International Science & Technology Center (ISTC)

Production of High-Purity (>99.99% wt.) Condensed Beryllium

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)

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 ...

Energy Technology Data Exchange (ETDEWEB)

The use of high-performance ion exchangers allows a trace-matrix-separation (SMT) directly followed by an ion chromatographic (IC) separation of the analytes. Based on the principles described in Part 1, a combined procedure IC-SMT-IC for metallic impurities in Mo and W is presented. Up to 12 metal traces (Fe, Cu, Pb, Zn, Ni, Co, Cd, Ca, Mn, Sr, Mg and Ba) can be determined in one run with 35 min. A special method for traces of U and Th is also given. Detection limits are typically 10-100 ng g{sup -1} in the metal sample. (author). 14 refs.; 10 figs.; 6 tabs.

Science.gov (United States)

... Accession Number : ADD151811. Title : Ultra High Strength Beta Titanium Alloy for Fasteners. Descriptive Note : Journal article,. ...

KoreaScience (Korea)

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KoreaScience (Korea)

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KoreaScience (Korea)

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Science.gov (United States)

_! Packaging, Cleanlines_, Preparation j Handling ..... 35. 'I. 40. WATER ................ , ......... Sterile, High Purity, Ethylene Glycol-Water Solutions. Requirement For . ...

Energy Technology Data Exchange (ETDEWEB)

The NREL Sensitized Solar Cell (SSC) Core Program supports the Solar America Initiative by: (1) targeting new devices and processes for commercialization by 2015 that are less expensive, more efficient, highly reliable, and environmentally benign; (2) collaborating with DOE OS/BES to conduct basic research targeting breakthroughs in key areas, such as ultra-high efficiency and/or ultra-low cost materials and devices.

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)

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 mechanical performances ...

International Nuclear Information System (INIS)

An Ultra-Low-Carbon 19% Cr-11% Ni Stainless Steels used in nuclear fuel reprocessing plants where highly corrosion resistance in nitric acid is required has been developed. This steel has optimized the chemistry composition to decrease inclusions and deformation-induced martensitic transformation. The formation of deformation-induced martensite has the potential danger of accelerating corrosion in nitric acid. In this paper, effects of cold reduction and martensitic transformation on corrosion resistance of Ultra-Low-Carbon Stainless Steels in nitric acid are discussed. The developed steel showed excellent corrosion resistance during long-term exposure to nitric acid. (author).

International Nuclear Information System (INIS)

High purity Fe-50mass%Cr alloys containing (C+N) in the range of 30 to 500 mass ppm were prepared and their corrosion resistance was investigated. Pitting potential in a 3.5mass%NaCl solution at 343K rose with reducing (C+N) content. Alloys containing (C+N) at less than 100 mass ppm did not sustain pitting corrosion. However, alloys containing 500 mass ppm (C+N) corroded severely in 6%FeCl_3+1/20N HCl solutions. Heat treatment at 923K was recognized as influencing corrosion resistance due to precipitation of carbonitrides only in the case of the alloy containing 500 mass ppm (C+N). (orig.).

International Nuclear Information System (INIS)

Three major monomeric hemoglobins have been isolated from the erythrocytes of Glycera dibranchiata. Their importance to structure-function studies of heme proteins lies in the fact that they have been shown to possess an exceptional amino acid substitution. In these proteins, the E-7 position is occupied by leucine rather than the more common distal histidine. This substitution alters the polarity of the heme ligand binding environment compared to myoglobin. Due to this, the G. dibranchiata monomer hemoglobins are attracting much attention. However, until now no purity criterion has been developed. Here the authors demonstrate that, for all of the Glycera momomer hemoglobins, multiple line patterns are shown on high-voltage isoelectric focusing (IEF) gels. Most of these lines are shown to be a consequence of heme-related phenomena and can be understood on the basis of changes in oxidation and ligation state of the heme iron. The multiple line ...

Energy Technology Data Exchange (ETDEWEB)

Iofetamine HCI {sup 123}I is the generic name for the hydrochloride salt of N-isopropyl-p-iodoamphetamine labeled with {sup 123}I, commonly called IMP. Iofetamine HCI {sup 123}I is prepared by isotopic exchange with [{sup 123}I]Nal and is formulated in isotonic aqueous NaCl solution containing 1 mCi/ml iofetamine HCI I 123, 0.15 mg/ml iofetamine HCI carrier, and phosphate buffer for pH control. The radiochemical purity is >97%, and the product is stable for more than 24 hours; the commercial product distributed today is prepared with high purity {sup 123}I with >98% radionuclidic purity. Two radioiodinated agents have seen significant clinical application for functional brain imaging: iofetamine HCI (IMP) (1) and N,N,N{prime}-trimethyl-N{prime}-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine HIPDM (2). lofetamine HCI {sup 123}I is commercially available in the United States, Europe, and ...

UK PubMed Central (United Kingdom)

When high-purity copper (≥99.98%_wt) is melted, held in its liquid state for a few hours with iterative thermal cycling, then allowed to resolidify, the ingot surface is found to have...Full Text Available

International Nuclear Information System (INIS)

The purpose of this study was to reveal the mechanism of wafer touch polishing using a high purity colloidal silica slurry containing organic surfactants such as hydroxyl-ethyl cellulose. The effect of the surfactant concentration on wafer touch polishing was studied to improve the roughness of wafer surfaces after polishing. The haze level and the micro-roughness decreased with decreasing surfactant concentration.

Energy Technology Data Exchange (ETDEWEB)

There is a growing interest in using {sup 242m}Am as a nuclear fuel. The advantages of {sup 242m}Am as a nuclear fuel derive from the fact that {sup 242m}Am has the highest thermal fission cross section. The thermal capture cross section is relatively low and the number of neutrons per thermal fission is high. These nuclear properties make it possible to obtain nuclear criticality with ultra-thin fuel elements. The possibility of having ultra-thin fuel elements enables the use of these fission products directly, without the necessity of converting their energy to heat, as is done in conventional reactors. There are three options of using such highly energetic and highly ionized fission products. - Using the fission products themselves for ionic propulsion. - Using the fission products in an MHD generator, in order to obtain electricity directly. - Using the fission products to heat ...

International Nuclear Information System (INIS)

The conventional Calzination-Reduction-Carburization (CRC) process offers the potential to manufacture commercial WC powders with median SEM grain sizes below 0.5 pm (ultra fine grades). Strict process control and a high degree of automation have led to increased powder uniformity and high lot-to-lot reliability. The high potential and flexibility of the CRC process is shown by the development of tailor made WC powders with regard to subsequent alloy manufacturing. R and D powders have successfully been processed in full-scale units exhibiting SEM grain sizes of 0.15 - 0.20 pm. This paper discusses the powder characteristics of various ultra fine WC powder grades, stemming from the conventional CRC process. Analytical characterization include also field-emission SEM, bright field TEM, EDX analysis and XRD-line broadening. (author)

CERN Document Server

Ultra-high resolution radiographs can be obtained using synchrotron X-rays. A collaboration team consisting of K-JIST, POSTECH and YUMC has recently commissioned a new beamline (5C1) at Pohang Light Source (PLS) in Korea for medical applications using phase contrast radiology. Relatively simple image acquisition systems were set up on 5C1 beamline, and imaging studies were performed for resolution test patterns, mammographic phantom, and animals. Resolution test patterns and mammographic phantom images showed much better image resolution and quality with the 5C1 imaging system than the mammography system. Both fish and mouse images with 5C1 imaging system also showed much better image resolution with great details of organs and anatomy compared to those obtained with a conventional mammography system. A simple and inexpensive ultra-high resolution imaging system on 5C1 beamline was successfully implemented. The authors were able to acquire ...

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)

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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International Nuclear Information System (INIS)

Nuclear grade production tubing of Alloy 600 was evaluated for stress corrosion cracking (SCC) susceptibility in high purity water at 365, 345, 325, and 290 C. Reverse tube U-bend specimens provided crack initiation data and constant extension rate tests were employed to determine the crack velocities experienced in th crack propagation stage. Initial results indicate that a linear extrapolation of data received from high temperature tests can be used to predict the service life of steam generator tubing that has been plastically deformed or is continually deforming by ''denting.''.

International Nuclear Information System (INIS)

The manufacturing of TRIGA fuel rods with low enriched uranium follows in principle the same route as high-enriched uranium. The high purity of the primary metals (uranium, zirconium and erbium) is important for determining the equilibrium metal-hydrogen phases. The impurities from the metal, on the surface and from hydrogen may have an important influence on the hydriding process. This paper presents the aspects of the fuel contamination with oxygen during the manufacturing process of the low enriched uranium fuel. The continuous control of the oxygen concentration in the working zone ensures avoidance of the accidental contamination. Key words: manufacturing, fuel, oxygen, contamination. (authors)

Science.gov (United States)

ing materials were ASARCO, 59 purity, copper, silver and gold, while the silicon was Dow-Corning semi- conductor grade (69 purity). ...

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)

Ultra High Vacuum (UHV) test setup for electron gun testing has been developed. The development of next generation light sources and accelerators require development of klystron as a radio frequency power source, and in turn electron gun. This UHV electron gun test setup can be used to test the electron guns ranging from high average current, quasi-continuous wave to high peak current, single pulse etc. An electron gun has been designed, fabricated, assembled and tested for insulation up to 80 kV under the programme to develop high power klystron for future accelerators. Further testing includes the electron emission parameters characterization of the cathode, as it determines the development of a reliable and efficient electron gun with high electron emission current and high life time as well. This needs a clean ultra ...

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 ...

International Nuclear Information System (INIS)

In an attempt to enhance the electrical and mechanical properties of the high temperature superconducting oxides, high T(sub c) composites were prepared composed of the 123 compounds and AgO. The presence of extra oxygen due to the decomposition of AgO at high temperature is found to stabilize the superconducting 123 phase. Ag is found to serve as clean flux for grain growth and precipitates as pinning center. Consequently, almost two orders of magnitude enhancement in critical current densities were also observed in these composites. In addition, these composites also show much improvement in workability and shape formation. On the other hand, proper oxygen treatment of Y5Ba6Cu11Oy was found to possibly stabilize superconducting phase with T(sub c) near 250 K. I-V, ac susceptibility, and electrical resistivity measurements indicate the existence of this ultra high T(sub c) phase in ...

International Nuclear Information System (INIS)

As researchers explore new applications for positron emission tomography radiopharmaceuticals, the demand for effective and readily available radiopharmaceuticals continues to increase. The syntheses of two such radiopharmaceuticals, ["1"1C]acetate and ["1"1C]palmitate, can be automated on the GE Tracerlab FX_C_-_P_r_o by utilizing Grignard reactions. Radiochemical purities of the ["1"1C]acetate and the ["1"1C]palmitate products were high (>98% and >99.9%, respectively) with average non-corrected yields of 18% (n=3) and 10% (n=5), respectively. These data comprise the validation trials for site qualification of clinical production of both radiopharmaceuticals. -- Graphical abstract: Automated syntheses of ["1"1C]acetate and ["1"1C]palmitate using a modified GE Tracerlab FX_C_-_P_r_o are reported. Radiochemical purities of the ["1"1C]acetate and the ["1"1C]palmitate products were high (>98% and ...

International Nuclear Information System (INIS)

Recovery of uranium by ion-exchange processes from impure acid leach liquors is described, which produce a concentrated and pure eluate employing 10% sulphuric acid elution. In situations where resin is loaded to 45 g/ltr or more the acid consumption at ambient temperature is less than 4 kg of H_2SO_4 per kilogram of U_3O_8. Precipitation with an alkali such as ammonia or magnesia produces a yellow cake of high purity. (author).

Energy Technology Data Exchange (ETDEWEB)

To evaluate the effect of porosity on superplasticity behavior, it is essential to use materials of similar initial grain sizes. This can be achieved by HIPing, which provides an effective way of reducing initial porosity while avoiding appreciable grain growth; various levels of porosity can be achieved for similar grain sizes. This note is concerned with the influence of porosity on superplasticity tensile deformation of a fine grained high-purity alumina doped with copper oxide and containing a grain growth inhibitor. Specimens were prepared by slip casting to net-shape and sintering; some presintered specimens were HIPed to reduce porosity. The subsequent superplasticity behavior is related to porosity in the material.

Energy Technology Data Exchange (ETDEWEB)

The CASTOC project addresses environmentally assisted cracking (EAC) phenomena in low alloy steels used for pressure boundary components in both Western type boiling water reactors (BWR) and Russian type pressurised water reactors (VVER). It comprises the four work packages (WP): inter-laboratory comparison test (WP1); EAC behaviour under static load (WP2), EAC behaviour under cyclic load and load transients (WP3); evaluation of the results with regard to their relevance for components in practice (WP4). The use of sophisticated test facilities and measurement techniques for the on-line detection of crack advances have provided a more detailed understanding of the mechanisms of environmentally assisted cracking and provided quantitative data of crack growth rates as a function of loading events and time, respectively. The effect of several major parameters controlling EAC was investigated with particular emphasis on the transferability of the results to components in service. The ...

