Norbert
Different types of modular micro components such as pumps, values, reactors, separators, residence structures, extractors have been developed. Silicon was used as basic material. Most external dimensions of all different modules are equal. The components contain deep micro structures like channels or groves produced in dry or in wet chemical etching procedures. Different types of bonding technologies were applied to cover the flow structures. Openings positioned at the surface allow the connection with external standard tubes. These openings are arranged on each module at the same position. Due to this basic design a highly flexible combination of the micro modules is possible. Specific process conditions of chemical reactions can be adapted very easily and cost effective by means of module combinations. Holders for the modules contain the fluidic/electric connectors and allow their flexible combination. They are made of PEEK or PTFE. Fixing and sealing of external tubes to the modules can be realised by simple screwing procedures of standard tubes into the holders. Due to this simple screwing procedure all modules can be exchanged on demand. Operating pressures up to the limitation values of the external tubes can be applied to the modules. Electrical contacts arranged inside the holders allow the electrical connection of the modules to an external power supply, as well as a read out of electrical signals delivered from possibly integrated specific sensors. Stand alone examinations of single modules as well as specific chemical reactions in modular combinations were carried out to verify the performance of the micro devices. Successful and hopeful results were found in all cases.
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
64. SOUTH PLANT PROCESS PIPING, CHEMICAL STORAGE TANKS AND BUILDINGS. VIEW TO NORTHEAST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
2. OVERHEAD CHEMICAL PROCESS PIPING BETWEEN BUILDINGS 422, ON RIGHT, AND 431, ON LEFT. - Rocky Mountain Arsenal, Crude Mustard & Aldrin Manufacturing, 1200 feet South of December Seventh Avenue; 600 feet East of D Street, Commerce City, Adams County, CO
Notification: Efficiency of the Chemical Safety Board (CSB) Investigation Process
October 17, 2012. The EPA OIG plans to begin fieldwork with a modified objective from our May 15, 2012, preliminary research objective on the U.S. Chemical Safety and Hazard Investigation Board's (CSB's) investigation process.
Chemical etching for automatic processing of integrated circuits
NASA Technical Reports Server (NTRS)
Kennedy, B. W.
Chemical etching for automatic processing of integrated circuits is discussed. The wafer carrier and loading from a receiving air track into automatic furnaces and unloading onto a sending air track are included.
61 FR 1604 - Process Safety Management of Highly Hazardous Chemicals
Federal Register 2010, 2011, 2012, 2013, 2014
... Occupational Safety and Health Administration Process Safety Management of Highly Hazardous Chemicals AGENCY... approval for the paperwork requirements of 29 CFR 1910.119, Process Safety Management of Highly Hazardous... current OMB approval of the paperwork requirements in 29 CFR 1910.119, Process Safety Management of...
Chemical characterisation of rainwater at Stromboli Island (Italy): The effect of post-depositional processes
NASA Astrophysics Data System (ADS)
Cangemi, Marianna; Madonia, Paolo; Favara, Rocco
Volcanoes emit fluids and solid particles into the atmosphere that modify the chemical composition of natural precipitation. We have investigated the geochemistry of Stromboli's rainfall during the period from November 2014 to March 2016 using a network of a new type of sampler specifically designed for operations on volcanic islands. We found that most of the chemical modifications are due to processes occurring after the storage of rainwater in the sampling bottles. These processes include dissolution of volcanogenic soluble salts encrusting volcanic ash and a variable contribution of sea spray aerosol. Our data showed noticeably less scatter than has previously been achieved with a different sampling system that was more open to the atmosphere. This demonstrates the improved efficacy of the new sampler design. The data showed that post-depositional chemical alteration of rain samples dominates over processes occurring during droplet formation ad precipitation. This has important implications for the calculation of fluxes of chemicals from rainfall in volcanic regions.
Some aspects of mathematical and chemical modeling of complex chemical processes
NASA Technical Reports Server (NTRS)
Nemes, I.; Botar, L.; Danoczy, E.; Vidoczy, T.; Gal, D.
Some theoretical questions involved in the mathematical modeling of the kinetics of complex chemical process are discussed. The analysis is carried out for the homogeneous oxidation of ethylbenzene in the liquid phase. Particular attention is given to the determination of the general characteristics of chemical systems from an analysis of mathematical models developed on the basis of linear algebra.
Whitaker, J Michael; McGinnis, Brent; Laughter, Mark D; Morgan, Jim; Bjornard, Trond; Bean, Robert; Durst, Phillip; Hockert, John; DeMuth, Scott; Lockwood, Dunbar
The Safeguards-by-Design (SBD) approach incorporates safeguards into the design and construction of nuclear facilities at the very beginning of the design process. It is a systematic and structured approach for fully integrating international and national safeguards for material control and accountability (MC&A), physical protection, and other proliferation barriers into the design and construction process for nuclear facilities. Implementing SBD is primarily a project management or project coordination challenge. This paper focuses specifically on the design process; the planning, definition, organization, coordination, scheduling and interaction of the safeguards experts and stakeholders as they participate in the design and construction of a nuclear facility. It delineates the steps in a nuclear facility design and construction project in order to provide the project context within which the safeguards design activities take place, describes the involvement of the safeguards experts in the design process, the nature of their analyses, interactions and decisions, and describes the documents created and how they are used. This report highlights the project context of safeguards activities, and identifies the safeguards community (nuclear facility operator, designer/builder, state regulator, SSAC and IAEA) must accomplish in order to implement SBD within the project.
Chemical mass transfer in magmatic processes
NASA Astrophysics Data System (ADS)
Ghiorso, Mark S.; Carmichael, Ian S. E.
Numerical examples of the approach described in Part I of this series (Ghiorso, 1985) are presented in this paper. These examples include the calculation of the compositions and proportions of liquid and solid phases produced during (1) the equilibrium crystallization of a basaltic andesite at 1 bar, (2) the fractional crystallization of an olivine tholeiite at 1 bar and elevated pressures, (3) the fractional and equilibrium crystallization of an olivine boninite at 1 bar, and (4) the (a) isothermal and (b) isenthalpic assimilation of olivine (Fo90) into a liquid/solid assemblage of quartz dioritic composition at ˜1,125° C and 3 kbars. The numerical results on the crystallization of the basaltic andesite are verified by comparison with experimental data while those calculations performed using olivine tholeiitic and olivine boninitic compositions are favorably compared against whole rock and mineral analytical data and petrographic and field observations. In each of the examples presented, the heat effects associated with the modelled process are calculated (e.g. heat of crystallization, heat of assimilation), and free energies of crystallization are examined as a function of the degree of mineral supersaturation. The former quantities are on the order of 173 cal/grm for the cooling and fractional crystallization of an olivine tholeiite to a rhyolitic residuum (corresponding to a 400° C temperature interval). The latter represents an important petrological parameter, in that it quantifies the driving force for the rate of crystal growth and rate of nucleation in magmatic systems. Calculated free energies of crystallization are small (on the order of hundreds of calories per mole per 25° C of undercooling) which indicates that the kinetics of crystallization in magmatic systems are affinity controlled. Melt oxygen fugacity and the degree of oxygen metasomatism play a major role in controlling the fractionation trends produced from crystallizing basaltic liquids
Central Processing of the Chemical Senses: An Overview
Our knowledge regarding the neural processing of the three chemical senses has been considerably lagging behind that of our other senses. It is only during the last 25 years that significant advances have been made in our understanding of where in the human brain odors, tastants, and trigeminal stimuli are processed. Here, we provide an overview of the current knowledge of how the human brain processes chemical stimuli based on findings in neuroimaging studies using positron emission tomography and functional magnetic resonance imaging. Additionally, we provide new insights from recent meta-analyses, on the basis of all published neuroimaging studies of the chemical senses, of where the chemical senses converge in the brain. PMID:21503268
Modeling operators' emergency response time for chemical processing operations.
Murray, Susan L; Harputlu, Emrah; Mentzer, Ray A; Mannan, M Sam
Operators have a crucial role during emergencies at a variety of facilities such as chemical processing plants. When an abnormality occurs in the production process, the operator often has limited time to either take corrective actions or evacuate before the situation becomes deadly. It is crucial that system designers and safety professionals can estimate the time required for a response before procedures and facilities are designed and operations are initiated. There are existing industrial engineering techniques to establish time standards for tasks performed at a normal working pace. However, it is reasonable to expect the time required to take action in emergency situations will be different than working at a normal production pace. It is possible that in an emergency, operators will act faster compared to a normal pace. It would be useful for system designers to be able to establish a time range for operators' response times for emergency situations. This article develops a modeling approach to estimate the time standard range for operators taking corrective actions or following evacuation procedures in emergency situations. This will aid engineers and managers in establishing time requirements for operators in emergency situations. The methodology used for this study combines a well-established industrial engineering technique for determining time requirements (predetermined time standard system) and adjustment coefficients for emergency situations developed by the authors. Numerous videos of workers performing well-established tasks at a maximum pace were studied. As an example, one of the tasks analyzed was pit crew workers changing tires as quickly as they could during a race. The operations in these videos were decomposed into basic, fundamental motions (such as walking, reaching for a tool, and bending over) by studying the videos frame by frame. A comparison analysis was then performed between the emergency pace and the normal working pace operations
National toxicology program chemical nomination and selection process
Selkirk, J.K.
The National Toxicology Program (NTP) was organized to support national public health programs by initiating research designed to understand the physiological, metabolic, and genetic basis for chemical toxicity. The primary mandated responsibilities of NTP were in vivo and vitro toxicity testing of potentially hazardous chemicals; broadening the spectrum of toxicological information on known hazardous chemicals; validating current toxicological assay systems as well as developing new and innovative toxicity testing technology; and rapidly communicating test results to government agencies with regulatory responsibilities and to the medical and scientific communities. 2 figs.
ACToR Chemical Structure processing using Open Source ...
ACToR (Aggregated Computational Toxicology Resource) is a centralized database repository developed by the National Center for Computational Toxicology (NCCT) at the U.S. Environmental Protection Agency (EPA). Free and open source tools were used to compile toxicity data from over 1,950 public sources. ACToR contains chemical structure information and toxicological data for over 558,000 unique chemicals. The database primarily includes data from NCCT research programs, in vivo toxicity data from ToxRef, human exposure data from ExpoCast, high-throughput screening data from ToxCast and high quality chemical structure information from the EPA DSSTox program. The DSSTox database is a chemical structure inventory for the NCCT programs and currently has about 16,000 unique structures. Included are also data from PubChem, ChemSpider, USDA, FDA, NIH and several other public data sources. ACToR has been a resource to various international and national research groups. Most of our recent efforts on ACToR are focused on improving the structural identifiers and Physico-Chemical properties of the chemicals in the database. Organizing this huge collection of data and improving the chemical structure quality of the database has posed some major challenges. Workflows have been developed to process structures, calculate chemical properties and identify relationships between CAS numbers. The Structure processing workflow integrates web services (PubChem and NIH NCI Cactus) to d
Engineering design: A cognitive process approach
NASA Astrophysics Data System (ADS)
Strimel, Greg Joseph
The intent of this dissertation was to identify the cognitive processes used by advanced pre-engineering students to solve complex engineering design problems. Students in technology and engineering education classrooms are often taught to use an ideal engineering design process that has been generated mostly by educators and curriculum developers. However, the review of literature showed that it is unclear as to how advanced pre-engineering students cognitively navigate solving a complex and multifaceted problem from beginning to end. Additionally, it was unclear how a student thinks and acts throughout their design process and how this affects the viability of their solution. Therefore, Research Objective 1 was to identify the fundamental cognitive processes students use to design, construct, and evaluate operational solutions to engineering design problems. Research Objective 2 was to determine identifiers within student cognitive processes for monitoring aptitude to successfully design, construct, and evaluate technological solutions. Lastly, Research Objective 3 was to create a conceptual technological and engineering problem-solving model integrating student cognitive processes for the improved development of problem-solving abilities. The methodology of this study included multiple forms of data collection. The participants were first given a survey to determine their prior experience with engineering and to provide a description of the subjects being studied. The participants were then presented an engineering design challenge to solve individually. While they completed the challenge, the participants verbalized their thoughts using an established "think aloud" method. These verbalizations were captured along with participant observational recordings using point-of-view camera technology. Additionally, the participant design journals, design artifacts, solution effectiveness data, and teacher evaluations were collected for analysis to help achieve the
Priorities in the design of chemical shops at coke plants
V.I. Rudyka; Y.E. Zingerman; V.V. Grabko; L.A. Kazak
Recent trends in the design of chemical equipment at coke plants are described, through the lens of experience at Giprokoks. The main priorities were to improve the removal of impurities from coke oven gas; to improve equipment design on the basis of new materials; to reduce reagent consumption; to reduce the materials and energy consumed in the construction of new equipment; and to minimize impacts on the environment and worker health. Some technological equipment is briefly characterized.
Sealed-bladdered chemical processing method and apparatus
Harless, D. Phillip
A method and apparatus which enables a complete multi-stepped chemical treatment process to occur within a single, sealed-bladdered vessel 31. The entire chemical process occurs without interruption of the sealed-bladdered vessel 31 such as opening the sealed-bladdered vessel 31 between various steps of the process. The sealed-bladdered vessel 31 is loaded with a batch to be dissolved, treated, decanted, rinsed and/or dried. A pressure filtration step may also occur. The self-contained chemical processing apparatus 32 contains a sealed-bladder 32, a fluid pump 34, a reservoir 20, a compressed gas inlet, a vacuum pump 24, and a cold trap 23 as well as the associated piping 33, numerous valves 21,22,25,26,29,30,35,36 and other controls associated with such an apparatus. The claimed invention allows for dissolution and/or chemical treatment without the operator of the self-contained chemical processing apparatus 38 coming into contact with any of the process materials.
Dust as interstellar catalyst. I. Quantifying the chemical desorption process
NASA Astrophysics Data System (ADS)
Minissale, M.; Dulieu, F.; Cazaux, S.; Hocuk, S.
Context. The presence of dust in the interstellar medium has profound consequences on the chemical composition of regions where stars are forming. Recent observations show that many species formed onto dust are populating the gas phase, especially in cold environments where UV- and cosmic-ray-induced photons do not account for such processes. Aims: The aim of this paper is to understand and quantify the process that releases solid species into the gas phase, the so-called chemical desorption process, so that an explicit formula can be derived that can be included in astrochemical models. Methods: We present a collection of experimental results of more than ten reactive systems. For each reaction, different substrates such as oxidized graphite and compact amorphous water ice were used. We derived a formula for reproducing the efficiencies of the chemical desorption process that considers the equipartition of the energy of newly formed products, followed by classical bounce on the surface. In part II of this study we extend these results to astrophysical conditions. Results: The equipartition of energy correctly describes the chemical desorption process on bare surfaces. On icy surfaces, the chemical desorption process is much less efficient, and a better description of the interaction with the surface is still needed. Conclusions: We show that the mechanism that directly transforms solid species into gas phase species is efficient for many reactions.
Design of chemical space networks incorporating compound distance relationships
de la Vega de León, Antonio; Bajorath, Jürgen
Networks, in which nodes represent compounds and edges pairwise similarity relationships, are used as coordinate-free representations of chemical space. So-called chemical space networks (CSNs) provide intuitive access to structural relationships within compound data sets and can be annotated with activity information. However, in such similarity-based networks, distances between compounds are typically determined for layout purposes and clarity and have no chemical meaning. By contrast, inter-compound distances as a measure of dissimilarity can be directly obtained from coordinate-based representations of chemical space. Herein, we introduce a CSN variant that incorporates compound distance relationships and thus further increases the information content of compound networks. The design was facilitated by adapting the Kamada-Kawai algorithm. Kamada-Kawai networks are the first CSNs that are based on numerical similarity measures, but do not depend on chosen similarity threshold values. PMID:28184279
Design of chemical space networks incorporating compound distance relationships.
de la Vega de León, Antonio; Bajorath, Jürgen
Networks, in which nodes represent compounds and edges pairwise similarity relationships, are used as coordinate-free representations of chemical space. So-called chemical space networks (CSNs) provide intuitive access to structural relationships within compound data sets and can be annotated with activity information. However, in such similarity-based networks, distances between compounds are typically determined for layout purposes and clarity and have no chemical meaning. By contrast, inter-compound distances as a measure of dissimilarity can be directly obtained from coordinate-based representations of chemical space. Herein, we introduce a CSN variant that incorporates compound distance relationships and thus further increases the information content of compound networks. The design was facilitated by adapting the Kamada-Kawai algorithm. Kamada-Kawai networks are the first CSNs that are based on numerical similarity measures, but do not depend on chosen similarity threshold values.
Chemical Changes in Carbohydrates Produced by Thermal Processing.
ERIC Educational Resources Information Center
Hoseney, R. Carl
Discusses chemical changes that occur in the carbohydrates found in food products when these products are subjected to thermal processing. Topics considered include browning reactions, starch found in food systems, hydrolysis of carbohydrates, extrusion cooking, processing of cookies and candies, and alterations in gums. (JN)
Identifying and designing chemicals with minimal acute aquatic toxicity.
Kostal, Jakub; Voutchkova-Kostal, Adelina; Anastas, Paul T; Zimmerman, Julie Beth
Industrial ecology has revolutionized our understanding of material stocks and flows in our economy and society. For this important discipline to have even deeper impact, we must understand the inherent nature of these materials in terms of human health and the environment. This paper focuses on methods to design synthetic chemicals to reduce their intrinsic ability to cause adverse consequence to the biosphere. Advances in the fields of computational chemistry and molecular toxicology in recent decades allow the development of predictive models that inform the design of molecules with reduced potential to be toxic to humans or the environment. The approach presented herein builds on the important work in quantitative structure-activity relationships by linking toxicological and chemical mechanistic insights to the identification of critical physical-chemical properties needed to be modified. This in silico approach yields design guidelines using boundary values for physiochemical properties. Acute aquatic toxicity serves as a model endpoint in this study. Defining value ranges for properties related to bioavailability and reactivity eliminates 99% of the chemicals in the highest concern for acute aquatic toxicity category. This approach and its future implementations are expected to yield very powerful tools for life cycle assessment practitioners and molecular designers that allow rapid assessment of multiple environmental and human health endpoints and inform modifications to minimize hazard.
Chemical design of biocompatible iron oxide nanoparticles for medical applications.
Ling, Daishun; Hyeon, Taeghwan
Iron oxide nanoparticles are one of the most versatile and safe nanomaterials used in medicine. Recent progress in nanochemistry enables fine control of the size, crystallinity, uniformity, and surface properties of iron oxide nanoparticles. In this review, the synthesis of chemically designed biocompatible iron oxide nanoparticles with improved quality and reduced toxicity is discussed for use in diverse biomedical applications.
The Engineering Process in Construction & Design
ERIC Educational Resources Information Center
Stoner, Melissa A.; Stuby, Kristin T.; Szczepanski, Susan
Recent research suggests that high-impact activities in science and math classes promote positive attitudinal shifts in students. By implementing high-impact activities, such as designing a school and a skate park, mathematical thinking can be linked to the engineering design process. This hands-on approach, when possible, to demonstrate or…
The report describes the design of the hydropyrolysis reactor system of the Hynol process. (NOTE: A bench scale methanol production facility is being constructed to demonstrate the technical feasibility of producing methanol from biomass using the Hynol process. The plant is bein...
Chemical process simulation has long been used as a design tool in the development of chemical plants, and has long been considered a means to evaluate different design options. With the advent of large scale computer networks and interface models for program components, it is po...
Process characterization and Design Space definition.
Hakemeyer, Christian; McKnight, Nathan; St John, Rick; Meier, Steven; Trexler-Schmidt, Melody; Kelley, Brian; Zettl, Frank; Puskeiler, Robert; Kleinjans, Annika; Lim, Fred; Wurth, Christine
Quality by design (QbD) is a global regulatory initiative with the goal of enhancing pharmaceutical development through the proactive design of pharmaceutical manufacturing process and controls to consistently deliver the intended performance of the product. The principles of pharmaceutical development relevant to QbD are described in the ICH guidance documents (ICHQ8-11). An integrated set of risk assessments and their related elements developed at Roche/Genentech were designed to provide an overview of product and process knowledge for the production of a recombinant monoclonal antibody (MAb). This chapter describes the tools used for the characterization and validation of MAb manufacturing process under the QbD paradigm. This comprises risk assessments for the identification of potential Critical Process Parameters (pCPPs), statistically designed experimental studies as well as studies assessing the linkage of the unit operations. Outcome of the studies is the classification of process parameters according to their criticality and the definition of appropriate acceptable ranges of operation. The process and product knowledge gained in these studies can lead to the approval of a Design Space. Additionally, the information gained in these studies are used to define the 'impact' which the manufacturing process can have on the variability of the CQAs, which is used to define the testing and monitoring strategy.
De Novo Fragment Design for Drug Discovery and Chemical Biology.
Rodrigues, Tiago; Reker, Daniel; Welin, Martin; Caldera, Michael; Brunner, Cyrill; Gabernet, Gisela; Schneider, Petra; Walse, Björn; Schneider, Gisbert
Automated molecular de novo design led to the discovery of an innovative inhibitor of death-associated protein kinase 3 (DAPK3). An unprecedented crystal structure of the inactive DAPK3 homodimer shows the fragment-like hit bound to the ATP pocket. Target prediction software based on machine learning models correctly identified additional macromolecular targets of the computationally designed compound and the structurally related marketed drug azosemide. The study validates computational de novo design as a prime method for generating chemical probes and starting points for drug discovery.
Field programmable chemistry: integrated chemical and electronic processing of informational molecules towards electronic chemical cells.
Wagler, Patrick F; Tangen, Uwe; Maeke, Thomas; McCaskill, John S
The topic addressed is that of combining self-constructing chemical systems with electronic computation to form unconventional embedded computation systems performing complex nano-scale chemical tasks autonomously. The hybrid route to complex programmable chemistry, and ultimately to artificial cells based on novel chemistry, requires a solution of the two-way massively parallel coupling problem between digital electronics and chemical systems. We present a chemical microprocessor technology and show how it can provide a generic programmable platform for complex molecular processing tasks in Field Programmable Chemistry, including steps towards the grand challenge of constructing the first electronic chemical cells. Field programmable chemistry employs a massively parallel field of electrodes, under the control of latched voltages, which are used to modulate chemical activity. We implement such a field programmable chemistry which links to chemistry in rather generic, two-phase microfluidic channel networks that are separated into weakly coupled domains. Electric fields, produced by the high-density array of electrodes embedded in the channel floors, are used to control the transport of chemicals across the hydrodynamic barriers separating domains. In the absence of electric fields, separate microfluidic domains are essentially independent with only slow diffusional interchange of chemicals. Electronic chemical cells, based on chemical microprocessors, exploit a spatially resolved sandwich structure in which the electronic and chemical systems are locally coupled through homogeneous fine-grained actuation and sensor networks and play symmetric and complementary roles. We describe how these systems are fabricated, experimentally test their basic functionality, simulate their potential (e.g. for feed forward digital electrophoretic (FFDE) separation) and outline the application to building electronic chemical cells.
Green chemistry is a rapid developing new field that provides us a pro-active avenue for the sustainable development of future science and technologies. When designed properly, clean chemical technology can be developed in water as a reaction media. The technologies generated f...
Planar Inlet Design and Analysis Process (PINDAP)
NASA Technical Reports Server (NTRS)
Slater, John W.; Gruber, Christopher R.
The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.
Considerations for designing chemical screening strategies in plant biology
Serrano, Mario; Kombrink, Erich; Meesters, Christian
Traditionally, biologists regularly used classical genetic approaches to characterize and dissect plant processes. However, this strategy is often impaired by redundancy, lethality or pleiotropy of gene functions, which prevent the isolation of viable mutants. The chemical genetic approach has been recognized as an alternative experimental strategy, which has the potential to circumvent these problems. It relies on the capacity of small molecules to modify biological processes by specific binding to protein target(s), thereby conditionally modifying protein function(s), which phenotypically resemble mutation(s) of the encoding gene(s). A successful chemical screening campaign comprises three equally important elements: (1) a reliable, robust, and quantitative bioassay, which allows to distinguish between potent and less potent compounds, (2) a rigorous validation process for candidate compounds to establish their selectivity, and (3) an experimental strategy for elucidating a compound's mode of action and molecular target. In this review we will discuss details of this general strategy and additional aspects that deserve consideration in order to take full advantage of the power provided by the chemical approach to plant biology. In addition, we will highlight some success stories of recent chemical screenings in plant systems, which may serve as teaching examples for the implementation of future chemical biology projects. PMID:25904921
Signal Processing For Chemical Sensing: Statistics or Biological Inspiration
NASA Astrophysics Data System (ADS)
Marco, Santiago
Current analytical instrumentation and continuous sensing can provide huge amounts of data. Automatic signal processing and information evaluation is needed to overcome drowning in data. Today, statistical techniques are typically used to analyse and extract information from continuous signals. However, it is very interesting to note that biology (insects and vertebrates) has found alternative solutions for chemical sensing and information processing. This is a brief introduction to the developments in the European Project: Bio-ICT NEUROCHEM: Biologically Inspired Computation for Chemical Sensing (grant no. 216916) Fp7 project devoted to biomimetic olfactory systems.
Interdisciplinary Learning for Chemical Engineering Students from Organic Chemistry Synthesis Lab to Reactor Design to Separation
ERIC Educational Resources Information Center
Armstrong, Matt; Comitz, Richard L.; Biaglow, Andrew; Lachance, Russ; Sloop, Joseph
A novel approach to the Chemical Engineering curriculum sequence of courses at West Point enabled our students to experience a much more realistic design process, which more closely replicated a real world scenario. Students conduct the synthesis in the organic chemistry lab, then conduct computer modeling of the reaction with ChemCad and…
Design of penicillin fermentation process simulation system
NASA Astrophysics Data System (ADS)
Qi, Xiaoyu; Yuan, Zhonghu; Qi, Xiaoxuan; Zhang, Wenqi
Real-time monitoring for batch process attracts increasing attention. It can ensure safety and provide products with consistent quality. The design of simulation system of batch process fault diagnosis is of great significance. In this paper, penicillin fermentation, a typical non-linear, dynamic, multi-stage batch production process, is taken as the research object. A visual human-machine interactive simulation software system based on Windows operation system is developed. The simulation system can provide an effective platform for the research of batch process fault diagnosis.
Conservation of Life as a Unifying Theme for Process Safety in Chemical Engineering Education
ERIC Educational Resources Information Center
Klein, James A.; Davis, Richard A.
This paper explores the use of "conservation of life" as a concept and unifying theme for increasing awareness, application, and integration of process safety in chemical engineering education. Students need to think of conservation of mass, conservation of energy, and conservation of life as equally important in engineering design and analysis.…
ELI ECO Logic International, Inc.'s Thermal Desorption Unit (TDU) is specifically designed for use with Eco Logic's Gas Phase Chemical Reduction Process. The technology uses an externally heated bath of molten tin in a hydrogen atmosphere to desorb hazardous organic compounds fro...
Conceptual design of industrial process displays.
Pedersen, C R; Lind, M
Today, process displays used in industry are often designed on the basis of piping and instrumentation diagrams without any method of ensuring that the needs of the operators are fulfilled. Therefore, a method for a systematic approach to the design of process displays is needed. This paper discusses aspects of process display design taking into account both the designer's and the operator's points of view. Three aspects are emphasized: the operator tasks, the display content and the display form. The distinction between these three aspects is the basis for proposing an outline for a display design method that matches the industrial practice of modular plant design and satisfies the needs of reusability of display design solutions. The main considerations in display design in the industry are to specify the operator's activities in detail, to extract the information the operators need from the plant design specification and documentation, and finally to present this information. The form of the display is selected from existing standardized display elements such as trend curves, mimic diagrams, ecological interfaces, etc. Further knowledge is required to invent new display elements. That is, knowledge about basic visual means of presenting information and how humans perceive and interpret these means and combinations. This knowledge is required in the systematic selection of graphical items for a given display content. The industrial part of the method is first illustrated in the paper by a simple example from a plant with batch processes. Later the method is applied to develop a supervisory display for a condenser system in a nuclear power plant. The differences between the continuous plant domain of power production and the batch processes from the example are analysed and broad categories of display types are proposed. The problems involved in specification and invention of a supervisory display are analysed and conclusions from these problems are made. It is
Illinois Occupational Skill Standards: Chemical Process Technical Operators.
ERIC Educational Resources Information Center
Illinois Occupational Skill Standards and Credentialing Council, Carbondale.
This document, which is intended for workforce preparation program providers, details the Illinois Occupational Skill Standards for programs preparing students for employment as chemical process technical operators. The document begins with a brief overview of the Illinois perspective on occupational skill standards and credentialing, the process…
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
26. PROCESS PIPING AND CHEMICAL STORAGE TANKS AT SOUTH PLANT NORTH EDGE FROM DECEMBER 7TH AVENUE. VIEW TO SOUTHWEST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO
GREENSCOPE: A Method for Modeling Chemical Process Sustainability
Current work within the U.S. Environmental Protection Agency's National Risk Management Research Laboratory is focused on the development of a method for modeling chemical process sustainability. The GREENSCOPE methodology, defined for the four bases of Environment, Economics, Ef...
Secondary cleanup of Idaho Chemical Processing Plant solvent
Mailen, J.C.
Solvent from the Idaho Chemical Processing Plant (ICPP) (operated by Westinghouse Idaho Nuclear Company, Inc.) has been tested to determine the ability of activated alumina to remove secondary degradation products - those degradation products which are not removed by scrubbing with sodium carbonate.
Hazardous Waste Processing in the Chemical Engineering Curriculum.
ERIC Educational Resources Information Center
Dorland, Dianne; Baria, Dorab N.
Describes a sequence of two courses included in the chemical engineering program at the University of Minnesota, Duluth that deal with the processing of hazardous wastes. Covers course content and structure, and discusses developments in pollution prevention and waste management that led to the addition of these courses to the curriculum.…
21 CFR 570.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2011 CFR
... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Pesticide chemicals in processed foods. 570.19 Section 570.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES General Provisions § 570.19...
