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Sample records for advanced thermally stable

  1. Advanced Thermally Stable Jet Fuels

    Energy Technology Data Exchange (ETDEWEB)

    A. Boehman; C. Song; H. H. Schobert; M. M. Coleman; P. G. Hatcher; S. Eser

    1998-01-01

    The Penn State program in advanced thermally stable jet fuels has five components: 1) development of mechanisms of degradation and solids formation; 2) quantitative measurement of growth of sub-micrometer and micrometer-sized particles during thermal stressing; 3) characterization of carbonaceous deposits by various instrumental and microscopic methods; 4) elucidation of the role of additives in retarding the formation of carbonaceous solids; and 5) assessment of the potential of producing high yields of cycloalkanes and hydroaromatics from coal.

  2. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  3. Advanced thermally stable jet fuels. Technical progress report, August 1992--October 1992

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Walsh, P.M.; Coleman, M.M.; Bortiatynski, J.; Burgess, C.; Dutta, R.; Gergova, K.; Lai, W.C.; Li, J.; McKinney, D.; Parfitt, D.; Peng, Y.; Sanghani, P.; Yoon, E.

    1993-02-01

    The Penn State program in advanced thermally stable coal-based jet fuels has five borad objectives: (1) development of mechanisms of degradation and solids formation; (2) quantitative measurement of growth of sub-micrometer and miocrometer-sized particles suspended in fuels during thermal stressing; (3) characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) elucidation of the role of additives in retarding the formation of carbonaceous solids; and (5) assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Pyrolysis of four isomers of butylbenzene was investigated in static microautoclave reactors at 450{degrees}C under 0.69 MPa of UHP N{sub 2}. Thee rates of disappearance of substrates were found to depend upon the bonding energy of C{alpha}-C{beta} bond in the side chain in the initial period of pyrolysis reactions. Possible catalytic effects of metal surfaces on thermal degradation and deposit formation at temperatures >400{degrees}C have been studied. Carbon deposition depends on the composition of the metal surfaces, and also depends on the chemical compositions of the reactants. Thermal stressing of JP-8 was conducted in the presence of alumina, carbonaceous deposits recovered from earlier stressing experiments, activated carbon, carbon black, and graphite. The addition of different solid carbons during thermal stressing leads to different reaction mechanisms. {sup 13}C NMR spectroscopy, along with {sup 13}C-labeling techniques, have been used to examine the thermal stability of a jet fuel sample mixed with 5% benzyl alcohol. Several heterometallic complexes consisting of two transition metals and sulfur in a single molecule were synthesized and tested as precursors of bimetallic dispersed catalysts for liquefaction of a Montana subbituminous and Pittsburgh No. 8 bituminous coals.

  4. Advanced thermally stable jet fuels: Technical progress report, October 1994--December 1994

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Boehman, A.; Coleman, M.M.

    1995-02-01

    There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 5 subtasks which are described: Literature review on thermal stability of jet fuels; Pyrolytic and catalytic reactions of potential endothermic fuels: cis- and trans-decalin; Use of site specific {sup 13}C-labeling to examine the thermal stressing of 1-phenylhexane: A case study for the determination of reaction kinetics in complex fuel mixtures versus model compound studies; Estimation of critical temperatures of jet fuels; and Surface effects on deposit formation in a flow reactor system. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Characterization of solid gums, sediments, and carbonaceous deposits, is subtask, Studies of surface chemistry of PX-21 activated carbon during thermal degradation of jet A-1 fuel and n-dodecane; under Task 4, Coal-based fuel stabilization studies, is subtask, Exploratory screening and development potential of jet fuel thermal stabilizers over 400 C; and under Task 5, Exploratory studies on the direct conversion of coal to high quality jet fuels, are 4 subtasks: Novel approaches to low-severity coal liquefaction and coal/resid co-processing using water and dispersed catalysts; Shape-selective naphthalene hydrogenation for production of thermally stable jet fuels; Design of a batch mode and a continuous mode three-phase reactor system for the liquefaction of coal and upgrading of coal liquids; and Exploratory studies on coal liquids upgrading using mesopores molecular sieve catalysts. 136 refs., 69 figs., 24 tabs.

  5. Advanced thermally stable jet fuels. Technical progress report, January 1995--March 1995

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.; Eser, S.; Song, C. [and others

    1995-06-01

    Quantitative structure-property relationships have been applied to study the thermal stability of pure hydrocarbons typical of jet fuel components. A simple method of chemical structure description in terms of Benson groups was tested in searching for structure-property relationships for the hydrocarbons tested experimentally in this program. Molecular connectivity as a structure-based approach to chemical structure-property relationship analysis was also tested. Further development of both the experimental data base and computational methods will be necessary. Thermal decomposition studies, using glass tube reactors, were extended to two additional model compounds: n-decane and n-dodecane. Efforts on refining the deposit growth measurement and characterization of suspended matter in stressed fuels have lead to improvements in the analysis of stressed fuels. Catalytic hydrogenation and dehydrogenation studies utilizing a molybdenum sulfide catalyst are also described.

  6. Advanced thermally stable jet fuels. Technical progress report, November 1992--January 1993

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.; Eser, S.; Song, C.; Hatcher, P.G.; Walsh, P.M.; Coleman, M.M.; Arumugam, R.; Bortiatynski, J.; Dutta, R.; Gergova, K.; Hou, L.; Lai, W-C.; Li, J.; McKinney, D.; Peng, Y.; Sanghani, P.; Selvaraj, L.; Sobkowiak, M.

    1993-03-01

    The pyrolysis of octylbenzene (OB) at various temperatures, 400{degrees}C, 425{degrees}C and 450{degrees}C, has been studied. This work represents a continuous effort in the study of the effects of alkylbenzenes in the high temperature thermal degradation of jet fuels, following up the detailed study of the behavior of four isomers of butylbenzenes (1). There are some general similarities in the reactions of OB and butylbenzenes. For example, both produce a large amount of smaller alkylbenzenes during pyrolysis. Reaction kinetics of OB have been calculated based on the temperature range mentioned above, and the major chemical process in its thermal reactions have been analyzed. As expected, temperature plays the most significant role in the degradation process, as shown in Figure 1. The reaction shows only a moderate rate at 400{degrees}C, 8.18 mol% of OB remaining after 16 hours of stressing. At 450{degrees}C, however, there is virtually no OB left after 8 hours of stressing. Rough comparison of the yields (wt%) of gaseous, liquid and solid products formed (Figures 2, 3 and 4) shows a uniform change in this temperature range. For example, a steady increase of the yields (wt%) of gas and solid formation can be observed in Figures 2 and 3. Global kinetics of the reaction of octylbenzene have been calculated.

  7. Advanced thermal management materials

    CERN Document Server

    Jiang, Guosheng; Kuang, Ken

    2012-01-01

    ""Advanced Thermal Management Materials"" provides a comprehensive and hands-on treatise on the importance of thermal packaging in high performance systems. These systems, ranging from active electronically-scanned radar arrays to web servers, require components that can dissipate heat efficiently. This requires materials capable of dissipating heat and maintaining compatibility with the packaging and dye. Its coverage includes all aspects of thermal management materials, both traditional and non-traditional, with an emphasis on metal based materials. An in-depth discussion of properties and m

  8. Thermally Stable, Latent Olefin Metathesis Catalysts

    OpenAIRE

    Thomas, Renee M.; Fedorov, Alexey; Keitz, Benjamin K.; Grubbs, Robert H.

    2011-01-01

    Highly thermally stable N-aryl,N-alkyl N-heterocyclic carbene (NHC) ruthenium catalysts were designed and synthesized for latent olefin metathesis. These catalysts showed excellent latent behavior toward metathesis reactions, whereby the complexes were inactive at ambient temperature and initiated at elevated temperatures, a challenging property to achieve with second generation catalysts. A sterically hindered N-tert-butyl substituent on the NHC ligand of the ruthenium complex was found to i...

  9. Thermally Stable, Latent Olefin Metathesis Catalysts

    Science.gov (United States)

    Thomas, Renee M.; Fedorov, Alexey; Keitz, Benjamin K.

    2011-01-01

    Highly thermally stable N-aryl,N-alkyl N-heterocyclic carbene (NHC) ruthenium catalysts were designed and synthesized for latent olefin metathesis. These catalysts showed excellent latent behavior toward metathesis reactions, whereby the complexes were inactive at ambient temperature and initiated at elevated temperatures, a challenging property to achieve with second generation catalysts. A sterically hindered N-tert-butyl substituent on the NHC ligand of the ruthenium complex was found to induce latent behavior toward cross-metathesis reactions, and exchange of the chloride ligands for iodide ligands was necessary to attain latent behavior during ring-opening metathesis polymerization (ROMP). Iodide-based catalysts showed no reactivity toward ROMP of norbornene-derived monomers at 25 °C, and upon heating to 85 °C gave complete conversion of monomer to polymer in less than 2 hours. All of the complexes were very stable to air, moisture, and elevated temperatures up to at least 90 °C, and exhibited a long catalyst lifetime in solution at elevated temperatures. PMID:22282652

  10. Thermally Stable, Latent Olefin Metathesis Catalysts.

    Science.gov (United States)

    Thomas, Renee M; Fedorov, Alexey; Keitz, Benjamin K; Grubbs, Robert H

    2011-12-26

    Highly thermally stable N-aryl,N-alkyl N-heterocyclic carbene (NHC) ruthenium catalysts were designed and synthesized for latent olefin metathesis. These catalysts showed excellent latent behavior toward metathesis reactions, whereby the complexes were inactive at ambient temperature and initiated at elevated temperatures, a challenging property to achieve with second generation catalysts. A sterically hindered N-tert-butyl substituent on the NHC ligand of the ruthenium complex was found to induce latent behavior toward cross-metathesis reactions, and exchange of the chloride ligands for iodide ligands was necessary to attain latent behavior during ring-opening metathesis polymerization (ROMP). Iodide-based catalysts showed no reactivity toward ROMP of norbornene-derived monomers at 25 °C, and upon heating to 85 °C gave complete conversion of monomer to polymer in less than 2 hours. All of the complexes were very stable to air, moisture, and elevated temperatures up to at least 90 °C, and exhibited a long catalyst lifetime in solution at elevated temperatures. PMID:22282652

  11. Lightweight Thermally Stable Multi-Meter Aperture Submillimeter Reflectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future astrophysics missions will require lightweight, thermally stable, submillimeter reflectors in sizes of 4m and greater. To date, graphite fiber reinforced...

  12. Advanced solar thermal receiver technology

    Science.gov (United States)

    Kudirka, A. A.; Leibowitz, L. P.

    1980-01-01

    Development of advanced receiver technology for solar thermal receivers designed for electric power generation or for industrial applications, such as fuels and chemical production or industrial process heat, is described. The development of this technology is focused on receivers that operate from 1000 F to 3000 F and above. Development strategy is mapped in terms of application requirements, and the related system and technical requirements. Receiver performance requirements and current development efforts are covered for five classes of receiver applications: high temperature, advanced Brayton, Stirling, and Rankine cycle engines, and fuels and chemicals.

  13. Advanced Thermal Control Flight Experiment.

    Science.gov (United States)

    Kirkpatrick, J. P.; Brennan, P. J.

    1973-01-01

    The advanced Thermal Control Flight Experiment on the Applications Technology Satellite (ATS-F) will evaluate, for the first time in a space environment, the performance of a feedback-controlled variable conductance heat pipe and a heat pipe thermal diode. In addition, the temperature control aspects of a phase-change material (PCM) will be demonstrated. The methanol/stainless steel feedback-controlled heat pipe uses helium control gas that is stored in a wicked reservoir. This reservoir is electrically heated through a solid state controller that senses the temperature of the heat source directly. The ammonia/stainless steel diode heat pipe uses excess liquid to block heat transfer in the reverse direction. The PCM is octadecane. Design tradeoffs, fabrication problems, and performance during qualification and flight acceptance tests are discussed.

  14. Lightweight Thermally Stable Multi-Meter Aperture Submillimeter Reflectors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of the Phase II effort will be an affordable demonstrated full-scale design for a thermally stable multi-meter submillimeter reflector. The Phase I...

  15. Thermally-Stable High Strain Deployable Structures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is for the development of a thermally-stable composite made of carbon fibers and elastomeric resin. This combination of materials will allow...

  16. New developments in thermally stable polymers

    Science.gov (United States)

    Hergenrother, Paul M.

    1991-01-01

    Advances in high-temperature polymers since 1985 are discussed with the emphasis on the chemistry. High-temperature polymers refer to materials that exhibit glass-transition temperatures greater than 200 C and have the chemical structure expected to provide high thermooxidative stability. Specific polymers or series of polymers were selected to show how the chemical structure influences certain properties. Poly(arylene ethers) and polyimides are the two principal families of polymers discussed. Recent work on poly(arylene ethers) has concentrated on incorporating heterocyclic units within the polymer backbone. Recent polyimide work has centered on the synthesis of new polymers from novel monomers, several containing the trifluoromethyl group strategically located on the molecule. Various members in each of these polymer families display a unique combination of properties, heretofore unattainable. Other families of polymers are also briefly discussed with a polymer from an AB maleimidobenzocyclobutene exhibiting an especially attractive combination of properties.

  17. Thermally stable crystalline mesoporous metal oxides with substantially uniform pores

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, Ulrich; Orilall, Mahendra Christopher; Lee, Jinwoo; DiSalvo, Jr., Francis J

    2015-01-27

    Highly crystalline metal oxide-carbon composites, as precursors to thermally stable mesoporous metal oxides, are coated with a layer of amorphous carbon. Using a `one-pot` method, highly crystalline metal oxide-carbon composites are converted to thermally stable mesoporous metal oxides, having highly crystalline mesopore walls, without causing the concomitant collapse of the mesostructure. The `one-pot` method uses block copolymers with an sp or sp 2 hybridized carbon containing hydrophobic block as structure directing agents which converts to a sturdy, amorphous carbon material under appropriate heating conditions, providing an in-situ rigid support which maintains the pores of the oxides intact while crystallizing at temperatures as high as 1000 deg C. A highly crystalline metal oxide-carbon composite can be heated to produce a thermally stable mesoporous metal oxide consisting of a single polymorph.

  18. Thermally stable surfactants and compositions and methods of use thereof

    Science.gov (United States)

    Chaiko, David J.

    2008-09-02

    There are provided novel thermally stable surfactants for use with fillers in the preparation of polymer composites and nanocomposites. Typically, surfactants of the invention are urethanes, ureas or esters of thiocarbamic acid having a hydrocarbyl group of from 10 to 50 carbons and optionally including an ionizable or charged group (e.g., carboxyl group or quaternary amine). Thus, there are provided surfactants having Formula I: ##STR00001## wherein the variables are as defined herein. Further provided are methods of making thermally stable surfactants and compositions, including composites and nanocomposites, using fillers coated with the surfactants.

  19. Advanced Spacecraft Thermal Modeling Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For spacecraft developers who spend millions to billions of dollars per unit and require 3 to 7 years to deploy, the LoadPath reduced-order (RO) modeling thermal...

  20. JPL Advanced Thermal Control Technology Roadmap - 2012

    Science.gov (United States)

    Birur, Gaj; Rodriguez, Jose I.

    2012-01-01

    NASA's new emphasis on human exploration program for missions beyond LEO requires development of innovative and revolutionary technologies. Thermal control requirements of future NASA science instruments and missions are very challenging and require advanced thermal control technologies. Limited resources requires organizations to cooperate and collaborate; government, industry, universities all need to work together for the successful development of these technologies.

  1. Fiber Optic Cable Thermal Preparation to Ensure Stable Operation

    Science.gov (United States)

    Thoames Jr, William J.; Chuska, Rick F.; LaRocca, Frank V.; Switzer, Robert C.; Macmurphy, Shawn L.; Ott, Melanie N.

    2008-01-01

    Fiber optic cables are widely used in modern systems that must provide stable operation during exposure to changing environmental conditions. For example, a fiber optic cable on a satellite may have to reliably function over a temperature range of -50 C up to 125 C. While the system requirements for a particular application will dictate the exact method by which the fibers should be prepared, this work will examine multiple ruggedized fibers prepared in different fashions and subjected to thermal qualification testing. The data show that if properly conditioned the fiber cables can provide stable operation, but if done incorrectly, they will have large fluctuations in transmission.

  2. Development of Zero Coefficient of Thermal Expansion composite tubes for stable space structures

    Science.gov (United States)

    Strock, John D.

    1992-09-01

    Advanced composite materials are well suited for stable space structures due to their low Coefficient of Thermal Expansion (CTE), high stiffness and light weight. For a given design application, composite hardware can be tailored for strength, stiffness, CTE, and Coefficient of Moisture Expansion (CME). Computer modeling and laminate testing of high modulus graphite/epoxy tubes were evaluated for compressive strength, stiffness, CTE, CME and microcracking. Thermal cycling and microcracking effects on CTE were evaluated. Thin graphite/epoxy plies exhibited reduced microcracking. A zero CTE thin wall tube design resulted from the development program. Recent work on low moisture absorption resin systems is also discussed.

  3. IMPULSE - advanced nuclear thermal propulsion

    Energy Technology Data Exchange (ETDEWEB)

    Ivanenok, J.F. III; Wett, J.F. [Westinghouse Electric Corp., Pittsburgh, PA (United States)

    1993-12-31

    The IMPULSE nuclear thermal rocket concept provides an evolutionary step toward high thrust-to-weight and specific impulse over a wide operating range. Most of the components and features of the concept are based on demonstrated or proven technology from the NER VA/Rover program. The performance increase is due to the use of a new solid nuclear fuel shape. The new fuel shape provides a large flow area while maintaining flow control and eliminating hot spots due to fuel-to-fuel contact. The control and eliminating hot spots due to fuel-to-fuel contact. The IMPULSE reactor utilizes a multi-pass, series flow configuration to provide excess turbine power while improving the thermal efficiency of the overall system. This configuration also provides a large area for moderator. The IMPULSE concept can provide a specific impulse of up to 1000 seconds and trust to weight ratios approaching 40. The improved performance will reduce the Initial Mass In Low Earth Orbit (IMLEO) and provide a consequent reduction in launch costs and logistics problems.

  4. Thermoelectric Devices Advance Thermal Management

    Science.gov (United States)

    2007-01-01

    Thermoelectric (TE) devices heat, cool, and generate electricity when a temperature differential is provided between the two module faces. In cooperation with NASA, Chico, California-based United States Thermoelectric Consortium Inc. (USTC) built a gas emissions analyzer (GEA) for combustion research. The GEA precipitated hydrocarbon particles, preventing contamination that would hinder precise rocket fuel analysis. The USTC research and design team uses patent-pending dimple, pin-fin, microchannel and microjet structures to develop and design heat dissipation devices on the mini-scale level, which not only guarantee high performance of products, but also scale device size from 1 centimeter to 10 centimeters. USTC continues to integrate the benefits of TE devices in its current line of thermal management solutions and has found the accessibility of NASA technical research to be a valuable, sustainable resource that has continued to positively influence its product design and manufacturing

  5. Preparation and performance of novel thermal stable composite nanofiltration membrane

    Institute of Scientific and Technical Information of China (English)

    Chunrui WU; Shouhai ZHANG; Fajie YANG; Chun YAN; Xigao JIAN

    2008-01-01

    The novel thermal stable composite nanofiltra-tion membranes were prepared through the interfacial polymerization of piperazine and trimesoyl chloride on the poly (phthalazinone ether) ultrafiltration substrate. The effects of polymerization and testing conditions on membrane performance were studied. The surface morphologies of the substrate and the composite mem-branes were observed by means of scanning electron microscopy (SEM) and atomic force microscopy (AFM). The separation properties of membranes for dyes and salts were tested. The composite membranes show good ther-mal stability. The rejection for Na2SO4 was kept over 96%, 1.0 MPa and 80℃. When tested at 1.0 MPa and 60℃, the rejection of the composite membrane for dyes was kept at the rejection for NaCl was lower than 20%.

  6. JPL Advanced Thermal Control Technology Roadmap - 2008

    Science.gov (United States)

    Birur, Gaj

    2008-01-01

    This slide presentation reviews the status of thermal control technology at JPL and NASA.It shows the active spacecraft that are in vairous positions in the solar syatem, and beyond the solar system and the future missions that are under development. It then describes the challenges that the past missions posed with the thermal control systems. The various solutions that were implemented duirng the decades prior to 1990 are outlined. A review of hte thermal challenges of the future misions is also included. The exploration plan for Mars is then reviewed. The thermal challenges of the Mars Rovers are then outlined. Also the challenges of systems that would be able to be used in to explore Venus, and Titan are described. The future space telescope missions will also need thermal control technological advances. Included is a review of the thermal requirements for manned missions to the Moon. Both Active and passive technologies that have been used and will be used are reviewed. Those that are described are Mechanically Pumped Fluid Loops (MPFL), Loop Heat Pipes, an M3 Passive Cooler, Heat Siwtch for Space and Mars surface applications, phase change material (PCM) technology, a Gas Gap Actuateor using ZrNiH(x), the Planck Sorption Cooler (PCS), vapor compression -- Hybrid two phase loops, advanced pumps for two phase cooling loops, and heat pumps that are lightweight and energy efficient.

  7. Nuclear Thermal Propulsion for Advanced Space Exploration

    Science.gov (United States)

    Houts, M. G.; Borowski, S. K.; George, J. A.; Kim, T.; Emrich, W. J.; Hickman, R. R.; Broadway, J. W.; Gerrish, H. P.; Adams, R. B.

    2012-01-01

    The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced Nuclear Electric Propulsion (NEP).

  8. Advanced Thermal Hydraulics Design of Commercial SFRs

    International Nuclear Information System (INIS)

    Prototype Fast Breeder Reactor (PFBR) is a 500 MWe pool type sodium cooled fast reactor, which is in an advanced stage of construction in India. As a follow-up to PFBR, six commercial sodium cooled fast reactors (Commercial SFR) of similar capacity are to be constructed, wherein the focus is improved economy and enhanced safety. These reactors are envisaged to have twin-unit concept. Design and construction experiences from PFBR provided the motivation to achieve an optimum design for the Commercial SFR with significant design changes. Some of the changes include, (i) provision of four primary pipes per primary sodium pump, (ii) inner vessel with single torus, (iii) dome shaped roof slab supported on reactor vault, (iv) machined thick plate rotating plugs, (v) reduced main vessel diameter with narrow-gap cooling baffles and (vi) safety vessel integrated with reactor vault. Advanced computational fluid dynamic studies have been performed towards thermal hydraulic design of these components. This paper covers thermal hydraulic design validation of the chosen options, including hot pool thermal hydraulics, influence of control plug shape on pool hydraulics, flow requirement for main vessel cooling, safety analysis of primary pipe rupture event and thermal management top shield and reactor vault. (author)

  9. Minimized thermal conductivity in highly stable thermal barrier W/ZrO2 multilayers

    Science.gov (United States)

    Döring, Florian; Major, Anna; Eberl, Christian; Krebs, Hans-Ulrich

    2016-10-01

    Nanoscale thin-film multilayer materials are of great research interest since their large number of interfaces can strongly hinder phonon propagation and lead to a minimized thermal conductivity. When such materials provide a sufficiently small thermal conductivity and feature in addition also a high thermal stability, they would be possible candidates for high-temperature applications such as thermal barrier coatings. For this article, we have used pulsed laser deposition in order to fabricate thin multilayers out of the thermal barrier material ZrO2 in combination with W, which has both a high melting point and high density. Layer thicknesses were designed such that bulk thermal conductivity is governed by the low value of ZrO2, while ultrathin W blocking layers provide a high number of interfaces. By this phonon scattering, reflection and shortening of mean free path lead to a significant reduction in overall thermal conductivity even below the already low value of ZrO2. In addition to this, X-ray reflectivity measurements were taken showing strong Bragg peaks even after annealing such multilayers at 1300 K. Those results identify W/ZrO2 multilayers as desired thermally stable, low-conductivity materials.

  10. Development of demonstration advanced thermal reactor

    International Nuclear Information System (INIS)

    The design of the advanced thermal demonstration reactor with 600 MWe output was started in 1975. In order to make the compact core, 648 fuel assemblies, each comprising 36 fuel rods, were used, and the mean channel output was increased by 20% as compared with the prototype reactor. The heavy water dumping mechanism for the calandria was abolished. Advanced thermal reactors are suitable to burn plutonium, since the control rod worth does not change, the void reactivity coefficient of coolant shifts to the negative side, and the harmful influence of high order plutonium is small. The void reactivity coefficient is nearly zero, the fluctuation of output in relation to pressure disturbance is small, and the local output change of fuel by the operation of control rods is small, therefore, the operation following load change is relatively easy. The coolant recirculation system is of independent loop construction dividing the core into two, and steam and water are separated in respective steam drums. At present, the rationalizing design is in progress by the leadership of the Power Reactor and Nuclear Fuel Development Corp. The outline of the demonstration reactor, the reactor construction, the nuclear-thermal-hydraulic characteristics and the output control characteristics are reported. (Kako, I.)

  11. Advanced Mirror Technology Development (AMTD) Thermal Trade Studies

    Science.gov (United States)

    Brooks, Thomas

    2015-01-01

    Advanced Mirror Technology Development (AMTD) is being done at Marshall Space Flight Center (MSFC) in preparation for the next large aperture UVOIR space observatory. A key science mission of that observatory is the detection and characterization of 'Earth-like' exoplanets. Direct exoplanet observation requires a telescope to see a planet which will be 10(exp -10) times dimmer than its host star. To accomplish this using an internal coronagraph requires a telescope with an ultra-stable wavefront error (WFE). This paper investigates parametric relationships between primary mirror physical parameters and thermal WFE stability. Candidate mirrors are designed as a mesh and placed into a thermal analysis model to determine the temperature distribution in the mirror when it is placed inside of an actively controlled cylindrical shroud at Lagrange point 2. Thermal strains resulting from the temperature distribution are found and an estimation of WFE is found to characterize the effect that thermal inputs have on the optical quality of the mirror. This process is repeated for several mirror material properties, material types, and mirror designs to determine how to design a mirror for thermal stability.

  12. Advanced materials for thermal protection system

    Science.gov (United States)

    Heng, Sangvavann; Sherman, Andrew J.

    1996-03-01

    Reticulated open-cell ceramic foams (both vitreous carbon and silicon carbide) and ceramic composites (SiC-based, both monolithic and fiber-reinforced) were evaluated as candidate materials for use in a heat shield sandwich panel design as an advanced thermal protection system (TPS) for unmanned single-use hypersonic reentry vehicles. These materials were fabricated by chemical vapor deposition/infiltration (CVD/CVI) and evaluated extensively for their mechanical, thermal, and erosion/ablation performance. In the TPS, the ceramic foams were used as a structural core providing thermal insulation and mechanical load distribution, while the ceramic composites were used as facesheets providing resistance to aerodynamic, shear, and erosive forces. Tensile, compressive, and shear strength, elastic and shear modulus, fracture toughness, Poisson's ratio, and thermal conductivity were measured for the ceramic foams, while arcjet testing was conducted on the ceramic composites at heat flux levels up to 5.90 MW/m2 (520 Btu/ft2ṡsec). Two prototype test articles were fabricated and subjected to arcjet testing at heat flux levels of 1.70-3.40 MW/m2 (150-300 Btu/ft2ṡsec) under simulated reentry trajectories.

  13. Single-domain antibody based thermally stable electrochemical immunosensor.

    Science.gov (United States)

    Singh, Aparajita; Pasha, Syed Khalid; Manickam, Pandiaraj; Bhansali, Shekhar

    2016-09-15

    Conventional monoclonal and polyclonal antibodies are sensitive to changes in environmental factors such as temperature, pH, humidity, etc. This limits the current cost-effective and portable electrochemical immunosensors in harsh environments. Using Ricin Chain-A, a naturally occurring toxin, as a model analyte we report fabrication of a thermally stable electrochemical immunosensor. Single-domain antibodies (sdAb) or nanobodies have been employed as recognition elements for direct detection of Ricin at temperatures great than 4°C. Immunosensor fabricated using the conventional Ricin monoclonal and polyclonal antibodies have also been demonstrated for comparison. In the case of sdAb immunosensor, Ricin was detected in a linear range of 1log(fg/mL)-1log(μg/mL) with a sensitivity of 0.07μA/log(g/mL)/cm(2) using cyclic voltammetry. The fabricated miniaturized sensors have demonstrated higher shelf life and stability at temperatures up to 40°C. Therefore these electrochemical sensors can be integrated as a part of a portable device for point-of-care immunosensing. PMID:27125838

  14. Highly conductive and thermally stable self-doping propylthiosulfonated polyanilines

    Institute of Scientific and Technical Information of China (English)

    Han Chien-Chung

    2004-01-01

    A new type of highly conductive self-doping polyaniline, MPS-Pan, containing a sulfonic acid moiety covalently bonded to the polymer backbone through an electron-donating propylthio linkage has been successfully prepared via a novel concurrent reduction and substitution route. At a similar self-doping level, the resultant MPS-Pans displayed much higher conductivity than the corresponding sulfonated-polyaniline (S-Pan). Furthermore, for fully doped samples, contrary to the trend of decreasing conductivity with the sulfonation degree in S-Pan, the conductivity of MPS-Pan was found to increase with its substitution degree. These results agreed with the expectation that electron-deficient charge carriers (e.g. semiquinone radical cations) on acid-doped polyaniline chains will be better stabilized by the electron-donating alkylthio-substituent. Surprisingly, TG and XPS studies showed that MPS-Pan was thermally much more stable than S-Pan, with S-Pan started to lose its sulfonic acid dopant at 185 ℃, while MPS-Pan remained intact up to ca. 260 ℃.

  15. Evaluation of Erosion Resistance of Advanced Turbine Thermal Barrier Coatings

    Science.gov (United States)

    Zhu, Dongming; Kuczmarski, Maria A.; Miller, Robert A.; Cuy, Michael D.

    2007-01-01

    The erosion resistant turbine thermal barrier coating system is critical to aircraft engine performance and durability. By demonstrating advanced turbine material testing capabilities, we will be able to facilitate the critical turbine coating and subcomponent development and help establish advanced erosion-resistant turbine airfoil thermal barrier coatings design tools. The objective of this work is to determine erosion resistance of advanced thermal barrier coating systems under simulated engine erosion and/or thermal gradient environments, validating advanced turbine airfoil thermal barrier coating systems based on nano-tetragonal phase toughening design approaches.

  16. Thermal fatigue durability for advanced propulsion materials

    Science.gov (United States)

    Halford, Gary R.

    1989-01-01

    A review is presented of thermal and thermomechanical fatigue (TMF) crack initiation life prediction and cyclic constitutive modeling efforts sponsored recently by the NASA Lewis Research Center in support of advanced aeronautical propulsion research. A brief description is provided of the more significant material durability models that were created to describe TMF fatigue resistance of both isotropic and anisotropic superalloys, with and without oxidation resistant coatings. The two most significant crack initiation models are the cyclic damage accumulation model and the total strain version of strainrange partitioning. Unified viscoplastic cyclic constitutive models are also described. A troika of industry, university, and government research organizations contributed to the generation of these analytic models. Based upon current capabilities and established requirements, an attempt is made to project which TMF research activities most likely will impact future generation propulsion systems.

  17. Chemically and Thermally Stable High Energy Density Silicone Composites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thermal energy storage systems with 300 ? 1000 kJ/kg energy density through either phase changes or chemical heat absorption are sought by NASA. This proposed...

  18. Advanced Multi-Component Defect Cluster Oxide Doped Zirconia-Yttria Thermal Barrier Coatings

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.

    2003-01-01

    The advantages of using ceramic thermal barrier coatings in gas turbine engine hot sections include increased fuel efficiency and improved engine reliability. However, current thermal barrier coatings will not have the low thermal conductivity and necessary sintering resistance under higher operating temperatures and thermal gradients required by future advanced ultra efficient and low emission aircraft engines. In this paper, a novel oxide defect cluster design approach is described for achieving low thermal conductivity and excellent thermal stability of the thermal barrier coating systems. This approach utilizes multi-component rare earth and other metal cluster oxide dopants that are incorporated in the zirconia-yttna based systems, thus significantly reducing coating thermal conductivity and sintering resistance by effectively promoting the formation of thermodynamically stable, essentially immobile defect clusters and/or nanoscale phases. The performance of selected plasma-sprayed cluster oxide thermal barrier coating systems has been evaluated. The advanced multi-component thermal barrier coating systems were found to have significantly lower initial and long-term thermal conductivities, and better high temperature stability. The effect of oxide cluster dopants on coating thermal conductivity, sintering resistance, oxide grain growth behavior and durability will be discussed.

  19. Synthesis of High-Thermal Stable Titanium Dioxide Nanoparticles

    OpenAIRE

    Rashidzadeh, M.

    2008-01-01

    Nanosized crystals of anatase phase T i O 2 with high-thermal stability was synthesized in the range of 15–17 nm via sol-gel method using titanium n-butoxide precursor. Synthesize was done at two different temperatures, that is, 200 and 3 0 0 ∘ C and the final products were calcined at 4 0 0 ∘ C . The final products were characterized by N 2 adsorption, X-ray diffraction, FT-IR, and TEM and tested in a photoreactor using fluorescien as model molecule. For thermal stability investigation, the ...

  20. Viscosity and thermal conductivity of stable graphite suspensions near percolation.

    Science.gov (United States)

    Ma, Lei; Wang, Jianjian; Marconnet, Amy M; Barbati, Alexander C; McKinley, Gareth H; Liu, Wei; Chen, Gang

    2015-01-14

    Nanofluids have received much attention in part due to the range of properties possible with different combinations of nanoparticles and base fluids. In this work, we measure the viscosity of suspensions of graphite particles in ethylene glycol as a function of the volume fraction, shear rate, and temperature below and above the percolation threshold. We also measure and contrast the trends observed in the viscosity with increasing volume fraction to the thermal conductivity behavior of the same suspensions: above the percolation threshold, the slope that describes the rate of thermal conductivity enhancement with concentration reduces compared to below the percolation threshold, whereas that of the viscosity enhancement increases. While the thermal conductivity enhancement is independent of temperature, the viscosity changes show a strong dependence on temperature and exhibit different trends with respect to the temperature at different shear rates above the percolation threshold. Interpretation of the experimental observations is provided within the framework of Stokesian dynamics simulations of the suspension microstructure and suggests that although diffusive contributions are not important for the observed thermal conductivity enhancement, they are important for understanding the variations in the viscosity with changes of temperature and shear rate above the percolation threshold. The experimental results can be collapsed to a single master curve through calculation of a single dimensionless parameter (a Péclet number based on the rotary diffusivity of the graphite particles). PMID:25469709

  1. The critical power to maintain thermally stable molecular junctions

    Science.gov (United States)

    Wang, Yanlei; Xu, Zhiping

    2014-07-01

    With the rise of atomic-scale devices such as molecular electronics and scanning probe microscopies, energy transport processes through molecular junctions have attracted notable research interest recently. In this work, heat dissipation and transport across diamond/benzene/diamond molecular junctions are explored by performing atomistic simulations. We identify the critical power Pcr to maintain thermal stability of the junction through efficient dissipation of local heat. We also find that the molecule-probe contact features a power-dependent interfacial thermal resistance RK in the order of 109 kW-1. Moreover, both Pcr and RK display explicit dependence on atomic structures of the junction, force and temperature. For instance, Pcr can be elevated in multiple-molecule junctions, and streching the junction enhances RK by a factor of 2. The applications of these findings in molecular electronics and scanning probing measurements are discussed, providing practical guidelines in their rational design.

  2. A Thermally Conductive Separator for Stable Li Metal Anodes.

    Science.gov (United States)

    Luo, Wei; Zhou, Lihui; Fu, Kun; Yang, Zhi; Wan, Jiayu; Manno, Michael; Yao, Yonggang; Zhu, Hongli; Yang, Bao; Hu, Liangbing

    2015-09-01

    Li metal anodes have attracted considerable research interest due to their low redox potential (-3.04 V vs standard hydrogen electrode) and high theoretical gravimetric capacity of 3861 mAh/g. Battery technologies using Li metal anodes have shown much higher energy density than current Li-ion batteries (LIBs) such as Li-O2 and Li-S systems. However, issues related to dendritic Li formation and low Coulombic efficiency have prevented the use of Li metal anode technology in many practical applications. In this paper, a thermally conductive separator coated with boron-nitride (BN) nanosheets has been developed to improve the stability of the Li metal anodes. It is found that using the BN-coated separator in a conventional organic carbonate-based electrolyte results in the Coulombic efficiency stabilizing at 92% over 100 cycles at a current rate of 0.5 mA/cm(2) and 88% at 1.0 mA/cm(2). The improved Coulombic efficiency and reliability of the Li metal anodes is due to the more homogeneous thermal distribution resulting from the thermally conductive BN coating and to the smaller surface area of initial Li deposition. PMID:26237519

  3. Advanced thermal management materials for concentrator photovoltaic arrays

    Science.gov (United States)

    Zweben, Carl

    2010-08-01

    Thermal management is a critical issue for photovoltaics (PVs), especially concentrator photovoltaic systems. Thermal management problems are similar for all semiconductors, including those used in microelectronics and other optoelectronic applications, such as lasers, light-emitting diodes (LEDs), detectors and displays. We divide the thermal management problem into two parts: heat dissipation and thermal stresses. Heat dissipation affects efficiency and lifetime. Thermal stresses affect manufacturing yield and lifetime. Traditional thermal management materials all have serious deficiencies. Copper and aluminum have high coefficients of thermal expansion (CTEs), which can cause severe thermal stresses during manufacturing and in service. Compliant attach materials, used to minimize thermal stresses, all have major drawbacks. Traditional low-CTE thermal management materials have relatively low thermal conductivities and are hard to machine. In response to these deficiencies, new thermal management materials have been, and are continuing to be developed, which have low CTEs and thermal conductivities up to four times that of copper. Some are reportedly are cheaper than copper. In this paper, we survey the six categories of advanced thermal materials, including properties, state of maturity and cost. We also review a CPV application in which an advanced metal matrix composite with a tailored CTE eliminated solder joint failure and provided other benefits.

  4. Shelf-stable egg-based products processed by high pressure thermal sterilization

    Science.gov (United States)

    Producing a thermally sterilized egg-based product with increased shelf life without losing the sensory and nutritional properties of the freshly prepared product is challenging. Until recently, all commercial shelf-stable egg-based products were sterilized using conventional thermal processing; how...

  5. Properties of thermally stable PM Al-Cr based alloy

    International Nuclear Information System (INIS)

    The presented paper describes properties of Al-6.0 wt.%Cr-2.3 wt.%Fe-0.4 wt.%Ti-0.7 wt.%Si alloy produced by powder metallurgy (PM). The powder alloy was prepared by the pressure nitrogen melt atomization. The granulometric powder fraction of less than 45 μm was then hot-extruded at 450 deg. C to produce a rod of 6 mm in diameter. Microstructure of the as-extruded material was composed of recrystallized α(Al) grains (the average grain size of 640 nm) and Al13Cr2 spheroids (the average particle diameter of 130 nm and interparticle spacing of 290 nm). Metastable phases were not observed due to their decomposition on the hot extrusion. Hardness of the as-extruded material was 108 HV1, ultimate tensile strength, 327 MPa, yield strength, 258 MPa and elongation, 14%. Mechanical properties resulted mainly from Hall-Petch strengthening. The room-temperature mechanical properties were also measured after a long-term annealing at 400 deg. C. The investigated PM material was compared with the commercial Al-11.8 wt.%Si-0.9 wt.%Ni-1.2 wt.%Cu-1.2 wt.%Mg casting alloy generally applied at elevated temperatures. The PM alloy showed much higher thermal stability, since its room temperature hardness and tensile properties did not degradate significantly even after annealing at 400 deg. C/200 h. In contrast, the hardness and strength of the casting alloy reduced rapidly already after a 30 min annealing. The excellent thermal stability of the investigated PM material was a consequence of very slow diffusivities and low equilibrium solubilities of chromium and iron in solid aluminium

  6. Properties of thermally stable PM Al-Cr based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Vojtech, D. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic)], E-mail: Dalibor.Vojtech@vscht.cz; Verner, J. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Serak, J. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Simancik, F. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3 (Slovakia); Balog, M. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3 (Slovakia); Nagy, J. [Institute of Materials and Machine Mechanics, Slovak Academy of Sciences, Racianska 75, 831 02 Bratislava 3 (Slovakia)

    2007-06-15

    The presented paper describes properties of Al-6.0 wt.%Cr-2.3 wt.%Fe-0.4 wt.%Ti-0.7 wt.%Si alloy produced by powder metallurgy (PM). The powder alloy was prepared by the pressure nitrogen melt atomization. The granulometric powder fraction of less than 45 {mu}m was then hot-extruded at 450 deg. C to produce a rod of 6 mm in diameter. Microstructure of the as-extruded material was composed of recrystallized {alpha}(Al) grains (the average grain size of 640 nm) and Al{sub 13}Cr{sub 2} spheroids (the average particle diameter of 130 nm and interparticle spacing of 290 nm). Metastable phases were not observed due to their decomposition on the hot extrusion. Hardness of the as-extruded material was 108 HV1, ultimate tensile strength, 327 MPa, yield strength, 258 MPa and elongation, 14%. Mechanical properties resulted mainly from Hall-Petch strengthening. The room-temperature mechanical properties were also measured after a long-term annealing at 400 deg. C. The investigated PM material was compared with the commercial Al-11.8 wt.%Si-0.9 wt.%Ni-1.2 wt.%Cu-1.2 wt.%Mg casting alloy generally applied at elevated temperatures. The PM alloy showed much higher thermal stability, since its room temperature hardness and tensile properties did not degradate significantly even after annealing at 400 deg. C/200 h. In contrast, the hardness and strength of the casting alloy reduced rapidly already after a 30 min annealing. The excellent thermal stability of the investigated PM material was a consequence of very slow diffusivities and low equilibrium solubilities of chromium and iron in solid aluminium.

  7. Advanced Treatment Planning in Cancer Thermal Therapies

    Institute of Scientific and Technical Information of China (English)

    Theodoros SAMARAS; Esra NEUFELD; Niels KUSTER

    2016-01-01

    CEM43 thermal dose is a very common concept in thermal oncology. Thermal dose is the maximum amount of energy that can be transmitted during hyperthermia therapy conducted on temperature-sensitive tissue. Thermal dose is also the maximum value of local energy accumulation in human bodies, which can lead to tissue injury and pain. Thermal dose can also decrease the ifnishing temperature and reduce the energy to the tolerable range. There are two functions of the individualized hyperthermia treatment plan: it determines the setting and location that can realize the best tumor hyperthermia therapy; at the same time, it can decrease the effect of hyperthermia therapy on healthy tissues. There are four steps in the treatment plan of hyperthermia therapy for tumors: the ifrst step is to establish a three dimensional human body model and its corresponding an atomical structure that can be used in numerical algorithmvia medical imaging resources; the second step is to determine the volume of the electromagnetic energy accumulation. Based on the peculiarity of frequency and materials, even full-wave electromagnetic wave or quasi-static technique can be used to determine the tissue distribution. Evaluation of the therapy can be conducted based on thermal dose and the corresponding tissue damage model; the third step is to use Arrhenius model to provide direct evaluation of tissues in the thermal ablation zone, solidiifcation zone, as well as the necrotic area; the last step is the optimization of the treatment plan.

  8. Thermally stable magnetic skyrmions in multilayer synthetic antiferromagnetic racetracks

    Science.gov (United States)

    Zhang, Xichao; Ezawa, Motohiko; Zhou, Yan

    2016-08-01

    A magnetic skyrmion is a topological magnetization structure with a nanometric size and a well-defined swirling spin distribution, which is anticipated to be an essential building block for novel skyrmion-based device applications. We study the motion of magnetic skyrmions in multilayer synthetic antiferromagnetic (SAF) racetracks as well as in conventional monolayer ferromagnetic (FM) racetracks at finite temperature. There is an odd-even effect of the constituent FM layer number on the skyrmion Hall effect (SkHE). Namely, due to the suppression of the SkHE, the magnetic skyrmion has no transverse motion in multilayer SAF racetracks packed with even FM layers. It is shown that a moving magnetic skyrmion is stable even at room temperature (T =300 K) in a bilayer SAF racetrack but it is destructed at T =100 K in a monolayer FM racetrack. Our results indicate that the SAF structures are reliable and promising candidates for future applications in skyrmion electronics and skyrmion spintronics.

  9. Theoretical design and preparation of high thermal-stable jet fuel

    Institute of Scientific and Technical Information of China (English)

    LIU GuoZhu; QU HaiJie; SHEN HuiMing; ZHANG XiangWen; MI ZhenTao

    2008-01-01

    A high thermal-stable jet fuel design method was developed using composition-properties relations and basic specification properties of jet fuel.Tannery diagrams were provided to visualize relationships among three main components (n-paraffins,iso-paraffins, cycloparaffins, or aromatics) with four major specification properties (density, flash point, freezing point, net heat of combustion) and thermal sta-bility.An optimum chemical composition was established to meet performance requirements: n-paraffins 25%-45%, iso-paraffins 15%-30%, cycloparaffins 30%-50%, and aromatics 5%.The thermal stability test on four fuel samples with and without optimal composition indicated that the thermal stabilities of fuel samples with optimal composition are higher than RP-3 jet fuel, and that the theoretical design method is a reliable method to screen the basic oil for the high thermal-stable jet fuel.

  10. Theoretical design and preparation of high thermal-stable jet fuel

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A high thermal-stable jet fuel design method was developed using composition-properties relations and basic specification properties of jet fuel. Tannery diagrams were provided to visualize relationships among three main components (n-paraffins, iso-paraffins, cycloparaffins, or aromatics) with four major specification properties (density, flash point, freezing point, net heat of combustion) and thermal sta- bility. An optimum chemical composition was established to meet performance requirements: n-paraffins 25%-45%, iso-paraffins 15%-30%, cycloparaffins 30%-50%, and aromatics 5%. The thermal stability test on four fuel samples with and without optimal composition indicated that the thermal stabilities of fuel samples with optimal composition are higher than RP-3 jet fuel, and that the theoretical design method is a reliable method to screen the basic oil for the high thermal-stable jet fuel.

  11. Advanced Thermal Simulator Testing: Thermal Analysis and Test Results

    Science.gov (United States)

    Bragg-Sitton, Shannon M.; Dickens, Ricky; Dixon, David; Reid, Robert; Adams, Mike; Davis, Joe

    2008-01-01

    Work at the NASA Marshall Space Flight Center seeks to develop high fidelity, electrically heated thermal simulators that represent fuel elements in a nuclear reactor design to support non-nuclear testing applicable to the development of a space nuclear power or propulsion system. Comparison between the fuel pins and thermal simulators is made at the outer fuel clad surface, which corresponds to the outer sheath surface in the thermal simulator. The thermal simulators that are currently being tested correspond to a SNAP derivative reactor design that could be applied for Lunar surface power. These simulators are designed to meet the geometric and power requirements of a proposed surface power reactor design, accommodate testing of various axial power profiles, and incorporate imbedded instrumentation. This paper reports the results of thermal simulator analysis and testing in a bare element configuration, which does not incorporate active heat removal, and testing in a water-cooled calorimeter designed to mimic the heat removal that would be experienced in a reactor core.

  12. Advanced Fuel Cell System Thermal Management for NASA Exploration Missions

    Science.gov (United States)

    Burke, Kenneth A.

    2009-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA exploration program. An analysis of a state-of-the-art fuel cell cooling systems was done to benchmark the portion of a fuel cell system s mass that is dedicated to thermal management. Additional analysis was done to determine the key performance targets of the advanced passive thermal management technology that would substantially reduce fuel cell system mass.

  13. Thermally Stable Nanocatalyst for High Temperature Reactions: Pt-Mesoporous Silica Core-Shell Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Joo, Sang Hoon; Park, J.Y.; Tsung, C.-K.; Yamada, Y.; Yang, P.; Somorjai, G.A.

    2008-10-25

    Recent advances in colloidal synthesis enabled the precise control of size, shape and composition of catalytic metal nanoparticles, allowing their use as model catalysts for systematic investigations of the atomic-scale properties affecting catalytic activity and selectivity. The organic capping agents stabilizing colloidal nanoparticles, however, often limit their application in high-temperature catalytic reactions. Here we report the design of a high-temperature stable model catalytic system that consists of Pt metal core coated with a mesoporous silica shell (Pt{at}mSiO{sub 2}). While inorganic silica shells encaged the Pt cores up to 750 C in air, the mesopores directly accessible to Pt cores made the Pt{at}mSiO{sub 2} nanoparticles as catalytically active as bare Pt metal for ethylene hydrogenation and CO oxidation. The high thermal stability of Pt{at}mSiO{sub 2} nanoparticles permitted high-temperature CO oxidation studies, including ignition behavior, which was not possible for bare Pt nanoparticles because of their deformation or aggregation. The results suggest that the Pt{at}mSiO{sub 2} nanoparticles are excellent nanocatalytic systems for high-temperature catalytic reactions or surface chemical processes, and the design concept employed in the Pt{at}mSiO{sub 2} core-shell catalyst can be extended to other metal-metal oxide compositions.

  14. New Organic thermally stable materials for optoelectronics devices - A linear spectroscopy study

    OpenAIRE

    Prelipceanu, O. S.; Prelipceanu, M.; Tudose, O. G.; Grimm, B; Schrader, S.

    2007-01-01

    Thermally stable polymers have attracted a lot of interest due to their potential use as the active component in electronic, optical and optoelectronic applications, such as light-emitting diodes, light emitting electrochemical cells, photodiodes, photovoltaic cells, field effect transistors, optocouplers and optically pumped lasers in solution and solid state.We report results of investigations into the use of thermal treatment of poly(p-phenylene vinylene) (PPV) films grown on a variety of ...

  15. Description of a stable scheme for steady-state coupled Monte Carlo-thermal-hydraulic calculations

    OpenAIRE

    Dufek, Jan; Eduard Hoogenboom, J.

    2014-01-01

    We provide a detailed description of a numerically stable and efficient coupling scheme for steady-state Monte Carlo neutronic calculations with thermal-hydraulic feedback. While we have previously derived and published the stochastic approximation based method for coupling the Monte Carlo criticality and thermal-hydraulic calculations, its possible implementation has not been described in a step-by-step manner. As the simple description of the coupling scheme was repeatedly requested from us...

  16. Thermal hydraulic R and D of Chinese advanced reactors

    International Nuclear Information System (INIS)

    The Chinese government sponsors a program of research, development, and demonstration related to advanced reactors, both small modular reactors and larger systems. These advanced reactors encompass innovative reactor concepts, such as CAP1400 - Chinese large advanced passive pressurized water reactor, Hualong one - Chinese large advanced active and passive pressurized water reactor, ACP100 - Chinese small modular reactor, SCWR- R and D of super critical water-cooled reactor in China, CLEAR - Chinese lead-cooled fast reactor, TMSR - Chinese Thorium molten-salt reactor. The thermal hydraulic R and D of those reactors are summarised. (J.P.N.)

  17. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds

    Science.gov (United States)

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-01

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg-1 by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template.An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high

  18. Synthesis of a Novel Organic Soluble and Thermal-stable Fullerene-perylene Dyad

    Institute of Scientific and Technical Information of China (English)

    Jian Li HUA; Fang DING; Fan Shun MENG; He TIAN

    2004-01-01

    A novel organic soluble and thermal-stable fullerene-perylene dyad, in which a perylene moietyis attached to C60, has been prepared by 1, 3-dipolar cycloaddition of the azomethine ylides generated in situ from the aldehyde and N-methylglycine and characterized by NMR, FT-IR, TGA, absorption and fluorescent spectra etc.

  19. Gas separation properties of a thermally stable and chemically resistant polytriazole membrane

    NARCIS (Netherlands)

    Gebben, B.; Mulder, M.H.V.; Smolders, C.A.

    1989-01-01

    The polymer poly (1,3-phenyl-1,4-phenyl)-4-phenyl-1,3,4-triazole has been investigated for its gas separation properties. This thermally stable and chemically resistant polymer can be processed into membranes by the phase-inversion technique because of its unexpectedly good solubility in formic acid

  20. High-Temperature Adhesives for Thermally Stable Aero-Assist Technologies

    Science.gov (United States)

    Eberts, Kenneth; Ou, Runqing

    2013-01-01

    Aero-assist technologies are used to control the velocity of exploration vehicles (EVs) when entering Earth or other planetary atmospheres. Since entry of EVs in planetary atmospheres results in significant heating, thermally stable aero-assist technologies are required to avoid the high heating rates while maintaining low mass. Polymer adhesives are used in aero-assist structures because of the need for high flexibility and good bonding between layers of polymer films or fabrics. However, current polymer adhesives cannot withstand temperatures above 400 C. This innovation utilizes nanotechnology capabilities to address this need, leading to the development of high-temperature adhesives that exhibit high thermal conductivity in addition to increased thermal decomposition temperature. Enhanced thermal conductivity will help to dissipate heat quickly and effectively to avoid temperature rising to harmful levels. This, together with increased thermal decomposition temperature, will enable the adhesives to sustain transient high-temperature conditions.

  1. Advanced materials for thermal management of electronic packaging

    CERN Document Server

    Tong, Xingcun Colin

    2011-01-01

    The need for advanced thermal management materials in electronic packaging has been widely recognized as thermal challenges become barriers to the electronic industry's ability to provide continued improvements in device and system performance. With increased performance requirements for smaller, more capable, and more efficient electronic power devices, systems ranging from active electronically scanned radar arrays to web servers all require components that can dissipate heat efficiently. This requires that the materials have high capability of dissipating heat and maintaining compatibility

  2. Advanced Filter Technology For Nuclear Thermal Propulsion

    Science.gov (United States)

    Castillon, Erick

    2015-01-01

    The Scrubber System focuses on using HEPA filters and carbon filtration to purify the exhaust of a Nuclear Thermal Propulsion engine of its aerosols and radioactive particles; however, new technology may lend itself to alternate filtration options, which may lead to reduction in cost while at the same time have the same filtering, if not greater, filtering capabilities, as its predecessors. Extensive research on various types of filtration methods was conducted with only four showing real promise: ionization, cyclonic separation, classic filtration, and host molecules. With the four methods defined, more research was needed to find the devices suitable for each method. Each filtration option was matched with a device: cyclonic separators for the method of the same name, electrostatic separators for ionization, HEGA filters, and carcerands for the host molecule method. Through many hours of research, the best alternative for aerosol filtration was determined to be the electrostatic precipitator because of its high durability against flow rate and its ability to cleanse up to 99.99% of contaminants as small as 0.001 micron. Carcerands, which are the only alternative to filtering radioactive particles, were found to be non-existent commercially because of their status as a "work in progress" at research institutions. Nevertheless, the conclusions after the research were that HEPA filters is recommended as the best option for filtering aerosols and carbon filtration is best for filtering radioactive particles.

  3. Thermal Characterization of Nanostructures and Advanced Engineered Materials

    Science.gov (United States)

    Goyal, Vivek Kumar

    to heat-sinking units. This dissertation presents results of the experimental investigation and theoretical interpretation of thermal transport in the advanced engineered materials, which include thin films for thermal management of nanoscale devices, nanostructured superlattices as promising candidates for high-efficiency thermoelectric materials, and improved TIMs with graphene and metal particles as fillers providing enhanced thermal conductivity. The advanced engineered materials studied include chemical vapor deposition (CVD) grown ultrananocrystalline diamond (UNCD) and microcrystalline diamond (MCD) films on Si substrates, directly integrated nanocrystalline diamond (NCD) films on GaN, free-standing polycrystalline graphene (PCG) films, graphene oxide (GOx) films, and "pseudo-superlattices" of the mechanically exfoliated Bi2Te3 topological insulator films, and thermal interface materials (TIMs) with graphene fillers.

  4. High-energy, stable and recycled molecular solar thermal storage materials using AZO/graphene hybrids by optimizing hydrogen bonds.

    Science.gov (United States)

    Luo, Wen; Feng, Yiyu; Qin, Chengqun; Li, Man; Li, Shipei; Cao, Chen; Long, Peng; Liu, Enzuo; Hu, Wenping; Yoshino, Katsumi; Feng, Wei

    2015-10-21

    An important method for establishing a high-energy, stable and recycled molecular solar heat system is by designing and preparing novel photo-isomerizable molecules with a high enthalpy and a long thermal life by controlling molecular interactions. A meta- and ortho-bis-substituted azobenzene chromophore (AZO) is covalently grafted onto reduced graphene oxide (RGO) for solar thermal storage materials. High grafting degree and close-packed molecules enable intermolecular hydrogen bonds (H-bonds) for both trans-(E) and cis-(Z) isomers of AZO on the surface of nanosheets, resulting in a dramatic increase in enthalpy and lifetime. The metastable Z-form of AZO on RGO is thermally stabilized with a half-life of 52 days by steric hindrance and intermolecular H-bonds calculated using density functional theory (DFT). The AZO-RGO fuel shows a high storage capacity of 138 Wh kg(-1) by optimizing intermolecular H-bonds with a good cycling stability for 50 cycles induced by visible light at 520 nm. Our work opens up a new method for making advanced molecular solar thermal storage materials by tuning molecular interactions on a nano-template.

  5. Development and characterization of thermally stable electro-optic polymers and devices (Presentation Recording)

    Science.gov (United States)

    Otomo, Akira; Aoki, Isao; Yamada, Chiyumi; Yamada, Toshiki

    2015-10-01

    Electro-optic (EO) polymers are key materials for next generation optical communications not only in wide area network but also in local area and storage area network because EO polymer modulator can be operated at fast speed more than 100 GHz with low energy consumption and can be miniaturized in combination with silicon photonics. In practical applications, thermal stability is one of the important issues to be considered for developing EO polymers. Since EO activity of the polymer is proportional to dipole orientation factor of the EO moieties, electric field assisted poling around glass transition temperature (Tg) of the polymer is necessary. However, the poled order of the molecules relaxes gradually at finite temperature, and then EO activity decreases after long period of time. We have successfully developed thermally stable EO polymers that have high-Tg up to 180 °C. They show excellent thermal stability with the Telcordia thermal test. Thermal stability is also characterized by thermally stimulated depolarization current (TSDC) measurement. Analyzing the TSDC, we can estimate the activation energy and relaxation time of polarization at any temperature. We will discuss thermal stability of the high-Tg EO polymers and devices.

  6. Organic light emitting diodes with environmentally and thermally stable doped graphene electrodes

    DEFF Research Database (Denmark)

    Kuruvila, Arun; Kidambi, Piran R.; Kling, Jens;

    2014-01-01

    We present a comparative study of the environmental and thermal stability of graphene charge transfer doping using molybdenum– trioxide (MoO3), vanadium–pentoxide (V2O5) and tungsten–trioxide (WO3). Our results show that all these metal oxides allow a strong and stable p-type doping of graphene, ......, as well as functioning as effective hole-injection layers for highly efficient organic light emitting diodes...

  7. Recent advances on thermal analysis of stretchable electronics

    Directory of Open Access Journals (Sweden)

    Yuhang Li

    2016-01-01

    Full Text Available Stretchable electronics, which offers the performance of conventional wafer-based devices and mechanical properties of a rubber band, enables many novel applications that are not possible through conventional electronics due to its brittle nature. One effective strategy to realize stretchable electronics is to design the inorganic semiconductor material in a stretchable format on a compliant elastomeric substrate. Engineering thermal management is essential for the development of stretchable electronics to avoid adverse thermal effects on its performance as well as in applications involving human body and biological tissues where even 1–2 °C temperature increase is not allowed. This article reviews the recent advances in thermal management of stretchable inorganic electronics with focuses on the thermal models and their comparisons to experiments and finite element simulations.

  8. Long term thermal energy storage with stable supercooled sodium acetate trihydrate

    DEFF Research Database (Denmark)

    Dannemand, Mark; Schultz, Jørgen M.; Johansen, Jakob Berg;

    2015-01-01

    Utilizing stable supercooling of sodium acetate trihydrate makes it possible to store thermal energy partly loss free. This principle makes seasonal heat storage in compact systems possible. To keep high and stable energy content and cycling stability phase separation of the storage material must...... be avoided. This can be done by the use of the thickening agents carboxymethyl cellulose or xanthan rubber. Stable supercooling requires that the sodium acetate trihydrate is heated to a temperature somewhat higher than the melting temperature of 58 °C before it cools down. As the phase change material melts...... it expands and will cause a pressure built up in a closed chamber which might compromise stability of the supercooling. This can be avoided by having an air volume above the phase change material connected to an external pressure less expansion tank. Supercooled sodium acetate trihydrate at 20 °C stores up...

  9. Advanced Reactors Thermal Energy Transport for Process Industries

    Energy Technology Data Exchange (ETDEWEB)

    P. Sabharwall; S.J. Yoon; M.G. McKellar; C. Stoots; George Griffith

    2014-07-01

    The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as liquid fuel production, district heating, desalination, hydrogen production, and other process heat applications, etc. Some of the major technology challenges that must be overcome before the advanced reactors could be licensed on the reactor side are qualification of next generation of nuclear fuel, materials that can withstand higher temperature, improvement in power cycle thermal efficiency by going to combined cycles, SCO2 cycles, successful demonstration of advanced compact heat exchangers in the prototypical conditions, and from the process side application the challenge is to transport the thermal energy from the reactor to the process plant with maximum efficiency (i.e., with minimum temperature drop). The main focus of this study is on doing a parametric study of efficient heat transport system, with different coolants (mainly, water, He, and molten salts) to determine maximum possible distance that can be achieved.

  10. Thermal Analysis of the Advanced Technology Large Aperture Space Telescope (ATLAST) 8 Meter Primary Mirror

    Science.gov (United States)

    Hornsby, Linda; Stahl, H. Philip; Hopkins, Randall C.

    2010-01-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) preliminary design concept consists of an 8 meter diameter monolithic primary mirror enclosed in an insulated, optical tube with stray light baffles and a sunshade. ATLAST will be placed in orbit about the Sun-Earth L2 and will experience constant exposure to the sun. The insulation on the optical tube and sunshade serve to cold bias the telescope which helps to minimize thermal gradients. The primary mirror will be maintained at 280K with an active thermal control system. The geometric model of the primary mirror, optical tube, sun baffles, and sunshade was developed using Thermal Desktop(R) SINDA/FLUINT(R) was used for the thermal analysis and the radiation environment was analyzed using RADCAD(R). A XX node model was executed in order to characterize the static performance and thermal stability of the mirror during maneuvers. This is important because long exposure observations, such as extra-solar terrestrial planet finding and characterization, require a very stable observatory wave front. Steady state thermal analyses served to predict mirror temperatures for several different sun angles. Transient analyses were performed in order to predict thermal time constant of the primary mirror for a 20 degree slew or 30 degree roll maneuver. This paper describes the thermal model and provides details of the geometry, thermo-optical properties, and the environment which influences the thermal performance. All assumptions that were used in the analysis are also documented. Parametric analyses are summarized for design parameters including primary mirror coatings and sunshade configuration. Estimates of mirror heater power requirements are reported. The thermal model demonstrates results for the primary mirror heated from the back side and edges using a heater system with multiple independently controlled zones.

  11. Advanced thermal hydraulic method using 3x3 pin modeling

    International Nuclear Information System (INIS)

    Advanced thermal hydraulic methods are being developed as part of the US DOE sponsored Nuclear Hub program called CASL (Consortium for Advanced Simulation of LWRs). One of the key objectives of the Hub program is to develop a multi-physics tool which evaluates neutronic, thermal hydraulic, structural mechanics and nuclear fuel rod performance in rod bundles to support power uprates, increased burnup/cycle length and life extension for US nuclear plants. Current design analysis tools are separate and applied in series using simplistic models and conservatisms in the analysis. In order to achieve key Nuclear Hub objectives a higher fidelity, multi-physics tool is needed to address the challenge problems that limit current reactor performance. This paper summarizes the preliminary development of a multi-physics tool by performing 3x3 pin modeling and making comparisons to available data. (author)

  12. Thermal Storage Advanced Thruster System (TSATS) Experimental Program

    Science.gov (United States)

    Rose, M. Frank; Lisano, Michael E., II

    1991-01-01

    The Thermal Storage Advanced Thruster System (TSATS) rocket test stand is completely assembled and operational. The first trial experimental runs of a low-energy TSATS prototype rocket was made using the test stand. The features of the rocket test stand and the calibration of the associated diagnostics are described and discussed. Design and construction of the TSATS prototype are discussed, and experimental objectives, procedures, and results are detailed.

  13. Facility level thermal systems for the Advanced Technology Solar Telescope

    Science.gov (United States)

    Phelps, LeEllen; Murga, Gaizka; Fraser, Mark; Climent, Tània

    2012-09-01

    The management and control of the local aero-thermal environment is critical for success of the Advanced Technology Solar Telescope (ATST). In addition to minimizing disturbances to local seeing, the facility thermal systems must meet stringent energy efficiency requirements to minimize impact on the surrounding environment and meet federal requirements along with operational budgetary constraints. This paper describes the major facility thermal equipment and systems to be implemented along with associated energy management features. The systems presented include the central plant, the climate control systems for the computer room and coudé laboratory, the carousel cooling system which actively controls the surface temperature of the rotating telescope enclosure, and the systems used for active and passive ventilation of the telescope chamber.

