International Science & Technology Center (ISTC)

Nanostructured Materials from Impulse Plasma in Liquid: Studying of Physical-Chemical Properties, Optimization of Conditions of Obtaining

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 ...

International Nuclear Information System (INIS)

Full text: It was recently-established for hexagonal barium ferrite-industrially important magnetically hard material that refinement of the crystallite dimensions into the nanoscale regime, typically #<=# 10 nm, leads after heat treatment at temperatures 800-1000 deg C to significant coercivity increase of up to 6.5 kOe (#approx#3-4 times) with saturation magnetisation values of 50-55 emu/g (#approx#95% of bulk at room temperature). High-energy mechanochemical processing has been applied to prepare nanostructural (nanocrystalline-amorphous) composites. High resolution electron microscopy studies reveal that the enhancement of the final magnetic properties was due to formation of magnetically noninteracting #approx#l,#mu#m Ba-ferrite particles with 5-10 nm amorphous surface layer - depending on annealing parameters. Similar situation was established also for ball milled strontium ferrite (SrFe_1_2O_1_9) powders where short annealing 4 h at ...

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.

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. ...

International Nuclear Information System (INIS)

A study of the thin gold film growth, during the deposition on glass substrate under UHV conditions at low temperatures, is presented. The complementary methods, the atomic force microscopy and grazing incidence x-ray reflectometry, are used for the research. It is shown that due to variation of the time of deposition from 2 to 50 min different kinds of thin Au films nanostructures are obtained: from discontinuous films consisting of isolated islands, via formation of the chains of islands, up to continuous films. (author)

International Science & Technology Center (ISTC)

Development of the Method of Electrodepositing Nanostructured Composite Coatings with Improved Engineering Properties

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.

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.

British Library Electronic Table of Contents (United Kingdom)

Deposition of CN-based films by a novel version of active screen plasma nitriding, aiming at surface modification of polymers, is reported. The approach relies on the use of pure graphite as the grid material, which was found to act both as an active screen and as a dry source of carbon atoms for the synthesis of thin films consisting mainly of a stoichiometric CN layer with columnar-type structure and dome-like nanostructured morphology.

CERN Document Server

material, and that these magnetic properties vary systematically with the diameter of the spherical pores within the films. A new oscillation effect has been observed for the coercivity of macroporous Ni sub 8 sub 0 Fe sub 2 sub 0 film with different pore layer thickness. sphere templates, the resulting films show well-formed, regular, two- and three-dimensional macroporous networks consisting of spherical pores arranged in a highly ordered face centred cubic (fee) structure. The spherical voids are interconnected by a series of smaller windows that form an open porous structure embedded in the material framework. The diameter of the spherical pores can be precisely changed over the range from 200 to 1000 nm by changing the diameter of the latex spheres used to form the templates. The resulting macroporous material structures are robust, self-supported, dense, polycrystalline, uniform and free from filling defects and ...

International Nuclear Information System (INIS)

Based on the results obtained for C-N and Si-C-N films, a systematic investigation of reactive magnetron sputtering of hard quaternary Si-B-C-N materials has been carried out. The Si-B-C-N films were deposited on p-type Si(100) substrates by dc magnetron co-sputtering using a single C-Si-B target (at a fixed 20% boron fraction in the target erosion area) in nitrogen-argon gas mixtures. Elemental compositions of the films, their surface bonding structure and mechanical properties, together with their oxidation resistance in air, were controlled by the Si fraction (5-75%) in the magnetron target erosion area, the Ar fraction (0-75%) in the gas mixture, the rf induced negative substrate bias voltage (from a floating potential to -500 V) and the substrate temperature (180-350 deg. C). The total pressure and the discharge current on the magnetron target were held constant at 0.5 Pa and 1 A, respectively. The energy and flux of ions bombarding the ...

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.

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^-...

British Library Electronic Table of Contents (United Kingdom)

Here in the present paper, we report on growth of stoichiometric and nonstoichiometric nanostructured heterojunction solar cell of CdS/CuInSXSe2-X varying X from 0 to 2 in the interval of 0.5 using cost effective, simple, chemical ion exchange method at room temperature on ITO glass substrate. The as-grown varying composition solar cells annealed at 200degreeC in air and characterized for structural, compositional, optical and illumination studies. The X-ray diffraction pattern obtained from CdS/CuInSXSe2-X solar cell confirms the formation of CuInSe2, CuInS0.5Se1.5, CuInS1Se1, CuInS1.5Se0.5 and CuInS2 phases having tetragonal structure with varying crystallite size from 19, 19.37, 28, 33 and 20nm respectively. The energy dispersive X-ray analysis (EDAX) confirms the expected elemental com...

Energy Technology Data Exchange (ETDEWEB)

Previously we have used atomic force anodisation lithography, with a self-assembled monolayer of hexadecyltrichlorosilane as a resist, to pattern silicon oxide nanostructures onto a p-type silicon (1 0 0) substrate. A condensation reaction was used to immobilise carbon nanotubes with high carboxylic acid functionality directly to the silicon oxide. A further condensation reaction using this surface attached the molecule ferrocenemethanol to the bound nanotubes. These new nanostructures were used as electrodes to observe the oxidation and reduction of ferrocene. However, because the small currents measured are near the detection limits of the electrochemical system used, important electrode kinetics could not to be obtained. A scribing approach made larger regions of oxidised silicon leading to the creation of larger scale patterned arrangements of carbon nanotubes allowing measurement of important electrochemical parameters ...

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

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)

As part of a study into the properties of ferroelectric single crystals at nanoscale dimensions, the effects that focused ion beam (FIB) processing can have, in terms of structural damage and ion implantation, on perovskite oxide materials has been examined, and a post-processing procedure developed to remove such effects. Single crystal material of the perovskite ferroelectric barium titanate (BaTiO_3) has been patterned into thin film lamellae structures using a FIB microscope. Previous work had shown that FIB patterning induced gallium impregnation and associated creation of amorphous layers in a surface region of the single crystal material some 20 nm thick, but that both recrystallization and expulsion of gallium could be achieved through thermal annealing in air. Here we confirm this observation, but find that thermally induced gallium expulsion is associated with the formation of gallium-rich platelets on the surface ...

British Library Electronic Table of Contents (United Kingdom)

To improve the friction and wear behavior of carbon fabric reinforced polymer composites (CFRP), nano-SiO2 was deposited on the fabric surface. The friction and wear behavior of the resulting composites were investigated on a model ring-on-block test rig. Experimental results revealed that fiber surface treatment contributed to largely improve the tribological properties of the CFRP composites. Scanning electron microscope (SEM) investigation showed that the worn surface of the surface modified CFRP composite was smoother under given load and sliding rate. Field emission scanning electron microscopy (FESEM), FTIR and X-ray photoelectron spectroscopy (XPS) studies of the carbon fiber surface showed that nanostructured Sio2 thin film can be obtained by SiO2 sols deposition, which improved th...

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...

KoreaScience (Korea)

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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, ...

British Library Electronic Table of Contents (United Kingdom)

Electrodeposition of tertiary alumina/yttria/carbon nanotube (Al2O3/Y2O3/CNT) nanocomposite by using pulsed current has been studied in this investigation. Coating process has been performed on nickel sulphate bath and nanostructure of obtained compound layer is examined with high precision figure analysis of SEM nanographs. The effects of process variables, i.e., Y2O3 concentration, treatment time, frequency and duty cycle, have been experimentally studied. Statistical methods are used to achieve the minimum of corrosion rate and average size of nanoparticles. Finally the contribution percentage of different effective factors is revealed and confirmation run shows the validity of obtained results. Also it has been revealed that by changing the size of nanoparticles, corrosion properties o...

International Nuclear Information System (INIS)

Focused Ion Beams are an important approach for nanostructure fabrication in the semiconductor industry and material sciences. Applications in sputtering and ion induced deposition of materials are investigated. The IMSA FIB system equipped with the high resolution Orsay Physics CANION M31plus ion column with current densities up to 10 A/cm"2 including a gas injection system is applied. In this work the ion beam induced chemical vapour deposition of tungsten, wherefore tungsten hexacarbonyl as precursor gas is used for a first investigation. Conductive tungsten-nanowires with smallest cross-section upon a substrate of Si and SiO_2 are produced. The ion beam parameters of this focused ion beam system are optimized for the metal deposition. A short insight in the theory of layer nucleation and growth induced by the ion beam during the metal deposition is given. The layer quality is determined by Auger electron analysis which ...

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

We present computer modeling along with experimental data on the formation of sharp conical tips on silicon-based three-layer structures that consist of a single-crystal Si layer on a 1 {mu}m layer of silica on a bulk Si substrate. The upper Si layers with thicknesses in the range of 0.8-4.1 {mu}m were irradiated by single pulses from a KrF excimer laser focused onto a spot several micrometers in diameter. The computer simulation includes two-dimensional time-dependent heat transfer and phase transformations in Si films that result from the laser irradiation (the Stefan problem). After the laser pulse, the molten material self-cools and resolidifies, forming a sharp conical structure, the height of which can exceed 1 {mu}m depending on the irradiation conditions. We also performed computer simulations for experiments involving single-pulse irradiation of bulk silicon, reported by other groups. We discuss conditions under which different types of structures (cones ...

Energy Technology Data Exchange (ETDEWEB)

Chemical looping combustion (CLC) is an emerging technology for clean combustion. We have previously demonstrated that the embedding of metal nanoparticles into a nanostructured ceramic matrix can result in unusually active and sinter-resistant nanocomposite oxygen carrier materials for CLC which maintain high reactivity and high-temperature stability even when sulfur contaminated fuels are used in CLC. Here, we propose a novel process scheme for in situ desulfurization of syngas with simultaneous CO{sub 2}-capture in chemical looping combustion by using these robust nanocomposite oxygen carriers simultaneously as sulfur-capture materials. We found that a nanocomposite Cu-BHA carrier can indeed strongly reduce the H{sub 2}S concentration in the fuel reactor effluent. However, during the process the support matrix is also sulfidized and takes part in the redox process of CLC. This results in SO{sub 2} production during the ...

International Nuclear Information System (INIS)

Single-crystalline nanostructures often exhibit gradients of surface (and/or interface) curvature that emerge from fabrication and growth processes or from thermal fluctuations. Thus, the system-inherent capillary force can initiate morphological transformations during further processing steps or during operation at elevated temperature. Therefore and because of the ongoing miniaturization of functional structures which causes a general rise in surface-to-volume ratios, solid-state capillary phenomena will become increasingly important: On the one hand diffusion-mediated capillary processes can be of practical use in view of non-conventional nanostructure fabrication methods based on self-organization mechanisms, on the other hand they can destroy the integrity of nanostructures which can go along with the failure of functionality. Additionally, capillarity-induced shape transformations are effected and can thereby be ...

Energy Technology Data Exchange (ETDEWEB)

The starting material for two certified and one candidate reference material was obtained from dried grass specially cultivated on a selected and well prepared soil. The Community Bureau of Reference (BCR) of the Commission of the European Communities produced two certified reference materials (CRM`s) from this dried grass: a rye grass material (CRM 281) certified in 1988 for the quality control of trace and toxic element analyses and a hay powder material (CRM 129) certified in 1989 for monitoring trace and minor elements. A fraction of the dried grass was used in 1993 for the preparation of a hay powder with a particle size of < 63 {mu}m using newly developed grinding techniques. This paper compares the production methods of these three materials and the obtained particle size distribution of the powders. The ...

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)

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.

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)

Nuclear forensics is the analysis of nuclear materials recovered from either the capture of unused materials, or from the radioactive debris following a nuclear explosion and can contribute significantly to the identification of the sources of the materials and the industrial processes used to obtain them. In the case of an explosion, nuclear forensics can also reconstruct key features of the nuclear device. Nuclear forensic analysis works best in conjunction with other law enforcement, radiological protection dosimetry, traditional forensics, and intelligence work to provide the basis for attributing the materials and/or nuclear device to its originators. Nuclear forensics is a piece of the overall attribution process, not a stand-alone activity

International Nuclear Information System (INIS)

The determination of the origin of seized nuclear material is important for authorities in the context of the criminal investigation, in order to return the material to its last legal owner and to help preventing any further diversion of material from this source. Origin determination is based on a complex pattern of parameters obtained through analytical measurements. The information required to determine the origin of nuclear materials may be divided into two categories: endogenous information (e.g. age or mode of production of the material) which is self-explanatory; whereas exogenous information (e.g. dimensions, surface roughness, impurities) requires a database to which the parameters can be compared. The Institute for Transuranium Elements has developed methods to determine characteristic parameters like impurities, surface roughness, or microstructural ...