21 CFR 170.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2011 CFR
... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.19...
21 CFR 170.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2013 CFR
... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.19...
21 CFR 170.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2012 CFR
... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Pesticide chemicals in processed foods. 170.19 Section 170.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES General Provisions § 170.19...
21 CFR 570.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2013 CFR
... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Pesticide chemicals in processed foods. 570.19 Section 570.19 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES General Provisions § 570.19...
Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey
MTR AND ETR COMPLEXES. CAMERA FACING EASTERLY TOWARD CHEMICAL PROCESSING PLANT. MTR AND ITS ATTACHMENTS IN FOREGROUND. ETR BEYOND TO RIGHT. INL NEGATIVE NO. 56-4100. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
Chemical vapor deposition for automatic processing of integrated circuits
NASA Technical Reports Server (NTRS)
Kennedy, B. W.
Chemical vapor deposition for automatic processing of integrated circuits including the wafer carrier and loading from a receiving air track into automatic furnaces and unloading on to a sending air track is discussed. Passivation using electron beam deposited quartz is also considered.
Observations of chemical processing in the circumstellar environment
NASA Technical Reports Server (NTRS)
Mundy, L. G.; McMullin, J. P.; Blake, G. A.
High resolution interferometer and single-dish observations of young, deeply embedded stellar systems reveal a complex chemistry in the circumstellar environments of low to intermediate mass stars. Depletions of gas-phase molecules, grain mantle evaporation, and shock interactions actively drive chemical processes in different regions around young stars. We present results for two systems, IRAS 05338-0624 and NCG 1333 IRAS 4, to illustrate the behavior found and to examine the physical processes at work.
Forest Canopy Processes in a Regional Chemical Transport Model
NASA Astrophysics Data System (ADS)
Makar, Paul; Staebler, Ralf; Akingunola, Ayodeji; Zhang, Junhua; McLinden, Chris; Kharol, Shailesh; Moran, Michael; Robichaud, Alain; Zhang, Leiming; Stroud, Craig; Pabla, Balbir; Cheung, Philip
Forest canopies have typically been absent or highly parameterized in regional chemical transport models. Some forest-related processes are often considered - for example, biogenic emissions from the forests are included as a flux lower boundary condition on vertical diffusion, as is deposition to vegetation. However, real forest canopies comprise a much more complicated set of processes, at scales below the "transport model-resolved scale" of vertical levels usually employed in regional transport models. Advective and diffusive transport within the forest canopy typically scale with the height of the canopy, and the former process tends to dominate over the latter. Emissions of biogenic hydrocarbons arise from the foliage, which may be located tens of metres above the surface, while emissions of biogenic nitric oxide from decaying plant matter are located at the surface - in contrast to the surface flux boundary condition usually employed in chemical transport models. Deposition, similarly, is usually parameterized as a flux boundary condition, but may be differentiated between fluxes to vegetation and fluxes to the surface when the canopy scale is considered. The chemical environment also changes within forest canopies: shading, temperature, and relativity humidity changes with height within the canopy may influence chemical reaction rates. These processes have been observed in a host of measurement studies, and have been simulated using site-specific one-dimensional forest canopy models. Their influence on regional scale chemistry has been unknown, until now. In this work, we describe the results of the first attempt to include complex canopy processes within a regional chemical transport model (GEM-MACH). The original model core was subdivided into "canopy" and "non-canopy" subdomains. In the former, three additional near-surface layers based on spatially and seasonally varying satellite-derived canopy height and leaf area index were added to the original model
Process design for Al backside contacts
Chalfoun, L.L.; Kimerling, L.C.
It is known that properly alloyed aluminum backside contacts can improve silicon solar cell efficiency. To use this knowledge to fullest advantage, we have studied the gettering process that occurs during contact formation and the microstructure of the contact and backside junction region. With an understanding of the alloying step, optimized fabrication processes can be designed. To study gettering, single crystal silicon wafers were coated with aluminim on both sides and subjected to heat treatments. Results are described.
Influence of surface coverage on the chemical desorption process
Minissale, M.; Dulieu, F.
In cold astrophysical environments, some molecules are observed in the gas phase whereas they should have been depleted, frozen on dust grains. In order to solve this problem, astrochemists have proposed that a fraction of molecules synthesized on the surface of dust grains could desorb just after their formation. Recently the chemical desorption process has been demonstrated experimentally, but the key parameters at play have not yet been fully understood. In this article, we propose a new procedure to analyze the ratio of di-oxygen and ozone synthesized after O atoms adsorption on oxidized graphite. We demonstrate that the chemical desorption efficiency of the two reaction paths (O+O and O+O{sub 2}) is different by one order of magnitude. We show the importance of the surface coverage: for the O+O reaction, the chemical desorption efficiency is close to 80% at zero coverage and tends to zero at one monolayer coverage. The coverage dependence of O+O chemical desorption is proved by varying the amount of pre-adsorbed N{sub 2} on the substrate from 0 to 1.5 ML. Finally, we discuss the relevance of the different physical parameters that could play a role in the chemical desorption process: binding energy, enthalpy of formation, and energy transfer from the new molecule to the surface or to other adsorbates.
Process for preparing a chemical compound enriched in isotope content
Michaels, Edward D.
A process to prepare a chemical enriched in isotope content which includes: (a) A chemical exchange reaction between a first and second compound which yields an isotopically enriched first compound and an isotopically depleted second compound; (b) the removal of a portion of the first compound as product and the removal of a portion of the second compound as spent material; (c) the conversion of the remainder of the first compound to the second compound for reflux at the product end of the chemical exchange reaction region; (d) the conversion of the remainder of the second compound to the first compound for reflux at the spent material end of the chemical exchange region; and the cycling of the additional chemicals produced by one conversion reaction to the other conversion reaction, for consumption therein. One of the conversion reactions is an oxidation reaction, and the energy that it yields is used to drive the other conversion reaction, a reduction. The reduction reaction is carried out in a solid polymer electrolyte electrolytic reactor. The overall process is energy efficient and yields no waste by-products.
Design of an embedded inverse-feedforward biomolecular tracking controller for enzymatic reaction processes.
Foo, Mathias; Kim, Jongrae; Sawlekar, Rucha; Bates, Declan G
Feedback control is widely used in chemical engineering to improve the performance and robustness of chemical processes. Feedback controllers require a 'subtractor' that is able to compute the error between the process output and the reference signal. In the case of embedded biomolecular control circuits, subtractors designed using standard chemical reaction network theory can only realise one-sided subtraction, rendering standard controller design approaches inadequate. Here, we show how a biomolecular controller that allows tracking of required changes in the outputs of enzymatic reaction processes can be designed and implemented within the framework of chemical reaction network theory. The controller architecture employs an inversion-based feedforward controller that compensates for the limitations of the one-sided subtractor that generates the error signals for a feedback controller. The proposed approach requires significantly fewer chemical reactions to implement than alternative designs, and should have wide applicability throughout the fields of synthetic biology and biological engineering.
Focused chemical libraries--design and enrichment: an example of protein-protein interaction chemical space.
Zhang, Xu; Betzi, Stéphane; Morelli, Xavier; Roche, Philippe
One of the many obstacles in the development of new drugs lies in the limited number of therapeutic targets and in the quality of screening collections of compounds. In this review, we present general strategies for building target-focused chemical libraries with a particular emphasis on protein-protein interactions (PPIs). We describe the chemical spaces spanned by nine commercially available PPI-focused libraries and compare them to our 2P2I3D academic library, dedicated to orthosteric PPI modulators. We show that although PPI-focused libraries have been designed using different strategies, they share common subspaces. PPI inhibitors are larger and more hydrophobic than standard drugs; however, an effort has been made to improve the drug-likeness of focused chemical libraries dedicated to this challenging class of targets.
Flexible Processing and the Design of Grammar
ERIC Educational Resources Information Center
Sag, Ivan A.; Wasow, Thomas
We explore the consequences of letting the incremental and integrative nature of language processing inform the design of competence grammar. What emerges is a view of grammar as a system of local monotonic constraints that provide a direct characterization of the signs (the form-meaning correspondences) of a given language. This…
An Exploration of Design Students' Inspiration Process
ERIC Educational Resources Information Center
Dazkir, Sibel S.; Mower, Jennifer M.; Reddy-Best, Kelly L.; Pedersen, Elaine L.
Our purpose was to explore how different sources of inspiration influenced two groups of students' inspiration process and their attitudes toward their design projects. Assigned sources of inspiration and instructor's assistance in the search for inspiration varied for two groups of students completing a small culture inspired product design…
Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance
NASA Technical Reports Server (NTRS)
Molina, Mario J.
The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HCl vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow-chemical ionization mass spectrometry and optical ellipsometry, among others.
Interface design in the process industries
NASA Technical Reports Server (NTRS)
Beaverstock, M. C.; Stassen, H. G.; Williamson, R. A.
Every operator runs his plant in accord with his own mental model of the process. In this sense, one characteristic of an ideal man-machine interface is that it be in harmony with that model. With this theme in mind, the paper first reviews the functions of the process operator and compares them with human operators involved in control situations previously studied outside the industrial environment (pilots, air traffic controllers, helmsmen, etc.). A brief history of the operator interface in the process industry and the traditional methodology employed in its design is then presented. Finally, a much more fundamental approach utilizing a model definition of the human operator's behavior is presented.
Chemical measurements with optical fibers for process control.
Boisde, G; Blanc, F; Perez, J J
Several aspects of remote in situ spectrophotometric measurement by means of optical fibers are considered in the context of chemical process control. The technique makes it possible to measure a species in a particular oxidation state, such as plutonium(VI), sequentially, under the stringent conditions of automated analysis. For the control of several species in solution, measurements at discrete wavelengths on the sides of the absorption peaks serve to increase the dynamic range. Examples are given concerning the isotopic separation of uranium in the Chemex process. The chemical control of complex solutions containing numerous mutually interfering species requires a more elaborate spectral scan and real-time processing to determine the chemical kinetics. Photodiode array spectrophotometers are therefore ideal for analysing the uranium and plutonium solutions of the Purex process. Remote on-line control by ultraviolet monitoring exhibits limitations chiefly due to Rayleigh scattering in the optical fibers. The measurement of pH in acidic (0.8-3.2) and basic media (10-13) has also been attempted. Prior calibration, signal processing and optical spectra modeling are also discussed.
Basic physical and chemical processes in space radiation effects on polymers
NASA Technical Reports Server (NTRS)
Kamaratos, E.; Wilson, J. W.; Chang, C. K.; Xu, Y. J.
The effects of space ionizing radiation on polymers is investigated in terms of operative physical and chemical processes. A useful model of charged particle impact with a polymer was designed. Principle paths of molecular relaxation were identified and energy handling processes were considered. The focus of the study was on energy absorption and the immediately following events. Further study of the radiation degradation of polymers is suggested.
Designing chemical processes for environment requires consideration of several indexes of environmental impact including ozone depletion and global warming potentials, human and aquatic toxicity, and photochemical oxidation, and acid rain potentials. Current methodologies like t...
Design of forging process variables under uncertainties
NASA Astrophysics Data System (ADS)
Repalle, Jalaja; Grandhi, Ramana V.
Forging is a complex nonlinear process that is vulnerable to various manufacturing anomalies, such as variations in billet geometry, billet/die temperatures, material properties, and workpiece and forging equipment positional errors. A combination of these uncertainties could induce heavy manufacturing losses through premature die failure, final part geometric distortion, and reduced productivity. Identifying, quantifying, and controlling the uncertainties will reduce variability risk in a manufacturing environment, which will minimize the overall production cost. In this article, various uncertainties that affect the forging process are identified, and their cumulative effect on the forging tool life is evaluated. Because the forging process simulation is time-consuming, a response surface model is used to reduce computation time by establishing a relationship between the process performance and the critical process variables. A robust design methodology is developed by incorporating reliability-based optimization techniques to obtain sound forging components. A case study of an automotive-component forging-process design is presented to demonstrate the applicability of the method.
The design of a nanolithographic process
NASA Astrophysics Data System (ADS)
Johannes, Matthew Steven
This research delineates the design of a nanolithographic process for nanometer scale surface patterning. The process involves the combination of serial atomic force microscope (AFM) based nanolithography with the parallel patterning capabilities of soft lithography. The union of these two techniques provides for a unique approach to nanoscale patterning that establishes a research knowledge base and tools for future research and prototyping. To successfully design this process a number of separate research investigations were undertaken. A custom 3-axis AFM with feedback control on three positioning axes of nanometer precision was designed in order to execute nanolithographic research. This AFM system integrates a computer aided design/computer aided manufacturing (CAD/CAM) environment to allow for the direct synthesis of nanostructures and patterns using a virtual design interface. This AFM instrument was leveraged primarily to study anodization nanolithography (ANL), a nanoscale patterning technique used to generate local surface oxide layers on metals and semiconductors. Defining research focused on the automated generation of complex oxide nanoscale patterns as directed by CAD/CAM design as well as the implementation of tip-sample current feedback control during ANL to increase oxide uniformity. Concurrently, research was conducted concerning soft lithography, primarily in microcontact printing (muCP), and pertinent experimental and analytic techniques and procedures were investigated. Due to the masking abilities of the resulting oxide patterns from ANL, the results of AFM based patterning experiments are coupled with micromachining techniques to create higher aspect ratio structures at the nanoscale. These relief structures are used as master pattern molds for polymeric stamp formation to reproduce the original in a parallel fashion using muCP stamp formation and patterning. This new method of master fabrication provides for a useful alternative to
Coexistence of superconductivity and magnetism by chemical design.
Coronado, Eugenio; Martí-Gastaldo, Carlos; Navarro-Moratalla, Efrén; Ribera, Antonio; Blundell, Stephen J; Baker, Peter J
Although the coexistence of superconductivity and ferromagnetism in one compound is rare, some examples of such materials are known to exist. Methods to physically prepare hybrid structures with both competing phases are also known, which rely on the nanofabrication of alternating conducting layers. Chemical methods of building up hybrid materials with organic molecules (superconducting layers) and metal complexes (magnetic layers) have provided examples of superconductivity with some magnetic properties, but not fully ordered. Now, we report a chemical design strategy that uses the self assembly in solution of macromolecular nanosheet building blocks to engineer the coexistence of superconductivity and magnetism in [Ni(0.66)Al(0.33)(OH)(2)][TaS(2)] at ∼4 K. The method is further demonstrated in the isostructural [Ni(0.66)Fe(0.33)(OH)(2)][TaS(2)], in which the magnetic ordering is shifted from 4 K to 16 K.
Ketusky, E; Neil Davis, N; Renee Spires, R
The Savannah River Site (SRS) has 49 high level waste (HLW) tanks that must be emptied, cleaned, and closed as required by the Federal Facilities Agreement. The current method of chemical cleaning uses several hundred thousand gallons per tank of 8 weight percent (wt%) oxalic acid to partially dissolve and suspend residual waste and corrosion products such that the waste can be pumped out of the tank. This adds a significant quantity of sodium oxalate to the tanks and, if multiple tanks are cleaned, renders the waste incompatible with the downstream processing. Tank space is also insufficient to store this stream given the large number of tanks to be cleaned. Therefore, a search for a new cleaning process was initiated utilizing the TRIZ literature search approach, and Chemical Oxidation Reduction Decontamination--Ultraviolet (CORD-UV), a mature technology currently used for decontamination and cleaning of commercial nuclear reactor primary cooling water loops, was identified. CORD-UV utilizes oxalic acid for sludge dissolution, but then decomposes the oxalic acid to carbon dioxide and water by UV treatment outside the system being treated. This allows reprecipitation and subsequent deposition of the sludge into a selected container without adding significant volume to that container, and without adding any new chemicals that would impact downstream treatment processes. Bench top and demonstration loop measurements on SRS tank sludge stimulant demonstrated the feasibility of applying CORD-UV for enhanced chemical cleaning of SRS HLW tanks.
Modeling the high-temperature gas-cooled reactor process heat plant: a nuclear to chemical conversion process
Pfremmer, R.D.; Openshaw, F.L.
The high-temperature heat available from the High-Temperature Gas-Cooled Reactor (HTGR) makes it suitable for many process applications. One of these applications is a large-scale energy production plant where nuclear energy is converted into chemical energy and stored for industrial or utility applications. This concept combines presently available nuclear HTGR technology and energy conversion chemical technology. The design of this complex plant involves questions of interacting plant dynamics and overall plant control. This paper discusses how these questions were answered with the aid of a hybrid computer model that was developed within the time-frame of the conceptual design studies. A brief discussion is given of the generally good operability shown for the plant and of the specific potential problems and their anticipated solution. The paper stresses the advantages of providing this information in the earliest conceptual phases of the design.
Modeling the high-temperature gas-cooled reactor process heat plant a nuclear to chemical conversion process
Pfremmer, R.D.; Openshaw, F.L.
The high-temperature heat available from the high-temperature gas-cooled reactor (HTGR) makes it suitable for many process applications. One of these applications is a large-scale energy production plant where nuclear energy is converted into chemical energy and stored for industrial or utility applications. This concept combines presently available nuclear HTGR technology and energy conversion chemical technology. The design of this complex plant involves questions of interacting plant dynamics and overall plant control. This paper discusses how these questions were answered with the aid of a hybrid computer model that was developed within the time-frame of the conceptual design studies. A brief discussion is given of the generally good operability shown for the plant and of the specific potential problems and their anticipated solution. The paper stresses the advantages of providing this information in the earliest conceptual phases of the design.
Devising efficient biotechnological processes for the production of fuels and chemicals from biomass
NASA Astrophysics Data System (ADS)
Villet, R. H.
Research directed toward improving ethanol processes based on readily fermentable feedstocks is discussed. Efforts were also made to develop novel fermentation systems. Reducing the cost of producing ethanol and other chemicals requires using cellulosics as feedstocks, which when hydrolyzed form hexose sugars readily metabolized by yeast. A program was undertaken to discover thermophilic organisms that convert various biopolymers to ethanol and other chemical products. Lipids suitable as diesel oil extenders are produced by microorganisms. A screening program was undertaken to identify microbial strains with a biotechnological potential. This involved a precise, quantitative chemical analysis of lipid products. Some work on developing a 2,3-butanediol fermentation process is described. During the fermentation process ethanol is also produced. To improve the ratio of butanediol to ethanol, a program of genetic and physiological research was designed and initiated.
Microfabricated Instrumentation for Chemical Sensing in Industrial Process Control
Ramsey, J. M.
The monitoring of chemical constituents in manufacturing processes is of economic importance to most industries. The monitoring and control of chemical constituents may be of importance for product quality control or, in the case of process effluents, of environmental concern. The most common approach now employed for chemical process control is to collect samples which are returned to a conventional chemical analysis laboratory. This project attempts to demonstrate the use of microfabricated structures, referred to as 'lab-on-a-chip' devices, that accomplish chemical measurement tasks that emulate those performed in the conventional laboratory. The devices envisioned could be used as hand portable chemical analysis instruments where samples are analyzed in the field or as emplaced sensors for continuous 'real-time' monitoring. This project focuses on the development of filtration elements and solid phase extraction elements that can be monolithically integrated onto electrophoresis and chromatographic structures pioneered in the laboratory. Successful demonstration of these additional functional elements on integrated microfabricated devices allows lab-on-a-chip technologies to address real world samples that would be encountered in process control environments. The resultant technology has a broad application to industrial environmental monitoring problems. such as monitoring municipal water supplies, waste water effluent from industrial facilities, or monitoring of run-off from agricultural activities. The technology will also be adaptable to manufacturing process control scenarios. Microfabricated devices integrating sample filtration, solid phase extraction, and chromatographic separation with solvent programming were demonstrated. Filtering of the sample was accomplished at the same inlet with an array of seven channels each 1 {micro}m deep and 18 {micro}m wide. Sample concentration and separation were performed on channels 5 {micro}m deep and 25 {micro
Heat and power networks in process design, part II, design procedure for equipment selection and process matching
Townsend, D.W.; Linnhoff, B.
In Part I, criteria for heat engine and heat pump placement in chemical process networks were derived, based on the ''temperature interval'' (T.I) analysis of the heat exchanger network problem. Using these criteria, this paper gives a method for identifying the best outline design for any combined system of chemical process, heat engines, and heat pumps. The method eliminates inferior alternatives early, and positively leads on to the most appropriate solution. A graphical procedure based on the T.I. analysis forms the heart of the approach, and the calculations involved are simple enough to be carried out on, say, a programmable calculator. Application to a case study is demonstrated. Optimization methods based on this procedure are currently under research.
Composting process design criteria. II. Detention time
Haug, R.T.
Attention has always been directed to detention time as a criteria for design and operation of composting systems. Perhaps this is a logical outgrowth of work on liquid phase systems, where detention time is a fundamental parameter of design. Unlike liquid phase systems, however, the interpretation of detention time and actual values required for design have not been universally accepted in the case of composting. As a case in point, most compost systems incorporate facilities for curing the compost product. However, curing often is considered after the fact or as an add on with little relationship to the first stage, high-rate phase, whether reactor (in-vessel), static pile, or windrow. Design criteria for curing and the relationships between the first-stage, high-rate and second-stage, curing phases of a composting system have been unclear. In Part 2 of this paper, the concepts of hydraulic retention time (HRT) and solids residence time (SRT) are applied to the composting process. Definitions and design criteria for each are proposed. Based on these criteria, the first and second-stages can be designed and integrated into a complete composting system.
Process Control Systems in the Chemical Industry: Safety vs. Security
Jeffrey Hahn; Thomas Anderson
Traditionally, the primary focus of the chemical industry has been safety and productivity. However, recent threats to our nation's critical infrastructure have prompted a tightening of security measures across many different industry sectors. Reducing vulnerabilities of control systems against physical and cyber attack is necessary to ensure the safety, security and effective functioning of these systems. The U.S. Department of Homeland Security has developed a strategy to secure these vulnerabilities. Crucial to this strategy is the Control Systems Security and Test Center (CSSTC) established to test and analyze control systems equipment. In addition, the CSSTC promotes a proactive, collaborative approach to increase industry's awareness of standards, products and processes that can enhance the security of control systems. This paper outlines measures that can be taken to enhance the cybersecurity of process control systems in the chemical sector.
Chemical processes induced by OH attack on nucleic acids
NASA Astrophysics Data System (ADS)
Kuwabara, Mikinori
Recent studies concerning the chemical processes in nucleic acids starting with OH attack to produce free radicals and ending with the formation of stable products were reviewed. Using nucleosides, nucleotides and homopolynucleotides as model compounds, and DNA itself, free radicals produced by OH attack on nucleic acids have been mainly studied by a method combining ESR, spin trapping and high-performance liquid chromatography. For identification of final products in both base and sugar moieties of nucleic acids, mass and NMR spectroscopies combined with gas chromatography or high-performance liquid chromatography are usually employed. Kinetic measurements of structural alterations in the polynucleotides and DNA after OH attack have been made by a method combining electron-pulse irradiation and laser-light scattering. From these studies, the chemical reaction processes from the generation of free radicals in nucleic acids by OH attack, through the formation of unstable intermediates, to the formation of final products can be described.
Processing and Properties of Chemically Derived Calcium Silicate Cements
1991 Air Force Grant No. AFOSR-88-0184 Prepared for AIR FORCE OFFICE OF SCIENTIFIC RESEARCH ELECTRONIC AND MATERIAL SCIENCES DIRECTORATE Principal...Heiland, Processing and Properties of Chemically Derived Calcium Silicate Cement. Master of Science , Solid State Science , The Pennsylvania State...University, May 1990. Appendix IV Kelly Markowski, A Fundamental Study of the Surface Chemistry of Calcium Silicate Hydrate, Bachelor of Science Thesis
Processing Research on Chemically Vapor Deposited Silicon Nitride.
the feasi- bility of synthesizing free-standing plate and figured geometries of phase-pure silicon nitride by the chemical vapor deposition (CVD) method...ates toward moisture and the probability that they all contain absorbed ammonium chloride and ammonia. A strong ammoniacal odor indicates that...solid (V- L -S) processes favored by high ammonia/silicon ratios, high concentrations and long times. Whisker formation would be favored by the opposite
Architectural design of heterogeneous metallic nanocrystals--principles and processes.
Yu, Yue; Zhang, Qingbo; Yao, Qiaofeng; Xie, Jianping; Lee, Jim Yang
CONSPECTUS: Heterogeneous metal nanocrystals (HMNCs) are a natural extension of simple metal nanocrystals (NCs), but as a research topic, they have been much less explored until recently. HMNCs are formed by integrating metal NCs of different compositions into a common entity, similar to the way atoms are bonded to form molecules. HMNCs can be built to exhibit an unprecedented architectural diversity and complexity by programming the arrangement of the NC building blocks ("unit NCs"). The architectural engineering of HMNCs involves the design and fabrication of the architecture-determining elements (ADEs), i.e., unit NCs with precise control of shape and size, and their relative positions in the design. Similar to molecular engineering, where structural diversity is used to create more property variations for application explorations, the architectural engineering of HMNCs can similarly increase the utility of metal NCs by offering a suite of properties to support multifunctionality in applications. The architectural engineering of HMNCs calls for processes and operations that can execute the design. Some enabling technologies already exist in the form of classical micro- and macroscale fabrication techniques, such as masking and etching. These processes, when used singly or in combination, are fully capable of fabricating nanoscopic objects. What is needed is a detailed understanding of the engineering control of ADEs and the translation of these principles into actual processes. For simplicity of execution, these processes should be integrated into a common reaction system and yet retain independence of control. The key to architectural diversity is therefore the independent controllability of each ADE in the design blueprint. The right chemical tools must be applied under the right circumstances in order to achieve the desired outcome. In this Account, after a short illustration of the infinite possibility of combining different ADEs to create HMNC design
Mimicry of natural material designs and processes
Bond, G.M.; Richman, R.H.; McNaughton, W.P.
Biological structural materials, although composed of unremarkable substances synthesized at low temperatures, often exhibit superior mechanical properties. In particular, the quality in which nearly all biologically derived materials excel is toughness. The advantageous mechanical properties are attributable to the hierarchical, composite, structural arrangements common to biological systems. Materials scientists and engineers have increasingly recognized that biological designs or processing approaches applied to man-made materials (biomimesis) may offer improvements in performance over conventional designs and fabrication methods. In this survey, the structures and processing routes of marine shells, avian eggshells, wood, bone, and insect cuticle are briefly reviewed, and biomimesis research inspired by these materials is discussed. In addition, this paper describes and summarizes the applications of biomineralization, self-assembly, and templating with proteins to the fabrication of thin ceramic films and nanostructure devices.
Extended Characterization of Chemical Processes in Hot Cells Using Environmental Swipe Samples
Olsen, Khris B.; Mitroshkov, Alexandre V.; Thomas, M-L; Lepel, Elwood A.; Brunson, Ronald R.; Ladd-Lively, Jennifer
Environmental sampling is used extensively by the International Atomic Energy Agency (IAEA) for verification of information from State declarations or a facility's design regarding nuclear activities occurring within the country or a specific facility. Environmental sampling of hot cells within a facility under safeguards is conducted using 10.2 cm x 10.2 cm cotton swipe material or cellulose swipes. Traditional target analytes used by the IAEA to verify operations within a facility include a select list of gamma-emitting radionuclides and total and isotopic U and Pu. Analysis of environmental swipe samples collected within a hot-cell facility where chemical processing occurs may also provide information regarding specific chemicals used in fuel processing. However, using swipe material to elucidate what specific chemical processes were/are being used within a hot cell has not been previously evaluated. Staff from Pacific Northwest National Laboratory (PNNL) and Oak Ridge National Laboratory (ORNL) teamed to evaluate the potential use of environmental swipe samples as collection media for volatile and semivolatile organic compounds. This evaluation was initiated with sample collection during a series of Coupled End-to-End (CETE) reprocessing runs at ORNL. The study included measurement of gamma emitting radionuclides, total and isotopic U and Pu, and volatile and semivolatile organic compounds. These results allowed us to elucidate what chemical processes used in the hot cells during reprocessing of power reactor and identify other legacy chemicals used in hot cell operations which predate the CETE process.
Active biopolymers in green non-conventional media: a sustainable tool for developing clean chemical processes.
Lozano, Pedro; Bernal, Juana M; Nieto, Susana; Gomez, Celia; Garcia-Verdugo, Eduardo; Luis, Santiago V
The greenness of chemical processes turns around two main axes: the selectivity of catalytic transformations, and the separation of pure products. The transfer of the exquisite catalytic efficiency shown by enzymes in nature to chemical processes is an important challenge. By using appropriate reaction systems, the combination of biopolymers with supercritical carbon dioxide (scCO2) and ionic liquids (ILs) resulted in synergetic and outstanding platforms for developing (multi)catalytic green chemical processes, even under flow conditions. The stabilization of biocatalysts, together with the design of straightforward approaches for separation of pure products including the full recovery and reuse of enzymes/ILs systems, are essential elements for developing clean chemical processes. By understanding structure-function relationships of biopolymers in ILs, as well as for ILs themselves (e.g. sponge-like ionic liquids, SLILs; supported ionic liquids-like phases, SILLPs, etc.), several integral green chemical processes of (bio)catalytic transformation and pure product separation are pointed out (e.g. the biocatalytic production of biodiesel in SLILs, etc.). Other developments based on DNA/ILs systems, as pathfinder studies for further technological applications in the near future, are also considered.
Supercritical Water Process for the Chemical Recycling of Waste Plastics
NASA Astrophysics Data System (ADS)
Goto, Motonobu
The development of chemical recycling of waste plastics by decomposition reactions in sub- and supercritical water is reviewed. Decomposition reactions proceed rapidly and selectively using supercritical fluids compared to conventional processes. Condensation polymerization plastics such as PET, nylon, and polyurethane, are relatively easily depolymerized to their monomers in supercritical water. The monomer components are recovered in high yield. Addition polymerization plastics such as phenol resin, epoxy resin, and polyethylene, are also decomposed to monomer components with or without catalysts. Recycling process of fiber reinforced plastics has been studied. Pilot scale or commercial scale plants have been developed and are operating with sub- and supercritical fluids.