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)

Oxygenated fuels increase fuel consumption due to their low enthalpy of combustion; however, their high antiknock index renders them suitable for use in engines with a high compression rate, increasing their thermal yield. This study evaluated the performance of biorenewable oxygenated fuels (ethanol and isoamyl alcohol) and partially renewable fuels (ETBE: ethyl tert-butyl ether, TAEE: tert-amyl ethyl ether and di-TAE: di-tert-amyl ether) with high degree of purity and in mixtures with automotive gasoline, based on tests with Otto cycle engines. Among the oxygenated fuels evaluated here, di-TAE was found to present the best characteristics of performance, both individually and in mixtures with gasoline. 40 refs., 5 figs., 2 tabs.

International Nuclear Information System (INIS)

Surface study techniques were used to investigate films on Type 304 stainless steel which were formed during exposure to high purity water at 288"0C. The results indicated that the film chemistry depended strongly upon the concentration of the dissolved O_2 in the water. Films formed in water having 8 ppm O_2 were stoichiometric mixed oxides; whereas those formed in water with 10 ppb O_2 were highly defective oxyhydroxides. The latter films are not as protective as the stoichiometric oxides. Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS) were used to investigate the films. (Auth.).

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)

Full text: Production: This radio iodine produced by three methods: 1) Wet method: The irradiated tellurium is dissolved in an oxidizing mixture which also converts iodine in to iodide. This is a chemical method and iodine that it produced with this method has low purity and efficiency. 2). Dry Method: The irradiated tellurium is dissolved in furnace (750 deg. C) with sublimation method and iodine absorbed in sodium solution . In this case we have more than 99.5 % purity and 80 % efficiency. We are using this type in Iran. 3) Fission fragment method: In this case the iodine separated from fission fragment directly and we have high purity (career free) and specific activity of iodine. Application: Iodine is a versatile tracer element. It is used to determine thyroid cancer metastases, and size, shape and activity of the thyroid gland. Critical organ of iodine is thyroid gland. One of the common ...

Energy Technology Data Exchange (ETDEWEB)

Elemental analysis of some medicinal plants used in the Indian Ayurvedic system was performed by employing instrumental neutron activation analysis (INAA) and atomic absorption spectroscopy (AAS) techniques. The samples were irradiated with thermal neutrons in a nuclear reactor and the induced activity was counted by gamma ray spectrometry using an efficiency calibrated high resolution high purity germanium (HPGe) detector. Most of the medicinal plants were found to be rich in one or more of the elements under study. The variation in elemental concentration in same medicinal plants samples collected in summer, winter and rainy seasons was studied and the biological effects of these elements on human beings are discussed. (orig.)

International Nuclear Information System (INIS)

Lipophilic tertiary amines attached to cylcopentadienyl technetium-99m tricarbonyl (cytectrene) have been prepared with high radiochemical yield and purity. Biodistribution studies in mice showed that ["9"9"mTc]-cytectrenes, containing in their structure an N-methylpiperidine, were accumulated in the brain up to 2.8% of injected dose with high brain-to-blood ratios at 15 min p.i. They therefore indicate some potential as brain imaging agents. It has to be pointed out that the N-methylpiperidine ester showed similar biological behaviour as the keto derivatives. This indicates that the conversion to polar metabolite(s) via hydrolysis of the ester group - as described for ["9"9"mTc]-ECD -is not essential for brain retention. (Author).

Energy Technology Data Exchange (ETDEWEB)

From their genesis by weathering and sedimentation, bauxites, the principal aluminium ores, contain appreciable amounts of uranium and thorium. High resolution gamma spectrometry with a high purity germanium detector was used for an analysis of four industrially used bauxites from Gondama, Sierra Leone; Boke, Guinea; Weipa, Queensland, Australia; Gove, Northern Territory, Australia. Significant differences in uranium to thorium ratios and in activities of the uranium and thorium daughters were observed for the four bauxites. It was found that the bauxite from Gondama, Sierra Leone has an activity of only 10% compared with the others. Red mud tailings from such a bauxite may well be used as an additive to bricks, which is now illegal for normal red mud from more active bauxites. (author).

International Nuclear Information System (INIS)

#alpha#/#beta# sialon based composites containing silicon nitride whisker and silicon carbide platelet were fabricated by hot pressing. Effect of the reinforcing agents on the #alpha# to #beta# phase transformation of the sialon as well as on the mechanical properties was investigated. Silicon nitride whisker and silicon carbide platelet promoted the phase transformation. TEM/EDS analysis revealed that the grain containing the whisker had 'core-rim' structure; core being high purity Si_3N_4 whisker and rim being #beta#-sialon. Flexural strength of the composite decreased with the reinforcement addition which, on the other hand, improved fracture toughness of it. High temperature strength was measured at 1300 deg C to be about 130 MPa lower than that measured at RT for the whisker reinforced composite. (author).

British Library Electronic Table of Contents (United Kingdom)

High purity W and W-0.9La2O3 (wt.%) nanopowders were produced by a wet chemical route. The precursor was prepared by the reaction of ammonium paratungstate (APT) with lanthanum salt in aqueous solutions. High resolution electron microscopy investigations revealed that the tungstate particles were coated with oxide precipitates. The precursor powder was reduced to tungsten metal with dispersed lanthanum oxide. Powders were consolidated by spark plasma sintering (SPS) at 1300 and 1400degreeC to suppress grain growth during sintering. The final grain size relates to the SPS conditions, i.e. temperature and heating rate, regardless of the starting powder particle size. Scanning electron microscopy revealed that oxide phases were mainly accumulated at grain boundaries while the tungsten matrix ...

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 analysis of capacitance-voltage characteristics ...

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.

Energy Technology Data Exchange (ETDEWEB)

The main driver in ultra-shallow formation for the 65 nm technology node and beyond is to find solutions that both reduce boron transient enhanced diffusion and can be integrated in the CMOS process flow. To this end, many studies have recently focused on using co-doping techniques with fluorine and most recently with carbon. In most cases, one or both of these is co-implanted with a dopant specie in pre-amorphized silicon. In this work, we show a comparative study of fluorine or carbon co-implanted with low-energy boron to form source and drain extension junctions for PMOS devices. We will show that by a systematic optimization of germanium, boron, fluorine or carbon energies and doses, spike annealing technology can be extended to the 65 nm node. These results will be used to discuss how the different formed junctions offer potential solutions for either low-power or high-performance PMOS device fabrication.

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)

Full Text Available

International Nuclear Information System (INIS)

As part of the general QC/QA management of the k_0-standardization, three types of 'SMELS' (synthetic multi-element standards) are being developed to check the performance of k_0-NAA when implemented in a laboratory. Phenol-formaldehyde resin is proposed in this paper as the matrix of choice. Based on previous work, this material could be prepared with sufficient purity so as to make interferences with the spiking elements negligible. The matrix was found to be adequately resistant towards high neutron flux irradiation. A selection was made of compounds, soluble in ethyl alcohol, for spiking the prepolymer ethanolic solution with the elements of interest. Finally, some prototypes were prepared and a satisfactory homogeneity of the spiked elements was found for 50 mg sample intake.

British Library Electronic Table of Contents (United Kingdom)

Size-controllable Ag nanoparticle ultrathin films, which were fabricated by vacuum deposition method from high purity Ag wire onto cleaned indium tin oxide conducting glass, have different color fabricated by variation of preparation conditions. The UV/Vis spectra showed that optical absorption peak of these Ag nanoparticle films can be tuned in a range from 457nm to >650nm. Scanning electron microscopy images showed that with increasing film thickness Ag particle size was larger. Ag/WO3 composite films were prepared by cathodic electrodeposition of WO3 onto the surface of Ag nanoparticle films. Spectroelectrochemistry and electrochromic properties of the resulting composite films were characterized. It was found that the electrochemical and electrochromatic properties of the composite fil...

Energy Technology Data Exchange (ETDEWEB)

Passive films formed on stainless steels in a borate buffer solution (pH 9.2) have been investigated by capacitance measurements and photoelectrochemistry. The study was carried out on films formed on AISI type 304 and 316 stainless steels and high purity alloys with differing chromium, nickel, and molybdenum contents. Complementary research by Auger analysis shows that the passive films are composed essentially of an inner chromium region in contact with the metallic substrate and an outer iron oxide region developed at the film/electrolyte interface. The semiconducting properties of the passive films are determined by those of the constituent chromium and iron oxides which are of p-type and n-type, respectively. Thus the influence of the alloying elements on the semiconducting properties of the passive films is explained by changes in the electronic structure of each of these two oxide regions.

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Passive films were formed on a high purity Fe-23 Cr alloy in acid sulfate solutions in the presence and absence of chloride ion. The resulting film composition was investigated by Auger depth profiling. The passivated samples were exposed to a 1M NaCl solution at a constant potential slightly above the critical pitting potential, and the current-time transient was measured in order to compare the relative stability of the different films. The results obtained suggest that the formation conditions influence the chloride content of the passive film and the breakdown behavior. Passive films formed in the presence of chloride contain and are slightly less stable towards breakdown. No chloride was found in films formed in sulfate and subsequently exposed to chloride well below the pitting potential.

International Nuclear Information System (INIS)

Initial rates of resistivity-measured low-temperature damage production by fission-spectrum fast neutrons have been determined for 14 metals in the same very well characterized irradiation facility. Six of these metals were fcc, 5 bcc, and 3 hcp. Most were of quite high purity. Observed damage rates, after correction for all known extraneous resistivity-producing effects, were compared with rates predicted by the damage calculation code RECOIL, using parameters chosen from the literature. These parameters, effective displacement threshold energy, E/sub d/, and Frenkel-pair resistivity, rho/sub F/, were in many cases only best estimates, the further refinement of which may be aided by the present results. Damage efficiencies (measured/predicted rates) follow the same trends by crystal classes as seen in other fast-neutron studies.

British Library Electronic Table of Contents (United Kingdom)

The aim of this study is to evaluate the specificities of the irradiation of drugs in frozen aqueous solution. The structures of the degradation products were determined to gain insight into the radiolysis mechanisms occurring in frozen aqueous solutions. Metoclopramide hydrochloride and metoprolol tartrate were chosen as models. The frozen solutions were irradiated at dry ice temperature by high energy electrons at various doses. The drug purity (chemical potency) and the radiolysis products were quantified by HPLC-DAD. Characterization of the degradation products was performed by LC-APCI-MS-MS. The structures of the radiolysis products detected in irradiated frozen aqueous solutions were compared to those detected in solid-state and aqueous solutions (previous studies). For both metoclop...

International Nuclear Information System (INIS)

The study of passive films formed on a nickel base alloy type Inconel 600 is performed by capacitance measurements (Mott-Schottky approach). This research is supported by the passivation study of the alloying elements Ni, Cr, Fe and high purity alloys Ni-Cr, Ni-Fe, Ni-Cr-Fe. The results obtained show that the capacitive behaviour of the Inconel 600 in the passive state is similar to that on a p-n heterojunction to which a barrier zone of nickel oxide is added. The individual or combined action of alloying elements on the development of this kind of electronic structure is discussed. (authors). 5 refs., 6 figs.

International Nuclear Information System (INIS)

This report summarizes work performed by Argonne National Laboratory (ANL) on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) during the six months from October 1993 to March 1994. EAC and fatigue of piping, pressure vessels, and core components in LWRs are important concerns in operating plants and as extended reactor lifetimes are envisaged. Topics that have been investigated include (a) fatigue of low-alloy steel used in piping, steam generators, and reactor pressure vessels, (b) EAC of wrought and cast austenitic stainless steels (SSs), and (c) radiation-induced segregation and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS after accumulation of relatively high fluence. Fatigue tests have been conducted on A302-Gr B low-alloy steel to verify whether the current predictions of modest decreases of fatigue life in simulated pressurized water reactor water are valid for high-sulfur heats ...

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The high-purity-oxygen activated sludge process will be used to expand secondary treatment capacity and improve water quality in Santa Monica Bay. The facility is operated by the city of Los Angeles Department of Public Works` Bureau of Sanitation. The overall Hyperion Full Secondary Project is 30% complete, including a new headworks, a new primary clarifier battery, an electrical switch yard, and additional support facilities. The upgrading of secondary facilities is 50% complete, and construction of the digester facilities, the waste-activated sludge thickening facility, and the second phase of the three-phase modification to existing primary clarifier batteries has just begun. The expansion program will provide a maximum monthly design capacity of 19,723 L/s(450 mgd). Hyperion`s expansion program uses industrial treatment techniques rarely attempted in a municipal facility, particularly on such a large scale, including: a user-friendly intermediate pumping ...

