Pulmonary Alveolar Proteinosis in Workers at an Indium Processing Facility
UK PubMed Central (United Kingdom)
Two cases of pulmonary alveolar proteinosis, including one death, occurred in workers at a facility producing indium-tin oxide (ITO), a compound used in recent years to make flat panel displays. Both...Full Text Available
2010-03-01
Simple chemical method for nanoporous network of In2S3 platelets for buffer layer in CIS solar cells
British Library Electronic Table of Contents (United Kingdom)
Indium sulfide thin films consisting of porous network of nanoplatelets, have been deposited using chemical bath deposition (CBD) method onto the tin-doped indium oxide (ITO) coated glass substrate. Aqueous solutions of indium sulfate and thioacetamide have been used as indium and sulfur precursors. As a complexing agent, acetic acid was used. The chemically deposited indium sulfide thin films were examined for their structural, surface morphological and optical characterizations. The X-ray diffraction analysis revealed the formation of the cubic b-In2S3 onto the substrate. From scanning electron micrograph, it is observed that the surface of substrate is covered by nanoporous platelets type morphology. The optical studies showed a direct band gap of 2.84eV for indium sulfide platelets. Ph...
2008-01-01
Electrochemical deposition of indium sulfide thin films using two-step pulse biasing
British Library Electronic Table of Contents (United Kingdom)
Indium sulfide thin films were deposited onto indium-tin-oxide coated glass substrate by electrochemical deposition from an aqueous solution containing In2 (SO4) 3 and Na2S2O3. The deposition conditions were optimized on the basis of data obtained by scanning electron microscope, Auger electron spectroscopy and optical transmission measurements. Furthermore, the photosensitivity of the films was observed by means of photoelectrochemical measurements, which confirmed that the indium sulfide showed n-type conduction. The X-ray diffraction and Raman studies revealed that the as-grown films were amorphous or nanocrystalline in nature and became polycrystalline In2S3 after annealing.
2008-01-01
Tin doping in spray pyrolysed indium sulfide thin films for solar cell applications
British Library Electronic Table of Contents (United Kingdom)
This paper presents studies carried out on tin-doped indium sulfide films prepared using Chemical Spray Pyrolysis (CSP) technique. Effect of both in-situ and ex-situ doping were analyzed. Ex-situ doping was done by thermal diffusion, which was realized by annealing Sn/In2S3 bilayer films. In-situ doping was accomplished by introducing Sn into the spray solution by using SnCl45H2O. Interestingly, it was noted that by ex-situ doping, conductivity of the sample enhanced considerably without affecting any of the physical properties such as crystallinity or band gap. Analysis also showed that higher percentage of doping resulted in samples with low crystallinity and negative photosensitivity. In-situ doping resulted in amorphous films. In contrast to ex-situ doping, `in- situ doping' resulted i...
2010-01-01
International Nuclear Information System (INIS)
The description is presented of binary phase diagrams of titanium alloyed with the following elements: silver, aluminium, arsenic, gold, boron, barium, beryllium, bismuth, carbon, calcium, cadmium, cobalt, chromium, copper, iron, gallium, germanium, hydrogen, hafnium, indium, iridium, potassium, lithium, magnesium, manganese, molybdenum, nitrogen, sodium, niobium, nickel, oxygen, osmium, phosphorus, lead, palladium, platinum, plutonium, rhenium, lanthanium, cerium, preseodymium, neodymium, gadolinium, erbium, terbium, thulium, lutetium, rhodium, ruthenium, scandium, silicon, tin, strontium, tantalum, technetium, thorium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc and zirconium.
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...
2010-01-01
On the mechanism of the anodic protection of aluminium alloy AA5182 by emeraldine base coatings
Energy Technology Data Exchange (ETDEWEB)
Aluminium AA5182 coupons covered by a polyaniline film in the emeraldine base (EB) form showed increasing corrosion potential and decreasing corrosion current as a function of the thickness of the polymer layer. The cathodic reaction was proved not limited by diffusion of species inside the electrolyte solution and oxygen had no effect on the electrochemical behaviour of the coated samples. An EB coating on indium tin oxide conducting layer appeared slightly electroactive in neutral media. The IR spectra of aluminium coated samples, before and after heating in argon atmosphere, confirmed a redox reaction between the polymer film and the metal. This galvanic coupling can explain the good protective behaviour of emeraldine base against corrosion of aluminium.
2007-03-01
UK PubMed Central (United Kingdom)
Attention has shifted from the treatment of colorectal cancer (CRC) to chemoprevention using aspirin and folic acid as agents capable of preventing the onset of colon cancer. However, no sensitive...Full Text Available
2010-09-01
SOLID STATE RESEARCH OF THE APPLIED PHYSICS ...
... 10 TIN TELLURIDE Preparation of Tin Telluride Single Crystals ..... 12 ... TIN TELLURIDE Preparation of Tin Telluride Single Crystals ...
1962-07-16
Energy Technology Data Exchange (ETDEWEB)
One of the most challenging topics in the area of organic electronic devices is the growth of transparent electrodes onto flexible polymeric substrates that will be characterized by enhanced conductivity in combination with high optical transparency. An essential aspect for these materials is their synthesis and/or microstructure which define the transparency, the stability and the interfacial chemistry which in turn determine the performance and stability of the organic electronic devices, such as organic light emitting diodes, organic photovoltaics, etc. In this work, we will discuss the latest advances in the growth of organic (e.g. PEDOT:PSS) and inorganic (e.g. zinc oxide-ZnO, indium tin oxide-ITO) conductive materials and their deposition onto flexible polymeric substrates. We will compare the optical, structural, nano-mechanical and nano-topographical properties of the inorganic and organic materials and we investigate the effect of ...
2009-12-15
Monitoring interface traps in operating organic light-emitting diodes using impedance spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Electronic trap densities at the indium tin oxide (ITO)/hole transport layer (HTL) interface in operating organic light-emitting diodes (OLEDs) are characterized in situ using impedance spectroscopy. For OLEDs with a high density of active trap states, negative values of the frequency derivative of resistance are clearly observable for frequencies on the order of 10 kHz, whereas positive values are observed when the trap density is low With this technique, it is revealed that the trap density is minimized via the introduction of a TPD-Si{sub 2} (4,4'-bis[(p-trichlorosilylpropylphenyl) phenylamino]-biphenyl) passivation layer at the ITO/HTL interface or by the application of large electric fields during device operation. Furthermore, impedance spectroscopy illustrates that the ITO/HTL interface is not a simple series resistance when traps are present since they are shown not to contribute to high frequency conduction. Overall, this ...
2007-04-09
Metal cation inhibitors for controlling denting corrosion in steam generators. Final report. [PWR
Metal cations of arsenic, antimony, tin, manganese, zinc, cadmium, indium, and thallium have been evaluated in a preliminary way as possible3 inhibitors for controlling denting corrision observed in steam generators used with pressurized water reactors (PWR). The rationale for this approach was based upon the well-known inhibition effects of metal cations on corrosion rates in electrolyte/metal systems. A review of corrosion inhibition by metal cations (H. Leidheiser, Jr., Corrosion 36, 339 (1982)) has identified eleven inhibition mechanisms. The major test methods used for this evaluation were: (1) Isothermal capsule tests of carbon/steel/Inconel 600 tube bulging rates at temperatures up to 288/sup 0/C in seawater/copper-nickel chloride bulge-accelerating solutions. (2) Immersion weight-loss tests of steel coupled to Inconel 600 in boiling (102/sup 0/C) 3% sodium chloride solutions. In addition, electrochemical measuremens and surface analyses ...
1982-12-01
International Nuclear Information System (INIS)
Research was conducted at Pacific Northwest Laboratory to develop high photosensitivity adaptive optical elements utilizing ion implanted lanthanum-doped lead-zirconate-titanate (PLZT). One centimeter square samples were prepared by implanting ferroelectric and anti-ferroelectric PLZT with a variety of species or combinations of species. These included Ne, O, Ni, Ne/Cr, Ne/Al, Ne/Ni, Ne/O, and Ni/O, at a variety of energies and fluences. An indium-tin oxide (ITO) electrode coating was designed to give a balance of high conductivity and optical transmission at near uv to near ir wavelengths. Samples were characterized for photosensitivity; implanted layer thickness, index of refraction, and density; electrode (ITO) conductivity; and in some cases, residual stress curvature. Thin film anti-ferroelectric PLZT was deposited in a preliminary experiment. The structure was amorphous with x-ray diffraction showing the beginnings of a structure at substrate temperatures of ...
We study the emission zone in a single-layer polymer light-emitting diode. The emission zone is found by studying the angular distribution of the electroluminescence. The emission is modeled by accounting for optical interference. We account for birefringence of the anode layer in our model. The active polymer was, however, found to be isotropic. The anode consists of a single-layer of the conducting polymer complex poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate) (PEDOT-PSS), with enhanced conductivity. As a cathode we use plain aluminum. By using only PEDOT-PSS we avoid having a thin metal layer or indium-tin-oxide as the anode in the path of the escaping light. The active material is a substituted polythiophene with excellent film forming properties. A comparison between the experimental and calculated angular distribution of light emission from a single-layered polymer light-emitting diode was shown to be in good agreement for the spectral region ...
2001-06-01
Synthesis and Structural Characterization of a Novel Indium ...
Robert A. Martock. Cleveland State University, Cleveland, Ohio. Synthesis and Structural Characterization of a. Novel Indium Mercapto Derivative. [Clln(SCH. 2 ...
Energy Technology Data Exchange (ETDEWEB)
A specific radiochemical procedure for indium determination in semiconductor-grade silicon, using an inorganic ion exchanger (cerium oxalate) is proposed.
1982-12-23
Tin Whisker Observations on Pure Tin-Plated Ceramic Chip - NASA
was to mount Pd-Ag terminated MLCCs onto gold plated mounting pads of a ... to protect against incorrect shipment of pure tin-plated MLCCs when Pd-Ag ...
Implant damage and redistribution of indium in indium-implanted thin silicon-on-insulator
Energy Technology Data Exchange (ETDEWEB)
The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10{sup 14} cm{sup -2}) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure.
2004-12-15
Implant damage and redistribution of indium in indium-implanted thin silicon-on-insulator
International Nuclear Information System (INIS)
The indium implant damage and diffusion behavior in thin silicon-on-insulator (SOI) with a 200 nm top silicon layer were studied for different implantation energies and doses. Rutherford backscattering spectrometry in the channeling mode (RBS/C) was used to characterize the implant damage before and after annealing. Secondary ion mass spectrometry (SIMS) was used to study the indium transient enhanced diffusion (TED) behavior in the top Si layer of the SOI structure. An anomalous redistribution of indium after relatively high energy (200 keV) and dose (1 x 10"1"4 cm"-"2) implantation was observed in both bulk Si and SOI substrates. However, there exist differences in these two substrates that are attributable to the more predominant out-diffusion of indium as well as the influence of the buried oxide layer in the SOI structure.
2004-12-15
Half-lives of 35 radionuclides
International Nuclear Information System (INIS)
... 67 gamma detection hafnium 180 half-life indium 111 iodine 125 iodine 131
International Nuclear Information System (INIS)
A highly reliable screening method was developed for the determination of lead in tin plated layers and tin-bismuth plated layers. The contents of lead in the layers of the various samples were determined by inductively coupled plasma optical emission spectrometry. The calibration curve for lead in the tin and tin-bismuth plated layers by using WD-XRF exhibited linear correlation from 130 #mu#g/g to 2070 #mu#g/g. Calibration curve of lead normalized with Pb-L#alpha#/Sn-K#alpha# intensity was more linear, and this method was possible to evaluate very small sample. The calibration curve for lead in the tin plated layers by using ED-XRF was good linearly, but it for lead in the tin-bismuth plated layers was affected by Pb-L#alpha# spectrum and Bi-L#alpha# spectrum overlap each other. It was effective for decreasing affect of Bi-L#alpha# spectrum by using curve ...
2009-03-01
Energy Technology Data Exchange (ETDEWEB)
We developed a new systematic calibration procedure which was applied to the prediction of the diffusivity, the segregation, and transient enhanced diffusion (TED) of an indium impurity. The TED of the indium impurity was studied using four different experimental conditions. Although indium is susceptible to TED, rapid thermal annealing (RTA) is effective in suppressing the TED effect and maintaining a steep retrograde profile. Like boron impurities, the indium shows significant oxidation-enhanced diffusion in silicon and has segregation coefficients much less than 1 at the Si/SiO{sub 2} interface. In contrast to boron, the segregation coefficient of indium decreases as the temperature increases. The accuracy of the proposed procedure was validated by using secondary ion mass spectrometry (SIMS) data and by using the 0.13-{mu}m device characteristics, such as V{sub th} and I{sub ...
2005-02-15
International Nuclear Information System (INIS)
We developed a new systematic calibration procedure which was applied to the prediction of the diffusivity, the segregation, and transient enhanced diffusion (TED) of an indium impurity. The TED of the indium impurity was studied using four different experimental conditions. Although indium is susceptible to TED, rapid thermal annealing (RTA) is effective in suppressing the TED effect and maintaining a steep retrograde profile. Like boron impurities, the indium shows significant oxidation-enhanced diffusion in silicon and has segregation coefficients much less than 1 at the Si/SiO_2 interface. In contrast to boron, the segregation coefficient of indium decreases as the temperature increases. The accuracy of the proposed procedure was validated by using secondary ion mass spectrometry (SIMS) data and by using the 0.13-#mu#m device characteristics, such as V_t_h and I_d_s_a_t, for ...
2005-02-01
Development of zirconium alloys. Part II
A number of alloys of zirconium have been investigated as part of a program aimed at improving the high-temperature tensile and creep strength of zirconium. These alloys include aluminum, beryllium, lead, magnesium, molybdenum, niobium, tantalum, tin, titanium, tungsten, vanadium, and zinc, binary and ternary alloys. The data indicate that aluminum, lead, molybdenum niobium, tin, titanium, tungsten, and vanadium can be used successfully to harden zirconium, and that aluminum, tin, titanium, and vanadium are particularly effective in maintaining the strength of zirconium at elevated temperatures.
1952-01-02
The synthesis and structural characterization of a novel In(III) complex is described. The reaction
2004-01-01
International Nuclear Information System (INIS)
It has been demonstrated that, by incorporating a thin #approx#20 nm Si_1_-_yC_y (with y as low as 0.1%) layer at the deep indium implant end-of-range (EOR) region, the EOR defects and enhanced diffusion behavior associated with indium implant can be eliminated. The Si_1_-_yC_y layer was grown epitaxially followed by a silicon epitaxy cap of 60 nm. Indium implantations were performed at 1x10"1"4 cm"-"2 at 115 keV followed by spike annealing at 1050 deg. C. The experimentally observed EOR defect and enhanced diffusion elimination are explained based on the undersaturation of implantation-induced silicon interstitials with the presence of substitutional carbon at the Si_1_-_yC_y layer.
2003-11-17
Indium(III) Compounds Containing the Neopentyl Substituent ...
... learn more about the thermal stability of InNP2 Me, a sample contained in a previously evacuated tube was heated at 100°C for 13 days. Neither ...
1989-02-24
British Library Electronic Table of Contents (United Kingdom)
Within the framework of the effective-mass approximation, using a variational method, we have calculated the effect of intense laser radiation on the binding energy of the shallow-donor impurities in a Ga1- x In x N y As1- y /GaAs single quantum well for different nitrogen and indium mole concentrations. Our numerical results show that the binding energy strongly depends on the laser intensity and frequency (via the laser dressing parameter) and it also depends on the nitrogen and indium concentrations. Impurity binding energy under intense laser fields can be tuned by changing the nitrogen and indium mole fraction.
2011-01-01
Bandgap properties of the indium sulfide thin-films grown by co-evaporation
British Library Electronic Table of Contents (United Kingdom)
In the present study the optical properties of co-evaporated indium sulfide thin films are investigated. Before being optically characterized, the composition as well as the crystalline properties of the film have been checked with the help of energy dispersive spectroscopy (EDX) and X-Ray diffraction (XRD) analyses. The optical absorption coefficient ? of this indium sulfide film has been deduced from reflectivity R(?) and transmission T(?) measurements. The fit of the curve representing ?(h?) suggests that the ?-In2S3 has an indirect bandgap of 2.01?eV. Density functional theory (DFT) calculations are performed on this indium sulfide compound, using TB-LMTO code. Through these band structure investigations, an indirect bandgap is predicted as observed experimentally. The top of the valen...
2009-01-01
Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)
Energy Technology Data Exchange (ETDEWEB)
Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has ...
2006-06-15
Target fabrication of low-density and nano porous materials to generate extreme ultraviolet (EUV)
International Nuclear Information System (INIS)
Our institute has been investigating laser-produced tin, lithium and xenon plasma for extreme ultraviolet (EUV) light source of EUV lithography system, and found the highest conversion efficiency of 3% at 13.5 nm in 2% bandwidth. In the present paper, we introduce fabrication methods of density-controlled tin targets to generate relatively monochromatic EUV, and higher conversion efficiency than bulk tin. The first method is the nano-template method, where liquid tin solution was immersed into a polymer film with monodispersed size nano-particle. The density can be controlled by tin concentration of the solution. The target can be classified into mass-limited target. We have shown a tendency of monochromatic EUV emission around 13.5 nm with decreasing of tin density. The intensity was higher than tin foil with bulk density. The tendency has ...
2006-06-01
Flow Vaporization of CO{sub 2} in Microchannel Tubes
Energy Technology Data Exchange (ETDEWEB)
Carbon dioxide is receiving renewed interest as an efficient and environmentally safe refrigerant in a number of applications, including mobile air conditioning and heat pump systems, and hot water heat pumps. Compact heat exchangers for CO{sub 2} systems are designed with small-diameter tubing. The purpose of this study is therefore to provide a better basis for understanding and predicting heat transfer and pressure drop during flow vaporization of CO{sub 2} in microchannels. The ''unusual'' properties of carbon dioxide give heat transfer and two-phase flow characteristics that are very different from those of conventional refrigerants. Examples of these differences are the much higher pressure, the resulting high vapour density, a very low surface tension, and a low liquid viscosity. High pressure and low surface tension has a major effect on nucleate boiling characteristics, and earlier test data have shown a clear dominance of nucleate boiling ...
2002-07-01
Evaluating the cytotoxicity of palladium/magnetite nano-catalysts intended for wastewater treatment
International Nuclear Information System (INIS)
Palladium/magnetite nanoparticulate catalysts were developed for efficient elimination of halogenated organic pollutants from contaminated wastewater. Particle recovery from treated water can be ensured via magnetic separation. However, in worst-case scenarios, this catalyst removal step might fail, leading to particle release into the environment. Therefore, a toxicological study was conducted to investigate the impact of both pure magnetite and palladium/magnetite nanoparticle exposure upon human skin (HaCaT) and human colon (CaCo-2) cell lines and a cell line from rainbow trout gills (RTgill-W1). To quantify cell viability after particle exposure, three endpoints were examined for all tested cell lines. Additionally, the formation of reactive oxygen species was studied for the human cells. The results showed only minor effects of the particles on the tested cell systems and support the assumption that palladium/magnetite nano-catalysts can be implemented for a ...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
The effect of heat treatment on the corrosion behavior of reactive plasma sprayed TiN coatings in simulated seawater was investigated by electrochemical methods such as the corrosion potential-time curve (Ecorr-t), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and SEM, etc. The results showed that the corrosion potential of TiN coatings increased after heat treatment; the corrosion current of the TiN coatings after heat treatment (be hereafter referred to as HT-TiN) was 13.3% of the untreated coatings (be hereafter referred to as UT-TiN), and the polarization resistance of HT-TiN was 20 times of UT-TiN, which indicated that the heat treatment had significantly increased the corrosion resistance of the coatings. The corrosion behavior of the coatings was mainly ...