UK PubMed Central (United Kingdom)

Therapeutic embolization is defined as the voluntary occlusion of one or several vessels, and this is achieved by inserting material into the lumen to obtain transient or permanent thrombosis in the...Full Text Available

UK PubMed Central (United Kingdom)

X-ray diffuse scattering was measured from oriented stacks and unilamellar vesicles of dioleoylphosphatidylcholine lipid bilayers to obtain the temperature dependence of the structure and of the material...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Many investigations of anode materials for lithium-ion secondary batteries have been carried out in order to obtain batteries of higher capacity and energy density. Recently, SnO-based glasses, which were prepared by the usual melt quenching technique, have been proposed as a new anode for lithium-ion secondary batteries by Idota et al. It has been reported that the capacity per unit weight was higher than 600 mAh g{sup {minus}1} and the capacity per unit volume was higher than 2,200 mAh cm{sup {minus}3}, values which are almost double those for carbon materials used as anodes of commercial lithium-ion batteries at present. Thus SnO-based glasses have attracted much interest as high-capacity anode materials for lithium-ion secondary batteries. Amorphous materials in the system SnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5}, with or without the addition of Li{sub 2}O, were synthesized by ...

Energy Technology Data Exchange (ETDEWEB)

Ribbon parachute fabrics were tested during development and production of a 24 ft parachute, and after 2.5 years ambient exposure at several storage sites. The effects of sewing, packing, and parachute deployment on material strength were obtained in the 1000 lb Kevlar ribbon after moisture exposure during packing, and when packed parachutes absorbed moisture or were thermal cycled. Individual yarn samples from the low strength ribbons exhibited little change in strength indicating that the material itself had not degraded. Factors leading to the change in ribbon strength are discussed. Considering all materials, there have been no indications to date of any uncontrollable changes in material strength that would limit the use of Kevlar in parachute applications.

International Nuclear Information System (INIS)

The widespread use of building materials with relatively high radium concentrations may increase population exposure. A method is presented for measuring effective diffusion coefficients and exhalation rates of radon from such materials. Equations for use in the experimental determination of these values are obtained theoretically. The experimental set-up consists of a container which is hermetically sealed to a slab of the building material. Nitrogen is blown through the container and then through an ionization chamber which is connected to an electrometer and X-Y plotter, and the radon concentration is measured continuously. Exhalation rates of radon from some major building materials measured by this method will be used as reference levels. The method can also be used to determine other properties such as porosity. (author).

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)

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.

British Library Electronic Table of Contents (United Kingdom)

A formula is obtained which describes the kinetics of low-temperature radiation hardening caused by creation of dislocation loops of interstitial type during irradiation. The radiation hardening of aluminum and vanadium is estimated using this formula and results of experiments on studying processes of nucleation and growth of interstitial dislocation loops in these materials by transparent electron microscopy. It is shown that the proposed formula is valid for description of the kinetics of low-temperature radiation hardening.

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. ...

Energy Technology Data Exchange (ETDEWEB)

In this paper, we review some of the work our group has done in the past few years to obtain the electron self-energy of high temperature superconductors by analysis of angle-resolved photoemission data. We focus on three examples which have revealed: (1) a d-wave superconducting gap, (2) a collective mode in the superconducting state, and (3) pairing correlations in the pseudogap phase. In each case, although a novel result is obtained which captures the essence of the data, the conventional physics used leads to an incomplete picture. This indicates that new physics needs to be developed to obtain a proper understanding of these materials.

Energy Technology Data Exchange (ETDEWEB)

The development of a silicon carbide (SiC) heat exchanger is a critical step in the development of the Externally-Fired Combined Cycle (EFCC) power system. SiC is the only material that provides the necessary combination of resistance to creep, thermal shock, and oxidation. While the SiC structure materials provide the thermomechanical and thermophysical properties needed for an efficient system, the mechanical properties of the SiC tubes are severely degraded through corrosion by the coal combustion products. To obtain the necessary service life of thousands of hours at temperature, a protective coating is needed that is stable with both the SiC tube and the coal combustion products, resists erosion from the particle laden gas stream, is thermal shock resistant, adheres to SiC during repeated thermal shocks (start-up, process upsets, shut-down), and allows the EFCC system to be cost competitive. This demanding set of ...

International Nuclear Information System (INIS)

The evolution of metallic substance atomic structure is studied on temperature variation including crystal heating up to melting points, a crystal- liquid phase transition and initiation of a high-density liquid specific structure. It is marked that heat induced changes of simple metal structure can be described as changes around a natural elementary cell which is common for both a crystal and a liquid and consists of a central atom and Z_1 atoms of the first coordination sphere. On this basis the vacancy model of melting is verified. Concentrations of melting vacancies are determined by coordination numbers in the form of Z_1/(1+Z_1)"2 which are the same for both a crystal and a natural elementary cell. The size of natural elementary cells is in an agreement with that of the coordination sphere featured in the liquid and phase transition statistical theory. Calculated data are given for a number of metals, Cs, Eu, Ni, V included

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)

Since information has been regarded os a physical entity, the field of quantum information theory has blossomed. This brings novel applications, such as quantum computation. This field has attracted the attention of numerous researchers with backgrounds ranging from computer science, mathematics and engineering, to the physical sciences. Thus, we now have an interdisciplinary field where great efforts are being made in order to build devices that should allow for the processing of information at a quantum level, and also in the understanding of the complex structure of some physical processes at a more basic level. This thesis is devoted to the theoretical study of structures at the nanometer-scale, 'nanostructures', through physical processes that mainly involve the solid-state and quantum optics, in order to propose reliable schemes for the processing of quantum information. Initially, the main results of quantum information theory and quantum ...

Energy Technology Data Exchange (ETDEWEB)

This study was the analyse the relationship between properties of ion nitrided Fe sintered material and parameters of plasma nitriding process. Pure fe sintered materials (relative density : 92%) were fabricated by hot-pressing and nitrided under pulsed DC plasma for 4 hours. The large number of parameters in plasma diffusion treatment allows close control of the process so that surface layers with defined microstructures and properties can be obtained. The number of micropores in nitriding layer can be reduced in pulsed DC plasma by reducing the plasma power and by varying the gas mixture. The phase constitution of compound layer of nitrided Fe sintered material were influenced by gas mixture (N{sub 2} : H{sub 2}) and pulsed ratio (pulse on/off time ratio)

Energy Technology Data Exchange (ETDEWEB)

An experimental capability, developed at Lawrence Livermore National Laboratory (LLNL), is being used to study the yield behavior of elastic-plastic materials. The objective of our research is to develop better constitutive equations for polycrystalline metals. We are experimentally determining the multidimensional yield surface of the material, both in its initial state and as it evolves during large inelastic deformations. These experiments provide a more complete picture of material behavior than can be obtained from traditional uniaxial tests. Experimental results show that actual material response can differ significantly from that predicted by simple idealized models. These results are being used to develop improved constitutive models of anisotropic plasticity for use in continuum computer codes.

British Library Electronic Table of Contents (United Kingdom)

This paper introduces the application of independent component analysis mixture modelling (ICAMM) in non-destructive testing (NDT). The application consists of discriminating patterns for material quality control from homogeneous and defective materials inspected by impact-echo testing. This problem is modelled as a mixture of independent component analysis (ICA) models, representing a class of defective or homogeneous material by an ICA model whose parameters are learned from the impact-echo signal spectrum. These parameters define a kind of particular signature for the different defects. The proposed procedure is intended to exploit to the maximum the information obtained with the cost efficiency of only a single impact. To illustrate this capability, four levels of classification detail...

CERN Document Server

In the paper the role of conservation laws in evolutionary processes, which proceed in material systems (in material media) and lead to generation of physical fields, is shown using skew-symmetric differential forms. In present paper the skew-symmetric differential forms on deforming (nondifferentiable) manifolds were used in addition to exterior forms, which have differentiable manifolds as a basis. Such skew-symmetric forms (which were named evolutionary ones since they possess evolutionary properties), as well as the closed exterior forms, describe the conservation laws. But in contrast to exterior forms, which describe conservation laws for physical fields, the evolutionary forms correspond to conservation laws for material systems. The evolutionary forms possess an unique peculiarity, namely, the closed exterior forms are obtained from these forms. It is just this that enables one to describe the ...

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)

Neutron radiography (NR) is a useful non-destructive method for determination of hydrogen content in various building and technical materials. Monitoring of transport processes of moisture and hydrogenous liquids in porous building materials is enabled by fast, quasi-real-time NR methods based on novel imaging plate neutron detectors (IP-NDs). Hydrogen content in the samples is determined by quantitative analysis of measured profiles of neutron attenuation in the samples. Detailed description of quantitative NR method is presented by the authors in another accompanying contribution at this conference. Deterioration of building materials is originated by different processes that all require presence of water therefore it is essential to limit or prevent the transport of water through the porous material. In this presentation, results of a study of clay brick impregnation by silicone based hydrophobic ...

Energy Technology Data Exchange (ETDEWEB)

We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool ...

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Vanadium doped manganese bi-oxide has been obtained from a solution containing both cations. The X-ray diffraction of this material indicates a rutile-type phase but the enlargement of some lines supports the existence of several lattice defects. Also the particle size of the doped material is significantly smaller than the one of the non-doped material obtained in the same conditions. The presence of pentavalent vanadium inside the lattice leads to a small amount of trivalent manganese. Electron microscopy shows the existence of defects which have a tendency of becoming well-ordered and to stabilize a sur-structure. At ambient temperature, the electrochemical behaviour of doped manganese bi-oxide is greatly improved when compared to the non-doped phase. This behaviour is due to the presence of numerous lattice defects and to the smaller size of crystallites. In polymer batteries, ...

British Library Electronic Table of Contents (United Kingdom)

New nanofibers containing poly(vinyl pyrrolidone)-iodine complex (PVP-iodine) were obtained by electrospinning in order to prepare materials suitable for wound dressings. Different approaches were used: a one-step method based on electrospinning of PVP-iodine or poly(ethylene oxide)/PVP-iodine solutions and a three-step method based on electrospinning of PVP or poly(ethylene oxide)/PVP mixed solutions followed by photo-mediated crosslinking of the obtained nanofibers and subsequent complexation with iodine. The average diameters of the fibers were in the range 150-470nm depending on the composition and on the applied field strength (AFS) and increased with increasing the amount of PEO in the spinning solutions. Higher AFS resulted in greater fiber diameter and in size distribution broadeni...

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.

International Nuclear Information System (INIS)

It has been prepared composites materials by means of monomer penetration in pores of wood samples and later curing by means of gamma irradiation. The studied species were Hura crepitans L. (catahua), Aniba puchury-minor (C. Martinez) (mohena amarilla), and Calycophyllum spruceanum (Benth.) (capirona). These new materials exhibit smaller water absorption and better mechanical properties in comparison with native wood. The test tubes of catahua treated with the styrene-polyester mixture absorb only up to 10% humidity compared to the native species whereas its hardness is increased in a 100%. (author).

Energy Technology Data Exchange (ETDEWEB)

Full text: Magnetic multilayer materials are becoming technologically important as they provide a more efficient means of magnetic reading and storage through utilisation of their giant magnetoresistance and oscillatory magnetic coupling. This study presents preliminary tight-binding calculations with a view of developing a consistent tight-binding model of `spin valve` Fe-Cu-Fe tri-layer materials. Further work involves using a self-consistent tight-binding approach to obtain a more accurate picture of this system and a better understanding of surface effects at the Fe-Cu interface 1 fig., 4 refs.