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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 ...

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The automotive industry desires to optimize safety and lightweight construction for the production of cars and trucks. The resulting task for steel suppliers is to make steel grades available that can fulfil these requirements. Different projects have shown optimistic outlooks for optimization of safety and reduction of the weight of automobile bodies by using different high strength and ultra high strength steels. In the last group the dual phase steels play the lead. In recent years different steel grades have been developed and optimized for these applications. On one hand developing the mechanical properties as well as joining and forming of dual phase steels is one of the first steps. On the other hand different coated surfaces for various applications of dual phase steels is another step. Starting with characteristic production conditions for cold rolled hot dip galvanised dual phase steels, the mechanical properties ...

British Library Electronic Table of Contents (United Kingdom)

A qualitative method, involving supported liquid?liquid extraction (SLE) and ultra high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS?MS), was developed for the rapid tentative identification of various drugs of abuse in urine. In this study, 28 drugs and metabolites were covered by the screening procedure. Before analysis, urine samples were extracted by SLE and good extraction recoveries were obtained for most investigated compounds. The UHPLC strategy was then selected for the rapid separation of amphetamines, cocaine, opiates and related compounds in urine. Using columns packed with sub-2??m particles, analysis time was reduced down to 2?min, while maintaining acceptable performance. Finally, the detection was by tandem MS operating in the single reaction...

CERN Document Server

The current primary standards at NPL for the measurement of absorbed dose to water in high energy photon and electron beams are graphite calorimeters. However, the quantity of interest in radiation dosimetry is absorbed dose to water. Therefore, a new absorbed dose to water standard based on water calorimetry has been developed for use in high energy photon and electron beams. The calorimeter operates at 4 deg C, with temperature control being provided by liquid cooling. The sealed glass inner vessel of the calorimeter was designed to minimise the effect of non-water materials on the measurement of absorbed dose. The temperature sensing thermistor probes were designed and constructed so that glass is the only material in contact with high purity water inside the vessel. Initial measurements of absorbed dose to water made in 6, 10, and 19 MV photons, and 16 MeV electrons agreed, within the measurement ...

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In order to gain a wider knowledge of corrosion phenomena in OFHC (oxygen free high conductivity) copper pipes of the stator cooling circuit of a power plant turboalternator, a research program was laid out which is based on the use of an experimental loop simulating real operating conditions as closely as possible. The samples examined were either copper foils or hollow conductors of the type that is normally used in the stator cooling system, and the circulating fluid was high purity water with controlled O/sub 2/, H/sub 2/ and C0/sub 2/ contents. Investigations were focused on the kinetics of O/sub 2/ removal through catalytic resins covered with metallic palladium (at different temperatures and pressures) and on the kinetics of CO/sub 2/ removal through mixed bed resins. Subsequently, attention was directed to the corrosion of copper (in the form of foils or hollow conductors) under different experimental conditions ...

International Nuclear Information System (INIS)

Post-irradiation annealing was used to help identify the role of radiation-induced segregation (RIS) in irradiation-assisted stress corrosion cracking (IASCC) by preferentially removing dislocation loop damage from proton-irradiated austenitic stainless steels while leaving the RIS of major and minor alloying elements largely unchanged. The goal of this study is to better understand the underlying mechanisms of IASCC. Simulations of post-irradiation annealing of RIS and dislocation loop microstructure predicted that dislocation loops would be removed preferentially over RIS due to both thermodynamic and kinetic considerations. To verify the simulation predictions, a series of post-irradiation annealing experiments were performed. Both a high purity 304L (HP-304L) and a commercial purity 304 (CP-304) stainless steel alloy were irradiated with 3.2 MeV protons at 360 deg. C to doses of 1.0 and 2.5 dpa. Following irradiation, ...

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A comprehensive understanding of dopant activation mechanisms in crystalline Si is required in order to form shallow junctions. In this paper, we will review several experimental assessments on boron clustering and novel methods to form shallow junctions. Boron marker-layer structures have been used to investigate the fundamental aspects of formation and ripening boron-interstitial clusters (BICs) and their influence on the associated transient enhanced diffusion (TED). The samples were damaged by Si implants at different doses in the sub-amorphizing range and annealed at high temperatures. We found that BICs act as a sink for interstitials at supersaturations values S(t)>10{sup 4}. This implies that silicon self-interstitial defects are the primary source of interstitials driving TED, and that BICs act as a secondary 'buffer' for the interstitial supersaturation. These clusters are less sensitive to the ripening process than pure ...

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A new organic-inorganic hybrid membrane has been prepared with exceptional performance in dewatering applications. The only precursor used in the sol-gel synthesis of the selective layer was organically linked 1,2-bis(triethoxysilyl)ethane (BTESE). The microporous structure of this layer enables selective molecular sieving of small molecules from larger ones. In the dehydration of n-butanol with 5% of water, the membrane shows a high separation factor of over 4000 and ultra-fast water transport at a rate of more than 20 kg m{sup -2} h{sup -1} at 150C. This can be related to the high adsorption capacity of the material and the sub-micron thickness of the selective layer. The selectivity has now remained constant over almost one and a half years under continuous process testing conditions. Apart from the hydrothermal stability, the membrane exhibits a high tolerance for acid contamination. A slow ...

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).

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.

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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)

Mixed-conducting Sr-Fe-Co oxides have potential applications in dense ceramic membranes for high-purity oxygen separation and/or methane conversion to produce syngas (CO + H{sub 2}), because of their combined high electronic/ionic conductivity and significant oxygen permeability. We studied the crystal structure and microstructure of the system in X-ray diffraction experiments and by using scanning electron microscopy, respectively. Thermogravimetric analysis was conducted on the SrFeCo{sub 0.5}O{sub x} sample in environments of various oxygen partial pressures (pO{sub 2}). Conductivity increased while weight decreased with increasing temperature. Activation energy decreased while conductivity increased with increasing pO{sub 2}. The pO{sub 2}-dependent conducting behavior of the SrFeCo{sub 0.5}O{sub x} system can be understood by considering the trivalent-to-divalent transition of transition-metal ions.

International Nuclear Information System (INIS)

In developing new Tc-99m brain perfusion imaging agents for SPECT, a series of BAT (bis-aminoethanethiol) derivatives was prepared. These N/sub 2/S/sub 2/ ligands formed stable and neutral complexes with reduced Tc-99m, either by Sn(II)-PPi or sodium borohydride reduction. The purity of the Tc-99m complexes was >95% (HPLC reverse-phase column, acetonitrile: pH 7.0 buffer, 85:15). The biodistribution in rats was evaluated using I-125 iodoantipyrine (IAP), a free diffusible tracer, as the internal reference. Compounds with a free hydroxyl group (I and IV) showed lower brain uptake, inspite of high P.C.; this may be related to in vivo instability of the complexes. High initial brain uptake was observed for three compounds (II, III and V), however, only compound V (P.C.=384) showed significant brain retention. Planar imaging with compound V in a monkey demonstrated that the compound localized in brain and the retention time ...

Energy Technology Data Exchange (ETDEWEB)

The electrical conductivity of Vitox-alumina (99.2%), Wesgo-alumina (99.9%) and AlN (99.6%) has been measured during and after irradiation with an experimental set-up which allows fusion relevant loading conditions. All irradiations were performed in high vacuum at 450 C using a 104 MeV {alpha}-particle beam with an applied DC electric field of 100 kV/m. In the high purity Vitox-alumina the in-situ and postirradiation bulk conductivities {sigma} and {sigma}{sub 0} show the highest irradiation induced electrical breakdown ever observed. The saturation level near 4 x 10{sup -2} ({Omega}m){sup -1}, reached already after 0.015 dpa (O-sublattice), is already above the critical value necessary to avoid MHD pressure drop with 10 {mu}m coatings in flowing liquid metal coolants. Under the same conditions no radiation induced electrical degradation at all has been found in Wesgo-alumina and AlN. (orig.).

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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 mechanical properties of Mod.9Cr-1Mo steel were evaluated ...

International Nuclear Information System (INIS)

... 2.1 Yellow Cake Specification3 Storage and Handling 2.2 Dissolution 2.3

Science.gov (United States)

The steroidogenic factor 1 (SF-1, also known as NR5A1) is a transcription factor belonging to the nuclear receptor superfamily. Whereas most of the members of this family have been extensively characterized, the therapeutic potential and pharmacology of SF-1 still remains elusive. Described here is the identification and characterization of selective inhibitory chemical probes of SF-1 by a rational ultra-high-throughput screening (uHTS) strategy. A set of 64,908 compounds from the National Institute of Health's Molecular Libraries Small Molecule Repository was screened in a transactivation cell-based assay employing a chimeric SF-1 construct. Two analogous isoquinolinones, ethyl 2-[2-[2-(2,3-dihydro-1,4-benzodioxin-7-ylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate (SID7969543) and ethyl 2-[2-[2-(1,3-benzodioxol-5-ylmethylamino)-2-oxoethyl]-1-oxoisoquinolin-5-yl]oxypropanoate and (SID7970631), were identified as potent submicromolar inhibitors, yielding ...

Energy Technology Data Exchange (ETDEWEB)

The theoretical analysis of a partially-ionized hydrogen gas flow (gas temperatures of approximately 10,000 to 20,000 K) through a particular class of magnetohydrodynamic (MHD) generators and the preliminary design of these MHD generators as open cycle, electric power supplies are performed. Analysis of the gas flow through these ultra-high temperature MHD generators requires a coupled gas dynamics/radiative heat transfer solution. Gas dynamics are modeled by a set of quasi-one-dimensional, nonlinear differential equations which account for friction, convective and radiative heat transfer and the interaction between the ionized gas and applied magnetic field. Radiative heat transfer is modeled using non-gray, absorbing-emitting two- and three-dimensional P-1 approximations which permit an arbitrary variation of the spectral absorption coefficient with frequency. Gas dynamics and radiative heat transfer are coupled through the energy equation, and through 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 observed at room temperature and became significant at 300^oC and higher temperature. The mechanism of ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes an investigation of electrodeposited Zn-14% Ni and aluminium-based SermeTel 1140/962 coatings as possible replacements for cadmium. Slow strain rate tests were performed to measure the extent of direct hydrogen embrittlement of a high strength steel substrate as a result of the coating process and of hydrogen re-embrittlement caused by coating corrosion. The level of re-embrittlement was shown to depend on both the electrochemical potential of the coating and its barrier properties. Zn-14% Ni coatings caused the most re-embrittlement as they had the most active potential and contained through-thickness defects which left the steel exposed to hydrogen uptake. The microstructure of the high strength steel was also shown to be an important factor affecting the extent of embrittlement. AerMet 100 steel was more resistant than 300M steel and this was attributed to the presence of reverted austenite surrounding the martensite ...

Science.gov (United States)

A developed flue gas desulfurization and dust removal process with a cross-flow moving bed filled with activated coke (AC) was tested on a pilot scale with the gas treatment capacity of 1000 mg x h(-t). The results show that a easy-operating and stable-running pilot-scale testing equipment can be reached, and under the conditions of testing space velocity, the feed gas temperature of 120 degrees C, SO2 concentrations of 3232-6006 mg x m(-3) and dust concentration of 89.3-1599.7 mg x m(-3), the high efficiency of flue gas desulfurization and dust removal is reached with the purity of dust less than 50 mg x m(-3). In the technology, the spent AC was regenerated by heating, and the SO2 concentration in the desorption gas is about 40.1%, which can be efficiently recovered as a sulfur resource. Favorable economy benefit can be reached by using the process. PMID:16850821

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A gamma-ray spectrometer (GRS) has been built and delivered to the Mercury MESSENGER spacecraft which launched on August 3, 2004, from Cape Canaveral, Florida. The GRS, a part of seven scientific instruments on board MESSENGER, is based on a coaxial high-purity germanium detector. Gamma-ray detectors based on germanium have the advantage of providing excellent energy resolution, which is critical to achieving the science goals of the mission. However, germanium has the disadvantage that it must operate at cryogenic temperatures (typically {approx}80 K). This requirement is easy to satisfy in the laboratory but difficult near Mercury, which has an extremely hot thermal radiation environment. To cool the detector, a Stirling cycle mechanical cooler is employed. In addition, radiation and conduction techniques a are used to reduce the GRS heat load. Before delivering the flight sensor, a complete thermal prototype was built and tested. The results of these test, ...

