Energy Technology Data Exchange (ETDEWEB)

Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications ...

British Library Electronic Table of Contents (United Kingdom)

The formation of nanoparticles during the radiation-induced chemical reduction of silver ions, copper ions, and nickel ions in films based on poly(acrylic acid)-poly(ethylenimine) complexes are studied via electron microscopy. This approach allows preparation of composites containing nanoparticles that are randomly distributed in the polymer matrix and materials with a regular spatial distribution of nanoparticles across the film thickness and in subsurface layers. The structure of metal-polymer hybrid materials is dependent on the irradiation conditions, the type of reduced metal ions, and their initial content in polymer matrices. The ratio between the rate of nucleation and the rate of growth of nanoparticles in the matrices of interpolyelectrolyte complexes depends on the intensity of ...

International Nuclear Information System (INIS)

This paper presents the effect of precursor powder size on the thermoelectric properties of sintered nanostructured bulk materials. The transport properties of the nanostructured bulk show a dramatic size effect. There are a lower thermal and electrical conductivity for the bulk with smaller nanopowders. The dimensionless figure-of merit values (ZT) of almost all the samples are much lower than those of the list reported data in the paper because the decrease in the thermal conductivity is counteracted by the reduction in the electrical conductivity and the Seebeck coefficient. The combination route of hydro/solvothermal synthesis and spark-plasma-sintering method provide a well controlled way to significantly reduce the thermal conductivity.

Energy Technology Data Exchange (ETDEWEB)

Recent research has shown that biologically inspired approaches to materials synthesis and self-assembly, hold promise of unprecedented atomic level control of structure and interfaces. In particular, the use of organic molecules to control the production of inorganic technological materials has the potential for controlling grain structure to enhance material strength; controlling facet expression for enhanced catalytic activity; and controlling the shape of nanostructured materials to optimize optical, electrical and magnetic properties. In this work, we use organic molecules to modify silver crystal shapes towards understanding the metal-organic interactions that lead to nanoparticle shape control. Using in situ electrochemical AFM (EC-AFM) as an in situ probe, we study the influence of a cationic surfactant cetyltrimethylamminobromide (CTAB) on Ag growth ...

British Library Electronic Table of Contents (United Kingdom)

The physics and technology of a new class of efficient composite piezoelectrics are described. This material combines nanostructured and micropiezoelectric matrix composites. They consist of a polymer matrix, an insulating nanodimensional phase, and a microdimensional piezoelectric phase. It is shown that the nanostructuring of the near-surface region of polymer-PZT piezoelectric composites greatly improves their piezoelectric, mechanical, and electromechanical characteristics. A plausible mechanism underlying this effect is suggested.

Science.gov (United States)

The Energy crisis happens to be one of the greatest challenges we are facing today. In this view, much effort has been made in developing new, cost effective, environmentally friendly energy conversion and storage devices. The performance of such devices is fundamentally related to material properties. Hence, innovative materials engineering is important in solving the energy crisis problem. One such innovation in materials engineering is porous materials for energy storage. Porous electrode materials for lithium-ion batteries (LIBs) offer a high degree of electrolyte-electrode wettability, thus enhancing the electrochemical activity within the material. Among the porous materials, mesoporous materials draw special attention, owing to shorter diffusion lengths for Li+ and electronic movement. ...

Science.gov (United States)

Silicon is an attractive alloy-type anode material because of its highest known capacity (4200 mAh/g). However, lithium insertion into and extraction from silicon are accompanied by a huge volume change, up to 300%, which induces a strong strain on silicon and causes pulverization and rapid capacity fading due to the loss of the electrical contact between part of silicon and current collector. Si nanostructures such as nanowires, which are chemically and electrically bonded to the current collector, can overcome the pulverization problem, however, the heavy metal current collectors in these systems are larger in weight than Si active material. Herein we report a novel anode structure free of heavy metal current collectors by integrating a flexible, conductive carbon nanotube (CNT) network into a Si anode. The composite film is free-standing and has a structure similar to the steel ...

International Nuclear Information System (INIS)

Nanocrystalline materials can exhibit properties which are considerably different from their coarse-grained counterparts, making them unique for basic or applied research and also very promising for potential applications. The topics which are addressed in the present paper are magnetic properties and magnetic correlations on the nanometer scale, mechanical properties, in particular the influence of grain boundaries on the elastic and plastic behaviour, and vibration models of grain boundary atoms in nanostructured materials. (author)

Scientific Electronic Library Online (English)

Abstract in english Structural characterisations using the SAXS technique in a number of nanoheterogeneous materials and liquid solutions are reviewed. The studied systems are protein (lysozyme)/water solutions, colloidal ZnO particles/water sols, nanoporous NiO-based xerogels, hybrid organic-inorganic siloxane-PEG and PPG nanocomposites and PbTe semiconductor nanocrystals embedded in a glass matrix. These investigations also focus on the transformations of time-varying structures and on str (more) uctural changes related to variations in temperature and composition. The reviewed investigations aim at explaining the unusual and often interesting properties of nanostructured materials and solutions. Most of the reported studies were carried out using the SAXS beamline at the National Synchrotron Light Laboratory (LNLS), Campinas, Brazil.

International Nuclear Information System (INIS)

A mass separated focused ion beam (FIB) is a very useful tool to fabricate nanostructures by writing implantation within an ion beam synthesis process. In these investigations the IMSA-OrsayPhysics FIB, equipped with a Co_3_6Nd_6_4 alloy liquid metal ion source, was applied. Si(100) and (111) wafers were implanted with 60 keV Co"+"+ ions in the dose range of 2 . 10"1"6 to 2 . 10"1"7 cm"-"2. Implantation parameters were investigated, like pixel dwell time, relaxation time (time between two cycles), dose rate as well as the pixel overlapping factor. The subsequent annealing was done in a two step process, namely 600 deg. C for 60 min and 1000 deg. C for 30 min in a N_2 ambient. The results obtained by SEM investigations in terms of continuous nanowire structures following the direction and interrupted CoSi_2 pattern in the direction show a clear dependence on the time scale as well as the scanning mode of the irradiation. Structure sizes as ...

International Nuclear Information System (INIS)

The aim of this work is to investigate the acoustic wave generation by pulsed and periodically modulated ion beams in different solid materials depending on the beam parameters and to demonstrate the possibility to apply an intensity modulated focused ion beam (FIB) for acoustic emission and for nondestructive investigation of the internal structure of materials on a microscopic scale. The combination of a FIB and an ultrasound microscope in one device can provide the opportunity of nondestructive investigation, production and modification of micro- and nanostructures simultaneously. This work consists of the two main experimental parts. In the first part the process of elastic wave generation during the irradiation of metallic samples by a pulsed beam of energetic ions was investigated in an energy range from 1.5 to 10 MeV and pulse durations of 0.5-5 #mu#s, applying ions with different masses, e.g. ...

British Library Electronic Table of Contents (United Kingdom)

The aim of this study was to develop a nanostructured Nb2O5-natural hydroxyapatite bulk composite to serve as an alternative biocompatible bulk material for implants. A set of samples of hydroxyapatite from fish bones with different concentrations of Nb2O5 were designed. They were prepared through a milling process, compacted under different pressures (350, 450, 550 and 650MPa) and sintered in air atmosphere at 1000^oC for 1h. The results revealed that the prepared composites presented strong interactions between the two elements and showed improvement in the sinterability with significant densification and microstructure changes, suggesting that they are promising for implants meant to replace bone tissues.

Energy Technology Data Exchange (ETDEWEB)

The Dynamic Transmission Electron Microscope (DTEM) is introduced as a novel tool for in situ processing of materials. Examples of various types of dynamic studies outline the advantages and differences of laser-based heating in the DTEM in comparison to conventional (resistive) heating in situ TEM methods. We demonstrate various unique capabilities of the drive laser, namely, in situ processing of nanoscale materials, rapid and high temperature phase transformations, and controlled thermal activation of materials. These experiments would otherwise be impossible without the use of the DTEM drive laser. Thus, the potential of the DTEM to as a new technique to process and characterize the growth of a myriad of micro and nanostructures is demonstrated.

Energy Technology Data Exchange (ETDEWEB)

Full text of publication follows: Energy and environment are two major concerns in our modern society due to the coming shortage in fossil energy sources and the growing of greenhouse gas emissions. The challenge for the coming years is to discover new energy resources and to develop devices that are compatible with a sustainable development and generate few (or zero) emission. One of these devices is the fuel cell feed by hydrogen, whose application fields are very large. In particular, the proton exchange membrane fuel cell (PEMFC) is the most realistic device for automotive application. However, hydrogen storage remains one of the most important challenges regarding its development. Although different techniques are available for storing hydrogen, no ideal solution has been found yet. Compression needs elaborated tanks in shape for supporting high pressures, liquefaction requires an expensive hydrogen cooling and adapted tanks. Chemical storage by hydrides imposes heavy devices. A ...

Energy Technology Data Exchange (ETDEWEB)

The preparation by sputtering of artificial metallic superlattices is described, as are the results of x-ray structural determinations. Tunneling and resistivity measurements on these materials are reported.

Energy Technology Data Exchange (ETDEWEB)

The investigated hybrid nanocomposite consists of a porous silicon template with electrochemically embedded Ni or Co nanostructures and offers magnetic characteristics which can be tailored by the electrochemical process parameters during fabrication. A twofold magnetic behaviour can be observed, a first one due to the spinmagnetism at magnetic fields below the saturation magnetization of the deposited metals and a second non-saturating term at higher fields (>1 T up to 7 T) above the saturation magnetization. In case of Ni deposited within the pores this non-saturating term shows a paramagnetic characteristic and follows exactly the Curie-Weiss law, whereas for Co/porous silicon samples the temperature dependent magnetization shows some deviations from the Curie Weiss law. In this high field region a difference in the temperature dependence between Ni and Co is observed whereas the non-saturating term does not depend on the geometry of ...

Energy Technology Data Exchange (ETDEWEB)

We demonstrate the rapid optical characterization of large numbers of individual metal nanoparticles freely diffusing in colloidal solution by confocal laser spectroscopy. We find that hollow gold nanospheres and solid silver nanoparticles linked with a bifunctional ligand, both designed nanostructures, exhibit significantly higher monodispersity in their Rayleigh and Raman scattering response than randomly aggregated gold and silver nanoparticles. We show that measurements of rotational diffusion timescales allow sizing of particles significantly more reliably than can be obtained using translational diffusion timescales.

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Some results and experimental procedures of laboratory are reported in the frame of researches conducted for the development of new nanostructured composite materials. These new materials, which are constituted by an organic phase: the polymer and an inorganic phase: the silicate, are being strongly investigated nowadays so it is expected that they could provide, among other, better electrical insulation properties and flame-delay in electrical and electronic applications. The laboratory experimental work has been developed from two families of polymers, thermoplastics and thermosets and clays silicates providing lamellar type. There are now some preliminary results, such as obtaining thin films of these nanocomposite materials, their complete characterization by X-ray diffraction, scanning microscopy and thermogravimetric analysis, they do well to wait for future research activities. (author)

International Nuclear Information System (INIS)

Several recent experiments on micro- (or nano-) structured samples of ferromagnetic materials are introduced. Magnetization reversal phenomena are investigated on submicron wire samples of trilayer structure using the giant magnetoresistance effect. Domain wall movements are sensitively monitored by resistivity measurements and the velocity of propagation is determined. The contribution of domain wall to the resistivity is argued from the results on artificially designed samples of a spring-magnet system. In circular dots of permalloy, the existence of vortex magnetization is confirmed and the reversal of the vortex core magnetization is studied from magnetic force microscopy measurements. (author)

British Library Electronic Table of Contents (United Kingdom)

As portable electronics become more advanced and alternative energy demands become more prevalent, the development of advanced energy storage technologies is becoming ever more critical in today's society. In order to develop higher power and energy density batteries, innovative electrode materials that provide increased storage capacity, greater rate capabilities, and good cyclability must be developed. Nanostructured materials are gaining increased attention because of their potential to mitigate current electrode limitations. Here we report on the use of vertically aligned multi-walled carbon nanotubes (VA-MWNTs) as the active electrode material in lithium-ion batteries. At low specific currents, these VA-MWNTs have shown high reversible specific capacities (up to 782mAhg^-^1 at 57mAg^-...

International Nuclear Information System (INIS)

Focused Ion Beam (FIB) milling is a powerful tool to produce ordered magnetic nanostructures. However, it is impossible to produce out-of-plane magnetized nanoscale structures from multilayer films by direct FIB writing. Co/Pt multilayers exhibit an out-of-plane easy axis due to strong perpendicular interface anisotropy. The interface contribution is known to be very sensitive to high energy ion irradiation. In case of 30 keV Ga ions it needs less than one ion per 100 surface atoms to destroy the perpendicular interface anisotropy. We demonstrate how this problem can be overcome by milling a Co/Pt multilayer, which has been deposited on a SiN membrane, from the rear side, through the SiN. The effect of the ions is determined as a function of applied dose utilizing the domain structure imaged by soft X-ray holography. When the magnetic material is removed we find only a very narrow range of destruction around the holes in contrast to the ...