Process for converting cellulosic materials into fuels and chemicals
Scott, Charles D.; Faison, Brendlyn D.; Davison, Brian H.; Woodward, Jonathan
A process for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attritor and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system.
Solar Processes for the Destruction of Hazardous Chemicals
Blake, D. M.
Solar technologies are being developed to address a wide range of environmental problems. Sunlight plays a role in the passive destruction of hazardous substances in soil, water, and air. Development of processes that use solar energy to remediate environmental problems or to treat process wastes is underway in laboratories around the world. This paper reviews progress in understanding the role of solar photochemistry in removing man-made chemicals from the environment, and developing technology that uses solar photochemistry for this purpose in an efficient manner.
Multiplexed chemical sensing and thin film metrology in programmable CVD process
NASA Astrophysics Data System (ADS)
Cai, Yuhong
Mass spectrometry (mass spec) has proven valuable in understanding and controlling chemical processes used in semiconductor fabrication. Given the complexity of spatial distributions of fluid flow, thermal, and chemical parameters in such processes, multi-point chemical sampling would be beneficial. This dissertation discusses the design and development a multiplexed mass spec gas sampling system for real-time, in situ measurement of gas species concentrations in a spatially programmable chemical vapor deposition (SP-CVD) reactor prototype, where such chemical sensing is essential to achieve the benefits of a new paradigm for reactor design. The spatially programmable reactor, in which across-wafer distributions of reactant are programmable, enables (1) uniformity at any desired process design point, or (2) intentional nonuniformity to accelerate process optimization through combinatorial methods. The application of multiplexed mass spec sensing is well suited to our SP-CVD design, which is unique in effectively segmenting the showerhead gas flows by using exhaust gas pumping through the showerhead for each segment. In turn, mass spec sampling signals for each segment are multiplexed to obtain real-time signatures of reactor spatial behavior. In this dissertation, we have reported the results using inert gases to study the spatial distributions of species, validate SP-CVD reactor models, and lead to an understanding of fundamental phenomena associated with the reactor design. This novel multiplexed mass spec sensing system has been employed to monitor the process among three segments in real time. Deliberate non uniform W SP-CVD was performed using H2 reduction of WF6. A process based metrology, which reflects the relationship between the process recipe and film thickness was established. From the process based metrology, a recipe for uniform film deposition was determined and the re-programmability of the SP-CVD system was proven. Meanwhile, a mass spec sensor
Chip Design Process Optimization Based on Design Quality Assessment
NASA Astrophysics Data System (ADS)
Häusler, Stefan; Blaschke, Jana; Sebeke, Christian; Rosenstiel, Wolfgang; Hahn, Axel
Nowadays, the managing of product development projects is increasingly challenging. Especially the IC design of ASICs with both analog and digital components (mixed-signal design) is becoming more and more complex, while the time-to-market window narrows at the same time. Still, high quality standards must be fulfilled. Projects and their status are becoming less transparent due to this complexity. This makes the planning and execution of projects rather difficult. Therefore, there is a need for efficient project control. A main challenge is the objective evaluation of the current development status. Are all requirements successfully verified? Are all intermediate goals achieved? Companies often develop special solutions that are not reusable in other projects. This makes the quality measurement process itself less efficient and produces too much overhead. The method proposed in this paper is a contribution to solve these issues. It is applied at a German design house for analog mixed-signal IC design. This paper presents the results of a case study and introduces an optimized project scheduling on the basis of quality assessment results.
Martino, C.; Herman, D.; Pike, J.; Peters, T.
Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.
Computer-aided software development process design
NASA Technical Reports Server (NTRS)
Lin, Chi Y.; Levary, Reuven R.
The authors describe an intelligent tool designed to aid managers of software development projects in planning, managing, and controlling the development process of medium- to large-scale software projects. Its purpose is to reduce uncertainties in the budget, personnel, and schedule planning of software development projects. It is based on dynamic model for the software development and maintenance life-cycle process. This dynamic process is composed of a number of time-varying, interacting developmental phases, each characterized by its intended functions and requirements. System dynamics is used as a modeling methodology. The resulting Software LIfe-Cycle Simulator (SLICS) and the hybrid expert simulation system of which it is a subsystem are described.
Cogeneration handbook for the chemical process industries. [Contains glossary
Fassbender, A.G.; Fassbender, L.L.; Garrett-Price, B.A.; Moore, N.L.; Eakin, D.E.; Gorges, H.A.
The desision of whether to cogenerate involves several considerations, including technical, economic, environmental, legal, and regulatory issues. Each of these issues is addressed separately in this handbook. In addition, a chapter is included on preparing a three-phase work statement, which is needed to guide the design of a cogeneration system. In addition, an annotated bibliography and a glossary of terminology are provided. Appendix A provides an energy-use profile of the chemical industry. Appendices B through O provide specific information that will be called out in subsequent chapters.
Slaughterhouse wastewater treatment by combined chemical coagulation and electrocoagulation process.
Bazrafshan, Edris; Kord Mostafapour, Ferdos; Farzadkia, Mehdi; Ownagh, Kamal Aldin; Mahvi, Amir Hossein
Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD(5) removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater.
Slaughterhouse Wastewater Treatment by Combined Chemical Coagulation and Electrocoagulation Process
Bazrafshan, Edris; Kord Mostafapour, Ferdos; Farzadkia, Mehdi; Ownagh, Kamal Aldin; Mahvi, Amir Hossein
Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD5 removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater. PMID:22768233
A process for treatment of mixed waste containing chemical plating wastes
Anast, K.R.; Dziewinski, J.; Lussiez, G.
The Waste Treatment and Minimization Group at Los Alamos National Laboratory has designed and will be constructing a transportable treatment system to treat low-level radioactive mixed waste generated during plating operations. The chemical and plating waste treatment system is composed of two modules with six submodules, which can be trucked to user sites to treat a wide variety of aqueous waste solutions. The process is designed to remove the hazardous components from the waste stream, generating chemically benign, disposable liquids and solids with low level radioactivity. The chemical and plating waste treatment system is designed as a multifunctional process capable of treating several different types of wastes. At this time, the unit has been the designated treatment process for these wastes: Destruction of free cyanide and metal-cyanide complexes from spent plating solutions; destruction of ammonia in solution from spent plating solutions; reduction of Cr{sup VI} to Cr{sup III} from spent plating solutions, precipitation, solids separation, and immobilization; heavy metal precipitation from spent plating solutions, solids separation, and immobilization, and acid or base neutralization from unspecified solutions.
Solubility Interactions and the Design of Chemically Selective Sorbent Coatings for Chemical Sensors and Arrays
for n - hexane , 2.91 for cyclohexane, and 4.69 for n -decane. Values of log L16 for alkanes increase with increase in their normal boiling points and...x H 0.38 for N - methylacetamide , compared to 0.33 for ethanol), so the presence of RNHCOR' functionality in a polymer would give rise to significant...Naval Research Laboratory V Washington, DC 20375-5000 I NRL Memorandum Report 6692 N Solubility Interactions and the Design of Ln Chemically
DAWN (Design Assistant Workstation) for advanced physical-chemical life support systems
NASA Technical Reports Server (NTRS)
Rudokas, Mary R.; Cantwell, Elizabeth R.; Robinson, Peter I.; Shenk, Timothy W.
This paper reports the results of a project supported by the National Aeronautics and Space Administration, Office of Aeronautics and Space Technology (NASA-OAST) under the Advanced Life Support Development Program. It is an initial attempt to integrate artificial intelligence techniques (via expert systems) with conventional quantitative modeling tools for advanced physical-chemical life support systems. The addition of artificial intelligence techniques will assist the designer in the definition and simulation of loosely/well-defined life support processes/problems as well as assist in the capture of design knowledge, both quantitative and qualitative. Expert system and conventional modeling tools are integrated to provide a design workstation that assists the engineer/scientist in creating, evaluating, documenting and optimizing physical-chemical life support systems for short-term and extended duration missions.
Progress and challenges in control of chemical processes.
Lee, Jay H; Lee, Jong Min
This review covers key developments and trends in chemical process control during the past two decades. Control methodologies and related supporting technologies are covered, and recent trends in applications are also examined. After the widespread adoption of model-based techniques by industry, control interest has begun to move beyond the traditional realm of readily measured variables to include chemical compositions and particle features. However, the shift is being slowed by the shortage of accurate, reliable, and inexpensive sensing devices. Although the past two decades saw no new major theoretical or methodological advances, several important incremental improvements and extensions have been made to help the ripening of the technologies developed in the preceding two decades. Control is regaining its importance owing to society's renewed focus on energy and the maturation of various emerging technologies, but a community-wide consensus on what general problems should be solved is lacking.
Chemical evolution of the Earth: Equilibrium or disequilibrium process?
NASA Technical Reports Server (NTRS)
Sato, M.
To explain the apparent chemical incompatibility of the Earth's core and mantle or the disequilibrium process, various core forming mechanisms have been proposed, i.e., rapid disequilibrium sinking of molten iron, an oxidized core or protocore materials, and meteorite contamination of the upper mantle after separation from the core. Adopting concepts used in steady state thermodynamics, a method is devised for evaluating how elements should distribute stable in the Earth's interior for the present gradients of temperature, pressure, and gravitational acceleration. Thermochemical modeling gives useful insights into the nature of chemical evolution of the Earth without overly speculative assumptions. Further work must be done to reconcile siderophile elements, rare gases, and possible light elements in the outer core.
Laboratory Studies of Heterogeneous Chemical Processes of Atmospheric Importance
NASA Technical Reports Server (NTRS)
Molina, Mario J.
The objective of this study is to conduct measurements of chemical kinetics parameters for heterogeneous reactions of importance in the stratosphere and the troposphere. It involves the elucidation of the mechanism of the interaction of HC1 vapor with ice surfaces, which is the first step in the heterogeneous chlorine activation processes, as well as the investigation of the atmospheric oxidation mechanism of soot particles emitted by biomass and fossil fuels. The techniques being employed include turbulent flow- chemical ionization mass spectrometry and optical ellipsometry, among others. The next section summarizes our research activities during the first year of the project, and the section that follows consists of the statement of work for the second year.
CHO gene expression profiling in biopharmaceutical process analysis and design.
Schaub, Jochen; Clemens, Christoph; Schorn, Peter; Hildebrandt, Tobias; Rust, Werner; Mennerich, Detlev; Kaufmann, Hitto; Schulz, Torsten W
Increase in both productivity and product yields in biopharmaceutical process development with recombinant protein producing mammalian cells can be mainly attributed to the advancements in cell line development, media, and process optimization. Only recently, genome-scale technologies enable a system-level analysis to elucidate the complex biomolecular basis of protein production in mammalian cells promising an increased process understanding and the deduction of knowledge-based approaches for further process optimization. Here, the use of gene expression profiling for the analysis of a low titer (LT) and high titer (HT) fed batch process using the same IgG producing CHO cell line was investigated. We found that gene expression (i) significantly differed in HT versus LT process conditions due to differences in applied chemically defined, serum-free media, (ii) changed over the time course of the fed batch processes, and that (iii) both metabolic pathways and 14 biological functions such as cellular growth or cell death were affected. Furthermore, detailed analysis of metabolism in a standard process format revealed the potential use of transcriptomics for rational media design as is shown for the case of lipid metabolism where the product titer could be increased by about 20% based on a lipid modified basal medium. The results demonstrate that gene expression profiling can be an important tool for mammalian biopharmaceutical process analysis and optimization.
Reliability Methods for Shield Design Process
NASA Technical Reports Server (NTRS)
Tripathi, R. K.; Wilson, J. W.
Providing protection against the hazards of space radiation is a major challenge to the exploration and development of space. The great cost of added radiation shielding is a potential limiting factor in deep space operations. In this enabling technology, we have developed methods for optimized shield design over multi-segmented missions involving multiple work and living areas in the transport and duty phase of space missions. The total shield mass over all pieces of equipment and habitats is optimized subject to career dose and dose rate constraints. An important component of this technology is the estimation of two most commonly identified uncertainties in radiation shield design, the shielding properties of materials used and the understanding of the biological response of the astronaut to the radiation leaking through the materials into the living space. The largest uncertainty, of course, is in the biological response to especially high charge and energy (HZE) ions of the galactic cosmic rays. These uncertainties are blended with the optimization design procedure to formulate reliability-based methods for shield design processes. The details of the methods will be discussed.
Process for the preparation of fiber-reinforced ceramic composites by chemical vapor deposition
Lackey, Jr., Walter J.; Caputo, Anthony J.
A chemical vapor deposition (CVD) process for preparing fiber-reinforced ceramic composites. A specially designed apparatus provides a steep thermal gradient across the thickness of a fibrous preform. A flow of gaseous ceramic matrix material is directed into the fibrous preform at the cold surface. The deposition of the matrix occurs progressively from the hot surface of the fibrous preform toward the cold surface. Such deposition prevents the surface of the fibrous preform from becoming plugged. As a result thereof, the flow of reactant matrix gases into the uninfiltrated (undeposited) portion of the fibrous preform occurs throughout the deposition process. The progressive and continuous deposition of ceramic matrix within the fibrous preform provides for a significant reduction in process time over known chemical vapor deposition processes.
Bioactives from fruit processing wastes: Green approaches to valuable chemicals.
Banerjee, Jhumur; Singh, Ramkrishna; Vijayaraghavan, R; MacFarlane, Douglas; Patti, Antonio F; Arora, Amit
Fruit processing industries contribute more than 0.5billion tonnes of waste worldwide. The global availability of this feedstock and its untapped potential has encouraged researchers to perform detailed studies on value-addition potential of fruit processing waste (FPW). Compared to general food or other biomass derived waste, FPW are found to be selective and concentrated in nature. The peels, pomace and seed fractions of FPW could potentially be a good feedstock for recovery of bioactive compounds such as pectin, lipids, flavonoids, dietary fibres etc. A novel bio-refinery approach would aim to produce a wider range of valuable chemicals from FPW. The wastes from majority of the extraction processes may further be used as renewable sources for production of biofuels. The literature on value addition to fruit derived waste is diverse. This paper presents a review of fruit waste derived bioactives. The financial challenges encountered in existing methods are also discussed.
Integration between chemical oxidation and membrane thermophilic biological process.
Bertanza, G; Collivignarelli, M C; Crotti, B M; Pedrazzani, R
Full scale applications of activated sludge thermophilic aerobic process for treatment of liquid wastes are rare. This experimental work was carried out at a facility, where a thermophilic reactor (1,000 m(3) volume) is operated. In order to improve the global performance of the plant, it was decided to upgrade it, by means of two membrane filtration units (ultrafiltration -UF-, in place of the final sedimentation, and nanofiltration -NF-). Subsequently, the integration with chemical oxidation (O(3) and H(2)O(2)/UV processes) was taken into consideration. Studied solutions dealt with oxidation of both the NF effluents (permeate and concentrate). Based on experimental results and economic evaluation, an algorithm was proposed for defining limits of convenience of this process.
Saving Material with Systematic Process Designs
NASA Astrophysics Data System (ADS)
Kerausch, M.
Global competition is forcing the stamping industry to further increase quality, to shorten time-to-market and to reduce total cost. Continuous balancing between these classical time-cost-quality targets throughout the product development cycle is required to ensure future economical success. In today's industrial practice, die layout standards are typically assumed to implicitly ensure the balancing of company specific time-cost-quality targets. Although die layout standards are a very successful approach, there are two methodical disadvantages. First, the capabilities for tool design have to be continuously adapted to technological innovations; e.g. to take advantage of the full forming capability of new materials. Secondly, the great variety of die design aspects have to be reduced to a generic rule or guideline; e.g. binder shape, draw-in conditions or the use of drawbeads. Therefore, it is important to not overlook cost or quality opportunities when applying die design standards. This paper describes a systematic workflow with focus on minimizing material consumption. The starting point of the investigation is a full process plan for a typical structural part. All requirements are definedaccording to a predefined set of die design standards with industrial relevance are fulfilled. In a first step binder and addendum geometry is systematically checked for material saving potentials. In a second step, blank shape and draw-in are adjusted to meet thinning, wrinkling and springback targets for a minimum blank solution. Finally the identified die layout is validated with respect to production robustness versus splits, wrinkles and springback. For all three steps the applied methodology is based on finite element simulation combined with a stochastical variation of input variables. With the proposed workflow a well-balanced (time-cost-quality) production process assuring minimal material consumption can be achieved.
Fluid Assisted Fault Weakening: Mechanical vs. Chemical Processes
NASA Astrophysics Data System (ADS)
Collettini, C.
The influx of fluids into fault zones can trigger two main types of weakening process that operate over different timescales, facilitate fault movement and influence fault slip behaviour. During the seismic cycle fluids can be trapped by low permeability fault zones or stratigraphic barriers favoring fluid overpressure (mechanical weakening) and earthquake nucleation. In the entire fault history fluids can react with fault rocks to produce weak mineral phases (chemical weakening) that alter the mechanical properties of the fault zones. Here I will present two examples of mechanical and chemical fault-weakening from the Apennines of Italy. Seismic profiles and deep borehole data show that the strongest earthquakes of the Apennines nucleate within overpressured Evaporites consisting of dolostones and anhydrites. Field and experimental studies on exhumed faults within the same lithology depict a cataclastic inner fault that can generate frictional instabilities with localization and increasing sliding velocity. The outer fault core presents barrier-like portions associated with foliated anhydrites, 10-21 ≤ permeability ≤10-19 m2. The combination of field observations and rock deformation measurements suggests a fault zone structure capable of developing fluid overpressures during the seismic cycle: fluid overpressures can potentially promote earthquake nucleation and aftershock triggering. Field studies from an exhumed regional low-angle normal fault show that in the long term fluids reacted (diffusion-mass transfer processes) with fine-grained cataclasites in the fault core to produce a phyllosilicates-rich and foliated fault rock. Within the foliated microstructure, that is rich in talc, smectite and chlorite, deformation occurs by frictional sliding along 50-200-nm-thick lamellae. Rock deformation experiments show that the foliated fault rock is weak, 0.2 < friction< 0.35, it is characterized by a stable sliding slip-behaviour with no strength recovery with
Nuclear Technology Series. Course 23: Nuclear Chemical Processes.
ERIC Educational Resources Information Center
Center for Occupational Research and Development, Inc., Waco, TX.
This technical specialty course is one of thirty-five courses designed for use by two-year postsecondary institutions in five nuclear technician curriculum areas: (1) radiation protection technician, (2) nuclear instrumentation and control technician, (3) nuclear materials processing technician, (4) nuclear quality-assurance/quality-control…
Flexible processing and the design of grammar.
Sag, Ivan A; Wasow, Thomas
We explore the consequences of letting the incremental and integrative nature of language processing inform the design of competence grammar. What emerges is a view of grammar as a system of local monotonic constraints that provide a direct characterization of the signs (the form-meaning correspondences) of a given language. This "sign-based" conception of grammar has provided precise solutions to the key problems long thought to motivate movement-based analyses, has supported three decades of computational research developing large-scale grammar implementations, and is now beginning to play a role in computational psycholinguistics research that explores the use of underspecification in the incremental computation of partial meanings.
Subfemtosecond directional control of chemical processes in molecules
NASA Astrophysics Data System (ADS)
Alnaser, Ali S.; Litvinyuk, Igor V.
Laser pulses with a waveform-controlled electric field and broken inversion symmetry establish the opportunity to achieve directional control of molecular processes on a subfemtosecond timescale. Several techniques could be used to break the inversion symmetry of an electric field. The most common ones include combining a fundamental laser frequency with its second harmonic or with higher -frequency pulses (or pulse trains) as well as using few-cycle pulses with known carrier-envelope phase (CEP). In the case of CEP, control over chemical transformations, typically occurring on a timescale of many femtoseconds, is driven by much faster sub-cycle processes of subfemtosecond to few-femtosecond duration. This is possible because electrons are much lighter than nuclei and fast electron motion is coupled to the much slower nuclear motion. The control originates from populating coherent superpositions of different electronic or vibrational states with relative phases that are dependent on the CEP or phase offset between components of a two-color pulse. In this paper, we review the recent progress made in the directional control over chemical processes, driven by intense few-cycle laser pulses a of waveform-tailored electric field, in different molecules.
Inhomogeneous chemical evolution of r-process elements
NASA Astrophysics Data System (ADS)
Wehmeyer, B.; Pignatari, M.; Thielemann, F.-K.
We report the results of a galactic chemical evolution (GCE) study for r-process- and alpha elements. For this work, we used the inhomogeneous GCE model "ICE", which allows to keep track of the galactic abundances of elements produced by different astrophysical sites. The main input parameters for this study were: a) The Neutron Star Merger (NSM) coalescence time scale, the probability of NSMs, and for the sub-class of "magneto-rotationally driven Supernovae" ("Jet-SNe"), their occurence rate in comparison to "standard" Supernovae (SNe).
Rainwater as a chemical agent of geologic processes; a review
Carroll, Dorothy
Chemical analyses of the rainwater collected at several localities are given to show the variations of the principal constitutents. In rock weathering and soil-forming processes, the chemical composition of rainwater has an important effect which has been evaluated for only a few arid areas. In humid regions the important amounts of calcium, magnesium, sodium, and potassium added yearly by rain may be expected to influence the composition of the soil water and thereby the cations in the exchange positions of soil clay minerals. The acquisition of cations by clay minerals may slow down chemical weathering. The stability of soil clay minerals is influenced by the constant accession of cations from rainwater. Conversely, the clay minerals modify the amounts and kinds of cations that are leached out by drainage waters. The stability of micaceous minerals in soils may be partly due to accessions of K +1 ions from rainwater. The pH of rainwater in any area varies considerably and seems to form a seasonal and regional pattern. The recorded pH values range from 3.0 to 9.8.
[Design of an HACCP program for a cocoa processing facility].
López D'Sola, Patrizia; Sandia, María Gabriela; Bou Rached, Lizet; Hernández Serrano, Pilar
The HACCP plan is a food safety management tool used to control physical, chemical and biological hazards associated to food processing through all the processing chain. The aim of this work is to design a HACCP Plan for a Venezuelan cocoa processing facility.The production of safe food products requires that the HACCP system be built upon a solid foundation of prerequisite programs such as Good Manufacturing Practices (GMP) and Sanitation Standard Operating Procedures (SSOP). The existence and effectiveness of these prerequisite programs were previously assessed.Good Agriculture Practices (GAP) audit to cocoa nibs suppliers were performed. To develop the HACCP plan, the five preliminary tasks and the seven HACCP principles were accomplished according to Codex Alimentarius procedures. Three Critical Control Points (CCP) were identified using a decision tree: winnowing (control of ochratoxin A), roasting (Salmonella control) and metallic particles detection. For each CCP, Critical limits were established, the Monitoring procedures, Corrective actions, Procedures for Verification and Documentation concerning all procedures and records appropriate to these principles and their application was established. To implement and maintain a HACCP plan for this processing plant is suggested. Recently OchratoxinA (OTA) has been related to cocoa beans. Although the shell separation from the nib has been reported as an effective measure to control this chemical hazard, ochratoxin prevalence study in cocoa beans produced in the country is recommended, and validate the winnowing step as well
Magnetically assisted chemical separation (MACS) process: Preparation and optimization of particles for removal of transuranic elements
Nunez, L.; Kaminski, M.; Bradley, C.; Buchholz, B.A.; Aase, S.B.; Tuazon, H.E.; Vandegrift, G.F.; Landsberger, S.
The Magnetically Assisted Chemical Separation (MACS) process combines the selectivity afforded by solvent extractants with magnetic separation by using specially coated magnetic particles to provide a more efficient chemical separation of transuranic (TRU) elements, other radionuclides, and heavy metals from waste streams. Development of the MACS process uses chemical and physical techniques to elucidate the properties of particle coatings and the extent of radiolytic and chemical damage to the particles, and to optimize the stages of loading, extraction, and particle regeneration. This report describes the development of a separation process for TRU elements from various high-level waste streams. Polymer-coated ferromagnetic particles with an adsorbed layer of octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted with tributyl phosphate (TBP) were evaluated for use in the separation and recovery of americium and plutonium from nuclear waste solutions. Due to their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can then be recovered from the solution by using a magnet. The partition coefficients were larger than those expected based on liquid[liquid extractions, and the extraction proceeded with rapid kinetics. Extractants were stripped from the particles with alcohols and 400-fold volume reductions were achieved. Particles were more sensitive to acid hydrolysis than to radiolysis. Overall, the optimization of a suitable NMCS particle for TRU separation was achieved under simulant conditions, and a MACS unit is currently being designed for an in-lab demonstration.
Bio/chemical microsystem designed for wafer scale testing
NASA Astrophysics Data System (ADS)
Jorgensen, Anders M.; Mogensen, Klaus B.; Rong, Weimin; Telleman, Pieter; Kutter, Joerg P.
We have designed a bio/chemical microsystem for online monitoring of glucose concentrations during fermentation. The system contains several passive microfluidic components including an enzyme reactor, a flow lamination part and a detector. Detection is based on the reaction of hydrogen peroxide, that is produced from glucose in an enzyme reactor, with luminol. This chemiluminescent reaction generates light that is detected by an integrated back-side contacted photodiode array. Various tests during fabrication are outlined with the emphasis on microwave detected photo conductance decay. The presented microsystem has both fluidic and electrical connection points accessible from the backside. This allows simultaneous testing of both fluidic and electrical parts before dicing the wafer.
Quantum-chemical foundations of the topological substructural molecular design.
Estrada, Ernesto
The topological substructural molecular design (TOPS-MODE) approach is formulated as a tight-binding quantum-chemical method. The approach is based on certain postulates that permit to express any molecular property as a function of the spectral moments of certain types of molecular and environment-dependent energies. We use several empirical potentials to account for these intrinsic and external molecular energies. We prove that any molecular property expressed in terms of a quantitative structure-property and structure-activity relationships (QSPR/QSAR) model developed by using the TOPS-MODE method can be expressed as a bond additivity function. In addition, such a property can also be expressed as a substructural cluster expansion function. The conditions for such bond contributions being transferable are also analyzed here. Several new statistical-mechanical electronic functions are introduced as well as a bond-bond thermal Green's function or a propagator accounting for the electronic hopping between pairs of bonds. All these new concepts are applied to the development and application of a new QSAR model for describing the toxicity of polyhalogenated-dibenzo-1,4-dioxins. The QSAR model obtained displays a significant robustness and predictability. It permits an easy structural interpretation of the structure-activity relationship in terms of bond additivity functions, which display some resemblances with other theoretical parameters obtained from first principle quantum-chemical methods.
Process for converting cellulosic materials into fuels and chemicals
Scott, C.D.; Faison, B.D.; Davison, B.H.; Woodward, J.
A process is described for converting cellulosic materials, such as waste paper, into fuels and chemicals utilizing enzymatic hydrolysis of the major constituent of paper, cellulose. A waste paper slurry is contacted by cellulase in an agitated hydrolyzer. The cellulase is produced from a continuous, columnar, fluidized-bed bioreactor utilizing immobilized microorganisms. An attrition mill and a cellobiase reactor are coupled to the agitated hydrolyzer to improve reaction efficiency. The cellulase is recycled by an adsorption process. The resulting crude sugars are converted to dilute product in a fluidized-bed bioreactor utilizing microorganisms. The dilute product is concentrated and purified by utilizing distillation and/or a biparticle fluidized-bed bioreactor system. 1 fig.
Remote Maintenance Design Guide for Compact Processing Units
Draper, J.V.
Oak Ridge National Laboratory (ORNL) Robotics and Process Systems (RPSD) personnel have extensive experience working with remotely operated and maintained systems. These systems require expert knowledge in teleoperation, human factors, telerobotics, and other robotic devices so that remote equipment may be manipulated, operated, serviced, surveyed, and moved about in a hazardous environment. The RPSD staff has a wealth of experience in this area, including knowledge in the broad topics of human factors, modular electronics, modular mechanical systems, hardware design, and specialized tooling. Examples of projects that illustrate and highlight RPSD's unique experience in remote systems design and application include the following: (1) design of a remote shear and remote dissolver systems in support of U.S. Department of Energy (DOE) fuel recycling research and nuclear power missions; (2) building remotely operated mobile systems for metrology and characterizing hazardous facilities in support of remote operations within those facilities; (3) construction of modular robotic arms, including the Laboratory Telerobotic Manipulator, which was designed for the National Aeronautics and Space Administration (NASA) and the Advanced ServoManipulator, which was designed for the DOE; (4) design of remotely operated laboratories, including chemical analysis and biochemical processing laboratories; (5) construction of remote systems for environmental clean up and characterization, including underwater, buried waste, underground storage tank (UST) and decontamination and dismantlement (D&D) applications. Remote maintenance has played a significant role in fuel reprocessing because of combined chemical and radiological contamination. Furthermore, remote maintenance is expected to play a strong role in future waste remediation. The compact processing units (CPUs) being designed for use in underground waste storage tank remediation are examples of improvements in systems processing
Role of pyro-chemical processes in advanced fuel cycles
NASA Astrophysics Data System (ADS)
Nawada, Hosadu Parameswara; Fukuda, Kosaku
Partitioning and Transmutation (P&T) of Minor Actinides (MAs) and Long-Lived Fission Products (LLFP) arising out of the back-end of the fuel cycle would be one of the key-steps in any future sustainable nuclear fuel cycle. Pyro-chemical separation methods would form a critical stage of P&T by recovering long-lived elements and thus reducing the environmental impact by the back-end of the fuel-cycle. This paper attempts to overview global developments of pyro-chemical process that are envisaged in advanced nuclear fuel cycles. Research and development needs for molten-salt electro-refining as well as molten salt extraction process that are foreseen as partitioning methods for spent nuclear fuels such as oxide, metal and nitride fuels from thermal or fast reactors; high level liquid waste from back-end fuel cycle as well as targets from sub-critical Accelerator Driven Sub-critical reactors would be addressed. The role of high temperature thermodynamic data of minor actinides in defining efficiency of recovery or separation of minor actinides from other fission products such as lanthanides will also be illustrated. In addition, the necessity for determination of accurate high temperature thermodynamic data of minor actinides would be discussed.