Energy Technology Data Exchange (ETDEWEB)

The Ohio State University Research Reactor (OSURR) is licensed to operate at a maximum power level of 500 kW. A pool-type reactor using flat-plate, low enriched fuel elements, the OSURR provides several experimental facilities including two 6-inch i.d. beam ports, a graphite thermal column, several graphite-isotope-irradiation elements, a pneumatic transfer system (Rabbit), various dry tubes, and a Central Irradiation Facility (CIF). The core arrangement and accessibility facilitates research programs involving material activation or core parameter studies. The OSURR control room is large enough to accommodate laboratory groups which can use control instrumentation for monitoring of experiments. The control instrumentation is relatively simple, without a large amount of duplication. This facilitates opportunities for hands-on experience in reactor operation by nuclear engineering students making reactor parameter measurements. For neutron activation analysis and analyses of natural ...

International Nuclear Information System (INIS)

The half-life of "1"0"9Cd was measured by following the decay of sources from a radiochemically pure solution with two different measuring systems: an ionisation chamber and a high-purity germanium (HPGe) detector. The measurements were performed over a period of 3.6 years, i.e. about 2.8 half-lives of "1"0"9Cd. The resulting half-life values and detailed uncertainty budgets (k=1) are presented for both systems. The result obtained with the ionisation chamber, 462.36 (33) days, and the one obtained with the HPGe detector, 461.92 (76) days, are mutually consistent. The weighted mean of our measured values, T_1_/_2("1"0"9Cd)=462.29 (30) days, is consistent with the currently recommended values of 461.4 (12) days and 462.0 (3) days. From a set of selected experimental values published after 1970, a 'partially weighted mean' of T_1_/_2("1"0"9Cd)=462.36 (39) days was calculated. More measurements are needed to resolve the discrepancies among literature data and to ...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) is a 400-MWt, sodium-cooled reactor located on the Hanford Site near Richland, Washington, USA. The FFTF is owned by the U.S. Department of Energy and is operated by the Westinghouse Hanford Company. The FFTF was designed to test fuels and materials for use in liquid metal reactors. Since initial operation in 1982, anticipated breaches of experimental fuel pins have released fission products, including cesium, into the primary sodium. Because of its high volatility, cesium vaporizes into the cover gas space, where it condenses on components and equipment and is transported into the cover gas outlet. Because of the long half-life of "1"3"7Cs, these deposits result in long-term, local radiation levels that make contact maintenance difficult. Thus, a cesium trap was installed in FFTF to reduce the cesium level in the sodium. The trap could also permit a Run Beyond Cladding Breach (RBCB) program without compromising the sodium ...

Energy Technology Data Exchange (ETDEWEB)

Substantial roles of precipitates such as Zr-Fe-Cr type intermetallic compounds on uniform corrosion and hydrogen pickup of zirconium alloys in pure water autoclave tests were investigated from an electrochemical point of view. In the previous paper, corrosion mechanism was elucidated by the anodic protection-precipitates degradation model. This paper describes the roles on hydrogen pickup. 633 K pure water autoclave test was performed on high purity zirconium, Zr-0.2Fe, Zr-0.2Cr, and Zr-0.1Fe-0.1Cr alloys. Hydrogen analysis after the corrosion test showed that hydrogen pickup ratio of Zr-0.2Fe alloy was about 80%. It was much higher than about 30% of pure Zr and about 10% of both Zr-0.2Cr and Zr-0.1Fe-0.1Cr alloys. Larger hydrogen content was introduced into Zr-0.2Fe alloy than the other ones by the cathodic hydrogen charging under coulombic equivalence. The precipitates at metal-oxide interface could act not only as cathodic sites in the ...

Energy Technology Data Exchange (ETDEWEB)

Theoretical work supported by this grant has lead to the concept of the specific pinning force Q and the development of new methods to sum elementary interaction forces to find Q. Pinning due to changes in transition temperature or thermodynamic critical field in thin layers (e.g., a grain boundary), is greatly reduced due to the proximity effect and the stress field interaction due to the dislocations in the grain boundary has been shown to be negligible. The crystalline anisotropy (CA) and electron scattering (ES) interactions have been computed for the first time for an arbitrary boundary. Experiments on niobium bicrystals, polycrystalline niobium thin foils doped with oxygen, lead-bismuth alloy thin films and lead-bismuth alloy films in which either lead or thallium has been allowed to diffuse down the grain boundaries and out into the grains provide evidence that confirms the predictions of the theory. These results suggest that further improvements in grain boundary pinning in ...

Science.gov (United States)

The Abrasive Waterjet Cutting process was evaluated to determine if the equivalent could be utilized for cutting uranium metal at the Feed Materials Production Center (FMPC). In the process, a thin stream of ultrahigh pressure water carried grit material through a designated piecepart. In order to be acceptable for use at the FMPC, the equipment must be cost effective, minimize waste, and be adaptableto operating in an enclosure, and improve health and safety conditions. Observation of the cutting process showed that health and safety aspects could be optimized with an enclosed ventilated system. Also the equipment can be easily automated. The cutting action produced sparks similar to the sparks caused by a grinding operation. The sparks are captured in a water container under the workpiece that not only catches the sparks, but also serves to dissipiate the stream of water and residues produced by the cut. Metallographic tests performed on the cut surface of the block of depleted ...

International Nuclear Information System (INIS)

Serotonin is one of the neurotransmitters found in the brain and mediates brain functions. It is very well known that serotonin related brain abnormalities are exerted mainly via serotonin receptors in a similar manner to other neurotransmitters found in the brain. Recently, it has also been found that serotonin is involved in Alzheimer's disease either directly or indirectly by its actions on serotonergic neurons. To understand and treat the diseases caused by abnormalities in the serotonergic system in the brain, it is certain that its mechanism of function has to be well investigated. So far several 5-HT receptors and receptor subtypes have been well characterized. Moreover, serotonin agonists and antagonists acting on specific receptors are chemically synthesized and are now available for the prevention or treatment of serotonergic related diseases. In recent years, a great demand for developing neuroimaging agents has emerged for the diagnosis of abnormal brain functions in the ...

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 ...

International Nuclear Information System (INIS)

Full text. Here we present a status report of the Schenberg antenna, which started commissioning runs in September 2006 under the full support of FAPESP. In its first commissioning runs we tested three preliminary parametric transducer systems, which did not achieve a high enough performance for placing the antenna sensitivity in the range of the calibrator capacitor. Instead of improving the calibrator, making it capable of introducing a larger input force, we decided to go to a radical upgrading operation: replacing the three transducers for a complete set of six transducers, with better sensitivity and arranged according to the truncated icosahedron configuration, plus two extra ones; starting to install the dilution refrigerator; installing wires, cables, and amplifiers for the complete set of transducer circuits; and a new suspension and vibration isolation system for the cabling and microstrip antennas. We also have been developing a new set of transducers, ...

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 ...

International Nuclear Information System (INIS)

High quality single-walled carbon nanotubes (SWNT) have been synthesized at large scales by the method of direct evaporation of carbon black and metallic catalyst mixtures, using induction thermal plasma technology. The processing system consists mainly of an RF plasma torch, which generates a plasma jet of extremely high temperature (?15 000 K), with a high energy density and abundance of reactive species (ions and neutrals). With the present reactor system, it has been demonstrated that carbon soot product which contains approximately 40 wt% of SWNT can be continuously synthesized at the high production rate of ?100 g h-1. The processing parameters involved have been examined closely in order to evaluate their individual influences on SWNT synthesis. The results have shown that the quality and purity of the SWNT produced are critically affected by the grade of carbon black, the ...

Energy Technology Data Exchange (ETDEWEB)

Some of the results of property measurements of CeO{sub 2} and its solid solutions were reviewed. The deviation from stoichiometry of undoped and doped CeO{sub 2} was presented in several figures, which suggested that CeO{sub 2} fired at high temperatures in air might be nonstoichiometric in some degree. At low temperatures, the deviation from stoichiometry in doped CeO{sub 2} is higher than undoped CeO{sub 2}. As another interesting property, CeO{sub 2} shows high solubility to trivalent cations such as rare earth elements. A possible reason behind this high solubility was presented. The nonstoichiometric defect in undoped CeO{sub 2} and the trivalent cation in solid solution with CeO{sub 2} have to be compensated by other defects. The possible defect structures in this solid solution were reviewed and the most probable structure was chosen based on density measurement and impurity dependence of oxygen diffusion ...

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 ...

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 basis of the ...

International Nuclear Information System (INIS)

The 10.3-h "1"6"5Er, decaying by electron capture to stable "1"6"5Ho, 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 "1"6"5Er 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 "1"6"9Er and "1"7"1Er radioactive impurities in the reactor-produced "1"6"5Er sample are experimentally determined. Whole-body dose estimates for "1"6"5Er are given. These compare favorably with "9"9Tc dose.

Energy Technology Data Exchange (ETDEWEB)

The ability to monitor the corrosion degradation of key components in fossil fuel power plants is of utmost importance for Futuregen and ultra-supercritical power plants. Fireside corrosion occurs in the high temperature sections of energy production facilities due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Problems occur when equipment designed for either oxidizing or reducing conditions is exposed to alternating oxidizing and reducing conditions. This can happen especially near the burners. The use of low NOx burners is becoming more commonplace and can produce reducing environments that accelerate corrosion. One method of addressing corrosion of these surfaces is the use of corrosion probes to monitor when process changes cause corrosive conditions. In such a case, corrosion rate could become a process control variable that directs the operation of a coal combustion or ...

Energy Technology Data Exchange (ETDEWEB)

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.

CERN Document Server

Of the many ways of detecting high redshift galaxies, the selection of objects due to their redshifted Ly-alpha emission has become one of the most successful. But what types of galaxies are selected in this way? Until recently, Ly-alpha emitters were understood to be small star-forming galaxies, possible building-blocks of larger galaxies. But with increased number of observations of Ly-alpha emitters at lower redshifts, a new picture emerges. Ly-alpha emitters display strong evolution in their properties from higher to lower redshift. It has previously been shown that the fraction of ultra-luminous infrared galaxies (ULIRGs) among the Ly-alpha emitters increases dramatically between redshift three and two. Here, the fraction of AGN among the LAEs is shown to follow a similar evolutionary path. We argue that Ly-alpha emitters are not a homogeneous class of objects, and that the objects selected with this method reflect the general star forming ...

Energy Technology Data Exchange (ETDEWEB)

The detection limit of Instrumental Neutron Activation Analysis (INAA), about a few microgram per kg, is not sufficient to determine iridium concentrations in most geological samples. Use of the coincidence counting of the 316 and 468 keV gamma-rays emitted during the decay of {sup 192}Ir, improved the sensitivity (0.01 microgram per kg). The high iridium content of the clay layers from the Cretaceous-Tertiary transition (KTB) has been considered as an evidence of the extra-terrestrial origin of the KTB mass extinction. However some results indicate that a significant part of the iridium content in sediments has a volcanic origin. Radiochemical Neutron Activation Analysis (RNAA) in some KTB samples and in basic and ultra-basic rocks show that, unlike in volcanic products, no PGE (platinoids) fractionation appears in KTB samples. The nearby chondritic PGE pattern supports an extra-terrestrial origin for the KTB iridium anomaly. 2 figs., 2 tabs., ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

Three copper-based alloys, CDA 102 (oxygen-free, high-purity copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni), are candidates for the fabrication of high-level radioactive-waste disposal containers. Waste will include spent fuel assemblies from reactors as well as borosilicate glass, and will be sent to the prospective repository site at Yucca Mountain in Nye County, Nevada. The decay of radionuclides will result in the generation of substantial heat and in fluxes of gamma radiation outside the containers. In this environment, container materials might degrade by atmospheric oxidation, general aqueous phase corrosion, localized corrosion (LC), and stress corrosion cracking (SCC). This volume is a critical survey of available data on pitting and crevice corrosion of the copper-based candidates. Pitting and crevice corrosion are two of the most common forms of LC of these materials. Data on the SCC of these alloys is surveyed in Volume ...

Energy Technology Data Exchange (ETDEWEB)

The Segmented Rail Phased Induction Motor (SERAPHIM) is a compact, pulsed linear induction motor (LIM) offering a unique capability for very high speed train propulsion. It uses technology developed for the Sandia coilgun, an electromagnetic launcher designed to accelerate projectiles to several kilometers per second. Both aluminum cylinders and plates were accelerated to a kilometer per second (Mach 3) by passing through a sequence of coils which were energized at the appropriate time. Although this technology was developed for ultra-high velocity, it can be readily adapted to train propulsion for which, at sea level, the power required to overcome air resistance limits the operational speed to a more modest 300 mph. Here, the geometry is reversed. The coils are on the vehicle and the ``projectiles`` are fixed along the roadbed. SERAPHIM operates not by embedding flux in a conductor, but by excluding it. In this propulsion scheme, pairs of ...