International Science & Technology Center (ISTC)

Multi-functional Bioactive Nano-structured Coatings for Load-Bearing Implants

International Nuclear Information System (INIS)

Scanning thermal microscopy (SThM) was used to map thermal conductivity images in an ultrafine-grained copper surface layer produced by surface mechanical attrition treatment (SMAT). It is found that the deformed surface layer shows different thermal conductivities that strongly depend on the grain size of the microstructure: the thermal conductivity of the nanostructured surface layer decreases obviously when compared with that of the coarse-grained matrix of the sample. The role of the grain boundaries in thermal conduction is analyzed in correlation with the heat conduction mechanism in pure metal. A theoretical approach, based on this investigation, was used to calculate the heat flow from the probe tip to the sample and then estimate the thermal conductivities at different scanning positions. Experimental results and theoretical calculation demonstrate that SThM can be used as a tool for the thermal property and microstructural analysis of ...

International Nuclear Information System (INIS)

An important application of metal hydrides is as a moderator material in nuclear reactors. The fundamental properties of hydrides are illustrated and an impression given of the current research into hydrogen in transition metals. Phase diagrams, magnetic properties, temperature dependence of the diffusion coefficient, energy level schemes and superconductivity are considered. (C.F.).

International Nuclear Information System (INIS)

... fast reactors fbr type reactors fuels liquid metal cooled reactors materials nuclear

British Library Electronic Table of Contents (United Kingdom)

Statement of problem The opacity of the metal framework in metal ceramic restorations results in reduced light transmission through the tooth that diminishes the esthetics of the tooth. Purpose The purpose of this study was to investigate the color change that occurs apically to a metal ceramic restoration as a result of altering the metal framework design. Material and methods Color change relative to the unprepared tooth (DE) between various metal ceramic restorations was determined using computer imaging and CIELAB coordinates and compared to previously determined levels of clinical acceptability. Color change was evaluated by examining 2 conditions (the metal copings and the completed metal ceramic restorations), 4 framework designs (metal collar and porcelain margins with 0-mm, 1-mm, ...

CERN Document Server

We compare the metallicities of stars with radial velocity planets to the metallicity of a sample of field dwarfs. We confirm recent work indicating that the stars-with-planet sample as a whole is iron rich. However, the lowest mass stars tend to be iron poor, with several having [Fe/H]0.48) that contributes to but does not explain the mass-metallicity trend in the stars-with-planets sample. We use Monte Carlo models to show that adding an average of 6.5 Earth masses of iron to each star can explain both the mass-metallicity and the age-metallicity relations of the stars-with-planets sample. However, for at least one star, HD 38529, there is good evidence that the bulk metallicity is high. We conclude that the observed metallicities and metallicity trends are the result of the interaction of three effects; accretion of ...

Science.gov (United States)

A novel reactor combining a flame-deposited nanostructured titanium dioxide film and a set of embedded ceramic electrodes was designed, developed and tested for degradation of methyl tert-butyl ether (MTBE) in water. On applying a voltage to the ceramic electrodes, a surface coro...

Energy Technology Data Exchange (ETDEWEB)

This document contains a listing of the written scientific information originating in the Materials Joining (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1989. This registry of documents is as much as possible, in the order of issue date. A complete cross-referenced listing of the technical literature of the Metals and Ceramics Division is also available.

Environmental Research Database

Objectives1. To develop new photoactive materials and fabricate demonstration QD (quantum dot) solar cells. This will be achieved by:~%~1.1. Materials preparation and characterisation of QD/polymer systems~%~1.2. Optimising structures of QDs, nanorods and polymer for quantum yield and charge transfer~%~1.3 Fabricating demonstration QD/polymer solar cells and measuring power conversion efficiencies~%~2. To demonstrate multiexciton generation (MEG) and harvesting within nanostructured QDs. This will involv [continued...]DescriptionWidespread implementation of photovoltaic electricity to meet changing energy demands requires a step-change in the cost of photovoltaic power. This proposal assembles a consortium of chemists, physicists, materials scientists and electrical engineers from The University of Manchester and Imperial College London to address this need through the development of new low-cost, ...

Energy Technology Data Exchange (ETDEWEB)

Certain transition metal chalcogenides are promising materials for use as cathodes in nonaqueous lithium batteries involving the intercalation into these layered compounds. The electrochemical behavior of the chalcogenides depends on various properties such as structure, stoichiometry, electrical conductivity, crystal morphology, etc. The influence of these properties and of the ultimate practical application of the battery on the selection of cathode material is discussed. Battery performance of selected cathode materials is discussed and life limitations due to the limited cycle life of lithium anodes are outlined. 15 refs.

International Nuclear Information System (INIS)

High temperature fatigue crack growth (FCG) and creep crack growth (CCG) experiments have been conducted in air on weld metal, heat affected zone (HAZ) and base metal of the austenitic Alloy 800 and the nickel base Alloy 617. Tests were performed on specimens machined from pipes, in the temperature range 550-900 deg. C. The crack propagation mode was examined. At all temperatures and for both materials, FCG of base metal was found to be the highest, whereas the weld metal exhibited the lowest FCG rate. The FCG rate in the HAZ was found to lie in between of those observed for base and weld metal. The crack propagation mode remained transgranular in base metal and transdendritic in weld metal at all temperatures. CCG behaviour could be described using the energy rate integral C*. Base metal and weld ...

Science.gov (United States)

Transition-metal chemistry in ionic liquids (IL) has achieved intrinsic fascination in the last few years. The use of an IL as environmental friendly solvent, offers many advantages over traditional materials synthesis methods. The change from molecular to ionic reaction media leads to new types of materials being accessible. Room-temperature IL have been found to be excellent media for stabilising transition-metal clusters in solution and to crystallise homo- and heteronuclear transition-metal complexes and clusters. Furthermore, the use of IL as solvent provides the option to replace high-temperature routes, such as crystallisation from the melt or gas-phase deposition, by convenient room- or low-temperature syntheses. Inorganic IL composed of alkali metal cations and polynuclear transition-metal cluster anions are also known. Each of ...

Energy Technology Data Exchange (ETDEWEB)

Composite ZnO/Ag nanoparticles have been formed via the photocatalytic reduction of silver nitrate over the ZnO nanocrystals, their optical, electrophysical and photochemical properties have been investigated. Mie theory has been applied to analyze the structure of the absorption spectra of ZnO/Ag nanocomposite. The irradiation effects upon the optical properties of ZnO/Ag nanostructure have been investigated. It has been found that the irradiation of ZnO/Ag nanoparticles results in electrons accumulation by both the semiconductor and the metallic components of the nanocomposite. It has been found that silver nitrate can be photochemically deposited onto the surface of ZnO nanoparticles under the illumination with the visible light in the presence of the sensitizer - methylene blue. Kinetics of the sensitized Ag(I) photoredution has been studied. It has been concluded that the key stage of this process is the electron injection from ...

International Nuclear Information System (INIS)

We report a study of the physical characteristics of the pillars of C, Pt and W grown by 10-30 keV Ga focused ion beam (FIB) as a function of Ga ion flux, and present a quantitative analysis of the elements using energy-dispersive analysis of X-rays (EDAX). All the FIB grown pillars exhibit a rough morphology with whisker like protrusions on the cylindrical surface and broadening of the base as compared to the nominal size. For a constant fluence, the height of the pillar initially increases and then reduces after going through a maximum as a function of ion flux in all the cases. The compositional analysis shows good metallic quality for Pt structures but reveals significant contamination of Ga in C and Ga and C in W structures at higher ion fluxes. Explanation to all these observations has been sought in the light of secondary ion and electron effects and the different processes involved which lead to the FIB induced deposition.

Energy Technology Data Exchange (ETDEWEB)

This report presents a brief description of the fabrication and advantages of a composite, carbon-metal fiber material which does not require lubrication.

International Nuclear Information System (INIS)

Russian Mar 1973. German Democratic Republic Elovskaya, LT

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Titanium is the most biocompatible metal used for dental casting; however, there is concern about its marginal accuracy after porcelain application since this aspect has direct influence on marginal fit. Purpose The purpose of this study was to determine the effect that metal selection and the porcelain firing procedure have on the marginal accuracy of metal ceramic prostheses. Material and methods Cast CP Ti, milled CP Ti, cast Ti-6Al-7Nb, and cast Ni-Cr copings (n=5) were fired with compatible porcelains (Triceram for titanium-based metals and VITA VMK 95 for Ni-Cr alloy). The Ni-Cr alloy fired with its porcelain served as the control. Photographs of metal copings placed on a master die were made. Marginal discrepancy was determined on the photographs using an image ...

Energy Technology Data Exchange (ETDEWEB)

An alkali metal manganese oxide secondary cell is disclosed which can provide a high rate of discharge, good cycling capabilities, good stability of the cathode material, high specific energy (energy per unit of weight) and high energy density (energy per unit volume). The active material in the anode is an alkali metal and the active material in the cathode comprises an orthorhombic alkali metal manganese oxide which undergoes intercalation and deintercalation without a change in phase, resulting in a substantially linear change in voltage with change in the state of charge of the cell. The active material in the cathode is an orthorhombic structure having the formula M.sub.x Z.sub.y Mn.sub.(1-y) O.sub.2, where M is an alkali metal; Z is a metal capable of substituting for manganese in the ...

Energy Technology Data Exchange (ETDEWEB)

This document contains a listing of the written scientific information originating in the Materials Joining (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1991. This registry of documents is as much as possible, in the order of issue date.

International Nuclear Information System (INIS)

Preparation and electrocatalytic reactions of nano porous materials in biodegradable fluids were studied. Electrochemical etching was conducted to selectively extract metallic elements from alloys to form porous structures. Electrocatalytic properties of the porous electrodes were characterized. Comparative studies on the electrochemical activities of the nano porous metallic electrodes with bulk metallic wire catalysts were performed. It is found that the current density at the nano porous electrode is three times higher than that of the bulk electrode

Energy Technology Data Exchange (ETDEWEB)

A method is described for converting radioactive alkali metal into a low level disposable solid waste material. The radioactive alkali metal is atomized and introduced into an aqueous caustic solution having caustic present in the range of from about 20 wt % to about 70 wt % to convert the radioactive alkali metal to a radioactive alkali metal hydroxide. The aqueous caustic containing radioactive alkali metal hydroxide and CO{sub 2} are introduced into a thin film evaporator with the CO{sub 2} present in an amount greater than required to convert the alkali metal hydroxide to a radioactive alkali metal carbonate, and thereafter the radioactive alkali metal carbonate is separated from the thin film evaporator as a dry powder. Hydroxide solutions containing toxic metal hydroxide ...

International Nuclear Information System (INIS)

The radionuclide X-ray fluorescence and particle induced X-ray emission methods were used for rapid and nondestructive analysis of metallic glasses. The methods were compared for accuracy and precision with the atomic absorption method. Some results of the analyses of Fe_xNi_8_0_-_xB_2_0 materials are briefly reviewed. The distribution of elements along the width as well as the length and a qualitative analysis of the composition of material surfaces are considered. (author).

Energy Technology Data Exchange (ETDEWEB)

This document contains a listing of the written scientific information originating in the Materials Joining Group (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1987. It is a registry of about 400 documents as nearly as possible in the order in which they were issued.

Energy Technology Data Exchange (ETDEWEB)

Nanoimprinting is a fast-growing technique for nanoscale patterning. One of the remaining issues in nanoimprinting is the removal of the residual layer after nanoimprinting. Traditionally the residual layer is removed by an oxygen reactive-ion etching (RIE) step. The need for a vacuum environment and dedicated equipment in this step lowers the throughput and increases the cost of the nanoimprinting process. It also prevents the possibility of patterning isolated functional polymers because oxygen RIE destroys the functional materials. In this work, novel nanoimprinting schemes are developed to nondestructively remove the residual layer in thermal nanoimprinting by solvent developing and dewetting. Combined with a transfer-bonding technique, three-dimensional polymer scaffolds are achieved. The techniques developed here eliminate the RIE step in thermal nanoimprinting and are compatible with roller nanoimprinting for large-scale patterning of polymer micro- or ...

British Library Electronic Table of Contents (United Kingdom)

Metal iodates with a lone-pair containing I(V) that is in an asymmetric coordination geometry can form a diversity of unusual structures and many of them are promising new second homonic generation (SHG) materials. They exhibit wide transparency wavelength regions, large SHG coefficients and high optical-damage thresholds as well as moderately high thermal stability. In this paper, the structures and properties of the metal iodates are reviewed. The combination of d0 transition-metal cations with the iodate groups afforded a large number of metal iodates, with cations covering alkali metal, alkaline earth and lanthanide elements. Many of them are noncentrosymmetric (NCS) and display excellent SHG properties due to the additive effects of polarizations from both types of the asymmetric unit...

Energy Technology Data Exchange (ETDEWEB)

The Cu- and Ni-based bulk metallic glass matrix composites were fabricated by spark plasma sintering of a mixture of gas-atomized metallic glass powders and ductile brass powders. The brass powders added for the enhancement of plasticity are well distributed in the matrix after consolidation. The matrix of the composite materials remains as a fully amorphous phase after consolidation process. With increasing the brass content, the level of plasticity strain increased, although the level of strength decreased. The successful consolidation of metallic glass matrix composite with high density was attributed to viscous flow in the supercooled liquid state during spark plasma sintering.

Energy Technology Data Exchange (ETDEWEB)

The importance of indigenous soil Mn level on plant Mn uptake from metal salt or sewage sludge amended soils was investigated. Twelve soil materials, six surface and six subsurface, were amended with either varying rates of a composite of Cd, Cu, Ni, and Zn sulfate salts, equivalent to the total of these metals present in a digested sewage sludge (Washington, DC) at rates of 0 to 896 dry metric tons/ha or with the sludge itself, at 224 dry metric tons/ha. Corn (Zea mays L.) was grown in the greenhouse for 30 days, 1 year after amendment application. Two pH levels of about 5.5 and 6.5 were maintained during the experiment on the metal salt amended soil materials. Plant tissue Mn levels increased with the application of Cd, Cu, Ni, and Zn (in combination) as metal salts or as sewage sludge over the range of soil materials used. The amount of ...