Nuclear criticality safety evaluation -- DWPF Late Wash Facility, Salt Process Cell and Chemical Process Cell
Williamson, T.G.
The Savannah River Site (SRS) High Level Nuclear Waste will be vitrified in the Defense Waste Processing Facility (DWPF) for long term storage and disposal. This is a nuclear criticality safety evaluation for the Late Wash Facility (LWF), the Salt Processing Cell (SPC) and the Chemical Processing Cell (CPC). of the DWPF. Waste salt solution is processed in the Tank Farm In-Tank Precipitation (ITP) process and is then further washed in the DWPF Late Wash Facility (LWF) before it is fed to the DWPF Salt Processing Cell. In the Salt Processing Cell the precipitate slurry is processed in the Precipitate Reactor (PR) and the resultant Precipitate Hydrolysis Aqueous (PHA) produce is combined with the sludge feed and frit in the DWPF Chemical Process Cell to produce a melter feed. The waste is finally immobilized in the Melt Cell. Material in the Tank Farm and the ITP and Extended Sludge processes have been shown to be safe against a nuclear criticality by others. The precipitate slurry feed from ITP and the first six batches of sludge feed are safe against a nuclear criticality and this evaluation demonstrates that the processes in the LWF, the SPC and the CPC do not alter the characteristics of the materials to compromise safety.
Enhanced Chemical Cleaning: A New Process for Chemically Cleaning Savannah River Waste Tanks
Ketusky, Edward; Spires, Renee; Davis, Neil
At the Savannah River Site (SRS) there are 49 High Level Waste (HLW) tanks that eventually must be emptied, cleaned, and closed. The current method of chemically cleaning SRS HLW tanks, commonly referred to as Bulk Oxalic Acid Cleaning (BOAC), requires about a half million liters (130,000 gallons) of 8 weight percent (wt%) oxalic acid to clean a single tank. During the cleaning, the oxalic acid acts as the solvent to digest sludge solids and insoluble salt solids, such that they can be suspended and pumped out of the tank. Because of the volume and concentration of acid used, a significant quantity of oxalate is added to the HLW process. This added oxalate significantly impacts downstream processing. In addition to the oxalate, the volume of liquid added competes for the limited available tank space. A search, therefore, was initiated for a new cleaning process. Using TRIZ (Teoriya Resheniya Izobretatelskikh Zadatch or roughly translated as the Theory of Inventive Problem Solving), Chemical Oxidation Reduction Decontamination with Ultraviolet Light (CORD-UV{reg_sign}), a mature technology used in the commercial nuclear power industry was identified as an alternate technology. Similar to BOAC, CORD-UV{reg_sign} also uses oxalic acid as the solvent to dissolve the metal (hydr)oxide solids. CORD-UV{reg_sign} is different, however, since it uses photo-oxidation (via peroxide/UV or ozone/UV to form hydroxyl radicals) to decompose the spent oxalate into carbon dioxide and water. Since the oxalate is decomposed and off-gassed, CORD-UV{reg_sign} would not have the negative downstream oxalate process impacts of BOAC. With the oxalate destruction occurring physically outside the HLW tank, re-precipitation and transfer of the solids, as well as regeneration of the cleaning solution can be performed without adding additional solids, or a significant volume of liquid to the process. With a draft of the pre-conceptual Enhanced Chemical Cleaning (ECC) flowsheet, taking full
Chemical tension and global equilibrium in VLS nanostructure growth process: from nanohillocks to nanowires
NASA Astrophysics Data System (ADS)
Li, N.; Tan, T. Y.; Gösele, U.
We formulate a global equilibrium model to describe the growth of one-dimensional nanostructures in the VLS process by including also the chemical tension in addition to the physical tensions, i.e. surface energies. The chemical tension derives from the Gibbs free energy change due to the growth of a crystal layer of an elementary thickness. The system global equilibrium is arrived at via the balance of the static physical tensions and the dynamic chemical tension. The model predicts and provides conditions for the growth of nanowires of all sizes exceeding a lower thermodynamic limit. The model also predicts the conditions distinguishing the growth of nanohillocks from nanowires. These predictions will allow the verification of the model by future experiments specifically designed for this purpose.
Chemical distribution of hazardous natural radionuclides during monazite mineral processing.
Hamed, Mostafa M; Hilal, M A; Borai, E H
It is very important to calculate the radioactivity concentration for low-grade monazite ore (50%) and different other materials produced as results of chemical processing stages to avoid the risk to workers. Chemical processing of low-grade monazite pass through different stages, washing by hydrochloric acid and digested with sulfuric acid and influence of pH on the precipitation of rare earth elements has been studied. The radioactivity concentrations of (238)U((226)Ra) and (232)Th as well as (40)K were calculated in crude low-grade ore and found to be 54,435 ± 3138, 442,105 ± 29,200 and 5841 ± 345 Bq/kg, respectively. These values are greatly higher than the exempt levels 25 Bq/kg. After chemical digestion of the ore, the results demonstrated that un-reacted material contains significant radioactivity reached to approximately 8, 13 and 23% for (238)U, (232)Th and (40)K, respectively. The results show that 60% of (232)Th are located in the digested white slurry with small portions of (238)U and (40)K. Most of (238)U radioactivity is extracted in the green phosphoric acid which produced from conversion of P2O5 by H2SO4 into phosphoric acid. The average values of the Raeq for monazite ore, un-reacted black precipitate, white precipitate, brown precipitate and crystalline material samples were calculated and found to be 687,095 ± 44,921, 85,068 ± 5339, 388,381 ± 22,088, 313,046 ± 17,923 and 4531 ± 338 Bq/kg, respectively. The calculated values of Raeq are higher than the average world value (it must be less than 370 Bq/kg). Finally the external hazardous, internal hazardous and Iγr must be less than unity. This means that specific radiation protection program must be applied and implemented during monazite processing.
Chemical and crystallographic events in the caries process.
LeGeros, R Z
The chemical and crystallographic events associated with the caries process can be described based on the results from the following studies: (a) effects of carbonate, magnesium, fluoride, and strontium on the physico-chemical properties--lattice parameters, crystallinity (crystal size and strain); dissolution properties of synthetic apatites; (b) factors influencing the in vitro formation and transformation of DCPD, OCP, AP (Ca-deficient apatites), FAP, beta-TCMP (Mg-substituted), and CaF2; and (c) studies on properties (crystallinity, composition, chemical, and thermal stabilities) of enamel, dentin, and bone. The dissolution of CO3-rich/Mg-rich/F-poor dental apatite crystals and re-precipitation of CO3-poor/Mg-poor/F-rich apatite in the presence of F- ions in solution contribute to a more acid-resistant surface layer of the caries lesion. Fluoride promotes the formation of less Ca-deficient and more stable apatite crystals. The presence of Ca, P, and F in solution inhibits dissolution of apatite more than does the presence of F alone. Low levels of F in solution promote the formation of (F, OH)-apatite, even under very acid conditions; an increase in F levels causes the formation of CaF2 at the expense of DCPD or apatite, especially in acid conditions. F in apatite and/or in solution suppresses extensive dissolution of dental apatite and enhances the formation of (F, OH)-apatite crystals which are more resistant against acid-dissolution than are F-free apatite crystals.
The production of chemicals from food processing wastes using a novel fermenter separator
Dale, M.C.; Havlik, S.; Lee, W.C.; Lineback, D.S.; Park, C.H.; Okos, M.R.
A range of chemicals can be made from fermentation processes, and most fermentations are characterized by product inhibition. As product concentration increases, inhibitory products can substantially limit the rate of fermentation processes. Product recovery costs are a strong function of concentration. It is expensive to recover low levels of product from a fermentation broth. Thus, fermentation costs (which increase with higher product concentration) traditionally must be balanced against product recovery costs (which decrease with product concentration). A novel reactor-separator process has been developed at Purdue University to minimize product inhibition of fermentation rates. This reactor has been shown to exhibit very high productivities --- simultaneously producing and removing a inhibitory product while maintaining a high viable cell concentration in the reactor. The basic objective of this study is to develop an energy efficient and economical process to convert food wastes to usable fuels and chemicals. The work is divided into two major efforts: an applied phase which involves design and building of a whey to ethanol process as well as process design and optimization; and a basic phase which involves investigating alternative fermentation systems and fundamental research on immobilized cell reactor systems. This document discusses the study and its results.
Chemical biology approaches to designing defined carbohydrate vaccines.
Anish, Chakkumkal; Schumann, Benjamin; Pereira, Claney Lebev; Seeberger, Peter H
Carbohydrate antigens have shown promise as important targets for developing effective vaccines and pathogen detection strategies. Modifying purified microbial glycans through synthetic routes or completely synthesizing antigenic motifs are attractive options to advance carbohydrate vaccine development. However, limited knowledge on structure-property correlates hampers the discovery of immunoprotective carbohydrate epitopes. Recent advancements in tools for glycan modification, high-throughput screening of biological samples, and 3D structural analysis may facilitate antigen discovery process. This review focuses on advances that accelerate carbohydrate-based vaccine development and various technologies that are driving these efforts. Herein we provide a critical overview of approaches and resources available for rational design of better carbohydrate antigens. Structurally defined and fully synthetic oligosaccharides, designed based on molecular understanding of antigen-antibody interactions, offer a promising alternative for developing future carbohydrate vaccines.
High Lifetime Solar Cell Processing and Design
NASA Technical Reports Server (NTRS)
Swanson, R. M.
In order to maximize efficiency a solar cell must: (1) absorb as much light as possible in electron-hole production, (2) transport as large a fraction as possible of the electrons to the n-type terminal and holes to the p-type terminal without their first recombining, and (3) produce as high as possible terminal voltage. Step (1) is largely fixed by the spectrum of sunlight and the fundamental absorption characteristics of silicon, although some improvements are possible through texturizing induced light trapping and back surface reflectors. Steps (2) and (3) are, however, dependent on the recombination mechanisms of the cell. The recombination, on the contrary, is strongly influenced by cell processing and design. Some of the lessons during the development of point-contact-cell are discussed. Cell dependence on recombination, surface recombination, and contact recombination are discussed. Results show the overwhelming influence of contact recombination on the operation of the cell when the other sources of recombination are reduced by careful processing.
Parametric Design within an Atomic Design Process (ADP) applied to Spacecraft Design
NASA Astrophysics Data System (ADS)
Ramos Alarcon, Rafael
This thesis describes research investigating the development of a model for the initial design of complex systems, with application to spacecraft design. The design model is called an atomic design process (ADP) and contains four fundamental stages (specifications, configurations, trade studies and drivers) that constitute the minimum steps of an iterative process that helps designers find a feasible solution. Representative design models from the aerospace industry are reviewed and are compared with the proposed model. The design model's relevance, adaptability and scalability features are evaluated through a focused design task exercise with two undergraduate teams and a long-term design exercise performed by a spacecraft payload team. The implementation of the design model is explained in the context in which the model has been researched. This context includes the organization (a student-run research laboratory at the University of Michigan), its culture (academically oriented), members that have used the design model and the description of the information technology elements meant to provide support while using the model. This support includes a custom-built information management system that consolidates relevant information that is currently being used in the organization. The information is divided in three domains: personnel development history, technical knowledge base and laboratory operations. The focused study with teams making use of the design model to complete an engineering design exercise consists of the conceptual design of an autonomous system, including a carrier and a deployable lander that form the payload of a rocket with an altitude range of over 1000 meters. Detailed results from each of the stages of the design process while implementing the model are presented, and an increase in awareness of good design practices in the teams while using the model are explained. A long-term investigation using the design model consisting of the
Chemical mechanical polishing: An enabling fabrication process for surface micromachining technologies
Sniegowski, J.J.
Chemical-mechanical polishing (CMP), once it is set-up and developed in a fabrication line can be readily adapted as a planarization technique for use in polysilicon surface micromachining technology. Although the planarization is a conceptually simple step, the benefit of its inclusion in the overall fabrication process is immense. Manufacturing impediments are removed while novel, expanded processes and designs become possible. The authors anticipate that CMP planarization, in the near future, will become a standard within the MEMS community for polysilicon surface micromachining. In addition, other MEMS fabrication technologies such as bulk micromachining and LIGA can potentially benefit from CMP.
P80 SRM low torque flex-seal development - thermal and chemical modeling of molding process
NASA Astrophysics Data System (ADS)
Descamps, C.; Gautronneau, E.; Rousseau, G.; Daurat, M.
The development of the flex-seal component of the P80 nozzle gave the opportunity to set up new design and manufacturing process methods. Due to the short development lead time required by VEGA program, the usual manufacturing iterative tests work flow, which is usually time consuming, had to be enhanced in order to use a more predictive approach. A newly refined rubber vulcanization description was built up and identified on laboratory samples. This chemical model was implemented in a thermal analysis code. The complete model successfully supports the manufacturing processes. These activities were conducted with the support of ESA/CNES Research & Technologies and DGA (General Delegation for Armament).
Wiersma, B.
Radioactive waste is stored in high level waste tanks on the Savannah River Site (SRS). Savannah River Remediation (SRR) is aggressively seeking to close the non-compliant Type I and II waste tanks. The removal of sludge (i.e., metal oxide) heels from the tank is the final stage in the waste removal process. The Enhanced Chemical Cleaning (ECC) process is being developed and investigated by SRR to aid in Savannah River Site (SRS) High-Level Waste (HLW) as an option for sludge heel removal. Corrosion rate data for carbon steel exposed to the ECC treatment tank environment was obtained to evaluate the degree of corrosion that occurs. These tests were also designed to determine the effect of various environmental variables such as temperature, agitation and sludge slurry type on the corrosion behavior of carbon steel. Coupon tests were performed to estimate the corrosion rate during the ECC process, as well as determine any susceptibility to localized corrosion. Electrochemical studies were performed to develop a better understanding of the corrosion mechanism. The tests were performed in 1 wt.% and 2.5 wt.% oxalic acid with HM and PUREX sludge simulants. The following results and conclusions were made based on this testing: (1) In 1 wt.% oxalic acid with a sludge simulant, carbon steel corroded at a rate of less than 25 mpy within the temperature and agitation levels of the test. No susceptibility to localized corrosion was observed. (2) In 2.5 wt.% oxalic acid with a sludge simulant, the carbon steel corrosion rates ranged between 15 and 88 mpy. The most severe corrosion was observed at 75 C in the HM/2.5 wt.% oxalic acid simulant. Pitting and general corrosion increased with the agitation level at this condition. No pitting and lower general corrosion rates were observed with the PUREX/2.5 wt.% oxalic acid simulant. The electrochemical and coupon tests both indicated that carbon steel is more susceptible to localized corrosion in the HM/oxalic acid environment than
Conceptual design of clean processes: Tools and methods
Hurme, M.
Design tools available for implementing clean design into practice are discussed. The application areas together with the methods of comparison of clean process alternatives are presented. Environmental principles are becoming increasingly important in the whole life cycle of products from design, manufacturing and marketing to disposal. The hinder of implementing clean technology in design has been the necessity to apply it in all phases of design starting from the beginning, since it deals with the major selections made in the conceptual process design. Therefore both a modified design approach and new tools are needed for process design to make the application of clean technology practical. The first item; extended process design methodologies has been presented by Hurme, Douglas, Rossiter and Klee, Hilaly and Sikdar. The aim of this paper is to discuss the latter topic; the process design tools which assist in implementing clean principles into process design. 22 refs., 2 tabs.
Hydrogeochemical processes and chemical characteristics around Sahand Mountain, NW Iran
NASA Astrophysics Data System (ADS)
Pazand, Kaveh; Hezarkhani, Ardeshir
The chemical analysis of 21 water wells in Sahand area, NW of Iran has been evaluated to determine the hydrogeochemical processes and ion, heavy and trace metal concentration background in the region. The dominated hydrochemical types are Ca-Mg-HCO3, Ca-SO4 and Na-Cl that vary in different group sample. The pH and Eh of the groundwater in the study area indicating an acidic to alkaline nature of the samples in group II, acidic nature in group I and neutral in group III. Also in Group III than Group I and II, the oxidizing condition is dominant, while in the other groups relative reducing conditions prevail. Due to Cu and other metal mineralization in I and II site, Cu, As, Au and other metal concentration in this water groups is higher than group III.
Chemical Reactions in the Processing of Mosi2 + Carbon Compacts
NASA Technical Reports Server (NTRS)
Jacobson, Nathan S.; Lee, Kang N.; Maloy, Stuart A.; Heuer, Arthur H.
Hot-pressing of MoSi2 powders with carbon at high temperatures reduces the siliceous grain boundary phase in the resultant compact. The chemical reactions in this process were examined using the Knudsen cell technique. A 2.3 wt pct oxygen MoSi2 powder and a 0.59 wt pct oxygen MoSi2 powder, both with additions of 2 wt pct carbon, were examined. The reduction of the siliceous grain boundary phase was examined at 1350 K and the resultant P(SiO)/P(CO) ratios interpreted in terms of the SiO(g) and CO(g) isobars on the Si-C-O predominance diagram. The MoSi2 + carbon mixtures were then heated at the hot-pressing temperature of 2100 K. Large weight losses were observed and could be correlated with the formation of a low-melting eutectic and the formation and vaporization of SiC.
Corrosion study in the chemical air separation (MOLTOX trademark ) process
Kang, Doohee; Wong, Kai P.; Archer, R.A.; Cassano, A.A.
This report presents the results of studies aimed at solving the corrosion problems encountered during operation of the MOLTOX{trademark} pilot plant. These studies concentrated on the screening of commercial and developmental alloys under conditions simulating operation conditions in this high temperature molten salt process. Process economic studies were preformed in parallel with the laboratory testing to ensure that an economically feasible solution would be achieved. In addition to the above DOE co-funded studies, Air Products and Chemicals pursued proprietary studies aimed at developing a less corrosive salt mixture which would potentially allow the use of chemurgically available alloys such as stainless steels throughout the system. These studies will not be reported here; however, the results of corrosion tests in the new less corrosive salt mixtures are reported. Because our own studies on salt chemistry impacts heavily on the overall process and thereby has an influence on the experimental work conducted under this contract, some of the studies discussed here were impacted by our own proprietary data. Therefore, the reasons behind some of the experiments presented herein will not be explained because that information is proprietary to Air Products. 14 refs., 42 figs., 21 tabs.
Mechanical Design Support System Based on Thinking Process Development Diagram
NASA Astrophysics Data System (ADS)
Mase, Hisao; Kinukawa, Hiroshi; Morii, Hiroshi; Nakao, Masayuki; Hatamura, Yotaro
This paper describes a system that directly supports a design process in a mechanical domain. This system is based on a thinking process development diagram that draws distinctions between requirement, tasks, solutions, and implementation, which enables designers to expand and deepen their thoughts of design. The system provides five main functions that designers require in each phase of the proposed design process: (1) thinking process description support which enables designers to describe their thoughts, (2) creativity support by term association with thesauri, (3) timely display of design knowledge including know-how obtained through earlier failures, general design theories, standard-parts data, and past designs, (4) design problem solving support using 46 kinds of thinking operations, and (5) proper technology transfer support which accumulates not only design conclusions but also the design process. Though this system is applied to mechanical engineering as the first target domain, it can be easily expanded to many other domains such as architecture and electricity.
Dynamic designing of microstructures by chemical gradient-mediated growth
Shim, Tae Soup; Yang, Seung-Man; Kim, Shin-Hyun
Shape is one of the most important determinants of the properties of microstructures. Despite of a recent progress on microfabrication techniques, production of three-dimensional micro-objects are yet to be fully achieved. Nature uses reaction–diffusion process during bottom-up self-assembly to create functional shapes and patterns with high complexity. Here we report a method to produce polymeric microstructures by using a dynamic reaction–diffusion process during top-down photolithography, providing unprecedented control over shape and composition. In radical polymerization, oxygen inhibits reaction, and therefore diffusion of oxygen significantly alters spatial distribution of growth rate. Therefore, growth pathways of the microstructures can be controlled by engineering a concentration gradient of oxygen. Moreover, stepwise control of chemical gradients enables the creation of highly complex microstructures. The ease of use and high controllability of this technology provide new opportunities for microfabrication and for fundamental studies on the relationships between shape and function for the materials. PMID:25766762
Radioactive decay as a forced nuclear chemical process: Phenomenology
NASA Astrophysics Data System (ADS)
Timashev, S. F.
Concepts regarding the mechanism of radioactive decay of nuclei are developed on the basis of a hypothesis that there is a dynamic relationship between the electronic and nuclear subsystems of an atom, and that fluctuating initiating effects of the electronic subsystem on a nucleus are possible. Such relationship is reflected in experimental findings that show the radioactive decay of nuclei might be determined by a positive difference between the mass of an initial nucleus and the mass of an atom's electronic subsystem, i.e., the mass of the entire atom (rather than that of its nucleus) and the total mass of the decay products. It is established that an intermediate nucleus whose charge is lower by unity than the charge of the initial radioactive nucleus is formed as a result of the above fluctuating stimuli that initiate radioactive decay, and its nuclear matter is thus in an unbalanced metastable state of inner shakeup, affecting the quark subsystem of nucleons. The intermediate nucleus thus experiences radioactive decay with the emission of α or β particles. At the same time, the high energy (with respect to the chemical scale) of electrons in plasma served as a factor initiating the processes in different nuclear chemical transformations and radioactive decays in low-temperature plasma studied earlier, particularly during the laser ablation of metals in aqueous solutions of different compositions and in near-surface cathode layers upon glow discharge. It is shown that a wide variety of nucleosynthesis processes in the Universe can be understood on the same basis, and a great many questions regarding the formation of light elements in the solar atmosphere and some heavy elements (particularly p-nuclei) in the interiors of massive stars at late stages of their evolution can also be resolved.
Accelerating chemical database searching using graphics processing units.
Liu, Pu; Agrafiotis, Dimitris K; Rassokhin, Dmitrii N; Yang, Eric
The utility of chemoinformatics systems depends on the accurate computer representation and efficient manipulation of chemical compounds. In such systems, a small molecule is often digitized as a large fingerprint vector, where each element indicates the presence/absence or the number of occurrences of a particular structural feature. Since in theory the number of unique features can be exceedingly large, these fingerprint vectors are usually folded into much shorter ones using hashing and modulo operations, allowing fast "in-memory" manipulation and comparison of molecules. There is increasing evidence that lossless fingerprints can substantially improve retrieval performance in chemical database searching (substructure or similarity), which have led to the development of several lossless fingerprint compression algorithms. However, any gains in storage and retrieval afforded by compression need to be weighed against the extra computational burden required for decompression before these fingerprints can be compared. Here we demonstrate that graphics processing units (GPU) can greatly alleviate this problem, enabling the practical application of lossless fingerprints on large databases. More specifically, we show that, with the help of a ~$500 ordinary video card, the entire PubChem database of ~32 million compounds can be searched in ~0.2-2 s on average, which is 2 orders of magnitude faster than a conventional CPU. If multiple query patterns are processed in batch, the speedup is even more dramatic (less than 0.02-0.2 s/query for 1000 queries). In the present study, we use the Elias gamma compression algorithm, which results in a compression ratio as high as 0.097.
Universal Design: Process, Principles, and Applications
ERIC Educational Resources Information Center
Burgstahler, Sheryl
Designing any product or environment involves the consideration of many factors, including aesthetics, engineering options, environmental issues, safety concerns, industry standards, and cost. Typically, designers focus their attention on the average user. In contrast, universal design (UD), according to the Center for Universal Design," is…
In vitro perturbations of targets in cancer hallmark processes predict rodent chemical carcinogenesis.
Kleinstreuer, Nicole C; Dix, David J; Houck, Keith A; Kavlock, Robert J; Knudsen, Thomas B; Martin, Matthew T; Paul, Katie B; Reif, David M; Crofton, Kevin M; Hamilton, Kerry; Hunter, Ronald; Shah, Imran; Judson, Richard S
Thousands of untested chemicals in the environment require efficient characterization of carcinogenic potential in humans. A proposed solution is rapid testing of chemicals using in vitro high-throughput screening (HTS) assays for targets in pathways linked to disease processes to build models for priority setting and further testing. We describe a model for predicting rodent carcinogenicity based on HTS data from 292 chemicals tested in 672 assays mapping to 455 genes. All data come from the EPA ToxCast project. The model was trained on a subset of 232 chemicals with in vivo rodent carcinogenicity data in the Toxicity Reference Database (ToxRefDB). Individual HTS assays strongly associated with rodent cancers in ToxRefDB were linked to genes, pathways, and hallmark processes documented to be involved in tumor biology and cancer progression. Rodent liver cancer endpoints were linked to well-documented pathways such as peroxisome proliferator-activated receptor signaling and TP53 and novel targets such as PDE5A and PLAUR. Cancer hallmark genes associated with rodent thyroid tumors were found to be linked to human thyroid tumors and autoimmune thyroid disease. A model was developed in which these genes/pathways function as hypothetical enhancers or promoters of rat thyroid tumors, acting secondary to the key initiating event of thyroid hormone disruption. A simple scoring function was generated to identify chemicals with significant in vitro evidence that was predictive of in vivo carcinogenicity in different rat tissues and organs. This scoring function was applied to an external test set of 33 compounds with carcinogenicity classifications from the EPA's Office of Pesticide Programs and successfully (p = 0.024) differentiated between chemicals classified as "possible"/"probable"/"likely" carcinogens and those designated as "not likely" or with "evidence of noncarcinogenicity." This model represents a chemical carcinogenicity prioritization tool supporting targeted
Designing Allosteric Control into Enzymes by Chemical Rescue of Structure
Deckert, Katelyn; Budiardjo, S. Jimmy; Brunner, Luke C.; Lovell, Scott; Karanicolas, John
Ligand-dependent activity has been engineered into enzymes for purposes ranging from controlling cell morphology to reprogramming cellular signaling pathways. Where these successes have typically fused a naturally allosteric domain to the enzyme of interest, here we instead demonstrate an approach for designing a de novo allosteric effector site directly into the catalytic domain of an enzyme. This approach is distinct from traditional chemical rescue of enzymes in that it relies on disruption and restoration of structure, rather than active site chemistry, as a means to achieve modulate function. We present two examples, W33G in a {beta}-glycosidase enzyme ({beta}-gly) and W492G in a {beta}-glucuronidase enzyme ({beta}-gluc), in which we engineer indole-dependent activity into enzymes by removing a buried tryptophan side chain that serves as a buttress for the active site architecture. In both cases, we observe a loss of function, and in both cases we find that the subsequent addition of indole can be used to restore activity. Through a detailed analysis of {beta}-gly W33G kinetics, we demonstrate that this rescued enzyme is fully functionally equivalent to the corresponding wild-type enzyme. We then present the apo and indole-bound crystal structures of {beta}-gly W33G, which together establish the structural basis for enzyme inactivation and rescue. Finally, we use this designed switch to modulate {beta}-glycosidase activity in living cells using indole. Disruption and recovery of protein structure may represent a general technique for introducing allosteric control into enzymes, and thus may serve as a starting point for building a variety of bioswitches and sensors.
Economic-Oriented Stochastic Optimization in Advanced Process Control of Chemical Processes
Dobos, László; Király, András; Abonyi, János
Finding the optimal operating region of chemical processes is an inevitable step toward improving economic performance. Usually the optimal operating region is situated close to process constraints related to product quality or process safety requirements. Higher profit can be realized only by assuring a relatively low frequency of violation of these constraints. A multilevel stochastic optimization framework is proposed to determine the optimal setpoint values of control loops with respect to predetermined risk levels, uncertainties, and costs of violation of process constraints. The proposed framework is realized as direct search-type optimization of Monte-Carlo simulation of the controlled process. The concept is illustrated throughout by a well-known benchmark problem related to the control of a linear dynamical system and the model predictive control of a more complex nonlinear polymerization process. PMID:23213298
Lessons learned from the design of chemical space networks and opportunities for new applications.
Vogt, Martin; Stumpfe, Dagmar; Maggiora, Gerald M; Bajorath, Jürgen
The concept of chemical space is of fundamental relevance in chemical informatics and computer-aided drug discovery. In a series of articles published in the Journal of Computer-Aided Molecular Design, principles of chemical space design were evaluated, molecular networks proposed as an alternative to conventional coordinate-based chemical reference spaces, and different types of chemical space networks (CSNs) constructed and analyzed. Central to the generation of CSNs was the way in which molecular similarity relationships were assessed and a primary focal point was the network-based representation of biologically relevant chemical space. The design and comparison of CSNs based upon alternative similarity measures can be viewed as an evolutionary path with interesting lessons learned along the way. CSN design has matured to the point that such chemical space representations can be used in practice. In this contribution, highlights from the sequence of CSN design efforts are discussed in context, providing a perspective for future practical applications.
Lessons learned from the design of chemical space networks and opportunities for new applications
NASA Astrophysics Data System (ADS)
Vogt, Martin; Stumpfe, Dagmar; Maggiora, Gerald M.; Bajorath, Jürgen
The concept of chemical space is of fundamental relevance in chemical informatics and computer-aided drug discovery. In a series of articles published in the Journal of Computer- Aided Molecular Design, principles of chemical space design were evaluated, molecular networks proposed as an alternative to conventional coordinate-based chemical reference spaces, and different types of chemical space networks (CSNs) constructed and analyzed. Central to the generation of CSNs was the way in which molecular similarity relationships were assessed and a primary focal point was the network-based representation of biologically relevant chemical space. The design and comparison of CSNs based upon alternative similarity measures can be viewed as an evolutionary path with interesting lessons learned along the way. CSN design has matured to the point that such chemical space representations can be used in practice. In this contribution, highlights from the sequence of CSN design efforts are discussed in context, providing a perspective for future practical applications.
