text: Chemical and Bioprocess Engineering Research Collection http://hdl.handle.net/10197/2709 2015-04-02T07:56:57Z 2015-04-02T07:56:57Z Understanding particle deposition kinetics on NF membranes: A focus on micro-beads & membrane interactions at different environmental conditions Cao, H. Habimana, Olivier Correia-Semião, Andrea Joana C. Allen, Ashley Heffernan, Rory Casey, Eoin http://hdl.handle.net/10197/6360 2015-02-19T10:05:15Z 2015-02-01T00:00:00Z Understanding particle deposition kinetics on NF membranes: A focus on micro-beads & membrane interactions at different environmental conditions Cao, H.; Habimana, Olivier; Correia-Semião, Andrea Joana C.; Allen, Ashley; Heffernan, Rory; Casey, Eoin The significance of nanofiltration membrane surface properties when interacting with microbeads with and without permeate flux was investigated. This was achieved by characterising the surface tension and zeta potential of micro-beads and NF90 membranes to determine the colloid–membrane interaction forces. Dynamic adhesion assays under different ionic strengths (0.1 M and 0.01 M) and pH (5, 7, and 9) were conducted. Experimental results showed that at high ionic strength, pH does not have a significant effect on adhesion rates, while at low ionic strength the adhesion rate increased at pH 7 (4.56 s−1 cm−2) compared to pH 5 and pH 9, with rates of 2.69 and 3.66 s−1 cm−2 respectively. A model was devised to predict colloidal adhesion onto membranes under increasing permeate flux conditions, taking into account all interaction forces. Model predictions indicate that drag force overwhelms all other colloid–membrane interaction forces when the permeate flux increases to 7.2 L h−1 m−2. This study suggests that altering membrane surface properties for the prevention of fouling may be limited in its success as an antifouling strategy. 2015-02-01T00:00:00Z Characterisitics of Streptomyces griseus biofilms in continuous flow tubular reactors Winn, Michael Habimana, Olivier Casey, Eoin Murphy, Cormac D. http://hdl.handle.net/10197/6341 2015-02-05T12:27:40Z 2014-03-01T00:00:00Z Characterisitics of Streptomyces griseus biofilms in continuous flow tubular reactors Winn, Michael; Habimana, Olivier; Casey, Eoin; Murphy, Cormac D. The purpose of this study was to investigate the feasibility of cultivating the biotechnologically important bacterium Streptomyces griseus in single-species and mixed- species biofilms using a Tubular Biofilm Reactor (TBR). Streptomyces griseus biofilm development was found to be cyclical, starting with the initial adhesion and subsequent development of a visible biofilm after 24 hours growth, followed by the complete detachment of the biofilm as a single mass, and ending with the re-colonization of the tube. Fluorescence microscopy revealed that the filamentous structure of the biofilm was lost upon treatment with protease, but not DNase or metaperiodate, indicating that the extracellular polymeric substance is predominantly protein. When the biofilm was cultivated in conjunction with Bacillus amyloliquefaciens, no detachment was observed after 96 h, although once subjected to flow detachment occurred. Electron microscopy confirmed the presence of both bacteria in the biofilm and revealed a network of fimbriae-like structures that were much less apparent in single-species biofilm, and are likely to increase mechanical stability when developing in a TBR. This study presents the very first attempt in engineering Streptomyces griseus biofilms for continuous bioprocess applications. 2014-03-01T00:00:00Z Succinonitrile-based solid-state electrolytes for dye-sensitised solar cells Byrne, Owen Coughlan, Aoife Surolia, Praveen K. Thampi, Ravindranathan http://hdl.handle.net/10197/6152 2014-12-12T04:00:10Z 2013-12-12T00:00:00Z Succinonitrile-based solid-state electrolytes for dye-sensitised solar cells Byrne, Owen; Coughlan, Aoife; Surolia, Praveen K.; Thampi, Ravindranathan Succinonitrile (SCN), a solid ion conductor (10−4 to 10−3 S/cm) in solid form at room temperature, is mixed with either 1,2-dimethyl-3-propylimidazoliuum iodide or 1-butyl-3-methyl imidazolium iodide ionic liquids for forming a solid plastic phase electrolyte for use in dye-sensitised solar cell (DSSC). Cells containing these two electrolytes showed best energy conversion efficiencies of 6.3% and 5.6%, respectively. The commonly used DSSC electrolyte additives inhibit the formation of the SCN plastic phase. However, for the first time, an SCN-additive (additive = guanidinium thiocyanate) electrolyte composition is reported here, which remains as a solid at room temperatures. By using these new solid electrolytes, a simple and rapid single-step filling procedure for making solid-state DSSC is outlined. This process, which reduces the required manufacturing steps from four to one, is most suitable for continuous, high-throughput, commercial DSSC manufacturing lines. These new electrolytes have been tested under low incident light levels (200 lx) to investigate their suitability for indoor DSSC applications 2013-12-12T00:00:00Z Renewable energy technologies and its adaptation in an urban environment Thampi, Ravindranathan Byrne, Owen Surolia, Praveen K. http://hdl.handle.net/10197/6120 2014-11-07T10:07:17Z 2014-02-01T00:00:00Z Renewable energy technologies and its adaptation in an urban environment Thampi, Ravindranathan; Byrne, Owen; Surolia, Praveen K. This general article is based on the inaugural talk delivered at the opening of OMTAT 2013 conference. It notes that the integration of renewable energy sources into living and transport sectors presents a daunting task, still. In spite of the fact that the earth and its atmosphere continually receive 1.7 × 1017 watts of radiation from the sun, in the portfolio of sustainable and environment friendly energy options, which is about 16% of the world's energy consumption and mostly met by biomass, only a paltry 0.04% is accredited to solar. First and second generation solar cells offer mature technologies for applications. The most important difficulty with regards to integration with structures is not only the additional cost, but also the lack of sufficient knowledge in managing the available energy smartly and efficiently. The incorporation of PV as a part of building fabric greatly reduces the overall costs compared with retrofitting. BIPV (Building Integrated photovoltaic) is a critical technology for establishing aesthetically pleasing solar structures. Infusing PV and building elements is greatly simplified with some of the second generation thin film technologies now manufactured as flexible panels. The same holds true for 3rd generation technologies under development such as, and dye- and quantum dot- sensitized solar cells . Additionally, these technologies offer transparent or translucent solar cells for incorporation into windows and skylights. This review deals with the present state of solar cell technologies suitable for BIPV and the status of BIPV applications and its future prospects. Optoelectronic Materials and Thin Films: OMTAT 2013. Kochi, Kerala, India, 3–5 January 2013 2014-02-01T00:00:00Z The optimisation of dye sensitised solar cell working electrodes for graphene and SWCNTs containing quasi-solid state electrolytes Byrne, Owen Ahmad, Iftikhar Surolia, Praveen K. Thampi, Ravindranathan et al. http://hdl.handle.net/10197/6108 2014-10-22T14:27:37Z 2014-12-01T00:00:00Z The optimisation of dye sensitised solar cell working electrodes for graphene and SWCNTs containing quasi-solid state electrolytes Byrne, Owen; Ahmad, Iftikhar; Surolia, Praveen K.; Thampi, Ravindranathan; et al. In this study, we report improved power conversion efficiencies of various carbon based quasi-solid state electrolytes/DSSCs by optimising the thickness of TiO2 layer, incorporation of TiO2 scattering layer and application of dense compact surface layers of TiO2 on working electrodes. Single wall carbon nanotube (SWCNT) based quasi-solid state electrolytes showed increased power conversion efficiencies from 1.43% to 3.49%. For the mixture of graphene and SWCNTs the power conversion efficiencies improved from 2.50% to 2.93%. However, graphene based quasi-solid state electrolytes displayed small decreases in power conversion efficiencies from 2.10% to 1.96% due to the more viscous nature of this electrolyte. Electrochemical Impedance Spectroscopy (EIS) demonstrated that the addition of these various carbon based nanomaterials into PMII significantly decreases the charge transfer resistance at the counter electrode and hence the much better performance obtained with carbon based quasi-solid state electrolytes compared to pure PMII based DSSCs. 2014-12-01T00:00:00Z A physical impact of organic fouling layers on bacterial adhesion during nanofiltration Heffernan, R. Habimana, Olivier Correia-Semião, Andrea Joana C. Cao, H. Safari, Ashkan Casey, Eoin http://hdl.handle.net/10197/6048 2014-10-15T09:18:38Z 2014-12-15T00:00:00Z A physical impact of organic fouling layers on bacterial adhesion during nanofiltration Heffernan, R.; Habimana, Olivier; Correia-Semião, Andrea Joana C.; Cao, H.; Safari, Ashkan; Casey, Eoin Organic conditioning films have been shown to alter properties of surfaces, such as hydrophobicity and surface free energy. Furthermore, initial bacterial adhesion has been shown to depend on the conditioning film surface properties as opposed to the properties of the virgin surface. For the particular case of nanofiltration membranes under permeate flux conditions, however, the conditioning film thickens to form a thin fouling layer. This study hence sought to determine if a thin fouling layer deposited on a nanofiltration membrane under permeate flux conditions governed bacterial adhesion in the same manner as a conditioning film on a surface. Thin fouling layers (less than 50 μm thick) of humic acid or alginic acid were formed on Dow Filmtec NF90 membranes and analysed using Atomic Force Microscopy (AFM), confocal microscopy and surface energy techniques. Fluorescent microscopy was then used to quantify adhesion of Pseudomonas fluorescens bacterial cells onto virgin or fouled membranes under filtration conditions.It was found that instead of adhering on or into the organic fouling layer, the bacterial cells penetrated the thin fouling layer and adhered directly to the membrane surface underneath. Contrary to what surface energy measurements of the fouling layer would indicate, bacteria adhered to a greater extent onto clean membranes (24 ± 3% surface coverage) than onto those fouled with humic acid (9.8 ± 4%) or alginic acid (7.5 ± 4%). These results were confirmed by AFM measurements which indicated that a considerable amount of energy (10−7 J/μm) was dissipated when attempting to penetrate the fouling layers compared to adhering onto clean NF90 membranes (10−15 J/μm). The added resistance of this fouling layer was thusly seen to reduce the number of bacterial cells which could reach the membrane surface under permeate conditions. This research has highlighted an important difference between fouling layers for the particular case of nanofiltration membranes under permeate flux conditions and surface conditioning films which should be considered when conducting adhesion experiments under filtration conditions. It has also shown AFM to be an integral tool for such experiments. 