  14. Keeping your options open: Maintenance of thermal plasticity during adaptation to a stable environment.

    Science.gov (United States)

    Fragata, Inês; Lopes-Cunha, Miguel; Bárbaro, Margarida; Kellen, Bárbara; Lima, Margarida; Faria, Gonçalo S; Seabra, Sofia G; Santos, Mauro; Simões, Pedro; Matos, Margarida

    2016-01-01

    Phenotypic plasticity may allow species to cope with environmental variation. The study of thermal plasticity and its evolution helps understanding how populations respond to variation in temperature. In the context of climate change, it is essential to realize the impact of historical differences in the ability of populations to exhibit a plastic response to thermal variation and how it evolves during colonization of new environments. We have analyzed the real-time evolution of thermal reaction norms of adult and juvenile traits in Drosophila subobscura populations from three locations of Europe in the laboratory. These populations were kept at a constant temperature of 18ºC, and were periodically assayed at three experimental temperatures (13ºC, 18ºC, and 23ºC). We found initial differentiation between populations in thermal plasticity as well as evolutionary convergence in the shape of reaction norms for some adult traits, but not for any of the juvenile traits. Contrary to theoretical expectations, an overall better performance of high latitude populations across temperatures in early generations was observed. Our study shows that the evolution of thermal plasticity is trait specific, and that a new stable environment did not limit the ability of populations to cope with environmental challenges. PMID:26626438

  15. Thermal analysis of the Advanced Technology Large Aperture Space Telescope (ATLAST) 8-meter primary mirror

    Science.gov (United States)

    Hornsby, Linda; Hopkins, Randall C.; Stahl, H. Philip

    2010-07-01

    The Advanced Technology Large Aperture Space Telescope (ATLAST) preliminary design concept consists of an 8 meter diameter monolithic primary mirror enclosed in an insulated, optical tube with stray light baffles and a sunshade. ATLAST will be placed in orbit about the Sun-Earth L2 point and will experience constant exposure to the sun. The insulation on the optical tube and sunshade serve to cold bias the telescope which helps to minimize thermal gradients. The objective is to maintain the primary mirror at 280K with an active thermal control system. The geometric model of the primary mirror, optical tube, sun baffles, and sunshade was developed using Thermal Desktop®1. A detailed model of the primary mirror was required in order to characterize the static performance and thermal stability of the mirror during maneuvers. This is important because long exposure observations, such as extra-solar terrestrial planet finding and characterization, require a very stable observatory wave front. Steady state thermal analyses served to predict mirror temperatures for several different sun angles. Transient analyses were performed in order to predict thermal time constant of the primary mirror for a 20 degree slew and a 30 degree roll maneuver. This paper describes the thermal model and provides details of the geometry, thermo-optical properties, and the solar environment that influences the thermal performance. All assumptions that were used in the analysis are also documented. Estimates of mirror heater power requirements are reported. The thermal model is used to predict gradients across and through the primary mirror using an idealized boundary temperature on the back and sides of the mirror of 280 K.

  16. Options of microclimate optimization in stable objects with respect to thermal comfort

    Directory of Open Access Journals (Sweden)

    Anna Šimková

    2013-05-01

    Full Text Available The study was carried out at the farm in Petrovice. Dairy cows and heifers were included in the experiment. The relative humidity, temperature, cooling value environment and flow rate in stables were measured. The flow rate was measured by the handheld anemometer. The relative humidity and the temperature were obtained by the data logger with sensors. The cooling value environment was obtained by the psychrometer. The rectal temperature was measured simultaneously as further value. It was rated 3 different groups of dairy cows and heifers in 2 stables. The aim of this work was finding how this values impact thermal comfort of the animals. The temperature is the most significant factor because it is very variable value. The animals immediately react for change of this. All these measured values are important for optimal welfare of animals. They influence the productivity of dairy cows and heifers, milk quality, reproduction and health of animals.

  17. Preparation and study of thermally stable washcoat aluminas for automotive catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Ismagilov, Z.R.; Shkrabina, R.A.; Koryabkina, N.A.; Arendarskii, D.A.; Shikina, N.V. [Boreskov Institute of Catalysis, Novosibirsk (Russian Federation)

    1998-12-31

    Porous and thermally stable washcoating layer on mechanically strong support is an important component in both oxidative and three-way catalysts used for car exhaust gas cleaning. The washcoat provides a high and stable surface area for dispersion of the active component of the catalysts consisting of platinum and /or palladium. Usually for the preparation of this layer aluminas modified by La, Ce, Zr, Si etc. are used. As it was shown elsewhere the properties of modified aluminas depend on the method of introduction of the additives. In this work we present the results on the preparation and study of model alumina systems modified by La, Ce and Zr as well as of monolith supports washcoated by optimal compositions of alumina and additives. 6 refs.

  18. A thermally stable heating mechanism for the intracluster medium: turbulence, magnetic fields and plasma instabilities

    CERN Document Server

    Kunz, M W; Cowley, S C; Binney, J J; Sanders, J S

    2010-01-01

    We consider the problem of self-regulated heating and cooling in galaxy clusters and the implications for cluster magnetic fields and turbulence. Viscous heating of a weakly collisional magnetised plasma is regulated by the pressure anisotropy with respect to the local direction of the magnetic field. The intracluster medium is a high-beta plasma, where pressure anisotropies caused by the turbulent stresses and the consequent local changes in the magnetic field will trigger very fast microscale instabilities. We argue that the net effect of these instabilities will be to pin the pressure anisotropies at a marginal level, controlled by the plasma beta parameter. This gives rise to local heating rates that turn out to be comparable to the radiative cooling rates. Furthermore, we show that a balance between this heating and Bremsstrahlung cooling is thermally stable, unlike the often conjectured balance between cooling and thermal conduction. Given a sufficient (and probably self-regulating) supply of turbulent ...

  19. Advanced concepts in ground thermal energy storage systems

    Science.gov (United States)

    Woods, Kevin David

    In recent years, ground thermal energy storage has become a topic of interest in the energy community for solar thermal energy storage systems, ground sourced heat pump systems, and data center thermal management systems due to an increase in the energy efficiency of such systems utilizing the ground as a thermal reservoir. The most common method for transferring thermal energy to the ground formation is the geothermal borehole. This dissertation presents the state of the art in geothermal borehole modeling and derives novel analytical functions to model advanced concepts concerning their operation. The novel solutions derived allow a geothermal borehole designer to better understand and design ground energy storage systems. The state of the art in geothermal borehole modeling is the stationary line source solution which is limited to boreholes operating without groundwater flow. Novel solutions for modeling a geothermal borehole with groundwater advection are presented through derivation of a transient moving line source solution as well as a transient moving cylindrical surface source solution. These solutions are applied to model a specific type of open loop geothermal borehole called a standing column well with groundwater advection and are compared to empirical and numerical data for validation. The dissertation then moves into derivation of a property determination method for geothermal boreholes with groundwater advection. The traditional property determination method used to obtain ground formation properties is based on the stationary transient line source method and fails in the presence of groundwater flow. The proposed novel property determination method calculates the thermal conductivity, thermal diffusivity, and superficial flow velocity of groundwater within a ground formation. These methods and solutions are novel tools allowing for geothermal borehole designers to grasp a better understanding of the systems they are designing as well as open other

  20. Validation Database Based Thermal Analysis of an Advanced RPS Concept

    Science.gov (United States)

    Balint, Tibor S.; Emis, Nickolas D.

    2006-01-01

    Advanced RPS concepts can be conceived, designed and assessed using high-end computational analysis tools. These predictions may provide an initial insight into the potential performance of these models, but verification and validation are necessary and required steps to gain confidence in the numerical analysis results. This paper discusses the findings from a numerical validation exercise for a small advanced RPS concept, based on a thermal analysis methodology developed at JPL and on a validation database obtained from experiments performed at Oregon State University. Both the numerical and experimental configurations utilized a single GPHS module enabled design, resembling a Mod-RTG concept. The analysis focused on operating and environmental conditions during the storage phase only. This validation exercise helped to refine key thermal analysis and modeling parameters, such as heat transfer coefficients, and conductivity and radiation heat transfer values. Improved understanding of the Mod-RTG concept through validation of the thermal model allows for future improvements to this power system concept.

  1. Applications for thermal NDT on advanced composites in aerospace structures

    Science.gov (United States)

    Baughman, Steve R.

    1998-03-01

    Following several years of investigating active thermal imaging techniques, Lockheed Martin Aeronautical Systems Company (LMASC) has introduced a portable, time-dependent thermography (TDT) system into the production inspection environment. Originally pursued as a rapid, non-contacting, nondestructive evaluation (NDE) tool for inspecting large surface areas, the TDT system has proven most useful as a rapid verification tool on advanced composite assemblies. TDT is a relatively new NDE methodology as compared to conventional ultrasonic and radiography testing. SEveral technical issues are being addressed as confidence in the system's capabilities increase. These include inspector training and certification, system sensitivity assessments, and test results interpretation. Starting in 1991, LMASC began a beta-site evaluation of a prototype TDT system developed by the Institute of Manufacturing Research at Wayne State University. This prototype was the forerunner of the current production system, which is offered commercially as a fully integrated thermal NDE system. Applications investigated to data include quality assurance of advanced aerospace composite structures/assemblies for disbonds/voids between skin and core. TDT has a number of advantages over traditional NDT methods. The process of acquiring thermal images is fast, and can decrease inspection time required to locate suspect areas. The system also holds promise for depot level inspections due to its portability. This paper describes a systematic approach to implementing TDT into the production inspection arena.

  2. Equipping simulators with an advanced thermal hydraulics model EDF's experience

    International Nuclear Information System (INIS)

    The development of an accelerated version of the advanced CATHARe-1 thermal hydraulics code designed for EDF training simulators (CATHARE-SIMU) was successfully completed as early as 1991. Its successful integration as the principal model of the SIPA Post-Accident Simulator meant that its use could be extended to full-scale simulators as part of the renovation of the stock of existing simulators. In order to further extend the field of application to accidents occurring in shutdown states requiring action and to catch up with developments in respect of the CATHARE code, EDF initiated the SCAR Project designed to adapt CATHARE-2 to simulator requirements (acceleration, parallelization of the computation and extension of the simulation range). In other respects, the installation of SIPA on workstations means that the authors can envisage the application of this remarkable training facility to the understanding of thermal hydraulics accident phenomena

  3. Thermal hydraulic evaluation of advanced wire-wrapped assemblies

    International Nuclear Information System (INIS)

    The thermal-hydraulic analyses presented in this report are based on application of the subchannel concept in association with the use of bulk parameters for coolant velocity and coolant temperature within a subchannel. The interactions between subchannels are due to turbulent interchange, pressure-induced diversion crossflow, directed sweeping crossflow induced by the helical wire wrap, and transverse thermal conduction. The FULMIX-II computer program was successfully developed to perform the steady-state temperature predictions for LMFBR fuel assemblies with the reference straight-start design and the advanced wire-wrap designs. Predicted steady-state temperature profiles are presented for a typical CRBRP 217-rod wire-wrapped assembly with the selected wire-wrap designs

  4. High-coercivity, thermally stable and low unblocking temperature magnetic phase: Implications for Archeomagnetic studies

    Science.gov (United States)

    Hartmann, G. A.; Gallet, Y.; Trindade, R. I.; Genevey, A.; Berquo, T. S.; Neumann, R.; Le Goff, M.

    2013-05-01

    The thermoremanent magnetization in baked clay archeological materials provide very useful information on the time evolution of the Earth's magnetic field over the past few millennia. In these materials, a thermally stable magnetic phase characterized by high coercivities (>400 mT) and low unblocking temperatures (~200 degrees Celsius) has recently been recognized in European bricks, tiles, kilns and hearth samples. Both the identification and the origin of this phase remain, however, poorly constrained. The very same high-coercivity, thermally stable, low unblocking temperature (HCSLT) magnetic phase has been identified in Brazilian bricks fragments dated of the past five centuries. We report here a large set of measurements on a selected collection of samples showing variable contributions of the HCSLT phase. These measurements include low-field magnetic susceptibility vs. temperature curves, hysteresis loops, isothermal remanent magnetization (IRM) acquisition, thermal demagnetization of the three-axis IRM, first order reversal curves (FORC), low-temperature magnetization experiments (remanent magnetization curves and alternating current susceptibility), Mössbauer spectroscopy and X-ray diffraction. Results show the coexistence of low-coercivity magnetic minerals (magnetite and titanomagnetite) and high-coercivity minerals (hematite, HCSLT phase and, in some cases, goethite). We note that the HCSLT magnetic phase is always found in association with hematite. We further observe that the Mössbauer spectroscopy, X-ray diffraction spectra, and the FORC diagrams are also very similar to results previously obtained from annealed clays in which nontronite or iron-rich montmorillonite was transformed into Al-substituted hematite by heating. The HCSLT magnetic phase is thus confidently identified as being hematite with Al substitution. Moreover, considering the abundance of montmorillonite in clay mining settings, we suggest that the widespread occurrence of HCSLT in

  5. Fabrication and Catalytic Activity of Thermally Stable Gold Nanoparticles on Ultrastable Y (USY Zeolites

    Directory of Open Access Journals (Sweden)

    Keiko Iida

    2013-07-01

    Full Text Available Au was deposited on ultrastable Y (USY zeolites using an ion-exchange method. Up to 5.5 wt% Au was introduced into the NH4-form of USY zeolites. In contrast, deposition of Au hardly took place on the H- and Na-forms of Y-type zeolites, NH4-forms of mordenite, and ZSM-5. Treatment of the Au-loaded USY zeolite in a H2 atmosphere, afforded Au0 nanoparticles. These particles were thermally stable even at 973 K, where their mean particle diameter was 3.7 nm. In contrast, highly aggregated Au particles were observed after thermal treatment at temperatures lower than 523 K, followed by storage in air for a month. The resulting particle sizes were in good correlation with the IR band intensity of the adsorbed CO and the catalytic activity of Au in the aerobic oxidation of benzyl alcohol. The Au nanoparticles showed highest activity when the Au/USY zeolite was thermally treated at 673–973 K. A negligible deactivation was observed after repeating the reaction at least 12 times. In the case of Au/TiO2 catalyst prepared by the deposition-precipitation method, the highest activity was observed at 573 K, which was lower than the temperature used for the Au/USY zeolites. This study demonstrated the potential use of the NH4-form of USY zeolites for supporting Au.

  6. THERMALLY STABLE POLYMERS CONTAINING 1,3,4-OXADIAZOLE UNITS OBTAINED FROM HUISGEN REACTION

    Institute of Scientific and Technical Information of China (English)

    Y.Mansoori; G.Barghian; B.Koohi-Zargar; Gh.Imanzadeh; M.Zamanloo

    2012-01-01

    Thermally stable polymers containing 1,3,4-oxadiazole units have been synthesized through Huisgen reaction of thc aromatic/aliphatic bis-tetrazole compounds with the aromatic/aliphatic bis-acid chlorides in pyridine as solvent.The obtained polymers are insoluble or slightly soluble even in polar aprotic solvents such as DMSO and DMF.Relatively high inherent viscosity values (0.61-1.33 dL/g,in 0.125% H2SO4 at 25℃) were observed for these compounds.Thermal analyses of the polymers using DSC and TGA techniques showed that the polymers have improved thermal stabilities.The glass transition temperature has not been observed in the fully aromatic polymers,but the polymers obtained from 5-[6-(1H-tetrazol-5-yl)hexyl]-1H-tetrazole (Ⅳ) showed very clear Tg.A model reaction was also investigated and the resulting bis-1,3,4-oxadiazole compound was characterized by conventional spectroscopy methods.

  7. Characterization and dispersibility of improved thermally stable amide functionalized graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Rani, Sumita [Electronic Science Department, Kurukshetra University, Kurukshetra, Haryana 136119 (India); Kumar, Mukesh, E-mail: kumarmukesh@gmail.com [Electronic Science Department, Kurukshetra University, Kurukshetra, Haryana 136119 (India); Kumar, Rajiv [Department of Chemistry, Kurukshetra University, Kurukshetra, Haryana 136119 (India); Kumar, Dinesh; Sharma, Sumit [Electronic Science Department, Kurukshetra University, Kurukshetra, Haryana 136119 (India); Singh, Gulshan [Department of Chemistry, Kurukshetra University, Kurukshetra, Haryana 136119 (India)

    2014-12-15

    Graphical abstract: Improved thermal stability and surface study of amide functionalized graphene oxide. - Highlights: • Amide functionalized graphene oxides (AGOs) were synthesized from aniline, 2-aminothiazole and 2-aminopyrimidine. • Achieved enhancement in thermal stability of AGOs as compare to GO. • AGOs are found to be highly dispersible in water, DMSO and DMF. • Dispersibility is stable for more than two and half months. - Abstract: Amidation of graphene oxide (GO) with aniline, 2-aminothiazole and 2-aminopyrimidine results in the synthesis of amide functionalized graphene oxides (AGOs). Scanning electron microscopy, X-ray diffraction, thermogravimetric analysis (TGA), UV–vis and Raman spectroscopy were used to investigate the properties of AGOs. It was found that, contrary to GO, AGOs are soluble in water, dimethyl sulfoxide, dimethylformamide and can be stabilized for months. TGA of AGOs shows the major weight loss above 670 °C as compared to GO in which significant weight loss occurs near 200 °C. Thus AGOs show strong improvement in thermal properties.

  8. A lab-on-a-disc with reversible and thermally stable diaphragm valves.

    Science.gov (United States)

    Kim, Tae-Hyeong; Sunkara, Vijaya; Park, Juhee; Kim, Chi-Ju; Woo, Hyun-Kyung; Cho, Yoon-Kyoung

    2016-10-01

    A lab-on-a-disc is a unique microfluidic platform that utilizes centrifugal force to pump liquids. This offers many benefits for point-of-care devices because it eliminates the need for connections to multiple pumps and complex tubing connections. A wide range of applications including clinical chemistry, immunoassay, cell analysis, and nucleic acid tests could be demonstrated on a spinning disc. To enable the performance of assays in a fully integrated and automated manner, the robust actuation of integrated valves is a prerequisite. However, conventional passive-type valves incur a critical drawback in that their operation is dependent on the rotational frequency, which is easily influenced by the channel geometry and chemistry, in addition to the physical properties of the liquids to be transferred. Even though a few active-type valving techniques permit the individual actuation of valves, independent of the rotational frequency, complex procedures for the fabrication as well as actuation mechanisms have prevented their broader acceptance in general applications. Here, we report on a lab-on-a-disc incorporating individually addressable diaphragm valves (ID valves) that enable the reversible and thermally stable actuation of multiple valves with unprecedented ease and robustness. These ID valves are configured from an elastic epoxy diaphragm embedded on a 3D printed push-and-twist valve, which can be easily actuated by a simple automatic driver unit. As a proof of concept experiment, an enzyme-linked immunosorbent assay (ELISA) and a polymerase chain reaction (PCR) were performed on a disc in a fully automated manner to demonstrate the robust, reversible, leak-free, and thermally stable actuation of the valves.

  9. Programmable permanent data storage characteristics of nanoscale thin films of a thermally stable aromatic polyimide.

    Science.gov (United States)

    Kim, Dong Min; Park, Samdae; Lee, Taek Joon; Hahm, Suk Gyu; Kim, Kyungtae; Kim, Jin Chul; Kwon, Wonsang; Ree, Moonhor

    2009-10-01

    We have synthesized a new thermally and dimensionally stable polyimide, poly(4,4'-amino(4-hydroxyphenyl)diphenylene hexafluoroisopropylidenediphthalimide) (6F-HTPA PI). 6F-HTPA PI is soluble in organic solvents and is thus easily processed with conventional solution coating techniques to produce good quality nanoscale thin films. Devices fabricated with nanoscale thin PI films with thicknesses less than 77 nm exhibit excellent unipolar write-once-read-many-times (WORM) memory behavior with a high ON/OFF current ratio of up to 10(6), a long retention time and low power consumption, less than +/-3.0 V. Furthermore, these WORM characteristics were found to persist even at high temperatures up to 150 degrees C. The WORM memory behavior was found to be governed by trap-limited space-charge limited conduction and local filament formation. The conduction processes are dominated by hole injection. Thus the hydroxytriphenylamine moieties of the PI polymer might play a key role as hole trapping sites in the observed WORM memory behavior. The properties of 6F-HTPA PI make it a promising material for high-density and very stable programmable permanent data storage devices with low power consumption.

  10. Cobalt-Based Electrolytes for Dye-Sensitized Solar Cells: Recent Advances towards Stable Devices

    Directory of Open Access Journals (Sweden)

    Federico Bella

    2016-05-01

    Full Text Available Redox mediators based on cobalt complexes allowed dye-sensitized solar cells (DSCs to achieve efficiencies exceeding 14%, thus challenging the emerging class of perovskite solar cells. Unfortunately, cobalt-based electrolytes demonstrate much lower long-term stability trends if compared to the traditional iodide/triiodide redox couple. In view of the large-scale commercialization of cobalt-based DSCs, the scientific community has recently proposed various approaches and materials to increase the stability of these devices, which comprise gelling agents, crosslinked polymeric matrices and mixtures of solvents (including water. This review summarizes the most significant advances recently focused towards this direction, also suggesting some intriguing way to fabricate third-generation cobalt-based photoelectrochemical devices stable over time.

  11. Thermally highly stable amorphous zinc phosphate intermediates during the formation of zinc phosphate hydrate.

    Science.gov (United States)

    Bach, Sven; Celinski, Vinicius R; Dietzsch, Michael; Panthöfer, Martin; Bienert, Ralf; Emmerling, Franziska; Schmedt auf der Günne, Jörn; Tremel, Wolfgang

    2015-02-18

    The mechanisms by which amorphous intermediates transform into crystalline materials are still poorly understood. Here we attempt to illuminate the formation of an amorphous precursor by investigating the crystallization process of zinc phosphate hydrate. This work shows that amorphous zinc phosphate (AZP) nanoparticles precipitate from aqueous solutions prior to the crystalline hopeite phase at low concentrations and in the absence of additives at room temperature. AZP nanoparticles are thermally stable against crystallization even at 400 °C (resulting in a high temperature AZP), but they crystallize rapidly in the presence of water if the reaction is not interrupted. X-ray powder diffraction with high-energy synchrotron radiation, scanning and transmission electron microscopy, selected area electron diffraction, and small-angle X-ray scattering showed the particle size (≈20 nm) and confirmed the noncrystallinity of the nanoparticle intermediates. Energy dispersive X-ray, infrared, and Raman spectroscopy, inductively coupled plasma mass spectrometry, and optical emission spectrometry as well as thermal analysis were used for further compositional characterization of the as synthesized nanomaterial. (1)H solid-state NMR allowed the quantification of the hydrogen content, while an analysis of (31)P{(1)H} C rotational echo double resonance spectra permitted a dynamic and structural analysis of the crystallization pathway to hopeite.

  12. Recoil induced room temperature stable Frenkel pairs in α-hafnium upon thermal neutron capture

    International Nuclear Information System (INIS)

    Ultrapure hafnium metal (110 ppm zirconium) was neutron activated with a thermal neutron flux of 6.6 . 1012cm-2s-1 in order to obtain 181Hf for subsequent time differential perturbed angular correlation (TDPAC) experiments using the nuclear probe 181Hf(β-)181Ta. Apart from the expected nuclear quadrupole interaction (NQI) signal for a hexagonal close-packed (hcp) metal, three further discrete NQIs were observed with a few percent fraction each. The TDPAC spectra were recorded for up to 11 half lives with extreme statistical accuracy. The fitted parameters vary slightly within the temperature range between 248 K and 373 K. The signals corresponding to the three additional sites completely disappear after 'annealing' at 453 K for one minute. Based on the symmetry of the additional NQIs and their temperature dependencies, they are tentatively attributed to Frenkel pairs produced by recoil due to the emission of a prompt 5.694 MeV γ-ray following thermal neutron capture and reported by the nuclear probe in three different positions. These Frenkel pairs are stable up to at least 373 K. (orig.)

  13. A highly thermal stable solid phase microextraction fiber prepared by an inorganic binder.

    Science.gov (United States)

    Liu, Hongmei; Ran, Fanpeng; Tao, Caihong; Zhao, Mengmeng; Jia, Yulong; Guo, Yong

    2016-04-28

    An easy method to prepare solid phase microextraction fibers by introducing an inorganic binder was demonstrated in this study, where MoS2 was selected as the extraction phase material because of its graphite-like layered structure with large specific adsorption area and good stability, and was then adhered to a stainless steel wire by acid aluminum phosphate binder with the spraying method. The as-prepared solid phase microextraction fiber coupled with gas chromatography was then used to extract some polycyclic aromatic hydrocarbons target analytes including the low-volatile benzo(a)pyrene etc. from a standard sample. Comparing with the MoS2-epoxy resin and commercial polyacrylate fibers, the MoS2-acid aluminum phosphate fiber has a higher thermal stability because of highly thermal stable acid aluminum phosphate, which is durable for a long service life at a high temperature (320 °C), and has the advantage in the extraction of low-volatility analytes. After the optimization of adsorption and desorption factors (ionic strength, adsorption time and temperature, and desorption temperature), method detection limits of service life, which is useful for the detection of low-volatility target analytes in practical applications. PMID:27046208

  14. Preparation and performance of novel thermally stable polyamide/PPENK composite nanofiltration membranes

    Science.gov (United States)

    Hu, Lijie; Zhang, Shouhai; Han, Runlin; Jian, Xigao

    2012-09-01

    Novel thermally stable composite nanofiltration (NF) membranes were prepared from piperazine (PIP) and trimesoyl chloride (TMC) on poly (phthalazione ether nitrile ketone) (PPENK) ultrafiltration (UF) membranes by interfacial polymerization. The effects of monomers concentration, reaction time and organic solvents on the performance of composite membranes were investigated. The effects of operating pressure and the salt solution concentration on the performance of composite membranes were also discussed. The different salts rejection of PPENK composite membranes decreased in the order of Na2SO4 > MgSO4 > Al2(SO4)3 > NaCl > MgCl2, which indicated a negative charge at the membrane surface. The flux and Na2SO4 rejection of PPENK composite membranes reached 57.9 L/m2 h and 98.4% under the optimized conditions and operating pressure of 1.0 MPa. Furthermore, the morphology and chemical structure of membranes were examined by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Moreover, the thermal stability of PPENK NF membranes was also investigated. When temperature of the feed solution raised from 20 °C to 80 °C, the permeation flux increased about four times without significant change of rejection. The flux increased first then reached a plateau and the rejection kept constant when PPENK NF membranes in boiling de-ionized water were boiled to 3 h.

  15. Synthesis, characterization, conductivity and antimicrobial study of a novel thermally stable polyphenol containing azomethine group

    Science.gov (United States)

    Yılmaz Baran, Nuray; Karakışla, Meral; Demir, Hacı Ökkeş; Saçak, Mehmet

    2016-11-01

    Poly(4-[[(4-methylphenyl)methylene]amino]phenol) (P(4-MMAP)), which is a Schiff base polymer, was synthesized by an oxidative polycondensation reaction of 4-[[(4-methylphenyl)methylene]amino]phenol (4-MMAP) with the oxidants NaOCl, H2O2 and O2 in an aqueous alkaline medium. The polymerizations were carried out at various temperatures and times, and the highest polymer yield could be obtained when using 37% with NaOCl oxidant. The structures of the monomer and polymer were characterized by UV-Vis, FTIR 1H NMR and X-ray diffraction techniques. The thermal behaviors of the monomer and polymer were identified by the TG and DTG techniques. The thermal degradation of the polymer which was observed thermally stable up to 1000 °C, was also supported by the Thermo-IR spectra recorded in the temperature range of 25-800 °C. The number average molecular weight (Mn), weight average molecular weight (Mw) and polydispersity index (PDI) of the polymer were found to be 16682, 57796 g/mol and 3.4, respectively. The highest electrical conductivity value of P(4-MMAP) doped with iodine vapor at different temperatures and times was measured to be 7.8 × 10-5 Scm-1 after doping for 48 h at 60 °C. The antibacterial and antifungal activities of 4-MMAP and P(4-MMAP) were also assayed against the bacteria Sarcina lutea, Enterobacter aerogenes, Escherichia coli, Enterococcus faecalis, Klebsiella pneumoniae, Bacillus subtilis and the fungi Candida albicans, Saccharomyces cerevisiae, respectively.

  16. Preparation and performance of novel thermally stable polyamide/PPENK composite nanofiltration membranes

    International Nuclear Information System (INIS)

    Highlights: ► Composite nanofiltration membranes based on PPENK UF membranes were prepared. ► Preparation parameters of polyamide/PPENK nanofiltration membranes were studied. ► Polyamide/PPENK nanofitration membrane shows excellent thermal resistance. - Abstract: Novel thermally stable composite nanofiltration (NF) membranes were prepared from piperazine (PIP) and trimesoyl chloride (TMC) on poly (phthalazione ether nitrile ketone) (PPENK) ultrafiltration (UF) membranes by interfacial polymerization. The effects of monomers concentration, reaction time and organic solvents on the performance of composite membranes were investigated. The effects of operating pressure and the salt solution concentration on the performance of composite membranes were also discussed. The different salts rejection of PPENK composite membranes decreased in the order of Na2SO4 > MgSO4 > Al2(SO4)3 > NaCl > MgCl2, which indicated a negative charge at the membrane surface. The flux and Na2SO4 rejection of PPENK composite membranes reached 57.9 L/m2 h and 98.4% under the optimized conditions and operating pressure of 1.0 MPa. Furthermore, the morphology and chemical structure of membranes were examined by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Moreover, the thermal stability of PPENK NF membranes was also investigated. When temperature of the feed solution raised from 20 °C to 80 °C, the permeation flux increased about four times without significant change of rejection. The flux increased first then reached a plateau and the rejection kept constant when PPENK NF membranes in boiling de-ionized water were boiled to 3 h.

  17. Preparation and performance of novel thermally stable polyamide/PPENK composite nanofiltration membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lijie [State Key Laboratory of Fine Chemical, Dalian 116024 (China); Liaoning High Performance Polymer Engineering Research Center, Dalian 116024 (China); Liaoning Key Laboratory of Polymer Science and Engineering, Dalian 116024 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Zhang, Shouhai, E-mail: zhangshh@dlut.edu.cn [State Key Laboratory of Fine Chemical, Dalian 116024 (China); Liaoning High Performance Polymer Engineering Research Center, Dalian 116024 (China); Liaoning Key Laboratory of Polymer Science and Engineering, Dalian 116024 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Han, Runlin [School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Jian, Xigao, E-mail: jian4616@dl.cn [State Key Laboratory of Fine Chemical, Dalian 116024 (China); Liaoning High Performance Polymer Engineering Research Center, Dalian 116024 (China); Liaoning Key Laboratory of Polymer Science and Engineering, Dalian 116024 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer Composite nanofiltration membranes based on PPENK UF membranes were prepared. Black-Right-Pointing-Pointer Preparation parameters of polyamide/PPENK nanofiltration membranes were studied. Black-Right-Pointing-Pointer Polyamide/PPENK nanofitration membrane shows excellent thermal resistance. - Abstract: Novel thermally stable composite nanofiltration (NF) membranes were prepared from piperazine (PIP) and trimesoyl chloride (TMC) on poly (phthalazione ether nitrile ketone) (PPENK) ultrafiltration (UF) membranes by interfacial polymerization. The effects of monomers concentration, reaction time and organic solvents on the performance of composite membranes were investigated. The effects of operating pressure and the salt solution concentration on the performance of composite membranes were also discussed. The different salts rejection of PPENK composite membranes decreased in the order of Na{sub 2}SO{sub 4} > MgSO{sub 4} > Al{sub 2}(SO{sub 4}){sub 3} > NaCl > MgCl{sub 2}, which indicated a negative charge at the membrane surface. The flux and Na{sub 2}SO{sub 4} rejection of PPENK composite membranes reached 57.9 L/m{sup 2} h and 98.4% under the optimized conditions and operating pressure of 1.0 MPa. Furthermore, the morphology and chemical structure of membranes were examined by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Moreover, the thermal stability of PPENK NF membranes was also investigated. When temperature of the feed solution raised from 20 Degree-Sign C to 80 Degree-Sign C, the permeation flux increased about four times without significant change of rejection. The flux increased first then reached a plateau and the rejection kept constant when PPENK NF membranes in boiling de-ionized water were boiled to 3 h.

  18. Thermal flow analysis for design and development of advanced vitrification melter

    International Nuclear Information System (INIS)

    The numerical analysis of thermal flow of molten glass in a melter, which is carried out to support design and development of advanced melter, is introduced. Control of noble metal, which is involved in waste composition, is important for operation of joule-heated ceramic melter. If molten glass has high noble metal content, it has high viscosity and joule-heating efficiency is decreased by low electrical resistance and possibility of deterioration of operational performance is increased. Case study was carried out by thermal flow analysis to determine the suitable structure of melter and operational condition as the change of temperature distribution of molten glass is under the condition of suitable control. In the computational fluid dynamics model, enthalpy, velocity, pressure, electric potential and concentration of noble metal particles are coupled each other. Non-steady state simulation was performed to simulate temperature response by operational sequence. Stable batch-cycle operation as mentioned above is maintained with developed furnace shape and operating conditions. The adaptability of analysis model of behavior of noble metal particles in molten glass will be confirmed by mock-up test data of advanced melter. The analysis model aims to be applied to evaluate the operating mode such as recovery operation in case of transient state. (author)

  19. A thermally stable gold(III) hydride: synthesis, reactivity, and reductive condensation as a route to gold(II) complexes.

    Science.gov (United States)

    Roşca, Dragoş-Adrian; Smith, Dan A; Hughes, David L; Bochmann, Manfred

    2012-10-15

    Going for gold: The first thermally stable gold(III) hydride [(C N C)*AuH] is presented. It undergoes regioselective insertions with allenes to give gold(III) vinyl complexes, and reductive condensation with [(C N C)*AuOH] to the air-stable Au(II) product, [(C N C)*(2)Au(2)], with a short nonbridged gold-gold bond.

  20. Development of vacuum glazing with advanced thermal properties - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Koebel, M.; Manz, H.

    2009-03-15

    Windows constitute a weak link in the building envelope and hence contribute significantly to the total heating energy demand in buildings. By evacuating the glazing cavity a vacuum glazing is created and heat transfer can be significantly reduced. This project was designed to build knowledge and technology necessary to fabricate vacuum glazing with advanced thermal properties. More specifically, various strategies for improvement of conventional technology were investigated. Of central importance was the development of a novel edge sealing approach which can in theory circumvent the main limitation of conventional glass soldering technology. This approach which is rapid, low temperature, low cost and completely vacuum compatible was filed for patenting in 2008. With regards to thermal insulation performance and glazing deflection, numerical studies were performed demonstrating the importance of nonlinear behavior with glazing size and the results published. A detailed service life prediction model was elaborated which defines a set of parameters necessary to keep the expected pressure increase below a threshold value of 0.1 Pa after 30 years. The model takes into account four possible sources of pressure increase and a getter material which acts as a sink. For the production of 0.5 m by 0.5 m glazing assembly prototypes, a high vacuum chamber was constructed and a first sealing prototype realized therein. The manufacture of improved prototypes and optimization of the anodic bonding edge sealing technology with emphasis on process relevant aspects is the goal of a follow-up project. (authors)

  1. Thermally stable anomalous Hall behavior in perpendicular Co/Pt multilayers sandwiched by HfO2 layers

    Science.gov (United States)

    Jiang, Shao-Long; Li, Xu-Jing; Liu, Yi-Wei; Chen, Xi; Liu, Qian-Qian; Han, Gang; Yang, Guang; Wang, Dong-Wei; Zhang, Jing-Yan; Teng, Jiao; Yu, Guang-Hua

    2016-01-01

    The effect of annealing on the anomalous Hall effect (AHE) in perpendicular Co/Pt multilayers sandwiched by HfO2 layers has been studied. It was found that thermally stable AHE features can be obtained in perpendicular Co/Pt multilayers with the introduction of two Co/HfO2 interfaces, leading to the improvement of the skew scattering contribution to the AHE after annealing. On the contrary, thermally stable AHE behavior cannot be observed in Co/Pt multilayers sandwiched by Pt layers or MgO layers because of Co-Pt interdiffusion during annealing.

  2. Production of stable, non-thermal atmospheric pressure rf capacitive plasmas using gases other than helium or neon

    Science.gov (United States)

    Park, Jaeyoung; Henins, Ivars

    2005-06-21

    The present invention enables the production of stable, steady state, non-thermal atmospheric pressure rf capacitive .alpha.-mode plasmas using gases other than helium and neon. In particular, the current invention generates and maintains stable, steady-state, non-thermal atmospheric pressure rf .alpha.-mode plasmas using pure argon or argon with reactive gas mixtures, pure oxygen or air. By replacing rare and expensive helium with more readily available gases, this invention makes it more economical to use atmospheric pressure rf .alpha.-mode plasmas for various materials processing applications.

  3. Operational experiences in MOX fuel fabrication for the FUGEN advanced thermal reactor

    International Nuclear Information System (INIS)

    The Japan Nuclear Cycle Development Institute, JNC, has fabrication the MOX fuel for the Advanced Thermal Reactor, ATR, ''FUGEN'' in the Plutonium Fuel Fabrication Facility, PFFF, since 1974. For these 25 years, the MOX fuel fabrication has progressed in stable manner after overcoming several problems at the start up of FUGEN fuel fabrication. Through the experience, improvements on process equipment and conditions have been taken place to achieve efficient MOX fuel fabrication on an engineering scale as 10 tons MOX per year. Main features of current fabrication process are digested as one step blending with ball milling, pelletizing without granulation and sintering with batch type furnaces. This fabrication process has been demonstrated and confirmed to be applicable techniques for the MOX fuel fabrication on this scale. This paper discusses the FUGEN fuel fabrication focused on the MOX pellet fabrication with operational experiences and improvements to the process. (author)

  4. Development of thermally stable and mechanically strong polymer composite materials for high impact applications

    International Nuclear Information System (INIS)

    The focus of this work was to develop thermally stable and mechanically strong polymer blend / composite systems for certain high impact applications. Two different commercially available polymers Polyamide (Nylon 6) and Polycarbonate (PC) were selected for this purpose. In order to improve the thermal and mechanical properties of Nylon, organically Modified clay was incorporated in the thermo-plastic matrix material. The uniform distribution and dispersion of clay was achieved by optimizing various parameters like temperature, time of mixing, torque during flush and cycle mode of operation of the co- rotating conical twin screw mini-extrusion machine. Duration of ten minutes under cycle mode at 250 degree C was found to be optimum for uniform exfoliation and distribution of organically modified clay platelets in the matrix. For the development of polycarbonate (PC) based nanocomposites with improved thermal and mechanical properties, Polymethylmethacrylate (PMMA) was blended in 5, 10 and 15 wt. % ratios with PC. Good miscibility in PC/PMMA blends was observed by melt blending them at 260 degree C for 20 minutes. The properties of the blends were further enhanced by incorporating 0.1, 0.2 and 0.3 wt. % of both pristine and carboxylic group (-COOH) functionalized carbon nanotubes (CNTs). While maintaining PC/PMMA blending ratios as 95/5 and 90/10, shear mixing of CNTs in the blend was carried out in the co-rotating conical twin screw extruder at 260 degree C for 20 minutes. Characterization of these composites was performed using FTIR, XRD, Dynamic thermo-mechanical analysis (DTMA) and mechanical testing using universal testing machine. The TMA and XRD results exhibited formation of miscible blends of PC/PMMA when melt blending is performed at 260 degree C for 20 minutes. Although miscible blends were achieved by incorporating up to 15 wt.% PMMA in PC, however, only the combination in 90/10 ratio of PC/PMMA and their composites were found to have high thermal

  5. Derivation of a stable coupling scheme for Monte Carlo burnup calculations with the thermal-hydraulic feedback

    OpenAIRE

    Dufek, Jan; Anglart, Henryk

    2013-01-01

    Numerically stable Monte Carlo burnup calculations of nuclear fuel cycles are now possible with the previously derived Stochastic Implicit Euler method based coupling scheme. In this paper, we show that this scheme can be easily extended to include the thermal-hydraulic feedback during the Monte Carlo burnup simulations, while preserving its unconditional stability property. At each time step, the implicit solution (for the end-of-step neutron flux, fuel nuclide densities and thermal-hydrauli...

  6. Programmable digital memory devices based on nanoscale thin films of a thermally dimensionally stable polyimide

    International Nuclear Information System (INIS)

    We have fabricated electrically programmable memory devices with thermally and dimensionally stable poly(N-(N',N'-diphenyl-N'-1,4-phenyl)-N,N-4,4'-diphenylene hexafluoroisopropylidene-diphthalimide) (6F-2TPA PI) films and investigated their switching characteristics and reliability. 6F-2TPA PI films were found to reveal a conductivity of 1.0 x 10-13-1.0 x 10-14 S cm-1. The 6F-2TPA PI films exhibit versatile memory characteristics that depend on the film thickness. All the PI films are initially present in the OFF state. The PI films with a thickness of >15 to 10. Therefore, these WORM memory devices can provide an efficient, low-cost means of permanent data storage. On the other hand, the 100 nm thick PI films exhibit excellent dynamic random access memory (DRAM) characteristics with polarity. The ON/OFF current ratio of the DRAM devices is as high as 1011. The observed electrical switching behaviors were found to be governed by trap-limited space-charge-limited conduction and local filament formation and further dependent on the differences between the highest occupied molecular orbital and the lowest unoccupied molecular orbital energy levels of the PI film and the work functions of the top and bottom electrodes as well as the PI film thickness. In summary, the excellent memory properties of 6F-2TPA PI make it a promising candidate material for the low-cost mass production of high density and very stable digital nonvolatile WORM and volatile DRAM memory devices.

  7. Thermally stable lanthanum-doped mesoporous alumina as a stable support for palladium in catalytic oxidation of C3H8

    Institute of Scientific and Technical Information of China (English)

    江莉龙; 王玉玲; 王秀云; 罗永晋; 曹彦宁; 魏可镁

    2013-01-01

    High thermally stable mesoporous alumina doped with lanthanum was synthesized using inorganic nitrates as precursors and employing pluronic P123 (P123, (EO20PO70EO20, EO=ethylene oxide, PO=propylene oxide)) as a structure-directing agent. After calcination at 400 ºC, the resultant lanthanum doped alumina exhibited aγ-Al2O3 phase, which was the same as pure alumina. After the thermal treatment up to 1200 ºC, La-doped Al2O3 generated only one phase ofθ-Al2O3 rather than two mixed phase ofθ-Al2O3 andα-Al2O3 and the surface area could still maintain 101 m2/g with a keeping pore volume of 0.66 cm3/g. The excellent thermal sta-bility was explained by the titration of strong Lewis acid sites ofγ-Al2O3 with the assistance of highly dispersed lanthanum species covering on alumina. Furthermore, the lanthanum modified mesoporous alumina was preliminarily employed as a stable support for Pd in the catalytic oxidation of C3H8.

  8. Novel thermally stable poly(vinyl chloride) composites for sulfate removal

    Energy Technology Data Exchange (ETDEWEB)

    Nadagouda, Mallikarjuna N., E-mail: Nadagouda.mallikarjuna@epa.gov [Water Supply and Water Resources Division, National Risk Management Research Laboratory U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive Cincinnati, Ohio 45268 (United States); Pressman, Jonathan; White, Colin; Speth, Thomas F.; McCurry, Daniel L. [Water Supply and Water Resources Division, National Risk Management Research Laboratory U.S. Environmental Protection Agency, 26 W. Martin Luther King Drive Cincinnati, Ohio 45268 (United States)

    2011-04-15

    Graphical abstract: Barium carbonate and/or barium carbonate-loaded silica aero-gels dispersed polyvinyl chloride (PVC) composites were prepared by dissolving PVC in tetrahydrofuran (THF), dispersing BaCO{sub 3} and/or BaCO{sub 3}-loaded silica aero-gels, re-precipitating the PVC with water at room temperature. The PVC composites were then characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The obtained composites had better thermal properties than the control PVC. The composites were tested for sulfate removal and found to significantly reduce sulfate when compared with control PVC. - Abstract: BaCO{sub 3} dispersed PVC composites were prepared through a polymer re-precipitation method. The composites were tested for sulfate removal using rapid small scale column test (RSSCT) and found to significantly reduce sulfate concentration. The method was extended to synthesize barium carbonate-loaded silica aero-gels-polyvinyl chloride (PVC) polymer composites. The PVC composites were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray mapping, X-ray diffraction (XRD), thermogravimetric analysis (TGA) and inductively coupled plasma mass spectrometry (ICP-MS) analysis. The method has advantages over conventional sulfate precipitation (sulfate removal process) using BaCO{sub 3} wherein clogging of the filter can be avoided. The method is environmentally friendly and does not interfere with natural organic matter as the conventional resin does. Some of the composites were thermally more stable as compared with the pure PVC discussed in the literature.

  9. Separation of selected stable isotopes by liquid-phase thermal diffusion and by chemical exchange

    International Nuclear Information System (INIS)

    Useful applications of enriched stable nuclides are unduly restricted by high cost and limited availability. Recent research on liquid phase thermal diffusion (LTD) has resulted in practical processes for separating 34S, 35Cl, and 37Cl in significant quantities (100 to 500 g/yr) at costs much lower than those associated with the electromagnetic (Calutron) process. The separation of the isotopes of bromine by LTD is now in progress and 79Br is being produced in relatively simple equivalent at a rate on the order of 0.5 g/day. The results of recent measurements show that the isotopes of Zn can be separated by LTD of zinc alkyls. The isotopes of calcium can be separated by LTD and by chemical exchange. The LTD process is based on the use of aqueous Ca(NO3)2 as a working fluid. The chemical exchange method involves isotopically selective exchange between an aqueous phase containing a calcium salt and an organic phase containing calcium in the form of a complex with a macrocyclic ligand. The LTD method is suitable for high enrichments at low through-puts; whereas, the chemical exchange techniques is appropriate for lower enrichments at much higher production rates. Current research is directed toward reducing these concepts to practical processes

  10. Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems

    International Nuclear Information System (INIS)

    The objectives of the project are to study thermal hydraulic characteristics of advanced nuclear reactor system for evaluating key thermal-hydraulic phenomena relevant to new safety concepts. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. The Followings are main research topics: - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation-induced Thermal Mixing in a Pool - Development of Thermal-Hydraulic Models for Two-Phase Flow - Construction of T-H Data Base

  11. A review of thermally stable gels for fluid diversion in petroleum production

    Energy Technology Data Exchange (ETDEWEB)

    Moradi-Araghi, A. [103 GB Philips Research Center, Phillips Petroleum Company, Bartlesville, OK (United States)

    2000-05-01

    The use of water-soluble polymers coupled with proper concentration of cross-linker(s) as flow-diverting agents have become a common practice in recent years for oil recovery applications. In such practice a solution containing the polymer and cross-linker(s), referred to as gelant, is injected in desired zones and allowed sufficient time to set into a solid gel. These gels are used in injection wells to divert the flow of injected water or gas (CO{sub 2}) to un-swept zones where additional oil can be recovered. The gels are also used to shut off the flow of water that strongly interferes with hydrocarbon production and substantially reduces the profitability of wells. There are a number of gelling systems available for treatment of lower temperature reservoirs. However, gels that can tolerate the harsh conditions of elevated temperatures and high salinity and divalent cations commonly present in deeper reservoirs are limited. When high molecular weight polyacrylamides are cross-linked to treat these hot reservoirs, their acrylamide groups will thermally hydrolyze. The resulting gel will further cross-link with the divalent cations available in the media, shrinking it to a fraction of its original volume. This process, which is referred to syneresis, can be avoided by selection of acrylamide-based polymers that are protected from extensive thermal hydrolysis. While other remedies such as lower-molecular-weight polyacrylamides, retarding agents or cooling of the target zones are attempted; these options often create unintended results. Recent studies include gelation of high molecular weight polyacrylamides with hydroquinone (HQ) and hexamethylenetetramine (HMTA) or terephtalaldehyde, terphthalic acid with hyroquinone, dihydroxynaphthalene and dibasic esters. These gelling systems are often prepared in seawater and require 2% sodium bicarbonate for their stability. Due to health and environmental concerns, the use of compounds such as HQ and formaldehyde is

  12. Synthesis and characterization of thermally stable large-pore mesoporous nanocrystallineanatase

    Energy Technology Data Exchange (ETDEWEB)

    Ermokhina, Natalia I.; Nevinskiy, Vitaly A.; Manorik, Piotr A.; Ilyin, Vladimir G. [L.V. Pisarzhevskiy Institute of Physical Chemistry, National Academy of Sciences of Ukraine, 31 Prospekt Nauki, Kyiv 03028 (Ukraine); Novichenko, Viktor N.; Shcherbatiuk, Mykola M.; Klymchuk, Dmitro O. [M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, 2Tereshchenkivska St., 01601, Kyiv (Ukraine); Tsyba, Mykola M. [Institute for Sorption and Problems of Endoecology, National Academy of Sciences of Ukraine, 13 Naumov St., Kyiv 03164 (Ukraine); Puziy, Alexander M., E-mail: alexander.puziy@ispe.kiev.ua [Institute for Sorption and Problems of Endoecology, National Academy of Sciences of Ukraine, 13 Naumov St., Kyiv 03164 (Ukraine)

    2013-04-15

    Thermally stable mesoporous nanocrystalline TiO{sub 2} with a pure anatase structure was obtained by sol–gel synthesis (in combination with hydrothermal treatment) using titanium tetrabutoxide and dibenzo-18-crown-6 as a structure-directing agent in presence of surfactant and/or La{sup 3+} ions additives. Nanocrystalline TiO{sub 2} demonstrates various textures with a well-defined spherical morphology (micro- and nanospheres), a crystallite size of no greater than 10 nm (XRD), and a narrow pore size distribution. Spherical particles of micrometer scale in the presence of La{sup 3+} ions do not form. TiO{sub 2} calcined (at 500 °C) after hydrothermal treatment (at 175 °C) has a significantly more developed porous structure as compared with TiO{sub 2} which was not treated hydrothermally. For example, specific surface area amounts 137 m{sup 2} g{sup −1} and 69 m{sup 2} g{sup −1}, pore volume 0.98 cm{sup 3} g{sup −1} and 0.21 cm{sup 3} g{sup −1}, pore diameter 17.5 nm and 12.5 nm respectively for samples hydrothermally treated and not treated. - Graphical abstract: Large-pore mesoporous nanocristalline anatase. Highlights: ► Large-pore mesoporous nanocrystalline TiO{sub 2} was obtained by sol–gel synthesis. ► Crown ether was used as template in presence of surfactant and/or La{sup 3+} ions. ► Anatase (crystalline size<11 nm) is the only crystalline phase present in TiO{sub 2}. ► TiO{sub 2} shows well-defined homogeneous spherical morphology (micro- and nano-spheres)

  13. Solvent-resistant organic transistors and thermally stable organic photovoltaics based on cross-linkable conjugated polymers

    KAUST Repository

    Kim, Hyeongjun

    2012-01-10

    Conjugated polymers, in general, are unstable when exposed to air, solvent, or thermal treatment, and these challenges limit their practical applications. Therefore, it is of great importance to develop new materials or methodologies that can enable organic electronics with air stability, solvent resistance, and thermal stability. Herein, we have developed a simple but powerful approach to achieve solvent-resistant and thermally stable organic electronic devices with a remarkably improved air stability, by introducing an azide cross-linkable group into a conjugated polymer. To demonstrate this concept, we have synthesized polythiophene with azide groups attached to end of the alkyl chain (P3HT-azide). Photo-cross-linking of P3HT-azide copolymers dramatically improves the solvent resistance of the active layer without disrupting the molecular ordering and charge transport. This is the first demonstration of solvent-resistant organic transistors. Furthermore, the bulk-heterojunction organic photovoltaics (BHJ OPVs) containing P3HT-azide copolymers show an average efficiency higher than 3.3% after 40 h annealing at an elevated temperature of 150 °C, which represents one of the most thermally stable OPV devices reported to date. This enhanced stability is due to an in situ compatibilizer that forms at the P3HT/PCBM interface and suppresses macrophase separation. Our approach paves a way toward organic electronics with robust and stable operations. © 2011 American Chemical Society.

  14. Flexible Fabrics with High Thermal Conductivity for Advanced Spacesuits

    Science.gov (United States)

    Trevino, Luis A.; Bue, Grant; Orndoff, Evelyne; Kesterson, Matt; Connel, John W.; Smith, Joseph G., Jr.; Southward, Robin E.; Working, Dennis; Watson, Kent A.; Delozier, Donovan M.

    2006-01-01

    This paper describes the effort and accomplishments for developing flexible fabrics with high thermal conductivity (FFHTC) for spacesuits to improve thermal performance, lower weight and reduce complexity. Commercial and additional space exploration applications that require substantial performance enhancements in removal and transport of heat away from equipment as well as from the human body can benefit from this technology. Improvements in thermal conductivity were achieved through the use of modified polymers containing thermally conductive additives. The objective of the FFHTC effort is to significantly improve the thermal conductivity of the liquid cooled ventilation garment by improving the thermal conductivity of the subcomponents (i.e., fabric and plastic tubes). This paper presents the initial system modeling studies, including a detailed liquid cooling garment model incorporated into the Wissler human thermal regulatory model, to quantify the necessary improvements in thermal conductivity and garment geometries needed to affect system performance. In addition, preliminary results of thermal conductivity improvements of the polymer components of the liquid cooled ventilation garment are presented. By improving thermal garment performance, major technology drivers will be addressed for lightweight, high thermal conductivity, flexible materials for spacesuits that are strategic technical challenges of the Exploration

  15. Configurable three-dimensional boron nitride-carbon architecture and its tunable electronic behavior with stable thermal performances.

    Science.gov (United States)

    Loeblein, Manuela; Tay, Roland Yingjie; Tsang, Siu Hon; Ng, Wei Beng; Teo, Edwin Hang Tong

    2014-08-13

    Recent developments of 3D-graphene and 3D-boron-nitride have become of great interest owing to their potential for ultra-light flexible electronics. Here we demonstrate the first synthesis of novel 3D-BNC hybrids. By specifically controlling the compositions of C and BN, new fascinating properties are observed, such as highly tunable electrical conductivity, controllable EMI shielding properties, and stable thermal conductivity. This ultra-light hybrid opens up many new applications such as for electronic packaging and thermal interface materials (TIMs). PMID:24789084

  16. New thermally stable polyesters based on 2,5-pyridinedicarbonyl dichloride and aromatic diols: Synthesis and characterization

    Institute of Scientific and Technical Information of China (English)

    Hossein Nasr Isfahani; Khalil Faghihi

    2009-01-01

    Six new thermally stable polyesters (4a-f) were synthesized through the solution polycondensation reaction of 2,5-pyridine dicarbonyldichloride (2) with six aromatic diols in N,N'-dimethyl acetamide (DMAc) solution and in the presence of pyridine as a base. The polycondensation reactions produce a series of new polyesters (4a-f) in high yields, and inherent viscosity between 0.30 and 0.55 dL/g. The resulting polyesters were characterized by elemental analysis, viscosity measurements, thermal gravimetric analysis (TGA and DTG), solubility test, Fourier transform infrared (FT-IR) spectroscopy and gel permeation chromatography (GPC).

  17. [Research advances in identifying nitrate pollution sources of water environment by using nitrogen and oxygen stable isotopes].

    Science.gov (United States)

    Mao, Wei; Liang, Zhi-wei; Li, Wei; Zhu, Yao; Yanng, Mu-yi; Jia, Chao-jie

    2013-04-01

    Water body' s nitrate pollution has become a common and severe environmental problem. In order to ensure human health and water environment benign evolution, it is of great importance to effectively identify the nitrate pollution sources of water body. Because of the discrepant composition of nitrogen and oxygen stable isotopes in different sources of nitrate in water body, nitrogen and oxygen stable isotopes can be used to identify the nitrate pollution sources of water environment. This paper introduced the fractionation factors of nitrogen and oxygen stable isotopes in the main processes of nitrogen cycling and the composition of these stable isotopes in main nitrate sources, compared the advantages and disadvantages of five pre-treatment methods for analyzing the nitrogen and oxygen isotopes in nitrate, and summarized the research advances in this aspect into three stages, i. e. , using nitrogen stable isotope alone, using nitrogen and oxygen stable isotopes simultaneously, and combining with mathematical models. The future research directions regarding the nitrate pollution sources identification of water environment were also discussed.

  18. Reduced graphene oxide enwrapped phosphors for long-term thermally stable phosphor converted white light emitting diodes

    Science.gov (United States)

    Anoop, Gopinathan; Rani, Janardhanan R.; Lim, Juhwan; Jang, Myoung Soo; Suh, Dong Wook; Kang, Shinill; Jun, Seong Chan; Yoo, Jae Soo

    2016-09-01

    The long-term instability of the presently available best commercial phosphor-converted light-emitting diodes (pcLEDs) is the most serious obstacle for the realization of low-cost and energy-saving lighting applications. Emission from pcLEDs starts to degrade after approximately 200 h of operation because of thermal degradation of the phosphors. We propose a new strategy to overcome this thermal degradation problem of phosphors by wrapping the phosphor particles with reduced graphene oxide (rGO). Through the rGO wrapping, we have succeeded in controlling the thermal degradation of phosphors and improving the stability of fabricated pcLEDs. We have fabricated pcLEDs with long-term stability that maintain nearly 98% of their initial luminescence emission intensity even after 800 h of continuous operation at 85 °C and 85% relative humidity. The pcLEDs fabricated using SrBaSi2O2N2:Eu2+ phosphor particles wrapped with reduced graphene oxide are thermally stable because of enhanced heat dissipation that prevents the ionization of Eu2+ to Eu3+. We believe that this technique can be applied to other rare-earth doped phosphors for the realization of highly efficient and stable white LEDs.

  19. Reduced graphene oxide enwrapped phosphors for long-term thermally stable phosphor converted white light emitting diodes

    Science.gov (United States)

    Anoop, Gopinathan; Rani, Janardhanan R.; Lim, Juhwan; Jang, Myoung Soo; Suh, Dong Wook; Kang, Shinill; Jun, Seong Chan; Yoo, Jae Soo

    2016-01-01

    The long-term instability of the presently available best commercial phosphor-converted light-emitting diodes (pcLEDs) is the most serious obstacle for the realization of low-cost and energy-saving lighting applications. Emission from pcLEDs starts to degrade after approximately 200 h of operation because of thermal degradation of the phosphors. We propose a new strategy to overcome this thermal degradation problem of phosphors by wrapping the phosphor particles with reduced graphene oxide (rGO). Through the rGO wrapping, we have succeeded in controlling the thermal degradation of phosphors and improving the stability of fabricated pcLEDs. We have fabricated pcLEDs with long-term stability that maintain nearly 98% of their initial luminescence emission intensity even after 800 h of continuous operation at 85 °C and 85% relative humidity. The pcLEDs fabricated using SrBaSi2O2N2:Eu2+ phosphor particles wrapped with reduced graphene oxide are thermally stable because of enhanced heat dissipation that prevents the ionization of Eu2+ to Eu3+. We believe that this technique can be applied to other rare-earth doped phosphors for the realization of highly efficient and stable white LEDs. PMID:27671271

  20. Advanced thermal barrier coating system development. Technical progress report, August 1, 1996--September 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-10-04

    Objectives of this program are to provide an advanced thermal barrier coating system with improved reliability and temperature capability. This report describes the coating/deposition process, repair, and manufacturing.

  1. Advanced Thermal Interface Material Systems for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The ultimate aim of proposed efforts are to develop innovative material and process (M&P) engineering technology to reduce thermal resistance between space...

  2. Thermal Characterization of Nanostructures and Advanced Engineered Materials

    OpenAIRE

    Goyal, Vivek Kumar

    2011-01-01

    Continuous downscaling of Si complementary metal-oxide semiconductor (CMOS) technology and progress in high-power electronics demand more efficient heat removal techniques to handle the increasing power density and rising temperature of hot spots. For this reason, it is important to investigate thermal properties of materials at nanometer scale and identify materials with the extremely large or extremely low thermal conductivity for applications as heat spreaders or heat insulators in the nex...

  3. Analytical investigation of thermal barrier coatings on advanced power generation gas turbines

    Science.gov (United States)

    Amos, D. J.

    1977-01-01

    An analytical investigation of present and advanced gas turbine power generation cycles incorporating thermal barrier turbine component coatings was performed. Approximately 50 parametric points considering simple, recuperated, and combined cycles (including gasification) with gas turbine inlet temperatures from current levels through 1644K (2500 F) were evaluated. The results indicated that thermal barriers would be an attractive means to improve performance and reduce cost of electricity for these cycles. A recommended thermal barrier development program has been defined.

  4. Including Thermal Fluctuations in Actomyosin Stable States Increases the Predicted Force per Motor and Macroscopic Efficiency in Muscle Modelling.

    Science.gov (United States)

    Marcucci, Lorenzo; Washio, Takumi; Yanagida, Toshio

    2016-09-01

    Muscle contractions are generated by cyclical interactions of myosin heads with actin filaments to form the actomyosin complex. To simulate actomyosin complex stable states, mathematical models usually define an energy landscape with a corresponding number of wells. The jumps between these wells are defined through rate constants. Almost all previous models assign these wells an infinite sharpness by imposing a relatively simple expression for the detailed balance, i.e., the ratio of the rate constants depends exponentially on the sole myosin elastic energy. Physically, this assumption corresponds to neglecting thermal fluctuations in the actomyosin complex stable states. By comparing three mathematical models, we examine the extent to which this hypothesis affects muscle model predictions at the single cross-bridge, single fiber, and organ levels in a ceteris paribus analysis. We show that including fluctuations in stable states allows the lever arm of the myosin to easily and dynamically explore all possible minima in the energy landscape, generating several backward and forward jumps between states during the lifetime of the actomyosin complex, whereas the infinitely sharp minima case is characterized by fewer jumps between states. Moreover, the analysis predicts that thermal fluctuations enable a more efficient contraction mechanism, in which a higher force is sustained by fewer attached cross-bridges. PMID:27626630

  5. Including Thermal Fluctuations in Actomyosin Stable States Increases the Predicted Force per Motor and Macroscopic Efficiency in Muscle Modelling

    Science.gov (United States)

    2016-01-01

    Muscle contractions are generated by cyclical interactions of myosin heads with actin filaments to form the actomyosin complex. To simulate actomyosin complex stable states, mathematical models usually define an energy landscape with a corresponding number of wells. The jumps between these wells are defined through rate constants. Almost all previous models assign these wells an infinite sharpness by imposing a relatively simple expression for the detailed balance, i.e., the ratio of the rate constants depends exponentially on the sole myosin elastic energy. Physically, this assumption corresponds to neglecting thermal fluctuations in the actomyosin complex stable states. By comparing three mathematical models, we examine the extent to which this hypothesis affects muscle model predictions at the single cross-bridge, single fiber, and organ levels in a ceteris paribus analysis. We show that including fluctuations in stable states allows the lever arm of the myosin to easily and dynamically explore all possible minima in the energy landscape, generating several backward and forward jumps between states during the lifetime of the actomyosin complex, whereas the infinitely sharp minima case is characterized by fewer jumps between states. Moreover, the analysis predicts that thermal fluctuations enable a more efficient contraction mechanism, in which a higher force is sustained by fewer attached cross-bridges. PMID:27626630

  6. Light stable isotope study of the Roosevelt Hot Springs thermal area, Southwestern Utah

    Energy Technology Data Exchange (ETDEWEB)

    Rohrs D.T.; Bowman, J.R.

    1980-05-01

    The isotopic composition of hydrogen, oxygen, and carbon has been determined for regional cold springs, thermal fluids, and rocks and minerals from the Roosevelt Hot Springs thermal area. The geothermal system has developed within plutonic granitic rocks and amphibolite facies gneiss, relying upon fracture-controlled permeability for the migration of the thermal fluids. Probably originating as meteoric waters in the upper elevations of the Mineral Mountains, the thermal waters sampled in the production wells display an oxygen isotopic shift of at least +1.2. Depletions of delta /sup 18/O in wole rock, K-feldspar, and biotite have a positive correlation with alteration intensity. W/R mass ratios, calculated from the isotopic shifts of rock and water, range up to 3.0 in a producing horizon of one well, although the K-feldspar has experienced only 30% exchange with the thermal waters. While veinlet quartz has equilibrated with the thermal waters, the /sup 18/O values of K-mica clay, an alteration product of plagioclase, mimic the isotopic composition of K-feldspar and whole rock. This suggests that locally small W/R ratios enable plagioclase to influence its alteration products by isotopic exchange.

  7. Fabrication of extremely thermal-stable GaN template on Mo substrate using double bonding and step annealing process

    Science.gov (United States)

    Qing, Wang; Yang, Liu; Yongjian, Sun; Yuzhen, Tong; Guoyi, Zhang

    2016-08-01

    A new layer transfer technique which comprised double bonding and a step annealing process was utilized to transfer the GaN epilayer from a sapphire substrate to a Mo substrate. Combined with the application of the thermal-stable bonding medium, the resulting two-inch-diameter GaN template showed extremely good stability under high temperature and low stress state. Moreover, no cracks and winkles were observed. The transferred GaN template was suitable for homogeneous epitaxial, thus could be used for the direct fabrication of vertical LED chips as well as power electron devices. It has been confirmed that the double bonding and step annealing technique together with the thermal-stable bonding layer could significantly improve the bonding strength and stress relief, finally enhancing the thermal stability of the transferred GaN template. Project supported by the Guangdong Innovative Research Team Program (No. 2009010044), the China Postdoctoral Science Foundation (No. 2014M562233), the National Natural Science Foundation of Guangdong, China (No. 2015A030312011), and the Opened Fund of the State Key Laboratory on Integrated Optoelectronics (No. IOSKL2014KF17).

  8. Advanced field theory micro, macro, and thermal physics

    CERN Document Server

    Umezawa, Hiroomi

    1995-01-01

    This work begins by distinguishing the difference between quantum mechanics and quantum field theory. It then attempts to extend field theory by adding a thermal degree of freedom to phenomena occurring within a vacuum. The resulting quantum field theory is called Thermo Field Dynamics (TFD).

  9. Advances in NASA's Nuclear Thermal Propulsion Technology project

    Science.gov (United States)

    Peecook, Keith M.; Stone, James R.

    1993-01-01

    The status of the Nuclear Thermal Propulsion (NTP) project for space exploration and the future plans for NTP technology are discussed. Current activities in the framework of the NTP project deal with nonnuclear material tests; instrumentation, controls, and health management; turbopumps; nozzles and nozzle extension; and an exhaust plume.

  10. Advanced Stirling Radioisotope Generator (ASRG) Thermal Power Model in MATLAB

    Science.gov (United States)

    Wang, Xiao-Yen, J.