Energy Technology Data Exchange (ETDEWEB)

The need for a hydrogen economy is driven by increasing fuel prices, depleting oil reserves and uncertainty over supplies, and concerns about global warming and environmental pollution. Alternative methods to portable energy sources such as fossil fuels are being developed that are more efficient and carbon-emission-neutral. A prospective method is to produce hydrogen as an energy carrier. This paper presented a study on the degradation of materials under conditions of the sulphur-iodine (SI) thermochemical cycle. The paper provided background information on the study and presented a schematic of the SI cycle. A literature review was presented along with materials selected, such as refractory metals, reactive metals, superalloys, glassy metals, ceramics, cermets, polymers, composites, and coatings. The experimental method was then described. A capsule method was developed to rapidly ...

Science.gov (United States)

Titanium metal-matrix composites (MMC) are prime candidate materials for aerospace applications be-cause of their excellent high-temperature longitudinal strength and stiffness and low density compared with nickel- and steel-base materials. This article examines the steps GE Aircraft Engines (GEAE) has taken to develop an induction plasma deposition (IPD) processing method for the fabrication of Ti6242/SiC MMC material. Information regarding process methodology, microstructures, and mechani-cal properties of consolidated MMC structures will be presented. The work presented was funded under the GE-Aircraft Engine IR & D program.

Energy Technology Data Exchange (ETDEWEB)

This is an adsorbent for removal of heavy metal impurities from gases. In addition to activated charcoal and ferric chloride, it contains a nonwoven dacron filter material to increase the purification level. The filter material has the following mass % composition: 27-54 activated charcoal, 7-35 ferric chloride, the remainder dacron filter material. The activated charcoal is applied to the dacron filter and the resulting mixture is treated with a ferric chloride solution. The activated charcoal is applied in the form of a suspension with a particle diameter of 0.1-0.16 mm. The treatment solution is 3-20% ferric chloride.

Science.gov (United States)

This report presents a general investigation of the transport requirements associated with the construction and operation of conceptual fusion reactors. Projections of amounts of construction and operating materials requiring transportation are presented for several proposed designs. The material to be shipped is described along with the shipping containers that might be used, the transport modes and the expected impact of transporting these materials. Transportation of both radioactive and nonradioactive materials will be required. Most of these materials are routinely shipped by the transportation industry. Transportation requirements of a representative fusion reactor are also compared with Liquid Metal Fast Breeder Reactor (LMFBR) requirements.

Energy Technology Data Exchange (ETDEWEB)

The ceramic composite armor has been lucubrated in the past 40 years. Ceramic can provide the same protection as metal, but it has lighter weight than metal. Ceramic has excellent ability of resisting kinetic energy projectile, because it can transfer energy to a large range by its fragmented cone and has higher ability of eroding the projectile than metal. But the researches indicated the full potential of the ceramic hard face has not been achieved because the significant interface between ceramic and metal has the unfavorable impedance effects and would induce tensile failure. FGM is a new type composite with continuous transition from ceramic to metal; it has no significant discrete materials interfaces between ceramic and metal. This paper deals with the impact response of Ceramic/FGM/Metal armor by numerical and ...

British Library Electronic Table of Contents (United Kingdom)

Magnetic pulse welding is a solid state impact welding process, similar to explosive welding, which produces metallurgical bond by oblique high-speed impact between two metal bodies. This violent impact removes the metal surface oxide layers and then joins the two atomic level clean metal surfaces together by the incidental compression pressure. The impact velocity is at 200?400?m/s and the being welded metal surface undergoes severe plastic deformation with strain rate in the order of 106?107?s?1. The ultrafine-grained structure was observed on the welded interface. This article studied two types of similar material lap joint interfaces and the base metals were aluminum alloy 6061 and copper alloy 110. Nano-indentation testing shows that the welded interfaces have significantly greater ha...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Repassivation resulting from the bared metal surface is a critical process for judging whether or not material suffers from corroding or immunizing. Nickel based alloys with high chromium content were developed to increase the corrosion resistant to sulphur compounds. Active humps resulting from active dissolution of nickel were obtained by creating the bared metal surfaces in thiosulphate solutions. The lower the Cr content the higher is the dissolution rate. The passive films formed on the bared metal surface were examined by ac impedance. Results suggest the formation of multi-layers oxide which were affected by active dissolution reactions during repassivation. (author).

International Science & Technology Center (ISTC)

Investigation of Interaction of Laser Radiation with Radioactive Deposits on the metal Surface and Creation of Experimental Stand for Development of Laser Technology for Remote Treatment of Materials Contaminated with Radioactive Substances at the Atomic Power Plants

Science.gov (United States)

Quantitative metallography is often used to confirm the proper processing of aerospace metallic materials. A microstructural feature of great importance for titanium alloys processed in the alpha-beta phase field is the volume fraction of primary alpha. S...

Energy Technology Data Exchange (ETDEWEB)

The 52 papers discuss the following subjects: 1. Preparation and structural development; 2. Structural constitution; 3. Structural formation and phase transition; 4. Structure and mechanical properties; 5. Structural formation of metallic and nonmetallic materials; 6. Quantitative metallography, and 7. Quality assurance.

British Library Electronic Table of Contents (United Kingdom)

The review provides a general idea about the types of metallic alloys and the pure metals used as implant materials in dental and orthopedic surgery. Their corrosive behavior in both real solutions and various media that model human biological fluids is described. Based on the literature data, it is concluded that multicomponent alloys containing titanium, niobium, zirconium, tungsten, molybdenum, aluminum, and silicon are the most resistant to corrosion. Implants made of different types of stainless steel are preferred when manufacturing orthopedic devices for short-term use.

Science.gov (United States)

A method of simultaneously removing SO.sub.2 and NO from oxygen-containing flue gases resulting from the combustion of carbonaceous material by contacting the flue gas with an aqueous scrubber solution containing an aqueous sulfur dioxide sorbent and an active metal chelating agent which promotes a reaction between dissolved SO.sub.2 and dissolved NO to form hydroxylamine N-sulfonates. The hydroxylamine sulfonates are then separated from the scrubber solution which is recycled.

International Nuclear Information System (INIS)

Compositions (oligomers with suitable properties and Al, Fe, Cu, Ta, W powders) were hardured by the flux of accelerated electrons at 10 mA beam current and 1.5 MeV energy. Dielectric and mechanical properties of metal-filled polymeric compositions as well as their radioply sicl properties in SHF-range are studied. It is shown that the produced compositions belong tot he absorbing protective materials in which the protection effect is mainly achieved through the absorption losses. 6 refs.; 3 tabs.

International Nuclear Information System (INIS)

In the present paper we propose a model of physical phenomena behind the front face of the electrodes in an impulse plasma accelerator. The model is based on the results of recent experimental observations and measurements. It correlates plasma dynamics with mechanism of phenomena in a column of pinching plasma. On the contrary to the previous model the current one suggests the series of relatively short pulses of metallic ions from the erosion of electrode material. Till now the pinch was treated rather as a nearly continuous source of metallic plasma, feeding the process with ions from the erosion of electrode material. (author)

Energy Technology Data Exchange (ETDEWEB)

A method of assembling two or more parts together that may be metal, ceramic, metal and ceramic parts, or parts that have different CTE. Individual parts are formed and sintered from particles that leave a network of interconnecting porosity in each sintered part. The separate parts are assembled together and then a fill material is infiltrated into the assembled, sintered parts using a method such as capillary action, gravity, and/or pressure. The assembly is then cured to yield a bonded and fully or near-fully dense part that has the desired physical and mechanical properties for the part's intended purpose. Structural strength may be added to the parts by the inclusion of fibrous materials.

Energy Technology Data Exchange (ETDEWEB)

One of our research objectives is to develop chemistry of transition metal chalcogenides which are relevant to new inorganic materials, environmental catalysts, metalloenzymes. In this context, this research project has been aimed at rational syntheses of chalcogenide complexes of electron-deficient transition metals, construction of hetero metallic clusters with high nuclearity, and elucidation of chemical properties characteristic of these metal chalcogenide compounds. We were successful in synthesizing a series of sulfide (selenide)/thiolate complexes of group 4,5 and 6 transition metal elements by making use of C-S bond cleaving reactions and anhydrous chalcogenide reagents. We also achieved construction of unprecedented large chalcogenide clusters of mixed metal systems such as [Cu{sub 4}(dppm){sub 4}MS{sub 4}] [PF{sub 6}]{sub 2} (M=Mo, ...

International Nuclear Information System (INIS)

In this study, dissimilar welds between HP heat-resistant steel and Incoloy 800 were made with four different filler materials including: 309 stainless steel and nickel-based Inconel 82, 182 and 617. The microstructure of the base metals, weld metals and their interfaces were characterized by utilizing optical and scanning electron microscopy. Grain boundaries migration in the weld metals was studied. It was found that the migration of grain boundaries in the Inconel 82 weld metal was very extensive. Precipitates of TiC and M_2_3C_6 (M = Cr and Mo) in the Inconel 617 weld metal are identified. The necessary conditions for the formation of cracks close to the fusion line of the 309-HP joints are described. Furthermore unmixed zone near the fusion line between HP steel base metal and Inconel 82 weld metal is discussed. An ...

Energy Technology Data Exchange (ETDEWEB)

As part of our effort to develop a semicontinuous PuO/sub 2/ reduction process, we are investigating promising materials for containing a 900/sup 0/C molten CaCl/sub 2/ . CaO chlorination reaction. We want the material to contain this reaction and to be reusable. We tested candidate materials in a simulated salt (no plutonium) using anhydrous HCl as the chlorinating agent. Data are presented on the performance of 36 metals and alloys, 9 ceramics, and 3 coatings.

Energy Technology Data Exchange (ETDEWEB)

The pollution of the environment with toxic metals is a result of many human activities, such as mining and metallurgy, and the effects of these metals on the ecosystems are of large economic and public-healthsignificance. This paper presents the features and advantages of the unconventional removal method of heavy metals - biosorption - as a part of bioremediation. Bioremediation consists of a group of applications, which involve the detoxification of hazardous substances instead of transferring them from one medium to another, by means of microbes and plants. This process is characterized as less disruptive and can be often carried out on site, eliminating the need to transport the toxic materials to treatment sites. The biosorption (sorption of metallic ions from solutions by live or dried biomass) offers an alternative to the remediation of industrial effluents as well as the ...

Energy Technology Data Exchange (ETDEWEB)

The Integral Fast Reactor is an innovative liquid metal reactor concept that is being developed by Argonne National Laboratory. It takes advantage of the properties of metallic fuel and liquid metal cooling to offer significant improvements in reactor safety, operation, fuel cycle economics, environmental protection, and safeguards. The plans for demonstrating the IFR fuel cycle, including its waste processing options, by processing irradiated fuel from the Experimental Breeder Reactor-II fuel in its associated Fuel Cycle Facility have been developed for the first refining series. This series has been designed to provide the data needed for the further development of the IFR program. An important piece of the data needed is the recovery of TRU material during the reprocessing and waste operations.

International Nuclear Information System (INIS)

This paper discusses how the U.S. Liquid Metal Reactor Development Program has been restructured to carry out R and D on advanced reactor technology. The program gives particular emphasis to improvements to reactor safety. The new directions are based on the technology of the integral fast reactor (IFR). Much of the basis for superior safety performance using IFR technology has been experimentally verified and aggressive programs continue in EBR-II and TREAT. Progress has been made in demonstrating both the metallic fuel and the new electrochemical processes of the IFR. The FFTF facility is converting to metallic fuel; however, FFTF also maintains a considerable U.S. program in oxide fuels. In addition, generic programs are continuing in steam generator testing, materials development, and with international cooperation, aqueous reprocessing.

Energy Technology Data Exchange (ETDEWEB)

A metal spray apparatus is provided with a supersonic nozzle. Molten metal is injected into a gas stream flowing through the nozzle under pressure. By varying the pressure of the injected metal, the droplet can be made in various selected sizes with each selected size having a high degree of size uniformity. A unique one piece graphite heater provides easily controlled uniformity of temperature in the nozzle and an attached tundish which holds the pressurized molten metal. A unique U-shaped gas heater provides extremely hot inlet gas temperatures to the nozzle. A particularly useful application of the spray apparatus is coating of threads of a fastener with a shape memory alloy. This permits a fastener to be easily inserted and removed but provides for a secure locking of the fastener in high temperature environments.

Energy Technology Data Exchange (ETDEWEB)

Dissimilar metal welds between ferritic low-alloy and austenitic stainless steels commonly occur in power plant application. In order to overcome some of the problems encountered here, a trimetallic configuration using an intermediate piece (such as Alloy 800) between the austenitic and ferritic steels has been suggested. This paper describes some features of the joints between modified 9Cr-1Mo steel and Alloy 800, produced with Inconel 82/182 filler material. The joints require heat-treatment after welding and the results have shown that a treatment at 760 C for 2 h would be optimal. Although most tensile failures occurred in the weld metal the welds were found to exhibit strength properties that are at least equal to those of Alloy 800, with a tensile elongation lying between those of the two base materials. Similarly, while the weld metals are slightly less tough than the two ...

