Energy Technology Data Exchange (ETDEWEB)

We discuss the possibility of extending solid state laser technology to high average power and of improving the efficiency of such lasers sufficiently to make them reasonable candidates for a number of demanding applications. A variety of new design concepts, materials, and techniques have emerged over the past decade that, collectively, suggest that the traditional technical limitations on power (a few hundred watts or less) and efficiency (less than 1%) can be removed. The core idea is configuring the laser medium in relatively thin, large-area plates, rather than using the traditional low-aspect-ratio rods or blocks. This presents a large surface area for cooling, and assures that deposited heat is relatively close to a cooled surface. It also minimizes the laser volume distorted by edge effects. The feasibility of such configurations is supported by recent developments in materials, fabrication processes, and optical ...

Energy Technology Data Exchange (ETDEWEB)

A procedure and software have been developed to transform the area distribution of the residual surface heights available from the measurement with the Micromap interferometric microscope into a two-dimensional (2D) power spectral density (PSD) distribution of the surface height. The procedure incorporates correction of one of the spectral distortions of the PSD measurement. The distortion appears as a shape difference between the tangential and sagittal PSD spectra deduced from the 2D PSD distribution for an isotropic surface. A detailed investigation of the origin of the anisotropy was performed, and a mathematical model was developed and used to correct the distortion. The correction employs a modulation transfer function (MTF) of the detector deduced analytically based on an experimentally confirmed assumption about the origin of the anisotropy due to the ...

Energy Technology Data Exchange (ETDEWEB)

Low power rf measurements, S11, of electro-discharge machined (EDM) diffusion bonded mm-wave traveling wave rf cavities were not in satisfactory agreement with electromagnetic simulations. During subsequent mechanical inspection, the cell-to-cell iris were found to be distorted. This led to a series of systematic experiments to study the mechanical properties of oxygen free high conductivity Copper (OFHC) and Glidcop AL-15. Results of these studies which include cell-to-cell iris distortion, EDM machining accuracies, surface quality, and the results of different bonding techniques are presented. The results of our mechanical studies are used to develop a set of mechanical design constraints for a second series of constant impedance W-Band structures that also used wire EDM and high temperature bonding for their manufacture.

Energy Technology Data Exchange (ETDEWEB)

There are two types in quench distortion of steel parts: thermal distortion and transformation distortion. Quench distortion is caused mainly by uneven cooling rate of steel parts from Austenitising temperature. The rapid cooled side is lengthened (convex deformation); the slow cooled side is shortened (concave deformation). So, to control the quench distortion, it is necessary to regulate the cooling rate of steel parts during quenching. TWO COMPONENTS produce the quench distortion of steel parts: the thermal stress and transformation stress. Generally, the effect of the thermal stress on the quench distortion is stronger than the transformation stress. The quench distortion is caused by uneven cooling rate of the steel parts, from Austenitising temperature to Ms point and Ms-Mf range. So, to control the quench ...

Energy Technology Data Exchange (ETDEWEB)

The major problem of measurement of a power spectral density (PSD) distribution of surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments, which tends to distort the PSD at higher spatial frequencies. The special mathematical properties of binary pseudo-random patterns make them an ideal basis for developing MTF calibration test surfaces. Two-dimensional binary pseudo-random arrays (BPRAs) have been fabricated and used for the MTF calibration of the MicroMap{trademark}-570 interferometric microscope with all available objectives. An investigation into the effects of fabrication imperfections on the quality of the MTF calibration and a procedure for accounting for such imperfections are presented.

UK PubMed Central (United Kingdom)

The interior of 237 nm spherical vinylsilsesquioxane nanoparticles has been covalently modified and their surface functionalized under mild conditions to yield a novel type of hybrid silsesquioxane...Full Text Available

International Nuclear Information System (INIS)

We describe a position-sensitive event-counting microchannel plate detector with a quadrant anode readout system that combines the advantages of several centroid-finding readout techniques. The relative amount of charge collected by each quadrant of the anode mounted behind the output side of the microchannel plate is used to localize each event. The position-sensitive area is about 80% of the active microchannel plate surface. By changing a single voltage a remote-controlled image magnification can be achieved. Due to a correction function that minimizes image distortions the imaging characteristics of this low-cost readout system are similar to those of expensive resistive anodes. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Epitaxial films grown pseudomorphically on substrates provide a way to stabilise non-equilibrium structures of materials. Obviously, there always is a certain lattice misfit between substrate and film material in its bulk equilibrium structure. In the pseudomorphic regime, this misfit can either lead to the growth of films in a strained bulk structure or even yield structures that are not stable in the bulk. Large misfits do not necessarily imply large lateral stress. Theory can help to predict e.g. geometry, stress and magnetic properties of pseusomorphically grown metal films. In this work, we considered the fcc-bcc epitaxial Bain path of 3d, 4d, and 5d transition metals, which provides a reasonable description of tetragonally distorted films on substrates. We carried out density functional calculations in the implementation of the full potential local orbital program package FPLO. Emphasis is put on similarities among the transition metals.

Energy Technology Data Exchange (ETDEWEB)

The major problem of measurement of a power spectral density (PSD) distribution of the surface heights with surface profilometers arises due to the unknown Modulation Transfer Function (MTF) of the instruments. The MTF tends to distort the PSD at higher spatial frequencies. It has been suggested [Proc. SPIE 7077-7, (2007), Opt. Eng. 47 (7), 073602-1-5 (2008)] that the instrumental MTF of a surface profiler can be precisely measured using standard test surfaces based on binary pseudo-random (BPR) patterns. In the cited work, a one dimensional (1D) realization of the suggested method based on use of BPR gratings has been demonstrated. Here, we present recent achievements made in fabricating and using two-dimensional (2D) BPR arrays that allow for a direct 2D calibration of the instrumental MTF. The 2D BPRAs were used as standard test surfaces for 2D MTF ...

International Nuclear Information System (INIS)

Most surface-acoustic-wave and thin-film optical devices are made by the planar fabrication process. The exposure of the pattern in the polymer film is the first and most crucial step in ensuring desired device geometry, dimensional control, and freedom from pattern distortion. The methods of exposing the polymer film include: optical projection, conventional contact printing, conformable photomask contact printing, holographic recording, scanning electron beam lithography, projection electron lithography, and x-ray lithography. In this paper scanning electron beam lithography, conformable photomask contact printing, holographic recording, and x-ray lithography are discussed. In the last section, ion beam etching of relief structures is discussed.

International Nuclear Information System (INIS)

Magnetic structures and magnetocrystalline anisotropy (MCA) of tetragonal phase Fe_3Pt with an L1_2 atomic ordering in bulk and thin film are investigated by means of the first-principles full-potential linearized augmented plane-wave method. The results obtained predict that the tetragonal phase, in which the tetragonal distortion with (c/a) = 0.95 makes an asymmetry of magnetic properties along the c-axis (out-of-plane) and a-axis (in-plane), has an out-of-plane MCA. In addition, from the thin film calculations, the presence of surface is found to strongly enhance the out-of-plane MCA.

Energy Technology Data Exchange (ETDEWEB)

The research supported by this Department of Energy contract has primarily been devoted to the study of the electronic properties of surfaces with sub-micron size. In previous years, we have studied the photoexcitation of electrons from field emission tips by a focussed Argon-ion laser beam tuned to operate at specific photon energy. The photoexcited electrons escape into the vacuum by tunneling through a surface potential barrier which is distorted by the application of a strong electric field. The interest in these experiments lies in a better understanding of the photoexcitation process at low photon energies. The techniques that have been developed directly measure the excited state energy distribution of electrons emitted through the surface potential barrier. The basic information gained from this research is relevant to opto-electronic devices which rely on photoexcitation of electrons in the ...

British Library Electronic Table of Contents (United Kingdom)

In the MnIII complex of the title compound, [MnIII(C18H12N4O2)(H2O)2]ClO4, the MnIII atom is coordinated by four N atoms from the bpb2- [1,2-bis(pyridine-2-carboxamido)benzene] ligand located in the equatorial plane and two O atoms of water molecules at axial positions, yielding a distorted MnN4O2 octahedral coordination geometry. The bpb2- ligand is nearly planar, with a maximum deviation of 0.2311 (3) A from the mean plane. The MnIII complex cation and the perchlorate anion, both of which are located on twofold rotation axes, are connected by O-H...O and C-H...O hydrogen bonds into a three-dimensional supramolecular network structure.

International Nuclear Information System (INIS)

We report the oxygen, hydrogen, and deuterium effects on nitrogen implantation of stainless steel. Oxygen is absorbed on the surface creating a potential barrier and diminishing the nitrogen retention. Deuterium removes more oxygen from the surface than hydrogen, augmenting the nitrogen chemical potential and yielding faster nitrogen diffusion into the bulk material.

International Nuclear Information System (INIS)

Isotopically selective IR multiphoton dissociation of molecules (SF_6, CF_3I) in a pulsed gas-dynamic flow interacting with a solid surface was studied for the first time. A noticeable (severalfold) increase in the yield of products (compared to excitation of molecules in an unperturbed flow) without a substantial decrease in the selectivity of the process was observed. Possible reasons for the effect are discussed. (laser applications and other topics in quantum electronics)

International Nuclear Information System (INIS)

The optical emission of excited H reflected from clean Cu(110) after impingement of H"+ and H_2"+ in the energy range of 250 eV to 20 keV per nucleon at 70"0 angle of incidence to the surface normal was measured. For incident 10 keV H_2"+, the highest excited hydrogen state detected was the n=10 level. The Hsub(#alpha#) yield was found to be fluence and energy dependent. This effect is attributed either to fast sputtered hydrogen, surface roughness or to an increase with hydrogen concentration in electron states of p-like symmetry near the Fermi level of copper. The Hsub(#alpha#) yield per reflected nucleon shows approximately an exponential dependence on both projectile energy per nucleon and scattered particle reciprocal velocity perpendicular to the surface. (orig.).

Energy Technology Data Exchange (ETDEWEB)

One aspect of the research program SFB 570 'Distortion engineering' is the in situ X-Ray diffraction analysis of phases and residual stresses during complete heat treatment cycles. These investigations result in experimental evidence available for the extensive computations. The optimisation of the instrumentation will be reported. A surface decarburisation of samples made from the ball bearing steel 100Cr6 could be avoided for a temperature range from 800 to 900 C and a holding time of one hour by a combination of evacuate the furnace and using a certain nitrogen flow as protective gas. At lower temperatures small amounts of ferrite caused by an increased diffusion rate of carbon lead again to a surface decarburisation up to a depth of 2 {mu}m. It was proved that with an evacuation of the X-Ray beam path at constant power of the X-Ray source the intensity of diffraction lines could be increased by more ...

Science.gov (United States)

An improved acousto-optic laser Q-switch uses a chirped fm pulse in the acousto-optic cell to diffract and focus the input beam into a resonating high-Q mode. When the rf acoustic pulse is not wholly within the cell, the beam is diverted to the output. A reflective surface is placed on the cell to yield only one output beam and to yield a retroflective beam back into the cavity for a high Q condition whenever a correctly generated chirp acoustic wave is in the proper postion within the cell.

Energy Technology Data Exchange (ETDEWEB)

The utilization of electrically heated rods for the simulation of nuclear fuel pins represents a generally adopted method by the nuclear industry to study thermalhydraulic problems. Usually its is necessary to determine the time variation of the electric linear power to simulate a given nuclear power transient in order to yield the same temperature and heat flux conditions in the surface of the electrical heater that would be observed in the nuclear fuel pin. The present work analyzes the limits of the usually adopted simulation methods and shows a manner to obtain the required electrical linear power that reduces oscillations and yields accurate results for the thermal conditions of the rod surface wall. (author). 5 refs, 5 figs, 1 tab.

International Nuclear Information System (INIS)

We show how the formulation of the matrix models as conformal field theories on a Riemann surfaces can be used to compute the genus expansion of the observables. Here we consider the simplest example of the Hermitian matrix model, where the classical solution is described by a hyperelliptic Riemann surface. To each branch point of the Riemann surface we associate an operator which represents a twist field dressed by the modes of the twisted boson. The partition function of the matrix model is computed as a correlation function of such dressed twist fields. The perturbative construction of the dressing operators yields a set of Feynman rules for the genus expansion, which involve vertices, propagators and tadpoles. The vertices are universal, the propagators and the tadpoles depend on the Riemann surface. As a demonstration we evaluate the genus-two free energy using the Feynman ...

Energy Technology Data Exchange (ETDEWEB)

A technique capable of measuring the electron energy fluence spectra in a scattering medium was designed. These measurements were performed by setting a bremsstrahlung conversion target on the surface of a phantom, at an intermediate depth, and at a depth equal to electron mean range. The bremsstrahlung produced by the deceleration of electrons in the target was passed through an air channel in the phantom and passed forward by a pinhole collimator into a Na(Tl) detector. The measured pulse height data were unfolded to correct for the distortion of the spectrometer system by using the FORIST unfolding code. The unfolded bremsstrahlung spectra represent the electron energy fluence spectra convolution with the bremsstrahlung produced in the target. To generate the electron energy fluence spectra, the unfolded bremsstrahlung spectra were deconvoluted by using the MAZE2 unfolding code. CYLTRAN, a coupled electron-photon Monte Carlo transport code, ...

Science.gov (United States)

Near-ideal Schottky barrier contacts to n-type Al0.22Ga0.78N have been developed by a two-step surface treatment technique. Plasma etching of the AlxGa1-xN surface prior to Schottky metal deposition, combined with sequential chemical treatment of the etched surface, holds promise for developing high quality low-leakage Schottky contacts for low noise applications and for recessed gate high electron mobility transistors. In this work, the effect of postetch chemical treatment of the n-type Al0.22Ga0.78N surface on the performance of the Ni/Au based Schottky contact has been investigated. Three different types of chemical treatment: viz, reactive ion etching, reactive ion etching plus dipping in hot aqua regia, and reactive ion etching plus dipping in hot KOH, are studied. Detailed current-voltage studies of three different surface treated diodes and a comparison with as-deposited ...