2011-01-01
New and old Sn isomers produced in heavy-ion collisions
International Nuclear Information System (INIS)
The energy level schemes of tin isotopes produced in the heavy ion reactions are presented. The using of #gamma# spectroscopy technique is also described. 4 refs, 12 figs.
1991-12-01
ELECTRICAL AND OPTICAL PROPERTIES OF LEAD-TIN ...
... Abstract : Single crystals of Pb(x)Sn(1-x)Te alloy have been grown with o = or thin film evaporator. ...
1969-09-03
Counting characteristics of X-ray detectors fabricated from indium-doped, gallium-doped, and chlorine-doped CdTe have been investigated. The detectors fabricated from indium-doped and gallium-doped crystals showed radiation-induced polarization, namely, a progressive decrease of count rate with an increase of photon fluence in the high-photon-fluence region, while the detectors fabricated from chlorine-doped crystals did not. Results from current-voltage characteristics of the detectors indicated that the different counting characteristics of these detectors originated from the difference in internal electric fields in each detector.
1995-08-01
NREL preprints for the 23rd IEEE Photovoltaic Specialists Conference
Energy Technology Data Exchange (ETDEWEB)
Topics covered include various aspects of solar cell fabrication and performance. Aluminium-gallium arsenides, cadmium telluride, amorphous silicon, and copper-indium-gallium selenides are all characterized in their applicability in solar cells.
1993-05-01
Indium Arsenide (InAs) Quantum ... - Glenn Research Center - NASA
Oct 16, 2006 ... Williams, F.; and Nozik, A.J.: Irreversibilities in Mechanism of Photoelectrolysis. Nature, vol. 271, no. 5641, 1978, pp. 137-139. Luque, A.; and ...
Energy Technology Data Exchange (ETDEWEB)
We report on the elimination of defect formation which is associated with high dose indium implantations under solid phase epitaxial regrowth (SPER) annealing conditions of 650-800 deg. C. This is achieved by incorporating a layer of epitaxially grown Si{sub 1-y}C {sub y} layer, strategically located at the end-of-range (EOR) of the implant profile. An indium implant of 115 keV at 1 x 10{sup 14} cm{sup -2} was performed followed by annealing at temperature ranges of 650-800 deg. C. Samples with the Si{sub 1-y}C {sub y} layer revealed the elimination of secondary EOR defects with effectively suppressed indium transient enhanced diffusion (TED), indicating the function of carbon as an efficient sink for silicon interstitials at reduced annealing temperatures, in the SPER dopant activation regime.
2006-05-10
2-[(4-MepyH)2]2+ - GLTRS - NASA
Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [Clln(SCH2(CO)O)2]2-[(4-MepyH)2]2+. AUTHOR(S): ...
+ 2004 - The NASA Glenn Research Center Technical Report Server
May 31, 2011 ... Synthesis and Structural Characterization of a Novel Indium Mercapto Derivative [Clln(SCH2(CO)O)2]2-[(4-MepyH)2]2+. 284. System Mass ...
Design and fabrication of a traveling-wave muffin-tin accelerating structure at 90 GHz
Energy Technology Data Exchange (ETDEWEB)
A prototype of a muffin-tin accelerating structure operating at 32 times the SLAC frequency (2.856 GHz) was built for research in high gradient acceleration. A traveling-wave design with single input and output feeds was chosen for the prototype which was fabricated by wire electrodischarge machining. Features of the mechanical design for the prototype are described. Design improvements are presented including considerations of cooling and vacuum.
1997-05-01
Characterization of TiN coatings deposited on plasma nitrided tool steel surfaces
Energy Technology Data Exchange (ETDEWEB)
Wear-resistant TiN coatings deposited on tool steels are used frequently in industry. There is a trend towards further optimizing these coatings, e.g. by plasma nitriding the tool surface prior to TiN deposition. In this work the influence of the nitriding conditions on the surface properties of AISI 304 and ASP 23 tool steels was investigated. The plasma nitriding was carried out in a triode ion plating configuration normally used to deposit TiN coatings. At the surface of AISI 304 stainless steel, only a thin compound layer (Fe{sub 4}N, Fe{sub 3}N) was found, probably as a consequence of the rather slow nitrogen diffusion in the austenite matrix. For ASP 23 high speed steel, the different nitriding behaviour of the martensitic matrix causes the formation of a diffusion layer which results in an increase in hardness at the surface. On an analogous set of specimens the TiN deposition was started ...
1991-07-07
Thermoluminescence of irradiated RbCl and RbCl:Sn crystals
International Nuclear Information System (INIS)
The thermoluminescence (TL) and emission of coloured RbCl and RbCl:Sn crystals are studied in the temperature range 300 to 560 K. The glow peaks responsible for F centres and tin centres in different valence states are identified using optical bleaching studies. The glow peaks are analysed using total curve fitting method and the kinetic parameters are determined. In moderately #gamma#-irradiated tin-doped RbCl crystals, the TL emission bands observed at 4.0, 3.6, and 2.2 eV are attributed to Sn"0, Sn"+, and Sn"- centers, respectively. A comprehensive energy level diagram depicting the various TL processes in these undoped and tin-doped RbCl crystals is proposed. (author).
Effect on substrate-film adherence of TiN film enhanced plasma nitriding
International Nuclear Information System (INIS)
The combined process of low temperature plasma nitriding and TiN film deposition was realized on the plasma-assisted vacuum arc plating set. The process of plasma nitriding can be done below 200 degree C. The low temperature plasma nitriding and TiN film deposition was realized on the same device. By the SEM analysis of the plating structure, low hardness grads from the substrate to the film was obtained, and it was found that the mixed nitride plating formed at the interface between the substrate and the film. The quantitative measurement of substrate-film adherence showed that the adherence was improved notably by using the process. The adherence between film and substrate can reach to 59.6 MPa without the bias voltage supplying
2002-01-01
Tin-oxide-coated anodized aluminium selective absorber surfaces. Pt. 2. Aging and durability
Energy Technology Data Exchange (ETDEWEB)
Accelerated aging tests on tin-oxide-coated anodized aluminium selective absorber surfaces have been performed. It is shown that the tin oxide layer provides excellent protection for the anodized surface. The thermal stability of the double layer is equal to, or better than, the stability of the bare anodized surface. Both surfaces degrade very slowly at 450deg C. The anodic layer is porous and therefore not very scratch resistant and it degrades when exposed to humidity, both acidic and alcaline. It is shown that the tin oxide film, which is hard and chemically very stable, almost completely protects the anodized surface from chemical degradation. The mechanical wear resistance is also considerably improved. The optical selectivity does not quite match that of the the anodized surface, but the remarkable stability together with the solar parameters of {alpha}=0.91 and hemispherical emittance {epsilon}= 0.16 (normal ...
1991-03-01
Structural properties of Cu(In,Ga)Se2 thin films prepared from chemically processed precursor layers
International Nuclear Information System (INIS)
We have developed a chemical process for incorporating copper into indium gallium selenide layers with the goal of creating a precursor structure for the formation of copper indium gallium diselenide (CIGS) photovoltaic absorbers. Stylus profilometry, EDX, Raman spectroscopy, XRD and SIMS measurements show that when indium gallium selenide layers are immersed in a hot copper chloride solution, copper is incorporated as copper selenide with no increase in the thickness of the layers. Further measurements show that annealing this precursor structure in the presence of selenium results in the formation of CIGS and that the supply of selenium during the annealing process has a strong effect on the morphology and preferred orientation of these layers. When the supply of Se during annealing begins only once the substrate temperature reaches ? 400 deg. C , the resulting CIGS layers are smoother and have more pronounced preferred ...
2009-02-02
Measurement of the Electron Affinities of Indium and Thallium
Energy Technology Data Exchange (ETDEWEB)
The electron affinities of indium and thallium were measured in separate experiments using the laser-photodetachment electron spectroscopy technique. The measurements were performed at the University of Nevada, Reno. Negative ion beams of both indium and thallium were extracted from a cesium-sputter negative ion source, and mass analyzed using a 90{sup o} bending magnet. The negative ion beam of interest was then crossed at 90{sup o} with a photon beam from a cw 25-Watt Ar{sup +} laser. The resulting photoelectrons were energy analyzed with a 160{sup o} spherical-sector spectrometer. The electron affinity of In({sup 2}P{sub 1/2}) was determined to be 0.404 {+-} 0.009 eV and the electron affinity of thallium was determined to be 0.377 {+-} 0.013 eV. The fine-structure splittings in the ground states of the negative ions were also determined. The experimental measurements will be compared to several recent theoretical predictions.
1999-03-20
All-metal divided vaccum joints with small force of sealing
International Nuclear Information System (INIS)
The structure of a demountable vacuum joint designed for operation from -120 to +120 deg C is developed and tested. Requirements of especially low gas release from the materials used have been fulfilled; the same concerns low sealing efforts, repeated action and keeping tightness under loads, indium being used as a sealant. Experimental studies of demountable vacuum joints, dia 100,125,140,160,180 and 200 mm, with an indium sealant permit to make the following conclusions: 1. The joints are sealed at sealing specific efforts of 0.4 kg/mm (without considering atmospheric pressure). 2. The joints retain tightness at opening and closing a cover five times and under +-120 deg C. 3. To ensure repeated operation of the joint with continued stable sealing effort, one should make sure the sealed surfaces coincide at repeated sealing. 4. When operating demountable vaccum joints with indium sealant, one must take into account the ...
Rigid muffin-tin approximation for the electron-phonon interaction in transition metals
Energy Technology Data Exchange (ETDEWEB)
Progress in calculating the electron-phonon parameters of transition metals has been based on either the rigid muffin-tin approximation (RMTA) or the fitted modified tight-binding approximation (FMTBA). The RMTA has been shown to be remarkably accurate for average electron-phonon properties, but there are indications that RMTA matrix elements may be too small at low momentum transfer. An attempt is made to demonstrate these assertions concerning the accuracy of RMTA and the numerous electron-phonon calculations are placed in a broader perspective by a demonstration of how they can be used to explain the trends in the strength of the electron-phonon coupling among the transition metals and the A-15 compounds. (GHT)
1980-01-01
Characterization of (In1−xAlx)2S3 thin films grown by co-evaporation
British Library Electronic Table of Contents (United Kingdom)
In this paper, it is shown that (In1?xAlx)2S3 thin films can be grown through the co-evaporation of elemental indium, aluminum and sulfur. It is nevertheless observed that the introduction of aluminum within the indium sulfide thin films hinders the crystallites size and even yields almost amorphous films when x is 0.2. The investigations of the optical properties of the films reveal that contrary to what could be expected, the band gap increase is low; the highest values measured do not exceed 2.2eV. However, as suggested by X-ray photoelectron spectroscopy measurements, such widening most probably affects the lower conduction band states.
2010-01-01
The development of in vitro mutagenicity testing systems using T-lymphocytes
Energy Technology Data Exchange (ETDEWEB)
This annual report describes progress in studies on hprt mutations induced by radon or Indium 111 along with the corresponding mutation frequency, cloning and molecular spectra in human T-lymphocytes. Parallel studies on the mutation susceptibility between individuals is being investigated by hprt mutation studies on ataxia telangiectasia and xeroderma pigmentosum.
1993-05-01
Proposed high-resolution vertex detector using superconductive thin strips
Energy Technology Data Exchange (ETDEWEB)
The possibility of fabricating a superconductive vertex detector is discussed on the basis of a preliminary experiment. The experiment has shown that an indium strip 15 mm long, 20 ..mu..m wide and 0.1 ..mu..m thick is changed from the superconductive state to the normal state when struck by a single 5.4 MeV alpha particle.
1984-06-01
Lyme myocarditis diagnosed by indium-111-antimyosin antibody scintigraphy
Energy Technology Data Exchange (ETDEWEB)
We report a new case of Lyme disease with cardiac manifestations, which has been possible to follow during the long period of 12 years. We have detected the usual ECG abnormalities, and concentric hypertrophic myocardiopathy, by echocardiography. The acute myocarditis was demonstrated by /sup 111/In-antimyosin scintigraphy, which showed global myocardial uptake of the tracer, constituting the first report, to our knowledge, of Lyme myocarditis diagnosed by this method.
1989-06-01
UK PubMed Central (United Kingdom)
Materials with high electrical conductivity and optical transparency are needed for future flat panel display, solar energy, and other opto-electronic technologies. InxCd1-xO...Full Text Available
2001-06-19
Detection of aortoarterial graft infections by leukocyte scintigraphy
Energy Technology Data Exchange (ETDEWEB)
Infections of aortoarterial prostheses are serious, difficult to detect, and difficult to treat. Scintigraphy with indium-111 labeled autologous leukocytes is an accurate noninvasive method of assessing the presence and extent of such an infection. In three cases of aorto-arterial bypass graft infections, the leukocyte study was successful in establishing the diagnosis and in assessing the extent of infection. Other noninvasive diagnostic techniques are useful, but all have serious limitations. The leukocyte study alone appears to be free of likely sources of error.
1983-09-01
Stability studies on refined soybean oil stored in various conditions
International Nuclear Information System (INIS)
The 12 months stability study of freshly produced refined soybean oil revealed that refined soybean oil stored in plastic containers in dark was more hydrolytically and oxidatively stable than that stored in other containers in light condition. There was no significant difference at P < 0.05 in free fatty acids and acid value of oil stored under light and dark conditions in tin and glass containers but there was significant difference at P < 0.05 in peroxide value of oil stored in light and dark conditions in all the storage containers. Light increased the degree of oxidative rancidity of refined soybean oil, the most in tin containers, followed by glass containers and the least in plastic containers. (author)
2008-01-01
Plasma diagnostics by spectra from LHD and atomic data
International Nuclear Information System (INIS)
We have observed EUV spectra from the Large Helical Device (LHD) at the National Institute for Fusion Science (NIFS). We measured spectra of impurity ions; carbon, iron, xenon, tin and tungsten ions. In some cases, the plasma evolution was stable and a steady discharge was obtained, but sometimes the plasma underwent radiation collapse and rapid cooling. For carbon and iron spectra, we studied plasma diagnostics by intensity ratios of spectral lines. For other spectra of higher Z element, xenon, tin and tungsten, we studied mainly on line identifications comparing with theoretical calculations and experimental data. Related atomic data for these researches will be also discussed. (author)
2009-04-01
Partial wave expansion of ion-atom elastic scattering in solids
International Nuclear Information System (INIS)
Elastic scattering cross sections of keV protons in solids (Z=3-82) are calculated using the partial wave expansion technique and the ''muffin-tin'' bound-atom potential. The differential cross sections for small scattering angles of less than 10deg are smaller than those with the Ziegler-Biersack-Littmark potential at all energies and for all solids, although, for larger angles, the two cross sections agree with each other. The mean free paths of the protons in the solids, obtained from the total cross sections, decrease very slowly with decreasing energy. Furthermore, at low energies they approach half the nearest-neighbor distance, which is taken as the radius of the augmented plane wave sphere in the muffin-tin model of crystalline solids. (orig.).
Electronic structure of Ba(Sn,Sb)O_3: Absence of superconductivity
International Nuclear Information System (INIS)
The electronic structures of BaSnO_3, BaSbO_3, and BaPbO_3, calculated using an extended general-potential linearized augmented-plane-wave method, are reported. The electronic structures of BaSnO_3 and its 6s analog BaPbO_3 are found to be very different, explaining the absence of superconductivity in the Ba(Sn,Sb)O_3 system. These differences are explained by a combination of the relativistic lowering of the 6s states and ion-size effects. Muffin-tin-approximation augmented-plane-wave calculations for BaSnO_3 are also reported and the utility of the muffin-tin approximation for this and similar materials is discussed in terms of the differences between the two sets of calculations.
An overview of the IGC internal tin Nb_3Sn conductor
International Nuclear Information System (INIS)
We discuss the current state of the art in the IGC Internal Tin Nb_3Sn process which routinely is delivering current densities greater than 1 x 10"3 A/mm"2 at 10 Tesla. We focus especially on the conductors suitability for high current density applications such as High Energy Physics and small magnets. Projections are also made as to its suitability for high field applications such as in Fusion. A discussion of the manufacturing process is given with comparisons made to other accepted Nb_3Sn processes and NbTi. Superconductor characteristics such as filament quality and Nb_3Sn phase uniformity are compared to those obtained in conventional bronze process.
1984-09-09
An X-ray photoelectron spectroscopic study of B-N-Ti system
International Nuclear Information System (INIS)
Composite nitrides (such as BN, TiN) are widely used in various industrial applications because of their extreme wear and corrosion resistance, thermal and electrical properties. in order to obtain composite materials with these optimal properties, it is important to elucidate whether any chemical reactions occur at nitride/metal interfaces, e.g., those involving BN-Ti/TiN. Materials of interest include the deposition by PVD of Ti and TiN on BN substrates. Some of these systems were then subjected to varying degrees of physical and thermal alteration. Detailed X-ray photoelectron spectroscopy (XPS) has therefore been rendered of these interfaces using cross-sectional display and sputter etching. Resulting structural and morphological features have been investigated with transmission electron microscopy (TEM) and X-ray diffraction (XRD). Diffusion of the nitridation, oxynitride formation and interfacial growth are of general interest.
1997-04-04
Position of nuclear-medical techniques for evaluation of loosened total hip endroprostheses
Energy Technology Data Exchange (ETDEWEB)
For diagnosis of loosening or infection after implantation of a single-side or double-side total hip endoprosthesis 59 patients being in pain were investigated by a combination of bone scan (Technetium-99m DPD) and leucocyte scan (Indium-111 labelled leucocytes). The correlation between clinical results and scintigraphic findings revealed: bone scintigraphy detects loosening of prostheses with 95% sensitivity (45/47); bone scintigraphy excludes an instable prosthesis with 89% specificity (3/27). 45% of the loosened prostheses revealed an infection (21/47): leucocyte scintigraphy could detect 17 correct positive. Three leucocyte scans of 53 prostheses without clinical signs of infection were false positive. Therefore, leucocyte scintigraphy had a sensitivity of 91% and a specificity of 94% for detecting infection. Bone scintigraphy can detect loosening of prostheses with 93% accuracy, Indium-111 labelled leucocyte scintigraphy can detect ...