Chemical Processing and Characterization of Fiber Reinforced Nanocomposite Silica Materials
NASA Astrophysics Data System (ADS)
Burnett, Steven Shannon
Ultrasound techniques, acoustic and electroacoustic spectroscopy, are used to investigate and characterize concentrated fluid phase nanocomposites. In particular, the data obtained from ultrasound methods are used as tools to improve the understanding of the fundamental process chemistry of concentrated, multicomponent, nanomaterial dispersions. Silicon nitride nanofibers embedded in silica are particularly interesting for lightweight nanocomposites, because silicon nitride is isostructural to carbon nitride, a super hard material. However, the major challenge with processing these composites is retarding particle-particle aggregation, to maintain highly dispersed systems. Therefore, a systematic approach was developed to evaluate the affect of process parameters on particle-particle aggregation, and improving the chemical kinetics for gelation. From the acoustic analysis of the nanofibers, this thesis was able to deduce that changes in aspect ratio affects the ultrasound propagation. In particular, higher aspect ratio fibers attenuate the ultrasound wave greater than lower aspect fibers of the same material. Furthermore, our results confirm that changes in attenuation depend on the hydrodynamical interactions between particles, the aspect ratio, and the morphology of the dispersant. The results indicate that the attenuation is greater for fumed silica due to its elastic nature and its size, when compared to silica Ludox. Namely, the larger the size, the greater the attenuation. This attenuation is mostly the result of scattering loss in the higher frequency range. In addition, the silica nanofibers exhibit greater attenuation than their nanoparticle counterparts because of their aspect ratio influences their interaction with the ultrasound wave. In addition, this study observed how 3M NH 4 Cl's acoustic properties changes during the gelation process, and during that change, the frequency dependency deviates from the expected squared of the frequency, until the
62 FR 46525 - Chemical Process Safety at Fuel Cycle Facilities; Availability of NUREG
Federal Register 2010, 2011, 2012, 2013, 2014
... COMMISSION Chemical Process Safety at Fuel Cycle Facilities; Availability of NUREG AGENCY: Nuclear Regulatory... completion and availability of NUREG-1601, ``Chemical Process Safety at Fuel Cycle Facilities,'' dated July.... SUPPLEMENTARY INFORMATION: NRC is announcing the availability of NUREG-1601, ``Chemical Process Safety at...
72 FR 31453 - Interpretation of OSHA's Standard for Process Safety Management of Highly Hazardous Chemicals
Federal Register 2010, 2011, 2012, 2013, 2014
... Occupational Safety and Health Administration 29 CFR Part 1910 Interpretation of OSHA's Standard for Process...'' in the ``Application'' section of OSHA's Process Safety Management of Highly Hazardous Chemicals... chemical process safety standard to prevent accidental releases of hazardous chemicals that could pose...
Lessons from nature: computational design of biomimetic compounds and processes.
Bozkurt, Esra; Ashari, Negar; Browning, Nicholas; Brunk, Elizabeth; Campomanesa, Pablo; Perez, Marta A S; Rothlisberger, Ursula
Through millions of years of evolution, Nature has accomplished the development of highly efficient and sustainable processes and the idea to understand and copy natural strategies is therefore very appealing. However, in spite of intense experimental and computational research, it has turned out to be a difficult task to design efficient biomimetic systems. Here we discuss a novel strategy for the computational design of biomimetic compounds and processes that consists of i) target selection; ii) atomistic and electronic characterization of the wild type system and the biomimetic compounds; iii) identification of key descriptors through feature selection iv) choice of biomimetic template and v) efficient search of chemical and sequence space for optimization of the biomimetic system. As a proof-of-principles study, this general approach is illustrated for the computational design of a 'green' catalyst mimicking the action of the zinc metalloenzyme Human Carbonic Anhydrase (HCA). HCA is a natural model for CO2 fixation since the enzyme is able to convert CO2 into bicarbonate. Very recently, a weakly active HCA mimic based on a trihelical peptide bundle was synthetized. We have used quantum mechanical/molecular mechanical (QM/MM) Car-Parrinello simulations to study the mechanisms of action of HCA and its peptidic mimic and employed the obtained information to guide the design of improved biomimetic analogues. Applying a genetic algorithm based optimization procedure, we were able to re-engineer and optimize the biomimetic system towards its natural counter part. In a second example, we discuss a similar strategy for the design of biomimetic sensitizers for use in dye-sensitized solar cells.
Feasibility study of an Integrated Program for Aerospace vehicle Design (IPAD). Volume 2: The design process
NASA Technical Reports Server (NTRS)
Gillette, W. B.; Turner, M. J.; Southall, J. W.; Whitener, P. C.; Kowalik, J. S.
The extent to which IPAD is to support the design process is identified. Case studies of representative aerospace products were developed as models to characterize the design process and to provide design requirements for the IPAD computing system.
Proceedings of the first international conference on pervaporation processes in the chemical industry
Bakish, R.
These proceedings collect papers given at conference on chemical pervaporation processes. Topics include: evaporation and evaporators; fermentation and distillation; biomass conversion and waste processing.
Novel designed enediynes: molecular design, chemical synthesis, mode of cycloaromatization and guanine-specific DNA cleavage.
Toshima, K; Ohta, K; Kano, T; Nakamura, T; Nakata, M; Kinoshita, M; Matsumura, S
The molecular design and chemical synthesis of novel enediyne molecules related to the neocarzinostatin chromophore (1), and their chemical and DNA cleaving properties are described. The 10-membered enediyne triols 16-18 were effectively synthesized from xylitol (10) in a short step, and found to be quite stable when handled at room temperature. The representative and acylated enediyne 16 was cycloaromatized by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in cyclohexa-1,4-diene-benzene to give the benzenoid product 21 through a radical pathway. On the other hand, the enediyne 16 was cycloaromatized by diethylamine in dimethyl sulfoxide-Tris-HCl, pH 8.5 buffer to afford another benzenoid product 22 as a diethylamine adduct through a polar pathway. Furthermore, the enediynes 16-18 were found to exhibit guanine-specific DNA cleavage under weakly basic conditions with no additive.
Parameter Optimization of Nitriding Process Using Chemical Kinetics
NASA Astrophysics Data System (ADS)
Özdemir, İ. Bedii; Akar, Firat; Lippmann, Nils
Using the dynamics of chemical kinetics, an investigation to search for an optimum condition for a gas nitriding process is performed over the solution space spanned by the initial temperature and gas composition of the furnace. For a two-component furnace atmosphere, the results are presented in temporal variations of gas concentrations and the nitrogen coverage on the surface. It seems that the exploitation of the nitriding kinetics can provide important feedback for setting the model-based control algorithms. The present work shows that when the nitrogen gas concentration is not allowed to exceed 6 pct, the Nad coverage can attain maximum values as high as 0.97. The time evolution of the Nad coverage also reveals that, as long as the temperature is above the value where nitrogen poisoning of the surface due to the low-temperature adsorption of excess nitrogen occurs, the initial ammonia content in the furnace atmosphere is much more important in the nitriding process than is the initial temperature.
Process Improvements to Biomass Pretreatment of Fuels and Chemicals
Teymouri, Farzaneh
MBI, a 501c(3) company focusing on de-risking and scaling up bio-based technologies, has teamed with Michigan State University and the Idaho National Laboratory to develop and demonstrate process improvements to the ammonia fiber expansion (AFEX) pretreatment process. The logistical hurdles of biomass handling are well known, and the regional depot concept - in which small, distributed bioprocessing operations collect, preprocess, and densify biomass before shipping to a centralized refinery - is a promising alternative to centralized collection. AFEXTM (AFEX is a trademark of MBI) has unique features among pretreatments that would make it desirable as a pretreatment prior to densification at the depot scale. MBI has developed a novel design, using a packed bed reactor for the AFEX process that can be scaled down economically to the depot scale at a lower capital cost as compared to the traditional design (Pandia type reactor). Thus, the purpose of this project was to develop, scale-up, demonstrate, and improve this novel design The key challenges are the recovery of ammonia, consistent and complete pretreatment performance, and the overall throughput of the reactor. In this project an engineering scale packed bed AFEX system with 1-ton per day capacity was installed at MBI's building. The system has been operational since mid-2013. During that time, MBI has demonstrated the robustness, reliability, and consistency of the process. To date, nearly 500 runs have been performed in the reactors. There have been no incidences of plugging (i.e., inability to remove ammonia from biomass after the treatment), nor has there been any instance of a major ammonia release into the atmosphere. Likewise, the sugar released via enzyme hydrolysis has remained consistent throughout these runs. Our economic model shows a 46% reduction in AFEX capital cost at the 100 ton/day scale compared to the traditional design of AFEX (Pandia type reactor). The key performance factors were
Physical conditions and chemical processes during single-bubble sonoluminescence
NASA Astrophysics Data System (ADS)
Flannigan, David J.
In order to gain insight into the physical conditions and chemical processes associated with single-bubble sonoluminescence (SBSL), nonvolatile liquids such as concentrated sulfuric acid (H2SO 4) were explored. The SBSL radiant powers from H2SO 4 aqueous solutions were found to be over 103 times larger than those typically observed for SBSL from water. In addition, the emission spectra contain extensive bands and lines from molecules, atoms, and ions. The population of high-energy states of atoms (20 eV) and ions (37 eV) provides definitive experimental evidence of the formation of a plasma. By using various techniques (e.g., small molecules and atoms as intra-cavity probes, standard methods of plasma diagnostics, and spectrometric methods of pyrometry), it was possible to quantify the heavy particle temperatures (15,000 K), heavy particle densities (1021 cm-3) and pressures (4,000 bar), and plasma electron densities (1018 cm -3) generated during SBSL from H2SO4. It was also found that SBSL from H2SO4 containing mixtures of noble gas and air was quenched up to a critical acoustic pressure, above which the radiant powers increased by 104. From the spectral profiles it was determined that the air limited heating and plasma formation by endothermic chemical reactions and energy-transfer reactions. Simultaneous stroboscopic and spectroscopic studies of SBSL in H2SO4 containing alkali-metal sulfates showed that dramatic changes in the bubble dynamics correlated with the onset of emission from nonvolatile species such as Na and K atoms. These effects were attributed to the development of interfacial instabilities with increasing translational velocity of the bubble.
Process ichnology and the elucidation of physico-chemical stress
NASA Astrophysics Data System (ADS)
Gingras, Murray K.; MacEachern, James A.; Dashtgard, Shahin E.
This paper sets out a philosophical approach to ichnological (trace fossil) analysis, which focuses on the interpretation of trace fossils as sedimentary structures rather than as paleontological entities per se. Using wide-ranging datasets and a large number of observations and interpretations, a "Process Ichnology" framework is proposed. This interpretive framework provides an improved means of estimating the presence and magnitude of various physical and chemical (i.e., physico-chemical) depositional stresses (e.g., water turbidity, sedimentation rates, substrate consistency, salinity, and oxygenation) in ancient sedimentary environments. Ichnological datasets that are considered include: 1) trace-fossil distributions; 2) ethological diversity and the range of diversity; 3) the significance of burrow linings; 4) trace-fossil size; and, 5) post-depositional compaction of trace fossils. From these data, higher-resolution estimates can be made for the determination of sedimentation rates, temporal variation in sedimentation rate, sediment consistency, and aspects of the bottom- and interstitial-water chemistries. Additionally, the character of depositional bypassing of sediment grains can be determined. The methodologies and interpretations herein are intended for use by non-ichnologists in a manner akin to the interpretation of physical sedimentary structures. However, the outlined framework is complementary to other methods of ichnological analysis, such as ichnofacies- or ichnofabric-analysis, and can be applied as such. Indeed, this method is a derivative of these and other earlier techniques, and should be employed where a systematic approach to obtaining high-resolution sedimentological interpretations is a required aspect of the study.
Creativity Processes of Students in the Design Studio
ERIC Educational Resources Information Center
Huber, Amy Mattingly; Leigh, Katharine E.; Tremblay, Kenneth R., Jr.
The creative process is a multifaceted and dynamic path of thinking required to execute a project in design-based disciplines. The goal of this research was to test a model outlining the creative design process by investigating student experiences in a design project assignment. The study used an exploratory design to collect data from student…
Trace chemical contaminant generation rates for spacecraft contamination control system design
NASA Technical Reports Server (NTRS)
Perry, J. L.
A spacecraft presents a unique design challenge with respect to providing a comfortable environment in which people can live and work. All aspects of the spacecraft environmental design including the size of the habitable volume, its temperature, relative humidity, and composition must be considered to ensure the comfort and health of the occupants. The crew members and the materials selected for outfitting the spacecraft play an integral part in designing a habitable spacecraft because material offgassing and human metabolism are the primary sources for continuous trace chemical contaminant generation onboard a spacecraft. Since these contamination sources cannot be completely eliminated, active control processes must be designed and deployed onboard the spacecraft to ensure an acceptably clean cabin atmosphere. Knowledge of the expected rates at which contaminants are generated is very important to the design of these processes. Data from past spacecraft missions and human contaminant production studies have been analyzed to provide this knowledge. The resulting compilation of contaminants and generation rates serve as a firm basis for past, present, and future contamination control system designs for space and aeronautics applications.
Hierarchical methods are often used in the conceptual stages of process design to synthesize and evaluate process alternatives. In this work, the methods of hierarchical process design will be focused on environmental aspects. In particular, the design methods will be coupled to ...
Effects of chemical protective equipment on team process performance in small unit rescue operations.
Grugle, Nancy L; Kleiner, Brian M
In the event of a nuclear, biological, or chemical terrorist attack against civilians, both military and civilian emergency response teams must be able to respond and operate efficiently while wearing protective equipment. Chemical protective equipment protects the user by providing a barrier between the individual and hazardous environment. Unfortunately, the same equipment that is designed to support the user can potentially cause heat stress, reduced task efficiency, and reduced range-of-motion. Targeted Acceptable Responses to Generated Events of Tasks (TARGETS), an event-based team performance measurement methodology was used to investigate the effects of Mission Oriented Protective Posture (MOPP) on the behavioral processes underlying team performance during simulated rescue tasks. In addition, this study determined which team processes were related to team performance outcomes. Results of six primary analyses indicated that team process performance was not degraded by MOPP 4 on any rescue task and that the team processes critical for successful task performance are task-dependent. This article discusses the implications of these results with respect to the study design and the limitations of using an event-based team performance measurement methodology.
Launch Vehicle Design Process: Characterization, Technical Integration, and Lessons Learned
NASA Technical Reports Server (NTRS)
Blair, J. C.; Ryan, R. S.; Schutzenhofer, L. A.; Humphries, W. R.
Engineering design is a challenging activity for any product. Since launch vehicles are highly complex and interconnected and have extreme energy densities, their design represents a challenge of the highest order. The purpose of this document is to delineate and clarify the design process associated with the launch vehicle for space flight transportation. The goal is to define and characterize a baseline for the space transportation design process. This baseline can be used as a basis for improving effectiveness and efficiency of the design process. The baseline characterization is achieved via compartmentalization and technical integration of subsystems, design functions, and discipline functions. First, a global design process overview is provided in order to show responsibility, interactions, and connectivity of overall aspects of the design process. Then design essentials are delineated in order to emphasize necessary features of the design process that are sometimes overlooked. Finally the design process characterization is presented. This is accomplished by considering project technical framework, technical integration, process description (technical integration model, subsystem tree, design/discipline planes, decision gates, and tasks), and the design sequence. Also included in the document are a snapshot relating to process improvements, illustrations of the process, a survey of recommendations from experienced practitioners in aerospace, lessons learned, references, and a bibliography.
The production of fuels and chemicals from food processing wastes & cellulosics. Final research report
Dale, M.C.; Okos, M.; Burgos, N.
High strength food wastes of about 15-20 billion pounds solids are produced annually by US food producers. Low strength food wastes of 5-10 billion pounds/yr. are produced. Estimates of the various components of these waste streams are shown in Table 1. Waste paper/lignocellulosic crops could produce 2 to 5 billion gallons of ethanol per year or other valuable chemicals. Current oil imports cost the US about $60 billion dollars/yr. in out-going balance of trade costs. Many organic chemicals that are currently derived from petroleum can be produced through fermentation processes. Petroleum based processes have been preferred over biotechnology processes because they were typically cheaper, easier, and more efficient. The technologies developed during the course of this project are designed to allow fermentation based chemicals and fuels to compete favorably with petroleum based chemicals. Our goals in this project have been to: (1) develop continuous fermentation processes as compared to batch operations; (2) combine separation of the product with the fermentation, thus accomplishing the twin goals of achieving a purified product from a fermentation broth and speeding the conversion of substrate to product in the fermentation broth; (3) utilize food or cellulosic waste streams which pose a current cost or disposal problem as compared to high cost grains or sugar substrates; (4) develop low energy recovery methods for fermentation products; and finally (5) demonstrate successful lab scale technologies on a pilot/production scale and try to commercialize the processes. The scale of the wastes force consideration of {open_quotes}bulk commodity{close_quotes} type products if a high fraction of the wastes are to be utilized.
Production of chemicals from food processing wastes using a novel fermenter separator. Technical progress report, September 27-December 31, 1985
Dale, M.C.; Koo, Y.M.; Park, C.H.; Chen, C.; Lin, J.; Okos, M.R.; Wankat, P.C.
The objective of this project is to perform fundamental, engineering design and operational studies in the area of food processing waste fermentation. Studies addressing the fermentation kinetics and nutritional requirement of immobilized cells and examining different packing materials and energy efficient ethanol separation concentration and recovery methods are underway. These data will be used to develop process design models to aid in designing enery efficient and cost effective processes for conversion of food processing wastes into chemicals. This project focuses on using a novel immobilized cell reactor separator (ICRS) for the production of volatile chemicals from waste food sources such as whey lactose, glucose from waste starch, or any other sort of waste fermentable carbohydrate. 53 refs., 3 figs.
Hynol Process Engineering: Process Configuration, Site Plan, and Equipment Design
wood, and natural gas is used as a co-feed stock. Compared with other methanol production processes, direct emissions of carbon dioxide can be...co-feedstock. Compared with other methanol production processes, direct emissions of carbon dioxide (CO 2) can be substantially reduced by using the...gas provides for reduced CO2 emissions per unit of fossil fuel carbon processed compared with separate natural gas and biomass processes. In accordance
Characterization of biomass burning particles: chemical composition and processing
NASA Astrophysics Data System (ADS)
Hudson, P. K.; Murphy, D. M.; Cziczo, D. J.; Thomson, D. S.; Degouw, J.; Warneke, C.
During the Intercontinental Transport and Chemical Transformation (ITCT) mission in April and May of 2002, a forest fire plume was intercepted over Utah on May 19. Gas phase species acetonitrile (CH3CN) (a biomass burning tracer) and carbon monoxide (CO) measured greater than five fold enhancements over background concentrations during this plume crossing. In the 100 sec plume crossing, the Particle Analysis by Laser Mass Spectrometry (PALMS) instrument acquired 202 positive mass spectra of biomass burning particles. Many of these particles contained potassium in addition to organics, carbon, and NO+ (which is a signature for any nitrogen containing compound such as ammonium or nitrate). From characterization of the particle mass spectra obtained during the plume crossing, a qualitative signature has been determined for identifying biomass burning particles. By applying this analysis to the entire ITCT mission, several transport events of smoke plumes have been identified and were confirmed by gas phase measurements. Additional species, such as sulfate, found in the mass spectra of the transported particles indicated processing or aging of the biomass burning particles that had taken place. The analysis has been extended to other field missions (Crystal-Face, ACCENT, and WAM) to identify biomass burning particles without the added benefit of gas phase measurements.
Detecting and characterizing interactions among chemicals is an important environmental issue. Traditional factorial designs become infeasible as the number of compounds under study increases. Ray designs, which reduce the amount of experimental effort, can be...
Lunar fiberglass: Properties and process design
NASA Technical Reports Server (NTRS)
Dalton, Robert; Nichols, Todd
A Clemson University ceramic engineering design for a lunar fiberglass plant is presented. The properties of glass fibers and metal-matrix composites are examined. Lunar geology is also discussed. A raw material and site are selected based on this information. A detailed plant design is presented, and summer experiments to be carried out at Johnson Space Center are reviewed.
Computer Applications in the Design Process.
ERIC Educational Resources Information Center
Winchip, Susan
Computer Assisted Design (CAD) and Computer Assisted Manufacturing (CAM) are emerging technologies now being used in home economics and interior design applications. A microcomputer in a computer network system is capable of executing computer graphic functions such as three-dimensional modeling, as well as utilizing office automation packages to…
Application of Process Modeling Tools to Ship Design
NAVSEA Frank Waldman; LATTIX May 2011 APPLICATION OF PROCESS MODELING TOOLS TO SHIP DESIGN Report Documentation Page Form ApprovedOMB No. 0704-0188...00-00-2011 4. TITLE AND SUBTITLE Application of Process Modeling Tools to Ship Design 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT...design teams – Long design schedules – Complicated acquisition procedures • We are applying commercial process modeling techniques for: – Better
Instructional Design and Directed Cognitive Processing.
ERIC Educational Resources Information Center
Bovy, Ruth Colvin
This paper argues that the information processing model provides a promising basis on which to build a comprehensive theory of instruction. Characteristics of the major information processing constructs are outlined including attention, encoding and rehearsal, working memory, long term memory, retrieval, and metacognitive processes, and a unifying…
Sustainability Indicators for Chemical Processes : II. Data Needs
In order to begin repair of the environmental quality of the planet, there is a need to embrace sustainable development at many levels of the chemical industry and society. One way that the chemical industry is responding to this need is through sustainability evaluations, retrof...
Presidential Green Chemistry Challenge: 2002 Designing Greener Chemicals Award
Presidential Green Chemistry Challenge 2002 award winner, Chemical Specialties, developed an alkaline copper quaternary wood preservative to replace chromated copper arsenate preservative phased out due to risk to children.
Control and optimization system and method for chemical looping processes
Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao
A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.
Control and optimization system and method for chemical looping processes
Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao
A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.
In vitro Perturbations of Targets in Cancer Hallmark Processes Predict Rodent Chemical Carcinogenesis
Thousands of untested chemicals in the environment require efficient characterization of carcinogenic potential in humans. A proposed solution is rapid testing of chemicals using in vitro high-throughput screening (HTS) assays for targets in pathways linked to disease processes ...
40 CFR 790.26 - Initiation and completion of rulemaking proceedings on ITC-designated chemicals.
Code of Federal Regulations, 2010 CFR
... proceedings on ITC-designated chemicals. 790.26 Section 790.26 Protection of Environment ENVIRONMENTAL... completion of rulemaking proceedings on ITC-designated chemicals. (a) Where EPA concludes that a consensus... the end of subpart E. (c) Where the testing recommendations of the ITC raise unusually complex...
Introduction to Chemical Engineering Reactor Analysis: A Web-Based Reactor Design Game
ERIC Educational Resources Information Center
Orbey, Nese; Clay, Molly; Russell, T.W. Fraser
An approach to explain chemical engineering through a Web-based interactive game design was developed and used with college freshman and junior/senior high school students. The goal of this approach was to demonstrate how to model a lab-scale experiment, and use the results to design and operate a chemical reactor. The game incorporates both…
Study on Product Innovative Design Process Driven by Ideal Solution
NASA Astrophysics Data System (ADS)
Zhang, Fuying; Lu, Ximei; Wang, Ping; Liu, Hui
Product innovative design in companies today relies heavily on individual members' experience and creative ideation as well as their skills of integrating creativity and innovation tools with design methods agilely. Creative ideation and inventive ideas generation are two crucial stages in product innovative design process. Ideal solution is the desire final ideas for given problem, and the striving reaching target for product design. In this paper, a product innovative design process driven by ideal solution is proposed. This design process encourages designers to overcome their psychological inertia, to foster creativity in a systematic way for acquiring breakthrough creative and innovative solutions in a reducing sphere of solution-seeking, and results in effective product innovative design rapidly. A case study example is also presented to illustrate the effectiveness of the proposed design process.
Electric utility engineer`s FGD manual -- Volume 1: FGD process design. Final report
Part 1 of the Electric Utility Engineer`s Flue Gas Desulfurization (FGD) Manual emphasizes the chemical and physical processes that form the basis for design and operation of lime- and limestone-based FGD systems applied to coal- or oil-fired steam electric generating stations. The objectives of Part 1 are: to provide a description of the chemical and physical design basis for lime- and limestone-based wet FGD systems; to identify and discuss the various process design parameters and process options that must be considered in developing a specification for a new FGD system; and to provide utility engineers with process knowledge useful for operating and optimizing a lime- or limestone-based wet FGD system.
Development of a polysilicon process based on chemical vapor deposition (phase 1)
NASA Technical Reports Server (NTRS)
Mccormick, J.; Arvidson, A.; Sawyer, D.; Plahutnik, F.
A dichlorosilane-based reductive chemical vapor deposition (CVD) process demonstrated is capable of producing, at low cost, high quality polycrystalline silicon. Testing of decomposition reactor heat shields to insure that the shield provides adequate personnel protection assuming a worst case explosion was completed. Minor modifications to a production reactor heat shield provided adequate heat shield integrity. Construction of the redesigned PDU (Process Development Unit) to accommodate all safety related information proceeded on schedule. Structural steel work was completed as is the piping and instrumentation design work. Major pieces of process equipment were received and positioned in the support structure and all transfer piping and conduits to the PDU were installed. Construction was completed on a feed system for supplying DCS to an intermediate sized reactor. The feed system was successfully interfaced with a reactor equipped with a modified heat shield. Reactor checkout was completed.
Hydrodeoxygenation processes: advances on catalytic transformations of biomass-derived platform chemicals into hydrocarbon fuels.
De, Sudipta; Saha, Basudeb; Luque, Rafael
Lignocellulosic biomass provides an attractive source of renewable carbon that can be sustainably converted into chemicals and fuels. Hydrodeoxygenation (HDO) processes have recently received considerable attention to upgrade biomass-derived feedstocks into liquid transportation fuels. The selection and design of HDO catalysts plays an important role to determine the success of the process. This review has been aimed to emphasize recent developments on HDO catalysts in effective transformations of biomass-derived platform molecules into hydrocarbon fuels with reduced oxygen content and improved H/C ratios. Liquid hydrocarbon fuels can be obtained by combining oxygen removal processes (e.g. dehydration, hydrogenation, hydrogenolysis, decarbonylation etc.) as well as by increasing the molecular weight via C-C coupling reactions (e.g. aldol condensation, ketonization, oligomerization, hydroxyalkylation etc.). Fundamentals and mechanistic aspects of the use of HDO catalysts in deoxygenation reactions will also be discussed.
Designing Educative Curriculum Materials: A Theoretically and Empirically Driven Process
ERIC Educational Resources Information Center
Davis, Elizabeth A.; Palincsar, Annemarie Sullivan; Arias, Anna Maria; Bismack, Amber Schultz; Marulis, Loren M.; Iwashyna, Stefanie K.
In this article, the authors argue for a design process in the development of educative curriculum materials that is theoretically and empirically driven. Using a design-based research approach, they describe their design process for incorporating educative features intended to promote teacher learning into existing, high-quality curriculum…
Learning Objects: A User-Centered Design Process
ERIC Educational Resources Information Center
Branon, Rovy F., III
Design research systematically creates or improves processes, products, and programs through an iterative progression connecting practice and theory (Reinking, 2008; van den Akker, 2006). Developing a new instructional systems design (ISD) processes through design research is necessary when new technologies emerge that challenge existing practices…
Experimental investigation of Mars meandering rivers: Chemical precipitation process
NASA Astrophysics Data System (ADS)
Kim, W.; Lim, Y.; Cleveland, J.; Reid, E.; Jew, C.
On Earth, meandering streams occur where the banks are resistant to erosion, which enhances narrow and deep channels. Often this is because the stream banks are held firm by vegetation. The ancient, highly sinuous channels with cutoffs found on Mars are enigmatic because vegetation played no role in providing bank cohesion and enhancing fine sediment deposition. Possible causes of the meandering therefore include ice under permafrost conditions and chemical processes. We conducted carbonate flume experiments to investigate possible mechanisms creating meandering channels other than vegetation. The experiment includes a tank that dissolves limestone by adding CO2 gas and produces artificial spring water, peristaltic pumps to drive water through the system, a heater to control the temperature of the spring water, and a flume where carbonate sediment deposits. Spring water containing dissolved calcium and carbonate ions moves through a heater to increase temperature, and then into the flume. The flume surface is open to the air to allow CO2 degassing, decrease temperature, and increase pH, which promotes carbonate precipitation. A preliminary experiment was done and successfully created a meander pattern that evolved over a 3-day experiment. The experiment showed lateral migration of the bend and avulsion of the stream, similar to a natural meander. The lateral variation in flow speed increased the local residence time of water, thus increasing the degassing of CO2 on the two sides of the flow and promoting more precipitation. This enhanced precipitation on the sides provided a mechanism to build levees along the channel and created a stream confined in a narrow path. This mechanism also potentially applies to Earthly single thread and/or meandering rivers developed and recorded before vegetation appeared on Earth's surface.
Chemical Equilibrium And Transport (CET)
NASA Technical Reports Server (NTRS)
Mcbride, B. J.
Powerful, machine-independent program calculates theoretical thermodynamic properties of chemical systems. Aids in design of compressors, turbines, engines, heat exchangers, and chemical processing equipment.
64 FR 33527 - Process Safety Management of Highly Hazardous Chemicals; Extension of the Office of Management...
Federal Register 2010, 2011, 2012, 2013, 2014
... Occupational Safety and Health Administration Process Safety Management of Highly Hazardous Chemicals... extension of the information collection requirements contained in the standard on Process Safety Management.... 657.) In this regard, the information collection requirements in the Process Safety Management...
Whole Wafer Design and Fabrication for the Alignment of Nanostructures for Chemical Sensor Applications
NASA Technical Reports Server (NTRS)
Biaggi-Labiosa, Azlin M.; Hunter, Gary W.