    2012-01-01

    This paper presents a one-dimensional steady-state mathematical thermal power model of the ASRG. It aims to provide a guideline of understanding how the ASRG works and what can change its performance. The thermal dynamics and energy balance of the generator is explained using the thermal circuit of the ASRG. The Stirling convertor performance map is used to represent the convertor. How the convertor performance map is coupled in the thermal circuit is explained. The ASRG performance characteristics under i) different sink temperatures and ii) over the years of mission (YOM) are predicted using the one-dimensional model. Two Stirling converter control strategies, i) fixing the hot-end of temperature of the convertor by adjusting piston amplitude and ii) fixing the piston amplitude, were tested in the model. Numerical results show that the first control strategy can result in a higher system efficiency than the second control strategy when the ambient gets warmer or the general-purpose heat source (GPHS) fuel load decays over the YOM. The ASRG performance data presented in this paper doesn't pertain to the ASRG flight unit. Some data of the ASRG engineering unit (EU) and flight unit that are available in public domain are used in this paper for the purpose of numerical studies.

  11. Advanced Signal Processing for Thermal Flaw Detection; TOPICAL

    International Nuclear Information System (INIS)

    Dynamic thermography is a promising technology for inspecting metallic and composite structures used in high-consequence industries. However, the reliability and inspection sensitivity of this technology has historically been limited by the need for extensive operator experience and the use of human judgment and visual acuity to detect flaws in the large volume of infrared image data collected. To overcome these limitations new automated data analysis algorithms and software is needed. The primary objectives of this research effort were to develop a data processing methodology that is tied to the underlying physics, which reduces or removes the data interpretation requirements, and which eliminates the need to look at significant numbers of data frames to determine if a flaw is present. Considering the strengths and weakness of previous research efforts, this research elected to couple both the temporal and spatial attributes of the surface temperature. Of the possible algorithms investigated, the best performing was a radiance weighted root mean square Laplacian metric that included a multiplicative surface effect correction factor and a novel spatio-temporal parametric model for data smoothing. This metric demonstrated the potential for detecting flaws smaller than 0.075 inch in inspection areas on the order of one square foot. Included in this report is the development of a thermal imaging model, a weighted least squares thermal data smoothing algorithm, simulation and experimental flaw detection results, and an overview of the ATAC (Automated Thermal Analysis Code) software that was developed to analyze thermal inspection data

  12. RF-driven tokamak reactor with sub-ignited, thermally stable operation

    International Nuclear Information System (INIS)

    A Radio-Frequency Driven Tokamak Reactor (RFDTR) can use RF-power, programmed by a delayed temperature measurement, to thermally stabilize a power equilibrium below ignition, and to drive a steady state current. We propose the parameters for such a device generating approx. = 1600 MW thermal power and operating with Q approx. = 40 (= power out/power in). A one temperature zero-dimensional model allows simple analytical formulation of the problem. The relevance of injected impurities for locating the equilibrium is discussed. We present the results of a one-dimensional (radial) code which includes the deposition of the supplementary power, and compare with our zero-dimensional model

  13. Bacterial cellulose nanofibrous membrane as thermal stable separator for lithium-ion batteries

    Science.gov (United States)

    Jiang, Fengjing; Yin, Lei; Yu, Qingchun; Zhong, Chunyan; Zhang, Junliang

    2015-04-01

    Thermal shrinkage is a severe problem for the conventional polyolefin separators. In this work, we report the excellent performance of bacterial cellulose (BC) nanofibrous membranes as separators for lithium (Li) ion batteries. Properties of BC separator including morphology, ionic conductivity, electrochemical stability, thermal stability, mechanical strength and battery charge-discharge performance are characterized and compared to a commercial separator membrane (Celgard® 2325). Because of the unique fibrous and cross-linked three-dimensional network structure, BC separator shows excellent dimensional stability up to 180 °C, good ionic conductivity and competitive battery performance.

  14. Cluster-assembled cubic zirconia films with tunable and stable nanoscale morphology against thermal annealing

    Science.gov (United States)

    Borghi, F.; Sogne, E.; Lenardi, C.; Podestà, A.; Merlini, M.; Ducati, C.; Milani, P.

    2016-08-01

    Nanostructured zirconium dioxide (zirconia) films are very promising for catalysis and biotechnological applications: a precise control of the interfacial properties of the material at different length scales and, in particular, at the nanoscale, is therefore necessary. Here, we present the characterization of cluster-assembled zirconia films produced by supersonic cluster beam deposition possessing cubic structure at room temperature and controlled nanoscale morphology. We characterized the effect of thermal annealing in reducing and oxidizing conditions on the crystalline structure, grain dimensions, and topography. We highlight the mechanisms of film growth and phase transitions, which determine the observed interfacial morphological properties and their resilience against thermal treatments.

  15. Advanced welding for closed structure. Pt. 3 The thermal approach

    Energy Technology Data Exchange (ETDEWEB)

    Sacripanti, A.; Bonanno, G.; Paoloni, M.; Sagratella, G. [ENEA Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione; Arborino, A.; Varesi, R.; Antonucci, A. [DUNE, (Italy)

    1999-07-01

    This report describes the activities developed for the European Contract BRITE AWCS III to study the use of thermal sensing techniques to obtain an accurate detection of the internal reinforcement of the closed steel structures employed in the shipbuilding industry. After a description of the methods, normally developed in Russia, about the techniques and problems, for the thermal testing of materials in the conventional approach, a new thermal detector was utilized, a new bolometric thermo camera is introduced with a special software for the on line image analysis, there are also shown the experimental tests and results. The obtained conclusion shows that the thermal non destructive testing techniques with the new detector should be useful to assemble a complete sensing system with one ultrasonic head. [Italian] Questo rapporto descrive le attivita' sperimentali sviluppate nell'ambito del contratto europeo BRITE AWCS III, in cui si sono utilizzate tecniche termiche per ottenere un preciso rilevamento dei rinforzi interni di strutture metalliche chiuse utilizzate nell'industria delle costruzioni navali. Dopo la descrizione dei metodi sviluppati essenzialmente in Russia, circa le tecniche e i problemi riguardanti il testing termico dei materiali, e' stato introdotto un approccio innovativo basato su un nuovo sensore: una termocamera bolometrica connessa con un software dedicato per l'analisi online del setto; vengono inoltre mostrati i risultati sperimentali ottenuti. Le conclusioni ottenute mostrano che nel nuovo approccio, il testing termico non distruttivo dovrebbe essere utile per assemblare un sistema sensoriale completo che utilizzi anche un sensore di tipo ultrasonico.

  16. Advanced homogenization strategies in material modeling of thermally sprayed TBCs

    International Nuclear Information System (INIS)

    Thermal barrier coatings (TBC), obtained by atmospheric plasma spraying (APS), have a complex microstructure (lamellar, porous, micro-cracked). Process parameters take an influence on this microstructure. Two methods based on the homogenization for periodic structures are presented in this article. The methods are used to calculate the effective material behavior of APS-TBCs made of partially yttria stabilized zirconia (PYSZ) depending on the microstructure. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  17. Advanced Liquid-Cooling Garment Using Highly Thermally Conductive Sheets

    Science.gov (United States)

    Ruemmele, Warren P.; Bue, Grant C.; Orndoff, Evelyne; Tang, Henry

    2010-01-01

    This design of the liquid-cooling garment for NASA spacesuits allows the suit to remove metabolic heat from the human body more effectively, thereby increasing comfort and performance while reducing system mass. The garment is also more flexible, with fewer restrictions on body motion, and more effectively transfers thermal energy from the crewmember s body to the external cooling unit. This improves the garment s performance in terms of the maximum environment temperature in which it can keep a crewmember comfortable. The garment uses flexible, highly thermally conductive sheet material (such as graphite), coupled with cooling water lines of improved thermal conductivity to transfer the thermal energy from the body to the liquid cooling lines more effectively. The conductive sheets can be layered differently, depending upon the heat loads, in order to provide flexibility, exceptional in-plane heat transfer, and good through-plane heat transfer. A metal foil, most likely aluminum, can be put between the graphite sheets and the external heat source/sink in order to both maximize through-plane heat transfer at the contact points, and to serve as a protection to the highly conductive sheets. Use of a wicking layer draws excess sweat away from the crewmember s skin and the use of an outer elastic fabric ensures good thermal contact of the highly conductive underlayers with the skin. This allows the current state of the art to be improved by having cooling lines that can be more widely spaced to improve suit flexibility and to reduce weight. Also, cooling liquid does not have to be as cold to achieve the same level of cooling. Specific areas on the human body can easily be targeted for greater or lesser cooling to match human physiology, a warmer external environment can be tolerated, and spatial uniformity of the cooling garment can be improved to reduce vasoconstriction limits. Elements of this innovation can be applied to other embodiments to provide effective heat

  18. Advanced High Temperature Adhesives for Thermally Stable Aero-assist Technologies Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Aero-assist technologies are used to control the velocity of exploration vehicles (EV) when entering earth or other planetary atmospheres. Since entry of EVs in...

  19. Thermal Properties of Oxides With Magnetoplumbite Structure for Advanced Thermal Barrier Coatings

    Science.gov (United States)

    Bansal, Narottam P.; Zhu, Dongming; Eslamloo-Grami, Maryam

    2007-01-01

    Oxides having magnetoplumbite structure are promising candidate materials for applications as high temperature thermal barrier coatings because of their high thermal stability, high thermal expansion, and low thermal conductivity. In this study, powders of LaMgAl11O19, GdMgAl11O19, SmMgAl11O19, and Gd0.7Yb0.3MgAl11O19 magnetoplumbite oxides were synthesized by citric acid sol-gel method and hot pressed into disk specimens. The thermal expansion coefficients (CTE) of these oxide materials were measured from room temperature to 1500 C. The average CTE value was found to be approx.9.6x10(exp -6)/C. Thermal conductivity of these magnetoplumbite-based oxide materials was also evaluated using steady-state laser heat flux test method. The effects of doping on thermal properties were also examined. Thermal conductivity of the doped Gd0.7Yb0.3MgAl11O19 composition was found to be lower than that of the undoped GdMgAl11O19. In contrast, thermal expansion coefficient was found to be independent of the oxide composition and appears to be controlled by the magnetoplumbite crystal structure. Thermal conductivity testing of LaMgAl11O19 and LaMnAl11O19 magnetoplumbite oxide coatings plasma sprayed on NiCrAlY/Rene N5 superalloy substrates indicated resistance of these coatings to sintering even at temperatures as high as 1600 C.

  20. STABLE ISOTOPE GEOCHEMISTRY OF THERMAL FLUIDS FROM LASSEN VOLCANIC NATIONAL PARK, CALIFORNIA.

    Science.gov (United States)

    Janik, Cathy J.; Nehring, Nancy L.; Truesdell, Alfred H.

    1983-01-01

    In the Lassen vapor-dominated geothermal system, surface manifestations of thermal fluids at high elevations (1800-2500 m) include superheated and drowned fumaroles, steam-heated acid-sulfate hot springs, and low-chloride bicarbonate springs. Neutral high-chloride hot water discharges at lower elevations. Deuterium and oxygen-18 data establish genetic connections between these fluids and with local meteoric waters. Steam from the highest temperature fumarole at Bumpass Hell and water from the highest chloride hot spring have isotopic compositions corresponding to vapor-liquid equilibrium at 235 degree C. Carbon and sulfur isotope data suggest that the CO//2 and H//2S in the system did not entirely originate from magmatic sources, but probably include contributions from thermal metamorphism of marine sedimentary rocks. Observations suggest that carbon and sulfur isotope variations are useful indicators of gas reactions and flow paths in geothermal systems. Refs.

  1. Thermally stable and efficient polymer solar cells based on a novel donor-acceptor copolymer

    Science.gov (United States)

    Synooka, O.; Eberhardt, K.-R.; Balko, J.; Thurn-Albrecht, T.; Gobsch, G.; Mitchell, W.; Berny, S.; Carrasco-Orozco, M.; Hoppe, H.

    2016-06-01

    We report high photovoltaic performance of a novel donor-acceptor (D-A) conjugated polymer poly[2,6[4,8-bis(2-ethyl-hexyl)benzo[1,2-b4,5-b‧]dithiophene-co-2,5-thiophene-co-4,7[5,6-bis-octyloxy-benzo[1,2,5]thiadiazole]-co-2,5-thiophene] (PBDTTBTZT) in bulk heterojunctions with [6,6]-phenyl-C71-butyric acid methyl ester (PC70BM). A power conversion efficiency (PCE) of more than 7% is obtained for optimized charge-extracting electrodes. Upon application of thermal stress via annealing, a superior thermal stability is demonstrated as compared to poly[N-9″-hepta-decanyl-2,7-carbazole-alt-5,5-(4‧,7‧-di-2-thienyl-2‧,1‧,3‧-benzothiadiazole)] (PCDTBT).

  2. High Molecular Weight Thermally Stable Poly (Sodium Methacrylate / Magnetites Nanocomposites Via Emulsion Polymerization

    Directory of Open Access Journals (Sweden)

    Rasha A. El-Ghazawya,

    2014-04-01

    Full Text Available Core/shell type magnetite nanocomposites (MN were synthesized using sodium methacrylate (NMA monomer. Functionalized and bare magnetite nanoparticles were prepared by conventional co-precipitation method giving particles with 3-10 nm in diameter. Microemulsion polymerization was used for constructing core/shell structure with magnetite nanoparticles as core and poly (sodium methacrylate as shell. Chemical structure and morphology of the synthesized PNMA/magnetite nanocomposites were investigated using FTIR and TEM, respectively. The synthesized nanocomposites show effective encapsulation of different treated magnetite nanoparticles in the polymer matrix and exhibited good thermal stability. Such magnetite nanocomposites with high molecular weight and thermal stability have potential application in enhanced oil recovery application.

  3. Application of Niobium Enriched Ormosils as Thermally Stable Coatings for Aerospace Aluminium Coatings

    OpenAIRE

    Varma, P.C. Rajath; Oubaha, Mohamed; Periyat, Pradeepan; McDonagh, Colette; Duffy, Brendan

    2011-01-01

    The aim of this experimental research is to study the ability of niobium rich sol-gel coatings to withstand thermal stress, while remaining impermeable to corrosive agents for the protection of aerospace alloys. The coating material is developed via polymeric sol-gel synthesis employing 3-(trimethoxysilyl)propylmethacrylate (MAPTMS) and niobium ethoxide precursors as a source of silicon and niobium, respectively. The beneficial effect of niobium inclusion within coating was characterised spec...

  4. Synthesis and Characterization of Thermally Stable Photocurable Polymer with Cyclohexane Moiety.

    Science.gov (United States)

    Kim, Dong Mm; Yu, Seong Hun; Lee, Jun Young

    2016-03-01

    Photocurable polymers with high transparency and thermal stability were synthesized by reaction between a commercial epoxy resin (NC9110) containing cyclohexane moiety and various kinds of cinnamic acids such as trans-cinnamic acid (CA), 3-hydroxy-trans-cinnamic acid (HCA) and 4-methoxy-trans-cinnamic acid (MCA). The photocurable polymers were synthesized with equal equivalent weight ratio of epoxy and cinnamate group. The chemical structures of the synthesized polymers were confirmed by 1H-NMR and FT-IR spectroscopies. Optical transmittance and thermal stability of the photocured polymers were investigated using UV-Visible spectroscopy and thermogravimetric analysis (TGA), respectively. It was confirmed that the polymers could form thin films with very smooth surface and could be efficiently cured by UV irradiation. It was also found that the polymer after curing showed a good thermal stability and optical transmittance. There was no significant transmittance change after heat treatment at 250 degrees C for 1 h and showed no noticeable weight loss up to 360 degrees C.

  5. Thermal-Hydraulic Experiments and Modelling for Advanced Nuclear Reactor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Song, C. H.; Chung, M. K.; Park, C. K. and others

    2005-04-15

    The objectives of the project are to study thermal hydraulic characteristics of reactor primary system for the verification of the reactor safety and to evaluate new safety concepts of new safety design features. To meet the research goal, several thermal hydraulic experiments were performed and related thermal hydraulic models were developed with the experimental data which were produced through the thermal hydraulic experiments. Followings are main research topics; - Multi-dimensional Phenomena in a Reactor Vessel Downcomer - Condensation Load and Thermal Mixing in the IRWST - Development of Thermal-Hydraulic Models for Two-Phase Flow - Development of Measurement Techniques for Two-Phase Flow - Supercritical Reactor T/H Characteristics Analysis From the above experimental and analytical studies, new safety design features of the advanced power reactors were verified and lots of the safety issues were also resolved.

  6. Advanced Computational Methods for Thermal Radiative Heat Transfer.

    Energy Technology Data Exchange (ETDEWEB)

    Tencer, John; Carlberg, Kevin Thomas; Larsen, Marvin E.; Hogan, Roy E.,

    2016-10-01

    Participating media radiation (PMR) in weapon safety calculations for abnormal thermal environments are too costly to do routinely. This cost may be s ubstantially reduced by applying reduced order modeling (ROM) techniques. The application of ROM to PMR is a new and unique approach for this class of problems. This approach was investigated by the authors and shown to provide significant reductions in the computational expense associated with typical PMR simulations. Once this technology is migrated into production heat transfer analysis codes this capability will enable the routine use of PMR heat transfer in higher - fidelity simulations of weapon resp onse in fire environments.

  7. Advanced Computational Methods for Thermal Radiative Heat Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Tencer, John; Carlberg, Kevin Thomas; Larsen, Marvin E.; Hogan, Roy E.,

    2016-10-01

    Participating media radiation (PMR) in weapon safety calculations for abnormal thermal environments are too costly to do routinely. This cost may be s ubstantially reduced by applying reduced order modeling (ROM) techniques. The application of ROM to PMR is a new and unique approach for this class of problems. This approach was investigated by the authors and shown to provide significant reductions in the computational expense associated with typical PMR simulations. Once this technology is migrated into production heat transfer analysis codes this capability will enable the routine use of PMR heat transfer in higher - fidelity simulations of weapon resp onse in fire environments.

  8. Preparation and characterization of form-stable paraffin/polyurethane composites as phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Highlights: • Paraffin/polyurethane composite as form-stable phase change material was prepared by bulk polymerization. • Paraffin/polyurethane composite possesses typical character of dual phase transition. • Total latent heat of n-eicosane/PUPCM is as high as 141.2 J/g. • Maximum encapsulation ratio for n-octadecane/PUPCM composites is 25% w/w. - Abstract: Polyurethane phase change material (PUPCM) has been demonstrated to be effective solid–solid phase change material for thermal energy storage. However, the high cost and complex process on preparation of PUPCMs with high enthalpy and broad phase transition temperature range can prohibit industrial-scale applications. In this work, a series of novel form-stable paraffin/PUPCMs composites (n-octadecane/PUPCM, n-eicosane/PUPCM and paraffin wax/PUPCM) with high enthalpy and broad phase transition temperature range (20–65 °C) were directly synthesized via bulk polymerization. The composites were prepared at different mass fractions of n-octadecane (10, 20, 25, 30% w/w). The results indicated that the maximum encapsulation ratio for n-octadecane/PUPCM10000 composites was around 25% w/w. The chemical structure and crystalline properties of these composites were characterized by Fourier transform infrared spectroscopy (FT-IR), polarizing optical microscopy (POM), wide-angle X-ray diffraction (WAXD). Thermal properties and thermal reliability of the composites were determined using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). From DSC analysis, the composites showed a typical dual phase change temperature. The enthalpy for the composite with 25% w/w n-eicosane was as high as 141.2 J/g. TGA analysis indicated that the composites degraded at considerably high temperatures. The process of preparation of PUPCMs and their composites was very simple, inexpensive, environmental friendly and easy to process into desired shapes, which could find the promising applications in solar

  9. Spin wave differential circuit for realization of thermally stable magnonic sensors

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Taichi, E-mail: goto@ee.tut.ac.jp; Kanazawa, Naoki; Buyandalai, Altansargai; Takagi, Hiroyuki; Nakamura, Yuichi; Inoue, Mitsuteru [Department of Electrical and Electronic Information Engineering, Toyohashi University of Technology, 1-1 Hibari-Ga-Oka, Tempaku, Toyohashi, Aichi 441-8580 (Japan); Okajima, Shingo; Hasegawa, Takashi [Murata Manufacturing Co., Ltd., Kyoto 617-8555 (Japan); Granovsky, Alexander B. [Faculty of Physics, Moscow State University, Leninskie Gory, Moscow 119992 (Russian Federation); Sekiguchi, Koji [Department of Physics, Keio University, Yokohama 223-8522 (Japan); JST-PRESTO, Kawaguchi, Saitama 332-0012 (Japan); Ross, Caroline A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States)

    2015-03-30

    A magnetic-field sensor with a high sensitivity of 38 pT/Hz was demonstrated. By utilizing a spin-wave differential circuit (SWDC) using two yttrium iron garnet (YIG) films, the temperature sensitivity was suppressed, and the thermal stability of the phase of the spin waves was −0.0095° K{sup −1}, which is three orders of magnitude better than a simple YIG-based sensor, ∼20° K{sup −1}. The SWDC architecture opens the way to design YIG-based magnonic devices.

  10. A study on the advanced statistical core thermal design methodology

    International Nuclear Information System (INIS)

    A statistical core thermal design methodology for generating the limit DNBR and the nominal DNBR is proposed and used in assessing the best-estimate thermal margin in a reactor core. Firstly, the Latin Hypercube Sampling Method instead of the conventional Experimental Design Technique is utilized as an input sampling method for a regression analysis to evaluate its sampling efficiency. Secondly and as a main topic, the Modified Latin Hypercube Sampling and the Hypothesis Test Statistics method is proposed as a substitute for the current statistical core thermal design method. This new methodology adopts 'a Modified Latin Hypercube Sampling Method' which uses the mean values of each interval of input variables instead of random values to avoid the extreme cases that arise in the tail areas of some parameters. Next, the independence between the input variables is verified through 'Correlation Coefficient Test' for statistical treatment of their uncertainties. And the distribution type of DNBR response is determined though 'Goodness of Fit Test'. Finally, the limit DNBR with one-sided 95% probability and 95% confidence level, DNBR95/95' is estimated. The advantage of this methodology over the conventional statistical method using Response Surface and Monte Carlo simulation technique lies in its simplicity of the analysis procedure, while maintaining the same level of confidence in the limit DNBR result. This methodology is applied to the two cases of DNBR margin calculation. The first case is the application to the determination of the limit DNBR where the DNBR margin is determined by the difference between the nominal DNBR and the limit DNBR. The second case is the application to the determination of the nominal DNBR where the DNBR margin is determined by the difference between the lower limit value of the nominal DNBR and the CHF correlation limit being used. From this study, it is deduced that the proposed methodology gives a good agreement in the DNBR results with

  11. High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner For Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Ellis, David; Singh, Jogender

    2014-01-01

    Advanced high thermal conductivity materials research conducted at NASA Marshall Space Flight Center (MSFC) with state of the art combustion chamber liner material NARloy-Z showed that its thermal conductivity can be increased significantly by adding diamond particles and sintering it at high temperatures. For instance, NARloy-Z containing 40 vol. percent diamond particles, sintered at 975C to full density by using the Field assisted Sintering Technology (FAST) showed 69 percent higher thermal conductivity than baseline NARloy-Z. Furthermore, NARloy-Z-40vol. percent D is 30 percent lighter than NARloy-Z and hence the density normalized thermal conductivity is 140 percent better. These attributes will improve the performance and life of the advanced rocket engines significantly. By one estimate, increased thermal conductivity will directly translate into increased turbopump power up to 2X and increased chamber pressure for improved thrust and ISP, resulting in an expected 20 percent improvement in engine performance. Follow on research is now being conducted to demonstrate the benefits of this high thermal conductivity NARloy-Z-D composite for combustion chamber liner applications in advanced rocket engines. The work consists of a) Optimizing the chemistry and heat treatment for NARloy-Z-D composite, b) Developing design properties (thermal and mechanical) for the optimized NARloy-Z-D, c) Fabrication of net shape subscale combustion chamber liner, and d) Hot fire testing of the liner for performance. FAST is used for consolidating and sintering NARlo-Z-D. The subscale cylindrical liner with built in channels for coolant flow is also fabricated near net shape using the FAST process. The liner will be assembled into a test rig and hot fire tested in the MSFC test facility to determine performance. This paper describes the development of this novel high thermal conductivity NARloy-Z-D composite material, and the advanced net shape technology to fabricate the combustion

  12. THEHYCO-3DT: Thermal hydrodynamic code for the 3 dimensional transient calculation of advanced LMFBR core

    Energy Technology Data Exchange (ETDEWEB)

    Vitruk, S.G.; Korsun, A.S. [Moscow Engineering Physics Institute (Russian Federation); Ushakov, P.A. [Institute of Physics and Power Engineering, Obninsk (R)] [and others

    1995-09-01

    The multilevel mathematical model of neutron thermal hydrodynamic processes in a passive safety core without assemblies duct walls and appropriate computer code SKETCH, consisted of thermal hydrodynamic module THEHYCO-3DT and neutron one, are described. A new effective discretization technique for energy, momentum and mass conservation equations is applied in hexagonal - z geometry. The model adequacy and applicability are presented. The results of the calculations show that the model and the computer code could be used in conceptual design of advanced reactors.

  13. Biologically active and thermally stable polymeric Schiff base and its metal polychelates: Their synthesis and spectral aspects

    Science.gov (United States)

    Rasool, Raza; Hasnain, Sumaiya

    2015-09-01

    New metal polychelates of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) obtained by the interaction of metal acetates with polymeric Schiff base containing formaldehyde and piperazine, have been investigated. Structural and spectroscopic properties have been evaluated by elemental analysis, FT-IR and 1H-NMR. Geometry of the chelated polymers was confirmed by magnetic susceptibility measurements, UV-Visible spectroscopy and Electron Spin Resonance. The molecular weight of the polymer was determined by gel permeation chromatography (GPC). Thermogravimetric analysis indicated that metal polychelates were more thermally stable than their corresponding ligand. All compounds were screened for their antimicrobial activities against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, (bacteria) and Candida albicans, Microsporum canis, Cryptococcus neoformans (fungi) by agar well diffusion method. Interestingly, the polymeric Schiff base was found to be antimicrobial in nature but less effective as compared to the metal polychelates. On the basis of thermal and antimicrobial behavior, these polymers hold potential applications as thermally resistant antimicrobial and antifouling coating materials as well as antimicrobial packaging materials.

  14. The thermal neutron absorption cross-sections, resonance integrals and resonance parameters of silicon and its stable isotopes

    International Nuclear Information System (INIS)

    The data available up to the end of November 1968 on the thermal neutron absorption cross-sections, resonance absorption integrals, and resonance parameters of silicon and its stable isotopes are collected and discussed. Estimates are given of the mean spacing of the energy levels of the compound nuclei near the neutron binding energy. It is concluded that the thermal neutron absorption cross-section and resonance absorption integral of natural silicon are not well established. The data on these two parameters are somewhat correlated, and three different assessments of the resonance integral are presented which differ over-all by a factor of 230. Many resonances have been detected by charged particle reactions which have not yet been observed in neutron cross-section measurements. One of these resonances of Si28, at En = 4 ± 5 keV might account for the large resonance integral which is derived, very uncertainly, from integral data. The principal source of the measured resonance integral of Si30 has not yet been located. The thermal neutron absorption cross-section of Si28 appears to result mainly from a negative energy resonance, possibly the resonance at En = - 59 ± 5 keV detected by the Si28 (d,p) reaction. (author)

  15. Advanced wellbore thermal simulator GEOTEMP2 user manual

    Energy Technology Data Exchange (ETDEWEB)

    Mondy, L.A.; Duda, L.E.

    1984-11-01

    GEOTEMP2 is a wellbore thermal simulator computer code designed for geothermal drilling and production applications. The code treats natural and forced convection and conduction within the wellbore and heat conduction within the surrounding rock matrix. A variety of well operations can be modeled including injection, production, forward, and reverse circulation with gas or liquid, gas or liquid drilling, and two-phase steam injection and production. Well completion with several different casing sizes and cement intervals can be modeled. The code allows variables suchas flow rate to change with time enabling a realistic treatment of well operations. This user manual describes the input required to properly operate the code. Ten sample problems are included which illustrate all the code options. Complete listings of the code and the output of each sample problem are provided.

  16. Thermally stable single-atom platinum-on-ceria catalysts via atom trapping

    Energy Technology Data Exchange (ETDEWEB)

    Jones, John; Xiong, Haifeng; DelaRiva, Andrew; Peterson, Eric J.; Pham, Hien; Challa, Sivakumar R.; Qi, Gongshin; Oh, Se H.; Wiebenga, Michelle H.; Pereira Hernandez, Xavier I.; Wang, Yong; Datye, Abhaya K.

    2016-07-08

    Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/ aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst.

  17. Thermally stable single-atom platinum-on-ceria catalysts via atom trapping.

    Science.gov (United States)

    Jones, John; Xiong, Haifeng; DeLaRiva, Andrew T; Peterson, Eric J; Pham, Hien; Challa, Sivakumar R; Qi, Gongshin; Oh, Se; Wiebenga, Michelle H; Pereira Hernández, Xavier Isidro; Wang, Yong; Datye, Abhaya K

    2016-07-01

    Catalysts based on single atoms of scarce precious metals can lead to more efficient use through enhanced reactivity and selectivity. However, single atoms on catalyst supports can be mobile and aggregate into nanoparticles when heated at elevated temperatures. High temperatures are detrimental to catalyst performance unless these mobile atoms can be trapped. We used ceria powders having similar surface areas but different exposed surface facets. When mixed with a platinum/aluminum oxide catalyst and aged in air at 800°C, the platinum transferred to the ceria and was trapped. Polyhedral ceria and nanorods were more effective than ceria cubes at anchoring the platinum. Performing synthesis at high temperatures ensures that only the most stable binding sites are occupied, yielding a sinter-resistant, atomically dispersed catalyst. PMID:27387946

  18. Fabrication of robust and thermally stable superhydrophobic nanocomposite coatings based on thermoplastic polyurethane and silica nanoparticles

    Science.gov (United States)

    Seyfi, Javad; Jafari, Seyed Hassan; Khonakdar, Hossein Ali; Sadeghi, Gity Mir Mohamad; Zohuri, Gholamhossein; Hejazi, Iman; Simon, Frank

    2015-08-01

    In this paper, superhydrophobic nanocomposite coatings based on thermoplastic polyurethane (TPU) and modified nanosilica were fabricated using a simple solution-based method. The main challenge was to impart superhydrophobicity to an intrinsically hydrophilic polymer substrate. The prepared nanocomposite coatings were characterized by means of scanning electron microscopy, confocal microscopy and X-ray photoelectron spectroscopy. Based on the obtained results, it was proved that in order to achieve superhydrophobicity, no TPU macromolecule should be present on the coating's top layer, thus a complete coverage of coating's top layer by nanosilica particles was necessary for achieving ultra water repellent coatings. Mechanical and thermal resistance of the coatings, which are the main challenges in commercializing superhydrophobic surfaces, were also studied by drop impact and thermal annealing tests, respectively. It was proved that using TPU as a sublayer results in improving mechanical resistance of the coatings as compared with the pure silica nanocoating. Moreover, the samples showed an excellent resistance against elevated temperatures (150 °C) and remained superhydrophobic; however, further increment of the annealing temperatures to 200 °C caused the TPU macromolecules to migrate onto the top layer of the coatings significantly reducing the water repellency, which was visually proved by SEM.

  19. Fabrication of robust and thermally stable superhydrophobic nanocomposite coatings based on thermoplastic polyurethane and silica nanoparticles

    International Nuclear Information System (INIS)

    Highlights: • Superhydrophobic coatings were prepared from an intrinsically hydrophilic polymer. • The superhydrophobicity remained intact at elevated temperatures. • Polyurethane plays a key role in improving the mechanical robustness of the coatings. • A complete surface coverage of nanosilica is necessary for superhydrophobicity. - Abstract: In this paper, superhydrophobic nanocomposite coatings based on thermoplastic polyurethane (TPU) and modified nanosilica were fabricated using a simple solution-based method. The main challenge was to impart superhydrophobicity to an intrinsically hydrophilic polymer substrate. The prepared nanocomposite coatings were characterized by means of scanning electron microscopy, confocal microscopy and X-ray photoelectron spectroscopy. Based on the obtained results, it was proved that in order to achieve superhydrophobicity, no TPU macromolecule should be present on the coating's top layer, thus a complete coverage of coating's top layer by nanosilica particles was necessary for achieving ultra water repellent coatings. Mechanical and thermal resistance of the coatings, which are the main challenges in commercializing superhydrophobic surfaces, were also studied by drop impact and thermal annealing tests, respectively. It was proved that using TPU as a sublayer results in improving mechanical resistance of the coatings as compared with the pure silica nanocoating. Moreover, the samples showed an excellent resistance against elevated temperatures (150 °C) and remained superhydrophobic; however, further increment of the annealing temperatures to 200 °C caused the TPU macromolecules to migrate onto the top layer of the coatings significantly reducing the water repellency, which was visually proved by SEM

  20. Coupled granular/continuous medium for thermally stable perpendicular magnetic recording

    International Nuclear Information System (INIS)

    We studied coupled granular/continuous (CGC) perpendicular media consisting of a continuous multilayer structure and a granular layer. The addition of Co/Pt multilayers decreased the nucleation field from 200 to -1800 Oe and increased the squareness from 0.9 to 1.0. The moment decay at room temperature was significantly reduced from -4.8% to -0.05% per decade. At elevated temperatures, strong exchange coupling between a granular layer and a continuous layer is needed for thermal stability. The exchange-coupled continuous layer reduces thermal demagnetization as it effectively increases the grain size, tightens the grain distribution, and prevents the reversal of individual grains. Magnetic Force Microscope image showed a larger magnetic cluster size for the CGC structure. Compared to the CoCr18Pt12 medium, the CGC medium had 2.3 dB higher output. However, the noise for the CGC medium increased with the recording density, while the noise for the CoCr18Pt12 medium remained constant from 4 to 15 kfc/mm. Further optimization and noise reduction are still required for future high density recording

  1. Fabrication of robust and thermally stable superhydrophobic nanocomposite coatings based on thermoplastic polyurethane and silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Seyfi, Javad [School of Chemical Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Jafari, Seyed Hassan, E-mail: shjafari@ut.ac.ir [School of Chemical Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Khonakdar, Hossein Ali [Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, D-01069 Dresden (Germany); Sadeghi, Gity Mir Mohamad [Department of Polymer Engineering & Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Zohuri, Gholamhossein [Polymer Group, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Hejazi, Iman [Department of Polymer Engineering & Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Simon, Frank [Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, D-01069 Dresden (Germany)

    2015-08-30

    Highlights: • Superhydrophobic coatings were prepared from an intrinsically hydrophilic polymer. • The superhydrophobicity remained intact at elevated temperatures. • Polyurethane plays a key role in improving the mechanical robustness of the coatings. • A complete surface coverage of nanosilica is necessary for superhydrophobicity. - Abstract: In this paper, superhydrophobic nanocomposite coatings based on thermoplastic polyurethane (TPU) and modified nanosilica were fabricated using a simple solution-based method. The main challenge was to impart superhydrophobicity to an intrinsically hydrophilic polymer substrate. The prepared nanocomposite coatings were characterized by means of scanning electron microscopy, confocal microscopy and X-ray photoelectron spectroscopy. Based on the obtained results, it was proved that in order to achieve superhydrophobicity, no TPU macromolecule should be present on the coating's top layer, thus a complete coverage of coating's top layer by nanosilica particles was necessary for achieving ultra water repellent coatings. Mechanical and thermal resistance of the coatings, which are the main challenges in commercializing superhydrophobic surfaces, were also studied by drop impact and thermal annealing tests, respectively. It was proved that using TPU as a sublayer results in improving mechanical resistance of the coatings as compared with the pure silica nanocoating. Moreover, the samples showed an excellent resistance against elevated temperatures (150 °C) and remained superhydrophobic; however, further increment of the annealing temperatures to 200 °C caused the TPU macromolecules to migrate onto the top layer of the coatings significantly reducing the water repellency, which was visually proved by SEM.

  2. Advanced Thermal Storage System with Novel Molten Salt: December 8, 2011 - April 30, 2013

    Energy Technology Data Exchange (ETDEWEB)

    Jonemann, M.

    2013-05-01

    Final technical progress report of Halotechnics Subcontract No. NEU-2-11979-01. Halotechnics has demonstrated an advanced thermal energy storage system with a novel molten salt operating at 700 degrees C. The molten salt and storage system will enable the use of advanced power cycles such as supercritical steam and supercritical carbon dioxide in next generation CSP plants. The salt consists of low cost, earth abundant materials.

  3. Advanced Thermal Storage for Central Receivers with Supercritical Coolants

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Bruce D.

    2010-06-15

    The principal objective of the study is to determine if supercritical heat transport fluids in a central receiver power plant, in combination with ceramic thermocline storage systems, offer a reduction in levelized energy cost over a baseline nitrate salt concept. The baseline concept uses a nitrate salt receiver, two-tank (hot and cold) nitrate salt thermal storage, and a subcritical Rankine cycle. A total of 6 plant designs were analyzed, as follows: Plant Designation Receiver Fluid Thermal Storage Rankine Cycle Subcritical nitrate salt Nitrate salt Two tank nitrate salt Subcritical Supercritical nitrate salt Nitrate salt Two tank nitrate salt Supercritical Low temperature H2O Supercritical H2O Two tank nitrate salt Supercritical High temperature H2O Supercritical H2O Packed bed thermocline Supercritical Low temperature CO2 Supercritical CO2 Two tank nitrate salt Supercritical High temperature CO2 Supercritical CO2 Packed bed thermocline Supercritical Several conclusions have been drawn from the results of the study, as follows: 1) The use of supercritical H2O as the heat transport fluid in a packed bed thermocline is likely not a practical approach. The specific heat of the fluid is a strong function of the temperatures at values near 400 °C, and the temperature profile in the bed during a charging cycle is markedly different than the profile during a discharging cycle. 2) The use of supercritical CO2 as the heat transport fluid in a packed bed thermocline is judged to be technically feasible. Nonetheless, the high operating pressures for the supercritical fluid require the use of pressure vessels to contain the storage inventory. The unit cost of the two-tank nitrate salt system is approximately $24/kWht, while the unit cost of the high pressure thermocline system is nominally 10 times as high. 3) For the supercritical fluids, the outer crown temperatures of the receiver tubes are in the range of 700 to 800 °C. At temperatures of 700 °C and above

  4. Relaxation behavior and nonlinear properties of thermally stable polymers based on glycidyl derivatives of quercetin

    Science.gov (United States)

    Mishurov, Dmytro; Voronkin, Andrii; Roshal, Alexander; Brovko, Oleksandr

    2016-07-01

    Cross-linked polymers on the basis of di-, tri and tetraglycidyl ethers of quercetin (3,3‧,4‧,5,7-pentahydroxyflavone) were synthesized, and then, poled in electrical field of corona discharge. Investigations of structural, thermal and optical parameters of the polymer films were carried out. It was found that the polymers obtained from di- and triglycidyl quercetin ethers had high values of macroscopic quadratic susceptibilities and substantial stability of nonlinear optical (NLO) properties after the poling. Tetraglycidyl ether of quercetin forms the polymer of lower quadratic susceptibility, which demonstrates noticeable relaxation process resulting in decrease of the NLO effect. It is supposed that the difference of the NLO properties is due to peculiarities of physical network of the polymers, namely to the ratio between numbers of hydrogen bonds formed by hydroxyl groups of chromophore fragments and by the ones of interfragmental parts of the polymeric chains.

  5. Strategic Need for Multi-Purpose Thermal Hydraulic Loop for Support of Advanced Reactor Technologies

    Energy Technology Data Exchange (ETDEWEB)

    James E. O' Brien; Piyush Sabharwall; Su-Jong Yoon; Gregory K. Housley

    2014-09-01

    This report presents a conceptual design for a new high-temperature multi fluid, multi loop test facility for the INL to support thermal hydraulic, materials, and thermal energy storage research for nuclear and nuclear-hybrid applications. In its initial configuration, the facility will include a high-temperature helium loop, a liquid salt loop, and a hot water/steam loop. The three loops will be thermally coupled through an intermediate heat exchanger (IHX) and a secondary heat exchanger (SHX). Research topics to be addressed with this facility include the characterization and performance evaluation of candidate compact heat exchangers such as printed circuit heat exchangers (PCHEs) at prototypical operating conditions, flow and heat transfer issues related to core thermal hydraulics in advanced helium-cooled and salt-cooled reactors, and evaluation of corrosion behavior of new cladding materials and accident-tolerant fuels for LWRs at prototypical conditions. Based on its relevance to advanced reactor systems, the new facility has been named the Advanced Reactor Technology Integral System Test (ARTIST) facility. Research performed in this facility will advance the state of the art and technology readiness level of high temperature intermediate heat exchangers (IHXs) for nuclear applications while establishing the INL as a center of excellence for the development and certification of this technology. The thermal energy storage capability will support research and demonstration activities related to process heat delivery for a variety of hybrid energy systems and grid stabilization strategies. Experimental results obtained from this research will assist in development of reliable predictive models for thermal hydraulic design and safety codes over the range of expected advanced reactor operating conditions. Proposed/existing IHX heat transfer and friction correlations and criteria will be assessed with information on materials compatibility and instrumentation

  6. Strategic need for a multi-purpose thermal hydraulic loop for support of advanced reactor technologies

    Energy Technology Data Exchange (ETDEWEB)

    O' Brien, James E. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sabharwall, Piyush [Idaho National Lab. (INL), Idaho Falls, ID (United States); Yoon, Su -Jong [Idaho National Lab. (INL), Idaho Falls, ID (United States); Housley, Gregory K. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This report presents a conceptual design for a new high-temperature multi fluid, multi loop test facility for the INL to support thermal hydraulic, materials, and thermal energy storage research for nuclear and nuclear-hybrid applications. In its initial configuration, the facility will include a high-temperature helium loop, a liquid salt loop, and a hot water/steam loop. The three loops will be thermally coupled through an intermediate heat exchanger (IHX) and a secondary heat exchanger (SHX). Research topics to be addressed with this facility include the characterization and performance evaluation of candidate compact heat exchangers such as printed circuit heat exchangers (PCHEs) at prototypical operating conditions, flow and heat transfer issues related to core thermal hydraulics in advanced helium-cooled and salt-cooled reactors, and evaluation of corrosion behavior of new cladding materials and accident-tolerant fuels for LWRs at prototypical conditions. Based on its relevance to advanced reactor systems, the new facility has been named the Advanced Reactor Technology Integral System Test (ARTIST) facility. Research performed in this facility will advance the state of the art and technology readiness level of high temperature intermediate heat exchangers (IHXs) for nuclear applications while establishing the INL as a center of excellence for the development and certification of this technology. The thermal energy storage capability will support research and demonstration activities related to process heat delivery for a variety of hybrid energy systems and grid stabilization strategies. Experimental results obtained from this research will assist in development of reliable predictive models for thermal hydraulic design and safety codes over the range of expected advanced reactor operating conditions. Proposed/existing IHX heat transfer and friction correlations and criteria will be assessed with information on materials compatibility and instrumentation

  7. Heat engine requirements for advanced solar thermal power systems

    Science.gov (United States)

    Jaffe, L. D.; Pham, H. Q.

    1981-01-01

    Requirements and constraints are established for power conversion subsystems, including heat engine, alternator and auxiliaries, of dish concentrator solar thermal power systems. In order to be competitive with conventional power systems, it is argued that the heat engine should be of less than 40 kW rated output, in a subsystem with an efficiency of at least 40% at rated output and at least 37% at half power. An interval between major overhauls of 50,000 hours is also desirable, along with minor maintenance and lubrication not more than four times a year requiring no more than one man-hour each time, and optimal reliability. Also found to be important are the capability for hybrid operation using heat from a solar receiver, fuel-fired combustor or both simultaneously, operation at any attitude, stability to transients in input power and output loading, operation at ambient temperatures from -30 to 50 C, and compatibility with environmental and safety requirements. Cost targets include a price of $180/kWe, and operation, maintenance and replacement costs averaging $0.001/kWh for 30 years of operation.

  8. Trichoderma harzianum Produces a New Thermally Stable Acid Phosphatase, with Potential for Biotechnological Application.

    Science.gov (United States)

    Souza, Amanda Araújo; Leitão, Vanessa Oliveira; Ramada, Marcelo Henrique; Mehdad, Azadeh; Georg, Raphaela de Castro; Ulhôa, Cirano José; de Freitas, Sonia Maria

    2016-01-01

    Acid phosphatases (ACPases) are produced by a variety of fungi and have gained attention due their biotechnological potential in industrial, diagnosis and bioremediation processes. These enzymes play a specific role in scavenging, mobilization and acquisition of phosphate, enhancing soil fertility and plant growth. In this study, a new ACPase from Trichoderma harzianum, named ACPase II, was purified and characterized as a glycoprotein belonging to the acid phosphatase family. ACPase II presents an optimum pH and temperature of 3.8 and 65 °C, respectively, and is stable at 55 °C for 120 min, retaining 60% of its activity. The enzyme did not require metal divalent ions, but was inhibited by inorganic phosphate and tungstate. Affinity for several phosphate substrates was observed, including phytate, which is the major component of phosphorus in plant foods. The inhibition of ACPase II by tungstate and phosphate at different pH values is consistent with the inability of the substrate to occupy its active site due to electrostatic contacts that promote conformational changes, as indicated by fluorescence spectroscopy. A higher affinity for tungstate rather than phosphate at pH 4.0 was observed, in accordance with its highest inhibitory effect. Results indicate considerable biotechnological potential of the ACPase II in soil environments. PMID:26938873

  9. Trichoderma harzianum Produces a New Thermally Stable Acid Phosphatase, with Potential for Biotechnological Application.

    Directory of Open Access Journals (Sweden)

    Amanda Araújo Souza

    Full Text Available Acid phosphatases (ACPases are produced by a variety of fungi and have gained attention due their biotechnological potential in industrial, diagnosis and bioremediation processes. These enzymes play a specific role in scavenging, mobilization and acquisition of phosphate, enhancing soil fertility and plant growth. In this study, a new ACPase from Trichoderma harzianum, named ACPase II, was purified and characterized as a glycoprotein belonging to the acid phosphatase family. ACPase II presents an optimum pH and temperature of 3.8 and 65 °C, respectively, and is stable at 55 °C for 120 min, retaining 60% of its activity. The enzyme did not require metal divalent ions, but was inhibited by inorganic phosphate and tungstate. Affinity for several phosphate substrates was observed, including phytate, which is the major component of phosphorus in plant foods. The inhibition of ACPase II by tungstate and phosphate at different pH values is consistent with the inability of the substrate to occupy its active site due to electrostatic contacts that promote conformational changes, as indicated by fluorescence spectroscopy. A higher affinity for tungstate rather than phosphate at pH 4.0 was observed, in accordance with its highest inhibitory effect. Results indicate considerable biotechnological potential of the ACPase II in soil environments.

  10. Thermally stable coexistence of liquid and solid phases in gallium nanoparticles

    Science.gov (United States)

    Losurdo, Maria; Suvorova, Alexandra; Rubanov, Sergey; Hingerl, Kurt; Brown, April S.

    2016-09-01

    Gallium (Ga), a group III metal, is of fundamental interest due to its polymorphism and unusual phase transition behaviours. New solid phases have been observed when Ga is confined at the nanoscale. Herein, we demonstrate the stable coexistence, from 180 K to 800 K, of the unexpected solid γ-phase core and a liquid shell in substrate-supported Ga nanoparticles. We show that the support plays a fundamental role in determining Ga nanoparticle phases, with the driving forces for the nucleation of the γ-phase being the Laplace pressure in the nanoparticles and the epitaxial relationship of this phase to the substrate. We exploit the change in the amplitude of the evolving surface plasmon resonance of Ga nanoparticle ensembles during synthesis to reveal in real time the solid core formation in the liquid Ga nanoparticle. Finally, we provide a general framework for understanding how nanoscale confinement, interfacial and surface energies, and crystalline relationships to the substrate enable and stabilize the coexistence of unexpected phases.

  11. Projected techno-economic improvements for advanced solar thermal power plants

    Science.gov (United States)

    Fujita, T.; Manvi, R.; Roschke, E. J.

    1979-01-01

    The projected characteristics of solar thermal power plants (with outputs up to 10 MWe) employing promising advanced technology subsystems/components are compared to current (or pre-1985) steam-Rankine systems. Improvements accruing to advanced technology development options are delineated. The improvements derived from advanced systems result primarily from achieving high efficiencies via solar collector systems which (1) capture a large portion of the available insolation and (2) concentrate this captured solar flux to attain high temperatures required for high heat engine/energy conversion performance. The most efficient solar collector systems employ two-axis tracking. Attractive systems include the central receiver/heliostat and the parabolic dish.

  12. The formation of thermally evaporated stable Schottky barriers on p-ZnxPb(1-x)Te thin films

    Science.gov (United States)

    Khairnar, U. P.; Jadhav, S. R.

    2013-06-01

    Metal-semiconductor contacts are drawing increasing attention due to their potential for applications in devices and integrated circuits. Experimentally, lower barrier heights have been reported more often for metallic contacts on p-type semiconductors. Here we report our results regarding barrier heights of Ag/Au on p-ZnxPb(1-x)Te. The barrier heights can be perceived using data on the interface reaction and the phase formation in direct contacts with ZnxPb(1-x)Te. In such contacts which are normally thought to be responsible for the observation of low barrier heights on p-type semiconductor. Thermally stable Ag/Au-contacts with a barrier height of 0.56 eV were produced.

  13. Reduction of complex ventricular arrhythmias after enalapril treatment in patients with advanced stable heart failure.

    Science.gov (United States)

    Pomini, G; Gribaldo, R; Rugna, A; Lupia, M; Molfese, G; Carenza, P

    1991-01-01

    We studied, by 48-hour Holter monitoring, 33 patients with chronic stable heart failure (radionuclide ejection fraction less than 35%), complex ventricular arrhythmias and no electrolyte abnormalities, after a period during which they were treated with digoxin and diuretics. Before Holter monitoring blood samples were analyzed for serum concentration of sodium, potassium, magnesium, urea, creatinine, digoxin, aldosterone and for plasmatic renin activity in addition to urinary aldosterone and catecholamines determination. After these investigations in 23 patients, 5-20 mg of enalapril were progressively added to the conventional therapy, while 10 patients continued the previous therapy. After 8 weeks 30 patients were subjected to a second 48-hour Holter monitoring and to the same biochemical and hormonal tests. One patient died and 2 were lost to follow up. Only the enalapril group showed a significant decrease in the number of premature ventricular complexes (PVC) (p less than 0.01), and the frequency of couplets and episodes of ventricular tachycardia (VT) declined significantly (P less than 0.01). In the two groups there were no significant changes in digoxin, sodium, or magnesium, while potassium concentration increased in both groups (p less than 0.01). In the enalapril group heart rate and systolic and diastolic pressure declined significantly (p less than 0.01), and New York Heart Association class (NYHA) improved (p less than 0.001). In the other group there were no significant changes in these parameters. Enalapril caused a significant increase in the plasmatic renin activity (p less than 0.01) and a significant fall of plasma and urinary aldosterone (p less than 0.01; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2055378

  14. Preparation and properties of lauric acid/silicon dioxide composites as form-stable phase change materials for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Fang Guiyin, E-mail: gyfang@nju.edu.cn [Department of Physics, Nanjing University, Hankou Road 22, Nanjing, Jiangsu 210093 (China); Li Hui [Department of Material Science and Engineering, Nanjing University, Nanjing 210093 (China); Liu Xu [Department of Physics, Nanjing University, Hankou Road 22, Nanjing, Jiangsu 210093 (China)

    2010-08-01

    Form-stable lauric acid (LA)/silicon dioxide (SiO{sub 2}) composite phase change materials were prepared using sol-gel methods. The LA was used as the phase change material for thermal energy storage, with the SiO{sub 2} acting as the supporting material. The structural analysis of these form-stable LA/SiO{sub 2} composite phase change materials was carried out using Fourier transformation infrared spectroscope (FT-IR). The microstructure of the form-stable composite phase change materials was observed by a scanning electronic microscope (SEM). The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the LA was well dispersed in the porous network of SiO{sub 2}. The DSC results indicated that the melting latent heat of the form-stable composite phase change material is 117.21 kJ kg{sup -1} when the mass percentage of the LA in the SiO{sub 2} is 64.8%. The results of the TGA showed that these materials have good thermal stability. The form-stable composite phase change materials can be used for thermal energy storage in waste heat recovery and solar heating systems.

  15. Preparation and properties of lauric acid/silicon dioxide composites as form-stable phase change materials for thermal energy storage

    International Nuclear Information System (INIS)

    Form-stable lauric acid (LA)/silicon dioxide (SiO2) composite phase change materials were prepared using sol-gel methods. The LA was used as the phase change material for thermal energy storage, with the SiO2 acting as the supporting material. The structural analysis of these form-stable LA/SiO2 composite phase change materials was carried out using Fourier transformation infrared spectroscope (FT-IR). The microstructure of the form-stable composite phase change materials was observed by a scanning electronic microscope (SEM). The thermal properties and thermal stability were investigated by a differential scanning calorimeter (DSC) and a thermogravimetric analysis apparatus (TGA), respectively. The SEM results showed that the LA was well dispersed in the porous network of SiO2. The DSC results indicated that the melting latent heat of the form-stable composite phase change material is 117.21 kJ kg-1 when the mass percentage of the LA in the SiO2 is 64.8%. The results of the TGA showed that these materials have good thermal stability. The form-stable composite phase change materials can be used for thermal energy storage in waste heat recovery and solar heating systems.

  16. Preparation, characterization and thermal properties of styrene maleic anhydride copolymer (SMA)/fatty acid composites as form stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Sari, Ahmet; Alkan, Cemil; Karaipekli, Ali; Oenal, Adem [Department of Chemistry, Gaziosmanpasa University, 60240, Tokat (Turkey)

    2008-02-15

    Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA) and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the major drawback of them, limiting their utility area in thermal energy storage. The use of fatty acids as form stable PCMs will increase their feasibilities in practical applications due to the reduced cost of the LHTES system. In this regard, a series of styrene maleic anhydride copolymer (SMA)/fatty acid composites, SMA/SA, SMA/PA, SMA/MA, and SMA/LA, were prepared as form stable PCMs by encapsulation of fatty acids into the SMA, which acts as a supporting material. The encapsulation ratio of fatty acids was as much as 85 wt.% and no leakage of fatty acid was observed even when the temperature of the form stable PCM was over the melting point of the fatty acid in the composite. The prepared form stable composite PCMs were characterized using optic microscopy (OM), viscosimetry and Fourier transform infrared (FT-IR) spectroscopy methods, and the results showed that the SMA was physically and chemically compatible with the fatty acids. In addition, the thermal characteristics such as melting and freezing temperatures and latent heats of the form stable composite PCMs were measured by using the differential scanning calorimetry (DSC) technique, which indicated they had good thermal properties. On the basis of all the results, it was concluded that form stable SMA/fatty acid composite PCMs had important potential for practical LHTES applications such as under floor space heating of buildings and passive solar space heating of buildings by using wallboard, plasterboard or floors impregnated with a form stable PCM due to their satisfying thermal properties, easy preparation in desired dimensions, direct usability without needing additional encapsulation thereby eliminating the thermal resistance caused by the shell and, thus, reducing the cost of

  17. Till death do us part: stable sponge-bacteria associations under thermal and food shortage stresses.

    Directory of Open Access Journals (Sweden)

    Lucía Pita

    Full Text Available Sporadic mass mortality events of Mediterranean sponges following periods of anomalously high temperatures or longer than usual stratification of the seawater column (i.e. low food availability suggest that these animals are sensitive to environmental stresses. The Mediterranean sponges Ircinia fasciculata and I. oros harbor distinct, species-specific bacterial communities that are highly stable over time and space but little is known about how anomalous environmental conditions affect the structure of the resident bacterial communities. Here, we monitored the bacterial communities in I. fasciculata (largely affected by mass mortalities and I. oros (overall unaffected maintained in aquaria during 3 weeks under 4 treatments that mimicked realistic stress pressures: control conditions (13°C, unfiltered seawater, low food availability (13°C, 0.1 µm-filtered seawater, elevated temperatures (25°C, unfiltered seawater, and a combination of the 2 stressors (25°C, 0.1 µm-filtered seawater. Bacterial community structure was assessed using terminal restriction fragment length polymorphism (T-RFLP analysis of 16S rRNA gene sequences and transmission electron microscopy (TEM. As I. fasciculata harbors cyanobacteria, we also measured chlorophyll a (chl a levels in this species. Multivariate analysis revealed no significant differences in bacterial T-RFLP profiles among treatments for either host sponge species, indicating no effect of high temperatures and food shortage on symbiont community structure. In I. fasciculata, chl a content did not significantly differ among treatments although TEM micrographs revealed some cyanobacteria cells undergoing degradation when exposed to both elevated temperature and food shortage conditions. Arguably, longer-term treatments (months could have eventually affected bacterial community structure. However, we evidenced no appreciable decay of the symbiotic community in response to medium-term (3 weeks environmental

  18. Thermally stable narrow-bandpass filter prepared by reactive ion-assisted sputtering.

    Science.gov (United States)

    Tsai, R Y; Chang, C S; Chu, C W; Chen, T; Dai, F; Lin, D; Yan, S; Chang, A

    2001-04-01

    Thermal stabilities of three-cavity narrow-bandpass (NB) filters with high-index half-wave spacers and 78-102 layers of Ta(2)O(5) and SiO(2) prepared by reactive ion-assisted bipolar direct-current (dc) magnetron sputtering of tantalum and silicon targets, respectively, were investigated. Pure argon and pure oxygen were used as the sputtering gas and the reactant, respectively. The oxygen gas was introduced and ionized through the ion gun and toward the unheated BK7 glass substrate. The refractive indices of single-layer Ta(2)O(5) and SiO(2) films were 2.1 and 1.45, respectively, at 1550 nm, which were comparable with those of films prepared by other ion-assisted coating techniques. The moisture-resistant properties of the films were excellent as evidenced from the water-immersion test, implying that the packing density of the films was close to that of their bulk materials. The temperature-dependant wavelength shifts of the NB filters were <3 x 10(-3) nm/ degrees C at temperatures of <75 degrees C, indicating that the temperature-induced wavelength shift of the filter was <0.15 nm when the temperatures were raised from room temperature to 75 degrees C, which was compliant with Bellcore GR-1209-CORE generic requirements of NB filters used for optical-fiber communication systems. PMID:18357152

  19. Preparation and Luminescent Properties of Sm3+-Doped High Thermal Stable Sodium Yttrium Orthosilicate Phosphor.

    Science.gov (United States)

    Xue, Na; Hei, Zhoufei; Zhao, Ze; Wang, Jing; Wang, Ting; Li, Mengxue; Noh, Hyeon Mi; Jeong, Jung Hyun; Yu, Ruijin

    2016-04-01

    Orange-red-emitting sodium yttrium orthosilicate NaYSiO4:xSm3+ (x = 0.005, 0.01, 0.02, 0.05, 0.10, 0.15, and 0.20) were synthesized. The phase structure and photoluminescence properties of these phosphors were investigated. The emission spectrum obtained by excitation into 406 nm contains exclusively the characteristic emissions of Sm3+ at 571 nm, 602 nm, 648 nm, and 710 nm, which correspond to the transitions from 4G5/2 to 6H5/2, 6H7/2, 6H9/2, and 6H11/2 of Sm3+, respectively. The strongest one is located at 602 nm due to the 4G5/2 --> 6H7/2 transition of Sm3+, generating bright orange-red light. The optimum dopant concentration of Sm3+ ions in NaYSiO4:xSm3+ is around 2 mol%, and the critical transfer distance of Sm3+ is calculated as 23 Å. The thermal quenching temperature is above 500 K. The fluorescence lifetime of Sm3+ in NaYSiO4:0.02Sm3+ is 1.83 ms. The NaYSiO4:Sm3+ phosphors may be potentially used as red phosphors for white light emitting diodes. PMID:27451656

  20. Thermally-nucleated self-assembly of water and alcohol into stable structures at hydrophobic interfaces

    Science.gov (United States)

    Voïtchovsky, Kislon; Giofrè, Daniele; José Segura, Juan; Stellacci, Francesco; Ceriotti, Michele

    2016-01-01

    At the interface with solids, the mobility of liquid molecules tends to be reduced compared with bulk, often resulting in increased local order due to interactions with the surface of the solid. At room temperature, liquids such as water and methanol can form solvation structures, but the molecules remain highly mobile, thus preventing the formation of long-lived supramolecular assemblies. Here we show that mixtures of water with methanol can form a novel type of interfaces with hydrophobic solids. Combining in situ atomic force microscopy and multiscale molecular dynamics simulations, we identify solid-like two-dimensional interfacial structures that nucleate thermally, and are held together by an extended network of hydrogen bonds. On graphite, nucleation occurs above ∼35 °C, resulting in robust, multilayered nanoscopic patterns. Our findings could have an impact on many fields where water-alcohol mixtures play an important role such as fuel cells, chemical synthesis, self-assembly, catalysis and surface treatments. PMID:27713413

  1. Surface Catalytic Efficiency of Advanced Carbon Carbon Candidate Thermal Protection Materials for SSTO Vehicles

    Science.gov (United States)

    Stewart, David A.

    1996-01-01

    The catalytic efficiency (atom recombination coefficients) for advanced ceramic thermal protection systems was calculated using arc-jet data. Coefficients for both oxygen and nitrogen atom recombination on the surfaces of these systems were obtained to temperatures of 1650 K. Optical and chemical stability of the candidate systems to the high energy hypersonic flow was also demonstrated during these tests.

  2. Advances in thermal hydraulic and neutronic simulation for reactor analysis and safety

    Energy Technology Data Exchange (ETDEWEB)

    Tentner, A.M.; Blomquist, R.N.; Canfield, T.R.; Ewing, T.F.; Garner, P.L.; Gelbard, E.M.; Gross, K.C.; Minkoff, M.; Valentin, R.A.

    1993-03-01

    This paper describes several large-scale computational models developed at Argonne National Laboratory for the simulation and analysis of thermal-hydraulic and neutronic events in nuclear reactors and nuclear power plants. The impact of advanced parallel computing technologies on these computational models is emphasized.

  3. Advanced modeling of thermal NDT problems: from buried landmines to defects in composites

    Science.gov (United States)

    Vavilov, Vladimir P.; Burleigh, Douglas D.; Klimov, Alexey G.

    2002-03-01

    Advanced thermal models that can be used in the detection of buried landmines and the TNDT (thermographic nondestructive testing) of composites are discussed. The interdependence between surface temperature signals and various complex parameters, such as surface and volumetric moisture, the shape of a heat pulse, material anisotropy, etc., is demonstrated.

  4. Monte Carlo simulations to advance characterisation of landmines by pulsed fast/thermal neutron analysis

    NARCIS (Netherlands)

    Maucec, M.; Rigollet, C.

    2004-01-01

    The performance of a detection system based on the pulsed fast/thermal neutron analysis technique was assessed using Monte Carlo simulations. The aim was to develop and implement simulation methods, to support and advance the data analysis techniques of the characteristic gamma-ray spectra, potentia

  5. Advances in Thermal Insulation. Vacuum Insulation Panels and Thermal Efficiency to Reduce Energy Usage in Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Thorsell, Thomas

    2012-07-01

    We are coming to realize that there is an urgent need to reduce energy usage in buildings and it has to be done in a sustainable way. This thesis focuses on the performance of the building envelope; more precisely thermal performance of walls and super insulation material in the form of vacuum insulation. However, the building envelope is just one part of the whole building system, and super insulators have one major flaw: they are easily adversely affected by other problems in the built environment. Vacuum Insulation Panels are one fresh addition to the arsenal of insulation materials available to the building industry. They are composite material with a core and an enclosure which, as a composite, can reach thermal conductivities as low as 0.004 W/(mK). However, the exceptional performance relies on the barrier material preventing gas permeation, maintaining a near vacuum into the core and a minimized thermal bridge effect from the wrapping of barrier material round the edge of a panel. A serpentine edge is proposed to decrease the heat loss at the edge. Modeling and testing shows a reduction of 60 % if a reasonable serpentine edge is used. A diffusion model of permeation through multilayered barrier films with metallization coatings was developed to predict ultimate service life. The model combines numerical calculations with analytical field theory allowing for more precise determination than current models. The results using the proposed model indicate that it is possible to manufacture panels with lifetimes exceeding 50 years with existing manufacturing. Switching from the component scale to the building scale; an approach of integrated testing and modeling is proposed. Four wall types have been tested in a large range of environments with the aim to assess the hydrothermal nature and significance of thermal bridges and air leakages. The test procedure was also examined as a means for a more representative performance indicator than R-value (in USA). The

  6. Study on thermal property of lauric–palmitic–stearic acid/vermiculite composite as form-stable phase change material for energy storage

    Directory of Open Access Journals (Sweden)

    Nan Zhang

    2015-09-01

    Full Text Available The form-stable composite phase change material of lauric–palmitic–stearic acid ternary eutectic mixture/vermiculite was prepared by vacuum impregnation method for thermal energy storage. The maximum mass fraction of lauric–palmitic–stearic acid ternary eutectic mixture retained in vermiculite was determined as 50 wt% without melted phase change material seepage from the composite phase change material. Fourier transformation infrared spectroscope and scanning electron microscope were used to characterize the structure and morphology of the prepared lauric–palmitic–stearic acid ternary eutectic mixture/vermiculite form-stable composite phase change material, and the results indicate that lauric–palmitic–stearic acid ternary eutectic mixture was well confined into the layer porous structure of vermiculite by physical reaction. The melting and freezing temperatures and latent heats were measured by differential scanning calorimeter as 31.4°C and 30.3°C, and 75.8 and 73.2 J/g, respectively. Thermal cycling test showed that there was no significant change in the thermal properties of lauric–palmitic–stearic acid ternary eutectic mixture/vermiculite form-stable composite phase change material after 1000 thermal cycles. Moreover, 2 wt% expanded graphite was added to improve the thermal conductivity of lauric–palmitic–stearic acid ternary eutectic mixture/vermiculite form-stable composite phase change material. All results indicated that the prepared lauric–palmitic–stearic acid ternary eutectic mixture/vermiculite form-stable composite phase change material had suitable thermal properties and good thermal reliability for the application of thermal energy storage in building energy efficiency.