International Nuclear Information System (INIS)

The utilization of electrically heated rods for the simulation of nuclear fuel rods represents an universally adopted method by the nuclear industry to study thermalhydraulic problems. The present work represents the development of a method to obtain the time variation of the electric linear power necessary to simulate a given nuclear power transient in order to yield the same temperature and heat flux conditions in the surface of the electrical heater that would be obtained by the nuclear fuel rod. (Author).

Energy Technology Data Exchange (ETDEWEB)

Gas and plasma nitriding processes were executed in the magnesium with modification by titanium in search for an effective surface treatment method for magnesium alloys. Magnesium-nitrogen system has completely no solid solution or solubility, so that nitride should be only formed by eutectic reaction in the liquid phase. Hence, magnesium is difficult or nearly impossible to have its surface modified by nitriding. Addition of nitride forming element into magnesium enables us to lower the onset temperature of nitriding. Magnesium-titanium alloys with 1 to 5 wt% are yielded by the bulk mechanical alloying and, subjected to gas nitriding for various process conditions. Successful co-formation of Mg{sub 3}N{sub 2} as well as TiN becomes a proof to demonstrate the possibility of gas/plasma nitriding in the solid-state magnesium with aid of nitride former. (orig.)

British Library Electronic Table of Contents (United Kingdom)

In this paper we present the results of time series analysis for a coal mining region based on partial unmixing. We test the method also known as mixture tuned matched filtering on an eight image Landsat 5 TM and Landsat 7 ETM+ time series covering the period from 1987 to 2003. Common change detection methods often include the comparison of two interactively generated classification results, such as derived from Maximum Likelihood classification. These approaches often yield highly accurate results. However, disadvantages include a strong analyst bias and hardly repeatable results. For a quantitative monitoring of a single surface class' development over time they are often not recommendable. Our goal was to test an unbiased quantitative way to assess the development of coal surfaces, such...

Science.gov (United States)

Ever-present water vapor and dust distort or block incoming radiations. ... were among the first scientific sensors to be attached to the earliest space rockets. ...

Science.gov (United States)

... to changes in some of the system parameters by means of figures which show the two standard isotherme and two slightly distorted isotherms. ...

CERN Document Server

In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions for preventing this spurious electron load include reducing residual gas ionization by the beam, minimizing beam photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.

International Nuclear Information System (INIS)

One approach in the design of neutral oxotechnetium complexes is based on the simultaneous substitution of a tridentate dianionic ligand and a monodentate monoanionic coligand on a [Tc(V)O]"+"3 precursor. Following this ''mixed ligand'' concept, a novel "9"9"mTc complex with N,N-bis(2-mercaptoethyl)-N'N'-diethylethylenediamine as ligand and 1-octanethiol as coligand is prepared and evaluated as potential brain radiopharmaceutical. Preparation of the complex at tracer level was accomplished by using "9"9"mTc-glucoheptonate as precursor. The substitution was optimized and a coligand/ligand ratio of 5 was selected. Under this conditions the labeling yield was over 80% and a major product (with radiochemical purity > 80%) was isolated by HPLC methods and used for biological evaluation. Chemical characterization at carrier level was developed using the corresponding rhenium complex as structural model. The Re complex was also prepared by substitution method and ...

Energy Technology Data Exchange (ETDEWEB)

Decay processes of H{sub 2}{sup -} anions in {gamma}-rays-irradiated solid parahydrogen were studied by using ESR spectrometer. The following interesting results were obtained. First, the initial amount of ortho-H{sub 2}{sup -} anions in the {gamma}-irradiated solid parahydrogen was three times as large as those of para-H{sub 2}{sup -} anions. Second, the amount of para-H{sub 2}{sup -} anions decreases faster than that of ortho-H{sub 2}{sup -} anions upon storage of the irradiated samples at 4.2 K. Third, the decay rate of H{sub 2}{sup -} anions is accelerated by the addition of D{sub 2} molecules. Forth, H{sub 2}{sup -} anions at 2.2 K decay faster than at 4.2 K. According to the parity conservation rule in a homonuclear diatomic molecule, the energy of ortho-H{sub 2}{sup -} anions at the ground state is lower than that of para-H{sub 2}{sup -} anions, whereas that of ortho-H{sub 2} molecules is higher than that of para-H{sub 2} molecules at low temperatures. The first and second ...

International Nuclear Information System (INIS)

The Ti-6Al-4V alloy was treated by inductively coupled rf plasma nitriding. The effects of plasma-processing time in the range of 5-35 min on the microstructure and the mechanical properties of the plasma-nitrided Ti-6Al-4V samples were studied. The plasma power input was adjusted at 450 W and pure N_2 gas was introduced to establish a treatment pressure of 8.0-8.4 x 10"-"2 mbar. The characteristics of the nitrided layers have been investigated by microhardness testing, surface roughness measurements, optical microscopy, and x-ray diffraction. The results show that the surface microhardness increases as the plasma-processing time increases to reach 2000 HV0.1 at a plasma-processing time of 35 min. A high nitriding rate of 2.81 #mu#m"2 s"-"1 at a plasma-processing time of 25 min was achieved. The formation of the hard phases TiN, Ti_2N, and Ti(N) in the Ti-6Al-4V surfaces are found to be the reason for the increased ...

International Nuclear Information System (INIS)

FT-IR spectra of the products obtained in each step of the tetramethyltin (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 and TMT/Al_2O_3-SiO_2 system preparation are presented and discussed. The obtained spectra show that TMT reacts with alumina-silica hydroxyl groups already at room temperature, yielding surface methyltin compounds; NH_4ReO_4 reacts with alumina-silica surface at temperatures up to 423 K, yielding rhenium surface species and ammonia, which is strongly bonded by acidic sites of the Broensted kind. FT-IR spectrum of the system (TMT)/3-wt.% Re_2O_7/Al_2O_3-SiO_2 indicated the absence of surface methyl tin compounds observed on the surface system TMT/Al_2O_3-SiO_2 , and the presence of physically adsorbed TMT; after 5 h of evacuation of the TMT/3-wt.% Re_2O_7/Al_2O_3-SiO_2 system, the FT-IR spectrum indicated the presence of only a single ...

British Library Electronic Table of Contents (United Kingdom)

Excessive use of poultry litter (PL) on agricultural land is known to cause eutrophication of surface waters. Consequently, both poultry producers and PL users have to meet strict state and federal guidelines on litter storage and land application. This study examined the environmental benefits of adding lime, alum, ferrous sulfate, fly ash (FA), fluidized bed ash (FBA) and soil fix (SF) to PL for immobilizing excess phosphorus (P) while providing sufficient nutrients for proper growth of soybean [Glycine max (L.)] and corn [Zea mays (L.)] on a rotation. Amending PL with lime, alum, SF, FA and FBA significantly (p>0.05) increased corn and soybean yield. In contrast control plots that received a 10-10-10 (N-P2O5-K2) fertilizer showed lower yield and corn quality. Increased yield was ob...

Energy Technology Data Exchange (ETDEWEB)

FT-IR spectroscopic studies of the adsorption of natural and {sup 18}O-enriched NO gases on thermally and cleaned MgO powders were carried out. The temperature dependence of the IR spectra was investigated to characterize the adsorbate species. Three types [1, 2, and 3] of NO adsorptions were obtained in the wavenumber region of 1500--1000 cm{sup {minus}1}. Those types were examined using density functional theory [(U)B3-LYP/6-31G*] vibrational analyses of (MgO){sub n}-NO cluster calculations. Types 1, 2, and 3 were assigned to monodentate, asymmetric, and symmetric bidentate geometries, respectively. A type 4, a tridentate model which involves a NO{sub 3}-like species, was calculated and was found to give wavenumbers of less than 1,000 cm{sup {minus}1}. The splitting of IR bands of type 3 due to the {sup 15}N{sup 18}O adsorbate was ascribed to the oxygen exchange, {sup 15}N{sup 18}O {yields} {sup 15}N{sup 16}O, via the reaction {sup 16}O-{sup 15}N-{sup 18}O ...

Energy Technology Data Exchange (ETDEWEB)

Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments or the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

Energy Technology Data Exchange (ETDEWEB)

Two new surfactant molecules are reported which contain thermally labile Diels-Alder adducts connecting the polar and non-polar sections of each molecule. The two surfactants possess identical non-polar dodecyl tail segments but exhibit different polar headgroups. The surfactants become soluble in water when anionic salts are formed through the deprotonation of the surfactant headgroups by the addition of potassium hydroxide. When either surfactant is exposed to temperature above about 60.degree. C., the retro Diels-Alder reaction occurs, yielding hydrophilic and hydrophobic fragments and the aqueous solutions of the surfactants subsequently exhibit loss of all surface-active behavior.

Energy Technology Data Exchange (ETDEWEB)

The various factors that affect the open-circuit voltage ([ital V][sub oc]) of a two-terminal GaInP[sub 2]/GaAs tandem cell are examined. These include a) an anomalous problem associated with the GaAs bottom cell and b) back surface passivation of the thin GaInP[sub 2] top cell. Solutions to these problems are presented and yield tandem [ital V][sub oc]s close to the practical theoretical limits.

Energy Technology Data Exchange (ETDEWEB)

Data for the excitation of the 2/sub 1//sup +/ and 2/sub 2//sup +/ states in the /sup 88/Sr(p,p') reaction at 25 and 31 MeV indicate sustantial contributions from the interior of the nucleus, Microscopic DWBA calculations reproduce this and yield a fair description of the data. A detailed description, especially of the 2/sub 2//sup +/ state, is sensitive to the effective nucleon-nucleon interaction used and the non-locality of the optical potential, which are insufficiently known at present.

CERN Document Server

The interaction of accretion disks with the magnetospheres of young stars can produce X-winds and funnel flows. With the assumption of axial symmetry and steady state flow, the problem can be formulated in terms of quantities that are conserved along streamlines, such as the Bernoulli integral (BI), plus a partial differential equation (PDE), called the Grad-Shafranov equation (GSE), that governs the distribution of streamlines in the meridional plane. The GSE plus BI yields a PDE of mixed type, elliptic before critical surfaces where the flow speed equals certain characteristic wave speeds are crossed and hyperbolic afterward. The computational difficulties are exacerbated by the locations of the critical surfaces not being known in advance. To overcome these obstacles, we consider a variational principle by which the GSE can be attacked by extremizing an action integral, with all other conserved quantities of the problem ...

British Library Electronic Table of Contents (United Kingdom)

A non-similar boundary layer analysis is presented to study the flow, heat and mass transfer characteristics of non-Darcian mixed convection of a non-Newtonian fluid from a vertical isothermal plate embedded in a homogeneous porous medium with the effect of Soret and Dufour and in the presence of either surface injection or suction. The value of the mixed-convection parameter lies between 0 and 1. In addition, the power-law model is used for non-Newtonian fluids with exponent n1 for dilatant fluids. Furthermore, the coordinates and dependent variables are transformed to yield computationally efficient numerical solutions that are valid over the entire range of mixed convection, from the pure forced-convection limit to the pure free-conve...

Energy Technology Data Exchange (ETDEWEB)

The manual provides design information for four groups of sediment control structures and treatments which are suitable for use on small areas in surface coal mining. A detailed design procedure is given for each group which will estimate the total amount of settleable solids from a small area with a sediment control structure or treatment for a specific design storm. A procedure is also given for estimating the mean annual sediment yield from a small area. Information on design, installation, maintenance and cost is given for each sediment control measure. Methods for determining the maximum allowable area for each sediment control measure and for design of combined sediment control systems are presented. The design procedures contain numerous nomographs, graphs, and worksheets to facilitate the use of the design procedure. The sediment control measures, design procedures, and materials in the manual are applicable to coal-bearing regions of ...

Science.gov (United States)

A general model for the analysis of metal-semiconductor solar cells is presented. The model takes into account the cell optical properties, carrier recombination effects, semiconductor minority-carrier properties, series resistance, cell thickness, and active surface area. Numerical methods are used to solve the appropriate continuity equations and hence compute the photocurrent density under AMO conditions. The operation of the model is demonstrated using p- and n-type Si and GaAs with Au being taken as the barrier metal. Calculations are presented showing the effect on solar energy conversion efficiency of surface recombination velocity, barrier height, minority-carrier lifetime, barrier metal thickness, collecting grid configuration, and cell thickness. A comparison of practical and computed data for the Au/n-GaAs system yields good agreement. (AIP)

Energy Technology Data Exchange (ETDEWEB)

The aim of this work was to develop a method to distinguish between different ion formation processes and to determine the influence of these processes on the total number of detected monatomic ions of a certain element. A vector/matrix-formalism was developed, which describes the physical processes of sputtering, ion formation, mass separation and detection in laser-SNMS. In the framework of the method developed, based on this theoretic formalism, changes in the secondary flux contribution of the respective element were observed by comparing the detected monatomic ion yield obtained in specifically aligned (SIMS and) laser-SNMS experiments. The yields resulting from these experiments were used to calculate characteristic numbers to compare the flux composition from different surfaces. The potential of the method was demonstrated for the elements boron, iron and gadolinium by investigating the changes in the flux ...

Energy Technology Data Exchange (ETDEWEB)

Gas quenching for the hardening of steel parts is a lower-pollution alternative to quenching in quenchants such as oil or salt. As the surfaces of the cooled parts remain clean after gas quenching, there is no need to wash them after heat treatment, which reduces the consumption of oils and detergents. The fire risk and ventilation requirements of oil quenching are eliminated. In addition, some trials have shown that gas quenching has a positive effect on distortion, representing a saving in finishing work and thus a reduction in costs. Today, gas quenching is used almost solely in vacuum furnaces. Quenching is normally performed in the same chamber as heating, which means that besides quenching the batch, the quenching system must also remove heat from the heating elements and insulation of the furnace. Previous trials performed by IVF have shown that gas quenching with helium of ball bearing and carburizing steels (and other steels) in sizes ...