1985-10-01
Novel alloys to improve the electrochemical behavior of zinc anodes for zinc/air battery
Energy Technology Data Exchange (ETDEWEB)
In our continued efforts for improving the performance of zinc anodes for a Zn/air battery, we now report the preparation of three alloys and improved performances of anodes made up with these alloys. The alloys contained zinc, nickel, and indium with different weight percentages and were calcined at two different temperatures. Out of the six alloys, the alloy which has a composition of zinc 90%, nickel 7.5% and Indium 2.5% and fired at 500{sup o}C is found to be the best. In the case of the hydrogen evolution reaction, this alloy had its potential shifted to a more negative potential. As far as the cyclic voltammograms were concerned, the difference between the anodic and cathodic part was minimal when compared with other alloys. Surprisingly, this alloy had reversibility even after 100 cycles of the cyclic voltammogram. This is a clear indication that dendrite formation was reduced to a considerable extent. Images taken with a scanning ...
2006-10-06
Near-infrared photodetectors based on mercury indium telluride single crystals
Attempt to form the Schottky barrier on mercury indium telluride (MIT) surface by deposition transparent conducting electrode (TCE) and avoid the negative results by non-rectifier contacts nature, we have investigated the oxidation of clean MIT surfaces to form an insulating layer to overcome this disadvantage by metal-insulator-semiconductor (MIS) photodetectors designing. Oxide film is grown on the MIT surface by plasma enhance chemical vapor deposition (PECVD). Previously cleaned MIT wafers were dipped and boiled in solution, which consists of mixture of bromine and an organic solvent in ratio of 1:50. By the way of using these films as intermediate slightly conducting insulator, a fast-response MIT based surface-barrier photodetectors have been developed. Pt films were used as TCE frontal electrode by vacuum magnetron sputtering (VMS). The current-voltage characteristic is described quantitatively based on the energy diagram and the found parameters of the ...
2008-03-01
High-efficiency solar cell and method for fabrication
A high-efficiency 3- or 4-junction solar cell is disclosed with a theoretical AM0 energy conversion efficiency of about 40%. The solar cell includes p-n junctions formed from indium gallium arsenide nitride (InGaAsN), gallium arsenide (GaAs) and indium gallium aluminum phosphide (InGaAlP) separated by n-p tunnel junctions. An optional germanium (Ge) p-n junction can be formed in the substrate upon which the other p-n junctions are grown. The bandgap energies for each p-n junction are tailored to provide substantially equal short-circuit currents for each p-n junction, thereby eliminating current bottlenecks and improving the overall energy conversion efficiency of the solar cell. Additionally, the use of an InGaAsN p-n junction overcomes super-bandgap energy losses that are present in conventional multi-junction solar cells. A method is also disclosed for fabricating the high-efficiency 3- or 4-junction solar cell by metal-organic chemical ...
1999-08-31
The synthesis and structural characterization of a novel In(III) complex is described. The reaction between InCl3 with sodium mercapto-acetic acid, (NaSCH2(CO)OH) in 4-methylpyridine, (CH3(C5H5N), (4-Mepy)) at 25 C affords (ClIn(SCH2(CO)O)2)2- ((4-MepyH)2...
2004-01-01
Simple method for the high-temperature isolation of /sup 111/In from silver
Energy Technology Data Exchange (ETDEWEB)
A method is proposed for the quantitative high-temperature isolation of /sup 111/In from silver irradiated by ..cap alpha..-particles into a gas phase containing a mixture of HCl and H/sub 2/O with a total pressure of about 3 Pa for these gases. It is shown that the indium evolved into the gas phase probably occurs in the form of at least three compounds, viz.., the trichloride, monochloride, and oxychloride, which have adsorption temperatures on quartz of around 385, 475, and 655 K, respectively. All these compounds are readily washed from the surface of quartz apparatus by a weak (0.05 M) solution of hydrochloric acid.
1987-07-01
Aluminium, gallium and indium complexing with methylthymol blue
International Nuclear Information System (INIS)
Al, Ga and In complexing with methylthymol blue (H_6R) purified by gel filtration is studied. in the case of metal excess complexes with the ratio of components M:H_6R=2:1 with #lambda#=587(Al), 590(Ga) and 593 nm(In) appear. In the case of reacting agent excess complexes with the ratio of component 1:1 with #lambda#_m_a_x=480-490 (Al) and 480 nm(Ga, In) appear. The mechanism of complexing reactions is studied. Molar extinction coefficients and stability constants are calculated.
1988-01-01
The electron-phonon coupling constant in vanadium
International Nuclear Information System (INIS)
The electron-phonon coupling constant lambda has been calculated for vanadium. The electron energy bands and wave functions were obtained from a model augmented plane wave muffin-tin potential. The electron-phonon matrix elements were evaluated using the rigid-ion approximation and the measured phonon spectra. The results show that lambda is strongly affected by d-f scattering.
Energy Technology Data Exchange (ETDEWEB)
The oxide colloidal route, developed in the laboratory for mono-metallic catalysts, consists in preparing a metallic oxide hydro-sol which leads to the supported catalyst after deposition onto a support and an activation stage. In this work, this method has been adapted to the preparation of alumina supported bimetallic Pd-Sn catalysts to determine its interest for the control of the properties of the bimetallic phase (size, composition and structure). In the preliminary study concerning tin oxide sols, SnO{sub 2} (size=2,3 nm) and Sn{sub 6}O{sub 4}(OH){sub 4} (size = 25 nm) nano-particles were synthesized by neutralization respectively for tin(IV) and tin(H). The control through the pH of the aggregation of the PdO and SnO{sub 2} particles revealed that increasing oxide solubility promotes integral re-dispersion of the oxide particles. To synthesize oxide bimetallic sols, three strategies were defined. Copolymerization ...
2001-09-01
Reactive metal brazing of aluminum nitride
Energy Technology Data Exchange (ETDEWEB)
The addition of titanium to eutectic braze compositions causes these alloys to readily wet and bond to A1N ceramics. Electron microscopic characterizations of the metal-ceramic interfaces reveal the presence of TiN, along with other Ti- and Al-containing phases. The formation of such interfacial reaction products is an additional thermodynamic driving force for the creation of useful metal-ceramic bonds. 12 refs., 4 figs., 1 tab.
1990-01-01
Quality changes of irradiated spices stored in different indigenous packaging materials
International Nuclear Information System (INIS)
The changes in quality of irradiated spices, i.e., nutmeg (Myristica fragrans), black pepper and white pepper (Piper nigrum) stored in different indigenous packaging materials were evaluated. Packaging materials used were tin cans; tin can lined with polypropylene film, tin can lined with wrapping paper, woven polypropylene bag and woven polypropylene bag lined with polypropylene film. Packaging in woven polypropylene bag could cause significant changes in a_w-values and moisture contents of the spices. In the tin can, no significant change was found during storage. By applying a polypropylene film liner inside the plastic bag, the changes could be retarded. The other parameters observed, i.e. total plate count, total mould and yeast count and organoleptic scores of the samples were not significantly affected by the packaging method. A dose of 5 kGy could reduce the microbial load of the spices by about ...
1990-03-01
Plasma surface engineering of low alloy steel
Energy Technology Data Exchange (ETDEWEB)
The surface of low alloy steel (En40B) has been engineered in the plasma of a glow discharge via plasma nitriding and ion plating of titanium nitride (TiN) coatings on the nitrided substrates with the purpose of enhancing the surface properties and fatigue strength. The nitriding response of the steel has been accessed by the evaluation of phase composition, layer thickness, hardness profile, residual stresses and nitrogen and carbon distributions. The wear and fatigue characteristics of the plasma-nitrided steel have been investigated and simple models have been developed to describe the influence of such properties as depth and strength of the nitrided case on the fatigue limit and load-bearing capacity of the nitrided steel. In order to further improve the tribological properties and load-bearing capacity of the low alloy steel, a duplex plasma surface-engineering technique has been developed. This is achieved by plasma nitriding the steel first so as to produce ...
1991-07-07
Manufacture and characterization of Pb(1-x)Sn(x)Te photoconductors
A general account of the properties, growing technology and annealing of lead-tin-telluride single crystals is given. Photoconductors were made for the 8 to 14 micron. spectral range and responsivity, detectivity and spectral response measurements showed satisfactory results. Improvement in the growing and annealing of the single crystals promise good performance in the near future.
1984-03-01
International Nuclear Information System (INIS)
The feasibility of using a thermoplastic-powder metallurgy technique for the fabrication of porous niobium rods was investigated. Some early problems were overcome to successfully extrude the polymer coated niobium powder into long lengths. The effects of certain process variables were investigated. Residual porosity and extrusion pressure were found to be regulated by the polymer fraction. The procedures for taking the extruded polystyrene--niobium rods through the heat treatments to the final, tin infiltrated stage are explained.
1976-04-30
High resolution transmission electron microscopy of a #beta#'-sialon-TiN nanocomposite
International Nuclear Information System (INIS)
TEM and HRTEM have been used to characterise the microstructures of materials formed by hot-pressing silicon nitride with an Al_2O_3-SiO_2-TiO_2 densification aid system, to form #beta#'-sialon-TiN composites in which the TiN particles are of 20-100 nm dimension. (orig.).
1992-06-21
Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies
Energy Technology Data Exchange (ETDEWEB)
3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.
2010-09-15
Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies
International Nuclear Information System (INIS)
3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.
2010-09-01
Surface treatment of Ti-6Al-4V alloy by rf plasma nitriding
Energy Technology Data Exchange (ETDEWEB)
The Ti-6Al-4V alloy was treated by inductively coupled rf plasma nitriding. The effects of plasma-processing time in the range of 5-35 min on the microstructure and the mechanical properties of the plasma-nitrided Ti-6Al-4V samples were studied. The plasma power input was adjusted at 450 W and pure N{sub 2} gas was introduced to establish a treatment pressure of 8.0-8.4 x 10{sup -2} mbar. The characteristics of the nitrided layers have been investigated by microhardness testing, surface roughness measurements, optical microscopy, and x-ray diffraction. The results show that the surface microhardness increases as the plasma-processing time increases to reach 2000 HV0.1 at a plasma-processing time of 35 min. A high nitriding rate of 2.81 {mu}m{sup 2} s{sup -1} at a plasma-processing time of 25 min was achieved. The formation of the hard phases TiN, Ti{sub 2}N, and Ti(N) in the Ti-6Al-4V surfaces are found to be the reason for the increased ...
2007-10-03
Surface treatment of Ti-6Al-4V alloy by rf plasma nitriding
International Nuclear Information System (INIS)
The Ti-6Al-4V alloy was treated by inductively coupled rf plasma nitriding. The effects of plasma-processing time in the range of 5-35 min on the microstructure and the mechanical properties of the plasma-nitrided Ti-6Al-4V samples were studied. The plasma power input was adjusted at 450 W and pure N_2 gas was introduced to establish a treatment pressure of 8.0-8.4 x 10"-"2 mbar. The characteristics of the nitrided layers have been investigated by microhardness testing, surface roughness measurements, optical microscopy, and x-ray diffraction. The results show that the surface microhardness increases as the plasma-processing time increases to reach 2000 HV0.1 at a plasma-processing time of 35 min. A high nitriding rate of 2.81 #mu#m"2 s"-"1 at a plasma-processing time of 25 min was achieved. The formation of the hard phases TiN, Ti_2N, and Ti(N) in the Ti-6Al-4V surfaces are found to be the reason for the increased microhardness. Surface ...
2007-10-03
International Nuclear Information System (INIS)
We report the results of a linearized augmented-plane-wave calculation of the electronic structure of fcc La at three lattice constants corresponding to ambient pressure, 50, and 120 kbars. The Kohn-Sham-Gaspar approximation for exchange and correlation is used and the potential is allowed a fully non-muffin-tin form. The f bands lie approx.2--2.5 eV above the Fermi level and are approx.1 eV wide, resulting in a very small (0.05 electrons) localized f occupation. Under pressure the f bands rise and broaden appreciably, resulting in only a slight increase in f occupation. The rigid-muffin-tin approximation for the electron-phonon interaction lambda overestimates the superconducting transition temperature T/sub c/ by 40%, but we find that the drastic increase in T/sub c/ under pressure can be attributed primarily to changes in the electronic stiffness eta. Structural transitions which occur at 25 and 53 kbars may be related to changes in ...
Energy Technology Data Exchange (ETDEWEB)
In order to clarify a mechanism of melt-jet breakup and fragmentation entirely different from the mechanism of stripping, a series of experiments were carried out by using molten tin jets of 100 grams with initial temperatures from 250degC to 900degC. Molten tin jets with a small kinematic viscosity and a large thermal diffusivity were used to observe breakup and fragmentation of melt jets enhanced thermally and hydrodynamically. We observed jet columns with second-stage large-scale structures generated by the coalescence of large-scale structures recognized in the field of fluid mechanics. At a greater depth, the segmentation of jet columns between second-stage large-scale structures and the fragmentation of the segmented jet columns were observed. It is reasonable to consider that the segmentation and the fragmentation of jet columns are caused by the boiling of water hydrodynamically entrained within second-stage large-scale structures. ...
1999-07-01
Flux pinning and critical currents in A-15 superconductors
The relationship between processing, microstructure, and properties was studied for A-15 compounds in multifilamentary composites produced by solid-state diffusion and in thin-film samples produced by vapor deposition. Grain sizes of A-15 superconducting compounds were measured by transmission electron microscopy of multifilamentary composites reacted at various temperatures. Critical current densities at 4.2 K and fields up to 6 T were found to be similar for niobium-tin, vanadium-gallium, and vanadium-silicon of the same grain size. Study of the Cu-V-Si phase diagram led to the production of improved multifilamentary vanadium-silicon conductors. The effects of various alloying elements on A-15 layers produced by solid-state diffusion were studied. The most promising new observation was that tantalum can be incorporated into niobium-tin reaction layers, leading to an enhancement of critical currents at high fields. The critical temperature of ...
1978-02-01
Wear resistance of a laser surface alloyed Ti-6Al-4V alloy
Energy Technology Data Exchange (ETDEWEB)
Laser surface alloying with gaseous nitrogen was utilized to improve the wear resistance of a Ti-6Al-4V alloy. Wear-resistant composite coatings reinforced by hard TiN dendrites were produced 'in-situ' on a substrate of a Ti-6Al-4V alloy. The hardness and wear resistance of the laser alloyed coating under two-body abrasive and block-on-ring full-sliding wear conditions were significantly enhanced. (orig.)
2000-08-01
International Nuclear Information System (INIS)
A theoretical analysis is presented for the method of determining the concentration distribution of admixtures in zone melting and in the study of diffusion in melts. Continuous mode X-ray fluorescence analysis is considered. The convolution integral interpreting the analog output of the ratemeter was solved applying the mathematical apparatus of Z transformation. The feasibility of the method is tested on an example of the determination of tin distribution in tungsten. With respect to the statistical error (#delta#<1.5%), the maximum integration constant (100 s) and a very slow sample feed (0.025 mm/s) were used. The calculated transfer function reflects the total transfer function of the ratemeter and the recorder used. (M.D.).
1985-01-01
Energy Technology Data Exchange (ETDEWEB)
It is reported about the adsorptive stripping voltammetric determination of uranium, antimony, tin, vanadium and molybdenum using chloranilic acid as complex forming reagent. The determination limits are in the l{sup 1}-range. (orig.) [Deutsch] Es wird ueber die Bestimmung von Uran, Antimon, Zinn, Vanadium und Molybdaen durch Adsorptions-Stripping-Voltammetrie mit Chloranilsaeure als Komplexbildner berichtet. Die Bestimmungsgrenzen liegen im ng l{sup -1} Bereich. (orig.)
1996-12-01
Ab initio study of the elastic anomalies in Pd-Ag alloys
International Nuclear Information System (INIS)
Ab initio total-energy calculations, based on the exact muffin-tin orbital method, are used to determine the elastic properties of Pd1-xAgx random alloys in the face-centered-cubic crystallographic phase. The compositional disorder is treated within the coherent-potential approximation. The single crystal and polycrystalline elastic constants and the Debye temperature are calculated for the whole range of concentration, 0?x?1. It is shown that the variation in the elastic parameters of Pd-Ag alloys with chemical composition strongly deviates from a simple linear or parabolic trend. The complex electronic origin of these anomalies is demonstrated.
2009-02-15
British Library Electronic Table of Contents (United Kingdom)
We report the synthesis of four diorganotin(IV) compounds of Schiff base pyruvic acid hydrazone derivatives formulated as [R2SnLY]2, where L1 is 2-SC4H3CON2C(CH3)CO2 with Y = CH3CH2CH2CH2OH, R = n-Bu (1); L2 is C6H5CON2C(CH3)CO2 with Y = CH3CH2OH, R = p-F-Bz (2); L3 is 2-HOC6H4CON2C(CH3)CO2 with YH2O, R = p-CN-Bz (3); and L4 is 4-NO2-C6H4CON2C(CH3)CO2 with YCH3CH2OH, R = Bz (4). The structures of all compounds have been established by a combination of single-crystal X-ray diffraction analysis, 1H and 119Sn NMR spectroscopy, IR spectroscopy, and elemental analysis. Studies reveal that four ligands present the same coordination mode with tin center, which all present tridentate ONO donor Schiff bases and coordinate to the tin center in an enolic form. In compounds 1-4, each tin atom is seven...
2011-01-01
Quantification of the thrombogenicity of Dacron aortic prostheses
International Nuclear Information System (INIS)
Eight patients with double-velour Dacron aorto-femoral grafts implanted for 2-60 months were studied. Indium-111-labelled platelets were found to have a shortened mean platelet lifespan (MPLS) of 138 +- 32 hours compared with the normal platelet lifespan of 224 +- 23 hours. Labelled platelets accumulated on all grafts, irrespective of graft age, to a maximum of 1,80 +- 0,83% of whole body radioactivity; thereafter graft radio-activity decreased. This suggests that platelets on the graft are in dynamic equilibrium with those in the circulation. Platelets may be lost from the graft by embolization or radioactivity may be released because of platelet lysis. Although MPLS may depend on the age and surface area of the graft, concomitant arterial disease probably also contributes to the shortened MPLS.
British Library Electronic Table of Contents (United Kingdom)
In this paper, we study the optical properties of indium sulfide thin films to establish the best conditions to obtain a good solar cell buffer layer. The In2S3 buffer layers have been prepared by chemical bath deposition (CBD) and thermal evaporation (PVD). Optical behavior differences have been found between CBD and PVD In2S3 thin films that have been explained as due to structural, morphological and compositional differences observed in the films prepared by both methods. The resultant refractive index difference has to be attributed to the lower density of the CBD films, which can be related to the presence of oxygen. Its higher refractive index makes PVD film better suited to reduce overall reflectance in a typical CIGS solar cell.
2008-01-01
ELECTROMAGNETIC AND THERMAL SIMULATIONS FOR THE SWITCH REGION OF A COMPACT PROTON ACCELERATOR
Energy Technology Data Exchange (ETDEWEB)
A compact proton accelerator for medical applications is being developed at Lawrence Livermore National Laboratory. The accelerator architecture is based on the dielectric wall accelerator (DWA) concept. One critical area to consider is the switch region. Electric field simulations and thermal calculations of the switch area were performed to help determine the operating limits of rmed SiC switches. Different geometries were considered for the field simulation including the shape of the thin Indium solder meniscus between the electrodes and SiC. Electric field simulations were also utilized to demonstrate how the field stress could be reduced. Both transient and steady steady-state thermal simulations were analyzed to find the average power capability of the switches.