  7. Advancement in thermal interface materials for future high-performance electronic applications. Part 1.

    Energy Technology Data Exchange (ETDEWEB)

    Jakaboski, Blake Elaine; Wong, Chung-Nin Channy; Huber, Dale L.; Rightley, Michael J.; Emerson, John Allen

    2006-02-01

    As electronic assemblies become more compact and increase in processing bandwidth, escalating thermal energy has become more difficult to manage. The major limitation has been nonmetallic joining using poor thermal interface materials (TIM). The interfacial, versus bulk, thermal conductivity of an adhesive is the major loss mechanism and normally accounts for an order magnitude loss in conductivity per equivalent thickness. The next generation TIM requires a sophisticated understanding of material and surface sciences, heat transport at submicron scales, and the manufacturing processes used in packaging of microelectronics and other target applications. Only when this relationship between bond line manufacturing processes, structure, and contact resistance is well-understood on a fundamental level will it be possible to advance the development of miniaturized microsystems. This report examines using thermal and squeeze-flow modeling as approaches to formulate TIMs incorporating nanoscience concepts. Understanding the thermal behavior of bond lines allows focus on the interfacial contact region. In addition, careful study of the thermal transport across these interfaces provides greatly augmented heat transfer paths and allows the formulation of very high resistance interfaces for total thermal isolation of circuits. For example, this will allow the integration of systems that exhibit multiple operational temperatures, such as cryogenically cooled detectors.

  8. High-temperature stable absorber coatings for linear concentrating solar thermal power plants; Hochtemperaturstabile Absorberschichten fuer linear konzentrierende solarthermische Kraftwerke

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Christina

    2009-03-23

    This work describes the development of new absorber coatings for different applications - para-bolic trough and linear Fresnel collectors - and operating conditions - absorber in vacuum or in air. The demand for higher efficiencies of solar thermal power plants using parabolic trough technology results in higher temperatures in the collectors and on the absorber tubes. As heat losses increase strongly with increasing temperatures, the need for a lower emissivity of the absorber coating at constant absorptivity arises. The linear Fresnel application envisions ab-sorber tubes stable in air at high temperatures of about 450 C, which are to date commercially not available. This work comprises the theoretical background, the modeling and the fabrication of absorber tubes including the technology transfer to a production-size inline sputter coater. In annealing tests and accompanying optical measurements, degradation processes have been observed and specified more precisely by material characterization techniques. The simulations provided the capability of different materials used as potential IR-reflector. The highest selectivity can be achieved by applying silver which consequently has been chosen for the application in absorber coatings of the parabolic trough technology. Thin silver films how-ever need to be stabilized when used at high temperatures. Appropriate barrier layers as well as process and layer parameters were identified. A high selectivity was achieved and stability of the absorber coating for 1200 h at 500 C in vacuum has been demonstrated. For the application in air, silver was also analyzed as a potential IR-reflector. Even though the stability could be increased considerably, it nevertheless proved to be insufficient. The main factors influencing stability in a positive way are the use of higher quality polishing, additional barrier layers and adequate process parameters. This knowledge was applied for developing coatings which are stable in air at

  9. To MARS and Beyond with Nuclear Power - Design Concept of Korea Advanced Nuclear Thermal Engine Rocket

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2013-05-15

    The President Park of ROK has also expressed support for space program promotion, praising the success of NARO as evidence of a positive outlook. These events hint a strong signal that ROK's space program will be accelerated by the national eager desire. In this national eager desire for space program, the policymakers and the aerospace engineers need to pay attention to the advanced nuclear technology of ROK that is set to a major world nuclear energy country, even exporting the technology. The space nuclear application is a very much attractive option because its energy density is the most enormous among available energy sources in space. This paper presents the design concept of Korea Advanced Nuclear Thermal Engine Rocket (KANuTER) that is one of the advanced nuclear thermal rocket engine developing in Korea Advanced Institute of Science and Technology (KAIST) for space application. Solar system exploration relying on CRs suffers from long trip time and high cost. In this regard, nuclear propulsion is a very attractive option for that because of higher performance and already demonstrated technology. Although ROK was a late entrant into elite global space club, its prospect as a space racer is very bright because of the national eager desire and its advanced technology. Especially it is greatly meaningful that ROK has potential capability to launch its nuclear technology into space as a global nuclear energy leader and a soaring space adventurer. In this regard, KANuTER will be a kind of bridgehead for Korean space nuclear application.

  10. Intracellular surface-enhanced Raman scattering (SERS) with thermally stable gold nanoflowers grown from Pt and Pd seeds

    KAUST Repository

    Song, HyonMin

    2013-01-01

    SERS provides great sensitivity at low concentrations of analytes. SERS combined with near infrared (NIR)-resonant gold nanomaterials are important candidates for theranostic agents due to their combined extinction properties and sensing abilities stemming from the deep penetration of laser light in the NIR region. Here, highly branched gold nanoflowers (GNFs) grown from Pd and Pt seeds are prepared and their SERS properties are studied. The growth was performed at 80°C without stirring, and this high temperature growth method is assumed to provide great shape stability of sharp tips in GNFs. We found that seed size must be large enough (>30 nm in diameter) to induce the growth of those SERS-active and thermally stable GNFs. We also found that the addition of silver nitrate (AgNO3) is important to induce sharp tip growth and shape stability. Incubation with Hela cells indicates that GNFs are taken up and reside in the cytoplasm. SERS was observed in those cells incubated with 1,10-phenanthroline (Phen)-loaded GNFs. This journal is © 2013 The Royal Society of Chemistry.

  11. Functionally gradient materials for thermal barrier coatings in advanced gas turbine systems

    Energy Technology Data Exchange (ETDEWEB)

    Banovic, S.W.; Barmak, K.; Chan, H.M. [Lehigh Univ., Bethlehem, PA (United States)] [and others

    1995-10-01

    New designs for advanced gas turbine engines for power production are required to have higher operating temperatures in order to increase efficiency. However, elevated temperatures will increase the magnitude and severity of environmental degradation of critical turbine components (e.g. combustor parts, turbine blades, etc{hor_ellipsis}). To offset this problem, the usage of thermal barrier coatings (TBCs) has become popular by allowing an increase in maximum inlet temperatures for an operating engine. Although thermal barrier technology is over thirty years old, the principle failure mechanism is the spallation of the ceramic coating at or near the ceramic/bond coat interface. Therefore, it is desirable to develop a coating that combines the thermal barrier qualities of the ceramic layer and the corrosion protection by the metallic bond coat without the detrimental effects associated with the localization of the ceramic/metal interface to a single plane.

  12. Correlation between Pd metal thickness and thermally stable perpendicular magnetic anisotropy features in [Co/Pd]n multilayers at annealing temperatures up to 500 °C

    Directory of Open Access Journals (Sweden)

    Gwang Guk An

    2015-02-01

    Full Text Available We examine highly stable perpendicular magnetic anisotropy (PMA features of [Co/Pd]10 multilayers (MLs versus Pd thickness at various ex-situ annealing temperatures. Thermally stable PMA characteristics were observed up to 500 °C, confirming the suitability of these systems for industrial applications at this temperature. Experimental observations suggest that the choice of equivalent Co and Pd layer thicknesses in a ML configuration ensures thermally stable PMA features, even at higher annealing temperatures. X-ray diffraction patterns and cross-sectional transmission electron microscopy images were obtained to determine thickness, post-annealing PMA behavior, and to explore the structural features that govern these findings.

  13. Development of an advanced thermal hydraulics model for nuclear power plant simulation

    International Nuclear Information System (INIS)

    This paper summarizes the development of an advanced digital computer thermal hydraulics model for nuclear power plant simulation. A review of thermal hydraulics code design options is presented together with a review of existing engineering models. CAE has developed an unequal temperatures-unequal velocities five equation model based on the drift flux formalism. CAE has selected the model on the basis that phase separation and thermal non-equilibrium are required to simulate complex and important phenomena occurring in systems such as reactor cooling systems (RCS) and steam generators (SG). The drift flux approach to phase separation and countercurrent flow was selected because extensive testing and validation data supports full-range drift flux parameters correlations. The five equation model was also chosen because it conserves important quantities, i.e. mass and energy of each phase, and because of numerical advantages provided by the case of coupling phasic mass conservation equations with phasic energy conservation equations. The basis of CAE's model as well as supporting models for convection and conduction heat transfer, break flow, interphase mass and heat transfer are described. Comparison of code calculations with experimental measurements taken during a small break LOCA test with the OTIS facility are presented. The use of such advanced thermal hydraulics model as plant analyzer considerably improves simulation capabilities of severe transient as well as of normal operation of two phase systems in nuclear power plants. (orig./HP)

  14. An advanced Thermal-FSI approach to flow heating/cooling

    International Nuclear Information System (INIS)

    Actually, two-way thermal-energy exchange between working fluid and solid material of a casing is a leading problem for modern – semi automatic – design techniques. Many questions should be solved, especially, the turbulent mode of thermal energy transport both in fluid and solid, should be re-examined and reformulated from the primary principles. In the present paper, a group of researchers from Energy Conversion Department of IMP PAN at Gdańsk, tries to summarise a last three-years efforts towards to mathematical modelling of advanced models of thermal energy transport. This extremely difficult problem in 'thermal-FSI' ('Fluid Solid Interaction') means that the both for solid and fluid mathematical model of a surface layer should be self-equilibrated and self-concise. Taking these requirements into account, an advanced Reynolds-Stanton analogy has been discussed and implemented. Some numerical examples concerning of the benchmarks experiments and industrial applications have also been developed and presented.

  15. Fatty acid/poly(methyl methacrylate) (PMMA) blends as form-stable phase change materials for latent heat thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Alkan, Cemil; Sari, Ahmet [Gaziosmanpasa University, Department of Chemistry, Tasliciftlik, 60240 Tokat (Turkey)

    2008-02-15

    Fatty acids such as stearic acid (SA), palmitic acid (PA), myristic acid (MA), and lauric acid (LA) are promising phase change materials (PCMs) for latent heat thermal energy storage (LHTES) applications, but high cost is the most drawback which limits the utility area of them in thermal energy storage. The use of fatty acids as form-stable PCM will increase their feasibilities in practical LHTES applications due to reduced cost of the energy storage system. In this regard, a series of fatty acid/poly(methyl methacrylate) (PMMA) blends, SA/PMMA, PA/PMMA, MA/PMMA, and LA/PMMA were prepared as new kinds of form-stable PCMs by encapsulation of fatty acids into PMMA which acts as supporting material. The blends were prepared at different mass fractions of fatty acids (50, 60, 70, 80, and 90% w/w) to reach maximum encapsulation ratio. All blends were subjected to leakage test by heating the blends over the melting temperature of the PCM. The blends that do not allow leakage of melted PCM were identified as form-stable PCMs. The form-stable fatty acid/PMMA (80/20 wt.%) blends were characterized using optic microscopy (OM), viscosimetry, and Fourier transform infrared (FT-IR) spectroscopy methods, and the results showed that the PMMA was compatible with the fatty acids. In addition, thermal characteristics such as melting and freezing temperatures and latent heats of the form-stable PCMs were measured by using differential scanning calorimetry (DSC) technique and indicated that they had good thermal properties. On the basis of all results, it was concluded that form-stable fatty acid/PMMA blends had important potential for some practical LHTES applications such as under floor space heating of buildings and passive solar space heating of buildings by using wallboard, plasterboard or floor impregnated with a form-stable PCM due to their satisfying thermal properties, easily preparing in desired dimensions, direct usability without needing an add encapsulation and

  16. Fatty acid eutectic/polymethyl methacrylate composite as form-stable phase change material for thermal energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lijiu; Meng, Duo [School of Civil Engineering, Dalian University of Technology, Dalian 116024 (China)

    2010-08-15

    This work is focused on the preparation and characterization of fatty acid eutectic/polymethyl methacrylate (PMMA) form-stable phase change material (PCM). Capric acid (CA), lauric acid (LA), myristic acid (MA) and stearic acid (SA) were selected to prepare binary fatty acid eutectic for the sake of decreasing the phase change temperature. Using the method of self-polymerization, CA-LA, CA-MA, CA-SA and LA-MA eutectics acting as the heat-absorbing materials and PMMA serving as the supporting material were compounded in the ratio of 50/50 wt.%. The relations between mass fraction of LA-MA eutectic and latent heat and compressive strength of LA-MA/PMMA composite were discussed, and the feasible maximum mass fraction of LA-MA eutectic was determined to be 70%. CA-LA/PMMA, CA-MA/PMMA, CA-SA/PMMA and LA-MA/PMMA composites were examined to investigate their potential application in building energy conservation. Scanning electron microscope and polarizing optical microscope observations showed that fatty acid eutectic was coated by PMMA thus the composite remained solid when the sample was heated above the melted point of the fatty acid. Fourier-transform infrared results indicated that fatty acid and PMMA had no chemical reaction and exhibited good compatibility with each other. According to the differential scanning calorimetry results, phase change temperatures of CA-LA/PMMA, CA-MA/PMMA, CA-SA/PMMA and LA-MA/PMMA composites were 21.11 C, 25.16 C, 26.38 C and 34.81 C and their latent heat values were determined to be 76.3 kJ/kg, 69.32 kJ/kg, 59.29 kJ/kg and 80.75 kJ/kg, respectively. Moreover, thermal stability and expansibility of the form-stable PCMs were characterized by thermogravimetric analysis and volume expansion coefficient respectively, and the results indicated that the composites were available for building energy conservation. (author)

  17. High-temperature thermal storage systems for advanced solar receivers materials selections

    Science.gov (United States)

    Wilson, D. F.; Devan, J. H.; Howell, M.

    1990-01-01

    Advanced space power systems that use solar energy and Brayton or Stirling heat engines require thermal energy storage (TES) systems to operate continuously through periods of shade. The receiver storage units, key elements in both Brayton and Stirling systems, are designed to use the latent heat of fusion of phase-change materials (PCMs). The power systems under current consideration for near-future National Aeronautics and Space Administration space missions require working fluid temperatures in the 1100 to 1400 K range. The PCMs under current investigation that gave liquid temperatures within this range are the fluoride family of salts. However, these salts have low thermal conductivity, which causes large temperature gradients in the storage systems. Improvements can be obtained, however, with the use of thermal conductivity enhancements or metallic PCMs. In fact, if suitable containment materials can be found, the use of metallic PCMs would virtually eliminate the orbit associated temperature variations in TES systems. The high thermal conductivity and generally low volume change on melting of germanium and alloys based on silicon make them attractive for storage of thermal energy in space power systems. An approach to solving the containment problem, involving both chemical and physical compatibility, preparation of NiSi/NiSi2, and initial results for containment of germanium and NiSi/NiSi2, are presented.

  18. Thermally stable voltage-controlled perpendicular magnetic anisotropy in Mo|CoFeB|MgO structures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang, E-mail: xiang.li@ucla.edu; Yu, Guoqiang; Wong, Kin; Upadhyaya, Pramey; Akyol, Mustafa; Wang, Kang L., E-mail: wang@seas.ucla.edu [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Wu, Hao; Han, Xiufeng [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Ong, P. V.; Kioussis, Nicholas [Department of Physics and Astronomy, California State University Northridge, Northridge, California 91330 (United States); Hu, Qi; Ebrahimi, Farbod [Inston Inc., Los Angeles, California 90095 (United States); Khalili Amiri, Pedram, E-mail: pedramk@ucla.edu [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Inston Inc., Los Angeles, California 90095 (United States)

    2015-10-05

    We study voltage-controlled magnetic anisotropy (VCMA) and other magnetic properties in annealed Mo|CoFeB|MgO layered structures. The interfacial perpendicular magnetic anisotropy (PMA) is observed to increase with annealing over the studied temperature range, and a VCMA coefficient of about 40 fJ/V-m is sustained after annealing at temperatures as high as 430 °C. Ab initio electronic structure calculations of interfacial PMA as a function of strain further show that strain relaxation may lead to the increase of interfacial PMA at higher annealing temperatures. Measurements also show that there is no significant VCMA and interfacial PMA dependence on the CoFeB thickness over the studied range, which illustrates the interfacial origin of the anisotropy and its voltage dependence, i.e., the VCMA effect. The high thermal annealing stability of Mo|CoFeB|MgO structures makes them compatible with advanced CMOS back-end-of-line processes, and will be important for integration of magnetoelectric random access memory into on-chip embedded applications.

  19. Thermally stable voltage-controlled perpendicular magnetic anisotropy in Mo|CoFeB|MgO structures

    International Nuclear Information System (INIS)

    We study voltage-controlled magnetic anisotropy (VCMA) and other magnetic properties in annealed Mo|CoFeB|MgO layered structures. The interfacial perpendicular magnetic anisotropy (PMA) is observed to increase with annealing over the studied temperature range, and a VCMA coefficient of about 40 fJ/V-m is sustained after annealing at temperatures as high as 430 °C. Ab initio electronic structure calculations of interfacial PMA as a function of strain further show that strain relaxation may lead to the increase of interfacial PMA at higher annealing temperatures. Measurements also show that there is no significant VCMA and interfacial PMA dependence on the CoFeB thickness over the studied range, which illustrates the interfacial origin of the anisotropy and its voltage dependence, i.e., the VCMA effect. The high thermal annealing stability of Mo|CoFeB|MgO structures makes them compatible with advanced CMOS back-end-of-line processes, and will be important for integration of magnetoelectric random access memory into on-chip embedded applications

  20. Advanced thermal barrier coatings for operation in high hydrogen content fueled gas turbines.

    Energy Technology Data Exchange (ETDEWEB)

    Sampath, Sanjay [Stony Brook Univ., NY (United States)

    2015-04-02

    The Center for Thermal Spray Research (CTSR) at Stony Brook University in partnership with its industrial Consortium for Thermal Spray Technology is investigating science and technology related to advanced metallic alloy bond coats and ceramic thermal barrier coatings for applications in the hot section of gasified coal-based high hydrogen turbine power systems. In conjunction with our OEM partners (GE and Siemens) and through strategic partnership with Oak Ridge National Laboratory (ORNL) (materials degradation group and high temperature materials laboratory), a systems approach, considering all components of the TBC (multilayer ceramic top coat, metallic bond coat & superalloy substrate) is being taken during multi-layered coating design, process development and subsequent environmental testing. Recent advances in process science and advanced in situ thermal spray coating property measurement enabled within CTSR has been incorporated for full-field enhancement of coating and process reliability. The development of bond coat processing during this program explored various aspects of processing and microstructure and linked them to performance. The determination of the bond coat material was carried out during the initial stages of the program. Based on tests conducted both at Stony Brook University as well as those carried out at ORNL it was determined that the NiCoCrAlYHfSi (Amdry) bond coats had considerable benefits over NiCoCrAlY bond coats. Since the studies were also conducted at different cycling frequencies, thereby addressing an associated need for performance under different loading conditions, the Amdry bond coat was selected as the material of choice going forward in the program. With initial investigations focused on the fabrication of HVOF bond coats and the performance of TBC under furnace cycle tests , several processing strategies were developed. Two-layered HVOF bond coats were developed to render optimal balance of density and surface roughness

  1. Evaluation of Advanced Stirling Convertor Net Heat Input Correlation Methods Using a Thermal Standard

    Science.gov (United States)

    Briggs, Maxwell H.; Schifer, Nicholas A.

    2012-01-01

    The U.S. Department of Energy (DOE) and Lockheed Martin Space Systems Company (LMSSC) have been developing the Advanced Stirling Radioisotope Generator (ASRG) for use as a power system for space science missions. This generator would use two high-efficiency Advanced Stirling Convertors (ASCs), developed by Sunpower Inc. and NASA Glenn Research Center (GRC). The ASCs convert thermal energy from a radioisotope heat source into electricity. As part of ground testing of these ASCs, different operating conditions are used to simulate expected mission conditions. These conditions require achieving a particular operating frequency, hot end and cold end temperatures, and specified electrical power output for a given net heat input. In an effort to improve net heat input predictions, numerous tasks have been performed which provided a more accurate value for net heat input into the ASCs, including testing validation hardware, known as the Thermal Standard, to provide a direct comparison to numerical and empirical models used to predict convertor net heat input. This validation hardware provided a comparison for scrutinizing and improving empirical correlations and numerical models of ASC-E2 net heat input. This hardware simulated the characteristics of an ASC-E2 convertor in both an operating and non-operating mode. This paper describes the Thermal Standard testing and the conclusions of the validation effort applied to the empirical correlation methods used by the Radioisotope Power System (RPS) team at NASA Glenn.

  2. Method for net decrease of hazardous radioactive nuclear waste materials. [Thermal neutron irradiation of long-lived radionuclides to produce stable nuclides and short-lived radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, R.; Henyey, F.S.; Hochstim, A.R.

    1988-01-26

    A method of decreasing the amount of relatively long lived fission products in radioactive waste materials in excess of that due to their natural radioactive decay by producing relatively short lived radioactive nuclides and stable nuclides from the relatively long lived fission products is described comprising the steps of: (a) separating the fission products into at least (1) physically separate groups, and (2) relatively short lived fission product radioactive nuclides and stable nuclides; (b) storing the relatively short lived radioactive nuclides and stable nuclides; (c) exposing at least the groups containing Kr/sup 85/, Sr/sup 90/, Zr/sup 93/, Tc/sup 99/, Pd/sup 107/, I/sup 129/, Cs/sup 135/, Sm/sup 151/ + Eu, and actinides, to a high thermal neutron flux for separate, different predetermined periods of time selected in accordance with the long lived fission product nuclide in the corresponding group for inducing predetermined transformations of the relatively long lived fission product nuclides to produce relatively short lived radioactive nuclides and stable nuclides; (d) removing each exposed group containing the produced relatively short lived radioactive nuclides and stable nuclides from the high thermal neutron flux; (e) separating the removed group into (1) the produced short lived radioactive nuclides and stable nuclides, and (2) a plurality of further groups having long lived fission product nuclides respectively corresponding to at least some of the long lived fission product nuclides or the groups of step (a); (f) storing the produced short lived radioactive nuclides and stable nuclides; (g) joining at least one of the further groups to at least one of the groups of step (a) having a corresponding long lived fission product nuclide.

  3. Thermal and mechanical properties of advanced impregnation materials for HTS cables and coils

    Science.gov (United States)

    Bagrets, N.; Otten, S.; Weiss, K.-P.; Kario, A.; Goldacker, W.

    2015-12-01

    In the growing field of high-temperature superconducting (HTS) applications, finding an appropriate impregnation material for cables and coils remains a challenging task. In HTS cables and coils, tapes have to be able to withstand mechanical loads during operation. Impregnation is playing a role as mechanical stabilization. However, material properties usually change significantly when going to low temperatures which can decrease performance of superconducting devices. For example, a large mismatch in thermal expansion between a conductor and impregnation material at low temperatures can lead to delamination and to degradation of the critical current. Impregnation materials can insulate tapes thermally which can lead to damage of the superconducting device in case of quench. Thus, thermal conductivity is an important property which is responsible for the temperature distribution in a superconducting cable or in a coil. Due to Lorentz forces acting on structural materials in a superconducting device, the mechanical properties of these materials should be investigated at operating temperatures of this device. Therefore, it is important to identify an advanced impregnation material meeting all specific requirements. In this paper, thermal and mechanical properties of impregnation material candidates with added fillers are presented in a temperature range from 300 K to 4 K.

  4. Diffusion, Thermal Properties and Chemical Compatibilities of Select MAX Phases with Materials For Advanced Nuclear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Barsoum, Michel [Drexel Univ., Philadelphia, PA (United States); Bentzel, Grady [Drexel Univ., Philadelphia, PA (United States); Tallman, Darin J. [Drexel Univ., Philadelphia, PA (United States); Sindelar, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcia-Diaz, Brenda [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hoffman, Elizabeth [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-04

    The demands of Gen IV nuclear power plants for long service life under neutron irradiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ ºC) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the chemical compatibility of select MAX with potential materials that are important for nuclear energy, as well as to measure the thermal transport properties as a function of neutron irradiation. The chemical counterparts chosen for this work are: pyrolytic carbon, SiC, U, Pd, FLiBe, Pb-Bi and Na, the latter 3 in the molten state. The thermal conductivities and heat capacities of non-irradiated MAX phases will be measured.

  5. Advanced interface heat exchangers for the Space Station main thermal bus

    Science.gov (United States)

    Valenzuela, Javier A.

    1990-01-01

    Future evolution and growth of the Space Station will place increasing demands on the thermal management system by the addition of new payloads and from increased activity in the habitat modules. To meet this need, Creare is developing advanced evaporators, condensors, and single-phase heat exchangers for operation in microgravity. The objective is to achieve a several-fold increase in the heat flux capability of these components, while operating at the same temperature difference as specified for the present interface heat exchangers. Two prototype interface heat exchangers are presently being developed: one to interface the main thermal bus to a payload two-phase ammonia bus, and the other, to interface with the crew module single-phase water loop. The results achieved to date in the development of these heat exchangers are reviewed.

  6. Diffusion, Thermal Properties and Chemical Compatibilities of Select MAX Phases with Materials For Advanced Nuclear Systems

    Energy Technology Data Exchange (ETDEWEB)

    Barsoum, Michel [Drexel Univ., Philadelphia, PA (United States); Bentzel, Grady [Drexel Univ., Philadelphia, PA (United States); Tallman, Darin J. [Drexel Univ., Philadelphia, PA (United States); Sindelar, Robert [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Garcia-Diaz, Brenda [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Hoffman, Elizabeth [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-04-04

    The demands of Gen IV nuclear power plants for long service life under neutron irradiation at high temperature are severe. Advanced materials that would withstand high temperatures (up to 1000+ ºC) to high doses in a neutron field would be ideal for reactor internal structures and would add to the long service life and reliability of the reactors. The objective of this work is to investigate the chemical compatibility of select MAX with potential materials that are important for nuclear energy, as well as, to measure the thermal transport properties as a function of neutron irradiation. The chemical counterparts chosen for this work are: pyrolytic carbon, SiC, U, Pd, FLiBe, Pb-Bi and Na; the latter 3 in the molten state. The thermal conductivities and heat capacities of non-irradiated MAX phases will be measured.

  7. Improvement of environmental aspects of thermal power plant operation by advanced control concepts

    Directory of Open Access Journals (Sweden)

    Mikulandrić Robert

    2012-01-01

    Full Text Available The necessity of the reduction of greenhouse gas emissions, as formulated in the Kyoto Protocol, imposes the need for improving environmental aspects of existing thermal power plants operation. Improvements can be reached either by efficiency increment or by implementation of emission reduction measures. Investments in refurbishment of existing plant components or in plant upgrading by flue gas desulphurization, by primary and secondary measures of nitrogen oxides reduction, or by biomass co-firing, are usually accompanied by modernisation of thermal power plant instrumentation and control system including sensors, equipment diagnostics and advanced controls. Impact of advanced control solutions implementation depends on technical characteristics and status of existing instrumentation and control systems as well as on design characteristics and actual conditions of installed plant components. Evaluation of adequacy of implementation of advanced control concepts is especially important in Western Balkan region where thermal power plants portfolio is rather diversified in terms of size, type and commissioning year and where generally poor maintenance and lack of investments in power generation sector resulted in high greenhouse gases emissions and low efficiency of plants in operation. This paper is intended to present possibilities of implementation of advanced control concepts, and particularly those based on artificial intelligence, in selected thermal power plants in order to increase plant efficiency and to lower pollutants emissions and to comply with environmental quality standards prescribed in large combustion plant directive. [Acknowledgements. This paper has been created within WBalkICT - Supporting Common RTD actions in WBCs for developing Low Cost and Low Risk ICT based solutions for TPPs Energy Efficiency increasing, SEE-ERA.NET plus project in cooperation among partners from IPA SA - Romania, University of Zagreb - Croatia and Vinca

  8. Advanced storage concepts for solar thermal systems in low energy buildings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Furbo, S.; Andersen, Elsa; Schultz, Joergen M.

    2006-04-07

    The aim of Task 32 is to develop new and advanced heat storage systems which are economic and technical suitable as long-term heat storage systems for solar heating plants with a high degree of coverage. The project is international and Denmark's participation has focused on Subtask A, C, and D. In Subtask A Denmark has contributed to a status report about heat storage systems. In Subtask C Denmark has focused on liquid thermal storage tanks based on NaCH{sub 3}COO?3H{sub 2}O with a melting point of 58 deg. C. Theoretical and experimental tests have been conducted in order to establish optimum conditions for storage design. In Subtask D theoretical and experimental tests of optimum designs for advanced water tanks for solar heating plants for combined space heating and domestic hot water have been conducted. (BA)

  9. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2001-05-08

    The project involves using advanced reservoir characterization and thermal production technologies to improve thermal recovery techniques and lower operating and capital costs in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., CA. Through March 2001, project work has been completed on the following activities: data preparation; basic reservoir engineering; developing a deterministic three dimensional (3-D) geologic model, a 3-D deterministic reservoir simulation model and a rock-log model; well drilling and completions; and surface facilities on the Fault Block II-A Tar Zone (Tar II-A). Work is continuing on research to understand the geochemistry and process regarding the sand consolidation well completion technique, final reservoir tracer work, operational work and research studies to prevent thermal-related formation compaction in the Tar II-A steamflood area, and operational work on the Tar V steamflood pilot and Tar II-A post-steamflood projects. The project team spent the Second Quarter 2001 performing well work and reservoir surveillance on the Tar II-A post-steamflood project. The Tar II-A steamflood reservoirs have been operated over fifteen months at relatively stable pressures, due in large part to the bimonthly pressure monitoring program enacted at the start of the post-steamflood phase in January 1999. Starting in the Fourth Quarter 2000, the project team has ramped up activity to increase production and injection. This work will continue through 2001 as described in the Operational Management section. Expanding thermal recovery operations to other sections of the Wilmington Oil Field, including the Tar V horizontal well pilot steamflood project, is a critical part of the City of Long Beach and Tidelands Oil Production Company's development strategy for the field. The current steamflood operations in the Tar V pilot are economical, but recent performance is below projections because of wellbore mechanical

  10. The preparation of high performance polymers for composites and blends : A) thermally stable ion containing polymers B) epoxy and hydroxy functional polyolefin macromers

    OpenAIRE

    Facinelli, John Victor

    1996-01-01

    In this dissertation, two approaches were taken to design aqueous dispersable or soluble high performance ion containing polymers to be used as composite system interfacial modifiers and processing aids. In the first approach, thermally stable pyridine containing poly(ary/ene ether)s were designed which could be ionized by protonation in acidic aqueous media. A novel pyridine containing bisphenol monomer, 2,6-(p-hydroxyphenoxy)pyridine, was synthesized and utilized as a mono...

  11. Advanced thermal-hydraulic and neutronic codes: current and future applications. Summary and conclusions

    International Nuclear Information System (INIS)

    An OECD Workshop on Advanced Thermal-Hydraulic and Neutronic Codes Applications was held from 10 to 13 April 2000, in Barcelona, Spain, sponsored by the Committee on the Safety of Nuclear Installations (CSNI) of the OECD Nuclear Energy Agency (NEA). It was organised in collaboration with the Spanish Nuclear Safety Council (CSN) and hosted by CSN and the Polytechnic University of Catalonia (UPC) in collaboration with the Spanish Electricity Association (UNESA). The objectives of the Workshop were to review the developments since the previous CSNI Workshop held in Annapolis [NEA/CSNI/ R(97)4; NUREG/CP-0159], to analyse the present status of maturity and remnant needs of thermal-hydraulic (TH) and neutronic system codes and methods, and finally to evaluate the role of these tools in the evolving regulatory environment. The Technical Sessions and Discussion Sessions covered the following topics: - Regulatory requirements for Best-Estimate (BE) code assessment; - Application of TH and neutronic codes for current safety issues; - Uncertainty analysis; - Needs for integral plant transient and accident analysis; - Simulators and fast running codes; - Advances in next generation TH and neutronic codes; - Future trends in physical modeling; - Long term plans for development of advanced codes. The focus of the Workshop was on system codes. An incursion was made, however, in the new field of applying Computational Fluid Dynamic (CFD) codes to nuclear safety analysis. As a general conclusion, the Barcelona Workshop can be considered representative of the progress towards the targets marked at Annapolis almost four years ago. The Annapolis Workshop had identified areas where further development and specific improvements were needed, among them: multi-field models, transport of interfacial area, 2D and 3D thermal-hydraulics, 3-D neutronics consistent with level of details of thermal-hydraulics. Recommendations issued at Annapolis included: developing small pilot/test codes for

  12. Proceedings of the workshop on advanced thermal-hydraulic and neutronic codes: current and future applications

    International Nuclear Information System (INIS)

    An OECD Workshop on Advanced Thermal-Hydraulic and Neutronic Codes Applications was held from 10 to 13 April 2000, in Barcelona, Spain, sponsored by the Committee on the Safety of Nuclear Installations (CSNI) of the OECD Nuclear Energy Agency (NEA). It was organised in collaboration with the Spanish Nuclear Safety Council (CSN) and hosted by CSN and the Polytechnic University of Catalonia (UPC) in collaboration with the Spanish Electricity Association (UNESA). The objectives of the Workshop were to review the developments since the previous CSNI Workshop held in Annapolis [NEA/CSNI/ R(97)4; NUREG/CP-0159], to analyse the present status of maturity and remnant needs of thermal-hydraulic (TH) and neutronic system codes and methods, and finally to evaluate the role of these tools in the evolving regulatory environment. The Technical Sessions and Discussion Sessions covered the following topics: - Regulatory requirements for Best-Estimate (BE) code assessment; - Application of TH and neutronic codes for current safety issues; - Uncertainty analysis; - Needs for integral plant transient and accident analysis; - Simulators and fast running codes; - Advances in next generation TH and neutronic codes; - Future trends in physical modeling; - Long term plans for development of advanced codes. The focus of the Workshop was on system codes. An incursion was made, however, in the new field of applying Computational Fluid Dynamic (CFD) codes to nuclear safety analysis. As a general conclusion, the Barcelona Workshop can be considered representative of the progress towards the targets marked at Annapolis almost four years ago. The Annapolis Workshop had identified areas where further development and specific improvements were needed, among them: multi-field models, transport of interfacial area, 2D and 3D thermal-hydraulics, 3-D neutronics consistent with level of details of thermal-hydraulics. Recommendations issued at Annapolis included: developing small pilot/test codes for

  13. Steady-state thermal-hydraulic design analysis of the Advanced Neutron Source reactor

    International Nuclear Information System (INIS)

    The Advanced Neutron Source (ANS) is a research reactor that is planned for construction at Oak Ridge National Laboratory. This reactor will be a user facility with the major objective of providing the highest continuous neutron beam intensities of any reactor in the world. Additional objectives for the facility include providing materials irradiation facilities and isotope production facilities as good as, or better than, those in the High Flux Isotope Reactor. To achieve these objectives, the reactor design uses highly subcooled heavy water as both coolant and moderator. Two separate core halves of 67.6-L total volume operate at an average power density of 4.5 MW(t)/L, and the coolant flows upward through the core at 25 m/s. Operating pressure is 3.1 MPa at the core inlet with a 1.4-MPa pressure drop through the core region. Finally, in order to make the resources available for experimentation, the fuel is designed to provide a 17-d fuel cycle with an additional 4 d planned in each cycle for the refueling process. This report examines the codes and models used to develop the thermal-hydraulic design for ANS, as well as the correlations and physical data; evaluates thermal-hydraulic uncertainties; reports on thermal-hydraulic design and safety analysis; describes experimentation in support of the ANS reactor design and safety analysis; and provides an overview of the experimental plan

  14. Transformation Laplacian metamaterials: recent advances in manipulating thermal and dc fields

    Science.gov (United States)

    Han, Tiancheng; Qiu, Cheng-Wei

    2016-04-01

    The full control of single or even multiple physical fields has attracted intensive research attention in the past decade, thanks to the development of metamaterials and transformation optics. Significant progress has been made in vector fields (e.g., optics, electromagnetics, and acoustics), leading to a host of strikingly functional metamaterials, such as invisibility cloaks, illusion devices, concentrators, and rotators. However, metamaterials in vector fields, designed through coordinate transformation of Maxwell’s equations, usually require extreme parameters and impose challenges on the actual realization. In this context, metamaterials in scalar fields (e.g., thermal and dc fields), which are mostly governed by the Laplace equation, lead to more plausible and facile implementations, since there are native insulators and excellent conductors (serving as two extreme cases). This paper therefore is particularly dedicated to reviewing the most recent advances in Laplacian metamaterials in manipulating thermal (both transient and steady states) and dc fields, separately and (or) simultaneously. We focus on the theory, design, and realization of thermal/dc functional metamaterials that can be used to control heat flux and electric current at will. We also provide an outlook toward the challenges and future directions in this fascinating area.

  15. Thermal-hydraulic studies of the Advanced Neutron Source cold source

    International Nuclear Information System (INIS)

    The Advanced Neutron Source (ANS), in its conceptual design phase at Oak Ridge National Laboratory, was to be a user-oriented neutron research facility producing the most intense steady-state flux of thermal and cold neutrons in the world. Among its many scientific applications, the production of cold neutrons was a significant research mission for the ANS. The cold neutrons come from two independent cold sources positioned near the reactor core. Contained by an aluminum alloy vessel, each cold source is a 410-mm-diam sphere of liquid deuterium that functions both as a neutron moderator and a cryogenic coolant. With nuclear heating of the containment vessel and internal baffling, steady-state operation requires close control of the liquid deuterium flow near the vessel's inner surface. Preliminary thermal-hydraulic analyses supporting the cold source design were performed with heat conduction simulations of the vessel walls and multidimensional computational fluid dynamics simulations of the liquid deuterium flow and heat transfer. This report presents the starting phase of a challenging program and describes the cold source conceptual design, the thermal-hydraulic feasibility studies of the containment vessel, and the future computational and experimental studies that were planned to verify the final design

  16. Hafnia-Based Nanostructured Thermal Barrier Coatings for Advanced Hydrogen Turbine Technology

    Energy Technology Data Exchange (ETDEWEB)

    Ramana, Chintalapalle; Choudhuri, Ahsan

    2013-01-31

    Thermal barrier coatings (TBCs) are critical technologies for future gas turbine engines of advanced coal based power generation systems. TBCs protect engine components and allow further increase in engine temperatures for higher efficiency. In this work, nanostructured HfO{sub 2}-based coatings, namely Y{sub 2}O{sub 3}-stabilized HfO{sub 2} (YSH), Gd{sub 2}O{sub 3}-stabilized HfO{sub 2} (GSH) and Y{sub 2}O{sub 3}-stabilized ZrO{sub 2}-HfO{sub 2} (YSZH) were investigated for potential TBC applications in hydrogen turbines. Experimental efforts are aimed at creating a fundamental understanding of these TBC materials. Nanostructured ceramic coatings of YSH, GSH and YSZH were grown by physical vapor deposition methods. The effects of processing parameters and ceramic composition on the microstructural evolution of YSH, GSH and YSZH nanostructured coatings was studied using combined X-ray diffraction (XRD) and Electron microscopy analyses. Efforts were directed to derive a detailed understanding of crystal-structure, morphology, and stability of the coatings. In addition, thermal conductivity as a function of composition in YSH, YSZH and GSH coatings was determined. Laboratory experiments using accelerated test environments were used to investigate the relative importance of various thermo-mechanical and thermo-chemical failure modes of TBCs. Effects of thermal cycling, oxidation and their complex interactions were evaluated using a syngas combustor rig.

  17. Thermal-hydraulics numerical analyses of Pebble Bed Advanced High Temperature Reactor hot channel

    International Nuclear Information System (INIS)

    Background: The thermal hydraulics behavior of the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) hot channel was studied. Purpose: We aim to analyze the thermal-hydraulics behavior of the PB-AHTR, such as pressure drop, temperature distribution of coolant and pebble bed as well as thermal removal capacity in the condition of loss of partial coolant. Methods: We used a modified FLUENT code which was coupled with a local non-equilibrium porous media model by introducing a User Defined Scalar (UDS) in the calculation domain of the reactor core and subjoining different resistance terms (Ergun and KTA) to calculate the temperature of coolant, solid phase of pebble bed and pebble center in the core. Results: Computational results showed that the resistance factor has great influence on pressure drop and velocity distribution, but less impact on the temperature of coolant, solid phase of pebble bed and pebble center. We also confirmed the heat removal capacity of the PB-AHTR in the condition of nominal and loss of partial coolant conditions. Conclusion: The numerical analyses results can provide a useful proposal to optimize the design of PB-AHTR. (authors)

  18. Update to advanced neutron source steady-state thermal-hydraulic report

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, G.L.; Carbajo, J.J.; Morris, D.G.; Nelson, W.R.

    1996-05-01

    This report is intended to be a supplement to ORNL/TM-12398, Steady-State Thermal-Hydraulic Design Analysis of the Advanced Neutron Source Reactor. It updates the core thermal-hydrualic design to the latest three-element configuration and also provides the most recent information on the thermal-hydraulic statistical uncertainty analysis. In addition, it includes calculations of beam tube cooling and control rod lift forces, which were not addressed in the initial report. This report describes work that is a snapshot in time as it stood at the end of the project. The three-element core calculations include a description of changes made to the overall coolant system; however, most of the analysis is focused on fuel loading thermal-hydraulic calculations. This analysis uses updated uncertainty values and indicates that a two-dimensional fuel grading in the three-element core would still be necessary to meet the desired operating and safety criteria. Analysis of cooling in the reflector tank examines various cooling options for the reflector tank components. This work investigated multiple forced convection designs as well as natural convection cooling requirements. Lift forces on the inner control rods caused by the upward coolant flow were also examined. Initial control rod designs were such that a sheared control rod would tend to lift because of flow forces. Design changes were recommended that would eliminate this issue. They included geometry changes to the inner control rod cooling channels, changes to the orificing in the central hole region, and reduction of inner control rod coolant velocity.

  19. Design and Performance Optimizations of Advanced Erosion-Resistant Low Conductivity Thermal Barrier Coatings for Rotorcraft Engines

    Science.gov (United States)

    Zhu, Dongming; Miller, Robert A.; Kuczmarski, Maria A.

    2012-01-01

    Thermal barrier coatings will be more aggressively designed to protect gas turbine engine hot-section components in order to meet future rotorcraft engine higher fuel efficiency and lower emission goals. For thermal barrier coatings designed for rotorcraft turbine airfoil applications, further improved erosion and impact resistance are crucial for engine performance and durability, because the rotorcraft are often operated in the most severe sand erosive environments. Advanced low thermal conductivity and erosion-resistant thermal barrier coatings are being developed, with the current emphasis being placed on thermal barrier coating toughness improvements using multicomponent alloying and processing optimization approaches. The performance of the advanced thermal barrier coatings has been evaluated in a high temperature erosion burner rig and a laser heat-flux rig to simulate engine erosion and thermal gradient environments. The results have shown that the coating composition and architecture optimizations can effectively improve the erosion and impact resistance of the coating systems, while maintaining low thermal conductivity and cyclic oxidation durability

  20. Development of a steady thermal-hydraulic analysis code for the China Advanced Research Reactor

    Institute of Scientific and Technical Information of China (English)

    TIAN Wenxi; QIU Suizheng; GUO Yun; SU Guanghui; JIA Dounan; LIU Tiancai; ZHANG Jianwei

    2007-01-01

    A multi-channel model steady-state thermalhydraulic analysis code was developed for the China Advanced Research Reactor (CARR). By simulating the whole reactor core, the detailed mass flow distribution in the core was obtained. The result shows that structure size plays the most important role in mass flow distribution, and the influence of core power could be neglected under singlephase flow. The temperature field of the fuel element under unsymmetrical cooling condition was also obtained, which is necessary for further study such as stress analysis, etc. Of the fuel element. At the same time, considering the hot channel effect including engineering factor and nuclear factor, calculation of the mean and hot channel was carried out and it is proved that all thermal-hydraulic parameters satisfy the "Safety design regulation of CARR".

  1. Audio-band Coating Thermal Noise Measurement for Advanced LIGO with a Multi-mode Optical Resonator

    CERN Document Server

    Gras, S; Yam, W; Martynov, D; Evans, M

    2016-01-01

    In modern high precision optical instruments, such as in gravitational wave detectors or frequency references, thermally induced fluctuations in the reflective coatings can be a limiting noise source. This noise, known as coating thermal noise, can be reduced by choosing materials with low mechanical loss. Examination of new materials becomes a necessity in order to further minimize the coating thermal noise and thus improve sensitivity of next generation instruments. We present a novel approach to directly measure coating thermal noise using a high finesse folded cavity in which multiple Hermite-Gaussian modes co-resonate. This method is used to probe surface fluctuations on the order 10^-17 m\\rtHz in the frequency range 30-400 Hz. We applied this technique to measure thermal noise and loss angle of the coating used in Advanced LIGO.

  2. Predictions of thermal expansion coefficients of rare-earth zirconate pyrochlores: A quasi-harmonic approximation based on stable phonon modes

    Science.gov (United States)

    Lan, Guoqiang; Ouyang, Bin; Xu, Yushuai; Song, Jun; Jiang, Yong

    2016-06-01

    Rare-earth (RE) pyrochlores are considered as promising candidate materials for the thermal barrier coating. In this study, we performed first-principles calculations, augmented by quasi-harmonic phonon calculations, to investigate the thermal expansion behaviors of several RE2Zr2O7 (RE = La, Nd, Sm, Gd) pyrochlores. Our findings show that RE2Zr2O7 pyrochlores exhibit low-lying optical phonon frequencies that correspond to RE-cation rattling vibrational modes. These frequencies become imaginary upon volume expansion, preventing correct determination of the free energy versus volume relation and thereby quantification of thermal expansion using QH phonon calculations. To address this challenge, we proposed a QH approximation approach based on stable phonon modes where the RE-cation rattling modes were systematically eliminated. This approach is shown to provide accurate predictions of the coefficients of thermal expansion (CTEs) of RE2Zr2O7 pyrochlores, in good agreement with experimental measurements and data from first-principles molecular dynamics simulations. In addition, we showed that the QH Debye model considerably overestimates the magnitudes and wrongly predicts the trend for the CTEs of RE2Zr2O7 pyrochlores.

  3. Advanced neutron source reactor thermal-hydraulic test loop facility description

    Energy Technology Data Exchange (ETDEWEB)

    Felde, D.K.; Farquharson, G.; Hardy, J.H.; King, J.F.; McFee, M.T.; Montgomery, B.H.; Pawel, R.E.; Power, B.H.; Shourbaji, A.A.; Siman-Tov, M.; Wood, R.J.; Yoder, G.L.

    1994-02-01

    The Thermal-Hydraulic Test Loop (THTL) is a facility for experiments constructed to support the development of the Advanced Neutron Source Reactor (ANSR) at Oak Ridge National Laboratory. The ANSR is both cooled and moderated by heavy water and uses uranium silicide fuel. The core is composed of two coaxial fuel-element annuli, each of different diameter. There are 684 parallel aluminum-clad fuel plates (252 in the inner-lower core and 432 in the outer-upper core) arranged in an involute geometry that effectively creates an array of thin rectangular flow channels. Both the fuel plates and the coolant channels are 1.27 mm thick, with a span of 87 mm (lower core), 70 mm (upper core), and 507-mm heated length. The coolant flows vertically upwards at a mass flux of 27 Mg/m{sup 2}s (inlet velocity of 25 m/s) with an inlet temperature of 45{degrees}C and inlet pressure of 3.2 MPa. The average and peak heat fluxes are approximately 6 and 12 MW/m{sup 2}, respectively. The availability of experimental data for both flow excursion (FE) and true critical heat flux (CHF) at the conditions applicable to the ANSR is very limited. The THTL was designed and built to simulate a full-length coolant subchannel of the core, allowing experimental determination of thermal limits under the expected ANSR thermal-hydraulic conditions. For these experimental studies, the involute-shaped fuel plates of the ANSR core with the narrow 1.27-mm flow gap are represented by a narrow rectangular channel. Tests in the THTL will provide both single- and two-phase thermal-hydraulic information. The specific phenomena that are to be examined are (1) single-phase heat-transfer coefficients and friction factors, (2) the point of incipient boiling, (3) nucleate boiling heat-transfer coefficients, (4) two-phase pressure-drop characteristics in the nucleate boiling regime, (5) flow instability limits, and (6) CHF limits.

  4. Carbohydrates and thermal properties indicate a decrease in stable aggregate carbon following forest colonization of mountain grassland

    DEFF Research Database (Denmark)

    Guidi, Claudia; Cannella, David; Leifeld, Jens;

    2015-01-01

    was to investigate changes in the content and origin of soil C components involved into aggregate stabilization (i.e. carbohydrates) following forest expansion on abandoned grassland in the Alps, where only few studies have been conducted. Changes in carbohydrates and thermally labile C were assessed along a land......In mountainous areas of Europe, the abandonment of grasslands followed by forest expansion is the dominant land-use change. Labile (i.e. easily decomposable) litter represents the major source for soil microbial products, which promote soil aggregation and long-term C stabilization. Our objective...... of carbohydrate and thermal analyses revealed a lower abundance of microbially derived C components after forest colonization on abandoned grasslands, thus resulting in lower physical protection of soil C considering that carbohydrates of microbial origin actively promote soil aggregation....

  5. A Study on Advanced Ultrasonic Technique for Thermal Fatigue Crack Detection of Thermal Stratification Pipeline in NPPs

    International Nuclear Information System (INIS)

    Ultrasonic inspection techniques are widely used to ensure the reliable operation and lifetime extension of nuclear power plants. Thermal stratification typically occurs in the surge line or the main feed water lines in nuclear power plants. Thermal stratification is a flow condition in which hotter fluid flows over a colder region of fluid in pipeline. Since a change in temperature causes a change in the density of the pipe wall, these thermal conditions might lead to increased overall bending stresses in pipelines. In addition, cyclic changes in stratification height cause thermal stress. This cycling can lead to thermal fatigue crack initiation and crack growth. If thermal fatigue crack grows continuously, the leakage of water or steam will occur and this may cause serious problems on reactor cooling system. Therefore, these cracks must be detected before the crack growth reaches for leakage. In this study, an ultrasonic technique was employed for evaluation of thermal fatigue cracks due to thermal stratification in pipelines of nuclear power plants. The angle beam ultrasonic techniques(time-of-flight diffraction(TOFD) and shadow effect method) were used to detect thermal fatigue cracks which grow from the inner surface of the pipeline. The angle beam ultrasonic technique is usually used for the detection of cracks on the inside of the structures. When ultrasonic waves generated from the angle probe encounters a crack, ultrasonic waves of the shear modes are reflect or transmit from the crack wall. Also ultrasonic waves generated from the angle probe shear modes are diffracted from the tip of the crack, and the shear wave is reflected from the corner of the crack

  6. Smart, Sustainable, and Ecofriendly Chemical Design of Fully Bio-Based Thermally Stable Thermosets Based on Benzoxazine Chemistry.

    Science.gov (United States)

    Froimowicz, Pablo; R Arza, Carlos; Han, Lu; Ishida, Hatsuo

    2016-08-01

    A smart synthetic chemical design incorporating furfurylamine, a natural renewable amine, into a partially bio-based coumarin-containing benzoxazine is presented. The versatility of the synthetic approach is shown to be flexible and robust enough to be successful under more ecofriendly reaction conditions by replacing toluene with ethanol as the reaction solvent and even under solventless conditions. The chemical structure of this coumarin-furfurylamine-containing benzoxazine is characterized by FTIR, (1) H NMR spectroscopy and two-dimensional (1) H-(1) H nuclear Overhauser effect spectroscopy (2D (1) H-(1) H NOESY). The thermal properties of the resin toward polymerization are characterized by differential scanning calorimetry (DSC) and the thermal stability of the resulting polymers by thermogravimetric analysis (TGA). The results reveal that the furanic moiety induces a co-operative activating effect, thus lowering the polymerization temperature and also contributes to a better thermal stability of the resulting polymers. These results, in addition to those of natural renewable benzoxazine resins reviewed herein, highlight the positive and beneficial implication of designing novel bio-based polybenzoxazine and possibly other thermosets with desirable and competitive properties.

  7. Thionyl chloride assisted functionalization of amorphous carbon nanotubes: A better field emitter and stable nanofluid with better thermal conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, S.K.; Jha, A. [School of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700 032 (India); Chattopadhyay, K.K., E-mail: kalyan_chattopadhyay@yahoo.com [Thin Film & Nanoscience Laboratory, Department of Physics, Jadavpur University, Kolkata 700 032 (India); School of Materials Science and Nanotechnology, Jadavpur University, Kolkata 700 032 (India)

    2015-06-15

    Highlights: • Thionyl chloride assisted functionalization of amorphous carbon nanotubes (a-CNTs). • Improved dispersion enhanced thermal conductivity of engine oil. • Again f-a-CNTs showed enhanced field emission property compared to pure a-CNTs. - Abstract: Amorphous carbon nanotubes (a-CNTs) were synthesized at low temperature in open atmosphere and further functionalized by treating them in thionyl chloride added stearic acid-dichloro methane solution. The as prepared functionalized a-CNTs (f-a-CNTs) were characterized by Raman spectroscopy, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission and scanning electron microscopy. The nanofluid was prepared by dispersing f-a-CNTs in engine oil using ultrasonic treatment. The effective thermal conductivity of as prepared nanofluid was investigated at different loading (volume fraction of f-a-CNTs). Obtained experimental data of thermal conductivity were compared with the predicted values, calculated using existing theoretical models. Stability of the nanofluid was tested by means of zeta potential measurement to optimize the loading. The as prepared f-a-CNTs sample also showed improved field emission result as compared to pristine a-CNTs. Dependence of field emission behavior on inter electrode distance was investigated too.

  8. Correlation between Pd metal thickness and thermally stable perpendicular magnetic anisotropy features in [Co/Pd]{sub n} multilayers at annealing temperatures up to 500 °C

    Energy Technology Data Exchange (ETDEWEB)

    An, Gwang Guk; Lee, Ja Bin; Yang, Seung Mo; Yoon, Kap Soo [Novel Functional Materials and Devices Lab, The Research Institute for Natural Science, Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Kim, Jae Hong [Division of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Chung, Woo Seong [Nano Quantum Electronics Lab, Department of Electronics and Computer Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Hong, Jin Pyo, E-mail: jphong@hanyang.ac.kr [Novel Functional Materials and Devices Lab, The Research Institute for Natural Science, Department of Physics, Hanyang University, Seoul 133-791 (Korea, Republic of); Division of Nano-Scale Semiconductor Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-02-15

    We examine highly stable perpendicular magnetic anisotropy (PMA) features of [Co/Pd]{sub 10} multilayers (MLs) versus Pd thickness at various ex-situ annealing temperatures. Thermally stable PMA characteristics were observed up to 500 °C, confirming the suitability of these systems for industrial applications at this temperature. Experimental observations suggest that the choice of equivalent Co and Pd layer thicknesses in a ML configuration ensures thermally stable PMA features, even at higher annealing temperatures. X-ray diffraction patterns and cross-sectional transmission electron microscopy images were obtained to determine thickness, post-annealing PMA behavior, and to explore the structural features that govern these findings.

  9. Remote sensing of volcanic plumes using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)

    Science.gov (United States)

    Henney, Lorna Alison

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) has been used to quantify SO2 emissions from passively degassing volcanoes. This dissertation explores ASTER's capability to detect SO 2 with satellite validation, enhancement techniques and extensive processing of images at a variety of volcanoes. ASTER is compared to the Mini UV Spectrometer (MUSe), a ground based instrument, to determine if reasonable SO2 fluxes can be quantified from a plume emitted from Lascar, Chile. The two sensors were in good agreement with ASTER proving to be a reliable detector of SO2. ASTER illustrated the advantages of imaging a plume in 2D, with better temporal resolution than the MUSe. SO2 plumes in ASTER imagery are not always discernible in the raw TIR data. Principal Component Analysis (PCA) and Decorrelation Stretch (DCS) enhancement techniques were compared to determine how well they highlight a variety of volcanic plumes. DCS produced a consistent output and the composition of the plumes was easy to identify from explosive eruptions. As the plumes became smaller and lower in altitude they became harder to distinguish using DCS. PCA proved to be better at identifying smaller low altitude plumes. ASTER was used to investigate SO2 emissions at Lascar, Chile. Activity at Lascar has been characterized by cyclic behavior and persistent degassing (Matthews et al. 1997). Previous studies at Lascar have primarily focused on changes in thermal infrared anomalies, neglecting gas emissions. Using the SO2 data along with changes in thermal anomalies and visual observations it is evident that Lascar is at the end an eruptive cycle that began in 1993. Declining gas emissions and crater temperatures suggest that the conduit is sealing. ASTER and the Ozone Monitoring Instrument (OMI) were used to determine the annual contribution of SO2 to the troposphere from the Central and South American volcanic arcs between 2000 and 2011. Fluxes of 3.4 Tg/a for Central America and 3

  10. Morphology and thermal properties of electrospun fatty acids/polyethylene terephthalate composite fibers as novel form-stable phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Changzhong [Key Laboratory of Cellulose and Lignocellulosics Chemistry, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); Graduate School of Chinese Academy of Sciences, Beijing 100049 (China); Wang, Linge [Key Laboratory of Cellulose and Lignocellulosics Chemistry, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); Department of Chemistry, University of Sheffield, Sheffield S3 7HF (United Kingdom); Huang, Yong [Key Laboratory of Cellulose and Lignocellulosics Chemistry, Guangzhou Institute of Chemistry, Chinese Academy of Sciences, Guangzhou 510650 (China); State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080 (China)

    2008-11-15

    The ultrafine fibers based on the composites of polyethylene terephthalate (PET) and a series of fatty acids, lauric acid (LA), myristic acid (MA), palmitic acid (PA), and stearic acid (SA), were prepared successfully via electrospinning as form-stable phase change materials (PCMs). The morphology and thermal properties of the composite fibers were studied by field emission scanning electron microscopy (FE-SEM) and differential scanning calorimetry (DSC), respectively. It was found that the average fiber diameter increased generally with the content of fatty acid (LA) in the LA/PET composite fibers. The fibers with the low mass ratio maintained cylindrical shape with smooth surface while the quality became worse when the mass ratio is too high (more than 100/100). Moreover, the latent heat of the composite fibers increased with the increase of LA content and the phase transition temperature of the fibers have no obvious variations compared with LA. In contrast, both the latent heat and phase transition temperature of the fatty acid/PET composite fibers varied with the type of the fatty acids, and could be well maintained after 100 heating-cooling thermal cycles, which demonstrated that the composite fibers had good thermal stability and reliability. (author)

  11. Design of Higher-k and More Stable Rare Earth Oxides as Gate Dielectrics for Advanced CMOS Devices

    Directory of Open Access Journals (Sweden)

    Yi Zhao

    2012-08-01

    Full Text Available High permittivity (k gate dielectric films are widely studied to substitute SiO2 as gate oxides to suppress the unacceptable gate leakage current when the traditional SiO2 gate oxide becomes ultrathin. For high-k gate oxides, several material properties are dominantly important. The first one, undoubtedly, is permittivity. It has been well studied by many groups in terms of how to obtain a higher permittivity for popular high-k oxides, like HfO2 and La2O3. The second one is crystallization behavior. Although it’s still under the debate whether an amorphous film is definitely better than ploy-crystallized oxide film as a gate oxide upon considering the crystal boundaries induced leakage current, the crystallization behavior should be well understood for a high-k gate oxide because it could also, to some degree, determine the permittivity of the high-k oxide. Finally, some high-k gate oxides, especially rare earth oxides (like La2O3, are not stable in air and very hygroscopic, forming hydroxide. This topic has been well investigated in over the years and significant progresses have been achieved. In this paper, I will intensively review the most recent progresses of the experimental and theoretical studies for preparing higher-k and more stable, in terms of hygroscopic tolerance and crystallization behavior, Hf- and La-based ternary high-k gate oxides.

  12. Advanced materials for solid state hydrogen storage: “Thermal engineering issues”

    International Nuclear Information System (INIS)

    Hydrogen has been widely recognized as the “Energy Carrier” of the future. Efficient, reliable, economical and safe storage and delivery of hydrogen form important aspects in achieving success of the “Hydrogen Economy”. Gravimetric and volumetric storage capacities become important when one considers portable and mobile applications of hydrogen. In the case of solid state hydrogen storage, the gas is reversibly embedded (by physisorption and/or chemisorption) in a solid matrix. A wide variety of materials such as intermetallics, physisorbents, complex hydrides/alanates, metal organic frameworks, etc. have been investigated as possible storage media. This paper discusses the feasibility of lithium– and sodium–aluminum hydrides with emphasis on their thermodynamic and thermo-physical properties. Drawbacks such as poor heat transfer characteristics and poor kinetics demand special attention to the thermal design of solid state storage devices. - Highlights: • Advanced materials suitable for solid state hydrogen storage are discussed. • Issues related to thermodynamic and thermo-physical properties of hydriding materials are brought out. • Hydriding and dehydriding behavior including sorption kinetics of complex hydrides with emphasis on alanates are explained

  13. Advanced Multiphysics Thermal-Hydraulics Models for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Prashant K [ORNL; Freels, James D [ORNL

    2015-01-01

    Engineering design studies to determine the feasibility of converting the High Flux Isotope Reactor (HFIR) from using highly enriched uranium (HEU) to low-enriched uranium (LEU) fuel are ongoing at Oak Ridge National Laboratory (ORNL). This work is part of an effort sponsored by the US Department of Energy (DOE) Reactor Conversion Program. HFIR is a very high flux pressurized light-water-cooled and moderated flux-trap type research reactor. HFIR s current missions are to support neutron scattering experiments, isotope production, and materials irradiation, including neutron activation analysis. Advanced three-dimensional multiphysics models of HFIR fuel were developed in COMSOL software for safety basis (worst case) operating conditions. Several types of physics including multilayer heat conduction, conjugate heat transfer, turbulent flows (RANS model) and structural mechanics were combined and solved for HFIR s inner and outer fuel elements. Alternate design features of the new LEU fuel were evaluated using these multiphysics models. This work led to a new, preliminary reference LEU design that combines a permanent absorber in the lower unfueled region of all of the fuel plates, a burnable absorber in the inner element side plates, and a relocated and reshaped (but still radially contoured) fuel zone. Preliminary results of estimated thermal safety margins are presented. Fuel design studies and model enhancement continue.

  14. MATLAB/Simulink Framework for Modeling Complex Coolant Flow Configurations of Advanced Automotive Thermal Management Systems

    Energy Technology Data Exchange (ETDEWEB)

    Titov, Gene; Lustbader, Jason; Leighton, Daniel; Kiss, Tibor

    2016-04-05

    The National Renewable Energy Laboratory's (NREL's) CoolSim MATLAB/Simulink modeling framework was extended by including a newly developed coolant loop solution method aimed at reducing the simulation effort for arbitrarily complex thermal management systems. The new approach does not require the user to identify specific coolant loops and their flow. The user only needs to connect the fluid network elements in a manner consistent with the desired schematic. Using the new solution method, a model of NREL's advanced combined coolant loop system for electric vehicles was created that reflected the test system architecture. This system was built using components provided by the MAHLE Group and included both air conditioning and heat pump modes. Validation with test bench data and verification with the previous solution method were performed for 10 operating points spanning a range of ambient temperatures between -2 degrees C and 43 degrees C. The largest root mean square difference between pressure, temperature, energy and mass flow rate data and simulation results was less than 7%.

  15. A Combined Method for Segmentation and Registration for an Advanced and Progressive Evaluation of Thermal Images

    Directory of Open Access Journals (Sweden)

    Emilio Z. Barcelos

    2014-11-01

    Full Text Available In this paper, a method that combines image analysis techniques, such as segmentation and registration, is proposed for an advanced and progressive evaluation of thermograms. The method is applied for the prevention of muscle injury in high-performance athletes, in collaboration with a Brazilian professional soccer club. The goal is to produce information on spatio-temporal variations of thermograms favoring the investigation of the athletes’ conditions along the competition. The proposed method improves on current practice by providing a means for automatically detecting adaptive body-shaped regions of interest, instead of the manual selection of simple shapes. Specifically, our approach combines the optimization features in Otsu’s method with a correction factor and post-processing techniques, enhancing thermal-image segmentation when compared to other methods. Additional contributions resulting from the combination of the segmentation and registration steps of our approach are the progressive analyses of thermograms in a unique spatial coordinate system and the accurate extraction of measurements and isotherms.

  16. Containment vessel, its auxiliary system and plant air conditioning system of advanced thermal reactor Fugen

    International Nuclear Information System (INIS)

    The functional requirement for, the design and the construction of, and the functional test on the containment vessel, its auxiliary system, the plant air conditioning and ventilation system of the advanced thermal reactor, Fugen, are described in detail. The main specifications of the containment vessel are as follows: The type enclosed cylinder, the maximum operating pressure 1.35 kg/cm2g, the maximum operating temperature 100 deg C, the leak rate 0.4%/day, the inner diameter 36 m. The height 64 m, the volume 40,900 m3, and the material JIS G3118, SGV-49. The containment vessel is provided with an hatch of 5 m diameter for carrying equipments in two air locks, many high and low voltage cable penetrations, pipe penetrations, a transfer shoot and isolation values. The functions and the specifications of the containment vessel and its auxiliary equipments are explained. The relating auxiliary systems are composed of the containment vessel spray system, the pool facility for steam blow-down, the recirculation system for the air in the vessel, the annulus evacuation system and its pressure control devices, the pressure measuring instruments and pressure relief valves and the temperature measuring devices for the containment vessel, and the object, function, layout and installation of these systems are explained. Concerning the air conditioning system, each main building has the special subsystem, and they are introduced. The progress stage of construction works and the procedure and results of the functional test at the site are described. (Nakai, Y.)

