#### Sample records for central helium liquefier

1. Fermilab central helium liquefier operations

This chapter discusses the use of liquid helium to cool the Fermilab superconducting accelerator. Liquid from the Central Helium Liquefier (CHL) is transported in a six kilometer circular transfer line and each satellite withdraws the amount required to boost its refrigeration capacity to the necessary level. Topics considered include the compressor, the heater, the control system, gas storage, liquid storage, the nitrogen reliquefier, gas purification, initial and early operation, and recent operation. The liquid helium is warmed to near ambient temperature in the satellite heat exchangers. The satellite compressors return the excess inventory to the CHL via a 20 bar gas header. This gas is injected into the high pressure supply to the cold box. Some turbine instabilities have been experienced, including the destruction of a turbine during the initial start-up

2. Recent operating experience with the Fermilab central helium liquefier

Operating experience since the last report, Aug. 1983, is covered. The current mode of supplying liquid helium to the superconducting accelerator ring is explained including a dissussion of the interaction of the system with upsets in the ring. The method of controlling helium flow to the dewars, liquid helium pump, helium subcooler, and cold box is very stable and largely automatic. The capacity of the plant is 136 g/s at the current operating point with a peak demand flow of greater than 250 g/s using liquid pumped from dewar storage. The design specifications of the major equipment are tabulated giving the main characteristics of the compressors, cold box, and helium and nitrogen storage. The operating history is analyzed to yield a lifetime efficiency of 97% in 19840 hours of running, and a breakdown of major failures and their causes is given. The major sources of downtime have been contamination of the helium stream by dust, water, and nitrogen. The solutions to these problems are discussed. A new liquid helium pump has been commissioned which has improved the system reliability and performance. This reciprocating pump is described and test data is presented. A third compressor has been commissioned as a backup for the two original compressors. A new control system utilizing a Texas Instruments PM550 programmable controller is used to monitor and control the third compressor. The performance of the PM550 has been excellent, and it is being implemented to control other parts of the system

3. Indigenous development of helium liquefier

Helium Liquefiers/refrigerators have become an essential part of future accelerator developments in India. Apart from designing, systems operating at liquid helium temperature viz. 4.2 K or lower, require additional technical skills to make them work as designed. To get insight in these intricacies, development of helium liquefier was taken up at RRCAT. An indigenous helium liquefier has been developed. This system is based on reciprocating type expansion engine and uses cross counter flow type heat exchangers, based on high finned density copper tubes. The cyclic compressor is a four stage air cooled reciprocating type compressor. Its oil removal system is also designed and developed indigenously. Initially, a liquefaction rate of 6 lit/hr was achieved. More than 150 liters of liquid helium was collected during its maiden trial itself, while operating for more than 25 hours continuously. This liquefier has at present crossed a liquefaction rate of 10 lits/hr by further tuning and reducing thermal in-leaks. Based on the experience gained in the present system and validation of design parameters under actual working conditions, a second model is being designed, which will be able to produce about 35 lit/hr of liquid helium. Further work is also being initiated to develop aluminium plate fin heat exchangers for developing helium liquefiers of larger capacity in the range of 100-200 lits/hr. Design, development and performance details of indigenous development of helium liquefier will be presented and ongoing efforts to increase the liquefaction capacity will be discussed. (author)

4. Dynamic Simulation of a Helium Liquefier

Dynamic behavior of a helium liquefier has been studied in detail with a Cryogenic Process REal-time SimulaTor (C-PREST) at the National Institute for Fusion Science (NIFS). The C-PREST is being developed to integrate large-scale helium cryogenic plant design, operation and maintenance for optimum process establishment. As a first step of simulations of cooldown to 4.5 K with the helium liquefier model is conducted, which provides a plant-process validation platform. The helium liquefier consists of seven heat exchangers, a liquid-nitrogen (LN2) precooler, two expansion turbines and a liquid-helium (LHe) reservoir. Process simulations are fulfilled with sequence programs, which were implemented with C-PREST based on an existing liquefier operation. The interactions of a JT valve, a JT-bypass valve and a reservoir-return valve have been dynamically simulated. The paper discusses various aspects of refrigeration process simulation, including its difficulties such as a balance between complexity of the adopted models and CPU time

5. Conceptualization and development of a helium liquefier at BARC, Mumbai

Indigenous development of helium liquefiers is regarded as a high priority area at BARC, Mumbai. A precooled Collin's cycle based helium liquefier conceived to work between pressure limits of 0.105 and 1.3 MPa (a) and with mass flow rate of 62 g/s is reported in the present paper. The system is designed to achieve a liquefaction rate of about 57 l/hr with the lowest temperature as 4.86 K. Effect of different heat exchanger effectiveness and turbine efficiency values on the liquefier performance has also been theoretically studied and reported here. Design and development methodology of the liquefier cold box has been dealt with. The present paper also describes the current state of installation and commissioning activities of the above described helium liquefier at BARC, Mumbai. First trial runs are expected soon after the completion of the transferline circuit from the liquefier cold box to the liquid helium receiver vessel. (author)

6. Recent trials with the experimental helium liquefier developed by BARC

An experimental helium liquefier has been designed and fabricated by Cryo-Technology Division and installed at Bhabha Atomic Research Centre, Mumbai. The helium liquefaction process is based on a modified Collin's cycle consisting of one pre-cooler turboexpander, a pair of by-pass turboexpanders (warm and cold) and a series of 7 compact brazed plate fin high effectiveness heat exchangers. Liquid nitrogen pre-cooling facility along with another heat exchanger to recover cold of gaseous nitrogen has also been provided in the system. After the full installation of the process compressor and its integration with the helium liquefier cold box, trial runs were started. A lowest temperature of about 7.8 K was registered in a temperature sensor located downstream of the JT valve. (author)

7. Laptop-assisted Helium Liquefier: software for tailored monitoring and control

Marceddu, Marco

2016-01-01

Computer running human machine interfaces are fast supplanting conventional hardware dedicated to monitoring and supervising tasks. This kind of approach was successfully employed to develop a new monitoring and control software, running on a conventional laptop computer, for a small size helium liquefier. This software was realized with a SCADA development package and hallowed to manage all the liquefier functionalities. Being conceived as an open structure suitable for further upgrades, this liquefier HMI can be tailored on demand to satisfy specific needs of the end-user, even if not provided by the original manufacturer project.

8. Comparative design evaluation of plate fin heat exchanger and coiled finned tube heat exchanger for helium liquefier in the temperature range of 300-80 K

Present indigenous helium liquefaction system at RRCAT uses the cross-counter flow coiled-finned tube heat exchangers developed completely from Indian resources. These coiled-finned tube heat exchangers are mainly suitable up to medium capacity helium liquefiers. For large capacity helium liquefier, plate fin heat exchangers are more suitable options. This paper presents the comparative evaluation of the design of both types of heat exchangers in the temperature range of 300-80 K for helium liquefier. (author)

9. Cryogenic system for the Large Helical Device. The helium refrigerator/liquefier for Large Helical Device

A large-scale helium refrigerator/liquefier has been developed to provide reliable and safe operation for the Large Helical Device (LHD). The refrigerator is required to satisfy four different types of cooling methods: forced-flow supercritical helium, a pool boiling method, two-phase helium flow and forced-flow low-temperature (40-80 K) helium gas. The forced-flow supercritical helium is widely used in modern large-scale superconducting magnets. This method requires a much more complex refrigeration system than does pool boiling because of the circulation of low-temperature helium within a very long cooling path. The overall refrigeration system is fairly complicated because of these multi-refrigeration requirements. As a matter of fact, it is not likely to find this type of refrigeration plant in the world. The helium refrigerator has a total refrigeration capacity of 5.65 kW at 4.4 K and 20.6 kW at 80 K and 650 l/h liquefaction. The refrigerator was designed to have high processing efficiency since the construction expense is much less than the operating cost. In order to achieve this, the refrigerator has two precooling cycles (300 to 80 K and 80 to 20 K) and has two turboexpanders running in parallel with different temperature levels at the cold end. To achieve a high mass flow rate in a low-temperature regime, eight screw-type compressors are operated at room temperature. There are two compressor groups, group A and group B, to reduce the overall work load. Each group consists of 1st and 2nd stage compression processes. The total mass flow rate becomes 960 g/s at 1.864 MPa. This article reviews the basic characteristics of a 10 kW class helium refrigerator/liquefier and a simple refrigeration cycle. (author)

10. Cold box design optimization and capacity enhancement of indigenously developed Helium Liquefier system to 40 liters/hour

The Cryo-Engineering and Cryo-Module Development Division at RRCAT has taken up development, construction and commissioning of medium size helium liquefier system. Helium liquefier and refrigerator system are of subject of high importance to present and future particle accelerators and related technologies. Particle accelerators based on superconducting magnet or superconducting radio frequency (SCRF) technologies are heavily dependent of cryo technology for their operation below 2K. The state of art cryo system requires massive energy to run and slight improvement translate in impressive energy saving. An overview of system with newly developed plate fin heat exchanger with significant high heat transfer performance coupled with characteristic lesser pressure drop is discussed. An attempt has been made to alleviate relatively higher loss making sub-systems through thermodynamic evaluation and their mathematical modeling. The experimental testing of system demonstrates the ability of our model in accurately predicting the overall performance of the developed system. (author)

11. Central helium density measurements in PLT

The central helium density in PLT has been deduced from measurements of the ratio of d-3He to d-d fusion reactions during deuterium neutral beam injection. The inward transport time for 3He puffed at the edge plasma was 10 → 30 msec. The decay time of the central 3He density increased with electron density, varying from 0.3 sec to greater than 1.0 sec over the density range of (1 → 5) x 1013 cm-3

12. Development of a Measurement and Control System for a 40l/h Helium Liquefier based on Siemens PLC S7-300

Li, J.; Liu, L. Q.; Xu, X. D.; Liu, T.; Li, Q.; Hu, Z. J.; Wang, B. M.; Xiong, L. Y.; Dong, B.; Yan, T.

A 40l/h Helium Liquefier has been commissioned by the Technical Institute of Physics and Chemistry, Chinese Academy of Sciences. A measurement and control system based on Siemens PLC S7-300 for this Helium Liquefier is developed. Proper sensors are selected, for example, three types of transmitters are adopted respectively according to detailed temperature measurement requirements. Siemens S7-300 PLC CPU315-2PN/DP operates as a master station and three sets of ET200 M DP remote expand I/O operate asslave stations. Profibus-DP field communication is used between the master station and the slave stations. The upper computer HMI(Human Machine Interface) is compiled using Siemens configuration software WinCC V7.0. The upper computer communicates with PLC by means of industrial Ethernet. A specific control logic for this Helium Liquefier is developed. The control of the suction and discharge pressures of the compressor and the control of the turbo-expanders loop are being discussed in this paper. Following the commissioning phase, the outlet temperature of the second stage turbine has reached 8.6K and the temperature before the throttle valve has reached 13.1K.

13. Liquid nitrogen historical and current usage of the central helium liquefier at SNS

DeGraff, B.; Howell, M.; Kim, S.; Neustadt, T.

2015-12-01

The main cryogenic system for the Spallation Neutron Source (SNS) is comprised of a 4-K cold box, a 2-K cold box, six warm compressors, and ancillary support equipment. This system has been cold and operating with little disruption since 2005. Design and operation of liquid nitrogen (LN2) supplied from a single 20,000-gallon supply Dewar will be discussed. LN2 used to precool the 4-K cold box heat exchanger started to increase around 2011. LN2 Consumption during 2012 and 2013 was almost double the nominal usage rate. Studies of this data, plant parameter changes to respond to this information, and current interpretations are detailed in this paper. The usage rate of LN2 returned to normal in late 2013 and remained there until recent additional changes. Future study plans to understand potential causes of this including contamination migration within the 4-K cold box will also be addressed.

14. Hyperpolarized 3-helium MR imaging of the lungs: testing the concept of a central production facility

The aim of this study was to test the feasibility of a central production facility with distribution network for implementation of hyperpolarized 3-helium MRI. The 3-helium was hyperpolarized to 50-65% using a large-scale production facility based at a university in Germany. Using a specially designed transport box, containing a permanent low-field shielded magnet and dedicated iron-free glass cells, the hyperpolarized 3-helium gas was transported via airfreight to a university in the UK. At this location, the gas was used to perform in vivo MR experiments in normal volunteers and patients with chronic obstructive lung diseases. Following initial tests, the transport (road-air-road cargo) was successfully arranged on six occasions (approximately once per month). The duration of transport to imaging averaged 18 h (range 16-20 h), which was due mainly to organizational issues such as working times and flight connections. During the course of the project, polarization at imaging increased from 20% to more than 30%. A total of 4 healthy volunteers and 8 patients with chronic obstructive pulmonary disease were imaged. The feasibility of a central production facility for hyperpolarized 3-helium was demonstrated. This should enable a wider distribution of gas for this novel technology without the need for local start-up costs. (orig.)

15. Helium-Hydrogen Recovery System Project

National Aeronautics and Space Administration — Immense quantities of expensive liquefied helium are required at Stennis and Kennedy Space Centers for pre-cooling rocket engine propellant systems prior to filling...

16. Radon and helium in soil gases in the Phlegraean Fields, central Italy

The distribution and migration of radon and helium soil-gas concentrations in the Phlegraean Fields, Italy, are controlled by the tectonic features of the area. Radon is supplied from surficial sources and helium has both surficial and deep origins. There is no direct correlation between the two noble gases on a point-to-point basis but the areal distribution of both gases is similar, suggesting that the distribution is controlled primarily by fractures and movement of geothermal fluids

17. Small hydrogen liquefier

In this work the deign and construction of a small hydrogen liquefier (two liters per hour maximum production) is described. The isenthalpic expansion process is used, because its construction is simple and it is generally cheaper to operate. A comparison with other liquefier processes, and considerations about their basic theory are also presented. (author)

18. Magnetic liquefier for hydrogen

This document summarizes work done at the Astronautics Technology Center of the Astronautics Corporation of America (ACA) in Phase 1 of a four phase program leading to the development of a magnetic liquefier for hydrogen. The project involves the design, fabrication, installation, and operation of a hydrogen liquefier providing significantly reduced capital and operating costs, compared to present liquefiers. To achieve this goal, magnetic refrigeration, a recently developed, highly efficient refrigeration technology, will be used for the liquefaction process. Phase 1 project tasks included liquefier conceptual design and analysis, preliminary design of promising configurations, design selection, and detailed design of the selected design. Fabrication drawings and vendor specifications for the selected design were completed during detailed design. The design of a subscale, demonstration magnetic hydrogen liquefier represents a significant advance in liquefaction technology. The cost reductions that can be realized in hydrogen liquefaction in both the subscale and, more importantly, in the full-scale device are expected to have considerable impact on the use of liquid hydrogen in transportation, chemical, and electronic industries. The benefits to the nation from this technological advance will continue to have importance well into the 21st century

19. Magnetic liquefier for hydrogen

NONE

1992-12-31

This document summarizes work done at the Astronautics Technology Center of the Astronautics Corporation of America (ACA) in Phase 1 of a four phase program leading to the development of a magnetic liquefier for hydrogen. The project involves the design, fabrication, installation, and operation of a hydrogen liquefier providing significantly reduced capital and operating costs, compared to present liquefiers. To achieve this goal, magnetic refrigeration, a recently developed, highly efficient refrigeration technology, will be used for the liquefaction process. Phase 1 project tasks included liquefier conceptual design and analysis, preliminary design of promising configurations, design selection, and detailed design of the selected design. Fabrication drawings and vendor specifications for the selected design were completed during detailed design. The design of a subscale, demonstration magnetic hydrogen liquefier represents a significant advance in liquefaction technology. The cost reductions that can be realized in hydrogen liquefaction in both the subscale and, more importantly, in the full-scale device are expected to have considerable impact on the use of liquid hydrogen in transportation, chemical, and electronic industries. The benefits to the nation from this technological advance will continue to have importance well into the 21st century.

20. Helium-ion beam for stereotactic radiosurgery of central nervous system disorders

A new radiation beamline configuration for stereotactic heavy-ion Bragg peak radiosurgery of patients with intracranial deep arteriovenous malformations, including carotid-cavernous fistulas, has been developed using the 230 MeV/u helium ion beam at the 184-in. Synchrocyclotron at the University of California, Berkeley. The modified beam has five characteristics: (1) uniform field between 10 and 40 mm in diameter; (2) variable depth of penetration between 40 and 140 mm; (3) stopping region for primary ions that can be broadened up to 40 mm; (4) sharply defined lateral and distal borders; and (5) dose rate greater than 2 Gy/min. It is adapted to the ISAH (irradiation stereotactic apparatus for humans) at the 184-in. Synchrocyclotron, with effective stereotactic localization of defined volumes within the brain, and is designed to reach all intracranial targets. It has proven suitable for all patients with intracranial vascular disorders treated with stereotactic radiosurgery at our laboratory

1. Active Gas Regenerative Liquefier Project

National Aeronautics and Space Administration — We offer a novel liquefier that has the potential to simultaneously increase thermodynamic efficiency and significantly reduce complexity. The ?active gas...

2. Helium isotope investigation on magnetic reversal boundaries of loess-paleosol sequence at Luochuan, central Chinese Loess Plateau

2007-01-01

Extraterrestrial particles have higher 3He/4He ratios than those of terrestrial sediments ( ＞ 100 Ra versus ＜ 0.03 Ra, where Ra is the 3He/4He ratio normalized to the atmospheric value of 1.4×10-6). The interplanetary dust particles (IDPs), which are very rich in 3He, continuously bombard the Earth and can accumulate in deposits. IDPs sedimentation rate changes can significantly influence 3He concentration in the Earth surface sediments. Since IDPs are not easy to detect in terrestrial deposits, measuring helium isotopes is a helpful approach to examine changes in IDPs. Helium concentration and helium isotopic composition magnetic substances and the quartz particles were examined for helium concentration and helium isotopic ratio. Results show that the 3He/4He ratio and the 3He concentrations of the magnetic substances are clearly higher than those of the bulk samples and the quartz particles, and, the 3He/4He ratio of the extracted magnetic substances is also higher than that of the average level of the Earth's crust. The higher helium content in the magnetic fractions can be explained by an influx of IDPs.

3. Development of new technology in helium refrigerator

For the practical use of nuclear fusion apparatuses, the adoption of superconducting magnets is unavoidable, and as the additional effective heating method of plasma, neutral beam injection is regarded as important. For superconducting magnets and the cryopumps for NB1, helium liquefying refrigerators are required to produce extremely low temperature close to absolute zero. In Hitachi Ltd., the development of the large helium liquefying refrigerator of expansion turbine type has been advanced early, and in 1968, No.1 machine, and in 1979, No.2 machine with improved reliability and operational performance were developed. So far, four machines were delivered for the projects of nuclear fusion, accelerators and others. As the technical development, in addition to the development of expansion turbines, the development of such peripheral equipment as transfer tubes, liquid helium pumps and automatic control has been forwarded in parallel. In this paper, the new technology related to these peripheral equipment is described. The superinsulator, FRP rod type spacers and liquid nitrogen shield for transfer tubes, a centrifugal liquid helium pump with dynamic pressure gas bearings and the automatic control for a helium liquefying refrigerator using a Hitachi DSC-18 digital controller are reported. (Kako, I.)

4. Simplified Helium Refrigerator Cycle Analysis Using the Carnot Step'

P. Knudsen; V. Ganni

2006-05-01

An analysis of the Claude form of an idealized helium liquefier for the minimum input work reveals the ''Carnot Step'' for helium refrigerator cycles. As the ''Carnot Step'' for a multi-stage polytropic compression process consists of equal pressure ratio stages; similarly for an idealized helium liquefier the ''Carnot Step'' consists of equal temperature ratio stages for a given number of expansion stages. This paper presents the analytical basis and some useful equations for the preliminary examination of existing and new Claude helium refrigeration cycles.

5. Liquid hydrogen target cooled by circulating helium

Structure and characteristics of a liquid hydrogen target, where hydrogen is liquefied with liquid helium flow using evaporation heat of liquid helium and vapour cold, are described. Good thermal insulation of liquid helium supply line permits to remove out of the target the most volumetric and heavy component - helium tank - and to supply liquid helium along spreaded pipeline from the Dewar helium flask. It results in considerable reduction of dimensions and weight, the structure simplification and work facilitation with the target. The target having a working volume of 400 mm length and 60 mm diameter was tested. Vacuum casing of the working volume was made of foam plastic, heat flow to the working volume is equal to 1.5 W. Achieving mode of operation including structure cooling and hydrogen liquefaction took approximately 3 h, liquid helium flow rate for liquefaction of 1 l hydrogen is 2.7 l. Liquid helium flow rate in the mode of operation was equal to 0.7 l/h, i.e. target operation period without adding liquid helium to the Dewar flask is 4-5 days. The target described is notable for simplicity in fabrication, reliability in operation and is very suitable for using in experiment as compared to existing targets with hydrogen liquefaction with liquid helium. Unit structure of the target enables to easily change its configuration relative to problems of concrete physical experiment

6. Education in Helium Refrigeration

On the one hand, at the end of the time I was active in helium refrigeration, I noticed that cryogenics was stepping into places where it was not yet used. For example, a conventional accelerator, operating at room temperature, was to be upgraded to reach higher particle energy. On the other hand, I was a little bit worried to let what I had so passionately learned during these years to be lost. Retirement made time available, and I came gradually to the idea to teach about what was my basic job. I thought also about other kinds of people who could be interested in such lessons: operators of refrigerators or liquefiers who, often by lack of time, did not get a proper introduction to their job when they started, young engineers who begin to work in cryogenics... and so on.Consequently, I have assembled a series of lessons about helium refrigeration. As the audiences have different levels of knowledge in the field of cryogenics, I looked for a way of teaching that is acceptable for all of them. The course is split into theory of heat exchangers, refrigeration cycles, technology and operation of main components, process control, and helium purity

7. Helium-argon isotopic tracing for the Pb-Zn-Ag polymetallic ore deposits in the central-south segment of the Da Hinggan Ling Range

WANG Baode; NIU Shuyin; SUN Aiqun; HU Huabin; LIU Yaming; GUO Lijun; WANG Shuo

2008-01-01

In recent years big strides have been made in the exploration of ores in the central-south segment of the Da Hinggan Ling Range, though some debates still exist on the metallogenesis and sources of ore-forming materials.Pyrite and other sulfides in direct relation to the Pb-Zn-Ag ore deposits were chosen for the He and Ar isotopic analysis of ore-forming fluids, and the first He and Ar isotope data have been obtained from the study region.3He/4He ratios in 14 samples collected from 7 mining districts are 2.17x10-6-12.52×10-6, averaging 6.86×10-6 and their R/Ra ratios are 1.56-9.01 Ra, averaging 4.37 Ra. By projecting the data points onto the 3He-4He concentrations diagram, all the points fall near the mantle helium area. The calculated mantle-source helium ratios are within the range of 19.58%-76.96%, with an average of 49.52%. Argon isotopic characteristics are close to those of mantle source, indicating that the ore-forming material was transport upwards via the multi-stage evolution of mantle plume and concentrated as ores in the favorable loci of mantle branch structures.