Energy Technology Data Exchange (ETDEWEB)

This thesis details the first direct ultrafast measurements of the dynamic thermal expansion of a surface and the temperature dependent surface thermal diffusivity using a two-color reflection transient grating technique. Studies were performed on p-type, n-type, and undoped GaAs(100) samples over a wide range of temperatures. By utilizing a 90 fs ultraviolet probe with visible excitation beams, the effects of interband saturation and carrier dynamics become negligible; thus lattice expansion due to heating and subsequent contraction caused by cooling provided the dominant influence on the probe. At room temperature a rise due to thermal expansion was observed, corresponding to a maximum net displacement of {approximately} 1 {Angstrom} at 32 ps. The diffracted signal was composed of two components, thermal expansion of the surface and heat flow away from the surface, thus allowing a determination of the ...

Energy Technology Data Exchange (ETDEWEB)

Coal was treated at high temperature under high pressure in the binary system mixed solvent of water and organic solvent, and the solvent treated coal was liquefied. When the treated coal was treated again by the explosive method in which high temperature and pressure were released immediately, the oil yield was higher than that by the normal method in which high temperature and pressure were reduced gradually to room temperature and atmospheric pressure. In this study, an explosive treatment unit with increased scale of sample amount was newly fabricated. Illinois No.6 coal was treated by the explosive method in a mixed solvent of water and cyclohexanol using this unit. Changes in shape on the surface, specific surface area, and functional groups were analyzed. The explosively treated coal contained more amount of low boiling point components than the normally treated coal. It was suggested that the oil ...

Energy Technology Data Exchange (ETDEWEB)

The optical absorption spectra of the rhombohedral DyOF were measured at selected temperatures between 9 and 300 K. The emission spectra of the Dy{sup 3+} ion in the LaOF and GdOF matrices were obtained at 77 K and room temperature. The energy level scheme of Dy{sup 3+} (4f{sup 9} electron configuration) was simulated with a Hamiltonian of 20 parameters. The diagonalization of the energy matrices including simultaneously the free ion and crystal field (c.f.) interactions was carried out for the C{sub 3{upsilon}} point symmetry of the RE{sup 3+} site. Good correlation with an rms deviation of 17 cm{sup -1} was obtained between the experimental and calculated energy level schemes of 153 Kramers doublets. The c.f. parameters show only slight distortion from O{sub h} symmetry. A comparison to Pr{sup 3+} (4f{sup 2}), Nd{sup 3+} (4f{sup 3}), Sm{sup 3+} (4f{sup 5}), Eu{sup 3+} (4f{sup 6}), and Tb{sup 3+} (4f{sup 8} electron configuration) in other REOF matrices showed ...

International Nuclear Information System (INIS)

Recently developed oxygen O18 method [K. Franzreb, J. Lorincik, P. Williams, Surf. Sci. 573 (2004) 291; R.C. Sobers, K. Franzreb, P. Williams, Appl. Surf. Sci. 231-232 (2004) 729; P. Williams, R.C. Sobers Jr., K. Franzreb, J. Lorincik, Appl. Surf. Sci. 252 (2006) 6429] is able to quantitatively determine the flux ratio of oxygen to matrix species at dynamical SIMS sputtering. This flux ratio can be directly related to the surface oxygen concentration at dynamical sputtering - an important parameter controlling the ionization yield of emitted species. It is argued that the oxygen O18 method is a worthy step forward in gathering relevant experimental data that might eventually lead to the understanding of oxygen enhancement mechanism in SIMS. A current status of understanding of the ionization processes in SIMS is briefly discussed in terms of non-adiabatic strongly velocity dependent processes represented by the electron tunneling and ...

Energy Technology Data Exchange (ETDEWEB)

The laser grooved buried grid (LGBG) cell was developed at the University of New South Wales, Australia. The enormous advantage of the Saturn technology is the simple formation of a selective emitter via two step diffusion, which is optimised on the surface for the charge carrier generation and under the metal grid for contact formation. The reflection losses due to shading are simultaneously minimised by the installation of the contacts at right angles in the wafer surface. Due to the increased infeed compensation, particularly the compensation covering the costs, the economic importance of the energy yield of a PV plant is growing. Ultimately, it is not just the installed output (KWp) that matters to the customer, but increasingly the specific yield (kWh/kWp). An increased energy yield with optimally matched components with the Saturn technology means high annual compensation, ...

Science.gov (United States)

This paper proposes an optimization algorithm to reduce the distortion produced in the loop-filter of Continuous-Time Sigma-Delta Modulators. The aim of the algorithm is to find the loop-filter implementation that minimizes distortion at the output of the modulator, by modifying the output swing of every integrator. The algorithm is implemented in Matlab as an evolutive searching. During each step of the searching, the algorithm evaluates the harmonical distortion of a tone when it is applied to the modulator with a certain loop-filter implementation. The output of the algorithm is an optimum linear state-space representation of the loop-filter. This particular state-space representation leads to minimum distortion at the output of the modulator when the loop-filter is implemented with some specific circuitry previously defined. As long as the search is of evolutive type, the solution represents a local ...

Energy Technology Data Exchange (ETDEWEB)

Groom-Bailey decomposition analysis was carried out to investigate regional 3-D galvanic distortion on MT data in the central part of Northeastern Japan. Measuring sites were located nearly along the east-west line crossing Northeastern Japan. Three measuring lines (A, B, C) from the north to the south were prepared, and only data on the C line were analyzed in this paper. As a result, twist and shear were estimated to be not zero depending on local distortion in most of the sites. It was thus clarified that this method is not always perfect. This method was effective for regional 2-D structures, however, its application was doubtful to complicated 3-D underground structures in Japan. In order to obtain more accurate results, 2-D analysis using the impedance including no local distortion effect was necessary after the preliminary Groom-Bailey decomposition analysis. The direction of the wide area geological structure of ...

UK PubMed Central (United Kingdom)

The 3-D spectral-domain optical coherence tomography (SD-OCT) images of the retina often do not reflect the true shape of the retina and are distorted differently along the x and y...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Mesoporous V2O5/Nafion composite films have been used for the immobilization of tris(2,2prime-bipyridyl)ruthenium (II) (Ru(bpy)$\\rm{ {_{3}^{2+}}}$) on an electrode surface to yield a solid-state electrogenerated chemiluminescence (ECL) sensor. The electrochemical and ECL behavior of Ru(bpy)$\\rm{ {_{3}^{2+}}}$ ion-exchanged into the composite films has been characterized as a function of the amount of Nafion incorporated into the V2O5/Nafion composite. The composite film with 80% Nafion content has the largest pore diameter (4.19 nm) and yields the maximum ECL response for tripropylamine (TPA) because of the fast diffusion of analyte into the film with large pores. Due to the enlarged pore size and enhanced conductivity of the V2O5/Nafion composite, the present ECL sensor based on the compo...

International Nuclear Information System (INIS)

In this paper, results on ozone production by atmospheric pulsed discharge, are reported. In the research, two types of ozonizer (Type I and Type II) have been used to investigate improvements of ozone concentration and production efficiency. The ozonizer has plane-to-plane metal electrodes structure, and pre-ionization electrodes are placed on the high voltage electrodes (Type I). In Type II, the surface of grounded electrode with 20 mm of width is covered partly by dielectric (thin rubber) with 11 mm of width, while the geometry of both metal electrodes is same to Type I. In the case of Type I, maximum concentration of about 100 ppm and maximum yield of 70 g/kWh were obtained at input power of 0.3 W. On the other hands, in the case of Type II, 800 ppm and 100 g/kWh were obtained at input power of 1.5 W. It was found that the ozone concentration and production yield were improved by using electrode covered by dielectric. ...

Energy Technology Data Exchange (ETDEWEB)

Three-dimensional magnetohydrodynamic simulations are executed in a full toroidal geometry to clarify the physical mechanisms of the Internal Reconnection Event (IRE), which is observed in the spherical tokamak experiments. The simulation results reproduce several main properties of IRE. Comparison between the numerical results and experimental observation indicates fairly good agreements regarding nonlinear behavior, such as appearance of localized helical distortion, appearance of characteristic conical shape in the pressure profile during thermal quench, and subsequent appearance of the m=2/n=1 type helical distortion of the torus. (author)

International Nuclear Information System (INIS)

Analysis of steady-state and transient photoconductivity measurements at room temperature performed on c-axis oriented GaN nanowires yielded estimates of free carrier concentration, drift mobility, surface band bending, and surface capture coefficient for electrons. Samples grown (unintentionally n-type) by nitrogen-plasma-assisted molecular beam epitaxy primarily from two separate growth runs were examined. The results revealed carrier concentration in the range of (3-6)x10"1"6 cm"-"3 for one growth run, roughly 5x10"1"4-1x10"1"5 cm"-"3 for the second, and drift mobility in the range of 500-700 cm"2/(V s) for both. Nanowires were dispersed onto insulating substrates and contacted forming single-wire, two-terminal structures with typical electrode gaps of #approx =#3-5 #mu#m. When biased at 1 V bias and illuminated at 360 nm (3.6 mW/cm"2) the thinner (#approx =#100 nm diameter) nanowires with the higher background doping ...

Science.gov (United States)

Information about surface soil moisture conditions is of critical importance to real-world applications such as agricultural production, water resource management, flood prediction, fire prediction, water supply, military mobility, etc.. Near-surface soil moisture is currently available from non-ideal sensor configuration observations, and two missions targeted at measuring near-surface soil moisture with ideal sensor configuration are expected before the end of the decade (the European Space Agency (ESA), Soil Moisture and Ocean Salinity (SMOS) mission, and the National Aeronautics and Space Administration (NASA), Hydrospheric states "Hydros" mission). Though remote sensing can make spatially comprehensive measurements of surface soil moisture, it cannot provide information on the entire land surface hydrologic system, and the measurements represent only a snap shot in time. ...

British Library Electronic Table of Contents (United Kingdom)

Mesoporous films of platinized carbon nanotube-zirconia-Nafion composite have been used for the immobilization of tris(2,2prime-bipyridyl)ruthenium (II) (Ru(bpy)32+) on an electrode surface to yield a solid-state electrogenerated chemiluminescence (ECL) sensor. The composite films of Pt-CNT-zirconia-Nafion exhibit much larger pore diameter (3.55 nm) than that of Nafion (2.82 nm) and thus leading to much larger ECL response for tripropylamine (TPA) because of the fast diffusion of the analyte within the films. Due to the conducting and electrocatalytic features of CNTs and Pt nanoparticles, their incorporation into the zirconia-Nafion composite films resulted in the decreased electron transfer resistance within the films. The present ECL sensor based on the Pt-CNT-zirconia-Nafion gave a lin...

British Library Electronic Table of Contents (United Kingdom)

A distributed watershed hydrologic model soil and water assessment tool (SWAT, 2000 Version) was applied to simulate stream flow and nutrient loadings (including total nitrogen (TN) and total phosphorus (TP)) in Gucheng Lake Basin, which is located in the lower reach of Yangtze River Basin. Model parameters related to stream flow and nutrient loadings were calibrated and validated by the observed value, and the simulation showed that the simulated values were reasonably comparable to the observed data, suggesting the validity of SWAT model. The simulated surface runoff and nutrient yield between two stages, viz. 1981-2000 and 1951-1960, were compared, basically considering land reclamation in the mid-1970s. The result indicated that, the average annual runoff and output of TN and TP in 198...

International Nuclear Information System (INIS)

Ion desorption from a condensed gas solid Ne impacted by singly- and multiply-charged Ar"q"+ ions (q = 1-7) has been investigated. Various secondary ions such as cluster ions, Ne"+_n (n = 2-20) as well as atomic ions are observed. Mass spectral patterns, thickness dependence of the yields, and kinetic energy distributions of the desorbed Ne"+_n (n = 1,2) depend strongly on the projectile charge state. These results indicate that the dissipation of the projectile potential energy on the surface leads to the desorption of the monomer and small cluster ions by a Coulomb repulsion between adjacent target ions.

Energy Technology Data Exchange (ETDEWEB)

Modeling is performed for focused-ion-beam (FIB) sputtering and redeposition on trench sidewalls in a steady state approximation. Calculations are carried out to demonstrate the sputtered surface profile under known parameters such as sputtering yield as a function of ion incident angle, the FIB current density profile, and the FIB scan speed. It is found that a steplike slope with a gradient angle of {theta}{sub 0} is formed at the FIB bombarding position. Furthermore, the redeposition flux on the sidewalls is calculated as a function of {theta}{sub 0} for the FIB trench milling assuming the cosine law for the angular distribution of the sputtered atom. The redeposition will be more accurately predictable and controllable when more information about these assumptions is obtained.

Energy Technology Data Exchange (ETDEWEB)

The evolution of strain in the Pd-Si system during the growth of Pd{sub 2}Si thin films on Si (100) substrate has been followed in situ using a double optical beam technique. As was observed for the Pt-Si system, the reaction to form Pd{sub 2}Si yields a compressive intrinsic surface film stress as well as for the silicon-rich suicides as proposed by Angilello et al. [Thin Film Interfaces and Interactions, edited by J. Baglin and J. Poate (The Electrochemical Society, Pennington, NJ, 1980)]. A transmission electron microscopy analysis has revealed grain growth during the formation of Pd{sub 2}Si which cannot account for the compressive film stresses. The formation of silicide at the interfaces rather than the overall change in volume agrees with the sign of the stresses formed. 29 refs., 4 figs., 3 tabs.

CERN Document Server

We review a new theoretical approach to the kinetics of surfactant adsorption at fluid-fluid interfaces. It yields a more complete description of the kinetics both in the aqueous solution and at the interface, deriving all equations from a free-energy functional. It also provides a general method to calculate dynamic surface tensions. For non-ionic surfactants the results coincide with previous models. Common non-ionic surfactants are shown to undergo diffusion-limited adsorption, in agreement with experiments. Strong electrostatic interactions in salt-free ionic surfactant solutions are found to lead to kinetically limited adsorption. In this case the theory accounts for unusual experimental results which could not be understood using previous approaches. Added salt screens the electrostatic interactions and makes the ionic surfactant adsorption similar to the non-ionic case. The departure from the non-ionic behavior as the salt concentration ...

Energy Technology Data Exchange (ETDEWEB)

Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2 x the target value. Pre-oxidized and nitrided surface structure examination revealed ...