Energy Technology Data Exchange (ETDEWEB)

A new separation process of saturated fatty acids (lauric acid-myristic acid) using crystallization from an aqueous ethanol solution has been examined. There were two vessels in this separation process: an extraction vessel and a crystallization vessel. The fatty acids in the aqueous phase were first extracted from their organic phase (melt) in the extraction vessel. The fatty acids in the aqueous phase were continuously introduced to the crystallization vessel, and then the fatty acids were crystallized there. The crystals of the fatty acids were collected continuously above the aqueous phase in the crystallization vessel. In this process, the yield and the purity of the crystals over time were measured, and it was found that the purity of lauric acid increased unsteadily up to 0.98 mole fraction of lauric acid with an increase in the yield of the low yield range. The mole fraction of ethanol in the aqueous phase could be significant to ...

Energy Technology Data Exchange (ETDEWEB)

(methine-{sup 3}H)1,1-Di-(4-chlorophenyl)-2,2,2-trichloroethane ((methine-{sup 3}H)DDT) and its di-(4-nitrophenyl) analog, both of high purity with a moderately high specific activity were prepared. Chloro-benzene was condensed with (1-{sup 3}H)1-(4-chlorophenyl)-2,2,2-trichloro-ethanol, which has been synthesized by sodium boro({sup 3}H)hydride reduction of 4-chlorophenyl trichloromethyl ketone. The purified ({sup 3}H)DDT had a specific activity of 0.77 Ci/mmol (28.49 GBq/mmol). (methine-{sup 3}H)1,1-Diphenyl-2,2,2-trichloroethane was similarly synthesized and was nitrated to give (methine-{sup 3}H)1,1-di-(4-nitrophenyl)-2,2,2-trichloro-ethane of 1.63 Ci/mmol (60.31 GBq/mmol). Dehydrochlorination with housefly enzyme (glutathione-dependent DDT dehydrochlorinase) showed a remarkable isotope effect. For DDT, the observed tritium isotope effect on V{sub max}/K{sub m} was 11.51{plus minus}0.52. For the nitro-analog, the value ...

International Nuclear Information System (INIS)

Full text: A Large Sample Neutron Activation Analysis (LSNAA) facility is under development at GRR-1 research reactor, NCSR 'Demokritos'. The LSNAA facility design incorporates sample irradiation in the reactor's graphite thermal neutron column and subsequent measurement of the activity induced at a gamma spectroscopy system with gamma ray transmission measurement options included. Monte Carlo neutron and photon transport code MCNP-4C was used to model the facility. Appropriate correction factors accounting for neutron field perturbation during sample irradiation, high purity germanium detector efficiency for the volume source and gamma ray self-absorption within the sample itself were derived. The results of the computations were experimentally verified by activation foil measurements for a set of known materials and a range of sample sizes extending up to 10 litters. Moreover, the special issue of large sample analysis of non-homogeneous ...

CERN Document Server

Constrained quantum dynamics is used to propose a nonlinear dynamical equation for pure states of a generalized coarse-grained system. The relevant constraint is given either by the generalized purity or by the generalized invariant fluctuation, and the coarse-grained pure states correspond to the generalized coherent i.e. generalized nonentangled states. Open system model of the coarse-graining is discussed. It is shown that in this model and in the weak coupling limit the constrained dynamical equations coincide with an equation for pointer states, based on Hilbert-Schmidt distance, that was previously suggested in the context of the decoherence theory.

International Nuclear Information System (INIS)

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"-"6/s and its experimental verification could be carried out. And, it was also found that as a result of evaluation of ...

Energy Technology Data Exchange (ETDEWEB)

LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} was prepared through a solid-state reaction using various Ni precursors. The effect of precursors on the electrochemical performance of LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} was investigated. LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} made from Ni(NO{sub 3}){sub 2}.6H{sub 2}O shows the best charge-discharge performance. The reversible capacity of LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} is about 145 mAh g{sup -1} and remained 143 mAh g{sup -1} after 10 cycles at 3.0-5.0 V. The XRD results showed that the precursors and the dispersion methods had significant effect on their phase purity. Pure spinel phase can be obtained with high energy ball-milling method and Ni(NO{sub 3}){sub 2}.6H{sub 2}O as precursor. Trace amount of NiO and Li{sub 2}MnO{sub 3} phase were detected in LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} with manual-mixture method and using Ni(CH{sub 3}COO){sub 2}.6H{sub 2}O, NiO and Ni{sub 2}O{sub 3} as precursors. (author)

International Nuclear Information System (INIS)

Nitric acid leaching from the weak base anion (WBA) exchanger had been evaluated and based on this a 5% mixture of nitric acid loaded weak base anion exchanger with fresh weak base anion exchanger (NLWBA) at the bottom of the ion exchange column has been devised to maintain an outlet pH in the range of 5.0 to 5.5 during Gd removal from the moderator system of TAPP - 3 and 4. A three layered bed had been constituted wherein strong acid cation (SAC) exchanger is placed as the top layer while a mixed bed of SAC and WBA or pure WBA is used as the middle layer and the 5% NLWBA was used as the bottom most layer. This bed configuration would result in an iso-pH regime in the moderator system during the Gd removal along with quantitative removal of Gd. Two three-layer bed columns were prepared at TAPS - 3 and 4 in July 07. The resin was loaded in batches and after preparing the column, the column was deuterated with heavy water (> 99.75 % w/w) at a steady flow rate of 280 ml/min. After ...

Energy Technology Data Exchange (ETDEWEB)

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and has very limited therapeutic options. Recently, it has been found that hyaluronic acid (HA) shows selective binding to CD44 receptors expressed in most cancer histotypes. Since the trend in cancer treatment is the use of targeted radionuclide therapy, the aim of this research was to label HA with rhenium-188 and to evaluate its potential use as a hepatocarcinoma therapeutic radiopharmaceutical. Methods: {sup 188}Re-HA was prepared by a direct labelling method to produce a ReO(O-COO){sub 2}-type coordination complex. {sup 188}Re-HA protein binding and its stability in saline, phosphate buffer, human serum and cysteine solutions were determined. Biokinetic and dosimetric data were estimated in healthy mice (n=60) using the Medical Internal Radiation Dose methodology and mouse model beta-absorbed fractions. To evaluate liver toxicity, alanine aminotranferase (AST) and aspartate aminotranferase (ALT) levels in mice ...

Energy Technology Data Exchange (ETDEWEB)

This paper deals with an experimental study of ultra-precision diamond cutting of magnesium alloy (AZ31). In order to investigate the machinability such as the cutting force and the surface integrity and understand the problems in a micro cutting, the experiments on the diamond cutting of magnesium alloy and pure aluminum with an ultra-precision turning machine has been carried out. The machinability of magnesium alloy was compared with that of pure aluminum and discussed. Consequently, both the thrust force component and the surface roughness obtained by cutting of magnesium alloy became larger than that of pure aluminum. It was also found that the inclusions or the defects in the work material caused to generate the scratches on the finished surface and influenced the integrity of mirror surface. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Ultra-short-pulse reflectometry is studied by means of the numerical integration of a one-dimensional full-wave equation for ordinary modes propagating in a plasma. The numerical calculations illustrate the potential of using the reflection of ultra-short-pulse, microwaves as an effective probe of the density profile even in the presence of significant density fluctuations. The difference in time delays of differing frequency components of the microwaves can be used to deduce the density profile. The modification of the reflected pulses in the presence of density fluctuations is examined and can be understood based on considerations of Bragg resonance. A simple and effective profile-reconstruction algorithm using the zero-crossings of the reflected pulse and subsequent Abel inversion is demonstrated. The robustness of the profile reconstruction algorithm in the presence of a sufficiently small amplitude density perturbation is assessed.

International Nuclear Information System (INIS)

A set of advanced models implemented into the simulator Sentaurus Process was applied to simulate ultra shallow junction formation by flash lamp annealing (FLA). The full path transient enhanced diffusion model includes equations for small interstitial clusters (I_2, I_3, I_4), #left brace#3 1 1#right brace# defects and dislocation loops. A dopant-point defect clustering model is used for dopant activation simulation. Several cluster types are considered: B_2, B_2I, B_2I_2, B_3I, B_3I_2, B_3I_3 for boron and As_2, As_2V, As_3, As_3V, As_4, As_4V for arsenic. Different point defect and dopant-point defect pair charge states are taken into account to obtain accurate results in the high doping level region. The flux expressions in the three-phase segregation model include a dependence on the doping level and point defect supersaturation. The FLA process was performed at various peak temperatures in a Mattson Millios"T"M fRTP"T"M system. The ...

International Nuclear Information System (INIS)

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 ...

International Nuclear Information System (INIS)

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. ...

International Nuclear Information System (INIS)

The processes which are currently studied in the fabrication of B-doped ultra shallow junctions (USJ) usually involve a preamorphization step to reduce B channelling effect during implantation and to improve B electrical activation. At this stage a high amount of Si interstitial atoms (Is), which dramatically increases the B diffusivity, is introduced. The introduction of voids in Si is a promising tool to control B transient enhanced diffusion (TED), because of their ability to capture Is. In this work the efficiency of a cavity band to reduce B TED is checked in silicon interstitial supersaturation conditions, obtained by high dose Si implantation. He is implanted either at 10 keV or at 50 keV with a fluence of 5 x 10"1"6 cm"-"2. Conventional techniques to introduce and activate the B (conventional ion implantation and rapid thermal annealing (RTA)) are applied in order to have a better control of the technological ...

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 ...

Science.gov (United States)

In order to understand how matter 15 billion years ago in the form of quarks, gluons and leptons at a temperature of 2 (times) 10(sup 12) (degrees)K evolved to become today's Universe, the goal of relativistic and ultra-relativistic heavy ion physics is t...

Science.gov (United States)

Measurements using radioactive targets are important for the determination of key reaction path ways associated with the synthesis of the elements in nuclear astrophysics (sprocess), advanced fuel cycle initiative (transmutation of radioactive waste), and stockpile stewardship. High precision capture cross-section measurements are needed to interpret observations, predict elemental or isotopical ratios, and unobserved abundances. There are two new detector systems that are presently being commissioned at Los Alamos National Laboratory for very precise measurements of (n,{gamma}) and (n,f) cross-sections using small quantities of radioactive samples. DANCE (Detector for Advanced Neutron-Capture Experiments), a 4 {pi} gamma array made up of 160 BaF{sub 2} detectors, is designed to measure neutron capture cross-sections of unstable nuclei in the low-energy range (thermal to {approx}500 keV). The high granularity and high ...

Energy Technology Data Exchange (ETDEWEB)

For a wider application of GaAs single crystals for semiconductor devices a cheaper process to grow crystals with high purity and low dislocation density is required. According to todays knowledge the Czochralski method with a hot wall vessel should be the choice. The temperature of the vessel has to be 700deg C to avoid condensation of arsenic which vapourizes from the 1240deg C hot melt. Arsenic vapour is very agressive against all metals. Therefore the corrosion resistance of metals and alloys with a high melting point and also ceramics has been tested. All the alloys under investigation are corroded severely so that they have to be excluded as a material for the vessel. The metals tantalum, molybdenum and tungsten are more resistent, titanium forms initially a thick protection layer and further corrosion is greatly reduced. The ceramics investigated (TiB{sub 2}; ALN; Makor; BN) are not attacked by arsenic though they ...

British Library Electronic Table of Contents (United Kingdom)

Phycocyanin - a major phycobiliprotein constitutively produced by many cyanobacteria hold several promising applications in diagnostics, biomedical research, and therapeutics. This paper discusses a novel rapid method for the purification of cyanobacterial phycocyanin (C-PC) from Phormidium fragile using hydrophobic interaction chromatography. The protein was extracted and concentrated by grinding under liquid nitrogen and ammonium sulfate fractionation. C-PC was purified by single step hydrophobic interaction chromatography. Purified phycocyanin showed absorbance maximum (lmax) at 624nm. The criterion of purity (R) achieved was 4.52. Phycocyanin to phycoerythrin and phycocyanin to allophycocyanin purity ratio were 3.85 and 7.49, respectively. The purified protein showed a pI of 5.2 and ha...

International Nuclear Information System (INIS)

Classical beam line ion implantation is limited to low energies and cannot achieve P+/N junctions requested for <45nm ITRS node. RTA (rapid thermal annealing) needs to be improved for dopants activation and damage reductions. Spike annealing process also induces a large diffusion mainly due to TED (transient enhanced diffusion). Compared to conventional beam line ion implantation limited to a minimum energy implantation of 200eV, plasma immersion ion implantation (PIII) is an emerging technique to get ultimate shallow profiles (as-implanted) due to no lower limitation of energy and high dose rate. On the another hand, laser thermal processing (LTP) allows to obtain very shallow junction with no TED, abrupt profile and activated depth control. In this paper, we show the implementation of the BF_3 PIII associated with the LTP. Ions from BF_3"+ plasma have been implanted in 200mm n-type silicon wafers with energies from 100eV to 1keV and doses from 3E14 to ...