International Nuclear Information System (INIS)

A sample of garnet-biotite plagiogneiss, GBPg-1 is currently being developed as a certified reference material at the Vinogradov Institute of Geochemistry. It was used as the sample that was distributed round 7 of International Proficiency Testing Program (GeoPT7) and was analyzed by 76 geoanalytical laboratories around the world. Twenty Russian laboratories involved in the interlaboratory experiment also analyzed GBPg-1. The resultant analytical data obtained from these two experiments has allowed GBPg-1 to be certified as a state standard sample for 50 elements. It also enabled a comparison of the quality of data developed by the Russian and international geoanalytical laboratories, to optimize the outcome of this interlaboratory experiment.

International Nuclear Information System (INIS)

In a supercritical water-cooled reactor, property of water changes significantly around the critical point. It is expected that irradiation and change of water property will affect the chemistry and material corrosion. Deep understanding of interactions between supercritical water and materials under irradiation is important. However, comprehensive data on radiolysis, kinetics, corrosion and thermodynamics have not been obtained due to the severe experimental condition. To get such data by experiments and computer simulations, a national program funded by Ministry of Education, Culture, Sports, Science and Technology (MEXT) has been started since December 2002. (author)

British Library Electronic Table of Contents (United Kingdom)

In this paper we describe a Ni-Sn intermetallic material obtained via template electroplating synthesis. The structure and the morphology of this material are investigated by X ray diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. We demonstrate that Ni-Sn behaves as a sub-micrometric electrode showing a favourable response when cycled in a lithium cell. The results here reported suggest that the template electroplating is a promising synthetic approach that can lead to an optimized structure and morphology of the Ni-Sn electrode, such as to confer it a role of a high capacity anode in advanced lithium ion batteries.

Energy Technology Data Exchange (ETDEWEB)

A method, system and a radiation detector system for use therein are provided for determining the depth distribution of radiation-emitting material distributed in a source medium, such as a contaminated field, without the need to take samples, such as extensive soil samples, to determine the depth distribution. The system includes a portable detector assembly with an x-ray or gamma-ray detector having a detector axis for detecting the emitted radiation. The radiation may be naturally-emitted by the material, such as gamma-ray-emitting radionuclides, or emitted when the material is struck by other radiation. The assembly also includes a hollow collimator in which the detector is positioned. The collimator causes the emitted radiation to bend toward the detector as rays parallel to the detector axis of the detector. The collimator may be a hollow cylinder positioned so that its central axis is perpendicular to the upper ...

Energy Technology Data Exchange (ETDEWEB)

In January of 1977 the Paraho Development Company under contract with the United States Navy began a semi-works project to produce and refine up to 100,000 barrels of crude shale oil. Although the primary objective of the project was to produce specification turbine and diesel transportation fuels for field testing by the military field testing, the full-scale refinery run also produced a substantial quantity of hydrotreated shale oil residue. In 1978 the Electric Power Research Institute, recognizing the utilization potential of this material as a fuel for utility combustion turbines, obtained 4300 barrels of the residual shale oil product for future field testing. This report describes the processes involved in producing, handling, and storing the residual shale oil test material. The report also includes detailed chemical and physical analyses of the test material. In addition, guidelines which can ...

International Nuclear Information System (INIS)

Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alphy source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm diameter plexiglass cell can be extended to at ...

Energy Technology Data Exchange (ETDEWEB)

Resistance of Alloy 800 as a PWR S/G tube material to IGC/IGSCC and Ni, Co release into water was evaluated as compared with Alloys 600 and 690. The study to improve the resistance to IGSCC and general corrosion was also made, including the effects of shot-peening on the distribution of the residual stress of the U-bent tubes and the susceptibility to SCC, the stabilizing elements on IGC/IGSCC, and prior oxidation on general corrosion. From the results, shot-peened Alloy 800 was estimated to be the most reliable S/G tube material among the high nickel alloys tested. In addition, the Alloy 800 tube would obtain further reliability in IGSCC and general corrosion resistance by the combined addition of Ti, and Nb, and the prior oxidation of the inner tube surface, respectively.

International Nuclear Information System (INIS)

Control of thermal expansion is often necessary in the design and selection of electronic packages. In some instances, it is desirable to have a coefficient of thermal expansion intermediate between values readily attainable with single or two phase materials. The addition of a third phase in the form of fillers, whiskers, or fibers can be used to attain intermediate expansions. To help design the thermal expansion of multiphase materials for specific applications, a closed form model has been developed that accurately predicts the effective elastic properties of isotropic filled materials and transversely isotropic lamina. Properties of filled matrix materials are used as inputs to the lamina model to obtain the composite elastic properties as a function of the volume fraction of each phase. Hybrid composites with two or more fiber types are easily handled with this model. This ...

International Nuclear Information System (INIS)

Type 304 stainless steels (solution annealed material, cold worked material and fine grain material) were neutron irradiated to 3 x 10"2"5n/m"2 at 290degC and at 50degC. Each specimen was examined by SSRT test in high temperature water with 8 ppm dissolved oxygen and Ar gas environments. Results were as follows: (1) IASCC susceptibility of each material can be classified by 0.2% proof stress (PS) obtained from SSRT test in Ar gas: No IASCC susceptibility was observed in the PS range 850 MPa. (2) The uniform elongation (UE) in Ar gas environment decreased with increasing PS up to 800 MPa, and became about 0% in the PS range >800 MPa. (3) It was suggested that IASCC did not occur even if material had IASCC susceptibility, when under a condition that brittle fracture mechanism controls a specimen failure. (author)

Energy Technology Data Exchange (ETDEWEB)

The conception of a solar receiver intended to equip a tower power-station has to combine multiple requirements: very highly concentrated solar flux, unsteady in time and space; necessity to obtain a high efficiency; respect of the physical limits of the materials and of the fluid. The description of Themis solar receiver and of its operation is preceded by considerations which have led to the choice of the cavity, of the fluid and of its circulation.

International Nuclear Information System (INIS)

Structural units of a hydrogen fuel cell whose characteristics are advisable to investigate by different neutron scattering methods are discussed. The results obtained with the use of Bragg diffraction and small-angle neutron scattering from fuel membranes, nanocarbon-platinum catalysts, and Zn_1_-_xCu_xO hydrogen storage systems are presented.

Energy Technology Data Exchange (ETDEWEB)

Cellulose raw materials costs must be considered in order to obtain a minimized hexose cost. In recognition of this fact, it may be economically advantageous to operate at less than maximum hexose concentration in the reactor and to recycle unreacted cellulose. The objective of this article is to optimize a cellulose-recycle reactor system for producing hexose at minimum cost. A sensitivity analysis of the important variables in the mathematical model of this system is also discussed.

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)

The authors study the nonuniformity of a-Si:H films obtained by the method of vacuum condensation, with the help of x-ray small-angle scattering (SLS) and transmission electron microscopy. Films of hydrogenated amorphous silicon are greatest interest, because the electronic properties of this material can be controlled by doping. As a result of the compensation of the ruptured bonds, and possibly, effects of melting, the properties of such films are analogous to those of singlecrystalline silicon. XLS enables a quantitative determination of the prameters of the regions of low electron density (RLD) in such objects.

Energy Technology Data Exchange (ETDEWEB)

A number of interactions between magnetic fields and matter is reviewed. The resulting forces range in magnitude from the very large, obtained in high-energy fields, to the weak ones caused by the magnetostriction of ferromagnets. The fundamentals of these interactions are highlighted, and the examples discussed are forces on dipoles, particle alignment, magnetostrictive forces, magnetic forming, magnetic stirring, levitation melting, and magnetic pulsing of tool steels. (orig.)

Energy Technology Data Exchange (ETDEWEB)

We have used an electric gun to measure the initiation thresholds of more than twenty unusual explosive materials as well as the thresholds of several common explosives for comparison. The purpose of the work was to obtain experimental data for a theoretical study of the effects of various chemical groups on the detonation sensitivity of explosives. 2 refs., 3 figs., 1 tab.

International Nuclear Information System (INIS)

We report the implementation of positron wave function and lifetime calculations in the all-electron full-potential linearized augmented plane wave method. Calculations of lifetimes for more than 30 materials with two different forms of the enhancement factor were done and compared to prior calculations and experiment. We find that reasonable agreement with experiment can be obtained within the local density approximation when all-electron full-potential calculations are done.

Science.gov (United States)

The report gives results of a 4-year study to determine environmentally sound methods for disposing of wastes from nonregenerable flue gas desulfurization (FGD) systems. Data presented incorporates results obtained during the fourth year with material from report EPA-600/7-77-052...

Energy Technology Data Exchange (ETDEWEB)

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 materials, ...

Energy Technology Data Exchange (ETDEWEB)

Biodiesel is derived from triacylglycerides and is produced primarily through transesterification, a chemical reaction of vegetable oils with alcohol, methanol or ethanol. The cost of raw material should be considered since 85 per cent of production cost is related to vegetable oil. The purpose of this study was to evaluate oil expression of sunflower seed. It also examined the sunflower crude oil as a raw material for biodiesel by transesterification in both laboratory and pilot scale studies. Three different biodiesel purification methods were examined. The best result for oil expelling (68.4 per cent) at the experimental stage was obtained for seeds with a moisture content of 6.9 per cent at 25 degrees C and at a screw speed of 114 rpm. For biodiesel production at the laboratory scale, the best result for oil expelling was 87.5 per cent. It was obtained with an ethanol:oil molar ratio of 4.7:1 and ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, ...

International Nuclear Information System (INIS)

This study presents the findings of radiometric analysis carried out to determine the activity concentrations of natural radionuclides in raw materials (clay, kaolin, quartz, feldspar, dolomite, alumina, bauxite, zirconium minerals, red mud and frit) and end products (glazed ceramic wall and floor tiles) in the Turkish ceramics industry. Hundred forty-six samples were obtained from various manufacturers and suppliers throughout the country and analyzed using gamma-ray spectrometer with HPGe detectors. Radiological parameters such as radium equivalent activity, activity concentration index and alpha index were calculated to assess the radiological aspects of the use of the ceramic end products as decorative or covering materials in construction sector. Results obtained were examined in the light of the relevant national and international legislation and guidance and compared with the results of similar ...

International Nuclear Information System (INIS)

Boat sampling technique (BST) is a surface sampling technique, which has been developed for obtaining, in-situ, metal samples from the surface of an operating component without affecting its operating service life. The BST is non-destructive in nature and the sample is obtained without plastic deformation or without thermal degradation of the parent material. The shape and size of the sample depends upon the shape of the cutter and the surface geometry of the parent material. Miniature test specimens are generated from the sample and the specimens are subjected to various tests, viz. Metallurgical Evaluation, Metallographic Evaluation, Micro-hardness Evaluation, sensitisation test, small punch test etc. to confirm the integrity and assessment of safe operating life of the component. This paper highlights design objective of boat sampling technique, description of sampling module, sampling cutter and its ...

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 the embedded ...

British Library Electronic Table of Contents (United Kingdom)

The nanostructure Ni-doped CdO films have been prepared by sol gel spin coating method. Atomic force microscopy results indicate that the CdO films are formed from the nanoparticles and the grain size is changed with nickel content. X-ray diffraction patterns of the films indicate that the undoped and Ni-doped CdO films have polycrystalline structure with a cubic sodium chloride structure, showing two main characteristic peaks assigned to the (111) and (200) planes. The optical band gap values of undoped and Ni-doped CdO films were determined by optical absorption method. The Eg values of the CdO films were found to be in the range of 2.26?2.60?eV. The Eg values of the CdO films increase with the content of Ni dopant (up to 6% Ni). It is evaluated that the optical band gap and grain size o...

British Library Electronic Table of Contents (United Kingdom)

Herein, we report engineering of nanostructured p-CuIn3Se5/n-CdS heterojunction thin film on a glass substrate, which is prepared at room temperature using simple wet chemical approach involving ion exchange reactions between CdS and Cu^+, In^3^+ and Se^2^- ions in alkaline medium. The uniform deposition of heterojunction thin films is achieved by optimizing the pH, temperature and molarity of the reactant bath. The as-deposited thin-films were annealed at 200^oC in air for 1h and further characterized for structural, optical and electrical properties using UV-Vis spectrophotometer, X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), Hall effect for type of conductivity, and I-V measurement to investigate the char...