  17. Korean development of advanced thermal-hydraulic codes for water reactors and HTGRS: space and gamma

    International Nuclear Information System (INIS)

    Korea has been developing SPACE(Safety and Performance Analysis CodE) and GAMMA(GAs Multicomponent Mixture Analysis) codes for safety analysis of PWRs and HTGRs, respectively. SPACE is being developed by the Korea nuclear industry, which is a thermal-hydraulic analysis code for safety analysis of a PWR. It will replace outdated vendor supplied codes and will be used for the safety analysis of operating PWR and the design of an advanced PWR. It consists of the up-to-date physical models of two-phase flow dealing with multi-dimensional two-fluid, three-field flow. The GAMMA code consists of the multi-dimensional governing equations consisting of the basic equations for continuity, momentum conservation, energy conservation of the gas mixture, and mass conservation of n species. GAMMA is based on a porous media model so that we can deal with the thermo-fluid and chemical reaction behaviors in a multicomponent mixture system as well as heat transfer within the solid components, free and forced convection between a solid and a fluid, and radiative heat transfer between the solid surfaces. GAMMA has a model for helium turbines for HTGRs based on the throughflow calculation. We performed extensive code assessment for the V&V of SPACE and GAMMA. (author)

  18. 2D perovskite nanosheets with thermally-stable high-κ response: a new platform for high-temperature capacitors.

    Science.gov (United States)

    Kim, Yoon-Hyun; Kim, Hyung-Jun; Osada, Minoru; Li, Bao-Wen; Ebina, Yasuo; Sasaki, Takayoshi

    2014-11-26

    We investigated high-temperature dielectric responses of high-κ perovskite nanosheet (Ca2Nb3O10), an important material platform for postgraphene technology and ultrascale electronic devices. Through in situ characterizations using conducting atomic force microscopy, we found a robust high-temperature property of Ca2Nb3O10 nanosheet even in a monolayer form (∼2 nm). Furthermore, layer-by-layer assembled nanocapacitors retained both size-free high-εr characteristic (∼200) and high insulation resistance (∼1×10(-7) A/cm2) at high temperatures up to 250 °C. The simultaneous improvement of εr and thermal stability in high-κ nanodielectrics is of critical technological importance, and perovskite nanosheet has great potential for a rational design and construction of high-temperature capacitors.

  19. Preparation and characterization of electrospun poly(phthalazinone ether nitrile ketone) membrane with novel thermally stable properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gang; Zhang, Hao; Qian, Bingqing [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China); Wang, Jinyan, E-mail: wangjinyan@dlut.edu.cn [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116024 (China); Jian, Xigao [Department of Polymer Science and Materials, Dalian University of Technology, Dalian 116024 (China); Qiu, Jieshan, E-mail: jqiu@dlut.edu.cn [Carbon Research Laboratory, Liaoning Key Lab for Energy Materials and Chemical Engineering, State Key Lab of Fine Chemicals, Dalian University of Technology, Dalian 116024 (China)

    2015-10-01

    Highlights: • Poly (phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. • Electrospun membrane exhibits a good thermostability. • Electrospun membrane. - Abstract: Electrospun nanofibrous membranes have several applications because of their excellent properties, such as high porosity, small fiber diameter, and large surface area. However, high-temperature resistant electrospun membranes remain a challenge because of the absence of precursors that offer spinnability, scalability, and superior thermal stability. In this study, poly(phthalazinone ether nitrile ketone) (PPENK) was used to successfully prepare nanofiber membranes by electrospinning. Electrospun PPENK membranes were characterized by scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, and tensile stress–strain tests. Results indicated that the prepared electrospun membranes had a very high glass transition temperature, superior chemical resistance, and excellent mechanical strength. These desirable properties broaden their potential application in membranes and treatment of various hot fluid streams without strict temperature control.

  20. Generic Repository Concepts and Thermal Analysis for Advanced Fuel Cycles - 12477

    International Nuclear Information System (INIS)

    A geologic disposal concept for spent nuclear fuel (SNF) or high-level waste (HLW) consists of three components: waste inventory, geologic setting, and concept of operations. A set of reference geologic disposal concepts has been developed by the U.S. Department of Energy (DOE), Used Fuel Disposition campaign. Reference concepts are identified for crystalline rock, clay/shale, bedded salt, and deep borehole (crystalline basement) geologic settings. These were analyzed for waste inventory cases representing a range of waste types that could be produced by advanced nuclear fuel cycles. Concepts of operation consisting of emplacement mode, repository layout, and engineered barrier descriptions, were selected based on international progress. All of these disposal concepts are enclosed emplacement modes, whereby waste packages are in direct contact with encapsulating engineered or natural materials. Enclosed modes have less capacity to dissipate heat than open modes such as that proposed for a repository at Yucca Mountain. Thermal analysis has identified important relationships between waste package size and capacity, and the duration of surface decay storage needed to meet temperature limits for different disposal concepts. For the crystalline rock and clay/shale repository concepts, a waste package surface temperature limit of 100 deg. C was assumed to prevent changes in clay-based buffer material or clay-rich host rock. Surface decay storage of 50 to 100 years is needed for disposal of high-burnup LWR SNF in 4-PWR packages, or disposal of HLW glass from reprocessing LWR uranium oxide (UOX) fuel. High-level waste (HLW) from reprocessing of metal fuel used in a fast reactor could be disposed after decay storage of 50 years or less. For disposal in salt the rock thermal conductivity is significantly greater, and higher temperatures (200 deg. C) can be tolerated at the waste package surface. Decay storage of 10 years or less is needed for high-burnup LWR SNF in 4-PWR

  1. Generic Repository Concepts and Thermal Analysis for Advanced Fuel Cycles - 12477

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Ernest [Sandia National Laboratories, P.O. Box 5800 MS 0736, Albuquerque, NM 87185 (United States); Blink, James [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551-0808 (United States); Carter, Joe [Savannah River National Laboratory, Savannah River Site, Aiken, SC 29808 (United States); Fratoni, Massimiliano; Greenberg, Harris; Sutton, Mark [Lawrence Livermore National Laboratory (United States); Howard, Robert [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States)

    2012-07-01

    A geologic disposal concept for spent nuclear fuel (SNF) or high-level waste (HLW) consists of three components: waste inventory, geologic setting, and concept of operations. A set of reference geologic disposal concepts has been developed by the U.S. Department of Energy (DOE), Used Fuel Disposition campaign. Reference concepts are identified for crystalline rock, clay/shale, bedded salt, and deep borehole (crystalline basement) geologic settings. These were analyzed for waste inventory cases representing a range of waste types that could be produced by advanced nuclear fuel cycles. Concepts of operation consisting of emplacement mode, repository layout, and engineered barrier descriptions, were selected based on international progress. All of these disposal concepts are enclosed emplacement modes, whereby waste packages are in direct contact with encapsulating engineered or natural materials. Enclosed modes have less capacity to dissipate heat than open modes such as that proposed for a repository at Yucca Mountain. Thermal analysis has identified important relationships between waste package size and capacity, and the duration of surface decay storage needed to meet temperature limits for different disposal concepts. For the crystalline rock and clay/shale repository concepts, a waste package surface temperature limit of 100 deg. C was assumed to prevent changes in clay-based buffer material or clay-rich host rock. Surface decay storage of 50 to 100 years is needed for disposal of high-burnup LWR SNF in 4-PWR packages, or disposal of HLW glass from reprocessing LWR uranium oxide (UOX) fuel. High-level waste (HLW) from reprocessing of metal fuel used in a fast reactor could be disposed after decay storage of 50 years or less. For disposal in salt the rock thermal conductivity is significantly greater, and higher temperatures (200 deg. C) can be tolerated at the waste package surface. Decay storage of 10 years or less is needed for high-burnup LWR SNF in 4-PWR

  2. The GOES-R Advanced Baseline Imager: detector spectral response effects on thermal emissive band calibration

    Science.gov (United States)

    Pearlman, Aaron J.; Padula, Francis; Cao, Changyong; Wu, Xiangqian

    2015-10-01

    The Advanced Baseline Imager (ABI) will be aboard the National Oceanic and Atmospheric Administration's Geostationary Operational Environmental Satellite R-Series (GOES-R) to supply data needed for operational weather forecasts and long-term climate variability studies, which depend on high quality data. Unlike the heritage operational GOES systems that have two or four detectors per band, ABI has hundreds of detectors per channel requiring calibration coefficients for each one. This increase in number of detectors poses new challenges for next generation sensors as each detector has a unique spectral response function (SRF) even though only one averaged SRF per band is used operationally to calibrate each detector. This simplified processing increases computational efficiency. Using measured system-level SRF data from pre-launch testing, we have the opportunity to characterize the calibration impact using measured SRFs, both per detector and as an average of detector-level SRFs similar to the operational version. We calculated the spectral response impacts for the thermal emissive bands (TEB) theoretically, by simulating the ABI response viewing an ideal blackbody and practically, with the measured ABI response to an external reference blackbody from the pre-launch TEB calibration test. The impacts from the practical case match the theoretical results using an ideal blackbody. The observed brightness temperature trends show structure across the array with magnitudes as large as 0.1 K for and 12 (9.61 µm), and 0.25 K for band 14 (11.2 µm) for a 300 K blackbody. The trends in the raw ABI signal viewing the blackbody support the spectral response measurements results, since they show similar trends in bands 12 (9.61µm), and 14 (11.2 µm), meaning that the spectral effects dominate the response differences between detectors for these bands. We further validated these effects using the radiometric bias calculated between calibrations using the external blackbody and

  3. Application of Advanced Particle Swarm Optimization Techniques to Wind-thermal Coordination

    DEFF Research Database (Denmark)

    Singh, Sri Niwas; Østergaard, Jacob; Yadagiri, J.

    2009-01-01

    wind-thermal coordination algorithm is necessary to determine the optimal proportion of wind and thermal generator capacity that can be integrated into the system. In this paper, four versions of Particle Swarm Optimization (PSO) techniques are proposed for solving wind-thermal coordination problem...

  4. Springtime carbon emission episodes at the Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    Science.gov (United States)

    Jung, J.; Kawamura, K.

    2011-11-01

    In order to investigate the emission of carbonaceous aerosols at the Gosan background super-site (33.17° N, 126.10° E) in East Asia, total suspended particles (TSP) were collected during spring of 2007 and 2008 and analyzed for particulate organic carbon, elemental carbon, total carbon (TC), total nitrogen (TN), and stable carbon isotopic composition (δ13C) of TC. The stable carbon isotopic composition of TC (δ13CTC) was found to be lowest during pollen emission episodes (range: -26.2‰ to -23.5‰, avg. -25.2 ± 0.9‰), approaching those of the airborne pollen (-28.0‰) collected at the Gosan site. Based on a carbon isotope mass balance equation, we found that ~42% of TC in the TSP samples during the pollen episodes was attributed to airborne pollen from Japanese cedar trees planted around tangerine farms in Jeju Island. A negative correlation between the citric acid-carbon/TC ratios and δ13CTC was obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollen and then transported to the Gosan site. Thermal evolution patterns of organic carbon during the pollen episodes were characterized by high OC evolution in the OC2 temperature step (450 °C). Since thermal evolution patterns of organic aerosols are highly influenced by their molecular weight, they can be used as additional information on the formation of secondary organic aerosols and the effect of aging of organic aerosols during the long-range atmospheric transport and sources of organic aerosols.

  5. Springtime carbon emission episodes at the Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    Directory of Open Access Journals (Sweden)

    J. Jung

    2011-11-01

    Full Text Available In order to investigate the emission of carbonaceous aerosols at the Gosan background super-site (33.17° N, 126.10° E in East Asia, total suspended particles (TSP were collected during spring of 2007 and 2008 and analyzed for particulate organic carbon, elemental carbon, total carbon (TC, total nitrogen (TN, and stable carbon isotopic composition (δ13C of TC. The stable carbon isotopic composition of TC (δ13CTC was found to be lowest during pollen emission episodes (range: −26.2‰ to −23.5‰, avg. −25.2 ± 0.9‰, approaching those of the airborne pollen (−28.0‰ collected at the Gosan site. Based on a carbon isotope mass balance equation, we found that ~42% of TC in the TSP samples during the pollen episodes was attributed to airborne pollen from Japanese cedar trees planted around tangerine farms in Jeju Island. A negative correlation between the citric acid-carbon/TC ratios and δ13CTC was obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollen and then transported to the Gosan site. Thermal evolution patterns of organic carbon during the pollen episodes were characterized by high OC evolution in the OC2 temperature step (450 °C. Since thermal evolution patterns of organic aerosols are highly influenced by their molecular weight, they can be used as additional information on the formation of secondary organic aerosols and the effect of aging of organic aerosols during the long-range atmospheric transport and sources of organic aerosols.

  6. "Stable-on-the-Table" Biosensors: Hemoglobin-Poly (Acrylic Acid) Nanogel BioElectrodes with High Thermal Stability and Enhanced Electroactivity.

    Science.gov (United States)

    Ghimire, Ananta; Zore, Omkar V; Thilakarathne, Vindya K; Briand, Victoria A; Lenehan, Patrick J; Lei, Yu; Kasi, Rajeswari M; Kumar, Challa V

    2015-01-01

    In our efforts toward producing environmentally responsible but highly stable bioelectrodes with high electroactivities, we report here a simple, inexpensive, autoclavable high sensitivity biosensor based on enzyme-polymer nanogels. Met-hemoglobin (Hb) is stabilized by wrapping it in high molecular weight poly(acrylic acid) (PAA, M(W) 450k), and the resulting nanogels abbreviated as Hb-PAA-450k, withstood exposure to high temperatures for extended periods under steam sterilization conditions (122 °C, 10 min, 17-20 psi) without loss of Hb structure or its peroxidase-like activities. The bioelectrodes prepared by coating Hb-PAA-450k nanogels on glassy carbon showed well-defined quasi-reversible redox peaks at -0.279 and -0.334 V in cyclic voltammetry (CV) and retained >95% electroactivity after storing for 14 days at room temperature. Similarly, the bioelectrode showed ~90% retention in electrochemical properties after autoclaving under steam sterilization conditions. The ultra stable bioelectrode was used to detect hydrogen peroxide and demonstrated an excellent detection limit of 0.5 μM, the best among the Hb-based electrochemical biosensors. This is the first electrochemical demonstration of steam-sterilizable, storable, modular bioelectrode that undergoes reversible-thermal denaturation and retains electroactivity for protein based electrochemical applications. PMID:26393601

  7. Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies, Class III

    Energy Technology Data Exchange (ETDEWEB)

    City of Long Beach; Tidelands Oil Production Company; University of Southern California; David K. Davies and Associates

    2002-09-30

    The objective of this project was to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California through the testing and application of advanced reservoir characterization and thermal production technologies. It was hoped that the successful application of these technologies would result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs.

  8. Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies, Class III

    Energy Technology Data Exchange (ETDEWEB)

    City of Long Beach; Tidelands Oil Production Company; University of Southern California; David K. Davies and Associates

    2002-09-30

    The objective of this project was to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California through the testing and application of advanced reservoir characterization and thermal production technologies. The successful application of these technologies would result in expanding their implementation throughout the Wilmington Field and, through technology transfer, to other slope and basin clastic (SBC) reservoirs.

  9. Electrical, structural and surface morphological properties of thermally stable low-resistance W/Ti/Au multilayer ohmic contacts to n-type GaN

    International Nuclear Information System (INIS)

    A W/Ti/Au multilayer scheme has been fabricated for achieving thermally stable low-resistance ohmic contact to n-type GaN (4.0 x 1018 cm-3). It is shown that the as-deposited W/Ti/Au contact exhibits near linear I-V behaviour. However, annealing at temperature below 800 deg. C the contacts exhibit non-linear behaviour. After annealing at a temperature in excess of 850 deg. C, the W/Ti/Au contact showed ohmic behaviour. The W/Ti/Au contact produced specific contact resistance as low as 6.7 x 10-6 Ω cm2 after annealing at 900 deg. C for 1 min in a N2 ambient. It is noted that the specific contact resistance decreases with increase in annealing temperature. It is also noted that annealing the contacts at 900 deg. C for 30 min causes insignificant degradation of the electrical and thermal properties. It is further shown that the overall surface morphology of the W/Ti/Au stayed fairly smooth even after annealing at 900 deg. C. The W/Ti/Au ohmic contact showed good edge sharpness after annealing at 900 deg. C for 30 min. Based on the Auger electron spectroscopy and glancing angle X-ray diffraction results, possible explanation for the annealing dependence of the specific contact resistance of the W/Ti/Au contacts are described and discussed.

  10. The dependence of test-mass coating and substrate thermal noise on beam shape in the advanced Laser Interferometer Gravitational-Wave Observatory (advanced LIGO)

    CERN Document Server

    Lovelace, G

    2006-01-01

    In second-generation, ground-based interferometric gravitational-wave detectors such as advanced LIGO, the dominant noise at frequencies f ~ 40 Hz to 200 Hz is expected to be due to thermal fluctuations in the mirrors' substrates and coatings which induce random fluctuations in the shape of the mirror face. The laser-light beam averages over these fluctuations; the larger the beam and the flatter its light-power distribution, the better the averaging and the lower the resulting thermal noise. This has led O'Shaughnessy and Thorne to propose flattening and enlarging the beam shape to reduce the thermal noise. In this paper I derive and discuss simple scaling laws that describe the dependence of the thermal noise on the beam's (axisymmetric) light-power distribution. Each of these scaling laws has previously been deduced, from somewhat general arguments rather than detailed calculations, by O'Shaughnessy; independently, the same scaling laws have been found by Vyatchanin [for Brownian coating noise], by by O'Sh...

  11. Recent advances and progress towards an integrated interdisciplinary thermal-structural finite element technology

    Science.gov (United States)

    Namburu, Raju R.; Tamma, Kumar K.

    1993-01-01

    An integrated finite element approach is presented for interdisciplinary thermal-structural problems. Of the various numerical approaches, finite element methods with direct time integration procedures are most widely used for these nonlinear problems. Traditionally, combined thermal-structural analysis is performed sequentially by transferring data between thermal and structural analysis. This approach is generally effective and routinely used. However, to solve the combined thermal-structural problems, this approach results in cumbersome data transfer, incompatible algorithmic representations, and different discretized element formulations. The integrated approach discussed in this paper effectively combines thermal and structural fields, thus overcoming the above major shortcomings. The approach follows Lax-Wendroff type finite element formulations with flux and stress based representations. As a consequence, this integrated approach uses common algorithmic representations and element formulations. Illustrative test examples show that the approach is effective for integrated thermal-structural problems.

  12. Research and development of advanced aluminium/graphite composites for thermal management applications

    CERN Document Server

    Wyszkowska, Edyta; Bertarelli, Alessandro

    Thermal management materials are continuously gaining importance as a consequence of everlasting evolution in performance of electronic and electric devices. In particular, by improving the heat exchanger’s materials' properties (i.e. thermal conductivity) it is possible to boost further performance and miniaturization of such devices. Due to their high thermal conductivity, Copper and Aluminium are currently the most commonly used materials for thermal management applications. However, the mismatch in thermal expansion between Cooper/Aluminium and Silicon is limiting the heat transfer at the interface between the electronic chip and the heat exchanger. Furthermore, Copper is indeed characterized by a high thermal conductivity but at the same time its high density (8.9 g/cm3) increases weight of the final product, which in most of the cases does not meet specific application requirements. High cost of these materials is another constraint which limits their application. Due to aforementioned facts, monolith...

  13. AREVA NP's advanced Thermal Hydraulic Methods for Reactor Core and Fuel Assembly Design

    International Nuclear Information System (INIS)

    The main objective of the Thermal Hydraulic (TH) analysis of reactor core and fuel assembly design is the determination of pressure loss and critical heat flux (CHF). Especially the description of the latter effect requires the modeling of a large variety of physical phenomena starting with single phase quantities like turbulence or fluid-wall friction, two phase quantities like void distributions, heat transfer between fuel rod and fluid and ultimately the CHF mechanism itself. Additional complexity is added by the fact that the relevant geometric scales which have to be resolved, cover a wide range from the length of the fuel assembly (∼ 4000 mm), over the typical dimensions of sub-channel cross sections and the vanes on the spacer grids (∼ 10 mm) down to the microscopic scales set by bubble sizes and boundary layers (mm to sub mm). Due to the above described situation the necessary TH quantities are often determined by measurements. The main advantage of this technique is that measurements are widely accepted and trusted if the geometry and flow conditions are sufficiently close to real reactor conditions. The main disadvantage of experiments is that they are expensive both with respect to time and money; especially in high pressure tests they give only limited access to the test object. Consequently there is a strong interest to develop computer codes with the goal of minimizing the need of experiments, and hence, speeding up and reducing costs of fuel assembly and core design. Today most of the design work is based on sub-channel codes, originally developed in the 70's; they provide an effective description of the TH in fuel assemblies by regarding the fuel assembly as a system of communicating channels (the volume enclosed by four fuel rods = one sub-channel). Further development of these codes is one main focus of AREVA NP's Thermal Hydraulic method and code development strategy. To focus the know-how and resources existing in the different regions of

  14. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Among the...

  15. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Included among...

  16. Advanced Durable Flexible Ultra Low Outgassing Thermal Control Coatings for NASA Science Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I program proposes to synthesize novel nanoengineered ultra low out gassing elastomers and formulate high temperature capable flexible thermal control...

  17. Integrated MLI: Advanced Thermal Insulation Using Micro-Molding Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lightweight, high performance thermal insulation is critical to NASA's next generation Exploration spacecraft. Zero or low cryogenic propellant boiloff is required...

  18. Stable convergence and stable limit theorems

    CERN Document Server

    Häusler, Erich

    2015-01-01

    The authors present a concise but complete exposition of the mathematical theory of stable convergence and give various applications in different areas of probability theory and mathematical statistics to illustrate the usefulness of this concept. Stable convergence holds in many limit theorems of probability theory and statistics – such as the classical central limit theorem – which are usually formulated in terms of convergence in distribution. Originated by Alfred Rényi, the notion of stable convergence is stronger than the classical weak convergence of probability measures. A variety of methods is described which can be used to establish this stronger stable convergence in many limit theorems which were originally formulated only in terms of weak convergence. Naturally, these stronger limit theorems have new and stronger consequences which should not be missed by neglecting the notion of stable convergence. The presentation will be accessible to researchers and advanced students at the master's level...

  19. Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    1998-03-03

    The project involves improving thermal recovery techniques in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. using advanced reservoir characterization and thermal production technologies. The existing steamflood in the Tar zone of Fault Block (FB) II-A has been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the existing steam drive area to improve thermal efficiency. (7) Installing a 2100 foot insulated, subsurface harbor channel crossing to supply steam to an island location. (8) Test a novel alkaline steam completion technique to control well sanding problems and fluid entry profiles. (9) Advanced reservoir management through computer-aided access to production and

  20. Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    1997-08-08

    The project involves improving thermal recovery techniques in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. using advanced reservoir characterization and thermal production technologies. The existing steamflood in the Tar zone of Fault Block (FB) II-A has been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the existing steam drive area to improve thermal efficiency. (7) Installing a 2100 foot insulated, subsurface harbor channel crossing to supply steam to an island location. (8) Test a novel alkaline steam completion technique to control well sanding problems and fluid entry profiles. (9) Advanced reservoir management through computer-aided access to production and

  1. Microwave-hydrothermal synthesis and characterization of nanostructured copper substituted ZnM2O4 (M = Al, Ga) spinels as precursors for thermally stable Cu catalysts

    Science.gov (United States)

    Conrad, Franziska; Massue, Cyriac; Kühl, Stefanie; Kunkes, Edward; Girgsdies, Frank; Kasatkin, Igor; Zhang, Bingsen; Friedrich, Matthias; Luo, Yuan; Armbrüster, Marc; Patzke, Greta R.; Behrens, Malte

    2012-03-01

    Nanostructured CuxZn1-xAl2O4 with a Cu : Zn ratio of ¼ : ¾ has been prepared by a microwave-assisted hydrothermal synthesis at 150 °C and used as a precursor for Cu/ZnO/Al2O3-based catalysts. The spinel nanoparticles exhibit an average size of approximately 5 nm and a high specific surface area (above 250 m2 g-1). Cu nanoparticles of an average size of 3.3 nm can be formed by reduction of the spinel precursor in hydrogen and the accessible metallic Cu(0) surface area of the reduced catalyst was 8 m2 g-1. The catalytic performance of the material in CO2 hydrogenation and methanol steam reforming was compared with conventionally prepared Cu/ZnO/Al2O3 reference catalysts. The observed lower performance of the spinel-based samples is attributed to a lack of synergetic interaction of the Cu nanoparticles with ZnO due to the incorporation of Zn2+ in the stable spinel lattice. Despite its lower performance, however, the nanostructured nature of the spinel catalyst was stable after thermal treatment up to 500 °C in contrast to other Cu-based catalysts. Furthermore, a large fraction of the re-oxidized copper migrates back into the spinel upon calcination of the reduced catalyst, thereby enabling a regeneration of sintered catalysts after prolonged usage at high temperatures. Similarly prepared samples with Ga instead of Al exhibit a more crystalline catalyst with a spinel particle size around 20 nm. The slightly decreased Cu(0) surface area of 3.2 m2 g-1 due to less copper incorporation is not a significant drawback for the methanol steam reforming.Nanostructured CuxZn1-xAl2O4 with a Cu : Zn ratio of ¼ : ¾ has been prepared by a microwave-assisted hydrothermal synthesis at 150 °C and used as a precursor for Cu/ZnO/Al2O3-based catalysts. The spinel nanoparticles exhibit an average size of approximately 5 nm and a high specific surface area (above 250 m2 g-1). Cu nanoparticles of an average size of 3.3 nm can be formed by reduction of the spinel precursor in hydrogen

  2. Hydrothermal Alteration Maps of the Central and Southern Basin and Range Province of the United States Compiled From Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical operator algorithms were used to map...

  3. Springtime carbon episodes at Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    Science.gov (United States)

    Jung, J.; Kawamura, K.

    2011-05-01

    In order to investigate the carbon episodes at Gosan background super-site (33.17° N, 126.10° E) in East Asia during spring of 2007 and 2008, total suspended particles (TSP) were collected and analyzed for particulate organic carbon, elemental carbon, total carbon (TC), total nitrogen (TN), and stable carbon isotopic composition (δ13C) of TC. The carbon episodes at the Gosan site were categorized as long-range transported anthropogenic pollutant (LTP) from Asian continent, Asian dust (AD) accompanying with LTP, and local pollen episodes. The stable carbon isotopic composition of TC (δ13CTC) was found to be lowest during the pollen episodes (range: -26.2 ‰ to -23.5 ‰, avg.: -25.2 ± 0.9 ‰), followed by the LTP episodes (range: -23.5 ‰ to -23.0 ‰, avg.: -23.3 ± 0.3 ‰) and the AD episodes (range: -23.3 to -20.4 %, avg.: -21.8 ± 2.0 ‰). The δ13CTC of the airborne pollens (-28.0 ‰) collected at the Gosan site showed value similar to that of tangerine fruit (-28.1 ‰) produced from Jeju Island. Based on the carbon isotope mass balance equation and the TN and TC regression approach, we found that ∼40-45 % of TC in the TSP samples during the pollen episodes was attributed to airborne pollens from Japanese cedar trees planted around tangerine farms in Jeju Island. The δ13C of citric acid in the airborne pollens (-26.3 ‰) collected at the Gosan site was similar to that in tangerine fruit (-27.4 ‰). The negative correlation between the citric acid-carbon/TC ratios and δ13CTC were obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollens and then transported to the Gosan site. Based on the thermal evolution pattern of organic aerosols during the carbon episodes, we found that organic aerosols originated from East China are more volatile on heating and are more likely to form pyrolized organic carbon than the pollen-enriched organic aerosols and organic

  4. Fabrication of High Thermal Conductivity NARloy-Z-Diamond Composite Combustion Chamber Liner for Advanced Rocket Engines

    Science.gov (United States)

    Bhat, Biliyar N.; Greene, Sandra E.; Singh, Jogender

    2016-01-01

    NARloy-Z alloy (Cu-3 percent, Ag-0.5 percent, Zr) is a state of the art alloy currently used for fabricating rocket engine combustion chamber liners. Research conducted at NASA-MSFC and Penn State – Applied Research Laboratory has shown that thermal conductivity of NARloy-Z can be increased significantly by adding diamonds to form a composite (NARloy-Z-D). NARloy-Z-D is also lighter than NARloy-Z. These attributes make this advanced composite material an ideal candidate for fabricating combustion chamber liner for an advanced rocket engine. Increased thermal conductivity will directly translate into increased turbopump power and increased chamber pressure for improved thrust and specific impulse. This paper describes the process development for fabricating a subscale high thermal conductivity NARloy-Z-D combustion chamber liner using Field Assisted Sintering Technology (FAST). The FAST process uses a mixture of NARloy-Z and diamond powders which is sintered under pressure at elevated temperatures. Several challenges were encountered, i.e., segregation of diamonds, machining the super hard NARloy-Z-D composite, net shape fabrication and nondestructive examination. The paper describes how these challenges were addressed. Diamonds coated with copper (CuD) appear to give the best results. A near net shape subscale combustion chamber liner is being fabricated by diffusion bonding cylindrical rings of NARloy-Z-CuD using the FAST process.

  5. Design and Test of Advanced Thermal Simulators for an Alkali Metal-Cooled Reactor Simulator

    Science.gov (United States)

    Garber, Anne E.; Dickens, Ricky E.

    2011-01-01

    The Early Flight Fission Test Facility (EFF-TF) at NASA Marshall Space Flight Center (MSFC) has as one of its primary missions the development and testing of fission reactor simulators for space applications. A key component in these simulated reactors is the thermal simulator, designed to closely mimic the form and function of a nuclear fuel pin using electric heating. Continuing effort has been made to design simple, robust, inexpensive thermal simulators that closely match the steady-state and transient performance of a nuclear fuel pin. A series of these simulators have been designed, developed, fabricated and tested individually and in a number of simulated reactor systems at the EFF-TF. The purpose of the thermal simulators developed under the Fission Surface Power (FSP) task is to ensure that non-nuclear testing can be performed at sufficiently high fidelity to allow a cost-effective qualification and acceptance strategy to be used. Prototype thermal simulator design is founded on the baseline Fission Surface Power reactor design. Recent efforts have been focused on the design, fabrication and test of a prototype thermal simulator appropriate for use in the Technology Demonstration Unit (TDU). While designing the thermal simulators described in this paper, effort were made to improve the axial power profile matching of the thermal simulators. Simultaneously, a search was conducted for graphite materials with higher resistivities than had been employed in the past. The combination of these two efforts resulted in the creation of thermal simulators with power capacities of 2300-3300 W per unit. Six of these elements were installed in a simulated core and tested in the alkali metal-cooled Fission Surface Power Primary Test Circuit (FSP-PTC) at a variety of liquid metal flow rates and temperatures. This paper documents the design of the thermal simulators, test program, and test results.

  6. Advanced thermal barrier coating system development. Technical progress report, September 1, 1996--November 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-11

    Objectives of this program are to provide an improved thermal barrier coating system with improved temperature capability and reliability. This report describes the bond/coating process and manufacturing.

  7. Advanced thermal barrier coating system development. Technical progress report, March 1, 1997--May 31, 1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-06-13

    Objectives of this program are to provide an improved thermal barrier coating system with improved reliability and temperature capability. This report describes progress in manufacturing, bonding, deposition, non-destructive evaluation, repair, and maintenance.

  8. Advanced thermal barrier coating system development. Technical progress report, January 1, 1996--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-04-08

    Objectives of this program are to provide a thermal barrier coating system with increased temperature capability and improved reliability relative to current state of the art systems. This report describes the bond coat deposition process, manufacturing, and repair.

  9. Next Generation Advanced Binder Chemistries for High Performance, Environmentally DurableThermal Control Material Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This innovative SBIR Phase II proposal will develop next generation products for Thermal Control Material Systems (TCMS) an adhesives based on the next generation...

  10. Advanced latent heat of fusion thermal energy storage for solar power systems

    Science.gov (United States)

    Phillips, W. M.; Stearns, J. W.

    1985-01-01

    The use of solar thermal power systems coupled with thermal energy storage (TES) is being studied for both terrestrial and space applications. In the case of terrestrial applications, it was found that one or two hours of TES could shift the insolation peak (solar noon) to coincide with user peak loads. The use of a phase change material (PCM) is attractive because of the higher energy storage density which can be achieved. However, the use of PCM has also certain disadvantages which must be addressed. Proof of concept testing was undertaken to evaluate corrosive effects and thermal ratcheting effects in a slurry system. It is concluded that the considered alkali metal/alkali salt slurry approach to TES appears to be very viable, taking into account an elimination of thermal ratcheting in storage systems and the reduction of corrosive effects. The approach appears to be useful for an employment involving temperatures applicable to Brayton or Stirling cycles.

  11. Proceedings of the Twenty-First Water Reactor Safety Information Meeting: Volume 1, Plenary session; Advanced reactor research; advanced control system technology; advanced instrumentation and control hardware; human factors research; probabilistic risk assessment topics; thermal hydraulics; thermal hydraulic research for advanced passive LWRs

    International Nuclear Information System (INIS)

    This three-volume report contains 90 papers out of the 102 that were presented at the Twenty-First Water Reactor Safety Information Meeting held at the Bethesda Marriott Hotel, Bethesda, Maryland, during the week of October 25--27, 1993. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from France, Germany, Japan, Russia, Switzerland, Taiwan, and United Kingdom. The titles of the papers and the names of the authors have been updated and may differ from those that appeared in the final program of the meeting. Individual papers have been cataloged separately. This document, Volume 1 covers the following topics: Advanced Reactor Research; Advanced Instrumentation and Control Hardware; Advanced Control System Technology; Human Factors Research; Probabilistic Risk Assessment Topics; Thermal Hydraulics; and Thermal Hydraulic Research for Advanced Passive Light Water Reactors

  12. Proceedings of the Twenty-First Water Reactor Safety Information Meeting: Volume 1, Plenary session; Advanced reactor research; advanced control system technology; advanced instrumentation and control hardware; human factors research; probabilistic risk assessment topics; thermal hydraulics; thermal hydraulic research for advanced passive LWRs

    Energy Technology Data Exchange (ETDEWEB)

    Monteleone, S. [Brookhaven National Lab., Upton, NY (United States)] [comp.

    1994-04-01

    This three-volume report contains 90 papers out of the 102 that were presented at the Twenty-First Water Reactor Safety Information Meeting held at the Bethesda Marriott Hotel, Bethesda, Maryland, during the week of October 25--27, 1993. The papers are printed in the order of their presentation in each session and describe progress and results of programs in nuclear safety research conducted in this country and abroad. Foreign participation in the meeting included papers presented by researchers from France, Germany, Japan, Russia, Switzerland, Taiwan, and United Kingdom. The titles of the papers and the names of the authors have been updated and may differ from those that appeared in the final program of the meeting. Individual papers have been cataloged separately. This document, Volume 1 covers the following topics: Advanced Reactor Research; Advanced Instrumentation and Control Hardware; Advanced Control System Technology; Human Factors Research; Probabilistic Risk Assessment Topics; Thermal Hydraulics; and Thermal Hydraulic Research for Advanced Passive Light Water Reactors.

  13. Uses of Advanced Ceramic Composites in the Thermal Protection Systems of Future Space Vehicles

    Science.gov (United States)

    Rasky, Daniel J.

    1994-01-01

    Current ceramic composites being developed and characterized for use in the thermal protection systems (TPS) of future space vehicles are reviewed. The composites discussed include new tough, low density ceramic insulation's, both rigid and flexible; ultra-high temperature ceramic composites; nano-ceramics; as well as new hybrid ceramic/metallic and ceramic/organic systems. Application and advantage of these new composites to the thermal protection systems of future reusable access to space vehicles and small spacecraft is reviewed.

  14. Simulation of Thin-Film Damping and Thermal Mechanical Noise Spectra for Advanced Micromachined Microphone Structures

    OpenAIRE

    Hall, Neal A.; Okandan, Murat; Littrell, Robert; Bicen, Baris; Degertekin, F. Levent

    2008-01-01

    In many micromachined sensors the thin (2–10 μm thick) air film between a compliant diaphragm and backplate electrode plays a dominant role in shaping both the dynamic and thermal noise characteristics of the device. Silicon microphone structures used in grating-based optical-interference microphones have recently been introduced that employ backplates with minimal area to achieve low damping and low thermal noise levels. Finite-element based modeling procedures based on 2-D discretization of...

  15. High Thermal Conductivity Polymer Matrix Composites (PMC) for Advanced Space Radiators

    Science.gov (United States)

    Shin, E. Eugene; Bowman, Cheryl; Beach, Duane

    2007-01-01

    High temperature polymer matrix composites (PMC) reinforced with high thermal conductivity (approx. 1000 W/mK) pitch-based carbon fibers are evaluated for a facesheet/fin structure of large space radiator systems. Significant weight reductions along with improved thermal performance, structural integrity and space durability toward its metallic counterparts were envisioned. Candidate commercial resin systems including Cyanate Esters, BMIs, and polyimide were selected based on thermal capabilities and processability. PMC laminates were designed to match the thermal expansion coefficient of various metal heat pipes or tubes. Large, but thin composite panels were successfully fabricated after optimizing cure conditions. Space durability of PMC with potential degradation mechanisms was assessed by simulated thermal aging tests in high vacuum, 1-3 x 10(exp -6) torr, at three temperatures, 227 C, 277 C, and 316 C for up to one year. Nanocomposites with vapor-grown carbon nano-fibers and exfoliated graphite flakes were attempted to improve thermal conductivity (TC) and microcracking resistance. Good quality nanocomposites were fabricated and evaluated for TC and durability including radiation resistance. TC was measured in both in-plan and thru-the-thickness directions, and the effects of microcracks on TC are also being evaluated. This paper will discuss the systematic experimental approaches, various performance-durability evaluations, and current subcomponent design and fabrication/manufacturing efforts.

  16. Stable Chlorine Isotopes and Elemental Chlorine by Thermal Ionization Mass Spectrometry and Ion Chromatography; Martian Meteorites, Carbonaceous Chondrites and Standard Rocks

    Science.gov (United States)

    Nakamura, N.; Nyquist, L. E.; Reese, Y.; Shih, C.-Y.; Fujitani, T.; Okano, O.

    2011-01-01

    Recently significantly large mass fractionation of stable chlorine isotopes has been reported for terrestrial and lunar samples [1,2]. In addition, in view of possible early solar system processes [3] and also potential perchlorate-related fluid/microbial activities on the Martian surface [4,5], a large chlorine isotopic fractionation might be expected for some types of planetary materials. Due to analytical difficulties of isotopic and elemental analyses, however, current chlorine analyses for planetary materials are controversial among different laboratories, particularly between IRMS (gas source mass spectrometry) and TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1,6,7] for isotopic analyses, as well as between those doing pyrohydrolysis and other groups [i.e. 6,8]. Additional careful investigations of Cl isotope and elemental abundances are required to confirm real chlorine isotope and elemental variations for planetary materials. We have developed a TIMS technique combined with HF-leaching/ion chromatography at NASA JSC that is applicable to analysis of small amounts of meteoritic and planetary materials. We present here results for several standard rocks and meteorites, including Martian meteorites.

  17. Production, characterization, and flocculation mechanism of cation independent, pH tolerant, and thermally stable bioflocculant from Enterobacter sp. ETH-2.

    Directory of Open Access Journals (Sweden)

    Wei Tang

    Full Text Available Synthetic high polymer flocculants, frequently utilized for flocculating efficiency and low cost, recently have been discovered as producing increased risk to human health and the environment. Development of a more efficient and environmentally sound alternative flocculant agent is investigated in this paper. Bioflocculants are produced by microorganisms and may exhibit a high rate of flocculation activity. The bioflocculant ETH-2, with high flocculating activity (2849 mg Kaolin particle/mg ETH-2, produced by strain Enterobacter sp. isolated from activated sludge, was systematically investigated with regard to its production, characterization, and flocculation mechanism. Analyses of microscopic observation, zeta potential and ETH-2 structure demonstrates the bridging mechanism, as opposed to charge neutralization, was responsible for flocculation of the ETH-2. ETH-2 retains high molecular weight (603 to 1820 kDa and multi-functional groups (hydroxyl, amide and carboxyl that contributed to flocculation. Polysaccharides mainly composed of mannose, glucose, and galactose, with a molar ratio of 1:2.9:9.8 were identified as the active constituents in bioflocculant. The structure of the long backbone with active sites of polysaccharides was determined as a primary basis for the high flocculation activity. Bioflocculant ETH-2 is cation independent, pH tolerant, and thermally stable, suggesting a potential fit for industrial application.

  18. Thermally stable nanoparticles on supports

    Science.gov (United States)

    Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

    2012-11-13

    An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

  19. Integrated Advanced Monopropellant CMC Thruster / Thermal Stand-Off Assembly Project

    Data.gov (United States)

    National Aeronautics and Space Administration — High performance non-toxic monopropellants offer significant benefits relative to the current state-of-the-art. The benefits of these advanced monopropellants (AMP)...

  20. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2001-08-08

    The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California, through the testing and application of advanced reservoir characterization and thermal production technologies. The hope is that successful application of these technologies will result in their implementation throughout the Wilmington Field and, through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block II-A (Tar II-A) has been relatively inefficient because of several producibility problems which are common in SBC reservoirs: inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery and reduce operating costs, including: (1) Development of three-dimensional (3-D) deterministic and stochastic reservoir simulation models--thermal or otherwise--to aid in reservoir management of the steamflood and post-steamflood phases and subsequent development work. (2) Development of computerized 3-D visualizations of the geologic and reservoir simulation models to aid reservoir surveillance and operations. (3) Perform detailed studies of the geochemical interactions between the steam and the formation rock and fluids. (4) Testing and proposed application of a

  1. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2004-03-05

    The overall objective of this project is to increase heavy oil reserves in slope and basin clastic (SBC) reservoirs through the application of advanced reservoir characterization and thermal production technologies. The project involves improving thermal recovery techniques in the Tar Zone of Fault Blocks II-A and V (Tar II-A and Tar V) of the Wilmington Field in Los Angeles County, near Long Beach, California. A primary objective is to transfer technology which can be applied in other heavy oil formations of the Wilmington Field and other SBC reservoirs, including those under waterflood. The thermal recovery operations in the Tar II-A and Tar V have been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the

  2. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2003-06-04

    The overall objective of this project is to increase heavy oil reserves in slope and basin clastic (SBC) reservoirs through the application of advanced reservoir characterization and thermal production technologies. The project involves improving thermal recovery techniques in the Tar Zone of Fault Blocks II-A and V (Tar II-A and Tar V) of the Wilmington Field in Los Angeles County, near Long Beach, California. A primary objective is to transfer technology which can be applied in other heavy oil formations of the Wilmington Field and other SBC reservoirs, including those under waterflood. The thermal recovery operations in the Tar II-A and Tar V have been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the

  3. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2003-09-04

    The overall objective of this project is to increase heavy oil reserves in slope and basin clastic (SBC) reservoirs through the application of advanced reservoir characterization and thermal production technologies. The project involves improving thermal recovery techniques in the Tar Zone of Fault Blocks II-A and V (Tar II-A and Tar V) of the Wilmington Field in Los Angeles County, near Long Beach, California. A primary objective is to transfer technology which can be applied in other heavy oil formations of the Wilmington Field and other SBC reservoirs, including those under waterflood. The thermal recovery operations in the Tar II-A and Tar V have been relatively inefficient because of several producibility problems which are common in SBC reservoirs. Inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil, and nonuniform distribution of remaining oil have all contributed to poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated formation sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. The advanced technologies to be applied include: (1) Develop three-dimensional (3-D) deterministic and stochastic geologic models. (2) Develop 3-D deterministic and stochastic thermal reservoir simulation models to aid in reservoir management and subsequent development work. (3) Develop computerized 3-D visualizations of the geologic and reservoir simulation models to aid in analysis. (4) Perform detailed study on the geochemical interactions between the steam and the formation rock and fluids. (5) Pilot steam injection and production via four new horizontal wells (2 producers and 2 injectors). (6) Hot water alternating steam (WAS) drive pilot in the

  4. Advances in Front-end Enabling Technologies for Thermal Infrared `THz Torch' Wireless Communications

    Science.gov (United States)

    Hu, Fangjing; Lucyszyn, Stepan

    2016-05-01

    The thermal (emitted) infrared frequency bands (typically 20-40 and 60-100 THz) are best known for remote sensing applications that include temperature measurement (e.g. non-contacting thermometers and thermography), night vision and surveillance (e.g. ubiquitous motion sensing and target acquisition). This unregulated part of the electromagnetic spectrum also offers commercial opportunities for the development of short-range secure communications. The `THz Torch' concept, which fundamentally exploits engineered blackbody radiation by partitioning thermally generated spectral radiance into pre-defined frequency channels, was recently demonstrated by the authors. The thermal radiation within each channel can be independently pulse-modulated, transmitted and detected, to create a robust form of short-range secure communications within the thermal infrared. In this paper, recent progress in the front-end enabling technologies associated with the THz Torch concept is reported. Fundamental limitations of this technology are discussed; possible engineering solutions for further improving the performance of such thermal-based wireless links are proposed and verified either experimentally or through numerical simulations. By exploring a raft of enabling technologies, significant enhancements to both data rate and transmission range can be expected. With good engineering solutions, the THz Torch concept can exploit nineteenth century physics with twentieth century multiplexing schemes for low-cost twenty-first century ubiquitous applications in security and defence.

  5. Advances in Front-end Enabling Technologies for Thermal Infrared ` THz Torch' Wireless Communications

    Science.gov (United States)

    Hu, Fangjing; Lucyszyn, Stepan

    2016-09-01

    The thermal (emitted) infrared frequency bands (typically 20-40 and 60-100 THz) are best known for remote sensing applications that include temperature measurement (e.g. non-contacting thermometers and thermography), night vision and surveillance (e.g. ubiquitous motion sensing and target acquisition). This unregulated part of the electromagnetic spectrum also offers commercial opportunities for the development of short-range secure communications. The ` THz Torch' concept, which fundamentally exploits engineered blackbody radiation by partitioning thermally generated spectral radiance into pre-defined frequency channels, was recently demonstrated by the authors. The thermal radiation within each channel can be independently pulse-modulated, transmitted and detected, to create a robust form of short-range secure communications within the thermal infrared. In this paper, recent progress in the front-end enabling technologies associated with the THz Torch concept is reported. Fundamental limitations of this technology are discussed; possible engineering solutions for further improving the performance of such thermal-based wireless links are proposed and verified either experimentally or through numerical simulations. By exploring a raft of enabling technologies, significant enhancements to both data rate and transmission range can be expected. With good engineering solutions, the THz Torch concept can exploit nineteenth century physics with twentieth century multiplexing schemes for low-cost twenty-first century ubiquitous applications in security and defence.

  6. The General Discussion on Thermal Technologies in Advanced Space Transfer Vehicles

    Science.gov (United States)

    Qi, Feng; Wang, Guo-hui

    2016-07-01

    In recent years, the boundary of space exploration has been wider and wider. So the demand of new-generation spacecrafts, carriers and transfer vehicles becomes urged. In this article, thermal questions and first-stage counter-measure technical methods and the relative important recent improvements in these methods are discussed about two important types of new conceptive Space Transfer Vehicles (STVs), the nuclear-thermal propelling STV and laser propelled STV, especially on the heat generation, heat collection, heat transfer and heat control. At the end of this article, pieces of advice and several predictions are put forward, generally and principally.

  7. Advancing Reactive Tracer Methods for Measurement of Thermal Evolution in Geothermal Reservoirs: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; Laurence C. Hull; George D. Redden

    2011-07-01

    The injection of cold fluids into engineered geothermal system (EGS) and conventional geothermal reservoirs may be done to help extract heat from the subsurface or to maintain pressures within the reservoir (e.g., Rose et al., 2001). As these injected fluids move along fractures, they acquire heat from the rock matrix and remove it from the reservoir as they are extracted to the surface. A consequence of such injection is the migration of a cold-fluid front through the reservoir (Figure 1) that could eventually reach the production well and result in the lowering of the temperature of the produced fluids (thermal breakthrough). Efficient operation of an EGS as well as conventional geothermal systems involving cold-fluid injection requires accurate and timely information about thermal depletion of the reservoir in response to operation. In particular, accurate predictions of the time to thermal breakthrough and subsequent rate of thermal drawdown are necessary for reservoir management, design of fracture stimulation and well drilling programs, and forecasting of economic return. A potential method for estimating migration of a cold front between an injection well and a production well is through application of reactive tracer tests, using chemical whose rate of degradation is dependent on the reservoir temperature between the two wells (e.g., Robinson 1985). With repeated tests, the rate of migration of the thermal front can be determined, and the time to thermal breakthrough calculated. While the basic theory behind the concept of thermal tracers has been understood for some time, effective application of the method has yet to be demonstrated. This report describes results of a study that used several methods to investigate application of reactive tracers to monitoring the thermal evolution of a geothermal reservoir. These methods included (1) mathematical investigation of the sensitivity of known and hypothetical reactive tracers, (2) laboratory testing of novel

  8. ADVANCING REACTIVE TRACER METHODS FOR MONITORING THERMAL DRAWDOWN IN GEOTHERMAL ENHANCED GEOTHERMAL RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell A. Plummer; Carl D. Palmer; Earl D. Mattson; George D. Redden; Laurence C. Hull

    2010-10-01

    Reactive tracers have long been considered a possible means of measuring thermal drawdown in a geothermal system, before significant cooling occurs at the extraction well. Here, we examine the sensitivity of the proposed method to evaluate reservoir cooling and demonstrate that while the sensitivity of the method as generally proposed is low, it may be practical under certain conditions.

  9. Advances of study on thermal-hydraulic performance in tight-lattice rod bundles for reduced-moderation water reactors

    International Nuclear Information System (INIS)

    R and D project to investigate thermal-hydraulic performance in tight-lattice rod bundles for Reduced-Moderation Water Reactor (RMWR) is started at Japan Atomic Energy Research Institute in collaboration with power company, reactor vendors, universities since 2002. The RMWR can attain the favorable characteristics such as effective utilization of uranium resources, multiple recycling of plutonium, high burn-up and long operation cycle, based on matured LWR technologies. MOX fuel assemblies with tight lattice arrangement are used to increase the conversion ratio by reducing the moderation of neutron. Increasing the in-core void fraction also contributes to the reduction of neutron moderation. The confirmation of thermal-hydraulic feasibility is one of the most important R and D items for the RMWR because of the tight-lattice configuration. In this paper, we will show the R and D plan and describe some advances on experimental and analytical studies. The experimental study is performed mainly using large-scale (37-rod bundle) test facility and the analytical one aims to develop a predictable technology for geometry effects such as gap between rods, grid spacer configuration etc. using advanced 3-D two-phase flow simulation methods. Steady-state and transient critical power experiments are conducted with the test facility (Gap width between rods: 1.0 mm) and the experimental data reveal the feasibility of RMWR. (authors)

  10. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2001-06-27

    The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California through the testing and application of advanced reservoir characterization and thermal production technologies. The successful application of these technologies will result in expanding their implementation throughout the Wilmington Field and, through technology transfer, to other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block II-A (Tar II-A) has been relatively inefficient because of several producibility problems which are common in SBC reservoirs: inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early steam breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves. A suite of advanced reservoir characterization and thermal production technologies are being applied during the project to improve oil recovery and reduce operating costs.

  11. Springtime carbon episodes at Gosan background site revealed by total carbon, stable carbon isotopic composition, and thermal characteristics of carbonaceous particles

    Directory of Open Access Journals (Sweden)

    J. Jung

    2011-05-01

    Full Text Available In order to investigate the carbon episodes at Gosan background super-site (33.17° N, 126.10° E in East Asia during spring of 2007 and 2008, total suspended particles (TSP were collected and analyzed for particulate organic carbon, elemental carbon, total carbon (TC, total nitrogen (TN, and stable carbon isotopic composition (δ13C of TC. The carbon episodes at the Gosan site were categorized as long-range transported anthropogenic pollutant (LTP from Asian continent, Asian dust (AD accompanying with LTP, and local pollen episodes. The stable carbon isotopic composition of TC (δ13CTC was found to be lowest during the pollen episodes (range: −26.2 ‰ to −23.5 ‰, avg.: −25.2 ± 0.9 ‰, followed by the LTP episodes (range: −23.5 ‰ to −23.0 ‰, avg.: −23.3 ± 0.3 ‰ and the AD episodes (range: −23.3 to −20.4 %, avg.: −21.8 ± 2.0 ‰. The δ13CTC of the airborne pollens (−28.0 ‰ collected at the Gosan site showed value similar to that of tangerine fruit (−28.1 ‰ produced from Jeju Island. Based on the carbon isotope mass balance equation and the TN and TC regression approach, we found that ∼40–45 % of TC in the TSP samples during the pollen episodes was attributed to airborne pollens from Japanese cedar trees planted around tangerine farms in Jeju Island. The δ13C of citric acid in the airborne pollens (−26.3 ‰ collected at the Gosan site was similar to that in tangerine fruit (−27.4 ‰. The negative correlation between the citric acid-carbon/TC ratios and δ13CTC were obtained during the pollen episodes. These results suggest that citric acid emitted from tangerine fruit may be adsorbed on the airborne pollens and then transported to the Gosan site. Based on the thermal evolution pattern of organic aerosols during the carbon episodes, we found that organic aerosols originated from East China are more volatile on

  12. Assessment of groundwater pollution from ash ponds using stable and unstable isotopes around the Koradi and Khaperkheda thermal power plants (Maharashtra, India)

    Energy Technology Data Exchange (ETDEWEB)

    Voltaggio, M.; Spadoni, M. [CNR — Istituto di Geologia Ambientale e Geoingegneria, Via Salaria km. 29.300, 00010 Montelibretti, Roma (Italy); Sacchi, E. [Dept. of Earth and Environmental Sciences, University of Pavia and CNR-IGG, Via Ferrata 1, 27100 Pavia (Italy); Sanam, R.; Pujari, P.R.; Labhasetwar, P.K. [CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur 440020 (India)

    2015-06-15

    The impact on local water resources due to fly ash produced in the Koradi and Khaperkheda thermal power plants (district of Nagpur, Maharashtra — India) and disposed in large ponds at the surface was assessed through the study of environmental variation of ratios of stable and unstable isotopes. Analyses of oxygen and hydrogen isotopes suggest scarce interaction between the water temporarily stored in the ponds and the groundwater in the study area. Data also highlight that the high salinity of groundwater measured in the polluted wells is not due to evaporation, but to subsequent infiltration of stream waters draining from the ponds to the local aquifer. {sup 87}Sr/{sup 86}Sr values, when associated with Sr/Ca ratios, demonstrate the dominant role of waste waters coming from tens of brick kilns surrounding the pond sulfate pollution. Uranium isotopic analyses clearly show evidence of the interaction between groundwater and aquifer rocks, and confirm again the low influence of ash ponds. A new conceptual model based on the study of the isotopes of radium is also proposed and used to estimate residence times of groundwater in the area. This model highlights that high salinity cannot be in any case attributed to a prolonged water–rock interaction, but is due to the influence of untreated waste water of domestic or brick kiln origin on the shallow and vulnerable aquifers. - Highlights: • Ash ponds have wide environmental and social impact in India. • Isotope ratios can be used as tracers for possible pollution of groundwater. • Isotopes of O, H, Sr, U and Ra have been used to investigate the area of Koradi. • Salinity of groundwater is not due to fly ash but linked to local brick kilns. • A model for the residence time of water based on Ra isotopes is described.

  13. Assessment of groundwater pollution from ash ponds using stable and unstable isotopes around the Koradi and Khaperkheda thermal power plants (Maharashtra, India)

    International Nuclear Information System (INIS)

    The impact on local water resources due to fly ash produced in the Koradi and Khaperkheda thermal power plants (district of Nagpur, Maharashtra — India) and disposed in large ponds at the surface was assessed through the study of environmental variation of ratios of stable and unstable isotopes. Analyses of oxygen and hydrogen isotopes suggest scarce interaction between the water temporarily stored in the ponds and the groundwater in the study area. Data also highlight that the high salinity of groundwater measured in the polluted wells is not due to evaporation, but to subsequent infiltration of stream waters draining from the ponds to the local aquifer. 87Sr/86Sr values, when associated with Sr/Ca ratios, demonstrate the dominant role of waste waters coming from tens of brick kilns surrounding the pond sulfate pollution. Uranium isotopic analyses clearly show evidence of the interaction between groundwater and aquifer rocks, and confirm again the low influence of ash ponds. A new conceptual model based on the study of the isotopes of radium is also proposed and used to estimate residence times of groundwater in the area. This model highlights that high salinity cannot be in any case attributed to a prolonged water–rock interaction, but is due to the influence of untreated waste water of domestic or brick kiln origin on the shallow and vulnerable aquifers. - Highlights: • Ash ponds have wide environmental and social impact in India. • Isotope ratios can be used as tracers for possible pollution of groundwater. • Isotopes of O, H, Sr, U and Ra have been used to investigate the area of Koradi. • Salinity of groundwater is not due to fly ash but linked to local brick kilns. • A model for the residence time of water based on Ra isotopes is described

  14. Correlation between electrochemical characteristics and thermal stability of advanced lithium-ion batteries in abuse tests--short-circuit tests

    International Nuclear Information System (INIS)

    The shutdown function of a separator is an important factor in the safety of advanced lithium-ion batteries (ALB). When a separator without proper shutdown function is used, battery safety would depend on the thermal stability of electrode materials. Results show that thermal stability of a battery, contributed from both the anode and cathode, decreases noticeably after cycling. DSC shows that exothermicity from SEI decomposition and the reaction of the lithiated graphite and electrolyte around 140 deg. C increases as cycle number increase; main reason is the gradual thickening of passivation film, observed through three-electrode ac impedance measurements. DSC also shows a similar trend of exothermicity for LixCoO2 cathode. The lesser the amount of lithium (x-value) in LixCoO2, the larger the exothermicity and the lower the decomposition temperature. Using a three-electrode system to observe the changes of open-circuit potential in LixCoO2 cathode, thermal instability is a consequence of decreased lithium content as cycle increases

  15. Advanced WC-Co cermet composites with reinforcement of TiCN prepared by extended thermal plasma route

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, B. [Centre for Advanced Materials Processing, Central Mechanical Engineering Research Institute, Mahatma Gandhi Avenue, Durgapur 713 209, West Bengal (India)], E-mail: bnmondal@rediffmail.com; Das, P.K. [Central Glass and Ceramic Research Institute, Kolkata (India); Singh, S.K. [Institute of Minerals and Materials Technology (IIMT), Bhubeneswar (India)

    2008-12-20

    The synthesis of titanium carbonitride (TiCN) powders by thermal plasma using extended arc thermal plasma reactor and the effect of TiCN reinforcement for the development of advanced WC-Co cermets has been studied with respect to hardness and fracture toughness. These classes of materials are being investigated for future application in wear-resistant seals, cutting tools, etc. Metallurgical reactions and microstructural developments during sintering of cermets and functionally graded cemented carbonitrides are being investigated by analytical methods such as differential thermal analysis/thermo-gravimetric analysis, X-ray diffraction and analytical Scanning electron microscopy with energy dispersive X-ray spectroscopy. By an in-depth understanding of the complex phase reactions and the mechanisms that govern the sintering process and metallurgical reactions, new cermets and different types of functionally graded cemented carbonitrides with desired microstructures and properties have been attempted to develop. The significant improvement of micro-hardness was observed with optimal concentration of TiCN reinforcement addition in WC-Co system without sacrificing much fracture toughness value of the composite cermets.

  16. Blanch Resistant and Thermal Barrier NiAl Coating Systems for Advanced Copper Alloys

    Science.gov (United States)

    Raj, Sai V. (Inventor)

    2005-01-01

    A method of forming an environmental resistant thermal barrier coating on a copper alloy is disclosed. The steps include cleansing a surface of a copper alloy, depositing a bond coat on the cleansed surface of the copper alloy, depositing a NiAl top coat on the bond coat and consolidating the bond coat and the NiAl top coat to form the thermal barrier coating. The bond coat may be a nickel layer or a layer composed of at least one of copper and chromium-copper alloy and either the bond coat or the NiAl top coat or both may be deposited using a low pressure or vacuum plasma spray.

  17. ADVANCED COMPUTATIONALMETHODS FOR COMPLEX SIMULATION OF THERMAL PROCESSES IN POWER ENGINEERING

    Directory of Open Access Journals (Sweden)

    Risto V. Filkoski

    2007-04-01

    Full Text Available The overall frame and principal steps of complex numerical modelling of thermal processes in power boiler furnaces on pulverised coal with tangential disposition of the burners are presented in the paper. Computational fluid dynamics (CFD technique is used as a tool to perform comprehensive thermal analysis in two test cases. The methodology for creation of three-dimensional models of boiler furnaces is briefly described. Standard steady k- model is employed for description of the turbulent flow. The coupling of continuity and momentum is achieved by the SIMPLEC method. Coal combustion is modelled by the mixture fraction/probability density function approach for the reaction chemistry, with equilibrium assumption applied for description of the system chemistry. Thermal radiation is computed by means of the simplified P-N model, based on expansion of the radiation intensity into an orthogonal series of spherical harmonics.Comparison between the simulation predictions and available site measurements leads to a conclusion that the model produces realistic insight into the furnace processes. Qualitative agreement of the results indicates reasonability of the calculations and validates the employed sub-models. The described test cases and other experiences with CFD modelling stress the advantages over a purely field data study, such as the ability to quickly and cheaply analyse a variety of design options without actually modifying the object and the availability of significantly more data to interpret the results.

  18. Advances in thermal energy storage development at the German Aerospace Center(DLR)

    Institute of Scientific and Technical Information of China (English)

    Laing; Doerte; Steinmann; Wolf-Dieter; Tamme; Rainer; Wrner; Antje; Zunft; Stefan

    2012-01-01

    Thermal energy storage(TES)is a key technology for renewable energy utilization and the improvement of the energy efficiency of heat processes.Sectors include industrial process heat and conventional and renewable power generation.TES systems correct the mismatch between supply and demand of thermal energy.In the medium to high temperature range(100~1000℃),only limited storage technology is commercially available and a strong effort is needed to develop a range of storage technologies which are efficient and economical for the very specific requirements of the different application sectors.At the DLR’s Institute of Technical Thermodynamics,the complete spectrum of high temperature storage technologies,from various types of sensible over latent heat to thermochemical heat storages are being developed.Different concepts are proposed depending on the heat transfer fluid(synthetic oil,water/steam,molten salt,air)and the required temperature range.The aim is the development of cost effective,efficient and reliable thermal storage systems.Research focuses on characterization of storage materials,enhancement of internal heat transfer,design of innovative storage concepts and modelling of storage components and systems.Demonstration of the storage technology takes place from laboratory scale to field testing(5 kW~1 MW).The paper gives an overview on DLR’s current developments.

  19. Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems

    OpenAIRE

    Ho, Tony

    2012-01-01

    The Organic Flash Cycle (OFC) is proposed as a vapor power cycle that could potentially increase power generation and improve the utilization efficiency of renewable energy and waste heat recovery systems. A brief review of current advanced vapor power cycles including the Organic Rankine Cycle (ORC), the zeotropic Rankine cycle, the Kalina cycle, the transcritical cycle, and the trilateral flash cycle is presented. The premise and motivation for the OFC concept is that essentially by impro...

  20. Retarded-Advanced N-point Green Functions in thermal field theories

    OpenAIRE

    Guerin, F.

    1993-01-01

    The general relationship between a Retarded-Advanced Green function of the Real Time formalism and analytical continuations of the Imaginary Time Amplitude is obtained via perturbation theory. A 4-point R-A function is, at most, a linear combination of three analytical continuations, and a 5-point R-A function of seven continuations. The R-A functions are written as the sum of one analytical continuation plus discontinuities across single momentum transfer variables. These discontinuities

  1. Maximizing the Use of Satellite Thermal Infrared Data for Advancing Land Surface Temperature Analysis

    Science.gov (United States)

    Weng, Q.; Fu, P.; Gao, F.

    2014-12-01

    Land surface temperature (LST) is a crucial parameter in investigating environmental, ecological processes and climate change at various scales, and is also valuable in the studies of evapotranspiration, soil moisture conditions, surface energy balance, and urban heat islands. These studies require thermal infrared (TIR) images at both high temporal and spatial resolution to retrieve LST. However, currently, no single satellite sensors can deliver TIR data at both high temporal and spatial resolution. Thus, various algorithms/models have been developed to enhance the spatial or the temporal resolution of TIR data, but rare of those can enhance both spatial and temporal details. This paper presents a new data fusion algorithm for producing Landsat-like LST data by blending daily MODIS and periodic Landsat TM datasets. The original Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) was improved and modified for predicting thermal radiance and LST data by considering annual temperature cycle (ATC) and urban thermal landscape heterogeneity. The technique of linear spectral mixture analysis was employed to relate the Landsat radiance with the MODIS one, so that the temporal changes in radiance can be incorporated in the fusion model. This paper details the theoretical basis and the implementation procedures of the proposed data fusion algorithm, Spatio-temporal Adaptive Data Fusion Algorithm for Temperature mapping (SADFAT). A case study was conducted that predicted LSTs of five dates in 2005 from July to October in Los Angeles County, California. The results indicate that the prediction accuracy for the whole study area ranged from 1.3 K to 2 K. Like existing spatio-temporal data fusion models, the SADFAT method has a limitation in predicting LST changes that were not recorded in the MODIS and/or Landsat pixels due to the model assumption.

  2. Advances in understanding of the mechanism for generation of earthquake thermal precursors detected by satellites

    Science.gov (United States)

    Saraf, Arun K.; Rawat, Vineeta; Choudhury, Swapnamita; Dasgupta, Sudipta; Das, Josodhir

    2009-12-01

    Stresses building up during an earthquake preparation phase also manifest themselves in the form of a so called increased land surface temperature (LST) leading to a thermal precursor prior to the earthquake event. This phenomenon has now been validated by our observations of short-term thermal anomalies detected by infrared satellite sensors for several recent past earthquakes around the world. The rise in infrared radiance temperature was seen to vary between 5 and 12 °C for different earthquakes. We discuss in this paper different explanations for the generation of such anomalies that have been offered. Emission of gases due to the opening and closure of micropores upon induced stresses and also the participation of ground water have been propounded as a possible cause for generation of thermal anomalies. Seismo-ionosphere coupling, by which gases like radon move to the earth-atmosphere interface and cause air ionization thus bringing about a change in air temperature, relative humidity, etc., has been put forth by some workers. A mechanism of low frequency electromagnetic emission was tested and experimented by scientists with rock masses in stressed conditions as those that exist at tectonic locations. The workers proposed the positive hole pair theory, which received support from several scientific groups. Positive holes (sites of electron deficiency) are activated in stressed rocks from pre-existing yet dormant positive hole pairs (PHPs) and their recombination at rock-air interface leads to a LST rise. A combination of remote sensing detection of rock mechanics behavior with a perception of chemistry and geophysics has been applied to propose the remote sensing rock mechanics theory. Remote sensing detections of such anomalies confirm so far proposed lab theories for such a hotly debated field as earthquake precursor study by providing unbiased observations with consistency in time and space distribution.