2007-06-15
International Nuclear Information System (INIS)
The new compounds In_3_._7Mo_1_5S_1_9, In_1_._6Rb_2Mo_1_5S_1_9, In_2_._2CsMo_1_5S_1_9, and ScTl_2Mo_1_5S_1_9 have been synthesized by solid-state reaction in sealed molybdenum crucible at about 1250 deg. C. Their crystal structures were solved and refined from X-ray single-crystal data in the hexagonal space group P63/m. Their Mo-S framework consists of an equal mixture of Mo_6S_8S_6 and Mo_9S_1_1S_6 cluster units interconnected through Mo-S bonds. In In_3_._7Mo_1_5S_1_9, the In atoms occupy crystallographically different positions depending on their formal oxidation states of +1 or +3. This was confirmed by replacing partially or totally the monovalent indium by another monovalent cation such as the rubidium, cesium or thallium and the trivalent indium by the scandium to get the new In_1_._6Rb_2Mo_1_5S_1_9, In_2_._2CsMo_1_5S_1_9, and ScTl_2Mo_1_5S_1_9 compounds, respectively.
2004-11-30
Radiation dosimetry of "1"1"1In-oxinate labelled leucocytes
International Nuclear Information System (INIS)
The patients studied were referred for routine abscess localization with indium-111 labelled autologous leukocytes. One series (n=15) was studied at 1 day after reinjection of labelled cells and a second series (n=9) was studied between 4 hours and 4 days after reinjection of labelled cells. The leukocytes were isolated by a gravity sedimentation method and labelled with In-111 oxinate according to Roevekamp and co-workers. The labelled cell suspension administered to the patient contained between 11 and 15 MegaBq (300-400 microCi). The indium-111 concentration in the liver and spleen was quantitated using a scintillation camera and an on-line computer system. Phantom studies were carried out to obtain conversion factors from geometric mean counts to MegaBq of activity for both liver and spleen. Once determined, the amount of activity in liver and spleen was corrected for physical decay of In-111 and expressed as a percentage of the ...
1982-06-25
International Nuclear Information System (INIS)
Colorectal carcinoma is a highly prevalent and common cause of cancer in Taiwan. There is still no available cure for this malignant disease. To address this issue, we applied the multimodality of molecular imaging to explore the efficacy of diagnostic and therapeutic nanoradiopharmaceuticals in an animal model of human colorectal adenocarcinoma [colorectal cancer (CRC)] that stably expresses luciferase (luc) as a reporter. In this study, an in vivo therapeutic efficacy evaluation of dual-nanoliposome (100 nm in diameter) encaged vinorelbine (VNB) and "1"1"1In-oxine on HT-29/luc mouse xenografts was carried out. HT-29/luc tumor cells were transplanted subcutaneously into male SCID mice. Multimodality of molecular imaging approaches including bioluminescence imaging (BLI), gamma scintigraphy, whole-body autoradiography (WBAR) and in vivo tumor growth tracing, histopathology and biochemistry/hematology analyses were applied on xenografted SCID mice to study the treatments with 6% ...
2008-07-01
International Nuclear Information System (INIS)
High liver uptake and slow body clearance presently limit the usefulness of "1"1"1In labeled antibodies for tumor imaging. We have investigated "2"0"3Pb as an alternate and better antibody label. The DTPA and cyclohexyl EDTA (CDTA) conjugates of an anticolon carcinoma antibody, 17-1A were labeled (bicyclic anhydride method) with "2"0"3Pb and "1"1"1In with 60 and 90% labeling yields, respectively. The biodistribution of "2"0"3Pb-17-1A conjugates was compared with the corresponding "1"1"1In-labeled preparations and with "2"0"3Pb-DTPA, "2"0"3Pb-nitrate and nonrelevant antibody controls in normal and human tumor (SW948) xenografted nude mice at 24, and 96 hr. Lead-203-labeled CDTA and DTPA antibody conjugates gave similar in vivo distributions. Even though the lead bound to these chelate-antibody conjugates was more labile in serum and in vivo, compared to indium, it cleared much faster from the liver and the whole body. A new series of chelating agents based on the ...
1988-05-22
Energy Technology Data Exchange (ETDEWEB)
The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best possible adaptation of the TOF mass spectrometer for the ...
2006-12-21
International Nuclear Information System (INIS)
We have performed self-consistent (SC) band structure calculations for the A15 compounds V_3X and Nb_3X, X = Al, Ga, Si, Ge, and Sn, using the augmented-plane-wave (APW) method. Relativistic effects (except the spin-orbit interaction) have been included in each SC cycle, along with corrections to the usual muffin-tin approximation. The latter apply the APW wave functions outside of the muffin-tin spheres to compute the interstitial charge densities and potentials. The resulting interstitial potential has full cubic symmetry (no spherical averaging), although a spherically averaged muffin-tin form is retained inside the spheres. The final SC potentials were used to generate energies and wave functions on a cubic mesh of 35 k points in 1/48th of the Brillouin zone. These results were interpolated onto a finer mesh of 969 k points using a symmetrized Fourier method; the densities of states (DOS), N (E), were determined using ...
Surface modification of magnesium base alloys by gas/plasma nitridation
Energy Technology Data Exchange (ETDEWEB)
Gas and plasma nitriding processes were executed in the magnesium with modification by titanium in search for an effective surface treatment method for magnesium alloys. Magnesium-nitrogen system has completely no solid solution or solubility, so that nitride should be only formed by eutectic reaction in the liquid phase. Hence, magnesium is difficult or nearly impossible to have its surface modified by nitriding. Addition of nitride forming element into magnesium enables us to lower the onset temperature of nitriding. Magnesium-titanium alloys with 1 to 5 wt% are yielded by the bulk mechanical alloying and, subjected to gas nitriding for various process conditions. Successful co-formation of Mg{sub 3}N{sub 2} as well as TiN becomes a proof to demonstrate the possibility of gas/plasma nitriding in the solid-state magnesium with aid of nitride former. (orig.)
2000-07-01
Surface energy of semiconductors covered with thin layers of various materials
International Nuclear Information System (INIS)
Surface energy of III-V semiconductors ended by (110) clean surface and surface covered by atomic monolayer of aluminium, copper and sulfur has been calculated. We have used the Greens-function technique based on the scheme of linear muffin-tin orbitals in the atomic sphere approximation (LMTO-ASA) for the crystal potential and width the local density approximation (LDA) for electrons. Two types of coverage are considered: full monolayer with two additional atoms per two-dimensional unit cell and half monolayer with one additional atom per unit cell. Full monolayer of metallic atoms increases the surface energy. Cu atoms lead to greater destabilization than Al atoms. Sulfur atoms stabilize (110) surface for all considered compounds. (author)
1997-09-23
Secondary electron yield measurements from thin surface coatings for NLC electron cloud reduction
In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions for preventing this spurious electron load include reducing residual gas ionization by the beam, minimizing beam photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.
2004-01-01
Energy Technology Data Exchange (ETDEWEB)
Theoretical investigations of fatty acids as a phase change material (PCM) for energy storage system have been conducted in this study. The selected fatty acids were capric acid, lauric acid, myristic acid, palmitic acid and stearic acid. For the two-dimensional simulation model based on the enthalpy approach, calculations have been made for the melt fraction with conduction only. Glass, stainless steel, tin, aluminium mixed, aluminium and copper were used as heat exchanger materials in the numerical calculations. Theoretical results show that capric acid was found good compatibility with latent heat storage system. The large value of thermal conductivity of heat exchanger materials did not make significant contribution on the melt fraction. (author)
2005-11-01
Electron-phonon spectral function and mass enhancement of niobium
International Nuclear Information System (INIS)
The electron-phonon spectral distribution function #alpha#"2(#omega#) F (#omega#) has been calculated for niobium. The electron energy bands and wave functions were obtained from a self-consistent augmented-plane-wave muffin-tin potential, and the electron-phonon matrix elements were evaluated using the so-called rigid-ion approximation. With this approximation it is found that #alpha#"2(#omega#) is constant over the whole energy spectrum. The electron-phonon mass enhancement has also been calculated for local regions of the Fermi surface and found to be anisotropic. The calculated local values of the enhancement do not agree with experimental values available for different orbits from de Haas--van Alphen measurements. The discrepancy seems to arise because the bare-rigid-ion matrix elements are relatively small between states with nearly pure l = 2 character.
Effect of alumina incorporation on restricting grain growth of nanocrystalline tin(IV) oxide
British Library Electronic Table of Contents (United Kingdom)
In this project, nanocrystalline SnO2 powders were successfully prepared by (a) citrate sol-gel and (b) direct precipitation methods. Powders were characterized using thermal analysis techniques (DTA-TG-DSC), X-ray powder Diffraction (XRD), surface area (BET) and electrical conductivity measurements. XRD patterns showed the presence of the cassiterite structure. SnO2 particles, prepared through sol-gel method exhibit crystallite sizes in the range from 3.1 to 22.3 nm when the gel is heat treated at different temperatures up to 900?C. SnO2 nanocrystallites prepared by the precipitation method are comparatively larger in size. The higher specific surface area was obtained for the powder prepared using sol-gel method and the obtained average grain size (d) is relatively large compared with th...
2010-01-01
International Nuclear Information System (INIS)
A comparison is made of the response of a count ratemeter and a pulse counter using the mathematical tool of the Z transform. Transform Z is used for the solution of the convolution integral interpreting the analog output of the count ratemeter used for recording characteristic radiation, excited in the moving beam. The comparison of count rates obtained by the count ratemeter during continuous analysis and the pulse counter during discontinuous measurement gave the transfer function of the count ratemeter in the actual range of count rate. Also discussed is the use of the transfer function for localizing concentration changes in the sample. The use of the described method is demonstrated on the determination of the tin content in tungsten using continuous radionuclide X-ray fluorescence analysis. (B.S.).
1983-01-01
Platinum and ruthenium in carbon supported Pt and Pt-Ru catalysts were determined by direct and derivative spectrophotometric methods. Complexes of platinum and ruthenium with SnCl(3)(-) ligands (tin(II) chloride in HCl) were used to determine both metals in solutions obtained after digestion of the samples of the catalysts. Platinum in the Pt/C catalyst can be determined in solutions obtained by digestion of the samples in aqua regia. Derivative spectrophotometry was used to determine both metals in the presence of each other in solutions obtained after digestion of samples of the Pt-Ru/C catalyst in the mixture of HCl+HNO(3) (6:1). The first derivative at 377 nm (;zero-crossing' point of ruthenium) and the second-derivative values at 495 nm (;zero-crossing' point of platinum) were used to estimate the concentration of platinum and ruthenium, respectively. PMID:18967441
1999-01-01
Defect creation by electronic processes in MgO bombarded with GeV heavy ions
Energy Technology Data Exchange (ETDEWEB)
To study the defect creation induced by electronic processes in refractory oxides, MgO single crystals were irradiated with high energy tin, uranium and lead ions. Optical absorption measurements showed that F-type centers (oxygen vacancies with trapped electrons) were created during irradiation. The total number of centers per unit area of bombarded sample increases linearly with irradiating fluence. The main part of the point defects was found to arise from electronic processes. The concentration of F-type centers induced by ionization increases with the electronic energy losses. Assuming a saturation of point defect concentration at high fluences, F-type center creation cross sections could be estimated. The influence of irradiation temperature and of the velocity of the bombarding ions are discussed.
1996-12-31
Adsorption and Dissociation of Molecular Hydrogen on the (0001) Surface of DHCP Americium
Hydrogen molecule adsorption on the (0001) surface of double hexagonal closed packed americium has been studied in detail within the framework of density functional theory. Weak molecular hydrogen adsorptions were observed. The most stable configuration corresponded to a Hor2 approach molecular adsorption at the one-fold top site where the molecule's approach is perpendicular to a lattice vector. Adsorption energies and adsorption geometries for different adsorption sites will be discussed. The change in work functions, magnetic moments, partial charges inside muffin-tins, difference charge density distributions and density of states for the bare Am slab and the Am slab after adsorption of the hydrogen molecule will be discussed. Reaction barrier for the dissociation of hydrogen molecule will be presented. The implications of adsorption on Am 5f electron localization-delocalization will be summarized.
2009-03-01
"9"9"mTechnetium-heat damaged erythrocyte spleen scan
International Nuclear Information System (INIS)
"9"9"mTechnetium -heat damaged erythrocyte were used as spleen scanning agents in 12 patients from July, 1985 to April, 1986. We used this scan to evaluate situs inversus, asplenia, accessory spleen, hypersplenism, splenic infarction, tumor staging and evaluation of therapy, especially when the "9"9"mTc-tin colloid scans were not definite for diagnosis. The techniques applied to these scans were in vivo/in vitro-labeling method and heating-method to damage the erythrocytes. Liver-to-spleen uptake ratios were increased upto 100:1 and interference from the left lobe of the liver was eliminated. These scans were helpful to evaluate the spleen. (Author).
Heteroepitaxial growth of In-face InN on GaN (0001) by plasma-assisted molecular-beam epitaxy
International Nuclear Information System (INIS)
The thermodynamic aspects of indium-face InN growth by radio frequency plasma-assisted molecular-beam epitaxy (rf-MBE) and the nucleation of InN on gallium-face GaN (0001) surface were investigated. The rates of InN decomposition and indium desorption from the surface were measured in situ using reflected high-energy electron diffraction and the rf-MBE 'growth window' of In-face InN (0001) was identified. It is shown that sustainable growth can be achieved only when the arrival rate of active nitrogen species on the surface is higher than the arrival rate of indium atoms. The maximum substrate temperature permitting InN growth as a function of the active nitrogen flux was determined. The growth mode of InN on Ga-face GaN (0001) surface was investigated by reflected high-energy electron diffraction and atomic force microscopy. It was found to be of the Volmer-Weber-type for substrate temperatures less than 350 deg. C and of ...
2005-06-01
Visible-wavelength semiconductor lasers and arrays
Energy Technology Data Exchange (ETDEWEB)
The visible semiconductor laser includes an InAlGaP active region surrounded by one or more AlGaAs layers on each side, with carbon as the sole p-type dopant. Embodiments of the invention are provided as vertical-cavity surface-emitting lasers (VCSELs) and as edge-emitting lasers (EELs). One or more transition layers comprised of a substantially indium-free semiconductor alloy such as AlAsP, AlGaAsP, or the like may be provided between the InAlGaP active region and the AlGaAS DBR mirrors or confinement layers to improve carrier injection and device efficiency by reducing any band offsets. Visible VCSEL devices fabricated according to the invention with a one-wavelength-thick (1{lambda}) optical cavity operate continuous-wave (cw) with lasing output powers up to 8 mW, and a peak power conversion efficiency of up to 11%. 5 figs.
1996-09-17
International Nuclear Information System (INIS)
The minimum cardiac transit times (MTT's) at rest and following sub-maximum stresses were measured in 97 individual examinations of untrained persons and high performance athletes. It turned out that there is a strong dependence on cardiac frequency of the MTT's. This relation can be described quite satisfactorily by a hyperbolic function and in this way allows a frequency correction to be made of the MTT's. The MTT's standardized in this way (MTT.f values) represent the quotient of the end diastolic segment volume/beat volume. In the whole lesser circulatory system almost identical MTT.f values were found for the two groups under comparison at rest and following stress. In the ventricles, however, and especially so in the left ventricle, the MTT.f values were clearly higher with athletes than with untrained persons, but they strongly decreased after stresses, while the respective values remained almost constant in ordinary persons. (orig./RF).
Production of unsaturated nitriles using catalysts containing boron, gallium or indium
Energy Technology Data Exchange (ETDEWEB)
This patent describes a process for the preparation of acrylonitrile or methacrylonitrile by the reaction of propylene or isobutylene, molecular oxygen and ammonia at a temperature of about 200/sup 0/ to 600/sup 0/C in the presence of an oxidation catalyst. The improvement consists of using as the oxidation catalyst an antimony-free catalyst having the atomic ratios described by the formula: X/sub a/A/sub b/C/sub c/Fe/sub d/Bi/sub e/Mo/sub 12/O/sub x/ wherein X is Ga, In or mixtures thereof; A is alkali metal; C is Ni, Co or mixture thereof; and wherein a is 0.01 to about 4; b is 0 to about 4; c and d are 0.01 to about 12; e is 0.01 to about 6; and x is a number sufficient to satisfy the valence requirements of the other elements present. In a process for the preparation of acrylonitrile or methacryloniotrile by the reaction of propylene or isobutylene, molecular oxygen and ammonia at a temperature of about 200/sup 0/ to 600/sup 0/C in the presence of an oxidation catalyst.
1988-08-23
Platelet thrombosis in cardiac-valve prostheses
International Nuclear Information System (INIS)
The contribution of platelets and clotting factors in thrombosis on cardiovascular prostheses had been quantified with several tracers. Thrombus formation in vivo could be measured semiquantitatively in animal models and patients with indium-111, Technetium-99m labeled platelets, iodine-123, iodine-131 labeled fibrinogen, and In-111 and Tc-99m labeled antibody to the fibrinogen-receptor on the platelet- membrane, or fibrin. The early studies demonstrated that certain platelet-inhibitors, e.g. sulfinpyrazone, aspirin or aspirin- persantine increased platelet survival time with mechanical valves implanted in the baboon model and patients. Thrombus localization by imaging is possible for large thrombus on thrombogenic surface of prosthesis in the acute phase. The majority of thrombus was found in the sewing ring (Dacron) in the acute phase in both the mechanical and tissue valves. The amount of retained thrombus in both mechanical and tissue valves in our one-day ...
1989-06-08
Photoluminescence of europium doped LiInO2 powder
British Library Electronic Table of Contents (United Kingdom)
Abstract Lithium-indium oxide is one of the candidate materials as solid-state scintillators for solar neutrinos due to an inverse --decay of 115In to 115Sn. On the other hand, when doped with rare-earth ions such as Eu3+ or Sm3+, it becomes a promising phosphor material. In this report we present a simple solid-state procedure for preparation of LiInO2:Eu3+ powders. X-ray diffraction confirmed prod-uct in tetragonal structural form (space group: I41/amd) and no impurity phases were detected. Then, high resolution photoluminescence emission measurements were performed at room and low temperatures to find 5D0 - 7FJ. Emission kinetics from 5D0 level exhibited pure single exponential behavior with lifetime of about 1.5 ms. Maximum energy splitting of 7F1 manifold is recorded as a function of ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The Zollinger-Ellison syndrome (ZES) is taken as an example of the diagnostic and therapeutic strategy in gastro-entero-pancreatic endocrine tumours, given the standard characteristics of this procedure, whatever the nature of the primitive tumour. Management of ZES includes: anatomical localization of gastrinoma and of possible metastases, in 60 % of cases this step conditioning therapeutic indications and chances of cure; search of a type 1-multiple endocrine neoplasia (MEN A), in 25 % of cases; therapeutic indications: ablative surgery with curative intent in case of gastrinoma and of resectable liver metastases, palliative treatment otherwise: anti-secretory drugs, somatostatin analogues, chemotherapy and interferon {alpha}; long-term follow-up of patients with resected tumour. At each step, somatostatin receptor scintigraphy with indium 111-pentetreotide does play a pivotal role. (author). 110 refs.
