Energy Technology Data Exchange (ETDEWEB)

A railgun has an armature driven between two rail-like conductors. In other words, it is a linear drive device system that drives airframes by using the Lorentz`s force. The system is expected as a next-generation high-speed transport means, or as a means to create such ultimate fields as ultra-high pressures, ultra-high temperatures, and ultra-ferromagnetic fields. This paper is a report on investigations on the relevant technological trends as surveyed by the investigation committee at the Institute of Electrical Engineers of Japan using research reports published inside and outside the country. The reported themes cover explanations from the construction to the pulse power supply that forms the core of the technology, problems in switching, recent status of research and development, and to application fields. Compatibility in the high-level electrical and ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Mechanical properties of P-LDHA and V-ROL N steels of the Czech production are compared with other ultra-high strength steels produced in the world. The most important results can be summarized into following points: 1. Optimally heat treated P-LDHA steel exhibits substantially better strength characteristics then the V-ROL N steel. 2. Optimal tempering temperature of the P-LDHA steel is 300 C. 3. Basic mechanical properties of P-LDHA steel belong to the top of the UHS steels ranking and are well comparable with those of American 300 M steel. 4. In the low-cycle fatigue region, the P-LDHA steel exhibits slightly better fatigue resistance then the 300 M steel. On the other hand, the high-cycle fatigue resistance of 300 M steel is slightly better then that of the P-LDHA steel. (orig.)

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Experimental discussions were given on effect of V and W addition on the high temperature strength properties of 12% Cr-15% Mn austenite steels. The test samples were added with W at 0% to 3.5% and V at 0% to 0.5% in addition to C and N, and were given aging treatment or solution treatment. This paper describes the following matters on the results of high-temperature strength measurements and structural observation: A remarkable trend was observed that M23 Cb type carbides precipitate in the aging treatment, wherein aging hardening appears prominently which is attributable to ultra-fine deposits of vanadium nitride (VN) in the V-added material; the V addition is very effective in increasing the high-temperature tensile strength and creep fracture strength as compared with single W addition, wherein the said carbides that accelerate the precipitation as a result of the V addition ...

KoreaScience (Korea)

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In this book over 250 alloys are organized by AISI number into 10 major sections: Irons, Carbon Steels, Alloy Steels, Low Alloy Constructional Steels, Ultra High Strength Steels, Tool Steels, Maraging Steels, Wrought Stainless Steels, Heat Resistnat Casting Alloys, and Iron Based Rought Superalloys. Each alloy record lists the designation, specifications, UNS number, composition, product forms and a comment on the high-temperature properties and applications. Referenced data is then given for physical properties such as density, specific heat, thermal conductivity, thermal expansion, electrical conductivity, Poisson's ratio, moduli of elasticity and rigidity, etc. Mechanical properties follow, and include tensile properties, shearing and bearing properties, impact properties, creep, stress rupture and stress relaxation and fatigue properties. The last part of the alloy record gives other effects of ...

Energy Technology Data Exchange (ETDEWEB)

We investigated the electrical characteristics and the junction depth of ultra-shallow junctions formed by using the plasma-doping method. Compared with ultra-low energy boron-ion implantation at 500 eV, the junctions formed with the plasma-doping process exhibited shallow junction depths and low sheet resistances. The junction depths of the plasma-doped samples were 150 A and 330 A after annealing for 10 s at 900 .deg. C and 950 .deg. C, respectively. For the same junction depth, the sheet resistance of the B{sub 2}H{sub 6} plasma-doped sample was an order of magnitude less than that of the 500-eV B-ion implanted sample. Cross-sectional transmission electron microscopy and deep level transient spectroscopy showed that the defects formed by the B{sub 2}H{sub 6} plasma-doping process could be removed by annealing at 950 .deg. C for 10 s. The scaling of metal-oxide-semiconductor field-effect-transistor (MOSFET) device channel lengths for ...

Energy Technology Data Exchange (ETDEWEB)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The ...

Science.gov (United States)

Silicon carbide (SiC) based electronic devices are of great importance for applications under the condition of high temperature, high power and high radiation. Schottky diodes of Palladium/SiC are good candidates for hydrogen and hydrocarbon gas sensors at elevated temperature. The detection sensibility of the diodes has been found heavily temperature dependent. In this work, the electrical and chemical properties of Pd/SiC Schottky contacts were studied by XPS and AES at different annealing temperatures. Schottky diodes were made by depositing ultra-thin palladium films onto a silicon carbide substrate. No significant change in the Schottky barrier height of the Pd/SiC contact was found in the temperature range of 300-673K. Palladium diffusion into SiC and the formation of palladium silicides were ...

International Nuclear Information System (INIS)

Ultra-shallow junction formation in deep submicron Si devices is limited by anomalous diffusion of the dopant, which is related to the release of interstitials from defect clusters formed during the implantation of energetic ions or the subsequent annealing. The work described in this dissertation is concerned with the effects of low energy B ion implantation, especially damage formation, clustering and its annealing. After a review of the stopping and ranges of energetic ions in Si, the formation of implant damage, in particular of point defects, their migration, agglomeration and annihilation, including the involvement of dopant ions, is considered. A description of the Salford ultra low energy implanter is given and the main analysis technique, medium ion energy scattering (MEIS) reviewed. Additional analytical techniques used, such as secondary ion mass spectrometry (SIMS), 4-point probe and cross section transmission microscopy (XTEM) as ...

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A sodium-water reaction drove from the single tube break in steam generator of FBR might overheat labor tubes rapidly under internal pressure loadings. If the temperature of tube wall becomes too high, it has to be evaluated that the stress of tube does not exceed the material strength limit to prevent the propagation of tube rupture. This study clarified the tensile and creep properties of Mod.9Cr-1Mo steel at ultra-high temperature which will be used in evaluation of the tube burst by sodium-water reaction. The strain rates for tensile test are from 10%/min to 10%/sec, and creep-rupture time is maximum 277sec. The range of test temperature is 700degC to 1300degC. The main results obtained were as follows; (1) The evaluation data on the relationship between tensile strength and strain rate and creep-rupture strength in shorter time on Mod.9Cr-1Mo steel were acquired. (2) Short-term ...

Energy Technology Data Exchange (ETDEWEB)

The goal of this research program is to determine whether pulsed laser deposition is an effective alternative method for growing TiCN thin films. Pulsed laser deposition (PLD) is chosen because of its well-documented capability for growing uniform, stoichiometric films in ultra-high vacuum or gaseous environments. Processing of thin films by PLD is also achieved at relatively low temperatures compared with CVD processing. Given these attributes, the primary objectives in this article are to determine whether nitrogen may be readily incorporated into films resulting from the laser-ablation of TiC in an N{sub 2} environment, determine what effect nitrogen has on mechanical properties, and determine whether nitrogen incorporation is strongly influenced by processes unrelated to laser deposition (e.g., thermally-activated surface reactions).

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The ISI (In-Service Inspection) system has been developed so as to maintain the structural integrity of heat transfer tubes in the primary pressurized water cooler in the HTTR (High Temperature Engineering Test Reactor). This system consists of eddy current probes, ultra-sonic probes, insertion and extraction units, positioning unit and so on. Verification and performance tests of the developed ISI system were carried out using mock-up heat transfer tubes in the primary pressurized water cooler. The constitution of the system, R and D results of the inspection probes, and verification and performance test results of the ISI system for heat transfer tubes are described in this paper. (author)

Energy Technology Data Exchange (ETDEWEB)

The WEGA stellarator is used to confine low temperature, overdense (densities exceeding the cut-off density of the heating wave) plasmas by magnetic fields in the range of B=50-500 mT. Microwave heating systems are used to ignite gas discharges using hydrogen, helium, neon or argon as working gases. The produced plasmas have been analyzed using Langmuir and emissive probes, a single-channel interferometer and ultra-high resolution Doppler spectroscopy. For a typical argon discharge in the low field operation, B=56 mT, the maximum electron density is n{sub e}{proportional_to}10{sup 18} m{sup -3} with temperatures in the range of T=4-12 eV. The plasma parameters are determined by using Langmuir probes and are cross-checked with interferometry. It is demonstrated within this work that the joint use of emissive probes and ultra-high resolution Doppler spectroscopy allows a precise measurement of the radial ...

International Nuclear Information System (INIS)

Understanding human brain function, brain development and brain dysfunction is one of the great challenges of the twenty first century. Biomedical imaging has now run up against a number of technical constraints that are exposing limits to its potential. In order to overcome the current limits to high-field magnetic resonance cerebral imaging (MRI) and unleash its fullest potential, the Cea has built NeuroSpin, an ultra-high-field neuroimaging facility at its Saclay centre (in the Essonne). NeuroSpin already boasts three fully operational MRI systems. The first is a 3-tesla high-field system and the second is a very-high-field 7-tesla system, both of which are dedicated to clinical studies and investigations in humans, while the third is an ultra-high-field 17.65-tesla system designed for studies on small animals. In 2011, NeuroSpin will be commissioning an 11.7-tesla ...

Energy Technology Data Exchange (ETDEWEB)

This study aims to evaluate fatigue strength properties at long-term high temperature of 316FR steels developed for structural materials applied to high temperature components in the 21st Century such as Demonstration FBR, and to obtain design indicators on high temperature strength properties arranged on chemical composition and grain size on a base of 316FR stainless steels. As results obtained by the study, it could be found that as a result of systematic examinations on temperatures and strain rate dependence on symmetric triangular strain waveform of 316FR steels between 500 to 600degC, temperature of fatigue life, and strain rate dependence can be integrally evaluated by a parameter analysis method developed by authors and life prediction at ultra low strain rate of less than 10{sup -6}/s and ...

Energy Technology Data Exchange (ETDEWEB)

A design of a compact free-electron laser (FEL), generating ultra-fast, high-peak flux, XUV pulses is presented. The FEL is driven by ahigh-current, 0.5 GeV electron beam from the Lawrence Berkeley National Laboratory (LBNL) laser-plasma accelerator, whose active acceleration length is only a few centimeters. The proposed ultra-fast source (~;;10 fs) would be intrinsically temporally synchronized to the drive laser pulse, enabling pump-probe studies in ultra-fast science. Owing to the high current (>10 kA) of the laser-plasma-accelerated electron beams, saturated output fluxes are potentially greater than 10^13 photons/pulse. Devices based both on self-amplified spontaneous emission and high-harmonic generated input seeds, to reduce undulator length and fluctuations, are considered.

British Library Electronic Table of Contents (United Kingdom)

A wet air oxidation (WAO) process was applied to four selected pharmaceuticals (metoprolol, naproxen, amoxicillin, and phenacetin) individually dissolved in ultra-pure water, varying the temperature and oxygen pressure. Due to the moderate (amoxicillin) or low (metoprolol, naproxen, and phenacetin) efficiency found in the oxidation of these pollutants, a catalytic wet air oxidation (CWAO) process was then tested using a platinum catalyst supported on multi-walled carbon nanotubes (CNT). In this CWAO process, the pharmaceuticals were dissolved together in ultra-pure water and in four natural water matrices-a reservoir water, a groundwater, and two waters from different municipal wastewater treatment plants. On the basis of the measurements of their removals, a discussion is given of the inf...

Science.gov (United States)

The advanced technologies of Ka-Band systems such as high gain spot .... sometimes used based on link requirements for a specific application. .... received at NASA LeRC from a Ku-band satellite and retransmitted to the USAT at Ka-Band. .... and to the Office of Management and Budget, Paperwork Reduction Project ...

Energy Technology Data Exchange (ETDEWEB)

A major obstacle prohibiting the use of microwaves for soil disinfection and disinfestation is the large amount of energy required to obtain sufficient results. The present work presents an experimental study of the effect of initial soil temperature and soil moisture on energy consumption by application of microwaves for soil disinfection. All experiments were carried out by using a microwave generator of a nominal power output of 900 W. The ultra-high-frequency field (2450{+-}2 MHZ) was produced by a magnetron tube and channelled through a metal waveguide. The output opening of the waveguide was placed directly on the soil surface. It was found that a soil with 15% moisture content (w.b.) and an initial temperature of 20degC requires energy to be heated at a depth of 10 cm up to 61degC which is 3.2 times more than the energy required to heat the soil up to 5 cm depth at the same initial temperature. ...