  3. Advances in Thermal Modeling of Selective Laser Sintering of Metal Powders

    CERN Document Server

    Xiao, Bin

    2016-01-01

    Selective laser sintering (SLS) of single component metal powders is a rapid prototyping technology in which a high-energy laser beam scans, melts, shrinks and consolidates metal powders with single component. For better understanding physical mechanisms during laser sintering of single-component metal particles, a temperature transforming model with the consideration of shrinkage and convective flows is introduced to analyze the thermal/fluid behaviors in selective laser sintering of single powder layer. The model is also applied to investigate the sintering of powders on top of existing sintered layers under single- multiple-line scanning manners according to the practical manufacturing processes.

  4. Advanced welding for closed structure. Pt. 4 The thermal approach. A more deep parametric study

    Energy Technology Data Exchange (ETDEWEB)

    Sacripanti, A.; Bonanno, G. [ENEA Centro Ricerche Casaccia, Rome (Italy). Dipt. Innovazione

    1999-07-01

    This report describes the activities developed for the European Contract BRITE AWCS III to study the use of thermal sensing techniques to obtain an accurate detection of the internal reinforcement of the closed steel structures employed in the shipbuilding industry. In this paper there are described the study applied to the thermal transitory. The parametric experimental study on the heaters and on the steel plate. The mathematical theoretical approach to the problem, the study on the air-gap problem between plate and web and its theoretical and practical solution are discussed. [Italian] Questo rapporto descrive le attivita' sperimentali sviluppate nell'ambito del contratto europeo BRITE AWCS III, in cui si sono utilizzate tecniche termiche per ottenere un preciso rilevamento dei rinforzi interni di strutture metalliche chiuse utilizzate nell'industria delle costruzioni navali. In questo rapporto sono descritti gli approfondimenti sul transitorio termico, gli studi parametrici sui riscaldatori e sulle superfici in acciaio delle lamiere. E' stato sviluppato anche un modello matematico del transitorio termico ed affrontato il problema del gap di aria tra lamiera e web con una modellazione della soluzione teorica e pratica.

  5. Advanced Coupled Simulation of Borehole Thermal Energy Storage Systems and Above Ground Installations

    Science.gov (United States)

    Welsch, Bastian; Rühaak, Wolfram; Schulte, Daniel O.; Bär, Kristian; Sass, Ingo

    2016-04-01

    Seasonal thermal energy storage in borehole heat exchanger arrays is a promising technology to reduce primary energy consumption and carbon dioxide emissions. These systems usually consist of several subsystems like the heat source (e.g. solarthermics or a combined heat and power plant), the heat consumer (e.g. a heating system), diurnal storages (i.e. water tanks), the borehole thermal energy storage, additional heat sources for peak load coverage (e.g. a heat pump or a gas boiler) and the distribution network. For the design of an integrated system, numerical simulations of all subsystems are imperative. A separate simulation of the borehole energy storage is well-established but represents a simplification. In reality, the subsystems interact with each other. The fluid temperatures of the heat generation system, the heating system and the underground storage are interdependent and affect the performance of each subsystem. To take into account these interdependencies, we coupled a software for the simulation of the above ground facilities with a finite element software for the modeling of the heat flow in the subsurface and the borehole heat exchangers. This allows for a more realistic view on the entire system. Consequently, a finer adjustment of the system components and a more precise prognosis of the system's performance can be ensured.

  6. Recent advances in the GPUSPH model for the thermal and rheological evolution of lava flows

    Science.gov (United States)

    Zago, Vito; Bilotta, Giuseppe; Cappello, Annalisa; Dalrymple, Robert A.; Fortuna, Luigi; Ganci, Gaetana; Herault, Alexis; Del Negro, Ciro

    2016-04-01

    GPUSPH is a fully three-dimensional model for the simulation of the thermal and rheological evolution of lava flows that relies on the Smoothed Particle Hydrodynamics (SPH) numerical method. Thanks to the Lagrangian, meshless nature of SPH, the model incorporates a more complete physical description of the emplacement process and rheology of lava that considers the free surface, the irregular boundaries represented by the topography, the solidification fronts and the non-Newtonian rheology. Because of the very high degree of parallelism, GPUSPH is implemented very efficiently on high-performance graphics processing units (GPUs) employing the Compute Unified Device Architecture (CUDA), a parallel programming language developed by NVIDIA for GPU computing. GPUSPH follows the very general Herschel-Bulkley rheological model, which encompasses Newtonian, power-law and Bingham flow behaviour and can thus be used to explore in detail the impact of rheology on the behaviour of lava flows and on their emplacement. We present here the first validation tests of the GPUSPH model against well known analytical problems, considering the different rheological models, heat exchanges by thermal conduction and radiation, and providing the relative error estimates.

  7. Non-Thermal Plasma (NTP) session overview: Second International Symposium on Environmental Applications of Advanced Oxidation Technologies (AOTs)

    International Nuclear Information System (INIS)

    Advanced Oxidation Technologies (used in pollution control and treating hazardous wastes) has expanded from using hydroxyl radicals to treat organic compounds in water, to using reductive free radicals as well, and to application to pollutants in both gases and aqueous media. Non-Thermal Plasma (NTP) is created in a gas by an electrical discharge or energetic electron injection. Highly reactive species (O atoms, OH, N radicals, plasma electrons) react with entrained hazardous organic chemicals in the gas, converting them to CO2, H2O, etc. NTP can be used to simultaneously remove different kinds of pollutants (eg, VOCs, SOx, NOx in flue gases). This paper presents an overview of NTP technology for pollution control and hazardous waste treatment; it is intended as an introduction to the NTP session of the symposium

  8. Expected very-near-field thermal environments for advanced spent-fuel and defense high-level waste packages

    International Nuclear Information System (INIS)

    The very-near-field thermal environments expected in a nuclear waste repository in a salt formation have been evaluated for the Westinghouse Form I advanced waste package concepts. The repository descriptions used to supplement the waste package designs in these analyses are realistic and take into account design constraints to assure conservatism. As a result, areal loadings are well below the acceptable values established for salt repositories. Predicted temperatures are generally well below any temperature limits which have been discussed for waste packages in a salt formation. These low temperatures result from the conservative repository designs. Investigations are also made of the sensitivity of these temperatures to areal loading, canister separation, and other design features

  9. Thermal-hydraulic experiments of an advanced PIUS-type reactor

    International Nuclear Information System (INIS)

    The author constructed a semi-large scale experimental apparatus for simulating thermal-hydraulic behavior of the PIUS-type reactor with keeping the volumetric scaling ratio to the realistic reactor model. Fundamental experiments such as a steady state operation and a pump trip simulation were reported in ICONE-3(1995). In this paper the authors present two main results. One is a feedback control system using the upper density lock, and a start up simulation based on the non-uniform heating for both the primary loop and the poison loop. The other is a control system of small scale sub-loop attached to the poison loop in order to establish PIUS principle on the realistic operation of the PIUS-type reactor

  10. Consideration of a design optimization method for advanced nuclear power plant thermal-hydraulic components

    International Nuclear Information System (INIS)

    In order to meet the global energy demand and also mitigate climate change, we anticipate a significant resurgence of nuclear power in the next 50 years. Globally, Generation III plants (ABWR) have been built; Gen' III+ plants (EPR, AP1000 others) are anticipated in the near term. The U.S. DOE and Japan are respectively pursuing the NGNP and MSFR. There is renewed interest in closing the fuel cycle and gradually introducing the fast reactor into the LWR-dominated global fleet. In order to meet Generation IV criteria, i.e. thermal efficiency, inherent safety, proliferation resistance and economic competitiveness, plant and energy conversion system engineering design have to increasingly meet strict design criteria with reduced margin for reliable safety and uncertainties. Here, we considered a design optimization approach using an anticipated NGNP thermal system component as a Case Study. A systematic, efficient methodology is needed to reduce time consuming trial-and-error and computationally-intensive analyses. We thus developed a design optimization method linking three elements; that is, benchmarked CFD used as a 'design tool', artificial neural networks (ANN) to accommodate non-linear system behavior and enhancement of the 'design space', and finally, response surface methodology (RSM) to optimize the design solution with targeted constraints. The paper presents the methodology including guiding principles, an integration of CFD into design theory and practice, consideration of system non-linearities (such as fluctuating operating conditions) and systematic enhancement of the design space via application of ANN, and a stochastic optimization approach (RSM) with targeted constraints. Results from a Case Study optimizing the printed circuit heat exchanger for the NGNP energy conversion system will be presented. (author)

  11. Advanced exergy analysis and exergoeconomic performance evaluation of thermal processes in an existing industrial plant

    International Nuclear Information System (INIS)

    Highlights: • Exergoeconomic analysis of a complex industrial energy supply plant is presented. • Unavoidable exergy destruction is used to identify efficiency increase potential. • Measures for plant improvements are evaluated with respect to efficiency and costs. • Measures result with higher exergy efficiency and reduced fuel and product costs. - Abstract: Exergy analysis and exergoeconomics are often used to evaluate industrial energy systems performance from the thermodynamic and economic points of view. While the classical exergy analysis can be used to recognize the sources of inefficiency and irreversibilities, so called advanced exergy analysis is convenient for identifying real potential for thermodynamic improvements of the system by splitting exergy destruction into avoidable and unavoidable parts. In this paper, the advanced exergy analysis is used to identify performance critical components and the potential for exergy efficiency improvement of a complex industrial energy supply plant. This plant is a part of a rubber factory and its role is to provide steam, compressed air and cooling water to the production facilities, as well as hot water for space heating and sanitary use. The plant is first analyzed as is and the avoidable (and the unavoidable) part of exergy destruction is identified for each observed component. Then, the measures for removing the avoidable destruction are defined. Finally, the plant is analyzed as if the measures were implemented and avoidable losses eliminated. Numerical analysis is based on real data, some of which are collected during on site measurements. Large system of nonlinear and linear equations is defined and solved numerically using the Engineering Equation Solver. Results of the presented analysis show the difference in thermodynamic and economic operational parameters of the plant for the cases without and with the efficiency measures implemented, i.e. the current state and the state with the avoidable

  12. Thermohydraulic Design Analysis Modeling for Korea Advanced NUclear Thermal Engine Rocket for Space Application

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Choi, Jae Young; Venneria, Paolo F.; Jeong, Yong Hoon; Chang, Soon Heung [KAIST, Daejeon (Korea, Republic of)

    2015-05-15

    Space exploration is a realistic and profitable goal for long-term humanity survival, although the harsh space environment imposes lots of severe challenges to space pioneers. To date, almost all space programs have relied upon Chemical Rockets (CRs) rating superior thrust level to transit from the Earth's surface to its orbit. However, CRs inherently have insurmountable barrier to carry out deep space missions beyond Earth's orbit due to its low propellant efficiency, and ensuing enormous propellant requirement and launch costs. Meanwhile, nuclear rockets typically offer at least two times the propellant efficiency of a CR and thus notably reduce the propellant demand. Particularly, a Nuclear Thermal Rocket (NTR) is a leading candidate for near-term manned missions to Mars and beyond because it satisfies a relatively high thrust as well as a high efficiency. The superior efficiency of NTRs is due to both high energy density of nuclear fuel and the low molecular weight propellant of Hydrogen (H{sub 2}) over the chemical reaction by-products. A NTR uses thermal energy released from a nuclear fission reactor to heat the H{sub 2} propellant and then exhausted the highly heated propellant through a propelling nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub s}p) which represents the ratio of the thrust over the propellant consumption rate. If the average exhaust H{sub 2} temperature of a NTR is around 3,000 K, the I{sub s}p can be achieved as high as 1,000 s as compared with only 450 - 500 s of the best CRs. For this reason, NTRs are favored for various space applications such as orbital tugs, lunar transports, and manned missions to Mars and beyond. The best known NTR development effort was conducted from 1955 to1974 under the ROVER and NERVA programs in the USA. These programs had successfully designed and tested many different reactors and engines. After these projects, the researches on NERVA derived

  13. Thermohydraulic Design Analysis Modeling for Korea Advanced NUclear Thermal Engine Rocket for Space Application

    International Nuclear Information System (INIS)

    Space exploration is a realistic and profitable goal for long-term humanity survival, although the harsh space environment imposes lots of severe challenges to space pioneers. To date, almost all space programs have relied upon Chemical Rockets (CRs) rating superior thrust level to transit from the Earth's surface to its orbit. However, CRs inherently have insurmountable barrier to carry out deep space missions beyond Earth's orbit due to its low propellant efficiency, and ensuing enormous propellant requirement and launch costs. Meanwhile, nuclear rockets typically offer at least two times the propellant efficiency of a CR and thus notably reduce the propellant demand. Particularly, a Nuclear Thermal Rocket (NTR) is a leading candidate for near-term manned missions to Mars and beyond because it satisfies a relatively high thrust as well as a high efficiency. The superior efficiency of NTRs is due to both high energy density of nuclear fuel and the low molecular weight propellant of Hydrogen (H2) over the chemical reaction by-products. A NTR uses thermal energy released from a nuclear fission reactor to heat the H2 propellant and then exhausted the highly heated propellant through a propelling nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (Isp) which represents the ratio of the thrust over the propellant consumption rate. If the average exhaust H2 temperature of a NTR is around 3,000 K, the Isp can be achieved as high as 1,000 s as compared with only 450 - 500 s of the best CRs. For this reason, NTRs are favored for various space applications such as orbital tugs, lunar transports, and manned missions to Mars and beyond. The best known NTR development effort was conducted from 1955 to1974 under the ROVER and NERVA programs in the USA. These programs had successfully designed and tested many different reactors and engines. After these projects, the researches on NERVA derived NTR engines have continued as

  14. Preparation of organo clays thermally stable to be employed as filler in PET nano composites; Preparacao de argilas organofilicas estaveis termicamente para serem empregadas como cargas em nanocompositos de PET

    Energy Technology Data Exchange (ETDEWEB)

    Leite, I.F. [Universidade Federal de Pernambuco (PGMTR/CCEN/UFPE), Recife, PE (Brazil). Centro de Ciencias Exatas e da Natureza. Programa de Pos-Graduacao em Ciencia de Materiais; Soares, A.P.S.; Silva, S.M.L. [Universidade Federal de Campina Grande (UAEMa/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Malta, O.M.L. [Universidade Federal de Pernambuco (UFPE), Recife PE (Brazil). Centro de Ciencias Exatas e da Natureza. Dept. de Quimica Fundamental

    2009-07-01

    Thermal stability of organically modified clays is fundamental to melt processing polymer nanocomposites, especially, poly(terephthalate ethylene) (PET). However, the use of organic salts with high thermal stability is factor essential to obtaining of organoclays with great thermal properties. This work has as purpose to evaluate the influence of organic modifier based on alkyl ammonium, alkyl phosphonium and aryl phosphonium, in the clay organic modification visa to improve thermal properties to use as filler in nanocomposites preparation, where temperatures at about 260 deg C will be employed. The most common, and commercially available, surfactants used for cation exchange reactions with montmorillonites, rendering them organophilic, are quaternary ammonium salts, that when present as cations in montmorillonite, typically begin degradation at above 200 deg C. However, organoclays prepared with quaternary alkyl phosphonium salts may be potentially useful for the organoclays preparation stable thermally. In this study bentonite clay from Bentonit Uniao Nordeste/PB was purified and organically modified with the organic salts reported above. Organoclays were characterized by X-ray fluorescence, X-ray diffraction, infrared spectroscopy and analysis thermogravimetry. The results shown that the samples modified with the salts based on phosphonium presented higher thermal stability that the alkyl ammonium salt. (author)

  15. Advanced electro-mechanical micro-shutters for thermal infrared night vision imaging and targeting systems

    Science.gov (United States)

    Durfee, David; Johnson, Walter; McLeod, Scott

    2007-04-01

    Un-cooled microbolometer sensors used in modern infrared night vision systems such as driver vehicle enhancement (DVE) or thermal weapons sights (TWS) require a mechanical shutter. Although much consideration is given to the performance requirements of the sensor, supporting electronic components and imaging optics, the shutter technology required to survive in combat is typically the last consideration in the system design. Electro-mechanical shutters used in military IR applications must be reliable in temperature extremes from a low temperature of -40°C to a high temperature of +70°C. They must be extremely light weight while having the ability to withstand the high vibration and shock forces associated with systems mounted in military combat vehicles, weapon telescopic sights, or downed unmanned aerial vehicles (UAV). Electro-mechanical shutters must have minimal power consumption and contain circuitry integrated into the shutter to manage battery power while simultaneously adapting to changes in electrical component operating parameters caused by extreme temperature variations. The technology required to produce a miniature electro-mechanical shutter capable of fitting into a rifle scope with these capabilities requires innovations in mechanical design, material science, and electronics. This paper describes a new, miniature electro-mechanical shutter technology with integrated power management electronics designed for extreme service infra-red night vision systems.

  16. Advanced Spectroscopic and Thermal Imaging Instrumentation for Shock Tube and Ballistic Range Facilities

    Science.gov (United States)

    Grinstead, Jay H.; Wilder, Michael C.; Reda, Daniel C.; Cruden, Brett A.; Bogdanoff, David W.

    2010-01-01

    The Electric Arc Shock Tube (EAST) facility and Hypervelocity Free Flight Aerodynamic Facility (HFFAF, an aeroballistic range) at NASA Ames support basic research in aerothermodynamic phenomena of atmospheric entry, specifically shock layer radiation spectroscopy, convective and radiative heat transfer, and transition to turbulence. Innovative optical instrumentation has been developed and implemented to meet the challenges posed from obtaining such data in these impulse facilities. Spatially and spectrally resolved measurements of absolute radiance of a travelling shock wave in EAST are acquired using multiplexed, time-gated imaging spectrographs. Nearly complete spectral coverage from the vacuum ultraviolet to the near infrared is possible in a single experiment. Time-gated thermal imaging of ballistic range models in flight enables quantitative, global measurements of surface temperature. These images can be interpreted to determine convective heat transfer rates and reveal transition to turbulence due to isolated and distributed surface roughness at hypersonic velocities. The focus of this paper is a detailed description of the optical instrumentation currently in use in the EAST and HFFAF.

  17. Startup scenarios of an advanced fuel tokamak: First wall and shield thermal response

    International Nuclear Information System (INIS)

    Three different startup scenarios, one using pure D-3He, He, one using pure D-T to assist reaching the D-3 He operating point, and one using a mixture of D-T-3 He, have been analyzed, for the startup of ARIES-III. ARIES-III is a conceptual D-3He tokamak fusion power reactor operating in a second stability configuration. The process of starting the plasma up and bringing it to the desired operating point has been optimized to minimize the need for auxiliary ICRF heating during startup. In the second and third startup scenarios, seeding the plasma with tritium during startup reduces the amount of ICRF power required, but leads to a 14 MeV neutron pulse. Neutronics calculations have been performed to generate the nuclear heating profiles in the first wall and shield. The neutronics results were scaled with the neutron power to determine the nuclear heating profiles at different times during the startup phase. In this work, a two-dimensional transient thermal analysis is performed for the startup phases and the temperature distribution in the first wall and shield as a function of time is presented. The analysis is performed for the worst conditions at the midplane of the outboard region

  18. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2002-01-31

    The project involves using advanced reservoir characterization and thermal production technologies to improve thermal recovery techniques and lower operating and capital costs in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. Through September 2001, project work has been completed on the following activities: data preparation; basic reservoir engineering; developing a deterministic three dimensional (3-D) geologic model, a 3-D deterministic reservoir simulation model and a rock-log model; well drilling and completions; and surface facilities on the Fault Block II-A Tar Zone (Tar II-A). Work is continuing on research to understand the geochemistry and process regarding the sand consolidation well completion technique, final reservoir tracer work, operational work and research studies to prevent thermal-related formation compaction in the Tar II-A steamflood area, and operational work on the Tar V steamflood pilot and Tar II-A post-steamflood projects. The project team spent the Fourth Quarter 2001 performing routine well work and reservoir surveillance on the Tar II-A post-steamflood and Tar V pilot steamflood projects. The Tar II-A post-steamflood operation started in February 1999 and steam chest fillup occurred in September-October 1999. The targeted reservoir pressures in the ''T'' and ''D'' sands are maintained at 90 {+-} 5% hydrostatic levels by controlling water injection and gross fluid production and through the bimonthly pressure monitoring program enacted at the start of the post-steamflood phase. The project team ramped up well work activity from October 2000 through November 2001 to increase production and injection. In December, water injection well FW-88 was plug and abandoned and replaced by new well FW-295 into the ''D'' sands to accommodate the Port of Long Beach at their expense. Well workovers are planned for 2002 as described in the

  19. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2001-11-01

    The project involves using advanced reservoir characterization and thermal production technologies to improve thermal recovery techniques and lower operating and capital costs in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. Through June 2001, project work has been completed on the following activities: data preparation; basic reservoir engineering; developing a deterministic three dimensional (3-D) geologic model, a 3-D deterministic reservoir simulation model and a rock-log model; well drilling and completions; and surface facilities on the Fault Block II-A Tar Zone (Tar II-A). Work is continuing on research to understand the geochemistry and process regarding the sand consolidation well completion technique, final reservoir tracer work, operational work and research studies to prevent thermal-related formation compaction in the Tar II-A steamflood area, and operational work on the Tar V steamflood pilot and Tar II-A post-steamflood projects. The project team spent the Third Quarter 2001 performing well work and reservoir surveillance on the Tar II-A post-steamflood project. The Tar II-A post-steamflood operation started in February 1999 and steam chest fillup occurred in September-October 1999. The targeted reservoir pressures in the ''T'' and ''D'' sands are maintained at 90 {+-} 5% hydrostatic levels by controlling water injection and gross fluid production and through the bimonthly pressure monitoring program enacted at the start of the post-steamflood phase. The project team ramped up well work activity from October 2000 to September 2001 to increase production and injection. This work will continue through 2001 as described in the Operational Management section. Expanding thermal recovery operations to other sections of the Wilmington Oil Field, including the Tar V horizontal well pilot steamflood project, is a critical part of the City of Long Beach and Tidelands Oil

  20. Method and Process Development of Advanced Atmospheric Plasma Spraying for Thermal Barrier Coatings

    Science.gov (United States)

    Mihm, Sebastian; Duda, Thomas; Gruner, Heiko; Thomas, Georg; Dzur, Birger

    2012-06-01

    Over the last few years, global economic growth has triggered a dramatic increase in the demand for resources, resulting in steady rise in prices for energy and raw materials. In the gas turbine manufacturing sector, process optimizations of cost-intensive production steps involve a heightened potential of savings and form the basis for securing future competitive advantages in the market. In this context, the atmospheric plasma spraying (APS) process for thermal barrier coatings (TBC) has been optimized. A constraint for the optimization of the APS coating process is the use of the existing coating equipment. Furthermore, the current coating quality and characteristics must not change so as to avoid new qualification and testing. Using experience in APS and empirically gained data, the process optimization plan included the variation of e.g. the plasma gas composition and flow-rate, the electrical power, the arrangement and angle of the powder injectors in relation to the plasma jet, the grain size distribution of the spray powder and the plasma torch movement procedures such as spray distance, offset and iteration. In particular, plasma properties (enthalpy, velocity and temperature), powder injection conditions (injection point, injection speed, grain size and distribution) and the coating lamination (coating pattern and spraying distance) are examined. The optimized process and resulting coating were compared to the current situation using several diagnostic methods. The improved process significantly reduces costs and achieves the requirement of comparable coating quality. Furthermore, a contribution was made towards better comprehension of the APS of ceramics and the definition of a better method for future process developments.

  1. Advanced core physics and thermal hydraulics analysis of boiling water reactors using innovative fuel concepts

    International Nuclear Information System (INIS)

    The economical operation of a boiling water reactor (BWR) is mainly achieved by the axially uniform utilization of the nuclear fuel in the assemblies which is challenging because the neutron spectrum in the active reactor core varies with the axial position. More precisely, the neutron spectrum becomes harder the higher the position is resulting in a decrease of the fuel utilization because the microscopic fission cross section is smaller by several orders of magnitude. In this work, the use of two fuel concepts based on a mixed oxide (MOX) fuel and an innovative thorium-plutonium (ThPu) fuel is investigated by a developed simulation model encompassing thermal hydraulics, neutronics, and fuel burnup. The main feature of these fuel concepts is the axially varying enrichment in plutonium which is, in this work, recycled from spent nuclear fuel and shows a high fission fraction of the absorption cross section for fast incident neutron energies. The potential of balancing the overall fuel utilization by an increase of the fission rate in the upper part of the active height with a combination of the harder spectrum and the higher fission fraction of the absorption cross section in the BWR core is studied. The three particular calculational models for thermal hydraulics, neutronics, and fuel burnup provide results at fuel assembly and/or at core level. In the former case, the main focus lies on the thermal hydraulics analysis, fuel burnup, and activity evolution after unloading from the core and, in the latter case, special attention is paid to reactivity safety coefficients (feedback effects) and the optimization of the operational behavior. At both levels (assembly and core), the isotopic buildup and depletion rates as a function of the active height are analyzed. In addition, a comparison between the use of conventional fuel types with homogeneous enrichments and the use of the innovative fuel types is made. In the framework of the simulations, the ThPu and the MOX

  2. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER): Data Products for the High Spatial Resolution Imager on NASA's EOS-AMI Platform

    Science.gov (United States)

    Abrams, M.

    1999-01-01

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a high spatial resolution, multispectral imager with along-track stereo capabilities scheduled for launch on the first NASA spacecraft of the Earth Observing System (EOS AM-1) in mid-1999.

  3. Enhancement of methane production in mesophilic anaerobic digestion of secondary sewage sludge by advanced thermal hydrolysis pretreatment.

    Science.gov (United States)

    Abelleira-Pereira, Jose M; Pérez-Elvira, Sara I; Sánchez-Oneto, Jezabel; de la Cruz, Roberto; Portela, Juan R; Nebot, Enrique

    2015-03-15

    Studies on the development and evolution of anaerobic digestion (AD) pretreatments are nowadays becoming widespread, due to the outstanding benefits that these processes could entail in the management of sewage sludge. Production of sewage sludge in wastewater treatment plants (WWTPs) is becoming an extremely important environmental issue. The work presented in this paper is a continuation of our previous studies with the aim of understanding and developing the advanced thermal hydrolysis (ATH) process. ATH is a novel AD pretreatment based on a thermal hydrolysis (TH) process plus hydrogen peroxide (H2O2) addition that takes advantage of a peroxidation/direct steam injection synergistic effect. The main goal of the present research was to compare the performance of TH and ATH, conducted at a wide range of operating conditions, as pretreatments of mesophilic AD with an emphasis on methane production enhancement as a key parameter and its connection with the sludge solubilization. Results showed that both TH and ATH patently improved methane production in subsequent mesophilic BMP (biochemical methane potential) tests in comparison with BMP control tests (raw secondary sewage sludge). Besides other interesting results and discussions, a promising result was obtained since ATH, operated at temperature (115 °C), pretreatment time (5 min) and pressure (1 bar) considerably below those typically used in TH (170 °C, 30 min, 8 bar), managed to enhance the methane production in subsequent mesophilic BMP tests [biodegradability factor (fB) = cumulative CH4production/cumulative CH4production (Control) = 1.51 ± 0.01] to quite similar levels than conventional TH pretreatment [fB = 1.52 ± 0.03].

  4. Preliminary Thermo-hydraulic Core Design Analysis of Korea Advanced Nuclear Thermal Engine Rocket for Space Application

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Seung Hyun; Lee, Jeong Ik; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-05-15

    Nclear rockets improve the propellant efficiency more than twice compared to CRs and thus significantly reduce the propellant requirement. The superior efficiency of nuclear rockets is due to the combination of the huge energy density and a single low molecular weight propellant utilization. Nuclear Thermal Rockets (NTRs) are particularly suitable for manned missions to Mars because it satisfies a relatively high thrust as well as a high propellant efficiency. NTRs use thermal energy released from a nuclear fission reactor to heat a single low molecular weight propellant, i. e., Hydrogen (H{sub 2}) and then exhausted the extremely heated propellant through a thermodynamic nozzle to produce thrust. A propellant efficiency parameter of rocket engines is specific impulse (I{sub sp}) which represents the ratio of the thrust over the rate of propellant consumption. The difference of I{sub sp} makes over three times propellant savings of NTRs for a manned Mars mission compared to CRs. NTRs can also be configured to operate bimodally by converting the surplus nuclear energy to auxiliary electric power required for the operation of a spacecraft. Moreover, the concept and technology of NTRs are very simple, already proven, and safe. Thus, NTRs can be applied to various space missions such as solar system exploration, International Space Station (ISS) transport support, Near Earth Objects (NEOs) interception, etc. Nuclear propulsion is the most promising and viable option to achieve challenging deep space missions. Particularly, the attractions of a NTR include excellent thrust and propellant efficiency, bimodal capability, proven technology, and safe and reliable performance. The ROK has also begun the research for space nuclear systems as a volunteer of the international space race and a major world nuclear energy country. KANUTER is one of the advanced NTR engines currently under development at KAIST. This bimodal engine is operated in two modes of propulsion with 100 MW

  5. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2002-04-30

    The project involves using advanced reservoir characterization and thermal production technologies to improve thermal recovery techniques and lower operating and capital costs in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., Calif. Through December 2001, project work has been completed on the following activities: data preparation; basic reservoir engineering; developing a deterministic three dimensional (3-D) geologic model, a 3-D deterministic reservoir simulation model and a rock-log model; well drilling and completions; and surface facilities on the Fault Block II-A Tar Zone (Tar II-A). Work is continuing on research to understand the geochemistry and process regarding the sand consolidation well completion technique, final reservoir tracer work, operational work and research studies to prevent thermal-related formation compaction in the Tar II-A steamflood area, and operational work on the Tar V steamflood pilot and Tar II-A post-steamflood projects. During the First Quarter 2002, the project team developed an accelerated oil recovery and reservoir cooling plan for the Tar II-A post-steamflood project and began implementing the associated well work in March. The Tar V pilot steamflood project will be converted to post-steamflood cold water injection in April 2002. The Tar II-A post-steamflood operation started in February 1999 and steam chest fillup occurred in September-October 1999. The targeted reservoir pressures in the ''T'' and ''D'' sands are maintained at 90 {+-} 5% hydrostatic levels by controlling water injection and gross fluid production and through the bimonthly pressure monitoring program enacted at the start of the post-steamflood phase. Most of the 2001 well work resulted in maintaining oil and gross fluid production and water injection rates. Reservoir pressures in the ''T'' and ''D'' sands are at 88% and 91% hydrostatic levels

  6. MATLAB/Simulink Framework for Modeling Complex Coolant Flow Configurations of Advanced Automotive Thermal Management Systems: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Titov, Eugene; Lustbader, Jason; Leighton, Daniel; Kiss, Tibor

    2016-03-22

    The National Renewable Energy Laboratory's (NREL's) CoolSim MATLAB/Simulink modeling framework was extended by including a newly developed coolant loop solution method aimed at reducing the simulation effort for arbitrarily complex thermal management systems. The new approach does not require the user to identify specific coolant loops and their flow. The user only needs to connect the fluid network elements in a manner consistent with the desired schematic. Using the new solution method, a model of NREL's advanced combined coolant loop system for electric vehicles was created that reflected the test system architecture. This system was built using components provided by the MAHLE Group and included both air conditioning and heat pump modes. Validation with test bench data and verification with the previous solution method were performed for 10 operating points spanning a range of ambient temperatures between -2 degrees C and 43 degrees C. The largest root mean square difference between pressure, temperature, energy and mass flow rate data and simulation results was less than 7%.

  7. Increasing Heavy Oil Reserves in the Wilmington Oil Field through Advanced Reservoir Characterization and Thermal Production Technologies

    Energy Technology Data Exchange (ETDEWEB)

    City of Long Beach; David K.Davies and Associates; Tidelands Oil Production Company; University of Southern California

    1999-06-25

    The objective of this project is to increase the recoverable heavy oil reserves within sections of the Wilmington Oil Field, near Long Beach, California. This is realized through the testing and application of advanced reservoir characterization and thermal production technologies. It is hoped that the successful application of these technologies will result in their implementation throughout the Wilmington Field and through technology transfer, will be extended to increase the recoverable oil reserves in other slope and basin clastic (SBC) reservoirs. The existing steamflood in the Tar zone of Fault Block (FB) II-A has been relatively insufficient because of several producability problems which are common in SBC reservoir; inadequate characterization of the heterogeneous turbidite sands, high permeability thief zones, low gravity oil and non-uniform distribution of the remaining oil. This has resulted in poor sweep efficiency, high steam-oil ratios, and early breakthrough. Operational problems related to steam breakthrough, high reservoir pressure, and unconsolidated sands have caused premature well and downhole equipment failures. In aggregate, these reservoir and operational constraints have resulted in increased operating costs and decreased recoverable reserves.

  8. Unpredictably Stable

    DEFF Research Database (Denmark)

    Failla, Virgilio; Melillo, Francesca; Reichstein, Toke

    2014-01-01

    Is entrepreneurship a more stable career choice for high employment turnover individuals? We find that a transition to entrepreneurship induces a shift towards stayer behavior and identify job matching, job satisfaction and lock-in effects as main drivers. These findings have major implications...

  9. International benchmark study of advanced thermal hydraulic safety analysis codes against measurements on IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Hainoun, A., E-mail: pscientific2@aec.org.sy [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Doval, A. [Nuclear Engineering Department, Av. Cmdt. Luis Piedrabuena 4950, C.P. 8400 S.C de Bariloche, Rio Negro (Argentina); Umbehaun, P. [Centro de Engenharia Nuclear – CEN, IPEN-CNEN/SP, Av. Lineu Prestes 2242-Cidade Universitaria, CEP-05508-000 São Paulo, SP (Brazil); Chatzidakis, S. [School of Nuclear Engineering, Purdue University, West Lafayette, IN 47907 (United States); Ghazi, N. [Atomic Energy Commission of Syria (AECS), Nuclear Engineering Department, P.O. Box 6091, Damascus (Syrian Arab Republic); Park, S. [Research Reactor Design and Engineering Division, Basic Science Project Operation Dept., Korea Atomic Energy Research Institute (Korea, Republic of); Mladin, M. [Institute for Nuclear Research, Campului Street No. 1, P.O. Box 78, 115400 Mioveni, Arges (Romania); Shokr, A. [Division of Nuclear Installation Safety, Research Reactor Safety Section, International Atomic Energy Agency, A-1400 Vienna (Austria)

    2014-12-15

    Highlights: • A set of advanced system thermal hydraulic codes are benchmarked against IFA of IEA-R1. • Comparative safety analysis of IEA-R1 reactor during LOFA by 7 working teams. • This work covers both experimental and calculation effort and presents new out findings on TH of RR that have not been reported before. • LOFA results discrepancies from 7% to 20% for coolant and peak clad temperatures are predicted conservatively. - Abstract: In the framework of the IAEA Coordination Research Project on “Innovative methods in research reactor analysis: Benchmark against experimental data on neutronics and thermal hydraulic computational methods and tools for operation and safety analysis of research reactors” the Brazilian research reactor IEA-R1 has been selected as reference facility to perform benchmark calculations for a set of thermal hydraulic codes being widely used by international teams in the field of research reactor (RR) deterministic safety analysis. The goal of the conducted benchmark is to demonstrate the application of innovative reactor analysis tools in the research reactor community, validation of the applied codes and application of the validated codes to perform comprehensive safety analysis of RR. The IEA-R1 is equipped with an Instrumented Fuel Assembly (IFA) which provided measurements for normal operation and loss of flow transient. The measurements comprised coolant and cladding temperatures, reactor power and flow rate. Temperatures are measured at three different radial and axial positions of IFA summing up to 12 measuring points in addition to the coolant inlet and outlet temperatures. The considered benchmark deals with the loss of reactor flow and the subsequent flow reversal from downward forced to upward natural circulation and presents therefore relevant phenomena for the RR safety analysis. The benchmark calculations were performed independently by the participating teams using different thermal hydraulic and safety

  10. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  11. Research Progress in Highly Thermally Stable Alumina Aerogels%耐高温氧化铝气凝胶研究进展

    Institute of Scientific and Technical Information of China (English)

    温培刚; 巢雄宇; 袁武华; 顾立

    2016-01-01

    在众多气凝胶中,氧化铝气凝胶不仅热导率低,而且高温稳定性好(长期使用温度高达950℃),在高温催化、高温隔热等领域是一种理想的材料。但在工作温度超过1000℃时,氧化铝气凝胶的使用受到限制。简要介绍了氧化铝气凝胶的制备工艺,分析了氧化铝气凝胶的失效理论,并对其耐高温性能的改善进行了探讨。%Alumina aerogel have better thermal insulation properties and high thermal stability at high tempera-tures than common silica aerogel and would be a promising candidate for high-temperature thermal superinsulations and catalysts.But if working temperature is up to 1000 ℃,the use of alumina aerogel is restricted.This paper briefly introduces the preparation methods and sintering theory of alumina aerogel,and discusses the ways to improve high thermal stability.

  12. Innovative and Advanced Coupled Neutron Transport and Thermal Hydraulic Method (Tool) for the Design, Analysis and Optimization of VHTR/NGNP Prismatic Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rahnema, Farzad; Garimeela, Srinivas; Ougouag, Abderrafi; Zhang, Dingkang

    2013-11-29

    This project will develop a 3D, advanced coarse mesh transport method (COMET-Hex) for steady- state and transient analyses in advanced very high-temperature reactors (VHTRs). The project will lead to a coupled neutronics and thermal hydraulic (T/H) core simulation tool with fuel depletion capability. The computational tool will be developed in hexagonal geometry, based solely on transport theory without (spatial) homogenization in complicated 3D geometries. In addition to the hexagonal geometry extension, collaborators will concurrently develop three additional capabilities to increase the code’s versatility as an advanced and robust core simulator for VHTRs. First, the project team will develop and implement a depletion method within the core simulator. Second, the team will develop an elementary (proof-of-concept) 1D time-dependent transport method for efficient transient analyses. The third capability will be a thermal hydraulic method coupled to the neutronics transport module for VHTRs. Current advancements in reactor core design are pushing VHTRs toward greater core and fuel heterogeneity to pursue higher burn-ups, efficiently transmute used fuel, maximize energy production, and improve plant economics and safety. As a result, an accurate and efficient neutron transport, with capabilities to treat heterogeneous burnable poison effects, is highly desirable for predicting VHTR neutronics performance. This research project’s primary objective is to advance the state of the art for reactor analysis.

  13. Stable compactifications

    Energy Technology Data Exchange (ETDEWEB)

    Accetta, F.S.; Gleiser, M.; Holman, R.; Kolb, E.W.

    1986-03-01

    We show that compactifications of theories with extra dimensions are unstable if due to monopole configurations of an antisymmetric tensor field balanced against one-loop Casimir corrections. In the case of ten dimensional supergravity, it is possible, at least for a portion of the phase space, to achieve a stable compactification without fine-tuning by including the contribution of fermionic condensates to the monopole configurations. 23 refs., 2 figs.

  14. Thermally Stable Forms of Pure Polyaniline Catalyzed by an Acid-Exchanged Montmorillonite Clay Called Maghnite-H+ as an Effective Catalyst

    Directory of Open Access Journals (Sweden)

    Rahmouni Abdelkader

    2012-01-01

    Full Text Available Polyaniline salt form (PANI-ES was synthesized by oxidative polymerization of aniline using potassium persulfate as an oxidant and an acid-exchanged montmorillonite clay called Maghnite-H+ as an effective catalyst. The clay, which was used as a catalyst, was supplied by a local company known as ENOF Maghnia (Western Algeria. The chemical stability of PANI has been investigated by thermogravimetry and differential scanning calorimetry, that a good thermal stability of PANI could be improved by combining PANI with montmorillonite. TGA results illustrated that there were two major stages for weight loss of the ES-form PANI powder sample. The different forms of PANI were characterized by infrared spectroscopy, thermal analysis, and H-NMR spectroscopy and conductivity measurements.

  15. Thermally Stable Forms of Pure Polyaniline Catalyzed by an Acid-Exchanged Montmorillonite Clay Called Maghnite- H + as an Effective Catalyst

    OpenAIRE

    Rahmouni Abdelkader; Harrane Amine; Belbachir Mohammed

    2012-01-01

    Polyaniline salt form (PANI-ES) was synthesized by oxidative polymerization of aniline using potassium persulfate as an oxidant and an acid-exchanged montmorillonite clay called Maghnite-H+ as an effective catalyst. The clay, which was used as a catalyst, was supplied by a local company known as ENOF Maghnia (Western Algeria). The chemical stability of PANI has been investigated by thermogravimetry and differential scanning calorimetry, that a good thermal stability of PANI could be improved ...

  16. INCREASING HEAVY OIL RESERVES IN THE WILMINGTON OIL FIELD THROUGH ADVANCED RESERVOIR CHARACTERIZATION AND THERMAL PRODUCTION TECHNOLOGIES

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2002-11-08

    The project involves using advanced reservoir characterization and thermal production technologies to improve thermal recovery techniques and lower operating and capital costs in a slope and basin clastic (SBC) reservoir in the Wilmington field, Los Angeles Co., CA. Through June 2002, project work has been completed on the following activities: data preparation; basic reservoir engineering; developing a deterministic three dimensional (3-D) geologic model, a 3-D deterministic reservoir simulation model and a rock-log model; well drilling and completions; and surface facilities on the Fault Block II-A Tar Zone (Tar II-A). Work is continuing on research to understand the geochemistry and process regarding the sand consolidation well completion technique, final reservoir tracer work, operational work and research studies to prevent thermal-related formation compaction in the Tar II-A steamflood area, and operational work on the Tar V post-steamflood pilot and Tar II-A post-steamflood projects. During the Third Quarter 2002, the project team essentially completed implementing the accelerated oil recovery and reservoir cooling plan for the Tar II-A post-steamflood project developed in March 2002 and is proceeding with additional related work. The project team has completed developing laboratory research procedures to analyze the sand consolidation well completion technique and will initiate work in the fourth quarter. The Tar V pilot steamflood project terminated hot water injection and converted to post-steamflood cold water injection on April 19, 2002. Proposals have been approved to repair two sand consolidated horizontal wells that sanded up, Tar II-A well UP-955 and Tar V well J-205, with gravel-packed inner liner jobs to be performed next quarter. Other well work to be performed next quarter is to convert well L-337 to a Tar V water injector and to recomplete vertical well A-194 as a Tar V interior steamflood pattern producer. Plans have been approved to drill and

  17. Increasing Heavy Oil in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies. Annual Report, March 30, 1995--March 31, 1996

    International Nuclear Information System (INIS)

    The objective of this project is to increase heavy oil reserves in a portion of the Wilmington Oil Field, near Long Beach, California, by implementing advanced reservoir characterization and thermal production technologies. Based on the knowledge and experience gained with this project, these technologies are intended to be extended to other sections of the Wilmington Oil Field, and, through technology transfer, will be available to increase heavy oil reserves in other slope and basin clastic (SBC) reservoirs

  18. Thermally induced solid-state transformation of cimetidine. A multi-spectroscopic/chemometrics determination of the kinetics of the process and structural elucidation of one of the products as a stable N{sub 3}-enamino tautomer

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, Natalia L.; Simonetti, Sebastian O.; Maggio, Rubén M.; Kaufman, Teodoro S., E-mail: kaufman@iquir-conicet.gov.ar

    2015-05-22

    Highlights: • Thermally stressed cimetidine above its melting point affords a stable N{sub 3} tautomer. • Multi-spectroscopic/chemometric approach developed to monitor tautomerization. • First combined use of NMR, UV and IR spectroscopies with chemometrics. • Solid cimetidine suffers first order degradation upon submission to dry heat. • Theoretical chemistry analysis confirmed the relative stability of cimetidine tautomer. - Abstract: Exposure of cimetidine (CIM) to dry heat (160–180 °C) afforded, upon cooling, a glassy solid containing new and hitherto unknown products. The kinetics of this process was studied by a second order chemometrics-assisted multi-spectroscopic approach. Proton and carbon-13 nuclear magnetic resonance (NMR), as well as ultraviolet and infrared spectroscopic data were jointly used, whereas multivariate curve resolution with alternating least squares (MCR-ALS) was employed as the chemometrics method to extract process information. It was established that drug degradation follows a first order kinetics. One of the products was structurally characterized by mono- and bi-dimensional NMR experiments. It was found to be the N{sub 3}-enamino tautomer (TAU) of CIM, resulting from the thermal isomerization of the double bond of the cyanoguanidine moiety of the drug, from the imine form to its N{sub 3}-enamine state. The thus generated tautomer demonstrated to be stable for months in the glassy solid and in methanolic solutions. A theoretical study of CIM and TAU revealed that the latter is less stable; however, the energy barrier for tautomer interconversion is high enough, precluding the process to proceed rapidly at room temperature.

  19. Class III Mid-Term Project, "Increasing Heavy Oil Reserves in the Wilmington Oil Field Through Advanced Reservoir Characterization and Thermal Production Technologies"

    Energy Technology Data Exchange (ETDEWEB)

    Scott Hara

    2007-03-31

    The overall objective of this project was to increase heavy oil reserves in slope and basin clastic (SBC) reservoirs through the application of advanced reservoir characterization and thermal production technologies. The project involved improving thermal recovery techniques in the Tar Zone of Fault Blocks II-A and V (Tar II-A and Tar V) of the Wilmington Field in Los Angeles County, near Long Beach, California. A primary objective has been to transfer technology that can be applied in other heavy oil formations of the Wilmington Field and other SBC reservoirs, including those under waterflood. The first budget period addressed several producibility problems in the Tar II-A and Tar V thermal recovery operations that are common in SBC reservoirs. A few of the advanced technologies developed include a three-dimensional (3-D) deterministic geologic model, a 3-D deterministic thermal reservoir simulation model to aid in reservoir management and subsequent post-steamflood development work, and a detailed study on the geochemical interactions between the steam and the formation rocks and fluids. State of the art operational work included drilling and performing a pilot steam injection and production project via four new horizontal wells (2 producers and 2 injectors), implementing a hot water alternating steam (WAS) drive pilot in the existing steamflood area to improve thermal efficiency, installing a 2400-foot insulated, subsurface harbor channel crossing to supply steam to an island location, testing a novel alkaline steam completion technique to control well sanding problems, and starting on an advanced reservoir management system through computer-aided access to production and geologic data to integrate reservoir characterization, engineering, monitoring, and evaluation. The second budget period phase (BP2) continued to implement state-of-the-art operational work to optimize thermal recovery processes, improve well drilling and completion practices, and evaluate the

  20. Stable beams

    CERN Multimedia

    2015-01-01

    Stable beams: two simple words that carry so much meaning at CERN. When LHC page one switched from "squeeze" to "stable beams" at 10.40 a.m. on Wednesday, 3 June, it triggered scenes of jubilation in control rooms around the CERN sites, as the LHC experiments started to record physics data for the first time in 27 months. This is what CERN is here for, and it’s great to be back in business after such a long period of preparation for the next stage in the LHC adventure.   I’ve said it before, but I’ll say it again. This was a great achievement, and testimony to the hard and dedicated work of so many people in the global CERN community. I could start to list the teams that have contributed, but that would be a mistake. Instead, I’d simply like to say that an achievement as impressive as running the LHC – a machine of superlatives in every respect – takes the combined effort and enthusiasm of everyone ...

  1. Chiral bio-nanocomposites based on thermally stable poly(amide-imide) having phenylalanine linkages and reactive organoclay containing tyrosine amino acid.

    Science.gov (United States)

    Mallakpour, Shadpour; Dinari, Mohammad

    2013-03-01

    Montmorillonite clay modified with the bio-active trifunctional L-tyrosine amino acid salt was used as a reactive organoclay (OC) for the preparation of poly(amide-imide) (PAI)/OC hybrid films. One of the functional groups of the L-tyrosine as the swelling agent formed an ionic bond with the negatively charged silicates, whereas the remaining functional groups were available for further reaction with polymer matrix. The soluble PAI with amine end groups including phenylalanine amino acid was synthesised under green condition using molten tetra-butylammonium bromide by direct polymerization reaction of chiral diacid and 2-(3,5-diaminophenyl)benzimidazole. PAI/OC bio-nanocomposites films containing different contents of OC were prepared via solution intercalation method through blending of OC with the PAI solution. X-ray diffraction and transmission electron microscopy revealed that the dispersion of silicate layers in the PAI created an exfoliated structure as a result of using the trifunctional groups of the swelling agent. The structure and thermal behavior of the synthesised materials were characterized by a range of methods, including X-ray diffraction, Fourier transform infrared spectroscopy, (1)H-NMR, electron microscopy, elemental and thermogravimetric analysis techniques. Thermogravimetric analysis results indicated that the addition of OC into the PAI matrix was increased in the thermal decomposition temperatures of the resulted bio-nanocomposites.

  2. Advanced windows Information System (WIS): A uniform European tool to calculate the thermal and solar properties of windows

    NARCIS (Netherlands)

    Bakker, L.G.; Dijk, H.A.L. van; Geus, A.C. de

    1996-01-01

    WIS is a uniform, user friendly, PC-based, European software tool to determine the thermal and solar characteristics of window systems (glazing, frames, solar shading, etc.) and window components. WIS includes databases with component propertjes and routines for calculation of the thermal-optical in

  3. Advanced windows Information System (WIS): A uniform European tool to calculate the thermal and solar properties of windows

    NARCIS (Netherlands)

    Bakker, L.G.; Dijk, H.A.L. van

    1996-01-01

    WIS is a uniform, user friendly, PC-based, European software tool to determine the thermal and solar character-istics of window systems (glazing, frames, solar shading, etc.) and window components. WIS includes databases with component properties and routines for calculation of the thermal-optical i

  4. Recent advances in the management of chronic stable angina II. Anti-ischemic therapy, options for refractory angina, risk factor reduction, and revascularization

    Directory of Open Access Journals (Sweden)

    Richard Kones

    2010-08-01

    Full Text Available Richard KonesThe Cardiometabolic Research Institute, Houston, Texas, USAAbstract: The objectives in treating angina are relief of pain and prevention of disease ­progression through risk reduction. Mechanisms, indications, clinical forms, doses, and side effects of the traditional antianginal agents – nitrates, ß-blockers, and calcium channel ­blockers – are reviewed. A number of patients have contraindications or remain unrelieved from anginal discomfort with these drugs. Among newer alternatives, ranolazine, recently approved in the United States, indirectly prevents the intracellular calcium overload involved in cardiac ischemia and is a welcome addition to available treatments. None, however, are disease-modifying agents. Two options for refractory angina, enhanced external counterpulsation and spinal cord stimulation (SCS, are presented in detail. They are both well-studied and are effective means of treating at least some patients with this perplexing form of angina. Traditional modifiable risk factors for coronary artery disease (CAD – smoking, hypertension, dyslipidemia, ­diabetes, and obesity – account for most of the population-attributable risk. Individual therapy of high-risk patients differs from population-wide efforts to prevent risk factors from appearing or reducing their severity, in order to lower the national burden of disease. Current American College of Cardiology/American Heart Association guidelines to lower risk in patients with chronic angina are reviewed. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE trial showed that in patients with stable angina, optimal medical therapy alone and percutaneous coronary intervention (PCI with medical therapy were equal in preventing myocardial infarction and death. The integration of COURAGE results into current practice is discussed. For patients who are unstable, with very high risk, with left main coronary artery lesions, in

  5. Development of an Advanced Two-Dimensional Thermal Model for Large size Lithium-ion Pouch Cells

    International Nuclear Information System (INIS)

    In this work, a LiFePO4/graphite lithium-ion pouch cell with a rated capacity of 45Ah has been used and a two dimensional thermal model is developed to predict the cell temperature distribution over the surface of the battery, this model requires less input parameters and still has high accuracy. The used input parameters are the heat generation and thermal properties. The ANSYS FLUENT software has been used to solve the models. In addition, a new estimation tool has been developed for estimation of the thermal model parameters. Furthermore, the thermal behavior of the proposed battery has been investigated at different environmental conditions as well as during the abuse conditions. Thermal runaway is investigated in depth by the model

  6. Facile synthesis of new thermally stable and organosoluble polyamide-imides based on non-coplaner phosphorus and silicon containing amines

    Indian Academy of Sciences (India)

    Seema Agrawal; Anudeep Kumar Narula

    2014-11-01

    Two new kinds of diamines, 3-[bis-(3-aminophenyl)-phosphinoyl)-phenyl]-3-(triphenylphosphoranylidene)-pyrrolidene-2,5-dione, (DAP) with phosphorus moiety and bis-(5-amino-naphthalene-1-yl) dimethyl silane (DAS) with silicon moiety are synthesized. A series of novel aromatic polyamide-imides (PAIs) are prepared from three dicarboxylic acids and synthesized diamines. The phosphorus and silicon containing diamines and all polymers are characterized by FT-IR, NMR spectroscopic techniques and elemental analysis. The polymers obtained have good thermal stability and glass transition temperature (T) in the range of 254-315°C. All these novel polyamide-imides (PAIs) contain 10% weight loss at the temperature above 506°C and more than 59% residue at 600°C in nitrogen atmosphere. The resulting polymeric films exhibit high optical transparency and inherent viscosity in the range of 0.68 to 0.79 dL/g. These polymers are found to be soluble in aprotic polar solvents such as NMP, DMSO, DMF and DMAc.Wide angle X-ray diffraction revealed that these polymers are predominantly amorphous in nature.

  7. A QUICK AND GREEN IONIC LIQUID-MEDIATED APPROACH FOR THE SYNTHESIS OF HIGH-PERFORMANCE, ORGANOSOLUBLE AND THERMALLY STABLE POLYIMIDES

    Institute of Scientific and Technical Information of China (English)

    Mehdi Taghavi; Mousa Ghaemy; Marjan Hassanzadeh; Seyed Mojtaba Amini Nasab

    2013-01-01

    Three diamine monomers with different derivatives of imidazole heterocyclic ring and meta-linked aryl ethers were synthesized and used in polycodensation reaction with various commercial dianhydrides for preparation of a series of novel poly(ether-imide) (PEI)s.The polycodensation reactions were carried out by using conventional method and in a green medium of ionic liquid (IL) without using NMP-pyridine-acetic anhydride.The PEIs were obtained in good yields (80%-96%) with moderate viscosity (0.48-0.66 dL/g) in a shorter reaction time (10 h) in IL as compared with the conventional method (36 h).All of the polymers were amorphous in nature,showed excellent solubility in amide-type polar aprotic solvents with ability to form tough and flexible films,and excellent thermal stability with TgS in the range of 212-340 ℃ and 10% weight loss temperature (T10) up to 570 ℃ in N2 and 528 ℃ in air.

  8. Thermally induced solid-state transformation of cimetidine. A multi-spectroscopic/chemometrics determination of the kinetics of the process and structural elucidation of one of the products as a stable N3-enamino tautomer.

    Science.gov (United States)

    Calvo, Natalia L; Simonetti, Sebastian O; Maggio, Rubén M; Kaufman, Teodoro S

    2015-05-22

    Exposure of cimetidine (CIM) to dry heat (160-180°C) afforded, upon cooling, a glassy solid containing new and hitherto unknown products. The kinetics of this process was studied by a second order chemometrics-assisted multi-spectroscopic approach. Proton and carbon-13 nuclear magnetic resonance (NMR), as well as ultraviolet and infrared spectroscopic data were jointly used, whereas multivariate curve resolution with alternating least squares (MCR-ALS) was employed as the chemometrics method to extract process information. It was established that drug degradation follows a first order kinetics. One of the products was structurally characterized by mono- and bi-dimensional NMR experiments. It was found to be the N3-enamino tautomer (TAU) of CIM, resulting from the thermal isomerization of the double bond of the cyanoguanidine moiety of the drug, from the imine form to its N3-enamine state. The thus generated tautomer demonstrated to be stable for months in the glassy solid and in methanolic solutions. A theoretical study of CIM and TAU revealed that the latter is less stable; however, the energy barrier for tautomer interconversion is high enough, precluding the process to proceed rapidly at room temperature.

  9. Development of numerical procedure for thermal hydraulic design of nuclear reactors with advanced two-fluid model (1). Improvement of numerical stability of advanced two-fluid model

    International Nuclear Information System (INIS)

    Two-fluid model is still useful to simulate two-phase flow in large domain such as rod bundles. However, two-fluid model include a lot of constitutive equations, and the two-fluid model has problems that the results of analyses depend on accuracy of constitutive equations. To solve these problems, we have been developing an advanced two-fluid model. In this model, an interface tracking method is combined with the two-fluid model to predict large interface structure behavior without any constitutive equations, and constitutive equations to evaluate the effects of small bubbles or droplets are only required. In this study, we modified the advanced two-fluid model to improve the stability of the numerical simulation and reduce the computational time. In this paper, we describe the modification performed in this study and the numerical results of two-phase flow in various flow conditions are shown. (author)

  10. Recent advances in the management of chronic stable angina I: Approach to the patient, diagnosis, pathophysiology, risk stratification, and gender disparities

    Directory of Open Access Journals (Sweden)

    Richard Kones

    2010-07-01

    Full Text Available Richard KonesThe Cardiometabolic Research Institute, Houston, Texas 77054 USAAbstract: The potential importance of both prevention and personal responsibility in ­controlling heart disease, the leading cause of death in the USA and elsewhere, has attracted renewed ­attention. Coronary artery disease is preventable, using relatively simple and inexpensive lifestyle changes. The inexorable rise in the prevalence of obesity, diabetes, dyslipidemia, and ­hypertension, often in the risk cluster known as the metabolic syndrome, drives the ­ever-increasing incidence of heart disease. Population-wide improvements in personal health habits appear to be a fundamental, evidence based public health measure, yet numerous barriers prevent implementation. A common symptom in patients with coronary artery disease, classical angina refers to the typical chest pressure or discomfort that results when myocardial oxygen demand rises and coronary blood flow is reduced by fixed, atherosclerotic, obstructive lesions. Different forms of angina and diagnosis, with a short description of the significance of pain and silent ischemia, are discussed in this review. The well accepted concept of myocardial oxygen imbalance in the genesis of angina is presented with new data about clinical pathology of stable angina and acute coronary syndromes. The roles of stress electrocardiography and stress myocardial perfusion scintigraphic imaging are reviewed, along with the information these tests provide about risk and prognosis. Finally, the current status of gender disparities in heart disease is summarized. Enhanced risk stratification and identification of patients in whom procedures will meaningfully change management is an ongoing quest. Current guidelines emphasize efficient triage of patients with suspected coronary artery disease. Many experts believe the predictive value of current decision protocols for coronary artery disease still needs improvement in order to

  11. Advanced technology development program for lithium-ion batteries : thermal abuse performance of 18650 Li-ion cells.

    Energy Technology Data Exchange (ETDEWEB)

    Crafts, Chris C.; Doughty, Daniel Harvey; McBreen, James. (Bookhaven National Lab, Upton, NY); Roth, Emanuel Peter

    2004-03-01

    Li-ion cells are being developed for high-power applications in hybrid electric vehicles currently being designed for the FreedomCAR (Freedom Cooperative Automotive Research) program. These cells offer superior performance in terms of power and energy density over current cell chemistries. Cells using this chemistry are the basis of battery systems for both gasoline and fuel cell based hybrids. However, the safety of these cells needs to be understood and improved for eventual widespread commercial application in hybrid electric vehicles. The thermal behavior of commercial and prototype cells has been measured under varying conditions of cell composition, age and state-of-charge (SOC). The thermal runaway behavior of full cells has been measured along with the thermal properties of the cell components. We have also measured gas generation and gas composition over the temperature range corresponding to the thermal runaway regime. These studies have allowed characterization of cell thermal abuse tolerance and an understanding of the mechanisms that result in cell thermal runaway.

  12. Applying Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) spectral indices for geological mapping and mineral identification on the Tibetan Plateau

    CERN Document Server

    Corrie, Robert; Aitchison, Jonathan

    2011-01-01

    The Tibetan Plateau holds clues to understanding the dynamics and mechanisms associated with continental growth. Part of the region is characterized by zones of ophiolitic melange believed to represent the remnants of ancient oceanic crust and underlying upper mantle emplaced during oceanic closures. However, due to the remoteness of the region and the inhospitable terrain many areas have not received detailed investigation. Increased spatial and spectral resolution of satellite sensors have made it possible to map in greater detail the mineralogy and lithology than in the past. Recent work by Yoshiki Ninomiya of the Geological Survey of Japan has pioneered the use of several spectral indices for the mapping of quartzose, carbonate, and silicate rocks using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) thermal infrared (TIR) data. In this study, ASTER TIR indices have been applied to a region in western-central Tibet for the purposes of assessing their effectiveness for differentiatin...

  13. A New Way of Doing Business: Reusable Launch Vehicle Advanced Thermal Protection Systems Technology Development: NASA Ames and Rockwell International Partnership

    Science.gov (United States)

    Carroll, Carol W.; Fleming, Mary; Hogenson, Pete; Green, Michael J.; Rasky, Daniel J. (Technical Monitor)

    1995-01-01

    NASA Ames Research Center and Rockwell International are partners in a Cooperative Agreement (CA) for the development of Thermal Protection Systems (TPS) for the Reusable Launch Vehicle (RLV) Technology Program. This Cooperative Agreement is a 30 month effort focused on transferring NASA innovations to Rockwell and working as partners to advance the state-of-the-art in several TPS areas. The use of a Cooperative Agreement is a new way of doing business for NASA and Industry which eliminates the traditional customer/contractor relationship and replaces it with a NASA/Industry partnership.

  14. Bayesian stable isotope mixing models

    Science.gov (United States)

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixtur...

  15. Benchmarking of thermal hydraulic loop models for Lead-Alloy Cooled Advanced Nuclear Energy System (LACANES), phase-I: Isothermal steady state forced convection

    International Nuclear Information System (INIS)

    As highly promising coolant for new generation nuclear reactors, liquid Lead-Bismuth Eutectic has been extensively worldwide investigated. With high expectation about this advanced coolant, a multi-national systematic study on LBE was proposed in 2007, which covers benchmarking of thermal hydraulic prediction models for Lead-Alloy Cooled Advanced Nuclear Energy System (LACANES). This international collaboration has been organized by OECD/NEA, and nine organizations - ENEA, ERSE, GIDROPRESS, IAEA, IPPE, KIT/IKET, KIT/INR, NUTRECK, and RRC KI - contribute their efforts to LACANES benchmarking. To produce experimental data for LACANES benchmarking, thermal-hydraulic tests were conducted by using a 12-m tall LBE integral test facility, named as Heavy Eutectic liquid metal loop for integral test of Operability and Safety of PEACER (HELIOS) which has been constructed in 2005 at the Seoul National University in the Republic of Korea. LACANES benchmark campaigns consist of a forced convection (phase-I) and a natural circulation (phase-II). In the forced convection case, the predictions of pressure losses based on handbook correlations and that obtained by Computational Fluid Dynamics code simulation were compared with the measured data for various components of the HELIOS test facility. Based on comparative analyses of the predictions and the measured data, recommendations for the prediction methods of a pressure loss in LACANES were obtained. In this paper, results for the forced convection case (phase-I) of LACANES benchmarking are described.

  16. Mandate a Man to Fish?: Technological advance in cooling systems at U.S. thermal electric plants

    Science.gov (United States)

    Peredo-Alvarez, Victor M.; Bellas, Allen S.; Trainor-Guitton, Whitney J.; Lange, Ian

    2016-02-01

    Steam-based electrical generating plants use large quantities of water for cooling. The potential environmental impacts of water cooling systems have resulted in their inclusion in the Clean Water Act's (CWA) Sections 316(a), related to thermal discharges and 316(b), related to cooling water intake. The CWA mandates a technological standard for water cooling systems. This analysis examines how the performance-adjusted rates of thermal emissions and water withdrawals for cooling units have changed over their vintage and how these rates of change were impacted by imposition of the CWA. Results show that the rate of progress increased for cooling systems installed after the CWA whilethere was no progress previous to it.

  17. Advanced microbolometer detectors for a next-generation uncooled FPA for space-based thermal remote sensing

    Science.gov (United States)

    Williamson, Fraser; Marchese, Linda; Baldenberger, Georges; Châteauneuf, François; Provencal, Francis; Caron, Jean-Sol; Dupont, Fabien; Osouf, Jocelyne; Couture, Patrick; Ngo Phong, Linh; Pope, Tim

    2009-02-01

    INO has established a VOx-based uncooled microbolometer detector technology and an expertise in the development of custom detectors and focal plane arrays. Thanks to their low power consumption and broadband sensitivity, uncooled microbolometer detectors are finding an increased number of applications in the field of space-based thermal remote sensing. A mission requirement study has identified at least seven applications with a need for data in the MWIR (3-8 μm), LWIR (8-15 μm) and or FIR (15-100 μm) wavelength bands. The requirement study points to the need for two main classes of uncooled thermal detectors, the first requiring small and fast detectors for MWIR and LWIR imaging with small ground sampling distance, and the second requiring larger detectors with sensitivity out to the FIR. In this paper, the simulation, design, microfabrication and radiometric testing of detectors for these two classes of requirements will be presented. The performance of the experimental detectors closely approach the mission requirements and show the potential of microbolometer technology to fulfill the requirements of future space based thermal imaging missions.

  18. Argonne Liquid-Metal Advanced Burner Reactor : components and in-vessel system thermal-hydraulic research and testing experience - pathway forward.