1996-12-31
International Nuclear Information System (INIS)
The radiochemical purity of the cobalt-57 complex of bleomycin could be enhanced by adjusting the pH of the final product to a value between 5 and 6. This radiopharmaceutical appeared to have better tumor visualizing properties compared to the not neutralized preparation. The clinical use of the cobalt-57 bleomycin complex is however limited by the long physical half-life of the label, causing a risk of radioactive contamination. It appeared to be possible to label bleomycin with radioactive cations ("1"1"1In"3"+, sup(99m)Tc"4"+, "1"9"7Hg"2"+ and "6"7Cu"2"+) having suitable gamma ray energies and short half-lifes. These bleomycin complexes showed a high radiochemical purity judged by their behaviour on thin layer chromatography, paper chromatography, and electrophoresis, but their application as tumor visualizing radiopharmaceutical turned out to be disappointing compared with cobalt-57 bleomycin. (orig.).
Kapitza conductance of the (100) surface of copper
International Nuclear Information System (INIS)
Measurements of the Kapitza conductance to liquid helium II across the (100) surface of single crystals of copper are presented. The temperature range of these measurements was 1.6-- 2.1 K. The sample surfaces were subjected to several different treatments. Some surfaces were cleaned by low-energy argon ion bombardment, annealed in an ultrahigh-vacuum system, and preserved under vacuum until purified liquid helium was admitted. Other surfaces were intentionally damaged by machining and/or exposure to the atmosphere. The conductance after these latter treatments was found to be about a factor of three higher than that of the more ideally cleaned and annealed surfaces, and a significant difference in the temperature dependence of the conductance was also observed. Conductances were reproducible for similarly treated surfaces and correlated with surface damage determined by x-ray diffraction. The relationship of these results to the numerous current theories of the Kapitza conductance is ...
High bandgap window layer for GaAs solar cells and fabrication process therefor
The specification describes a semiconductor solar cell and fabrication process therefor wherein a thin N-type gallium arsenide layer is deposited on a larger P-type substrate layer which is selected from the group of III-V ternary compounds consisting of aluminum phosphide antimonide, AlPSb, and aluminum indium phosphide, AlInP. P-type impurities are diffused from the substrate layer into a portion of the thin N-type gallium arsenide layer to form P-type region wherein which defines a PN junction in the thin gallium arsenide layer. Thus, the quantity of gallium arsenide required to provide this PN photovoltaic junction layer in the cell is minimized, and th P-type substrate serves as a high bandgap window layer for the cell. Such high bandgap of this window material is especially well suited for efficiently transmitting the blue spectrum of sunlight to the PN junction, thus enhancing the power conversion efficiency of the solar cell.
1979-05-29
Heat capacity measurements of atoms and molecules adsorbed on evaporated metal films
Energy Technology Data Exchange (ETDEWEB)
Investigations of the properties of absorbed monolayers have received great experimental and theoretical attention recently, both because of the importance of surface processes in practical applications such as catalysis, and the importance of such systems to the understanding of the fundamentals of thermodynamics in two dimensions. We have adapted the composite bolometer technology to the construction of microcalorimeters. For these calorimeters, the adsorption substrate is an evaporated film deposited on one surface of an optically polished sapphire wafer. This approach has allowed us to make the first measurements of the heat capacity of submonolayer films of /sup 4/He adsorbed on metallic films. In contrast to measurements of /sup 4/He adsorbed on all other insulating substrates, we have shown that /sup 4/He on silver films occupies a two-dimensional gas phase over a broad range of coverages and temperatures. Our apparatus has been used to study the heat capacity of ...
1989-05-01
International Nuclear Information System (INIS)
Thirty-six patients with acquired immunodeficiency syndrome (AIDS), who were febrile but without localizing signs, underwent indium-111 leukocyte scintigraphy 24 hours after injection of labeled white blood cells (WBCs) and were restudied 48 hours after injection of gallium-67 citrate. Fifty-six abnormalities were identified as possible sources of the fever; 27 were confirmed with biopsy. Of these 27, 15 were identified only on In-111 WBC scans (including colitis, sinusitis, and focal bacterial pneumonia); six, only on Ga-67 scans (predominantly Pneumocystis carinii pneumonia and lymphadenopathy); and six, on both studies (predominantly pulmonary lesions). In-111 WBC scanning revealed 21 of 27 abnormalities (78%) and gallium scanning, 12 of 27 (44%). If only one scintigraphic study has been performed, particularly with Ga-67, a significant number of lesions would not have been detected. The authors believe radionuclide evaluation of the febrile AIDS patient without ...
Energy Technology Data Exchange (ETDEWEB)
W have introduced template-synthesized metal phosphate nanoparticle labels for electrochemical immunoassay. Such use of an apoferritin template offers a simple and convenient route to prepare metallic nanoparticle labels for electrochemical immunoassays and avoid the complicated and time-consuming nanoparticle synthesis process (QD synthesis). Releasing metal ions from metal phosphate in an acetate buffer (pH 4.6) eliminates the harsh condition in the traditional metallic nanoparticle dissolution (e.g., strong acid dissolution of QDs and gold nanoparticles). This method is ultrasensitive and its DL is low to 77fM. The simultaneous detection of multiple protein targets is easily performed by using different metal phosphate nanoparticle labels (cadmium phosphate and lead phosphate). This approach can be extended to prepare multiple metal (such as zinc, lead, cadmium, copper, indium, gold, silver) phosphate nanoparticle labels or hybrid metal (bimetallic or ...
2006-08-29
Energy Technology Data Exchange (ETDEWEB)
There is presently considerable interest in wear resistant coatings produced using closed field unbalanced magnetron sputtering technology. For example, layered films of diamond-like carbon (DLC) with tungsten or titanium additions have been widely reported. The benefit is that the mechanical properties are enhanced (e.g. giving greater toughness); also it is possible to control the stress state and enhance adhesion. Here we report the further development of this concept by the addition of TiN, TiCN and TiC layers in DLC-based composites, utilizing an additional source of electrons in the vicinity of substrate to enhance ionisation of the plasma and increase coating density. Composite coatings of ceramics TiN, TiC{sub x}N{sub y}, TiC, CrN, TiCrN, TiCrCN, TiCrC, metal doped Ti{sub x%}-DLC and their combinations were deposited on 316 stainless steel substrates. The mass flow of reactive gases into the chamber was controlled using plasma optical ...
1995-08-01
International Nuclear Information System (INIS)
The electronic structure and properties of the cubic Laves phase (C15) compounds ZrZn_2 and ZrV_2 have been determined using our all-electron full-potential linearized-augmented-plane-wave (FLAPW) method for bulk solids. The computations were performed in two stages: (i) self-consistent warped muffin tin and (ii) self-consistent full potential. Spin-orbit coupling was included after either stage. The effects of the inclusion of the nonspherical terms inside the muffin tins on the eigenvalues is found to be small (of order 1 mRy). However, due to the fact that some of the bands near the Fermi level are flat, this effect leads to a much higher value of the density of states at E/sub F/ in ZnZr_2. The most important difference between the materials ZrZn_2 and ZrV_2 is the position of the d bands derived from the Zr and V atoms. Consequently, these materials have completely different Fermi surfaces. We have investigated the magnetic properties of ...
Energy Technology Data Exchange (ETDEWEB)
The electronic structure and properties of the cubic Laves phase (C15) compounds ZrZn/sub 2/ and ZrV/sub 2/ have been determined using our all-electron full-potential linearized-augmented-plane-wave (FLAPW) method for bulk solids. The computations were performed in two stages: (i) self-consistent warped muffin tin and (ii) self-consistent full potential. Spin-orbit coupling was included after either stage. The effects of the inclusion of the nonspherical terms inside the muffin tins on the eigenvalues is found to be small (of order 1 mRy). However, due to the fact that some of the bands near the Fermi level are flat, this effect leads to a much higher value of the density of states at E/sub F/ in ZnZr/sub 2/. The most important difference between the materials ZrZn/sub 2/ and ZrV/sub 2/ is the position of the d bands derived from the Zr and V atoms. Consequently, these materials have completely different Fermi surfaces. We have investigated the ...
1988-03-01
Energy Technology Data Exchange (ETDEWEB)
In this work, {beta}-SnS{sub 2} thin films have been prepared on glass substrates by the spray pyrolysis technique using an alcohol solution which contains tin chloride (SnCl{sub 4}) and thiourea (SC(NH{sub 2}){sub 2}) as precursors. The structural study shows that {beta}-SnS{sub 2} thin film prepared using optimal experimental conditions: substrate temperature T{sub s} = 280 deg. C and the concentration ratio of sulfur and tin elements in the spray solution x = [S]/[Sn] = 2.5, crystallizes in the hexagonal phase with a strong (0 0 1) X-ray diffraction line. In the same way, microprobe analyses (EPMA) as well as X-ray photoelectron spectroscopy (XPS) show the presence of undiserable phase of SnO{sub 2}. From the transmission and reflectance spectra, the band gap energy is 2.65 eV. On the other hand, the photothermal properties of such films have been studied, the thermal conductivity was K{sub c} = 0.85 W m{sup -1} K{sup -1} and the thermal ...
2009-05-27
International Nuclear Information System (INIS)
In this work, ?-SnS2 thin films have been prepared on glass substrates by the spray pyrolysis technique using an alcohol solution which contains tin chloride (SnCl4) and thiourea (SC(NH2)2) as precursors. The structural study shows that ?-SnS2 thin film prepared using optimal experimental conditions: substrate temperature Ts = 280 deg. C and the concentration ratio of sulfur and tin elements in the spray solution x = [S]/[Sn] = 2.5, crystallizes in the hexagonal phase with a strong (0 0 1) X-ray diffraction line. In the same way, microprobe analyses (EPMA) as well as X-ray photoelectron spectroscopy (XPS) show the presence of undiserable phase of SnO2. From the transmission and reflectance spectra, the band gap energy is 2.65 eV. On the other hand, the photothermal properties of such films have been studied, the thermal conductivity was Kc = 0.85 W m-1 K-1 and the thermal diffusivity was Dc = 14.5 x 10-6 m2 s-1. The analysis of ?-SnS2 thin ...
2009-05-27
Measurement of K x-ray intensity ratio of tin, gadolinium and dysprosium
International Nuclear Information System (INIS)
Full text: Measurement of K_#beta# to K_#alpha# x-ray intensity ratios are important not only in the field of atomic physics, radiation physics and medical physics, but also to test the validity of assumptions made in the theoretical prediction. The intensity ratios can also give information on the effect of physical and chemical environment of the element in the compound. Many investigators have adopted a single and double reflection geometries to measure the K_#beta# to K_#alpha# x ray intensity ratios to understand the effect of physical and chemical environment on x-ray fluorescence. The targets are excited by a radioactive source of having activity of the order 100 MBq. in order to carry out accurate measurement K_#beta# to K_#alpha# x-ray intensity ratios, we have develop 2#pi# geometrical configuration method : placing a target right on the surface of the detector facing the target to measure the K shell fluorescence parameters such as fluorescence yield, fluorescence cross ...
2003-11-01
FT-IR spectroscopic studies of tin-modified rhenium alumina-silica metathesis catalyst
International Nuclear Information System (INIS)
FT-IR spectra of the products obtained in each step of the tetramethyltin (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 and TMT/Al_2O_3-SiO_2 system preparation are presented and discussed. The obtained spectra show that TMT reacts with alumina-silica hydroxyl groups already at room temperature, yielding surface methyltin compounds; NH_4ReO_4 reacts with alumina-silica surface at temperatures up to 423 K, yielding rhenium surface species and ammonia, which is strongly bonded by acidic sites of the Broensted kind. FT-IR spectrum of the system (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 indicated the absence of surface methyl tin compounds observed on the surface system TMT/Al_2O_3-SiO_2 , and the presence of physically adsorbed TMT; after 5 h of evacuation of the TMT/3-wt.% Re_2O_7/Al_2O_3-SiO_2 system, the FT-IR spectrum indicated the presence of only a single band at 2977 cm"-"1, which may be assigned to the C-H bond stretching of the methyl group in the surface bridged ...
2000-01-01
Energy Technology Data Exchange (ETDEWEB)
Soils and food crops from a former tin mining location in a high background radiation area on the Jos-Plateau, Nigeria were collected and analyzed by gamma spectrometry to measure their contents of {sup 40}K, {sup 238}U and {sup 232}Th. As well as collecting samples, in situ dose rates on farms were measured using a precalibrated survey meter. Activity concentrations determined in food crops were compared with the local food derivatives or diets to investigate the possible removal or addition of radionuclides during food preparation by cooking or other means. Potassium-40 was found to contribute the highest activity in all the food products. The activity concentration of {sup 40}K, {sup 238}U and {sup 232}Th in local prepared diets ranged between 60 and 494 Bq kg{sup -1}, between BDL and 48 Bq kg{sup -1} and between BDL and 17 Bq kg{sup -1}, respectively. The internal effective dose to individuals from the consumption of the food types was estimated on the basis of ...
2007-04-15
International Nuclear Information System (INIS)
Soils and food crops from a former tin mining location in a high background radiation area on the Jos-Plateau, Nigeria were collected and analyzed by gamma spectrometry to measure their contents of "4"0K, "2"3"8U and "2"3"2Th. As well as collecting samples, in situ dose rates on farms were measured using a precalibrated survey meter. Activity concentrations determined in food crops were compared with the local food derivatives or diets to investigate the possible removal or addition of radionuclides during food preparation by cooking or other means. Potassium-40 was found to contribute the highest activity in all the food products. The activity concentration of "4"0K, "2"3"8U and "2"3"2Th in local prepared diets ranged between 60 and 494 Bq kg"-"1, between BDL and 48 Bq kg"-"1 and between BDL and 17 Bq kg"-"1, respectively. The internal effective dose to individuals from the consumption of the food types was estimated on the basis of the measured radionuclide ...
2007-04-01
Valence electronic structure of Ni in Ni-Si alloys from relative K X-ray intensity studies
Energy Technology Data Exchange (ETDEWEB)
The K{beta}-to-K{alpha} X-ray intensity ratio of Ni in Ni{sub 3}Si, Ni{sub 2}Si and NiSi has been determined by energy dispersive X-ray fluorescence technique. It is found that the intensity ratio of Ni decreases from pure Ni to Ni{sub 2}Si and then increases from Ni{sub 2}Si to NiSi, in good agreement with the electronic structure calculations cited in the literature. We have also performed band structure calculations for pure Ni in various atomic configurations by means of linear muffin-tin orbital method and used this data with the normalized theoretical intensity ratios cited in the literature to estimate the 3d-occupation numbers of Ni in Ni-Si alloys. It is emphasized that investigation of alloying effect in terms of X-ray intensity ratios should be carried out for the stoichiometric alloys in order to make reliable and quantitative comparisons between theory and experiment in transition metal alloys.
2007-02-15
Tribological behavior of duplex coating improved by ion implantation
Energy Technology Data Exchange (ETDEWEB)
In the present paper the tribological behavior of the coatings are discussed. Duplex coatings were applied on cold working steel 100Cr6. Samples were plasma nitrided at different thickness of plasma surface layers. TiN was deposited with a classic BALZERS PVD equipment and subsequent ion implantation. Ion implantation was provided with N{sup 5+} ions. The other samples were produced with IBAD technology in DANFYSIK chamber. Wear resistance and exchanges of friction coefficient were measured with on-line test using special designed tribology equipment. Following the tests, the wear zone morphology and characteristics of surface layer structure as well as important properties were investigated by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). Scratch adhesion testing was performed using commercially available equipment. Energy dispersive X-ray analysis (EDAX) of the wear-scars on pins provided essential information on the wear ...
2004-07-01
Trace metal characterization of the U-Al matrix by atomic spectroscopy
International Nuclear Information System (INIS)
Uranium-aluminum alloys with a significant enrichment of uranium with "2"3"3U or "2"3"5U serve as nuclear fuels in research reactors. The quality assurance of this fuel requires, among other things, precise knowledge that all trace metal constituents that affect neutron economy, fuel integrity, and fuel fabrication process parameters are well within the specification limits. Trace metal characterization of "2"3"5U-Al alloy has been carried out by atomic spectrometry. The trace metal constituents of interest are grouped into common metals (silver, boron, calcium, cadmium, cobalt, chromium, copper, iron, magnesium, manganese, molybdenum, sodium, nickel, lead, silicon, tin, titanium, vanadium, tungsten, and zinc) and lanthanides (cerium, dysprosium, europium, gadolinium, holminium, lutetium, samarium, and terbium). The elements yttrium and zirconium are grouped with the latter in view of the chemical separation procedure used. The alloy samples are dissolved in 6 M ...
Surface modification of titanium by radio frequency plasma nitriding
Energy Technology Data Exchange (ETDEWEB)
Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti{sub 2}N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 {mu}m{sup 2}/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near to the surface of the ...
2006-02-21
Surface modification of titanium by radio frequency plasma nitriding
International Nuclear Information System (INIS)
Radio frequency (RF) plasma nitriding using different input plasma processing powers (250-600 W) improves the surface of titanium by forming hard phases of TiN, Ti_2N, and Ti (N) into the surface. The characteristics of the compound layer have been investigated by optical microscopy, microhardness measurements, and X-ray diffraction. The effect of plasma power on the sample temperature, electron temperature, and plasma density was studied using Langmuir double probe. The measured surface hardness value of the compound layer is 2190 HV 0.1 for treated sample at plasma power 500 W. The compound thickness continuously increases as the plasma power increases. The highest nitriding rate of 5.88 #mu#m"2/s was recorded when the input plasma power was adjusted at 550 W. This high nitriding rate of treated titanium samples is ascribed to the high concentration of active nitrogen species in the plasma atmosphere and the formed microcracks near to the surface of the sample ...
2006-02-21
SnPc on Ag(111) investigated by STM
Energy Technology Data Exchange (ETDEWEB)
The investigation of interfaces between thin organic films and metal surfaces is a field of highest interest because it represents the basis for future applications of organic electronic devices. In this context, phtalocyanines are of particular interest since repulsive intermolecular interaction was found recently for this group of organic molecules. Tin(II)-phtalocyanine (SnPc) is non-planar and can adsorb in two different geometries: with the Sn atom pointing downwards (Sn down) or upwards (Sn up). In our group different Pc molecules have previously been studied using several experimental techniques like SPA-LEED or XSW. Here we present STM studies of SnPc on Ag(111), taken at different coverages and temperatures, and discuss the results in the context of our previous findings. At low coverages the formation of chains can be observed for Sn down molecules while Sn up molecules tend to stay separated. This originates from a strong interaction with the substrate ...