2014-12-15T00:00:00Z Biofilm Development in a Membrane Aerated Biofilm Reactor: Effect of Flow Velocity on Performance Casey, Eoin Glennon, Brian Hamer, G. http://hdl.handle.net/10197/6010 2014-10-06T12:04:56Z 2000-02-20T00:00:00Z Biofilm Development in a Membrane Aerated Biofilm Reactor: Effect of Flow Velocity on Performance Casey, Eoin; Glennon, Brian; Hamer, G. The effect of liquid flow velocity on biofilm development in a membrane-aerated biofilm reactor was investigated both by mathematical modeling and by experiment, using Vibrio natriegens as a test organism and acetate as carbon substrate. It was shown that velocity influenced mass transfer in the diffusion boundary layer, the biomass detachment rate from the biofilm, and the maximum biofilm thickness attained. Values of the overall mass transfer coefficient of a tracer through the diffusion boundary layer, the biofilm, and the membrane were shown to be identical during different experiments at the maximum biofilm thickness. Comparison of the results with published values of this parameter in membrane attached biofilms showed a similar trend. Therefore, it was postulated that this result might indicate the mechanism that determines the maximum biofilm thickness in membrane attached biofilms. In a series of experiments, where conditions were set so that the active layer of the membrane attached biofilm was located close to the membrane biofilm interface, it was shown that the most critical effect on process performance was the effect of velocity on biofilm structure. Biofilm thickness and effective diffusivity influenced reaction and diffusion in a complex manner such that the yield of biomass on acetate was highly variable. Consideration of endogenous respiration in the mathematical model was validated by direct experimental measurements of yield coefficients. Good agreement between experimental measurements of acetate and oxygen uptake rates and their prediction by the mathematical model was achieved. 2000-02-20T00:00:00Z The significance of calcium ions on Pseudomonas fluorescens biofilms – a structural and mechanical study Safari, Ashkan Habimana, Olivier Allen, Ashley Casey, Eoin http://hdl.handle.net/10197/5972 2014-09-30T16:02:25Z 2014-08-13T00:00:00Z The significance of calcium ions on Pseudomonas fluorescens biofilms – a structural and mechanical study Safari, Ashkan; Habimana, Olivier; Allen, Ashley; Casey, Eoin The purpose of this study was to investigate the effects of calcium ions on the structural and mechanical properties of Pseudomonas fluorescens biofilms grown for 48 h. Advanced investigative techniques such as confocal laser scanning microscopy and atomic force spectroscopy were employed to characterize biofilm structure as well as biofilm mechanical properties following growth at different calcium concentrations. The presence of calcium during biofilm development led to higher surface coverage with distinct structural phenotypes in the form of a granular and heterogeneous surface, compared with the smoother and homogeneous biofilm surface in the absence of calcium. The presence of calcium also increased the adhesive nature of the biofilm, while reducing its elastic properties. These results suggest that calcium ions could have a functional role in biofilm development and have practical implications, for example, in analysis of biofouling in membrane-based water-treatment processes such as nanofiltration or reverse osmosis where elevated calcium concentrations may occur at the solid–liquid interface. 2014-08-13T00:00:00Z Upon impact: the fate of adhering Pseudomonas fluorescens cells during Nanofiltration Habimana, Olivier Correia-Semião, Andrea Joana C. Casey, Eoin http://hdl.handle.net/10197/5888 2014-09-24T07:42:19Z 2014-07-29T00:00:00Z Upon impact: the fate of adhering Pseudomonas fluorescens cells during Nanofiltration Habimana, Olivier; Correia-Semião, Andrea Joana C.; Casey, Eoin Nanofiltration (NF) is a high-pressure membrane filtration process increasingly applied in drinking water treatment and water reuse processes. NF typically rejects divalent salts, organic matter, and micropollutants. However, the efficiency of NF is adversely affected by membrane biofouling, during which microorganisms adhere to the membrane and proliferate to create a biofilm. Here we show that adhered Pseudomonas fluorescens cells under high permeate flux conditions are met with high fluid shear and convective fluxes at the membrane-liquid interface, resulting in their structural damage and collapse. These results were confirmed by fluorescent staining, flow cytometry, and scanning electron microscopy. This present study offers a 'first-glimpse' of cell damage and death during the initial phases of bacterial adhesion to NF membranes and raises a key question about the role of this observed phenomena during early-stage biofilm formation under permeate flux and cross-flow conditions. 2014-07-29T00:00:00Z Bacterial adhesion onto nanofiltration and reverse osmosis membranes: Effect of permeate flux Correia-Semião, Andrea Joana C. Habimana, Olivier Casey, Eoin http://hdl.handle.net/10197/5880 2014-09-23T07:28:38Z 2014-10-15T00:00:00Z Bacterial adhesion onto nanofiltration and reverse osmosis membranes: Effect of permeate flux Correia-Semião, Andrea Joana C.; Habimana, Olivier; Casey, Eoin The influence of permeate flux on bacterial adhesion to NF and RO membranes was examined using two model Pseudomonas species, namely Pseudomonas fluorescens and Pseudomonas putida. To better understand the initial biofouling profile during NF/RO processes, deposition experiments were conducted in cross flow under permeate flux varying from 0.5 up to 120 L/(h m2), using six NF and RO membranes each having different surface properties. All experiments were performed at a Reynolds number of 579. Complementary adhesion experiments were performed using Pseudomonas cells grown to early-, mid- and late-exponential growth phases to evaluate the effect of bacterial cell surface properties during cell adhesion under permeate flux conditions. Results from this study show that initial bacterial adhesion is strongly dependent on the permeate flux conditions, where increased adhesion was obtained with increased permeate flux, until a maximum of 40% coverage was reached. Membrane surface properties or bacterial growth stages was further found to have little impact on bacterial adhesion to NF and RO membrane surfaces under the conditions tested. These results emphasise the importance of conducting adhesion and biofouling experiments under realistic permeate flux conditions, and raises questions about the efficacy of the methods for the evaluation of antifouling membranes in which bacterial adhesion is commonly assessed under zero-flux or low flux conditions, unrepresentative of full-scale NF/RO processes. 2014-10-15T00:00:00Z Photo-active and dynamical properties of hematite (Fe2O3)-water interfaces: An experimental and theoretical study English, Niall J. Rahman, Mahfujur Wadnerkar, Nitin MacElroy, J. M. Don http://hdl.handle.net/10197/5395 2015-02-14T04:00:12Z 2014-02-01T00:00:00Z Photo-active and dynamical properties of hematite (Fe2O3)-water interfaces: An experimental and theoretical study English, Niall J.; Rahman, Mahfujur; Wadnerkar, Nitin; MacElroy, J. M. Don The dynamical properties of physically and chemically adsorbed water molecules at pristine hematite-(001) surfaces have been studied by means of equilibrium Born–Oppenheimer molecular dynamics (BOMD) in the NVT ensemble at 298 K. The dissociation of water molecules to form chemically adsorbed species was scrutinised, in addition to 'hopping' or swapping events of protons between water molecules. Particular foci have been dynamical properties of the adsorbed water molecules and OH− and H3O+ ions, the hydrogen bonds between protons in water molecules and the bridging oxygen atoms at the hematite surface, as well as the interactions between oxygen atoms in adsorbed water molecules and iron atoms at the hematite surface. Experimental results for photoelectrical current generation complement simulation findings of water dissociation. 2014-02-01T00:00:00Z Towards the design of novel boron- and nitrogen-substituted ammonia-borane and bifunctional arene ruthenium catalysts for hydrogen storage Bandaru, Sateesh English, Niall J. Phillips, Andrew D. MacElroy, J. M. Don http://hdl.handle.net/10197/5381 2015-02-05T04:00:08Z 2014-02-05T00:00:00Z Towards the design of novel boron- and nitrogen-substituted ammonia-borane and bifunctional arene ruthenium catalysts for hydrogen storage Bandaru, Sateesh; English, Niall J.; Phillips, Andrew D.; MacElroy, J. M. Don Electronic-structure density functional theory calculations have been performed to construct the potential energy surface for H2 release from ammonia-borane, with a novel bifunctional cationic ruthenium catalyst based on the sterically bulky β-diketiminato ligand (Schreiber et al., ACS Catal. 2012, 2, 2505). The focus is on identifying both a suitable substitution pattern for ammonia-borane optimized for chemical hydrogen storage and allowing for low-energy dehydrogenation. The interaction of ammonia-borane, and related substituted ammonia-boranes, with a bifunctional η6-arene ruthenium catalyst and associated variants is investigated for dehydrogenation. Interestingly, in a number of cases, hydride-proton transfer from the substituted ammonia-borane to the catalyst undergoes a barrier-less process in the gas phase, with rapid formation of hydrogenated catalyst in the gas phase. Amongst the catalysts considered, N,N-difluoro ammonia-borane and N-phenyl ammonia-borane systems resulted in negative activation energy barriers. However, these types of ammonia-boranes are inherently thermodynamically unstable and undergo barrierless decay in the gas phase. Apart from N,N-difluoro ammonia-borane, the interaction between different types of catalyst and ammonia borane was modeled in the solvent phase, revealing free-energy barriers slightly higher than those in the gas phase. Amongst the various potential candidate Ru-complexes screened, few are found to differ in terms of efficiency for the dehydrogenation (rate-limiting) step. To model dehydrogenation more accurately, a selection of explicit protic solvent molecules was considered, with the goal of lowering energy barriers for H-H recombination. It was found that primary (1°), 2°, and 3° alcohols are the most suitable to enhance reaction rate. © 2014 Wiley Periodicals, Inc. 2014-02-05T00:00:00Z Diffusive hydrogen inter-cage migration in hydrogen and hydrogen-tetrahydrofuran clathrate hydrates Cao, H. English, Niall J. MacElroy, J. M. Don http://hdl.handle.net/10197/5234 2014-01-14T09:32:58Z 2013-03-07T00:00:00Z Diffusive hydrogen inter-cage migration in hydrogen and hydrogen-tetrahydrofuran clathrate hydrates Cao, H.; English, Niall J.; MacElroy, J. M. Don Classical equilibrium molecular dynamics (MD) simulations have been performed to investigate the diffusive properties of inter-cage hydrogen migration in both pure hydrogen and mixed hydrogen-tetrahydrofuran sII hydrates at 0.05 kbar from 200 K and up to 250-260 K. For mixed H2- THF systems in which there is single H2 occupation of the small cage (labelled '1SC 1LC'), we found that no H2 migration occurs. However, for more densely-filled H2-THF and pure- H2 systems, in which there is more than single H2 occupation in the small cage, there is an onset of inter-cage H2 migration events from the small cages to neighbouring cavities at around 200 K. The mean square displacements of the hydrogen molecules were fitted to a mathematical model consisting of an anomalous term and a Fickian component, and non-linear regression fitting was conducted to estimate long-time (inter-cage) diffusivities. An approximate Arrhenius temperature relationship for the diffusion coefficient was examined and a rough estimation of the hydrogen hopping energy barrier was calculated for each system. 