    Energy Technology Data Exchange (ETDEWEB)

    Kasza, K.; Grandy, C.; Chang, Y.; Khalil, H.; Nuclear Engineering Division

    2007-06-30

    This white paper provides an overview and status report of the thermal-hydraulic nuclear research and development, both experimental and computational, conducted predominantly at Argonne National Laboratory. Argonne from the early 1970s through the early 1990s was the Department of Energy's (DOE's) lead lab for thermal-hydraulic development of Liquid Metal Reactors (LMRs). During the 1970s and into the mid-1980s, Argonne conducted thermal-hydraulic studies and experiments on individual reactor components supporting the Experimental Breeder Reactor-II (EBR-II), Fast Flux Test Facility (FFTF), and the Clinch River Breeder Reactor (CRBR). From the mid-1980s and into the early 1990s, Argonne conducted studies on phenomena related to forced- and natural-convection thermal buoyancy in complete in-vessel models of the General Electric (GE) Prototype Reactor Inherently Safe Module (PRISM) and Rockwell International (RI) Sodium Advanced Fast Reactor (SAFR). These two reactor initiatives involved Argonne working closely with U.S. industry and DOE. This paper describes the very important impact of thermal hydraulics dominated by thermal buoyancy forces on reactor global operation and on the behavior/performance of individual components during postulated off-normal accident events with low flow. Utilizing Argonne's LMR expertise and design knowledge is vital to the further development of safe, reliable, and high-performance LMRs. Argonne believes there remains an important need for continued research and development on thermal-hydraulic design in support of DOE's and the international community's renewed thrust for developing and demonstrating the Global Nuclear Energy Partnership (GNEP) reactor(s) and the associated Argonne Liquid Metal-Advanced Burner Reactor (LM-ABR). This white paper highlights that further understanding is needed regarding reactor design under coolant low-flow events. These safety-related events are associated with the transition

  19. Argonne Liquid-Metal Advanced Burner Reactor : components and in-vessel system thermal-hydraulic research and testing experience - pathway forward

    International Nuclear Information System (INIS)

    This white paper provides an overview and status report of the thermal-hydraulic nuclear research and development, both experimental and computational, conducted predominantly at Argonne National Laboratory. Argonne from the early 1970s through the early 1990s was the Department of Energy's (DOE's) lead lab for thermal-hydraulic development of Liquid Metal Reactors (LMRs). During the 1970s and into the mid-1980s, Argonne conducted thermal-hydraulic studies and experiments on individual reactor components supporting the Experimental Breeder Reactor-II (EBR-II), Fast Flux Test Facility (FFTF), and the Clinch River Breeder Reactor (CRBR). From the mid-1980s and into the early 1990s, Argonne conducted studies on phenomena related to forced- and natural-convection thermal buoyancy in complete in-vessel models of the General Electric (GE) Prototype Reactor Inherently Safe Module (PRISM) and Rockwell International (RI) Sodium Advanced Fast Reactor (SAFR). These two reactor initiatives involved Argonne working closely with U.S. industry and DOE. This paper describes the very important impact of thermal hydraulics dominated by thermal buoyancy forces on reactor global operation and on the behavior/performance of individual components during postulated off-normal accident events with low flow. Utilizing Argonne's LMR expertise and design knowledge is vital to the further development of safe, reliable, and high-performance LMRs. Argonne believes there remains an important need for continued research and development on thermal-hydraulic design in support of DOE's and the international community's renewed thrust for developing and demonstrating the Global Nuclear Energy Partnership (GNEP) reactor(s) and the associated Argonne Liquid Metal-Advanced Burner Reactor (LM-ABR). This white paper highlights that further understanding is needed regarding reactor design under coolant low-flow events. These safety-related events are associated with the transition from normal high

  20. Stable Boundary Layer Education (STABLE) Final Campaign Summary

    Energy Technology Data Exchange (ETDEWEB)

    Turner, David D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-01

    The properties of, and the processes that occur in, the nocturnal stable boundary layer are not well understood, making it difficult to represent adequately in numerical models. The nocturnal boundary layer often is characterized by a temperature inversion and, in the Southern Great Plains region, a low-level jet. To advance our understanding of the nocturnal stable boundary layer, high temporal and vertical resolution data on the temperature and wind properties are needed, along with both large-eddy simulation and cloud-resolving modeling.

  1. Method development for thermal analyses testing on Reillex HPQ resin using the advanced reactive system screening tool (ARSST)

    Energy Technology Data Exchange (ETDEWEB)

    Best, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    Reillex™ HPQ resin was developed by Los Alamos Laboratory and Reilly Industries Inc. in an effort to increase safety and process efficiency during the recovery and purification of plutonium. Ionac™ A-641, another strong base macroporous anion exchange resin used in the nuclear industry, was known to undergo a runaway reaction in hot nitric acid solutions. Because of this, an extensive amount of thermal analyses testing on the Reillex™ HPQ resin in SRNL was performed in 1999-2001 prior to use. A report on the thermal stability qualification of the Reillex™ HPQ resin in 8M (35%) and 12M (53%) HNO3 was reported in 2000. In 2001, the reactivity of Reillex™ HPQ resin in 14.4M (64%) HNO3 was evaluated. In January of 2001, thermal stability scoping tests were performed on irradiated Reillex™ HPQ resin in 14.4M (64%) HNO3 (as a worst case scenario) and the results sent to Fauske and Associates to calculate a rupture disk size for the HB-Line resin column. A technical report by Fauske and Associates was issued in February 2001 recommending a 2.0” vent line with a rupture disk set pressure of 60 psig. This calculation was based on ARSST thermal analyses scoping tests at SRNL in which 4 grams of dried resin and 6.0 grams of 64% nitric acid in a 10 gram test cell, produced a maximum pressure rate (dP/dt) of 720 psi/min (12 psi/sec) and a maximum temperature of 250 °C. In 2015, a new batch of Reillex™ HPQ resin was manufactured by Vertellus Industries. A test sample of the resin was sent to SRNL to perform acceptance and qualification thermal stability testing using the ARSST. During these tests, method development was performed to ensure that a representative resin to acid ratios were used while running the tests in the ARSST. Fauske and Associates recommended to either use a full test cell representative of the HB-Line column or a 10 gram sample in the test cell that was representative of the ratios of resin to nitric acid in

  2. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  3. Advanced thermal-energy-storage concept-definition study for solar Brayton power plants. Final technical report, Volume I

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    The detailed results are presented of a technical and economic assessment of phase change and thermochemical energy storage systems in a solar power plant employing a high temperature Brayton cycle thermal engine with helium as the heat transport fluid. The assessment included an examination of the storage system operation, efficiency, power plant interaction, design, materials, safety, maintenance, environmental impact, system life, and economics. These considerations are implemented in the conceptual design of three baseline storage systems and their components for use in a solar power plant module of 50 megawatt electrical power output. Rationale is provided to support the configuration, operation and material choices. A preliminary assessment of the technology development and experimental test program requirements are also included. The report is contained in four separate volumes. This volume is the technical report.

  4. Advances in nanotechnology in tumor thermal ablation%纳米技术在肿瘤热消融领域的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘士榕; 梁萍

    2015-01-01

    肿瘤热消融治疗技术发展快速,已成为继外科手术之后的一项有效治疗手段,但其在疗效及安全性方面也存在一定的局限性。随着各种新型纳米粒子的不断出现,纳米医学在肿瘤诊疗领域迅速发展,并取得了丰硕的成果。本文综述纳米技术在肿瘤热消融治疗领域的主要研究进展,为局部热消融联合纳米技术治疗肿瘤提供信息。%In recent years, local thermal ablation technique has become an effective method in treatment of solid tumors. However, each technique has its certain limitations that may prevent their widespread use in clinical applications. With rapid development of new types of nanoparticles, nanomedicine has made rapid progress in thefield of tumor diagnosis and treatment. Main advances in the application of nanotechnology combined local thermal ablation are reviewed in this paper in order to provide more information for it.

  5. The development and verification of thermal-hydraulic code on passive residual heat removal system of Chinese advanced PWR

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The technology of passive safety is the current trend among safety systems in nuclear power plant. Passive residual heat removal system (PRHRS), a major part of passive safety systems of Chinese advanced PWR, is a novel design with three-fold natural circulation. On the basis of reasonable physics and mathematics models, MITAP-PRHRS code was developed to analyze steady and transient characteristics of the PRHRS. The calculation and analysis show that the code simulates steady characteristics of the PRHRS very well, and it is able to simulate transient characteristics of all startup modes of the PRHRS. However, the quantitative description is poor during the initial stages of the transition process when water hammer occurs.

  6. Bayesian Stable Isotope Mixing Models

    OpenAIRE

    Parnell, Andrew C.; Phillips, Donald L.; Bearhop, Stuart; Semmens, Brice X.; Ward, Eric J.; Moore, Jonathan W.; Andrew L Jackson; Inger, Richard

    2012-01-01

    In this paper we review recent advances in Stable Isotope Mixing Models (SIMMs) and place them into an over-arching Bayesian statistical framework which allows for several useful extensions. SIMMs are used to quantify the proportional contributions of various sources to a mixture. The most widely used application is quantifying the diet of organisms based on the food sources they have been observed to consume. At the centre of the multivariate statistical model we propose is a compositional m...

  7. Neutron radiography as a non-destructive method for diagnosing neutron converters for advanced thermal neutron detectors

    Science.gov (United States)

    Muraro, A.; Albani, G.; Perelli Cippo, E.; Croci, G.; Angella, G.; Birch, J.; Cazzaniga, C.; Caniello, R.; Dell'Era, F.; Ghezzi, F.; Grosso, G.; Hall-Wilton, R.; Höglund, C.; Hultman, L.; Schimdt, S.; Robinson, L.; Rebai, M.; Salvato, G.; Tresoldi, D.; Vasi, C.; Tardocchi, M.

    2016-03-01

    Due to the well-known problem of 3He shortage, a series of different thermal neutron detectors alternative to helium tubes are being developed, with the goal to find valid candidates for detection systems for the future spallation neutron sources such as the European Spallation Source (ESS). A possible 3He-free detector candidate is a charged particle detector equipped with a three dimensional neutron converter cathode (3D-C). The 3D-C currently under development is composed by a series of alumina (Al2O3) lamellas coated by 1 μ m of 10B enriched boron carbide (B4C). In order to obtain a good characterization in terms of detector efficiency and uniformity it is crucial to know the thickness, the uniformity and the atomic composition of the B4C neutron converter coating. In this work a non-destructive technique for the characterization of the lamellas that will compose the 3D-C was performed using neutron radiography. The results of these measurements show that the lamellas that will be used have coating uniformity suitable for detector applications. This technique (compared with SEM, EDX, ERDA, XPS) has the advantage of being global (i.e. non point-like) and non-destructive, thus it is suitable as a check method for mass production of the 3D-C elements.

  8. Neutron radiography as a non-destructive method for diagnosing neutron converters for advanced thermal neutron detectors

    International Nuclear Information System (INIS)

    Due to the well-known problem of 3He shortage, a series of different thermal neutron detectors alternative to helium tubes are being developed, with the goal to find valid candidates for detection systems for the future spallation neutron sources such as the European Spallation Source (ESS). A possible 3He-free detector candidate is a charged particle detector equipped with a three dimensional neutron converter cathode (3D-C). The 3D-C currently under development is composed by a series of alumina (Al2O3) lamellas coated by 1 μ m of 10B enriched boron carbide (B4C). In order to obtain a good characterization in terms of detector efficiency and uniformity it is crucial to know the thickness, the uniformity and the atomic composition of the B4C neutron converter coating. In this work a non-destructive technique for the characterization of the lamellas that will compose the 3D-C was performed using neutron radiography. The results of these measurements show that the lamellas that will be used have coating uniformity suitable for detector applications. This technique (compared with SEM, EDX, ERDA, XPS) has the advantage of being global (i.e. non point-like) and non-destructive, thus it is suitable as a check method for mass production of the 3D-C elements

  9. Advanced activation trends for boron and arsenic by combinations of single, multiple flash anneals and spike rapid thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Lerch, W. [Mattson Thermal Products GmbH, Daimlerstrasse 10, 89160 Dornstadt (Germany)], E-mail: wilfried.lerch@mattson.com; Paul, S.; Niess, J. [Mattson Thermal Products GmbH, Daimlerstrasse 10, 89160 Dornstadt (Germany); McCoy, S.; Gelpey, J. [Mattson Technology Canada Inc., 605 W. Kent Avenue, Vancouver, BC V6P6T7 Canada (Canada); Cristiano, F.; Severac, F. [LAAS/CNRS, 7 av. Du Col. Roche, 31077 Toulouse (France); Fazzini, P. [CEMES/CNRS, 29 rue G. Marvig, 31055 Toulouse (France); Martinez-Limia, A.; Pichler, P. [Fraunhofer-IISB, Schottkystrasse 10, 91058 Erlangen (Germany); Kheyrandish, H. [CSMA-MATS, Queens Road, Stoke on Trent ST4 7LQ (United Kingdom); Bolze, D. [IHP, Im Technologiepark 25, 15326 Frankfurt (Oder) (Germany)

    2008-12-05

    Millisecond annealing as an equipment technology provides temperature profiles which favour dopant activation but nearly eliminate dopant diffusion to form extremely shallow, highly electrically activated junctions. For the 45-nm technology node and beyond, precisely controlled gate under-diffusion is required for optimum device performance. Therefore, on boron and arsenic beamline-implanted wafers, various annealing schemes were investigated for the formation of ultra-shallow and custom-shaped junctions. The main scheme consisted of flash annealing with peak temperatures ranging from 1250 to 1300 deg. C, combined with spike rapid thermal annealing with peak temperatures in the range from 900 to 1000 deg. C to achieve a desired junction depth. As alternative, to reduce the sheet resistance of pMOS and nMOS source-drain extensions, combinations of two or three flash anneals in succession were tested. Finally, the standard flash anneal condition of a 750 deg. C intermediate temperature followed by the flash anneal was changed to a high intermediate temperature of 950 deg. C followed by the flash anneal up to 1300 deg. C. The results of all these annealing schemes were analysed by four-point probe measurement. Selected samples were analysed by Hall-effect measurements for peak activation, and by secondary ion mass spectrometry for profile shape as well as diffusion effects. Transmission electron microscopy was used to study residual defects. Selected boron and arsenic dopant profiles were also compared to predictive simulation results which address the diffusion and activation at extrinsic concentrations.

  10. Identification of salt-alloy combinations for thermal energy storage applications in advanced solar dynamic power systems

    Science.gov (United States)

    Whittenberger, J. D.; Misra, A. K.

    Thermodynamic calculations based on the available data for flouride salt systems reveal that a number of congruently melting compositions and eutectics exist which have the potential to meet the lightweight, high energy storage requirements imposed for advanced solar dynamic systems operating between about 1000 and 1400 K. Compatibility studies to determine suitable containment alloys to be used with NaF-22CaF2-13MgF2, NaF-32CaF2, and NaF-23MgF2 have been conducted at the eutectic temperature + 25 K for each system. For these three NaF-based eutectics, none of the common, commercially available high temperature alloys appear to offer adequate corrosion resistance for a long lifetime; however mild steel, pure nickel and Nb-1Zr could prove useful. These latter materials suggest the possibility that a strong, corrosion resistant, nonrefractory, elevated temperature alloy based on the Ni-Ni3Nb system could be developed.

  11. Advancing the understanding of variations of Arctic sea ice optical and thermal behaviors through an international research and mobility project

    Institute of Scientific and Technical Information of China (English)

    Marcel Nicolaus; LEI Ruibo; LI Qun; LU Peng; Caixin Wang; Sebastian Gerland; LI Na; LI Zhijun; Bin Cheng; Don K Perovich; Mats A Granskog; SHI Liqiong

    2015-01-01

    In recent decades, significant changes of Arctic sea ice have taken place. These changes are expected to influence the surface energy balance of the ice-covered Arctic Ocean. To quantify this energy balance and to increase our understanding of mechanisms leading to observed changes in the Arctic sea ice, the project“Advancing Modelling and Observing solar Radiation of Arctic sea ice—understanding changes and processes (AMORA)”was initiated and conducted from 2009 to 2013. AMORA was funded and organized under a frame of Norway-China bilateral collaboration program with partners from Finland, Germany, and the USA. The primary goal of the project was achieved by developing an autonomous spectral radiation buoy, deploying it on drifting sea ice close to the North Pole, and receiving a high-resolution time series of spectral radiation over and under sea ice from spring (before melt onset) to autumn (after freeze-up) 2012. Beyond this, in-situ sea ice data were collected during several ifeld campaigns and simulations of snow and sea ice thermodynamics were performed. More autonomous measurements are available through deployments of sea ice mass balance buoys. These new observational data along with numerical model studies are helping us to better understand the key thermodynamic processes of Arctic sea ice and changes in polar climate. A strong scientiifc, but also cultural exchange between Norway, China, and the partners from the USA and Europe initiated new collaborations in Arctic reseach.

  12. Establishment and validation of an airliner experimental platform with stable thermal boundary condition in an aircraft cabin%稳态热边界客机座舱实验平台搭建及实验验证

    Institute of Scientific and Technical Information of China (English)

    沈忱; 刘俊杰; 刘炜; 闻济舟

    2014-01-01

    在一架暴露于室外环境的全尺寸 MD 82型飞机上建立了一个客机座舱实验平台,用来验证数值模拟模型的准确性和研究座舱气流组织。为了获得机舱稳态热边界条件,在飞机外表面铺设闭孔海绵保温材料,并通过地面空调机组向座舱内提供恒温空调送风,辅以模拟真人发热的假人模型。采用一套热电偶系统测量热边界条件,并建立了一维非稳态导热数值计算模型,对夏季室外条件下平台热边界进行预测。实测和数值模拟结果都证明,每一个实验日内座舱内壁面的热边界温度值波动都小于±0.25℃;但不同月份间壁面温度的变化值超过±1℃。因此需合理安排夏季实验日程,以避免室外高温导致的实验误差。%Establishes an airliner experimental platform in a full-size MD-82 aircraft cabin outside for the validation of numerical simulation models and the airflow distribution study in an aircraft cabin.To obtain stable thermal boundary conditions in the cabin,covers the aircraft with the insulation materials of closed-cell foam,and supplies the thermostatic air provided by a ground air conditioning unit,and then places the manikins to simulate real human generating heat.Uses a thermocouple system to measure thermal boundary conditions,and establishes a set of one-dimensional numerical simulation model of unsteady heat conduction to forecast the temperature of sidewalls in the cabin under the outdoor conditions in summer.The results of both measurement and numerical simulation all validates that the temperature fluctuation of thermal boundary in one experimental day is smaller than ±0.25 ℃,but the temperature fluctuation in different months would extend to more than ±1 ℃.Therefore,the experiment period needs to be arranged reasonably to avoid the measurement error from the high outdoor temperature.

  13. Application of Advanced Thermal Hydraulic TRACG Model to Preserve Operating Margins in BWRs at Extended Power Up-rate Conditions

    International Nuclear Information System (INIS)

    GE has developed TRACG, a customized BWR version of the TRAC model, for application to BWR analyses. This model was initially applied to special BWR challenges and for benchmarking the official simplified thermal-hydraulic design models. However, in past years extensive additional model development, qualification and application studies have been completed. This development has followed the CSAU methodology, where extensive model evaluation and qualification have been performed to demonstrate the applicability of the model and to quantify the uncertainty in the model parameters as well as in plant parameters and initial conditions. This has then been combined with a statistically based application methodology following the CSAU approach to generate tolerance limits for the critical safety and design parameters. This effort has resulted in application processes that have been reviewed and approved by the US NRC to enable routine application of the TRACG model to the design and licensing analyses and utilize the improved operating margin to optimize the fuel cycle design. These applications have been supported by development of programs that construct specific plant and problem base-decks that utilize BWR plant characteristics and system databases to standardize and streamline the application to several plants. The application of the TRACG model in Transient and LOCA analyses has assisted in allowing similar power peaking at higher power density conditions for BWRs. Also, the application of the TRACG model in Stability analyses has assisted in preserving the setpoints of stability monitoring systems to avoid margin loss for high power density applications. TRACG is being used for analysis of ATWS events. It has been used to support the development of emergency procedure guidelines, and it is currently being used to demonstrate that the suppression pool temperature limits can be met for up-rated conditions. Finally, the application of the TRACG model in Faulted Load

  14. Statistically based uncertainty analysis for ranking of component importance in the thermal-hydraulic safety analysis of the Advanced Neutron Source Reactor

    International Nuclear Information System (INIS)

    The Analytic Hierarchy Process (AHP) has been used to help determine the importance of components and phenomena in thermal-hydraulic safety analyses of nuclear reactors. The AHP results are based, in part on expert opinion. Therefore, it is prudent to evaluate the uncertainty of the AHP ranks of importance. Prior applications have addressed uncertainty with experimental data comparisons and bounding sensitivity calculations. These methods work well when a sufficient experimental data base exists to justify the comparisons. However, in the case of limited or no experimental data the size of the uncertainty is normally made conservatively large. Accordingly, the author has taken another approach, that of performing a statistically based uncertainty analysis. The new work is based on prior evaluations of the importance of components and phenomena in the thermal-hydraulic safety analysis of the Advanced Neutron Source Reactor (ANSR), a new facility now in the design phase. The uncertainty during large break loss of coolant, and decay heat removal scenarios is estimated by assigning a probability distribution function (pdf) to the potential error in the initial expert estimates of pair-wise importance between the components. Using a Monte Carlo sampling technique, the error pdfs are propagated through the AHP software solutions to determine a pdf of uncertainty in the system wide importance of each component. To enhance the generality of the results, study of one other problem having different number of elements is reported, as are the effects of a larger assumed pdf error in the expert ranks. Validation of the Monte Carlo sample size and repeatability are also documented

  15. stableGP

    Data.gov (United States)

    National Aeronautics and Space Administration — The code in the stableGP package implements Gaussian process calculations using efficient and numerically stable algorithms. Description of the algorithms is in the...

  16. Restrictions of stable bundles

    CERN Document Server

    Balaji, V

    2011-01-01

    The Mehta-Ramanathan theorem ensures that the restriction of a stable vector bundle to a sufficiently high degree complete intersection curve is again stable. We improve the bounds for the "sufficiently high degree" and propose a possibly optimal conjecture.

  17. TRAC-PF1/MOD1: an advanced best-estimate computer program for pressurized water reactor thermal-hydraulic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Liles, D.R.; Mahaffy, J.H.

    1986-07-01

    The Los Alamos National Laboratory is developing the Transient Reactor Analysis Code (TRAC) to provide advanced best-estimate predictions of postulated accidents in light-water reactors. The TRAC-PF1/MOD1 program provides this capability for pressurized water reactors and for many thermal-hydraulic test facilities. The code features either a one- or a three-dimensional treatment of the pressure vessel and its associated internals, a two-fluid nonequilibrium hydrodynamics model with a noncondensable gas field and solute tracking, flow-regime-dependent constitutive equation treatment, optional reflood tracking capability for bottom-flood and falling-film quench fronts, and consistent treatment of entire accident sequences including the generation of consistent initial conditions. The stability-enhancing two-step (SETS) numerical algorithm is used in the one-dimensional hydrodynamics and permits this portion of the fluid dynamics to violate the material Courant condition. This technique permits large time steps and, hence, reduced running time for slow transients.

  18. Report of the evaluation by the project evaluation committee on upgrade of MOX fuels for advanced thermal reactor. Result evaluation in fiscal year 2001

    International Nuclear Information System (INIS)

    Japan Nuclear Cycle Development Institute (JNC) consulted a post evaluation on the 'Upgrade of MOX fuels for advanced thermal reactor' to the Committee on projects evaluation of research and development' (committee on projects evaluation of fast breeder reactors and fuels cycle) on bases of the National guideline on the method of evaluation for government R and D (stipulated by the Prime Minister of Japan on August 7, 1997), the Guidelines on external evaluation of researches and developments' in JNC (enacted on October 1, 1998), and so on. On response to this, the committee on projects evaluation of fast breeder reactors and fuel cycle evaluated this projects on a base of its explanatory documents, and supplementary ones proposed by JNC and discussions at the committee, according to evaluation procedures set by this committee. As a result of its general evaluation, it could be judged that an aim to develop high performance MOX fuels for demonstration reactors was almost established on its narrow meaning. However, by losing the plan of development on the demonstration reactors, by its conservative target setting, and so on, its effect must be said to be restrictive. Nevertheless, it was highly evaluated to produce MOX fuels, irradiate them, test them, and accumulate some know-hows on them by using its independent technologies. (G.K.)

  19. Evaluation of New Thermally Conductive Geopolymer in Thermal Energy Storage

    Science.gov (United States)

    Černý, Matěj; Uhlík, Jan; Nosek, Jaroslav; Lachman, Vladimír; Hladký, Radim; Franěk, Jan; Brož, Milan

    This paper describes an evaluation of a newly developed thermally conductive geopolymer (TCG), consisting of a mixture of sodium silicate and carbon micro-particles. The TCG is intended to be used as a component of high temperature energy storage (HTTES) to improve its thermal diffusivity. Energy storage is crucial for both ecological and economical sustainability. HTTES plays a vital role in solar energy technologies and in waste heat recovery. The most advanced HTTES technologies are based on phase change materials or molten salts, but suffer with economic and technological limitations. Rock or concrete HTTES are cheaper, but they have low thermal conductivity without incorporation of TCG. It was observed that TCG is stable up to 400 °C. The thermal conductivity was measured in range of 20-23 W m-1 K-1. The effect of TCG was tested by heating a granite block with an artificial fissure. One half of the fissure was filled with TCG and the other with ballotini. 28 thermometers, 5 dilatometers and strain sensors were installed on the block. The heat transport experiment was evaluated with COMSOL Multiphysics software.

  20. Advances in study of temperature of thermal tolerance of fishes%鱼类热忍耐温度研究进展

    Institute of Scientific and Technical Information of China (English)

    陈全震; 曾江宁; 高爱根; 廖一波; 杨关铭

    2004-01-01

    The paper is a review of the studies on the temperature of the thermal tolerance in fishes. It was described from four aspect: (1) The key parameters of temperature of thermal tolerance in fishes; (2) The influence factors of temperature of thermal tolerance in fishes; (3) The research methods of thermal effect of fishes; (4) The evaluation of effects of thermal pollution on fishes, especially, with the coastal power station will be'built in China recent years, the effects of thermal discharge water on the marine fisheries resource wered iscussed.

  1. Stable carbon isotope analysis of heavy oils

    Energy Technology Data Exchange (ETDEWEB)

    Fixari, B.; Le Perchec, P.; Bigois, M.; Casabianca, H.; Jame, P. [CNRS, Vernaison (France). Lab. des Materiaux Organiques

    1994-03-01

    Stable carbon isotope analysis of various heavy oils and some thermo-catalytically converted products was performed with a thermal analyser coupled with an isotopic ratio mass spectrometer. The temperature-programmed oxidative pyroanalysis technique subdivides the classical {sup 13}C/{sup 12}C ratio, affording new insights into the structural composition of heavy oils such as the contribution of naphthenoaromatics, and appears to be of interest for following their thermal refining. 24 refs., 11 figs., 2 tabs.

  2. Thermal management for LED applications

    CERN Document Server

    Poppe, András

    2014-01-01

    Thermal Management for LED Applications provides state-of-the-art information on recent developments in thermal management as it relates to LEDs and LED-based systems and their applications. Coverage begins with an overview of the basics of thermal management including thermal design for LEDs, thermal characterization and testing of LEDs, and issues related to failure mechanisms and reliability and performance in harsh environments. Advances and recent developments in thermal management round out the book with discussions on advances in TIMs (thermal interface materials) for LED applications, advances in forced convection cooling of LEDs, and advances in heat sinks for LED assemblies. This book also: Presents a comprehensive overview of the basics of thermal management as it relates to LEDs and LED-based systems Discusses both design and thermal management considerations when manufacturing LEDs and LED-based systems Covers reliability and performance of LEDs in harsh environments Has a hands-on applications a...

  3. Proceedings of the ANS/ASME/NRC international topical meeting on nuclear reactor thermal-hydraulics: LMFBR and HTGR advanced reactor concepts and analysis methods

    International Nuclear Information System (INIS)

    Separate abstracts are included for each of the papers presented concerning the thermal-hydraulics of LMFBR type reactors; mathematical methods in nuclear reactor thermal-hydraulics; heat transfer in gas-cooled reactors; and thermal-hydraulics of pebble-bed reactors. Two papers have been previously abstracted and input to the data base

  4. Ocean thermal energy conversion (OTEC) power system development utilizing advanced, high-performance heat transfer techniques. Volume 1. Conceptual design report

    Energy Technology Data Exchange (ETDEWEB)

    1978-05-12

    The objective of this project is the development of a preliminary design for a full-sized, closed cycle, ammonia power system module for the 100 MWe OTEC Demonstration Plant. In turn, this Demonstration Plant is to demonstrate, by 1984, the operation and performance of an ocean thermal power plant having sufficiently advanced heat exchanger design to project economic viability for commercial utilization in the late 1980's and beyond. Included in this power system development are the preliminary designs for a proof-of-concept pilot plant and test article heat exchangers which are scaled in such a manner as to support a logically sequential, relatively low-cost development of the full-scale power system module. The conceptual designs are presented for the Demonstration Plant power module, the proof-of-concept pilot plant, and for a pair of test article heat exchangers. Costs associated with the design, development, fabrication, checkout, delivery, installation, and operation are included. The accompanying design and producibility studies on the full-scale power system module project the performance/economics for the commercial plant. This section of the report describes the full-size power system module, and summarizes the design parameters and associated costs for the Demonstration Plant module (prototype) and projects costs for commercial plants in production. The material presented is directed primarily toward the surface platform/ship basic reference hull designated for use during conceptual design; however, other containment vessels were considered during the design effort so that the optimum power system would not be unduly influenced or restricted. (WHK)

  5. Assessment of applicability of TRAC-BF1 for thermal hydraulic instability

    International Nuclear Information System (INIS)

    To assess the stability of advanced light water reactors or steam generators in FBR, JAEA has been developing a prediction method for thermal-hydraulic instability based on system analysis code TRAC-BF1. In the present paper, thermal-hydraulic instability experiments were analyzed with TRAC-BF1 code and the applicability of the code for thermal-hydraulic instability was estimated. The heat flux of the boundary between stable and unstable region is in agreement with the experimental data within about 10% of error. The onset of instability can be predicted with TRAC-BF1. (author)

  6. Advanced Spaceborne Thermal Emission and Reflection Radometer (ASTER) Enhanced Vegetation Index (EVI) Products from Global Earth Observation (GEO) Grid: An Assessment Using Moderate Resolution Imaging Spectroradiometer (MODIS) for Synergistic Applications

    OpenAIRE

    Satoshi Tsuchida; Tomoaki Miura; Hirokazu Yamamoto

    2012-01-01

    We assessed the compatibility of three Advanced Spaceborne Thermal Emission and Reflection Radometer (ASTER) based Enhanced Vegetation Index (EVI) products generated in the GEO Grid system to Moderate Resolution Imaging Spectroradiometer (MODIS) EVI. The three products were two forms of the two-band EVI with ASTER red and NIR bands but without a blue band and the original, three-band EVI computed with ASTER red and NIR, and MODIS blue reflectances. Our assessment results showed good compatibi...

  7. Thermal comfort

    DEFF Research Database (Denmark)

    d’Ambrosio Alfano, Francesca Romana; Olesen, Bjarne W.; Palella, Boris Igor;

    2014-01-01

    Thermal comfort is one of the most important aspects of the indoor environmental quality due to its effects on well-being, people's performance and building energy requirements. Its attainment is not an easy task requiring advanced design and operation of building and HVAC systems, taking into...... account all parameters involved. Even though thermal comfort fundamentals are consolidated topics for more than forty years, often designers seem to ignore or apply them in a wrong way. Design input values from standards are often considered as universal values rather than recommended values to be used...... under specific conditions. At operation level, only few variables are taken into account with unpredictable effects on the assessment of comfort indices. In this paper, the main criteria for the design and assessment of thermal comfort are discussed in order to help building and HVAC systems designers...

  8. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  9. Mapping hydrothermally altered rocks at Cuprite, Nevada, using the advanced spaceborne thermal emission and reflection radiometer (Aster), a new satellite-imaging system

    Science.gov (United States)

    Rowan, L.C.; Hook, S.J.; Abrams, M.J.; Mars, J.C.

    2003-01-01

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a 14-band multispectral instrument on board the Earth Observing System (EOS), TERRA. The three bands between 0.52 and 0.86 ??m and the six bands from 1.60 and 2.43 ??m, which have 15- and 30-m spatial resolution, respectively, were selected primarily for making remote mineralogical determinations. The Cuprite, Nevada, mining district comprises two hydrothermal alteration centers where Tertiary volcanic rocks have been hydrothermally altered mainly to bleached silicified rocks and opalized rocks, with a marginal zone of limonitic argilized rocks. Country rocks are mainly Cambrian phyllitic siltstone and limestone. Evaluation of an ASTER image of the Cuprite district shows that spectral reflectance differences in the nine bands in the 0.52 to 2.43 ??m region provide a basis for identifying and mapping mineralogical components which characterize the main hydrothermal alteration zones: opal is the spectrally dominant mineral in the silicified zone; whereas, alunite and kaolinite are dominant in the opalized zone. In addition, the distribution of unaltered country rocks was mapped because of the presence of spectrally dominant muscovite in the siltstone and calcite in limestone, and the tuffaceous rocks and playa deposits were distinguishable due to their relatively flat spectra and weak absorption features at 2.33 and 2.20 ??m, respectively. An Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) image of the study area was processed using a similar methodology used with the ASTER data. Comparison of the ASTER and AVIRIS results shows that the results are generally similar, but the higher spectral resolution of AVIRIS (224 bands) permits identification of more individual minerals, including certain polymorphs. However, ASTER has recorded images of more than 90 percent of the Earth's land surface with less than 20 percent cloud cover, and these data are available at nominal or no cost

  10. Stable Delaunay Graphs

    OpenAIRE

    Agarwal, Pankaj K.; Gao, Jie; Guibas, Leonidas J.; Kaplan, Haim; Rubin, Natan; Sharir, Micha

    2015-01-01

    Let $P$ be a set of $n$ points in $\\mathrm{R}^2$, and let $\\mathrm{DT}(P)$ denote its Euclidean Delaunay triangulation. We introduce the notion of an edge of $\\mathrm{DT}(P)$ being {\\it stable}. Defined in terms of a parameter $\\alpha>0$, a Delaunay edge $pq$ is called $\\alpha$-stable, if the (equal) angles at which $p$ and $q$ see the corresponding Voronoi edge $e_{pq}$ are at least $\\alpha$. A subgraph $G$ of $\\mathrm{DT}(P)$ is called {\\it $(c\\alpha, \\alpha)$-stable Delaunay graph} ($\\math...

  11. Study of variation of thermal diffusivity of advanced composite materials of E-glass fibre reinforced plastic (GFRP) in temperature range 5–300 K

    Indian Academy of Sciences (India)

    Kalobaran Das; S M Kamaruzzaman; Tapas Ranjan Middya; Siddhartha Datta

    2009-02-01

    Modified Angstrom method is applied to study the variation of thermal diffusivity of plain woven fabric composite in closed cycle cryo-refrigerator (CCR) based set up in the temperature range 5–300 K. The set up used is plug in type and its small size offers portability. The set up works without use of any liquid cryogen. The temperature versus thermal diffusivity curve shows three distinct regions viz. 5–30 K, 30–120 K and 120–300 K. In the first region thermal diffusivity varies exponentially and rapidly. In the second region thermal diffusivity changes exponentially but relatively slowly than that in the first region. In the last region the change in thermal diffusivity with temperature is exponential in nature but very slow.

  12. Advanced Welding Concepts

    Science.gov (United States)

    Ding, Robert J.

    2010-01-01

    Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.

  13. Compliant thermal microactuators

    DEFF Research Database (Denmark)

    Jonsmann, Jacques; Sigmund, Ole; Bouwstra, Siebe

    1999-01-01

    Two dimensional compliant metallic thermal microactuators are designed using topology optimisation, and microfabricated using rapid prototyping techniques. Structures are characterised using advanced image analysis, yielding a very high precision. Characterised structures behave in accordance...

  14. Compliant thermal microactuators

    DEFF Research Database (Denmark)

    Jonsmann, Jacques; Sigmund, Ole; Bouwstra, Siebe

    1999-01-01

    Two dimensional compliant metallic thermal microactuators are designed using topology optimisation, and microfabricated using rapid prototyping techniques. Structures are characterised using advanced image analysis, yielding a very high precision. Characterised structures behave in a way which can...

  15. How stable are the 'stable ancient shields'?

    Science.gov (United States)

    Viola, Giulio; Mattila, Jussi

    2014-05-01

    "Archean cratons are relatively flat, stable regions of the crust that have remained undeformed since the Precambrian, forming the ancient cores of the continents" (King, EPSL, 2005). While this type of statement is supported by a wealth of constraints in the case of episodes of thoroughgoing ductile deformation affecting shield regions of Archean and also Peleoproterozoic age, a growing amount of research indicates that shields are not nearly as structurally stable within the broad field of environmental conditions leading to brittle deformation. In fact, old crystalline basements usually present compelling evidence of long brittle deformation histories, often very complex and challenging to unfold. Recent structural and geochronological studies point to a significant mechanical instability of the shield areas, wherein large volumes of 'stable' rocks actually can become saturated with fractures and brittle faults soon after regional cooling exhumes them to below c. 300-350° C. How cold, rigid and therefore strong shields respond to applied stresses remains, however, still poorly investigated and understood. This in turn precludes a better definition of the shallow rheological properties of large, old crystalline blocks. In particular, we do not yet have good constraints on the mechanisms of mechanical reactivation that control the partial (if not total) accommodation of new deformational episodes by preexisting structures, which remains a key to untangle brittle histories lasting several hundred Myr. In our analysis, we use the Svecofennian Shield (SS) as an example of a supposedly 'stable' region with Archean nucleii and Paleoproterozoic cratonic areas to show how it is possible to unravel the details of brittle histories spanning more than 1.5 Gyr. New structural and geochronological results from Finland are integrated with a review of existing data from Sweden to explore how the effects of far-field stresses are partitioned within a shield, which was growing

  16. NASA and U.S. Geological Survey Long-Term Archive for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)

    Science.gov (United States)

    Abrams, M.; Meyer, D. F.

    2013-12-01

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a 14-channel optical imaging instrument on NASA's Terra spacecraft. ASTER is a joint project between Japan's Ministry of Economy, Trade and Industry; and U.S. National Aeronautics and Space Administration. Since its launch in December, 1999, ASTER has acquired over 2.4 million multispectral images. The Level 0 data are sent to Japan by NASA, where they are processed to Level 1A (reconstructed, unprocessed instrument data with geometric and radiometric parameters attached). A copy of the L1A data is sent to the U.S. to the Land Processes Distributed Active Archive Center (LPDAAC), operated for NASA by the U.S. Geological Survey (USGS) at the EROS Center. The joint US/Japan ASTER Science Team (AST) has provided algorithms to produce 14 Level 1, Level 2, and Level 3 products. The duplicate data distribution systems in Japan and the U.S. create these products 'on-demand' as users submit data requests. Only the L0 and L1A data are archived. After the termination of the mission, the USGS has the responsibility for creating, managing and distributing ASTER data products from a Long-Term Archive (LTA). In cooperation with the LPDAAC, the U.S. AST discussed various scenarios on how the LTA should operate. The two leading plans considered were: (1) duplicating the 'on-demand' system, fulfilling user requests as they arrived; this would require a high level of technical support for algorithm/software maintenance, user services to answer questions, hardware maintenance, and in general, was quite labor-intensive; (2) creating a static archive of all of the data products for every one of the L1A image granules; the LPDAAC would produce each of the 14 higher level data products from every L1A image currently archived. Users would order data products from this greatly expanded archive, with little human intervention. In both cases, complete documentation would be available to users, detailing the

  17. Research report - Solar thermal power 2000plus. Advancement and optimization of charging and discharging systems for tank and ground heat stores; Forschungsbericht - Solarthermie 2000plus. Weiterentwicklung und Optimierung von Be- und Entladesystemen fuer Tank- und Erdbeckenspeicher

    Energy Technology Data Exchange (ETDEWEB)

    Goeppert, Stefan; Lohse, Rolf; Urbaneck, Thorsten; Schirmer, Ulrich; Platzer, Bernd [Technische Univ. Chemnitz (Germany). Fakultaet fuer Maschinenbau; Buehl, Juergen; Nilius, Andreas [Technische Univ. Ilmenau (Germany). Fakultaet fuer Maschinenbau

    2009-07-01

    The authors of the contribution under consideration examine different constructions for the charging and discharging of thermal storage systems experimentally and by means of computerized simulation. The substantial goals of this investigation are: (a) Systematization and analysis of existing constructions; (b) Advancement and optimization of charging and discharging systems; (c) Deduction of guidelines for planning and design; (d) Investigation of the transferability from the experiment on medium and large storages; (e) Integration of industrial partners (co-operation and practice test). The results of these investigations and the realizations are described in this contribution in detail.

  18. Stable generalized complex structures

    CERN Document Server

    Cavalcanti, Gil R

    2015-01-01

    A stable generalized complex structure is one that is generically symplectic but degenerates along a real codimension two submanifold, where it defines a generalized Calabi-Yau structure. We introduce a Lie algebroid which allows us to view such structures as symplectic forms. This allows us to construct new examples of stable structures, and also to define period maps for their deformations in which the background three-form flux is either fixed or not, proving the unobstructedness of both deformation problems. We then use the same tools to establish local normal forms for the degeneracy locus and for Lagrangian branes. Applying our normal forms to the four-dimensional case, we prove that any compact stable generalized complex 4-manifold has a symplectic completion, in the sense that it can be modified near its degeneracy locus to produce a compact symplectic 4-manifold.

  19. Dynamic thermal environment and thermal comfort.

    Science.gov (United States)

    Zhu, Y; Ouyang, Q; Cao, B; Zhou, X; Yu, J

    2016-02-01

    Research has shown that a stable thermal environment with tight temperature control cannot bring occupants more thermal comfort. Instead, such an environment will incur higher energy costs and produce greater CO2 emissions. Furthermore, this may lead to the degeneration of occupants' inherent ability to combat thermal stress, thereby weakening thermal adaptability. Measured data from many field investigations have shown that the human body has a higher acceptance to the thermal environment in free-running buildings than to that in air-conditioned buildings with similar average parameters. In naturally ventilated environments, occupants have reported superior thermal comfort votes and much greater thermal comfort temperature ranges compared to air-conditioned environments. This phenomenon is an integral part of the adaptive thermal comfort model. In addition, climate chamber experiments have proven that people prefer natural wind to mechanical wind in warm conditions; in other words, dynamic airflow can provide a superior cooling effect. However, these findings also indicate that significant questions related to thermal comfort remain unanswered. For example, what is the cause of these phenomena? How we can build a comfortable and healthy indoor environment for human beings? This article summarizes a series of research achievements in recent decades, tries to address some of these unanswered questions, and attempts to summarize certain problems for future research. PMID:26171688

  20. Seasonal sensible thermal energy storage solutions

    OpenAIRE

    Lavinia Gabriela SOCACIU

    2012-01-01

    The thermal energy storage can be defined as the temporary storage of thermal energy at high or low temperatures. Thermal energy storage is an advances technology for storing thermal energy that can mitigate environmental impacts and facilitate more efficient and clean energy systems. Seasonal thermal energy storage has a longer thermal storage period, generally three or more months. This can contribute significantly to meeting society`s need for heating and cooling. The objectives of thermal...

  1. Thermodynamically Stable Pickering Emulsions

    NARCIS (Netherlands)

    Sacanna, S.; Kegel, W.K.; Philipse, A.P.

    2007-01-01

    We show that under appropriate conditions, mixtures of oil, water, and nanoparticles form thermodynamically stable oil-in-water emulsions with monodisperse droplet diameters in the range of 30–150 nm. This observation challenges current wisdom that so-called Pickering emulsions are at most metastabl

  2. Stable isotope studies

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  3. Stable Unhappy Marriages.

    Science.gov (United States)

    Heaton, Tim B.; Albrecht, Stan L.

    1991-01-01

    Examined prevalence and determinants of stable unhappy marriage using data from national survey. Results indicated age, lack of prior marital experience, commitment to marriage as an institution, low social activity, lack of control over one's life, and belief that divorce would detract from happiness were all predictive of stability in unhappy…

  4. Elliptic stable envelope

    CERN Document Server

    Aganagic, Mina

    2016-01-01

    We construct stable envelopes in equivariant elliptic cohomology of Nakajima quiver varieties. In particular, this gives an elliptic generalization of the results of arXiv:1211.1287. We apply them to the computation of the monodromy of $q$-difference equations arising the enumerative K-theory of rational curves in Nakajima varieties, including the quantum Knizhnik-Zamolodchikov equations.

  5. Normal modified stable processes

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler; Shephard, N.

    2002-01-01

    Gaussian (NGIG) laws. The wider framework thus established provides, in particular, for added flexibility in the modelling of the dynamics of financial time series, of importance especially as regards OU based stochastic volatility models for equities. In the special case of the tempered stable OU process...

  6. 2005 Economy: Stable Development

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ 2005 is the fifth year of China's Tenth Five-Year Plan, it is an important year to implement commitment for entering into WTO as well as a key year for deepening macro-control. With further deepening of macro control and development of regional economy, Chinese economy will operate in a more healthy and stable way.

  7. 2005 Economy: Stable Development

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

      2005 is the fifth year of China's Tenth Five-Year Plan, it is an important year to implement commitment for entering into WTO as well as a key year for deepening macro-control. With further deepening of macro control and development of regional economy, Chinese economy will operate in a more healthy and stable way.……

  8. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

  9. Stable isotope studies

    International Nuclear Information System (INIS)

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  10. Perioperative nursing of patients with advanced pancreatic carcinoma underwent thermal coagulation%热凝固治疗晚期胰体尾癌的围手术期护理

    Institute of Scientific and Technical Information of China (English)

    陆瑶; 周峥

    2010-01-01

    目的 总结热凝固治疗晚期胰体尾癌的围手术期护理体会.方法 精心的术前、术后护理,合理的健康教育,给予个体化的出院指导,并加强手术前后的心理护理.结果 本组27例患者均行射频消融或微波固化治疗,无围手术期死亡病例,1例患者出现胰瘘,无护理并发症发生.结论 加强热凝固治疗晚期胰体尾癌围手术期的护理,可大大提高患者围手术期的生活质量.%Objective To summarize the nursing experience during perioperative period of thermal coagulation therapy for patients with advanced pancreatic carcinoma. Methods Intensive perioperative nursing care, proper health education and individual discharge guidance performed for 27 cases. Results All patients underwent radiofrequency ablation or microwave coagulation therapy, no perioperative deaths case appeared.Only 1 case of pancreatic fistula occurred but no complications appeared. Conclusions Enhancing the perioperative nursing of thermal ablation can dramatically improve the quality of life for patients with advanced pancreatic carcinoma.

  11. Stable isotope dilution assays in mycotoxin analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rychlik, Michael; Asam, Stefan [Universitaet Muenchen, Lehrstuhl fuer Lebensmittelchemie der Technischen, Garching (Germany)

    2008-01-15

    The principle and applications of stable isotope dilution assays (SIDAs) in mycotoxin analysis are critically reviewed. The general section includes historical aspects of SIDAs, the prerequisites and limitations of the use of stable isotopically labelled internal standards, and possible calibration procedures. In the application section actual SIDAs for the analysis of trichothecenes, zearalenone, fumonisins, patulin, and ochratoxin A are presented. The syntheses and availability of labelled mycotoxins for use as internal standards is reviewed and specific advances in food analysis and toxicology are demonstrated. The review indicates that LC-MS applications, in particular, require the use of stable isotopically labelled standards to compensate for losses during clean-up and for discrimination due to ion suppression. As the commercial availability of these compounds continues to increase, SIDAs can be expected to find expanding use in mycotoxin analysis. (orig.)

  12. Super Stable Ferroelectrics with High Curie Point

    Science.gov (United States)

    Gao, Zhipeng; Lu, Chengjia; Wang, Yuhang; Yang, Sinuo; Yu, Yuying; He, Hongliang

    2016-04-01

    Ferroelectric materials are of great importance in the sensing technology due to the piezoelectric properties. Thermal depoling behavior of ferroelectrics determines the upper temperature limit of their application. So far, there is no piezoelectric material working above 800 °C available. Here, we show Nd2Ti2O7 with a perovskite-like layered structure has good resistance to thermal depoling up to 1400 °C. Its stable behavior is because the material has only 180° ferroelectric domains, complex structure change at Curie point (Tc) and their sintering temperature is below their Tc, which avoided the internal stresses produced by the unit cell volume change at Tc. The phase transition at Tc shows a first order behavior which involving the tilting and rotation of the octahedron. The Curie – Weiss temperature is calculated, which might explain why the thermal depoling starts at about 1400 °C.

  13. Advance on non-thermal plasma-photocatalysis technology for air polullant control%低温等离子体-光催化联合技术处理空气污染物的研究进展

    Institute of Scientific and Technical Information of China (English)

    梁文俊; 马琳; 李坚

    2011-01-01

    Non-thermal plasma-photocatalysis technology is a new technology in recent years,which effectively make up for the defects of non-thermal plasma and photocatalysis. The recent research results indicated that the technology was effective for the removal of air pollutants. The basic principles of and advance on non-thermal plasma-photocatalysis technology were introduced and its application prospects were also outlined.%低温等离子体-光催化联合技术是近年来兴起的一项新型技术,它有效弥补了低温等离子体和光催化的缺陷,该技术对空气污染物有较好的去除效果.介绍了低温等离子体-光催化联合技术的基本原理和国内外研究进展,并对该技术的应用前景进行了展望.

  14. Extended requirements on advanced thermal power plants as a necessary contribution to power systems transient stability. Fast valving for stable power plant operation; Erweiterte Anforderungen an neue thermische Kraftwerke als notwendiger Beitrag zur Systemstabilitaet. Schnellschlussventile fuer stabilen Kraftwerksbetrieb

    Energy Technology Data Exchange (ETDEWEB)

    Erlich, Istvan [Univ. Duisburg-Essen (Germany); Loewen, Jakob; Schmidt, Joerg M.; Winter, Wilhelm [Eon Netz GmbH, Bayreuth (Germany)

    2008-09-08

    Due to the expected intensive use of wind power new requirements regarding the control behavior of the electric power system arise. This is forced especially by the increasing concentration of several units in large wind farms. In this paper reconstruction, realization and monitoring of decentralized power generation systems are presented in detail. Presented is in this special case shortage avoidance by fast turbine valve operations. (GL)

  15. Stable local oscillator module.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert Wesley

    2007-11-01

    This report gives a description of the development of a Stable Local Oscillator (StaLO) multi-chip module (MCM). It is a follow-on report to SAND2006-6414, Stable Local Oscillator Microcircuit. The StaLO accepts a 100MHz input signal and produces output signals at 1.2, 3.3, and 3.6 GHz. The circuit is built as a multi-chip module (MCM), since it makes use of integrated circuit technologies in silicon and lithium niobate as well as discrete passive components. This report describes the development of an MCM-based version of the complete StaLO, fabricated on an alumina thick film hybrid substrate.

  16. Preparation and thermally stable luminescence properties of a new blue Sr5Cl0.75F0.25(PO4)3: Eu2+ phosphor for WLEDs

    International Nuclear Information System (INIS)

    Highlights: • A new blue phosphor Sr5Cl0.75F0.25(PO4)3: Eu2+ was prepared at 800 °C. • The broad excitation band of the phosphor matches well with n-UV LED chips. • The phosphor possesses higher thermal quenching stability than BAM. • A bright blue LED was fabricated by combination of n-UV chip and the phosphor. - Abstract: A series of new blue-emitting phosphors Sr5(1−x)Cl0.75F0.25(PO4)3: 5xEu2+ (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 mol%) were synthesized by high-temperature solid state reaction. X-ray powder diffraction (XRD) and field-emission scanning electron microscope (FE-SEM) were used to characterize the crystal structure and micro-morphology of the prepared samples. The photoluminescence properties of these phosphors were investigated by excitation and emission spectra. The effect of Eu2+ concentration on emission of the phosphor was investigated and the concentration quenching mechanism was discussed in detail. Also, the temperature-dependence luminescence properties of Sr5Cl0.75F0.25(PO4)3: Eu2+ were compared with those of the commercial blue phosphor BaMgAl10O17: Eu2+ (BAM). With the increase of temperature, the emission band exhibited blue shift and decreasing emission intensities. The phosphor Sr5Cl0.75F0.25(PO4)3: Eu2+ possesses higher thermal stability than BAM. Furthermore, a bright blue LED was fabricated by combination of n-UV InGaN chip and the phosphor. The results reveal that Sr5Cl0.75F0.25(PO4)3: Eu2+ is a potential blue phosphor for n-UV-pumped white light-emitting-diodes (WLEDs)

  17. Preparation and thermally stable luminescence properties of a new blue Sr{sub 5}Cl{sub 0.75}F{sub 0.25}(PO{sub 4}){sub 3}: Eu{sup 2+} phosphor for WLEDs

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhan-Chao, E-mail: wuzhan_chao@163.com; Wang, Shuai; Liu, Jie, E-mail: zsuliujie@163.com; Yin, Jin-Hua; Kuang, Shao-Ping

    2015-09-25

    Highlights: • A new blue phosphor Sr{sub 5}Cl{sub 0.75}F{sub 0.25}(PO{sub 4}){sub 3}: Eu{sup 2+} was prepared at 800 °C. • The broad excitation band of the phosphor matches well with n-UV LED chips. • The phosphor possesses higher thermal quenching stability than BAM. • A bright blue LED was fabricated by combination of n-UV chip and the phosphor. - Abstract: A series of new blue-emitting phosphors Sr{sub 5(1−x)}Cl{sub 0.75}F{sub 0.25}(PO{sub 4}){sub 3}: 5xEu{sup 2+} (x = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 mol%) were synthesized by high-temperature solid state reaction. X-ray powder diffraction (XRD) and field-emission scanning electron microscope (FE-SEM) were used to characterize the crystal structure and micro-morphology of the prepared samples. The photoluminescence properties of these phosphors were investigated by excitation and emission spectra. The effect of Eu{sup 2+} concentration on emission of the phosphor was investigated and the concentration quenching mechanism was discussed in detail. Also, the temperature-dependence luminescence properties of Sr{sub 5}Cl{sub 0.75}F{sub 0.25}(PO{sub 4}){sub 3}: Eu{sup 2+} were compared with those of the commercial blue phosphor BaMgAl{sub 10}O{sub 17}: Eu{sup 2+} (BAM). With the increase of temperature, the emission band exhibited blue shift and decreasing emission intensities. The phosphor Sr{sub 5}Cl{sub 0.75}F{sub 0.25}(PO{sub 4}){sub 3}: Eu{sup 2+} possesses higher thermal stability than BAM. Furthermore, a bright blue LED was fabricated by combination of n-UV InGaN chip and the phosphor. The results reveal that Sr{sub 5}Cl{sub 0.75}F{sub 0.25}(PO{sub 4}){sub 3}: Eu{sup 2+} is a potential blue phosphor for n-UV-pumped white light-emitting-diodes (WLEDs)

  18. Kinetic Stable Delaunay Graphs

    CERN Document Server

    Agarwal, Pankaj K; Guibas, Leonidas J; Kaplan, Haim; Koltun, Vladlen; Rubin, Natan; Sharir, Micha

    2011-01-01

    We consider the problem of maintaining the Euclidean Delaunay triangulation $\\DT$ of a set $P$ of $n$ moving points in the plane, along algebraic trajectories of constant description complexity. Since the best known upper bound on the number of topological changes in the full $\\DT$ is nearly cubic, we seek to maintain a suitable portion of it that is less volatile yet retains many useful properties. We introduce the notion of a stable Delaunay graph, which is a dynamic subgraph of the Delaunay triangulation. The stable Delaunay graph (a) is easy to define, (b) experiences only a nearly quadratic number of discrete changes, (c) is robust under small changes of the norm, and (d) possesses certain useful properties. The stable Delaunay graph ($\\SDG$ in short) is defined in terms of a parameter $\\alpha>0$, and consists of Delaunay edges $pq$ for which the angles at which $p$ and $q$ see their Voronoi edge $e_{pq}$ are at least $\\alpha$. We show that (i) $\\SDG$ always contains at least roughly one third of the Del...

  19. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  20. New optically active and thermally stable poly(amide-imide)s containing N,N'-(Bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic)-bis-L-alanine and aromatic diamines: synthesis and characterization

    International Nuclear Information System (INIS)

    Five new optically active poly(amide-imide)s (PAIs) 6a-e were prepared by direct polycondensation reaction of the newly synthesized N,N'-(bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetra carboxylic)-bis-L-alanine 4 with various aromatic diamines 5a-e using polar aprotic solvents such as N-methyl-2-pyrrolidone (NMP). In this technique triphenyl phosphite (TPP) and pyridine were used as condensing agents to form poly(amide-imide)s through the N-phosphonium salts of pyridine. All of the polymers were obtained in quantitative yields with inherent viscosities between 0.29-0.46 dL g-1 and were highly soluble in polar aprotic solvents such as N,N-dimethyl acetamide (DMAc), N,N-dimethyl formamide (DMF), dimethyl sulfoxide (DMSO), N-methyl- 2-pyrrolidone (NMP) and solvents such as sulfuric acid. They were fully characterized by means of 1H NMR, FTIR spectroscopy, elemental analyses, inherent viscosity, solubility test, specific rotation and thermal properties of these polymers were investigated using thermogravimetric analysis techniques (TGA and DTG). (author)

  1. Evaluation of adhesion strength of Er2O3 coating layer for an advanced breeding blanket system applied to thermal cycles using nano-scratch method

    International Nuclear Information System (INIS)

    The electrical insulator and hydrogen permeation barrier coatings are important materials to realize the liquid metal and molten-salt typed breeding blanket systems. We found that erbium oxide (Er2O3) is one of the promising materials as the electrical insulator and hydrogen permeation restraint coatings. Establishing the mechanical property evaluation method for these coating is extremely important to certify the durability of coating material in the blanket systems. The adhesion strength property, which is one of the key mechanical properties of coating materials, was investigated using the nano-scratch method. From the results, it was found that the nano-scratch test was able to evaluate the adhesion strength of the Er2O3 coating synthesized by the Metal Organic Chemical Vapor Deposition (MOCVD) process with high reproducibility. Furthermore, the adhesion strength of the Er2O3 coating before and after thermal cycling was evaluated using this method. The adhesion strength after 50 thermal cycles at 700degC was kept around 70% compared with that before thermal cycling. (author)

  2. Thermal behavior of polytriazole films: a thermal analysis study

    NARCIS (Netherlands)

    Gebben, B.; Mulder, M.H.V.; Smolders, C.A.

    1989-01-01

    The thermal behavior of poly(1,3-phenyl-1,4-phenyl)-4-phenyl-1,2,4-triazole has been investigated using different scanning calorimetry (DSC) and thermogravimetry (TG). Processes are studied for this thermally stable polymer that take place between 200 and 500°C. While the polycondensation reaction p

  3. Concentration quenching of Eu{sup 2+} in a thermal-stable yellow phosphor Ca{sub 2}BO{sub 3}Cl:Eu{sup 2+} for LED application

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xinguo; Zhang Jilin; Dong Zhiyue; Shi Jianxin [State Key Laboratory of Optoelectronic Materials and Technologies, Ministry of Education Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Gong Menglian, E-mail: cesgml@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, Ministry of Education Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2012-04-15

    A piece-shaped phosphor Ca{sub 2}BO{sub 3}Cl: Eu{sup 2+} was synthesized by solid-state reaction method. This phosphor exhibited wide absorption in ultra-violet and visible range, and bright yellow emission band centering at 570 nm. The concentration quenching mechanism was verified to be a dipole-dipole interaction, and its critical transfer distance was about 17 A by both calculated crystal structural method and experimental spectral method. This phosphor has a good thermal stability with a quenching temperature (T{sub 1/2}) of 200 Degree-Sign C. Yellow and white LEDs were fabricated with this phosphor and near UV chips, and the yellow LED has a high color purity of 97.0% and promising current tolerant property, while the white LED shows a luminous efficiency of 11.68 lm/W. - Highlights: Black-Right-Pointing-Pointer Broadband excitable and strong yellow-emitting Ca{sub 2}BO{sub 3}Cl: Eu{sup 2+} phosphor is obtained by solid state reaction. Black-Right-Pointing-Pointer Concentration quenching mechanism of Ca{sub 2}BO{sub 3}Cl: Eu{sup 2+} is dipole-dipole interaction. Black-Right-Pointing-Pointer Quenching temperature (T{sub 1/2}) of Ca{sub 2}BO{sub 3}Cl: Eu{sup 2+} is at 200 Degree-Sign C. Black-Right-Pointing-Pointer As synthesized material can be used for LED phosphor application.

  4. Paleoproxies: Heavy Stable Isotope Perspectives

    Science.gov (United States)

    Nagler, T. F.; Hippler, D.; Siebert, C.; Kramers, J. D.

    2002-12-01

    Recent advances in isotope ratio mass spectrometry, namely multiple collector ICP-MS and refined TIMS techniques, will significantly enhance the ability to measure heavy stable isotope fractionation, which will lead to the development of a wide array of process-identifying (bio)-geochemical tools. Thus far research in this area is not easily assessable to scientists outside the isotope field. This is due to the fact that analyzing heavy stable isotopes does not provide routine numbers which are per se true (the preciser the truer) but is still a highly experimental field. On the other hand resolving earth science problems requires specialists familiar with the environment being studied. So what is in there for paleoceanographers? In a first order approach, relating isotope variations to physical processes is straightforward. A prominent example are oxygen isotope variations with temperature. The total geological signal is of course far more complicated. At low temperatures, heavy stable isotopes variations have been reported for e.g. Ca, Cr, Fe, Cu, Zn, Mo and Tl. Fractionation mechanisms and physical parameters responsible for the observed variations are not yet resolved for most elements. Significant equilibrium isotope fractionation is expected from redox reactions of transition metals. However a difference in coordination number between two coexisting speciations of an element in the same oxidation state can also cause fractionation. Protonation of dissolved Mo is one case currently discussed. For paleoceanography studies, a principal distinction between transition metals essential for life (V to Zn plus Mo) or not will be helpful. In case of the former group, distinction between biogenic and abiogenic isotope fractionation will remain an important issue. For example, abiotic Fe redox reactions result in isotope fractionations indistinguishable in direction and magnitude from microbial effects. Only a combination of different stable isotope systems bears the

  5. Stable Complete Intersections

    CERN Document Server

    Robbiano, Lorenzo

    2011-01-01

    A complete intersection of n polynomials in n indeterminates has only a finite number of zeros. In this paper we address the following question: how do the zeros change when the coefficients of the polynomials are perturbed? In the first part we show how to construct semi-algebraic sets in the parameter space over which all the complete intersection ideals share the same number of isolated real zeros. In the second part we show how to modify the complete intersection and get a new one which generates the same ideal but whose real zeros are more stable with respect to perturbations of the coefficients.

  6. Properties of the thermally stable Al{sub 95}Cr{sub 3.1}Fe{sub 1.1}Ti{sub 0.8} alloy prepared by cold-compression at ultra-high pressure and by hot-extrusion

    Energy Technology Data Exchange (ETDEWEB)

    Vojtech, D., E-mail: Dalibor.Vojtech@vscht.cz [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Michalcova, A.; Prusa, F. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Dam, K.; Seda, P. [Department of Metals and Corrosion Engineering, Institute of Chemical Technology, Prague, Technicka 5, 166 28 Prague 6 (Czech Republic); Institute of Physics of the ASCR, Na Slovance 2, 182 21 Prague 8 (Czech Republic)

    2012-04-15

    An Al{sub 95}Cr{sub 3.1}Fe{sub 1.1}Ti{sub 0.8} (in at.%) alloy was made into rapidly solidified powder by melt atomization. The powder was compacted by two processes: 1) uni-axial cold compression at an ultra-high pressure of 6 GPa and 2) hot extrusion at 480 Degree-Sign C. The structures, mechanical properties and thermal stability of both materials were compared with the commercial AlSi{sub 12}Cu{sub 1}Mg{sub 1}Ni{sub 1} (in wt.%) casting alloy, which is generally considered to be thermally stable. It was found that cold compression at ultra-high pressure created a compact and porosity-free material, which was similar to the material that was prepared with the commonly used hot extrusion method. The Vickers hardness, compressive strength and compressive yield strength of the cold-compressed alloy were 161 HV, 680 MPa and 547 MPa, respectively, which were higher than the values obtained for the hot-extruded and casting alloys. The thermal stability of the hot-extruded Al{sub 95}Cr{sub 3.1}Fe{sub 1.1}Ti{sub 0.8} alloy was excellent because its mechanical properties did not change significantly, even after 100 h of annealing at 500 Degree-Sign C. The mechanical properties and thermal stability of the investigated materials were discussed in relation to their structures and diffusivities of the alloying elements. - Highlights: Black-Right-Pointing-Pointer The Al{sub 95}Cr{sub 3.1}Fe{sub 1.1}Ti{sub 0.8} alloy was prepared by compression at an ultra-high pressure of 6 GPa. Black-Right-Pointing-Pointer The resulting material was dense and porosity-free. Black-Right-Pointing-Pointer The material had high hardness of 161 HV and a compressive strength of 680 MPa. Black-Right-Pointing-Pointer The material had excellent thermal stability at 500 Degree-Sign C.

  7. Evolution of developments and applications of advanced thermal-hydraulics and neutronic codes. Conclusions from Annapolis Workshop and Ankara Seminar, Objectives of the Present Workshop

    International Nuclear Information System (INIS)

    In the nuclear reactor safety area, during the last 30-40 years, thermal-hydraulics has been one of the key disciplines for simulation and analysis of transient and accident scenarios and also for the definition of preventive and mitigative measures in relation to these scenarios. A workshop was organised by OECD/NEA-CSNI at Annapolis (1996) where codes, physical models, numeric and new computer architecture were examined. In parallel a Specialist meeting on instrumentation in two phase flows was held in Santa Barbara beginning of 1997 in order to investigate new techniques for getting measurements of new physical parameters necessary for assessing the new physical models. Among the different applications of thermal-hydraulic codes, the use of Best Estimate methods in safety evaluation is certainly one of the major challenges for which the safety and economic issues are quite important. For these reasons OECD/NEA-CSNI organised a seminar in Ankara in 1998 entirely devoted to the use of Best Estimate methods in thermal-hydraulics analysis. This seminar allowed to get a better view of where we were in such applications and which were the remaining problems and issues. The present workshop held in Barcelona beginning of year 2000 will be a good opportunity for providing an updated review of the gained progresses and for analysing if the objectives and programs are still progressing in the right direction. In order to do such exercise, we will first recall the questions which were raised in Annapolis and the main conclusions which were drawn from these questions. The conclusions of Ankara Meeting will be reviewed in a second step. Finally we will list the objectives of this workshop in Barcelona which is held in the continuity of Annapolis Workshop and Ankara Seminar. (authors)

  8. A rapid top-down response of the ocean carbon system at the onset of the Paleocene/Eocene Thermal Maximum from stable isotopes and first principal carbon cycling

    Science.gov (United States)

    Schaller, M. F.; Wright, J. D.