Energy Technology Data Exchange (ETDEWEB)

There are a number of characteristics exhibited by ceramic materials that may provide potential benefits for the reciprocating internal combustion engine. However, the brittle nature of these materials together with a variability in strength has created difficulties in applying ceramic materials to the engine environment. Although a wide range of physical properties is available from contemporary ceramic materials, a material offering consistently high strength has yet to be developed. For sliding-contact applications, desirable characteristics include good wear resistance, low friction, ability to join metals and good heat dissipation. Test results have shown that cam/follower components with cast iron cam sliding on a silicon nitride follower exhibit very low wear rates. The application of silicon carbide to face seals has also shown substantial reductions in ...

International Nuclear Information System (INIS)

The following methods of quartz ceramics alloying were considered: alloying of initial quartz glass; introduction of alloying additive into water slip of quartz glass; porous materials impregnation with salt aqueous solutions and subsequent salt thermal decomposition with formation of stable oxides in pores of ceramics. Oxygen free compounds BN, SiB_4, SiC, Si_3N_4, REM oxides and transition metal oxides were used as alloying additives. Main properties of the materials and compositions obtained are presented.

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

This bibliography contains citations concerning the migration of food-packaging materials into foods. Plastic, glass, cardboard, metal, and ceramic containers are discussed. Techniques for analyzing packaging contamination are included. (Contains 90 citations fully indexed and including a title list.).

CERN Document Server

We propose a new method to measure the metallicity of Type Ia supernova progenitors using Mn and Cr lines in the X-ray spectra of young supernova remnants. We show that the Mn to Cr mass ratio in Type Ia supernova ejecta is tightly correlated with the initial metallicity of the progenitor, as determined by the neutron excess of the white dwarf material before thermonuclear runaway. We use this correlation, together with the flux of the Cr and Mn Kalpha X-ray lines in the Tycho supernova remnant recently detected by Suzaku (Tamagawa et al. 2008) to derive a metallicity of log(Z) = -1.32 (+0.67,-0.33) for the progenitor of this supernova, which corresponds to log(Z/Zsun)= 0.60 (+0.31,-0.60) according to the latest determination of the solar metallicity by Asplund et al. (2005). The uncertainty in the measurement is large, but metallicities much smaller than the ...

Energy Technology Data Exchange (ETDEWEB)

In recent years, the influences of acid rain such as the acidification of lake water, on bio-system by the heavy metals from effluent of soils with acid rain and also on the structural materials of buildings are seriously discussed. Sulfur and nitrogen that are contained in fossil fuels are released into the atmosphere by the fuel combustion as their oxides dissolve in rain drops as sulfite and nitrous ions, where they are further oxidized into sulfate and nitrate ions These ions lower the pH of rain water resulting so-called acid rain. Therefore, it is important to accurately determine these ions in rain water for the investigation of reality of acid rain. However, it is not easy to accurately determine these ions, especially for sulfite ions in rain water, since they are quickly oxidized by the catalytic action of metallic ions such as ferric and manganous ions. And light, temperature, pH of solution and also species and ...

British Library Electronic Table of Contents (United Kingdom)

The evaluation of the bactericidal effect of different silver-containing materials where silver is available as Ag^+ (silver nitrate and different silver-exchanged zeolites), as metallic Ag^0 (commercial silver nanoparticles) or as oxide (silver (I) oxide) was carried out in order to elucidate the importance of the bioavailability of silver (i.e., as free ions, metallic particles, combination of them, clusters, complexes, partially soluble or insoluble salts, etc.) on its bactericidal action. For the different materials tested, their bactericidal effect is ordered in the following sequence: AgNO"3>Ag-ZSM-5>Ag"2O>commercial silver-exchanged zeolite (granular)>commercial silver-exchanged zeolite (pellets)>Ag nanoparticles. In general, as the content of bioavailable ionic silver increases, th...

Science.gov (United States)

The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual phenomenon as ...

UK PubMed Central (United Kingdom)

Skin protects the body from pathogens and degradation. Mummified skin in particular is extremely resistant to decomposition. External influences or the action of micro-organisms, however, can degrade...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

In the last two years, rapid progress has been made in the energy conversion efficiencies of GaAs solar cells fabricated from molecular beam epitaxy (MBE) material. The efficiencies of cells fabricated from MBE material are now comparable with those fabricated from metal-organic chemical vapor deposition material, even for cells of dimension 2 cmx4 cm. This paper reviews the progress in MBE cell efficiencies. Also discussed is the role oval defects play in GaAs diode and solar cell performance. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Lithium storage metals and alloys can be suitable high-capacity anode materials for lithium-ion batteries, when the morphology is specifically designed. Here, we compare three different Sn/SnSb multiphase anode materials in powder form, which have been prepared in aqueous and organic solution by chemical precipitation using NaBH{sub 4} or Zn as reductive agents. The obtained morphologies, chemical compositions, and the electrochemical performance will be comparatively discussed. The variety of synthesis parameters which have an effect on the morphology of the obtained anode materials will be particularly highlighted.

International Nuclear Information System (INIS)

Nanometre-sized materials, like nanowires, nanoparticles or nanobelts, are gaining huge interest as building blocks of modern electronic nanodevices. Their fabrication feasibility has been demonstrated in the last years, and different routes are already well established in order to synthesize these materials. However, the assessment of their electrical properties is still a challenging issue, due to the difficulty to perform a precise nanolithography process allowing the access to such small structures. The fabrication of metallic contacts with precision in the nanometre range is necessary, as well as achieving a flexible system that allows to contact individual structures. Such a system could be a dual-beam Focused Ion Beam instrument, which combines Scanning Electron Microscopy (SEM) and Focused Ion Beam (FIB) in one machine, able to assist deposition of materials with nanometre precision. In this ...

Energy Technology Data Exchange (ETDEWEB)

A method is proposed for making a filtering material (FM) through applying bitumen or tar to a porous substance and subsequent roasting. Blast furnace slag, pumice and other inorganic substances are used as the porous substance. The method makes it possible to acquire an inexpensive filtering material with a developed surface (Pv), which replaces activated charcoal. Example. Blast furnace slag is heated to 200 to 300 degrees and with mixing is impregnated by 5 to 15 percent bitumen or tar. The impregnated slag is roasted at 800 to 1,000 degrees until full carbonization of the bitumen or tar, acquiring in this way a filtering material, which is characterized by a specific surface of 700 to 1,000 square centimeters per gram and suitable as a replacement for activated charcoal for removing organic components and heavy metals from gaseous and liquid phases. The cost of the filtering ...

Energy Technology Data Exchange (ETDEWEB)

Biosorption of heavy metals by various biological materials has been studied extensively in the last decade due to its potential particularly in wastewater treatment. The presence of a large number of metals in industrial metal-bearing solutions makes it necessary to investigate their effect on the final metal uptake by individual biosorbent materials. Nonliving biomass of Sargassum, a brown marine alga, is capable of binding more than 10% of its dry weight in toxic cadmium ions. Although ubiquitous iron interferes with Cd uptake, only approximately 4.5% of it is sequestered (biomass dry weight). Biosorption of both metals at pH 4.5 could be described by Langmuir-type isotherms with b, the affinity-related coefficient (Cd: b = 0.015; Fe: b = 0.027). The interference of Fe with Cd uptake, and vice versa, was assessed by deriving ...

Energy Technology Data Exchange (ETDEWEB)

After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modeling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and chemically inert phases and coatings, e.g. for engine components. ...

International Nuclear Information System (INIS)

Past elastic-plastic fracture studies for leak-before-break (LBB) assessment of low alloy steel pipings have been focused mostly on the behavior of base metals and their weld metals. In contrast, the heat-affected zone (HAZ) of a welded pipe has not been studied in detail primarily because the size of the HAZ is too small to make specimens for mechanical properties measurements. In this study, microstructural analyses, microhardness tests, tensile tests and J-R tests have been conducted as a function of distance from a fusion line and temperature for HAZ materials of SA106Gr.C low alloy piping steels. For the ferrite-pearlite steels such as SA106Gr.C, the HAZ specimens showed a higher yield strength and fracture toughness compared with those of its base metal. These characteristics, despite of grain coarsening, can be explained by cleaner microstructures of HAZ materials with a ...

Energy Technology Data Exchange (ETDEWEB)

Only within the past decade has the potential of metal biosorption by biomass materials been well established. For economic reasons, of particular interest are abundant biomass types generated as a waste byproduct of large-scale industrial fermentations or certain metal-binding algae found in large quantities in the sea. These biomass types serve as a basis for newly developed metal biosorption processes foreseen particularly as a very competitive means for the detoxification of metal-bearing industrial effluents. The assessment of the metal-building capacity of some new biosorbents is discussed. Lead and cadmium, for instance, have been effectively removed from very dilute solutions by the dried biomass of some ubiquitous species of brown marine algae such as Ascophyllum and Sargassum, which accumulate more than 30% of biomass dry weight in the ...

International Nuclear Information System (INIS)

The principle is described of a method using low-activity emitters as the primary radiation source for analysis. The selection of the radiation source and the detection methods including the assessment of the applicability of various radiation detectors are discussed. The benefits and the constraints of the method are considered. Practical examples are presented showing the application possibilities of the method for testing the thickness of bearing layers, piston ring coats, lead layers, etc. The possibility is shown of applying the rapid test for the composition of tungsten and chromium alloyed metal materials in testing complex systems. (J.K.).

Energy Technology Data Exchange (ETDEWEB)

The crack growth behavior and fracture toughness of two laminated metal composites (6090/SiC/25p laminated with 5182 and ultrahigh-carbon steel laminated with brass) have been studied in both ``crack arrester`` and ``crack divider`` orientations. The mechanisms of crack growth were analyzed and extrinsic toughening mechanisms were found to contribute significantly to the toughness. The influence of laminate architecture (layer thickness and component volume function), component material properties and residual stress on these mechanisms and the resulting crack growth resistance are discussed.

International Nuclear Information System (INIS)

In this study, a range of joining technologies has been investigated for creating attachments between refractory metal and Ni-based superalloys. Refractory materials of interest include Mo-47%Re, T-111, and Ta-10%W. The Ni-based superalloys include Hastelloy X and MarM 247. During joining with conventional processes, these materials have potential for a range of solidification and intermetallic formation-related defects. For this study, three non-conventional joining technologies were evaluated. These included inertia welding, electro-spark deposition (ESD) welding, and magnetic pulse welding (MPW). The developed inertia welding practice closely paralleled that typically used for the refractory metals alloys. Metallographic investigations showed that forging during inertia welding occurred predominantly on the refractory metal side. It was also noted that at least some degree of ...

Energy Technology Data Exchange (ETDEWEB)

The weldability and high temperature strength properties of tungsten-inert-gas (TIG) weldments of Hastelloy alloy XR were investigated by using two different heats of filler metals; the first (HXRF1) was designed on the basis of multiple regression analysis; the second (HXRF2) was the reference material. Bend tests, the FISCO cracking test and optical metallography were used to evaluate weldability. Tensile and creep tests were performed at 900deg C to evaluate high temperature strength properties. The results of weldability tests for both alloys showed good performance. The tensile properties of the weldments were remarkably improved in particular with respect to high temperature ductility. The creep rupture strength in the weldments made with alloy-designed HXRF1 was much higher than those of the Hastelloy alloy XR-II base metal with a higher B content. Furthermore, the creep properties were stable with respect to ...

Energy Technology Data Exchange (ETDEWEB)

The surface coverage of amorphous silica gels used in the synthesis of silica polyamine composites has been investigated by 29Si NMR. By diluting the polyamine anchor silane, chloropropyl trichlorosilane, with methyl trichlorosilane it was found that surface coverage could be markedly improved for a range of amine polymers after grafting to the silica surface. The commensurate decrease in the number of anchor points and increase in the number of free amines results in an increase in metal capacity and/or an improvement in capture kinetics. Solid state CPMAS-13C NMR has been employed to investigate the structure and metal ion binding of a series of these composite materials. It is reported that the highly branched polymer, poly(ethyleneimine) (PEI) exhibits much broader 13C NMR resonances than the linear polymers poly(allylamine) (PAA) and poly(vinylamine) (PVA). These results are understood in terms of the low energy ...

International Nuclear Information System (INIS)

In a vacuum insulator, the narrow electron beam emitted from the cathode impinges on the anode and raises its temperature and also may produce high thermal stress. This high thermal stress, in conjuction with the surface electrostatic pressure may rupture the surface and detach particles from it. In this thesis, the interaction of high energy electron and laser beams with metals and semiconductors is investigated. The differential equations governing the physical processes involved in the interaction are solved by the finite element method. Effects of beam penetration into the material, variable beam reflectance at the surface, finite beam size and dependence of material properties on temperature are accounted for. The two-phase moving boundary problem, also known as the Stefan problem, is solved by an enthalpy formulation of the heat equation. Material deformation by thermal stresses caused by high ...

Energy Technology Data Exchange (ETDEWEB)

Over 100 candidates were examined, including commercial materials and many that were synthesized in house. The mixed oxides were based on Ti, V, Nb, Cr, Mo, W, Mn, Fe, Co, Ni, and Cu doped with other transition metals. A number of individual (single-metal) oxides were included for comparison. The candidates were tested in single cells with Li(Si) anodes and separators based on LiCl-KCl eutectic. Screening was done under constant-current conditions at current densities of 125 me/cm{sup 2} and, to a lesser extent, 50 me/cm{sup 2} at 500 C. Relative performance and limitations of the oxide cathodes are discussed.