A major objective in aerospace sensor development is to produce sensors that are small in size, easy to batch fabricate and low in cost, and have low power consumption The fabrication of chemical sensors involving nanostructured materials can provide these properties as well as the potential for the development of sensor systems with unique properties and improved performance. However, the fabrication and processing of nanostructures for sensor applications currently is limited in the ability to control their location on the sensor. Currently, our group at NASA Glenn Research Center has demonstrated the controlled placement of nanostructures in sensors using a sawtooth patterned electrode design. With this design the nanostructures are aligned between opposing sawtooth electrodes by applying an alternating current.
Understanding the Processes behind Student Designing: Cases from Singapore
ERIC Educational Resources Information Center
Lim, Susan Siok Hiang; Lim-Ratnam, Christina; Atencio, Matthew
A common perception of designing is that it represents a highly complex activity that is manageable by only a few. However it has also been argued that all individuals are innately capable of designing. Taking up this latter view, we explored the processes behind student designing in the context of Design and Technology (D&T), a subject taught…
Enhanced teaching and student learning through a simulator-based course in chemical unit operations design
NASA Astrophysics Data System (ADS)
Ghasem, Nayef
This paper illustrates a teaching technique used in computer applications in chemical engineering employed for designing various unit operation processes, where the students learn about unit operations by designing them. The aim of the course is not to teach design, but rather to teach the fundamentals and the function of unit operation processes through simulators. A case study presenting the teaching method was evaluated using student surveys and faculty assessments, which were designed to measure the quality and effectiveness of the teaching method. The results of the questionnaire conclusively demonstrate that this method is an extremely efficient way of teaching a simulator-based course. In addition to that, this teaching method can easily be generalised and used in other courses. A student's final mark is determined by a combination of in-class assessments conducted based on cooperative and peer learning, progress tests and a final exam. Results revealed that peer learning can improve the overall quality of student learning and enhance student understanding.
Lambert, D.; Zamecnik, J.; Best, D.
Savannah River Remediation is evaluating changes to its current Defense Waste Processing Facility flowsheet to replace formic acid with glycolic acid in order to improve processing cycle times and decrease by approximately 100x the production of hydrogen, a potentially flammable gas. Higher throughput is needed in the Chemical Processing Cell since the installation of the bubblers into the melter has increased melt rate. Due to the significant maintenance required for the safety significant gas chromatographs and the potential for production of flammable quantities of hydrogen, eliminating the use of formic acid is highly desirable. Previous testing at the Savannah River National Laboratory has shown that replacing formic acid with glycolic acid allows the reduction and removal of mercury without significant catalytic hydrogen generation. Five back-to-back Sludge Receipt and Adjustment Tank (SRAT) cycles and four back-to-back Slurry Mix Evaporator (SME) cycles were successful in demonstrating the viability of the nitric/glycolic acid flowsheet. The testing was completed in FY13 to determine the impact of process heels (approximately 25% of the material is left behind after transfers). In addition, back-to-back experiments might identify longer-term processing problems. The testing was designed to be prototypic by including sludge simulant, Actinide Removal Product simulant, nitric acid, glycolic acid, and Strip Effluent simulant containing Next Generation Solvent in the SRAT processing and SRAT product simulant, decontamination frit slurry, and process frit slurry in the SME processing. A heel was produced in the first cycle and each subsequent cycle utilized the remaining heel from the previous cycle. Lower SRAT purges were utilized due to the low hydrogen generation. Design basis addition rates and boilup rates were used so the processing time was shorter than current processing rates.
Processes and Knowledge in Designing Instruction.
ERIC Educational Resources Information Center
Greeno, James G.; And Others
Results from a study of problem solving in the domain of instructional design are presented. Subjects were eight teacher trainees who were recent graduates of or were enrolled in the Stanford Teacher Education Program at Stanford University (California). Subjects studied a computer-based tutorial--the VST2000--about a fictitious vehicle. The…
User-Centered Design (UCD) Process Description
mockups and prototypes. CONCLUSIONS AND RECOMMENDATIONS UCD provides guidance for improving total system performance by considering the real- world...against essential story scenarios, eventually leading to the development of high-fidelity mockups and prototypes. Figure 1. User-centered design (UCD
Reducing Design Cycle Time and Cost Through Process Resequencing
NASA Technical Reports Server (NTRS)
Rogers, James L.
In today's competitive environment, companies are under enormous pressure to reduce the time and cost of their design cycle. One method for reducing both time and cost is to develop an understanding of the flow of the design processes and the effects of the iterative subcycles that are found in complex design projects. Once these aspects are understood, the design manager can make decisions that take advantage of decomposition, concurrent engineering, and parallel processing techniques to reduce the total time and the total cost of the design cycle. One software tool that can aid in this decision-making process is the Design Manager's Aid for Intelligent Decomposition (DeMAID). The DeMAID software minimizes the feedback couplings that create iterative subcycles, groups processes into iterative subcycles, and decomposes the subcycles into a hierarchical structure. The real benefits of producing the best design in the least time and at a minimum cost are obtained from sequencing the processes in the subcycles.
Process optimization and consumable development for Chemical Mechanical Planarization (CMP) processes
NASA Astrophysics Data System (ADS)
Mudhivarthi, Subrahmanya R.
Chemical Mechanical Planarization (CMP) is one of the most critical processing steps that enables fabrication of multilevel interconnects. The success of CMP process is limited by the implementation of an optimized process and reduction of process generated defects along with post CMP surface characteristics such as dishing and erosion. This thesis investigates to identify various sources of defects and studies the effect of factors that can be used to optimize the process. The major contributions of this work are: Understanding the effect of temperature rise on surface tribology, electrochemistry and post CMP pattern effects during the CMP process; investigating the effect of pad conditioning temperature and slurry flow rate on tribology and post CMP characteristics; development of novel slurries using polymer hybrid particles and improvement in slurry metrology to reduce surface damage during CMP. From the current research, it was shown that the effect of temperature on CMP tribology is predominantly affected by the polishing parameters and the polishing pad characteristics more than the chemical nature of the slurry. The effect of temperature is minimal on the resulting surface roughness but the with-in die non-uniformity is significantly affected by the temperature at the interface. Secondly, in this research it was shown that the effectiveness and aggressiveness of the pad conditioning process is highly influenced by the conditioning temperature. This aspect can be utilized to optimize the parameters for the pad conditioning process. Further, post CMP characteristics such as dishing, erosion and metal loss on patterned samples were shown to decrease with increase in slurry flow rate. This research then concentrates on the development of novel low defect slurry using polymer hybrid abrasive particles. Several varieties of surface functionalized polymer particles were employed to make oxide CMP slurries. These novel slurries proved to be potential candidates to
NASA Now: Engineering Design Process: Hubble Space Telescope
In this episode of NASA Now, NASA engineer Russ Werneth discusses the continuous nature of the engineering design process and shares what it was like to design and plan the spacewalks that were key...
The Processes Involved in Designing Software.
compiler's task was to derive the sequence of IPL instructions that brought about that transformation. The other form of deflnillons was In terms of...used suitably generalized forms of means-ends analysis to generate sequences of IPL instructions that would meet the Input specifications. One branch...processes called critics are used to reorganize this more detailed plan Into an Internally consistent and efficient sequence of actions. The process
Integrating Thermal Tools Into the Mechanical Design Process
NASA Technical Reports Server (NTRS)
Tsuyuki, Glenn T.; Siebes, Georg; Novak, Keith S.; Kinsella, Gary M.
The intent of mechanical design is to deliver a hardware product that meets or exceeds customer expectations, while reducing cycle time and cost. To this end, an integrated mechanical design process enables the idea of parallel development (concurrent engineering). This represents a shift from the traditional mechanical design process. With such a concurrent process, there are significant issues that have to be identified and addressed before re-engineering the mechanical design process to facilitate concurrent engineering. These issues also assist in the integration and re-engineering of the thermal design sub-process since it resides within the entire mechanical design process. With these issues in mind, a thermal design sub-process can be re-defined in a manner that has a higher probability of acceptance, thus enabling an integrated mechanical design process. However, the actual implementation is not always problem-free. Experience in applying the thermal design sub-process to actual situations provides the evidence for improvement, but more importantly, for judging the viability and feasibility of the sub-process.
Conceptual design of distillation-based hybrid separation processes.
Skiborowski, Mirko; Harwardt, Andreas; Marquardt, Wolfgang
Hybrid separation processes combine different separation principles and constitute a promising design option for the separation of complex mixtures. Particularly, the integration of distillation with other unit operations can significantly improve the separation of close-boiling or azeotropic mixtures. Although the design of single-unit operations is well understood and supported by computational methods, the optimal design of flowsheets of hybrid separation processes is still a challenging task. The large number of operational and design degrees of freedom requires a systematic and optimization-based design approach. To this end, a structured approach, the so-called process synthesis framework, is proposed. This article reviews available computational methods for the conceptual design of distillation-based hybrid processes for the separation of liquid mixtures. Open problems are identified that must be addressed to finally establish a structured process synthesis framework for such processes.
The application of image processing software: Photoshop in environmental design
NASA Astrophysics Data System (ADS)
Dong, Baohua; Zhang, Chunmi; Zhuo, Chen
In the process of environmental design and creation, the design sketch holds a very important position in that it not only illuminates the design's idea and concept but also shows the design's visual effects to the client. In the field of environmental design, computer aided design has made significant improvement. Many types of specialized design software for environmental performance of the drawings and post artistic processing have been implemented. Additionally, with the use of this software, working efficiency has greatly increased and drawings have become more specific and more specialized. By analyzing the application of photoshop image processing software in environmental design and comparing and contrasting traditional hand drawing and drawing with modern technology, this essay will further explore the way for computer technology to play a bigger role in environmental design.
71 FR 4941 - Process Safety Management of Highly Hazardous Chemicals Standard; Extension of the Office of...
Federal Register 2010, 2011, 2012, 2013, 2014
... Occupational Safety and Health Administration Process Safety Management of Highly Hazardous Chemicals Standard... collection requirements specified by its Process Safety Management of Highly Hazardous Chemicals Standard (29... of the other elements of process safety management in the Standard. Under paragraph (c)(3)...
74 FR 46621 - Process Safety Management of Highly Hazardous Chemicals (PSM) Standard; Extension of the Office...
Federal Register 2010, 2011, 2012, 2013, 2014
... Occupational Safety and Health Administration Process Safety Management of Highly Hazardous Chemicals (PSM... specified in the Standard on Process Safety Management of Highly Hazardous Chemicals (PSM) (29 CFR 1910.119... of the information collection requirements contained in the Standard on Process Safety Management...
Chemical and Metallurgy Research (CMR) Sample Tracking System Design Document
Bargelski, C. J.; Berrett, D. E.
The purpose of this document is to describe the system architecture of the Chemical and Metallurgy Research (CMR) Sample Tracking System at Los Alamos National Laboratory. During the course of the document observations are made concerning the objectives, constraints and limitations, technical approaches, and the technical deliverables.
A design optimization process for Space Station Freedom
NASA Technical Reports Server (NTRS)
Chamberlain, Robert G.; Fox, George; Duquette, William H.
The Space Station Freedom Program is used to develop and implement a process for design optimization. Because the relative worth of arbitrary design concepts cannot be assessed directly, comparisons must be based on designs that provide the same performance from the point of view of station users; such designs can be compared in terms of life cycle cost. Since the technology required to produce a space station is widely dispersed, a decentralized optimization process is essential. A formulation of the optimization process is provided and the mathematical models designed to facilitate its implementation are described.
Design and Processing of Electret Structures
corrosion rate measurements in specially designed model systems (Fig. 1). The spatial resolution is determined by the optical properties of the setup and...and optical responses. Such molecules usually contain a chain of atoms forming a conjugated π- electron system with electron donor and acceptor...electrets from monodisperse polystyrene microspheres (electrets whose charge comes from an imbalance of ions, rather than from the transfer of electrons
The Process of Soviet Weapons Design
system on the BMP from an early 1940s German design. But the validity and usefulness of a theory, especially one that makes predictions about the future...when the 1940 publication of a highly significant Soviet discovery of spontaneous fission resulted in a complete lack of an American response, the...taken from I. N. Golovin , I. V. Khurchatov, Atomizdat, Moscow, 1973, and from Herbert York, The Advisors. Oppenheimer, Teller, and the Superbomb, W. H
Launch Vehicle Design Process Description and Training Formulation
NASA Technical Reports Server (NTRS)
Atherton, James; Morris, Charles; Settle, Gray; Teal, Marion; Schuerer, Paul; Blair, James; Ryan, Robert; Schutzenhofer, Luke
A primary NASA priority is to reduce the cost and improve the effectiveness of launching payloads into space. As a consequence, significant improvements are being sought in the effectiveness, cost, and schedule of the launch vehicle design process. In order to provide a basis for understanding and improving the current design process, a model has been developed for this complex, interactive process, as reported in the references. This model requires further expansion in some specific design functions. Also, a training course for less-experienced engineers is needed to provide understanding of the process, to provide guidance for its effective implementation, and to provide a basis for major improvements in launch vehicle design process technology. The objective of this activity is to expand the description of the design process to include all pertinent design functions, and to develop a detailed outline of a training course on the design process for launch vehicles for use in educating engineers whose experience with the process has been minimal. Building on a previously-developed partial design process description, parallel sections have been written for the Avionics Design Function, the Materials Design Function, and the Manufacturing Design Function. Upon inclusion of these results, the total process description will be released as a NASA TP. The design function sections herein include descriptions of the design function responsibilities, interfaces, interactive processes, decisions (gates), and tasks. Associated figures include design function planes, gates, and tasks, along with other pertinent graphics. Also included is an expanded discussion of how the design process is divided, or compartmentalized, into manageable parts to achieve efficient and effective design. A detailed outline for an intensive two-day course on the launch vehicle design process has been developed herein, and is available for further expansion. The course is in an interactive lecture
Lignocellulosic ethanol: Technology design and its impact on process efficiency.
Paulova, Leona; Patakova, Petra; Branska, Barbora; Rychtera, Mojmir; Melzoch, Karel
This review provides current information on the production of ethanol from lignocellulosic biomass, with the main focus on relationships between process design and efficiency, expressed as ethanol concentration, yield and productivity. In spite of unquestionable advantages of lignocellulosic biomass as a feedstock for ethanol production (availability, price, non-competitiveness with food, waste material), many technological bottlenecks hinder its wide industrial application and competitiveness with 1st generation ethanol production. Among the main technological challenges are the recalcitrant structure of the material, and thus the need for extensive pretreatment (usually physico-chemical followed by enzymatic hydrolysis) to yield fermentable sugars, and a relatively low concentration of monosaccharides in the medium that hinder the achievement of ethanol concentrations comparable with those obtained using 1st generation feedstocks (e.g. corn or molasses). The presence of both pentose and hexose sugars in the fermentation broth, the price of cellulolytic enzymes, and the presence of toxic compounds that can inhibit cellulolytic enzymes and microbial producers of ethanol are major issues. In this review, different process configurations of the main technological steps (enzymatic hydrolysis, fermentation of hexose/and or pentose sugars) are discussed and their efficiencies are compared. The main features, benefits and drawbacks of simultaneous saccharification and fermentation (SSF), simultaneous saccharification and fermentation with delayed inoculation (dSSF), consolidated bioprocesses (CBP) combining production of cellulolytic enzymes, hydrolysis of biomass and fermentation into one step, together with an approach combining utilization of both pentose and hexose sugars are discussed and compared with separate hydrolysis and fermentation (SHF) processes. The impact of individual technological steps on final process efficiency is emphasized and the potential for use
Reducing the emission of ozone depleting chemicals through use of a self-cleaning soldering process
Lichtenberg, L.; Martin, G.; Van Buren, P.; Iman, R.; Paffett, M.T.
Motorola has jointed with Sandia and Los Alamos National Laboratories to perform work under a Cooperative Research and Development Agreement (CRADA) to reduce the use of CFC`s and other ozone depleting printing wiring board (PWB) cleaning solvents. This study evaluated the use of a new soldering process that uses dilute adipic acid in lieu of rosin flux. The process consumes the adipic acid in lieu of rosin flux. The process consumes the adipic acid during the soldering process and precludes the need for subsequent cleaning with ozone depleting solvents. This paper presents results from a series of designed experiments that evaluated PWB cleanliness as a function of various levels of machine control parameters. The study included a comprehensive hardware reliability evaluation, which included environmental conditioning, cleanliness testing, surface chemical analysis, surface insulation resistance testing, along with electrical, mechanical and long term storage testing. The results of this study that the new process produces quality, reliable hardware over a wide range of processing parameters. Adoption of this process, which eliminates the need for supplemental cleaning, will have a positive impact on many environmental problems, including depletion of the ozone layer.
Reducing the emission of ozone depleting chemicals through use of a self-cleaning soldering process
Lichtenberg, L.; Martin, G.; Van Buren, P. . Government Electronics Group); Iman, R. ); Paffett, M.T. )
Motorola has jointed with Sandia and Los Alamos National Laboratories to perform work under a Cooperative Research and Development Agreement (CRADA) to reduce the use of CFC's and other ozone depleting printing wiring board (PWB) cleaning solvents. This study evaluated the use of a new soldering process that uses dilute adipic acid in lieu of rosin flux. The process consumes the adipic acid in lieu of rosin flux. The process consumes the adipic acid during the soldering process and precludes the need for subsequent cleaning with ozone depleting solvents. This paper presents results from a series of designed experiments that evaluated PWB cleanliness as a function of various levels of machine control parameters. The study included a comprehensive hardware reliability evaluation, which included environmental conditioning, cleanliness testing, surface chemical analysis, surface insulation resistance testing, along with electrical, mechanical and long term storage testing. The results of this study that the new process produces quality, reliable hardware over a wide range of processing parameters. Adoption of this process, which eliminates the need for supplemental cleaning, will have a positive impact on many environmental problems, including depletion of the ozone layer.
Classification of chemical reactions and chemoinformatic processing of enzymatic transformations.
Latino, Diogo A R S; Aires-de-Sousa, João
The automatic perception of chemical similarities between chemical reactions is required for a variety of applications in chemistry and connected fields, namely with databases of metabolic reactions. Classification of enzymatic reactions is required, e.g., for genome-scale reconstruction (or comparison) of metabolic pathways, computer-aided validation of classification systems, or comparison of enzymatic mechanisms. This chapter presents different current approaches for the representation of chemical reactions enabling automatic reaction classification. Representations based on the encoding of the reaction center are illustrated, which use physicochemical features, Reaction Classification (RC) numbers, or Condensed Reaction Graphs (CRG). Representation of differences between the structures of products and reactants include reaction signatures, fingerprint differences, and the MOLMAP approach. The approaches are illustrated with applications to real datasets.
Adding Users to the Website Design Process
ERIC Educational Resources Information Center
Tomeo, Megan L.
Alden Library began redesigning its website over a year ago. Throughout the redesign process the students, faculty, and staff that make up the user base were added to the conversation by utilizing several usability test methods. This article focuses on the usability testing conducted at Alden Library and delves into future usability testing, which…
A Design Methodology for Medical Processes
Bonacina, Stefano; Pozzi, Giuseppe; Pinciroli, Francesco; Marceglia, Sara
Summary Background Healthcare processes, especially those belonging to the clinical domain, are acknowledged as complex and characterized by the dynamic nature of the diagnosis, the variability of the decisions made by experts driven by their experiences, the local constraints, the patient's needs, the uncertainty of the patient's response, and the indeterminacy of patient's compliance to treatment. Also, the multiple actors involved in patient's care need clear and transparent communication to ensure care coordination. Objectives In this paper, we propose a methodology to model healthcare processes in order to break out complexity and provide transparency. Methods The model is grounded on a set of requirements that make the healthcare domain unique with respect to other knowledge domains. The modeling methodology is based on three main phases: the study of the environmental context, the conceptual modeling, and the logical modeling. Results The proposed methodology was validated by applying it to the case study of the rehabilitation process of stroke patients in the specific setting of a specialized rehabilitation center. The resulting model was used to define the specifications of a software artifact for the digital administration and collection of assessment tests that was also implemented. Conclusions Despite being only an example, our case study showed the ability of process modeling to answer the actual needs in healthcare practices. Independently from the medical domain in which the modeling effort is done, the proposed methodology is useful to create high-quality models, and to detect and take into account relevant and tricky situations that can occur during process execution. PMID:27081415
Laser studies of chemical reaction and collision processes
Flynn, G.
This work has concentrated on several interrelated projects in the area of laser photochemistry and photophysics which impinge on a variety of questions in combustion chemistry and general chemical kinetics. Infrared diode laser probes of the quenching of molecules with {open_quotes}chemically significant{close_quotes} amounts of energy in which the energy transferred to the quencher has, for the first time, been separated into its vibrational, rotational, and translational components. Probes of quantum state distributions and velocity profiles for atomic fragments produced in photodissociation reactions have been explored for iodine chloride.
The WAR Algorithm, a methodology for determining the potential environmental impact (PEI) of a chemical process, is presented with modifications that account for the PEI of the energy consumed within that process. From this theory, four PEI indexes are used to evaluate the envir...
Dynamic Processes of Conceptual Change: Analysis of Constructing Mental Models of Chemical Equilibrium.
ERIC Educational Resources Information Center
Chiu, Mei-Hung; Chou, Chin-Cheng; Liu, Chia-Ju
Investigates students' mental models of chemical equilibrium using dynamic science assessments. Reports that students at various levels have misconceptions about chemical equilibrium. Involves 10th grade students (n=30) in the study doing a series of hands-on chemical experiments. Focuses on the process of constructing mental models, dynamic…
Evaluation of alternative chemical additives for high-level waste vitrification feed preparation processing
Seymour, R.G.
During the development of the feed processing flowsheet for the Defense Waste Processing Facility (DWPF) at the Savannah River Site (SRS), research had shown that use of formic acid (HCOOH) could accomplish several processing objectives with one chemical addition. These objectives included the decomposition of tetraphenylborate, chemical reduction of mercury, production of acceptable rheological properties in the feed slurry, and controlling the oxidation state of the glass melt pool. However, the DEPF research had not shown that some vitrification slurry feeds had a tendency to evolve hydrogen (H{sub 2}) and ammonia (NH{sub 3}) as the result of catalytic decomposition of CHOOH with noble metals (rhodium, ruthenium, palladium) in the feed. Testing conducted at Pacific Northwest Laboratory and later at the Savannah River Technical Center showed that the H{sub 2} and NH{sub 3} could evolve at appreciable rates and quantities. The explosive nature of H{sub 2} and NH{sub 3} (as ammonium nitrate) warranted significant mitigation control and redesign of both facilities. At the time the explosive gas evolution was discovered, the DWPF was already under construction and an immediate hardware fix in tandem with flowsheet changes was necessary. However, the Hanford Waste Vitrification Plant (HWVP) was in the design phase and could afford to take time to investigate flowsheet manipulations that could solve the problem, rather than a hardware fix. Thus, the HWVP began to investigate alternatives to using HCOOH in the vitrification process. This document describes the selection, evaluation criteria, and strategy used to evaluate the performance of the alternative chemical additives to CHOOH. The status of the evaluation is also discussed.
Development of the chemical and electrochemical coal cleaning (CECC) process. Final report
Yoon, Roe-Hoan; Basilio, C.I.
The Chemical and Electrochemical Coal Cleaning (CECC) process developed at Virginia Polytechnic Institute and State University was studied further in this project. This process offers a new method of physically cleaning both low- and high-rank coals without requiring fine grinding. The CECC process is based on liberating mineral matter from coal by osmotic pressure. The majority of the work was conducted on Middle Wyodak, Pittsburgh No. 8 and Elkhorn No. 3 coals. The coal samples were characterized for a variety of physical and chemical properties. Parametric studies were then conducted to identify the important operating parameters and to establish the optimum conditions. In addition, fundamental mechanisms of the process were studied, including mineral matter liberation, kinetics of mineral matter and pyrite dissolution, ferric ion regeneration schemes and alternative methods of separating the cleaned coal from the liberated mineral matter. The information gathered from the parametric and fundamental studies was used in the design, construction and testing of a bench-scale continuous CECC unit. Using this unit, the ash content of a Middle Wyodak coal was reduced from 6.96 to 1.61% at a 2 lbs/hr throughput. With an Elkhorn No. 3 sample, the ash content was reduced from 9.43 to 1.8%, while the sulfur content was reduced from 1.57 to 0.9%. The mass balance and liberation studies showed that liberation played a more dominant role than the chemical dissolution in removing mineral matter and inorganic sulfur from the different bituminous coals tested. However, the opposite was found to be the case for the Wyodak coal since this coal contained a significant amount of acid-soluble minerals.
Design, fabrication, and bench testing of a solar chemical receiver
NASA Technical Reports Server (NTRS)
Summers, W. A.; Pierre, J. F.
Solar thermal energy can be effectively collected, transported, stored, and utilized by means of a chemical storage and transport system employing the reversible SO2 oxidation reaction. A solar chemical receiver for SO3 thermal decomposition to SO2 and oxygen was analyzed. Bench tests of a ten foot section of a receiver module were conducted with dissociated sulfuric acid (SO3 and H2O) in an electrical furnace. Measured percent conversion of SO3 was 85% of the equilibrium value. Methods were developed to fabricate and assemble a complete receiver module. These methods included applying an aluminide coating to certain exposed surfaces, assembling concentric tubes with a wire spacer, applying a platinum catalyst to the tubing wall, and coiling the entire assembly into the desired configuration.
Ceramic processing: Experimental design and optimization
NASA Technical Reports Server (NTRS)
Weiser, Martin W.; Lauben, David N.; Madrid, Philip
The objectives of this paper are to: (1) gain insight into the processing of ceramics and how green processing can affect the properties of ceramics; (2) investigate the technique of slip casting; (3) learn how heat treatment and temperature contribute to density, strength, and effects of under and over firing to ceramic properties; (4) experience some of the problems inherent in testing brittle materials and learn about the statistical nature of the strength of ceramics; (5) investigate orthogonal arrays as tools to examine the effect of many experimental parameters using a minimum number of experiments; (6) recognize appropriate uses for clay based ceramics; and (7) measure several different properties important to ceramic use and optimize them for a given application.
H-Coal process and plant design
Kydd, Paul H.; Chervenak, Michael C.; DeVaux, George R.
A process for converting coal and other hydrocarbonaceous materials into useful and more valuable liquid products. The process comprises: feeding coal and/or other hydrocarbonaceous materials with a hydrogen-containing gas into an ebullated catalyst bed reactor; passing the reaction products from the reactor to a hot separator where the vaporous and distillate products are separated from the residuals; introducing the vaporous and distillate products from the separator directly into a hydrotreater where they are further hydrogenated; passing the residuals from the separator successively through flash vessels at reduced pressures where distillates are flashed off and combined with the vaporous and distillate products to be hydrogenated; transferring the unseparated residuals to a solids concentrating and removal means to remove a substantial portion of solids therefrom and recycling the remaining residual oil to the reactor; and passing the hydrogenated vaporous and distillate products to an atmospheric fractionator where the combined products are fractionated into separate valuable liquid products. The hydrogen-containing gas is generated from sources within the process.
Clutter suppression interferometry system design and processing
NASA Astrophysics Data System (ADS)
Knight, Chad; Deming, Ross; Gunther, Jake
Clutter suppression interferometry (CSI) has received extensive attention due to its multi-modal capability to detect slow-moving targets, and concurrently form high-resolution synthetic aperture radar (SAR) images from the same data. The ability to continuously augment SAR images with geo-located ground moving target indicators (GMTI) provides valuable real-time situational awareness that is important for many applications. CSI can be accomplished with minimal hardware and processing resources. This makes CSI a natural candidate for applications where size, weight and power (SWaP) are constrained, such as unmanned aerial vehicles (UAVs) and small satellites. This paper will discuss the theory for optimal CSI system configuration focusing on sparse time-varying transmit and receive array manifold due to SWaP considerations. The underlying signal model will be presented and discussed as well as the potential benefits that a sparse time-varying transmit receive manifold provides. The high-level processing objectives will be detailed and examined on simulated data. Then actual SAR data collected with the Space Dynamic Laboratory (SDL) FlexSAR radar system will be analyzed. The simulated data contrasted with actual SAR data helps illustrate the challenges and limitations found in practice vs. theory. A new novel approach incorporating sparse signal processing is discussed that has the potential to reduce false- alarm rates and improve detections.
Chemical Changes in Lipids Produced by Thermal Processing.
ERIC Educational Resources Information Center
Nawar, Wassef W.
Describes heat effects on lipids, indicating that the chemical and physical changes that occur depend on the lipid's composition and conditions of treatment. Thermolytic and oxidation reactions, thermal/oxidative interaction of lipids with other food components and the chemistry of frying are considered. (JN)
Helping Students Develop a Critical Attitude towards Chemical Process Calculations.
ERIC Educational Resources Information Center
de Nevers, Noel; Seader, J. D.
Discusses the use of computer-assisted programs that allow chemical engineering students to study textbook thermodynamics problems from different perspectives, including the classical graphical method, while utilizing more than one property correlation and/or operation model so that comparisons can be made and sensitivities determined more…
The Chemistry of Lightsticks: Demonstrations to Illustrate Chemical Processes
ERIC Educational Resources Information Center
Kuntzleman, Thomas Scott; Rohrer, Kristen; Schultz, Emeric
Lightsticks, or glowsticks as they are sometimes called, are perhaps the chemist's quintessential toy. Because they are easy to activate and appealing to observe, experimenting with lightsticks provides a great way to get young people interested in science. Thus, we have used lightsticks to teach chemical concepts in a variety of outreach settings…
Bioreactor and process design for biohydrogen production.