Energy Technology Data Exchange (ETDEWEB)

Superplasticity of polycrystalline metallic materials is a phenomenon which shows hundreds to thousands of percents of large plastic deformation without necking in a steady state of low stress, when the uni-axial tensile loading is done in some special thermo-mechanical conditions (some limited ranges of properly high temperature and low strain rate). The main mechanism of superplastic phenomenon is the grain boundary sliding, while the main mechanism of usual plastic deformation is the trans-granular sliding. In this research, the possibility of superplastic deformation in a magnesium alloy (AZ31Mg alloy) was experimentally investigated, because generally speaking, the magnesium alloy whose atomic structure is hexagonal does not have enough formability in a form of trans-granular sliding mechanism. In this paper, the detail of experimental results are shown and discussed. Moreover, the constitutive equations of Mg alloy are proposed on the ...

Energy Technology Data Exchange (ETDEWEB)

Samples of ultra-high molecular weight polyethylene (UHMWPE) and nylon 66, of grades suitable for use in medical prostheses, were subjected to irradiation using a /sup 60/Co source. The effects of a 10 Mrad dose on percentage crystallinity, tensile behaviour and dynamic mechanical response were established 3 days after irradiation at intervals over a one year period. Crystallinity in UHMWPE was found to increase progressively during this period with consequent changes in mechanical behaviour. It is proposed that the observed ageing process arises from the breakdown of metastable groups in the polymer, which are formed on irradiation, with consequent release of long inter-lamella tie chains. This removes an inhibition to crystal perfection processes, which can occur at room temperature in polyethylene. Infra-red spectroscopic evidence supports the proposal that the metastable species is peroxy or hydroperoxy and that this decomposes on ageing to ...

International Nuclear Information System (INIS)

The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU's evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky trademark pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is ...

British Library Electronic Table of Contents (United Kingdom)

Tailor die quenching in the hot stamping of quenchable steel sheets was developed to produce ultra-high strength steel formed parts having strength distribution. Local portions of the heated sheet were quenched by holding grooved tools at the bottom dead centre during the stamping. Non-contact portions were generated in the sheet by grooving the tools, and thus the strength in the contact portions is high owing to the quenching and that in the non-contact portions is low owing to the lack of the quenching. Hat-shaped products having a tensile strength of approximately 1.5GPa only at four corners were formed.

Energy Technology Data Exchange (ETDEWEB)

We present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide under TE{sub 01} mode, performing switching by injecting carriers into the bulk silicon. Our current design uses a CMOS compatible process and the device was fabricated at SNF (Stanford Nanofabrication Facility). 300 ns switching time has been observed, while the switching speed can be improved further with 3-D device structure and faster driving circuit. Power handling capacity of the switch is at the level of 10 MW. The switch was designed for active X-band RF pulse compression systems--especially for NLC, but it is also possible to be modified for other applications and other frequencies.

Energy Technology Data Exchange (ETDEWEB)

High and ultra-high strength steels for pipelines are produced by properly handling the steel microstructure. The metallurgical principles involved in the microstructure control are presented, with emphasis on TMCP processing, that comprises conventional controlled rolling followed by accelerated cooling. (author)

International Nuclear Information System (INIS)

A procedure was developed for separating rubidium from irradiated aluminum encapsulated uranium. The separations procedure produces a final ultra-high purity RbCl product for subsequent high performance mass spectrometric analysis. The procedure involves first removing most of the macro-components and fission products by strong base anion exchange using, first, concentrated HCl, then oxalic acid media and second, selectively separating rubidium from alkaline-earth ions and other alkali-metal ions, including cesium, using Bio-Rex-40 cation-exchange resin. The resultant RbCl is then put through a final vacuum sublimation step. Ultra-pure reagents and specially clean glassware are used throughout the procedure to minimize contamination by naturally-occurring rubidium.

Energy Technology Data Exchange (ETDEWEB)

This paper describes how hydrogen transport affects the severity of hydrogen embrittlement in 300 M and AerMet100 ultra high strength steels. Slow strain rate tests were carried out on specimens coated with electrodeposited cadmium and aluminium-based SermeTel 1140/962. Hydrogen diffusivities were measured using two-cell permeation and galvanostatic charging methods and values of 8.0 x 10{sup -8} and 1.0 x 10{sup -9} cm{sup 2} s{sup -1} were obtained for 300 M and AerMet100, respectively. A two-dimensional diffusion model was used to predict the hydrogen distributions in the SSR specimens at the time of failure. The superior embrittlement resistance of AerMet100 was attributed to reverted austenite forming around martensite laths during tempering.

Energy Technology Data Exchange (ETDEWEB)

The effects of gate and drain bias stresses on thin film transistors fabricated in polysilicon films crystallized using the advanced sequential lateral solidification excimer laser annealing (SLS ELA) process, which yields very elongated polysilicon grains and allows the fabrication of TFTs without grain boundary barriers to current flow, are investigated as a function of the active layer thickness and of the TFT orientation relative to the grains. The application of hot carrier stress, with a condition of V{sub GS} = V{sub DS}/2, was determined to induce threshold voltage, subthreshold swing and transconductance degradation for TFTs in thicker polysilicon films and the associated stress-induced increase in the active layer trap density was evaluated. However, this device degradation was drastically reduced for TFTs fabricated in ultra-thin films. Furthermore, the application of the same stress condition to TFTs oriented vertically to the elongated grains resulted ...

KoreaScience (Korea)

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In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray ...

CERN Document Server

Gamma-ray burst (GRB) is one of the candidates of high-energy cosmic-ray acceleration sites. They may be also ultra-high-energy (above 3 EeV) cosmic-ray (UHECR) sources. In this paper, we discuss possibilities and implications of high-energy cosmic-ray acceleration in GRBs. (1) First, we show that not only protons but also heavier nuclei can be accelerated up to ultra-high energies in both usual high-luminosity (HL) and low-luminosity (LL) GRBs by using the Geant4. LL GRBs may also make a significant contribution to the observed UHECR flux if they form a distinct population, and we investigate cosmic-ray acceleration in LL GRBs in detail. (2) Second, we discuss implications of the GRB-UHECR hypothesis (and Hypernova-UHECR hypothesis) to cosmic-ray astronomy. HL GRBs and LL GRBs will lead to different source number densities as UHECR sources, so that the determination of the number ...

Energy Technology Data Exchange (ETDEWEB)

The invention relates to a pulsed laser ablation method of metals and/or dielectric films from the surface of a wafer, printed circuit board or a hybrid substrate. By utilizing a high-energy ultra-short pulses of laser light, such a method can be used to manufacture electronic circuits and/or electro-mechanical assemblies without affecting the material adjacent to the ablation zone.

International Nuclear Information System (INIS)

Studies are made in this program to enhance our understanding of the role of 5f electrons in chemical bonding. Most of our studies on the macroscopic scale emphasize certain isotopes available from the National Transplutonium Production Program centered at HFIR/TRU -namely, _9_6"2"4"8Cm, _9_7"2"4"9Bk, _9_8"2"4"9Cf, _9_9"2"5"3Es, and _9_9"2"5"4Es. Particular classes of compounds, such as hydrides, chalcogenides, and pnictides are often selected for study on the basis of their utility in bringing out significant chemical differences between the lanthanides and the actinides. High temperature/high pressure experiments on actinide metals and compounds reveal characteristics about the degree of 5f electron localization as a function of atomic number in the series. Magnetic properties of metals and compounds are investigated using ultra-sensitive methods and hydration numbers of ions in solution are investigated by neutron ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes high speed rolling and gauge control in cold tandem mill for ultra-thin gauge strip at the Chiba Works of Kawasaki Steel Corporation. To improve the plate-out property of rolling oil, cationic polymeric coagulant was prepared. Rolling oil with cohesion independent of inorganic inclusions or phosphatide was developed, to improve the lubrication for cold rolling, remarkably. In addition, a low-cost Ti-enhanced work roll having high wear resistance and excellent grindability was developed. Rolling can be conducted at the optimal rolling roughness and operation can be performed at the highest rolling speed independent of the rolling treatment amount. Rolling speed at 2800 m/min was confirmed by developing the rolling oil with excellent lubrication and the work roll having high wear resistance. For the improvement of strip thickness accuracy at the steady state rolling, use of the backup ...

Energy Technology Data Exchange (ETDEWEB)

MATRIX, a participating research team of Midwest x-ray scattering specialists, continues to operate beam line X-18A at NSLS. Operations of this line now provides state-of-the-art capabilities to a wide range of people in the Materials Science and Engineering research community. Improvements of the beam line continue to be a focus of MATRIX. Throughout this past year the emphasis has been shifting towards improvement in ``user friendly`` aspects. Simplified control operations and a shift to single-user personal computer has been a major part of the effort. Over the past year the full 242 operational days were utilized. Beam line test and evaluation consumed 21 days with eight MATRIX groups combining to use 170 days. General user demand for use of the beam line continues to be strong and three groups were provided 51 operating days. Research production has been growing as NSLS and the beam line become a more stable type of operation. For 1990 the MATRIX group published nine articles. To ...

Energy Technology Data Exchange (ETDEWEB)

The object of this research is the evaluation of the performance of ultra high speed relays (UHSR's) used for protection of a-c transmission lines. For purposes of this report, these are relays whose response time is less than a quarter of a cycle of the 60 Hz wave (i.e. 4.167 ms.). To identify relaying schemes that may comply with this definition, a literature survey was undertaken. The selected relays were studied in detail and modeled on a digital computer. A theoretical description of these relays is presented. Records of real transient data as well as of simulated data were used as input to the digital models of relays. The real data were recorded by means of monitoring stations connected to the Florida Power and Light Company transmission lines. The simulated data were obtained by modeling the relevant parts of the utility's transmission system using a University of British Columbia simplified version of the well known ...

International Nuclear Information System (INIS)

Energy deposition process by relativistic fast electrons produced by ultra-intense laser pulses is discussed. The process is calculated with a two dimensional Fokker-Planck simulation code including binary and collective collisions coupled with electromagnetic field. We focused on Velocity Distribution Function (VDF) dependence in the simulation. The results show that the spread angle of the fast electrons distribution affects energy deposition area and deposited energy is concentrated in the vicinity of the propagation axis of the fast electrons. It may be also suggested that self-pinch effect of a fast electron beam causes large deposition energy. (author)

Energy Technology Data Exchange (ETDEWEB)

We are investigating a novel insulator concept which involves the use of alternating layers of conductors and insulators with periods less than 1 mm. These structures perform many times better (about 1.5 to 4 times higher breakdown electric field) than conventional insulators in long pulse, short pulse, and alternating polarity applications. We present our ongoing studies investigating the degradation of the breakdown electric field resulting from surface roughness, the effect of gas pressure, and the performance of the insulator structure under bi-polar stress. Further, we present our initial modeling studies.

Energy Technology Data Exchange (ETDEWEB)

When searching for anisotropies in the arrival directions of Ultra High Energy Cosmic Rays, one must estimate the number of events expected in each direction of the sky in the case of a perfect isotropy. We present in this article a new method, developed for the Auger Observatory, based on a smooth estimate of the zenith angle distribution obtained from the data itself (which is essentially unchanged in the case of the presence of a large scale anisotropy pattern). We also study the sensitivity of several methods to detect large-scale anisotropies in the cosmic ray arrival direction distribution : Rayleigh analysis, dipole fitting and angular power spectrum estimation.

International Nuclear Information System (INIS)

Full text of publication follows: Radiation hardening and embrittlement due to high-energy neutron radiation around 623 K are the important issues on reduced-activation ferritic/martensitic (RAF/M) steels. It is expected that the improvement of radiation hardening might be one of effective ways to control the mechanical properties of RAF/M after irradiation. It has been reported that the weld joint has less hardening than the base metal from the tensile test results of TIG weldments irradiated in HFIR. This report indicated that radiation hardening can be reduced by the optimization of heat treatment condition for F82H. The purposes of this study are to establish the condition of heat treatment for minimum of radiation hardening in F82H steel using Neutron/Ion-irradiation and to examine a correlation between tensile property and micro-hardness before/after irradiation. The materials used in this study were F82H IEA heat and F82H heat treatment variants. Neutron ...

Science.gov (United States)

High-Temperature Solar Cell Development. Geoffrey A. Landis,. NASA John Glenn Research Center. 21000 Brookpark Road, Cleveland, OH 44135. Danielle ...