Energy Technology Data Exchange (ETDEWEB)

Pit lakes form when open-pit mining operations are discontinued and dewatering ceases. The increase in open-pit metal mining since the 1970s will lead to the formation of numerous pit lakes over the next 50 years. Many of these lakes will develop acid sulfate conditions with high levels of dissolved metals. Approaches to remediation of these conditions that have been recommended include the addition of lime or other alkaline materials and the stimulation of sulfate-reducing bacteria. However, prevention rather than remediation is probably the preferable approach. Measures to prevent oxidation of mining waste and wall rocks, including measures to fill pits quickly with water, to inhibit the activity of acidophilic sulfur-oxidizing bacteria, and to promote anoxic conditions at the lake bottoms may minimize the formation of acids and dissolved metals. (orig.)

British Library Electronic Table of Contents (United Kingdom)

Statement of problem Because noble dental casting alloys for metal ceramic restorations have a wide range of mechanical properties, knowledge of these properties is needed for rational alloy selection in different clinical situations where cast metal restorations are indicated. Purpose The purpose of this study was to compare the mechanical properties and examine both the fracture and polished surfaces of 6 noble casting alloys that span many currently marketed systems. Five alloys were designed for metal ceramic restorations, and a sixth Type GPT has Type IV alloy for fixed prosthodontics (Maxigold KF) was included for comparison. Material and methods Specimens (n=6) meeting dimensional requirements for ISO Standards 9693 and 8891 were loaded to failure in tension using a universal testin...

Energy Technology Data Exchange (ETDEWEB)

There have been a number of studies considering the possibility of removing and recovering heavy metals from diluted solutions. These are due, principally, because of the commercial value of some metals as well as in the environmental impact caused by them. The traditional methods for removing have several disadvantages when metals are present in concentrations lower than 100 mg/l. Biosorption, which uses biological materials as adsorbents, has been considered as an alternative method. In this work, variables like pH and biomass chemical pretreatment have been studied for its effect on the capacity for zinc biosorption by Thiobacillus ferrooxidans. Also, studies to determinate the time for zinc adsorption were carried out. Results indicate that a capacity as high as 82.61 mg of Zn(II)/g of dry biomass can be obtained at a temperature of 25 C and that the biosorption process occurs in a time of 30 min. ...

Energy Technology Data Exchange (ETDEWEB)

Metal dusting corrosion has been a serious problem in the petroleum and petrochemical industries, such as reforming and syngas production systems. This form of deterioration has led to worldwide material loss for 50 years. For the past three years, we have studied the mechanism of metal dusting for Fe- and Ni-base alloys. In this report, we present a correlation between the weight loss and depth of pits that form in Ni-base alloys. Nickel-base alloys were also tested at 1 and 14.8 atm (210 psi), in a high carbon activity environment. Higher system pressure was found to accelerate corrosion in most Ni-base alloys. To reduce testing time, a pre-pitting method was developed. Mechanical scratches on the alloy surface led to fast metal dusting corrosion. We have also developed preliminary data on the performance of weldments of several Ni-base alloys in a metal dusting environment. ...

CERN Document Server

We study spectroscopically determined iron abundances of 642 solar-type stars to search for the signature of accreted iron-rich material. We find that the metallicity [Fe/H] of a subset of 466 main sequence stars, when plotted as a function of stellar mass, mimics the pattern seen in lithium abundances in open clusters. Using Monte Carlo models we find that, on average, these stars have accreted about 0.4 Earth masses of iron while on the main sequence. A much smaller sample of 19 stars in the Hertzsprung gap, which are slightly evolved and whose convection zones are significantly more massive, have lower average [Fe/H], and their metallicity shows no clear variation with stellar mass. These findings suggest that terrestrial-type material is common around solar type stars.

Energy Technology Data Exchange (ETDEWEB)

Coordination chemistry on transition metal chalcogenides offer better conditions for multielectron charge transfer processes on solid/electrolyte interfaces. In this contribution, materials whose band energies are derived from d-states of the transition metal will be shown. Problems related to the reactivity, stability and photoactivity toward the generation and conversion of fuels will also be discussed. (orig.) [Deutsch] Die an halbleitenden Uebergangsmetall-Elektroden beobachtete Koordinationschemie bietet guenstige Voraussetzungen fuer den Mehrelektronen-Transfer an der Festkoerper/Elektrolyt Grenzflaeche. Beispielhaft werden in diesem Beitrag Elektrodenmaterialien vorgestellt, deren Energiebaender sich von d-Zustaenden der Uebergangsmetalle herleiten. Diskutiert werden Probleme der Reaktivitaet, der Stabilitaet und der Photoaktivitaet im Hinblick auf die Erzeugung und Umsetzung von Brennstoffen. (orig.)

British Library Electronic Table of Contents (United Kingdom)

''Hybrid'' hydrogen storage, where hydrogen is stored in both the solid material and as a high pressure gas in the void volume of the tank can improve overall system efficiency by up to 50% compared to either compressed hydrogen or solid materials alone. Thermodynamically, high equilibrium hydrogen pressures in metal-hydrogen systems correspond to low enthalpies of hydrogen absorption-desorption. This decreases the calorimetric effects of the hydride formation-decomposition processes which can assist in achieving high rates of heat exchange during hydrogen loading-removing the bottleneck in achieving low charging times and improving overall hydrogen storage efficiency of large hydrogen stores. Two systems with hydrogenation enthalpies close to -20kJ/mol H2 were studied to investigate the h...

Energy Technology Data Exchange (ETDEWEB)

The final report for a Laboratory Directed Research and Development project entitled, ``Capturing Recrystallization of Metals in a Multiscale Materials Model'' is presented. In this project, deformation and recrystallization processes have been followed experimentally and theoretically in order to incorporate essential mechanisms from the defect (dislocation) and grain size length scales. A nonlinear rotational gradient theory has been developed which enables the incorporation of microstructural parameters. The evolution of these parameters during deformation and recrystallization has been characterized qualitatively and quantitatively, applying various electron optic techniques ranging over several length scales. The theoretical and experimental framework developed is general. It has been exemplified by an application to recrystallization in single crystals and bicrystals of aluminum. The recrystallization process has been ...

British Library Electronic Table of Contents (United Kingdom)

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 Formula Not Shown ( Formula Not Shown metal, alkaline earth, lanthanide, or actinide; Formula Not Shown , Ru, or Os; Formula Not Shown , As, or Sb), certain lanthanide and actinide intermetallic compounds such as Formula Not Shown and Formula Not Shown ( Formula Not Shown , 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 com...

International Nuclear Information System (INIS)

Natural minerals and some industrial wastes are used as low cost sorbents for removal of metal ions from effluent streams. Apatite as natural mineral and red mud as an industrial waste have been tested for their sorption properties with respect to two important fission products "1"3"7Cs and "9"0Sr. Their ion exchanging capacity was tested after every 4 hours till 24 hours. The material gets saturated after 4-8 hours. Hence these materials can be considered for treating in treating LLW before discharge, industrial waste treatment and as backfill or admixture material for shallow land repository. (author)

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 ...

Energy Technology Data Exchange (ETDEWEB)

We describe the synthesis and characterization of superparamagnetic iron oxide nanoparticle based heavy metal sorbents with various surface chemistries that demonstrate an excellent affinity for the separation of heavy metals in contaminated water systems (i.e. spiked Columbia river water). The magnetic nanoparticle sorbents are prepared from an easy to synthesize iron oxide precursor, followed by a simple, one-step ligand exchange technique to introduce the organic surface functionality of interest chosen to target either specific or broader classes of heavy metals. Functionalized superparamagnetic nanoparticles are excellent sorbent materials for the extraction of heavy metal contaminants from environmental and clinical samples since they are easily removed from the media once bound to the contaminant by simply applying a magnetic field. These engineered magnetic nanoparticle ...

International Nuclear Information System (INIS)

The main reasons of tube failures in steam generators (SG) are considered. 1.Stress corrosion craining which has 28% of SG (most of them have stainless steel tubes). 2. Corrosion loss of metal, which accounts for 24% of tubes (phosphate corrosion due to addition of PO into water). 3.Denting-peripheral pressing of tubes in the openings of the foundation plates by the corrosive products, which are formed on internal surface of drillings in the foundation plates made of carbon steel. 4.Separation of a plating layer on tube panels. 5.Dratting-corrosion. 6.Metal fatigue. A series of experiments were conducted to study the influence of material selection on tube reliability (stainless steel 304, inconel-600, mone-400, incalloy-800). The problem of increase of SG elements reliability is a complex one and can be solved by direct selection of material, proper control of water-chemical conditions and other ...

Energy Technology Data Exchange (ETDEWEB)

This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Functionally graded material is an enabling technology for lightweight body armor improvements. The objective was to demonstrate the ability to produce functionally graded ceramic-polymer and ceramic-metal lightweight armor materials. This objective involved two aspects. The first and key aspect was the development of graded-porosity boron-carbide ceramic microstructures. The second aspect was the development of techniques for liquid infiltration of lightweight metals and polymers into the graded-porosity ceramic. The authors were successful in synthesizing boron-carbide ceramic microstructures with graded porosity. These graded-porosity boron-carbide hot-pressed pieces were then successfully liquid-infiltrated in vacuum with molten aluminum at 1,300 C, and ...

International Nuclear Information System (INIS)

Radionuclide X-ray fluorescence method with a Si/Li semiconductor detector and "2"3"8Pu exciting source was used in the study of Mn, Fe, Cu, Zn, and Pb content of solid emissions, raw and final materials of a brick factory. From the point of view of metal content, the working environment if the brick factory is safe for workers. (author) 2 refs.; 2 figs.; 1 tab.

Energy Technology Data Exchange (ETDEWEB)

The novel optical, electronic, and/or magnetic properties of metal and semiconductor nanoparticles have resulted in extensive research on new methods for their preparation. An ideal preparation method would allow the particle size, size distribution, crystallinity, and particle shape to be easily controlled, and would be applicable to a wide variety of material systems. Numerous preparation methods have been reported, each with its inherent advantages and disadvantages; however, an ideal method has yet to emerge. The most widely applied methods for nanoparticle preparation include the sonochemical reduction of organometallic reagents,(1&2) the solvothermal method of Alivisatos,(3) reactions in microemulsions,(4-6) the polyol method (reduction by alcohols),(7-9) and the use of polymer and solgel materials as hosts.(10-13) In addition to these methods, there are a variety of methods that take advantage of the unique ...

Energy Technology Data Exchange (ETDEWEB)

This thesis discusses an advanced dynamical two-dimensional cylinder symmetric model for the high temperature part of the carbothermic silicon metal process, and its computer encoding. The situation close to that which is believed to exist around one of three electrodes in full-scale industrial furnaces is modelled. This area comprises a gas filled cavity surrounding the lower tip of the electrode, the metal pool underneath and the lower parts of the materials above. The most important phenomena included are: Heterogeneous chemical reactions taking place in the high-temperature zone (above 1860 {sup o}C), Evaporation and condensation of silicon, Transport of materials by dripping, Turbulent or laminar fluid flow, DC electric arcs, Heat transport by convection, conduction and radiation. The results from the calculations, such as production rates, gas- and temperature distributions, furnace- and particle ...

Energy Technology Data Exchange (ETDEWEB)

A device for detecting neutrons includes a semi-insulated bulk semiconductor substrate having opposed polished surfaces. A blocking Schottky contact comprised of a series of metals such as Ti, Pt, Au, Ge, Pd, and Ni is formed on a first polished surface of the semiconductor substrate, while a low resistivity ("ohmic") contact comprised of metals such as Au, Ge, and Ni is formed on a second, opposed polished surface of the substrate. In one embodiment, n-type low resistivity pinout contacts comprised of an Au/Ge based eutectic alloy or multi-layered Pd/Ge/Ti/Au are also formed on the opposed polished surfaces and in contact with the Schottky and ohmic contacts. Disposed on the Schottky contact is a neutron reactive film, or coating, for detecting neutrons. The coating is comprised of a hydrogen rich polymer, such as a polyolefin or paraffin; lithium or lithium fluoride; or a heavy metal fissionable ...

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

A phosphorus-containing low alkali metal content zeolitic catalyst made from a clay starting material is provided. The catalyst is obtained by contacting a partially cation exchanged calcined zeolite-containing catalyst with an anion such as a dihydrogen phosphate anion or a dihydrogen phosphite anion and additionally with an ammonium salt other than a salt of an inorganic acid of phosphorus. A hydrocarbon catalytic cracking process utilizing the phosphorus-containing catalyst is also provided.

Energy Technology Data Exchange (ETDEWEB)

Drilling fluid additives are prepared by oxidation of sulfonated lignin-containing materials with manganese dioxide under highly acidic conditions to make manganese lignosulfonates. Additional improvements in the rheological properties of the additives may be obtained by complexing the manganese lignosulfonate so obtained with a heavy metal cation (preferably iron or copper), by, for example, addition of ferrous sulfate or ferric sulfate to the manganese lignosulfonate. These products show the requisite combination of rheological properties for a satisfactory drilling fluid additive or conditioner.

International Nuclear Information System (INIS)

Despite successful reduction of the general lead exposure, this heavy metal is still a matter of public concern due to the fact that associations with intellectual impairment or delayed puberty are found to correlate with very low lead blood concentrations. Lead in tap water is still an important contribution to lead exposure which may cause health risk for infants. Therefore, lead pipes should be completely sanitated by exchange against pipes made from more healthy materials. (orig.)