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. In general, the conversion of electric energy to useful ...

International Nuclear Information System (INIS)

Crystallization procedure is considered to have adaptability to new reprocessing process based on the PUREX process because it has an advantage in recovering rather pure uranium from contaminated uranium solution without reagent. NEXT (New Extraction System for TRU Recovery) process has been developed by JNC, and applying the crystallization process unit to NEXT process has a capability to contribute to an improvement of economical efficiency and reduction of liquid waste in NEXT process. Thus following studies were carried out. In crystallization process unit, UNH (Uranyl Nitrate Hydrate)-crystals are washed by a nitric acid solution to get high decontamination factor, but the data on UNH-crystals dissolution by washing procedure is insufficient to evaluate the effectiveness of crystallization process unit. So, in this study, the effect of a nitric acid concentration to UNH-crystals dissolution and decontamination factor was tested. As results, it was found that ...

Energy Technology Data Exchange (ETDEWEB)

6 mm diameter current leads made of M1, M3 copper and L62 brass are tested for extension of operation range of current leads supplying superconducting devices submerged into the cryostat. Data characterizing the effect of material purity on lead superheating are obtained. A theoretical model permitting to obtain analytical dependences for calculating the current lead maximum temperature is proposed and the possibility of its decrease by increasing current lead diameter in the hot part is considered.

International Nuclear Information System (INIS)

[5'-"3H]-3'-Azido-3'-deoxythymidine (3) was prepared at a specific activity of 14.0 Ci/mmol by a two-step synthetic sequence involving controlled oxidation of the unlabelled compound (1) to the 5'-aldehyde (2) followed by reduction with ["3H]-NaBH_4. Purification was performed by preparative TLC. The radiochemical purity was 99.2%. (author).

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 ...

International Nuclear Information System (INIS)

Aim: Compounds such "9"9"mTc-MDP and "9"9"mTc-HEDP are used regularly in bone scintigraphy for metastasis detection. The therapeutics properties of beta emitter radionuclides like "1"5"3Sm, "1"6"6Ho and "1"7"7Lu has been widely reported in literature being "1"7"7Lu the less developed for medical applications. With the purpose of study different radiopharmaceuticals alternatives, for metastasis bone palliation, we have evaluated, on a comparative basis, the labeling of "1"5"3Sm-MDP, "1"5"3Sm-HEDP, "1"6"6Ho-MDP, "1"6"6Ho-HEDP, "1"7"7Lu-MDP and "1"7"7Lu-HEDP from the exhibited radionuclidic purity and biological distribution point of view. Material and Methods: The radionuclides were produced at La Reina Research Reactor, Chilean Nuclear Energy Commission. The radionuclidic purity was determined by gamma-Ray spectrometry. The labeling was accomplished with MDP (Plenum) and HEDP synthesized in-house. The in-vitro affinity of labeled compounds to ...

International Nuclear Information System (INIS)

In this paper, we propose to characterize boron transient enhanced diffusion (TED) for processes currently used for P"+/N ultra-shallow junctions (USJ) fabrication. Indeed, the fundamental understanding of boron diffusion for low energy boron implantation is mandatory to evaluate the scalability of such processes for the coming complementary metal-oxide-semiconductor (CMOS) transistor generations. In these experiments, we characterize the boron anomalous diffusion, thanks to boron buried marker-layers obtained by epitaxial growth. B"+ and BF_2"+ ultra-low energy (ULE) implantations and plasma doping (PLAD) using BF_3 as precursor gas are carried out to compare the two techniques used for advanced USJ fabrication. Boron diffusion behaviors are analyzed via secondary ion mass spectrometry for annealing at 700 deg. C for 5 min and 15 min. Finally this paper brings some physical insights explaining the technological benefit coming from PLAD ...

CERN Document Server

The process of radiation induced electron capture by protons or deuterons producing new ultra low momentum neutrons and neutrinos may be theoretically described within the standard field theoretical model of electroweak interactions. For protons or deuterons in the neighborhoods of surfaces of condensed matter metallic hydride cathodes, such conversions are determined in part by the collective plasma modes of the participating charged particles, e.g. electrons and protons. The radiation energy required for such low energy nuclear reactions may be supplied by the applied voltage required to push a strong charged current across a metallic hydride surface employed as a cathode within a chemical cell. The electroweak rates of the resulting ultra low momentum neutron production are computed from these considerations.

Energy Technology Data Exchange (ETDEWEB)

In this paper, the design of large thin PIN detector with a membrane stress avoidance configuration is proposed, and the related device fabrication process is developed. Ultra-thin PIN detector {approx} 1.13 cm{sup 2} in area is fabricated on a thin ( {approx} 35{mu}m) silicon membrane, and characterized. Detector performance improvement has been successfully demonstrated. With the membrane stress avoidance design, the improved detector exhibits a leakage of 6nA, which is at least 5 times lower than that of detector of identical junction area. The new detector features a full depleted capacitance of 110 pF, and a FWHM of 40.86 keV energy resolution for 5.486 MeV alpha particle spectrography.

Science.gov (United States)

The authors studied the resolution of racemic glycidol through esterification with butyric acid catalyzed by porcine pancreatic lipase in organic media. A screening of seven solvents (log P values between 0.49 and 3.0, P being the n-octanol-water partition coefficient of the solvent) showed that neither log P nor the logarithm of the molar solubility of water in the solvent provides good correlations between enantioselectivity and the properties of the organic media. Chloroform was one of the best solvents as regards the enantiometic purity (e.p.) of the ester produced. In this solvent, the optimum temperature for the reaction was determined to be 35C. The enzyme exhibited maximum activity at a water content of 13 [plus minus] 2% (w/w). The enantiomeric purity obtained was 83 [plus minus] 2% of (S)-glycidol butyrate and did not depend on the alcohol concentration or the enzyme water content for values of these parameters up to 200 mM and 25% ...

International Nuclear Information System (INIS)

A cell calculation code SLAROM-UF was developed to improve calculation accuracy of effective cross sections for various fast reactor types. SLAROM-UF has a capability to calculate effective cross sections in ultra fine groups of about 100,000 below 50keV and in fine groups above the energy (maximum 900 groups). Resonance interaction among the fuel, the coolant, and the structure materials can be treated accurately even in a heterogeneous cell structure. Temperature can be set up freely in a cell by the ultra fine group calculation. Improvement in nuclear characteristics was observed in the analysis of JUPITER critical experiment, as 0.1% for criticality, 4% for sodium void reactivity, several % for radial reaction rate distribution, when SLAROM-UF was used instead of the typical cell calculation code. The effect of the ultra fine group calculation is remarkable in the non-leakage term of sodium void reactivity, and that of ...

Science.gov (United States)

Channel plasmon polaritons (CPPs) propagating along the bottom of subwavelength grooves cut into a metal surface were recently shown to exhibit strong confinement combined with low propagation loss, a feature that makes this guiding configuration very promising for the realisation of ultra-compact photonic components. Here, the results of our investigations of CPP guiding by V-grooves cut into gold are presented, demonstrating efficient large-angle bending and splitting of radiation as well as waveguide-ring resonators and Bragg grating filters.

International Nuclear Information System (INIS)

Technological processes of welding are significant sources of pollution in the working area. Evaluation of chemical quality of working area was made by means of radionuclide x-ray fluorescence analysis and activation analysis with fast neutrons. Welding aerosols were sampled by filtration method on Synpor 4 membrane ultra-filters. For selected types of welding filter metals, determination of heavy metals in aerosols was performed. (author).

Energy Technology Data Exchange (ETDEWEB)

A method based on the collection of [sup 99]Tc from 500 l sea water samples by anion exchange and further extraction of TcO[sub 4][sup -] into 5% triisooctylamine-xylene has been improved to include a decontamination factor 6.5x10[sup 5] for uranium. The detection limit for [sup 99]Tc is thereby reduced to 3 mBq/m[sup 3].

International Nuclear Information System (INIS)

The basic approach to radioactive labeling techniques in hemoglobin identification consists of mixing 14C labeled normal carrier globin with 3H labeled unknown globin and carrying out the subsequent separations and purifications looking at the distribution of 3H and 14C radioactivity. This technique was devised to ascertain the amino acid substitution in Hb Indianapolis and was instrumental in solving the structure of Hb Vicksburg. It was also useful in determining the purity of gamma-chains from cultures of human and baboon erythroid progenitors. Another use of this technique would be in identifying aberrant peaks of radioactivity in chain separation chromatograms, such as ''pre-peaks''.

Energy Technology Data Exchange (ETDEWEB)

An isotopic exchange method was used to label lipiodol with [sup 131]I. The labelling efficiency was > 92.5%, and the radiochemical purity of [[sup 131]I]lipiodol was above 98% as determined by ITLC. The influencing factors e.g. the heating temperature, reaction, pH and storage conditions were studied and the optimum conditions were determined. In a pilot study injecting [[sup 131]I]lipiodol for the treatment of hepatoma, about 70% of hepatoma patients had a response to the treatment with a reduction of [alpha]-fetoprotein and decrease of hepatoma sizes. The overall median survival was 9 months (range 2-17 months). (author).

Energy Technology Data Exchange (ETDEWEB)

Ohio State University (OSU) is uniquely poised to establish such a center, with interdisciplinary emphasis on modeling, simulation, design and control of hybrid-electric drives for a number of reasons, some of which are: (1) The OSU Center for Automotive Research (CAR) already provides an infrastructure for interdisciplinary automotive research and graduate education; the facilities available at OSU-CAR in the area of vehicle and powertrain research are among the best in the country. CAR facilities include 31,000 sq. feet of space, multiple chassis and engine dynamometers, an anechoic chamber, and a high bay area. (2) OSU has in excess of 10 graduate level courses related to automotive systems. A graduate level sequence has already been initiated with GM. In addition, an Automotive Systems Engineering (ASE) program cosponsored by the mechanical and electrical engineering programs, had been formulated earlier at OSU, independent of the GATE program proposal. The ...

International Nuclear Information System (INIS)

Fluorine is known to have a beneficial role for the B diffusion reduction in preamorphized Si, and is promising for the realization of ultra-shallow junctions. Thus, we studied the F incorporation in Si during the solid phase epitaxy (SPE) process, pointing out the effects of the implanted F energy and fluence and the role played by the possible presence of dopants. The incorporation of fluorine proceeds by F segregation at the amorphous-crystalline interface, with a kinetics driven by the SPE rate. In fact, the quicker the SPE rate, the higher is the F fluence retained. Moreover, we demonstrated that F incorporated in Si layers does not appreciably affect the Is emission from spatially separated end-of-range (EOR) defects. The modification, induced by the presence of F, of the point defect density (Is and Vs) was also studied by means of B and Sb spike layers, used as local markers for Is and Vs, respectively. We showed that F is not only able to completely ...

Energy Technology Data Exchange (ETDEWEB)

A 19.1 metre wind turbine blade was subjected to static tests. The purpose of the test series was to verify the abilities of different types of sensors to detect damage in wind turbine blades. Prior to each of the static test-series an artificial damage was made on the blade. The damage made for each test-series was surveyed during each series by acoustic emission, fiber optic micro bend displacement transducers and strain gauges. The propagation of the damage was determined by use of ultra sonic and X-ray surveillance during stops in the test series. By use of acoustic emission it was possible to measure damage propagation before the propagation was of visible size. By use of fiber optic micro bend displacement transducers and strain gauges it was possible to measure minor damage propagation. By use of both ultra sonic, and X-ray NDT-equipment it were possible to determine the size of propagated damage. (au)

Energy Technology Data Exchange (ETDEWEB)

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 photoelectron spectroscopy is reported for both the as-deposited and ...

British Library Electronic Table of Contents (United Kingdom)

An extremely sensitive stripping voltammetric procedure for ultra-trace determination of iridium(III) is reported. The method is based on the interfacial accumulation of the iridium(III)-CTAB complex onto the glassy carbon electrode, followed by the catalytic reduction of the adsorbed complex in the presence of bromate. 0.3molL^-^1 acetate buffer pH 4.7+6.9x10^-^2molL^-^1 NaBrO3+2.7x10^-^5molL^-^1 cetyltrimethylammonium bromide (CTAB)+0.2molL^-^1 KCl was employed as the supporting electrolyte. The analytical procedure was verified by the analysis of the standard reference materials: Sea Water BCR-CRM 403 and Fresh Water NIST-SRM 1643d. The accuracy, expressed as relative error e%, was satisfactory, being lower than 6%, while precision as repeatability, expressed as relative standard deviat...