8. Liquid helium

Atkins, K R

1959-01-01

Originally published in 1959 as part of the Cambridge Monographs on Physics series, this book addresses liquid helium from the dual perspectives of statistical mechanics and hydrodynamics. Atkins looks at both Helium Three and Helium Four, as well as the properties of a combination of the two isotopes. This book will be of value to anyone with an interest in the history of science and the study of one of the universe's most fundamental elements.

9. Helium cryogenics

Van Sciver, Steven W

2012-01-01

Twenty five years have elapsed since the original publication of Helium Cryogenics. During this time, a considerable amount of research and development involving helium fluids has been carried out culminating in several large-scale projects. Furthermore, the field has matured through these efforts so that there is now a broad engineering base to assist the development of future projects. Helium Cryogenics, 2nd edition brings these advances in helium cryogenics together in an updated form. As in the original edition, the author's approach is to survey the field of cryogenics with emphasis on helium fluids. This approach is more specialized and fundamental than that contained in other cryogenics books, which treat the associated range of cryogenic fluids. As a result, the level of treatment is more advanced and assumes a certain knowledge of fundamental engineering and physics principles, including some quantum mechanics. The goal throughout the work is to bridge the gap between the physics and engineering aspe...

10. Antiprotonic helium

2005-01-01

An exotic atom in w hich an electron and an antiproton orbit a helium nucleus could reveal if there are any differences between matter and antimatter. The author describes this unusual mirror on the antiworld (5 pages)

11. Helium Contamination Through Polymeric Walls

Gabal, M.; Lozano, M. P.; Oca, A.; Pina, M. P.; Sesé, J.; Rillo, C.

The concentration of impurities in helium gas is an important parameter for a recovery andliquefaction plant. A low level of impurities is necessary to maintain an optimum liquefaction rate inany kind of liquefier. The main origin of the impurities is the air contamination that enters into the helium mainstream at some point in the recovery cycle. In this work we have: i) identifiedthe main sources forimpurities in anexperimental helium recovery plant, ii) quantified the contamination rate and iii) proposeda mitigation strategy.An analysis of the He impurities composition revealsa nitrogen/oxygenratio different to the one existing in air. This observation is in accordance with the permeability values for nitrogenand oxygen through the polymer materials used in the plant.Experimental on line measurements for oxygen content in the He mainstream with sensitivity below 1 ppm, have been performed after recirculation through metal and polymericpipelines, respectively, to validate our hypothesis. In addition, the dependence of the impurities concentration with the Heretention time in the recovery gasbag has beenevaluated. Finally some operational recommendations are given for practical applications.

12. Experimental studies of frictional interactions between fuel pins and the centralizing grid under hot helium conditions for a GBR type fuel element

Experimental researches on the tribological phenomena taking place in a fast Gas Breeder Reactor (GBR) are presented, particular attention being given to positions where friction between fuel pins and the centralizing grid occurs. The tests were carried out in the framework of a joint contract at CRC Ispra. Experiments were performed at temperatures up to 7200C in helium atmospheres. The fuel pins used have an AISI 316 cladding. In a first series of tests AISI 410 was chosen for the grid. These tests demonstrated that lateral vibrations (vibration of the pins between grid protuberances) added to the cyclic longitudinal displacement of the pin favorize the pins sliding between protuberances, and in consequence, reduce wear. Furthermore, lateral vibrations (hammering) alone account for a negligible amount of wear. A second series of tests was carried out with AISI 410 grid proturberances under constant lateral loads of 2 and 4 Newtons. Under these pessimistic conditions, it was observed that the temperature increase taking place leads to a major cladding/protuberance interaction and a greater amount of wear. Plastic deformation occurs at between 600 and 7000C leading to greater forces to allow for the expansion/compression of the pin between protuberances. However a higher temperature also leads to a reduction in the aggressivity of matter broken-off by wear on the surfaces in contact. Most of the tests were conducted over a period of 10000 longitudinal cycles. It is concluded that severe damage risks due to wear are very small for the hot points of the cladding with a max-max of 6800C

13. Factors Affecting the Resinification of Liquefied Phenolated Wood

Zhang Qiu-hui; Zhao Guang-jie1; Hu Shi-yu

2005-01-01

Wood of Chinese fir and poplar were liquefied in phenol at 150℃ and atmospheric pressure. The liquefied wood were reacted with formaldehyde to synthesize the liquefied wood-based resin. The factors affecting the resinification and the properties of new resin were investigated. The results show that the formaldehyde/liquefied wood molar ratio, reaction temperature, reaction time and sodium hydroxide/liquefied wood molar ratio have important influence on the resin characteristics. With the increase of formaldehyde/liquefied wood molar ratio, the yield of resin increases, and the free phenol content of resins decreases, showing that the resinification of liquefied wood is more complete at higher formaldehyde/liquefied wood molar ratios. The reaction temperature on the viscosity of the liquefied resin has considerable effect; the viscosity of resin increased with increasing reaction temperature,and the amount of liquefied poplar resin increased more quickly than that of liquefied Chinese fir resin. The resinification time also has obvious influence on the viscosity of resin; the viscosity of liquefied poplar resin is more sensitive to resinification time compared with that of liquefied Chinese fir. The amount of sodium hydroxide can improve the water miscibility of liquefied wood resin.The optimum sodium hydroxide/liquefied wood molar ratio for preparation of liquefied wood-based resins exceeds 0.4.

14. An experience in the maintenance of a liquefier from the T-15 cryogenic system, results of its reliability and capacity enhancement

For the production of the liquid helium and realization of technological operation modes of cooling down, steady state and warming up cryogenic objects at Tokamak T-15 facility liquefiers with the present flow rate, 0.222 L/s (800 L/h) each, are used. In 1988 the liquefier was put into operation under conditions without implementation of the third turbine stage, at the liquid helium flow rate 0.0694 - 0.0972 L/s (250 - 350 L/h), for the time of continuous operation of 200 hours long. Since 1988, work has been done to enhance its reliability and capacity. This includes: Simplification pneumatic-hydraulic circuit-diagram of the liquefiers for increasing reliability. Start-up of the third turbine stages of the liquefiers. Piston expander and two variant of turbines were tested, only the last variant has demonstrated reliable and effective operation. Work out and realization of technological and circuit-diagram solution (usage of preliminary helium purification from neon, development and assembly of a neon adsorber) against freezing neon and hydrogen impurities -changing the mass flow ratio - in the valves and heat exchangers. Test of various prototype main turbines. Many prototype main turbines with various work pressure and various mass flow were tested. Turbines with optimal parameters have been selected. At present, the liquefier has the flow rate equal 0.222 L/s (800 L/h), at the compressed helium flow rate - 0.222 kg/s (800 kg/h), and the inlet liquefier pressure - 2.2 MPa

15. Development of the helium refrigerator control system using EPICS

cERL and STF are the facilities with the superconducting accelerating cavities in KEK. These cavities work at 2K. To operate the cavity at 2K, a helium liquefier manufactured by Sulzer (TCF200) and a 2K refrigerator developed by KEK were dedicated. The control systems of the 2K refrigerator were developed. The control system of liquefaction for cERL was also replaced. (author)

16. Western Pacific liquefied natural gas

This presentation addressed issues facing WestPac Terminals' proposed construction of a liquefied natural gas (LNG) terminal and associated facilities on the Ridley Island on the coast of British Columbia. WestPac Terminals Inc. has expertise in natural gas supply and demand, transportation, LNG and economic optimization. Although a review of proposals for receiving terminals in North America has demonstrated the urgency and attractiveness of LNG imports, west coast terminals are not proceeding, largely due to lack of support by local communities. WestPac's proposal includes a deep enough port to accommodate the largest LNG tankers; a port en route to west coast terminal locations to serve as a transshipment hub; sufficient space for LNG storage tanks and natural gas liquids extraction; sea, rail, air and highway access. Other solutions include selecting locations where communities are pro-development where LNG terminals can provide direct financial benefits to the community, and using existing infrastructure to minimize socio-economic impacts. The advantages of developing LNG at the proposed site were discussed in terms of serving energy markets and provincial benefits. LNG source and cost issues were reviewed along with existing markets and required infrastructure for LNG market development. tabs., figs

17. Orion A helium abundance

The 22.4-GHz (H,He)66-alpha and 36.5-GHz (H,He)56-alpha radio recombination lines have been observed at several Jaffe-Pankonin positions in the central part of the Orion A source. The measured relative abundance of ionized helium increases with distance, averaging 11.6 percent at peripheral points. The observed behavior is interpreted by a blister-type model nebula, which implies that Orion A has a true He abundance of 12 percent, is moving with a radial velocity of 5 km/sec, and is expanding. 18 references

18. 40 CFR 1065.720 - Liquefied petroleum gas.

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Liquefied petroleum gas. 1065.720... Standards § 1065.720 Liquefied petroleum gas. (a) Except as specified in paragraph (b) of this section, liquefied petroleum gas for testing must meet the specifications in the following table: Table 1 of §...

19. Role of expanders in helium liquefaction cycles: Parametric studies using Collins cycle

Large scale helium liquefaction/refrigeration plant is a key subsystem of fusion devices. Performance of these plants is dependent on a number of geometric and operating parameters of its constituting components such as compressors, heat exchangers, expanders, valves, etc. Expander has been chosen as the subject matter of analyses in the present study. As the sensible cold of helium vapor is lost in liquefiers, the expanders in liquefaction cycles have to provide more refrigeration than those in refrigeration cycles. The expander parameters such as rate of mass flow, operating pressure, inlet temperature, etc. are inter-dependent, and hence, it is difficult to predict the system behavior with variation of a particular parameter. This necessitates the use of process simulators. Parametric studies have been performed on Collins helium liquefaction cycle using Aspen HYSYS. Collins cycle has all the basic characteristics of a large-scale helium liquefier and the results of this study may be extrapolated to understand the behavior of large scale helium liquefiers. The study shows that the maximum liquid production is obtained when 80% of the compressor flow is diverted through the expanders and it is equally distributed between the two expanders. The relationships between the liquid production and the isentropic efficiency of expanders are almost linear and both the higher and lower temperature expanders exhibit similar trends.

20. Installation and Commissioning of the Helium Refrigeration System for the HANARO-CNS

The cold neutron source (CNS), which will be installed in the vertical CN hole of the reflector tank at HANARO, makes thermal neutrons to moderate into the cold neutrons with the ranges of 0.1 ∼ 10 meV passing through a moderator at about 22K. A moderator to produce cold neutrons is liquid hydrogen, which liquefies by the heat transfer with cryogenic helium flowing from the helium refrigeration system. For the maintenance of liquid hydrogen in the IPA, the CNS system is mainly consisted of the hydrogen system to supply the hydrogen to the IPA, the vacuum system to keep the cryogenic liquid hydrogen in the IPA, and the helium refrigeration system to liquefy the hydrogen gas. The helium refrigeration system can be divided into two sections: one is the helium compression part from the low pressure gas to the high pressure gas and the other is the helium expansion part from the high temperature gas and pressure to low temperature and pressure gas by the expansion turbine. The helium refrigeration system except the warm helium pipe and the helium buffer tank has been manufactured by Linde Kryotechnik, AG in Switzerland and installed in the research reactor hall, HANARO. Other components have been manufactured in the domestic company. This technical report deals with the issues, its solutions, and other particular points while the helium refrigeration system was installed at site, verified its performance, and conducted its commissioning along the reactor operation. Furthermore, the operation procedure of the helium refrigeration system is included in here for the normal operation of the CNS

1. Gaussian Basis Set Optimization for Excited Helium and Helium-like Ions

Šmydke, Jan; Kaprálová-Žďánská, Petra Ruth

Mariapfarr : Univerzity of Graz, 2012. [Central European Symposium on Theoretical Chemistry /11./. 25.09.2011-28.09.2011, Mariapfarr] Institutional support: RVO:61388955 Keywords : helium * Gaussian basis set oprimization Subject RIV: CF - Physical ; Theoretical Chemistry

2. Recovery of Bio-Oil from Industrial Food Waste by Liquefied Dimethyl Ether for Biodiesel Production

Kiyoshi Sakuragi; Peng Li; Maromu Otaka; Hisao Makino

2016-01-01

The development of new energy sources has become particularly important from the perspective of energy security and environmental protection. Therefore, the utilization of waste resources such as industrial food wastes (IFWs) in energy production is expected. The central research institute of electric power industry (CRIEPI, Tokyo, Japan) has recently developed an energy-saving oil-extraction technique involving the use of liquefied dimethyl ether (DME), which is an environmentally friendly s...

3. Electrons at helium interfaces

Leiderer, Paul

1984-01-01

Two-dimensional layers of charges trapped at the boundaries between the various helium phases strongly interact with these interfaces at high electric fields. The coupling, which leads to an electrohydrodynamic instability, provides new methods for studying helium properties.

4. ELECROGASDYNAMIC GENERATOR-EXPANDER FOR NATURAL GAS LIQUEFIERS

Бумагин, Г. И.; Бородин, Д. В.; Зиновьева, А. В.; Роханский, А. Е.; Рогальский, Е. И.

2015-01-01

The paper deals with various ways of obtaining liquefied natural gas (LNG) in liquefiers of different cold producing elements such as an expansion valve, a vortex tube and a turboexpander. It provides a brief analysis of their efficiency, advantages and disadvantages. The electrogasdynamic generator-expander as a cold producing element in natural gas liquefiers is proposed. Utilizing energy of compressed pipe-line natural gas should be taken into account. The circuits of the new stage and the...

5. 75 FR 53371 - Liquefied Natural Gas Facilities: Obtaining Approval of Alternative Vapor-Gas Dispersion Models

2010-08-31

... Pipeline and Hazardous Materials Safety Administration Liquefied Natural Gas Facilities: Obtaining Approval... Safety Administration (PHMSA) issues federal safety standards for siting liquefied natural gas (LNG...) NFPA 59A: Standard for the Production, Storage, and Handling of Liquefied Natural Gas. That...

6. Fuel tank for liquefied natural gas

DeLay, Thomas K. (Inventor)

2012-01-01

A storage tank is provided for storing liquefied natural gas on, for example, a motor vehicle such as a bus or truck. The storage tank includes a metal liner vessel encapsulated by a resin-fiber composite layer. A foam insulating layer, including an outer protective layer of epoxy or of a truck liner material, covers the composite layer. A non-conducting protective coating may be painted on the vessel between the composite layer and the vessel so as to inhibit galvanic corrosion.

7. Lightweight Tanks for Storing Liquefied Natural Gas

DeLay, Tom

2008-01-01

Single-walled, jacketed aluminum tanks have been conceived for storing liquefied natural gas (LNG) in LNG-fueled motor vehicles. Heretofore, doublewall steel tanks with vacuum between the inner and outer walls have been used for storing LNG. In comparison with the vacuum- insulated steel tanks, the jacketed aluminum tanks weigh less and can be manufactured at lower cost. Costs of using the jacketed aluminum tanks are further reduced in that there is no need for the vacuum pumps heretofore needed to maintain vacuum in the vacuum-insulated tanks.

8. Performance test of the HERA 3 x 6500 w helium refrigeration plant

The HERA magnet system will be cooled by a helium liquefier-refrigerator. The design of the plant is described and the first results of some performance tests for refrigeration power at 4.4 K and between 40 K and 80 K and for liquefaction rates at 4.4 K with one coldbox system out of three are presented. Preliminary values for coldbox and compressor group efficiencies were calculated

9. 30 CFR 57.4463 - Liquefied petroleum gas use underground.

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Liquefied petroleum gas use underground. 57... AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES... gas use underground. Use of liquefied petroleum gases underground shall be limited to maintenance...

10. Design, commissioning and operating experience of the PSI KA-IV multipurpose helium refrigerator

Amstutz, Markus; Baumann, Hans U.; Clerc, Roger; Gloor, Walter; Kurtcuoglu, Kirkor; Löhlein, Karl; Schulze, Reinhard M.; Zichy, János A.; Ziegler, Bruno

Early in 1991 the Paul Scherrer Institute (PSI), Villigen, Switzerland commissioned its fourth helium liquefier/refrigerator. The facility is used for cooling superconducting magnets, purification and liquefaction of helium. It provides 4000 W of refrigeration at ca. 60 K and 900 W at 4.5 K without nitrogen precooling. Its main features are: Reciprocating compressor with labyrinth pistons, three expansion turbines with dynamic gas bearings, fully automatic operation based on a programmable logic controller and graphic process visualization. The paper describes the operating requirements, the refrigerator, the control concept designed to optimize the performance, and finally the operating experience gained during start up and half a year of operation.

11. Solutions for Liquid Nitrogen Pre-Cooling in Helium Refrigeration Cycles

Wagner, U

2000-01-01

Pre-cooling of helium by means of liquid nitrogen is the oldest and one of the most common process features used in helium liquefiers and refrigerators. Its two principle tasks are to allow or increase the rate of pure liquefaction, and to permit the initial cool-down of large masses to about 80 K. Several arrangements for the pre-cooling process are possible depending on the desired application. Each arrangement has its proper advantages and drawbacks. The aim of this paper is to review the possible process solutions for liquid nitrogen pre-cooling and their particularities.

12. Cooling with Superfluid Helium

Lebrun, P

2014-01-01

The technical properties of helium II (‘superfluid’ helium) are presented in view of its applications to the cooling of superconducting devices, particularly in particle accelerators. Cooling schemes are discussed in terms of heat transfer performance and limitations. Large-capacity refrigeration techniques below 2 K are reviewed, with regard to thermodynamic cycles as well as process machinery. Examples drawn from existing or planned projects illustrate the presentation. Keywords: superfluid helium, cryogenics

13. Antiprotonic Helium Atoms

Kartavtsev, O. I.

1995-01-01

Metastable antiprotonic helium atoms $^{3,4}\\! H\\! e\\bar pe$ have been discovered recently in experiments of the delayed annihilation of antiprotons in helium media. These exotic atoms survive for an enormous time (about tens of microseconds) and carry the extremely large total angular momentum $L\\sim 30-40$. The theoretical treatment of the intrinsic properties of antiprotonic helium atoms, their formation and collisions with atoms and molecules is discussed.

14. Performance of the Helium Circulation System on a Commercialized MEG

T, Takeda; M, Okamoto; T, Miyazaki; K, Katagiri

2012-12-01

We report the performance of a helium circulation system (HCS) mounted on a MEG (Magnetoencephalography) at Nagoya University, Japan. This instrument is the first commercialized version of an HCS. The HCS collects warm helium gas at approximately 300 K and then cools it to approximately 40 K. The gas is returned to the neck tube of a Dewar of the MEG to keep it cold. It also collects helium gas in the region just above the liquid helium surface while it is still cold, re-liquefies the gas and returns it to the Dewar. A special transfer tube (TT) of approximately 3 m length was developed to allow for dual helium streams. This tube separates the HCS using a MEG to reduce magnetic noise. A refiner was incorporated to effectively collect contaminating gases by freezing them. The refiner was equipped with an electric heater to remove the frozen contaminants as gases into the air. A gas flow controller was also developed, which automatically controlled the heater and electric valves to clean up contamination. The developed TT exhibited a very low heat inflow of less than 0.1 W/m to the liquid helium, ensuring efficient operation. The insert tube diameter, which was 1.5 in. was reduced to a standard 0.5 in. size. This dimensional change enabled the HCS to mount onto any commercialized MEG without any modifications to the MEG. The HCS can increase liquid helium in the Dewar by at least 3 liters/Day using two GM cryocoolers (SRDK-415D, Sumitomo Heavy Industries, Ltd.). The noise levels were virtually the same as before this installation.

15. Performance of the Helium Circulation System on a Commercialized MEG

We report the performance of a helium circulation system (HCS) mounted on a MEG (Magnetoencephalography) at Nagoya University, Japan. This instrument is the first commercialized version of an HCS. The HCS collects warm helium gas at approximately 300 K and then cools it to approximately 40 K. The gas is returned to the neck tube of a Dewar of the MEG to keep it cold. It also collects helium gas in the region just above the liquid helium surface while it is still cold, re-liquefies the gas and returns it to the Dewar. A special transfer tube (TT) of approximately 3 m length was developed to allow for dual helium streams. This tube separates the HCS using a MEG to reduce magnetic noise. A refiner was incorporated to effectively collect contaminating gases by freezing them. The refiner was equipped with an electric heater to remove the frozen contaminants as gases into the air. A gas flow controller was also developed, which automatically controlled the heater and electric valves to clean up contamination. The developed TT exhibited a very low heat inflow of less than 0.1 W/m to the liquid helium, ensuring efficient operation. The insert tube diameter, which was 1.5 in. was reduced to a standard 0.5 in. size. This dimensional change enabled the HCS to mount onto any commercialized MEG without any modifications to the MEG. The HCS can increase liquid helium in the Dewar by at least 3 liters/Day using two GM cryocoolers (SRDK-415D, Sumitomo Heavy Industries, Ltd.). The noise levels were virtually the same as before this installation.

16. A Cryogen Recycler with Pulse Tube Cryocooler for Recondensing Helium and Nitrogen

Wang, C.; Lichtenwalter, B.

2015-12-01

We have developed a cryogen recycler using a 4 K pulse tube cryocooler for recondensing helium and nitrogen in a NMR magnet. The liquid helium cooled NMR magnet has a liquid nitrogen cooled radiation shield. The magnet boils off 0.84 L/day of liquid helium and 6 L/day of liquid nitrogen. The recycler is designed with both a liquid helium return tube and a liquid nitrogen return tube, which are inserted into the fill ports of liquid helium and nitrogen. Therefore the recycler forms closed loops for helium and nitrogen. A two-stage 4 K pulse tube cryocooler, Cryomech model PT407 (0.7W at 4.2 K), is selected for the recycler. The recycler was first tested with a Cryomech's test cryostat and resulted in the capacities of recondensing 8.2 L/day of nitrogen and liquefying 4 L/day of helium from room temperature gas. The recycler has been installed in the NMR magnet at University of Sydney since August, 2014 and continuously maintains a zero boil off for helium and nitrogen.