Energy Technology Data Exchange (ETDEWEB)

An ignition device of the plasma jet type is disclosed. The device has a cylindrical cavity formed in insulating material with an electrode at one end. The other end of the cylindrical cavity is closed by a metal plate with a small orifice in the center which plate serves as a second electrode. An arc jumping between the first electrode and the orifice plate causes the formation of a highly-ionized plasma in the cavity which is ejected through the orifice into the engine cylinder area to ignite the main fuel mixture. Two improvements are disclosed to enhance the operation of the device and the length of the plasma plume. One improvement is a metal hydride ring which is inserted in the cavity next to the first electrode. During operation, the high temperature in the cavity and the highly excited nature of the plasma breaks down the metal hydride, liberating hydrogen which acts as an additional fuel to ...

International Nuclear Information System (INIS)

To respond to an increase of social problems concerning orphan sources in Japan, a working group was formed in the Japan Health Physics Society. In this working group, we investigated how to prevent acute radiation hazard or social panic regarding orphan sources in scrap metal and detection system for orphan sources brought into scrap yards before recycle. For detection system in a scrap yard we conducted an experiment on detectability of monitoring instrument using a radiation source mixed in scrap metal on a truck. The result showed that it was not easy to detect even a high-level source if it was shielded by scrap metal. We also estimated detection limits for radioactive materials in scrap metal by calculation that was validated with experimental data. We summarized present status about orphan sources in Japan and proposed a categorization of orphan sources according to dose ...

Energy Technology Data Exchange (ETDEWEB)

The meeting was arranged into the following sessions: introductory; advanced ceramics and ceramic composites; ceramic and metal matrix composites; electronic materials and devices; acoustoelasticity, stress, and texture; composites-porosity, strength, and UT propagation; process modeling and monitoring; thermal wave physics; material properties, composites, surfaces, and interfaces; acoustic emission; ferromagnetic materials; new sensors; NDE reliability assessment; elastic wave scattering and propagation; image analysis, data storage, and signal processing; UT transducers; weldments and bonded materials; eddy current models; unified life cycle engineering; x rays, CT, and NMR; eddy current probes and instruments; acoustic microscopy imaging, and reconstruction; signal processing, measurement techniques, and systems; NDE applications of artificial intelligence; crack behavior ...

International Nuclear Information System (INIS)

A single plasma process involving three consecutive steps has been developed for producing high gas flow catalytic nanostructures on the electrodes of proton exchange membrane (PEM) fuel cells (FC). Using a high density helicon radio frequency (13.56 MHz) plasma, nickel is sputtered onto a porous carbon support. Changing the background gas from argon to methane/hydrogen allowed 2 ?m long, 37 nm diameter carbon nanofibres (CNFs) to be grown by diffusion through the nickel clusters in a 'tip growth' mechanism at the relatively low temperature of 400 deg. C. The third step involves plasma sputtering of platinum onto the CNFs, resulting in nanoclusters (3-8 nm) being formed on the periphery of the CNFs. Four FC cathodes were synthesized on carbon paper and PTFE/carbon loaded cloth (known as gas diffusion layer, GDL), both with and without CNFs, with the Pt/CNFs nanostructures grown on PTFE/carbon loaded cloth having the best FC performances. ...

Science.gov (United States)

Nanosized particles are important because of their unique properties, different from the bulk, which leads to their enhanced catalytic, photocatalytic and electronic properties. This work has dealt with three different nanoparticle systems in the context of three different aspects of nanoparticle properties: (a) photocatalytis (TiO2/metal) system, (b) luminescence (CdSe) (c) alloying (Pt-Ag and Pd-Ag). The initial photocatalytic enhancement obtained by adding noble metal on semiconductor nanoparticles, degrades as fast as in 15 minutes and questions their long-term performance. XANES measurements on such irradiated systems like TiO2/Au, TiO2/Pt, TiO2/Ir indicates a positive oxidation state of these noble metals which renders them as recombination centers for photo-excited electrons and explains the decreased photocurrent. The oxidation is caused by holes. The EXAFS results also indicate a change of the interfacial structure ...

Energy Technology Data Exchange (ETDEWEB)

The divertor collector plate in the INTOR reactor will be subjected to high heat, particle, and neutron fluxes, making it the most severely damaged torus component. The collector plate is composed of a protection plate, which is directly exposed to the particle flux, and a heat sink which provides support for the protection plate and carries the water coolant. The high-Z refractory metals have been considered for use as the protection plate material, and austenitic stainless steels and copper alloys have been considered as the heat sink material. Tungsten and Type 316 stainless steels have been selected for the protection plate and heat sink, respectively. The protection plate has a sputtering lifetime of 1.75 y at a 50% duty factor, while the heat sink is expected to last the lifetime of the reactor.

International Nuclear Information System (INIS)

Waste electrical and Electronic Equipment (WEEE) constitutes 4% of the municipal waste in Europe, being increased by 16-28% every five years. Nowadays, Europe produces 6,5 million tonnes of WEEE per year and currently 90% goes to landfill. WEEE waste is growing 3 times faster than municipal waste and this figure is expected to be increased up to 12 million tones by 2015. Applying a new technology to separate non-ferrous metal Waste from WEEE is the aim of this paper, by identifying multi-and hyper-spectral materials and inserting them in a recycling plant. This technology will overcome the shortcomings passed by current methods, which are unable to separate valuable materials very similar in colour, size or shape. For this reason, it is necessary to develop new algorithms able to distinguish among these materials and to face the timing requirements. (Author). 22 refs.

International Nuclear Information System (INIS)

A brief overview is given of a report on Emergency Core Cooling Systems (ECCS) Recirculation Reliability Knowledge Base compiled by the International Working Group on ECCS Reliability for the OECD/NEA/CSNI. Four safety issues are identified which arise in the context of loss of coolant accidents (LOCAs) and are connected with materials and/or processes that interfere with the ECCS safety function in ways other than just strainer head loss generation. They are: the generation of missiles during a LOCA from encapsulated insulation materials used to reduce insulation debris production; clogging of BWR pressure suppression containment vent pipes by insulation jackets or metallic insulation foil pieces; strainer or sump debris ingestion and the effects of ingested debris on ECCS equipment and core cooling; miscellaneous items such as material aging and self-cleaning strainer concepts. The emphasis is mainly ...

Energy Technology Data Exchange (ETDEWEB)

The sulfur-iodine (SI) thermochemical cycle is one of the main candidate methods to produce hydrogen from non-fossil sources like nuclear (GEN IV reactor) or solar thermal power. A major issue for the successful implementation of the SI cycle is the selection of technically viable and economic materials for construction of process components, particularly heat exchangers. Challenging conditions are encountered in each of the three sections of the SI cycle due to the corrosive chemicals present, including sulfuric acid, iodine, hydroiodic acid, sulfur dioxide, hydrogen, oxygen, and others. In Section I, aqueous, non-aqueous (liquid iodine), and gaseous multi-component phases are present at about 120 {sup o}C and 0.7 MPa. Section II involves gaseous and aqueous phases of sulfuric acid, sulfur dioxide, and oxygen at up to about 830 {sup o}C and 3.6 MPa. In Section III , aqueous, non-aqueous, and gaseous phases, at up to 310 {sup o}C and 2.2 MPa, containing iodine, ...

British Library Electronic Table of Contents (United Kingdom)

The present investigation deals with the synthesis of nanostructured nickel ferrite (NiFe2O4) and their liquid petroleum gas-sensing characteristics. The 15-20nm size nickel ferrite has been synthesized at 700degreeC by a simple molten-salt route using sodium chloride as grain growth inhibitor. These nanoparticles exhibit significantly high response towards liquid petroleum gas (LPG) in comparison with ethanol vapor, hydrogen sulfide, ammonia and hydrogen. The gas response towards various gases at their 200ppm concentrations is investigated at 200-450degreeC. Different characterization techniques have been employed, such as differential thermal analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission elec...

Energy Technology Data Exchange (ETDEWEB)

Micro-Vickers hardness measurement has been used to determine the composition of functionally graded materials (FGMs). Materials used in the present study are Al-SiC, Al-Shirasu and Al-Al{sub 3}Ni FGMs, which are fabricated by a centrifugal method. The micro-hardness of the aluminum matrix for Al-SiC FGM markedly increases as the volume fraction of SiC particles increases. However, the tendency is not so clear in the cases of Al-Shirasu and Al-Al{sub 3}Ni FGMs. Plastic strain energy due to thermal misfits between the matrix and dipersed particles is calculated based on an elasto-plastic analysis by applying a shell theory after Lee et al. The hardness is correlated theoretically with the composition gradient through the mean plastic strain energy (responsible for dislocation density). It is concluded that the composition gradient of metal-based FGMs can be determined from micro-hardness measurements. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Proof-of-principle experiments are reported for a new concept in electrically rechargeable zinc-air battery. The zinc electrode is a porous flow-thru type using a copper foam metal substrate with zinc deposition onto the foam metal from concentrated zincate electrolyte (as used in zinc-slurry type batteries). The bifunctional air electrode employs low-cost materials, being fabricated entirely from carbon-based precursors and small amounts of nickel and/or cobalt oxide. Corrosion measurements on the graphite materials in the air electrode indicate sufficient corrosion resistance for 8000 h life on charge. A prototype single cell was constructed having 1.5 Ah capacity producing 1.2 V discharge -2.0 charge at the three hour rate and has produced stable voltages for more than 150 cycles. Based on the 1.5 Ah prototype characteristics, design calculations for a 32 kWh battery project an energy density of ...

Energy Technology Data Exchange (ETDEWEB)

A necessary condition for crevice corrosion is that a crevice former create a sufficiently tight, restricted geometry on the metal surface to support the development of critical crevice chemistry. Crevice corrosion is affected by the crevice geometry (tightness) and the properties of the crevice former. The objective of this study is to determine the effect of the crevice former material on the evolution of localized corrosion-damage. A standard crevice corrosion test method is modified by (a) the use of ceramic, metal or polymer materials as the crevice former and (b) the variation of size and shape of the crevice. This study focuses on the post initiation stage of crevice corrosion and addresses factors that may limit the initiation of localized corrosion and also slow or stop the continued propagation of corrosion. Controlled crevice corrosion tests are performed under aggressive, accelerated ...

International Nuclear Information System (INIS)

Decommissioning of radiological and nuclear installations is for this century the new challenge. One of the performance criteria is the reduction of total quantities of radioactive materials (liquid or solid) arising from dismantling and decontamination of radiological and nuclear installations. In this work we present a new application of the water soluble polymers used as: - flocculation agents in treatment and conditioning process within the management of radioactive liquid materials; - strippable coatings on solid materials based on the water soluble polymers. The parameters of water soluble polymers made in our Institute by radiation processing have been analysed, namely the molecular average weight, composition, and efficiency of utilization of these polymeric materials as well as the content of ash, additives, decontamination factor, consumption per surfaces/liter, corrosion aspects, ...

British Library Electronic Table of Contents (United Kingdom)

The corrosion behavior of hard metals with VC and Cr3C2 grain growth inhibitors was investigated in alkaline solutions by electrochemical methods. The two inhibitors have opposite effects on the corrosion behavior: Cr3C2 significantly improves the corrosion behavior, whereas VC-containing alloys show a poor resistance. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and analytical transmission electron microscopy (TEM) analyses of the distributions of Cr and V in the composite material, as well as in the surface layers formed during corrosion were employed to clarify the influence of these elements on the corrosion behavior. The measurements showed that VC is precipitated mostly along the WC/binder interface after the liquid-phase sintering process, while Cr3C2 is almost homogene...

Energy Technology Data Exchange (ETDEWEB)

This book presents the proceedings of a conference dedicated to the design and operation of pipework in all its aspects, involving both metallic and non-metallic materials. Topics considered include a study of single mitre pipe bends using the finite element method; tests to failure of GRP pipe bends under in-plane flexural loading; finite element stress analysis of an equal diameter branch pipe intersection subjected to internal pressure and in-plane moment loadings; finite element stress analysis of extruded outlet tee junctions; design of pipework on the British PWR; a review of advanced remanent life methods for pipes operating in the creep range; pipe whip analysis and design; damping values for piping systems; pipework snubbers based on electro-rheological fluids; and the seismic design of piping systems in the flexible range.

Energy Technology Data Exchange (ETDEWEB)

Metals for potential use in the dissociator and the synthesizer reactors of a distributed solar receiver thermochemical transport loop utilizing SO/sub 3//SO/sub 2//O/sub 2/ molecular chemistry were tested in SO/sub 2//O/sub 2/ mixtures at 500/sup 0/C and 900/sup 0/C, respectively, for times of up to four weeks. They included titanium, aluminum and nickel, and iron-base, nickel-base and cobalt-base superalloys. Weight gain measurements determine the oxidation/sulfidation kinetics. Electron microprobe analysis identifies any possible penetration of oxygen and sulfur into the metal and the formation of internal oxides and sulfides. The most promising candidates as a result of these tests are the cobalt-base superalloys.

International Nuclear Information System (INIS)

A major initiative to develop and irradiate a long-life, mixed-oxide fuel system in the Fast Flux Test Facility (FFTF) has been implemented by Westinghouse Hanford Company for the US Department of Energy. The FFTF, shown in Figures 1 and 2, is a 400 megawatt thermal, fast liquid metal reactor that tests liquid metal, space and fusion fuels and materials. The new fuel system, called the Core Demonstration Experiment (CDE) demonstrates the capability of achieving a three- to four-year life in a prototypic heterogeneous reactor environment under prototypic power and temperature conditions. This fuel system will greatly increase fuel performance and lifetime from the current standard FFTF driver fuel. New design features, fabrication development, CDE assembly fabrication, and irradiation status have been described.