British Library Electronic Table of Contents (United Kingdom)

We present a forward modelling technique for calculating the surface X-ray spectra for a variety of lunar terrains. Our calculations considered variations in solar fluxes from solar quiescent condition to large flare activity (M1 flare), and expected elemental concentrations in the target, as well as yield, instrumental, and viewing geometry parameters for X-ray induced fluorescence from the lunar surface. Additionally, we present estimates of anticipated XRF signals from prominent Ka lines observable by a collimated 14cm2 X-ray detector from a 100km lunar orbit with 20km spatial resolution. Our results show that Mg, Al and Si characteristic Ka lines can be observed for all solar conditions. The Ca Ka lines line can be differentiated from a fixed background during more energetic solar cond...

British Library Electronic Table of Contents (United Kingdom)

Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr2N, CrN, TiN, V2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited...

Energy Technology Data Exchange (ETDEWEB)

The tensile and compressive properties as well as LCF and HCF performance of the extruded magnesium alloys AZ31 and AZ80 were determined in extrusion (L) and long-transverse (T) directions. Owing to marked crystallographic textures, both alloys showed pronounced directional mechanical properties in monotonic as well as cyclic loading with strength values in L-direction being significantly superior to those in T-direction. Thermomechanical treatments such as pressing, swaging and rolling were found to increase yield stresses and HCF strengths and to alter the directionality in properties due to textural modifications. To further improve HCF strengths, mechanical surface treatments such as shot peening, roller-burnishing and deep rolling were utilized. The results indicate marked improvements provided that suitable process parameters are used. The improvement of the HCF strengths is explained by the process-induced changes in ...

Energy Technology Data Exchange (ETDEWEB)

Nitridation of Cr-bearing alloys can yield low interfacial contact resistance (ICR), electrically- conductive and corrosion-resistant CrN or Cr2N base surfaces of interest for a range of electrochemical devices, including fuel cells, batteries, and sensors. This paper presents results of exploratory studies of the nitridation of two high Cr (30-35 wt%) commercially available Ni-Cr alloys and a ferritic high Cr (29 wt.%) stainless steel for proton exchange membrane fuel cell (PEMFC) bipolar plates. A high degree of corrosion resistance in sulfuric acid solutions designed to simulate bipolar plate conditions and low ICR values were achieved via nitridation. Oxygen impurities in the nitriding environment were observed to play a significant role in the nitrided surface structures that formed, with detrimental effects for the Ni-Cr base alloys, but beneficial effects for the stainless steel alloy. Results of single-cell fuel ...

International Nuclear Information System (INIS)

An energy analyzer has been constructed and operated in UHV for the purpose of analyzing the energy of neutral atoms scattered from solid surfaces. The analyzer consists of a LiF single crystal located at an angle close to the normal to the sample crystal so that the diffraction pattern obtained by scanning the LiF crystal yields the energy of the scattered atoms. Two designs which have been used are described. The temperature of both sample and analyzer crystal is near 20 K and once cleaned they can be maintained in the state of initial preparation for many weeks. The sample was a (001) Cu surface in this case. Such an energy analyzer can only be used, in most cases, for He atom scattering although Ne atoms could be used if the scattered intensities were adequate. The detector developed in this study is able to detect about 2 x 10"5 atoms/s. The resolution of the spectrometer depends on the incident energy of the atom and ...

International Nuclear Information System (INIS)

Radiation hardening in austenitic stainless steels is shown to modify deformation characteristics and correlate well with an increased susceptibility to intergranular stress corrosion cracking (IGSCC). Available data on neutron-irradiated materials have been analyzed and correlations developed between fluence, yield strength and cracking susceptibility in high-temperature water environments. Large heat-to-heat differences in the critical fluence (0.2 to 2.5 x10"2"1 n/cm"2) for IGSCC are documented. In many cases, this variability is consistent with yield strength differences among irradiated materials. IGSCC correlates better to yield strength than to fluence for most heats suggesting a possible role of radiation-induced hardening and microstructure on cracking. Microstructural evolution during proton and heavy-ion irradiation has been characterized in low-carbon 304SSs. Hardening results from a dispersion of dislocation ...

Energy Technology Data Exchange (ETDEWEB)

Single and binary metal molybdates of the formula AMoO{sub 4}, where A=Ni, Co, Mg,Mn and/or Zn, were investigated for the oxydehydrogenation of propane to propylene, as well as some ternary molybdates of the formula NiO{sub 0.45}Co{sub 0.45}X{sub 0.066}MoO{sub 4} where X=P, Bi, Fe, Cr, V and Ce. All catalysts were supported on SiO{sub 2} with an active phase/support ratio of 80/20 (wt%). The reaction is catalytic and not a gas phase initiated reaction. It is first order in propane, consistent with the abstraction of the methylene hydrogen being the rate limiting step. Propane conversions and propylene yields vary greatly depending on the metal of the molybdate and surface area of the catalyst. Highest propylene yields (16% at 26.6% propane conversion) are obtained with NiMoO{sub 4}/SiO{sub 2}. Conversion and yield are significantly influenced by the molybdenum content of the compositions. The effect is ...

Energy Technology Data Exchange (ETDEWEB)

The major focus of this oil-shale investigation has been on specific localities of oil-shale resource potential. Three main areas of oil-shale occurrence have been studied in detail: the Elko area, Pinon Range area, and Coal Mine Canyon. Geologic mapping, stratigraphic studies, and sampling to delimit the lateral extent of the oil shale deposits were in progress prior to the cooperative agreement with Nevada DOE. These surface geologic studies have been summarized in this report. The results of surface geologic studies conducted near Elko suggested that the Elko area represented the best and most accessible oil-shale deposits; therefore, the Elko area was selected as the site of a shallow exploratory drilling program. Essential to this study was the obtaining of fresh, unweathered oil-shale samples from the Elko area. The samples were obtained from the core-drilling program and tested for oil yield by Fischer assays. The ...

International Science & Technology Center (ISTC)

Development of Technology for Metal Surface Decontamination in Aqueous Solutions

International Nuclear Information System (INIS)

We show how to obtain positive energy representations of the group G of smooth maps from a union of circles to U(N) from geometric data associated with a Riemann surface having these circles as boundary. Using covering spaces we can reduce to the case where N=1. Then our main result shows that Mackey induction may be applied and yields representations of the connected component of the identity of G which have the form of a Fock representation of an infinite dimensional Heisenberg group tensored with a finite dimensional representation of a subgroup isomorphic to the first cohomology group of the surface obtained by capping the boundary circles with discs. We give geometric sufficient conditions for the correlation functions to be positive definite and derive explicit formulae for them and for the vacuum (or cyclic) vector. (This gives a geometric construction of correlation functions which had been obtained earlier using ...

Science.gov (United States)

Cross sections for excitation induced by electron collision between low-lying 1s{sup 2}2s{sup 2}2p{sup 5} and 1s{sup 2}2s2p{sup 6} states of f-like selenium and from these states to singly excited states with the excited electron occupying the M shell have been calculated by relativistic distorted-wave Born procedures. The GRASP{sup 2} code was used for the atomic structure calculations. The continuum orbitals for the construction of continuum states were computed in the distorted-wave approximation, in which the distorted-wave potential used was the spherically averaged potential of the nucleus plus the potential of the bound electrons of the bound state. The cross sections for excitations were computed first by a 233-level multiconfiguration Dirac-Fock (MCDF) configuration expansion and then by a 279-level MCDF configuration expansion. The latter procedure, which also took into account contributions from all the ...

International Nuclear Information System (INIS)

The Bragg-curve detector of the parallel plate ionization chamber type generates a signal that is a distorted replica of the original Bragg-curve. In result of this distortion, the signal peak height is not only a function of the atomic number of the heavy ion, as it is often stated, but also of the particle mass. This mass effect was studied with the aid of computer simulation, and it was found to be dependent on the Frisch grid to anode gap width and on the detector gas. The charge resolution of the detector is affected very significantly by this mass dependence of the signal peak height. Therefore, a careful selection of the detector gas and the grid to anode gap width is necessary, if good charge resolution over a wide range of heavy ions is required. (orig.).

CERN Document Server

To investigate the origin and nature of inertia, we introduce a new concept of hypothetical 2D, so-called, "master-space" (MS), subject to certain rules. The MS, embedded in the background 4D-spacetime, is an indispensable individual companion to the particle of interest, without relation to every other particle. We argue that a deformation/(distortion of local internal properties) of MS is the origin of inertia. With this perspective in sight, we construct the alternative relativistic theory of inertia (RTI), which allows to compute the relativistic inertial force acting on an arbitrary point-like observer due to its "absolute acceleration". We go beyond the hypothesis of locality with an emphasis on distortion of MS, which allows to improve essentially the standard metric and other relevant geometrical structures related to the noninertial reference frame of an arbitrary accelerated observer. We compute the inertial force exerted on the ...

Energy Technology Data Exchange (ETDEWEB)

Arc distortion can lead to the measuring signal deformation and, consequently, to the erroneous identification or localisation of the fault. In the paper, a study on the short circuit loop resistance and reactance is presented referring to the algorithms using correlation between the sine and cosine functions as well as the least-square method (LSM). In the study, both the static and the dynamic models of the short circuit arc have been employed. The very advantageous features of the LSM-based algorithm have been underlined regarding accuracy of estimation of the short circuit mesh parameters (including the arc voltage at the location where the fault occurs) as well as susceptibility to the presence of a non-periodic short circuit current component. (Author)

International Nuclear Information System (INIS)

The contribution of exchange processes (heavy stripping and substitution) into the amplitude of the 25-30 MeV #alpha#-particle elastic scattering by "1"2C and "4"0Ca nuclei is examined taking into account the distortion of plane waves of initial and finite particles. The eikonal approximation is used for accounting for distortions. The matrix elements of exchange processes are calculated. The results of calculations show that the Wronskian cutoff radii are close to those which have been obtained for calculation of exchange processes in the plane-wave approximation. The moduli of the values defining the contribution of exchange processes to the total S matrix are plotted. Also presented are Argand diagrams and angular distributions for both reactions. It has been established that the account for exchange processes improves the agreement of theoretical curves with the experiment in the whole range of angles, as compared with the optical model.

Energy Technology Data Exchange (ETDEWEB)

Formulae are obtained for the angular correlation function of inelastically scattered ..cap alpha.. particles and ..gamma.. quanta of a pure EL multipolarity, which are emitted by an excited nucleus, in the case of exchange processes, if distortions are introduced into the eikonal approximation. The matrix element of the exchange processes is considered as a coherent sum of contributions from two mechanisms: replacement and stripping of a heavy particle. Concrete calculations are performed for the reaction /sup 12/C(..cap alpha.., ..cap alpha..'..gamma..)/sup 12/C. The obtained results show that the developed formalism enables one to get an agreement between the theoretical angular correlation functions with the experimental data at reasonable values of the calculation parameters.

Energy Technology Data Exchange (ETDEWEB)

We study the surface and interface roughness of a two-liquid film system using neutron reflectometry. The middle phase and bottom phase are extracted from a three-phase microemulsion containing 2 wt% non-ionic surfactant C{sub 10}E{sub 4}, 81 wt% D{sub 2}O and 17 wt% octane (C{sub 8}H{sub 18}). The system is formed by spreading a few drops of the middle phase of the microemulsion on the bottom phase of the microemulsion. The middle phase does not wet the bottom phase, but demixes to form a top octane-water mixture layer with a thickness of {proportional_to}580 A. The mean surface roughness of the system is found to be 7 A but the data are insensitive to interface roughness. An extended capillary wave model for a two-liquid-film system is derived to account for the coupling between the surface and interface. The dispersion relation yields two fundamental modes. In a calculation of mean-square roughness ...

Energy Technology Data Exchange (ETDEWEB)

We have demonstrated in this work (1) that methane is readily activated at mild conditions (100{degree}C, 1 torr) over a relatively noble metal, Pd. This was observed using a stepped and kinked Pd(679) crystal (1), and other crystal faces are now being investigated to establish whether the cracking of the C-H bond of methane on Pd is structure sensitive or structure insensitive. Oxygen chemisorption is extremely structure sensitive: weakly bonded, highly reactive oxygen overlayers form on Pd(100) surface (2), while strongly bonded, moderately reactive oxygen overlayers form on Pd(111) and Pd(679). Reaction of the weakly bonded oxygen with surface carbide gives rise to CO{sub 2} over clean Pd(100) but to CO over halogen-doped Pd(100) (3--5). The effect of halogens is primarily ensemble-controlling, or oxygen-supply restricting, but long range influence of surface Cl on the strength of the Pd-O bond has also been observed ...

Science.gov (United States)

In this paper, we evaluate the performance of the 1- and 5-site models of methane on the description of adsorption on graphite surfaces and in graphitic slit pores. These models have been known to perform well in the description of the fluid-phase behavior and vapor-liquid equilibria. Their performance in adsorption is evaluated in this work for nonporous graphitized thermal carbon black, and simulation results are compared with the experimental data of Avgul and Kiselev (Chemistry and Physics of Carbon; Dekker: New York, 1970; Vol. 6, p 1). On this nonporous surface, it is found that these models perform as well on isotherms at various temperatures as they do on the experimental isosteric heat for adsorption on a graphite surface. They are then tested for their performance in predicting the adsorption isotherms in graphitic slit pores, in which we would like to explore the effect of confinement on the molecule packing. ...

Energy Technology Data Exchange (ETDEWEB)

A prediction of delayed neutron yields for actinides which are important in the nuclear energy field is given. The prediction is based on a correlation related to a suggested cluster structure of the nucleus. (author).

International Nuclear Information System (INIS)

Two sets of experiments have been performed in sodium with two seven pin electrically heated bundles: the first with a nominal arrangement, the second with one dummy pin enlarged 20% in diameter in peripheral position. In this paper a rapid review of experimental results and theoretical works, related to the temperature distribution in these geometries, is presented together with a short description of the developed test section technology.