International Nuclear Information System (INIS)

We explore the relation of nanostructures with the appearance of giant magnetoresistance (GMR) in melt-spun CuCo ribbons. We find by energy-filtered transmission electron microscopy that the ribbons are composed of a periodic distribution of Co within the Cu, as in spinodal decomposition. The lamellar structure should thus be associated with GMR, as only a small percentage of the Co is present in the form of grains. This is counterintuitive, for no clear interfaces are present as required by standard models, and the period of the composition oscillation (43-52 nm) is an order of magnitude larger than the mean free paths for electrons. Upon annealing, a secondary spinodal decomposition appears following the same direction as the original.

Energy Technology Data Exchange (ETDEWEB)

We investigate the formation of nanostructures in 2D strained alloys on face centered cubic (111) surfaces by means of equilibrium Monte Carlo simulations. In the framework of an off-lattice model, we consider one monolayer of two bulk-immiscible adsorbates A and B with negative and positive misfit relative to the substrate, respectively. Simulations show that the adsorbates partly self-organize into island or stripe-like patterns. We show how these structures depend on the relative misfits, interaction, and concentration of components. The morphology is quite different for phase separation and intermixing regimes.

Energy Technology Data Exchange (ETDEWEB)

This paper reports the presence of face centered cubic cobalt precipitates inside tungsten carbide in nanocomposite of WC-Co synthesized by spray conversion processing. EDS was used to identify the presence and micro-diffraction was employed to determine the nature of the precipitates. There is entrapment of cobalt in tungsten carbide during the spray conversion process used to form WC/Co powder. During consolidation, at high temperatures, the cobalt attains enough mobility to precipitate inside WC. A vanadium containing compound was seen at the interfaces in samples which incorporated VC as a grain growth inhibitor. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The dispersion of more than 20 vol pct submicrometer ceramic particles within a metallic matrix and the deposition of such a cermet to form a thick and tough coating presents problems. Most of the coating techniques have failed in attempting to homogeneously disperse very fine and hard particles in large amounts while avoiding their decomposition or reaction with the metal matrix during the deposition process. A simple and efficient method has been developed for producing ceramic-containing composite coatings. It consists in synthesizing cermet-based materials and in depositing them by a rapid solidification process, such as thermal spraying. Boride- and carbide-based materials have been successfully obtained by plasma spraying reactive powders comprising the basic reagents. These materials, with a microstructure of submicrometer ceramic particles dispersed in a metallic matrix, exhibit good ...

International Nuclear Information System (INIS)

First structural wall material (FSW) materials in inertial fusion energy (IFE) power reactors will be irradiated under typical repetition rates of 1-10 Hz, for an operation time as long as the total reactor lifetime. The main objective of the present work is to determine whether a continuous-pulsed (CP) approach can be an efficient method in modeling the pulsed activation process for operating conditions of FSW materials. The accuracy and practicability of this method was investigated both analytically and (for reaction/decay chains of two and three nuclides) by computational simulation. It was found that CP modeling is an accurate and practical method for calculating the neutron-activation of FSW materials. Its use is recommended instead of the equivalent steady-state method or the exact pulsed modeling. Moreover, the applicability of this method to components of an IFE power plant subject to ...

Energy Technology Data Exchange (ETDEWEB)

The present invention concerns a device for peeling off activated concretes in processing for discarding a reactor of a nuclear reactor facility. The device comprises a gyrotron for generation microwaves, an irradiator for irradiating output microwaves, a reflection mirror for reflecting and converging the microwaves and irradiating them to a material to be irradiated and a first rotating means for rotating the irradiator and the reflection mirror in parallel with the axis of the gyrotron while maintaining the positional relation between the irradiator and the reflection mirror. When the position of the microwaves irradiated on concrete walls are moved in a circumferential direction and the central axes of the rotational axis and the material to be irradiated are aligned, then the intensity of the irradiation of the microwaves at each of the irradiation points can be maintained constant without changing the focal distance of the reflected ...

International Nuclear Information System (INIS)

Cylindrical test pieces of concrete are used for measurements of "2"2"2Rn exhalation rates. Except one flat end surface of a test piece, other parts of its exteriority are covered with sealant. Radon atoms can escape only through its end surface from the interior into the outside air. This treatment makes the radon transport in the concrete one dimensional phenomena. The piece is put in an airtight container. Time variations of radon concentrations in the air of the container are measured with a plane multiwire-electrode ionization chamber. From this result, the radon areal exhalation rate is deduced for the piece. Exhalation rates are measured for four pieces with different length. Then, the diffusion coefficient is obtained for radon in the concrete as (5.0 #+-# 1.0) x 10"-"8m"2s"-"1 (a one-block method). A two-block method has been invented to obtain simultaneously values of three parameters: diffusion coefficient, porosity of concrete, and ...

International Nuclear Information System (INIS)

In radiation processing of food, the product often has to be prepackaged to prevent microbial recontamination during and after irradiation. The packaging material is exposed to radiation during radiation processing and radiation stability is a key consideration in the selection of packaging materials. The effects of ionizing radiation on many food packaging materials at the dose levels recommended for food precessing can be minimized by selecting appropriate radiation resistant materials. It is important to select materials in which chemicals formed as a result of the radiation treatment do not migrate and interact with the food, affecting its organoleptic and toxicological aspects. It is also important to select materials in which the physical properties are not altered to the extent they cannot resist damage during commercial production, shipment and storage. ...

International Nuclear Information System (INIS)

Nuclear Forensics is a key element in the response process which is initiated after detection of illicit nuclear or other radioactive material. Credible nuclear forensics relies on appropriate sampling procedures, on validated analytical methods and on thorough data analysis and interpretation. Nuclear forensics aims at providing clues on the history and the potential origin of the material. Elemental and isotopic composition of the material, as well as its macroscopic and microscopic appearance reflect the technological processes used for the fabrication of the material. The nuclear forensic analysis first of all results in measurement data. Through appropriate processing of these data information on the nature and the history of the material can be obtained. A number of data evaluation techniques serving this purpose are conceivable and have been applied. On ...

International Nuclear Information System (INIS)

A comprehensive assessment on the eligibility of reduced activation (RA) steels as structural chamber material in Inertial Fusion Energy thick-liquid concepts is performed. As far as alloying elements, it is shown that the activation of tungsten is a question to discuss. Regarding impurity elements, it is analyzed if they could question the possibility of obtaining real RA steels for shallow land burial (SLB). The effect of the thickness of the liquid wall on the SLB response of alloying and impurity elements is computed. It seems that a reasonable liquid thickness of about 80 cm is allowable to obtain SLB acceptability of real RA steels. And above all, we have estimated the impact of cross section uncertainties when addressing the former questions, and we identify those to be improved. The necessary improvement of some tungsten and niobium cross sections is justified. (authors)

Energy Technology Data Exchange (ETDEWEB)

In situ X-Ray microtomography offers new opportunities for analysing sintering mechanisms since it allows 3D observation of the microstructural evolution of the powder all along a sintering cycle. With synchrotron radiation at ESRF, a 3D image with a resolution of 2 {mu}m can be obtained in about one minute. In addition to the visual examination of the images, relevant microstructural parameters can be measured through quantitative image analysis using recently developed tools. In this paper the results obtained with two materials, loose copper powder and compacted steel powder, are resumed. For copper powder, the dispersion of local parameters such as particle co-ordination number and porosity is investigated. Concerning steel compacts, data about pore morphology evolution and on local strains provides clues for understanding the anisotropic shrinkage of such compacts. (authors)

International Nuclear Information System (INIS)

Potassium clusters arrayed in zeolite A are known to show ferromagnetic properties at low temperature. The origin of the spontaneous magnetization has been explained by a model of spin-canting in an antiferromagnetically ordered state. The direct information for the magnetic structure, however, has not been obtained so far. In the present work, we measure the neutron powder diffraction by using pulsed neutron source at KEK-KENS below and above the Curie temperature. No significant temperature-dependence was, however, obtained within the statistical errors, namely, magnetic scattering could not be detected separately. We also estimate the intensity of magnetic scattering by assuming some possible magnetic structures with considering the magnetic form factor of the cluster wave function. The intensity of magnetic scattering is estimated to be extremely weak and higher S/N of ?104 or more is required to detect the magnetic scattering of this ...

Energy Technology Data Exchange (ETDEWEB)

Grooving CVD diamond films using a focused ion beam (FIB) to quarry micro parts is described. The substrate-side surface of a polycrystalline diamond film which is prepared by means of microwave plasma CVD, is able to be grooved by a focused Ga ion beam scanned straight repeatedly. The groove has cross section whose shape is like an inverted Gaussian distribution curve. And the surface roughness of the films before grooved influences that of grooves. Under the same irradiation conditions, deeper, narrower, in short, high aspect ratio grooves are obtained on B-doped semiconducting microwave plasma CVD diamond films. Coating electrical conductive material is also effective method to obtain high aspect ratio grooves. It is supposed that these results are due to the degree of electrification on the surface and that FIB irradiation is a suitable method for micromachining semiconducting diamond films.

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The authors obtain the critical load levels corresponding to the onset of spalling microdamage for Armco iron and steels St.3 and 12Kh18N10T in a broad temperature range (-196-800 degrees C. The results of the investigation of the effect of the temperature on spalling fracture are presented. The effect of the loading time on the strength of the investigated materials is also given. The authors assume that at -196 degrees C impact-wave strain-hardening may also be characterized by the value of H obtained for the center of the specimen since measurements on great thicknesses, including those reaching as far as the opposite surface, did not reveal any substantial change of microhardness.

Energy Technology Data Exchange (ETDEWEB)

Using a quasi-static approach valid for Stefan numbers less than one, we derive approximate equations governing the movement of a phase change front for materials which generate internal heat. These models are applied for both constant surface temperature and constant surface heat flux boundary conditions, in cylindrical, spherical, plane wall and semi-infinite geometries. Exact solutions with the constant surface temperature condition are obtained for the steady-state solidification thickness using the cylinder, sphere, and plane wall geometries which show that the thickness depends on the inverse square root of the internal heat generation. Under constant surface heat flux conditions, closed form equations can be obtained for the three geometries. In the case of the semi-infinite wall, we show that for constant temperature and constant heat flux out of the wall conditions, the solidification layer grows then remelts. ...

International Nuclear Information System (INIS)

Thienyl oxazoles and thienyl isoxazoles, are composite molecules having two subsystems thiophene and oxazole molecules connected together by a single bond that they have 13 isomers. They are potential candidates for many kinds of applications such as OLED and nonlinear optical materials. Initially equilibrium geometries of title compounds have been obtained without any restriction using density functional theory with 6-311++g(2d,p) basis set. We obtained structural parameters, dipole moment and electronic energy. At the second stage, we have calculated some electronic and nonlinear optical properties such as HOMO and LUMO energies, polarizability, anisotropic polarizability and hyper polarizability using same level of theory.

British Library Electronic Table of Contents (United Kingdom)

The deportation of trophoblast debris from the placenta was first documented over 100 years ago, and today we know that the deported material ranges from multinucleated syncytial knots/sprouts to trophoblast-derived nanoparticles. However little is known about the effect of trophoblast debris on maternal physiology since it is difficult to investigate these effects in vivo in women. Animal models have been reported but they have provided relatively little information. Most of our current knowledge regarding the effects of trophoblast debris on maternal systems is provided by studies using trophoblast debris obtained from in vitro models of the human placenta. Herein we review the animal models and the in vitro studies, which, between them, suggest that deported trophoblast material may pla...

Energy Technology Data Exchange (ETDEWEB)

Calcium sulfate dihydrate which is co-produced in the scrubbing of waste gases from bituminous coal power plants is employed in the underground road securing after recrystallization. Beta-sulfate semi hydrate is obtained from the dihydrate by recrystallisation and it is used as such or as a stiff mixture with additives as a stowing material. Particularly fly ash from coal combustion units, washery refuses and development rocks from coal mining or slags from the metallurgical industry can be used as additives. The compressive and the bending tensile strength of the stowing material can be adjusted by the water content in case beta sulfate semihydrate is used as such.