International Nuclear Information System (INIS)

Development of the engineering technology basis of pyrometallurgical reprocessing is a key issue for industrialization. For development of the transport technologies of molten salt and liquid cadmium at around 773 K, a salt transport test rig and a metal transport test rig were newly installed in an Ar glove box. Function of the salt transport test rig was confirmed with LiCl-KCl molten salt, and the transport behaviour of molten salt was found to follow that of water. The molten salt/liquid metal contactor for Ln/An separation was newly designed and installed. The test with a single-stage contactor was successful with simulated elements, and a three-stage contactor is now under development. A large-scale electro-refiner with a function to transport molten salt and liquid cadmium were newly designed, and to be installed for demonstration test with simulated materials. (authors)

Energy Technology Data Exchange (ETDEWEB)

Forensic signatures are present in any Pu sample that can determine the sample`s origin: isotopic ratio of Pu, progeny species that grow into the sample, and contaminant species left over from incomplete purification of the Pu in fuel reprocessing. In the context of intelligence information, this can result in attribution of responsibility for the product of clandestine proliferant operations or material smuggled from existing stockpiles. A list of signature elements and what can be determined from them have been developed. Work needs to be done in converting concentrations of signature species into a quantitative forensic analysis, particularly in regard to reactor performance, but this should require only a small effort. A radiochemical analysis scheme has been developed for measuring these nuclides; more work is needed, particularly for determining fission product concentrations. A sample of Pu metal has been analyzed and several parameters ...

Energy Technology Data Exchange (ETDEWEB)

Catalytic activity of industrial metallic wastes in coal liquefaction was examined in a 100lb/day continuous coal processing development unit. Red mud, a waste material from the aluminium industry, and an electric furnace flue dust containing Ni, Mo, Co and Fe showed a pronounced effect on the conversion of a Kentucky bituminous coal. Coal conversion and oil production increased significantly with the addition of red mud and flue dust. Comparison of the catalytic activity of pyrite, red mud, and flue dust, based on selectivity analysis, showed that red mud was the most desirable disposable catalyst. However, if the primary goal of coal liquefaction is high oil production, irrespective of hydrogen consumption, pyrite is the most active catalyst among those discussed in the paper.

International Nuclear Information System (INIS)

It is generally known that a number of metallic glasses have excellent corrosion resistance in a variety of chemically hostile environments. Consequently, the use of laser cladding to coat a massive crystalline material such as aluminium with a layer of a metallic glass has obvious advantages. In this paper, the authors will show that the formation of a predominantly amorphous layer of Zr_6_0Al_1_5NI_2_5 alloy by laser processing is possible, if the obstacles to amorphization are overcome. In addition, evidence of the excellent corrosion resistance of this alloy in a NaCl solution will be given. A comparative study of the corrosion behavior of this amorphous alloy with pure aluminium and Al-Cr alloy will be done, in order to complete previous studies of laser processed coatings of aluminum substrates.

International Nuclear Information System (INIS)

Experimental results of compatibility tests on ceramics-metal bonded structures performed under high heat flux conditions in splash test apparatus are reported. Emphasis is placed on results of the channel wall design and its critical operating conditions under MHD environment. The module design of one cold type and three semihot type insulators have been tested. These materials were Al_2O_3, Al_2MgO_4, LaAlO_4, MgO and Sialon ceramics. The methods of cold type ceramics-metal bonding structure were studied on Al_2O_3 and Spinel spray coating technology. The refractory metallizing and ceramics-metal graded structure manufactured by HIP technologies were applied to bonding between the MgO or LaAlO_4 and metallic cooling system. The Sialon non-bonding structure was tested with mechanical supported cooling system by shrinc fitting method. The results indicated that ...

Energy Technology Data Exchange (ETDEWEB)

Guidelines for uranium residual radioactive material in soil were derived for the B&T Metals Company site in Columbus, Ohio. This site has been identified for remedial action under the US Department of Energy`s (DOE`s) Formerly Utilized Sites Remedial Action Program (FUSRAP). Single-nuclide and total-uranium guidelines were derived on the basis of the requirement that following remedial action, the 50-year committed effective dose equivalent to a hypothetical individual living or working in the immediate vicinity of the site should not exceed a dose constraint of 30 mrem/yr for the current use and likely future use scenarios or a dose limit of 100 n-mrem/yr for less likely future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation. RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material ...

UK PubMed Central (United Kingdom)

After slow progress in the efforts to develop phase plates for electron microscopes, functional phase plate using thin carbon film has been reported recently. It permits collecting high-contrast images...Full Text Available

Science.gov (United States)

In this Communication, we report the fabrication of well-crystallized rutile-phase TiO2 hollow spheres using potassium titanium oxalate as the precursor. The spheres exhibited unique three-dimensional hierarchical architectures and demonstrated a significantly improved photocatalytic performance. The synthetic strategy used in this process represents a general approach and therefore may contribute to the formation mechanisms of hollow nanostructures. PMID:16634578

International Nuclear Information System (INIS)

When materials such as metal are into the secondary side of steam generator, they, so called foreign objects, may have influences on the integrity of the steam generator tubes. They cause the tube wear due to the relative motion between the tubes and foreign objects and the tube impact due to flow. The best way to avoid the effects is to remove all the foreign objects. However, it is not easy to remove the foreign materials thoroughly due to their condition such as the location. If the locations of the foreign materials are in the middle of tube bundle and the tube arrangement of the steam generator is the triangle type, the equipment such as FOSAR(Foreign Object Search and Retrieval) can not reach their locations. If the foreign materials stick together with the tubes or tube sheet, they can not be removed. In the case of operating the steam generator with the foreign ...

International Nuclear Information System (INIS)

The profile imaging technique is used to study the oxidation of ZnTe and InP surfaces induced by in situ reaction due to the electron beam of the microscope and by ex situ heating in air. For both materials, in situ reaction with the electron beam resulted in desorption of the anion species and the formation of the metal oxide. The observation of In metal particles, and the fact that the rate of formation of In_2O_3 was substantially reduced by an improvement of the vacuum near the specimen region, suggested that the presence of oxygen is not involved in the desorption process. The ex situ heating of ZnTe up to 260 degrees C in air resulted in crystals of ZnO and Te metal, generally in a layered surface region with the sequence of ZnTe/Te/ZnO. The large Te crystals usually had an epitaxial relationship with the bulk ZnTe but the small ZnO crystals had random orientations. The ex situ heating of InP to ...

Science.gov (United States)

The theory of a method of determination of reactivity from power spectral density measurements with /sup 252/Cf and the results of experiments with a critical assembly mockup of a liquid-metal fast breeder reactor (LMFBR) and with uranium (93.2 wt % /sup 235/U) metal cylinders and a sphere are presented. This method of reactivity determination has an advantage over existing methods in that it determines the reactivity only from properties of the reactor at the subcritical state of interest and thus does not require a calibration near delayed criticality. In these experiments, the reactivity was varied by changing the fissile loading or the amount of neutron absorber inserted; for the LMFBR mockup, the reactivity varied to approximately 75 dollars subcritical, and for the uranium metal assemblies to approximately 30 dollars subcritical. These experiments verified for the first time the predictions of theory that could be ...

Energy Technology Data Exchange (ETDEWEB)

We demonstrate tuning of Schottky energy barriers in organic electronic devices by utilizing chemically tailored electrodes. The Schottky energy barrier of Ag on poly[2-methoxy], 5-(2{prime}-ethyl-hexyloxy)- 1,4-phenylene was tuned over a range of more than 1 eV by using self-assembled monolayers (SAM{close_quote}s) to attach oriented dipole layers to the Ag prior to device fabrication. Kelvin probe measurements were used to determine the effect of the SAM{close_quote}s on the Ag surface potential. {ital Ab} {ital initio} Hartree-Fock calculations of the molecular dipole moments successfully describe the surface potential changes. The chemically tailored electrodes were then incorporated in organic diode structures and changes in the metal/organic Schottky energy barriers were measured using an electroabsorption technique. These results demonstrate the use of self-assembled monolayers to control metal/organic interfacial electronic properties. ...

Energy Technology Data Exchange (ETDEWEB)

The /sup 252/Cf-source-driven neutron noise analysis method for obtaining the subcriticality of an assembly of fissile material from cross-power spectral densities (CPSDs) was developed to avoid some difficulties inherent in other measurement methods. This method requires measurement of frequency-dependent CPSD between a pair of detectors in or near the fissile assembly and CPSDs between these detectors and a source of correlated neutron noise from an ionization chamber containing /sup 252/Cf, also in or near the fissile assembly. Also, the auto-power spectral density of the source is required. The ratio of spectral densities is then formed and is related to the subcriticality. To date various measurements have been performed which demonstrate the usefulness of the method including measurements with single uranium metal cylinders. The experiments described here, which used coupled uranium (93.15 wt % /sup 235/U) metal ...

Energy Technology Data Exchange (ETDEWEB)

Recently the increase of steam temperature and pressure of power plant is required to enhance the thermal efficiency and reduce the CO{sub 2} emission. For the application to advanced USC (Ultra Super Critical) boiler with steam temperature around 700 C, the application of Ni-based alloy such as Alloy617 will be necessary. A new Ni-based alloy USC141 (20Cr-10Mo-2Ti-Al-bal.Ni) with excellent creep rupture strength and low thermal expansion has been developed by Hitachi Ltd. and Hitachi Metals Ltd. as the candidate material for 700 C USC turbine components. In present work, to investigate the possibility for boiler tube application of USC141, its weldability and high temperature strength properties were experimentally examined. The tested material as solution-treated condition shows higher creep rupture strength than that of Alloy617. GTAW (Gas Tungsten Arc Welding) trials of tubular specimen using NIMONIC263 filler wire were ...

Energy Technology Data Exchange (ETDEWEB)

In processes of this invention aqueous waste solutions containing a variety of mixed waste contaminants are treated to remove the contaminants by a sequential addition of chemicals and adsorption/ion exchange powdered materials to remove the contaminants including lead, cadmium, uranium, cesium-137, strontium-85/90, trichloroethylene and benzene, and impurities including iron and calcium. Staged conditioning of the waste solution produces a polydisperse system of size enlarged complexes of the contaminants in three distinct configurations: water-soluble metal complexes, insoluble metal precipitation complexes, and contaminant-bearing particles of ion exchange and adsorbent materials. The volume of the waste is reduced by separation of the polydisperse system by cross-flow microfiltration, followed by low-temperature evaporation and/or filter pressing. The water produced as filtrate is discharged if it ...

Energy Technology Data Exchange (ETDEWEB)

As the first step for development of the corrosion resistant superheater tube materials of 500 C, 100 ata used in high efficient waste-to-energy plants, field corrosion tests of six conventional alloys were carried out at metal temperatures of 450 C and 550 C for 700 and 3,000 hours in four typical Japanese waste incineration plants. The test results indicate that austenitic alloys containing approximately 80 wt% [Cr+Ni] show excellent corrosion resistance. When the corrosive environment is severe, intergranular corrosion of 40{approximately}200 {micro}m depth occurs in stainless steel and high alloyed materials. It is confirmed quantitatively that corrosion behavior is influenced by environmental corrosion factors such as Cl concentration and thickness of deposits on tube surface, metal temperature, and flue gas temperature. The excellent corrosion resistance of high [Cr+Ni+Mo] alloys such as Alloy 625 ...

Energy Technology Data Exchange (ETDEWEB)

Natural, formaldehyde-treated and copolymer-grafted orange peels were evaluated as adsorbents to remove lead ions from aqueous solutions. The optimum pH for lead adsorption was found to be pH 5. The adsorption process was fast, reaching 99% of sorbent capacity in 10 min for the natural and treated biomasses and 20 min for the grafted material. The treated biomass showed the highest sorption rate and capacity in the batch experiments, with the results fitting well to a pseudo-first order rate equation. In the continuous test with the treated biomass, the capacity at complete exhaustion was 46.61 mg g{sup -1} for an initial concentration of 150 mg L{sup -1}. Scanning electronic microscopy and energy dispersive X-ray spectroscopy indicated that the materials had a rough surface, and that the adsorption of the metal took place on the surface. Fourier transform infrared spectroscopy revealed that the functional groups ...

Energy Technology Data Exchange (ETDEWEB)

In order to understand the chemistry of altermetal dopants in antimony oxide, the detailed structural characterization of two ..beta..-Sb/sub 2/O/sub 4/ compounds is reported, Mo-doped ..beta..-Sb/sub 2/O/sub 4/ (1.5 metal%) and V-doped ..beta..-Sb/sub 2/O/sub 4/ (5 metal%). The methods used to characterize these materials are X-ray and neutron diffraction, scanning electron microscopy, Mo K-edge extended X-ray absorption fine structure spectroscopy, and elemental analysis. The atomic position of each of these dopants in Sb/sub 2/O/sub 4/ is radically different as is the overall effect on the host structure. Molybdenum does not substitute for Sb atoms, rather the Mo atoms are found in channels of electron density formed by Sb/sup 3 +/ lone pairs. The two nearest Sb/sup 3 +/ are absent and the oxygen stoichiometry is preserved. The formula is Sb/sub 1.97/Mo/sub 0.015/O/sub 4/. Vanadium incorporates substitutionally for the ...