17. Helium the disappearing element

Sears, Wheeler M

2015-01-01

The subject of the book is helium, the element, and its use in myriad applications including MRI machines, particle accelerators, space telescopes, and of course balloons and blimps. It was at the birth of our Universe, or the Big Bang, where the majority of cosmic helium was created; and stellar helium production continues. Although helium is the second most abundant element in the Universe, it is actually quite rare here on Earth and only exists because of radioactive elements deep within the Earth. This book includes a detailed history of the discovery of helium, of the commercial industry built around it, how the helium we actually encounter is produced within the Earth, and the state of the helium industry today. The gas that most people associate with birthday party balloons is running out. “Who cares?” you might ask. Well, without helium, MRI machines could not function, rockets could not go into space, particle accelerators such as those used by CERN could not operate, fiber optic cables would not...

18. 29 CFR 779.360 - Classification of liquefied-petroleum-gas sales.

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Classification of liquefied-petroleum-gas sales. 779.360... Establishments Liquefied-Petroleum-Gas and Fuel Oil Dealers § 779.360 Classification of liquefied-petroleum-gas... ultimate consumer of liquefied-petroleum-gas, whether delivered in portable cylinders or in bulk to...

19. Liquefied Gaseous Fuels Spill Test Facility

The US Department of Energy's liquefied Gaseous Fuels Spill Test Facility is a research and demonstration facility available on a user-fee basis to private and public sector test and training sponsors concerned with safety aspects of hazardous chemicals. Though initially designed to accommodate large liquefied natural gas releases, the Spill Test Facility (STF) can also accommodate hazardous materials training and safety-related testing of most chemicals in commercial use. The STF is located at DOE's Nevada Test Site near Mercury, Nevada, USA. Utilization of the Spill Test Facility provides a unique opportunity for industry and other users to conduct hazardous materials testing and training. The Spill Test Facility is the only facility of its kind for either large- or small-scale testing of hazardous and toxic fluids including wind tunnel testing under controlled conditions. It is ideally suited for test sponsors to develop verified data on prevention, mitigation, clean-up, and environmental effects of toxic and hazardous gaseous liquids. The facility site also supports structured training for hazardous spills, mitigation, and clean-up. Since 1986, the Spill Test Facility has been utilized for releases to evaluate the patterns of dispersion, mitigation techniques, and combustion characteristics of select materials. Use of the facility can also aid users in developing emergency planning under US P.L 99-499, the Superfund Amendments and Reauthorization Act of 1986 (SARA) and other regulations. The Spill Test Facility Program is managed by the US Department of Energy (DOE), Office of Fossil Energy (FE) with the support and assistance of other divisions of US DOE and the US Government. DOE/FE serves as facilitator and business manager for the Spill Test Facility and site. This brief document is designed to acquaint a potential user of the Spill Test Facility with an outline of the procedures and policies associated with the use of the facility

20. Risk management technique for liquefied natural gas facilities

Fedor, O. H.; Parsons, W. N.

1975-01-01

Checklists have been compiled for planning, design, construction, startup and debugging, and operation of liquefied natural gas facilities. Lists include references to pertinent safety regulations. Methods described are applicable to handling of other hazardous materials.

1. Sources of Groundwater Based on Helium Analyses in and near the Freshwater/Saline-Water Transition Zone of the San Antonio Segment of the Edwards Aquifer, South-Central Texas, 2002-03

Hunt, Andrew G.; Lambert, Rebecca B.; Fahlquist, Lynne

2010-01-01

This report evaluates dissolved noble gas data, specifically helium-3 and helium-4, collected by the U.S. Geological Survey, in cooperation with the San Antonio Water System, during 2002-03. Helium analyses are used to provide insight into the sources of groundwater in the freshwater/saline-water transition zone of the San Antonio segment of the Edwards aquifer. Sixty-nine dissolved gas samples were collected from 19 monitoring wells (categorized as fresh, transitional, or saline on the basis of dissolved solids concentration in samples from the wells or from fluid-profile logging of the boreholes) arranged in five transects, with one exception, across the freshwater/saline-water interface (the 1,000-milligrams-per-liter dissolved solids concentration threshold) of the Edwards aquifer. The concentration of helium-4 (the dominant isotope in atmospheric and terrigenic helium) in samples ranged from 63 microcubic centimeters per kilogram at standard temperature (20 degrees Celsius) and pressure (1 atmosphere) in a well in the East Uvalde transect to 160,587 microcubic centimeters per kilogram at standard temperature and pressure in a well in the Kyle transect. Helium-4 concentrations in the 10 saline wells generally increase from the western transects to the eastern transects. Increasing helium-4 concentrations from southwest to northeast in the transition zone, indicating increasing residence time of groundwater from southwest to northeast, is consistent with the longstanding conceptualization of the Edwards aquifer in which water recharges in the southwest, flows generally northeasterly (including in the transition zone, although more slowly than in the fresh-water zone), and discharges at major springs in the northeast. Excess helium-4 was greater than 1,000 percent for 60 of the 69 samples, indicating that terrigenic helium is largely present and that most of the excess helium-4 comes from sources other than the atmosphere. The helium data of this report cannot be

2. A Comparative Study of Liquefied Natural Gas: An Overview

2014-01-01

Natural gas is the world’s fastest growing fuel and being produced by many countries of the world in the commercial quantities. Increasing natural gas price and new development in the technologies, liquefied natural gas industry is economically attractive in the major gas exporting countries. Liquefied Natural Gas (LNG) is an important energy source and continued to contribute the growth of natural gas industry. The new advance LNG technology is used for natural gas transportation for long di...

3. The Descending Helium Balloon

Helseth, Lars Egil

2014-01-01

I describe a simple and fascinating experiment wherein helium leaks out of a rubber balloon, thereby causing it to descend. An estimate of the volumetric leakage rate is made by measuring its rate of descent.

4. Commissioning and operational results of helium refrigeration system at JLab for the 12GeV upgrade

Knudsen, Peter N. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Ganni, Venkatarao [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Dixon, Kelly D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Norton, Robert O. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Creel, Jonathan D. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

2015-12-01

The new 4.5 K refrigerator system at the Jefferson Lab (JLab) Central Helium Liquefier (CHL-2) for the 12 GeV upgrade was commissioned in late spring of 2013, following the commissioning of the new compressor system, and has been supporting 12 GeV LINAC commissioning since that time. Six design modes were tested during commissioning, consisting of a maximum capacity, nominal capacity, maximum liquefaction, maximum refrigeration, maximum fill and a stand-by/reduced load condition. The maximum capacity was designed to support a 238 g/s, 30 K and 1.16 bar cold compressor return flow, a 15 g/s, 4.5 K liquefaction load and a 12.6 kW, 35-55 K shield load. The other modes were selected to ensure proper component sizing and selection to allow the cold box to operate over a wide range of conditions and capacities. The cold box system is comprised of two physically independent cold boxes with interconnecting transfer-lines. The outside (upper) 300-60 K vertical cold box has no turbines and incorporates a liquid nitrogen pre-cooler and 80-K beds. The inside (lower) 60-4.5 K horizontal cold box houses seven turbines that are configured in four expansion stages including one Joule-Thompson expander and a 20-K bed. The helium compression system has five compressors to support three pressure levels in the cold box. This paper will summarize the analysis of the test data obtained over the wide range of operating conditions and capacities which were tested.

5. Role of heat exchangers in helium liquefaction cycles: Simulation studies using Collins cycle

Highlights: ► Role of heat exchangers in basic helium liquefier analyzed to design large-scale ones. ► Heat exchangers that determine inlet temperature to expanders are more significant. ► Limiting values of nondimensional UA for each heat exchanger have been determined. ► Extra area distributed such that effectiveness of all heat exchangers increase uniformly. ► Heat exchanger performance variation have little influence on the optimum expander flow. - Abstract: Energy efficiency of large-scale helium liquefiers generally employed in fusion reactors and accelerators is determined by the performance of their constituting components. Simulation with Aspen HYSYS® V7.0, a commercial process simulator, helps to understand the effects of heat exchanger parameters on the performance of a helium liquefier. Effective UA (product of overall heat transfer coefficient U, heat transfer surface area A and deterioration factor F) has been taken as an independent parameter, which takes into account all thermal irreversibilities and configuration effects. Nondimensionalization of parameters makes the results applicable to plants of any capacity. Rate of liquefaction is found to increase linearly with the effectiveness of heat exchangers. Performance of those heat exchangers that determine the inlet temperatures to expanders have more influence on the liquid production. Variation of sizes of heat exchangers does not affect the optimum rate of flow through expanders. Increasing UA improves the rate of liquid production; however, the improvement saturates at limiting UA. Maximum benefit in liquefaction is obtained when the available heat transfer surface area is distributed in such a way that the effectiveness remains equal for all heat exchangers. Conclusions from this study may be utilized in analyzing and designing large helium plants.

6. Helium bubbles in UO2

A certain part of helium generated in MOX fuel could form additional bubbles in fuel pellets as a result of the combination of radiation defects and high temperature. In the present study, the helium infusion treatments were conducted at high temperature with highly pressurized helium for both polycrystalline UO2 fragments and hyperstoichiometric single crystal UO2+x particles. Annealing tests for polycrystalline UO2 were followed by the helium infusion treatment to evaluate formation of helium bubble. In case of as helium-infused polycrystalline sample, it was confirmed that helium bubbles were formed after slight oxidative annealing at more than 1573K. On the other hand, the cavity observed in as-helium-infused single crystal sample grew up to form a negative crystal. Formation mechanism of helium bubble and negative crystal were discussed. (author)

7. Compact, ultra-low vibration, closed-cycle helium recycler for uninterrupted operation of MEG with SQUID magnetometers

Wang, Chao; Sun, Limin; Lichtenwalter, Ben; Zerkle, Brent; Okada, Yoshio

2016-06-01

A closed-cycle helium recycler was developed for continuous uninterrupted operation for magnetometer-based whole-head magnetoencephalography (MEG) systems. The recycler consists of a two stage 4 K pulse-tube cryocooler and is mounted on the roof of a magnetically shielded room (MSR). A flexible liquid helium (LHe) return line on the recycler is inserted into the fill port of the MEG system in the MSR through a slotted opening in the ceiling. The helium vapor is captured through a line that returns the gas to the top of the recycler assembly. A high-purity helium gas cylinder connected to the recycler assembly supplies the gas, which, after it is liquefied, increases the level of LHe in the MEG system during the start-up phase. No storage tank for evaporated helium gas nor a helium gas purifier is used. The recycler is capable of liquefying helium with a rate of ∼17 L/d after precooling the MEG system. It has provided a fully maintenance-free operation under computer control for 7 months without refill of helium. Although the recycler is used for single-orientation operation at this initial testing site, it is designed to operate at ±20° orientations, allowing the MEG system to be tilted for supine and reclining positions. Vibration of the recycler is dampened to an ultra-low level by using several vibration isolation methods, which enables uninterrupted operation during MEG measurements. Recyclers similar to this system may be quite useful even for MEG systems with 100% magnetometers.

8. Helium-3 induced enhancement of tritium production for fusion reactors

This report provides the results of an inquiry into the feasibility of enhancing tritium production levels through the activation of helium-3 following its external addition to the moderator system of a CANDU reactor. The physical basis for the scheme lies in the fact that the cross section for the activation of helium-3 to tritium is several orders of magnitude larger than the cross section for deuterium activation. The imminent introduction of a centralized facility for the removal, immobilization, and storage of tritium ensures a supply of helium-3, the product of tritium decay

9. Helium in Alberta

1979-06-01

Helium is found in small quantities in natural gas in Alberta and most natural gases throughout the world. This report outlines its properties and its present day uses such as the space program, welding of metals, controlled atmospheres for growing crystals for semi-conductors, chromatography, heat transfer, leak-testing, and research and medical-biological applications. It also appears that liquid helium will be necessary to provide a practical source of the low temperature necessary for the many potential applications of superconductivity. These offer many possibilities for savings in energy-related applications. This report also examines helium supply and demand in the USA, the principal source of supply to the Western world, Japan, which must import all its requirements, and Canada. Since the failure of Canadian Helium's Saskatchewan plant in 1977, Canada has no indigenous supply and no apparent sources which are viable under current technology. Alberta had 33.1 billion feet/sup 3/ of helium as of December 31, 1977 contained in its proved reserves of natural gas. None of this is economically recoverable under current commercial technology. By 1985, when a commercial plant would come on stream, 72% of the ultimate reserve of 47 Bcf will still be available. Alberta now has a process being field-tested which has an energy requirement only 25-30% of that of the presently available method. Should the test be successful, it will make possible the economic recovery of helium from the province's pipeline gases and the sale of the technology to other countries. 17 refs., 4 figs., 1 tab.

10. Helium process cycle

Ganni, Venkatarao

2007-10-09

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

11. Helium process cycle

Ganni, Venkatarao

2008-08-12

A unique process cycle and apparatus design separates the consumer (cryogenic) load return flow from most of the recycle return flow of a refrigerator and/or liquefier process cycle. The refrigerator and/or liquefier process recycle return flow is recompressed by a multi-stage compressor set and the consumer load return flow is recompressed by an independent consumer load compressor set that maintains a desirable constant suction pressure using a consumer load bypass control valve and the consumer load return pressure control valve that controls the consumer load compressor's suction pressure. The discharge pressure of this consumer load compressor is thereby allowed to float at the intermediate pressure in between the first and second stage recycle compressor sets. Utilizing the unique gas management valve regulation, the unique process cycle and apparatus design in which the consumer load return flow is separate from the recycle return flow, the pressure ratios of each recycle compressor stage and all main pressures associated with the recycle return flow are allowed to vary naturally, thus providing a naturally regulated and balanced floating pressure process cycle that maintains optimal efficiency at design and off-design process cycle capacity and conditions automatically.

12. Is solid helium a supersolid?

Recent experiments suggest that helium-4 atoms can flow through an experimental cell filled with solid helium. But that incompletely understood flow is quite different from the reported superfluid-like motion that so excited physicists a decade ago

13. Onset Properties of Supersolid Helium

Yu, Yongle

2010-01-01

Supersolid helium has a rather low transition temperature and a small critical velocity, compared with liquid helium. These properties could be explained in terms of helium's spectrum structure and quantum jumps involving large momentum transfer. A grain in the solid helium possess valleys (local minima) in its many-body dispersion curve, and an exchange of large momenta with the grain's surroundings occurs in a jump between a level in one valley and another level in the neighboring valley. S...

14. Helium Production and Possible Projection

Steve Mohr; James Ward

2014-01-01

The future availability of helium has been raised as an issue in the literature. However, a disaggregated projection of helium production has not been attempted, presumably due to the difficult nature of accessing disaggregated historic production data to test the accuracy of this issue. This paper presents collated and estimated historic helium production statistics from 1921 to 2012 for each helium producing country in the world and by U.S. state. A high and regular growth projection of hel...

15. Helium in Chemically Peculiar Stars

Leone, F.

1998-01-01

For the purpose of deriving the helium abundances in chemically peculiar stars, the importance of assuming a correct helium abundance has been investigated for determining the effective temperature and gravity of main sequence B-type stars, making full use of the present capability of reproducing their helium lines. Even if the flux distribution of main sequence B-type stars appears to depend only on the effective temperature for any helium abundance, the effective temperature, gravity and he...

16. Preparation of two-component polyurethane coatings from bleached liquefied wood

Pori, Pavel; Tavzes, Črtomir; Hrastnik, David; Budija, Franc; Pavlič, Matjaž; Petrič, Marko; Cheumani-Yona, Arnaud Maxime

2016-01-01

Liquefied wood-based polyurethane wood coatings of an aesthetically acceptable light colour were prepared and characterised. Liquefied black poplar wood was obtained by solvolysis in a polyethylene glycol/glycerol mixture, and it was bleached with hydrogen peroxide. The bleaching treatment converted liquefied wood from a dark brown to a yellowish product. Polyurethane films were prepared by the curing of liquefied wood with polymeric diphenylmethane diisocyanate or trimethylolpropane toluene ...

17. Fine structure of helium and light helium-like ions

2010-01-01

Calculational results are presented for the fine-structure splitting of the 2^3P state of helium and helium-like ions with the nuclear charge Z up to 10. Theoretical predictions are in agreement with the latest experimental results for the helium fine-structure intervals as well as with the most of the experimental data available for light helium-like ions. Comparing the theoretical value of the 2^3P_0-2^3P_1 interval in helium with the experimental result [T. Zelevinsky et al. Phys. Rev. Let...

18. Liquefied gaseous fuels safety and environmental control assessment program: a status report

None

1979-05-01

Progress is reported in research on the safety and environmental aspects of four principal liquefied gaseous material systems: liquefied natural gas (LNG), liquefied petroleum gas (LPG), hydrogen, and ammonia. Each section of the report has been abstracted and indexed individually. (JGB)

19. Broken symmetry makes helium

Gray, P L

2003-01-01

"The subatomic pion particle breaks the charge symmetry rule that governs both fusion and decay. In experiments performed at the Indiana University Cyclotron Laboratory, physicists forced heavy hydrogen (1 proton + 1 neutron) to fuse into helium in a controlled, measurable environment" (1 paragraph).

20. Recent run-time experience and investigation of impurities in turbines circuit of Helium plant of SST-1

One of the key sub-systems of Steady State superconducting Tokamak (SST-1) is cryogenic 1.3 kW at 4.5 K Helium refrigerator/liquefier system. The helium plant consists of 3 nos. of screw compressors, oil removal system, purifier and cold-box with 3 turbo expanders (turbines) and helium cold circulator. During the recent SST-1 plasma campaigns, we observed high pressure drop of the order of 3 bar between the wheel outlet of turbine A and the wheel inlet of turbine - B. This was significant higher values of pressures drop across turbines, which reduced the speed of turbine A and B and in turn reduced the overall plant capacity. The helium circuits in the plant have 10-micron filter at the mouth of turbine - B. Initially, major suspects of such high blockage are assumed to be air-impurity, dust particles or collapse of filter. Several breaks in plant operation have been taken to warm up the turbines circuits up to 90 K to remove condensation of air-impurities at filter. Still this exercise did not solve blockage of filter in turbine circuits. A detailed investigation exercise with air/water regeneration and rinsing of cold box as well as purification of helium gas in buffer tanks are carried out to remove air impurities from cold-box. A trial run of cold box was executed in liquefier mode with turbines up to cryogenic temperatures and solved blockage in turbine circuits. The paper describes run-time experience of helium plant with helium impurity in turbine circuits, methods to remove impurity, demonstration of turbine performance and lessons learnt during this operation. (author)

1. Helium anion formation inside helium droplets

Jabbour Al Maalouf, Elias; Reitshammer, Julia; Ribar, Anita; Scheier, Paul; Denifl, Stephan

2016-07-01

The formation of He∗- is examined with improved electron energy resolution of about 100 meV utilizing a hemispherical electron monochromator. The work presented provides a precise determination of the three previously determined resonance peak positions that significantly contribute to the formation of He∗- inside helium nanodroplets in the energy range from 20 eV to 29.5 eV. In addition, a new feature is identified located at 27.69 ± 0.18 eV that we assign to the presence of O2 as a dopant inside the droplet. With increasing droplet size a small blue shift of the resonance positions is observed. Also for the relatively low electron currents used in the present study (i.e., 15-70 nA) a quadratic dependence of the He∗- ion yield on the electron current is observed.

2. The development of Liquefied Petroleum Gases world market

This paper presents a sectorial analysis of Liquefied Petroleum Gases market in the world. Informations on LPG consumption, uses sectors, production, supply and demand, prices are given. The great consumption areas (USA, Europe, Japan) and the exporting countries (Middle East, Algeria, Venezuela) are briefly described

3. Neutral muonic helium(3)

Neutral muonic helium, He++μ-e-, can be considered in two pieces. The (He++μ-)+-system is a hydrogenic ion halfway in size between an atom and a nucleus. It acts like a singly charged pseudo-nucleus to the electron surrounding it. The whole system appears like one hydrogen inside another. Neutral muonic helium can be formed in the ground state in which the coupling of the magnetic moments gives rise to a hyperfine structure (hfs). 3He++μ-e- has three spin one half particles interact without any restrictions by the Pauli exclusion principle. The level diagram of the ground state is shown. There is a large muonic hfs splitting corresponding to the He++μ- ion to be in one of the two spin states with total spin quantum number G = 0 and G = 1. To measure the atomic hfs superimposed on the G = 1 triplet state is the aim of this experiment. (Auth.)

4. Helium abundance in the Orion A source

The H, He 66α (22.4 GHz) and H, He 56α (36.5 GHz) recombination line observations were made at several positions of the central region of Orion A (R ∼ 3'). The observed relative helium abundance y' is found to increase with the angular distance from the nebular centre and to amount the mean value of 11.6% at the peripherycal positions. The comparison with the results of low frequency observations (H, He 109α, ν ∼ 5.0 GHz) shows that measurements towards the centre (y'=8-9%) is in agreement with the low frequency measurements of y', however y' at the peripherycal positions are higher than that at low frequency. The nebula model of a ''blister'' type is constructed to explain such behaviour. The conclusions are made that the actual helium abundance y in Orion A is ∼ 12%, the Orion Nebula expands and its radial velocity is ∼ 5 km/s

5. Ionized helium afterglow study

In order to take into account the characteristics of ionized helium, under relaxation conditions, in the determination of the unknown coefficients of the reaction rates and more particularly those of the recombination of H2+ ions, a method has been developed which consists in recovering, using a system of differential equations with coupled partial derivatives, the set of all the physical quantities which can at the moment be measured as a function of time in a helium after-discharge. The energy balance of the maxwellian electrons and the speed distribution function of the electrons were studied in details and calculated as a function of time and location in space. The non-maxwellian electrons were included in the calculations. Measurements were made over a large range of experimental conditions using 5 different diagnoses: UHF interferometry in the X band, UHF radiometry in the X band, mass spectrometry, optical absorption spectrometry and optical emission spectrometry. All experimental data, obtained at 293 deg K and at seven different pressures ranging from 5 to 100 Torr were perfectly reproduced by the proposed system of differential equations, with the same reaction rate coefficients and the same constants. The method developed here gives a complete solution for the helium after-discharge at room temperature over a wide range of experimental conditions. It underlines the important reactions within the ionized gas, gives the absolute value and the dependences of the electron-He2+ ion recombination coefficient and allows the determination of the elementary mechanisms causing these dependences. It also gives the coefficients and the reaction rates of all the other elementary mechanisms which, besides recombination, determine the relaxation of ionized helium

6. Antiprotonic helium atomcules

Sauge Sébastien

2012-10-01

Full Text Available About 3% of antiprotons ( stopped in helium are long-lived with microsecond lifetimes, against picoseconds in all other materials. This unusual longevity has been ascribed to the trapping of on metastable bound states in He+ helium atom-molecules thus named atomcules. Apart from their unique dual structure investigated by laser spectroscopy – a near-circular quasi-classical Rydberg atom with l ~ n – 1 ~ 37 or a special diatomic molecule with a negatively charged nucleus in high rotational state with J = l – the chemical physics aspects of their interaction with other atoms or molecules constitute an interesting topic for molecular physics. While atomcules may resist to million collisions in helium, molecular contaminants such as H2 are likely to destroy them in a single one, down to very low temperatures. In the Born-Oppenheimer framework, we interpret the molecular interaction obtained by ab initio quantum chemical calculations in terms of classical reactive channels, with activation barriers accounting for the experiments carried out in He and H2. From classical trajectory Monte Carlo simulations, we show that the thermalization stage strongly quenches initial populations, thus reduced to a recovered 3 % trapping fraction. This work illustrates the pertinence of chemical physics concepts to the study of exotic processes involving antimatter. New insights into the physico-chemistry of cold interstellar radicals are anticipated.