Energy Technology Data Exchange (ETDEWEB)

Overhead persistent surveillance systems are becoming more capable at acquiring wide-field image sequences for long time-spans. The need to exploit this data is becoming ever greater. The ability to track a single vehicle of interest or to track all the observable vehicles, which may number in the thousands, over large, cluttered regions while they persist in the imagery is very desirable. Typically, this imagery has many thousands of pixels on a side and is characterized by lower resolutions (e.g. {approx}0.5 meters/pixel to {approx}2.0 meters/pixel) and lower frame rates (e.g. {approx} sub-Hz to several Hz). We describe our ultra-scale capable implementation of a multiple-vehicle tracking algorithm for overhead persistent surveillance imagery. This work builds upon an earlier report, where now the algorithm has been modified for improved performance and has been substantially improved to handle much larger datasets in a much shorter time.

Energy Technology Data Exchange (ETDEWEB)

There is growing interest in using {sup 242m}Am as a nuclear fuel for space reactors and nuclear batteries. In this paper, we discuss different {sup 242m}Am enrichments, as well as fuel weight requirements, to produce a critical reactor. It was found that relatively low enrichments of {sup 242m}Am, about 10 w/o, are enough to guarantee criticality. Such low enrichments might eliminate the need for a {sup 242m}Am enrichment process. It was also found that the best results for low {sup 242m}Am requirements are obtained with a moderator to fuel volume ratio of 10,000.

Energy Technology Data Exchange (ETDEWEB)

Zeolite Y is the active component of most commercial cracking catalysts. Interaction of H[sub 3]PO[sub 4] with extraframework aluminum of ultra-stable zeolite (USY) leads to the formation of different types of aluminum phosphates, while there is no indication of the formation of SAPO zeotype structures. The total acidity of USY slightly decreases upon the H[sub 3]PO[sub 4] treatment, while the maximum in the distribution of acid strength is shifted to milder acidities. Dealumination of the zeolite and creation of POH sites associated with AIPO[sub 4] are responsible for the modifications observed. 37 refs., 8 figs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

It is shown that all contracting, spatially homogeneous, orthogonal Bianchi cosmologies that are sourced by an ultra-stiff fluid with an arbitrary and, in general, varying equation of state asymptote to the spatially flat and isotropic universe in the neighbourhood of the big crunch singularity. This result is employed to investigate the asymptotic dynamics of a collapsing Bianchi type IX universe sourced by a scalar field rolling down a steep, negative exponential potential. A toroidally compactified version of M*-theory that leads to such a potential is discussed and it is shown that the isotropic attractor solution for a collapsing Bianchi type IX universe is supersymmetric when interpreted in an 11-dimensional context.

Science.gov (United States)

Current dewatering methods for ultra-fine coal suspensions are inadequate and usually require subsequent expensive thermal drying. This unique dewatering method is based on pressurized electroosmosis, the movement of water by an electrical field through a porous medium, under modest pressure, e.g., 110 psi. More ultra-fine coal can be utilized since an effective dewatering process can be realized by combining known filtration techniques with electroosmosis. The dewatering efficiency can be significantly improved, the residual moisture of the cake can be substantially reduced and handling problems can be eliminated. Bench-scale testing is being used to optimize the parameters which influence pressurized electroosmotic dewatering (PED) of ultra-fine coal suspensions. Particle size distribution is being addressed to obtain a maximum density for a given pressure such that pore saturation is maintained allowing electroosmosis to ...

Science.gov (United States)

The primary goal of this project is to obtain a better understanding of thermophilic microorganisms which convert acetic acid to CH[sub 4]. The previous funding period represents a departure from earlier research in this laboratory, which was more physiological and ecological. The present work is centered on the biochemistry of the thermophile Methanothrix sp. strain CALS-1. this organism presents a unique opportunity, with its purity and relatively rapid growth, to do comparative biochemical studies with the other major acetotrophic genus Methanosarcina. We previously found that Methanothrix is capable of using acetate at concentrations 100 fold lower than Methanosarcina. This finding suggests that there are significant differences in the pathways of methanogenesis from acetate in the two genera.

Energy Technology Data Exchange (ETDEWEB)

Heavy ion irradiation on tantalum metal target with 57 MeV {sup 11}B{sup 4+} leads to the production of no-carrier-added radioisotopes of platinum, {sup 187,188}Pt and iridium, {sup 187,188}Ir in the matrix, which have been effectively separated from the bulk target and from each other with suitable anion exchangers employing liquid-liquid extraction (LLX). Also {sup 188,189}Pt and {sup 188,189}Ir radionuclides have been produced, from their short-lived precursors {sup 188,189}Au, in {sup 12}C{sup 6+} irradiated tantalum matrix. Gamma-spectroscopy has been utilised to determine the production, extent of separation and purity of the radiotracers at different stages of the experiment. (orig.)

Energy Technology Data Exchange (ETDEWEB)

A LLX procedure for carrier-free separation of the radioisotopes, {sup 47}Sc, {sup 48}V and {sup 48},{sup 49},{sup 51}Cr, the 40 MeV {alpha}-particle activation products of titanium has been developed. Sequential separations of the radionuclides produced in the titanium matrix through the nuclear reactions ({alpha}, {alpha}p{chi}n), ({alpha}, p{chi}n) and {alpha}, ({chi}n) have been performed through LLX from aqueous H{sub 2}SO{sub 4} and HClO{sub 4} acid media using the liquid cation exchanger, HDEHP, as an extractant. Purity of the carrier-free radiotracers at different stages of their separations has been verified by {gamma}-ray spectrometry. (author).

International Nuclear Information System (INIS)

We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10-6 S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

Energy Technology Data Exchange (ETDEWEB)

Corrosion failures in circuits of foreign NPPs are considered. According to American statistics there are more corrosion failures in two-circuit NPPs than in NPPs with one circuit. Steam generators mostly suffer from ''corrosion denting''. Lately pitting corrosion becomes a potentially serious problem. Steam generator vertical tubes are mainly subjected to this corrosion type. Attention is drawn to intercrystalline corrosion. The causes of corrosion are described. The problem of optimization of structural materials is discussed to reduce corrosion failures as well as other methods of decreasing corrosion failures. Organization of nondestructive testing, increased requirements to water and steam purity are of great importance.

Energy Technology Data Exchange (ETDEWEB)

The availability of polysilicon feedstock has become a major issue for the photovoltaic (PV) industry in recent years. Most of the current polysilicon feedstock is derived from rejected material from the semiconductor industry. However, the reject material can become scarce and more expensive during periods of expansion in the integrated-circuit industry. Continued rapid expansion of the PV crystalline-silicon industry will eventually require a dedicated supply of polysilicon feedstock to produce solar cells at lower costs. The photovoltaic industry can accept a lower purity polysilicon feedstock (solar-grade) compared to the semiconductor industry. The purity requirements and potential production techniques for solar-grade polysilicon have been reviewed. One interesting process from previous research involves reactive gas blowing of the molten silicon charge. As an example, Dosaj et all reported a reduction of metal and boron impurities from ...

Energy Technology Data Exchange (ETDEWEB)

The formation, migration and agglomeration in silicon of fluorine-vacancy complexes have been monitored by single-detector Doppler broadening spectroscopy. After electronics engineers found that fluorine ion implantation effectively eliminated the transient-enhanced diffusion of dopants in the creation of ultra-shallow junctions, a vital step in the further miniaturization of device structures, positron beams have played a pivotal role in providing an insight into the mechanisms underlying this phenomenon, being able to detect FV complexes in implanted and annealed samples. Secondary Ion Mass Spectrometry has provided complementary information on fluorine concentrations so that the nature of the F{sub m}V{sub n} complexes can be further assessed. New results on Si and SiGe structures are presented.

Energy Technology Data Exchange (ETDEWEB)

The conductive ultra thin films were fabricated from mixed monolayers containing stearic acid and Head-to-Tail poly(3-alkylthiophene). These films exhibited well-defined layered structures as determined by optical absorption and X-ray diffraction measurements. The UV-Vis absorption spectra of these films showed lower energy absorption shifts of 48 nm from that of the random poly(3-alkylthiophene)/stearic acid LB films. The blue shift of absorption maximum of the LB film is attributed to the increase of {pi}-conjugation length caused by no steric hindrance of alkyl side chains. The conductivity of the Head-to-Tail poly(3-hexylthiophene)/stearic acid LB films was greatly improved in the range of 67-100 S/cm. (orig.)

British Library Electronic Table of Contents (United Kingdom)

A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function...

Energy Technology Data Exchange (ETDEWEB)

Availability of a natural gas-powered van that meets California`s ultra low emission vehicle requirements and has a 300-km range was reported. A similar van with an electric system giving a range of 240 km was also within sight. Regarding the limitations of electric batteries it was suggested that a super capacitor may allow systems to achieve higher energy densities; a refuelable zinc-air battery could be considered for vehicle use. While the prospect for emissions improvement of gasoline vehicles has clearly improved in recent years, the relative costs of infrastructure, vehicle and fuel for the the alternative fuels compared with gasoline demonstrate the difficulty the alternative fuels have in taking market share from gasoline. For the next decade, gasoline, propane and CNG are expected to be the dominant fuels for vehicles. After that, the leading fuel will be the one that has been most extensively researched and developed during the decade. 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.).

Science.gov (United States)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional and multi-component seismic area is being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil-in-place will result in additional oil production by primary and enhanced recovery processes.

Science.gov (United States)

The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, methods for improved completion efficiency and the suitability of waterflooding in Red River and Ratcliffe shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing three-dimensional and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with extended-reach jetting lance and other ultra-short-radius lateral technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil in place will result in additional oil recovery by primary and enhanced recovery processes.

British Library Electronic Table of Contents (United Kingdom)

In many drug dispensing devices, such as syringes and inhalers, an elatomeric gasket is used to prevent the formulation from leaking from the chamber. During device actuation, the seal is subjected to friction, which in turn causes its deformation and can cause unintentional leakage, thus dose variability. Additionally, friction of seal is responsible for a host of potential problems such undue effort required for actuation and potential wear. The mechanism of friction generation in the seal conjunction is complex, arising from adhesion of rubber in contact with the moving interface, viscous action of a thin film of fluid and deformation of seal asperities. Therefore, the first step in understanding the conjunctional behaviour of rubber seals is a fundamental study of mechanisms of frictio...

Energy Technology Data Exchange (ETDEWEB)

Reducing implant energy is an effective way to eliminate transient enhanced diffusion (TED) due to excess interstitials from the implant. It is shown that TED from a fixed Si dose implanted at energies from 0.5 to 20 keV into boron doping-superlattices decreases linearly with decreasing Si ion range, virtually disappearing at sub-keV energies. However, for sub-keV B implants diffusion remains enhanced and x{sub j} is limited to {ge} 100 nm at 1,050 C. The authors term this enhancement, which arises in the presence of B atomic concentrations at the surface of {approx} 6%, Boron-Enhanced-Diffusion (BED).

Energy Technology Data Exchange (ETDEWEB)

The Advanced Neutron Source will be a new world-class facility for research using hot, thermal, cold, and ultra-cold neutrons. The heart of the facility will be a 330-MW (fission), heavy-water cooled and heavy-water moderated reactor. The reactor will be housed in a central reactor building, with supporting equipment located in an adjoining reactor support building. An array of cold neutron guides will fan out into a large guide hall, housing about 30 neutron research stations. Appropriate office, laboratory, and shop facilities will be included to provide a complete facility for users. The ANS is scheduled to begin operation at the Oak Ridge National Laboratory early in the next decade. This PDR document defines the plant-level requirements for the design, construction, and operation of ANS. It also defines and provides input to the individual System Design Description (SDD) documents. Together, this PDR document and the set of SDD documents will define and ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is to determine the thermal reliability of stearic acid, palmitic acid, myristic acid and lauric acid as latent heat energy storage materials with respect to various numbers of thermal cycles. The fatty acids, as phase change materials (PCMs), of industrial grade (purity between 90% and 97%) were subjected to accelerated thermal cycle tests. The differential scanning calorimetry (DSC) analysis technique was applied to the PCMs after 0, 120, 560, 850 and 1200 melt/freeze cycles in order to measure the melting temperatures and the latent heats of fusion of the PCMs. The DSC results indicated that the change in melting temperature for the PCMs was in the range of 0.07-7.87 {sup o}C, and the change in latent heat of fusion was -1.0% to -27.7%, except for stearic acid between 560 and 1200 melt/freeze cycles. However, the decrease in the latent heats of fusion for all the PCMs was not regular with increasing thermal cycles. The experimental ...