2013-03-07T00:00:00Z The influence of Ti and Si doping on the structure, morphology and photo-response properties of α-Fe2O3 for efficient water splitting: experiment and first-principle calculations Rahman, Mahfujur Wadnerkar, Nitin English, Niall J. MacElroy, J. M. Don http://hdl.handle.net/10197/5226 2014-01-13T12:56:45Z 2014-01-30T00:00:00Z The influence of Ti and Si doping on the structure, morphology and photo-response properties of α-Fe2O3 for efficient water splitting: experiment and first-principle calculations Rahman, Mahfujur; Wadnerkar, Nitin; English, Niall J.; MacElroy, J. M. Don Ti- and Si- doping effects on morphology, structure, optical and photo-response of α-Fe2O3 nanoscale coatings from atmospheric-pressure chemical vapour deposition (APCVD) have been studied. Si- and Ti-doping led to larger clusters with finer grains and smaller clusters with larger grains, respectively. Photocurrent performance was increased remarkably by doping, especially Si. Excellent agreement was found for band gaps and optical properties compared to hybrid-Density Functional Theory. Substitutional replacement of Fe by Si shrinks the volume more than Ti-doping; it is conjectured that this affects hopping probability of localised charge-carriers more and leads to enhanced photocurrent activity for Si-doping, supported by experiment. 2014-01-30T00:00:00Z Implicit and explicit solvent models for modelling a bifunctional arene ruthenium hydrogen-storage catalyst: a classical and ab initio molecular simulation study Bandaru, Sateesh English, Niall J. MacElroy, J. M. Don http://hdl.handle.net/10197/5214 2014-07-28T11:34:14Z 2014-04-01T00:00:00Z Implicit and explicit solvent models for modelling a bifunctional arene ruthenium hydrogen-storage catalyst: a classical and ab initio molecular simulation study Bandaru, Sateesh; English, Niall J.; MacElroy, J. M. Don Classical and ab initio, density functional theory- and semiempirical-based molecular simulation, including molecular dynamics, have been carried out to compare and contrast the effect of explicit and implicit solvation representation of tetrahydrofuran (THF) solvent on the structural, energetic, and dynamical properties of a novel bifunctional arene ruthenium catalyst embedded therein. Particular scrutiny was afforded to hydrogen-bonding and energetic interactions with the THF liquid. It was found that the presence of explicit THF solvent molecules is required to capture an accurate picture of the catalyst's structural properties, particularly in view of the importance of hydrogen bonding with the surrounding THF molecules. This has implications for accurate modeling of the reactivity of the catalyst. 2014-04-01T00:00:00Z The role of cell-surface interactions in bacterial initial adhesion and consequent biofilm formation on nanofiltration/reverse osmosis membranes Habimana, Olivier Correia-Semião, Andrea Joana C. Casey, Eoin http://hdl.handle.net/10197/5212 2014-09-23T07:25:18Z 2014-03-15T00:00:00Z The role of cell-surface interactions in bacterial initial adhesion and consequent biofilm formation on nanofiltration/reverse osmosis membranes Habimana, Olivier; Correia-Semião, Andrea Joana C.; Casey, Eoin Until recently, the realization that membrane biofouling during nanofiltration (NF) and reverse osmosis (RO) processes is an unavoidable occurrence, has led to a paradigm shift in which biofouling management approaches rather than biofouling prevention are now being considered. To implement this new concept, it is crucial to understand the fundamentals of cell-surface interactions during bacterial adhesion, a prerequisite to biofouling of membranes. As such, with membrane biofouling already being widely studied and documented, greater attention should be given to the factors involved in the initial bioadhesion onto membranes during NF/RO processes. This review focuses on the interactions between bacterial cells and NF/RO membranes, emphasizing the mechanisms of bacterial adhesion to NF/RO membranes with particular reference to the effects of micro-environmental conditions experienced at the membrane interface, such as feed-water composition, hydrodynamics, permeate flux and conditioning layers. This review also discusses membrane surface properties and how it relates to bacterial adhesion as well as latest advancements in antibacterial membranes, identifying areas that need further investigation. 2014-03-15T00:00:00Z A fluid-structure interaction study of biofilm detachment Safari, Ashkan Ivankovic, Alojz Tuković, Zeljko et al. http://hdl.handle.net/10197/4594 2014-07-31T08:30:48Z 2009-07-01T00:00:00Z A fluid-structure interaction study of biofilm detachment Safari, Ashkan; Ivankovic, Alojz; Tuković, Zeljko; et al. During the biofilm development process, bacterial cells may detach from the biofilm into the surrounding fluid. The key question in relation to detachment from bacterial biofilm is the mechanical response to hydrodynamic forces. In this study, a Finite Volume Method (FVM) based Fluid-Structure Interaction (FSI) solver in OpenFOAM package has been developed to model the biofilm response to flow [1]. Dynamic interaction was simulated between an incompressible Newtonian fluid and a bacterial biofilm described as a linear viscoelastic solid. Viscoelastic response of the biofilm was represented by the hereditary integral form of constitutive relation [2] while tensile relaxation modulus was expressed by the Generalised Maxwell Model (GMM) in the form of Prony series (a discrete retardation spectrum). GMM was obtained from the rheometry creep experimental data using a three-step method proposed by Dooling et al. [3]. The creep curves were all viscoelastic in nature and approximated by a linear viscoelastic model represented by Generalised Voigt Model (GVM). Elastic shear modulus (G), obtained from the three-step method, ranged from 583Pa to 1368Pa which were similar to the previous rheometry studies. In this two-dimensional model, biofilm was considered as semi-semispherical shape (thickness of 100μm and width of 346μm) attached to the center of the bottom boundary of the square cross-section flow cell. Fluid flow through the flow cell was in laminar regime. Simulation results predicted the potential site for biofilm detachment subjected to increasing fluid flow rate through the flow cell. Computational and Mathematical Biomedical Engineering (CMBE09) 2009-07-01T00:00:00Z Disinfection of a polyamide nanofiltration membrane using ethanol Heffernan, R. Correia-Semião, Andrea Joana C. Desmond, P. Cao, H. Safari, Ashkan Habimana, Olivier Casey, Eoin http://hdl.handle.net/10197/4556 2014-09-23T07:24:47Z 2013-12-15T00:00:00Z Disinfection of a polyamide nanofiltration membrane using ethanol Heffernan, R.; Correia-Semião, Andrea Joana C.; Desmond, P.; Cao, H.; Safari, Ashkan; Habimana, Olivier; Casey, Eoin It is imperative that nanofiltration membranes are disinfected before they are used for laboratory-scale bacterial adhesion or biofouling experiments, yet currently no suitable disinfection protocol exists. This study aimed to determine if an ethanol treatment at a minimum inhibitory concentration (MIC) could be used to effectively disinfect nanofiltration membranes without altering membrane properties which could affect research. Two strains of bacteria, Pseudomonas fluorescens and Staphylococcus sp., were exposed to a range of ethanol concentrations to determine the MIC required for a 4log10 reduction in bacteria. In parallel, ethanol's effects on the filtration, surface and mechanical properties of a Dow Filmtec NF90 membrane were analysed. A 1.5 hour treatment with 40% ethanol was shown to effectively disinfect the membrane without significantly affecting any of the membranes properties tested. This treatment protocol can now be safely used to disinfect the studied membrane prior to bacterial adhesion or biofouling experiments. This study also acts as a guideline for researchers using other membranes to determine a suitable disinfection protocol for their needs. 2013-12-15T00:00:00Z Simulation studies of process scale membrane aerated biofilm reactor configurations Casey, Eoin http://hdl.handle.net/10197/4455 2013-07-18T11:22:02Z 2007-01-01T00:00:00Z Simulation studies of process scale membrane aerated biofilm reactor configurations Casey, Eoin In the membrane aerated biofilm reactor oxygen diffuses through the membrane into the biofilm where oxidation of pollutants, supplied from the biofilm side of the membrane takes place. Despite numerous studies at the laboratory scale showing the potential of the technology, efforts to scale-up the technology to process scale have been hampered by problems such as excessive biofilm growth and consequent flow distribution problems. This paper presents results of simulation studies which utilise Computational Fluid Dynamics (CFD) to examine performance of several technical scale MABR design configurations. The simulations suggest that plate-and-frame membrane configuration with a suitable liquid inlet distributor will deliver superior performance compared to hollow fibre configuration with respect to liquid flow distribution. 4th International Water Association Membranes Conference, Harrogate, UK, January, 2007 2007-01-01T00:00:00Z Detachment characteristics of a mixed culture biofilm using particle size analysis Walter, Maik Safari, Ashkan Ivankovic, Alojz Casey, Eoin http://hdl.handle.net/10197/4370 2014-04-25T13:41:50Z 2013-07-15T00:00:00Z Detachment characteristics of a mixed culture biofilm using particle size analysis Walter, Maik; Safari, Ashkan; Ivankovic, Alojz; Casey, Eoin Detachment is a critically important aspect of biofilm processes; it impacts not only on the characteristics of the biofilm itself but also has general implications for the dissemination of pathogenic bacteria and the operation of biofilm reactors. The mechanisms of biofilm detachment are of fundamental importance in the analysis of biofilm processes. However the complexity of biofilm detachment creates difficulties in performing and analyzing experiments. It is necessary to identify if, under steady conditions, biofilms experiments are reproducible with respect to detachment. In this study mixed culture biofilms were cultivated under low shear conditions over four days in glass flow cells in triplicate under non-recirculation conditions. Detached particles were regularly sampled, were stained, filtered and analyzed using a fluorescence microscope to establish size distributions of detached cells and cell clumps. This study has shown that, despite the existence of a complex particle size distribution, reproducibility is possible in four day old mixed culture biofilms. This has important implications for the study of active or passive detachment in biofilm systems. This study also distinguished between erosion and sloughing following step increases in shear stress. 