Energy Technology Data Exchange (ETDEWEB)

Supermetal with critical characteristics is under advanced investigation for further improvement of metal materials. Although iron is most frequently used as structural material among various metals, it should be used more carefully and effectively because of resource limitation and global environmental problem. It is essential to draw various excellent properties much more from iron and to improve recyclability. In particular, the best way to meet these requirements is achievement of more fine structure and higher purity. Since the lowest crystalline grain size is now limited to nearly 10{mu}m, metallic structure composed of grains below 1{mu}m is expected by mesoscopic control. Various methods have been studied to achieve ultra-fine crystalline structure, and study of precise heat treatment control and ultra-strength metallurgy is required. Heat treatment in magnetic field and layered structure by mechanical alloying are also promising. ...

International Nuclear Information System (INIS)

Development of a front end system for a high energy proton accelerator is in progress at Korea Atomic Energy Research Institute (KAERI) for basic science and industrial applications. The proper vacuum components has been installed and operated successfully between ion source and RFQ. The reliable operation of the accelerator has been completed at vacuum system in the high and ultra high vacuum range under operating conditions. Proper control system for the vacuum instruments, based on PC operated by Windows, has been designed and constructed by control group at PAL. As PC operated by windows with inherent instability does not proper, embedded system can be replaced for reliable operation system, such as VME system operated by vxWorks.

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Advanced lithium batteries presently under development operate either at the high temperatures associated with the LiCl-KCl molten salt (350-450/degree/C), or at ambient temperatures employing organic solvent based electrolytes. An intermediate temperature lithium battery is proposed as an alternative if it reduces corrosion problems present at high temperatures and improved kinetic performance with respect to ambient temperature cells. 17 refs.

Energy Technology Data Exchange (ETDEWEB)

Ultra-thin, uniform, pinhole-free solid polymer electrolyte films having a fixed carboxylic ester group of approximately 1 {mu}m thickness were prepared by polymerization of methyl acrylate and tris(2-methoxyethoxy)vinylsilane in a glow discharge plasma. The carboxylic ester group of the plasma polymer were transformed to lithium carboxylate groups by treatment with lithium iodide. This process give a single lithium ion conductive film. These solid polymer electrolyte films showed ionic conductivities of the order of 10{sup -8} S cm{sup -1} (10{sup 4} {omega} cm{sup 2} resistance per unit area) at room temperature. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Oregon State University (OSU) and the Pacific Northwest National Laboratory (PNNL) were funded by the U.S. Department of Energy to conduct research focused on resolving the key technical issues that limited the deployment of efficient and extremely compact microtechnology based heat actuated absorption heat pumps and gas absorbers. Success in demonstrating these technologies will reduce the main barriers to the deployment of a technology that can significantly reduce energy consumption in the building, automotive and industrial sectors while providing a technology that can improve our ability to sequester CO{sub 2}. The proposed research cost $939,477. $539,477 of the proposed amount funded research conducted at OSU while the balance ($400,000) was used at PNNL. The project lasted 42 months and started in April 2001. Recent developments at the Pacific Northwest National Laboratory and Oregon State University suggest that the performance of absorption and desorption systems can be ...

Science.gov (United States)

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KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

Short communication. 6 refs., 2 figs.

International Science & Technology Center (ISTC)

Development of Ceramic Composite Materials and Structural Elements for High-Temperature Nuclear Reactors

International Nuclear Information System (INIS)

A new high strength titanium alloy has been developed primarily intended for fastener applications. While Ti-6Al-4V is used extensively as a fastener alloy in the aerospace industry, its shear strength allowable is limited to 655 MPa (95 ksi). For higher shear strength requirements, various steels or nickel-based alloys are used (up to 860 MPa (125 ksi)), but with the attendant density penalty. This new alloy is intended to provide the 860 MPa shear strength at roughly a 40% weight savings. After screening various alloy systems, the optimum chemistry has been selected as follows: Ti-6.0V-6.2Mo-5.7Fe-3Al. In light of its 125 ksi shear strength goal, the alloy has been designated TIMETAL reg-sign 125.

Energy Technology Data Exchange (ETDEWEB)

Discovery of better biomarkers for diagnosis, prognosis, and therapy-response prediction is the most critical task of a scientific quest aimed at developing newly designed, tailor-made therapies for patients with cancer. Consequently, a proteome wide analysis, in addition to genomic studies, is an absolute requirement for a complete functional understanding of tumor biology. Ultra-sensitive, high-performance Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) currently holds an important role in fulfilling the demands of biomarker discovery. In this review, we describe the applicability of FTICR MS for breast cancer proteomics, particularly for the analysis of complex protein mixtures obtained from a limited number of cells typically available from clinical specimens.

Energy Technology Data Exchange (ETDEWEB)

At present the cooler synchrotron COSY a synchrotron and storage ring for medium energy physics is being commissioned at Juelich. The construction of the ring was finished during September 1992. The cooler ring will deliver protons in the momentum range from 270 to 3300 MeV/c. The phase density of the circulating protons will be increased with electron cooling at injection and with stochastic cooling at momenta between 1500 and 3300 MeV/c. High luminosity internal experiments as well as high resolution external experiments will be possible. Details of the lattice, to match the different ion optical requirements for cooling, acceleration, internal experiments and ultra-slow extraction will be discussed. An overview of the performance of the ion sources, the injector cyclotron, the ring, the injection beamline are given. The realization status of the extraction beamlines to the external experimental area is given. The ...

Energy Technology Data Exchange (ETDEWEB)

An advanced ceramic dome cavity receiver is discussed which heats pressurized gas to temperatures above 1800/sup 0/F (1000/sup 0/C) for use in solar Brayton power systems of the dispersed receiver/dish or central receiver type. Optical, heat transfer, structural, and ceramic material design aspects of the receiver are reported and the development and experimental demonstration of a high-temperature seal between the pressurized gas and the high-temperature silicon carbide dome material is described.

Energy Technology Data Exchange (ETDEWEB)

The high-strength and ultra high-strength steels developed and produced by Thyssen Krupp Stahl make a major contribution to automotive lightweighting. Proven and newly-developed coatings are used to meet increasingly important corrosion protection requirements. Design for materials, optimized forming and joining processes and the use of modern simulation techniques help to exploit the potential of the new steels. Future development work will focus on reducing the density of steels without compromising their well-known advantages - in particular their strength. The use of high-strength and ultra high-strength steels in the automotive industry is on the increase. Steel will remain the material of choice for auto manufacture, above all due to its potential for cost-efficient lightweight construction and its full recyclability. (orig.) [German] Einen wesentlichen ...

International Nuclear Information System (INIS)

'Full text:' The use of fuel cell technology in military applications will depend on safe, high energy density systems being developed. An important part of using this technology is also the development of alternative hydrogen producing fuels with high energy densities and are easy to transport. Fuel cells are now a very large R and D effort for several military applications around the world. The major reason is because of the high power demands needed requires electrical energy sources that far exceed the capabilities of batteries currently being fielded for portable applications. Fuel cells are regarded as highly efficient, tactical energy converters that can be adapted for wide range of power requirements. They are potentially the lowest weight power source when coupled with batteries or capacitors to form hybrid systems. Generally electrical power is needed to support a number of applications from ...

British Library Electronic Table of Contents (United Kingdom)

Faserbewehrter Beton wird heute zunehmend auch bei Tunnelbauwerken (Tunnelinnenschalen, Tubbinge) eingesetzt. Wesentliche Vorteile sind das hohe Tragvermogen, das daraus entstehende Einsparungspotential an herkommlicher stabformiger Bewehrung (Biegebewehrung, Bugelbewehrung in der Randzone), die Aufnahme von Spaltzugbeanspruchungen durch die Fasern, Rissbreitenbegrenzung, erhohte Dauerhaftigkeit, verbesserter Brandwiderstand (insbesondere bei Verwendung von Kunststofffasern), Optimierung der Arbeitsablaufe etc. Neue Entwicklungen in der Betontechnologie haben in den letzten Jahrzehnten den faserbewehrten ultrahochfesten Beton (engl. UHPFRC - Ultra High Performance Fibre Reinforced Concrete) hervorgebracht. Im Rahmen dieser Arbeit wird der Einsatz des ultrahochfesten, stahlfaserbewehrten Be...

International Nuclear Information System (INIS)

Pre-amorphization of ultrashallow implanted boron in Silicon-on-insulator is optimized to produce an abrupt box-like doping profile with negligible electrical deactivation and significantly reduced transient enhanced diffusion. The effect is achieved by positioning the as-implanted amorphous/crystalline interface close to the buried oxide interface, to minimize interstitials whilst leaving a single-crystal seed to support solid-phase epitaxy. Based on a simple physical model of our results, we estimate that the interface between the Si overlayer and the buried oxide is an efficient interstitial sink with a recombination length of the order of 10nm or less under our experimental conditions. (author)

CERN Document Server

Using ultra-high-frequency data extracted from the order flows of 23 stocks traded on the Shenzhen Stock Exchange, we study the empirical regularities of order placement in the opening call auction, cool period and continuous auction. The distributions of relative logarithmic prices against reference prices in the three time periods are qualitatively the same with quantitative discrepancies. The order placement behavior is asymmetric between buyers and sellers and between the inside-the-book orders and outside-the-book orders. In addition, the conditional distributions of relative prices in the continuous auction are independent of the bid-ask spread and volatility. These findings are crucial to build an empirical behavioral microscopic model based on order flows for Chinese stocks.

Science.gov (United States)

... Voltage noise power spectral density measurements as a function of temperature, frequency, current, and magnetic field on DyBa2Cu3O7.x (DBCO ...

Energy Technology Data Exchange (ETDEWEB)

In the advance of fuel cell electric vehicles (EV), hybrid electric vehicles (HEV) can contribute to reduced emissions and energy consumption of personal cars as a short term solution. Trade-offs reveal better emission control for series hybrid vehicles, while parallel hybrid vehicles with different drive trains may significantly reduce fuel consumption as well. At present, costs and marketing considerations favor parallel hybrid vehicles making use of small, high power batteries. With ultra high power density cells in development, exceeding 1 kW/kg, high power batteries can be provided by adapting a technology closely related to consumer cell production. Energy consumption and emissions may benefit from regenerative braking and smoothing of the internal combustion engine (ICE) response as well, with limited additional battery weight. High power supercapacitors may assist the ...

International Nuclear Information System (INIS)

This paper describes a system for fast mass spectrometric characterization of high-temperature outgassing measurements and measuring the total quantity of gas evolved for boron nitride. 2 references, 1 figure, 2 tables.

International Nuclear Information System (INIS)

THe high-temperature reactor is one of the alternatives for the now predominantly employed water-reactors. In a recently published book designer Rudolf Schulten outlines his concept. In this article the book is reviewed. (author). 1 ref.; 1 fig.

Energy Technology Data Exchange (ETDEWEB)

The development of new steels is always a challenge for the manufacturer of filler metals. In many cases it is obvious that some properties of the base metal cannot be fulfilled with matching filler metals. In some cases, dissimilar filler metals can solve the problem in some cases, there is no chance to meet the requirements of the base metal (for example yield strengths of new ultra high strength steels). This paper deals with different kinds of new steels and the requirements for the weld metal with examples from motor car industry (Mangan Austenite), crane (Ultra high strength steels), earthmoving machinery (Wear-resistant steels) and offshore (Supermartensitic steels). Specific problems will be discussed and best solutions will be highlighted. These examples make clear that the success of new kinds of steels in the market depends on solving the joining problems of these steels. (Abstract Copyright ...

Energy Technology Data Exchange (ETDEWEB)

Results of experimental researches of impurity level crystals Fe1-xCoxSi are presented in this article. Magnetic properties in a temperature range up to T {<=} 1000 K are analyzed. It was established that with Co impurities increasing origin of magnetic ordering exists at low temperatures. At high temperatures a high temperature maximum of susceptibility of nominally pure iron monosilicide crystal is observed.

International Nuclear Information System (INIS)

Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.

International Science & Technology Center (ISTC)

Development of SHS-technologies for SiC, Si3N4 and Ceramic Composites on Their Basis from Rocks

Science.gov (United States)

... Abstract : High temperature testing of graphite/epoxy laminates and composite sandwich panels was performed while the Shuttle was on orbit to ...