    2013-12-01

    We present the largest carbon isotope excursion (CIE) yet identified for the onset of the Paleocene/Eocene Thermal Maximum (PETM) from shallow-water shelf localities on the Atlantic Margin, exceeding those of any other marine or terrestrial record. The excursion observed on the shelf at multiple localities is contained by the rhythmically bedded Marlboro Clay, which provides a powerful and precise chronometer sequencing the onset of the CIE. The magnitude of this excursion at the shallowest shelf sites suggests that the total atmospheric excursion was much larger than previously estimated. Furthermore, the magnitude of the observed δ13C anomaly is strongly correlated to site water depth along a shelf transect with deep sites showing the smallest excursions and shallow sites showing the largest. Such a response is only expected from a top-down propagation of a carbon isotope anomaly, and using our corrected timescale for the onset, is identical to the invasion of bomb-produced radiocarbon into the surface water system. Further, we use the observed difference between the δ13C and CaCO3 responses on the shelf, combined with first principal carbon cycling from the surface water invasion of bomb radiocarbon, to estimate the size of the initial atmospheric pulse over it's decadal invasion time. Unlike shelf sites, open ocean surface water localities are hopelessly overprinted by old carbon, due to the constant mixing between the surface and deep carbon reservoirs. A simple relationship with oceanographic parameters, such as water depth, carbon reservoir size and age shows a tight correlation with the total magnitude of the CIE at each site. However, this relationship is only quantitatively meaningful in light of our new data, which constrain the most extreme marine end-member. Only a rapid carbon injection, propagating from the atmosphere into the oceans, can explain the observed trends with reservoir size and age. The total magnitude of the carbon anomaly is

  9. Stable Umbral Chromospheric Structures

    CERN Document Server

    Henriques, V M J; Mathioudakis, M; Kiselman, D; Gallagher, P T; Keenan, F P

    2014-01-01

    Aims. To understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable structures, and examine their relationship with observables in the H-alpha line. Methods. Filtergrams in the core of the Ca II H and H-alpha lines as observed with the Swedish 1-m Solar Telescope are employed. We utilise a technique that creates composite images and tracks the flash propagation horizontally. Results. We find 0"15 wide horizontal structures, in all of the three target sunspots, for every flash where the seeing was moderate to good. Discrete dark structures are identified that are stable for at least two umbral flashes, as well as systems of structures that live for up to 24 minutes. We find cases of extremely extended structures with similar stability, with one such structure showing an extent of 5". Some of these structures have a correspondence in H-alpha but we ...

  10. Giant Thermal Rectification from Polyethylene Nanofiber Thermal Diodes

    CERN Document Server

    Zhang, Teng

    2015-01-01

    The realization of phononic computing is held hostage by the lack of high performance thermal devices. Here we show through theoretical analysis and molecular dynamics simulations that unprecedented thermal rectification factors (as large as 1.20) can be achieved utilizing the phase dependent thermal conductivity of polyethylene nanofibers. More importantly, such high thermal rectifications only need very small temperature differences (< 20 oC) across the device, which is a significant advantage over other thermal diodes which need temperature biases on the order of the operating temperature. Taking this into consideration, we show that the dimensionless temperature-scaled rectification factors of the polymer nanofiber diodes range from 12 to 25 - much larger than other thermal diodes (< 8). The polymer nanofiber thermal diode consists of a crystalline portion whose thermal conductivity is highly phase-sensitive and a cross-linked portion which has a stable phase. Nanoscale size effect can be utilized t...

  11. Heat transfer of nuclear thermal propulsion systems

    Energy Technology Data Exchange (ETDEWEB)

    El-Genk, M.S.; Metzger, J.D.

    1994-12-31

    Nuclear thermal propulsion offers performance capabilities beyond chemical propulsion and is enabling for many planetary missions. Because of the performance capabilities and the number of thermal design issues, NTP offers a productive area for advanced development and research.

  12. Stable, free-standing Ge nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, I.D.; Xu, Q.; Liao, C.Y.; Yi, D.O.; Beeman, J.W.; Liliental-Weber, Z.; Yu, K.M.; Zakharov, D.N.; Ager III, J.W.; Chrzan,D.C.; Haller, E.E.

    2005-01-28

    Free-standing Ge nanocrystals that are stable under ambient conditions have been synthesized in a two-step process. First, nanocrystals with a mean diameter of 5 nm are grown in amorphous SiO{sub 2} by ion implantation followed by thermal annealing. The oxide matrix is then removed by selective etching in diluted HF to obtain free-standing nanocrystals on a Si wafer. After etching, nanocrystals are retained on the surface and the size distribution is not significantly altered. Free-standing nanocrystals are stable under ambient atmospheric conditions, suggesting formation of a self-limiting native oxide layer. For free-standing as opposed to embedded Ge nanocrystals, an additional amorphous-like contribution to the Raman spectrum is observed and is assigned to surface reconstruction-induced disordering of near-surface atoms.

  13. Stable transport in proton driven Fast Ignition

    CERN Document Server

    Bret, A

    2009-01-01

    Proton beam transport in the context of proton driven Fast Ignition is usually assumed to be stable due to protons high inertia, but an analytical analysis of the process is still lacking. The stability of a charge and current neutralized proton beam passing through a plasma is therefore conducted here, for typical proton driven Fast Ignition parameters. In the cold regime, two fast growing Buneman-like modes are found, with an inverse growth-rate much smaller than the beam time-of-flight to the target core. The stability issue is thus not so obvious, and Kinetic effects are investigated. One unstable mode is found stabilized by the background plasma protons and electrons temperatures. The second mode is also damped, providing the proton beam thermal spread is larger than $\\sim$ 10 keV. In Fusion conditions, the beam propagation should therefore be stable.

  14. Stable umbral chromospheric structures

    Science.gov (United States)

    Henriques, V. M. J.; Scullion, E.; Mathioudakis, M.; Kiselman, D.; Gallagher, P. T.; Keenan, F. P.

    2015-02-01

    Aims: We seek to understand the morphology of the chromosphere in sunspot umbra. We investigate if the horizontal structures observed in the spectral core of the Ca II H line are ephemeral visuals caused by the shock dynamics of more stable structures, and examine their relationship with observables in the H-alpha line. Methods: Filtergrams in the core of the Ca II H and H-alpha lines as observed with the Swedish 1-m Solar Telescope are employed. We utilise a technique that creates composite images and tracks the flash propagation horizontally. Results: We find 0.̋15 wide horizontal structures, in all of the three target sunspots, for every flash where the seeing is moderate to good. Discrete dark structures are identified that are stable for at least two umbral flashes, as well as systems of structures that live for up to 24 min. We find cases of extremely extended structures with similar stability, with one such structure showing an extent of 5''. Some of these structures have a correspondence in H-alpha, but we were unable to find a one-to-one correspondence for every occurrence. If the dark streaks are formed at the same heights as umbral flashes, there are systems of structures with strong departures from the vertical for all three analysed sunspots. Conclusions: Long-lived Ca II H filamentary horizontal structures are a common and likely ever-present feature in the umbra of sunspots. If the magnetic field in the chromosphere of the umbra is indeed aligned with the structures, then the present theoretical understanding of the typical umbra needs to be revisited. Movies associated to Figs. 3 and 4 are available in electronic form at http://www.aanda.org

  15. Research advance in non-thermal plasma induced selective catalytic reduction NOx with low hydrocarbon compounds%低温等离子体诱导低碳烃选择性催化还原NOx研究进展

    Institute of Scientific and Technical Information of China (English)

    苏清发; 刘亚敏; 陈杰; 潘华; 施耀

    2009-01-01

    The emission of nitrogen oxides (NOx) from stationary sources, primarily from power stations, industrial heaters and cogeneration plants, represents a major environmental problem. This paper intends to give a general review over the advances in non-thermal plasma assisted selective catalytic reduction (SCR) of NOx with lower hydrocarbon compounds. In the last decade, the non-thermal plasma induced SCR of nitrogen oxide with low hydrocarbon compounds has received much attention. The different hydrocarbons (≤C3) used in the research are discussed. As we know,methane is more difficultly activated than non-methane hydrocarbons, such as ethylene and propylene etc. The reduction mechanism is also discussed. In addition, aiming at the difficulties existed, the direction for future research is prospected.%综述了近年来低温等离子体诱导低碳烃选择性催化还原NOx的研究进展,详细介绍了难活化的甲烷及较易活化的非甲烷低碳烃气体如乙烯、丙烯及丙烷等的研究现状,探讨了低温等离子体诱导低碳烃选择性催化还原NOx的反应机理,并展望了低温等离子体诱导低碳烃选择性催化还原NOx今后研究方向.

  16. Fundamental Thermal Fluid Physics of High Temperature Flows in Advanced Reactor Systems - Nuclear Energy Research Initiative Program Interoffice Work Order (IWO) MSF99-0254 Final Report for Period 1 August 1999 to 31 December 2002

    Energy Technology Data Exchange (ETDEWEB)

    McEligot, D.M.; Condie, K.G.; Foust, T.D.; McCreery, G.E.; Pink, R.J.; Stacey, D.E. (INEEL); Shenoy, A.; Baccaglini, G. (General Atomics); Pletcher, R.H. (Iowa State U.); Wallace, J.M.; Vukoslavcevic, P. (U. Maryland); Jackson, J.D. (U. Manchester, UK); Kunugi, T. (Kyoto U., Japan); Satake, S.-i. (Tokyo U. Science, Japan)

    2002-12-31

    The ultimate goal of the study is the improvement of predictive methods for safety analyses and design of advanced reactors for higher efficiency and enhanced safety and for deployable reactors for electrical power generation, process heat utilization and hydrogen generation. While key applications would be advanced gas-cooled reactors (AGCRs) using the closed Brayton cycle (CBC) for higher efficiency (such as the proposed Gas Turbine - Modular Helium Reactor (GT-MHR) of General Atomics [Neylan and Simon, 1996]), results of the proposed research should also be valuable in reactor systems with supercritical flow or superheated vapors, e.g., steam. Higher efficiency leads to lower cost/kwh and reduces life-cycle impacts of radioactive waste (by reducing waters/kwh). The outcome will also be useful for some space power and propulsion concepts and for some fusion reactor concepts as side benefits, but they are not the thrusts of the investigation. The objective of the project is to provide fundamental thermal fluid physics knowledge and measurements necessary for the development of the improved methods for the applications.

  17. Single- and two-phase flow modeling for coupled neutronics / thermal-hydraulics transient analysis of advanced sodium-cooled fast reactors

    International Nuclear Information System (INIS)

    Nuclear power is nowadays in the front rank as regards helping to meet the growing worldwide energy demand while avoiding an excessive increase in greenhouse gas emissions. However, the operating nuclear power plants are mainly thermal-neutron reactors and, as such, can not be maintained on the basis of the currently identified uranium resources beyond one century at the present consumption rate. Sustainability of nuclear power thus involves closure of the fuel cycle through breeding. With a uranium-based fuel, breeding can only be achieved using a fast-neutron reactor. Sodium-cooled fast reactor (SFR) technology benefits from 400 reactor-years of accumulated experience and is thus a prime candidate for the implementation of so-called Generation-IV nuclear energy systems. In this context, the safety demonstration of SFRs remains a major Research and Development related issue. The current research aims at the development of a computational tool for the in-depth understanding of SFR core behaviour during accidental transients, particularly those including boiling of the coolant. An accurate modelling of the core physics during such transients requires the coupling between 3D neutron kinetics and thermal-hydraulics in the core, to account for the strong interactions between the two-phase coolant flow and power variations caused by the sodium void effect. The present study is specifically focused upon models for the representation of sodium two-phase flow. The extension of the thermal-hydraulics TRACE code, previously limited to the simulation of single-phase sodium flow, has been carried out through the implementation of equations-of-state and closure relations specific to sodium. The different correlations have then been implemented as options. From the validation study carried out, it has been possible to recommend a set of models which provide satisfactory results, while considering annular flow as the dominant regime up to dryout and a smooth breakdown of the

  18. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO & DOE OCRWM Co-Sponsored Advanced Materials Program

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J; Haslam, J; Wong, F; Ji, S; Day, S; Branagan, D; Marshall, M; Meacham, B; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Buffa, E; Blue, C; Rivard, J; Beardsley, M; Weaver, D; Aprigliano, L; Kohler, L; Bayles, R; Lemieux, E; Wolejsza, T; Martin, F; Yang, N; Lucadamo, G; Perepezko, J; Hildal, K; Kaufman, L; Heuer, A; Ernst, F; Michal, G; Kahn, H; Lavernia, E

    2007-09-19

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent.

  19. High-Performance Corrosion-Resistant Materials: Iron-Based Amorphous-Metal Thermal-Spray Coatings: SAM HPCRM Program ? FY04 Annual Report ? Rev. 0 - DARPA DSO and DOE OCRWM Co-Sponsored Advanced Materials Program

    International Nuclear Information System (INIS)

    The multi-institutional High Performance Corrosion Resistant Materials (HPCRM) Team is cosponsored by the Defense Advanced Projects Agency (DARPA) Defense Science Office (DSO) and the Department of Energy (DOE) Office of Civilian Radioactive Waste Management (OCRWM), and has developed new corrosion-resistant, iron-based amorphous metals that can be applied as coatings with advanced thermal spray technology. Two compositions have corrosion resistance superior to wrought nickel-based Alloy C-22 (UNS No. N06022) in very aggressive environments, including concentrated calcium-chloride brines at elevated temperature. Corrosion costs the Department of Defense billions of dollars every year, with an immense quantity of material in various structures undergoing corrosion. For example, in addition to fluid and seawater piping, ballast tanks, and propulsions systems, approximately 345 million square feet of structure aboard naval ships and crafts require costly corrosion control measures. The use of advanced corrosion-resistant materials to prevent the continuous degradation of this massive surface area would be extremely beneficial. The Fe-based corrosion-resistant, amorphous-metal coatings under development may prove of importance for applications on ships. Such coatings could be used as an 'integral drip shield' on spent fuel containers, as well as protective coatings that could be applied over welds, thereby preventing exposure to environments that might cause stress corrosion cracking. In the future, such new high-performance iron-based materials could be substituted for more-expensive nickel-based alloys, thereby enabling a reduction in the $58-billion life cycle cost for the long-term storage of the Nation's spent nuclear fuel by tens of percent

  20. Construct validity of Stable-2000 and Stable-2007 scores.

    Science.gov (United States)

    Nunes, Kevin L; Babchishin, Kelly M

    2012-02-01

    We addressed the construct validity of Stable-2000 and Stable-2007 scores by examining correlations between selected items and validated independent measures of relevant constructs in samples of convicted sex offenders. In Study 1, the Child Molester Attitudes item of the Stable-2000 shared 23% of the variance with a self-report measure of beliefs supportive of child molestation, r(19) = .48. The Deviant Sexual Interests items of the Stable-2000 and Stable-2007 shared 7% to 66% of the variance, respectively, with an offense-history-based measure of pedophilic interests, r(18) = .27 for the Stable-2000 and r(11) = .81 for the Stable-2007. In Study 2, the Lovers/Intimate Partners, General Social Rejection/Loneliness, Rapist Attitudes, and Child Molester Attitudes items of the Stable-2000 shared 4% to 19% of the variance with self-report measures of, respectively, intimacy, r(90) = -.44; loneliness, r(88) = .34; beliefs supportive of rape, r(72) = .21; and beliefs supportive of child molestation, r(78) = .36. The results generally suggest that the Stable items examined are associated with measures of similar constructs; however, the degree of convergence was lower than expected. More systematic and comprehensive research is needed to examine convergence of the Stable items with other relevant measures and additional aspects of construct validity. Such efforts will provide a clearer understanding of dynamic risk factors, appropriate areas of focus for treatment efforts, and, more generally, why some sex offenders recidivate. PMID:21543623

  1. 区域RF加温治疗中晚期肿瘤的热剂量效应%Thermal dose effect of regional radiofrequency hyperthemia on metaphase and advanced stage tumor

    Institute of Scientific and Technical Information of China (English)

    王义善; 王钦文; 贾喜风; 戈仁群; 盛娜

    2007-01-01

    BACKGROUND: Foreign scholars use thermotherapy, a new pathway for synthetic therapy of tumor, to perform hyperpyrexia combined with chemical drug radiotherapy of intraperitoneal infiltration and metastasis or to study on the therapeutic effect of metaphase and advanced stage tumor. Especially, establishing thermal biology and thermal dosiology is a scientific and quantified track for synthetic therapy of thermal radiotherapy, thermal chemotherapy and hyperthermal perfusion of tumor.OBJECTIVE: To analyze the thermal dose effect of regional radiofrequency (RF) hyperthemia combined with radiotherapy, chemotherapy and thermal perfusion on metaphase and advanced stage tumor.DESIGN: Controlled observation.SETTING: Key Department of Traditional Chinese and Western Medicine for Tumor, the 107 Hospital of Chinese PLA (General Center for Non-traumatic Treatment and Diagnosis of Tumor).PARTICIPANTS: Totally 1 455 patients with metaphase and advanced-stage tumor admitted to the General Center for Non-traumatic Treatment and Diagnosis of Tumor, the 107 Hospital of Chinese PLA between June and September 2006 who received conservative palliative treatment in the Department of Internal Medicine were recruited in this study. They were all confirmed by pathology and imageology. ECOG was scored 2 to 4 points. Informed consents of detection and treatment were obtained from all the involved patients. The study was approved by the Hospital Ethics Committee.According to the therapeutic regimen, the patients were assigned into thermal perfusion group (n =53), thermal radiotherapy group (n =874), thermal chemotherapy group (n =458) and simple hyperthemia group (n =70).METHODS: After admission, patients in each group were performed peritoneal and pelvic cavity perfusion,intensity-modulated radiation therapy, routine chemotherapy and integrated traditional and western medicine palliative therapy, respectively. Meanwhile, they received RF hyperthemia using in vitro endogenic magnetic field

  2. Stable Principal Component Pursuit

    CERN Document Server

    Zhou, Zihan; Wright, John; Candes, Emmanuel; Ma, Yi

    2010-01-01

    In this paper, we study the problem of recovering a low-rank matrix (the principal components) from a high-dimensional data matrix despite both small entry-wise noise and gross sparse errors. Recently, it has been shown that a convex program, named Principal Component Pursuit (PCP), can recover the low-rank matrix when the data matrix is corrupted by gross sparse errors. We further prove that the solution to a related convex program (a relaxed PCP) gives an estimate of the low-rank matrix that is simultaneously stable to small entrywise noise and robust to gross sparse errors. More precisely, our result shows that the proposed convex program recovers the low-rank matrix even though a positive fraction of its entries are arbitrarily corrupted, with an error bound proportional to the noise level. We present simulation results to support our result and demonstrate that the new convex program accurately recovers the principal components (the low-rank matrix) under quite broad conditions. To our knowledge, this is...

  3. Thermal Performance Benchmarking

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xuhui; Moreno, Gilbert; Bennion, Kevin

    2016-06-07

    The goal for this project is to thoroughly characterize the thermal performance of state-of-the-art (SOA) in-production automotive power electronics and electric motor thermal management systems. Information obtained from these studies will be used to: evaluate advantages and disadvantages of different thermal management strategies; establish baseline metrics for the thermal management systems; identify methods of improvement to advance the SOA; increase the publicly available information related to automotive traction-drive thermal management systems; help guide future electric drive technologies (EDT) research and development (R&D) efforts. The thermal performance results combined with component efficiency and heat generation information obtained by Oak Ridge National Laboratory (ORNL) may then be used to determine the operating temperatures for the EDT components under drive-cycle conditions. In FY16, the 2012 Nissan LEAF power electronics and 2014 Honda Accord Hybrid power electronics thermal management system were characterized. Comparison of the two power electronics thermal management systems was also conducted to provide insight into the various cooling strategies to understand the current SOA in thermal management for automotive power electronics and electric motors.

  4. Enriching stable isotopes: Alternative use for Urenco technology

    Energy Technology Data Exchange (ETDEWEB)

    Rakhorst, H.; de Jong, P.G.T.; Dawson, P.D. [URENCO-NL, Almelo (Netherlands)

    1996-12-31

    The International Urenco Group utilizes a technologically advanced centrifuge process to enrich uranium in the fissionable isotope {sup 235}U. The group operates plants in the United Kingdom, the Netherlands, and Germany and currently holds a 10% share of the multibillion dollar world enrichment market. In the early 1990s, Urenco embarked on a strategy of building on the company`s uniquely advanced centrifuge process and laser isotope separation (LIS) experience to enrich nonradioactive isotopes colloquially known as stable isotopes. This paper summarizes the present status of Urenco`s stable isotopes business.

  5. Enriching stable isotopes: Alternative use for Urenco technology

    International Nuclear Information System (INIS)

    The International Urenco Group utilizes a technologically advanced centrifuge process to enrich uranium in the fissionable isotope 235U. The group operates plants in the United Kingdom, the Netherlands, and Germany and currently holds a 10% share of the multibillion dollar world enrichment market. In the early 1990s, Urenco embarked on a strategy of building on the company's uniquely advanced centrifuge process and laser isotope separation (LIS) experience to enrich nonradioactive isotopes colloquially known as stable isotopes. This paper summarizes the present status of Urenco's stable isotopes business

  6. Stable isotopes. Applications and production; Les isotopes stables. Applications - production

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.; Louvet, P.; Soulie, E. [eds.

    1994-12-31

    This conference presents 46 communications concerning stable isotope production, utilization and application, grouped in 6 sessions and posters. The various themes are: biological applications (pharmacology, medical diagnosis, metabolism and protein studies, toxicity and response studies, labelled compounds), analysis procedures (NMR analysis for macromolecules, tracer studies), nuclear applications (utilization of stable isotopes in nuclear reactors), biological, physical and chemical applications (mass transfer, mobility, crystallography, isotopic exchange), stable isotope production (ion chromatography, ion cyclotron resonance, cryogenic distillation).

  7. ATLAST ULE mirror segment performance analytical predictions based on thermally induced distortions

    Science.gov (United States)

    Eisenhower, Michael J.; Cohen, Lester M.; Feinberg, Lee D.; Matthews, Gary W.; Nissen, Joel A.; Park, Sang C.; Peabody, Hume L.

    2015-09-01

    The Advanced Technology Large-Aperture Space Telescope (ATLAST) is a concept for a 9.2 m aperture space-borne observatory operating across the UV/Optical/NIR spectra. The primary mirror for ATLAST is a segmented architecture with pico-meter class wavefront stability. Due to its extraordinarily low coefficient of thermal expansion, a leading candidate for the primary mirror substrate is Corning's ULE® titania-silicate glass. The ATLAST ULE® mirror substrates will be maintained at `room temperature' during on orbit flight operations minimizing the need for compensation of mirror deformation between the manufacturing temperature and the operational temperatures. This approach requires active thermal management to maintain operational temperature while on orbit. Furthermore, the active thermal control must be sufficiently stable to prevent time-varying thermally induced distortions in the mirror substrates. This paper describes a conceptual thermal management system for the ATLAST 9.2 m segmented mirror architecture that maintains the wavefront stability to less than 10 pico-meters/10 minutes RMS. Thermal and finite element models, analytical techniques, accuracies involved in solving the mirror figure errors, and early findings from the thermal and thermal-distortion analyses are presented.

  8. Holographic thermalization in noncommutative geometry

    CERN Document Server

    Zeng, Xiao-Xiong; Liu, Wen-Biao

    2014-01-01

    Gravitational collapse of a dust shell in noncommutative geometry is probed by the renormalized geodesic length and minimal area surface, which are dual to the two-point correlation function and expectation value of Wilson loop in the dual conformal field theory. For the spacetime without a horizon, we find the shell will not collapse all the time but will stop in a stable state. For the spacetime with a horizon, we investigate how the noncommutative parameter affects the thermalization process in detail. From the numeric results, we find that larger the noncommutative parameter is, longer the thermalization time is, which implies that the large noncommutative parameter delays the thermalization process. From the fitted functions of the thermalization curve, we find for both thermalization probes, there is a phase transition point during the thermalization process, which divides the thermalization into an acceleration phase and a deceleration phase. During the acceleration phase, the acceleration is found to ...

  9. The Conductive Thermal Control Material Systems for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is submitted to develop and demonstrate the feasibility of processing the space environment stable, multifunctional thermal control material system...

  10. Efficient Thermally Stable Spectral Control Filters for Thermophotovoltaics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The feasibility of radioisotope thermophotovoltaic (RTPV) power systems has been shown. The best efficiencies reported to date for a TPV module test include front...

  11. Method for forming thermally stable nanoparticles on supports

    Science.gov (United States)

    Roldan Cuenya, Beatriz; Naitabdi, Ahmed R.; Behafarid, Farzad

    2013-08-20

    An inverse micelle-based method for forming nanoparticles on supports includes dissolving a polymeric material in a solvent to provide a micelle solution. A nanoparticle source is dissolved in the micelle solution. A plurality of micelles having a nanoparticle in their core and an outer polymeric coating layer are formed in the micelle solution. The micelles are applied to a support. The polymeric coating layer is then removed from the micelles to expose the nanoparticles. A supported catalyst includes a nanocrystalline powder, thin film, or single crystal support. Metal nanoparticles having a median size from 0.5 nm to 25 nm, a size distribution having a standard deviation .ltoreq.0.1 of their median size are on or embedded in the support. The plurality of metal nanoparticles are dispersed and in a periodic arrangement. The metal nanoparticles maintain their periodic arrangement and size distribution following heat treatments of at least 1,000.degree. C.

  12. Novel Thermally Stable Poly (vinyl chloride) Composites for Sulfate Removal

    Science.gov (United States)

    BaCO3 dispersed PVC composites were prepared through a polymer re-precipitation method. The composites were tested for sulfate removal using rapid small scale column test (RSSCT) and found to significantly reduce sulfate concentration. The method was extended to synthe...

  13. 热稳定体相还原态对二氧化钛气敏应用重要性的实验证实%Experimental Validation of the Importance of Thermally Stable Bulk Reduction States in TiO2 for Gas Sensor Applications

    Institute of Scientific and Technical Information of China (English)

    邹晓新; 李国栋; 邹永存; 王培培; 苏娟; 赵君; 王宇宁; 陈接胜

    2012-01-01

    The relationship between bulk-reduction states and gas-sensing properties of TiO2 was predicted previously, but has not been validated yet experimentally. Herein, we present a chemical approach for the preparation of TiO2 nanoparticles with thermally stable bulk reduction states using porous amorphous titania as precursor. UV/vis diffuse reflectance, electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) confirm that the stable bulk reduction states are the thermally stable Ti3~ ions and electron-trapped oxygen vacancies. OE-temperature programmed desorption (O2-TPD) measurements demonstrate that the presence of the bulk reduction states can obviously enhance the oxygen adsorption on titania surfaces. Furthermore, the bulk-reduced nanomaterial exhibits not only enhanced sensitivity and ultrafast re- sponse/recovery (〈3 s) for the detection of organic vapors (ethanol, methanol and acetone), but also excellent selectivity to CO against CH4 and HE. The sensing performance testing results confirm the importance of bulk reduction states in TiO2 sensors for the first time, and the enhanced gas-sensing performances for bulk-reduced TiO2 materials can be related to the enhanced oxygen absorption on TiO2 surfaces.%TiO2中体相还原态与气敏性质之间的关系已有理论预测但一直未得到实验验证.在此,我们报道一种利用多孔无定型二氧化钛作前驱体制备含热稳定体相还原态TiO2的化学方法.紫外-可见漫反射光谱,电子顺磁共振波谱(EPR)以及X-射线光电子能谱(XPS)证明所获材料中含有的体相还原态为热稳定的Ti3+离子以及捕获电子的氧缺位.O2-程序升温脱附测量结果表明,体相还原态的存在可以显著提升二氧化钛表面对氧分子的吸附作用.所获得的体相还原纳米材料不仅表现出优越的对有机分子(乙醇、甲醇及丙酮)的传感性和快速响应性,而且具有对CO传感的

  14. Thermal Giant Gravitons

    CERN Document Server

    Armas, Jay; Obers, Niels A; Orselli, Marta; Pedersen, Andreas Vigand

    2012-01-01

    We study the giant graviton solution as the AdS_5 X S^5 background is heated up to finite temperature. The analysis employs the thermal brane probe technique based on the blackfold approach. We focus mainly on the thermal giant graviton corresponding to a thermal D3-brane probe wrapped on an S^3 moving on the S^5 of the background at finite temperature. We find several interesting new effects, including that the thermal giant graviton has a minimal possible value for the angular momentum and correspondingly also a minimal possible radius of the S^3. We compute the free energy of the thermal giant graviton in the low temperature regime, which potentially could be compared to that of a thermal state on the gauge theory side. Moreover, we analyze the space of solutions and stability of the thermal giant graviton and find that, in parallel with the extremal case, there are two available solutions for a given temperature and angular momentum, one stable and one unstable. In order to write down the equations of mot...

  15. The Development of an INL Capability for High Temperature Flow, Heat Transfer, and Thermal Energy Storage with Applications in Advanced Small Modular Reactors, High Temperature Heat Exchangers, Hybrid Energy Systems, and Dynamic Grid Energy Storage C

    International Nuclear Information System (INIS)

    The overall goal of this project is to support Idaho National Laboratory in developing a new advanced high temperature multi fluid multi loop test facility that is aimed at investigating fluid flow and heat transfer, material corrosion, heat exchanger characteristics and instrumentation performance, among others, for nuclear applications. Specifically, preliminary research has been performed at The Ohio State University in the following areas: 1. A review of fluoride molten salts' characteristics in thermal, corrosive, and compatibility performances. A recommendation for a salt selection is provided. Material candidates for both molten salt and helium flow loop have been identified. 2. A conceptual facility design that satisfies the multi loop (two coolant loops [i.e., fluoride molten salts and helium]) multi purpose (two operation modes [i.e., forced and natural circulation]) requirements. Schematic models are presented. The thermal hydraulic performances in a preliminary printed circuit heat exchanger (PCHE) design have been estimated. 3. An introduction of computational methods and models for pipe heat loss analysis and cases studies. Recommendations on insulation material selection have been provided. 4. An analysis of pipe pressure rating and sizing. Preliminary recommendations on pipe size selection have been provided. 5. A review of molten fluoride salt preparation and chemistry control. An introduction to the experience from the Molten Salt Reactor Experiment at Oak Ridge National Laboratory has been provided. 6. A review of some instruments and components to be used in the facility. Flowmeters and Grayloc connectors have been included. This report primarily presents the conclusions drawn from the extensive review of literatures in material selections and the facility design progress at the current stage. It provides some useful guidelines in insulation material and pipe size selection, as well as an introductory review of facility process and

  16. The Development of an INL Capability for High Temperature Flow, Heat Transfer, and Thermal Energy Storage with Applications in Advanced Small Modular Reactors, High Temperature Heat Exchangers, Hybrid Energy Systems, and Dynamic Grid Energy Storage C

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiaodong [The Ohio State Univ., Columbus, OH (United States); Zhang, Xiaoqin [The Ohio State Univ., Columbus, OH (United States); Kim, Inhun [The Ohio State Univ., Columbus, OH (United States); O' Brien, James [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sabharwall, Piyush [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-10-01

    The overall goal of this project is to support Idaho National Laboratory in developing a new advanced high temperature multi fluid multi loop test facility that is aimed at investigating fluid flow and heat transfer, material corrosion, heat exchanger characteristics and instrumentation performance, among others, for nuclear applications. Specifically, preliminary research has been performed at The Ohio State University in the following areas: 1. A review of fluoride molten salts’ characteristics in thermal, corrosive, and compatibility performances. A recommendation for a salt selection is provided. Material candidates for both molten salt and helium flow loop have been identified. 2. A conceptual facility design that satisfies the multi loop (two coolant loops [i.e., fluoride molten salts and helium]) multi purpose (two operation modes [i.e., forced and natural circulation]) requirements. Schematic models are presented. The thermal hydraulic performances in a preliminary printed circuit heat exchanger (PCHE) design have been estimated. 3. An introduction of computational methods and models for pipe heat loss analysis and cases studies. Recommendations on insulation material selection have been provided. 4. An analysis of pipe pressure rating and sizing. Preliminary recommendations on pipe size selection have been provided. 5. A review of molten fluoride salt preparation and chemistry control. An introduction to the experience from the Molten Salt Reactor Experiment at Oak Ridge National Laboratory has been provided. 6. A review of some instruments and components to be used in the facility. Flowmeters and Grayloc connectors have been included. This report primarily presents the conclusions drawn from the extensive review of literatures in material selections and the facility design progress at the current stage. It provides some useful guidelines in insulation material and pipe size selection, as well as an introductory review of facility process and components.

  17. A Lumped Thermal Model Including Thermal Coupling and Thermal Boundary Conditions for High Power IGBT Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Ma, Ke; Blaabjerg, Frede

    2017-01-01

    Detailed thermal dynamics of high power IGBT modules are important information for the reliability analysis and thermal design of power electronic systems. However, the existing thermal models have their limits to correctly predict these complicated thermal behavior in the IGBTs: The typically used...... thermal distribution under long-term studies. Meanwhile the boundary conditions for the thermal analysis are modeled and included, which can be adapted to different real field applications of power electronic converters. Finally, the accuracy of the proposed thermal model is verified by FEM simulations...... thermal model based on one-dimensional RC lumps have limits to provide temperature distributions inside the device, moreover some variable factors in the real-field applications like the cooling and heating conditions of the converter cannot be adapted. On the other hand, the more advanced three...

  18. Laser machining of advanced materials

    CERN Document Server

    Dahotre, Narendra B

    2011-01-01

    Advanced materialsIntroductionApplicationsStructural ceramicsBiomaterials CompositesIntermetallicsMachining of advanced materials IntroductionFabrication techniquesMechanical machiningChemical Machining (CM)Electrical machiningRadiation machining Hybrid machiningLaser machiningIntroductionAbsorption of laser energy and multiple reflectionsThermal effectsLaser machining of structural ceramicsIntrodu

  19. Thermal Properties Measurement Report

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, Jon [Idaho National Lab. (INL), Idaho Falls, ID (United States); Braase, Lori [Idaho National Lab. (INL), Idaho Falls, ID (United States); Papesch, Cynthia [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hurley, David [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tonks, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Gofryk, Krzysztof [Idaho National Lab. (INL), Idaho Falls, ID (United States); Harp, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States); Fielding, Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Knight, Collin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Meyer, Mitch [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-08-01

    The Thermal Properties Measurement Report summarizes the research, development, installation, and initial use of significant experimental thermal property characterization capabilities at the INL in FY 2015. These new capabilities were used to characterize a U3Si2 (candidate Accident Tolerant) fuel sample fabricated at the INL. The ability to perform measurements at various length scales is important and provides additional data that is not currently in the literature. However, the real value of the data will be in accomplishing a phenomenological understanding of the thermal conductivity in fuels and the ties to predictive modeling. Thus, the MARMOT advanced modeling and simulation capability was utilized to illustrate how the microstructural data can be modeled and compared with bulk characterization data. A scientific method was established for thermal property measurement capability on irradiated nuclear fuel samples, which will be installed in the Irradiated Material Characterization Laboratory (IMCL).

  20. Advanced Triangulation Displacement Sensors

    Science.gov (United States)

    Poteet, Wade M.; Cauthen, Harold K.

    1996-01-01

    Advanced optoelectronic triangulation displacement sensors undergoing development. Highly miniaturized, more stable, more accurate, and relatively easy to use. Incorporate wideband electronic circuits suitable for real-time monitoring and control of displacements. Measurements expected to be accurate to within nanometers. In principle, sensors mass-produced at relatively low unit cost. Potential applications numerous. Possible industrial application in measuring runout of rotating shaft or other moving part during fabrication in "zero-defect" manufacturing system, in which measured runout automatically corrected.

  1. Silicene: Recent theoretical advances

    KAUST Repository

    Lew Yan Voon, L. C.

    2016-04-14

    Silicene is a two-dimensional allotrope of silicon with a puckered hexagonal structure closely related to the structure of graphene and that has been predicted to be stable. To date, it has been successfully grown in solution (functionalized) and on substrates. The goal of this review is to provide a summary of recent theoretical advances in the properties of both free-standing silicene as well as in interaction with molecules and substrates, and of proposed device applications.

  2. 塔里木盆地海相油藏具有高热稳定性的地球化学条件探讨%Geochemical constraints on the thermally stable marine crude oil reservoirs in the Tarim Basin, NW China

    Institute of Scientific and Technical Information of China (English)

    廖泽文; 杨珊; 张海祖; 刘虎; 程斌; 田彦宽

    2015-01-01

    Some liquid hydrocarbon fluids were found to be still thermally stable and occur in the Tarim Basin, NW China, even over the burial depth of 8000 m or the oil reservoirs experienced temperature more than 200 ℃. Therefore, recently more exploration studies have been targeted to the deeper strata in order to find more marine crude oils in the Tarim Basin. High thermal stability of crude oil reservoirs in the Tarim Basin may be due to their fairly well preservation after accumulation. Based on the recent exploration progress in the Tarim Basin, this paper is aimed to probe the geochemical features of the thermally stable crude oil reservoirs concerning both their geological background and micro physiochemical properties of the petroleum fluids. It’s concluded that the low geothermal gradient in the Tarim Basin is the most important factor in influencing the preservation of the petroleum, and the common absence of oxide minerals in the reservoirs is another key factor for the extensive occurrence of the crude oil reservoirs. Furthermore, the formation water extensively occurred in the reservoirs throughout the Tarim Basin, is also favorable to the petroleum preservation because inside the oil reservoir water will inhibit the thermal degradation of hydrocarbons to some degree. More work should be focused on the study of physiochemical reaction mechanisms of hydrocarbon-water-rock interactions, especially for the evaluation of relative importance of the radical reaction and the carbon cation mechanisms during these chemical reactions, and thus the constrained factors for thermal stability of the crude oils in the Tarim Basin will be probed by using the geological reservoir rocks, the formation water and the crude oils. This kind of work will be helpful to the further exploration studies targeted to the deep marine crude oil reservoirs in the Tarim Basin, NW China.%塔里木盆地在埋深超过8000 m、油藏经历200℃以上高温改造仍然发现液态烃类流

  3. Nuclear physics and stable isotopes; Physique nucleaire et isotopes stables

    Energy Technology Data Exchange (ETDEWEB)

    Goutte, D. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee

    1994-12-31

    The aim of this paper is to show that fundamental research in nuclear physics requires utilization of stable isotopes; stable isotopes are essential as target material since a large quantity of nucleus have to be studied in order to appreciate all the complexity of the nuclear structure, but also as a tool, such as beams, for the same purpose. Examples are given with samarium, tin and germanium isotopes. 7 figs.

  4. Relative thermalization

    Science.gov (United States)

    del Rio, Lídia; Hutter, Adrian; Renner, Renato; Wehner, Stephanie

    2016-08-01

    Locally thermal quantum systems may contradict traditional thermodynamics: heat can flow from a cold body to a hotter one, if the two are highly entangled. We show that to recover thermodynamic laws, we must use a stronger notion of thermalization: a system S is thermal relative to a reference R if S is both locally thermal and uncorrelated with R . Considering a general quantum reference is particularly relevant for a thermodynamic treatment of nanoscale quantum systems. We derive a technical condition for relative thermalization in terms of conditional entropies. Established results on local thermalization, which implicitly assume a classical reference, follow as special cases.

  5. Thermal conductivity of boron carbides

    Science.gov (United States)

    Wood, C.; Emin, D.; Gray, P. E.

    1985-01-01

    Knowledge of the thermal conductivity of boron carbide is necessary to evaluate its potential for high-temperature thermoelectric energy conversion applications. Measurements have been conducted of the thermal diffusivity of hot-pressed boron carbide BxC samples as a function of composition (x in the range from 4 to 9), temperature (300-1700 K), and temperature cycling. These data, in concert with density and specific-heat data, yield the thermal conductivities of these materials. The results are discussed in terms of a structural model that has been previously advanced to explain the electronic transport data. Some novel mechanisms for thermal conduction are briefly discussed.

  6. Thermal Nanosystems and Nanomaterials

    CERN Document Server

    Volz, Sebastian

    2009-01-01

    Heat transfer laws for conduction, radiation and convection change when the dimensions of the systems in question shrink. The altered behaviours can be used efficiently in energy conversion, respectively bio- and high-performance materials to control microelectronic devices. To understand and model those thermal mechanisms, specific metrologies have to be established. This book provides an overview of actual devices and materials involving micro-nanoscale heat transfer mechanisms. These are clearly explained and exemplified by a large spectrum of relevant physical models, while the most advanced nanoscale thermal metrologies are presented.

  7. Giant Thermal Rectification from Polyethylene Nanofiber Thermal Diodes.

    Science.gov (United States)

    Zhang, Teng; Luo, Tengfei

    2015-09-01

    The realization of phononic computing is held hostage by the lack of high-performance thermal devices. Here, it is shown through theoretical analysis and molecular dynamics simulations that unprecedented thermal rectification factors (as large as 1.20) can be achieved utilizing the phase-dependent thermal conductivity of polyethylene nanofibers. More importantly, such high thermal rectifications only need very small temperature differences (rectification factors of the polymer nanofiber diodes range from 12 to 25-much larger than those of other thermal diodes (<8). The polymer nanofiber thermal diode consists of a crystalline portion whose thermal conductivity is highly phase-sensitive and a cross-linked portion which has a stable phase. Nanoscale size effect can be utilized to tune the phase transition temperature of the crystalline portion, enabling thermal diodes capable of operating at different temperatures. This work will be instrumental to the design of high performance, inexpensive, and easily processible thermal devices, based on which thermal circuits can be built to ultimately enable phononic computing.

  8. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13C, 15N, and 2H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2H, 13C, and 15N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  9. Procedurally fair and stable matching

    OpenAIRE

    Klaus, Bettina; Klijn, Flip

    2006-01-01

    We motivate procedural fairness for matching mechanisms and study two procedurally fair and stable mechanisms: employment by lotto (Aldershof et al., 1999) and the random order mechanism (Roth and Vande Vate, 1990, Ma, 1996). For both mechanisms we give various examples of probability distributions on the set of stable matchings and discuss properties that differentiate employment by lotto and the random order mechanism. Finally, we consider an adjustment of the random order mechanism, the eq...

  10. Changes in reactivity and in the margins to thermal limits by the inclusion of control rods of advanced type in the Laguna Verde Power plant; Cambios en la reactividad y en los margenes a limites termicos por la inclusion de barras de control de tipo avanzado en la Central Laguna Verde

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, J.L.; Perusquia, R.; Montes, J.L.; Ortiz, J.J.; Ramirez, J.R. [ININ, Depto. de Sistemas Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)]. E-mail: jlhm@nuclear.inin.mx

    2004-07-01

    The obtained results are presented when simulating with CM-PRESTO code the cycle 10 of the unit 1 of the Laguna Verde Central, using two advanced types of control bars, besides the originally loaded ones. The two advanced types, to those that are denominated 1AV and 2AV in this work, are of different design, however both have in some place of the bar, a section with hafnium like neutron absorber material. They thought about three different scenarios, in the first one, used as reference, is simulated the cycle 10 using the original control bars, while in the other two cases the advanced types are used. The values of the reactivity were compared and of some margins to the thermal limits obtained when using the bars of advanced type, with those obtained in the case in that alone they are considered those original bars. It was found that in condition of power both advanced types present bigger absorber power of neutrons that the original bars, being quantified in average this bigger power in 0.22 pcm/notch for the type 1AV and in 0.51 pcm/notch for the type 2AV. The affectation of the margins to the observed thermal limits is minimum. (Author)

  11. Implementation Method of Stable Model

    Directory of Open Access Journals (Sweden)

    Shasha Wu

    2008-01-01

    Full Text Available Software Stability Modeling (SSM is a promising software development methodology based on object-oriented programming to achieve model level stability and reusability. Among the three critical categories of objects proposed by SSM, the business objects play a critical role in connecting the stable problem essentials (enduringbusiness themes and the unstable object implementations (industry objects. The business objects are especially difficult to implement and often raise confusion in the implementation because of their unique characteristics: externally stable and internally unstable. The implementation and code level stability is not the major concern. How to implement the objects in a stable model through object-oriented programming without losing its stability is a big challenge in the real software development. In this paper, we propose new methods to realize the business objects in the implementation of stable model. We also rephrase the definition of the business objects from the implementation perspective, in hope the new description can help software developers to adopt and implement stable models more easily. Finally, we describe the implementation of a stable model for a balloon rental resource management scope to illustrate the advantages of the proposed method.

  12. Preparation and Thermal Properties of Fatty Acid/Inorganic Nano-particle Form-Stable Phase Change Material%脂肪酸/无机纳米颗粒基定形相变材料的制备与热性能

    Institute of Scientific and Technical Information of China (English)

    孟多; 王立久

    2013-01-01

    以工业水玻璃为纳米SiO2前驱物,以癸酸(CA)和月桂酸(LA)二元低共熔酸为相变芯材,在表面活性剂的参与下,采用溶胶-凝胶法一步制备出纳米级复合定形相变蓄热材料.利用透射电子显微镜,扫描电子显微镜,傅里叶红外光谱仪,方差扫描量热法和热重分析等测试技术对此定形相变蓄热材料的结构和性能进行分析,并采用瞬态热线法测量了其导热系数.结果表明:相变芯材在吸热熔化后不会产生流动和渗漏;复合相变材料中脂肪酸含量(质量分数)为46%,具有良好的相变蓄热性能(相变温度19.57℃,相变潜热71.28 J/g)和热稳定性;复合相变材料导热系数为0.178 W/(m·K),可作为一种良好的隔热、保温建筑材料.%A kind of form-stable phase change material (PCM) based on capric-lauric acid eutectic acting as the heat-absorbing material and nano silicon dioxide serving as the supportive material was prepared by sol-gel method. The morphology, chemical characteristics and thermal properties of the composite PCM were investigated by transmission electron microscopy(TEM), scanning electron microscopy (SEM), and Fourier-transform infrared (FT-IR), differential scanning calorimetry(DSC) and thermogravimetric analysis (TGA). The results indicate that fatty acid eutectic can be immobilized in the three-dimensional network structure when the composite PCM is heated to above the phase change temperature. The proportion of the CA-LA eutectic in the composite PCM is 46%(by mass). The phase change temperature and latent heat of the composite PCM were determined as 19. 57 °C and 71. 28 J/g, respectively. Mean-while, thermal conductivity of the composite was measured to be 0. 178 W/(m · K) by using the transient hot-wire method. Thus it can be applied for energy conservation as the thermal insulation material.

  13. Modelling of the Evolving Stable Boundary Layer

    Science.gov (United States)

    Sorbjan, Zbigniew

    2014-06-01

    A single-column model of the evolving stable boundary layer (SBL) is tested for self-similar properties of the flow and effects of ambient forcing. The turbulence closure of the model is diagnostic, based on the K-theory approach, with a semi-empirical form of the mixing length, and empirical stability functions of the Richardson number. The model results, expressed in terms of local similarity scales, are universal functions, satisfied in the entire SBL. Based on similarity expression, a realizability condition is derived for the minimum allowable turbulent heat flux in the SBL. Numerical experiments show that the development of "horse-shoe" shaped, fixed-elevation hodographs in the interior of the SBL around sunrise is controlled by effects imposed by surface thermal forcing.

  14. Development of Advanced Alloys using Fullerenes

    Science.gov (United States)

    Sims, J.; Wasz, M.; O'Brien, J.; Callahan, D. L.; Barrera, E. V.

    1994-01-01

    Development of advanced alloys using fullerenes is currently underway to produce materials for use in the extravehicular mobility unit (EMU). These materials will be directed toward commercial usages as they are continually developed. Fullerenes (of which the most common is C(sub 60)) are lightweight, nanometer size, hollow molecules of carbon which can be dispersed in conventional alloy systems to enhance strength and reduce weight. In this research, fullerene interaction with aluminum is investigated and a fullerene-reinforced aluminum alloy is being developed for possible use on the EMU. The samples were manufactured using standard commercial approaches including powder metallurgy and casting. Alloys have been processed having 1.3, 4.0 and 8.0 volume fractions of fullerenes. It has been observed that fullerene dispersion is related to the processing approach and that they are stable for the processing conditions used in this research. Emphasis will be given to differential thermal analysis and wavelength dispersive analysis of the processed alloys. These two techniques are particularly useful in determining the condition of the fullerenes during and after processing. Some discussion will be given as to electrical properties of fullerene-reinforced materials. Although the aluminum and other advanced alloys with fullerenes are being developed for NASA and the EMU, the properties of these materials will be of interest for commercial applications where specific Dual-Use will be given.

  15. Novel Materials through Non-Hydrolytic Sol-Gel Processing: Negative Thermal Expansion Oxides and Beyond

    Directory of Open Access Journals (Sweden)

    Cora Lind

    2010-04-01

    Full Text Available Low temperature methods have been applied to the synthesis of many advanced materials. Non-hydrolytic sol-gel (NHSG processes offer an elegant route to stable and metastable phases at low temperatures. Excellent atomic level homogeneity gives access to polymorphs that are difficult or impossible to obtain by other methods. The NHSG approach is most commonly applied to the preparation of metal oxides, but can be easily extended to metal sulfides. Exploration of experimental variables allows control over product stoichiometry and crystal structure. This paper reviews the application of NHSG chemistry to the synthesis of negative thermal expansion oxides and selected metal sulfides.

  16. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    徐峰; 文婷; 卢天健; Seffen; Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great...

  17. Hybrid Multifoil Aerogel Thermal Insulation

    Science.gov (United States)

    Sakamoto, Jeffrey; Paik, Jong-Ah; Jones, Steven; Nesmith, Bill

    2008-01-01

    This innovation blends the merits of multifoil insulation (MFI) with aerogel-based insulation to develop a highly versatile, ultra-low thermally conductive material called hybrid multifoil aerogel thermal insulation (HyMATI). The density of the opacified aerogel is 240 mg/cm3 and has thermal conductivity in the 20 mW/mK range in high vacuum and 25 mW/mK in 1 atmosphere of gas (such as argon) up to 800 C. It is stable up to 1,000 C. This is equal to commercially available high-temperature thermal insulation. The thermal conductivity of the aerogel is 36 percent lower compared to several commercially available insulations when tested in 1 atmosphere of argon gas up to 800 C.

  18. A novel thermooxidatively stable poly(ester-imide-benzoxazole)

    Energy Technology Data Exchange (ETDEWEB)

    Sundar, R.A.; Mathias, L.J. [Univ. of Sothern Mississippi, Hattiesburg, MS (United States)

    1993-12-31

    A poly(ester-amide-imide) was synthesized by the low temperature solution polycondensation of 4-amino-5-hydroxy-N,4{prime}-hydroxyphenyl phthalimide with isophthaloyl chloride. Subsequent thermal cyclodehydration of the poly(ester-amide-imide) at 320{degrees}C in vacuum afforded the poly(ester-imide-benzoxazole). This polymer was only soluble in sulfuric acid. FTIR and NMR spectra confirmed structure. The poly(ester-imide-benzoxazole) had no detectable thermal transitions up to 500{degrees}C in nitrogen, and was reasonably stable in air and nitrogen, with weight retentions of 95% at 500{degrees}C.

  19. Advanced Ceramics

    International Nuclear Information System (INIS)

    The First Florida-Brazil Seminar on Materials and the Second State Meeting about new materials in Rio de Janeiro State show the specific technical contribution in advanced ceramic sector. The others main topics discussed for the development of the country are the advanced ceramic programs the market, the national technic-scientific capacitation, the advanced ceramic patents, etc. (C.G.C.)

  20. Quantification of thermal damage in skin tissue

    Institute of Scientific and Technical Information of China (English)

    Xu Feng; Wen Ting; Lu Tianjian; Seffen Keith

    2008-01-01

    Skin thermal damage or skin burns are the most commonly encountered type of trauma in civilian and military communities. Besides, advances in laser, microwave and similar technologies have led to recent developments of thermal treatments for disease and damage involving skin tissue, where the objective is to induce thermal damage precisely within targeted tissue structures but without affecting the surrounding, healthy tissue. Further, extended pain sensation induced by thermal damage has also brought great problem for burn patients. Thus, it is of great importance to quantify the thermal damage in skin tissue. In this paper, the available models and experimental methods for quantification of thermal damage in skin tissue are discussed.

  1. Stable clocks and general relativity

    CERN Document Server

    Will, C M

    1995-01-01

    We survey the role of stable clocks in general relativity. Clock comparisons have provided important tests of the Einstein Equivalence Principle, which underlies metric gravity. These include tests of the isotropy of clock comparisons (verification of local Lorentz invariance) and tests of the homogeneity of clock comparisons (verification of local position invariance). Comparisons of atomic clocks with gravitational clocks test the Strong Equivalence Principle by bounding cosmological variations in Newton's constant. Stable clocks also play a role in the search for gravitational radiation: comparision of atomic clocks with the binary pulsar's orbital clock has verified gravitational-wave damping, and phase-sensitive detection of waves from inspiralling compact binaries using laser interferometric gravitational observatories will facilitate extraction of useful source information from the data. Stable clocks together with general relativity have found important practical applications in navigational systems s...

  2. Thermally driven ballistic rectifier

    Science.gov (United States)

    Matthews, J.; Sánchez, D.; Larsson, M.; Linke, H.

    2012-05-01

    The response of electric devices to an applied thermal gradient has, so far, been studied almost exclusively in two-terminal devices. Here we present measurements of the response to a thermal bias of a four-terminal, quasiballistic junction with a central scattering site. We find a novel transverse thermovoltage measured across isothermal contacts. Using a multiterminal scattering model extended to the weakly nonlinear voltage regime, we show that the device's response to a thermal bias can be predicted from its nonlinear response to an electric bias. Our approach forms a foundation for the discovery and understanding of advanced, nonlocal, thermoelectric phenomena that in the future may lead to novel thermoelectric device concepts.

  3. Stable light isotope biogeochemistry of hydrothermal systems

    Science.gov (United States)

    Des Marais, D. J.

    1996-01-01

    The stable isotopic composition of the elements O, H, S and C in minerals and other chemical species can indicate the existence, extent, conditions and the processes (including biological activity) of hydrothermal systems. Hydrothermal alteration of the 18O/16O and D/H values of minerals can be used to detect fossil systems and delineate their areal extent. Water-rock interactions create isotopic signatures which indicate fluid composition, temperature, water-rock ratios, etc. The 18O/16O values of silica and carbonate deposits tend to increase with declining temperature and thus help to map thermal gradients. Measurements of D/H values can help to decipher the origin(s) of hydrothermal fluids. The 34S/32S and 13C/12C values of fluids and minerals reflect the origin of the S and C as well as oxygen fugacities and key redox processes. For example, a wide range of 34S/32S values which are consistent with equilibration below 100 degrees C between sulfide and sulfate can be attributed to sulfur metabolizing bacteria. Depending on its magnitude, the difference in the 13C/12C value of CO2 and carbonates versus organic carbon might be attributed either to equilibrium at hydrothermal temperatures or, if the difference exceeds 1% (10/1000), to organic biosynthesis. Along the thermal gradients of thermal spring outflows, the 13C/12C value of carbonates and 13C-depleted microbial organic carbon increases, principally due to the outgassing of relatively 13C-depleted CO2.

  4. Effect of Sintering on Thermal Conductivity and Thermal Barrier Effects of Thermal Barrier Coatings

    Institute of Scientific and Technical Information of China (English)

    WANG Kai; PENG Hui; GUO Hongbo; GONG Shengkai

    2012-01-01

    Thermal barrier coatings (TBCs) are mostly applied to hot components of advanced turbine engines to insulate the components from hot gas.The effect of sintering on thermal conductivity and thermal barrier effects of conventional plasma sprayed and nanostructured yttria stabilized zirconia (YSZ) thermal barrier coatings (TBCs) are investigated.Remarkable increase in thermal conductivity occurs to both typical coatings after heat treatment.The change of porosity is just the opposite.The grain size of the nanostructured zirconia coating increases more drastically with annealing time compared to that of the conventional plasma sprayed coating,which indicates that coating sintering makes more contributions to the thermal conductivity of the nanostructured coating than that of the conventional coating.Thermal barrier effect tests using temperature difference technique are performed on both coatings.The thermal barrier effects decrease with the increase of thermal conductivity after heat treatment and the decline seems more drastic in low thermal conductivity range.The decline in thermal barrier effects is about 80 ℃for nanostructured coating after 100 h heat treatment,while the conventional coating reduces by less than 60 ℃ compared to the as-sprayed coating.

  5. Multipole surface solitons in layered thermal media

    CERN Document Server

    Kartashov, Yaroslav V; Torner, Lluis

    2008-01-01

    We address the existence and properties of multipole solitons localized at a thermally insulating interface between uniform or layered thermal media and a linear dielectric. We find that in the case of uniform media, only surface multipoles with less than three poles can be stable. In contrast, we reveal that periodic alternation of the thermo-optic coefficient in layered thermal media makes possible the stabilization of higher order multipoles.

  6. Aminodifluorosulfinium Tetrafluoroborate Salts as Stable and Crystalline Deoxofluorinating Reagents

    OpenAIRE

    Beaulieu, Francis; Beauregard, Louis-Philippe; Courchesne, Gabriel; Couturier, Michel; LaFlamme, François; L’Heureux, Alexandre

    2009-01-01

    Aminodifluorosulfinium tetrafluoroborate salts were found to act as efficient deoxofluorinating reagents when promoted by an exogenous fluoride source and, in most cases, exhibited greater selectivity by providing less elimination byproduct as compared to DAST and Deoxo-Fluor. Aminodifluorosulfinium tetrafluoroborates are easy handled crystalline salts that show enhanced thermal stability over dialkylaminosulfur trifluorides, are storage-stable, and unlike DAST and Deoxo-Fluor do not react vi...

  7. Metal stable isotope signatures as tracers in environmental geochemistry.

    Science.gov (United States)

    Wiederhold, Jan G

    2015-03-01

    The biogeochemical cycling of metals in natural systems is often accompanied by stable isotope fractionation which can now be measured due to recent analytical advances. In consequence, a new research field has emerged over the last two decades, complementing the traditional stable isotope systems (H, C, O, N, S) with many more elements across the periodic table (Li, B, Mg, Si, Cl, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ge, Se, Br, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, U) which are being explored and potentially applicable as novel geochemical tracers. This review presents the application of metal stable isotopes as source and process tracers in environmental studies, in particular by using mixing and Rayleigh model approaches. The most important concepts of mass-dependent and mass-independent metal stable isotope fractionation are introduced, and the extent of natural isotopic variations for different elements is compared. A particular focus lies on a discussion of processes (redox transformations, complexation, sorption, precipitation, dissolution, evaporation, diffusion, biological cycling) which are able to induce metal stable isotope fractionation in environmental systems. Additionally, the usefulness and limitations of metal stable isotope signatures as tracers in environmental geochemistry are discussed and future perspectives presented. PMID:25640608

  8. Thermal analysis of hadron multiplicities from RQMD

    CERN Document Server

    Sollfrank, J; Sorge, H; Xu, N

    1999-01-01

    Some questions arising in the application of the thermal model to hadron production in heavy ion collisions are studied. We do so by applying the thermal model of hadron production to particle yields calculated by the microscopic transport model RQMD(v2.3). We study the bias of incomplete information about the final hadronic state on the extraction of thermal parameters.It is found that the subset of particles measured typically in the experiments looks more thermal than the complete set of stable particles. The hadrons which show the largest deviations from thermal behaviour in RQMD(v2.3) are the multi-strange baryons and anti-baryons. We also looked on the influence of rapidity cuts on the extraction of thermal parameters and found that they lead to different thermal parameters and larger disagreement between the RQMD yields and the thermal model.

  9. Thermal measurements and inverse techniques

    CERN Document Server

    Orlande, Helcio RB; Maillet, Denis; Cotta, Renato M

    2011-01-01

    With its uncommon presentation of instructional material regarding mathematical modeling, measurements, and solution of inverse problems, Thermal Measurements and Inverse Techniques is a one-stop reference for those dealing with various aspects of heat transfer. Progress in mathematical modeling of complex industrial and environmental systems has enabled numerical simulations of most physical phenomena. In addition, recent advances in thermal instrumentation and heat transfer modeling have improved experimental procedures and indirect measurements for heat transfer research of both natural phe

  10. Radiation-stable polyolefin compositions

    International Nuclear Information System (INIS)

    This invention relates to compositions of olefinic polymers suitable for high energy radiation treatment. In particular, the invention relates to olefinic polymer compositions that are stable to sterilizing dosages of high energy radiation such as a gamma radiation. Stabilizers are described that include benzhydrol and benzhydrol derivatives; these stabilizers may be used alone or in combination with secondary antioxidants or synergists

  11. Approximation by Penultimate Stable Laws

    NARCIS (Netherlands)

    L.F.M. de Haan (Laurens); L. Peng (Liang); H. Iglesias Pereira

    1997-01-01

    textabstractIn certain cases partial sums of i.i.d. random variables with finite variance are better approximated by a sequence of stable distributions with indices \\\\alpha_n \\\\to 2 than by a normal distribution. We discuss when this happens and how much the convergence rate can be improved by using

  12. Stable interactions via proper deformations

    International Nuclear Information System (INIS)

    A new method is proposed for switching on interactions that are compatible with global symmetries and conservation laws of the original free theory. The method is applied to the control of stability in Lagrangian and non-Lagrangian theories with higher derivatives. By way of illustration, a wide class of stable interactions is constructed for the Pais–Uhlenbeck oscillator. (paper)

  13. Stable continuous-time autoregressive process driven by stable subordinator

    Science.gov (United States)

    Wyłomańska, Agnieszka; Gajda, Janusz

    2016-02-01

    In this paper we examine the continuous-time autoregressive moving average process driven by α-stable Lévy motion delayed by inverse stable subordinator. This process can be applied to high-frequency data with visible jumps and so-called "trapping-events". Those properties are often visible in financial time series but also in amorphous semiconductors, technical data describing the rotational speed of a machine working under various load regimes or data related to indoor air quality. We concentrate on the main characteristics of the examined subordinated process expressed in the language of the measures of dependence which are main tools used in statistical investigation of real data. However, because the analyzed system is based on the α-stable distribution therefore we cannot consider here the correlation (or covariance) as a main measure which indicates at the dependence inside the process. In the paper we examine the codifference, the more general measure of dependence defined for wide class of processes. Moreover we present the simulation procedure of the considered system and indicate how to estimate its parameters. The theoretical results we illustrate by the simulated data analysis.

  14. Application of enriched stable isotopes as tracers in biological systems

    DEFF Research Database (Denmark)

    Stürup, Stefan; Hansen, Helle Rüsz; Gammelgaard, Bente

    2008-01-01

    The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry...... (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments......, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched...

  15. ICONE-4: Proceedings. Volume 1 -- Part B: Basic technological advances

    International Nuclear Information System (INIS)

    The proceedings of this conference are divided into 5 volumes. Volume one is divided into Parts A and B. Here in Part B, the following subjects are covered: advances in thermal hydraulic computer codes for reactor analysis; human health effects of low level radiation; advances in liquid metal reactor technology; computational and experimental developments; two-phase flow and heat transfer fundamentals; advances in flow field analysis and testing; advanced reactor thermal hydraulic safety; thermal hydraulics of nuclear safety and reliability; advances in numerical simulation of steam explosions; and computational and experimental two-phase flow developments. Separate abstracts were prepared for most papers in this volume

  16. Advanced formal verification

    CERN Document Server

    Drechsler, Rolf

    2007-01-01

    Preface. Contributing Authors. Introduction; R. Drechsler. 1. Formal Verification. 2. Challenges. 3. Contributions to this Book. 1: What SAT-Solvers Can and Cannot Do; E. Goldberg. 1. Introduction. 2. Hard Equivalence Checking CNF Formulas. 3. Stable Sets of Points. 2: Advancements in Mixed BDD and SAT Techniques; G. Cabodi, S. Quer. 1. Introduction. 2. Background. 3. Comparing SAT and BDD Approaches: Are they Different? 4. Decision Diagrams as a Slave Engine in General SAT: Clause Compression by Means of ZBDDs. 5. Decision Diagram Preprocessing and Circuit-Based SAT. 6. Using SAT in Symbolic

  17. Advance care directives

    Science.gov (United States)

    ... advance directive; Do-not-resuscitate - advance directive; Durable power of attorney - advance care directive; POA - advance care directive; Health care agent - advance care directive; Health care proxy - ...

  18. Nuclear propulsion technology advanced fuels technology

    Science.gov (United States)

    Stark, Walter A., Jr.

    1993-01-01

    Viewgraphs on advanced fuels technology are presented. Topics covered include: nuclear thermal propulsion reactor and fuel requirements; propulsion efficiency and temperature; uranium fuel compounds; melting point experiments; fabrication techniques; and sintered microspheres.

  19. Advances in Solar Heating and Cooling Systems

    Science.gov (United States)

    Ward, Dan S.

    1976-01-01

    Reports on technological advancements in the fields of solar collectors, thermal storage systems, and solar heating and cooling systems. Diagrams aid in the understanding of the thermodynamics of the systems. (CP)

  20. Phases of stable representations of quivers

    CERN Document Server

    Engenhorst, Magnus

    2015-01-01

    We consider stable representations of non-Dynkin quivers with respect to a central charge. On one condition the existence of a stable representation with self-extensions implies the existence of infinitely many stables without self-extensions. In this case the phases of the stable representations approach one or two limit points. In particular, the phases are not dense in two arcs.