2013-07-15T00:00:00Z The importance of laboratory water quality for studying initial bacterial adhesion during NF filtration processes Correia-Semião, Andrea Joana C. Habimana, Olivier Cao, H. Heffernan, R. Safari, Ashkan Casey, Eoin http://hdl.handle.net/10197/4309 2014-09-23T07:25:59Z 2013-05-15T00:00:00Z The importance of laboratory water quality for studying initial bacterial adhesion during NF filtration processes Correia-Semião, Andrea Joana C.; Habimana, Olivier; Cao, H.; Heffernan, R.; Safari, Ashkan; Casey, Eoin Biofouling of nanofiltration (NF) and reverse osmosis (RO) membranes for water treatment has been the subject of increased research effort in recent years. A prerequisite for undertaking fundamental experimental investigation on NF and RO processes is a procedure called compaction. This involves an initial phase of clean water permeation at high pressures until a stable permeate flux is reached. However water quality used during the compaction process may vary from one laboratory to another. The aim of this study was to investigate the impact of laboratory water quality during compaction of NF membranes. A second objective was to investigate if the water quality used during compaction influences initial bacterial adhesion. Experiments were undertaken with NF270 membranes at 15 bar for permeate volumes of 0.5L, 2L, and 5L using MilliQ, deionized or tap water. Membrane autopsies were performed at each permeation point for membrane surface characterisation by contact angle measurements, profilometry, and scanning electron microscopy. The biological content of compacted membranes was assessed by direct epi-fluorescence observation following nucleic acid staining. The compacted membranes were also employed as substrata for monitoring the initial adhesion of Ps. fluorescens under dynamic flow conditions for 30 minutes at 5 minutes intervals. Compared to MilliQ water, membrane compaction using deionized and tap water led to decreases in permeate flux, increase in surface hydrophobicity and led to significant buildup of a homogenous fouling layer composed of both living and dead organisms (>10⁶cells.cm−2). Subsequent measurements of bacterial adhesion resulted in cell loadings of 0.2×10⁵, 1.0×10⁵cells×cm−2 and 2.6×10⁵ cells.cm−2 for deionized, tap water and MilliQ water, respectively. These differences in initial cell adhesion rates demonstrate that choice of laboratory water can significantly impact the results of bacterial adhesion on NF membranes. Standardized protocols are therefore needed for the fundamental studies of bacterial adhesion and biofouling formation on NF and RO membrane. This can be implemented by first employing pure water during all membrane compaction proceduresand for the modelled feed solutions used in the experiment. 2013-05-15T00:00:00Z Functional Assessment for Predicting Charge-Transfer Excitations of Dyes in Complexed State: A Study of Triphenylamine-Donor Dyes on Titania for Dye-Sensitized Solar Cells Dev, Pratibha Agrawal, Saurabh English, Niall J. http://hdl.handle.net/10197/4299 2014-07-30T08:42:07Z 2012-12-13T00:00:00Z Functional Assessment for Predicting Charge-Transfer Excitations of Dyes in Complexed State: A Study of Triphenylamine-Donor Dyes on Titania for Dye-Sensitized Solar Cells Dev, Pratibha; Agrawal, Saurabh; English, Niall J. Time-dependent density functional theory (TD-DFT) was employed to calculate the UV/vis spectra for three of the triphenylamine (TPA)-donor dyes, TC1, L1, and LJ1, in isolation as well as when complexed with a titania nanoparticle. TPA-donor dyes are a class of promising organic dyes for use in dye-sensitized solar cells (DSSCs). The three dyes studied here are among the smallest of these molecules and provide important insight into the entire series of TPA dyes that are being explored as possible sensitizers in titania-based DSSCs. An attempt to calculate the optical spectra for these dyes within the B3LYP approximation to the exchange correlation functional produces erroneous results. However, Coulomb attenuated approximation (CAM-B3LYP) captures the correct photophysics of the dyes and produces more accurate charge-transfer excitation energies of their complexes with titania. This work shows that the extent to which a given approximation fails or succeeds to correctly predict the charge-transfer excitation energies in the isolated dyes is propagated in that it fails (or succeeds) to correctly predict the values of the excitation energies for the complexes. It is, therefore, important to determine the most appropriate functional for a dye before considering it in more complicated structures such as dye-titania complexes. 2012-12-13T00:00:00Z Comparative studies for evaluation of CO2 fixation in the cavity of the Rubisco enzyme using QM, QM/MM and linear-scaling DFT methods El-Hendawy, Morad M. English, Niall J. Mooney, Damian A. http://hdl.handle.net/10197/4297 2014-04-04T15:41:16Z 2013-06-01T00:00:00Z Comparative studies for evaluation of CO2 fixation in the cavity of the Rubisco enzyme using QM, QM/MM and linear-scaling DFT methods El-Hendawy, Morad M.; English, Niall J.; Mooney, Damian A. We evaluate the minimum energy configuration (MM) and binding free energy (QM/MM and QM) of CO2 to Rubisco, of fundamental importance to the carboxylation step of the reaction. Two structural motifs have been used to achieve this goal, one of which starts from the initial X-ray Protein Data Bank structure of Rubisco's active centre (671 atoms), and the other is a simplified, smaller model (77 atoms) which has been used most successfully, thus far, for study. The small model is subjected to quantum chemical density functional theory (DFT) studies, both in vacuo and using implicit solvation. The effects of the protein environment are also included by means of a hybrid quantum mechanical/molecular mechanical (QM/MM) approach, using PM6/AMBER and B3LYP/AMBER schemes. Finally, linear-scaling DFT methods have also been applied to evaluate energetic features of the large motif, and the result obtained for the binding free energy of the CO2 underlines the importance of the accurate modelling of the surrounding protein milieu using a full DFT description. 2013-06-01T00:00:00Z Comparative economic analysis of full scale MABR configurations Casey, Eoin Syron, Eoin Shanahan, John W. Semmens, Michael J. http://hdl.handle.net/10197/4263 2013-04-18T16:47:45Z 2008-08-01T00:00:00Z Comparative economic analysis of full scale MABR configurations Casey, Eoin; Syron, Eoin; Shanahan, John W.; Semmens, Michael J. The membrane-aerated biofilm reactor (MABR) is a technology that can deliver oxygen at high rates and transfer efficiencies. This paper provides a comparative cost analysis of the MABR compared to the activated sludge process. Membrane cost and electricity cost were found to be the critical parameters determining the relative feasibility of the conventional process to the membrane based process. The general downward trend in the market price of membranes and the steady increase in energy costs in recent years may prove to be a strong driver for the further development of this technology. 2008 IWA North American Membrane Research Conference, University of Massachusetts, Amherst, USA, August 10-13, 2008 2008-08-01T00:00:00Z Dye sensitised solar cells with nickel oxide photocathodes prepared via scalable microwave sintering Gibson, Elizabeth A. Awais, Muhammad Dini, Danilo Dowling, Denis P. Pryce, Mary T. Vos, Johannes G. Boschloo, Gerrit Hagfeldt, Anders http://hdl.handle.net/10197/4200 2013-03-20T12:40:08Z 2012-12-06T00:00:00Z Dye sensitised solar cells with nickel oxide photocathodes prepared via scalable microwave sintering Gibson, Elizabeth A.; Awais, Muhammad; Dini, Danilo; Dowling, Denis P.; Pryce, Mary T.; Vos, Johannes G.; Boschloo, Gerrit; Hagfeldt, Anders Photoactive NiO electrodes for cathodic dye-sensitised solar cells (p-DSCs) have been prepared with thicknesses ranging between 0.4 and 3.0 mm by spray-depositing pre-formed NiO nanoparticles on fluorine-doped tin oxide (FTO) coated glass substrates. The larger thicknesses were obtained in sequential sintering steps using a conventional furnace (CS) and a newly developed rapid discharge sintering (RDS) method. The latter procedure is employed for the first time for the preparation of p-DSCs. In particular, RDS represents a scalable procedure that is based on microwave-assisted plasma formation that allows the production in series of mesoporous NiO electrodes with large surface areas for p-type cell photocathodes. RDS possesses the unique feature of transmitting heat from the bulk of the system towards its outer interfaces with controlled confinement of the heating zone. The use of RDS results in a drastic reduction of processing times with respect to other deposition methods that involve heating/calcination steps with associated reduced costs in terms of energy. P1-dye sensitized NiO electrodes obtained via the RDS procedure have been tested in DSC devices and their performances have been analysed and compared with those of cathodic DSCs derived from CS-deposited samples. The largest conversion efficiencies (0.12%) and incident photon-to-current conversion efficiencies, IPCEs (50%), were obtained with sintered NiO electrodes having thicknesses of B1.5–2.0 mm. In all the devices, the photogenerated holes in NiO live significantly longer (th B 1 s) than have previously been reported for P1-sensitized NiO photocathodes. In addition, P1-sensitised sintered electrodes give rise to relatively high photovoltages (up to 135 mV) when the triiodide–iodide redox couple is used. 2012-12-06T00:00:00Z Achieving enhanced DSSC performance by microwave plasma incorporation of carbon into TiO2 photoelectrodes Dang, Binh H.Q. MacElroy, J. M. Don Dowling, Denis P. http://hdl.handle.net/10197/4199 2014-01-15T09:04:21Z 2013-06-15T00:00:00Z Achieving enhanced DSSC performance by microwave plasma incorporation of carbon into TiO2 photoelectrodes Dang, Binh H.Q.; MacElroy, J. M. Don; Dowling, Denis P. The photoactivity of carbon-incorporated titanium dioxide (TiO2) has been widely reported. This study involves a novel approach to the incorporation of carbon into TiO2 through the use of microwave plasma processing. The process involved thermally treating printed TiO2 nanoparticle coatings in a microwave-induced argon-oxygen plasma containing low concentrations of methane. The resulting deposited carbon layer was characterized using XRD, XPS, Raman, UV–vis, ellipsometry, and optical profilometry. It was found that the methane gas was dissociated in the microwave plasma into its carbon species, which were then deposited as a nm-thick layer onto the TiO2 coatings, most likely in the form of graphite. The photovoltaic performances of both the TiO2 and the carbon-incorporated TiO2 were assessed through J-V and IPCE measurements of the N719-sensitized solar cells using the titania as their photoanodes. Up to a 72% improvement in the maximum power density (Pd-max) was observed for the carbon-incorporated TiO2 samples as compared to the TiO2, onto which no carbon was added. This improvement was found to be mainly associated with an increase in the short-circuit current density (Jsc), but independent from the open-circuit voltage (Voc), the filter factor (FF), and the level of dye adsorption. Possible contributory factors to the improved performance of the carbon-incorporated TiO2 were the enhanced electron conductivity and electron lifetime, both of which were elucidated through electrochemical impedance spectroscopy (EIS). When the surface layer was examined using XPS, the optimal carbon content on the TiO2 coating surface was found to be 8.4%, beyond which there was a reduction in the DSSC efficiency. 2013-06-15T00:00:00Z Spray deposited NiOx films on ITO substrates as photoactive electrodes for p-type dye-sensitized solar cells Awais, Muhammad Dowling, Denis P. Rahman, Mahfujur Vos, Johannes G. Decker, Franco Dini, Danilo http://hdl.handle.net/10197/4197 2014-02-02T04:00:15Z 2013-02-01T00:00:00Z Spray deposited NiOx films on ITO substrates as photoactive electrodes for p-type dye-sensitized solar cells Awais, Muhammad; Dowling, Denis P.; Rahman, Mahfujur; Vos, Johannes G.; Decker, Franco; Dini, Danilo Spray deposition followed by sintering of nickel oxide (NiO x ) nanoparticles (average diameter: 40 nm) has been chosen as method of deposition of mesoporous NiO x coatings onto indium tin oxide (ITO) substrates. This procedure allows the scalable preparation of NiO x samples with large surface area (~103 times the geometrical area) and its potential for applications such as electrocatalysis or electrochemical solar energy conversion, which require high electroactivity in confined systems. The potential of these NiO x films as semiconducting cathodes for dye-sensitized solar cell (DSC) purposes has been evaluated for 0.3–3-μm-thick films of NiO x sensitized with erythrosine B (ERY). The electrochemical processes involving the NiO x coatings in the pristine and sensitized states were examined and indicated surface confinement as demonstrated by the linear dependence of the current densities with the scan rate of the cyclic voltammetry. Cathodic polarization of NiO x on ITO can also lead to the irreversible reduction of the underlying ITO substrate because of the mesoporous nature of the sintered NiO x film that allows the shunting of ITO to the electrolyte. ITO-based reduction processes alter irreversibly the properties of charge transfer through the ITO/NiOx interface and limit the range of potential to NiO x coatings sintered for DSC purposes. 