Show, Kuan-Yeow; Lee, Duu-Jong; Chang, Jo-Shu
Biohydrogen is regarded as an attractive future clean energy carrier due to its high energy content and environmental-friendly conversion. It has the potential for renewable biofuel to replace current hydrogen production which rely heavily on fossil fuels. While biohydrogen production is still in the early stage of development, there have been a variety of laboratory- and pilot-scale systems developed with promising potential. This work presents a review of advances in bioreactor and bioprocess design for biohydrogen production. The state-of-the art of biohydrogen production is discussed emphasizing on production pathways, factors affecting biohydrogen production, as well as bioreactor configuration and operation. Challenges and prospects of biohydrogen production are also outlined.
Chemical Thinning Process for Fabricating UV-Imaging CCDs
NASA Technical Reports Server (NTRS)
Jones, TOdd; Grunthaner, Paula; Nikzad, Shouleh; Wilson, Rick
The thinning stage of the postfabrication process reported in the immediately preceding article is notable in its own right. Although the thinning process was described in the preceding article as part of an overall process of fabrication of a supported charge-coupled device (CCD), it is more generally applicable to both free-standing and supported devices that have been fabricated in die and wafer formats. Like the thermocompression bonding process described in the preceding article, the thinning process is compatible with CCD-fabrication processes, as well as postfabrication processes that enhance the response of CCDs to ultraviolet (UV) light, including the delta-doping process. CCDs that are thinned by this process and then delta-doped exhibit high quantum efficiencies that are stable with time and with exposure to the environment.
Engineering Design Handbook for Air Cleaning for Chemical Demilitarization
permissible leakage through closed damper; space required for service; airstream temperature range; orientation of damper in duct ; direction of airflow...4-91 S18.104.22.168. Enclosing Hoods ............. 4-91 126.96.36.199. Capturing Hoods ............. 4-92 4.2.2. Duct Design...Loss In Duct Design 4-97 4-46 Recommended Methods To Prevent Backflow 4-102 In Airlocks xviii LIST OF FIGURES (continued) Figure No. Title Page No. 4
Development of Integrated Programs for Aerospace-vehicle design (IPAD): Reference design process
NASA Technical Reports Server (NTRS)
Meyer, D. D.
The airplane design process and its interfaces with manufacturing and customer operations are documented to be used as criteria for the development of integrated programs for the analysis, design, and testing of aerospace vehicles. Topics cover: design process management, general purpose support requirements, design networks, and technical program elements. Design activity sequences are given for both supersonic and subsonic commercial transports, naval hydrofoils, and military aircraft.
Reboul, S.; Best, D.; Stone, M.; Click, D.
A combination of short-term beaker tests and longer-duration Sludge Receipt and Adjustment Tank (SRAT) simulations were performed to investigate the relative partitioning behaviors of gadolinium and iron under conditions applicable to the Chemical Processing Cell (CPC). The testing was performed utilizing non-radioactive simple Fe-Gd slurries, non-radioactive Sludge Batch 6 simulant slurries, and a radioactive real-waste slurry representative of Sludge Batch 7 material. The testing focused on the following range of conditions: (a) Fe:Gd ratios of 25-100; (b) pH values of 2-6; (c) acidification via addition of nitric, formic, and glycolic acids; (d) temperatures of {approx}93 C and {approx}22 C; and (e) oxalate concentrations of <100 mg/kg and {approx}10,000 mg/kg. The purpose of the testing was to provide data for assessing the potential use of gadolinium as a supplemental neutron poison when dispositioning excess plutonium. Understanding of the partitioning behavior of gadolinium in the CPC was the first step in assessing gadolinium's potential applicability. Significant fractions of gadolinium partitioned to the liquid-phase at pH values of 4.0 and below, regardless of the Fe:Gd ratio. In SRAT simulations targeting nitric and formic acid additions of 150% acid stoichiometry, the pH dropped to a minimum of 3.5-4.0, and the maximum fractions of gadolinium and iron partitioning to solution were both {approx}20%. In contrast, in a SRAT simulation utilizing a nitric and formic acid addition under atypical conditions (due to an anomalously low insoluble solids content), the pH dropped to a minimum of 3.7, and the maximum fractions of gadolinium and iron partitioning to solution were {approx}60% and {approx}70%, respectively. When glycolic acid was used in combination with nitric and formic acids at 100% acid stoichiometry, the pH dropped to a minimum of 3.6-4.0, and the maximum fractions of gadolinium and iron partitioning to solution were 60-80% and 3-5%, respectively
Indicators and Metrics for Evaluating the Sustainability of Chemical Processes
A metric-based method, called GREENSCOPE, has been developed for evaluating process sustainability. Using lab-scale information and engineering assumptions the method evaluates full-scale epresentations of processes in environmental, efficiency, energy and economic areas. The m...
Debating Professional Designations for Evaluators: Reflections on the Canadian Process
ERIC Educational Resources Information Center
Cousins, J. Bradley; Cullen, Jim; Malik, Sumbal; Maicher, Brigitte
This paper provides a reflective account of a consultation process on professional designations for evaluators initiated and coordinated by the Canadian Evaluation Society (CES). Described are: (1) the forces leading CES to generate discussion and debate about professional designations for Canadian evaluators, (2) the process of developing and…
An Analysis of Algorithmic Processes and Instructional Design.
ERIC Educational Resources Information Center
Schmid, Richard F.; Gerlach, Vernon S.
Describes algorithms and shows how they can be applied to the design of instructional systems by relating them to a standard information processing model. Two studies are briefly described which tested serial and parallel processing in learning and offered guidelines for designers. Future research needs are also discussed. (LRW)
Advancing alternatives analysis: The role of predictive toxicology in selecting safer chemical products and processes.
Malloy, Timothy; Zaunbrecher, Virginia; Beryt, Elizabeth; Judson, Richard; Tice, Raymond; Allard, Patrick; Blake, Ann; Cote, Ila; Godwin, Hilary; Heine, Lauren; Kerzic, Patrick; Kostal, Jakub; Marchant, Gary; McPartland, Jennifer; Moran, Kelly; Nel, Andre; Oguseitan, Oladele; Rossi, Mark; Thayer, Kristina; Tickner, Joel; Whittaker, Margaret; Zarker, Ken
Alternatives analysis (AA) is a method used in regulation and product design to identify, assess, and evaluate the safety and viability of potential substitutes for hazardous chemicals. It requires toxicological data for the existing chemical and potential alternatives. Predictive toxicology uses in silico and in vitro approaches, computational models, and other tools to expedite toxicological data generation in more cost-effective manner than traditional approaches. This article briefly reviews the challenges associated with using predictive toxicology in regulatory AA, then presents four recommendations for its advancement. It recommends using case studies to advance the integration of predictive toxicology into AA; adopting a stepwise process to employing predicative toxicology in AA beginning with prioritization of chemicals of concern; leveraging existing resources to advance the integration of predictive toxicology into the practice of AA, and supporting trans-disciplinary efforts. The further incorporation of predictive toxicology into AA would advance the ability of companies and regulators to select alternatives to harmful ingredients, and potentially increase the use of predictive toxicology in regulation more broadly. This article is protected by copyright. All rights reserved.
Solid propellant processing factor in rocket motor design
NASA Technical Reports Server (NTRS)
The ways are described by which propellant processing is affected by choices made in designing rocket engines. Tradeoff studies, design proof or scaleup studies, and special design features are presented that are required to obtain high product quality, and optimum processing costs. Processing is considered to include the operational steps involved with the lining and preparation of the motor case for the grain; the procurement of propellant raw materials; and propellant mixing, casting or extrusion, curing, machining, and finishing. The design criteria, recommended practices, and propellant formulations are included.
An Elective Course on Computer-Aided Process Design.
ERIC Educational Resources Information Center
Sommerfeld, Jude T.
Describes an undergraduate chemical engineering course which has been offered at the Georgia Institute of Technology. The objectives, structure, instructional materials and content of this course, which emphasizes the structure and usage of computer-aided design systems, are also included. (HM)
Programming-Free Form Conversion, Design, and Processing
Fan, Ting-Jun; Machlin, Rona S.; Wang, Christopher P.; Chang, Ifay F.
In this paper, we present the requirements and design considerations for programming-free form conversion, design, and processing. A set of object-oriented software tools are also presented to help users convert a paper form into an electronic form, design an electronic form, and fill in an electronic form directly on screen.
The Use of Computer Graphics in the Design Process.
ERIC Educational Resources Information Center
Palazzi, Maria
This master's thesis examines applications of computer technology to the field of industrial design and ways in which technology can transform the traditional process. Following a statement of the problem, the history and applications of the fields of computer graphics and industrial design are reviewed. The traditional industrial design process…
Bayesian approach to the design of chemical species tomography experiments.
Grauer, Samuel J; Hadwin, Paul J; Daun, Kyle J
Reconstruction accuracy in chemical species tomography depends strongly on the arrangement of optical paths transecting the imaging domain. Optimizing the path arrangement requires a scheme that can predict the quality of a proposed arrangement prior to measurement. This paper presents a new Bayesian method for scoring path arrangements based on the estimated a posteriori covariance matrix. This technique focuses on defining an objective function that incorporates the same a priori information about the flow needed to carry out limited data tomography. Constrained and unconstrained path optimization studies verify the predictive capabilities of the objective function, and that superior reconstruction quality is obtained with optimized path arrangements.
Efforts are currently underway at the USEPA to develop information technology applications to improve the environmental performance of the chemical process industry. These efforts include the use of genetic algorithms to optimize different process options for minimal environmenta...
The conventional drinking water treamtent processes of coagulation, flocculation, and filtration as well as specialized treatment processes have been examined for their capacity to remove endocrine disrupting chemicals (EDCs). A groupf od EDCs including 4-nonylphenol, diethylphth...
XML-based product information processing method for product design
NASA Astrophysics Data System (ADS)
Zhang, Zhen Yu
Design knowledge of modern mechatronics product is based on information processing as the center of the knowledge-intensive engineering, thus product design innovation is essentially the knowledge and information processing innovation. Analysis of the role of mechatronics product design knowledge and information management features, a unified model of XML-based product information processing method is proposed. Information processing model of product design includes functional knowledge, structural knowledge and their relationships. For the expression of product function element, product structure element, product mapping relationship between function and structure based on the XML model are proposed. The information processing of a parallel friction roller is given as an example, which demonstrates that this method is obviously helpful for knowledge-based design system and product innovation.
XML-based product information processing method for product design
NASA Astrophysics Data System (ADS)
Zhang, Zhen Yu
Design knowledge of modern mechatronics product is based on information processing as the center of the knowledge-intensive engineering, thus product design innovation is essentially the knowledge and information processing innovation. Analysis of the role of mechatronics product design knowledge and information management features, a unified model of XML-based product information processing method is proposed. Information processing model of product design includes functional knowledge, structural knowledge and their relationships. For the expression of product function element, product structure element, product mapping relationship between function and structure based on the XML model are proposed. The information processing of a parallel friction roller is given as an example, which demonstrates that this method is obviously helpful for knowledge-based design system and product innovation.
Research on chemical vapor deposition processes for advanced ceramic coatings
NASA Technical Reports Server (NTRS)
Rosner, Daniel E.
Our interdisciplinary background and fundamentally-oriented studies of the laws governing multi-component chemical vapor deposition (VD), particle deposition (PD), and their interactions, put the Yale University HTCRE Laboratory in a unique position to significantly advance the 'state-of-the-art' of chemical vapor deposition (CVD) R&D. With NASA-Lewis RC financial support, we initiated a program in March of 1988 that has led to the advances described in this report (Section 2) in predicting chemical vapor transport in high temperature systems relevant to the fabrication of refractory ceramic coatings for turbine engine components. This Final Report covers our principal results and activities for the total NASA grant of $190,000. over the 4.67 year period: 1 March 1988-1 November 1992. Since our methods and the technical details are contained in the publications listed (9 Abstracts are given as Appendices) our emphasis here is on broad conclusions/implications and administrative data, including personnel, talks, interactions with industry, and some known applications of our work.
Chemical Industry R&D Roadmap for Nanomaterials By Design. From Fundamentals to Function
Vision2020 agreed to join NNI and the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (DOE/EERE) in sponsoring the "Nanomaterials and the Chemical Industry Roadmap Workshop" on September 30-October 2, 2002. This roadmap, Chemical Industry R&D Roadmap for Nanomaterials By Design: From Fundamentals to Function, is based on the scientific priorities expressed by workshop participants from the chemical industry, universities, and government laboratories.
Laser processing with specially designed laser beam
NASA Astrophysics Data System (ADS)
Asratyan, A. A.; Bulychev, N. A.; Feofanov, I. N.; Kazaryan, M. A.; Krasovskii, V. I.; Lyabin, N. A.; Pogosyan, L. A.; Sachkov, V. I.; Zakharyan, R. A.
The possibility of using laser systems to form beams with special spatial configurations has been studied. The laser systems applied had a self-conjugate cavity based on the elements of copper vapor lasers (LT-5Cu, LT-10Cu, LT-30Cu) with an average power of 5, 10, or 30 W. The active elements were pumped by current pulses of duration 80-100 ns. The duration of laser generation pulses was up to 25 ns. The generator unit included an unstable cavity, where one reflector was a special mirror with a reflecting coating. Various original optical schemes used were capable of exploring spatial configurations and energy characteristics of output laser beams in their interaction with micro- and nanoparticles fabricated from various materials. In these experiments, the beam dimensions of the obtained zones varied from 0.3 to 5 µm, which is comparable with the minimum permissible dimensions determined by the optical elements applied. This method is useful in transforming a large amount of information at the laser pulse repetition rate of 10-30 kHz. It was possible to realize the high-precision micromachining and microfabrication of microscale details by direct writing, cutting and drilling (with the cutting width and through-hole diameters ranging from 3 to 100 µm) and produce microscale, deep, intricate and narrow grooves on substrate surfaces of metals and nonmetal materials. This system is used for producing high-quality microscale details without moving the object under treatment. It can also be used for microcutting and microdrilling in a variety of metals such as molybdenum, copper and stainless steel, with a thickness of up to 300 µm, and in nonmetals such as silicon, sapphire and diamond with a thickness ranging from 10 µm to 1 mm with different thermal parameters and specially designed laser beam.
Tools for efficient design of multicomponent separation processes
NASA Astrophysics Data System (ADS)
Huff, Joshua Lee
Separations account for as much as 85% of plant operating costs in chemical production; it is therefore important that they be designed with energy efficiency in mind. This can only be achieved if two things are achieved: the complete space of design options is known, and an accurate way is developed to compare all possible design options. For both membrane separation cascades and multicomponent distillation configurations, this dissertation explores methods for designing energy efficient separations. The operating cost of membranes used in production of nitrogen gas from air is largely driven by the compressors required to maintain a pressure differential. Optimization of the total compressor duty can reveal an ideal cascade arrangement and set of operating conditions for a given feed and recovery. With this optimization technique in hand, it is then possible to examine the effect of introducing extra stages to form intermediate stage cascades. Furthermore, the effect of varying the recovery of the nitrogen stream can be examined to discover a U-shaped relationship between recovery and energy requirement. Conventional distillation configurations use n -- 1 distillation columns to separate a multicomponent feed mixture into pure products. Past research has identified a way to quickly and algorithmically generate the complete ranklist of regular-column configurations using an integer programming formulation called the matrix method. Using this method, a formulation is here presented for the complete nonlinear programming problem which, for a given configuration, can ensure the globally minimum vapor duty of the configuration. Furthermore, a set of nonlinear equations designed to represent the capital and operating costs of the system are described. The need for a global optimization algorithm in the formulation of the cost product is demonstrated by comparison with a two-stage search algorithm; in addition, the cost formulation is compared to that of the vapor duty
Comprehensive Mass Analysis for Chemical Processes, a Case Study on L-Dopa Manufacture
To evaluate the "greenness" of chemical processes in route selection and process development, we propose a comprehensive mass analysis to inform the stakeholders from different fields. This is carried out by characterizing the mass intensity for each contributing chemical or wast...
Using a Readily Available Commercial Spreadsheet to Teach a Graduate Course on Chemical Process Simulation
ERIC Educational Resources Information Center
Clarke, Matthew A.; Giraldo, Carlos
Chemical process simulation is one of the most fundamental skills that is expected from chemical engineers, yet relatively few graduates have the opportunity to learn, in depth, how a process simulator works, from programming the unit operations to the sequencing. The University of Calgary offers a "hands-on" postgraduate course in…
Novel Photocatalysts and Processes for the Destruction of Chemical Warfare Agents (CWA)
1 NOVEL PHOTOCATALYSTS AND PROCESSES FOR THE DESTRUCTION OF CHEMICAL WARFARE AGENTS (CWA) Panagiotis G. Smirniotis Department of Chemical...Engineering, University of Cincinnati, Cincinnati, OH 45221-0171 ABSTRACT The present research project aims at developing novel photocatalysts ...reactors including "closed cycle" systems, photocatalysts , which operate with visible/solar radiation and finally use of novel processes such as
Defining process design space for monoclonal antibody cell culture.
Abu-Absi, Susan Fugett; Yang, LiYing; Thompson, Patrick; Jiang, Canping; Kandula, Sunitha; Schilling, Bernhard; Shukla, Abhinav A
The concept of design space has been taking root as a foundation of in-process control strategies for biopharmaceutical manufacturing processes. During mapping of the process design space, the multidimensional combination of operational variables is studied to quantify the impact on process performance in terms of productivity and product quality. An efficient methodology to map the design space for a monoclonal antibody cell culture process is described. A failure modes and effects analysis (FMEA) was used as the basis for the process characterization exercise. This was followed by an integrated study of the inoculum stage of the process which includes progressive shake flask and seed bioreactor steps. The operating conditions for the seed bioreactor were studied in an integrated fashion with the production bioreactor using a two stage design of experiments (DOE) methodology to enable optimization of operating conditions. A two level Resolution IV design was followed by a central composite design (CCD). These experiments enabled identification of the edge of failure and classification of the operational parameters as non-key, key or critical. In addition, the models generated from the data provide further insight into balancing productivity of the cell culture process with product quality considerations. Finally, process and product-related impurity clearance was evaluated by studies linking the upstream process with downstream purification. Production bioreactor parameters that directly influence antibody charge variants and glycosylation in CHO systems were identified.
Process-based design of dynamical biological systems
Tanevski, Jovan; Todorovski, Ljupčo; Džeroski, Sašo
The computational design of dynamical systems is an important emerging task in synthetic biology. Given desired properties of the behaviour of a dynamical system, the task of design is to build an in-silico model of a system whose simulated be- haviour meets these properties. We introduce a new, process-based, design methodology for addressing this task. The new methodology combines a flexible process-based formalism for specifying the space of candidate designs with multi-objective optimization approaches for selecting the most appropriate among these candidates. We demonstrate that the methodology is general enough to both formulate and solve tasks of designing deterministic and stochastic systems, successfully reproducing plausible designs reported in previous studies and proposing new designs that meet the design criteria, but have not been previously considered. PMID:27686219
Process-based design of dynamical biological systems
NASA Astrophysics Data System (ADS)
Tanevski, Jovan; Todorovski, Ljupčo; Džeroski, Sašo
The computational design of dynamical systems is an important emerging task in synthetic biology. Given desired properties of the behaviour of a dynamical system, the task of design is to build an in-silico model of a system whose simulated be- haviour meets these properties. We introduce a new, process-based, design methodology for addressing this task. The new methodology combines a flexible process-based formalism for specifying the space of candidate designs with multi-objective optimization approaches for selecting the most appropriate among these candidates. We demonstrate that the methodology is general enough to both formulate and solve tasks of designing deterministic and stochastic systems, successfully reproducing plausible designs reported in previous studies and proposing new designs that meet the design criteria, but have not been previously considered.
Implementation Plan for Chemical Industry R&D Roadmap for Nanomaterials by Design
The purpose of this effort is to develop an implementation plan to realize the vision and goals identified in the Chemical Industry R&D Roadmap for Nanomaterials By Design: From Fundamentals to Function.
Simplifying Chemical Reactor Design by using Molar Quantities Instead of Fractional Conversion.
ERIC Educational Resources Information Center
Brown, Lee F.; Falconer, John L.
Explains the advantages of using molar quantities in chemical reactor design. Advocates the use of differential versions of reactor mass balances rather than the integrated forms. Provides specific examples and cases to illustrate the principles. (ML)
Design criteria for extraction with chemical reaction and liquid membrane permeation
NASA Technical Reports Server (NTRS)
Bart, H. J.; Bauer, A.; Lorbach, D.; Marr, R.
The design criteria for heterogeneous chemical reactions in liquid/liquid systems formally correspond to those of classical physical extraction. More complex models are presented which describe the material exchange at the individual droplets in an extraction with chemical reaction and in liquid membrane permeation.
Strategic Considerations in the Design of a Screening System for Substructure Searches of Chemical Structure Files
ERIC Educational Resources Information Center
Adamson, George W.; And Others
A major problem in the design of screening systems for substructure searches of chemical structure files is the development of a methodology for selection of an optimal set of structural characteristics to act as screens. Distributions of several structural characteristics of the Chemical Abstracts Service Registry System are summarized. (13…
Peer Evaluation in Chemical Engineering Capstone Design via Wikis
ERIC Educational Resources Information Center
Heldt, Caryn L.
Inter-group peer evaluation through wikis was implemented as a method for senior capstone design teams to improve writing and the critical evaluation of data. Each group was evaluated by peers using a qualitative discussion and evaluated quantitatively by instructors. Students had an increased interest in contributing to online knowledge centers,…
Conceptual design for remote handling methods using the HIP process in the Calcine Immobilization Program
Berry, S.M.; Cox, C.G.; Hoover, M.A.
This report recommends the remote conceptual design philosophy for calcine immobilization using the hot isostatic press (HIP) process. Areas of remote handling operations discussed in this report include: (1) introducing the process can into the front end of the HIP process, (2) filling and compacting the calcine/frit mixture into the process can, (3) evacuating and sealing the process can, (4) non-destructive testing of the seal on the process can, (5) decontamination of the process can, (6) HIP furnace loading and unloading the process can for the HIPing operation, (7) loading an overpack canister with processed HIP cans, (8) sealing the canister, with associated non-destructive examination (NDE) and decontamination, and (9) handling canisters for interim storage at the Idaho Chemical Processing Plant (ICPP) located on the Idaho National Engineering Laboratory (INEL) site.
Perspectives on the design of safer nanomaterials and manufacturing processes
Geraci, Charles; Heidel, Donna; Sayes, Christie; Hodson, Laura; Schulte, Paul; Eastlake, Adrienne; Brenner, Sara
A concerted effort is being made to insert Prevention through Design principles into discussions of sustainability, occupational safety and health, and green chemistry related to nanotechnology. Prevention through Design is a set of principles that includes solutions to design out potential hazards in nanomanufacturing including the design of nanomaterials, and strategies to eliminate exposures and minimize risks that may be related to the manufacturing processes and equipment at various stages of the lifecycle of an engineered nanomaterial. PMID:26435688
Perspectives on the design of safer nanomaterials and manufacturing processes
NASA Astrophysics Data System (ADS)
Geraci, Charles; Heidel, Donna; Sayes, Christie; Hodson, Laura; Schulte, Paul; Eastlake, Adrienne; Brenner, Sara
A concerted effort is being made to insert Prevention through Design principles into discussions of sustainability, occupational safety and health, and green chemistry related to nanotechnology. Prevention through Design is a set of principles, which includes solutions to design out potential hazards in nanomanufacturing including the design of nanomaterials, and strategies to eliminate exposures and minimize risks that may be related to the manufacturing processes and equipment at various stages of the lifecycle of an engineered nanomaterial.
Presidential Green Chemistry Challenge: 1998 Designing Greener Chemicals Award
Presidential Green Chemistry Challenge 1998 award winner, Rohm and Haas, developed CONFIRM, a highly selective, reduced risk insecticide that disrupts the molting process of caterpillar pests in turf and a variety of crops.
Process Model Construction and Optimization Using Statistical Experimental Design,
Memo No. 88-442 ~LECTE March 1988 31988 %,.. MvAY 1 98 0) PROCESS MODEL CONSTRUCTION AND OPTIMIZATION USING STATISTICAL EXPERIMENTAL DESIGN Emmanuel...Sachs and George Prueger Abstract A methodology is presented for the construction of process models by the combination of physically based mechanistic...253-8138. .% I " Process Model Construction and Optimization Using Statistical Experimental Design" by Emanuel Sachs Assistant Professor and George
Design and Implementation of a Multimedia DBMS: Complex Query Processing
IMPLEMENTATION OF A MULTIMEDIA DBMS: COMPLEX QUERY PROCESSING by Huseyin Aygun September 1991 Thesis Advisor Vincent Y. Lum Approved for public release...type "trace in <function name>. 31 IV. DESIGN OF COMPLEX QUERY PROCESSING In Chapter II of this thesis the general architecture of the MDBMS...data to display. More detailed information about the modification can be found in the next chapter of this thesis . Because the design for the process
Model-based design space determination of peptide chromatographic purification processes.
Gétaz, David; Butté, Alessandro; Morbidelli, Massimo
Operating a chemical process at fixed operating conditions often leads to suboptimal process performances. It is important in fact to be able to vary the process operating conditions depending upon possible changes in feed composition, products requirements or economics. This flexibility in the manufacturing process was facilitated by the publication of the PAT initiative from the U.S. FDA [1]. In this work, the implementation of Quality-by-design in the development of a chromatographic purification process is discussed. A procedure to determine the design space of the process using chromatographic modeling is presented. Moreover, the risk of batch failure and the critical process parameters (CPP) are assessed by modeling. The ideal cut strategy is adopted and therefore only yield and productivity are considered as critical quality attributes (CQA). The general trends in CQA variations within the design space are discussed. The effect of process disturbances is also considered. It is shown that process disturbances significantly decrease the design space and that only simultaneous and specific changes in multiple process parameters (i.e. critical process parameters (CPP) lead to batch failure. The reliability of the obtained results is proven by comparing the model predictions to suitable experimental data. The case study presented in this work proves the reliability of process development using a model-based approach.
Defense Waste Processing Facility Simulant Chemical Processing Cell Studies for Sludge Batch 9
Smith, Tara E.; Newell, J. David; Woodham, Wesley H.
The Savannah River National Laboratory (SRNL) received a technical task request from Defense Waste Processing Facility (DWPF) and Saltstone Engineering to perform simulant tests to support the qualification of Sludge Batch 9 (SB9) and to develop the flowsheet for SB9 in the DWPF. These efforts pertained to the DWPF Chemical Process Cell (CPC). CPC experiments were performed using SB9 simulant (SB9A) to qualify SB9 for sludge-only and coupled processing using the nitric-formic flowsheet in the DWPF. Two simulant batches were prepared, one representing SB8 Tank 40H and another representing SB9 Tank 51H. The simulant used for SB9 qualification testing was prepared by blending the SB8 Tank 40H and SB9 Tank 51H simulants. The blended simulant is referred to as SB9A. Eleven CPC experiments were run with an acid stoichiometry ranging between 105% and 145% of the Koopman minimum acid equation (KMA), which is equivalent to 109.7% and 151.5% of the Hsu minimum acid factor. Three runs were performed in the 1L laboratory scale setup, whereas the remainder were in the 4L laboratory scale setup. Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles were performed on nine of the eleven. The other two were SRAT cycles only. One coupled flowsheet and one extended run were performed for SRAT and SME processing. Samples of the condensate, sludge, and off-gas were taken to monitor the chemistry of the CPC experiments.
Cognitive Design for Learning: Cognition and Emotion in the Design Process
ERIC Educational Resources Information Center
Hasebrook, Joachim
We are so used to accept new technologies being the driver of change and innovation in human computer interfaces (HCI). In our research we focus on the development of innovations as a design process--or design, for short. We also refer to the entire process of creating innovations and putting them to use as "cognitive processes"--or…
Chemical Changes in Proteins Produced by Thermal Processing.
ERIC Educational Resources Information Center
Dutson, T. R.; Orcutt, M. W.
Discusses effects of thermal processing on proteins, focusing on (1) the Maillard reaction; (2) heat denaturation of proteins; (3) aggregation, precipitation, gelation, and degradation; and (4) other thermally induced protein reactions. Also discusses effects of thermal processing on muscle foods, egg proteins, fruits and vegetables, and cereal…
21 CFR 570.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2014 CFR
... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES General Provisions § 570.19 Pesticide... processed food when ready to eat is higher than the tolerance prescribed for the raw agricultural commodity, the processed food is adulterated unless the higher concentration is permitted by a tolerance...
21 CFR 570.19 - Pesticide chemicals in processed foods.
Code of Federal Regulations, 2012 CFR
... (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES General Provisions § 570.19 Pesticide... processed food when ready to eat is higher than the tolerance prescribed for the raw agricultural commodity, the processed food is adulterated unless the higher concentration is permitted by a tolerance...
Evaluating two process scale chromatography column header designs using CFD.
Johnson, Chris; Natarajan, Venkatesh; Antoniou, Chris
Chromatography is an indispensable unit operation in the downstream processing of biomolecules. Scaling of chromatographic operations typically involves a significant increase in the column diameter. At this scale, the flow distribution within a packed bed could be severely affected by the distributor design in process scale columns. Different vendors offer process scale columns with varying design features. The effect of these design features on the flow distribution in packed beds and the resultant effect on column efficiency and cleanability needs to be properly understood in order to prevent unpleasant surprises on scale-up. Computational Fluid Dynamics (CFD) provides a cost-effective means to explore the effect of various distributor designs on process scale performance. In this work, we present a CFD tool that was developed and validated against experimental dye traces and tracer injections. Subsequently, the tool was employed to compare and contrast two commercially available header designs.
Ensuring competitive advantage with semantic design process management
Quazzani, A.; Bernard, A.; Bocquet, J.C.
In the field of design assistance, it is important to improve records of design history and management of design process. Indeed, we propose a modelling approach of design process that focuses on representation of semantic actions. We have identified two types of actions: physical design actions focusing on the product (e.g., parameter creation, shaft dimensioning) and management actions that allow management of the process from the planning and control viewpoint (e.g., synchronization actions, a resource allocation for a task). A taxonomy of these actions has been established according to several criteria (granularity, fields of action ... ) selected in consideration of our process management interests. Linkage with objective and rationale is also discussed.