Energy Technology Data Exchange (ETDEWEB)

The B-Factory which is constructed by National Laboratory for High Energy Physics is the device for elucidating the breakdown of symmetry of matter and antimatter by studying the behavior of B mesons which are generated in large quantity when the electrons and the positrons which are accelerated to light velocity level are collided. In order to maintain electron beam-positron beam bunch circling the ring at light velocity stably, the instability of the coupled bunch must be overcome. For this purpose, the ultrahigh speed beam position digital feedback control system was developed. This system is composed of the high speed input-output substrate using GaAs LSI, the feedback computation substrate using complementary metal oxide semiconductor and the memory mounted on it, and the real time operation device. The development of both substrates and their functions are explained. The real time data collection and the change of computation parameters ...

Energy Technology Data Exchange (ETDEWEB)

The 380 MW combined cycle gas turbine power station in Peterborough changed its water supply from town mains to high purity reverse osmosis permeate in October 2000. The high purity water is produced from secondary treated sewage effluent using advanced membrane technology. Alpheus Environmental and British Gas staff have recently completed a study of the power station's demineralization plant to identify the differences in operating costs associated with the change in feedwater. The results show that the ultrapure water produced after the change to a high purity feed is of improved quality and that the demineralization plant regeneration operating costs have been reduced by over 90%. The demineralization plant availability has increased from 78 to 98% enabling almost 20% more ultra pure water to be produced. The change in feedwater has also improved the local environment by significantly ...

International Nuclear Information System (INIS)

Else of solar energy as substitute for conventional fuels at a competitive cost requires efficient conversion from solar radiation to usable forms of energy. In solar thermal or thermochemical applications, high efficiency usually re- quires high temperature and high concentration of incoming radiation. The main form of energy loss from high temperature solar central receivers is thermal emission ('re radiation'), at an effective temperature close to the maximum receiver temperature. This loss is reduced if the aperture is divided into segments, most of which are maintained at lower temperatures. A two-stage partitioned receiver demonstrating this concept is under construction at the Weizman Solar Tower. The high-temperature stage is the DIAPR (Directly Irradiated Annular ...

Energy Technology Data Exchange (ETDEWEB)

The system study 'High Temperature Superconductivity (HTS) in power systems' lists the technical and economical advantages for power generation, transmission and distribution systems using components made of HTS material as seen in the light of current knowledge in the superconductivity area. This report lists the advantages of using high-temperature superconductivity in the power industry area and summarises the results obtained in various case studies on the subject.

International Nuclear Information System (INIS)

General corrosion behavior of ALLOY 800 in high temperature water was studied in relation to its surface film structure. The surface film formed in water was found to decrease the corrosion rate of ALLOY 800. This film is composed of Ni ferrite, and can be obtained by oxidation in air or steam. Based on these results, air or steam oxidation treatment to inhibit Ni and Co release of ALLOY 800 into high temperature water is proposed. (author).

International Nuclear Information System (INIS)

Ultra-low pure Pt-based electrodes (0.04-0.12 mg_P_t/cm"2) were prepared by dual ion-beam assisted deposition (dual IBAD) method on the surface of a non-catalyzed gas diffusion layer (GDL) substrate. Film thicknesses ranged between 250 and 750 A, these are compared with a control, a conventional Pt/C (1.0 mg_P_t_(_M_E_A_)/cm"2, E-TEK). The IBAD electrode constituted a significantly different morphology, where low density Pt deposits (largely amorphous) were formed with varying depths of penetration into the gas diffusion layer, exhibiting a gradual change towards increasing crystalline character (from 250 to 750 A). Mass specific power density of 0.297 g_P_t/kW is reported with 250 A IBAD deposit (0.04 mg_P_t/cm"2 for a total MEA loading of 0.08 mg_P_t/cm"2) at 0.65 V. This is contrasted with the commercial MEA with a loading of 1 mg_P_t_(_M_E_A_)/cm"2 where mass specific power density obtained was 1.18 g_P_t/kW (at 0.65 V), a value typical of current state of the ...

Energy Technology Data Exchange (ETDEWEB)

Graphite fluoride (CF{sub x}) is investigated as an additive for WS{sub 2} thin films to reduce its sensitivity to moisture. The films are grown onto hardened 440C stainless steel disks by pulsed laser deposition using the 248 nm line from an excimer laser. Substrate temperature and additive concentration are varied to control film chemistry and crystal structure. The effect of relative humidity (i.e., < 1 to 85% RH) on friction is evaluated. Coatings grown at RT from targets with a low concentration of CF{sub x} exhibit ultra-low friction (ULF) behavior in dry air (i.e., {mu} {<=} 0.01), but friction increases with RH. Mechanisms for the ULF behavior are proposed which suggest that further reductions in friction are possible. Films grown at 300 C or with higher concentrations of CF{sub x} are relatively insensitive to humidity, but have more typical friction coefficients ({mu} {<=} 0.04) in dry air. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Effect of strain rate, temperature and grain size in the climb-controlled dislocation creep region for AZ31 magnesium alloy was examined at lower temperature of {proportional_to}473 K. The flow stress was not affected by the difference in grain size. The strain rate sensitivity, m, was obtained 0.14 and 0.2 at low temperatures in high strain rate and at high temperature in low strain rate, respectively. It was found that the notion of effective diffusivity could express the dominant diffusion process during climb-controlled dislocation creep behavior uniquely. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Research and development has been performed on photochromic materials expected to be used in ultra-high density recording, high resolution indication and photoswitches. With regard to molecular orientation in the ternary system mixed LB film, the result of structural analysis by XPM spectrum revealed that the acceptor constituent in the LB film is so structured that it is separated and laminated with two other constituents, and that the sensitizer constituent and the donor constituent are not recognized of being separated definitely. Regarding the electron movement reaction in the solid phase system, a photo-current measuring experiment was carried out on the laminated film which is vacuum-deposited with the ternary system comprising of the donor, sensitizer, and acceptor. It was concluded that the observed photo-current reflects the electron movement reaction in the solid phase as it is. For the photo-current in the LB film, increase in the ...

Energy Technology Data Exchange (ETDEWEB)

This paper discussed the potential of biofuels with particular reference to the situation in Germany and Europe. Emphasis was on technical potential, such as biofuel production, utilization and environmental aspects. The Institute of Agricultural Technology and Biosystems Engineering ran vTI emission tests on diesel engines to evaluate the environmental impacts of biofuels. This testing facility is able to drive heavy-duty diesel engines in both stationary and dynamic test cycles, such as the European ESC and ETC. Additional analyses were conducted to determine the fine and ultra-fine particles, polycyclic aromatic hydrocarbons (PAH), aldehydes, ketones, and the usual regulated exhaust gas compounds. Ames tests were conducted to assess the mutagenic potential of tailpipe emissions. Previous study results showed that neat vegetable oils can render the exhaust high in mutagenic potency. Some of the non-regulated exhaust gas compounds were found ...

Energy Technology Data Exchange (ETDEWEB)

CuAg core-shell nanoparticles are synthesized by ultra-high vacuum thermal evaporation. We show on this system how the Energy-Filtered Transmission Electron Microscopy (EFTEM) technique allows one to improve the characterization by precisely pointing out the formation of core-shell arrangements in bimetallic nanoparticle assemblies. A criterion to measure the shell thickness from EFTEM images on unique core-shell nanoparticles is defined, that can be used for core-shell nanoparticles of any sizes, with shell thicknesses over 1 nm. It is based on the intensity variation along a line drawn across a core-shell nanoparticle on a EFTEM image. This criterion has been validated by a close comparison of the shell thickness measurements performed in this work and the ones obtained by acoustic micro-Raman spectroscopy. Using this criterion, we report a strong correlation between the size of the Cu cores and the formation of the core-shell arrangements in the nanoparticle ...

Energy Technology Data Exchange (ETDEWEB)

A method of preparing a high temperature superconductor from an amorphous phase. The method involves preparing a starting material of a composition of Bi.sub.2 Sr.sub.2 Ca.sub.3 Cu.sub.4 Ox or Bi.sub.2 Sr.sub.2 Ca.sub.4 Cu.sub.5 Ox, forming an amorphous phase of the composition and heat treating the amorphous phase for particular time and temperature ranges to achieve a single phase high temperature superconductor.

Science.gov (United States)

Molecular genetic markers can be used to identify quantitative trait loci (QTL) for thermal resistance and this has allowed characterization of a major QTL for knockdown resistance to high temperature in Drosophila melanogaster. The QTL showed trade-off associations with cold resistance under laboratory conditions. However, assays of thermal tolerance conducted in the laboratory may not necessarily reflect performance at varying temperatures in the field. Here we tested if lines with different genotypes in this QTL show different thermal performance under high and low temperatures in the field using a release recapture assay. We found that lines carrying the QTL genotype for high thermal tolerance were significantly better at locating resources in the field releases under hot temperatures while the QTL line carrying the contrasting genotype ...

Energy Technology Data Exchange (ETDEWEB)

Structural silicides have important high temperature applications in oxidizing and aggressive environments. Most prominent are MoSi{sub 2}-based materials, which are borderline ceramic-intermetallic compounds. MoSi{sub 2} single crystals exhibit macroscopic compressive ductility at temperatures below room temperature in some orientations. Polycrystalline MoSi{sub 2} possesses elevated temperature creep behavior which is highly sensitive to grain size. MoSi{sub 2}-Si{sub 3}N{sub 4} composites show an important combination of oxidation resistance, creep resistance, and low temperature fracture toughness. Current potential applications of MoSi{sub 2}-based materials include furnace heating elements, molten metal lances, industrial gas burners, aerospace turbine engine components, diesel engine glow plugs, and materials for glass processing.

International Nuclear Information System (INIS)

The service conditions for high-temperature heat-exchangers with helium coolant of HTGRs and requirements imposed on materials for their production are discussed. The choice of nickel-base alloys with solid-solution hardening for long-term service at high temperatures is grounded. Results of study on properties and structure of types Ni-25Cr-5W-5Mo and Ni-20Cr-20W alloy in the temperature range of 900 deg. - 1,000 deg. C are given. The ageing of Ni-25Cr-5W-5Mo alloy at 900 deg. - 950 deg. C results in decreased corrosion-mechanical properties and is caused by the change of structural metal stability. Alloy with 20% tungsten retains a high stability of both structure and properties after prolonged exposure in helium at above temperatures. The alloy has also increased resistance to delayed fracture and low-cycle fatigue at high ...

Energy Technology Data Exchange (ETDEWEB)

Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas after a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, more energetic photons of the x-ray ring, beryllium windows are ...

Energy Technology Data Exchange (ETDEWEB)

This paper investigates the dynamic recrystallization behavior of a directionally solidified (DS) nickel-base superalloy. The dynamic recrystallization occurs after the uncoated superalloy has been tested by tensile creep at elevated temperature for a long time. The dynamic recrystallization temperature is slightly lower than that of the static recrystallization. The dynamic recrystallization behavior of the DS superalloy below the static recrystallization temperature is mainly related to the high temperature oxidation and the free surface. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

British Library Electronic Table of Contents (United Kingdom)

Determination of the maximum temperature and temperature distribution along the rake face of the cutting tool is of particular importance because of its controlling influence on tool life, as well as, the quality of the machined part. Numerous attempts have been made to approach the problem with different methods including experimental, analytical and numerical analysis. Although considerable research effort has been made on the thermal problem in metal cutting, there is hardly a consensus on the basics principles. The unique tribological contact phenomenon, which occur in metal cutting is highly localized and non-linear, and occurs at high temperatures, high pressures and high strains. This has made it extremely difficult to predict in a precise manner or even assess the performance of va...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The lignite used for Phase I of the project was a Texas lignite from the Martin Lake mine obtained from the stockpile for the Martin Lake Power Plant of the Texas Utilities Generating Company. The power requirements for the fluid-energy mill were determined from the measured steam (or air) temperatures, pressures and pressure drops and the lignite flow rate. The instrument locations for the tests are shown on Figure 1. All of the instruments were connected to a microcomputer via an analog input interface board. Data were recorded on disks periodically throughout the tests. Appropriate calibration procedures were followed to assure that reliable data were being obtained. The combined grinding/drying tests were conducted in Vicksbuth, MS at Ergon, Inc.'s fluid-energy-mill facility. both steam and air were used as grinding fluids. With steam, tests were used as grinding fluids. With steam, tests were run with the following temperatures ...