2010-07-01
Energy Technology Data Exchange (ETDEWEB)
In this study, SnO{sub 2} thin films have been grown using spray pyrolysis technique on glass substrates under a substrate temperature (T{sub s} = 440 {sup o}C). The precursors were methanol CH{sub 4}O and anhydrous tin tetrachloride. XRD analyses yielded strong (1 1 0)-(1 0 1)-(2 0 0) X-ray diffraction peaks which are characteristics to tetragonal crystals. Atomic Force Microscopy (AFM) analyses showed the existence of clusters with particular pyramidal shapes. The main part of this study concerns the optical measurements of transmittance T({lambda}) and reflectance R({lambda}) spectra inside 250-1800 nm domain. Conjoint optical and thermal properties were deduced using the Amlouk-Boubaker Opto-Thermal Expansivity {psi}{sub AB}. The obtained value: {psi}{sub AB} {approx} 23.4 m{sup 3} s{sup -1} helped situating the performance of the as-grown SnO{sub 2} compound among most known PV-T oxides like ZnO and TiO{sub 2}.
2010-02-04
International Nuclear Information System (INIS)
In this study, SnO2 thin films have been grown using spray pyrolysis technique on glass substrates under a substrate temperature (Ts = 440 oC). The precursors were methanol CH4O and anhydrous tin tetrachloride. XRD analyses yielded strong (1 1 0)-(1 0 1)-(2 0 0) X-ray diffraction peaks which are characteristics to tetragonal crystals. Atomic Force Microscopy (AFM) analyses showed the existence of clusters with particular pyramidal shapes. The main part of this study concerns the optical measurements of transmittance T(?) and reflectance R(?) spectra inside 250-1800 nm domain. Conjoint optical and thermal properties were deduced using the Amlouk-Boubaker Opto-Thermal Expansivity ?AB. The obtained value: ?AB ? 23.4 m3 s-1 helped situating the performance of the as-grown SnO2 compound among most known PV-T oxides like ZnO and TiO2.
2010-02-04
Single-crystal microwires based on doped Bi for anisotropic thermoelectric devices
International Nuclear Information System (INIS)
We have investigated the possibility to use a microwire of BiSn to design an anisotropic thermoelectric generator. The glass-coated microwire of pure and Sn-doped bismuth was obtained by the Ulitovsky method; it was a cylindrical single-crystal with orientation (1011) along the wire axis; the C3 axis was inclined at an angle of 70 degrees to the microwire axis. It is found that doping of bismuth wires with tin increases the thermopower anisotropy in comparison with Bi by a factor of 2 - 3 in the temperature range of 200-300 K. For a Bi microwire with a core diameter of 10 ?m with a glass coating with outer diameter of 35 ?m, the transverse thermopower is ? 150 ?V/(K*cm); for BiSn, 300 ?V/(K*cm). The design of an anisotropic thermogenerator based on BiSn microwire is proposed. The miniature thermogenerator will be efficient for power supply of devices with low useful current. In addition to the considerable thermopower anisotropy of BiSn wires in a glass coating, ...
2011-07-07
Research on development of adsorbent for separating and collecting light element isotopes
International Nuclear Information System (INIS)
Lithium isotopes are used as the raw material of tritium which is the fuel for fusion power generation and the material for fusion reactors, accordingly those are indispensable for future nuclear fusion power generation. As for boron isotopes, the neutron absorption corss section is very large, therefore, they are used for shielding neutrons and controlling fast neutron reactors. In order to further develop the utilization of nuclear power, it is important to develop the technology for separating and refining light element isotopes in large amount. In fiscal year 1995, the relation of the ion sieve characteristics of inorganic ion exchanger and the behavior of lithium isotope separation was examined. The behavior of forming boron complex of polyol amine was examined by B-11 NMR. These experiments and the results are reported. It was shown to be feasible that lithium is adsorbed from seawater, and isotopes are concentrated. Titanium phosphate and its heat treated thing, and heat treated ...
Recent activites on electromagnetic processing of materials in Japan
Energy Technology Data Exchange (ETDEWEB)
Application of electromagnetic forces to materials processing, so-called {open_quotes}electromagnetic processing of materials (EPM){close_quotes} has been recognized as cutting edge technology, especially in the fields of steelmaking and advanced materials processing in Japan. The history of EPM in Japan is mentioned and the background to promote EPM is described. The current status of research and development of EPM is shown briefly introducing several examples. Regarding the application of high-frequency magnetic field, two topics are dealt with. The first is the improvement of the surface quality of cast steel where an alternating magnetic field is imposed on the molten steel from the outside of the mold, and the second is the induction cold crucible where a considerably large amount of molten intermetallic compound is levitated. Examples of the application of DC magnetic field are the control of molten steel flow in a mold and the suppression of the mixing of steel in the strand of ...
1995-01-01
Radio-frequency plasma nitriding and nitrogen plasma immersion ion implantation of Ti-6Al-4V alloy
Energy Technology Data Exchange (ETDEWEB)
Nitrogen ion implantation improves the wear resistance of Ti-6Al-4V alloys by forming a hard TiN superficial passivation layer. However, the thickness of the layer formed by traditional ion implantation is typically 100-200 nm and may not be adequate for many industrial applications. We propose to use radio-frequency (RF) plasma nitriding and nitrogen plasma immersion ion implantation (PIII) to increase the layer thickness. By using a newly designed inductively coupled RF plasma source and applying a series of negative high voltage pulses to the Ti-6Al-4V samples. RF plasma nitriding and nitrogen PIII can be achieved. Our process yields a substantially thicker modified layer exhibiting more superior wear resistance characteristics, as demonstrated by data from micro-hardness testing, pin-on-disc wear testing, scanning electron microscopy (SEM), as well as Auger electron spectroscopy (AES). The performance of our newly developed inductively coupled RF plasma source ...
1997-09-01
Radio-frequency plasma nitriding and nitrogen plasma immersion ion implantation of Ti-6Al-4V alloy
International Nuclear Information System (INIS)
Nitrogen ion implantation improves the wear resistance of Ti-6Al-4V alloys by forming a hard TiN superficial passivation layer. However, the thickness of the layer formed by traditional ion implantation is typically 100-200 nm and may not be adequate for many industrial applications. We propose to use radio-frequency (RF) plasma nitriding and nitrogen plasma immersion ion implantation (PIII) to increase the layer thickness. By using a newly designed inductively coupled RF plasma source and applying a series of negative high voltage pulses to the Ti-6Al-4V samples. RF plasma nitriding and nitrogen PIII can be achieved. Our process yields a substantially thicker modified layer exhibiting more superior wear resistance characteristics, as demonstrated by data from micro-hardness testing, pin-on-disc wear testing, scanning electron microscopy (SEM), as well as Auger electron spectroscopy (AES). The performance of our newly developed inductively coupled RF plasma source ...
1996-09-15
Preparation of TiO2/NiO composite particles and their applications in dye-sensitized solar cells
British Library Electronic Table of Contents (United Kingdom)
This study investigates the applicability of n-type TiO2 and p-type NiO on the FTO-glass (Fluorine doped tin oxide, SnO2:F) substrate of the working electrode in a dye-sensitized solar cell (DSSC). The working electrode was designed and fabricated by depositing a film of TiO2/NiO composite particles, which were prepared by mixing the Ni powder with TiO2 particles using dry mixing method, on a FTO-glass substrate using a spin coating process. The working electrode was then immersed in the solution of N-719 (Ruthenium) dye at a temperature of 70degreeC for 6h. Moreover, a thin film of platinum (Pt) was deposited on the FTO-glass substrate of the counter electrode using an E-beam evaporator. Finally, the DSSC was assembled, and the short-circuit photocurrent, the open-circuit photovoltage and...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2x the...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited...
2010-01-01
Numerical heat transfer studies of PCMs used in a box-type solar cooker
Energy Technology Data Exchange (ETDEWEB)
Theoretical investigations on the phase change materials (PCMs) used as the heat storage media for box-type solar cookers have been conducted in this study. The selected PCMs are magnesium nitrate hexahydrate, stearic acid, acetamide, acetanilide and erythritol. For a two-dimensional simulation model based on the enthalpy approach, calculations have been made for the melt fraction with conduction only. Different materials such as glass, stainless steel, tin, aluminum mixed, aluminum and copper are used as the heat exchanger container materials in the numerical calculations. The large value of thermal conductivity of heat exchanger container material did not make a significant contribution on the melt fraction except for at very low thermal conductivities. Based on the theoretical results, stearic acid and acetamide are found to be good compatibility with latent heat storage system. It is also found that the initial temperature of PCM does not have very important ...
2008-05-15
New correlated electron physics from new materials
International Nuclear Information System (INIS)
Many important advances in the physics of strongly correlated electron systems have been driven by the development of new materials: for instance the filled skutterudites MT4X12 (M=alkali metal, alkaline earth, lanthanide, or actinide; T=Fe, Ru, or Os; X=P, As, or Sb), certain lanthanide and actinide intermetallic compounds such as URu2-xRexSi2 and CeTIn5 (T=Co, Rh, or Ir), and layered oxypnictides and related materials. These types of complex multinary d- and f-electron compounds have proven to be a vast reservoir of novel strongly correlated electron ground states and phenomena. In these materials, the occurrence of such a wide range of ground states and phenomena arises from a delicate interplay between competing interactions that can be tuned by partial or complete substitution of one element for another, as well as the application of pressure, and magnetic fields, resulting in rich and complex electronic phase diagrams in the hyperspace of temperature, ...
2009-10-15
Nb{sub 3}Sn ITER candidate conductor
Energy Technology Data Exchange (ETDEWEB)
An internal-tin-process Nb{sub 3}Sn conductor, which is a prototype for the International Thermonuclear Experimental Reactor (ITER), was tested. The axial strain measurements were made over a range of magnetic fields from 15 to 25 T. The conductor specifications are given in Table 5, and the measured data are presented in Table 6 and Figs. 8 through 10. The I{sub c} and J{sub c} values are based on an electric field criterion (E{sub c}) of 2 {mu}V/cm. The results show a zero-strain 15 T value of J{sub c} (referred to the noncopper area) which was 0.50 GA/m{sup 2} and a peak (strain-free) J{sub c} value of 0.55 GA/m{sup 2}. The irreversible strain limit was reasonably high, 0.92%, and the compressive prestrain was 0.28%. The sample did not fracture until 1.09% strain.
1994-01-01
Energy Technology Data Exchange (ETDEWEB)
Microstructural evolution due to thermal effects was studied in micro solder joints (55 {+-} 5 {micro}m). The composition of the Sn/Pb solder studied was found to be hypereutectic with a tin content of 65--70 wt%.This was determined by Energy Dispersive X-ray analysis and confirmed with quantitative stereology. The quantitative stereological value of the surface-to-volume ratio was used to characterize and compare the coarsening during thermal cycling from 0--160 C to the coarsening during annealing at 160 C. The initial coarsening of the annealed samples was more rapid than the cycled samples, but tapered off as time to the one-half as expected. Because the substrates to which the solder was bonded have different thermal expansion coefficients, the cycled samples experienced a mechanical strain with thermal cycling. The low-strain cycled samples had a 2.8% strain imposed on the solder and failed by 1,000 cycles, despite undergoing less coarsening than the annealed ...
1998-12-01
Metallization of large silicon wafers. Final report
A metallization scheme has been developed which allows selective plating of silicon solar cell surfaces. The system is comprised of three layers. Palladium, through the formation of palladium silicide at 300/sup 0/C in nitrogen, makes ohmic contact to the silicon surface. Nickel, plated on top of the palladium silicide layer, forms a solderable interface. Lead-tin solder on the nickel provides conductivity and allows a convenient means for interconnection of cells. To apply this metallization, three chemical plating baths are employed. Palladium is deposited with an immersion palladium solution and an electroless palladium solution, and nickel is deposited with an electroless nickel solution. Solder is applied with a molten solder dip. Extensive development work has been performed to achieve an effective immersion palladium solution formulation, leading to reproducible formation of the palladium silicide contact layer. This metallization system has been repeatedly ...
Mechanical properties of excimer laser modified titanium surfaces
Energy Technology Data Exchange (ETDEWEB)
Excimer laser processing enables both thermally-driven transformations and the incorporation of solutes into the surface of materials through melting and diffusional mixing. We have examined the effect of excimer laser processing on the microstructure and surface mechanical properties of titanium alloys. Changes in the surface hardness due to laser processing were studied using a Nanoindenter [trademark]. Alloying experiments using both mixing of evaporated surface layers of boron and laser gas alloying in air and in nitrogen all result in changes in the surface hardness of the material. Alloying with boron results in an amorphous surface which is somewhat harder than the as polished surface. Laser processing in air and pure nitrogen results in incorporation of oxygen and nitrogen and the development of fine ([approximately] 50 nm) precipitates of TiO and TiN respectively. Substantial increases in surface hardness result due to solution and precipitation ...
1993-01-01
Mechanical properties and tribological behavior of TiN-CrAlN and CrN-CrAlN multilayer coatings
Energy Technology Data Exchange (ETDEWEB)
There is an increasing number of applications for hard coatings in engineering where the properties of the single-layer coating are not sufficient. One way to solve this problem is to use a multilayer coating that combines the properties of several coating materials. In this study, TiN-CrAlN and CrN-CrAlN multilayer coatings were deposited on 100Cr6 and S6-5-2 (DIN) steel substrates, by means of unbalanced magnetron sputtering. For comparison, TiN, CrN and CrAlN single-layer coatings were also prepared. For all depositions the coating temperature was below 473 K. Indentation testing, hardness measurements and scratch tests were performed to characterize the mechanical properties. The correlation between the wear behavior in rolling contact and the mechanical properties of the multilayer coatings is reported. A ball crater preparation technique through scratch tests and wear tracks was used to observe the deformation and fracture behavior occurring as a result of ...
1999-02-01
International Nuclear Information System (INIS)
Focused ion beam (FIB) milling techniques are presented aiming at the manipulation of both tin dioxide (SnO_2) inverted opals and polystyrene (PS) direct opals. Different SnO_2 opals are considered in order to estimate the regularity of their bulk after the production. A SnO_2 mesoporous monolith is FIB micromachined to make it suitable for optical applications. PS direct opals are structured by FIB milling at different scales. Ordered arrays of PS opals are modified by selectively removing a single sphere. In performing this task, we discuss the effects on the FIB milling due to the gas-assisted enhanced etching and to the binding of the nearest neighbours. Techniques to achieve imaging of PS opals in absence of a conductive coating are also brought up. Furthermore, isolated PS spheres are drilled with or without enhanced etching in order to produce controlled defects on them. The FIB-assisted manipulations we show may find potential applications in the field of ...
2008-08-01
Management of industrial solid wastes in Alexandria, Egypt
This paper presents a summary of the first phase of the EPA project, which encompasses surveys of residues from industrial sources in Alexandria. Studies to date indicate that wastes from various industries can be recovered economically. Wastes such as tin cans, glass, wastepaper, and food residues from processing of fruits, starch, and beer are examples of reusable industrial wastes in Egypt. The results of experimental studies for reuse of residues from oil refining, starch and yeast processing, and steel pickling are presented. Spent clay from edible oil refining is currently discarded, causing both handling and disposal problems. This clay contains as much as 40% oil; 90% can be recovered by extraction. The recovered oil can be successfully used in soap production, and the spent clay can be reused in oil bleaching. Other examples include starch and yeast wastes, which can be used for animal feed, and spent pickling liquor, which can be used as a coagulant aid ...
1983-03-01
Linear augmented-plane-wave calculation of the structural properties of bulk Cr, Mo, and W
International Nuclear Information System (INIS)
A scalar-relativistic procedure for calculating the valence-electron contribution to the total energy of bulk and thin-film solids has been developed and applied to the fcc and bcc phases of the group-VIB transition elements Cr, Mo, and W. This approach, which is based on the linear augmented-plane-wave method and local-density-functional theory, contains no shape approximations for either the charge density or potential. The formulation adopts a rigid-core approximation and incorporates an exact treatment of the core-charge tails that extend beyond the muffin-tin spheres. The application of this procedure to bcc Cr, Mo, and W yields calculated lattice parameters and bulk moduli that are in good (Cr) to excellent (Mo and W) agreement with experiment. The present calculated properties also agree quite well with the results of previous calculations involving a variety of band-structure methods. The calculated fcc-bcc energy difference for Cr, Mo, and W increases in a ...
International Nuclear Information System (INIS)
Ten different alloys of zirconium have been tested with regard to the effect of irradiation on their mechanical properties and their sensitivity to environmentally induced failure. Two different environments were used: iodine vapour and liquid cesium with an addition of 2% cadmium. The neutron dose was 10"2"1n/cm"2 (E>1MeV) and the irradiation temperature was about 300 degrees C. All alloy additions increased the irradiation hardening. Especially notable was the large effect of titanium and tin on irradiation hardening. A limited amount of transmission electron microscopy was carried out in order to find an explanation to the effects. The testing in different environments showed that there is no clear correlation between environmental sensitivity and yield stress. For materials of similar yield stress an alloyed material tends to be more sensitive to environmental cracking than a material which only contains oxygen as an impurity. There also seems to be an ...
1991-08-25
Identification of water quality and benthos characteristics in Daya Bay, China, from 2001 to 2004
British Library Electronic Table of Contents (United Kingdom)
Physicochemical and benthos data were collected from 12 marine monitoring stations in Daya Bay, during 2001-2004. 12 stations in Daya Bay could be grouped into three clusters: cluster I consisted of stations in the southern part of Daya Bay (stations S1, S2 and S6); cluster II consisted of stations in the cage culture areas (stations S3, S4, S5 and S8); cluster III consisted of stations in the southwest, the middle and the northeast of the Bay (stations S7, S9, S10, S11 and S12). Calculation with bivariate correlations between benthos and major physicochemical factors showed that the density of benthos in all stations correlated positively with temperature, DO, pH, NH4-N, SiO3-Si, SiO3-Si /PO4-P and chlorophyll a and was negatively correlated with salinity, Secchi, COD, NO3-N, NO2-N, TIN, ...
2011-01-01
Growth and characterisation of electrodeposited ZnO thin films
Energy Technology Data Exchange (ETDEWEB)
The electrochemical method has been used to deposit zinc oxide (ZnO) thin films from aqueous zinc nitrate solution at 80 deg. C onto fluorine doped tin oxide (FTO) coated glass substrates. ZnO thin films were grown between - 0.900 and - 1.025 V vs Ag/AgCl as established by voltammogram. Characterisation of ZnO films was carried out for both as-deposited and annealed films in order to study the effect of annealing. Structural analysis of the ZnO films was performed using X-ray diffraction, which showed polycrystalline films of hexagonal phase with (002) preferential orientation. Atomic force microscopy was used to study the surface morphology. Optical studies identified the bandgap to be {approx} 3.20 eV and refractive index to 2.35. The photoelectrochemical cell signal indicated that the films had n-type electrical conductivity and current-voltage measurements showed the glass/FTO/ZnO/Au devices exhibit rectifying properties. The thickness of the ZnO films was ...
2008-04-30
Effect of intermetallic growth rate on spontaneous whisker growth from a tin coating on copper
British Library Electronic Table of Contents (United Kingdom)
Intermetallic compound (IMC) growth at the interface between a Sn coating and a Cu substrate with or without a Ni underlayer and its related stress state was evaluated by real-time measurements using the flexure beam method. For the Sn coating without a Ni underlayer, pyramid-shaped IMC grains of Cu6Sn5 grew along the grain boundaries of Sn from the Cu substrate, especially at the triple grain boundary junctions and the IMC grains rapidly increased their volume during the initial 3?days, During this time, the IMC growth rate was 2.3??m3/day and the compressive stress in the Sn coating rapidly developed and became saturated at about ?11?MPa. In contrast, platelet IMC grains of Ni3Sn4 formed at the surface of the Ni underlayer and the IMCs grew at a rate of 1.0??m3/day for the Sn/Ni coating....