Wastenet

... Quenching is one of the most fundamentally complex processes in the heat treatment of metals, and it is something on which mechanical properties and distortion of engineering components depend. AU$236.36 ex-GST Terms and Conditions Eyes on the Skies: 400... Adopted as the official book of the International Year of Astronomy (IYA) 2009, this stunningly illustrated history of telescopic discovery spans the range ...

CERN Document Server

The indirect detection of particle dark matter (DM) is based on the search for anomalous components in cosmic rays (CRs) due to the annihilation of DM pairs in the galactic halo, on the top of the standard astrophysical production. These additional exotic components are potentially detectable at Earth as spectral distortions for the various cosmic radiations: $\\chi + \\chi \\to q \\bar{q}, W^+ W^-, ... \\to \\bar{p}, \\bar{D}, e^+ \\gamma and \

Energy Technology Data Exchange (ETDEWEB)

The oil shales of the Eastern United States represent a very large energy resource that also lies close to the marketplace. Although estimates vary, one estimate shows that more than 400 billion barrels of oil are recoverable from surface-mineable Devonian oil shales in the states of Alabama, Indiana, Kentucky, Michigan, Ohio, and Tennessee. Conventional thermal retorting of Eastern and Western oil shales with comparable organic carbon contents results in a much lower oil yield for the Eastern shales. This discouraged research and development of this energy resource, until about ten years ago, when the Institute of Gas Technology discovered that retorting Eastern oil shales in a hydrogen-rich atmosphere at elevated pressures gives oil yields that are 2.5 times those possible by thermal retorting. Over the last ten years many research, development, and feasibility programs, both Government- and industry-funded, have been ...

International Nuclear Information System (INIS)

The objective of this study is to evaluate the lifetime of Zr-2.5Nb pressure tube at Wolsung Unit-1. The testing materials (Effective full power year: 9.3 year, Accumulated nuetron fluence: 7.66#approx#8.91 x 1025 n/m"2) were sampled from M-11 tube at various position(inlet, middle and outlet). The cutting was carried out at hot cell to fabricate CT(Compact tension) specimen with 48 ppm hydrogen content. In the result of DHC test, irradiation-damaged specimen showed 4#approx#6 times faster DHC velocity(5.298E-0.8#approx#7.039E-8 m/s: 182 .deg. C) than non-irradiated specimen. These DHCV results also show slight faster than one of specimen from Pickering plant (average DHCV: 4.5E-8 m/s: 182 .Deg C). This faster DHCV can be explained with the fact that Wolsung Unit-1 have been operated in a severe conditions(higher cooling water temperature, high power and efficiency) than Pickering one. The striation spacing which was seen DHC fracture surface at irradiated specimen ...

Energy Technology Data Exchange (ETDEWEB)

Proton and alpha particle spectral shapes and multiplicities have been measured in coincidence with evaporation residues from {sup 28}Si+{sup 165}Ho and {sup 16}O + {sup 197}Au, {sup 208}Pb fusion reactions. Our experiments used 145 to 220 MeV {sup 28}Si and 115 and 140 MeV {sup 16}O beams produced with the Stony Brook LINAC. ER`s were separated using an electrostatic deflector and detected with large area surface barrier detectors. Light charged particles were detected at forward and backward angles with fourteen single NaI detectors. In the context of the statistical model, charged particle spectra yield information about emission barriers and compound nucleus equilibrium level densities. These are significant ingredients in calculations determining fission timescales from other observables such as pre-scission neutron multiplicities or fusion-evaporation excitation functions. Results will also be compared to analyses of pre-scission charged ...

International Nuclear Information System (INIS)

This paper deals with the characterization of passive films formed on stainless steel (26% Cr and 0 to 3%Mo). The influence of the applied passivation potential and the effect of molybdenum additions to steel upon the composition profiles of passive films formed in an aqueous NaCl solution (3.5% at pH 2.5) are studied. The technique involved is Auger electron spectroscopy combined with ion sputtering. Some electrochemical techniques have been used in conjunction. A quantitative approach of the Auger spectra during the progressive removal of the passive film is described. The peak-to-peak height of the Auger lines are treated in order to yield the atomic fraction of the various elements present in a given subsurface layer. The analytical study of the film by electron spectroscopy indicates that molybdenum plays a part at the metal-oxide interface where this element acts on the chromium diffusion process. This phenomenon, which depends on the imposed potential, may ...

Energy Technology Data Exchange (ETDEWEB)

This project has received DOE support since July 1, 1978. During this period, 40 papers have been published dealing predominantly with chlorophyll-photosensitized electron transfer reactions in a variety of media (solutions, polymer films, lipid bilayer membranes). The overall theme of this work has been to develop mechanistic strategies f or photochemical energy storage via chlorophyll, using the green plant photosynthetic system as a paradigm for designing in vitro systems. Microheterogeneous lipid vesicle suspensions allow ready application of time-resolved optical spectroscopy to follow the course of light-induced electron transfer processes. Both the yields and the lifetimes of electron transfer products were markedly improved in the vesicle systems. In subsequent studies, this compartmentalization was favorably manipulated by controlling the electrical charge on the membrane surface, by controlling the solubility properties of the ...

Energy Technology Data Exchange (ETDEWEB)

Monodisperse noble metal nanoparticles are of tremendous interest for numerous applications, such as surface-enhanced Raman spectroscopy, catalysis or biosensing. However, preparation of monodisperse metal nanoparticles is still a challenging task, because typical preparation methods yield nanoparticle ensembles with broad shape and/or size distributions. To overcome this drawback, tailoring of metal nanoparticles with laser light has been developed, which is based on the pronounced shape- and size-dependent optical properties of metal nanoparticles. I will demonstrate that nanoparticle tailoring with ns-pulsed laser light is a suitable method to prepare nanoparticle ensembles with a narrow shape and/or size distribution. While irradiation with ns-pulsed laser light during nanoparticle growth permits a precise shape tailoring, post-grown irradiation allows a size tailoring. For example, the initial broad Gaussian size distribution of silver ...

British Library Electronic Table of Contents (United Kingdom)

High surface ozone concentration is increasingly being recognized as a factor that negatively affects crop yields in Asia. However, little progress has been made in developing ozone-tolerant genotypes of rice-Asias major staple crop. This study aimed to identify possible tolerance mechanisms by characterizing two quantitative trait loci (QTLs) that were previously shown to influence visible leaf symptoms under ozone exposure (120 nl l-1, 7 h d-1, 13 d). Two chromosome segment substitution lines (SL15 and SL41) that carried introgressions of the QTLs OzT3 and OzT9, respectively, were exposed to ozone at 120 nl l-1 along with their parent Nipponbare. In accordance with the expected QTL effect, SL15 showed stronger visible symptoms of ozone damage than Nipponbare, whereas SL41 had fewer sympt...

CERN Document Server

Increasing the speed and complexity of semiconductor integrated circuits requires advanced processes that put extreme constraints on the level of metal contamination allowed on the surfaces of silicon wafers. Such contamination degrades the performance of the ultrathin SiO sub 2 gate dielectrics that form the heart of the individual transistors. Ultimately, reliability and yield are reduced to levels that must be improved before new processes can be put into production. It should be noted that much of this metal contamination occurs during the wet chemical etching and rinsing steps required for the manufacture of integrated circuits and industry is actively developing new processes that have already brought the metal contamination to levels beyond the measurement capabilities of conventional analytical techniques. The measurement of these extremely low contamination levels has required the use of synchrotron radiation total reflection X-ray ...

Energy Technology Data Exchange (ETDEWEB)

Three typical Japanese coals of non-coking coal, coking coal and anthracite were heat-treated with KOH, and change in their pore structure was examined by absorption of N2, X-ray diffraction and TEM observation. In addition, the relation between a coal rank and pore structure was also studied by absorption experiment of N2. In experiment, the mixture of coal and KOH in a nickel holder was heat-treated in N2 gas flow at heating rate of 2{degree}C/min, and held at a fixed temperature for one hour. To clarify the pore structure, N2 absorption isotherms were measured at -196{degree}C under nearly 76cmHg using a commercially available full-automatic absorption measurement equipment. Based on the X-ray diffraction and TEM observation results on activated coals, the relation between the N2 absorption and pore structure was studied. The results are summarized as follows: (1) The yield and absorption ability of coals increase with a coal rank, (2) The specific ...

CERN Document Server

This paper describes a study of comparison of global and one-dimensional local optimization methods to operating system scheduler tuning. The operating system scheduler we use is the Linux 2.6.23 Completely Fair Scheduler (CFS) running in simulator (LinSched). We have ported the Hackbench scheduler benchmark to this simulator and use this as the workload. The global optimization approach we use is Particle Swarm Optimization (PSO). We make use of Response Surface Methodology (RSM) to specify optimal parameters for our PSO implementation. The one-dimensional local optimization approach we use is the Golden Section method. In order to use this approach, we convert the scheduler tuning problem from one involving setting of three parameters to one involving the manipulation of one parameter. Our results show that the global optimization approach yields better response but the one- dimensional optimization approach converges to a solution faster ...

CERN Document Server

Optical sections of the cornea are obtained by illumination with a collimated beam expanded in a fan shape by a small rotary cylindrical lens. The light diffused from the cornea is observed by two cameras and processed in order to yield the surfaces' profiles. The optical system used to project a thin rotating line on the cornea consists of a white light source provided with optical fiber bundle output which is first conditioned by a set of lenses so that it would produce a spot on the cornea. A small cylinder lens is used to expand the beam in one direction so that a thin line illuminates the cornea, rather than a spot. The cylinder lens is provided with motor driven rotation about an axis normal to its own in order to rotate the line on the cornea such that the projected line scans the whole cornea; the illuminator is completed with a slit aperture. The cornea is not perfectly transparent, scattering some of the light that traverses it; this ...

Energy Technology Data Exchange (ETDEWEB)

The role played by planetary boundary layer (PBL) in the development and evolution of a severe convective storm is studied by means of meso-scale modeling and surface and upper air observations. The severe convective precipitation event that occurred on 14 September 1999 in the northeast of the Iberian Peninsula was simulated by means of the mesoscale model MM5 (version 3) using three different PBL schemes. The numerical results show a large impact of the PBL schemes on the precipitation fields associated to the convective storm. The schemes are based on different physical assumptions: the nonlocal first order medium-range forecast (MRF) and blackadar (BLA) scheme and the local, one-and-a-half order ETA scheme. Surface and radar observations are used to validate the model results. The comparison focuses on three aspects: the evolution, the spatial distribution and the 24-h accumulated precipitation. The comparison with rain gauge observations ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

... spatially defined fashion. Many surface modification techniques require a sequential chemical treatment of the surface.6 ...

Science.gov (United States)

Surface crystallization and surface-to-bulk ratio in high-level waste glasses.

Energy Technology Data Exchange (ETDEWEB)

In this issue it has been investigated the yield of Helical CT in the study of lung vessels, the incidence of the angiogram sign and its actual value. July 1997 to December 1998, were studied 30 cases of pulmonary collapse of different origin. It was found 15 cases of passive collapse (10 from pleural effusion, 2 from diaphragmatic compression, 2 from traumatic pneumothorax, and 1 from isthmic aortic aneurysm), 12 cases of obstructive collapse (9 from bronchogenic carcinoma, 1 from mucoid obstruction, 1 from ilar lymphadenopathy, and 1 from mediastinal cancer), 2 cases of adhesive collapse and 1 case of round atelectasis. All the examinations were performed with the Helical technique during nonionic iodinated contrast agent injection (bolus, 300-350 mg/mL); it was used an automatic injector set at 2-3 mL/s. It was studied the images for the angiogram sign, that is hyperdense bands, usually longer than 2 cm, through the collapsed lung, which correspond to normal ...

Energy Technology Data Exchange (ETDEWEB)

The gas phase high resolution spectroscopic study of weakly bound clusters can provide the information necessary to develop an intermolecular potential energy surface. This surface can then be used to better understand condensed phases. In this work, a tunable far infrared laser spectrometer is used to study weakly bound dimers produced in the newly developed continuous planar supersonic jet expansion apparatus. The water dimer is an extensively studied hydrogen bonded dimer. It undergoes several tunneling motions which result in splittings and perturbations of the rovibrational energy levels. A review is presented of much of the experimental and theoretical work done on water dimer, including a description of the combined fit of all the high resolution spectroscopic results by Coudert and Hougen. Also included is a discussion of the measurement of the K = 1 lower {yields} K = 2 lower band performed using the tunable far ...

Energy Technology Data Exchange (ETDEWEB)

Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr{sub 2}N, CrN, TiN, V{sub 2}N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, which exhibited {approx}5-20% better peak power output than untreated Fe-20Cr-4V, ...

Energy Technology Data Exchange (ETDEWEB)

We studied the interaction of Pu(VI) with Pseudomonas stutzeri ATCC 17588 and Bacillus sphaericus ATCC 14577, representatives of the main aerobic groups of soil bacteria present in the upper soil layers. The accumulation studies have shown that these soil bacteria accumulate high amounts of Pu(VI). The sorption efficiency toward Pu(VI) decreased with increasing biomass concentration due to increased agglomeration of the bacteria resulting in a decreased total surface area and number of available complexing groups. Spores of Bacillus sphaericus showed a higher biosorption than the vegetative cells at low biomass concentration which decreased significantly with increasing biomass concentration. At higher biomass concentrations (> 0.7 g/L), the vegetative cells of both strains and the spores of B. sphaericus showed comparable sorption efficiencies. Investigations on the pH dependency of the biosorption and extraction studies with 0.01 M EDTA solution have shown ...

Energy Technology Data Exchange (ETDEWEB)

The object and the purpose of the present work was to develop, to assemble and to start running a new TOF (time of flight) mass spectrometer for imaging SNMS analytic which is optimized for the analysis of highly molecular secondary ions. The most important purpose was the characterization of the TOF mass spectrometer. The obtained mass spectra of indium, tantalum and silver clusters reflect the excellent properties of the TOF mass spectrometer for the detection of large clusters with good detection efficiency up to masses of 16000 amu. The possibility of the deflection of selected saturated atom and cluster peaks serves for further improvement of the detection efficiency for large molecules. The accessible mass resolution was determined to be of the order of m/{delta}m=1000 in the high mass region. Numerous measurements were carried out to characterize the useful yield of this spectrometer. For a best possible adaptation of the TOF mass spectrometer for the ...