2013-02-01T00:00:00Z Evaluation of microwave plasma oxidation treatments for the fabrication of photoactive un-doped and carbon-doped TiO2 coatings Dang, Binh H.Q. Rahman, Mahfujur MacElroy, J. M. Don Dowling, Denis P. http://hdl.handle.net/10197/3744 2012-08-17T14:07:26Z 2012-05-25T00:00:00Z Evaluation of microwave plasma oxidation treatments for the fabrication of photoactive un-doped and carbon-doped TiO2 coatings Dang, Binh H.Q.; Rahman, Mahfujur; MacElroy, J. M. Don; Dowling, Denis P. The photoactivity of both un-doped and carbon-doped titanium dioxide (TiO2) coatings has been widely reported. In this paper, the use of a microwave plasma as a novel oxidation treatment for the fabrication of these coatings is evaluated. The photoactivity performance of the microwave plasma-formed coatings is benchmarked against those fabricated through air furnace oxidation as well as those deposited using reactive magnetron sputtering. The un-doped and carbon-doped TiO2 coatings were prepared respectively by microwave plasma-oxidizing titanium metal sheets and sputter deposited titanium carbide thin films. The resulting oxides were characterized using XPS, XRD, FEG-SEM, and optical profilometry. The oxide layer thicknesses achieved over the 15 to 45 minute oxidation times were in the range of 0.15 to 3.44 µm. These coatings were considerably thicker than those obtained by air furnace oxidation. The microwave plasma-formed oxides also exhibited significantly higher surface roughness values compared with the magnetron-sputtered coatings. The photoactivity performance of both un-doped and carbon-doped coatings was assessed using photocurrent density measurements. Comparing the un-doped TiO2 coatings, it was observed that those obtained using the microwave plasma oxidation route yielded photocurrent density measurements that were 4.3 times higher than the TiO2 coatings of the same thickness that were deposited by sputtering. The microwave plasma-oxidized titanium carbide coatings did not perform as well as the un-doped TiO2 probably due to the presence of un-oxidized carbide in the coatings, which reduced their photoactivity. 2012-05-25T00:00:00Z Mechanism of Atmospheric CO2 Fixation in the Cavities of a Dinuclear Cryptate El-Hendawy, Morad M. English, Niall J. Mooney, Damian A. http://hdl.handle.net/10197/3743 2013-05-29T10:58:11Z 2012-05-07T00:00:00Z Mechanism of Atmospheric CO2 Fixation in the Cavities of a Dinuclear Cryptate El-Hendawy, Morad M.; English, Niall J.; Mooney, Damian A. Using density functional theory (DFT) methods, we have investigated two possible mechanisms for atmospheric CO2 fixation in the cavity of the dinuclear zinc (II) octaazacryptate, and the subsequent reaction with methanol whereby this latter reaction transforms the (essentially) chemically inert CO2 into useful products. The first mechanism (I) was proposed by Chen et al. [Chem. Asian J. 2007, 2, 710], and involves the attachment of one CO2 molecule onto the hydroxyl-cryptate form, resulting in the formation of a bicarbonate-cryptate species and subsequent reaction with one methanol molecule. In addition, we suggest another mechanism that is initiated via the attachment of a methanol molecule onto one of the Zn-centres, yielding a methoxy-cryptate species. The product is used to activate a CO2 molecule and generate a methoxycarbonate-cryptate. The energy profiles of both mechanisms were determined and we conclude that, while both mechanisms are energetically feasible, free energy profiles suggest that the scheme proposed by Chen et al. is most likely. 2012-05-07T00:00:00Z Hydrogen bond dynamical properties of adsorbed liquid water monolayers with various TiO2 interfaces English, Niall J. Kavathekar, Ritwik S. MacElroy, J. M. Don http://hdl.handle.net/10197/3742 2013-05-29T10:34:02Z 2012-04-12T00:00:00Z Hydrogen bond dynamical properties of adsorbed liquid water monolayers with various TiO2 interfaces English, Niall J.; Kavathekar, Ritwik S.; MacElroy, J. M. Don Equilibrium classical molecular dynamics (MD) simulations have been performed to investigate the hydrogen bonding kinetics of water in contact with rutile-(110), rutile-(101), rutile-(100), and anatase-(101) surfaces at room temperature (300 K). It was observed that anatase-(101) exhibits the longest-lived hydrogen bonds in terms of overall persistence, followed closely by rutile-(110). The relaxation times, defined as the integral of the autocorrelation of the hydrogen bond persistence function, were also larger for these two cases, while decay of autocorrelation function was slower. The increased number and overall persistence of hydrogen bonds in the adsorbed water monolayers at these surfaces, particularly for anatase-(101), may serve to promote possible water photolysis activity thereon. 2012-04-12T00:00:00Z Dynamical cage behaviour and hydrogen migration in hydrogen and hydrogen-tetrahydrofuran clathrate hydrates Gorman, Paul D. English, Niall J. MacElroy, J. M. Don http://hdl.handle.net/10197/3625 2012-06-07T15:10:15Z 2012-01-24T00:00:00Z Dynamical cage behaviour and hydrogen migration in hydrogen and hydrogen-tetrahydrofuran clathrate hydrates Gorman, Paul D.; English, Niall J.; MacElroy, J. M. Don Classical equilibrium molecular dynamics(MD) simulations have been performed to investigate dynamical properties of cage radial breathing modes and intra- and inter-cage hydrogen migration in both pure hydrogen and mixed hydrogen-tetrahydrofuran sII hydrates at 0.05 kbar and up to 250K. For the mixed H2-THF system in which there is single H2 occupation of the small cage (labelled '1SC 1LC'), we find that no H2 migration occurs, and this is also the case for pure H2 hydrate with single small-cavity occupation and quadruple occupancy for large cages (dubbed '1SC 4LC'). However, for the more densely-filled H2-THF and pure- H2 systems, in which there is double H2 occupation in the small cage (dubbed '2SC 1LC' and '2SC 4LC', respectively), there is an onset of inter-cage H2 migration events from the small cages to neighbouring cavities at around 200 K, with an approximate Arrhenius temperature-dependence for the migration rate from 200 to 250 K. It was found that these 'cage hopping' events are facilitated by temporary openings of pentagonal small-cage faces with the relaxation and reformation of key stabilising hydrogen bonds during and following passage. The cages remain essentially intact up to 250 K, save for transient hydrogen bond weakening and reformation during and after inter-cage hydrogen diffusion events in the 200 to 250 K range. The 'breathing modes', or underlying frequencies governing the variation in the cavities' radii, exhibit a certain overlap with THF rattling motion in the case of large cavities, while a there is some overlap of small cages' radial breathing modes with lattice acoustic modes. 2012-01-24T00:00:00Z Mechanisms for thermal conduction in hydrogen hydrate English, Niall J. Gorman, Paul D. MacElroy, J. M. Don http://hdl.handle.net/10197/3495 2012-02-07T15:09:54Z 2012-01-23T00:00:00Z Mechanisms for thermal conduction in hydrogen hydrate English, Niall J.; Gorman, Paul D.; MacElroy, J. M. Don Extensive equilibrium molecular dynamics (MD) simulations have been performed to investigate thermal conduction mechanisms via the Green-Kubo approach for (type II) hydrogen hydrate, at 0.05 kbar and between 30 and 250 K, for both lightly-filled H2 hydrates (1s4l) and for more densely-filled H2 systems (2s4l), in which four H2 molecules are present in the large cavities, with respective single- and double-occupation of the small cages. The TIP4P water model was used in conjunction with a fully atomistic hydrogen potential along with long-range Ewald electrostatics. It was found that substantially less damping in guest-host energy transfer is present in hydrogen hydrate as is observed in common type I clathrates (e.g., methane hydrate), but more akin in to previous results for type II and H methane hydrate polymorphs. This gives rise to larger thermal conductivities relative to common type I hydrates, and also larger than type II and H methane hydrate polymorphs, and a more crystal-like temperature dependence of the thermal conductivity. 2012-01-23T00:00:00Z A TD-DFT study of the effects of structural variations on the photochemistry of polyene dyes Agrawal, Saurabh Dev, Pratibha English, Niall J. Thampi, Ravindranathan MacElroy, J. M. Don http://hdl.handle.net/10197/3438 2013-05-01T10:28:01Z 2011-10-06T00:00:00Z A TD-DFT study of the effects of structural variations on the photochemistry of polyene dyes Agrawal, Saurabh; Dev, Pratibha; English, Niall J.; Thampi, Ravindranathan; MacElroy, J. M. Don We report a TD-DFT study of three polyene dyes namely: NKX-2553, NKX-2554 and NKX-2569 in isolation as well as upon their adsorption on TiO2 nanoparticles. By choosing closely related dyes we wish to focus on the effects of structural variations on the absorption and charge-transfer properties of these systems. These three dyes show a non-intuitive trend in their respective efficiencies and therefore, were chosen to shed light on the structural components that contribute to this behaviour. Although, NKX-2554 has an additional donor group, it is less efficient compared to the simpler NKX-2553 dye that contains only one donor group. When NKX-2554 structure is slightly modified by lengthening the linker-group, one obtains the most efficient dye among this set, namely, NKX-2569. In this work, we show that the changes in the donor moiety has very little or no effect on the efficiency of these dyes as can be seen in the case of NKX-2553 and NKX-2554. On the other hand, the improved performance of NKX-2569-titania complex can be understood to be a result of the longer linker group. A better understanding of these properties within different dye-titania complexes is important for the continual improvement of DSSCs. In this regards, this study will serve to provide guidelines to improve efficiencies of novel organic dyes. 2011-10-06T00:00:00Z Study of translational, librational and intra-molecular motion of adsorbed liquid water monolayers at various TiO2 interfaces Kavathekar, Ritwik S. English, Niall J. MacElroy, J. M. Don http://hdl.handle.net/10197/3387 2013-05-29T10:56:02Z 2011-10-19T00:00:00Z Study of translational, librational and intra-molecular motion of adsorbed liquid water monolayers at various TiO2 interfaces Kavathekar, Ritwik S.; English, Niall J.; MacElroy, J. M. Don Equilibrium classical molecular dynamics (MD) simulations have been performed to investigate the vibrational motion of water in contact with rutile-(110), rutile-(100), rutile-(001), anatase-(101) and anatase-(001) surfaces at room temperature (300 K). The vibrational density of states (VDOS) of the first adsorbed monolayer of liquid water has been analysed for each surface. These have been compared with reported experimental INS values involving rutile and anatase polymorph surfaces, along with ab initio MD results. It is observed that good qualitative agreement is obtained for the rutile-(110) and the anatase-(101) surfaces with the corresponding experimental VDOS. A significant contribution from librational dynamics is found for planar rutile surfaces, but no such demarcation is seen in the experimental VDOS. 2011-10-19T00:00:00Z Electrophoretic deposition of poly(3-decylthiophene) onto gold-mounted cadmium selenide nanorods Garate, Jose-Antonio English, Niall J. Singh, Ajay Ryan, Kevin M. Mooney, Damian A. MacElroy, J. M. Don http://hdl.handle.net/10197/3386 2012-11-26T15:11:32Z 2011-09-21T00:00:00Z Electrophoretic deposition of poly(3-decylthiophene) onto gold-mounted cadmium selenide nanorods Garate, Jose-Antonio; English, Niall J.; Singh, Ajay; Ryan, Kevin M.; Mooney, Damian A.; MacElroy, J. M. Don Molecular mechanisms of electrophoretic deposition (EPD) of poly(3-decylthiophene) (P3DT) molecules onto vertically aligned cadmium selenide arrays have been studied using large-scale, nonequilibrium molecular dynamics (MD), in the absence and presence of static external electric fields. The field application and larger polymer charges accelerated EPD. Placement of multiple polymers at the same lateral displacement from the surface reduced average deposition times due to "crowding", giving monolayer coverage. These findings were used to develop and validate Brownian dynamics simulations of multilayer polymer EPD in scaled-up systems with larger inter-rod spacings, presenting a generalized picture in qualitative agreement with random sequential adsorption. 