Energy Technology Data Exchange (ETDEWEB)

A 2-stage cold (non-tritium) PMR system was tested with the ITER mix in61 days of continuous operation. No decrease in performance was observed over the duration of the test. Decontamination factor (DF) was found to increase with decreasing inlet rate. Decontamination factors in excess of 1.4 {times} 10{sup 5} were obtained, but the exact value of the highest DF could not be determined because of analysis limitations. Results of the 61-day test were used to design a 2-stage PMR system for use in tritium testing. The PMR system was scaled up by a factor of 6 and built into a glovebox in the Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory. This system is approximately 1/5th of the expected full ITER scale. The ITER mix was injected into the PMR system for 31 hours, during which 4.5 g of tritium were processed. The 1st stage had DF = 200 and the 2nd stage had DF = 2.9 {times} 10{sup 6}. The overall DF = 5.8 {times} 10{sup 8}, which is greater than ITER ...

Science.gov (United States)

The 10.3-h /sup 165/Er, decaying by electron capture to stable /sup 165/Ho, offers an excellent promise for use in diagnostic nuclear medicine, especially in conjuction with multiwire proportional-counter cameras. Using an ultra-high-resolution Si(Li) photon spectrometer, L and K x-ray photon yields in /sup 165/Er decay have been measured. The ratio P/sub L//P/sub K/ of electron-capture probabilities in L and K shells is determined to be 0.196 +- 0.030, in good agreement with theory. Estimates of Auger electron yields and yields of very-low-energy electrons from Coster--Kronig transitions are presented. Levels of /sup 169/Er and /sup 171/Er radioactive impurities in the reactor-produced /sup 165/Er sample are experimentally determined. Whole-body dose estimates for /sup 165/Er are given. These compare favorably with /sup 99/Tc dose.

International Nuclear Information System (INIS)

The main challenges for PMOS ultra shallow junction formation remain the transient enhanced diffusion (TED) and the solid solubility limit of boron in silicon. It has been demonstrated that low energy boron implantation and spike annealing are key in meeting the 90nm technology node ITRS requirements. To meet the 65nm technology requirements many studies have used fluorine co-implantation with boron and Si"+ or Ge"+ pre-amorphization (PAI) and spike annealing. Although using BF_2"+ can be attractive for its high throughput, self-amorphization and the presence of fluorine, many studies have shown that the fluorine successfully reduce TED, its energy needs to be well optimized with respect to the boron's, therefore BF_2"+ does not present the right fluorine/boron energy ratio for the optimum junction formation. In this work we optimize the fluorine energy for boron energies down to 200eV. We show the dependence of optimized junction on Ge"+ ...

International Nuclear Information System (INIS)

Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was #epsilon# #approx#7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

International Nuclear Information System (INIS)

Laser frequency stabilization giving a 500-Hz Allan deviation for a 2-ms integration time with drift reduced to 7 kHz/min over several minutes was achieved at 1536 nm in the optical communication band. A continuously regenerated spectral hole in the inhomogeneously broadened "4I_1_5_/_2(1)#->#"4I_1_3_/_2(1) optical absorption of an Er"3"+:Y_2SiO_5 crystal was used as the short-term frequency reference, while a variation on the locking technique allowed simultaneous use of the inhomogeneously broadened absorption line as a long-term reference. The reported frequency stability was achieved without vibration isolation. Spectral hole burning frequency stabilization provides ideal laser sources for high-resolution spectroscopy, real-time optical signal processing, and a range of applications requiring ultra-narrow-band light sources or coherent detection; the time scale for stability and the compatibility with spectral hole burning devices make ...

International Nuclear Information System (INIS)

Boron is implanted in crystalline silicon through oxide layers with different thicknesses. The implantation is carried out at various doses and energies of interest in ultra large scale integration (ULSI) application. Rapid thermal annealings (RTA) are used to obtain shallow junctions and electrical activation of the B atoms. However, transient enhanced diffusion induced by implantation damage can be observed. The boron concentration profiles before and after annealing are obtained with secondary ion mass spectrometry (SIMS). It is found that the diffusion transient in the tail region of the boron profile increases with decreasing oxide thickness. Even more, if the implantation damage concerns mostly the oxide, i.e. when the concentration peak is located in this oxide, the oxygen knocked into the silicon substrate could play this way an important role in restricting the boron diffusion, which is good to obtain very shallow junctions. On the other hand, for thinner ...

Energy Technology Data Exchange (ETDEWEB)

The global production of steel is predicted to increase rapidly to meet future demands. In order to conserve the natural resources, certain measures must be taken. These include perfecting the recycling of steel, improving the performance to extend the life of the material, and reduce the need for massive production of steel by increasing the strength of the material. This paper presented a design concept for ultrafine complex microstructure steel. The National Research Institute for Metals in Japan has worked on a project which investigated 800 MPa ferrite steel for welded structures with a chemical composition similar to 400 MPa-class plain carbon steel. The doubled strength was attributed to grain refinement. Novel welding techniques were also used for joining the ultrafine microstructure. In this study, low carbon Si-Mn ferrite-pearlite steels were subjected to a thermo-mechanical treatment to produce a microstructure of 1 micron order ultrafine grain ferrite plus finely dispersed ...

CERN Document Server

Present and future ultra-high-energy-cosmic-ray facilities (e.g., the Pierre Auger Observatory with South and North components) and TeV-gamma-ray telescope arrays (e.g., HESS/VERITAS and CTA) have the potential to set stringent indirect bounds on the nine Lorentz-violating parameters of nonbirefringent modified Maxwell theory minimally coupled to standard Dirac theory. Theoretically, the most interesting case is isotropic Lorentz violation, which is described by a single parameter [taken to vanish for the case of the standard Lorentz-invariant theory]. It appears possible to obtain in the future an upper (lower) indirect bound on this single isotropic Lorentz-violating parameter at the +10^{-21} (-10^{-17}) level. Comparison is made with existing and future direct bounds from laboratory experiments. The possible physics implications of upper bounds at the 10^{-21} level are also briefly discussed.

International Nuclear Information System (INIS)

We present an approach for fabrication of intentionally positioned epitaxial InAs QDs in a micron sized light emitting diode. For site-selective growth, a combination of molecular beam epitaxy (MBE) and focused ion beam (FIB) implantation technology in an all-ultra-high-vacuum (UHV) setup has been employed. Single dot occupancy of almost 55 % on FIB patterned nano-depressions was successfully achieved. Thereafter, carrier injection and subsequent radiative recombination from the positioned InAs/GaAs self-assembled QDs was investigated by embedding these QDs in the intrinsic part of a GaAs-based micron sized p-i-n junction device. Few or single dot are expected to be electrically addressed in these devices. We report results from electroluminescence (EL) measurement which proves the single dot characteristics of our device. The EL spectra consist of sharp emission lines and their dependence on injection current shows linear behavior for exciton and quadratic ...

British Library Electronic Table of Contents (United Kingdom)

Only 15mol% of l-proline in ethanol proved to be a very efficient catalyst for the one-pot synthesis of a wide variety of highly substituted pyridines at room temperature. The methodology is mild, efficient, high yielding, and the products can be directly recrystallized from hot ethanol.

Energy Technology Data Exchange (ETDEWEB)

Low transition temperature (low-{Tc}) and high-{Tc} Superconducting QUantum Interference Devices (SQUIDs) have been used to perform high-resolution magnetic measurements on samples whose temperatures are much higher than the operating temperatures of the devices. Part 1 of this work focuses on measurements of the rigidity of flux vortices in high-{Tc} superconductors using two low-{Tc} SQUIDs, one on either side of a thermally-insulated sample. The correlation between the signals of the SQUIDs is a direct measure of the extent of correlation between the movements of opposite ends of vortices. These measurements were conducted under the previously-unexplored experimental conditions of nominally-zero applied magnetic field, such that vortex-vortex interactions were unimportant, and with zero external current. At specific temperatures, the ...

Energy Technology Data Exchange (ETDEWEB)

To our knowledge, the fluorescence studies of lanthanides in LiCl-KCl eutectic molten salt at a high temperature are not reported yet. The fluorescence of the lanthanide-ions was generally decreased when the temperature was increased. Moreover, the fluorescence of the lanthanides was strong when the sample was solidified to or from the melt. The temperature, where the fluorescence was decreased, was identified to be different depending on the species of the lanthanides and the substrates was considered to possibly be from quenching of the fluorescence due to either the collisions of melted samples induced by high temperature media or the re-absorption of fluorescence by the samples. Several comparison experiments were performed to explain and understand this phenomenon and improve the fluorescence. In this way, an on-line monitoring of chemical species and the ...

Energy Technology Data Exchange (ETDEWEB)

The laminar incompressible hydrodynamically fully developed and thermally developing flow is studied in a curved square duct with four longitudinal fins. The duct is successively subjected to constant wall temperature, to circumferentially uniform temperature and axially linearly or exponentially varying temperature. The local and fully developed Nusselt numbers are examined for various values of the Dean number and it is found that the heat transfer rate increases for high fins. The parameters that affect the entry length are studied and the fluctuations of the local Nu that appear in the entrance region are investigated. Temperature contour plots are presented for the visualization of the temperature field and functional relations for the Nusselt number are proposed in terms of the Dean and Prandtl numbers. (orig.)

British Library Electronic Table of Contents (United Kingdom)

The effect of particle/matrix interface debonding on composites consisting of elastic particles and viscoelastic matrix is studied. The interface debonding is represented by a nonlinear cohesive law for the high explosive PBX 9501. The Mori-Tanaka method gives the constitutive relation of the composite in terms of the properties of elastic particles, viscoelastic matrix, and nonlinear cohesive law for interfaces. For the example of a composite with spherical particles subject to hydrostatic tension, simple analytical expressions of the composite stress-strain relation are obtained. The strain rate and temperature have strong effects on the composite behavior. High strain rate and low temperature give high strength of the composite. However, the rate and temperature effects decrease as the ...

International Nuclear Information System (INIS)

The A-15 compounds with the highest critical temperatures and critical fields are stable only at high temperatures and sometimes are not stable at any temperature. Fabrication of such materials thus necessarily involves the creation and manipulation of metastable phases. It follows that the bronze matrix technique now under development for Nb_3Sn- and V_3Ga-based composite superconductors is not suitable for high-T/sub c/ materials of the Nb_3 (Al, Ge, Ga, Si) family. Alternative technologies will be necessary for such materials. Efforts to develop suitable alternatives, using Nb_3Al, are described.

Science.gov (United States)

... The LVS bulk capacitance can be implemented using high temperature aluminum electrolytic capacitors with relatively low component volume. ...

Science.gov (United States)

Ti-Ag and Ti-Pd-Ag solar cell contacts structure and degradation dependence on high temperature and humidity environmental exposure

International Nuclear Information System (INIS)

A novel adhesive for carbon materials composed of phenol-formaldehyde resin, boron carbide and fumed silica, was prepared. The adhesive property of graphite joints bonded by the above adhesive treated at high-temperatures was tested. Results showed that the adhesive was found to have outstanding high-temperature bonding properties for graphite. The adhesive structure was dense and uniform even after the graphite joints were heat-treated at 1500 deg. C. Bonding strength was 17.1 MPa. The evolution of adhesive structure was investigated. The results indicated that the addition of the secondary additive, fumed silica, improved the bonding performance greatly. Borosilicate phase with better stability was formed during the heat-treatment process, and the volume shrinkage was restrained effectively, which was responsible for the satisfactory high-temperature bonding performance of graphite.

Energy Technology Data Exchange (ETDEWEB)

Short communication

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In this letter, examples of microstructural instabilities that can significantly affect the low crystal fatigue (LCF) life are pointed out.

International Nuclear Information System (INIS)

... Dozaki, Koji Takiguchi, Hideki Japan Atomic Power Company, Tokyo (Japan)

Energy Technology Data Exchange (ETDEWEB)

The absence of high-temperature electronics is an obstacle to the development of untapped energy resources (deep oil, gas and geothermal). US natural gas consumption is projected to grow from 22 trillion cubic feet per year (tcf) in 1999 to 34 tcf in 2020. Cumulatively this is 607 tcf of consumption by 2020, while recoverable reserves using current technology are 177 tcf. A significant portion of this shortfall may be met by tapping deep gas reservoirs. Tapping these reservoirs represents a significant technical challenge. At these depths, temperatures and pressures are very high and may require penetrating very hard rock. Logistics of supporting 6.1 km (20,000 ft) drill strings and the drilling processes are complex and expensive. At these depths up to 50% of the total drilling cost may be in the last 10% of the well depth. Thus, as wells go deeper it is increasingly important that drillers are able to monitor conditions ...