International Nuclear Information System (INIS)

A high-precision Li isotope analysis was developed for determining the Li"+ ion emitted from lithium phosphate as an ion source material by a Re double-filament ionization method in the thermal ionization mass spectrometry. In this method, Li isotopic fractionation is distinctly less sensitive to the filament temperature than those in the previous methods, and stable and high ion beam intensity of more than 8 x 10"-"1"1 A for "7Li is obtained. These advantages in determining the "7Li/"6Li ratio result in the analytical reproducibility of 0.26 per mille (1#sigma#). Furthermore, the sample preparation is simple and the low temperature (850degC) required by this method ensures the analysis of the isotopic composition of small amounts of Li with less influence of Li contamination to the sample, compared with the previous methods. (author).

International Nuclear Information System (INIS)

A set of 35 uranium ore and 10 yellow cake samples, collected worldwide from different mines and production sites, were analyzed for their impurity spectrum by ICP-MS. Pattern recognition techniques such as cluster analysis were applied to the data set in order to characterize samples with relation to their geographical origin. The results obtained show a clear relationship between samples taken from the same geological origin and constitute a satisfactory fingerprint for establishing the origin of the material. In addition to the impurity data, data on the isotopic composition of radiogenic lead is used to resolve ambiguity when impurity cluster analysis fails to deliver unambiguous origin data. (author)

Energy Technology Data Exchange (ETDEWEB)

The heat capacity and heat of fusion were measured for a number of minerals using differential scanning calorimetry (DSC). The DSC measurements showed that the heat of fusion for the minerals is very low compared to the heat of fusion for pure crystalline phases reported elsewhere. A model for the melting behaviour of mineral materials in terms of melting interval, heat capacities and heat of fusion has been developed. The only model input is the chemical composition of the mineral material. The model was developed to be implemented in a detailed model of a cupola furnace, thus the focus for the development was not only precision but also to obtain a model that was continuous and differentiable. The model is based on several different submodels that each covers a part of the heating and melting of rocks. Each submodel is based on large amounts of empirical data. Comparison of the model and the DSC measurements showed ...

British Library Electronic Table of Contents (United Kingdom)

Abstract Nanocomposites based on SnO2 with carbon scaffold were used as highly porous anode films on Ni substrates. The films were obtained by in situ deposition of the particles without any binder or excess carbon black avoiding any secondary treatment. Compared to similarly prepared uncoated SnO2 nanoparticles as well as conventionally prepared powder samples the capacity loss of the in situ deposited nanocomposite films is significantly reduced. Thus, this newly developed anode material combined with in situ film formation is a promising approach for high capacity anodes in Li-ion batteries. SEM-micrograph of a SnO2/C nanoparticle film.

Energy Technology Data Exchange (ETDEWEB)

Considering beryllium as plasma facing armour this paper presents recent results obtained in Russia. A special process of joining beryllium to a Cu-alloy material structure is described and recent results of thermal cycling tests of such joints are presented. Summarizing the results, the authors show that a Cu-alloy heat sink structure armoured with beryllium can survive high heat fluxes ({>=}10 MW/m{sup 2}) during 1000 heating/cooling cycles without serious damage to the armour material and its joint. The principal feasibility of thermal cycling of beryllium grades and their joints directly in the core of a nuclear reactor is demonstrated and the main results of this test are presented. The paper also describes the thermal cycling of different beryllium grades having cracks initiated by previously applied high heat loads simulating plasma disruptions. (orig.)

International Nuclear Information System (INIS)

Interest in making complex net-shape ceramic parts with good surface finishing and sharp tolerances without machining is a driving force for studying the injection molding technique. This method consists of softhening the ceramic material by means of adding some plastic and heating in order to inject the mixture under pressure into a relatively cold mold where solidification takes place. Essentially, it is the same process used in thermoplastic industry but, in the present case, the ceramic powder load ranges between 80 to 90 wt.%. This work shows results obtained from the fabrication of pieces of different ceramic materials (alumina, barium titanate ferrites, etc.) in a small scale, using equipments developed and constructed in the laboratory. (Author).

International Nuclear Information System (INIS)

The alloy type 'alloy 800' with its different variants is used for numerous components in high-temperature reactor (HTR) plants, e.g. for hot-gas conductors, the high-pressure part of steam generators, superheaters, steam collecting vessels and live steam conductors. This study deals with the evaluation of creep rupture tests on 28 welded joints of alloy 800 with an accumulated test duration of 410 years, with the objective to obtain quantitative information on a possible loss of strength in comparison with the unwelded material. The longest test period of an individual test amounted to 98,000 h and the analyzed test temperature range lay between 550"0 and 1000"0C. (orig./MM).

International Nuclear Information System (INIS)

Composite nitrides (such as BN, TiN) are widely used in various industrial applications because of their extreme wear and corrosion resistance, thermal and electrical properties. in order to obtain composite materials with these optimal properties, it is important to elucidate whether any chemical reactions occur at nitride/metal interfaces, e.g., those involving BN-Ti/TiN. Materials of interest include the deposition by PVD of Ti and TiN on BN substrates. Some of these systems were then subjected to varying degrees of physical and thermal alteration. Detailed X-ray photoelectron spectroscopy (XPS) has therefore been rendered of these interfaces using cross-sectional display and sputter etching. Resulting structural and morphological features have been investigated with transmission electron microscopy (TEM) and X-ray diffraction (XRD). Diffusion of the nitridation, oxynitride formation and interfacial growth are of general ...

British Library Electronic Table of Contents (United Kingdom)

Purpose - The purpose of this paper is to encourage other libraries to provide access to their own original content via the web. By way of case study, the process of identifying materials, scanning them and creating web access to original content will be explored. Design/methodology/approach - To implement a book digitization project, three major things need to be present. The library must own material that was published prior to 1923, making them safely out of copyright in the USA; the library needs access to server space on the web and the library needs to own scanning equipment. Findings - This project demonstrated that a library does not necessarily need to obtain grant funding to begin an effective and successful digitization program. It also revealed a few things that would improve t...

International Nuclear Information System (INIS)

General estimates and references are made in connection with the role of technological physics in obtaining materials with specific features. The first part of the paper presents the modification of weak wood essences as well as technological processes at bench-scale and semi industrial scale of wood-plastic composites, under various irradiation conditions. Two technological installations for the fabrication of wood-plastic composites on both scales with technical and practical specifications of their performances are presented. Experimental data for different wood-plastic composite systems using some local wood essences in combination with several polymer and copolymer systems are given. Impregnation and polymerization levels are mentioned for every specific system. The radiation dose rate and integrated dose are given for every experimental polymerization system. The features of the wood-plastic composites are compared with the initial wood ...

Energy Technology Data Exchange (ETDEWEB)

We have developed an ion probe technique for the in situ measurement of oxygen isotope ratios, {sup 18}O/{sup 16}O and {sup 17}O/{sup 16}O, with high spatial resolution in polished thin sections of silicate minerals. This technique allows the isotopic analysis of samples as small as picomoles of material which represents only 10{sup -7} of the sample size required by conventional fluorination oxygen isotope measurement methods and thus has wide application to the study of many terrestrial and extra-terrestrial samples that have heterogeneous oxygen isotope compositions on a scale of tens of micrometres. To illustrate the breadth of studies that are made possible by the ion probe, we report here oxygen isotope measurements from an authigenic quartz overgrowth obtained from the Penrith sandstone, UK, and measurements of magnetite grains from the Orgueil and Yamato 82162 carbonaceous chondrites which may be used to constrain possible formation ...

Energy Technology Data Exchange (ETDEWEB)

National Research Institute for Materials started in FY1966 a creep data sheet project aiming at obtaining the creep test data until 360Ms (about 11 years and half) in maximum, and has continuously been conducting the above on more than 40 kinds of heat resistant metallic materials for practical use for 30 years already as of January, 1996. The 360Ms creep rupture strength which has been aimed at by this project is the basic important strength property referred to at the time of determining design allowable stress of high temperature structural members. The Institute has published the accumulation of the test data of long range creeps lasting beyond 360Ms of the Institute as a creep data sheet, and in this article, the tremendous volume of this long range creep test data is analyzed and studied systematically, the new knowledge concerning the high temperature strength properties thereby obtained is ...

Energy Technology Data Exchange (ETDEWEB)

An analysis is given of a survey of the teaching of high energy physics in British universities. The subject changes quickly, and there is a continual conflict between new and old material. Different courses may deal with this in different ways. To find out what is actually being taught to students, details were obtained from all 50 university physics departments in the United Kingdom (UK) by means of a questionnaire. This covered the course structure - whether it was optional or compulsory or contained both elements - the number of lectures given, and the topics covered in the syllabus. The replies give a comprehensive picture of the state of undergraduate teaching of high energy physics in the UK. (Author).

Energy Technology Data Exchange (ETDEWEB)

The performance of a thermophotovoltaic (TPV) converter for solar energy is compared with that of direct solar energy conversion by silicon and germanium solar cells. The optical selectivity of an intermediate emitter is computed. Experimental results on selective emission, based on selectively emitting materials and on antireflection coatings on metals, are reported. For a TPV converter equipped with silicon solar cells, no selective emitter is found to yield better results than would be obtained by direct conversion. A TPV converter with germanium cells operating with a ThO/sub 2/-coated tungsten emitter, however, may achieve a conversion efficiency superior to that of direct solar energy conversion by either silicon or germanium solar cells.

International Nuclear Information System (INIS)

Criticality was first achieved with the Fast Flux Test Facility (FFTF) a little more than 10 yr ago on February 9, 1980. Although the FFTF was designed and built primarily for testing fuels, materials, and components for the liquid-metal fast breeder reactor program, it has, over its first 10 yr of operation, provided valuable information in many other areas. This paper provides a summary of the contributions to the physics of liquid-metal reactors (LMRs) obtained from operation of and testing in the FFTF, with emphasis on some of the more significant and interesting accomplishments.

International Nuclear Information System (INIS)

An advanced video system has been assembled from commercially available equipment to support the real-time neutron radiography facility established jointly by the University of Virginia Department of Nuclear Engineering and Engineering Physics, and the Philip Morris Research Center. A schematic diagram of the equipment used for real-time neutron radiography is presented. To obtain quantitative density measurements with this system, several modifications of both hardware and image processing software were required. After implementation of these changes, the system was capable of determining material densities by measuring the degree of neutron attenuation.

Energy Technology Data Exchange (ETDEWEB)

We present the synthesis, magnetic and UV spectrometry of NiZn-ferrite nanofiber. The single phase of spinel ferrite was obtained at 600 {sup o}C. The NiZn-ferrite fibers fabricated by an electrospinning process were formed as a polygonal grain growth with firing temperature in fiber matrix. It appeared that the saturation magnetization (M{sub S}) of NiZn-ferrite nanofiber was dependent on Ni/Zn molar ratio which is similar to that of the inverse spinel ferrites. The NiZn-ferrite fibers showed good DNA adsorption efficiency that can be modified and utilized for DNA separation with magnetic nanofiber as a novel material in clinical applications.

Energy Technology Data Exchange (ETDEWEB)

Bragg peaks obtained in X-ray stress analysis studies are often asymmetric. The use of K/sub ..beta../ rather than K/sub ..cap alpha../ radiation simplifies the problem of peak location, as only one Bragg peak needs to be analysed. It is shown, however, that the common practice of fitting a parabola to the top 15% of the data in a Bragg peak in order to determine the peak position, when the fitted region is asymmetric, can lead to large errors in the calculated stress. Asymmetric pseudo-Lorentzian functions have been found to provide the most satisfactory fits.

Science.gov (United States)

The possibility of using lead and lead-bismuth mixed oxides as positive active materials in organic electrolyte lithium cells with a working voltage similar to those of silver zinc cells has been considered. Button cells of SR 44 size have been developed as a test vehicle and studied under various conditions of discharge rate and storage. This paper describes the performance characteristics obtained under these conditions and suggests in conclusion the possible replacement of silver zinc cells by such systems for a large range of low-rate applications on the basis of cost effectiveness.