2011-01-01
Effect of hot air aging on properties of EPDM/SmBO3/EVA and EPDM/ATO/EVA composites
British Library Electronic Table of Contents (United Kingdom)
Abstract Ethylene-propylene-diene rubber (EPDM)/samarium borate (SmBO3)/ethylene-vinyl acetate (EVA) copolymer and EPDM/antimony-doped tin oxide (ATO)/EVA composites are aged at 150C for different intervals. Surface modification is used to improve filler to matrix interphase. The main aim is to investigate the effect of filler type and vinyl acetate (VA) content in EVA on stability of EPDM composites. It is found that acidic ATO particles can lower pH level of EPDM composites and then promote the degradation of acetic acid during aging. Moreover, when VA content exceeds 14 wt %, the instable VA content causes more acetic acids escape during aging. With the increasing of aging time, EPDM/SmBO3 control and EPDM/SmBO3/EVA composites tend to become darker while EPDM/ATO and EPDM/ATO/EVA compos...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
Labelling yield and radiochemical purity, higher than 95%, of sup(99m)Tc-colloid preparations were determined by using the paper chromatography method. Less than 3% of labelled citric acid, added to the preparation as a buffer solution, has been found in sup(99m)Tc-sulphur colloid. High radiochemical purity and optimum size of colloid particles has also been proved by biodistribution studies on experimental animals. The analysis performed has shown that more than 50% of sup(99m)Tc-colloid preparations excreted by urine is sup(99m)TcO/sup -/, the remaining past 50% being protein bound sup(99m)Tc. Biological half-time of excretion of the fast phase is the same for both preparations, i.e. 10 min, while for the slow component it is 120 min in sup(99m)Tc-S-colloid and 160 min in sup(99m)Tc-Sn colloid.
1981-12-01
British Library Electronic Table of Contents (United Kingdom)
A type of Si3N4-based nanocomposites ceramic cutting tool material was prepared by the addition of nano-scale Si3N4W whisker and nano-scale TiN particle. Cutting performance of the Si3N4/Si3N4W/TiN nanocomposite ceramic tool in machining of cast iron was investigated in comparison with a commercial sialon ceramic tool, and the tool wear mechanism was studied. The two types of cutting tools have similar cutting performance at relatively low cutting parameters, while Si3N4/Si3N4W/TiN nanocomposite tool exhibits a better wear resistance than sialon tool at the relatively high cutting parameters. The wear of sialon ceramic cutting tool is dominated by the plastic deformation, abrasive action, microcracking, pullout of grains and chemical action at the higher cutting parameters. The higher mech...
2011-01-01
Anisotropic magnetism in hybridizing uranium systems
International Nuclear Information System (INIS)
The isostructural uranium monopnictides and monochalcogenides have become prototype systems in actinide research with respect to their unusual magnetic properties. We have investigated the origins in the electronic structure of the variation in magnetic behavior as the degree of 5f-electron localization changes from localized to itinerant on going up the pnictogen or chalcogen column, thus decreasing the U-U separation. We have applied a synthesis of: (1) A phenomenological theory of orbitally driven magnetic ordering which includes both the hybridization-induced and the RKKY exchange interactions on an equal footing, and (2) Ab initio electronic structure calculations, based on the linear-muffin-tin-orbital method, allowing a first-principles evaluation of the parameters entering the model Hamiltonian. We have investigated systematically characteristic trends and changes of the 5f-state resonance width, the hybridization potential, and the hybridization-induced ...
This work investigates the impingement of a liquid microdroplet onto a glass substrate at different temperatures. A finite-element model is applied to simulate the transient fluid dynamics and heat transfer during the process. Results for impingement under both isothermal and non-isothermal conditions are presented for four liquids: isopropanol, water, dielectric fluid (FC-72) and eutectic tin-lead solder (63Sn-37Pb). The objective of the work is to select liquids for a combined numerical and experimental study involving a high resolution, laser-based interfacial temperature measurement to measure interfacial heat transfer during microdroplet deposition. Applications include spray cooling, micro-manufacturing and coating processes, and electronics packaging. The initial droplet diameter and impact velocity are 80 {\\mu}m and 5 m/s, respectively. For isothermal impact, our simulations with water and isopropanol show very good agreement with experiments. The ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
In the Ti-Si-C and Ti-Si-C-N systems, metastable layers were precipitated by means of non-reactive magnetron sputtering of hot-pressed two-phase TiC/SiC and TiN/SiC targets with 20 mole% and 50 mole% SiC. The preparation parameters were varied as follows: ion bombardment during precipitation (bias sputtering), substrate temperature, and annealing times when annealing amorphous 50%:50% TiC/SiC and 50%:50% TiN/SiC layers. Sputtering of targets containing 20% SiC was found to result in monophase fcc layers (NaCl structure). This was documented on the basis of X-ray and electron diffraction patterns. Direct precipitation of targets with 50 mole% SiC resulted in amorphous layers. Increasing the ion bombardment during accretion, raising the substrate temperature, and annealing amorphous 50%:50% TiC/SiC and 50%:50% TiN/SiC (layers precipitated directly) resulted in the crystallization of TiC and TiN nanocrystallites, respectively, imbedded in an amorphous SiC matrix. ...
1992-10-01
Thin-film solar cells on flexible, lightweight, space-qualified substrates provide an attractive approach to fabricating solar arrays with high mass-specific power. A polycrystalline chalcopyrite absorber layer is among the new generation of photovoltaic device technologies for thin film solar cells. At NASA Glenn Research Center we have focused on the development of new single-source precursors (SSPs) for deposition of semiconducting chalcopyrite materials onto lightweight, flexible substrates. We describe the syntheses and thermal modulation of SSPs via molecular engineering. Copper indium disulfide and related thin-film materials were deposited via aerosol-assisted chemical vapor deposition using SSPs. Processing and post-processing parameters were varied in order to modify morphology, stoichiometry, crystallography, electrical properties, and optical properties to optimize device quality. Growth at atmospheric pressure in a horizontal hotwall reactor at 395 C ...
2008-01-01
Proton-neutron interaction in odd--odd indium nuclei
International Nuclear Information System (INIS)
Low-lying nuclear energy levels in "1"1"0In and "1"1"2In were determined from de-excitation #gamma#-rays produced with "1"0"7Ag(#alpha#,n#gamma#)-"1"1"0In, "1"0"8Pd("6Li,4n#gamma#)"1"1"0In, "1"0"9Ag(#alpha#,n#gamma#)"1"1"2In and "1"1"0Pd("6Li,4n#gamma#)"1"1"2In reactions. In addition, the "1"1"4In energy level structure was investigated with the "1"1"0Pd("7Li,3n#gamma#)"1"1"4In reaction. Properties of de-excitation #gamma#-rays were determined from #gamma#-#gamma# coincidence, excitation, and angular distribution measurements conducted with Ge(Li) and Ge(intr.) #gamma#-ray detectors. A sequence of intraconnected levels in each of "1"1"0,"1"1"2,"1"1"4In were assigned to the (#pi#g"-"1/sub 9/2/, #nu#h/sub 11/2/) configuration. For the "1"1"0,"1"1"2,"1"1"4In energy level schemes a model calculation has been performed using the pairing-plus-quadrupole model, which reproduced states of the (#pi#g"-"1/sub 9/2/, #nu#h/sub 11/2/) multiplets quite well. A value of the proton-neutron coupling ...
1977-01-01
Proton-neutron interaction in odd--odd indium nuclei
International Nuclear Information System (INIS)
An experimental study was performed in order to study the nuclear structure in odd--odd In isotopes. Low lying nuclear energy levels in "1"1"0In and "1"1"2In were determined from de-excitation #gamma#-rays produced with "1"0"7AG(#alpha#,n#gamma#)"1"1"0In, "1"0"8Pd("6Li,4n#gamma#)"1"1"0In, "1"0"9Ag(#alpha#,n#gamma#)"1"1"2In and "1"1"0Pd("6Li,4n#gamma#)"1"1"2In reactions. In addition, the "1"1"4In energy level structure was investigated with the "1"1"0Pd("7Li,3n#gamma#)"1"1"4In reaction. Properties of de-excitation #gamma#-rays were determined from #gamma#--#gamma# coincidence excitation and angular distribution measurements conducted with Ge(Li) and Ge(intr.) #gamma#-ray detectors. A sequence of intraconnected levels in each of "1"1"0 "1"1"2 "1"1"4In were assigned to the (#pi#"-"1/sub 9/2/, #nu#h/sub 11/2) configuration. For the "1"1"0 "1"1"2"1"1"4In energy level schemes a model calculation was performed using the pairing-plus-quadrupole model, which reproduced states of the ...
1977-01-01
Energy Technology Data Exchange (ETDEWEB)
We describe the growth, fabrication, and characterization of an ultraviolet (UV) photoconductive detector based on In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloy that is lattice matched to GaN. The detector consisted of 0.1 {mu}m In{sub x}Al{sub y}Ga{sub 1-x-y}N alloy grown on 0.5-1.0 {mu}m GaN epilayer by metalorganic chemical vapor deposition. With varying indium concentration, the cut-off wavelength of the In{sub x}Al{sub y}Ga{sub 1-x-y}N detectors could be varied to the deep UV range. The most important and intriguing result is that the responsivity of the In{sub x}Al{sub y}Ga{sub 1-x-y}N quaternary alloy exceeded that of AlGaN alloy of a comparable cutoff wavelength by a factor of five. This makes the nitride quaternary alloy very important material for solar blind UV detectors applications particularly in the deep UV range where Al rich AlGaN alloys have problems with low quantum efficiency and cracks due in part to lattice mismatch with GaN. The ...
2000-08-07
Photoresponsivity of ultraviolet detectors based on In_xAl_yGa_1_-_x_-_yN quaternary alloys
International Nuclear Information System (INIS)
We describe the growth, fabrication, and characterization of an ultraviolet (UV) photoconductive detector based on In_xAl_yGa_1_-_x_-_yN quaternary alloy that is lattice matched to GaN. The detector consisted of 0.1 #mu#m In_xAl_yGa_1_-_x_-_yN alloy grown on 0.5-1.0 #mu#m GaN epilayer by metalorganic chemical vapor deposition. With varying indium concentration, the cut-off wavelength of the In_xAl_yGa_1_-_x_-_yN detectors could be varied to the deep UV range. The most important and intriguing result is that the responsivity of the In_xAl_yGa_1_-_x_-_yN quaternary alloy exceeded that of AlGaN alloy of a comparable cutoff wavelength by a factor of five. This makes the nitride quaternary alloy very important material for solar blind UV detectors applications particularly in the deep UV range where Al rich AlGaN alloys have problems with low quantum efficiency and cracks due in part to lattice mismatch with GaN. The advantages of In_xAl_yGa_1_-_x_-_yN quaternary over ...
2000-08-07
International Nuclear Information System (INIS)
Nuclear analytical techniques were applied to determine the elemental compositions of suspended and bottom sediments, collected at different sites in Haiphong harbor area (North Viet nam). The study was aimed at: 1/Understanding the origin of the sediment filling up the access channel and causing large expenditures for dredging operations. 2/Determining the background concentrations of trace elements in sediment. This would allow to detect in the future any pollution caused by the discharge of industrial wastes in the water due to the growing industrialization of the area. 3/Identifying the elements, which can be served as activatable tracers in sediment transport studies. The results obtained for the concentrations of nearly 30 elements show rather similar elemental compositions, reflecting a common origin of the sediments taken from different locations in the harbour area. The results could not allow to identify the pathway of the sediment transported to and deposited on the bottom ...
1992-03-09
Characterization of tris(N-substituted-2-methyl-3-hydroxy-4-pyridinonato)technetium(IV) cations
Energy Technology Data Exchange (ETDEWEB)
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with [{sup 99m}Tc(pap){sub 3}]{sup +} showing elevated levels in ...
1994-11-23
Characterization of tris(N-substituted-2-methyl-3-hydroxy-4-pyridinonato)technetium(IV) cations
International Nuclear Information System (INIS)
A burgeoning interest in technetium coordination chemistry has been spurred by its widespread use in nuclear medicine. Recent focus has been on the design and preparation of new technetium complexes, the lipophilicity, polarity, and overall charge of which can be readily altered by simple substitutions in the molecular framework of the ligand in order to optimize the biodistribution and target specific organs. Examples are cationic (Cardiolite) and neutral (Ceretec) technetium complexes, used as myocardial and brain imaging agents, respectively. The authors have been pursuing a continuing study of tris(3-hydroxy-4-pyridinonato)gallium and -indium complexes that are water soluble, are hydrolytically stable, and are of varying lipophilicity and neutral charge. Studies of in vivo in rabbits and mice have revealed that several of these cationic complexes may be useful as morphologic kidney imaging agents, with ["9"9"mTc(pap)_3]"+ showing elevated levels in the kidneys ...
Fission product speciation in Phebus tests FPT0 and FPT1 and the possible influence of boron
Energy Technology Data Exchange (ETDEWEB)
The thermochemical calculations performed with a large number of elements to describe the chemical system in a Phebus FP test allow the following conclusions: The metallic absorber materials play a significant role in fission product speciation. At around 1000 C and above, silver iodide is the dominant iodine carrier in a full steam atmosphere in both FPT0 and FPT1. At lower temperatures, cadmium iodide takes over. In a reduced environment, indium iodide becomes important. Caesium iodide does certainly appear; at certain test conditions it becomes the major iodine transporting vehicle. But its role is not greater than that of the other iodides. It has more chances in FPT1 than in FPT0. Chlorine, which was present in FPT0 as a contaminant in relatively large amounts, does not prevent the iodine from forming Csl. Both share the caesium like partners. The evolution of caesium chloride and iodide proceeds in parallel. When CsCl is abundant, Csl is strong, too. Should ...
1996-01-01
Radiation damage measurements in room temperature semiconductor radiation detectors
Energy Technology Data Exchange (ETDEWEB)
The literature of radiation damage measurements on cadmium zinc telluride (CZT), cadmium telluride (CT), and mercuric iodide (HgI{sub 2}) is reviewed and in the case of CZT supplemented by new alpha particle data. CZT strip detectors exposed to intermediate energy (1.3 MeV) proton fluences exhibit increased interstrip leakage after 10{sup 10} p/cm{sup 2} and significant bulk leakage after 10{sup 12} p/cm{sup 2}. CZT exposed to 200 MeV protons shows a two-fold loss in energy resolution after a fluence of 5 {times} 10{sup 9} p/cm{sup 2} in thick (3 mm) planar devices but little effect in 2 mm devices. No energy resolution effects were noted from moderated fission spectrum of neutrons after fluences up to 10{sup 10} n/cm{sup 2}, although activation was evident. Exposures of CZT to 5 MeV alpha particle at fluences up to 1.5 {times} 10{sup 10} {alpha}/cm{sup 2} produced a near linear decrease in peak position with fluence and increases in FWHM beginning at about 7.5 {times} 10{sup 9} ...
1998-12-01
Energy Technology Data Exchange (ETDEWEB)
Indium-111 is currently the radionuclide of choice for colonic transit study. However, it is expensive and not available in many hospitals. Technetium-99m has been proposed for colonic transit study but the short half-life has limited its use. Gallium-67 citrate is inexpensive and available in most countries. Most importantly, it has a suitable half-life for colonic transit study. Attempts have been made in some studies to use {sup 67}Ga citrate to label activated charcoal, but the results have not been good because of poor stability. In this study, we successfully labelled activated charcoal with {sup 67}Ga citrate by adding alcohol and 5% glucose solution. To evaluate the in vitro stability, the {sup 67}Ga-activated charcoal was incubated in a milieu mimicking the intestinal content, containing lipase, trypsin and glycochenodeoxycholate at different pH values (6.0, 7.0, 7.4 and 8.0) and for different durations (0 h, 24 h, 48 h, 72 h and 96 h). For the in vivo ...
2003-06-01
Evaluation of small-bowel transit for solid and liquid test meal in healthy men and women
International Nuclear Information System (INIS)
Evaluation of severe functional gastrointestinal motility disorders requires an investigation of the entire gastrointestinal tract. This should be possible with a single radionuclide imaging study. The purpose of this study was (1) to define normal values of small-bowel transit in men and women and (2) to assess a possible difference between gender or test meal, since it has been shown that women have slower gastric emptying than men, and gastric emptying of solids is slower than liquids. A standard gastric-emptying test for a solid (technetium-99m sulphur colloids, 230 Kcal) and liquid (indium-111 DTPA water) test meal was performed in 12 healthy male and 12 healthy female volunteers. After 135 min, the volunteer was place in the supine position for static imaging of the abdomen every 15 min for 6 h. Decay and crossover-corrected geometric mean gastric-emptying data were fit to a modified power exponential function to determine the 10% stomach emptying time for ...
1999-12-01
Energy Technology Data Exchange (ETDEWEB)
{gamma}-ray excitation functions have been measured for the interaction of fast neutrons with {sup 48}Ti (neutron energy from 1 MeV to 250 MeV). The Los Alamos National Laboratory spallation neutron source, at the LANSCE/WNR facility, provided a ''white'' neutron beam which is produced by bombarding a natural W target with a pulsed proton beam. The prompt-reaction {gamma} rays were measured with the large-scale Compton-suppressed Ge spectrometer, GEANIE. Neutron energies were determined by the time-of-flight technique. Excitation functions were converted to partial {gamma}-ray cross sections, taking into account the dead-time correction, the target thickness, the detector efficiency, and neutron flux (monitored with an in-line fission chamber). The data analysis is presented here for neutron energies between 1 to 20 MeV. Partial {gamma}-ray cross sections for transitions in {sup 47,48}Ti, {sup 48}Sc, and {sup 45}Ca have been determined. These results ...
2005-01-06
Wear and friction behaviour of duplex-treated AISI 4140 steel
Energy Technology Data Exchange (ETDEWEB)
In this study samples of AISI 4140 steel were pretreated by plasma nitriding and coated with two different physical vapour deposited coatings (TiN and TiAlN). A hardened AISI 4140 sample and a coated sample were also included in the investigation. To examine the influence of the nitrided zone on the performance of the coating-substrate composite, two different nitriding conditions - a conventional 25% N{sub 2} and an N{sub 2}-poor gas mixture - were used. The specimens were investigated with respect to their microhardness, surface roughness, scratch adhesion and dry sliding wear resistance. Wear tests in which the duplex-treated pins were mated to hardened ball bearing steel discs were performed in a pin-on-disc machine under dry sliding conditions. Metallography, scanning electron microscopy and profilometry were used to analyse the worn surfaces in order to determine the dominant friction and wear characteristics of the samples investigated. The results show ...