7. Applications of Groundwater Helium

Kulongoski, Justin T.; Hilton, David R.

2011-01-01

Helium abundance and isotope variations have widespread application in groundwater-related studies. This stems from the inert nature of this noble gas and the fact that its two isotopes ? helium-3 and helium-4 ? have distinct origins and vary widely in different terrestrial reservoirs. These attributes allow He concentrations and 3He/4He isotope ratios to be used to recognize and quantify the influence of a number of potential contributors to the total He budget of a groundwater sample. These are atmospheric components, such as air-equilibrated and air-entrained He, as well as terrigenic components, including in situ (aquifer) He, deep crustal and/or mantle He and tritiogenic 3He. Each of these components can be exploited to reveal information on a number of topics, from groundwater chronology, through degassing of the Earth?s crust to the role of faults in the transfer of mantle-derived volatiles to the surface. In this review, we present a guide to how groundwater He is collected from aquifer systems and quantitatively measured in the laboratory. We then illustrate the approach of resolving the measured He characteristics into its component structures using assumptions of endmember compositions. This is followed by a discussion of the application of groundwater He to the types of topics mentioned above using case studies from aquifers in California and Australia. Finally, we present possible future research directions involving dissolved He in groundwater.

8. A reexamination of quenches in Helium 4 and Helium 3

Karra, G.; Rivers, R. J.

1998-01-01

In the light of recent difficulties in observing vortices in quenches of liquid helium 4 to its superfluid state we re-examine the Zurek scenario for their production. We argue that experiments in helium 4 are unlikely to produce true vortices in the numbers originally anticipated, if at all, because of the wide Ginzberg regime and the slowness of the mechanical quenches. On the other hand, the observed production of unambiguous vortices in neutron-bombarded helium 3, with its narrow Ginzberg...

9. Helium anion formation inside helium droplets

Maalouf, Elias Jabbour Al; Reitshammer, Julia; Ribar, Anita; Scheier, Paul; Denifl, Stephan

2016-07-01

The formation of He∗- is examined with improved electron energy resolution of about 100 meV utilizing a hemispherical electron monochromator. The work presented provides a precise determination of the three previously determined resonance peak positions that significantly contribute to the formation of He∗- inside helium nanodroplets in the energy range from 20 eV to 29.5 eV. In addition, a new feature is identified located at 27.69 ± 0.18 eV that we assign to the presence of O2 as a dopant inside the droplet. With increasing droplet size a small blue shift of the resonance positions is observed. Also for the relatively low electron currents used in the present study (i.e., 15-70 nA) a quadratic dependence of the He∗- ion yield on the electron current is observed. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

10. Cavitation pressure in liquid helium

Caupin, Frederic; Balibar, Sebastien

2001-01-01

Recent experiments have suggested that, at low enough temperature, the homogeneous nucleation of bubbles occurs in liquid helium near the calculated spinodal limit. This was done in pure superfluid helium 4 and in pure normal liquid helium 3. However, in such experiments, where the negative pressure is produced by focusing an acoustic wave in the bulk liquid, the local amplitude of the instantaneous pressure or density is not directly measurable. In this article, we present a series of measur...

11. Operation and maintenance of 2 kW helium refrigerator

In Japan Atomic Energy Research Institute, for the research and development of the superconducting coils for nuclear fusion, the helium refrigerator was constructed, and the operation corresponding to diversified objectives has been carried out. This refrigerator possess the liquefaction and refrigerating capacity of 350 L/h at maximum and 1.2 kW at 4.4 K. For the purpose of protecting the turbine expansion machine from the impurities in the system which are originated in refrigeration load side and the variation of thermal load, the separated cycle was adopted. The main cycle and the turbine cycle are respectively independent, and thermally connected in the cold box. The main operation patterns are the refrigerating operation for large coil experiment and the experiment using cryostats and the liquefaction operation for producing liquefied helium. This time, large coil experiment is explained in detail. The refining operation for purifying the system including a large test coil, the initial period refrigeration for cooling down and normal operation are explained. The management of machinery and equipment during operation and the maintenance management of machinery and equipment are reported. (K.I.)

12. Helium cryopumping for fusion applications

Large quantities of helium and hydrogen isotopes will be exhausted continuously from fusion power reactors. This paper summarizes two development programs undertaken to address vacuum pumping for this application: (i) A continuous duty cryopump for pumping helium and/or hydrogen species using charcoal sorbent and (ii) a cryopump configuration with an alternative shielding arrangement using charcoal sorbent or argon spray. A test program evaluated automatic pumping of helium, helium pumping by charcoal cryosorption and with argon spray, and cryosorption of helium/hydrogen mixtures. The continuous duty cryopump pumped helium continuously and conveniently. Helium pumping speed was 7.7 l/s/cm2 of charcoal, compared to 5.8 l/s/cm2 for the alternative pump. Helium speed using argon spray was 18% of that obtained by charcoal cryosorption in the same (W-panel) pump. During continuous duty cryopump mixture tests with helium and hydrogen copumped on charcoal, gas was released sporadically. Testing was insufficient to explain this unacceptable event

13. 48 CFR 52.208-8 - Required Sources for Helium and Helium Usage Data.

2010-10-01

... Helium and Helium Usage Data. 52.208-8 Section 52.208-8 Federal Acquisition Regulations System FEDERAL... Provisions and Clauses 52.208-8 Required Sources for Helium and Helium Usage Data. As prescribed in 8.505, insert the following clause: Required Sources for Helium and Helium Usage Data (APR 2002) (a)...

14. Cavitation in liquid helium

Finch, R. D.; Kagiwada, R.; Barmatz, M.; Rudnick, I.

1963-11-15

Ultrasonic cavitation was induced in liquid helium over the temperature range 1.2 to 2.3 deg K, using a pair of identical transducers. The transducers were calibrated using a reciprocity technique and the cavitation threshold was determined at 90 kc/s. It was found that this threshold has a sharp peak at the lambda point, but is, at all temperatures quite low, with an approximate range of 0.001 to 0.01 atm. The significance of the results is discussed. (auth)

15. Lateral response of pile foundations in liquefiable soils

2015-10-01

Full Text Available Liquefaction has been a main cause of damage to civil engineering structures in seismically active areas. The effects of damage of liquefaction on deep foundations are very destructive. Seismic behavior of pile foundations is widely discussed by many researchers for safer and more economic design purposes. This paper presents a pseudo-static method for analysis of piles in liquefiable soil under seismic loads. A free-field site response analysis using three-dimensional (3D numerical modeling was performed to determine kinematic loads from lateral ground displacements and inertial loads from vibration of the superstructure. The effects of various parameters, such as soil layering, kinematic and inertial forces, boundary condition of pile head and ground slope, on pile response were studied. By comparing the numerical results with the centrifuge test results, it can be concluded that the use of the p-y curves with various degradation factors in liquefiable sand gives reasonable results.

16. High Efficiency Regenerative Helium Compressor Project

National Aeronautics and Space Administration — Helium plays several critical rolls in spacecraft propulsion. High pressure helium is commonly used to pressurize propellant fuel tanks. Helium cryocoolers can be...

17. Liquefied natural gas experimental and theoretical safety research overview

Schneider, A.L.

1979-01-01

A liquefied natural gas experimental and theoretical safety research overview covers 14 categories under the three main sections of onshore facilities, ocean tansport, and basic properties, and indicates that the current understanding of the material is sufficient to design, operate, and regulate LNG transportation and storage. Future research will fine-tune this understanding, perhaps allowing the use of less conservative values in design and operation.

18. Synthesis and Properties of Polyurethane Resins from Liquefied Benzylated Wood

Yu Ping WEI; Fa CHENG; Hou Ping LI; Jiu Gao YU

2005-01-01

In this paper, polyurethane resins were synthesized from liquefied benzylated wood and TDI (toluene diisocyanate)-TMP (trihydromethylene propane) prepolymer. And the relation between microphase structure and properties of PU samples were also studied. The results indicated that coatings obtained had good mechanical and thermal properties. The amount of the curing agent has great effect on the degree of phase segregation. In addition, with increased the curing agent amount, the thermal stabilities were also improved.

19. Ion temperature anisotropy in high power helium neutral beam fuelling experiments in JET

Maas, A.C.; Core, W.G.F.; Gerstel, U.C.; Von Hellermann, M.G.; Koenig, R.W.T.; Marcus, F.B. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

1994-07-01

During helium beam fuelling experiments in JET, distinctive anisotropic features have been observed in the velocity distribution function describing both fast and thermal alpha particle populations. During the initial fuelling phase the central helium ion temperature observed perpendicular to the magnetic field is higher than the central electron temperature, while the central helium ion temperature observed parallel to the magnetic field is lower than or equal to the central electron temperature. In order to verify temperature measurements of both perpendicular and parallel lines of sight, other independent methods of deducing the ion temperature are investigated: deuterium ion temperature, deuterium density, comparison with neutron rates and profiles (influence of a possible metastable population of helium). 6 refs., 7 figs.

20. Liquid helium vessel thermal heat load calculation and modification of the liquid helium cryostat for improved thermal performances

A room temperature bore superconducting (SC) solenoid magnet has been developed at Control Instrumentation Division (CnID) for carrying out liquid PbLi Magneto Hydro Dynamic (MHD) and corrosion experimental studies for ITER TBM. The SC solenoid magnet is designed to generate central bore magnetic field of 4 Tesla in a bore diameter of 300 mm and length of 800 mm with a field uniformity of 0.5% or better. The SC magnet is made up of low temperature NbTi copper composite wire whose critical temperature (Tc) is 9.8 K. The SC magnet needs to be cooled to liquid helium temperature (4.2 K) for its stable operation. Considering the operational requirement, an adiabatically stable SC magnet is under development. The adiabatically cooled SC magnet is completely immersed inside the liquid helium vessel. As the latent heat of vaporisation of liquid helium is less, heat load on liquid helium vessel needs to be reduced. In this paper we discuss about the liquid helium cryostat developed with conduction cooled thermal shield. Various heat loads on the liquid helium cryostat is calculated. Design modification of the existing cryostat to reduce the heat load and improved thermal performance is discussed. (author)

1. Quantum cavitation in liquid helium

Guilleumas, Montserrat; Barranco Gómez, Manuel; Jezek, Dora M.; Lombard, Roland J.; Pi Pericay, Martí

1996-01-01

Using a functional-integral approach, we have determined the temperature below which cavitation in liquid helium is driven by thermally assisted quantum tunneling. For both helium isotopes, we have obtained the crossover temperature in the whole range of allowed negative p essures. Our results are compatible with recent experimental results on 4He.

2. Helium behaviour in nuclear glasses

The present thesis focuses on the study of helium behavior in R7T7 nuclear waste glass. Helium is generated by the minor actinides alpha decays incorporated in the glass matrix. Therefore, four types of materials were used in this work. These are non radioactive R7T7 glasses saturated with helium under pressure, glasses implanted with 3He+ ions, glasses doped with curium and glasses irradiated in nuclear reactor. The study of helium solubility in saturated R7T7 glass has shown that helium atoms are inserted in the glass free volume. The results yielded a solubility of about 1016 at. cm-3 atm.-1. The incorporation limit of helium in this type of glass has been determined; its value amounted to about 2*1021 at. cm-3, corresponding to 2.5 at.%. Diffusion studies have shown that the helium migration is controlled by the single population dissolved in the glass free volume. An ideal diffusion model was used to simulate the helium release data which allowed to determine diffusion coefficients obeying to the following Arrhenius law: D = D0exp(-Ea/kBT), where D0 = 2.2*10-2 and 5.4*10-3 cm2 s-1 and Ea = 0.61 eV for the helium saturated and the curium doped glass respectively. These results reflect a thermally activated diffusion mechanism which seems to be not influenced by the glass radiation damage and helium concentrations studied in the present work (up to 8*1019 at. g-1, corresponding to 0.1 at.%). Characterizations of the macroscopic, structural and microstructural properties of glasses irradiated in nuclear reactor did not reveal any impact associated with the presence of helium at high concentrations. The observed modifications i.e. a swelling of 0.7 %, a decrease in hardness by 38 %, an increase between 8 and 34 % of the fracture toughness and a stabilization of the glass structure under irradiation, were attributed to the glass nuclear damage induced by the irradiation in reactor. Characterizations by SEM and TEM of R7T7 glasses implanted with helium at high

3. 46 CFR 58.16-7 - Use of liquefied petroleum gas.

2010-10-01

... requirements of 46 CFR 25.45-2 or 184.05, as applicable. (c) Systems using liquefied petroleum gas for cooking... 46 Shipping 2 2010-10-01 2010-10-01 false Use of liquefied petroleum gas. 58.16-7 Section 58.16-7... MACHINERY AND RELATED SYSTEMS Liquefied Petroleum Gases for Cooking and Heating § 58.16-7 Use of...

4. Effects of helium on titanium films and the helium diffusion

SONG YingMin; LUO ShunZhong; LONG XingGui; AN Zhu; LIU Ning; PANG HongChao; WU XingChun; YANG BenFu; ZHENG SiXiao

2008-01-01

Using direct current-magnetron sputtering, Helium-trapped Ti films with a He/Ar mixture was studied. The relative helium content, helium depth profiles for the Ti films and crystallization capacity were analyzed by Enhanced Proton Backscattering Spectrometry (EPBS) and X-ray diffraction (XRD). It was found that helium diffusion enhanced as more helium trapping into Ti films, and the He holding ratios were 95.9%, 94.9%, 93.9%, 82.8% when the Ti films with the He/Ti of concentrations of 9.7 at.Q, 19.5 at.Q, 19.7 at.Q, 48.3 at.% were measured again 4 months later, respectively. The diffraction peaks be-came weak and wider, the peak of (002) plane was shifted to smaller diffraction angles and the relevant interplanar spacing d(hkl) increased gradually as more helium trapping into Ti films. The main peak was made trending to the (101) plane by both higher deposition temperature and more helium trapping.

5. On the Formation of (Anionic) Excited Helium Dimers in Helium Droplets

Huber, Stefan E.; Mauracher, Andreas

2014-01-01

Metastable atomic and molecular helium anions exhibiting high-spin quartet configurations can be produced in helium droplets via electron impact. Their lifetimes allow detection in mass spectrometric experiments. Formation of atomic helium anions comprises collision-induced excitation of ground state helium and concomitant electron capture. Yet the formation of molecular helium anions in helium droplets has been an unresolved issue. In this work, we explore the interaction of excited helium a...

6. Photoionization of helium dimers

The helium dimer is one of the most weakly bound systems in the universe. This makes it an interesting quantum mechanical object for investigation. These Van der Waals Clusters can be produced in an expansion of a cryogenic gas jet through a small nozzle into vacuum. In the present experiment we examine the interaction of He dimers with synchrotron radiation at an energy range from 64 to 78 eV. We observed different pathways leading to single ionization of both He atoms of the dimer compound. This two close standing ions begin now to dissociate in cause of their coulomb potential. All charged fragments were detected in coincidence with a COLTRIMS system. Especially Interatomic Coulombic Decay (ICD) and the two step process (TS1) were clearly identified. Furthermore a distribution of the internuclear distance was obtained from the measured Kinetic Energy Release (KER). (orig.)

7. Exotic helium molecules

We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range 4He2(23S1-23P0) molecule, or a 4He2(23S1-23S1) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 ± 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range 4He2(23S1-23S1) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime τ = (1.4 ± 0.3) μs is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

8. Electronic properties of physisorbed helium

This thesis deals with electronic excitations of helium physisorbed on metal substrates. It is studied to what extent the electronic properties change compared to the gas phase due to the increased helium density and the proximity of the metal. Furthermore, the influence of different substrate materials is investigated systematically. To this end, up to two helium layers were adsorbed onto Ru (001), Pt (111), Cu (111), and Ag (111) surfaces in a custom-made cryostat. These samples were studied spectroscopically using synchrotron radiation and a time-of-flight detector. The experimental results were then analyzed in comparison with extensive theoretical model calculations.

9. Electronic properties of physisorbed helium

Kossler, Sarah

2011-09-22

This thesis deals with electronic excitations of helium physisorbed on metal substrates. It is studied to what extent the electronic properties change compared to the gas phase due to the increased helium density and the proximity of the metal. Furthermore, the influence of different substrate materials is investigated systematically. To this end, up to two helium layers were adsorbed onto Ru (001), Pt (111), Cu (111), and Ag (111) surfaces in a custom-made cryostat. These samples were studied spectroscopically using synchrotron radiation and a time-of-flight detector. The experimental results were then analyzed in comparison with extensive theoretical model calculations.

10. Trapping fermionic and bosonic helium atoms

Stas, R.J.W.

2005-01-01

This thesis presents experimental and theoretical work performed at the Laser Centre of the Vrije Universiteit in Amsterdam to study laser-cooled metastable triplet helium atoms. Samples containing about 3x10^8 helium atoms-either fermionic helium-3 atoms, bosonic helium-4 atoms or mixtures thereof

11. Lattice site of helium implanted in magnesium aluminate spinel

Allen, W.R. (Metals and Ceramics Div., Oak Ridge National Lab., TN (United States))

1993-01-01

The lattice site of helium implanted at 60 keV in magnesium aluminate spinel (MgAl[sub 2]O[sub 4]) has been investigated with channeling effect measurements that apply the ion-induced [sup 3]He(d, p)[sup 4]He nuclear reaction. Within the spinel crystal structure, numerous interstices characterized by octahedral anion coordination are intrinsically unfilled by cations. For implantation at 300 K, a typical helium atom locates centrally in one of these vacant octahedral interstices with a probability of approximately 95%. Significant occupation of other lattice sites of either high or low symmetry was rejected. In particular helium neither clusters in defect complexes nor locates in tetrahedral interstices or substitutional sites. (orig.).

12. Lattice site of helium implanted in magnesium aluminate spinel

The lattice site of helium implanted at 60 keV in magnesium aluminate spinel (MgAl2O4) has been investigated with channeling effect measurements that apply the ion-induced 3He(d, p)4He nuclear reaction. Within the spinel crystal structure, numerous interstices characterized by octahedral anion coordination are intrinsically unfilled by cations. For implantation at 300 K, a typical helium atom locates centrally in one of these vacant octahedral interstices with a probability of approximately 95%. Significant occupation of other lattice sites of either high or low symmetry was rejected. In particular helium neither clusters in defect complexes nor locates in tetrahedral interstices or substitutional sites. (orig.)

13. Lattice site of helium implanted in magnesium aluminate spinel

Alien, W. R.

1993-01-01

The lattice site of helium implanted at 60 keV in magnesium aluminate spinel (MgAl 2O 4) has been investigated with channeling effect measurements that apply the ion-induced 3He(d, p) 4He nuclear reaction. Within the spinel crystal structure, numerous interstices characterized by octahedral anion coordination are intrinsically unfilled by cations. For implantation at 300 K, a typical helium atom locates centrally in one of these vacant octahedral interstices with a probability of approximately 95%. Significant occupation of other lattice sites of either high or low symmetry was rejected. In particular, helium neither clusters in defect complexes nor locates in tetrahedral interstices or substitutional sites.

14. Development of liquid helium-3 target for experimental studies of antikaon-nucleon interaction at J-PARC

Iio, M; Sato, M; Enomoto, S; Hashimoto, T; Suzuki, S; Iwasaki, M; Hayano, R S

2012-01-01

A liquid helium-3 target system was developed for experimental studies of kaonic atoms and kaonic nuclei at J-PARC. helium-3 gas is liquefied in a heat exchanger cooled below 3.2 K by decompression of liquid helium-4. To maintain a large acceptance of the cylindrical detector system for decay particles of kaonic nuclei, efficient heat transport between the separate target cell and the main unit is realized using circulation of liquid helium-3. To minimize the amount of material, a vacuum vessel containing a carbon fiber reinforced plastic cylinder having an inside diameter of 150 mm and a thickness of 1 mm was produced. A target cell made of pure beryllium and beryllium-aluminum alloy was developed not only to minimize the amount of material but to obtain also high x-ray transmission. During a cooling test, the target cell was kept at 1.3 K at a pressure of 33 mbar. The total estimated heat load to the components including the target cell and heat exchanger cooled by liquid helium-4 decompression, was 0.21 W,...

15. Cover stones on liquefiable soil bed under waves

Sumer, B. Mutlu; Hatipoglu, Figen; Fredsøe, Jørgen

2010-01-01

The paper describes the results of an experimental study on the behavior of cover stones on a liquefiable soil bed exposed to a progressive wave. The soil was silt with d50=0.098mm. Stones, the size of 4cm, were used as cover material. The effect of packing density of stones, and that of number of...... stone layers (including the effect of an intermediate filter layer) were investigated. Pore pressure was measured across the soil depth. The experiments show that the soil liquefaction depended mainly on two parameters: the packing density of stones, and the number of stone layers. When the liquefaction...

16. Microcellular Injection Molding Using Helium

In comparison with conventional foaming process microcellular injection molding process has advantages such as small bubble size, the removal of sink mark, scale reliability, and weight lightening. So microcellular injection molded parts are applied to electrical product and automobile part. Conventional microcellular foaming process used carbon dioxide and nitrogen as a foaming agent. And it has been never researched and applied about microcellular injection molding process using helium. In this paper, we did a microcellular injection molding process using helium based on previous research result and made samples. From this we can certificate the possibility of microcellular continuous process using helium. Helium is lighter and faster in diffusion than carbon dioxide or nitrogen so through this technique, it can be solved the problem such as spray or labeling

17. Implanting helium into nanocrystalline hydrogen storage alloy

The possibility of implanting helium into LaNixAly alloy by high energy ball milling is explored. By analyzing the sample after ball milling, it is shown that Helium can be implanted into the material. Helium lies in the interfacial free volume rather than the crystal lattice. The implanted helium has high thermal stability. Quantity of Helium implanted by this method is very little

18. Spectra of cold molecular ions from hot helium nanodroplets

The function of a molecule is intimately related to its structure. Accordingly, in the quest for a better understanding of molecular function, the development of spectroscopic methods to elucidate molecular structures increasingly takes central stage. The amount of detail that can be derived from spectra depends on the experimental conditions, most notably on the temperature of the sample and the intermolecular interactions a molecule experiences. Helium nanodroplets provide in this respect an almost ideal matrix. For neutral molecules, helium nanodroplet spectroscopy thus has led to important discoveries related to the structure of key molecular systems and has provided insight into the mechanisms underlying chemical reactions. Compared to the level of sophistication that has been reached for neutrals, the spectroscopic exploration of ions is still in its infancy. The use of helium droplets as a cryogenic matrix could potentially solve many of the technical challenges associated with recording high-resolution spectra of cold molecular ions. Here, we present a method to record spectra of ion containing helium nanodroplets that finds its roots in the nonthermal cooling dynamics of excited molecular ions. In addition, spectra of several molecular ions are present, and the influence of the helium environment on these spectra are discussed.