International Nuclear Information System (INIS)

The report is divided into three sections. The first section contains a general introduction to ion exchange resins used in various processes, the second section describes characteristic properties of the polymer materials and the inter relation between them. This will, in turn, be useful to interpret the data obtained from the various tests carried out on the resins in the laboratory. In the third section of the report, are given the details of each method used for a particular test to be carried out on a routine basis. Each method describes the principle involved, the reagents and apparatus used in the experiment, the actual procedure and calculations and recording of the data. 3 refs. (author).

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)

Bases of the algorithm for assessing the reinforcement status in reinforced concrete products by gamma-absorption method are presented. Analytical equations are obtained for estimation of error of the parameter characterizing the degree of reinforcement destruction. It is recommended to use high-energy Bremsstrahlung sources-betatrons of 4-10 MeV maximum energy for testing products of 500-600 mm thick. Linear radiation attenuation factor (LAF) of concrete in estimated equation is replaced by effective LAF of concrete, and LAF of reinforcement and corrosion materials - by differential LAF. Corresponding LAF of nonevident form in the algorithm is assessed by the results of processing of direct-shadow radiographs of defectometers

International Nuclear Information System (INIS)

The composite wave variational version of the APW (augmented plane wave) method is used to obtain the electronic band structure of the compounds boron phosphide and boron arsenide at the high symmetry points #GAMMA#, X, and L. The tight binding interpolation scheme of Slater and Koster is used to calculate the rest of the band structure. The results show that both these materials are indirect band gap semiconductors. The density of states, and the imaginary part of the dielectric constant is also calculated. The theoretical results are compared with the reported experimental and theoretical data. (author).

International Nuclear Information System (INIS)

Nonparabolicity of the heavy hole band in diamond-like semiconductors, which occurs within the framework of the three band model with the perturbation from the other bands taken into account according to the Loewdin procedure, is studied. A direct dependence of nonparabolicity on the band anisotropy (caused by the different effect of Gamma/sub 15c/ and Gamma/sub 12c/ bands) and the inverse dependence on the magnitude of the spin-orbit splittiing is established. A connection between the effective mass of heavy holes and their energy is obtained, which is valid for the majority of diamond-like semiconductors, except for materials with a very strong nonparabolicity of the band of silicon type.

Energy Technology Data Exchange (ETDEWEB)

Solar energy can be economically converted into electrical energy for small and medium power outputs. A typical solar power plant consists of a parabolic dish, cavity receiver and gas turbine. To obtain high gas turbine efficiencies, the working fluid used has to be heated to high temperatures. This necessitates the use of expensive high-quality materials for the tubes in the receiver. This expense must be kept to a minimum. The present paper demonstrates how this aim can be achieved by meeting the so-called Bammert Criterion.

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.

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 Nuclear Information System (INIS)

The identification, and hence origin determination, of unknown nuclear material that might be found undeclared away from designated locations in the nuclear fuel cycle, is an important task in the frame of nuclear forensics. Material with forensic importance can be found at the microscopic level as particles in environmental samples indicating possible clandestine production of fissile material, and as bulky samples in the case of illicit trafficking of nuclear material. The objective of this work is to present, at a theoretical level, an isotopic finger-printing methodology which would determine the origin of unknown nuclear material with forensic importance. This is demonstrated for the case when the unknown nuclear material is spent nuclear fuel. The methodology is based on multivariate statistics, such as cluster and factor analysis, complemented by spent ...

International Nuclear Information System (INIS)

To reduce the radiation dose that accumulated on the reactor coolant pump, decontamination work was carried out at the Maanshan Nuclear Power Plant. A four-step alkaline permanganate (AP)-CanDecon process was applied to remove the activity on the turning vane diffuser and pump impeller. The first step consisted of 8 h of AP treatment and 7 h of decontamination. It was followed by 2.5 h of AP treatment and 5 h of decontamination. An average decontamination factor of 2.9 was obtained. To understand the corrosion of the decontaminating reagents on the materials, coupons were installed in the decontamination tank. These were as-received and sensitized 304SS, alloy 600, casting stainless steel (CF-8), stellite-6, and carbon steels (A508 and A533). The exposure rates (mR h"-"1) of the carbon steels were approximately five times higher in magnitude than those of the other materials. The decontamination levels (dpm per 100 cm"2) of ...

International Nuclear Information System (INIS)

Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combination of sample preparation techniques and transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). Scanning electron microscopy (SEM) is well known for the determination of surface characteristics and morphology. However, the desire to understand the three dimensional relationships of meso-scale hierarchies has led to the development of advanced microscopy techniques, to give a further complementary approach. A focused ion beam (FIB) can be used as a nano-scalpel and hence allows us to reveal internal microstructure in a site-specific manner. Whilst FIB instruments have been used to study and verify the ...

International Nuclear Information System (INIS)

We obtained the ratios of "1"3"4Cs/"1"3"7Cs and "1"5"4Eu/"1"3"7Cs in spent PWR fuels with gamma scanning equipment of irradiated material examination facility. The fuel segments, of which the burn-up is about 40 GWD/MTU and its cooling time is 8.4 years, are prepared in Post Irradiated Examination Facility and transported to IMEF. By considering of multi-peaks of "1"3"4Cs and "1"5"4Eu, we obtained the relative efficiency of the gamma scanning system as a function of energy. And finally we obtained the number ratios of radioactive nuclides in 72 fuel pellets, radioactive "1"3"4Cs/"1"3"7Cs and "1"5"4Eu/"1"3"7Cs. (author). 4 refs., 27 tabs., 28 figs.

Energy Technology Data Exchange (ETDEWEB)

The paper studied a possibility of estimating characteristics of coal liquefaction residue from liquefaction conditions in the case of fixing coal kind in the NEDOL process coal liquefaction PSU. Wyoming coal was used for the study, and the already proposed simplified liquefaction reaction models were used. Among material balances explained by the models, those of asphaltene, preasphaltene, THF insoluble matters are concerned with residue composition. Ash content is separately calculated from ash balance. Reaction velocity constants of simplified liquefaction reaction models which influence the residue composition were obtained by the multiple regression method from experimental results in the past. The estimation expression of residue viscosity was introduced from residue ash/composition. When the residue composition is estimated by the model from liquefaction conditions, and the residue viscosity is obtained using it, the ...

Energy Technology Data Exchange (ETDEWEB)

A novel process was proposed to synthesize nano Sb-encapsulated pyrolytic polyacrylonitrile composite for anode material in lithium secondary batteries. The preparation started with the dissolution of SbCl{sub 3} and polyacrylonitrile (PAN) in dimethylformamide (DMF) solution, followed by the addition of KBH{sub 4} to reduce Sb{sup 3+} in the solution. The Sb composite was obtained by pyrolysis of the Sb/PAN mixture that precipitated out when the DMF solution was added by plentiful water. The TEM analysis showed that about 100-200 nm Sb particles were embedded by the pyrolyzed PAN, which provided a conductive matrix to relieve the morphological change of Sb during electrochemical cycling. As-prepared composite presented good cycleability for lithium storage. The proposed process paves an effective way to prepare high performance alloy based composite anode materials for high performance lithium-ion batteries. (author)

International Nuclear Information System (INIS)

ZrO_2/O'-sialon composites were obtained via reaction sintering of ZrSiO_4 and Si_3N_4 powders at about 1700 deg C. Y_2O_3 was effective in both stabilizing of zirconia and densifying the composites. However, it is not easy to select an optimum value of the single additive to balance these two requirements simultaneously. With low Y_2O_3 addition, some tetragonal zirconia grains in the sintered samples are transformable during mechanical grinding but the full densification of the material is then sacrificed. On the other hand, addition more Y_2O_3 to achieve complete densification results in the zirconia being stabilized into undesirable t' or cubic forms. Therefore no improved toughening effects have been achieved in the composites. Heat-treatment of the materials at 1400 deg C. results in the diffusion of yttria from the grain boundary phase to zirconia and the formation of the O'-cubic zirconia composite may still ...

International Nuclear Information System (INIS)

Heat losses in duct flow and heat transfer enhancement are investigated through an analysis of natural convection about a horizontal cylinder with a porous or fibrous coating. The porous substrate may be used for two purposes. According to its properties, it may be employed as an insulating material or as a means to surface augmentation. An optimization study is then carried out in order to find the best conditions that allow good thermal insulation or heat transfer rate improvement. The flow motion and heat transfer coefficient are predicted for various conditions. The results show that an efficient insulation which means less than 10% in heat losses is obtained for a porous layer thickness of 0.8x tube diameter and a permeability corresponding to Da #<=# 10"-"7. Nevertheless, there is a Darcy number limit above which convection must be accounted for. Porous or fibrous materials may also be used as a heat transfer ...

International Nuclear Information System (INIS)

Laser glazing, using a KrF excimer laser (> = 248 nm, >a = 22 ns), has been used to improve the corrosion resistance properties of crystallized Fe_4_0Ni_3_8Mo_4B_1_8 (Metglas 2826 MB) and the permanent magnet material Nd_1_5Fe_7_7B_8. The formation of an amorphous layer was confirmed by conversion-electron Mossbauer Spectroscopy (CEMS), and the thickness of the amorphous layer was determined from the attenuation of the x-rays diffracted from the underlying crystalline material. The variation with laser fluence of the amorphous layer thickness on the Metglas were measured. The corrosion properties of the original, crystalline and laser glazed Metglas were measured potentiodynamically in acid electrolyte. Similar voltametric characteristics were obtained for the laser glazed surface and original Metglas, both showing a lower current in the passive region than the crystalline material. Laser glazing ...

Energy Technology Data Exchange (ETDEWEB)

The characterization data obtained to date are described for Approved Testing Material (ATM)-106 spent fuel from Assembly BT03 of pressurized-water reactor Calvert Cliffs No. 1. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well- characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCWRM) program. ATM-106 consists of 20 full-length irradiated fuel rods with rod-average burnups of about 3700 GJ/kgM (43 MWd/kgM) and expected fission gas release of /approximately/10%. Characterization data include (1) as-fabricated fuel design, irradiation history, and subsequent storage and handling; (2) isotopic gamma scans; (3) fission gas analyses; (4) ceramography of the fuel and metallography of the cladding; (5) ...

Energy Technology Data Exchange (ETDEWEB)

The characterization data obtained to date are described for Approved Testing Material 104 (ATM-104), which is spent fuel from Assembly DO47 of the Calvert Cliffs Nuclear Power Plant (Unit 1), a pressurized-water reactor. This report is one in a series being prepared by the Materials Characterization Center at Pacific Northwest Laboratory (PNL) on spent fuel ATMs. The ATMs are receiving extensive examinations to provide a source of well-characterized spent fuel for testing in the US Department of Energy Office of Civilian Radioactive Waste Management (OCRWM) Program. ATM-104 consists of 128 full-length irradiated fuel rods with rod-average burnups of about 42 MWd/kgM and expected fission gas release of about 1%. A variety of analyses were performed to investigate cladding characteristics, radionuclide inventory, and redistribution of fission products. Characterization data include (1) fabricated fuel design, irradiation ...

Energy Technology Data Exchange (ETDEWEB)

Four types of cellulose, in particular carboxy methyl cellulose (CMC), are tested as potential binding materials in graphitic anodes for lithium ion batteries. It is shown that a minimum content of a cellulose which gives acceptable anode properties (reversible capacity > 300 mA hg{sup -1} during the first 10 cycles, irreversible loss < 20%) is about 2 wt.%, which is less than in the case of conventional polymeric binders (5-10 wt.%). Kinetics of insertion-deinsertion and passivation processes seem not to be affected by the presence of cellulose. Explanation for the electrode failure at cellulose contents lower than 1 wt.% is given based on X-ray diffraction and microscopy investigations. Finally, the structure (distribution) of cellulose in the composite anode material is discussed and (indirectly) checked with a series of experiments. Most results are compared with the corresponding results obtained either ...

Energy Technology Data Exchange (ETDEWEB)

A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10 ..mu..m in diameter and 250 ..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. Several attributes that make CBCF particularly suitable for the heat source application have been identified. These include light weight, low thermal conductivity, chemical compatibility, and high-temperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific ...