1999-11-01
Energy Technology Data Exchange (ETDEWEB)
Emission inventories were estimated for the airborne emissions of: Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Mercury, Manganese, Molybdenum, Nickel, Lead, Antimony, Selenium, Tellur, Thallium, Zinc, Platinum, Palladium, Rhodium, Tin. The inventories were made for the status of 1985 and 1990. A prognosis was given for 1995. The investigations were made for the whole area of the Federal Republic of Germany including the former German Democratic Republic. Working point was an overview about the plant-specific emissions for the various industrial branches and the production statistics. The results are given as total emissions from the existing plants and industrial branches. (orig.) [Deutsch] Es erfolgte eine Abschaetzung der luftseitigen Emissionen fuer die Elemente: Arsen, Beryllium, Cadmium, Chrom, Kobalt, Kupfer, Quecksilber, Mangan, Molybdaen, Nickel, Blei, Antimon, Selen, Tellur, Thallium, Zink, Platin, Palladium, Rhodium und Zink. Die Erhebungen ...
1995-03-01
International Nuclear Information System (INIS)
The ternary stannides RE_3Ru_4Sn_1_3 (RE = La, Ce, Pr, Nd) were obtained by arc-melting of the elements. The polycrystalline samples were characterized by powder X-ray diffraction. The structures of three compounds were refined from single-crystal diffractometer data: Yb_3Rh_4Sn_1_3 type, Pm anti 3n, a = 977.74(3) pm, wR2 = 0.0379, 280 F"2 values for La_3Ru_4Sn_1_3, a = 971.34(9) pm, wR2 = 0.0333, 274 F"2 values for Ce_3Ru_4Sn_1_3, a = 970.68(8) pm, wR2 = 0.0262, 272 F"2 values for Nd_3Ru_4Sn_1_3 with 13 variables per refinement. The structures consist of three-dimensional networks of condensed RuSn_6_/_2 trigonal prisms with the RE (CN 16) and Sn2 (CN 12) atoms in two different types of cavities of the networks. The two crystallographically independent tin sites have been resolved by "1"1"9Sn Moessbauer spectroscopy. Temperature-dependent magnetic susceptibility measurements of Ce_3Ru_4Sn_1_3 gave a reduced magnetic moment of 2.32 ?_B per Ce atom, indicating ...
2011-07-01
Sandia LSI accelerated aging and data acquisition techniques
Energy Technology Data Exchange (ETDEWEB)
The purpose of the Microelectronic Evaluation Laboratory at Sandia is to develop a program for evaluating CMOS LSI (complementary metal oxide silicon - large scale integrated) technology devices which are being used for the first time in a weapon system. These evaluations are based on accelerated aging studies and electrical tests to determine the reliability and life of the devices. In accelerated aging, specific, controlled stresses are applied to the device to accelerate time-to-failure. Data are used tin mathematical models to estimate life in acutal use. The stresses used for this technology are temperature and voltage. The devices are stored at temperatures with or without voltage applied (steady-state or cyclical) and periodically tested until at least 50% failures are encountered. Since most current technologies use epoxy-die-attachment, aging temperatures must be under 200/sup 0/C. This delays device failure, and a 16% failure level is used when this ...
1980-04-01
Saddle field fast atom beam source: A new low pressure plasma nitriding method for a alloy Ti-6Al-4V
Energy Technology Data Exchange (ETDEWEB)
Ti and its alloys (Ti-6Al-4V) have been used in different engineering applications due to their several outstanding properties. Nevertheless, their use in practical applications is limited in many cases due to their poor tribological property. Researches are ongoing on surface modification of Ti based materials by different plasma and ion based techniques to overcome this problem. However, the conventional plasma nitriding techniques have several problems such as formation of an arc, increased possibility of surface contamination due to a comparatively higher operating pressure, production of a very thin nitrided layer after a long processing time, etc. In this present work, the possibility of a new low-pressure plasma nitriding process using a Plasma Enhanced Chemical Vapor Deposition (PECVD) based saddle field fast atom beam source on a Ti-6Al-4V alloy sample is investigated. Plasma nitriding was carried out at 900 deg. C and at a pressure 0.1 Pa for 8 h by using a beam current 0.5 ...
2006-09-25
Saddle field fast atom beam source: A new low pressure plasma nitriding method for a alloy Ti-6Al-4V
International Nuclear Information System (INIS)
Ti and its alloys (Ti-6Al-4V) have been used in different engineering applications due to their several outstanding properties. Nevertheless, their use in practical applications is limited in many cases due to their poor tribological property. Researches are ongoing on surface modification of Ti based materials by different plasma and ion based techniques to overcome this problem. However, the conventional plasma nitriding techniques have several problems such as formation of an arc, increased possibility of surface contamination due to a comparatively higher operating pressure, production of a very thin nitrided layer after a long processing time, etc. In this present work, the possibility of a new low-pressure plasma nitriding process using a Plasma Enhanced Chemical Vapor Deposition (PECVD) based saddle field fast atom beam source on a Ti-6Al-4V alloy sample is investigated. Plasma nitriding was carried out at 900 deg. C and at a pressure 0.1 Pa for 8 h by using a beam current 0.5 ...
2006-09-25
Energy Technology Data Exchange (ETDEWEB)
Out of the R and D of mesoscopic metal group composite materials, the paper described the fiscal 1997 results. In the in-situ method as a composite material making method, elucidated to some degree were chemical composition of Fe-C-Cr-V-Nb-Mo-W-Ni base multi-dimensional alloys, and wear resistance and oxidation resistance of MC type carbide dispersion multi-phase texture crystallizing as primary crystal and eutectic. In the composite material making with ceramic fiber and alloy by the pressure infiltration method, the paper clarified the texture formation mechanism in solidification/heat treatment by a combination of Al alloys and alumina long fiber, and the relation between fiber configuration and wear resistance. By MA and MG methods as the powder metallurgy composite material making method, a composed body of {alpha}-stainless steel of Fe-12%Cr composition and M23C6 of 40-90vol% are designed for alloy composition, and powder of amorphous or hyperfine texture was fabricated. By hot ...
1998-03-01
Energy Technology Data Exchange (ETDEWEB)
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2 x the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride particles for the treated Fe-20Cr-4V, but ...
2010-09-01
Energy Technology Data Exchange (ETDEWEB)
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, which exhibited {proportional_to}5-20% better peak power output than untreated Fe-20Cr-4V, 2205, and 904L metal stampings. ...
2010-09-01
Energy Technology Data Exchange (ETDEWEB)
Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, which exhibited {approx}5-20% better peak power output than untreated Fe-20Cr-4V, 2205, and 904L metal stampings. Durability ...
2010-09-01
Energy Technology Data Exchange (ETDEWEB)
Thermal (gas) nitridation of stainless steels can yield low interfacial contact resistance (ICR), electrically-conductive and corrosion-resistant nitride containing surfaces (Cr2N, CrN, TiN, V2N, VN, etc) of interest for fuel cells, batteries, and sensors. This paper presents the results of scale up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. A major emphasis was placed on selection of alloy foil composition and nitidation conditions potentially capable of meeting the stringent cost goals for automotive PEMFC applications. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. Promising behavior was observed under simulated aggressive anode- and cathode- side bipolar plate conditions for both materials. Variation in ICR values ...
2010-09-01
New correlated electron physics from new materials
Energy Technology Data Exchange (ETDEWEB)
Many important advances in the physics of strongly correlated electron systems have been driven by the development of new materials: for instance the filled skutterudites MT{sub 4}X{sub 12} (M=alkali metal, alkaline earth, lanthanide, or actinide; T=Fe, Ru, or Os; X=P, As, or Sb), certain lanthanide and actinide intermetallic compounds such as URu{sub 2-x}Re{sub x}Si{sub 2} and CeTIn{sub 5} (T=Co, Rh, or Ir), and layered oxypnictides and related materials. These types of complex multinary d- and f-electron compounds have proven to be a vast reservoir of novel strongly correlated electron ground states and phenomena. In these materials, the occurrence of such a wide range of ground states and phenomena arises from a delicate interplay between competing interactions that can be tuned by partial or complete substitution of one element for another, as well as the application of pressure, and magnetic fields, resulting in rich and complex electronic phase diagrams in ...
2009-10-15
Energy Technology Data Exchange (ETDEWEB)
During third quarter 1994, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Eight parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards (PDWS). Bis(2-ethylhexyl) phthalate exceeded final PDWS in one well. Aluminum, iron, manganese, tin, and total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone of the Crouch Branch Confining Unit were also similar to ...
1994-12-01
International Nuclear Information System (INIS)
The isostructural #gamma#-#alpha# phase transition of Ce which occurs at 8 kbar has been studied by means of fully self-consistent (non-muffin-tin potential) linearized-augmented-plane-wave energy band calculations carried out for five different values of the lattice constant. In contradiction to the 4f electron promotional model of the transition, the results yield essentially one 4f electron to be occupied in each phase but with the 4f wave function somewhat less localized, and therefore more bandlike, in the ''collapsed'' #alpha# phase. A singly occupied 4f state is shown to be consistent with the available experimental data. These results strongly support the picture of a 4f localized bold-arrow-left-right itinerant transition at the #gamma#-#alpha# transition and conflict with the promotional model in which some fraction of 4f electrons are transferred to the sd conduction bands. The weaker bonding of the 4f electrons, compared to that of the 6s-5d valence ...
Heat capacity of VT1-0 commercial titanium and VT5 and VT5-1 titanium base alloys at low temperature
International Nuclear Information System (INIS)
The temperature dependences of the heat capacity of commercial titanium VT1-0 and alloys on its base, VT5 and VT5-1, have been derived in the temperature range of 4 to 290 K. For comparison, similar measurements have been conducted on pure titanium and specially prepared solid solutions on its base (Ti+3.7 at.% Al and Ti+0.82 at.% Sn). The measurement accuracy has been sufficient for comparing the results with calculation data. The obtained results are interpreted using the known concepts of the role of the mass of interstitial atoms and changes in the interatomic bond forces. It is shown that the phonon components of the molar heat capacities of solid solutions of Al in titanium have lower values in the entire temperature range, as compared to titanium. The corresponding differences are proportional to the Al concentrations. The lower molar heat capacity in the case of dissolution of Al is due to the low mass of the impurity atoms and stronger interatomic bonds in their neighbourhood. ...
1978-01-01
Formation of metal oxides by cathodic arc deposition
Energy Technology Data Exchange (ETDEWEB)
Cathodic arc deposition is an established and industrially applied technique for the formation of nitrides (e.g. TiN); it can also be used for metal oxide thin film formation. A cathodic arc plasma source with the desired cathode material is operated in an oxygen atmosphere of appropriate pressure, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on accelerator components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}-Y{sub ...
1995-11-01
International Nuclear Information System (INIS)
We apply our previously developed first-principles nonlocal pseudopotentials (obtained for all atoms of rows 1--5 in the Periodic Table) to study self-consistently the electronic structure of Si and Ge and the transition metals Mo and W. For Si and Ge we find that the first-principles pseudopotentials yield valence-band states in good agreement with the empirically adjusted pseudopotential and photoemission data, whereas the low conduction-band states appear to be consistently lower in energy due apparently to incomplete cancellation of the self-interaction effects. The calculated x-ray scattering factors (obtained by core orthogonalization of the pseudo-wave-functions) are in excellent agreement with experiment. The self-consistent valence charge density shows a distinct elongation of the covalent bond along the internuclear axis, in good agreement with the experimentally synthesized density. The systematic deviations of the empirical pseudopotential results from the present are ...
Annihilation of a positron in a vacancy in aluminum
International Nuclear Information System (INIS)
Results of an augmented-plane-wave calculation of the positron lifetime and the angular-correlation curves for aluminum, both in the vacancy-free crystal and in the crystal with a vacancy, are presented. The environment of the vacancy was simulated by a face-centered-cubic supercell with a volume 27 times that of the standard primitive unit cell of the Al lattice. The calculated positron-vacancy binding energy is 3.36 eV at room temperature. The temperature dependences of the trapping potential, the positron-vacancy binding energy, and the positron lifetime both in the Bloch state and in the vacancy-trapped state, associated only with the static thermal expansion of the lattice, have been calculated. It is found that the fractional increase in positron lifetime in the Bloch state is only approx.80% of the fractional increase in the volume of the lattice. The lifetime in the vacancy-trapped state is also found to vary with temperature, showing a fractional increase of approx.50% of the ...
International Nuclear Information System (INIS)
Ab initio total energy calculations within the framework of density functional theory have been performed for atomic hydrogen and oxygen chemisorption on the (0001) surface of double hexagonal packed (dhcp) americium using a full-potential all-electron linearized augmented plane wave plus local orbitals method. Chemisorption energies were optimized with respect to the distance of the adatom from the relaxed surface for three adsorption sites, namely top, bridge, and hollow hcp sites, the ad-layer structure corresponding to the coverage of a 0.25 monolayer in all cases. Chemisorption energies were computed at the scalar-relativistic level (no spin-orbit coupling NSOC) and at the fully relativistic level (with spin-orbit coupling SOC). The two-fold bridge adsorption site was found to be the most stable site for O at both the NSOC and SOC theoretical levels with chemisorption energies of 8.204 eV and 8.368 eV respectively, while the three-fold hollow hcp adsorption site was found to be ...
2008-02-01
Energy Technology Data Exchange (ETDEWEB)
Some crops of important nutritive requirements have been collected from farmlands located in Bitsichi an old tin mining town in north central region of Nigeria. The food crops were analyzed in order to determine trace element concentrations level using Neutron Activation Analysis (NAA). The activity concentrations due to natural radionuclides in the food samples and soil samples collected within the root zone of the crops were also determined using gamma-ray spectrometry (GRS). The NAA results obtained showed higher concentration of Potassium among the essential elements in all the crops. Calcium concentration in both maize and Guinea corn was below detection limit and also Zn in Green beans, sweet potato and cassava. The trace elements; Sc, Hf, Sm, and Th, were below detection limit in all the crops except in Green beans. Rubidium (Rb) and lanthanum (La) were below detection limits only in Cabbage. The activity concentrations of the natural radionuclides in the ...
2007-01-15
International Nuclear Information System (INIS)
Some crops of important nutritive requirements have been collected from farmlands located in Bitsichi an old tin mining town in north central region of Nigeria. The food crops were analyzed in order to determine trace element concentrations level using Neutron Activation Analysis (NAA). The activity concentrations due to natural radionuclides in the food samples and soil samples collected within the root zone of the crops were also determined using gamma-ray spectrometry (GRS). The NAA results obtained showed higher concentration of Potassium among the essential elements in all the crops. Calcium concentration in both maize and Guinea corn was below detection limit and also Zn in Green beans, sweet potato and cassava. The trace elements; Sc, Hf, Sm, and Th, were below detection limit in all the crops except in Green beans. Rubidium (Rb) and lanthanum (La) were below detection limits only in Cabbage. The activity concentrations of the natural radionuclides in the ...
International Nuclear Information System (INIS)
To investigate the effect of external loads arising from differential thermal expansion between a substrate and a surface-mount component during thermomechanical cycling, specimens with a nickel surface-mount component on a copper substrate were prepared. Specimens consisted of two 100 #mu#m thick 1 mm"2 solder joints about 9 mm apart, with two designs. In one specimen (denoted 'dual-shear'), the as-fabricated joints were not stressed due to differential contraction during solidification and cool down. In the other specimen (denoted 'component'), a continuous copper substrate between the joints caused the nickel component to be put in compression during cool down, which imposed shear on the joints. To impose differential thermal shear strains, the 'dual-shear' specimen was clamped to a copper block to cause a significant reversal in sign of the shear imposed on the solder joint during cycling. In the 'component' specimen configuration, the existing compressive strain in the component ...
2006-04-15
International Nuclear Information System (INIS)
The compost bioreactor ('anaerobic cell') components of three composite passive remediation systems constructed to treat acid mine drainage (AMD) at the former Wheal Jane tin mine, Cornwall, UK were studied over a period of 16 months. While there was some amelioration of the preprocessed AMD in each of the three compost bioreactors, as evidenced by pH increase and decrease in metal concentrations, only one of the cells showed effective removal of the two dominant heavy metals (iron and zinc) present. With two of the compost bioreactors, concentrations of soluble (ferrous) iron draining the cells were significantly greater than those entering the reactors, indicating that there was net mobilisation (by reductive dissolution) of colloidal and/or solid-phase ferric iron compounds within the cells. Soluble sulfide was also detected in waters draining all three compost bioreactors which was rapidly oxidised, in contrast to ferrous iron. Oxidation and hydrolysis of iron, ...
2005-02-01
International Nuclear Information System (INIS)
Full text: As you know, thin films which generate anomalous big photovoltage (APhV) , as film photo resistive structures made of the combinations of A_2B_6 respond to X-ray and #gamma#- radiations. In this work the influence of X-ray and #gamma#-radiations on the quantity of APhV in the system APhV-film-photoresistor was investigated. Earlier polycrystal films with anomalous photo voltage properties were received only on the clean and flat surface with high isolation property (R>10"1"4 #OMEGA#). We worked out the technology of receiving APhV films CdTe on the surface of the photosensitive film CdS. The main condition under which this effect may be observed is that the lining must be slant concerning to the direction of the motion of evaporated substance's molecular bunch during the growing of the film, i.e. received film must have a dendritic structure. That is why photosensitive film CdS was received with thermo vacuum slanting pulverization (#alpha#=30-60 deg.), with the ...
2004-08-23
Energy Technology Data Exchange (ETDEWEB)
A cooperative effort of the Center for Solar Energy and Hydrogen Research (ZSW) and Phototronics Solartechnik GmbH (PST) aimed at the transfer of highly efficient solar cells developed on a laboratory scale, to large-area thin-film solar modules suitable for production. This work was based on research and development at the Institute for Physical Electronics (IPE) of Stuttgart University and ZSW on one hand, and on the know-how of PST in regard to large-area module fabrication on the other hand. The various thin-film layers of the cells and modules comprize molybdenum as rear contact, copper-indium(gallium)-diselenide (CIGS) as absorber material, the combination of cadmium sulphide (CdS) and ZnO as window layer. To produce these layers on large areas (30x30 cm{sup 2}), equipment was constructed and procedures were developed. Monolithic series connection of cells, used in other thin-film technologies, was studied and optimized by suitable patterning procedures, such ...
1998-06-01
GRAIN REFINEMENT OF PERMANENT MOLD CAST COPPER BASE ALLOYS
Energy Technology Data Exchange (ETDEWEB)
Grain refinement behavior of copper alloys cast in permanent molds was investigated. This is one of the least studied subjects in copper alloy castings. Grain refinement is not widely practiced for leaded copper alloys cast in sand molds. Aluminum bronzes and high strength yellow brasses, cast in sand and permanent molds, were usually fine grained due to the presence of more than 2% iron. Grain refinement of the most common permanent mold casting alloys, leaded yellow brass and its lead-free replacement EnviroBrass III, is not universally accepted due to the perceived problem of hard spots in finished castings and for the same reason these alloys contain very low amounts of iron. The yellow brasses and Cu-Si alloys are gaining popularity in North America due to their low lead content and amenability for permanent mold casting. These alloys are prone to hot tearing in permanent mold casting. Grain refinement is one of the solutions for reducing this problem. However, to use this ...
2004-04-29
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