International Nuclear Information System (INIS)

The large girth and immense size of the baobab has caused many to speculate about its age. Unfortunately reliable age estimates cannot be determined from growth rates as the girth varies in response to different moisture regimes. In a similar way, ages cannot be determined from ring-width measurements or X-ray densitometry as the absorbent nature of the soft fibrous wood and distortion upon drying prevent the application of these techniques. The Southern Hemisphere bomb radiocarbon curve was used to demonstrate that the rings of a recently-fallen baobab (Adansonia digitata L.) from Kruger National Park appear to be annual. The detrended C isotope values of finely-ground wholewood from another baobab specimen were found to be highly associated with January precipitation (r = 0.72; p < 0.01). This study demonstrates that high resolution information about past climates may be obtained by analysing the C isotope values from baobab samples even if ...

Science.gov (United States)

This paper proposes a new pattern recognition system employing optical joint transform correlation (JTC) technique which offers a great number of advantages over similar digital techniques, including very fast operation, simple architecture and capability of updating the reference image in real time. The proposed JTC technique incorporates a synthetic discriminant function (SDF) of the target image estimated from different training images to make the pattern recognition performance invariant to noise and distortion. It then involves four different phase-shifted versions of the same target SDF reference image, which are individually joint transform correlated with the given input scene. When the correlation signals are combined, it produces a single cross-correlation peak corresponding to each potential target present in the given input scene. The proposed technique also includes a fringe-adjusted filter to generate a delta-like correlation peak with high ...

International Science & Technology Center (ISTC)

Highly Precision Method for Nondestructive Analysis of Surfaces in a Subnanometer Depth Range

Energy Technology Data Exchange (ETDEWEB)

The principle of conservation and transferability of chemical bonds explains the recent discovery by extended x-ray absorption fine-structure measurements of two unequal anion-cation bond lengths R/sub A/C and R/sub B/C in A/sub x/B/sub 1-x/C zinc-blende semiconductor alloys despite the close adherence of the lattice constant to the average value (Vegard rule). This bond alternation, manifested as a structural distortion to a local chalcopyrite coordination around the anions, explains also most of the observed optical bowing in semiconductor alloys.

Energy Technology Data Exchange (ETDEWEB)

AuxZn1-x alloys undergo a shape memory martensitic transformation whose temperature and nature (continuous or discontinuous) is strongly composition dependent. Neutron diffraction experiments were performed on single crystals of x=50 and 52 to explore the structural changes occurring at the transition temperature. A transverse modulation with wavevector q0=(1/3,1/3,0) develops below the transition temperature, with no observable change in lattice parameter. However, the Bragg peak width shows a broadening suggesting an unresolved rhombohedral distortion similar to what has been observed in NiTi-Fe alloys.

Energy Technology Data Exchange (ETDEWEB)

The report deals with: (1) two-phase flow regime transitions, (2) liquid entrainment in break flow, (3) vapor pull-through, and (4) CCFL in horizontal ducts. The first three processes influence the mass flow through the break, whereas the fourth one imposes a limit on liquid flow from the steam generator through the hot leg break into the core. Correlations available in the literature which deal with these processes are presented and applied to a hot leg of a PWR, LOFT and Semiscale for quantitative estimates, as well as for determining the scale distortion in the latter two facilities.

British Library Electronic Table of Contents (United Kingdom)

Magnetic resonance (MR) imaging and histopathology were used to diagnose an articular process synovial myxoma in a dog. On MR images, the tumor was characterized by distortion of the left L1-L2 articular process, widening of the articular process joint, and the presence of a mass contiguous with the synovium of the articular process that displaced the spinal cord. The tumor was T2-hyperintense, T1-hypointense, relative to muscle, and had mild contrast enhancement. The MR features of articular process synovial myxoma may be distinct from other diseases of the articular process joint.

International Nuclear Information System (INIS)

The wide-angle spectra of the 134-MeV (p,n) reaction on "4"8Ca, "5"4Fe, "8"8Sr, and "2"0"8Pb are each dominated by the excitation of a single state at low excitation energy. These excitations correspond to the ''0h#omega#'' stretched states and are seen to be fragmented much less than ''1h#omega#'' stretched states in medium- and heavy-mass nuclei. The normalization factors required for comparison with distorted-wave impulse-approximation calculations are >0.50 and indicate that these are the purest particle-hole states known in these nuclei.

International Nuclear Information System (INIS)

Direct nuclear reactions are commonly understood in terms of distorted wave (DW) formalisms. In the case of a single nucleon knockout or transfer reaction the DW analysis provides a reasonable understanding of the observed data. On the other hand the predictions based on different available information inputs have been verified with the observations consistently. In the case of direct reactions involving nuclear clusters however, the DW predictions have been found to disagree with the observations in most cases. The outcome of these and other improvements in the intermediate energy nuclear phenomena involving direct reactions are highlighted. (author). 13 refs., 18 figs.

International Nuclear Information System (INIS)

Absolute, cascade-free excitation cross sections in an ion have been measured for the resonance "2S#->#"2P transition in Zn"+ using electron-energy-loss and merged electron-ion beams methods. Measurements were carried out at electron energies of below threshold to 6 times threshold. Comparisons are made with 2-, 5-, and 15-state close-coupling and distorted-wave theories. There is good agreement between experiment and the 15-state close-coupling cross sections over the energy range of the calculations.

International Nuclear Information System (INIS)

The present investigation was conducted at Ismaillia Research Station-Agricultural Research Center, Ismaillia Governorate, during the two successive seasons of 2000 and 2001. Two varieties of peanut (Arachis hypogaea L) namely Giza 4 and Giza 5 were treated with gamma ray doses; 10,15, 20, 25 Kr in order to induce genetic variability and to study the importance of the relative contribution of peanut yield components by employing some statistical procedures, i.e. simple correlation, multiple linear regression and stepwise regression analysis. The results showed that, there was significant positive correlation between seed yield/plant and no. of pods/plant, 100 seed weight, shelling percentage and pod yield/plant, and there was significant positive correlation between pod yield/plant and no of seed/plant,100 pod weight and 100 seed weight. The multiple linear regression analysis clearly showed that the ...

UK PubMed Central (United Kingdom)

BackgroundThe production of high yields of recombinant proteins is an enduring bottleneck in the post-genomic sciences that has yet to be addressed in a truly rational manner. Typically...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Three possibilities to observe the Higgs-top interaction at future {gamma}{gamma}-colliders are discussed: (a) associated Higss production via the {gamma}{gamma}{yields}tanti tH reaction, (b) Higgs obliged radiative correction to the {gamma}{gamma}{yields}tanti t channel, (c) Higgs resonance production via {gamma}{gamma}{yields}H{yields}ZZ. The results obtained show windows of the Higss mass where the Yukawa interaction of the Higss with the top quark can be studied at {gamma}{gamma}-colliders. (orig.).

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

British Library Electronic Table of Contents (United Kingdom)

Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. The uncertainty of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain fissioning isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

... data deuteron beams energy dependence errors gamma radiation lead 203

UK PubMed Central (United Kingdom)

Grain yield is a major goal for the improvement of durum wheat, particularly in drought-prone areas. In this study, the genetic basis of grain yield (GY), heading date (HD), and plant height (PH) was...Full Text Available

International Nuclear Information System (INIS)

The current methods used by the tissue analysis program at LASL for the determination of americium and plutonium in autopsy tissue are described. Problems affecting radiochemical yield are discussed. Included are problems associated with sample preparation, separation of plutonium from large amounts of bone ash, and reagent contamination. The average "2"4"2Pu tracer yield for 1800 Pu determinations is 78 +- 12%. The average "2"4"2Am tracer yield is 85 +- 7% for 40 determinations.

Energy Technology Data Exchange (ETDEWEB)

Sputter-removal rates of overlayer and interfacial species on silicon are analyzed to determine sputtering yields for the species involved. Sputtering yields up to two orders of magnitude lower than those measured for silicon are found, and the results are interpreted in terms of a cascade mixing process which continually reburies much of the overlayer material beyond the escape depth of the sputtered atoms.

Energy Technology Data Exchange (ETDEWEB)

Field-grown snap bean plants were treated with simulated acidic rain applied either alone or in combination with ambient rain and the effects on growth and yield were determined. In plots where ambient rain was excluded, a retractable canopy was activated to shield the crop. Four levels of acidity at pH values of 5.0, 4.2, 3.4 and 2.6 were applied in four replicate treatments and the experiment was conducted in two successive years (1981 and 1982). In plots that received only simulated rain, yield was not adversely affected by acidic rain; in 1981, a positive linear relationship was present between acidity of simulated rain and yield, but in 1981, no effect was found. In contrast, in plots that received both simulated and ambient rain, a negative linear relationship between acidity in simulated rain and yield was observed in both years.

International Nuclear Information System (INIS)

This investigation was carried out during the two seasons of 1998/1999 and 1999/2000 at the experimental farm belonging to the plant research department, nuclear research center, atomic energy authority in Inshas to evaluate four lupin mutant lines (L_1, L_2, L_3 and L_4) along with their original mother varieties giza 1 and giza 2 under different levels and nitrogen fertilizer levels. The results indicated that seed yield/ plant and its effective components number and weight of pods/plant were significantly higher in all the mutant lines as compared to their parents either in the first or second seasons. Concerning the effect of irrigation intervals on yield and its components for developed mutants and their mother varieties as well as the results gave an evidence that the wider interval showed the lesser values for yield and most of yield components. Obtained data also revealed that ...

International Nuclear Information System (INIS)

Although some polymer conductors of electricity (ex. Polyanilines) are materials known for more than 100 years, only recently have the interesting chemical, electrical and optic properties of their insulating and conducting forms been recognized. Advances made in the chemistry of polymer conductors have also led to improvements in processing them. This work studies a practical application of these materials: the use of polymer conductors for the remote welding of insulating thermoplastic polymers, using energy from microwaves for the local heating of the union. Many thermoplastics (for ex. Polyethylene) do not absorb, or absorb very little, energy from microwaves. Different conductor materials (conductor polymers, carbon nanotubes), however, heavily absorb energy from microwaves with the resulting heating. In this way the welding zone can be heated without affecting the rest of the piece. Conductor polymers (polyanilines) were synthesized chemically and they were characterized by ...

Energy Technology Data Exchange (ETDEWEB)

Measurements were made of the cross sections for the /sup 27/Al(/sup 16/O,/sup 15/N)/sup 28/Si, /sup 89/Y(/sup 15/N,/sup 16/O)/sup 88/Sr and /sup 89/Y(/sup 27/Al,/sup 28/Si)/sup 88/Sr reactions at energies near and below the Coulomb barrier. The first reaction required separate measurements of the transfer to elastic cross section ratio for particular charge states, the charge state distribution for /sup 27/Al and /sup 28/Si ions, and the absolute elastic scattering cross section for the /sup 27/Al + /sup 16/O system. The ratio measurement required the combined use of two relatively new scientific instruments: the momentum filter and the Bragg curve spectrometer. The latter two transfer measurements were performed using the same setup involving surface barrier detectors at backward angles. Additional elastic scattering data for the /sup 15/N + /sup 28/Si, /sup 89/Y + /sup 15/N, /sup 89/Sr + /sup 27/Al, and /sup 88/Sr + /sup 28/Si systems was collected to provide ...

Energy Technology Data Exchange (ETDEWEB)

The oxide colloidal route, developed in the laboratory for mono-metallic catalysts, consists in preparing a metallic oxide hydro-sol which leads to the supported catalyst after deposition onto a support and an activation stage. In this work, this method has been adapted to the preparation of alumina supported bimetallic Pd-Sn catalysts to determine its interest for the control of the properties of the bimetallic phase (size, composition and structure). In the preliminary study concerning tin oxide sols, SnO{sub 2} (size=2,3 nm) and Sn{sub 6}O{sub 4}(OH){sub 4} (size = 25 nm) nano-particles were synthesized by neutralization respectively for tin(IV) and tin(H). The control through the pH of the aggregation of the PdO and SnO{sub 2} particles revealed that increasing oxide solubility promotes integral re-dispersion of the oxide particles. To synthesize oxide bimetallic sols, three strategies were defined. Copolymerization (formation of a mixed oxide nano-sol by cross condensation of both ...

Science.gov (United States)

The gas-phase reaction of benzene with O(3P) is of considerable interest for modeling of aromatic oxidation, and also because there exist fundamental questions concerning the prominence of intersystem crossing in the reaction. While its overall rate constant has been studied extensively, there are still significant uncertainties in the product distribution. The reaction proceeds mainly through the addition of the O atom to benzene, forming an initial triplet diradical adduct, which can either dissociate to form the phenoxy radical and H atom, or undergo intersystem crossing onto a singlet surface, followed by a multiplicity of internal isomerizations, leading to several possible reaction products. In this work, we examined the product branching ratios of the reaction between benzene and O(3P) over the temperature range of 300 to 1000 K and pressure range of 1 to 10 Torr. The reactions were initiated by pulsed-laser photolysis of NO2 in the presence of benzene and ...

International Nuclear Information System (INIS)

Full text: Measurement of K_#beta# to K_#alpha# x-ray intensity ratios are important not only in the field of atomic physics, radiation physics and medical physics, but also to test the validity of assumptions made in the theoretical prediction. The intensity ratios can also give information on the effect of physical and chemical environment of the element in the compound. Many investigators have adopted a single and double reflection geometries to measure the K_#beta# to K_#alpha# x ray intensity ratios to understand the effect of physical and chemical environment on x-ray fluorescence. The targets are excited by a radioactive source of having activity of the order 100 MBq. in order to carry out accurate measurement K_#beta# to K_#alpha# x-ray intensity ratios, we have develop 2#pi# geometrical configuration method : placing a target right on the surface of the detector facing the target to measure the K shell fluorescence parameters such as fluorescence ...