British Library Electronic Table of Contents (United Kingdom)

The light-emitting properties of cubic silicon carbide films grown by vacuum vapor phase epitaxy on Si(100) and Si(111) substrates under conditions of decreased growth temperatures (T gr ? 900?700?C) have been discussed. Structural investigations have revealed a nanocrystalline structure and, simultaneously, a homogeneity of the phase composition of the grown 3C-SiC films. Photoluminescence spectra of these structures under excitation of the electronic subsystem by a helium-cadmium laser (?excit = 325 nm) are characterized by a rather intense luminescence band with the maximum shifted toward the ultraviolet (?3 eV) region of the spectral range. It has been found that the integral curve of photoluminescence at low temperatures of measurements is split into a set of Lorentzian components. Th...

Energy Technology Data Exchange (ETDEWEB)

We report the simultaneous formation of self-assembled surface ripples in Cd{sub 2}Nb{sub 2}O{sub 7} pyrochlore caused by focused ion beam (FIB) patterning and uniformly distributed metallic nanodots induced by phase decomposition under ion bombardment. The characteristic wavelength of the surface ripples is controllable from the nm to the sub-{micro}m scale. High-density Cd metallic nanoparticles, {approx} 5 nm, formed and the distribution of nanoparticles is consistent with the morphological characteristics of the ripple pattern. This approach provides a means of fabricating surface nanostructure with various patterns and a controllable particle size and distribution by combining ion beam-induced phase decomposition with high-precision FIB patterning.

Energy Technology Data Exchange (ETDEWEB)

Thin films of sodium montmorillonite clay and cationic polyacrylamide were grown on a polyethylene terephthalate film using layer-by-layer assembly. After 30 clay-polymer layers are deposited, with a thickness of 571 nm, the resulting transparent film has an oxygen transmission rate (OTR) below the detection limit of commercial instrumentation (< 0.005 cc/m{sup 2}/day/atm). This low OTR, which is unprecedented for a clay-filled polymer composite, is believed to be due to a brick wall nanostructure comprised of completely exfoliated clay in polymeric mortar. With an optical transparency greater than 90% and potential for microwaveability, this thin composite is a good candidate for foil replacement in food packaging and may also be useful for flexible electronics packaging.

CERN Document Server

The controlled growth of nanowires (NWs) with dimensions comparable to the Fermi wavelengths of the charge carriers allows fundamental investigations of quantum confinement phenomena. Here, we present studies of proximity-induced superconductivity in undoped Ge/Si core/shell NW heterostructures contacted by superconducting leads. By using a top gate electrode to modulate the carrier density in the NW, the critical supercurrent can be tuned from zero to greater than 100 nA. Furthermore, discrete sub-bands form in the NW due to confinement in the radial direction, which results in stepwise increases in the critical current as a function of gate voltage. Transport measurements on these superconductor-NW-superconductor devices reveal high-order (n = 25) resonant multiple Andreev reflections, indicating that the NW channel is smooth and the charge transport is highly coherent. The ability to create and control coherent superconducting ordered states in semiconductor-superconductor hybrid ...

British Library Electronic Table of Contents (United Kingdom)

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

Science.gov (United States)

... Materials (PREM) Synopsis of Program: The objective of PREM is to enhance diversity in materials ... careers in materials research.The Partnerships for Research and Education in Materials (PREM ...

Science.gov (United States)

... Materials Research - Major Instrumentation Project (IMR-MIP) program in the Division of Materials ... for materials preparation and characterization essential for researchers studying materials in a ...

Science.gov (United States)

... Materials Development Program TECHNOLOGY EDUCATION INSTRUCTIONAL MATERIALS Elementary - High School ... of technology education materials through its Instructional Materials Development (IMD) program. The ...

International Nuclear Information System (INIS)

Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT images were ...

Energy Technology Data Exchange (ETDEWEB)

Out of the R and D of mesoscopic metal group composite materials, the paper described the fiscal 1997 results. In the in-situ method as a composite material making method, elucidated to some degree were chemical composition of Fe-C-Cr-V-Nb-Mo-W-Ni base multi-dimensional alloys, and wear resistance and oxidation resistance of MC type carbide dispersion multi-phase texture crystallizing as primary crystal and eutectic. In the composite material making with ceramic fiber and alloy by the pressure infiltration method, the paper clarified the texture formation mechanism in solidification/heat treatment by a combination of Al alloys and alumina long fiber, and the relation between fiber configuration and wear resistance. By MA and MG methods as the powder metallurgy composite material making method, a composed body of {alpha}-stainless steel of Fe-12%Cr composition and M23C6 of 40-90vol% are designed for ...

International Nuclear Information System (INIS)

Studies were made on different types of packaging materials used for packing dried fish in the Philippines with a view to finding a suitable packaging material for irradiated dried fish. Among these packaging materials (polyethylene, cello/polyethylene, polyester/polyethylene, Kraft paper, polypropylene and interwoven polypropylene sacks), polyester/polyethylene laminate was the most resistant material against penetration by Dermestes carnivorous. No insect damage occurred on the dried fish packed in interwoven polypropylene lined with polyester/polyethylene laminate. The cost per sack of such packaging material having a capacity of 50-80 kg is US$ 0.50. The sack lined with polyester/polyethylene proved to be durable for surface transportation from Bacolod City to Manila (approx. 360 miles). Radiation treatment at 225 krad was effective against bacterial contamination but not ...

Energy Technology Data Exchange (ETDEWEB)

Amorphous materials in the system xLi{sub 2}S{center_dot}(100-x)SiS{sub 2}, where x ranged from 50 to 70 mol %, and (100-y) (0.6Li{sub 2}S{center_dot}0.4SiS{sub 2}){center_dot}yLi{sub 4}SiO{sub 4}, where y ranged from 0 to 10 mol %, were synthesized by mechanical milling of crystalline starting materials, Li{sub 2}S, SiS{sub 2} and Li{sub 4}SiO{sub 4}. At the compositions with large amounts of Li{sup +} ions, a part of crystalline Li{sub 2}S used as a starting material remained in the milled powder samples. It was found that the milled powder samples in both systems obtained by mechanical milling exhibited high conductivities in the order of 10{sup -4}S{center_dot}cm{sup -1} at room temperature in spite of the presence of small amounts of Li{sub 2}S crystals. The conductivity values of the pelletized samples of xLi{sub 2}S{center_dot}(100-x)SiS{sub 2} powders maximized at the composition of about x=60. ...

Energy Technology Data Exchange (ETDEWEB)

The Materials & Fuel Complex (MFC) facilities 799 Sodium Processing Facility (a single building consisting of two areas: the Sodium Process Area (SPA) and the Carbonate Process Area (CPA), 799A Caustic Storage Area, and 770C Nuclear Calibration Laboratory have been declared excess to future Department of Energy mission requirements. Transfer of these facilities from Nuclear Energy to Environmental Management, and an associated schedule for doing so, have been agreed upon by the two offices. The prerequisites for this transfer to occur are the removal of nonexcess materials and chemical inventory, deinventory of the calibration source in MFC-770C, and the rerouting and/or isolation of utility and service systems. This report provides a description of the current physical condition and any hazards (material, chemical, nuclear or occupational) that may be associated with past operations of these facilities. This ...

Energy Technology Data Exchange (ETDEWEB)

The General-Purpose Heat Source (GPHS), an improved radioisotope heat source, employs a unique thermal insulation material, carbon-bonded carbon fiber (CBCF), to protect the fuel capsule and to help achieve the highest possible specific power. The CBCF insulation is made from chopped rayon fiber about 10 ..mu..m in diameter and 250 ..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF shapes, both tubes and plates, are formed in a multiple molding facility by vacuum molding a water slurry of the carbonized chopped-rayon fiber (54 wt %) and phenolic resin (46 wt %). The molded shapes are subsequently dried and cured. Final carbonization of the resin is at 1600/sup 0/C. Machining to close tolerances (+-0.08 mm) is accomplished by conventional tooling and fixturing. The resulting material is an excellent lightweight insulation with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W(m.K) in ...

International Nuclear Information System (INIS)

The projector augmented-wave (PAW) method was developed by Bloechl as a method to accurately and efficiently calculate the electronic structure of materials within the framework of density-functional theory. It contains the numerical advantages of pseudopotential calculations while retaining the physics of all-electron calculations, including the correct nodal behavior of the valence-electron wave functions and the ability to include upper core states in addition to valence states in the self-consistent iterations. It uses many of the same ideas developed by Vanderbilt in his open-quotes soft pseudopotentialclose quotes formalism and in earlier work by Bloechl in his open-quotes generalized separable potentials,close quotes and has been successfully demonstrated for several interesting materials. We have developed a version of the PAW formalism for general use in structural and dynamical studies of materials. In the present ...

Science.gov (United States)

It is well known that one of the main advantages of the high speed forming (HSF) processes is the improvement in the forming limits of the used materials.Using the Electromagnetic Forming (EMF) technology two materials have been tested with different mechanical and physical properties: the AA5754 aluminium and the AZ31B magnesium alloys.The EMF process principle can be described as follows: A significant amount of electrical energy is stored in a bank of capacitors which are suddenly discharged releasing all the stored energy. This electric discharge runs through a coil which generates an intense transient magnetic field. At the same time transient Eddy currents are induced in the electrically conductive part placed some millimetres far from the coil. Another intense magnetic field is generated due to those Eddy currents but on the opposite direction as the one generated by the coil. A big magnetic repulsion force is created between the part ...

Science.gov (United States)

PCR detection of genetic material of the parasites present in faeces may be an alternative for microscopic and serological tests routinely used for diagnosing parasitic enteral infections. However, small amount of target DNA combined with low efficiency of total DNA extraction, and presence of PCR inhibitors in the samples to be amplified, may cause false negative detection results. The aim of this work was to evaluate the impact of DNA isolation procedure used on the amplification of DNA fragments from the genomes of protozoan Cryptosporidium parvum and the nematode Trichinella spiralis. Two methods based on different principles of biological material lysis were evaluated; NucliSENS miniMAG employing simultaneously applied chemical lysis and mechanical disruption or mechanical disruption followed by enzymatic lysis in case of QIAamp DNA Stool Mini Kit. Both of the analyzed systems for nucleic acids purification allowed isolation of DNA from ...

International Nuclear Information System (INIS)

A number of ion exchange materials are being evaluated as part of the Tank Waste Remediation System (TWRS) Pacific Northwest Laboratory (PNL) Pretreatment Project for the removal of "1"3"7Cs from aqueous tank wastes. Two of these materials are organic resins; a phenol-formaldehyde resin (Duolite CS-100) produced by Rohm and Haas Co. (Philadelphia, Pennsylvania) and a resorcinol-formaldehyde (RF) resin produced by Boulder Scientific Co. (Mead, Colorado). One of the key parameters in the assessment of the organic based ion exchange materials is its useful lifetime in the radioactive and chemical environment that will be encountered during waste processing. The focus of the work presented in this report is the radiation stability of the CS-100 and the RF resins. The scope of the testing included one test with a sample of the CS-100 resin and testing of two batches of the RF resin (BSC-187 and BSC-210). Samples of the ...

Energy Technology Data Exchange (ETDEWEB)

The modification of polymers by radiation grafting has been utilized for several decades. The penetrability of gamma rays allows to modify the internal surfaces of porous materials retaining its mechanical properties. In recent years applications of these materials to obtain chromatographic supports and biocatalysts have been reported. In this work, we described the grafting of glycidyl methacrylate (GMA) onto a macroporous polysulfone polymer. Reproducible amount of grafting, from 10% to 60% was obtained by choosing favourable monomer concentration and gamma radiation doses from 6 kGy up. Afterwards, iminodiacetic acid (IDA) and amino phenyl arsine oxide (PAO) were covalently attached to the grafted polyGMA, in correspondence with the grafting degree. Later on, a recombinant histidin-patch thioredoxin protein (HP-rTrx) was immobilized onto this surface by two different ways, involving specific protein ...