International Nuclear Information System (INIS)

The synthesis of ["1"1C]phenobarbital, ["1"1C]pentobarbital and["1"1C]amobarbital labelled in the 5-[1-"1"1C]ethyl position is reported. The malonic esters R- CH(CO_2Et)_2 [R phenyl-, 1-methylbutyl-, and 3- methylbutyl- were alkylated with [1-"1"1C]ethyl iodide prepared from ["1"1C]carbon dioxide. Ring closure of the 2-[1-"1"1C]ethyl-labelled malonic esters with urea afforded 5-[1-"1"1C]ethyl-phenobarbital,-phenobarbital, -pentobarbital and -amobarbital synthesis times of 42-47 min, counted from ["1"1C] carbon dioxide. In typical syntheses starting with 3 GBq pentobarbitol and (81 mCi) ["1"1C]carbon dioxide, 150-215 MBq (4-6 mCi) were produced in 25-30% decay corrected -amobarbital radiochemical yields with radiochemical purities greater than 98%. (author).

Science.gov (United States)

Plerocercoids of the tapeworm Spirometra mansonoides produce a substance that stimulates growth of experimental hosts. We report purification of plerocercoid growth factor (PGF) to homogeneity by a process involving isolation and solubilization of plerocercoid membranes, isoelectric point selection by chromatofocusing chromatography or preparative isoelectric focusing, and anion-exchange chromatography. A radioreceptor assay (RRA) for human growth hormone (hGH) was used to detect PGF and purity of the 27.5-kDa protein was judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Proteolytic activity was detected in the 27.5-kDa protein by gelatin substrate PAGE. Characterization of PGF as a neutral cysteine proteinase was based on substrate and inhibitor specificities and dependence on pH and thiol-containing reagents. The association of hGH agonist and proteinase activities was shown by comparing RRA and hydrolytic activities in the presence ...

Energy Technology Data Exchange (ETDEWEB)

A method was developed to synthesize /sup 14/C-labelled n-alkanes for use in cigarette smoke studies. Specifically, n-(18-/sup 14/C)-octatriacontane was synthesized from 1 mCi (1-/sup 14/C)stearic acid in a radiochemical yield of 20%. The key features of this synthesis were two consecutive alkylations of tosylmethyl isocyanide followed by acid hydrolysis to (18-/sup 14/C)-19-octatriacontanone and modified Wolff-Kishner reduction to the n-alkane. After purification on silica gel 25 mg of (18-/sup 14/C)octatriacontane was obtained with a total radioactivity of 200 ..mu..Ci, a specific activity of 4.3 mCi/mmol, and a radiochemical purity in excess of 98% by thin layer radiochromatography. The method has also been applied to the synthesis of unlabeled n-pentatriacontane and is considered to be generally applicable to the synthesis of radiolabeled alkanes from radiolabeled fatty acids.

Energy Technology Data Exchange (ETDEWEB)

A radiochemical charged particle activation procedure for production and separation of carrier free {sup 52,56}Mn, {sup 55,56,58}Co and {sup 56,57}Ni has been developed. The radioisotopes produced on bombardment of an iron foil target with a 40 MeV {alpha}-particle beam through the nuclear reactions, Fe({alpha}, {alpha}pxn){sup 52,56}Mn, Fe({alpha}, pxn){sup 55,56,58}Co and Fe({alpha}, nx){sup 56,57}Ni, have been separated by LLX. The target element and the activation products have been sequentially separated from an HCl medium using diethylether and the liquid anion exchanger, TIOA, as extractants. Extent of separation and purity of the carrier free radiotracers at different stages of their LLX separation have been verified by taking recourse to {gamma}-ray spectrometry. (Author).

Energy Technology Data Exchange (ETDEWEB)

The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a matter of seconds, with a chemical yield and radioactive ...

CERN Document Server

We study an exactly solvable model where an uniformly accelerated detector is linearly coupled to a massless scalar field initially in the Minkowski vacuum. Using the exact correlation functions we show that as soon as the coupling is switched on one can see information flowing from the detector to the field and propagating with the radiation into null infinity. By expressing the reduced density matrix of the detector in terms of the two-point functions, we calculate the purity function in the detector and study the evolution of quantum entanglement between the detector and the field. Only in the ultraweak coupling regime could some degree of recoherence in the detector appear at late times, but never in full restoration, as an earlier work seems to suggest. We explicitly show that under the most general conditions the detector never recovers its quantum coherence and the entanglement between the detector and the field remains large at late times. To the extent ...

CERN Document Server

In single-qubit quantum secret sharing, a secret is shared between N parties via manipulation and measurement of one qubit at a time. Each qubit is sent to all N parties in sequence; the secret is encoded in the first participant's preparation of the qubit state and the subsequent participants' choices of state rotation or measurement basis. We present a protocol for single-qubit quantum secret sharing using polarization entanglement of photon pairs produced in type-I spontaneous parametric downconversion. We investigate the protocol's security against eavesdropping attack under common experimental conditions: a lossy channel for photon transmission, and imperfect preparation of the initial qubit state. A protocol which exploits entanglement between photons, rather than simply polarization correlation, is more robustly secure. We implement the entanglement-based secret-sharing protocol with 87% secret-sharing fidelity, limited by the purity of the entangled state ...

International Nuclear Information System (INIS)

In this study, perovskite type oxide YAlO_3 has been doped with different amounts of the divalent cation Ca to synthesize Y_1_-_xCa_xAlO_3_-_#delta# (x = 0-0.21) compositions. The effect of dopant concentration on the crystal structure and electrical properties of YAlO_3 synthesized by citrate gel route has been investigated. The phase purity of the samples has been carried out using X-ray diffraction. The microstructural evaluation of the samples has been conducted by scanning electron microscopy and energy dispersive spectrum analysis. Thermal analysis has been conducted to monitor the decomposition of the intermediate products. The electrical conductivity studies have been performed using a.c. impedance spectroscopy as a function of temperature in the range 200-800 "oC in air. The Y_0_._9_4Ca_0_._0_6AlO_3_-_#delta# composition exhibits a total conductivity of 2.5 mS/cm at 800 "oC.

International Nuclear Information System (INIS)

A simple and rapid laser fluorometric determination of trace and ultra trace level of uranium in a wide variety of low uranium content materials like soil, basic and ultra basic rocks, plant ash, coal fly ash and red mud samples is described. Interference studies of some common major, minor and trace elements likely to be present in different geological materials on uranium fluorescence are studied using different fluorescence enhancing reagents like sodium pyrophosphate, orthophosphoric acid, penta sodium tri-polyphosphate and sodium hexametaphosphate. The accurate determination of very low uranium content samples which are rich in iron, manganese and calcium, is possible only after the selective separation of uranium. Conditions suitable for the quantitative single step extraction of 25 ng to 20 #mu#g uranium with tri-n-octylphosphine oxide and single step quantitative stripping with dilute neutral sodium pyrophosphate, which also acts as ...

International Nuclear Information System (INIS)

Ultra low loading noble metal (0.04-0.12 mg_P_t/cm"2) based electrodes were obtained by direct metallization of non-catalyzed gas diffusion layers via dual ion beam assisted deposition (IBAD) method. Fuel cell performance results reported earlier indicate significant improvements in terms of mass specific power density of 0.297 g_P_t/kW with 250 A thick 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 in contrast to the state of the art power density of 1.18 g_P_t/kW using 1 mg_P_t_(_M_E_A_)/cm"2 at 0.65 V. In this article we report the peroxide radical initiated attack of the membrane electrode assembly utilizing IBAD electrodes in comparison to commercially available E-TEK (now BASF Fuel Cell GmbH) electrodes and find the pathway of membrane degradation as well. A novel segmented fuel cell is used for this purpose to relate membrane degradation to peroxide generation at the electrode/electrolyte interface by means of ...

International Nuclear Information System (INIS)

To accomplish the environmental radiological surveillance need of India's ambitious nuclear power programme, Health Physics Division is infusing new technologies and improved analytical techniques for day to day measurements of various radionuclides in different environmental matrices. It is essential to have techniques for measuring the concentration of radionuclides just above the background level since the discharges from the nuclear facilities are very low i.e. in the range of 5-10% of the prescribed discharge limits by the regulatory bodies. In view of developing ultra-sensitive techniques, the aim of ongoing programmes of the division is to meet the challenges of measuring ultra trace level of radioactivity by adopting state of art new instrumentation and improved sample processing techniques. This will allow us to measure the lowest level of radioactivity (3H, 90Sr, 137Cs, 239+240Pu, etc.) in the environment and thereby estimating the ...

International Nuclear Information System (INIS)

Oxide superconducting thin films were irradiated with X-rays and ultra-violet (UV) light, and induced radiation effects on electrical and chemical properties were examined by transport measurement, X-ray diffraction analysis (XRD), diamagnetization measurement and X-ray photoemission spectroscopy (XPS). After irradiation for ErBa_2Cu_3O_x films with X-rays emitted from a Rh tube for 100 hours, superconductivity was remarkably damaged, destroying the zero-resistance state. The UV-light irradiation for Bi_2Sr_2CaCu_2O_x films was performed in He gas of about 500 Pa with a low pressure mercury lamp. The superconductivity was gradually degraded with the UV irradiation time up to 70 minutes. In both cases, adequate oxygen-annealing treatments restored superconductivity. The X-ray photoemission spectra showed that the mean Cu valence of the films was decreased approximately from +2 to +1 by the irradiation. From these results we can find that irradiation with the X-ray ...

International Nuclear Information System (INIS)

Critical experiments have been analyzed to verify a nuclear analysis system for fast reactors used in Japan Nuclear Cycle Development Institute (JNC). The experiments were performed in a collaboration work between JNC and the Institute of Physics and Power Engineering of Russia to dispose Russian surplus weapons plutonium, focusing on the effect of the introduction of uranium-plutonium mixed-dioxide (MOX) fuel and stainless steel reflector into the current BN-600 core that is comprised of UO_2 fuel and blanket. The analysis results agreed well with measured values on most of the nuclear characteristics. The accuracies are comparable to those obtained for the conventional MOX fueled fast reactors. It suggests that the JNC analysis system can analyze accurately nuclear characteristics in uranium fueled cores as well. A significant improvement was achieved on the sodium void reactivity by employing an ultra fine group cell calculation system. A change in adjoint ...

Scientific Electronic Library Online (English)

Abstract in english Frontal weapon is the term used to designate the apparatus consisting of frontal gland and associated structures that participate in the chemical defense of termite soldiers. The ultra structure of the frontal gland and the scanning microscopy of the soldier head was investigated in the termite Amiitermes euamignathus Silvestri, 1901.Campaniform sensilla was not observed but there were 80 to100 sensory bristles around the frontal pore. The glandular epithelium shows only (more) class 1 cells according 10 the classification of NOIROT & QUENNEDEY (1974, 1991). The glandular cells are characterized by apical microvilli, a basal labyrinth and a large quantity of smooth endoplasmic reticulum which forms dense zones throughout the cytoplasm. The secretion is concentrated mainly in the basal pole of the cell and consists of large lipid droplets. The secretory epithelium is covered by a thick apical cuticle composed of a thin outer epicuticle, a ...

Energy Technology Data Exchange (ETDEWEB)

In this study, the effects of 325nm wavelength ultraviolet light irradiation on pitting corrosion behavior of type 340 stainless steel in a neutral chloride solution are studied. Further, the change of passive film with the light irradiation is analyzed using x-ray photoelectron spectroscopy. The mains results obtained therefrom are stated below. Pitting potential can be shifted in noble direction by the ultraviolet light irradiation. The effect of ultraviolet light irradiation is ore prominent in the pitting corrosion process than that in the passive film formation. The result of the analysis in terms of the birth and death stochastic probability process shows that pitting corrosion rate is decreased remarkably by the ultraviolet light irradiation at the formation of passive film, while the repassivation is slightly expedited by the ultraviolet light irradiation. On the other hand, the repassivation rate is increased a little by the ultraviolet light irradiation during the pitting ...

Energy Technology Data Exchange (ETDEWEB)

We report the direct molecular dynamics simulations for molecular ball bearings composed of fullerene molecules (C{sub 60} and C{sub 20}) and multi-walled carbon nanotubes. The comparison of friction levels indicates that fullerene ball bearings have extremely low friction (with minimal frictional forces of 5.283 x 10{sup -7} and 6.768 x 10{sup -7} nN/atom for C{sub 60} and C{sub 20} bearings) and energy dissipation (lowest dissipation per cycle of 0.013 and 0.016 meV/atom for C{sub 60} and C{sub 20} bearings). A single fullerene inside the ball bearings exhibits various motion statuses of mixed translation and rotation. The influences of the shaft's distortion on the long-ranged potential energy and normal force are discussed. The phonic dissipation mechanism leads to a non-monotonic function between the friction and the load rate for the molecular bearings.