19. 46 CFR 61.15-10 - Liquefied-petroleum-gas piping for heating and cooking.

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Liquefied-petroleum-gas piping for heating and cooking. 61.15-10 Section 61.15-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND INSPECTIONS Periodic Tests of Piping Systems § 61.15-10 Liquefied-petroleum-gas piping for heating and cooking. (a)...

20. 30 CFR 75.1106-3 - Storage of liquefied and nonliquefied compressed gas cylinders; requirements.

2010-07-01

... compressed gas cylinders; requirements. 75.1106-3 Section 75.1106-3 Mineral Resources MINE SAFETY AND HEALTH... Fire Protection § 75.1106-3 Storage of liquefied and nonliquefied compressed gas cylinders; requirements. (a) Liquefied and nonliquefied compressed gas cylinders stored in an underground coal mine...

1. 30 CFR 75.1106-2 - Transportation of liquefied and nonliquefied compressed gas cylinders; requirements.

2010-07-01

... compressed gas cylinders; requirements. 75.1106-2 Section 75.1106-2 Mineral Resources MINE SAFETY AND HEALTH... Fire Protection § 75.1106-2 Transportation of liquefied and nonliquefied compressed gas cylinders; requirements. (a) Liquefied and nonliquefied compressed gas cylinders transported into or through...

2. Design optimization of a 0.1-ton/day active magnetic regenerative hydrogen liquefier

Zhang, L.; Sherif, S. A.; DeGregoria, A. J.; Zimm, C. B.; Veziroglu, T. N.

2000-04-01

A design optimization procedure of a 0.1-ton/day active magnetic regenerative (AMR) hydrogen liquefier model is described. The liquefier is proposed for the industrial liquid hydrogen market with overall efficiency being the primary measure of performance. This performance is described here in terms of particle size, bed length, and inter-stage temperature. Efficiency comparable to larger gas cycle plants is predicted. The magnetic liquefier may be modified to operate as a two-stage magnetic refrigerator between 77 and 20 K with high efficiency. The paper describes an optimization method as applied to the design of a two-stage AMR hydrogen liquefier and presents the associated results. A five-parameter optimization process is performed since there are five changeable parameters; the low- and high-stage particle sizes, the low- and high-stage bed lengths, and the inter-stage temperature. Model results are presented and compared with experimental results of an actual liquefier.

3. Suspension Dynamics of Liquefied Lignocellulosic Biomass in Pipeflow using Echo Particle Image Velocimetry

Demarchi, Nicholas; White, Christopher

2015-11-01

Echo particle image velocimetry (EPIV) is used to acquire planar fields of velocity in pipeflow of liquefied biomass. The biomass used is acid washed corn stover liquefied by enzymatic hydrolysis. The liquefaction process produces a complex multiphase fluid suspension with a microstructure consisting of insoluble solid particles dispersed within a continuous liquid phase. The solid particles are generally heavier than the liquid phase, non-spherical, and distributed over a wide range of aspect ratios and sizes. Batches of liquefied biomass are produced at incremental mass loadings doubling from 1.5% to 12%. The rheology, microstructure, and solid particle settling velocities of the liquefied biomass as a function of mass loading is first quantified. Next, EPIV is used to measure and quantify the flow dynamics of liquefied biomass suspensions under laminar pressure driven pipeflow conditions. Finally, Information gathered from the experimental data is used to simulate particle settling rates and predict the particle physics under the same pipeflow conditions.?

4. Thermal and hydraulic analysis of 3-stream multi fluid (He/He/N2) plate fin heat exchanger for helium plant

One of the key components of helium refrigerator/liquefier (HRL) plant is heat exchangers working at cryogenic temperature. For some cases, heat exchangers with effectiveness less than 90% can be a reason for failure of helium plant to produce liquid helium. To achieve such high effectiveness, it is necessary to use plate fin heat exchangers, which provides very high heat transfer surface area per unit volume. For the heat exchangers of HRL, high effectiveness, compact volume and low pressure drop are main optimizing parameters. The first heat exchanger whose temperature range is ∼310 K to ∼90 K is analysed with plate-fin type heat exchanger. This heat exchanger is a part of indigenous development work of HRL of ∼2 kW cooling capacity at 4.5 Kat IPR. Liquid nitrogen (LN2) is used to cool incoming hot He gas around ∼80 K. The detailed thermal and hydraulic analysis is discussed in this paper. (author)

5. Liquefied natural gas: safety issues, public concerns, and decision making

Van Horn, A.J.; Wilson, R.

1976-11-01

Natural gas is an important, widely used fossil fuel which is convenient and relatively non-polluting. Because U.S. domestic suppliers have been declining since 1972, suppliers have sought to import additional gas in the form of liquefied natural gas (LNG), which is 1/600 the volume of natural gas and is therefore convenient for transportation and storage. If present plans and proposals pending approval are implemented, there will be a rapid increase in the use of liquefied natural gas in the United States. The facilities required include liquefaction plants, large ocean-going tankers, import-receiving terminals, storage depots, and gas-transmission pipelines. A description is presented of the risks and impacts presented by LNG operations in the near future. The safety issues are summarized and the origins of public concern in two LNG facilities siting disputes are examined. Some of the important criteria that need to be evaluated for responsible decision making are suggested. On balance, the overall risks of LNG supply systems are probably less than those of some energy systems now in use. Nevertheless, continued attention to the potential risks is needed to ensure that this remains true.

6. A Comparative Study of Liquefied Natural Gas: An Overview

2014-05-01

Full Text Available Natural gas is the world’s fastest growing fuel and being produced by many countries of the world in the commercial quantities. Increasing natural gas price and new development in the technologies, liquefied natural gas industry is economically attractive in the major gas exporting countries. Liquefied Natural Gas (LNG is an important energy source and continued to contribute the growth of natural gas industry. The new advance LNG technology is used for natural gas transportation for long distances. LNG can be transported by the large insulated cryogenic tankers at affordable cost. This study presents an overview of LNG liquidation facilities from natural gas as feed gas to LNG storage and transport. The main objective of the study is to highlight the current data for reviewers on LNG world market, mainly on LNG production, supply, demand, price and new development of LNG plants. The technology is growing gradually with increasing number of LNG consuming countries in overall the world. In the near future, LNG price may be affected by the advanced shale gas production in the United States of America and China. Australia becomes the world second largest exporter of LNG market after Qatar. Australia will increase LNG supply by 15 Bcf/day from 2014 and accounting for 25% of world LNG production by 2030. Global LNG production forecast will be reached 540 Bcm by 2020 and LNG trade will be reached 425 Mtpa by 2025. New countries are interested to enter in the LNG world market as importers and exporters.

7. Principles and characteristics of surface radon and helium techniques used in uranium exploration

Studies were carried out to determine the nature of some of the surface radon and helium techniques used for uranium exploration. By performing radon and helium measurements at three sites with differing geology and accessibility, we were able to examine the constraints on the features determined. The sites are the Red Desert in south central Wyoming, Copper Mountain in central Wyoming, and Spokane Mountain in eastern Washington. The radon techniques employed were: zinc sulfide detectors, an ionization chamber, alpha track detectors, thermoluminescence detectors, charcoal canisters, and the partial extraction of lead-210 from soil samples. Helium was measured in soil-gas samples, soil gas from collectors, and soil samples. The ratio helium-4/argon-36 was measured in soil gas

8. Absolute calibration of TFTR helium proportional counters

The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 msec and 50 msec depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments

9. Development of a Liquefied Noble Gas Time Projection Chamber

Lesser, Ezra; White, Aaron; Aidala, Christine

2015-10-01

Liquefied noble gas detectors have been used for various applications in recent years for detecting neutrinos, neutrons, photons, and potentially dark matter. The University of Michigan is developing a detector with liquid argon to produce scintillation light and ionization electrons. Our data collection method will allow high-resolution energy measurement and spatial reconstruction of detected particles by using multi-pixel silicon photomultipliers (SiPM) and a cylindrical time projection chamber (TPC) with a multi-wire endplate. We have already designed a liquid argon condenser and purification unit surrounded by an insulating vacuum, constructed circuitry for temperature and pressure sensors, and created software to obtain high-accuracy sensor readouts. The status of detector development will be presented. Funded through the Michigan Memorial Phoenix Project.

10. Transient Analysis of Monopile Foundations Partially Embedded in Liquefied Soil

Barari, Amin; Bayat, Mehdi; Meysam, Saadati;

2015-01-01

In this study, the authors present a coupled fluid-structures-seabed interaction analysis of a monopile type of wind turbine foundations in liquefiable soils. A two dimensional analysis is performed with a nonlinear stiffness degradation model incorporated in the finite difference program Fast...... Lagrangian Analysis of Continua (FLAC), which captured the fundamental mechanisms of the monopiles in saturated granular soil. The effects of inertia and the kinematic flow of soil are investigated separately, to highlight the importance of considering the combined effect of these phenomena on the seismic...... design of offshore monopiles. Different seismic loads, such as those experienced in the Kobe, Santa Cruz, Loma Prieta, Kocaeli, and Morgan Hill earthquakes, are analyzed. The pore water pressure development, relative displacements, soil skeleton deformation and monopile bending moment are obtained for...

11. Magnetically insulated helium ion diode

Wessel, F.J.; Heidbrink, W.W.; Drum, S.; Hoang, K.; Layton, P. (Physics Department, University of California, Irvine, California 92717 (US))

1990-01-01

A gas-puff magnetically insulated ion diode is under development as a pulsed source of high-energy alpha particles for magnetic fusion experiments. The diode is patterned after the Cornell gas-puff diode (J. B. Greenly, M. Ueda, G. D. Rondeau, and D. A. Hammer, J. Appl. Phys. {bold 63}, 1872 (1988)), but with modifications to accomodate higher voltages ({lt}1 MeV) and operation in helium. The diode is designed to yield current densities approaching 200 A/cm{sup 2} one meter downstream from the source; in our first test of the new source, a helium beam was obtained.

12. Metallic helium in massive planets

Stevenson, David J.

2008-01-01

In this issue of PNAS, Stixrude and Jeanloz (4) show that band closure in pure helium occurs at lower pressures than previously thought, provided the effect of high temperatures is taken into account. This suggests that helium behaves as a metal, at least at the highest pressures encountered in Jupiter and perhaps over a wider range of pressures in the many, often much hotter, planets of Jupiter’s mass and larger that are now evidently common in the universe (5). The full thermodynamic and tr...

13. Helium retention properties of plasma facing materials

In a fusion reactor, the continuous removal of helium from the core plasma is needed in order to sustain the ignition condition. For this purpose, it has been proposed to place helium selective pumping metals, which can trap more helium than hydrogen, in the vicinity of the divertor. In this study, the helium and hydrogen trapping properties of nickel, tungsten, molybdenum, SS 304 and Inconel 625 were examined. Namely, the dependencies of irradiation temperature on the amount of trapped helium and hydrogen were obtained by thermal desorption spectroscopy (TDS), after helium or hydrogen plasma irradiation. In those metals, nickel showed the most suitable selective pumping capability. Nickel had the helium selective pumping property above 100 C. The maximum amount of trapped helium was (2-3) x 1016 He/cm2 at an irradiation temperature of 200 C and 600 C. The optimum temperature becomes about 600 C when nickel is used for a selective pumping material. (orig.)

14. Pierre Gorce working on a helium pump.

1975-01-01

This type of pump was designed by Mario Morpurgo, to circulate liquid helium in superconducting magnets wound with hollow conductors. M. Morpurgo, Design and construction of a pump for liquid helium, CRYIOGENICS, February 1977, p. 91

15. Primary population of antiprotonic helium states

Révai, J.; Shevchenko, N.V.(Nuclear Physics Institute, Řež, 25068, Czech Republic)

2003-01-01

A full quantum mechanical calculation of partial cross-sections leading to different final states of antiprotonic helium atom was performed. Calculations were carried out for a wide range of antiprotonic helium states and incident (lab) energies of the antiproton.

16. Recovery of Bio-Oil from Industrial Food Waste by Liquefied Dimethyl Ether for Biodiesel Production

Kiyoshi Sakuragi

2016-02-01

Full Text Available The development of new energy sources has become particularly important from the perspective of energy security and environmental protection. Therefore, the utilization of waste resources such as industrial food wastes (IFWs in energy production is expected. The central research institute of electric power industry (CRIEPI, Tokyo, Japan has recently developed an energy-saving oil-extraction technique involving the use of liquefied dimethyl ether (DME, which is an environmentally friendly solvent. In this study, three common IFWs (spent coffee grounds, soybean, and rapeseed cakes were evaluated with respect to oil yield for biodiesel fuel (BDF production by the DME extraction method. The coffee grounds were found to contain 16.8% bio-oil, whereas the soybean and rapeseed cakes contained only approximately 0.97% and 2.6% bio-oil, respectively. The recovered oils were qualitatively analysed by gas chromatography-mass spectrometry. The properties of fatty acid methyl esters derived from coffee oil, such as kinematic viscosity, pour point, and higher heating value (HHV, were also determined. Coffee grounds had the highest oil content and could be used as biofuel. In addition, the robust oil extraction capability of DME indicates that it may be a favourable alternative to conventional oil extraction solvents.

17. Charged Condensate and Helium Dwarf Stars

2008-01-01

White dwarf stars composed of carbon, oxygen or heavier elements are expected to crystallize as they cool down below certain temperatures. Yet, simple arguments suggest that the helium white dwarf cores may not solidify, mostly because of zero-point oscillations of the helium ions that would dissolve the crystalline structure. We argue that the interior of the helium dwarfs may instead form a macroscopic quantum state in which the charged helium-4 nuclei are in a Bose-Einstein condensate, whi...

18. Atomic spectra in a helium bubble

Nakatsukasa, Takashi; Yabana, Kazuhiro; Bertsch, George F.

2002-01-01

Density functional theory (DFT) is applied to atomic spectra under perturbations of superfluid liquid helium. The atomic DFT of helium is used to obtain the distribution of helium atoms around the impurity atom, and the electronic DFT is applied to the excitations of the atom, averaging over the ensemble of helium configurations. The shift and broadening of the D1 and D2 absorption lines are quite well reproduced by theory, suggesting that the DFT may be useful for describing spectral perturb...

19. Study of the hadron-helium and helium-helium scattering at high energy

Multiple scattering Glauber's theory is used to calculate the hadron-helium and helium-helium elastic differential cross-section. The theory is very sensitive to the 4He wave functions. We use better 4He wave functions than experimental ones. These wave functions have correct asymptotic shape. In some calculations, we take into account the spin effects and the 4He, S, S' and D states contribution. At high energy, we use inelastic corrections, to complete the differential cross-section. A study of the diffractive and coherent p-4He → 4He-X dissociation is developed. We use Humble's amplitudes with a peripherical character and an helicity structure. The agreement with experimental results is good for 24 to 400 GeV

20. Helium distribution functions in tokamak plasmas

Two different methods are used to obtain information on the helium distribution. The first method is a machine that measures the velocity distribution of neutral helium particles escaping from the plasma (NPA). The second method is charge exchange spectroscopy that measures the helium density and temperature as a function of time and place from the Doppler broadened intensity of He lines. (orig./HP)

1. Helium compounds and solidification of α particles

Helium is not rare gas in the universe, and also not inert gas, for there are Helium com- pounds, α-Particles emitted from plutonium can be solidified based on the formation of helium compounds, then, the coefficient expansion of plutonium is negligible with such a solidification, otherwise, will be remarkable to 6.8%. (author)

2. 21 CFR 184.1355 - Helium.

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Helium. 184.1355 Section 184.1355 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1355 Helium. (a) Helium (empirical formula He, CAS Reg. No. 7440-59-7) is...

3. 21 CFR 582.1355 - Helium.

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Helium. 582.1355 Section 582.1355 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS... Helium. (a) Product. Helium. (b) Conditions of use. This substance is generally recognized as safe...

4. Helium isotope characteristics of Andean geothermal fluids and lavas

Hilton, D. R.; Hammerschmidt, K.; Teufel, S.; Friedrichsen, H.

1993-12-01

The first comprehensive helium isotope survey of the Andes is reported here. We have sampled geothermal fluids and phyric lava flows from the Southern (svz) and Central (cvz) Volcanic Zones, the volcanically active Puna region and the Precordillera, Salta Basin, Longitudinal Valley and the aseismic region between the two volcanic zones. Although the active areas are characterized by significant differences in crustal age and thickness, the svz, cvz and Puna are characterized by a wide and overlapping range in He-3/He-4 ratios (for fluids and phenocrysts) from predominantly radiogenic values to close to the Mid-Ocean Ridge Basalt (MORB) ratio. The measured ranges in He-3/He-4 ratios (R) (reported normalised to the air He-3/He-4 -- R(sub A)) are: svz (0.18 less than R/R(sub A) less than 6.9); cvz (0.82 less than R/R(sub A) less than 6.0); and Puna (1.8 less than R/R(sub A) less than 5.4). Modification of magmatic He-3/He-4 ratios by water/rock interactions (fluids) or post-eruptive grow-in of radiogenic He-4 or preferential diffusive loss of He-3 (phenocrysts) is considered unlikely; this means that the wide range reflects the helium isotope characteristics of magma bodies in the Andean crust. The mechanism controlling the He-3/He-4 ratios appears to be a mixing between mantle (MORB-like) helium and a radiogenic helium component derived from radioactive decay within the magma (magma aging) and/or interaction with He-4-rich country rock: a process expected to be influenced by pre-eruptive degassing of the mantle component. Assimilation of lower crust is also capable of modifying He-3/He-4 ratios, albeit to a much lesser extent. However, it is possible that the highest measured values in each zone were established by the addition of lower crustal radiogenic helium to MORB helium. In this case, the higher 'base level' ratios of the svz would reflect the younger crustal structure of this region. In contrast to helium, there is no overlap in the Sr or Pb isotope

5. Why Helium Ends in "-Ium"

Jensen, William B.; Holme, Thomas; Cooper, Melanie; White, Carol

2004-01-01

Edward Frankland and Norman Lockyer researched upon a gaseous spectra in relation to the physical constitution of the sun and named it as "helium" (from Greek "helios" meaning "sun"). Since Lockyer apparently never formally proposed the name in print, it is not known why he chose to use a metallic end "ium".

6. Liquid helium level measurement system

The Liquid Helium level measurement system at the PLF, Mumbai has been recently upgraded. Monitoring liquid helium levels is crucial for steady operation of superconducting Linac booster. A Superconducting wire (NbTi) based sensor (American Magnetic make) is used to measure the liquid helium level. Resistance of the sensor changes with the liquid level and the change in resistance is measured using a four wire readout. The Electronics hardware is developed around Silicon lab module C8051F020, which has a 12 bit ADC on board. The sensor is excited with 80 mA constant current and the voltage across the sensor is measured using 12 bit ADC and processed further to get resistance. The measured resistance is converted to fractional level (0 to 100 %) and can be displayed on the LCD panel of the local unit as well as on the remote PC through serial communication. Each unit is capable of reading upto four level sensors. One of the important features of this measurement system is the auto calibration with a single button for all the four level sensors. Two control stations are designed, developed and successfully installed to monitor helium levels in all eight cryostats of the Linac. (author)

7. Liquid helium fluid dynamics studies

The present report describes the work carried out under the sponsorship of the Division of High Energy Physics. The report is divided into sections according to the original grant proposal (hydrodynamic studies of single phase helium; two phase flow studies; component development studies; and new research areas). Following the text is a listing of publications which have resulted from work under the grant

8. Direct photoionization of excited helium

The sensitivity of direct photoionization characteristics of the excited helium to the inclusion of the closed channels and to the choice of the structure models of the continuum and initial states in an energy region below the resonances converging to the second threshold is investigated. 37 refs.; 6 figs.; 5 tabs

9. Stability of submerged rock berms exposed to motion of liquefied soil in waves

Sumer, B. Mutlu; Dixen, Figen Hatipoglu; Fredsøe, Jørgen

2011-01-01

The paper describes the results of an experimental study on the behaviour of a submerged rock berm in liquefied backfill soil. The soil is liquefied by waves, and the rock berm is subject to the orbital motion of the liquefied soil. The soil used in the experiments was silt with d50=0.075mm....... Various berm materials were used, stones of size 0.74–2.5cm, plastic balls of size 3.6cm, brass of size 2.5cm and steel of size 1.0cm. The experiments show that rock berms that are stable under very large waves can be unstable when they are exposed to the motion of liquefied soil. The limited data...

10. Numerical simulation of detonation of an explosive atmosphere of liquefied petroleum gas in a confined space

Niculae Serban Costin

2014-09-01

Full Text Available The detonation of an explosive atmosphere from liquefied petroleum gas disseminated in air in a confined space is studied using numerical modeling with software product ANSYS AUTODYN.

11. Observation and Analysis of Affinity Law Deviations through Tested Performance of Liquefied Gas Reaction Turbines

Sarah D. Alison-Youel

2008-01-01

Liquefied gas reaction turbines are subject to the hydraulic affinity laws. Particularly for liquefied hydrocarbon gas-driven turbines, deviations from the affinity laws are encountered. In the case of reaction turbines, where the geometry is fixed, the affinity law relationships between flow, head, and rotational speed are relevant. Field experience confirms that the affinity law relationships are adequate, but that the predictions made also tend to deviate from real turbine performance. Par...

12. Dynamic Instability of Pile-Supported Structures in Liquefiable Soils during Earthquakes

2008-01-01

Piles are long slender columns installed deep into the ground to support heavy structures such as oil platforms, bridges, and tall buildings where the ground is not strong enough to support the structure on its own. In seismic prone zones, in the areas of soft soils (loose to medium dense soil which liquefies like a quick sand) piles are routinely used to support structures (buildings/ bridges). The pile and the building vibrate, and often collapse, in liquefiable soils during major earthquak...