2011-09-21T00:00:00Z Dynamical and energetic properties of hydrogen and hydrogen–tetrahydrofuran clathrate hydrates Gorman, Paul D. English, Niall J. MacElroy, J. M. Don http://hdl.handle.net/10197/3385 2012-11-26T15:13:03Z 2011-10-03T00:00:00Z Dynamical and energetic properties of hydrogen and hydrogen–tetrahydrofuran clathrate hydrates Gorman, Paul D.; English, Niall J.; MacElroy, J. M. Don Classical equilibrium molecular dynamics (MD) simulations have been performed to investigate the dynamical and energetic properties in hydrogen and mixed hydrogen-tetrahydrofuran sII hydrates at 30 and 200K and 0.05 kbar, and also at intermediate temperatures, using SPC/E and TIP4P-2005 water models. The potential model is found to have a large impact on overall density, with the TIP4P-2005 systems being on average 1 % more dense than their SPC/E counterparts, due to the greater guest-host interaction energy. For the lightly-filled mixed H2-THF system, in which there is single H2 occupation of the small cage (1s1l), we find that the largest contribution to the interaction energy of both types of guest is the van der Waals component with the surrounding water molecules in the constituent cavities. For the more densely-filled mixed H2-THF system, in which there is double H2 occupation in the small cage (2s1l), we find that there is no dominant component (i.e., van der Waals or Coulombic) in the H2 interaction energy with the rest of the system, but for the THF molecules, the dominant contribution is again the van der Waals interaction with the surrounding cage-water molecules; again, the Coulombic component increases in importance with increasing temperature. The lightly-filled pure H2 hydrate (1s4l) system exhibits a similar pattern vis-à-vis the H2 interaction energy as for the lightly-filled mixed H2-THF system, and for the more densely-filled pure H2 system (2s4l), there is no dominant component of interaction energy, due to the multiple occupancy of the cavities. By consideration of Kubic harmonics, there is some evidence of preferential alignment of the THF molecules, particularly at 200 K; this was found to arise at higher temperatures due to transient hydrogen bonding of the oxygen atom in THF molecules with the surrounding cage-water molecules. 2011-10-03T00:00:00Z First-principles study of the excited-state properties of coumarin-derived dyes in dye-sensitized solar cells Agrawal, Saurabh Dev, Pratibha English, Niall J. Thampi, Ravindranathan MacElroy, J. M. Don http://hdl.handle.net/10197/3016 2012-12-20T14:21:22Z 2011-06-23T00:00:00Z First-principles study of the excited-state properties of coumarin-derived dyes in dye-sensitized solar cells Agrawal, Saurabh; Dev, Pratibha; English, Niall J.; Thampi, Ravindranathan; MacElroy, J. M. Don Using Time-Dependent Density Functional Theory (TD-DFT), we have investigated the optical properties of dye-sensitized solar cells (DSSCs) comprised of TiO2 nanoparticle sensitized with two coumarins, namely, NKX-2311 and NKX-2593. The two sensitizers (dyes) differ only in their linker moieties and are shown to have different absorption spectra when adsorbed on to the TiO2 surface. Knowledge of different light absorption and charge transfer (CT) behavior within these complexes is useful for further improving the photo-dynamics of newer organic dyes presently being designed and investigated worldwide. Moreover, we have also investigated the effect of deprotonation of the sensitizers' carboxylic groups during adsorption on the titania surface and the excited state electronic properties of the resulting species. 2011-06-23T00:00:00Z Disinfection of meticillin-resistant Staphylococcus aureus and Staphylococcus epidermidis biofilms using a remote non-thermal gas plasma Cotter, John J. Maguire, Paul Soberon, Felipe Daniels, Stephen O'Gara, James P. Casey, Eoin http://hdl.handle.net/10197/2972 2011-06-08T16:34:28Z 2011-05-01T00:00:00Z Disinfection of meticillin-resistant Staphylococcus aureus and Staphylococcus epidermidis biofilms using a remote non-thermal gas plasma Cotter, John J.; Maguire, Paul; Soberon, Felipe; Daniels, Stephen; O'Gara, James P.; Casey, Eoin The effective disinfection of hospital surfaces is recognised as an important factor in preventing hospital-acquired infections. The purpose of this study was to quantify the disinfection rate of a novel gas plasma system on clinically relevant biofilms. Clinical isolates of Staphylococcus epidermidis and methicillin-resistant Staphylococcus aureus (MRSA) were grown as biofilms on glass surfaces and tested in a disinfection container remote from the plasma source. The strains used in this study were known to produce substantial quantities of biofilm and average log10 counts were 9.0 and 9.1 cfu/cm2 for S. epidermidis and MRSA respectively. Counts were reduced by between 4 and 4.5 log10 after 1 h of exposure for MRSA and S. epidermidis respectively. More prolonged treatment in the case of MRSA biofilms resulted in a 5.5 log10 reduction after 90 min. Biofilm samples were also placed in medical device packaging bags and similar rates of disinfection were observed. 2011-05-01T00:00:00Z Factors influencing 4-fluorobenzoate degradation in biofilm cultures of Pseudomonas knackmussii B13 Misiak, Katarzyna Casey, Eoin Murphy, Cormac D. http://hdl.handle.net/10197/2960 2011-05-30T15:17:56Z 2011-05-01T00:00:00Z Factors influencing 4-fluorobenzoate degradation in biofilm cultures of Pseudomonas knackmussii B13 Misiak, Katarzyna; Casey, Eoin; Murphy, Cormac D. Membrane aerated biofilm reactors (MABRs) have potential in wastewater treatment as they permit simultaneous COD minimisation, nitrification and denitrification. Here we report on the application of the MABR to the removal of fluorinated xenobiotics from wastewater, employing a Pseudomonas knackmussii monoculture to degrade the model compound 4-fluorobenzoate. Growth of biofilm in the MABR using the fluorinated compound as the sole carbon source occurred in two distinct phases, with early rapid growth (up to 0.007 h−1) followed by ten-fold slower growth after 200 h operation. Furthermore, the specific 4-fluorobenzoate degradation rate decreased from 1.2 g g−1 h−1 to 0.2 g g−1 h−1, indicating a diminishing effectiveness of the biofilm as thickness increased. In planktonic cultures stoichiometric conversion of substrate to the fluoride ion was observed, however in the MABR, approximately 85% of the fluorine added was recovered as fluoride, suggesting accumulation of 'fluorine' in the biofilm might account for the decreasing efficiency. This was investigated by culturing the bacterium in a tubular biofilm reactor (TBR), revealing that there was significant fluoride accumulation within the biofilm (0.25 M), which might be responsible for inhibition of 4-fluorobenzoate degradation. This contention was supported by the observation of the inhibition of biofilm accumulation on glass cover slips in the presence of 40 mM fluoride. These experiments highlight the importance of fluoride ion accumulation on biofilm performance when applied to organofluorine remediation. 2011-05-01T00:00:00Z Conversion of amorphous TiO2 coatings into their crystalline form using a novel microwave plasma treatment Dang, Binh H.Q. Rahman, Mahfujur MacElroy, J. M. Don Dowling, Denis P. http://hdl.handle.net/10197/2896 2011-07-14T13:32:44Z 2011-07-25T00:00:00Z Conversion of amorphous TiO2 coatings into their crystalline form using a novel microwave plasma treatment Dang, Binh H.Q.; Rahman, Mahfujur; MacElroy, J. M. Don; Dowling, Denis P. Crystalline titanium dioxide (TiO2) coatings have been widely used in photo-electrochemical solar cell applications. In this study, TiO2 and carbon-doped TiO2 coatings were deposited onto unheated titanium and silicon wafer substrates using a DC closed-field magnetron sputtering system. The resultant coatings had an amorphous structure and a post-deposition heat treatment is required to convert this amorphous structure into the photoactive crystalline phase(s) of TiO2. This study investigates the use of a microwave plasma heat treatment as a means of achieving this crystalline conversion. The treatment involved placing the sputtered coatings into a 2.45 GHz microwave-induced nitrogen plasma where they were heated to approximately 550°C. It was observed that for treatment times as short as 1 minute, the 0.25-µm thick coatings were converted into the anatase crystalline phase of TiO2. The coatings were further transformed into the rutile crystalline phase after treatments at higher temperatures. The doping of TiO2 with carbon was found to result in a reduction in this phase transformation temperature, with higher level of doping (up to 5.8% in this study) leading to lower anatase-to-rutile transition temperature. The photoactivity performance of both doped and un-doped coatings heat-treated using both furnace and microwave plasma was compared. The carbon-doped TiO2 exhibited a 29% increase in photocurrent density compared to that observed for the un-doped coating. Comparing carbon-doped coatings heat-treated using the furnace and microwave plasma, it was observed that the latter yielded a 19% increase in photocurrent density. This enhanced performance may be correlated to the differences in the coatings' surface morphology and band gap energy, both of which influence the coatings' photoabsorption efficiency. 2011-07-25T00:00:00Z Activation of hematite nanorod arrays for photoelectrochemical water splitting Morrish, Rachel Rahman, Mahfujur MacElroy, J. M. Don Wolden, Colin Andrew http://hdl.handle.net/10197/2886 2011-07-14T13:38:22Z 2011-04-18T00:00:00Z Activation of hematite nanorod arrays for photoelectrochemical water splitting Morrish, Rachel; Rahman, Mahfujur; MacElroy, J. M. Don; Wolden, Colin Andrew Hematite nanorod arrays were activated through proper control of annealing conditions. The 100-fold improvement in photocurrent was correlated with increased absorption and Sn doping from the tin oxide coated glass substrate. The low onset potential is attributed to a reduction in surface defects, while the morphology is credited for promoting tin diffusion and facilitating electron transport. 