Science.gov (United States)

The x-ray diffraction technique described previously for measurement of growth kinetics of Pd/sub 2/Si layers from their solid state reaction couples has been extended by the use of a one-dimensional position-sensitive detector (PSD). Additionally, the method has been extended to include measurement of the Pd layer. A detailed description of the experimental arrangement and analytical procedures is presented. The kinetics of epitaxial Pd/sub 2/Si film growth were measured in situ over a range of 170--230 /sup 0/C. The PSD results, using data obtained from both the Pd/sub 2/Si and Pd layers, were able to confirm parabolic growth behavior for the Pd/sub 2/Si film. The rate constants followed Arrhenius behavior and yielded an activation energy of E = 1.32 +- 0.07 eV with a prefactor k/sub 0/ = 0.49 cm/sup 2//s for the Pd/sub 2/Si layer analysis and E = 1.34 +- 0.17 eV with a prefactor of 0.72 cm/sup 2//s for the Pd layer analysis. The PSD technique significantly ...

International Nuclear Information System (INIS)

Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946-58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10 days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-, biological-, and environmental-specific impacts of residual high activity (hot) particle contamination. The aim of the present study was twofold; (i) to characterize the levels ...

International Nuclear Information System (INIS)

Soil erosion and small annual additions of organic matter from plant-sources are the major causes of low organic-matter content in our soils. The tops of the plants, fallen to the soil- surface, remain there are incorporated, the plant-roots, shrubs, grasses. And other native plants contribution much towards the soil organic matter. Populus spp. Are grown commonly around farmers' fields in the state of Azad Jammu and Kashmir. A pot-experiment was conducted to study the effect of addition of populus euramericana leaves on various physical and chemical characteristics of the soil. Soil was kept at field-capacity level and incubated at room temperature for 10 months after adding 25, 50, and 75 g of Populus curamericana leaves per pot. Changes in organic-matter content. PH, cation-exchange capacity extractable potassium, water-holding capacity, and bulk density were investigated, after incubation for 6,8,and 10 months. There was a linear increase in organic-matter ...

Energy Technology Data Exchange (ETDEWEB)

Work continued on the correlations of catalytic activity of metals and surface structure. Work is described in the following areas: CO oxidation on a Cu/Rh(100) Bimetallic catalysts; electronic properties of bimetallic surfaces; and reflection absorption spectroscopy of bimetallic surfaces. 5 figs. (CBS)

Wastenet

...Surface Aerators Products and Equipment Find and compare a variety of surface aerators products and equipment on the world's largest environmental industry portal. ...

Science.gov (United States)

Understanding climate development in the central Andes is important in determining the relationship between mountain range uplift and climate change. Recent work along the western margin of the central Andes has led to the development of two competing hypotheses: 1) that climate change is directly responsible for uplift or 2) that uplift controls climate change. In the first scenario, uplift results from increased friction at the plate boundary due to sediment-starvation of the trench which is a function of decreased run-off (particularly post 14 Ma) due to global cooling. In the second scenario progressive uplift of the Andean Cordillera during the Miocene resulted in a strong orographic effect with a concomitant rainshadow west of the Andes. To determine the relationship between climate change and uplift it is necessary to ascertain precisely, when the climate changed, the nature of that change and when uplift occurred. With respect to climate change a key question that has been ...

Science.gov (United States)

Raytheon's Santa Barbara Remote Sensing (SBRS) division designed and built the MTSAT-1R Japanese Advanced Meteorological Imager for the Japanese Ministry of Transport between March, 1999 and July, 2002. In order to meet the stressing requirements of a geosynchronous orbit, a combination of structural, thermal, and optical (STOP) analyses were used to design and optimize the beryllium three-mirror anastigmat (TMA) telescope. This modeling approach was used to characterize and minimize the thermal distortion around local midnight. On-orbit temperatures and structural deformations were predicted using thermal Desktop/SINDA and PATRAN/NASTRAN software, respectively. The resulting optical performance was evaluated using Raytheon developed HEXAGON software. The telescope design was successfully optimized to attain specified visible channel performance for most of the 24 hour orbit.

British Library Electronic Table of Contents (United Kingdom)

This study emphasizes the need for a systematic and in-depth connection between the progress in quantum theory of energetic ion collisions and applications to hadron therapy. Scattering theory for fast ion beams has reached its stage of development where accurate and robustly applicable methodologies can advantageously be exported to applied fields such as space research, fusion energy program, medicine, etc. In particular, distorted wave collision theories at high energies readily provide total, partial and fully differential cross sections for inelastic collisions of ionic projectiles with any target system. By numerous and thorough testings, such theoretical cross sections were found to exhibit excellent agreement with experimental data on atomic targets. Adequate extensions of these me...

Science.gov (United States)

Electron collisional data are required for population kinetics modeling and spectral predictions of highly ionized ions in high-temperature plasmas. Nickel-like ions are especially interesting for their potential use in soft X-ray laser schemes pumped by electron collisional excitation and recombination. For highly stripped ions of moderate to high Z, relativistic effects begin to play a role in the atomic-physics calculations. A relativistic multiconfigurational distored-wave model has been used for the calculation of electron excitation cross sections and rate coefficients between the 3s2 3p6 3d10 Ni-like Gd ground state and the singly excited states with an N-shell electron.

British Library Electronic Table of Contents (United Kingdom)

The decline of classical epistemology on unity-identity-totality shows it becomes more urgent to leave formal conventionalism behind, and to use a new diverging language. Every scientist must feel the emotion of the beginner. Nevertheless, we must not have illusions. Pure observation does not exist. Moreover, there are no laws that can remove the asymmetries of a system. The knowledge and scientific practice free themselves from the obsession of clarity, of linearity and from the idea of evolution that follows and precedes through pre-determined ways and versions. What we need is a multiple, connected intellection that allows us to look at science and at the world without the distorting effect of ingenuous methodologies and classifications that, if on the one hand put us at our ease, on th...

Science.gov (United States)

A 100-bit slitlike aperture array spatial light modulator has been developed using 8.8/65/35 PLZT for a high-bit-density 1-D hologram memory. The most desirable characteristics, such as distortion-free diffraction-limited Fourier transform patterns and good uniformity of displayed bit patterns over 100 bits, have been realized. The lowest SNR was 86, and rise time and fall time have been 30 microsec and 8 microsec, respectively, at 190-V halfwave voltage. One-dimensional holographic storage experiments have been successfully performed using this PLZT spatial light modulator. PMID:20216813

CERN Document Server

We study the prospects of pinning down the effects of non-standard antineutrino interactions in the source and in the detector at the Daya Bay neutrino facility. It is well known that if the non-standard interactions in the detection process are of the same type as those in the production, their net effect can be subsumed into a mere shift in the measured value of the leptonic mixing angle theta_13. Relaxing this assumption, the ratio of the antineutrino spectra measured by the Daya Bay far and near detectors is distorted in a characteristic way, and good fits based on the standard oscillation hypothesis are no longer viable. We show that, under certain conditions, three years of Daya Bay running can be sufficient to provide a clear hint of non-standard neutrino physics.

Energy Technology Data Exchange (ETDEWEB)

The neutron transition multipole moment, M/sub n/, for (0/sup +/..-->..2/sup +/, 1.84 MeV) transition is inferred by measuring the (..cap alpha..,..cap alpha..') angular distribution at E/sub ..cap alpha../ = 50 MeV and comparing it with a microscopic distorted-wave Born approximation calculation. Proton transition densities are taken from electron scattering data. M/sub n//M/sub p/ is found to be substantially less than N/Z in agreement with the (p,p') result.

Energy Technology Data Exchange (ETDEWEB)

The effects of spin diffusion on the free induction decay (FID) of protons associated with the noncrystalline domains of two polymers, polyethylene and blended Nylon 66 (ZYTEL-408), have been examined using Goldman--Shen NMR pulse sequence ((1/2)..pi..x-t/sub 0/-(1/2)..pi..x-bar-tau-(1/2)..pi..x-t). At tau< or approx. =100 ..mu..s, the FID is drastically distorted from the exponential form while at longer tau(tau> or approx. =500 ..mu..s) an exponential FID is observed; but its transverse spin relaxation rate is smaller than that of the FID obtained after a single (1/2)..pi..x pulse and approaches this value at the limit of large tau. These findings are interpreted in terms of the theory of rapid spin diffusion. The spatial variation in the spin relaxation rate within the noncrystalline domain is inferred.

International Nuclear Information System (INIS)

A crossed-electron-ion-beam experiment was used to measure the total ionization cross section for Ar"8"+ in the energy range from 50 to 600 eV. The present results are roughly in agreement with the previous measurements of Defrance et al. [Nucl. Instrum. Methods Phys. Res. B 23, 256 (1987)] above 450 eV. However, the present measurements show a significant contribution below the threshold for direct ionization. The present measurements agree with the distorted-wave calculations of Pindzola et al. [Phys. Rev. A 41, 1375 (1990)] when 3% of the incident ion beam is assumed to be in metastable states and excitation autoionization from metastable states is included.

CERN Document Server

Jahn-Teller theorem, proposed in 1937, predicts a distortional instability for a molecule that has symmetry based degenerate electronic states. In 1939 Krishnan emphasized the importance of this theorem for the arrangement of water molecules around the transition metal or rare earth ions in aqueous solutions and hydrated saltes, in a short and interesting paper published in Nature by pointing out atleast four existing experimental results in support of the theorem. This paper of Krishnan has remained essentially unknown to the practitioners of Jahn-Teller effect, eventhough it pointed to the best experimental results that were available, in the 30's and 40's, in support of Jahn-Teller theorem. Some of the modern day experiments are also in conformity with some specific suggestions of Krishnan.

Energy Technology Data Exchange (ETDEWEB)

Many modern military systems used for communications, command and control, navigation, and surveillance depend on reliable and relatively noise-free transmission of radiowave signals through the earth`s ionosphere. Small-scale irregularities in the ionospheric density can cause severe distortion, known as radiowave scintillation, of both the amplitude and phase of these signals. The WBMOD computer program can he used to estimate these effects on a wide range of systems. The objective of this study is to investigate improvements to the WBMOD model based on extensive data sets covering both the equatorial and high-latitude regimes. This report summarizes the work completed during the third year of this project, which includes completion of the new model for the high-latitude (auroral and polar cap) region of the WBMOD model.

International Nuclear Information System (INIS)

Gravitational waves are propagating fluctuations of gravitational fields, that is, '' ripples '' in space-time, generated mainly by moving massive bodies. These distortions of space-time travel with the speed of light. Every body in the path of such a wave feels a tidal gravitational force that acts perpendicular to the wave's direction of propagation; these forces change the distance between points, and the size of the changes is proportional to the distance between these points thus gravitational waves can be detected by devices which measure the induced length changes. The frequencies and the amplitudes of the waves are related to the motion of the masses involved. Thus, the analysis of gravitational waveforms allows us to learn about their source and, if there are more than two detectors involved in observation, to estimate the distance and position of their source on the sky. (author)

International Nuclear Information System (INIS)

The risks from mining and processing of ores is reviewed on a generic basis with particular reference to some of the confusions which can arise due to lack of consistency or common logic in the use of exclusion, exemption and clearance. The difference in exclusion and exemption are challenged by comparing doses received in high background radiation areas and the doses received from a mining practice. The common principle of risk to the human species is not applied consistently. The differences between IAEA recommendations and local regulatory conditions are compared, and the use of exemption levels as clearance levels is considered. A case study on management of mine tailings is presented with special focus on the use of clearance levels. In all areas of review the interpretation of regulation is subject to confusion resulting from inconsistencies which can distort free market economics. (author).

Energy Technology Data Exchange (ETDEWEB)

Primary energy consumption per unit of gross domestic product (GDP) indicates the importance of energy as an input to an economy. The most important determinant of energy consumption per GDP unit is economic structure, although the efficiency with which energy is used and the availability of non-commercial energy sources are also significant. Energy consumption intensities among the industrial nations reflect, in part, the vigor with which energy conservation and substitution policies have been pursued in the past decade. Energy production intensities indicate resource endowment, and may vary from zero to close to 100% of GDP. Comparisons of the seven world regions note that the centrally planned economies distort the figures because of their method of measuring economic output. 1 table.

Energy Technology Data Exchange (ETDEWEB)

A dynamic control rod worth measurement was performed for control bank D, C, B, and A of Yonggwang unit 1 cycle 14 during its low power physics test. MASTER was used for three-dimensional core kinetics calculations required to convert excore detector signal into static rod worth, using the same modeling and cross sections as ANC which was used for the core static design. A signal curve fitting method was proposed to solve a low signal problem due to large amount of rod worth, which leads to the distortion of resulting static worth. The static worths measured in this test well agreed with the predicted worth of design within {+-}15% which is a test requirement of rod worth measurement.

International Nuclear Information System (INIS)

The energy levels, wavelengths, oscillator strengths, Auger rates and level-to-level dielectronic recombination rate coefficients describing dielectronic recombination into excited levels of Ne-like titanium from F-like low-lying states are calculated. Our calculations are based on Dr. R.D. Cowan's semi-relativistic mass-velocity and Darwin corrections are included in the Hamiltonian, and the distorted-wave model is used for the calculation of free electron wavefunctions. In order to set the recombination rate coefficients on a level by level basis, in a manner compatible with detailed level population kinetics modelling of highly-stripped ions in plasma, the dielectronic recombination rate coefficients as a function of free electron temperatures are given in an analytical form, which is not only very convenient in practice, but also hopefully accurate compared with the exactly calculated numerical results. (orig.).

International Nuclear Information System (INIS)

Leptonic pair production on nuclei ad EMC-effect are discussed within the frames of the flucton model with scaling distortion. Cumulative production of direct photons and leptonic pairs as a test of the model of hard collisions is considered. The results of calculations of massive leptonic pair production cross sections on nucleus fluctons, caculations of the ratio of deuterium and iron structural functions, cross sections of direct photon production on sup(181)Ta nuclei at Esub(p)=400 GeV and cross section of #pi#-meson production in the model of hard collisions are presented. Experimental discovery of direct cumulative photons is concluded to be important for understanding the mechanism of parton hard scattering from nucleus fluctons.