13. Impact of Coaching and Mentoring in the Nigeria Liquefied Natural Gas Company Limited, Bonny

Agwu Mba Okechukwu; Luke Godday Raymond

2015-01-01

The paper examined the impact of coaching and mentoring in the Nigeria liquefied natural gas company limited, bonny. The research question addressed the extent at which improved employees job performance/reduced employees turnover  is influenced by the implementation of coaching and mentoring program in the Nigeria liquefied natural gas company limited, bonny. It views coaching and mentoring as learning relationships that improve employees’ job skills and develop their potentials for better p...

14. Precision spectroscopy of the helium atom

Shui-ming HU; Zheng-Tian LU; Zong-Chao YAN

2009-01-01

Persistent efforts in both theory and experiment have yielded increasingly precise understanding of the helium atom. Because of its simplicity, the helium atom has long been a testing ground for relativistic and quantum electrodynamic effects in few-body atomic systems theoretically and experimentally.Comparison between theory and experiment of the helium spectroscopy in ls2p3pJ can potentially extract a very precise value of the fine structure constant a. The helium atom can also be used to explore exotic nuclear structures. In this paper, we provide a brief review of the recent advances in precision calculations and measurements of the helium atom.

15. Trapping and release of helium in tungsten

Lhuillier, Pierre-Emile; Belhabib, Taieb; Desgardin, Pierre; Courtois, Blandine; Sauvage, Thierry; Barthe, Marie-France; Thomann, Anne-Lise; Brault, Pascal; Tessier, Yves

2011-01-01

The behavior of tungsten under irradiation and helium implantation is a major stake of the materialrelated issues of fusion reactors. In this perspective the fate of helium in tungsten was studied by mean of several characterization techniques. The aim of this study is to highlight the trapping mechanisms of helium in tungsten and their correlation with implantation-induced defects. Helium was implanted into tungsten at two different energies, 0.32 and 60 keV. The helium was studied as a func...

16. Liquefied Gaseous Fuels Safety and Environmental Control Assessment Program: second status report

1980-10-01

The Assistant Secretary for Environment has responsibility for identifying, characterizing, and ameliorating the environmental, health, and safety issues and public concerns associated with commercial operation of specific energy systems. The need for developing a safety and environmental control assessment for liquefied gaseous fuels was identified by the Environmental and Safety Engineering Division as a result of discussions with various governmental, industry, and academic persons having expertise with respect to the particular materials involved: liquefied natural gas, liquefied petroleum gas, hydrogen, and anhydrous ammonia. This document is arranged in three volumes and reports on progress in the Liquefied Gaseous Fuels (LGF) Safety and Environmental Control Assessment Program made in Fiscal Year (FY)-1979 and early FY-1980. Volume 1 (Executive Summary) describes the background, purpose and organization of the LGF Program and contains summaries of the 25 reports presented in Volumes 2 and 3. Annotated bibliographies on Liquefied Natural Gas (LNG) Safety and Environmental Control Research and on Fire Safety and Hazards of Liquefied Petroleum Gas (LPG) are included in Volume 1.

17. Helium solubility in imperfect ionic crystals

In the context of the intended use of helium as a coolant in high temperature gas cooled reactors a study is undertaken into helium interaction with crystals at the stage preceding the process of helium clusters formation. Experimental and theoretical investigations of helium solubility in imperfect ionic crystals CaF2, SrF2, KBr are carried out along with the degassing kinetics in the temperature range of 500-1200 K. An analysis is made for possible mechanisms of the occurrence of observed oscillations in helium solubility at temperature variations. The solution heat for helium atoms in cation vacancies and the energy of impurity-vacancy cluster dissociation are calculated. The reason for a catastrophic increase of dissolved helium concentration with saturation pressure is discussed

18. HeREF-2003 : Helium Refrigeration Techniques

2003-01-01

CERN Technical Training 2003: Learning for the LHC ! Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2003 is a course in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2003 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2003 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place.  Duration: 7 half days (4 mornings and 3 afternoons), 6-10 October, 2003  Cost per participant: 500.- CHF ...

19. HeREF-2003: Helium Refrigeration Techniques

2003-01-01

CERN Technical Training 2003: Learning for the LHC ! Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2003 is a course in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2003 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2003 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place. Duration: 7 half days (4 mornings and 3 afternoons), 6-10 October, 2003 Cost per participant: 500.- CHF Language: Bilingual English...

20. Carbon Shell or Core Ignitions in White Dwarfs Accreting from Helium Stars

Brooks, Jared; Schwab, Josiah; Paxton, Bill

2016-01-01

White dwarfs accreting from helium stars can stably burn at the accreted rate and avoid the challenge of mass loss associated with unstable Helium burning that is a concern for many Type Ia supernovae scenarios. We study binaries with helium stars of mass $1.25 M_\\odot\\le M_{\\rm{He}} \\le 1.8 M_\\odot$, which have lost their hydrogen rich envelopes in an earlier common envelope event and now orbit with periods ($P_{\\rm orb}$) of several hours with non-rotating $0.84$ and $1.0 M_\\odot$ C/O WDs. The helium stars fill their Roche lobes (RLs) after exhaustion of central helium and donate helium on their thermal timescales (${\\sim}10^5$yr). As shown by others, these mass transfer rates coincide with the steady helium burning range for WDs, and grow the WD core up to near the Chandrasekhar mass ($M_{\\rm Ch}$) and a core carbon ignition. We show here, however, that many of these scenarios lead to an ignition of hot carbon ashes near the outer edge of the WD and an inward going carbon flame that does not cause an explo...

1. Mixed helium-3 - helium-4 calorimeter. Very low temperature calorimetry

A description is given of a double-racket calorimeter using helium-4 and helium-3 as the cryogenic fluids and making it possible to vary the temperature continuously from 0.35 K to 4.2 K. By using an electric thermal regulator together with liquid hydrogen it is possible to extend this range up to about 30 K. In the second part, a review is made of the various, methods available for measuring specific heats. The method actually used in the apparatus previously described is described in detail. The difficulties arising from the use of an exchange gas for the thermal contact have been solved by the use of adsorption pumps. (author)

2. Laser spectroscopy of antiprotonic helium and pionic helium

ASACUSA (Atomic Spectroscopy and Collisions Using Slow Antiproton) experiment of CERN has observed two-photon spectroscopy by making non-linear transitions of the antiprotons which have occupied highly excited levels. The metastable antiproton helium atoms are studied by irradiating two laser light photons propagating in the counter direction. As the result, the spectrum of narrow line width was observed by making the Doppler width of the resonant transition to decrease. And the anti-proton helium transition frequency was measured with the accuracy of (2.3∼5) X10-9. The mass ratio of the antiproton and the electron has been decided to be Mp/me =1836.152674(23) from the comparison of quantum electrodynamics calculation and the present experimental result. The pion-Helium experiment instrument has been also constructed at the ring cyclotron of PSI (Paul Sherer Institute) toward the successful laser spectroscopy of this atom. When this atom is observed, the π- mass can be obtained with the accuracy higher than 6∼8 orders of magnitude which may contribute to the direct measurement of the upper limit value of muon neutrino mass in the Particle Data Book Mass although various difficulties may be encountered. This report describes briefly the laser spectroscopy at first and then the recent situation of the experiments. (S. Funahashi)

3. Rapidly pulsed helium droplet source

Pentlehner, Dominik; Riechers, Ricarda; Dick, Bernhard; Slenczka, Alkwin [Institute for Physical and Theoretical Chemistry, University of Regensburg, 93053 Regensburg (Germany); Even, Uzi; Lavie, Nachum; Brown, Raviv; Luria, Kfir [Sackler Faculty of Exact Sciences, School of Chemistry, Tel Aviv University, Ramat Aviv, 69978 Tel Aviv (Israel)

2009-04-15

A pulsed valve connected to a closed-cycle cryostat was optimized for producing helium droplets. The pulsed droplet beam appeared with a bimodal size distribution. The leading part of the pulse consists of droplets suitable for doping with molecules. The average size of this part can be varied between 10{sup 4} and 10{sup 6} helium atoms, and the width of the distribution is smaller as compared to a continuous-flow droplet source. The system has been tested in a single pulse mode and at repetition rates of up to 500 Hz with almost constant intensity. The droplet density was found to be increased by more than an order of magnitude as compared to a continuous-flow droplet source.

4. Confined helium on Lagrange meshes

Baye, Daniel

2015-01-01

The Lagrange-mesh method has the simplicity of a calculation on a mesh and can have the accuracy of a variational method. It is applied to the study of a confined helium atom. Two types of confinement are considered. Soft confinements by potentials are studied in perimetric coordinates. Hard confinement in impenetrable spherical cavities is studied in a system of rescaled perimetric coordinates varying in [0,1] intervals. Energies and mean values of the distances between electrons and between an electron and the helium nucleus are calculated. A high accuracy of 11 to 15 significant figures is obtained with small computing times. Pressures acting on the confined atom are also computed. For sphere radii smaller than 1, their relative accuracies are better than $10^{-10}$. For larger radii up to 10, they progressively decrease to $10^{-3}$, still improving the best literature results.

5. Elusive structure of helium trimers

Stipanović, Petar; Boronat, Jordi

2016-01-01

Over the years many He-He interaction potentials have been developed, some very sophisticated, including various corrections beyond Born-Oppenheimer approximation. Most of them were used to predict properties of helium dimers and trimers, examples of exotic quantum states, whose experimental study proved to be very challenging. Recently, detailed structural properties of helium trimers were measured for the first time, allowing a comparison with theoretical predictions and possibly enabling the evaluation of different interaction potentials. The comparisons already made included adjusting the maxima of both theoretical and experimental correlation functions to one, so the overall agreement between theory and experiment appeared satisfactory. However, no attempt was made to evaluate the quality of the interaction potentials used in the calculations. In this work, we calculate the experimentally measured correlation functions using both new and old potentials, compare them with experimental data and rank the po...

6. Helium atom scattering from surfaces

1992-01-01

High resolution helium atom scattering can be applied to study a number of interesting properties of solid surfaces with great sensitivity and accuracy. This book treats in detail experimental and theoretical aspects ofthis method as well as all current applications in surface science. The individual chapters - all written by experts in the field - are devoted to the investigation of surface structure, defect shapes and concentrations, the interaction potential, collective and localized surface vibrations at low energies, phase transitions and surface diffusion. Over the past decade helium atom scattering has gained widespread recognitionwithin the surface science community. Points in its favour are comprehensiveunderstanding of the scattering theory and the availability of well-tested approximation to the rigorous theory. This book will be invaluable to surface scientists wishing to make an informed judgement on the actual and potential capabilities of this technique and its results.

7. The maintenance record of the KSTAR helium refrigeration system

Korea Superconducting Tokamak Advanced Research (KSTAR) has a helium refrigeration system (HRS) with the cooling capacity of 9 kW at 4.5 K. Main cold components are composed of 300 tons of superconducting (SC) magnets, main cryostat thermal shields, and SC current feeder system. The HRS comprises six gas storage tanks, a liquid nitrogen tank, the room temperature compression sector, the cold box (C/B), the 1st stage helium distribution box (DB no.1), the PLC base local control system interconnected to central control tower and so on. Between HRS and cold components, there is another distribution box (DB#2) nearby the KSTAR device. The entire KSTAR device was constructed in 2007 and has been operated since 2008. This paper will present the maintenance result of the KSTAR HRS during the campaign and discuss the operation record and maintenance history of the KSTAR HRS.

8. Detecting scintillations in liquid helium

Huffman, P. R.; McKinsey, D. N.

2013-09-01

We review our work in developing a tetraphenyl butadiene (TPB)-based detection system for a measurement of the neutron lifetime using magnetically confined ultracold neutrons (UCN). As part of the development of the detection system for this experiment, we studied the scintillation properties of liquid helium itself, characterized the fluorescent efficiencies of different fluors, and built and tested three detector geometries. We provide an overview of the results from these studies as well as references for additional information.

9. Acoustic streaming in superfluid helium

Quantitative measurements of acoustic streaming velocity in liquid helium as a function of sound intensity (up to the cavitation threshold), frequency (1, 3, and 10 MHz), and temperature (1.43 K< or =T< or =2.19 K) are reported. A transition to superfluid turbulence, several flow regions and flow fluctuations are observed. Comparison with the predictions of the second-order Khalatnikov two- fluid hydrodynamic equations indicates good functional and quantitative agreement

10. Magnetically insulated helium ion diode

A gas-puff magnetically insulated ion diode is under development as a pulsed source of high-energy alpha particles for magnetic fusion experiments. The diode is patterned after the Cornell gas-puff diode [J. B. Greenly, M. Ueda, G. D. Rondeau, and D. A. Hammer, J. Appl. Phys. 63, 1872 (1988)], but with modifications to accomodate higher voltages (2 one meter downstream from the source; in our first test of the new source, a helium beam was obtained

11. Development status of liquefied natural gas industry in China

With the significant economic growth in China, energy related environmental issues become more and more serious. Most of air pollutants are produced by burning coal. In order to achieve a sustainable balance between economic growth and environmental protection, China has been taking measures to expand the role played by natural gas, especially since the beginning of the 21st century. As the liquid form of natural gas, liquefied natural gas (LNG) has also been paid more attention in the country. This paper explores main motives for the fast development of China's LNG industry. An overview of the industry is also described, covering LNG receiving terminals, plants and transportation. Despite a relatively short development history of LNG industry in China, there are many remarkable successes. City-gas supply by LNG is widely applied in many small to medium cities, and LNG vehicles and cold energy utilization are growing rapidly with governmental supports. At the end, the developmental trends of China's LNG industry are introduced. All the discussions show that LNG is strategically important in China's future energy infrastructure. - Research highlights: →Explore main momentums for the fast development of China's LNG industry→Analyze detailedly current states and future prospects of LNG infrastructure in China→Introduce and analyze the wide application of LNG-based gas supply mode in China→Discuss new developmental trends in China's LNG industry

12. The economics of the Nigerian liquefied natural gas project

Consideration for the environment is one of the major reasons for the ongoing global shift to gas as an energy source. Natural gas is a clean-burning fuel and poses less problems for the environment, when compared with current commercial sources of energy. This shift is gradually evolving a growing world demand for natural gas to be supplied either as pipeline gas or liquefied natural gas (LNG). Nigeria, with its relatively huge gas resources, is poised to supply a substantial part of this growing world demand with its LNG, which is expected to come on-stream by the final quarter of 1999. This paper examines the economics of Nigeria's LNG project. Nigeria is currently concentrating on the United States of America (USA) and Western European markets, because its LNG can be sold at competitive prices there. The study covers the demand and supply scenario in the world LNG trade. The activities of buyers and sellers in the world LNG trade are examined, with a view to identifying new markets for Nigeria's LNG. A payout time for the project is estimated and strategies for breaking into new markets are suggested. Finally, useful recommendations are made to ensure the sustainability of the LNG project

13. Thioredoxin liquefies and decreases the viscoelasticity of cystic fibrosis sputum.

Rancourt, Raymond C; Tai, Shusheng; King, Malcolm; Heltshe, Sonya L; Penvari, Churee; Accurso, Frank J; White, Carl W

2004-05-01

The persistent and viscous nature of airway secretions in cystic fibrosis (CF) disease leads to airway obstruction, opportunistic infection, and deterioration of lung function. Thioredoxin (Trx) is a protein disulfide reductase that catalyzes numerous thiol-dependent cellular reductive processes. To determine whether Trx can alter the rheological properties of mucus, sputum obtained from CF patients was treated with TRX and its reducing system (0.1 microM thioredoxin reductase + 2 mM NADPH), and liquid phase-gel phase ratio (percent liquid phase) was assessed by compaction assay. Exposure to low Trx concentrations (1 microM) caused significant increases in the percentage of liquid phase of sputum. Maximal increases in percent liquid phase occurred with 30 microM Trx. Additional measurements revealed that sputum liquefaction by the Trx reducing system is dependent on NADPH concentration. The relative potency of the Trx reducing system also was compared with other disulfide-reducing agents. In contrast with Trx, glutathione and N-acetylcysteine were ineffective in liquefying sputum when used at concentrations mucus, we suggest that Trx alters sputum rheology by enzymatic reduction of glycoprotein polymers present in sputum. PMID:14695120

14. Environmental hazards due to rupture of a liquefied propane pipeline

Accidental leakages of liquefied propane from high-pressure pipelines may occur despite the use of sophisticated safety equipment and following strict monitoring procedures. Environmental impact of steady and transient leakages were considered from toxicity and flammability viewpoints for two specific scenarios of full pipe ruptures. For each case, calculated mass flow rate, velocity, and temperature of leaking gas were utilized in an EPA-based dispersion model to predict the ground level concentration profiles in the downwind and crosswind directions. For the specific pipeline conditions considered here, the first scenario of a nonjet release (a cloud) produced steady toxic and flammable zones which were about 20 times bigger than those produced in the transient case. The second scenario of a free vertical jet resulted in the formation of a flammable vertical plume, while at ground level it did not produce flammable nor toxic zones. A parametric study of the first scenario confirmed the expected effects of both the gas release time and the atmospheric stability on the size of the dangerous zones. Within the typical range, the wind speed was found to have opposite effects for steady and transient releases. For a steady release, the dangerous zone was wider for slower winds and vice versa for a transient case. Moreover, the size of the dangerous zone was found to be an exponential function of the pipe diameter, while the effect of the initial pipe pressure was insignificant

15. Helium in inert matrix dispersion fuels

The behaviour of helium, an important decay product in the transmutation chains of actinides, in dispersion-type inert matrix fuels is discussed. A phenomenological description of its accumulation and release in CERCER and CERMET fuel is given. A summary of recent He-implantation studies with inert matrix metal oxides (ZrO2, MgAl2O4, MgO and Al2O3) is presented. A general picture is that for high helium concentrations helium and vacancy defects form helium clusters which convert into over-pressurized bubbles. At elevated temperature helium is released from the bubbles. On some occasions thermal stable nano-cavities or nano-pores remain. On the basis of these results the consequences for helium induced swelling and helium storage in oxide matrices kept at 800-1000 deg. C will be discussed. In addition, results of He-implantation studies for metal matrices (W, Mo, Nb and V alloys) will be presented. Introduction of helium in metals at elevated temperatures leads to clustering of helium to bubbles. When operational temperatures are higher than 0.5 melting temperature, swelling and helium embrittlement might occur

16. The Chemical Evolution of Helium

Balser, D S

2006-01-01

We report on measurements of the 4He abundance toward the outer Galaxy HII region S206 with the NRAO Green Bank telescope. Observations of hydrogen and helium radio recombination lines between 8-10 GHz were made toward the peak radio continuum position in S206. We derive 4He/H = 0.08459 +/- 0.00088 (random) +/- 0.0010 (known systematic), 20% lower than optical recombination line results. It is difficult to reconcile the large discrepancy between the optical and radio values even when accounting for temperature, density, and ionization structure or for optical extinction by dust. Using only M17 and S206 we determine dY/dZ = 1.41 +/- 0.62 in the Galaxy, consistent with standard chemical evolution models. High helium abundances in the old stellar population of elliptical galaxies can help explain the increase in UV emission with shorter wavelength between 2000 and 1200 Angstrom, called the UV-upturn or UVX. Our lower values of dY/dZ are consistent with a normal helium abundance at higher metallicity and suggest ...

17. On charged impurity structures in liquid helium

The thermoluminescence spectra of impurity-helium condensates (IHC) submerged in superfluid helium have been observed for the first time. Thermoluminescence of impurity-helium condensates submerged in superfluid helium is explained by neutralization reactions occurring in impurity nanoclusters. Optical spectra of excited products of neutralization reactions between nitrogen cations and thermoactivated electrons were rather different from the spectra observed at higher temperatures, when the luminescence due to nitrogen atom recombination dominates. New results on current detection during the IHC destruction are presented. Two different mechanisms of nanocluster charging are proposed to describe the phenomena observed during preparation and warm-up of IHC samples in bulk superfluid helium, and destruction of IHC samples out of liquid helium.

18. Precipitation in low energy helium irradiated molybdenum

The precipitation of low energy helium injected into molybdenum has been monitored by thermal helium desorption spectrometry (THDS). Precipitates nucleating at vacancies have been studied in the range from n = 1 to n = 2500 He per precipitate. The behaviour of the growing precipitates with respect to helium trapping, self-interstitial capture and emission, and helium release is discussed against the background of results of TEM work done for precipitates with n > 500 He. Evidence is found for (i) 'trap mutation' at n = 10 He, i.e. formation of bound self-interstitials around the helium filled vacancy, and (ii) emission of at least one of these 'mutation produced self-interstitials' (MPI) at n approx. 12 He. For larger precipitates (n > 20 He) the emission of single MPI is not apparent. At n = 1000 signs of helium binding to MPI-loops punched out by the precipitates are observed in the spectra. (author)

19. 43 CFR 16.2 - Applications for helium disposition agreements.

2010-10-01

... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Applications for helium disposition... HELIUM § 16.2 Applications for helium disposition agreements. The application for a helium disposition... Secretary to determine that the proposal will conserve helium that will otherwise be wasted, drained,...

20. Transparent Helium in Stripped Envelope Supernovae

Piro, Anthony L.; Morozova, Viktoriya S.

2014-01-01

Using simple arguments based on photometric light curves and velocity evolution, we propose that some stripped envelope supernovae (SNe) show signs that a significant fraction of their helium is effectively transparent. The main pieces of evidence are the relatively low velocities with little velocity evolution, as are expected deep inside an exploding star, along with temperatures that are too low to ionize helium. This means that the helium should not contribute to the shaping of the main S...

1. Pair Correlations in Superfluid Helium 3

Vollhardt, D.

1997-01-01

In 1996 Lee, Osheroff and Richardson received the Nobel Prize for their 1971 discovery of superfluid helium 3 -- a discovery which opened the door to the most fascinating system known in condensed matter physics. The superfluid phases of helium 3, originating from pair condensation of helium 3 atoms, turned out to be the ideal test-system for many fundamental concepts of modern physics, such as macroscopic quantum phenomena, (gauge-)symmetries and their spontaneous breakdown, topological defe...

2. Capture of slow antiprotons by helium atoms

Revai, J.; Shevchenko, N.V.(Nuclear Physics Institute, Řež, 25068, Czech Republic)

2004-01-01

A consistent quantum mechanical calculation of partial cross-sections leading to different final states of antiprotonic helium atom was performed. For the four-body scattering wave function, corresponding to the initial state, as well as for the antiprotonic helium wave function, appearing in the final tate, adiabatic approximations was used. Calculations were carried out for a wide range of antiprotonic helium states and incident energies of the antiproton. Obtained energy dependances of som...