Designing a process for executing projects under an international agreement
NASA Technical Reports Server (NTRS)
Mohan, S. N.
Projects executed under an international agreement require special arrangements in order to operate within confines of regulations issued by the State Department and the Commerce Department. In order to communicate enterprise-level guidance and procedural information uniformly to projects based on interpretations that carry the weight of institutional authority, a process was developed. This paper provides a script for designing processes in general, using this particular process for context. While the context is incidental, the method described is applicable to any process in general. The paper will expound on novel features utilized for dissemination of the procedural details over the Internet following such process design.
Reducing aquatic hazards of industrial chemicals: probabilistic assessment of sustainable molecular design guidelines.
Connors, Kristin A; Voutchkova-Kostal, Adelina M; Kostal, Jakub; Anastas, Paul; Zimmerman, Julie B; Brooks, Bryan W
Basic toxicological information is lacking for the majority of industrial chemicals. In addition to increasing empirical toxicity data through additional testing, prospective computational approaches to drug development aim to serve as a rational basis for the design of chemicals with reduced toxicity. Recent work has resulted in the derivation of a "rule of 2," wherein chemicals with an octanol-water partition coefficient (log P) less than 2 and a difference between the lowest unoccupied molecular orbital and the highest occupied molecular orbital (ΔE) greater than 9 (log P<2 and ΔE >9 eV) are predicted to be 4 to 5 times less likely to elicit acute or chronic toxicity to model aquatic organisms. The present study examines potential reduction of aquatic toxicity hazards from industrial chemicals if these 2 molecular design guidelines were employed. Probabilistic hazard assessment approaches were used to model the likelihood of encountering industrial chemicals exceeding toxicological categories of concern both with and without the rule of 2. Modeling predicted that utilization of these molecular design guidelines for log P and ΔE would appreciably decrease the number of chemicals that would be designated to be of "high" and "very high" concern for acute and chronic toxicity to standard model aquatic organisms and end points as defined by the US Environmental Protection Agency. For example, 14.5% of chemicals were categorized as having high and very high acute toxicity to the fathead minnow model, whereas only 3.3% of chemicals conforming to the design guidelines were predicted to be in these categories. Considerations of specific chemical classes (e.g., aldehydes), chemical attributes (e.g., ionization), and adverse outcome pathways in representative species (e.g., receptor-mediated responses) could be used to derive future property guidelines for broader classes of contaminants.
Sequential chemical-biological processes for the treatment of industrial wastewaters: review of recent progresses and critical assessment.
Guieysse, Benoit; Norvill, Zane N
When direct wastewater biological treatment is unfeasible, a cost- and resource-efficient alternative to direct chemical treatment consists of combining biological treatment with a chemical pre-treatment aiming to convert the hazardous pollutants into more biodegradable compounds. Whereas the principles and advantages of sequential treatment have been demonstrated for a broad range of pollutants and process configurations, recent progresses (2011-present) in the field provide the basis for refining assessment of feasibility, costs, and environmental impacts. This paper thus reviews recent real wastewater demonstrations at pilot and full scale as well as new process configurations. It also discusses new insights on the potential impacts of microbial community dynamics on process feasibility, design and operation. Finally, it sheds light on a critical issue that has not yet been properly addressed in the field: integration requires complex and tailored optimization and, of paramount importance to full-scale application, is sensitive to uncertainty and variability in the inputs used for process design and operation. Future research is therefore critically needed to improve process control and better assess the real potential of sequential chemical-biological processes for industrial wastewater treatment.
Alternative Processes for Water Reclamation and Solid Waste Processing in a Physical/chemical Bioregenerative Life Support System
NASA Technical Reports Server (NTRS)
Rogers, Tom D.
Viewgraphs on alternative processes for water reclamation and solid waste processing in a physical/chemical-bioregenerative life support system are presented. The main objective is to focus attention on emerging influences of secondary factors (i.e., waste composition, type and level of chemical contaminants, and effects of microorganisms, primarily bacteria) and to constructively address these issues by discussing approaches which attack them in a direct manner.
Context-Aware Design for Process Flexibility and Adaptation
ERIC Educational Resources Information Center
Yao, Wen
Today's organizations face continuous and unprecedented changes in their business environment. Traditional process design tools tend to be inflexible and can only support rigidly defined processes (e.g., order processing in the supply chain). This considerably restricts their real-world applications value, especially in the dynamic and…
Design, processing, and testing of LSI arrays for space station
NASA Technical Reports Server (NTRS)
Ipri, A. C.
The applicability of a particular process for the fabrication of large scale integrated circuits is described. Test arrays were designed, built, and tested, and then utilized. A set of optimum dimensions for LSI arrays was generated. The arrays were applied to yield improvement through process innovation, and additional applications were suggested in the areas of yield prediction, yield modeling, and process reliability.
Model-based optimal design of polymer-coated chemical sensors.
Phillips, Cynthia; Jakusch, Michael; Steiner, Hannes; Mizaikoff, Boris; Fedorov, Andrei G
A model-based methodology for optimal design of polymer-coated chemical sensors is developed and is illustrated for the example of infrared evanescent field chemical sensors. The methodology is based on rigorous and computationally efficient modeling of combined fluid mechanics and mass transfer, including transport of multiple analytes. A simple algebraic equation for the optimal size of the sensor flow cell is developed to guide sensor design and validated by extensive CFD simulations. Based upon these calculations, optimized geometries of the sensor flow cell are proposed to further improve the response time of chemical sensors.
The Idaho Chemical Processing Plant Product Denitrator Upgrade
The upgrade and redesign of a fluidized-bed denitrator for production of uranium trioxide from uranyl nitrate solution is discussed. The success of the project in improving process efficiency and personnel safety is also addressed based on subsequent operation.
Mathematical modeling of quartz particle melting process in plasma-chemical reactor
Volokitin, Oleg Volokitin, Gennady Skripnikova, Nelli Shekhovtsov, Valentin; Vlasov, Viktor
Among silica-based materials vitreous silica has a special place. The paper presents the melting process of a quartz particle under conditions of low-temperature plasma. A mathematical model is designed for stages of melting in the experimental plasma-chemical reactor. As calculation data show, quartz particles having the radius of 0.21≤ r{sub p} ≤0.64 mm completely melt at W = 0.65 l/s particle feed rate depending on the Nusselt number, while 0.14≤ r{sub p} ≤0.44 mm particles melt at W = 1.4 l/s. Calculation data showed that 2 mm and 0.4 mm quartz particles completely melted during and 0.1 s respectively. Thus, phase transformations occurred in silicon dioxide play the important part in its heating up to the melting temperature.
Biological monitoring of occupational exposure to toxic chemicals. Collection, processing, and storage of specimens
Aitio, A.; Jaervisalo, J.
Exposure to at least 100 different chemicals may be estimated on an individual basis from their concentrations in blood or urine. The present document reviews sources of error in the collection, processing and storage of specimens for this biological monitoring. Physiological factors cause variation in the concentration of chemicals in the body fluids. Distribution of water depends on posture. Exercise and meals cause changes in blood constituents. The urine output varies and, thus, the concentrations of dissolved chemicals change. Many toxic chemicals show short half times in the blood; thus, their concentrations depend on the timing of the specimen collection. Skin absorption may result in dramatically different chemical concentrations in different parts of the circulation. The stability of chemicals in the collected specimens is generally limited: chemical deterioration, adsorption, precipitation, and evaporation are the main causes of losses. For many chemicals, especially for trace elements, contamination of the specimen is the overwhelmingly most important source of error. As the range of the chemicals measured is wide, the relative importance of the sources of error is different for different chemicals. Information on most chemicals is at present very limited. Thus, before commencing a program on biological exposure monitoring, it is advisable to search the optimal conditions for specimen collection, processing, and storage.
Processes for converting biomass-derived feedstocks to chemicals and liquid fuels
Held, Andrew; Woods, Elizabeth; Cortright, Randy; Gray, Matthew
The present invention provides processes, methods, and systems for converting biomass-derived feedstocks to liquid fuels and chemicals. The method generally includes the reaction of a hydrolysate from a biomass deconstruction process with hydrogen and a catalyst to produce a reaction product comprising one of more oxygenated compounds. The process also includes reacting the reaction product with a condensation catalyst to produce C.sub.4+ compounds useful as fuels and chemicals.
Gorensek, M.; Summers, W.; Boltrunis, C.; Lahoda, E.; Allen, D.; Greyvenstein, R.
This report documents a detailed study to determine the expected efficiency and product costs for producing hydrogen via water-splitting using energy from an advanced nuclear reactor. It was determined that the overall efficiency from nuclear heat to hydrogen is high, and the cost of hydrogen is competitive under a high energy cost scenario. It would require over 40% more nuclear energy to generate an equivalent amount of hydrogen using conventional water-cooled nuclear reactors combined with water electrolysis compared to the proposed plant design described herein. There is a great deal of interest worldwide in reducing dependence on fossil fuels, while also minimizing the impact of the energy sector on global climate change. One potential opportunity to contribute to this effort is to replace the use of fossil fuels for hydrogen production by the use of water-splitting powered by nuclear energy. Hydrogen production is required for fertilizer (e.g. ammonia) production, oil refining, synfuels production, and other important industrial applications. It is typically produced by reacting natural gas, naphtha or coal with steam, which consumes significant amounts of energy and produces carbon dioxide as a byproduct. In the future, hydrogen could also be used as a transportation fuel, replacing petroleum. New processes are being developed that would permit hydrogen to be produced from water using only heat or a combination of heat and electricity produced by advanced, high temperature nuclear reactors. The U.S. Department of Energy (DOE) is developing these processes under a program known as the Nuclear Hydrogen Initiative (NHI). The Republic of South Africa (RSA) also is interested in developing advanced high temperature nuclear reactors and related chemical processes that could produce hydrogen fuel via water-splitting. This report focuses on the analysis of a nuclear hydrogen production system that combines the Pebble Bed Modular Reactor (PBMR), under development by
A Biophysicochemical Model for NO Removal by the Chemical Absorption-Biological Reduction Integrated Process.
Zhao, Jingkai; Xia, Yinfeng; Li, Meifang; Li, Sujing; Li, Wei; Zhang, Shihan
The chemical absorption-biological reduction (CABR) integrated process is regarded as a promising technology for NOx removal from flue gas. To advance the scale-up of the CABR process, a mathematic model based on mass transfer with reaction in the gas, liquid, and biofilm was developed to simulate and predict the NOx removal by the CABR system in a biotrickling filter. The developed model was validated by the experimental results and subsequently was used to predict the system performance under different operating conditions, such as NO and O2 concentration and gas and liquid flow rate. NO distribution in the gas phase along the biotrickling filter was also modeled and predicted. On the basis of the modeling results, the liquid flow rate and total iron concentration were optimized to achieve >90% NO removal efficiency. Furthermore, sensitivity analysis of the model revealed that the performance of the CABR process was controlled by the bioreduction activity of Fe(III)EDTA. This work will provide the guideline for the design and operation of the CABR process in the industrial application.
Diamond-coated fiber Bragg grating through the hot filament chemical vapor process for chemical durability improvement.
Alberto, Nélia; José Kalinowski, Hypolito; Neto, Victor; Nogueira, Rogério
In recent years, the coating of fiber Bragg gratings (FBGs) with a specific material has opened up the possibility to broaden the limits of applicability of this technology. Diamond has a set of properties that makes it an attractive candidate to protect the optical fiber against chemically harsh environments, whose sensing is also a great challenge. One of the most used techniques to obtain these coatings is through the hot filament chemical vapor deposition (HFCVD); in this process, the temperature reaches, typically, around 850°C-900°C. In this work, the regeneration of a seed FBG during its coating with a nanocrystalline diamond thin film through the HFCVD process is presented. Simultaneously, the thermal monitoring of the process was also performed using the same grating. The resistance test in a corrosive medium reveals an improvement on the durability of the sensing properties of the diamond-coated FBG compared with an uncoated FBG, foreseeing a vast range of applications.
Integrating rock mechanics issues with repository design through design process principles and methodology
Bieniawski, Z.T.
A good designer needs not only knowledge for designing (technical know-how that is used to generate alternative design solutions) but also must have knowledge about designing (appropriate principles and systematic methodology to follow). Concepts such as {open_quotes}design for manufacture{close_quotes} or {open_quotes}concurrent engineering{close_quotes} are widely used in the industry. In the field of rock engineering, only limited attention has been paid to the design process because design of structures in rock masses presents unique challenges to the designers as a result of the uncertainties inherent in characterization of geologic media. However, a stage has now been reached where we are be able to sufficiently characterize rock masses for engineering purposes and identify the rock mechanics issues involved but are still lacking engineering design principles and methodology to maximize our design performance. This paper discusses the principles and methodology of the engineering design process directed to integrating site characterization activities with design, construction and performance of an underground repository. Using the latest information from the Yucca Mountain Project on geology, rock mechanics and starter tunnel design, the current lack of integration is pointed out and it is shown how rock mechanics issues can be effectively interwoven with repository design through a systematic design process methodology leading to improved repository performance. In essence, the design process is seen as the use of design principles within an integrating design methodology, leading to innovative problem solving. In particular, a new concept of {open_quotes}Design for Constructibility and Performance{close_quotes} is introduced. This is discussed with respect to ten rock mechanics issues identified for repository design and performance.
Fuel ethanol production: process design trends and integration opportunities.
Cardona, Carlos A; Sánchez, Oscar J
Current fuel ethanol research and development deals with process engineering trends for improving biotechnological production of ethanol. In this work, the key role that process design plays during the development of cost-effective technologies is recognized through the analysis of major trends in process synthesis, modeling, simulation and optimization related to ethanol production. Main directions in techno-economical evaluation of fuel ethanol processes are described as well as some prospecting configurations. The most promising alternatives for compensating ethanol production costs by the generation of valuable co-products are analyzed. Opportunities for integration of fuel ethanol production processes and their implications are underlined. Main ways of process intensification through reaction-reaction, reaction-separation and separation-separation processes are analyzed in the case of bioethanol production. Some examples of energy integration during ethanol production are also highlighted. Finally, some concluding considerations on current and future research tendencies in fuel ethanol production regarding process design and integration are presented.
Processing tungsten single crystal by chemical vapor deposition
NASA Astrophysics Data System (ADS)
Xiao, Zhigang; Zee, Ralph H.; Begg, Lester L.
A tungsten single crystal layer has been fabricated on molybdenum single crystal substrate through the hydrogen (H2) reduction of the tungsten hexafluoride (WF6) in low pressure. Substrate temperature, reaction chamber pressure, and flow rate of WF6 and H2, are critical process parameters during deposition. A comprehensive analysis for the effects of these parameters on single crystal layer growth has been processed and optimized growth conditions have been achieved. The different orientation of the substrate shows the different deposition rate for tungsten. Low index plane has higher deposition rate than high index plane. The kinetics of the deposition process has also been investigated. SEM surface analysis indicates that the single crystal layer is smooth in macro-scale and rough and step-growth format in micro-scale. .
Lunar missions using chemical propulsion: System design issues
NASA Technical Reports Server (NTRS)
Palaszewski, Bryan
To transport lunar base elements to the Moon, large high-energy propulsion systems will be required. Advanced propulsion systems for lunar missions can significantly reduce launch mass and increase the delivered payload, resulting in significant launch cost savings. In this report, the masses in low Earth orbit (LEO) are compared for several propulsion systems: nitrogen tetroxide/monomethyl hydrazine (NTO/MMH), oxygen/methane (O2/CH4), oxygen/hydrogen (O2/H2), and metallized O2/H2/Al propellants. Also addressed are payload mass increases enabled with these systems; system design issues involving the engine thrust levels, engine commonality between the transfer vehicle and the excursion vehicle; the number of launches to place the lunar mission vehicles into LEO; and analyses of small lunar missions launched from a single Space Transportation System-Cargo (STS-C) flight.
First principle chemical kinetics in zeolites: the methanol-to-olefin process as a case study.
Van Speybroeck, Veronique; De Wispelaere, Kristof; Van der Mynsbrugge, Jeroen; Vandichel, Matthias; Hemelsoet, Karen; Waroquier, Michel
To optimally design next generation catalysts a thorough understanding of the chemical phenomena at the molecular scale is a prerequisite. Apart from qualitative knowledge on the reaction mechanism, it is also essential to be able to predict accurate rate constants. Molecular modeling has become a ubiquitous tool within the field of heterogeneous catalysis. Herein, we review current computational procedures to determine chemical kinetics from first principles, thus by using no experimental input and by modeling the catalyst and reacting species at the molecular level. Therefore, we use the methanol-to-olefin (MTO) process as a case study to illustrate the various theoretical concepts. This process is a showcase example where rational design of the catalyst was for a long time performed on the basis of trial and error, due to insufficient knowledge of the mechanism. For theoreticians the MTO process is particularly challenging as the catalyst has an inherent supramolecular nature, for which not only the Brønsted acidic site is important but also organic species, trapped in the zeolite pores, must be essentially present during active catalyst operation. All these aspects give rise to specific challenges for theoretical modeling. It is shown that present computational techniques have matured to a level where accurate enthalpy barriers and rate constants can be predicted for reactions occurring at a single active site. The comparison with experimental data such as apparent kinetic data for well-defined elementary reactions has become feasible as current computational techniques also allow predicting adsorption enthalpies with reasonable accuracy. Real catalysts are truly heterogeneous in a space- and time-like manner. Future theory developments should focus on extending our view towards phenomena occurring at longer length and time scales and integrating information from various scales towards a unified understanding of the catalyst. Within this respect molecular
Reload design process at Yankee Atomic Electric Company
Weader, R.J.
Yankee Atomic Electric Company (YAEC) performs reload design and licensing for their nuclear power plants: Yankee Rowe, Maine Yankee, and Vermont Yankee. Significant savings in labor and computer costs have been achieved in the reload design process by the use of the SIMULATE nodal code using the CASMO assembly burnup code or LEOPARD pin cell burnup code inputs to replace the PDQ diffusion theory code in many required calculations for the Yankee Rowe and Maine Yankee pressurized water reactors (PWRs). An efficient process has evolved for the design of reloads for the Vermont Yankee boiling water reactor (BWR). Due to the major differences in the core design of the three plants, different reload design processes have evolved for each plant.
A review of laser machining of composites and the chemical by-product formed by such processes
NASA Astrophysics Data System (ADS)
Doyle, Daryl J.
The laser-cutting of polymers and polymer-based composites is reviewed with emphasis placed on the chemical by-products formed by such processes. It has been reported that toxic and potentially carcinogenic materials are formed; therefore, appropriate control measures need to be incorporated into the engineering design of laser-cutting facilities to maintain air quality of the workplace within the guidelines established by governmental regulatory agencies.
Case study: Lockheed-Georgia Company integrated design process
NASA Technical Reports Server (NTRS)
Waldrop, C. T.
A case study of the development of an Integrated Design Process is presented. The approach taken in preparing for the development of an integrated design process includes some of the IPAD approaches such as developing a Design Process Model, cataloging Technical Program Elements (TPE's), and examining data characteristics and interfaces between contiguous TPE's. The implementation plan is based on an incremental development of capabilities over a period of time with each step directed toward, and consistent with, the final architecture of a total integrated system. Because of time schedules and different computer hardware, this system will not be the same as the final IPAD release; however, many IPAD concepts will no doubt prove applicable as the best approach. Full advantage will be taken of the IPAD development experience. A scenario that could be typical for many companies, even outside the aerospace industry, in developing an integrated design process for an IPAD-type environment is represented.
Evaluation of multiple objectives is very important in designing environmentally benign processes. It requires a systematic procedure for solving multiobjective decision-making problems, due to the complex nature of the problems, the need for complex assessments, and complicated ...
Semantic Service Design for Collaborative Business Processes in Internetworked Enterprises
NASA Astrophysics Data System (ADS)
Bianchini, Devis; Cappiello, Cinzia; de Antonellis, Valeria; Pernici, Barbara
Modern collaborating enterprises can be seen as borderless organizations whose processes are dynamically transformed and integrated with the ones of their partners (Internetworked Enterprises, IE), thus enabling the design of collaborative business processes. The adoption of Semantic Web and service-oriented technologies for implementing collaboration in such distributed and heterogeneous environments promises significant benefits. IE can model their own processes independently by using the Software as a Service paradigm (SaaS). Each enterprise maintains a catalog of available services and these can be shared across IE and reused to build up complex collaborative processes. Moreover, each enterprise can adopt its own terminology and concepts to describe business processes and component services. This brings requirements to manage semantic heterogeneity in process descriptions which are distributed across different enterprise systems. To enable effective service-based collaboration, IEs have to standardize their process descriptions and model them through component services using the same approach and principles. For enabling collaborative business processes across IE, services should be designed following an homogeneous approach, possibly maintaining a uniform level of granularity. In the paper we propose an ontology-based semantic modeling approach apt to enrich and reconcile semantics of process descriptions to facilitate process knowledge management and to enable semantic service design (by discovery, reuse and integration of process elements/constructs). The approach brings together Semantic Web technologies, techniques in process modeling, ontology building and semantic matching in order to provide a comprehensive semantic modeling framework.
Functionalized sorbent for chemical separations and sequential forming process
Fryxell, Glen E [Kennewick, WA; Zemanian, Thomas S [Richland, WA
A highly functionalized sorbent and sequential process for making are disclosed. The sorbent includes organic short-length amino silanes and organic oligomeric polyfunctional amino silanes that are dispersed within pores of a porous support that form a 3-dimensional structure containing highly functionalized active binding sites for sorption of analytes.
Influence of process parameters on the surface and chemical properties of activated carbon obtained from biochar by chemical activation.
Angın, Dilek; Altintig, Esra; Köse, Tijen Ennil
Activated carbons were produced from biochar obtained through pyrolysis of safflower seed press cake by chemical activation with zinc chloride. The influences of process variables such as the activation temperature and the impregnation ratio on textural and chemical-surface properties of the activated carbons were investigated. Also, the adsorptive properties of activated carbons were tested using methylene blue dye as the targeted adsorbate. The experimental data indicated that the adsorption isotherms are well described by the Langmuir equilibrium isotherm equation. The optimum conditions resulted in activated carbon with a monolayer adsorption capacity of 128.21 mg g(-1) and carbon content 76.29%, while the BET surface area and total pore volume corresponded to 801.5m(2)g(-1) and 0.393 cm(3)g(-1), respectively. This study demonstrated that high surface area activated carbons can be prepared from the chemical activation of biochar with zinc chloride as activating agents.
Microlithographic wet chemical processing in a capillary space
NASA Astrophysics Data System (ADS)
Morgan, Russell
The patented device and procedure described provide a method of processing the flat, thin-film coated surfaces encountered in the ultraclean manufacture of integrated circuit wafers, photomasks, panel displays or other similar substrates. The device provides a means of delivering liquids and vapors to those surfaces while temperature, evaporation and particulate contamination are controlled as a natural consequent of its physical configuration. The essential mechanism exploits the surface tension of liquids and the differences in the wettability of surfaces. By juxtaposing the target surface with a prepared surface on the processing device and maintaining a separation of a few millimeters, the gap formed provides a reaction space into which liquids are easily distributed exploiting so-called capillary behavior. While placing the liquid reagent on the hydrophobic, horizontal surface of the processor, the hydrophilic substrate surface suspended above it is transported laterally. The substrate surface then engages the liquid edge which, driven by its own surface tension, quickly fills the gap. The ending of the reaction and removal of the liquid is effected by further transporting the substrate with its captive liquid reactants to a trench provided in the processor surface where the liquid flows down and away. Thus, the processor surface is seen as a series of 'mesas' allowing a sequence of wet process, rinse and vapor treatments, all with the simple lateral movement of the substrate. The effects of improved reaction kinetics on process precision as well as the benefits mentioned above are discussed and compared to previous immersion and spin methods. Critical dimension measurement data are presented from large photomask substrates processed by the instrument.
Radical formation, chemical processing, and explosion of interstellar grains
NASA Technical Reports Server (NTRS)
Greenberg, J. M.
The ultraviolet radiation in interstellar space is shown to create a sufficient steady-state density of free radicals in the grain mantle material consisting of oxygen, carbon, nitrogen, and hydrogen to satisfy the critical condition for initiation of chain reactions. The criterion for minimum critical particle size for maintaining the chain reaction is of the order of the larger grain sizes in a distribution satisfying the average extinction and polarization measures. The triggering of the explosion of interstellar grains leading to the ejection of complex interstellar molecules is shown to be most probable where the grains are largest and where radiation is suddenly introduced; i.e., in regions of new star formation. Similar conditions prevail at the boundaries between very dark clouds and H II regions. When the energy released by the chemical activity of the free radicals is inadequate to explode the grain, the resulting mantle material must consist of extremely large organic molecules which are much more resistant to the hostile environment of H II regions than the classical dirty-ice mantles made up of water, methane, and ammonia.
Development of the chemical and electrochemical coal cleaning process
NASA Astrophysics Data System (ADS)
Basilio, C. I.; Yoon, Roe-Hoan
The continuous testing of the Chemical and Electrochemical Coal Cleaning (CECC) was completed successfully using Middle Wyodak and Elkhorn No. 3 coal samples. The CECC unit was run under the optimum conditions established for these coal samples. For the Middle Wyodak coal, the ash content was reduced from 6.96 percent to as low 1.61 percent, corresponding to an ash rejection (by weight) of about 83 percent. The ash and sulfur contents of the Elkhorn No. 3 coal were reduced to as low as 1.8 percent and 0.9 percent. The average ash and sulfur rejections were calculated to be around 84 percent and 47 percent. The CECC continuous unit was used to treat -325 mesh Elkhorn No. 3 coal samples and gave ash and sulfur rejection values of as high as 77 percent and 66 percent. In these test, the clean -325 mesh coal particles were separated from the liberated mineral matter through microbubble column flotation, instead of wet-screening.
Rates of reaction and process design data for the Hydrocarb Process
Steinberg, M.; Kobayashi, Atsushi ); Tung, Yuanki )
In support of studies for developing the coprocessing of fossil fuels with biomass by the Hydrocarb Process, experimental and process design data are reported. The experimental work includes the hydropryolysis of biomass and the thermal decomposition of methane in a tubular reactor. The rates of reaction and conversion were obtained at temperature and pressure conditions pertaining to a Hydrocarb Process design. A Process Simulation Computer Model was used to design the process and obtain complete energy and mass balances. Multiple feedstocks including biomass with natural gas and biomass with coal were evaluated. Additional feedstocks including green waste, sewage sludge and digester gas were also evaluated for a pilot plant unit.
An investigation of radiometer design using digital processing techniques
NASA Technical Reports Server (NTRS)
Lawrence, R. W.
The use of digital signal processing techniques in Dicke switching radiometer design was investigated. The general approach was to develop an analytical model of the existing analog radiometer and identify factors which adversly affect its performance. A digital processor was then proposed to verify the feasibility of using digital techniques to minimize these adverse effects and improve the radiometer performance. Analysis and preliminary test results comparing the digital and analog processing approaches in radiometers design were analyzed.
Forced chemical vapor infiltration of tubular geometries: Modeling, design, and scale-up
Stinton, D.P.; Besmann, T.M.; Matlin, W.M.
In advanced indirectly fired coal combustion systems and externally fired combined cycle concepts, ceramic heat exchangers are required to transfer heat from the hot combustion gases to the clean air that drives the gas turbines. For high efficiencies, the temperature of the turbine inlet needs to exceed 1100{degrees}C and preferably be about 1260{degrees}C. The heat exchangers will operate under pressure and experience thermal and mechanical stresses during heating and cooling, and some transients will be severe under upset conditions. Silicon carbide-matrix composites are promising for such applications because of their high strength at elevated temperature, light weight, thermal and mechanical resistance, damage tolerance, and oxidation and corrosion resistance. Fiber-reinforced composite tubes of several fiber architectures were fabricated by forced chemical vapor infiltration (FCVI) and characterized. Unfortunately, long times ({approximately}150 hours) were required to thoroughly density the tubes. An objective of the current investigation was to optimize the forced CVI process so that composite tubes could be fabricated in much shorter times. To aid in such optimization, a computer code which models the CVI process was used to identify critical process parameters. Finally, successful demonstration of the utility of composite tubes for these applications will require the testing of near-full scale components. As a result a new infiltration system was designed and constructed to prepare 10-cm diameter tubes, and is described in this report.
Design of a New Type of Compact Chemical Heater for Isothermal Nucleic Acid Amplification
Shah, Kamal G.; Guelig, Dylan; Diesburg, Steven; Buser, Joshua; Burton, Robert; LaBarre, Paul; Richards-Kortum, Rebecca; Weigl, Bernhard
Previous chemical heater designs for isothermal nucleic acid amplification have been based on solid-liquid phase transition, but using this approach, developers have identified design challenges en route to developing a low-cost, disposable device. Here, we demonstrate the feasibility of a new heater configuration suitable for isothermal amplification in which one reactant of an exothermic reaction is a liquid-gas phase-change material, thereby eliminating the need for a separate phase-change compartment. This design offers potentially enhanced performance and energy density compared to other chemical and electric heaters. PMID:26430883
Designing School Accountability Systems: Towards a Framework and Process.
ERIC Educational Resources Information Center
Gong, Brian
This document presents three different views of accountability to address state needs as their departments of education design, improve, or review their state accountability and reporting systems. The first of three sections presents the system-design decision process as a linear sequence of ten steps from defining the purposes of the…
Risk Informed Design as Part of the Systems Engineering Process
NASA Technical Reports Server (NTRS)
Deckert, George
This slide presentation reviews the importance of Risk Informed Design (RID) as an important feature of the systems engineering process. RID is based on the principle that risk is a design commodity such as mass, volume, cost or power. It also reviews Probabilistic Risk Assessment (PRA) as it is used in the product life cycle in the development of NASA's Constellation Program.