2011-04-18T00:00:00Z A theoretical thermodynamic investigation of cascade reactions in dinuclear octa-azacryptates involving carbon dioxide English, Niall J. Mooney, Damian A. http://hdl.handle.net/10197/2877 2012-03-20T16:46:51Z 2011-01-01T00:00:00Z A theoretical thermodynamic investigation of cascade reactions in dinuclear octa-azacryptates involving carbon dioxide English, Niall J.; Mooney, Damian A. This paper investigates the thermodynamics of gas-phase CO2 cascade uptake-reactions in the form of carbonate or methoxycarbonate anions in the host cavity of various dinuclear octa-azacryptates of m-CH2C6H4CH2 and 2,5-furano-spaced hosts, L1 and L2 cryptands, using density functional theory (DFT). The cascade process involves two stages, namely the formation of dinuclear cryptate complexes and the subsequent formation of either μ-carbonato cryptate complexes or μ-monomethylcarbonato cryptates. The geometric and electronic structures are also investigated to determine the parameters which affect the stability of the complexes. Natural bond orbital (NBO) analysis has been used to investigate the interactions between the trapped anion and its host. The ion selectivity has been studied in terms of the formation of dinuclear crypate complexes, while the basicity and nucleophilicity of cryptands towards Lewis acids have also been studied, and good agreement was found vis-à-vis available experimental data. 2011-01-01T00:00:00Z Electronic structure and origin of visible-light activity of C-doped cubic In2O3 from first-principles calculations Long, Run English, Niall J. http://hdl.handle.net/10197/2792 2011-07-11T16:14:59Z 2010-08-19T00:00:00Z Electronic structure and origin of visible-light activity of C-doped cubic In2O3 from first-principles calculations Long, Run; English, Niall J. The origin of the experimentally observed band gap narrowing and red-shift of the adsorption edge of cubic In2O3 induced by C doping has been investigated using density functional theory calculations. We have compared the stability of all these doped systems based on the calculated formation energy as a function of the oxygen chemical potential. The calculated electronic structures show that: (I) at low C concentration, substitutional replacement of O by C could lead to small gap narrowing, owing to C 2p states below the conduction band minimum while interstitial C doping does not induce band gap narrowing; and (II) at high C concentration, C2p states mix well with O 2p states above the valence band, which may account for the experimentally observed red-shift of the absorption edge. 2010-08-19T00:00:00Z First-principles calculation of electronic structure of V-doped anatase TiO2 Long, Run English, Niall J. http://hdl.handle.net/10197/2790 2011-02-23T09:47:17Z 2010-08-23T00:00:00Z First-principles calculation of electronic structure of V-doped anatase TiO2 Long, Run; English, Niall J. The energetic and electronic structures of V-doped anatase TiO2 have been investigated systematically by the GGA+U approach, including replacement of Ti by V in the absence and presence of oxygen vacancies and the presence of an interstitial site. It was found that V should exist as a V4+ ion in the replacement of Ti in the anatase lattice, the electron transitions of which to the conduction band from V 3d states are responsible for the experimentally observed visible-light absorption. The influence of V dopant concentration on the electronic and magnetic properties is also discussed, such as the influence of the U value in systems containing oxygen vacancies and spin flip phenomena for interstitial V-doping. 2010-08-23T00:00:00Z Electronic properties of F/Zr co-doped anatase TiO2 photocatalysts from GGA + U calculations Long, Run English, Niall J. http://hdl.handle.net/10197/2789 2011-02-23T09:38:04Z 2010-10-08T00:00:00Z Electronic properties of F/Zr co-doped anatase TiO2 photocatalysts from GGA + U calculations Long, Run; English, Niall J. The energetic and electronic properties of F and/or Zr-doped anatase TiO2 are investigated by first-principles calculations. For F-doping, reduced Ti3+ ions are formed and Ti orbitals lie slightly below the conduction band, leading to band gap narrowing. For Zr-doping, Zr 4d orbitals reside well into the conduction band, with essentially no band gap change. For F/Zr–codoping, the electronic structure is similar to that for F–monodoping, where Ti3+ gap states are induced by both the oxygen vacancy and F dopant. The influence of oxygen vacancies indicates that interplay between dopants and oxygen vacancies is key for improvement of photocatalytic activity. The theoretical findings present a reasonable explanation of recent experimental results. 2010-10-08T00:00:00Z Model-based comparative performance analysis of membrane aerated biofilm reactor configurations Syron, Eoin Casey, Eoin http://hdl.handle.net/10197/2759 2011-02-15T12:41:36Z 2008-04-15T00:00:00Z Model-based comparative performance analysis of membrane aerated biofilm reactor configurations Syron, Eoin; Casey, Eoin The potential of the membrane aerated biofilm reactor (MABR) for high-rate bio-oxidation was investigated. A reaction-diffusion model was combined with a preliminary hollow-fiber MABR process model to investigate reaction rate-limiting regime and to perform comparative analysis on prospective designs and operational parameters. High oxidation fluxes can be attained in the MABR if the intra-membrane oxygen pressure is sufficiently high, however the volumetric oxidation rate is highly dependent on the membrane specific surface area and therefore the maximum performance, in volumetric terms, was achieved in MABRs with relatively thin fibers. The results show that unless the carbon substrate concentration is particularly high, there does not appear to be an advantage to be gained by designing MABRs on the basis of thick biofilms even if oxygen limitations can be overcome. 2008-04-15T00:00:00Z Studies on the effect of concentration of a self-inhibitory substrate on biofilm reaction rate under co-diffusion and counter diffusion configurations Syron, Eoin Kelly, Hugh Casey, Eoin http://hdl.handle.net/10197/2758 2011-02-15T12:36:57Z 2009-06-15T00:00:00Z Studies on the effect of concentration of a self-inhibitory substrate on biofilm reaction rate under co-diffusion and counter diffusion configurations Syron, Eoin; Kelly, Hugh; Casey, Eoin A simple mathematical model was developed to investigate the utilization rate of a self-inhibitory substrate in idealised biofilm reactors operating with either counter-diffusion or co-diffusion of oxygen and phenol. This study has implications for the development of membrane-supported biofilm technologies, such as the membrane-aerated biofilm reactor. An unsteady-state formulation of the model was used to investigate the effect of shock loads of phenol on biofilm performance. It was found that the counter-diffusion configuration may be advantageous under high phenol concentrations provided the biofilm thickness is above a critical value. The performance advantage of the counter-diffusion configuration is gained by the presence of an oxygen depleted layer, adjacent to the liquid–biofilm interface which acts as a diffusive barrier to phenol transport to the region of respiratory activity. 2009-06-15T00:00:00Z Membrane aerated biofilms for high rate biotreatment : performance appraisal, engineering principles, scale-up and development requirements Syron, Eoin Casey, Eoin http://hdl.handle.net/10197/2757 2011-02-15T12:19:10Z 2008-03-15T00:00:00Z Membrane aerated biofilms for high rate biotreatment : performance appraisal, engineering principles, scale-up and development requirements Syron, Eoin; Casey, Eoin Diffusion of the electron acceptor is the rate controlling step in virtually all biofilm reactors employed for aerobic wastewater treatment. The membrane-aerated biofilm reactor (MABR) is a technology that can deliver oxygen at high rates and transfer efficiencies, thereby enhancing the biofilm activity. This paper provides a comparative performance rate analysis of the MABR in terms of its application for carbonaceous pollutant removal, nitrification/denitrification and xenobiotic biotreatment. We also describe the mechanisms influencing process performance in the MABR and the inter-relationships between these factors. The challenges involved in scaling-up the process are discussed with recommendations for prioritization of research needs. 2008-03-15T00:00:00Z Tracer measurements reveal experimental evidence of biofilm consolidation Casey, Eoin http://hdl.handle.net/10197/2746 2011-01-26T15:02:10Z 2007-11-01T00:00:00Z Tracer measurements reveal experimental evidence of biofilm consolidation Casey, Eoin The ability to simultaneously measure both biofilm thickness and the mass transfer coefficient of an inert tracer through it provides a powerful method to study biofilm development. In this communication previously published data has been collated to interpret global trends in biofilm structure during the transition towards steady-state. It appears that sudden changes in biofilm structure (directly related to the rate of change of biofilm mass transfer resistance) may occur following transitions in rate of biomass production. These observations are consistent with the concept of consolidation, recently introduced into spatially structured biofilm mathematical models to account for structural realignment of the biofilm under dynamic conditions. 2007-11-01T00:00:00Z Characterisation of a modified rotating disk reactor for the cultivation of Staphylococcus epidermidis biofilm Cotter, John J. O'Gara, James P. Stewart, Philip S. Pitts, Betsey Casey, Eoin http://hdl.handle.net/10197/2745 2012-03-29T13:25:33Z 2010-12-01T00:00:00Z Characterisation of a modified rotating disk reactor for the cultivation of Staphylococcus epidermidis biofilm Cotter, John J.; O'Gara, James P.; Stewart, Philip S.; Pitts, Betsey; Casey, Eoin Aims: The purpose of this study was to develop a system that would allow biofilms to be cultivated under strictly defined conditions in terms of dissolved oxygen, fluid shear and to assess whether the method was suitable for the detection of respiratory activity stratification in biofilm samples. Methods: The system is a modified version a commercially available laboratory biofilm reactor and incorporates a number of features such as the provision of defined levels of dissolved oxygen, constant average shear, enhanced gas–liquid mass transfer, aseptic operation and the ability to remove biofilm for ex situ analysis during or after continuous cultivation. Conclusions: The system was shown to be effective for the characterization of the effects of dissolved oxygen on a pure culture of Staphylococcus epidermidis. The versatility of the system offers the potential for cultivating pure culture biofilm in defined, controlled conditions and facilitates a range of analyses that can be performed ex situ. Significance and Impact of the Study: The ability to provide strict regulation of environmental conditions and enhanced transfer of oxygen to the biofilm during cultivation are important, first because oxygen is known to regulate biofilm development in several micro-organisms and second because many conventional biofilm cultivation systems may not provide adequate oxygen supply to the biofilm. 2010-12-01T00:00:00Z


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ABC Adds Lottery Drama Pilot From 'Detroit 187' Duo
David Zabel and Jason Richman will pen the drama, marking the network's 12th hourlong pickup this season.