3. Critical Landau Velocity in Helium Nanodroplets

Brauer, N. B.; Smolarek, S.; Loginov, E.; Mateo, D; A. Hernando; Pi, M.; Barranco, M.; Buma, W. J.; M. Drabbels

2013-01-01

The best-known property of superfluid helium is the vanishing viscosity that objects experience while moving through the liquid with speeds below the so-called critical Landau velocity. This critical velocity is generally considered a macroscopic property as it is related to the collective excitations of the helium atoms in the liquid. In the present work we determine to what extent this concept can still be applied to nanometer-scale, finite size helium systems. To this end, atoms and molecu...

4. Helium flooded cryopump with increased hydrogen and helium entrainment factor

Superhigh-vacuum helium condensation-sorption pump with H2 and H entrainment factors 1.7 and 3.1 times respectively exceeding those in the known design cryopumps with the same diameters of casings and connecting flange flow sections is described. The N2 pumping-out rate is 6m3/s, the H2 one is 21 m3/s, the H2 pumping-out rate constitutes 12m3/s, the casing diameter is 0.5, the height - 0.8m, mass-35 kg. The pump is fabricated of titanium and aluminium

5. A high efficient 12kW helium refrigerator for the LEP 200 project at CERN

CERN has ordered helium refrigeration/liquefier plants for the LEP200 project in 1991 with an equivalent refrigeration capacity of 12kW at 4.5 K. The cold equipment of these plants is divided into two parts with a cut on a temperature level of roughly 20 K. One bigger coldbox with temperatures between ambient and 20 K is installed at ground level, whereas the smaller box between 20 and 4.5 K is placed in the underground LEP tunnel and is therefore limited regarding its constructional size. The boxes are interconnected by a four stream transferline system mainly vertically arranged in machine access shafts of 90 to 140 m depth. The helium refrigeration plant delivered by LINDE KRYOTECHNIK AG combines an extremely compact construction especially of the lower coldbox with a remarkably good cycle efficiency. This paper describes the thermodynamic process, the construction of the plant and the control concept of the system. In addition, the cold boxes are already prepared for a later expansion to 18kW refrigeration capacity without need of changing internal equipment

6. Low evaporation helium cryostat with a refrigerator

Improvement of a helium cryostat for a superconducting magnet is reported. A small refrigerator pre-cools the magnet and removes heat load. A gas filled thermal switch cools a helium vessel and thermally insulates the vessel when the refrigerator stops. Nb3Sn wires are used in the helium vessel to avoid resistive heating. The evaporation rate of the liquid helium is 1.0 - 1.7 1/day (with external current of 28A), when a magnet (maximum field 7T in 25mm bore) is set in the cryostat. (author)

7. Solid lubrication technology of HTGR under helium

Because Helium is used as coolant in High Temperature Gas-cooled Reactor (HTGR), the change of tribological properties of HTGR structure component under Helium is a big problem. Under Helium, tribological properties of material becomes worse and fluid lubrication can not be used. Bonded solid lubrication film and fusion sintering solid film are used in control rod and can solve the tribological problem well. Methods of replenishment solid lubricant are discussed for continuously operating friction components. The necessity and possibility for solid lubrication film used in Helium fan is also discussed

8. Trapping fermionic and bosonic helium atoms

Stas, R. J. W.

2005-01-01

This thesis presents experimental and theoretical work performed at the Laser Centre of the Vrije Universiteit in Amsterdam to study laser-cooled metastable triplet helium atoms. Samples containing about 3x10^8 helium atoms-either fermionic helium-3 atoms, bosonic helium-4 atoms or mixtures thereof-are cooled to a temperature around 1 mK and form the starting point of the presented studies. The studies include an investigation of cold ionizing collisions in the absence of resonant light, an i...

9. Helium supply demand in future years

Adequate helium will be available to the year 2000 AD to meet anticipated helium demands for present day applications and the development of new superconducting technologies of potential importance to the nation. It is almost certain that there will not be enough helium at acceptable financial and energy cost after the turn of the century to meet the needs of the many promising helium based technologies now under development. Serious consideration should be given to establishing priorities in development and application based upon their relative value to the country. In the first half of the next century, three ways of estimating helium demand lead to cumulative ranges of from 75 to 125 Gcf (economic study), 89 to 470 Gcf (projected national energy growth rates) and 154 to 328 Gcf (needs for new technologies). These needs contrast with estimated helium resources in natural gas after 2000 AD which may be as low as 10 or 126 Gcf depending upon how the federal helium program is managed and the nation's natural gas resources are utilized. The technological and financial return on a modest national investment in further helium storage and a rational long term helium program promises to be considerable

10. Liquefied Noble Gas (LNG) detectors for detection of nuclear materials

Liquefied-noble-gas (LNG) detectors offer, in principle, very good energy resolution for both neutrons and gamma rays, fast response time (hence high-count-rate capabilities), excellent discrimination between neutrons and gamma rays, and scalability to large volumes. They do, however, need cryogenics. LNG detectors in sizes of interest for fissionable material detection in cargo are reaching a certain level of maturity because of the ongoing extensive R and D effort in high-energy physics regarding their use in the search for dark matter and neutrinoless double beta decay. The unique properties of LNG detectors, especially those using Liquid Argon (LAr) and Liquid Xenon (LXe), call for a study to determine their suitability for Non-Intrusive Inspection (NII) for Special Nuclear Materials (SNM) and possibly for other threats in cargo. Rapiscan Systems Laboratory, Yale University Physics Department, and Adelphi Technology are collaborating in the investigation of the suitability of LAr as a scintillation material for large size inspection systems for air and maritime containers and trucks. This program studies their suitability for NII, determines their potential uses, determines what improvements in performance they offer and recommends changes to their design to further enhance their suitability. An existing 3.1 liter LAr detector (microCLEAN) at Yale University, developed for R and D on the detection of weakly interacting massive particles (WIMPs) was employed for testing. A larger version of this detector (15 liters), more suitable for the detection of higher energy gamma rays and neutrons is being built for experimental evaluation. Results of measurements and simulations of gamma ray and neutron detection in microCLEAN and a larger detector (326 liter CL38) are presented.

11. Helium stratification in HD 145792: a new Helium strong star

Catanzaro, G

2007-01-01

In this paper we report on the real nature of the star HD 145792, classified as He weak in {\\it `The General Catalogue of Ap and Am stars''}. By means of FEROS@ESO1.52m high resolution spectroscopic data, we refined the atmospheric parameters of the star, obtaining: T$_{\\rm eff}$ = 14400 $\\pm$ 400 K, $\\log g$ = 4.06 $\\pm$ 0.08 and $\\xi$ = 0 $^{+0.6}$ km s$^{-1}$. These values resulted always lower than those derived by different authors with pure photometric approaches. Using our values we undertook an abundance analysis with the aim to derive, for the first time, the chemical pattern of the star's atmosphere. For metals a pure LTE synthesis (ATLAS9 and SYNTHE) has been used, while for helium a hybrid approach has been preferred (ATLAS9 and SYNSPEC). The principal result of our study is that HD 145792 belongs to He strong class contrary to the previous classification. Moreover, helium seems to be vertically stratified in the atmosphere, decreasing toward deepest layers. For what that concerns metals abundanc...

12. Dielectric tracking in liquid helium

Measurements of the breakdown field of typical magnet insulators of thickness < 0.7 mm, under conditions in which the breakdown is by surface tracking across the narrow dimension, yield values which are characteristic of helium gas at the saturated vapour pressure for temperatures above the lambda point. Below the lambda point, the breakdown field rises again, but does not attain its 4.2 K value. Measurements also show that the tracking strength of a surface badly contaminated with metal particles is not appreciably less than that for a clean surface. (author)

13. Helium stars as supernova progenitors

Waldman, Roni; Yungelson, Lev R.; Barkat, Zalman

2007-01-01

We follow the evolution of helium stars of initial mass $(2.2 - 2.5) M_\\odot$, and show that they undergo off-center carbon burning, which leaves behind ${\\mathbf \\sim 0.01 M_\\odot}$ of unburnt carbon in the inner part of the core. When the carbon-oxygen core grows to Chandrasekhar mass, the amount of left-over carbon is sufficient to ignite thermonuclear runaway. At the moment of explosion, the star will possess an envelope of several $0.1 M_{\\odot}$, consisting of He, C, and possibly some H...

14. Helium transfer line installation details.

G. Perinic

2007-01-01

A particularity of the 32 m long four in one helium transfer line in between the cold box in USC55 and the cavern UX5 is the fact that the transfer line passes through a hole in the crane rail support beam. In order to ensure the alignment of the suspension rail in the interconnecting tunnel with the hole in the rail support as well as the connection points at both ends required precise measurements of the given geometries as well as the installation of a temporary target for the verification of the theoretical predictions.

15. Liquefied natural gas: a harbor plan; Plano diretor portuario para o gas natural liquefeito

Moreira, Aluisio de Souza; Baitelo, Ricardo Lacerda [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica; Rego, Erik Eduardo [Excelencia Energetica Consultoria Empresarial Ltda., Sao Paulo, SP (Brazil); Rosim, Sidney Olivieri [Rosim e Papaleo Consultoria e Participacoes Ltda., Sao Paulo, SP (Brazil)

2008-07-01

The objective of this article is to present the structuring of a port directing plan for the liquefied natural gas. In this sense, an integrated approach between the applied logistic and the requested market conditions was used. For the large distances transportation of liquefied natural gas, the marine modal must attain technical requirements that are not usual in the port routine. Apart from the proper dimensioning of the naval fleet in order to maximize the transported load, providing the optimization of the economic distance, the entire port infra-structure is planned for the reception of liquefied natural gas, in order to attend the physical peculiarities as well as security aspects of extreme importance. The selection of the studied local was motivated by the fuel supply shortage suffered by the country, especially in the northeast region, which owns already installed thermal units in need of the fuel supply to be operated. (author)

16. Application of liquefied wood as a new particle board adhesive system.

Kunaver, Matjaz; Medved, Sergej; Cuk, Natasa; Jasiukaityte, Edita; Poljansek, Ida; Strnad, Tatjana

2010-02-01

Different types of southern European hardwoods and softwoods were subjected to a liquefaction process with glycerol/diethylene glycol. The liquefied spruce wood was reacted in a condensation reaction in the hot press with different melamine-formaldehyde and melamine-urea-formaldehyde resin precursors and used as adhesives for wood particle boards. The mechanical properties of these particle boards and the determination of formaldehyde release, proved that addition of 50% of the liquefied wood to such resin precursors caused the product to meet the European standard quality demands for particle boards. Up to 40% reduction of the formaldehyde emission was achieved. The temperature of the press unit was lowered from 180 degrees C to 160 degrees C with no significant influence on the mechanical properties. On the basis of the presented results it was possible to conclude that liquefied wood can be used as substitute for synthetic resin precursors in adhesives that are used for the particle board production. PMID:19836945

17. 78 FR 44940 - Orders Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied...

2013-07-25

... Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied Natural Gas During... orders granting authority to import and export natural gas and to import and export liquefied natural gas... Regulatory Activities, Office of Oil and Gas Global Security and Supply, Office of Fossil Energy....

18. 78 FR 53739 - Orders Granting Authority To Import and Export Natural Gas, To Import and Export Liquefied...

2013-08-30

... Granting Authority To Import and Export Natural Gas, To Import and Export Liquefied Natural Gas and... export natural gas, to import and export liquefied natural gas and to vacate prior authority. These... inspection and copying in the Office of Fossil Energy, Office of Oil and Gas Global Security and...

19. 78 FR 65304 - Orders Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied...

2013-10-31

... Granting Authority To Import and Export Natural Gas, and To Import and Export Liquefied Natural Gas During... issued orders granting authority to import and export natural gas, and to import and export liquefied... available for inspection and copying in the Office of Oil and Gas Global Security and Supply, Office...

20. 77 FR 19277 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

2012-03-30

... Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During February 2012 FE..., ULC 12-13-NG ENCANA NATURAL GAS INC 11-163-NG ALCOA INC 12-11-NG JPMORGAN LNG CO 12-15-LNG CNE GAS... 2012, it issued Orders granting authority to import and export natural gas and liquefied natural...

1. 78 FR 46581 - Orders Granting Authority To Import and Export Natural Gas, and To Import Liquefied Natural Gas...

2013-08-01

... Granting Authority To Import and Export Natural Gas, and To Import Liquefied Natural Gas During June 2013... authority to import and export natural gas and to import liquefied natural gas. These orders are summarized... of Fossil Energy, Office of Natural Gas Regulatory Activities, Docket Room 3E-033, Forrestal...

2. 77 FR 12274 - Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During...

2012-02-29

... Orders Granting Authority To Import and Export Natural Gas and Liquefied Natural Gas During January 2012.... DOMINION COVE POINT LNG, LP 11-98-LNG ENERGY PLUS NATURAL GAS LLC 11-155-NG BROOKFIELD ENERGY MARKETING L.P... 2012, it issued Orders granting authority to import and export natural gas and liquefied natural...

3. 77 FR 4028 - Orders Granting, Amending and Vacating Authority To Import and Export Natural Gas and Liquefied...

2012-01-26

... Granting, Amending and Vacating Authority To Import and Export Natural Gas and Liquefied Natural Gas FE Docket Nos. Gas Natural Caxitlan, S. DE R.L 11-147-NG Jordan Cove Energy Project, L.P 11-127-LNG Irving..., amending and vacating authority to import and export natural gas and liquefied natural gas. These...

4. 78 FR 35014 - Orders Granting Authority to Import and Export Natural Gas, and to Import Liquefied Natural Gas...

2013-06-11

... Granting Authority to Import and Export Natural Gas, and to Import Liquefied Natural Gas During April 2013... INC 13-41-NG CASCADE NATURAL GAS CORPORATION 13-43-NG ENCANA MARKETING (USA) INC 13-44-NG CITIGROUP... natural gas and to import liquefied natural gas. These orders are summarized in the attached appendix...

5. Design of subcooled helium II refrigerator with helium-3 cold compressor

This paper will study the possibility of a He II refrigerator made up of three cold compressors by making use of helium-3 characteristics. This system is compact enough to fit inside a small cold box, so it can be easily connected with an existing helium-4 refrigerator. The authors designed the compressors, calculated the He II cooling capacity, 4.4 K refrigeration load, required inventory of helium-3, and Carnot efficiency. Though helium-3 is expensive, the required inventory of helium-3 to be filled inside this He II refrigerator was calculated to be small enough to prove practicality of constructing this refrigerator

6. Nanofabrication with a helium ion microscope

Maas, D.; Van veldhoven, E.; Chen, P.; Sidorkin, V.; Salemink, H.; Van der Drift, E.; Alkemade, P.

2010-01-01

The recently introduced helium ion microscope (HIM) is capable of imaging and fabrication of nanostructures thanks to its sub-nanometer sized ion probe [1,2]. The unique interaction of the helium ions with the sample material provides very localized secondary electron emission, thus providing a valu

7. Nanofabrication with a helium ion microscope

Maas, D.; Van Veldhoven, E.; Chen, P.; Sidorkin, V; Salemink, H.; Van der Drift, E.; Alkemade, P.

2009-01-01

The recently introduced helium ion microscope (HIM) is capable of imaging and fabrication of nanostructures thanks to its sub-nanometer sized ion probe [1,2]. The unique interaction of the helium ions with the sample material provides very localized secondary electron emission, thus providing a valu

8. Helium-flow measurement using ultrasonic technique

Sondericker, J. H.

1983-08-01

The ideal cryogenic instrumentation for the colliding beam accelerator helium distribution system does not add pressure drop to the system, functions over the entire temperature range, has high resolution, and delivers accurate mass flow measurement data. The design and testing of an ultrasonic flowmeter which measures helium flow under different temperatures are described.

9. Anomalous wetting of helium on cesium

The authors report studies of the anomalous wetting of a cesium substrate by a liquid helium film by means of the technique of third sound. A hysteretic pre-wetting transition is observed as a function of the amount of helium in the experimental cell. 10 refs., 2 figs

10. Helium Speech: An Application of Standing Waves

Wentworth, Christopher D.

2011-01-01

Taking a breath of helium gas and then speaking or singing to the class is a favorite demonstration for an introductory physics course, as it usually elicits appreciative laughter, which serves to energize the class session. Students will usually report that the helium speech "raises the frequency" of the voice. A more accurate description of the…

11. 30 CFR 256.11 - Helium.

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Helium. 256.11 Section 256.11 Mineral Resources... Helium. (a) Each lease issued or continued under these regulations shall be subject to a reservation by the United States, under section 12(f) of the Act, of the ownership of and the right to extract...

12. LOX Tank Helium Removal for Propellant Scavenging

Chato, David J.

2009-01-01

System studies have shown a significant advantage to reusing the hydrogen and oxygen left in these tanks after landing on the Moon in fuel cells to generate power and water for surface systems. However in the current lander concepts, the helium used to pressurize the oxygen tank can substantially degrade fuel cell power and water output by covering the reacting surface with inert gas. This presentation documents an experimental investigation of methods to remove the helium pressurant while minimizing the amount of the oxygen lost. This investigation demonstrated that significant quantities of Helium (greater than 90% mole fraction) remain in the tank after draining. Although a single vent cycle reduced the helium quantity, large amounts of helium remained. Cyclic venting appeared to be more effective. Three vent cycles were sufficient to reduce the helium to small (less than 0.2%) quantities. Two vent cycles may be sufficient since once the tank has been brought up to pressure after the second vent cycle the helium concentration has been reduced to the less than 0.2% level. The re-pressurization process seemed to contribute to diluting helium. This is as expected since in order to raise the pressure liquid oxygen must be evaporated. Estimated liquid oxygen loss is on the order of 82 pounds (assuming the third vent cycle is not required).

13. Helium-cooled high temperature reactors

Experience with several helium cooled reactors has been favorable, and two commercial plants are now operating. Both of these units are of the High Temperature Graphite Gas Cooled concept, one in the United States and the other in the Federal Republic of Germany. The initial helium charge for a reactor of the 1000 MW(e) size is modest, approx.15,000 kg

14. Nuclear fusion and the helium supply problem

Highlights: ► Fusion power plants will require helium as cryogenic medium and as coolant. ► High losses are expected: for a power plant like DEMO ≈ 2 t p.a. ► The same power plant is expected to produce only ≈0.6 t p.a. ► Global helium resources are finite: fusion will therefore exacerbate an already difficult situation. ► The “back-stop” technology will be the extraction helium of helium from the atmosphere. -- Abstract: The natural resources required for the operation of fusion power plants are – with the possible exception of the neutron multiplier beryllium – readily available. On the other hand, the supply of helium, which is required as cryogenic medium and coolant, may be a problem due to losses during operation and decommissioning. Helium is a rare element obtained as a by-product in the extraction of natural gas. The danger exists that the natural gas will be used up without the helium being conserved. We estimate the helium demand for a global 30% base-load contribution of fusion to electricity supply and also calculate the amount produced by the power plants themselves

15. Production of liquid nitrogen using liquefied natural gas as sole refrigerant

This patent describes a process for the liquefaction of a nitrogen stream produced by a cryogenic air separation unit having at least one distillation column. It comprises compressing the nitrogen stream to a pressure of at least 350 psi in a multi-stage compressor wherein interstage cooling is provided by heat exchange against vaporizing liquefied natural gas; condensing the compressed nitrogen stream by heat exchange against vaporizing liquefied natural gas; reducing the pressure of the condensed, compressed nitrogen stream thereby producing a two phase nitrogen stream; phase separating the two phase nitrogen stream into a liquid nitrogen stream and a nitrogen vapor stream; and warming the nitrogen vapor stream to recover refrigeration

16. Removal of organic contaminants from water or wastewater with liquefied gases

2002-01-01

This study utilized liquefied gases (LG) as extractant to remove various organic contaminants including halogenated hydrocarbons and phenols as well as aromatic compounds from aqueousmatrices. Orthogonal experiments were performed to optimize theoperating conditions such as temperature, co-solvents and so on.Under favorable conditions, high removal efficiencies can bereadily achieved for a great number of representative model organiccontaminants, the removal efficiencies for most of the hydrophobiccontaminants were greater than 90% in a single extraction stage.Tentative effort was also done for the removal of extractedcontaminants from recycled liquefied gases.

17. Liquefied Gaseous Fuels Safety and Environmental Control Assessment Program: second status report

None

1980-10-01

This document is arranged in three volumes and reports on progress in the Liquefied Gaseous Fuels (LGF) Safety and Environmental Control Assessment Program made in fiscal Year (FY)-1979 and early FY-1980. Volume 3 contains reports from 6 government contractors on LPG, anhydrous ammonia, and hydrogen energy systems. Report subjects include: simultaneous boiling and spreading of liquefied petroleum gas (LPG) on water; LPG safety research; state-of-the-art of release prevention and control technology in the LPG industry; ammonia: an introductory assessment of safety and environmental control information; ammonia as a fuel, and hydrogen safety and environmental control assessment.

18. Global helium particle balance in LHD

Global helium particle balance in long-pulse discharges is analyzed for the first time in the Large Helical Device (LHD) with the plasma-facing components of the first wall and the divertor tiles composed of stainless steel and carbon, respectively. During the 2-min discharge sustained by ion cyclotron resonance heating (ICRH) and electron cyclotron heating (ECH), helium is observed to be highly retained in the wall (regarded as both the first wall and the divertor tiles). Almost all (about 96%) puffed helium particles (1.3 × 1022 He) are absorbed in the wall near the end of the discharge. Even though a dynamic retention is eliminated, 56% is still absorbed. The analysis is also applied to longer pulse discharges over 40 min by ICRH and ECH, indicating that the helium wall retention is dynamically changed in time. At the initial phase of the discharge, a mechanism for adsorbing helium other than dynamical retention is invoked

19. Permeability of Hollow Microspherical Membranes to Helium

Zinoviev, V. N.; Kazanin, I. V.; Pak, A. Yu.; Vereshchagin, A. S.; Lebiga, V. A.; Fomin, V. M.

2016-01-01

This work is devoted to the study of the sorption characteristics of various hollow microspherical membranes to reveal particles most suitable for application in the membrane-sorption technologies of helium extraction from a natural gas. The permeability of the investigated sorbents to helium and their impermeability to air and methane are shown experimentally. The sorption-desorption dependences of the studied sorbents have been obtained, from which the parameters of their specific permeability to helium are calculated. It has been established that the physicochemical modification of the original particles exerts a great influence on the coefficient of the permeability of a sorbent to helium. Specially treated cenospheres have displayed high efficiency as membranes for selective extraction of helium.