Energy Technology Data Exchange (ETDEWEB)

During past two decades, the importance of rechargeable lithium cells has been emphasized and a large variety of materials has been discovered and evaluated for use as reversible cathodes and electrolytes. Materials that undergo intercalation or topochemical reactions with lithium have been investigated as candidates for cathodes in nonaqueous secondary lithium cells (1). Recent interest in researching cathode active materials has mainly focussed on crystalline transition metal chalcogenides. On the other hand, electrochemical behaviors of several amorphous materials have been reported, for example MoS/sub 2/,MoS/sub 3/,V/sub 2/S/sub 5/ (2) and LiV/sub 3/O/sub 8/ (3). However, no successful cycling behavior has been obtained except for MoS/sub 2/ in the amorphous state. This paper reports electrochemical data on rechargeable vanadate glasses in the system V/sub 2/O/sub 5/-P/sub ...

International Nuclear Information System (INIS)

With the exception of some minerals, the specific activity of natural radioactive material is below 370 Bq/g, their handling thus not being subject to authorization or the duty of reporting according to section 4 para. 2 of the Radiological Protection Ordinance. Moreover, there is required no handling license for prospecting, mining and processing of radioactive minerals; they are subject to the procedures for the plans of operation of the mining laws of the Federal States. License-free handling of natural radioactive material may result in the production of radioactive waste, the disposal of which must be authorized according to sect. 47 of the Radiological Protection Ordinance if the specific activity exceeds the free amounts of column 4 in Table IV of Appendix IV by a factor of 10"-"4/g. This inconsistency is discussed by means of the following examples: (1) fly ash and slag from coal power plants, (2) flue dust from sintering plants, (3) ...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) reactor, which started operating in 1982, is a 400 MWt sodium-cooled fast neutron reactor located in Hanford, Washington State, and operated by Westinghouse Hanford Co. under contract with U.S. Department of Energy. The reactor has a wide variety of functions for irradiation tests and special tests, and its major purpose is the irradiation of fuel and material for liquid metal reactor, nuclear reactor and space reactor projects. The review first describes major technical specifications and current conditions of the FFTF reactor. Then the plan for irradiation testing is outlined focusing on general features, fuel pin/assembly irradiation tests, and absorber irradiation tests. Assemblies for special tests include the material open test assembly (MOTA), fuel open test assembly (FOTA), closed loop in-reactor assembly (CLIRA), and other special fuel assemblies. An interim examination and ...

Energy Technology Data Exchange (ETDEWEB)

Small angle neutron scattering (SANS) has been a very powerful tool to study nanoscale (1-100 nm) bulk structures in various materials such as polymer, self assembled materials, nano-porous materials, nano-magnetic materials, metal and ceramics. Understanding the importance of the SANS instrument, the 8m SANS instrument was installed at the CN beam port of HANARO in 2001. However, without having a cold neutron source, the beam intensity is fairly low and the Q-range is rather limited due to short instrument length. In July 1, 2003, therefore, the HANARO cold neutron research facility project was launched and a state of the art 40m SANS instrument was selected as top-priority instrument. The development of the 40m SANS instrument was completed as a joint project between Korea Advanced Institute of Science and Technology and the HANARO in 2010. Here, we report the specification of a ...

Energy Technology Data Exchange (ETDEWEB)

Creation of new multi-composite materials is an essential issue to attain an innovative improvement of the current nuclear technology. In this paper, some highlights are focused on the research of creation of those materials and the relating subjects in NIRIM. (1) The KOH corrosion test method are expected to be efficiently available in the limited cases instead of Na corrosion test one. (2) The preliminary creation of the multi-composite ceramics were achieved by Y- ion implantation into sapphire and the RF sputtering, of which the specified orientation was realized by the existence of the buffer layer. The importance of the defect control are described with the relation to the corrosion resistance improvement. (3) The ion beam induced phenomena have been investigated on the surface change of silica glass and the crystallization of Cu film on SrTiO{sub 3}. (4) The electronic states of the alkali-metal adsorbed surfaces and ...

International Nuclear Information System (INIS)

The basic Quality Assurance Program Requirements standard for the National Waste Terminal Storage Program has been developed primarily for nuclear reactors and other fairly well established nuclear facilities. In the case of waste isolation, however, there are many ongoing investigations for which quality assurance practices and requirements have not been well defined. This paper points out these problems which require supplementary requirements. Briefly these are: (1) the language barrier, that is geologists and scientists are not familiar with quality assurance (QA) terminology; (2) earth sciences deal with materials that cannot be characterized as easily as metals or other materials that are reasonably homogeneous; (3) development and control of mathematical models and associated computer programs; (4) research and development.

British Library Electronic Table of Contents (United Kingdom)

The static corrosion tests in lead-bismuth eutectic (LBE) were conducted from 450degreeC to 600degreeC to understand corrosion behavior and develop corrosion resistant materials for heavy liquid metal systems. While increase of Cr content in steels enhances corrosion resistance in LBE, the effect approaches a constant value above 12wt% of Cr. Corrosion depth in LBE increases with increasing temperature and corrosion attack becomes severe above 550degreeC even under the condition of high oxygen concentration. Nickel dissolution and Pb-Bi penetration occur in 316SS and JPCA above 550degreeC under the condition of high oxygen concentration. When oxygen concentration decreases below the level of Fe oxide formation, corrosion attack on these steels also becomes violent due to dissolution of var...

Energy Technology Data Exchange (ETDEWEB)

Car weight corresponds directly to fuel consumption and driving performance. So in order to improve the fuel efficiency and performance of a car the weight has to be reduced. Magnesium as a light metal offers a wide range of weight saving opportunities, especially Magnesium wrought alloys with their improved mechanical properties have a high potential for structural applications. Mechanical properties in terms of their quality and anisotropy are dependent on the microstructure of the material and can be characterized by their degree of inhomogeneity, their grain size distribution and their crystallographic texture. Therefore the orientation distribution of grains, the grain size, its size distribution, the chemical composition (precipitates) itself influence the mechanical parameters and their anisotropy. In this presentation first results of mechanical anisotropy are given: differences in yield stress, r-values and their relation to the ...

British Library Electronic Table of Contents (United Kingdom)

Ruthenium(II) and Iridium(III) polypyridyl complexes have been intensively investigated due to their use in energy conversion and light-emitting devices and materials for non-linear optics. Quantum mechanical computer simulations of molecules and materials have become increasingly popular in the scientific community. Along with experimental investigations, such computational analyses can provide complementary information on the electronic and optical properties of transition metal compounds of interest for optoelectronic applications. Here, we provide a unified review of recent work carried out on computational investigations of a large series of Ruthenium(II) and Iridium(III) polypyridyl complexes, discussing the relations between their electronic structure and optical properties and thei...

Energy Technology Data Exchange (ETDEWEB)

The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements (PGE) and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a tandem Van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.

International Nuclear Information System (INIS)

The construction materials used in coolant systems in nuclear power plants become covered with oxide films as a result of exposure to the aqueous environment. The susceptibility of the materials to different forms of corrosion, as well as the extent of the incorporation of radioactive species on the surfaces of the primary circuit, are greatly influenced by the physical and chemical properties of these oxide films. The composition and characteristics of the oxide films in turn depend on the applied water chemistry. This work was undertaken in order to collect and evaluate the present views on the structure and behaviour of oxide films formed on iron- and nickel-based materials in aqueous environments. This survey should serve to recognise the areas in which more understanding and research effort is needed. The review begins with a discussion on the bulk oxides of iron, nickel and chromium, as well as their mixed oxides. In ...

Energy Technology Data Exchange (ETDEWEB)

Spray forming is an advanced materials processing technology that converts a bulk liquid metal to a near-net-shape solid by depositing atomized droplets onto a suitably shaped substrate. By combining rapid solidification processing with product shape control, spray forming can reduce manufacturing costs while improving product quality. De Laval nozzles offer an alternative method to the more conventional spray nozzle designs. Two applications are described: high-volume production of aluminum alloy strip, and the production of specialized tooling, such as injection molds and dies, for rapid prototyping.

Energy Technology Data Exchange (ETDEWEB)

Polymer electrolyte membrane fuel cells (PEMFCs) are energy conversion devices that produce electricity from a supply of fuel, such as hydrogen. One of the major challenges in achieving efficient energy conversion is the development of cost-effective materials that can act as electrocatalysts for PEMFCs. In this letter, we demonstrate that, instead of conventional noble metals, such as platinum, chromium nitride nanocrystals of fcc structure exhibit attractive catalytic activity for PEMFCs. Device testing indicates good stability of nitride nanocrystals in low temperature fuel cell operational environment.

International Nuclear Information System (INIS)

Production of titanium alloys from the mixture containing large amounts of metallurgy wastes is very promising. It is shown that unlimited possibilities of the waste material use in the mixture (up to 100%) are provided by garnissage melting, the size of the cast being limited only by that of the vessel. With garnissage being used as a consumed electrode the metal is refined from hydrogen and the blank ingots to serve as consumed electrodes in electro-slag remelting are chemically homogeneous. The ingots thus obtained have dense structure, rather fine grain homogeneous chemical composition, are no less pure than those obtained by vacuum arc remelting and provide for economic savings.

British Library Electronic Table of Contents (United Kingdom)

The increasing environmental concern and promotion of ''green processes'' are forcing the substitution of traditional acid and base homogeneous catalysts by solid ones. Among these heterogeneous catalysts, zeolites and zeotypes can be considered as real ''green'' catalysts, due to their benign nature from an environmental point of view. The importance of these inorganic molecular sieves within the field of heterogeneous catalysis relies not only on their microporous structure and the related shape selectivity, but also on the flexibility of their chemical composition. Modification of the zeolite framework composition results in materials with acidic, basic or redox properties, whereas multifunctional catalysts can be obtained by introducing metals by ion exchange or impregnation procedures...

International Nuclear Information System (INIS)

The Fast Flux Test Facility (FFTF) is a 400 MWt sodium-cooled fast reactor operated by Westinghouse Hanford Company for the US Department of Energy to conduct fuels and materials testing in support of the US Liquid Metal Fast Breeder Reactor programme. Early in 1982, the FFTF began its first 100 day irradiation cycle. Since that time the plant has operated very well, achieving a cycle capacity factor of 94 per cent in the most recent irradiation cycle. The authors describe the results achieved in the first three cycles of operation and carrying through to the fourth reactor cycle which began in January 1984. (author).

Energy Technology Data Exchange (ETDEWEB)

This Workpackage Report describes the introduction of fatigue cracks in bolts with ISO-metric threads M5x0.8, M8x1.0, M12x1.25 made from the materials Ti 6Al 4V, A-286 and INCONEL 718. Introdued cracks are verified by destructive testing. Results of the NDI of these bolts performed with special eddy current probes are reported. The detectability of cracks with a {>=} 0.65 and a/2c {approx equal} 0.3 located in the thread ground perpendicular to the load axis is demonstrated. (orig.).

Energy Technology Data Exchange (ETDEWEB)

A review of chemical decontamination methods for coatings indicates the following: the ease of both contamination and decontamination is a function of the radionuclide and the pH of the environment; the coating type is important in determining whether the contamination is loosely adsorbed, complexed, or contained in porous filler material; the condition of the coating is important to the decontamination factor obtained. Thus coatings can be decontaminated provided the solvent is sufficiently acid to solubilize the radionuclide and the complexant strength of the solvent is greater than that of the coating. Difficulties arise if the contamination is associated with fillers. Furthermore, though nothing has been said about temperature, decontamination of metal goes faster and, usually, with better efficiency at high temperatures. 11 references, 3 figures.

CERN Document Server

We have implemented a virtual Young's double slit experiment for hard X-ray photons with micro-fabricated bi-prisms. We observe fringe patterns with a scintillator, and quantify interferograms by detecting X-ray fluorescence from a scanned 30nm Cr metal film. The observed intensities are best modeled with a near-field, Fresnel analysis. The maximum fringe number in the overlap region is proportional to the ratio of real to imaginary parts refractive index of the prism material. The horizontal and vertical transverse coherence lengths at beamline APS 8-ID are measured.

Energy Technology Data Exchange (ETDEWEB)

MnO powder materials are investigated as anode active materials for Li-ion batteries. Lithium is stored reversibly in MnO through conversion reaction and interfacial charging mechanism, according to the results of ex situ XRD, TEM and galvanostatic intermittent titration technique. A layer of the solid electrolyte interphase with a thickness of 20-60 nm is covered on MnO particles after full insertion. MnO powder materials show reversible capacity of 650 mAh g{sup -1} with average charging voltage of 1.2 V. It can deliver 400 mAh g{sup -1} at a rate of 400 mA g{sup -1}. The cyclic performance of MnO is improved significantly after decreasing particle size and coating with a layer of carbon. Among observed transition metal oxides, MnO shows relatively lower voltage hysteresis (<0.7 V) between the discharging and the charging curves at 0.05 C. In addition to its environmental benign feature and ...

Science.gov (United States)

The liquid-phase synthesis of metal oxide nanoparticles in organic solvents under exclusion of water is nowadays a well-established alternative to aqueous sol-gel chemistry. In this article, we highlight some of the advantages of these routes based on selected examples. The first part reviews some recent developments in the synthesis of ternary metal oxide nanoparticles by surfactant-free nonaqueous sol-gel routes, followed by the discussion of the morphology-controlled synthesis of lanthanum hydroxide nanoparticles, and the presentation of structural peculiarities of manganese oxide nanoparticles with an ordered Mn vacancy superstructure. These examples show that nonaqueous systems, on the one hand, allow the preparation of compositionally complex oxides, and, on the other hand, make use of the organic components (initially present or formed in situ) in the reaction mixture to tailor the morphology. Furthermore, obviously even the crystal ...