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The amorphization of a quenched sample of the GaSb-II high-pressure phase was studied at ambient pressure by real-time neutron diffraction in the course of the sample heating from 100 K to room temperature at a rate of 0.4 K min{sup -1}. The transformation to the amorphous state begins at 140 K and is completed near room temperature. The {beta}-Sn type structure was shown to represent only the mean lattice of the high-pressure GaSb-II phase. The superstructure of this phase widely varied with temperature and is caused by the ordered displacement of atoms. The temperature range of the metastable crystalline phase relaxation is divided into three intervals according to the temperature dependence of the tetragonality ratio (c/a). At the boundaries of these temperature intervals, i.e. temperatures T = ...

International Nuclear Information System (INIS)

The inverse susceptibilities of the monopnictides and monochalcogenides of the light rare earths plotted vs. temperature flatten off at high temperatures. This behaviour is well explained by van Vleck paramagnetism of the excited states of the multiplet. For almost all actinide pnictides and chalcogenides a similar flattening-off is observed. Since spin orbit coupling is much stronger than in the light rare earth compounds an analogous interpretation is not possible. Susceptibility curves for uranium compounds can be fitted by adding a temperature dependent enhanced Pauli paramagnetism to the Curie-Weiss term (modified Curie-Weiss law). The high temperature susceptibility behaviour of neptunium compounds is very similar to uranium compounds i.e. an appreciable deviation from the Curie-Weiss law is only visible for the chalcogenides. The plutonium chalcogenides ...

Energy Technology Data Exchange (ETDEWEB)

A new characteristics temperature, an adiabatic limit flame temperature, was proposed as the basis to evaluate an effective energy emission and to examine a self combustion limit. Its characteristics were discussed using the reaction system between diatomic molecules as an example, and the low calorific limit of flammability was also discussed. Since the adiabatic limit flame temperature was the inherent temperature of a combustible mixture based on the thermochemical properties of constituents, it was, in particular, very important as considering a combustion system with energy recirculation between products and reactants. The available energy and efficiency of the combustion system should have been estimated on the basis of this temperature, instead of on an adiabatic flame temperature. It was also considerably high even in an extremely ...

UK PubMed Central (United Kingdom)

The presence of highly heat-resistant spores of Bacillus sporothermodurans in ultrahigh-temperature or sterilized consumer milk has emerged as an important item in the dairy industry....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In the context of the research project, the physical basis of the direct decoupling of highly concentrated solar radiation in materials without the detour via absorbing heat exchanger walls was examined. Also, the first chemical processes suitable for the effective long-term storage of solar energy were analysed, relevant experiments were carried out and the necessary receiver techniques for high temperature applications were provided. The principle of direct coupling was examined on fluidized beds on the one hand and on cavity receivers, on the other hand. The contribution shows the results achieved in detail. It is recorded that first processes for storing solar energy in chemical reactions were able to be examined. Alkaline earth hydroxides accommodated in ceramic honeycomb structures seem to be possible as stores for medium temperature ranges around 500deg C. Investigations on receiver structure ...

Science.gov (United States)

It is suggested that the large reduction of the superconducting transition temperature Tc due to defects observed experimentally in some A-15 compounds is caused by smearing of a high peak in the density of states at the Fermi level. The influence of defects on other physical properties (the magnetic susceptibility ?, the elastic modulus Cs, the structural transformation temperature Tm and the electrical resistivity ?) is also discussed from the same point of view. We expect the anomalous temperature dependence of ?, Cs and ? will be suppressed by defects.

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Carbide reactions occurring in a precipitation-hardening gamma/gamma-prime Ni-Cr alloy during prolonged high-temperature aging are investigated experimentally. It is found that the decomposition of primary MC carbides, which is accompanied by the precipitation of M23C6 particles, may lead to void nucleation and growth. The effect of carbide transformations on the residual properties of the material at temperatures above the equicohesion temperature is observed at the late stages of aging only. 6 references.

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Since the very high temperature reactor (VHTR) components such as hot gas ducts and intermediate heat exchanger (IHX) are operated during a design life of 30 to 60 years at 950 .deg. C and 3-8MPa in He impurities, their components are required to have good high temperature strength, creep-rupture strength, high temperature stability, and good corrosion resistance. Among them, creep properties are the most important, because the integrity of their components should be preserved during a design life of over 30 years at the maximum operating temperature up to 1000 .deg. C. So far, there are no materials approved by ASME III which is a nuclear code for temperatures reaching 1000 .deg. C, and until now, a material selection is still left as a key issue. Some leading candidate alloys can be selected from the ...

Energy Technology Data Exchange (ETDEWEB)

An experimental and modelling study was performed for a reverse flow catalytic converter attached to a natural gas/diesel dual fuel engine. The catalytic converter had a segmented ceramic monolith honeycomb substrate and a catalytic washcoat containing a predominantly palladium catalyst. A one-dimensional single channel model was used to simulate the operation of the converter. The kinetics of the CO and methane oxidation followed first-order behaviour. The activation energy for the oxidation of methane showed a change with temperature, dropping from a value of 129 to 35 kJ/mol at a temperature of 874 K. The reverse flow converter was able to achieve high reactor temperature under conditions of low inlet gas temperature, provided that the initial reactor temperature was sufficiently high. (author)

International Nuclear Information System (INIS)

High temperature deformation behavior of an alpha + beta titanium alloy Ti-3Al-2.5V has been investigated in the temperature range 830 deg. C to 910 deg. C by using the method of cross head speed cycling. On the basis of flow stress-strain rate and strain rate sensitivity data, it was found that the alloy exhibits a hardening effect in the entire temperature range studied, amount of hardening being significant at the highest test temperature of 910 deg. C which resulted in a degradation of superplastic properties of the alloy. Grain growth in beta-phase due to strain was considered responsible for the hardening effect observed.

British Library Electronic Table of Contents (United Kingdom)

Abstract Dynamic testing of a phosphoric acid-based high temperature PEM fuel cell shows a peculiar phenomenon. A certain current loss is observed after temperature cycling at constant voltage. This loss is incidentally recovered by applying a cell voltage spike to open circuit voltage. Experimental investigations into temperature, cell voltage, and ageing effects show that this phenomenon might occur due to the orientation of the adsorbed phosphate species on the platinum catalyst surface. Along with some supporting literature and experimental results, a hypothesis is presented in order to explain this occurrence. Phosphoric acid adsorption hysteresis on platinum catalyst due to temperature cycling could cause the temporary cell current loss. Electrode potential-dependent molecule symmetr...

International Nuclear Information System (INIS)

The interrelationship between the testing temperature and HfC strength increment of an arc-melted W-3.6Re-0.4HfC was determined from 1950 K to 2980 K in a vacuum of better than 1.3x10"-"5 Pa (10"-"7 torr). The present research was focused on the characteristic temperature at which the rapid coarsening of HfC particles occurred and the effect of the second-phase particle size on the high temperature strength properties of this material. It was found that the HfC particle strengthening was effective in a W-Re matrix up to a characteristic temperature of 2450 K in the short-term tensile test. Carbon was found to be the rate-limiting solute in the HfC particle growth. The strength of HfC strengthened alloy at temperature above 0.5 T_m is proportional to the square root of particle volume fraction. The yield strengths of W-3.6Re-0.26HfC calculated based on the ...

Energy Technology Data Exchange (ETDEWEB)

The high-temperature enthalpy increments of the phosphates La{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3}, Nd{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3}, Eu{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} and Lu{sub 1/3}Zr{sub 2}(PO{sub 4}){sub 3} have been measured by high-temperature drop calorimetry in the temperature range 484.5-1090.7 K. From these results the heat capacity of the studied compounds has been derived.

International Nuclear Information System (INIS)

Passive films formed on Alloy 690 in high-temperature alkaline environments were investigated by potentiodynamic polarization, X-ray photoelectron spectroscopy, transmission electron microscopy and Mott-Schottky approach. Passive current density and donor density of the passive films increase with increasing temperature, due to increased diffusion rates of metallic ions and dehydration of hydroxide phases. The passive films show a duplex structure including an inner layer of fine-grained Cr oxide or spinel oxide and an outer layer of Ni-Fe spinel oxide and Ni hydroxide. A growth model of the passive films on Alloy 690 in high-temperature alkaline environments is proposed and discussed.

Science.gov (United States)

In this paper we consider the adsorption of argon on the surface of graphitized thermal carbon black and in slit pores at temperatures ranging from subcritical to supercritical conditions by the method of grand canonical Monte Carlo simulation. Attention is paid to the variation of the adsorbed density when the temperature crosses the critical point. The behavior of the adsorbed density versus pressure (bulk density) shows interesting behavior at temperatures in the vicinity of and those above the critical point and also at extremely high pressures. Isotherms at temperatures greater than the critical temperature exhibit a clear maximum, and near the critical temperature this maximum is a very sharp spike. Under the supercritical conditions and very high pressure the excess of adsorbed density decreases towards zero value ...

International Nuclear Information System (INIS)

Structural instabilities are now being found in many high-temperature superconductors. Compounds with the A-15 (#beta#-W) structure comprise the most important group of these materials, and their properties have been extensively studied for over 15 years. A review is given of some of these results, particularly those relating to the elastic behavior. The empirical relation of the structural instability and the anharmonicity to the high superconducting transition temperature is discussed.

Energy Technology Data Exchange (ETDEWEB)

Research continued on low severity coal liquefaction. Research using high temperature infrared of cyclic olefins progressed well during this quarter. Several fluorinated solvents were found that provide a high temperature medium for isotetralin and its aromatic and aliphatic analogues.

International Nuclear Information System (INIS)

Investigated are the characteristics of high-temperature plastic deformation the velocity sensitivity of flow stresses, deformation curves, flow stresses, deformation before rupture - as well as the structure of beryllium alloys containing nickel (0.5-4 %), yttrium (0.5-2 %) and aluminium (38 %). The alloys containing nickel (2%) and yttrium (0.5 %) are superplastic, however, deformation before fracture of the alloys is lower than that of the unalloyed beryllium. The singularities of high-temperature plastic flow of the alloys and the causes of deterioration of their plasticity are determined.

International Nuclear Information System (INIS)

The heat transfer augmentation is reviewed in view of high temperature heat exchangers illuminating the contribution of radiative heat transfer. A number of means and/or devices are presented as well as the sophisticated concept which will be promoted to the extended applications in matured industries such as iron and steel, oir refinery, petro-chemical. It should be emphasized that the more creative and innovatory technology has to be promoted in order to stimulate and refresh the foregoing industries, recognizing the increasing importance of the energy resources.

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence analysis was used for the determination of Cu, Y and Ba in very thin high-temperature superconducting films. The precision of the method is better than 3% for about 1 #mu#m thick films. The atomic emission ICP spectrometry was used to testify results of XRF analysis. An acceptable agreement of both methods was obtained. (author) 4 refs.; 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

Results are described of the study of the analytical applicability of a highly efficient ion source developed for a mass spectrometer. Its ionizer is in the form of a partially closed cavity with a small aperture for leading out ions, heated to a high temperature. The new ion source increases the sensitivity of the apparatus in operations with transuranium elements by almost two orders of magnitude. It is possible to perform isotopic analyses with a high salt content in the sample, and to study the characteristics of nuclear fuel, even without chemical separation of the sample elements.

International Nuclear Information System (INIS)

The procedure of charge-coupled devices (CCD) are investigated by using MOS capacitors for enhancing their ionizing radiation tolerance. Authors have found that the gate oxidation temperature, thickness of SiO_2 gate insulator and high temperature processes after gate oxidation are crucial for determining the radiation tolerance of the devices, and proposed to decrease the thickness of gate insulator, perform gate oxidation at 1000 deg C by means of dry oxidation and minimize the number of high temperature procedure steps after gate oxidation. All stated above is a necessary preparation for priducing radiation hardened charge-coupled devices.