20. Determination of helium in beryl minerals

In order to obtain the diffusion coefficients of helium in beryl and phenacite samples at various temperatures, helium leak rates were measured in these minerals at these temperatures. Mass spectrometry (MS) was used to obtain helium leak rates and the gas flow was plotted against time. The gas quantity determined by MS was first obtained at various temperatures until no helium leak rate was detected. After that, these samples were irradiated with fast neutrons to produce helium which was measured again. This procedure was used to estimate the experimental error. The quantity of helium produced by interaction of gamma radiation with beryl minerals was theoretically calculated from the amount of thorium-232 at the neighbourhood of the samples. The quantity of helium produced in the minerals due to uranium and thorium decay was calculated using the amount of these heavy elements, and the results were compared with the amounts determined by MS. The amount of potassium-40 was determined in order to derive the quantity of argonium-40, since some workers found argonium in excess in these minerals. The quantity of helium in the beryl samples (s) was determined in the center and in the surface of the samples in order to obtain informations about the effectiveness of the Be(α, η) He reaction. Beryl and phenacite minerals were choosen in this research since they are opposite each other with respect to the helium contents. Both have beryllium in their compositon but beryl hold a large amount of helium while phenacite, in spite of having about three times more beryllium than beryl, do not hold the gas. (author)

1. Exotic helium molecules; Molecules exotiques d'helium

Portier, M

2007-12-15

We study the photo-association of an ultracold cloud of magnetically trapped helium atoms: pairs of colliding atoms interact with one or two laser fields to produce a purely long range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}P{sub 0}) molecule, or a {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) long range molecule. Light shifts in one photon photo-association spectra are measured and studied as a function of the laser polarization and intensity, and the vibrational state of the excited molecule. They result from the light-induced coupling between the excited molecule, and bound and scattering states of the interaction between two metastable atoms. Their analysis leads to the determination of the scattering length a = (7.2 {+-} 0.6) ruling collisions between spin polarized atoms. The two photon photo-association spectra show evidence of the production of polarized, long-range {sup 4}He{sub 2}(2{sup 3}S{sub 1}-2{sup 3}S{sub 1}) molecules. They are said to be exotic as they are made of two metastable atoms, each one carrying a enough energy to ionize the other. The corresponding lineshapes are calculated and decomposed in sums and products of Breit-Wigner and Fano profiles associated to one and two photon processes. The experimental spectra are fit, and an intrinsic lifetime {tau} = (1.4 {+-} 0.3) {mu}s is deduced. It is checked whether this lifetime could be limited by spin-dipole induced Penning autoionization. This interpretation requires that there is a quasi-bound state close to the dissociation threshold in the singlet interaction potential between metastable helium atoms for the theory to match the experiment. (author)

2. Report of working committee 3 ''liquefied gases''; Rapport du comite de travail 3 ''gaz liquefies''

Baudino, M.

2000-07-01

Working Committee 3's report concerns the evolution of the liquefied gas industry: both liquefied natural gas (LNG) and liquefied petroleum gases (LPG). Given the current state of the LNG market the Committee decided to concentrate on this area in particular. A number of aspects have been identified which the Committee has been looking at, while others have been given to Study Groups set up specifically for the purpose. The first aspects regard: - the development of LNG and LPG, new installations, future chains and relevant statistical data; - the role of LNG and LPG in starting up a gas industry; - operating and technological improvements in the LNG industry; - energy savings, cold utilization and reduction of CO{sub 2} emissions. The Study Groups which were set up dealt with the following subjects: Technological and Economical Developments for cost Reduction of LNG/LPG Facilities. Small Scale LNG Projects and Modular Systems. LNG/LPG Peak Shaving and Satellite Plants. LNG versus Pipeline Infrastructure. (author)

3. Torque and power characteristics of a helium charged Stirling engine with a lever controlled displacer driving mechanism

Karabulut, H.; Cinar, C.; Oztuerk, E.; Yuecesu, H.S. [Department of Mechanical Technology, Faculty of Technical Education, Gazi University, 06500 Teknikokullar, Ankara (Turkey)

2010-01-15

This study presents test results of a Stirling engine with a lever controlled displacer driving mechanism. Tests were conducted with helium and the working fluid was charged into the engine block. The engine was loaded by means of a prony type micro dynamometer. The heat was supplied by a liquefied petroleum gas (LPG) burner. The engine started to run at 118 C hot end temperature and the systematic tests of the engine were conducted at 180 C, 220 C and 260 C hot end external surface temperatures. During the test, cold end temperature was kept at 27 C by means of water circulation. Variation of the shaft torque and power with respect to the charge pressure and hot end temperature were examined. The maximum torque and power were measured as 3.99 Nm and 183 W at 4 bars charge pressure and 260 C hot end temperature. Maximum power corresponded to 600 rpm speed. (author)

4. Dynamic modelling of a forced flow supercritical helium loop with EcosimPro

HELIOS is an experimental supercritical helium loop in operation at CEA Grenoble since 2010. It is a scaled down circuit of the central solenoid (CS) magnet cooling loop of the JT60-SA tokamak. The purpose of this system is to study the pulsed heat load smoothing which is needed due to the cycling plasma operations. A model of the experimental loop has been developed using EcosimPro simulation software. The aim is twofold: firstly to create a fast running model to correctly simulate the transient behavior of the supercritical helium (SHe) loop and secondly to develop advanced control system to validate more complex heat load mitigation strategies. (author)

5. Electric response in superfluid helium

Chagovets, Tymofiy V.

2016-05-01

We report an experimental investigation of the electric response of superfluid helium that arises in the presence of a second sound standing wave. It was found that the signal of the electric response is observed in a narrow range of second sound excitation power. The linear dependence of the signal amplitude has been derived at low excitation power, however, above some critical power, the amplitude of the signal is considerably decreased. It was established that the rapid change of the electric response is not associated with a turbulent regime generated by the second sound wave. A model of the appearance of the electric response as a result of the oscillation of electron bubbles in the normal fluid velocity field in the second sound wave is presented. Possible explanation for the decrease of the electric response are presented.

6. In Beam Tests of Implanted Helium Targets

McDonald, J E; Ahmed, M W; Blackston, M A; Delbar, T; Gai, M; Kading, T J; Parpottas, Y; Perdue, B A; Prior, R M; Rubin, D A; Spraker, M C; Yeomans, J D; Weissman, L; Weller, H R; Delbar, Th.; Conn, LNS/U; Duke, TUNL/

2006-01-01

Targets consisting of 3,4He implanted into thin aluminum foils (approximately 100, 200 or 600 ug/cm^2) were prepared using intense (a few uA) helium beams at low energy (approximately 20, 40 or 100 keV). Uniformity of the implantation was achieved by a beam raster across a 12 mm diameter tantalum collimator at the rates of 0.1 Hz in the vertical direction and 1 Hz in the horizontal direction. Helium implantation into the very thin (approximately 80-100 ug/cm^2) aluminum foils failed to produce useful targets (with only approximately 10% of the helium retained) due to an under estimation of the range by the code SRIM. The range of low energy helium in aluminum predicted by Northcliffe and Shilling and the NIST online tabulation are observed on the other hand to over estimate the range of low energy helium ions in aluminum. An attempt to increase the amount of helium by implanting a second deeper layer was also carried out, but it did not significantly increase the helium content beyond the blistering limit (ap...

7. 29 CFR 1926.153 - Liquefied petroleum gas (LP-Gas).

2010-07-01

... of gas to the main burner, and pilot if used, in the event of flame failure. Such heaters, having... 29 Labor 8 2010-07-01 2010-07-01 false Liquefied petroleum gas (LP-Gas). 1926.153 Section 1926.153..., DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Fire Protection and...

8. Dynamic Instability of Pile-Supported Structures in Liquefiable Soils during Earthquakes

2008-01-01

Full Text Available Piles are long slender columns installed deep into the ground to support heavy structures such as oil platforms, bridges, and tall buildings where the ground is not strong enough to support the structure on its own. In seismic prone zones, in the areas of soft soils (loose to medium dense soil which liquefies like a quick sand piles are routinely used to support structures (buildings/ bridges. The pile and the building vibrate, and often collapse, in liquefiable soils during major earthquakes. In this paper an experimental and analytical approach is taken to characterize this vibration. The emphasis has been given to the dynamic instability of piled foundations in liquefied soil. The first natural frequency of a piled-structure vibrating in liquefiable soil is obtained from centrifuge tests. The experimental system is modelled using a fixed-free Euler-Bernoulli beam resting against an elastic support with axial load and tip mass with rotary inertia. Natural frequencies obtained from the analytical method are compared with experimental results. It was observed that the effective natural frequency of the system can reduce significantly during an earthquake.

9. 75 FR 38092 - The Dow Chemical Company; Application for Blanket Authorization To Export Liquefied Natural Gas

2010-07-01

... The Dow Chemical Company (Dow), requesting blanket authorization to export liquefied natural gas (LNG... with its principal place of business in Midland, Michigan. Dow is an international chemical and...\\ The Dow Chemical Company, DOE/FE Order No. 2754 issued February 25, 2010. Current Application In...

10. 75 FR 72877 - Pipeline Safety: Updates to Pipeline and Liquefied Natural Gas Reporting Requirements

2010-11-26

... reporting further would impact safety trending capability, therefore, we have chosen to maintain the... LNG facilities should be integrated into 49 CFR Parts 192 and 193 respectively. At present, reporting... Safety: Updates to Pipeline and Liquefied Natural Gas Reporting Requirements; Final Rule...

11. 75 FR 62512 - Sabine Pass Liquefaction, LLC; Application for Long-Term Authorization To Export Liquefied...

2010-10-12

... Pass Liquefaction, LLC; Application for Long-Term Authorization To Export Liquefied Natural Gas AGENCY... September 7, 2010, by Sabine Pass Liquefaction, LLC (Sabine Pass), requesting long-term, multi-contract... the future develops, the capacity to import LNG and with which trade is not prohibited by U.S. law...

12. 49 CFR 173.313 - UN Portable Tank Table for Liquefied Compressed Gases.

2010-10-01

... part of the shell, “sunshield” means a portable tank with a shield covering at least the upper third of the shell, “bare” means no sunshield or insulation is provided, and “insulated” means a complete... Petroleum gas, liquefied See MAWP definition in § 178.276(a) Allowed Normal See § 173.32(f) 1077...

13. Some insights in novel risk modeling of liquefied natural gas carrier maintenance operations

Nwaoha, T. C.; John, Andrew

2016-06-01

This study discusses the analysis of various modeling approaches and maintenance techniques applicable to the Liquefied Natural Gas (LNG) carrier operations in the maritime environment. Various novel modeling techniques are discussed; including genetic algorithms, fuzzy logic and evidential reasoning. We also identify the usefulness of these algorithms in the LNG carrier industry in the areas of risk assessment and maintenance modeling.

14. 75 FR 70350 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

2010-11-17

... Maritime Administration Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License.... Coast Guard received an application from Liberty Natural Gas LLC for all Federal authorizations required... the transportation, storage, and further handling of oil or natural gas for transportation to...

15. 76 FR 4417 - Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License Application

2011-01-25

... Maritime Administration Liberty Natural Gas LLC, Liberty Liquefied Natural Gas (LNG) Deepwater Port License... Deepwater Port License Application. The application describes an offshore natural gas deepwater port... appeared in the Federal Register on April 11, 2000 (65 FR 19477), see PRIVACY ACT. You may view...

16. 30 CFR 75.1106-4 - Use of liquefied and nonliquefied compressed gas cylinders; general requirements.

2010-07-01

... gas cylinders; general requirements. 75.1106-4 Section 75.1106-4 Mineral Resources MINE SAFETY AND...-UNDERGROUND COAL MINES Fire Protection § 75.1106-4 Use of liquefied and nonliquefied compressed gas cylinders... compressed gas unit, consisting of one oxygen cylinder and one additional gas cylinder, shall be used...

17. Kilohertz laser ablation for doping helium nanodroplets

Mudrich, M; Müller, S; Dvorak, M; Buenermann, O; Stienkemeier, F

2007-01-01

A new setup for doping helium nanodroplets by means of laser ablation at kilohertz repetition rate is presented. The doping process is characterized and two distinct regimes of laser ablation are identified. The setup is shown to be efficient and stable enough to be used for spectroscopy, as demonstrated on beam-depletion spectra of lithium atoms attached to helium nanodroplets. For the first time, helium droplets are doped with high temperature refractory materials such as titanium and tantalum. Doping with the non-volatile DNA basis Guanine is found to be efficient and a number of oligomers are detected.

18. Helium refrigeration considerations for cryomodule design

Many of the present day accelerators are based on superconducting radio frequency (SRF) cavities, packaged in cryo-modules (CM), which depend on helium refrigeration at sub-atmospheric pressures, nominally 2 K. These specialized helium refrigeration systems are quite cost intensive to produce and operate. Particularly as there is typically no work extraction below the 4.5-K supply, it is important that the exergy loss between this temperature level and the CM load temperature(s) be minimized by the process configuration choices. This paper will present, compare and discuss several possible helium distribution process arrangements to support the CM loads

19. Helium exhaust and forced flow effects with both-leg pumping in W-shaped divertor of JT-60U

The W-shaped divertor of JT-60U was modified from inner-leg pumping to both-leg pumping. After the modification, the pumping rate was improved from 3% with inner-leg pumping to 5% with both-leg pumping in a divertor-closure configuration, which means both separatrixes close to the divertor slots. Efficient helium exhaust was realized in the divertor-closure configuration with both-leg pumping. A global particle confinement time of τ*He=0.4s and τ*He/τE=3 was achieved in attached ELMy H-mode plasmas. The helium exhaust efficiency with both-leg pumping was extended by 45% as compared with inner-leg pumping. By using central helium fueling with He-beam injection, the helium removal from the core plasma inside the internal transport barrier (ITB) in reversed shear plasmas in the divertor-closure configuration was investigated for the first time. The helium density profiles inside the ITB were peaked as compared with those in ELMy H-mode plasmas. In the case of low recycling divertor, it was difficult to achieve good helium exhaust capability in reversed shear plasmas with ITB. However, the helium exhaust efficiency was improved with high recycling divertor. Carbon impurity reduction was observed by the forced flow with gas puff and effective divertor pumping. (author)

20. Steady-state exhaust of helium ash in the W-shaped divertor of JT-60U

By injecting a neutral beam of 60 keV helium (He) atoms as central fueling of helium into the ELMy H-mode plasmas, helium exhaust has been studied in the W-shaped pumped divertor on JT-60U. Efficient He exhaust was realized by He pumping using argon frosted cryopumps in the JT-60U new divertor. In steady state, good He exhaust capability (τHe*/τE=4 and high enrichment factor, where τHe* is a global particle confinement time of helium and τE is the energy confinement time) was successfully demonstrated in attached ELMy H-mode plasmas. Good He exhaust capability was also obtained in detached ELMy H-mode plasmas, which was comparable to one in attached plasmas. This result of the helium exhaust is sufficient to support a detached divertor operation on ITER. After the divertor modification, helium exhaust in reversed shear plasmas has been investigated using He gas puff. Helium removal inside the internal transport barrier (ITB) is about two times as difficult as that outside the ITB in reversed shear discharges. (author)

1. Liquefied Residue of Kenaf Core Wood Produced at Different Phenol-Kenaf Ratio

Liquefactions of kenaf core wood were carried out at different phenol-kenaf (P/ k) ratios. Characterizations of kenaf core wood liquefied residue were carried out to measure the degree of liquefaction. This provides a new approach to understand some fundamental aspects of the liquefaction reaction. Functional groups on the raw kenaf core wood and liquefied residue were examined using Fourier transform infrared spectroscopy (FTIR). The crystallinity index of the kenaf wood liquefied residue, which represents crystallinity changes of the cellulose component after the liquefaction process, was studied using X-ray diffraction (XRD). The surface morphology of the wood residue was observed using scanning electron microscopy (SEM). The thermal behavior of the residues was analyzed using thermogravimetric analysis (TGA). Abroad peak around 3450-3400 cm-1 representing OH stretching in lignin start to disappear as P/K ratio increases. The results showed that the higher the P/K ratio the greater the liquefaction of the lignin component in the kenaf core wood. The crystallinity index (CrI) on the kenaf liquefied residues increased with the increase in P/K ratio. SEM images showed that the small fragments attached on the liquefied kenaf residue surface were gradually removed as the P/K ratio was increased from 1.5/ 1.0 to 2.5/ 1.0, which is mainly attributed to the greater chemical penetration toward reactive site of the kenaf fibres. Residue content decreased as the P/K ratio increased from 1.5/ 1.0 to 2.5/ 1.0. TGA results showed the increase of heat resistance in the residue as the P/K ratio was increased. (author)

2. 21 CFR 868.1640 - Helium gas analyzer.

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Helium gas analyzer. 868.1640 Section 868.1640...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1640 Helium gas analyzer. (a) Identification. A helium gas analyzer is a device intended to measure the concentration of helium in a...

3. Control of the two-Photon Double Ionization of Helium with Intense Chirped Attosecond Laser Pulses

Barmaki, Samira; Laulan, Stephane

2014-05-01

We study the two-photon double ionization process of the helium atom by solving numerically the nonrelativistic time-dependent Schrödinger equation in its full dimensionality. We investigate with an intense chirped attosecond laser pulse of central carrier frequency that corresponds to the 29th harmonic of a Ti-sapphire laser the direct and sequential processes in helium. We show how it is possible by adjusting the chirp parameter to control the dominance of one process over the other within the atom. Attosecond chirped laser pulses offer a promising way to probe and control the two-photon double ionization of helium when compared with attosecond transform-limited pulses.

4. Behavior of helium bubble in helium-doped stainless steel weldment for nuclear power plant

The behavior of helium bubble in helium-doped austenitic stainless steel weldment was investigated using scanning electron microscopy, transmission electron microscopy and numerical calculation technique. The stainless steel was helium ion-implanted and welded by YAG laser apparatus. Helium ion implanting to the sample was carried out using 8 MeV implantation apparatus. The sample was doped 1.0x1019 atoms/m2 at 5 MeV and then doped 2.45x1019 atoms/m2 at 6 MeV. The region where helium bubbles formed in the heat-affected zone increased with increasing laser power. For low laser power, the helium concentration was above 10 appm in the weld metal and many large helium bubbles larger than 3 μm in diameter were observed at the bond region. The volume of weld metal increased and the size of helium bubble decreased with increasing laser power respectively. Number of fine helium bubbles below 0.1 μm in diameter were observed along the dendrite cell boundary in the weld metal. The increases of laser power and travel speed led to the initiation of cracking at the dendrite cell boundary in the weld metal, even at 2.9 appmHe. (author)

5. Helium bubble kinetics during laser welding of helium-doped stainless steel

Helium is generated within neutron-irradiated reactor components and entrapped in the stainless steel components. The repair of the components using conventional GTA welding practices is then exceedingly difficult, because of the creation of helium bubbles and weld cracking. In this research, the behavior of helium bubbles in austenitic stainless steel weldments was investigated using stainless steel helium ion-implanted and then welded using YAG Laser apparatus. Helium ion implanting of the sample was carried out using 8MeV implantation apparatus, the sample being doped 2.45χ1019/m2 at 6MeV and then doped 1χ1019/m2 at 5MeV. Helium bubbles are present at the bond region, heat-affected zone and weld metal. An increase of weld heat input causes the growth of helium bubbles and produce toe cracks and cracks along the dendrite cell boundary in the weld metal. The helium bubble phenomena can be simulated in the weld metal and in the heat-affected zone during repair welding using helium ion implanting technique. (author)

6. Helium cosmic ray flux measurements at Mars

The helium energy spectrum in Martian orbit has been observed by the MARIE charged particle spectrometer aboard the 2001 Mars Odyssey spacecraft. The orbital data were taken from March 13, 2002 to October 28, 2003, at which time a very intense Solar Particle Event caused a loss of communication between the instrument and the spacecraft. The silicon detector stack in MARIE is optimized for the detection of protons and helium in the energy range below 100MeV/n, which typically includes almost all of the flux during SPEs. This also makes MARIE an efficient detector for GCR helium in the energy range of 50-150MeV/n. We will present the first fully normalized flux results from MARIE, using helium ions in this energy range

7. Helium cosmic ray flux measurements at Mars

Lee, Kerry [University of Houston, 4800 Calhoun Rd. Houston, TX 77204 (United States)]. E-mail: ktlee@ems.jsc.nasa.gov; Pinsky, Lawrence [University of Houston, 4800 Calhoun Rd. Houston, TX 77204 (United States); Andersen, Vic [University of Houston, 4800 Calhoun Rd. Houston, TX 77204 (United States); Zeitlin, Cary [National Space Biomedical Research Institute, Baylor College of Medicine, Houston, TX (United States); Cleghorn, Tim [NASA Johnson Space Center, 2101 NASA Road 1, Houston, TX 77058 (United States); Cucinotta, Frank [NASA Johnson Space Center, 2101 NASA Road 1, Houston, TX 77058 (United States); Saganti, Premkumar [Prairie View A and M University, P.O. Box 519, Prairie View, TX 77446-0519 (United States); Atwell, William [The Boeing Company, Houston, TX (United States); Turner, Ron [Advancing National Strategies and Enabling Results (ANSER), Arlington, Virginia (United States)

2006-10-15

The helium energy spectrum in Martian orbit has been observed by the MARIE charged particle spectrometer aboard the 2001 Mars Odyssey spacecraft. The orbital data were taken from March 13, 2002 to October 28, 2003, at which time a very intense Solar Particle Event caused a loss of communication between the instrument and the spacecraft. The silicon detector stack in MARIE is optimized for the detection of protons and helium in the energy range below 100MeV/n, which typically includes almost all of the flux during SPEs. This also makes MARIE an efficient detector for GCR helium in the energy range of 50-150MeV/n. We will present the first fully normalized flux results from MARIE, using helium ions in this energy range.

8. Helium Find Thaws the Cold Fusion Trail.

Pennisi, E.

1991-01-01

Reported is a study of cold fusion in which trace amounts of helium, possible evidence of an actual fusion reaction, were found. Research methodology is detailed. The controversy over the validity of experimental results with cold fusion are reviewed. (CW)

9. Charged condensate and helium dwarf stars

White dwarf stars composed of carbon, oxygen and heavier elements are expected to crystallize as they cool down below certain temperatures. Yet, simple arguments suggest that the helium white dwarf cores may not solidify, mostly because of zero-point oscillations of the helium ions that would dissolve the crystalline structure. We argue that the interior of the helium dwarfs may instead form a macroscopic quantum state in which the charged helium-4 nuclei are in a Bose–Einstein condensate, while the relativistic electrons form a neutralizing degenerate Fermi liquid. We discuss the electric charge screening, and the spectrum of this substance, showing that the bosonic long-wavelength fluctuations exhibit a mass gap. Hence, there is a suppression at low temperatures of the boson contribution to the specific heat—the latter being dominated by the specific heat of the electrons near the Fermi surface. This state of matter may have observational signatures

10. Development of charcoal sorbents for helium cryopumping

Testing of the cryogenically cooled charcoal using fusion-compatible binders for pumping helium has shown promising results. The program demonstrated comparable or improved performance with these binders compared to the charcoal (type and size) using an epoxy binder
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