International Nuclear Information System (INIS)

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

Science.gov (United States)

Materials World Network: Cooperative Activity in Materials Research between US Investigators and ... Program Title: Materials World Network: Cooperative Activity in Materials Research between US ...

Energy Technology Data Exchange (ETDEWEB)

Ammonia borane (AB) and sodium borohydride (SBH) are candidate materials for on-board hydrogen storage that can be dehydrogenated upon demand. The rheological properties of the dehydrogenated by-products are important to quantify their removal and transportability from the hydrogen storage system. This paper presents visco-elastic property (elastic stiffness and viscous damping) measurements of the spent fuels obtained from AB hydrolysis, hydrothermolysis and thermolysis; and SBH hydrolysis. Smaller stiffness and larger mobility (or smaller viscous damping) indicate better transportability of the spent fuel. In addition, flow property (dynamic angle of repose and avalanching time) measurements for the hydrolysis spent fuels of AB and SBH are also presented. Comparing with the SBH hydrolysis spent fuel, the AB hydrolysis spent fuel had a lower stiffness and larger mobility, as well as lower angles of dynamic repose and avalanche power peaks, ...

Energy Technology Data Exchange (ETDEWEB)

New rare earth oxide emitters show greater efficiency than previous emitters. As a result, based on a simple model the efficiency of these emitters was calculated. Results indicate that the emission band of the selective emitter must be at relatively low energy (less than or equal to .52 eV) to obtain maximum efficiency at moderate emitter temperatures (less than or equal to 1500 K). Thus low bandgap energy PV materials are required to obtain an efficient thermophotovoltaic (TPV) system. Of the 4 specific rare earths (Nd, Ho, Er, Yb) studied Ho has the largest efficiency at moderate temperatures (72 percent at 1500 K). A comparison was made between a selective emitter TPV system and a TPV system that uses a thermal emitter plus a band pass filter to make the thermal emitter behave like a selective emitter. Results of the comparison indicate that only for very optimistic filter and thermal emitter properties will the filter ...

International Nuclear Information System (INIS)

In this work we report a study of the induced changes in structure and corrosion behavior of martensitic stainless steels nitrided by plasma immersion ion implantation (PI"3) at different previous heat treatments. The samples were characterized by x-ray diffraction and glancing angle x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and potentiodynamic measurements. Depending on the proportion of retained austenite in the unimplanted material, different phase transformations are obtained at lower and intermediate temperatures of nitrogen implantation. At higher temperatures, the great mobility of the chromium yields CrN segregations like spots in random distribution, and the #alpha#"'-martensite is degraded to#alpha#-Fe (ferrite). The nitrided layer thickness follows a fairly linear relationship with the temperature and a parabolic law with the process time. The corrosion resistance depends strongly on ...

International Nuclear Information System (INIS)

Several configurations of moderating and shielding materials have been designed and measured on the LVR-15 reactor for boron neutron capture therapy (BNCT) purposes. To determine the neutron and gamma ray space-energy distributions in the cylindrical geometry, the two-dimensional code DOT with the coupled neutron-gamma data library DLC-36 was used. The experimental verification of the beam parameters was performed in the LVR-15 reactor thermal column empty space with layers of graphite, aluminium, alumina, lead and bismuth. Attention was paid to establishing techniques and instrumentation for monitoring the neutron and gamma ray dose and beam quality. The thermal and epithermal flux densities were measured by activation foils, the neutron spectrum was determined with a Bonner spectrometer and gamma ray background with a scintillation spectrometer. The distribution of thermal neutrons in the human head phantom was mapped with a small semiconductor detector (Si"6Li). ...

CERN Document Server

Non-evaporable thin film getters of various compositions have been produced by sputtering. Among about 20 materials which have been studied, the lowest activation temperature (about 180 degree C) has been displayed by a Ti-Zr-V coating obtained from a cathode made of intertwisted elemental wires. In order to optimize the vacuum properties of this film various production parameters, including the substrate temperature during coating, have been varied. The films have been characterized by pumping speed measurement, secondary electron microscopy, and X-ray diffraction. It has been found that the substrate coating temperature affects significantly the activation temperature, the pumping speed and the gas surface capacity. The highest pumping speed values, obtained for substrate coating temperatures of 250 degree C and 300 degree C, are clearly correlated with the increased surface roughness and porosity of the Ti-Zr-V film.

International Nuclear Information System (INIS)

The authors present tensile data and creep-rupture data out to approximately 40,000 h duration on low-carbon Alloy 800. Each of the four casts was heat treated to three conditions in tube form. When the test programme was originally conceived, the prime object was to obtain 100,000 hour design data; the programme was designed prior to some of the more recently discovered effects such as that of #gamma#' on ductility. Therefore no specific attempt was made to control to a low level, the Al and Ti contents of the casts. A subsequent programme was embarked upon in 1976 where these factors were taken into account. The bulk data obtained show many characteristics which are probably typical of the low-carbon variant of this material and both the quantity and duration of the data are a contribution to the knowledge of the long-term behaviour of this class of alloy, whose future use lies, inter alia, in nuclear applications over ...

Energy Technology Data Exchange (ETDEWEB)

This report describes the combustion experiments performed using the SP Industry Calorimeter. In addition to measuring parameters such as heat release rate (HRR), mass loss rate, effective heat of combustion and smoke obscuration, considerable effort was put into the characterisation of the smoke gases in order to obtain a basis for evaluations of the toxic potency of the smoke. The materials studied were Nylon 66, polypropene, polystyrene (with and without fire retardant, respectively), PVC and chlorobenzene. A total of 19 large-scale, well ventilated combustions were carried out. The mass of sample burned ranged from 20 kg to 125 kg in an experiment. A procedure was designed for cleaning the smoke gas duct between experiments and was found to be effective. Measurements were carried out for the amounts of O{sub 2}, CO{sub 2}, CO, NO{sub x}, THC (unburned hydrocarbons), HCN, HCl, NH{sub 3} and individual organic compounds in the smoke. ...

International Nuclear Information System (INIS)

Experimentally investigated nuclear reactions for production of no-carrier-added "7"7Br and "7"7Kr were critically surveyed. The survey covered nine reactions for the formation of "7"7Br and six reactions for "7"7Kr. Both radionuclides are simultaneously produced in many of the studied nuclear processes. The experimental data were compared with the results of nuclear model calculations based on the computer code ALICE-IPPE and the third version of TALYS-based Evaluated Nuclear Data Library, TENDL-2010. Good agreement was found over extended energy regions for the p-, "3He- and #alpha#-particle induced reactions on several target materials. In case of d-induced reactions, however, considerable discrepancies were noted between the experimental and theoretical data. The concordant sets of experimental cross section data for each reaction were fitted by a polynomial function to obtain a trend curve. From the thus obtained trend ...

Energy Technology Data Exchange (ETDEWEB)

The forest products industry is the third largest economic sector in Alberta, producing pulp and paper, dimensional lumber, paneling, and value added products, providing some 40,000 jobs . 'Value added' is a key component of expanding economic activity within the forest products sector. Wood residues can play a key role in obtaining more value from forest resources by providing new products, serving as feedstock to energy and chemical production, and playing a role in agriculture and land reclamation. One of the principal roles of the Forest Products Development Branch of the Alberta Economics Department is to encourage the development of the industry by creating new uses for these materials and developing awareness of the scope of the resource. Distances to markets, economic competition from conventional energy sources and coordination of research efforts are substantial barriers to further development that the Forest ...

Energy Technology Data Exchange (ETDEWEB)

The difficulty in making good Ohmic contact at the interfaces with p-doped ZnSe is an important problem hindering the realization of blue-light-emitting diode lasers based on the II-VI semiconductor technology. So far no metal or semiconductor material has been found to have a low enough barrier at the (001) interface with ZnSe. A possible solution to this problem is the insertion of a so-called {ital barrier-reduction layer} at the interface with ZnSe. We have investigated the interface formation energies and valence-band offsets at the (001) interface between Al{sub x}Ga{sub 0.5{minus}x}In{sub 0.5}P and ZnSe. The results of our calculations show the existence of a strong interdependence between the valence-band offset and the interface geometric structure. The interface is found to have structural and electronic similarities to the GaAs-ZnSe(001) system. The very low values obtained for the valence-band offset confirm the possibility of using ...

Science.gov (United States)

The extensive reserves of mined coal types, their great variety and the complexity of the composition and properties, as well as their important role as an energy fuel and industrial feedstock, cause one to give special attention to their classification. Of course, one of the principal fields of technological processing of coal is coking. In addition to the production of blast furnace coke, in the future specialized plants will be developed for production of coke and other carbonized materials for non-blast-furnace processes (electrothermal processes, production of calcium carbide, ferroalloys, zinc, yellow phosphorus, copper, etc.). One important area is new nonfuel uses, including a number of processes for processing of coal feedstocks to obtain a wide range of carbonaceous materials (coal-graphite products, carbon black, adsorbents, etc.), liquid fuels, and chemical products. In choosing a given area of coal utilization ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes recent measurements of the subcritical neutron multiplication factor using the /sup 252/Cf source-driven neutron noise analysis method. This work was supported by a program of collaboration between the United States Department of Energy and the Power Reactor and Nuclear Fuel Development Corporation of Japan related to the development of fast breeder technology. The experiment reported consists of a configuration of two interacting tanks of uranyl nitrate aqueous solution with different uranium concentrations in each tank. The /sup 252/Cf-source-driven neutron noise analysis method obtains the subcriticality from the signals of three detectors: the first, a parallel plate ionization chamber with /sup 252/Cf electroplated on one of its plates that is located in or near the system containing the fissile material, and produces an electrical pulse for every spontaneous fission that occurs and thereby serves as a timed source of ...

International Nuclear Information System (INIS)

The dependence of the photoluminescent properties of In_0_._4_8(Al_yGa_1_-_y)_0_._5_2P alloys (0#<=#y#<=#0.5) on growth temperature and substrate misorientation off GaAs(100) has been studied. Samples were grown using low-pressure metalorganic vapor phase epitaxy. By studying the dependence of ordering behavior in InGaP as a function of substrate misorientation and growth temperature simultaneously, a very large range in low-temperature photoluminescence emission energy---135 meV---has been obtained. The photoluminescence linewidth exhibits a strong, continuous dependence on the extent of atomic ordering (the emission energy) in the alloys. The results indicate that inhomogeneity in the microstructure of the material (i.e., between ''ordered'' domains and the ''disordered'' matrix) is the dominant photoluminescence broadening mechanism. This investigation has allowed a significant optimization of the optical properties of these ...

Energy Technology Data Exchange (ETDEWEB)

PVD-chromium-nitride coated samples of substrates of the magnesium alloy AZ91hp and the roller and ball bearing steel 100Cr6 were investigated regarding structure, mechanical characteristics, adhesion and internal stresses. For the coatings the parameters layer thickness and substrate BIAS voltage were varied. Both substrate materials were coated in one lad. Results of the X-ray analysis of the internal stresses show significant differences between the coated magnesium and the coated steel substrates. In the case of the variation of the substrate BIAS voltage, for the coated steel a dependency of the internal stresses to coating parameters could be obtained. For the coated magnesium no dependency was recognizable. The coating structure was examined with scanning electron microscopy. Element depth profiles of the coated samples were performed with SIMS. (orig.)

International Nuclear Information System (INIS)

The optoelectronic compounds of GaAs and ZnSe are difficult to analyze by PIXE (particle-induced X-ray emission) due to the strong absorption of the As and Se K_#alpha# X-rays. As part of a program to investigate optoelectronic materials using ion beam techniques, we have explored the possibility of using the high sensitivity of PIXE to check these materials for stoichiometry and dopant concentrations. The K_#alpha# X-ray intensity ratios of Ga to As and Zn to Se have been investigated using H beams of 0.5 to 2.5 MeV and He beams of 1.0 to 2.5 MeV. The variation in the X-ray intensity ratio with beam energy and target thickness is modelled in terms of the cross section for X-ray production and the absorption coefficients of the X-rays in the target. The results of this model show the experimental conditions that must be satisfied in order that the X-ray intensity ratios are not strongly affected by X-ray absorption; and therefore, the ...

International Nuclear Information System (INIS)