Energy Technology Data Exchange (ETDEWEB)

A cellular membrane exchanges substances into and from the cell and protects the cell interior by maintaining semi-fluidity rather than be being solid. It is known that microorganisms maintain the fluidity in correspondence with varying environmental temperatures by changing and adjusting the composition of fatty acids which constitute the cellular membrane lipids. As part of the studies to elucidate the pressure withstanding mechanism in deep-sea bacteria, this paper investigates what variations the fatty acid composition, which constitutes cellular membranes of the DSS12 strain, a pressure withstanding bacterium growing well under either normal pressure or high pressures, will show under different culturing temperatures and pressures. Culture under low temperatures and culture under high pressures increase content of unsaturated fatty acids including icosapentanoic acid. Culture ...

Energy Technology Data Exchange (ETDEWEB)

Weldability and high temperature strength properties of Hastelloy Alloy XR were investigated in order to evaluate the materials performance of base metal and filler metal for the High Temperature Engineering Test Reactor (HTTR) uses. The weldability was examined by means of the chemical analysis in the deposited metals, optical microscopy, FISCO test, hardness measurements and bend test. The high temperature strength properties were investigated through tensile tests at R.T., 800, 900 and 950degC in air, and creep and creep rupture tests at 900 and 950degC in air. The results obtained by each test showed favorable performance. In particular, the bend test which is considered to be critical pass demonstrated low susceptibility to weld cracking through the optimization of B and C contents in the filler metal and by narrowing the groove. Creep rupture strength was ...

British Library Electronic Table of Contents (United Kingdom)

In order to provide pigs a comfortable sleeping area in hot weather, a floor cooling system was designed and applied to production buildings. Experiments were conducted to compare the floor temperatures and to observe the lying behaviour of pigs in the sleeping area of the buildings with and without floor cooling system. The results showed that, without the floor cooling system, the floor temperature was nearly the same as the air temperature in the open pig house. With the floor cooling system, the floor temperature of the sleeping area was controlled at 22-26degreeC, even though the air temperature was as high as 34degreeC, which improved the comfort of the pigs in the sleeping area. The pig lying behaviour was greatly affected by the floor temperature. More than 85% of the pigs were lyi...

British Library Electronic Table of Contents (United Kingdom)

Concrete is the primary material for building envelopes in some parts of the world, and its ability to store heat as well as its dynamic temperature changes will not only affect the deterioration rate of the exterior wall but will also greatly influence the energy efficiency of interior air conditioning. There are many methods for measuring the inner temperature of concrete, but they often have limitations, such as indirect estimation, cable installation requirements, high cost, or heterogeneity of the sample structure. In order to measure the internal temperature of concrete, this study integrated a Radio Frequency Integrated Circuit (RFIC) with a temperature sensor chip and embedded the device in concrete structures. A Smart Temperature Information Material (STIM) was thus developed. Thi...

Energy Technology Data Exchange (ETDEWEB)

Gasification and hydrogenation are the two basic routes for coal processing. Accounts are given of various low-temperature processes in coal gasification route A: air separation, removal of sour gas by the Rectisol process, liquid nitrogen washing, the material balance and utility consumption of these processes, plus low-temperature gas separation, partial condensation and methane washing. There are also accounts of the low-temperature processes involved in gasification route B: i.e., in the indirect coal liquefaction and direct liquefaction carried out in the Sasol II and III processes. (3 refs.) (In Japanese)

Energy Technology Data Exchange (ETDEWEB)

Even though the currently intensive research efforts on high- temperature superconducting materials have not yet converged on a well specified practical material, the indications are that such a material may be quite brittle, anisotropic, and may contain many flaws such as microcracks and voids at grain boundaries. Consequently, practical applications of high temperature superconducting materials will require a very careful strength analysis based on fracture mechanics considerations. Because of the high sensitivity of the strength of such materials to the presence of defects, methods of quantitative non-destructive evaluation may be expected to play an important role in strength determinations. This proposal is concerned with the use of ultrasonic methods to detect and characterize isolated cracks, clusters of microcracks and microcracks distributed throughout the material. ...

Energy Technology Data Exchange (ETDEWEB)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the absorber. With this arrangement, a high ...

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This paper describes the experimental results of long-life solid lubricated ball bearings tested under high-vacuum of 10 exp -4 Pa, high-temperature of 300 C, and high-speed (9000 rpm) conditions. For full ball-type bearings, the thin soft metals, either Ag or Pb, which were coated on the races and balls, appeared to have good torque properties. However, the durability of such bearings was less than 300 hours. The transfer films from the lamellar solid MoS2 and metal composite retainers improved the torque and wear properties. For ceramic, i.e., silicon nitride, balls used with steel rings, wear occurred on the inner rings. All ceramic bearings with composite retainers showed improved torque and wear properties. 18 refs.

International Nuclear Information System (INIS)

The determination of the oxidation state of ultra-trace elements in the environment, especially in the case of actinides, is of importance in many ways. Speciation techniques using radiation may comprise methods based on the detection of the nuclear and atomic radiations emitted in radioactive decay or methods using external sources of excitation. In the former instance, information can be obtained from the energy and intensity of radiation, but at present the partition method is still the most commonly used, although its reliability is questionable. Excitation with intense laser beams, as is currently being used for trace element analysis in photoacoustic and thermal lensing spectroscopic techniques, could conceivably be applied under suitable conditions to ultra-trace elements with a sensitivity approaching that of the radiochemical methods.

International Nuclear Information System (INIS)

Hazardous UV-radiation and short-wavelength visible (blue) light is emitted by the high temperature plasma above the welding-keyhole. Ozone and NO_x is produced due to UV-induced photodissociation of oxygen and high temperature gas-phase reactions. Spectral measurements of the plasma emission show that the allowed dose for UV-radiation and blue light exposure per work day can be exceeded in as short as a few seconds. Similarly, measurements and models of the ozone and NO_x concentration show that the maximum workplace concentrations might be reached quickly if no appropriate exhaust and filter system is installed. (author)

International Nuclear Information System (INIS)

A powder mixture of #alpha#-Si_3N_4, Al_2O_3, and TiO_2 was hot-pressed using different sintering cycles to search for an optimum in situ formed #beta#-O-sialon-TiN composite. The impulse excitation technique (IET), high-temperature X-ray diffraction (HTXRD), and scanning electron microscopy (SEM) were used to investigate the microstructure. Below the temperature of 1300 deg. C, the high-temperature internal friction (Q "-"1) decreases with the increase of sintering temperature, whereas the density of the material increases with the increase of sintering temperature. At a sintering temperature higher than 1850 deg. C, the ceramic could not be densified and O-sialon was not formed. Also, the mechanical properties of ceramics hot-pressed using different sintering cycles were assessed. The ceramic hot-pressed at 1700 deg. C for 10 min displays a combination of ...

Energy Technology Data Exchange (ETDEWEB)

In an attempt to establish a relationship between proton pumping and the photocycle intermediates of bacteriorhodopsin, we have studied the effects of pH and temperature of flash-induced proton pumping and the photointermediates O/sub 640/ and M/sub 412/. The relative quantum yield of flash-induced proton pumping is both pH and temperature dependent. It is high in the acid pH range and at low temperatures but decreases in the basic pH range and at high temperatures. The decay of M/sub 412/ is biphasic. The amplitude of the slowly decaying component (M/sup s/) was found to be pH dependent with a pK similar to that of the ..delta..pH. The pH dependence of the fast-decaying component (M/sup f/) is opposite to that of M/sup s/ and ..delta..pH. Like that of M/sup s/, the amplitude of O/sub 640/ is high in the acid pH range, but unlike the ...

Energy Technology Data Exchange (ETDEWEB)

Pitting behavior of alloy 800 was investigated as a function of temperature and prefilming in high-temperature water. The behavior was characterized in terms of pitting potential (U{sub p}) and pit density (n{sub p}). U{sub p} decreased with increasing temperature and chloride activity. Prefilming of test coupons over a period between 100 h and 5,000 h in ammoniated water at 300 C had no apparent influence on U{sub p} at room temperature, 180 C, and 300 C. However, the number of pits in prefilmed coupons was much higher than in coupons covered with an air passive layer. The effect of prefilming on pit nucleation was investigated in detail with regard to a model and test methods developed by Bianchi, et al. Density of pits in prefilmed coupons was at least 1 order of magnitude higher than in air passive coupons. Maximum pit density was measured after a prefilming period of 100 h. The effect was discussed ...

International Nuclear Information System (INIS)

As a hardening process, the attractiveness of nitriding lies in its low treatment temperature. Although the thickness of the case is less than that obtained by higher temperature processes such as carburising, there are a range of alloys and applications for which nitriding is the only possible alternative. Indeed, there are some alloys and applications for which even the normal nitriding temperatures (between 500 deg C and 600 deg C for ferrous alloys) are too high. In this paper, we report on developments, specifically the use of low pressure plasmas and high energy ion bombardment, which can extend the benefits of nitriding to lower temperatures. In this poster, we will present results from these collaborative projects, concentrating on the nitriding of austenitic stainless steel at temperatures below 450 deg C. In this ...

International Nuclear Information System (INIS)

Hydrogen is a potential alternative energy source and produced commercially by methane (natural gas) or LPG steam reforming, a process that requires high temperatures, which are produced by burning fossil fuels. However, since this process emits large amounts of CO_2, replacement of the combustion heat source with a nuclear heat source for 773-1173 K processes has been proposed in order to eliminate these CO_2 emissions. This paper proposes a novel method of low-temperature nuclear hydrogen production by reforming dimethyl ether (DME) with steam produced by a low-temperature nuclear reactor at about 573 K. The authors identified conditions that provide high hydrogen production fraction at low pressure and temperatures of about 523-573 K. By setting this low-temperature hydrogen production process at about 573K upstream from a turbine, it was ...

Energy Technology Data Exchange (ETDEWEB)

A-15 compounds are extremely brittle and difficult to process for practical applications. A novel processing technique was developed to greatly improve the mechanical and superconducting properties of A-15 alloys. The new processing technique can be described as follows: (1) to select compounds that can form the A-15 phase (the selected A-15 compounds in this research were Ti3Nb6Mo3Si4 and Nb99.5-(x + y)AlxSiyB0.5 alloys); (2) to rapidly solidify them into the amorphous state; (3) to anneal the quenched amorphous products into ultra fine-grained single A-15 phase. The extreme grain refinement greatly improved the flexibility and the critical current density of the alloys. The melt spinning technique was used to rapidly solidify Ti3Nb6Mo3Si4 and Nb99.5-(x + y)AlxSiyB0.5 alloys. Ti3Nb6Mo3Si4 alloys were relatively easily formed into the amorphous state. Nb3Al alloys required the addition of glass forming elements Si and B. It was found that, without boron, the ...

Energy Technology Data Exchange (ETDEWEB)

Surface analytical studies of high nitrogen austenitic stainless steels exposed to deaerated 0.1M HCl have revealed that nitrogen alloying additions influence the composition of salt layers and the passive film/alloy interface. In this study the authors employ electrochemical techniques and variable angle X-ray Photoelectron Spectroscopy (XPS) to examine the passive films formed on a series of austenitic stainless steels, Fe18Cr8Ni, Fe18Cr8Ni0.2N, Fe20Cr20Ni, Fe20Cr20Ni6Mo and Fe20Cr20Ni6Mo0.2N, in acidic chloride aqueous solution. In addition, several other model alloys, Fe19Cr, Fe19Cr9Ni, Fe19Cr2.5Mo, and Fe19Cr9Ni2.5Mo, were examined before and after electrochemical surface nitriding, a technique proven to have an effect analogous to N alloying. It was shown that nitrogen, nickel and molybdenum additions independently and in certain combinations stimulate selective dissolution of iron, resulting in a significant enrichment of chromium beneath the passive film. ...

Energy Technology Data Exchange (ETDEWEB)

This article described a full-scale green renovation project undertaken by a construction management firm in Newton, Massachusetts. Chapman Construction and Design began renovating its own office building in late 2007 and completed it in September 2008. The firm set out to achieve LEED Platinum certification from the United States Green Building Council. The project involved energy saving modifications to its mechanical systems; replacing plumbing fixtures with high efficiency alternatives to reduce water consumption by at least 40 per cent; installing skylights and additional windows to allow more natural light into the interior space; salvaging doors, lighting, metal studs and masonry whenever possible; and using sustainable products such as recyclable carpets, tiles and low-VOC paint. The main feature of the renovation was a new 47 kW (DC) photovoltaic (PV) solar power array installed on the rooftop. The PV array includes 208 panels and a SunPower SPR-225 system ...