ABC is adding yet another pilot to its portfolio.
The network has ordered Lucky 7, which revolves around seven employees of a service station in Queens whose lives are changed in many unexpected ways when they win a lottery jackpot. The drama is an adaptation of British series The Syndicate, now in its second season on BBC One.
Detroit 187's David Zabel and Jason Richman are attached to write the hourlong effort, which is set up at ABC Studios and Amblin TV. Zabel and Richman will exec produce alongside Amblin's Darryl Frank, Justin Falvey and Steven Spielberg.
STORY: TV Pilots 2013: The Complete Guide
This marks Zabel's second effort at ABC. He is also penning the net's Betrayal, a pilot about an unhappily married female photographer begins a torrid affair with a lawyer for a powerful family.
The news comes on the heels of another Amblin project being picked up to pilot at ABC. The half-hour Middle Age Rage centers on a middle-aged mother who is fed up with feeling invisible and begins to speak up and demand the respect she feels she's earned.
Zabel and Richman are repped by WME.
The Lucky 7 pickup marks the 12th drama ordered so far this pilot season at the network, joining Joss Whedon's S.H.I.E.L.D., Disney ride adaptation Big Thunder and David Shore's Doubt, among others.
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Park Meadows
- This property is an income restricted property. A maximum income limitation may apply. Not all renters will qualify and other restrictions may apply. Please contact the property for details.
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Contact for details (661) 846-2881
Basketball Court(s), Clubhouse, Fitness Center, On Site Maintenance, Playground, Swimming Pool
Breakfast Bar, Energy Star Appliances, Grilling Area, Kitchen Pantry, Mature Landscaping, Nearby Parks and Recreation, On-Site Car Wash, Online Payments Accepted, Private Patios, Public Transportation
Property Details
Full size Whirlpool Appliances in each Apartment...Affordable Housing-Lower Income Requirements Apply...14 acres of lush landscaping
Park Meadows is set on 14 acres of beautifully landscaped grounds. Choose from two, three, and four bedroom homes with spacious floor plans, each with a fully-equipped kitchen, full size washer & dryer and private patios or balcony. Enjoy the swimming pool, fitness room, or playground or simply take a stroll through the community.
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Our lease terms are: 12 months (Please note that lease terms may vary, are subject to change without notice, and are based on availability. Inquire with property staff for complete details).
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195 Harmony, RI Deck and Patio Professionals
When the Harmony, RI weather turns pretty, there's nothing like having an outdoor space at home where you can settle in and enjoy it. Whether you lack an al fresco living area or whether your existing one is old and dilapidated, a Rhode Island deck and patio contractor is your ticket to making the most of your yard and garden. More
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We are a design / build company specializing in custom decks, porches, sunrooms, patios, and additions. We have over 20 years experience listening to clients and building their... Read More
Outdoor Patio Supply is committed to providing great customer service for all your outdoor patio needs. Read More
a Division of Nehven Enterprises, LLC Bristol County Stamped Concrete of New England (888) 783- 7192 Pool Decks Bristol County Stamp Concrete, a division of Nehven... Read More
Manufacturing and shipping custom-made, modular sunrooms and conservatories throughout the northeastern US that, once completed, are "installed in a day, then enjoyed for a... Read More
Northeast Stonescapes is a full service hardscaping masonary company serving the greater Boston, MA region. We provide custom landscape and hardscape designs and installations,... Read More
BRENNER AWNINGS is one of the premier Awnings fabricators for Southeastern Massachusetts. We specialize in custom fabrication for your home or business. We fabricate and install... Read More
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Danielle Feneridis
Pepperdine Downs BYU, 5-2
Lorraine Guillermo extends her win streak to 10 in a row after prevailing in straight sets today at BYU.
#14 Pepperdine Blanks San Diego, 4-0
The Waves continue WCC play on Saturday with an 11 a.m. match at BYU.
Waves Shut Out Zags in WCC Opener
Pepperdine continues WCC action next week at San Diego on Wednesday and at BYU on Saturday.
#16 Waves Defeat #19 Arizona State
Next up, Pepperdine hosts Gonzaga on Sunday at 12 p.m.
#9 Cal Slides Past #21 Pepperdine, 4-3
#15 Lorraine Guillermo bests Cal ace #4 Maegan Manassee in singles, but Golden Bears take the team win 4-3.
Racquet Club Collegiate Invitational - Photos by Wallace Craig
Racquet Club Collegiate Invitational - Sept. 13-15, 2013 - Photos by Wallace Craig
2013 WCC Tournament Champions - Women's Tennis
Women's Tennis def. Saint Mary's 4-0 to win the 2013 WCC Tournament. Photos by Kyle Terada
CAREER: Member of the 2014 squad that won a program record 15 dual matches in a row.
PEPPERDINE 2013-14: Went 7-9 in singles as a sophomore, including a 3-2 record in dual action ... Played in the No. 6 spot in the lineup ... Perfect 3-0 in singles vs. WCC opponents ... 5-5 in doubles, including a 2-0 mark in dual matches ... Clinched doubles point with Pattaraporn Salirathavibhaga vs. Santa Clara (3/22) with an 8-5 triumph over Stephanie Skaras and Eline Chesoni ... Went on to clinch the dual for the Waves in singles with a 6-2, 3-6, 6-2 win vs. Chesoni ... Pepperdine Scholar-Athlete ... Earned WCC Commissioner's Honor Roll "bronze" honors.
PEPPERDINE 2012-13: Joined team in January ... Went 5-13 overall in singles ... Went 5-12 from the No. 6 spot in the singles lineup ... Went 3-6 overall in doubles including a 3-5 mark in duals ... Played at No. 3 alongside Lorraine Guillermo and posted a 3-2 record ... Delivered first collegiate singles win on March 26 vs. Sacramento State's Siobhan Ryan-Bovey, 7-6, 6-3.
NEW ZEALAND: Ranked as high as 205 in the ITF junior rankings ... Won an ITF tournament in Fiji ... Represented New Zealand on various junior national teams since the age of 12 ... Won first international ITF tournament in New Caledonia ... Member of the New Zealand 16s Federation Cup team that traveled to India for world qualifying.
HIGH SCHOOL: Graduated from Westlake Girls High School in 2012 ... Auckland secondary school singles champion ... Senior secondary school doubles champion ... Placed second in the New Zealand Team Nationals ... Also lettered in netball and table tennis ... North Harbour Champion in netball.
PERSONAL: Grew up in Auckland, New Zealand ... Daughter of Costa and Diane Feneridis ... Has one older sibling, Alex.
FAVORITES: Favorite pro tennis player is David Ferrer ... Favorite sport other than tennis is soccer ... Favorite TV show is Pretty Little Liars ... Favorite foods are oranges and Kit Kats.


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Pointe West Apartments
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Clubhouse, Controlled Access, Disability Access, Elevator, Fitness Center, On Site Maintenance, On Site Management, Playground, Recreation Room, Swimming Pool
BBQ/Picnic Area, Cable/Satellite TV, Community Room, Controlled Entry with Cameras, Game Room, Gourmet Kitchen, Heated Underground Parking, Laundry Facilities, Off Street Parking, Recycling Available, Self-cleaning Oven, Tot Lot, Updated Appliances, Walk-in Shower, Washer and Dryer in Most Units, Washer/Dryer in Most Homes
Property Details
Close to schools and shopping...Convenience with an abundance of amenities...The Finest in St. Cloud Living...
The new Pointe West Apartments sets a new standard by offering the finest in apartment living, going above and beyond what is currently available for today's residents. We offer a variety of different floorplans, great amenities, and construction techniques today has to offer. With all of this, we are sure to have the style of home to fit any lifestyle. In addition, we have an outdoor pool, workout room, and game room much more to offer all the residents at Pointe West!
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Lease Terms: 6, 9, 12 months. Security Deposit: $400. Pet Policy: Cats Welcome. 2 cats maximum. $250 deposit per cat ($125 non-refundable). Application Fee: $45.
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Spanish 'Rioja' garlic?
Hi all,
I bought some garlic for planting last week at the Hudson Valley Garlic Festival and one grower was selling Spanish "Rioja" garlic. I pointed out that I have always seen this variety spelled as Spanish "Roja", but he said he has seen it spelled both ways, and insisted it was the very same variety. Has anyone else ever seen it spelled as Rioja? Great wine, but I can't figure out why a professional grower who says he grows only this variety would not sell it under the well known name of Spanish Roja.
I have never seen it other than Spanish Roja. I think Roja translates to red? There is also a garlic called Ajo Rojo that was originally named Spanish Rojo, but to avoid confusion with Spanish Roja, they went with a different name. Not to mention there's also another garlic variety called Roja Spanish!
My goodness, they do make the world confusing!
Yes Roja does mean red, and Rioja is one of my favorite red wines from the Rioja district in northern Spain (will be drinking some tonight!). I did find two references to Spanish Rioja garlic on the internet, but I suspect that they and this grower are simply confusing the name with the more well known Rioja wine, or perhaps taking some poetic license. In any case I bought a dozen bulbs of this hardneck and will give it a whirl alongside Killarney Red, which should be virtually identical to the Roja.