Science.gov (United States)

Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists' capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically, awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted light-emitting diode (LED), tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the extended illumination periods often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 g ...

Energy Technology Data Exchange (ETDEWEB)

La{sub 1-x}Sr{sub x}MnO{sub 3} (LSMO) compounds (0.175{<=}x{<=}0.30) were prepared by conventional solid-state reaction method. Temperature dependence of the total hemispherical emittance ({epsilon}{sub H}) of the compounds from 173 to 373 K was measured on a calorimetric emissometer (CE) which was constructed based on the steady-state calorimetric method. The compounds show thermochromic properties and {epsilon}{sub H}'s have low value at low temperature and have high value at high temperature, because the compounds are dominated by metallic phase and insulator phase, respectively. We use the phase separation model to interpret the temperature dependence of {epsilon}{sub H}. (author)

Energy Technology Data Exchange (ETDEWEB)

Investigations of dislocation structure and mechanical properties of iron after rolling deformation in shaped rolls and after hydroextrusion are conducted. It is shown that dislocation iron structure slightly changes with deformation degree after rolling in shaped rolls and annealing and it is characterized by low density of screw dislocations. Cold brittleness temperature decreases in the result of rolling and the succeeding recrystallization and impact strength increases both at room temperature and at low temperatures. Screw dislocations having high Peierls barrier prevail in the structure after hydroextrusions. The iron deformed by hydroextrusion at 400 mPa and higher after annealing has high cold brittleness temperature and low impact strength.

International Nuclear Information System (INIS)

In the electrorefining step of the pyrochemical process, actinide ions dissolved in the LiCl-KCl eutectic salt are recovered as pure actinide metals at a cathode for a re-use as a nuclear fuel from the aspect of its nonproliferation of the nuclear fuel cycles. The lanthanide species dissolved in the LiCl-KCl eutectic salt play an important role in an effective metal purification during the electrorefining step, so it is necessary to understand the chemical and physical behaviors of lanthanides in molten salt. The in situ spectroscopic measurement system and studies according to temperature changes are essential for better understandable information. To our knowledge, the absorption studies of lanthanides at high temperatures have been reported before, but the fluorescence studies of those at high temperature are not reported yet. We will discuss here the fluorescence behaviors of ...

Energy Technology Data Exchange (ETDEWEB)

The thermophotovoltaic (TPV) option was not selected for further deep space mission technology development in NASA for several reasons. Chief among them was the large radiator required to keep the photovoltaic cells at a sufficiently low operating temperature. This led to significant integration problems with the spacecraft and limited sensor view angles. It is clear that the issue of cell temperature is crucial for space applications because of radiator size and system impact. Many efforts have focused on matching cell band gap to appropriate emitters in the 1 to 2 {mu}m range, resulting in band gaps in the 0.5 to 0.8 eV range. However, low band gaps lead to low open circuit voltages ({approximately}0.25 to 0.45 V) caused by high intrinsic carrier concentrations (n{sub i}{sup 2}). Thus, in order to obtain high performance. Photovoltaic cell temperatures must be kept near room ...

International Nuclear Information System (INIS)

Engineering details of a high voltage driven corona-plasma ozone generator are described. The plasma diode of generator has coaxial cylindrical geometry with cathode located inside anode. Cathode is made of a large number of radial gas nozzles arranged on central tubular mast which admits oxygen gas. The sharp endings of the nozzles along with a set of corona rings create the high electric field at the cathode required for formation of dense corona plume responsible for O_3 evolution. A model of coronal plasma generation and ozone production is presented. The plasma formation is strongly dependent on the electric field and temperature in side diode where a high electron density in a low temperature negative corona is suited for high ozone yields. These are established by suitable regulation of A-K gap, voltage, oxygen pressure, and cathode-nozzle population.

Energy Technology Data Exchange (ETDEWEB)

With regard to long-term high-temperature strength, molybdenum is an effective alloying element but rather expensive as well. The author describes its influence on high-temperature strength properties of CrMoV alloyed steel. Besides molybdenum, also vanadium and carbon have an increasing effect on limiting rupture stress which furthermore may be effected by heat treatment, the cooling rate being a dominating factor in this process. To guarantee optimum long-term high-temperature strength properties, a minimum of a least 0.5% Mo and 0.35% V is required. The cooling rate after austentizing must be high enough to enable transformation in the bainitic structure to take place. A two-to-three-hour tempering treatment at about 720/sup 0/C is regarded as an optimum.

UK PubMed Central (United Kingdom)

BackgroundMimivirus, a giant dsDNA virus infecting Acanthamoeba, is the prototype of the mimiviridae family, the latest addition to the family of the nucleocytoplasmic...Full Text Available

International Nuclear Information System (INIS)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd_2Si_2 have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd_2Si_2 is Curie-Wiess-like along the c axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

Energy Technology Data Exchange (ETDEWEB)

Titanium diboride was heated to high temperatures using microwaves. The highest temperature obtained was 2245/degree/C. Unfortunately, oxidation was a problem, especially at the higher temperatures, although an argon flush and a carbon getter were used. To completely stop oxidation, the oxygen potential must be below 10/sup /minus/18/ atmospheres. Using an argon flush and a carbon getter, titanium diboride was successfully densified to 82% of theoretical without measurable oxidation by heating with microwaves to 1860/degree/C. Density actually decreased upon reaching temperatures above 1860/degree/C due to void formation adjacent to the surface. Void formation is thought to be due to the formation of B/sub 2/O/sub 3/(g) which evolves rapidly above 1860/degree/C because of the loss of a TiO/sub 2/ protective film which melts at this temperature. 9 refs., 12 ...

Energy Technology Data Exchange (ETDEWEB)

Microwave-hydrothermal processing was compared with conventional hydrothermal processing in the crystallization of hematite from 1M ferric nitrate and hydroxyapatite from calcium oxide and phosphoric acid. Microwave-hydrothermal processing led to the crystallization of hematite while convention-hydrothermal process led to the crystallization of a mixture of goethite and hematite under the same temperature conditions. Thus the crystallization of hematite which is the stable iron oxide phase at high temperatures has been catalyzed by microwaves. Microwave-hydrothermal processing also led to highly crystalline hydroxyapatite powders compared to the conventional hydrothermal processing which also points to the catalytic role of microwaves. The microwave induced effects may be attributed to the generation of localized high temperatures at the reaction sites which ...

Energy Technology Data Exchange (ETDEWEB)

This paper summarizes the current scientific evidence that improved indoor environmental quality can improve work performance and health. The review indicates that work and school work performance is affected by indoor temperature and ventilation rate. Pollutant source removal can sometimes improve work performance. Based on formal statistical analyses of existing research results, quantitative relationships are provided for the linkages of work performance with indoor temperature and outdoor air ventilation rate. The review also indicates that improved health and related financial savings are obtainable from reduced indoor tobacco smoking, prevention and remediation of building dampness, and increased ventilation. Example cost-benefit analyses indicate that many measures to improve indoor temperature control and increase ventilation rates will be highly cost effective, with benefit-cost ratios as ...

Energy Technology Data Exchange (ETDEWEB)

The effects of boron addition on weldability and high temperature strength properties were investigated for Hastelloy alloy XR used TIG welding process with the filler metals. Four versions of filler metals with different boron contents were used. The results obtained may be summarized as follows: (1) The influence of boron addition on weldability was not observed within the range of the present experiment. (2) The result of chemical analysis for deposited metals showed that boron desorption did not occur during welding. (3) The tensile properties of weldments, particularly in high temperature ductility were raised with increasing boron content. (4) In the creep properties of weldments, creep rupture life increased with increasing boron content under the given stress conditions. (author).

Energy Technology Data Exchange (ETDEWEB)

To apply the CO{sub 2} absorber at about 1000{sup o}C for integrated coal gasification combined cycle (IGCC) furnace, the reactions of calcium oxide and CO{sub 2} at high temperatures was examined. Calcium carbonate reacts with sodium hydrogen carbonate below 200{sup o}C and forms sodium-calcium complex carbonate. The sodium-calcium complex carbonate melts at 813{sup o}C, and the carbon dioxide absorption and discharge reversible reactions of calcium-oxide takes place via liquid at around 1000{sup o}C. Sintering of calcium oxide at high temperature has been successfully avoided by the addition of sodium.

International Nuclear Information System (INIS)

Recent two major topics of Large Helical Device (LHD) towards fusion relevant conditions, high-density operation and high-ion-temperature operation, are reported. Super dense core plasma was obtained by the combination of repetitive hydrogen ice pellet injection and high power neutral beam injection (NBI) heating. A very peaked density profile with the highest central density of 1.1x1021 m-3 was produced showing that the particle transport was suppressed very well in the plasma core. The spatial density varies as the position of magnetic axis (Rax), and the steepest profile is obtained at Rax=3.95 m. The highest central ion temperature of 5.6 keV was obtained in hydrogen plasma at electron density of 1.6 x 1019 m-3 by NBI, where a peaked ion-temperature profile with internal ion energy transport barrier was observed. The profile of electron temperature did not ...

International Nuclear Information System (INIS)

The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. The 15"t"h Plansee Seminar was convened under the general theme 'Powder Metallurgy High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (boteke)

Energy Technology Data Exchange (ETDEWEB)

Qualifying corrosion inhibitors for use in high velocity multiphase flowlines in arctic or subsea environments is discussed. The tests include high velocity flow loop corrosion tests, pumpability through 0.125 (0.318 cm) inch capillary at low temperatures, compatibility with Nylon 11, emulsion tendency testing, and partitioning characteristics. Laboratory and field data show the importance for using the above criteria for inhibitor selection.

Energy Technology Data Exchange (ETDEWEB)

Products having balanced melting point and decomposition temperature have been developed by employing nylon 6T fundamental molecular structure and selected copolymer components, Arlen being one of the products. It has heat resistance as good as that of super-engineering plastics, low water absorption, and excellent cost-performance which can be used for normal injection molding machines. The unit price per kilogram is low when its high heat resistance is taken into consideration. The coefficient of water absorption is as low as about 1/3 of that of nylon 66, and it can be considered to be a low water absorbing amide. The molding temperature is from 320[degree]C to 350[degree]C, the decomposition temperature is 395[degree]C at 2% weight decreasing temperature, and normal injection molding can be employed. It has excellent soldering resistance, high ...

International Nuclear Information System (INIS)

Carbide ceramics such as boron carbide due to their unique properties such as low density, high refractoriness, and high strength to weight ratio have many applications in different industries. This study focuses on direct bonding of boron carbide for high temperature applications using nickel interlayer. The process variables such as bonding time, temperature, and pressure have been investigated. The microstructure of the joint area was studied using electron scanning microscope technique. At all the bonding temperatures ranging from 1150 to 1300degC a reaction layer formed across the ceramic/metal interface. The thickness of the reaction layer increased by increasing temperature. The strength of the bonded samples was measured using shear testing method. The highest strength value obtained was about 100 MPa and belonged to the samples ...

Energy Technology Data Exchange (ETDEWEB)

The Rocky Flats Plant (RFP) generates large volumes of a low level aqueous waste stream high in nitrate salts. The aqueous waste is concentrated by evaporation and then mixed with Portland cement prior to transport and disposal. Planned process upgrades include a new horizontal thin film evaporator. Temperature of brine at discharge end of the new evaporator will be near boiling point. Introduction of hot water to cement can degrade the monolithic waste form. However, the RFP salt waste contains high concentrations of compounds known to retard hydration. This paper discusses impact of introducing high temperature waste to cement. The study evaluated three waste compositions: (1) highest probable nitrate composition, (2) highest probable chloride composition, and (3) current composition. Results showed that compressive strength of final waste form increased with brine ...

Energy Technology Data Exchange (ETDEWEB)

Three dimensional computational fluid dynamic (CFD) calculations of a typical prismatic very high temperature gas-cooled reactor (VHTR) were conducted to investigate the influence of gap geometry on flow and temperature distributions in the reactor core using commercial CFD code FLUENT. Parametric calculations changing the gap width in a whole core length model of fuel and reflector columns were performed. The simulations show the effects of core by-pass flows in the heated core region by comparing results for several gap widths including zero gap width. The calculation results underline the importance of considering inter-column gap width for the evaluation of maximum fuel temperatures and temperature gradients in fuel blocks. In addition, it is shown that temperatures of core outlet flow from gaps and channels are strongly affected by the gap width of by-pass ...