Energy Technology Data Exchange (ETDEWEB)

In an effort to minimize the distortion of bearing steel rings during the production process, 100Cr6 steel billets are spray formed with a unique cooling control system to control the cooling and solidification behavior of the deposits. Effects of heating around the deposits, gas cooling at the substrate bottom and the gas flow over the deposits are investigated both by numerical simulation and experiment. Porosity profiles and microstructures of spray formed bearing steel are examined and evaluated. The investigation results show that the thermal boundary conditions of the deposits play important roles on the cooling and solidification behavior of the deposits, especially at the deposit periphery. Porosity in the 100Cr6 bearing steel deposit can be reduced significantly with the special cooling control system.

CERN Document Server

We describe a method of determining the system parameters in non-eclipsing interacting binaries. We find that the extent to which an observer sees the shape of the Roche-lobe of the secondary star governs the amount of distortion of the absorption line profiles. The width and degree of asymmetry of the phase-resolved absorption line profiles show a characteristic shape, which depends primarily on the binary inclination and gravity darkening exponent. We show that, in principle, by obtaining high spectral and time resolution spectra of quiescent cataclysmic variables or low mass X-ray binaries in which the mass-losing star is visible, fitting the shape of absorption line profiles will allow one to determine not only the mass function of the binary, but also the binary inclination and hence the mass of the binary components.

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional (3-D) prestack reverse-time migration algorithm for common-source P-wave data from anisotropic media is developed and illustrated by application to synthetic data. Both extrapolation of the data and computation of the excitation-time imaging condition are implemented using a second-order finite-difference solution of the 3-D anisotropic scalar-wave equation. Poorly focused, distorted images are obtained if data from anisotropic media are migrated using isotropic extrapolation; well focused, clear images are obtained using anisotropic extrapolation. A priori estimation of the 3-D anisotropic velocity distribution is required. Zones of anomalous, directionally dependent reflectivity associated with anisotropic fracture zones are detectable in both the 3-D common-source data and the corresponding migrated images.

Science.gov (United States)

The /sup 86,88/Sr(d, /sup 3/He)/sup 85,87/Rb reactions were studied at energy of 28 MeV and angular distributions were obtained for all observed states. Spectroseopic factors were extracted from distorted-wave Born-approximation calculations of the cross sections. These spectroacopic factors, and those from the /sup 86,88/Sr(/sup 3/He, d)/sup 87,89/ Y reactions, mixing in the ground state of /sup 88/Sr is inferred. The two g/sub (9/2) neutro n ton orbital populations in /sup 86/Sr. (auth)

Energy Technology Data Exchange (ETDEWEB)

Process solvent was hydrogenated in the brown coal liquefaction, to investigate the influence of it on the prethermal treatment and liquefaction. Consequently, it was found that the n-hexane soluble (HS) yield was improved. In this study, capacity of hydrogen transfer from solvent during prethermal treatment and effects of catalyst were investigated. Since prethermal treatment in oil was effective for improving the oil yield in the presence of hydrogen/catalyst or high hydrogen-donor solvent, influence of hydrogen-donor performance of solvent or addition of catalyst on the hydrogenation behavior of coal and the characteristics of products during prethermal treatment were investigated in relation to successive liquefaction results. As a result, it was found that the increase of HS yield was due to the acceleration of conversion of THF-insoluble using high hydrogen-donor solvent and/or by adding catalyst. It was also found ...

Energy Technology Data Exchange (ETDEWEB)

For developing coal liquefaction processes, it is an important problem to improve the light oil yield with increased oil yield. It was previously reported that distillate mainly containing lighter fraction can be produced with high oil yield by reducing the iron/sulfur catalyst addition in slurry, by recycling gas in the process operation, by utilizing these effects, and by using heavy oil as recycling solvent. In this study, the maximum distillate yield of Victorian brown coal was investigated through continuous liquefaction using a bench scale unit. In addition, operation conditions for obtaining sufficient oil yield were investigated under the reduced catalyst addition into one-third. Consequently, it was confirmed that the maximum content of lighter fraction in distillate product was obtained with reduced catalyst addition by using heavy oil as recycling solvent, by adopting new ...

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of Greek fir wood samples in a fluidized bed reactor was studied. The experimental conditions selected control the yield of gaseous, liquid and solid products. The factors examined were: pyrolysis temperature, mean particle size, pressure, residence time of volatiles, lignin content of biomass and moisture content. The experiments were performed on the basis of a 12-run Plackett-Burman fractional factorial design. Statistical analysis of the data showed that the pyrolysis temperature is the main factor affecting the distribution of the yields of liquids, their phenolic fraction and gases in the range of experimental conditions tested. Empirical expressions were obtained from linear regression giving the yields of liquids, phenols and gases in terms of temperature. The maximum predicted yields were 56 and 12 wt.% on a moisture-free basis at 520 C and 545 C for liquids and phenols, respectively. ...

International Nuclear Information System (INIS)

Doubly-excited 2s-12p-13pnp autoionizing resonance series of Ne atom as well as autoionizing resonances in the 2s region of Na and Mg atoms have been studied with monochromatized synchrotron radiation. Use of charge-separated photoion-yield method allowed us to detect these weak resonances in a clarified way in the yield curves of doubly-charged ions. The observed resonance states have been interpreted with the help of MCDF calculations, and the decay processes of these resonance states are discussed briefly.

Energy Technology Data Exchange (ETDEWEB)

An improved method for the synthesis of (/sup 15/N) 16-Doxyl stearate, a fatty-acid spin label, is reported. The method requires only one mole of (/sup 15/N) 2-amino-2-methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1-3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.

International Nuclear Information System (INIS)

The paper presents experimental investigations of main features of plasma surface interaction and energy transfer to the material surface in dependence on plasma heat loads. The experiments were performed with QSPA repetitive plasma pulses of the duration of 0.25 ms and the energy density up to 2.5 MJ/m2. Surface morphology of the targets exposed to QSPA plasma screams is analyzed. Relative contribution of the Lorentz force and plasma pressure gradient to the resulting surface profile is discussed. development of cracking on the tungsten surface and swelling of the surface are found to be in strong dependence on initial temperature of the target.

British Library Electronic Table of Contents (United Kingdom)

Triacontanol (TRIA) has been realized as a potent plant growth promoting substance for a number of agricultural and horticultural crops. Out of a large number of essential oil bearing plants, mint (Mentha arvensis L.) constitutes the most important source of therapeutic agents used in the alternative systems of medicine. The mint plant has marvelous medicinal properties. In view of enhancing growth, yield and quality of this medicinally important plant, a pot experiment was conducted according to simple randomized block design. The experiment was aimed at studying the effect of four concentrations of TRIA (10?0, 10?7, 10?6 and 10?5?M) on the performance of mint with regard to growth and other physiological attributes, crop yield and quality attributes and the yield and contents of active c...

Energy Technology Data Exchange (ETDEWEB)

The nature of some baryonic resonances is still an unresolved issue. The case of the N{sup *}(1535) is particularly interesting in this respect due to the nearby {eta} N threshold and interference with the N{sup *}(1650). The N{sup *}(1535) has been described as a threshold effect, as a genuine 3-quark resonance, or as dynamically generated from the interaction of the octet of baryons with the octet of mesons. In the scheme of dynamical generation, predictions for the interaction of the N{sup *}(1535) with the photon can be made. In this study, we simultaneously analyze the role of the N{sup *}(1535) in the {pi}N{yields}{pi}N and {gamma}N{yields}{pi}N reactions and compare to the respective amplitudes from partial-wave analyses. This test is very sensitive to the meson-baryon components of the N{sup *}(1535). (orig.)

Energy Technology Data Exchange (ETDEWEB)

Iodine-125 labelled vinyl and aryl iodides are formed via the reaction of sodium iodide-125 with vinyl- and arylboronic acids. Good yields of isomerically pure products are obtained.

Energy Technology Data Exchange (ETDEWEB)

The reaction {gamma}d{yields}{pi}{sup +}nn is calculated up to order {chi}{sup 5/2} in chiral perturbation theory, where {chi} denotes the ratio of the pion to the nucleon mass. Special emphasis is put on the role of nucleon recoil corrections that are the source of contributions with fractional power in {chi}. Using the known near-threshold production amplitude for {gamma}p{yields}{pi}{sup +}n as the only input, the total cross-section for {gamma}d{yields}{pi}{sup +}nn is described very well. A conservative estimate suggests that the theoretical uncertainty for the transition operator amounts to 3% for the computed amplitude near threshold. (orig.)

International Nuclear Information System (INIS)

Neutron yield from the "6","7Li + d reaction has been investigated. The results obtained are compared with the published data with some theoretical models.

UK PubMed Central (United Kingdom)

Mangroves are disappearing rapidly worldwide despite their well documented biodiversity and the ecosystem services they provide. Failure to link ecological processes and their societal benefits has...Full Text Available

Science.gov (United States)

Pulse radiolysis studies of the formation kinetics and the yields of various phenylcarbenium ions from several different solutes in 1,2-dichloroethane solution have been carried out. The results indicate that there are two kinetically distinguishable cationic species of the solvent which react selectively with the different solutes to form the phenylcarbenium ions. It is suggested that one is a cation radical (yield 0.68 molecule/100 eV) and the other a carbocation (yield 0.20 molecule/100 eV). Rate constants for their separate reactions with selected aromatic compounds and with ammonia have been determined. Molar extinction coefficients have been estimated for benzyl cation, diphenyl cation radical, and anthracene cation radical. 6 figures, 1 table.

British Library Electronic Table of Contents (United Kingdom)

Good performance in extended lactations of dairy cattle may have a beneficial effect on food costs, health, and fertility. Because data for extended lactation performance is scarce, lactation persistency has been suggested as a suitable selection criterion. Persistency phenotypes were calculated in several ways: P1 was yield relative to an approximate peak, P2 was the slope after peak production, and P3 was a measure derived to be phenotypically uncorrelated to yield and calculated as a function of linear regressions on test-day deviations of days in milk. Phenotypes P1, P2, and P3 were calculated for sires as solutions estimated from a random regression model fitted to milk yield. Because total milk yield, calculated as the sum of daily sire solutions, was correlated to P1 and P2 (r=0.30 ...

British Library Electronic Table of Contents (United Kingdom)

Nitrogen use efficiency (NUE) of tef, a major staple crop in Ethiopia, is very low, either caused by untimely use of nitrogen (N) fertilizers or lack of other essential nutrients like sulphur (S). The average grain yield of this crop is low, averaging ?1 in farmer?s fields of the semi-arid conditions. Therefore, the present study was conducted to see the effect of the timing of combined N and S fertilization on the yield, yield components, and N and S concentration in the plant parts of the crop. A factorial combination of three rates of N (0, 70, and 105?kg?ha?1) with four rates of S (0, 16, 32, and 48?kg?ha?1) was applied in randomized complete blocks in three replications. The experiment was carried out in the 2004 and 2005 cropping seasons in the Cambisols of the semi-arid area of Ethi...

CERN Document Server

The measurements of the total delayed neutron yield from fast neutron induced fission of sup 2 sup 3 sup 8 U were made. The experimental method based on the periodic irradiation of the fissionable sample by neutrons from a suitable nuclear reaction had been employed. The preliminary results on the energy dependence of the total delayed neutron yield from fission of sup 2 sup 3 sup 8 U are obtained. According to the comparison of experimental data with our prediction based on correlation properties of delayed neutron characteristics, it is concluded that the value of the total delayed neutron yield near the threshold of (n,f) reaction is not a constant.

Science.gov (United States)

... data on pollen from red maple, birch, beech, ash, oak, hemlock and elm trees isolated from cores of ...

Energy Technology Data Exchange (ETDEWEB)

Similitude theory is used to develop scale models for determining the earthquake response of pile foundations embedded in overconsolidated clay. The model is compared with full-scale foundations embedded in natural soil, for which dynamic response measurements had been made in previous work. Correlation of the model and prototype earthquake response constitutes a major difference in this work over previous efforts using scale models. Gravity effects are included in the models by scaling pile and soil material properties. The model pile material is selected to provide the correctly scaled stiffness and mass properties. The required model soil properties are achieved by developing a mixture of bentonite, aerosil, and veegum. Elastic properties of the model soil are compared with those of the prototype by standard monotonic stress and cyclic stress soil tests. It is found that scaling considerations must also apply to supporting static soil tests for determining soil properties, as well ...

International Nuclear Information System (INIS)

The structural transition and anomalous properties of the high temperature A-15 superconductors have been investigated from two different standpoints. The first is a Landau theory based on Gorkov's physical model of a Peierls-like charge density wave (CDW) transition involving electronic CDW order parameters coupled to phonon coordinates. Pretransition elastic anomalies, softening of the [1 anti 10] transverse ([1 anti 10] polarized) phonon, sublattice distortions, variation of transition temperature with stress and alloying and other effects have been accurately predicted, and a detailed comparison is made with experimental results. Central peaks in neutron scattering are shown to be non-dynamic in nature and no pretransition forbidden (300) reflection is predicted. The GAMMA_1_2 optic mode does not go soft at the transition, though its frequency is expected to be temperature dependent right up to room temperature. A tight binding, two (3-D) band model of the A-15 ...

Energy Technology Data Exchange (ETDEWEB)

The mechanism of chemical poisoning of model heterogeneously catalyzed reactions on transition metal surfaces is studied. Clean Mo(001) surfaces were characterized; results suggest a first-layer contraction of 10% of the bulk interlayer spacing. Characterization of clean Co(0001) surfaces is underway. Decomposition of formic acid on Mo(001) surfaces is being studied. (DLC)

Energy Technology Data Exchange (ETDEWEB)

An efficient method of hydrogen storage in nano-porous carbons is its reversible sorption by electrochemical decomposition of a KOH water solution according to the following equation: C + xH{sub 2}O + xe{sup -} {yields} (CH{sub x}) + xOH{sup -} where (CH{sub x}) stands for the hydrogen inserted into the nano-porous carbon during charging and oxidized during discharging. Although various carbon materials have been investigated as hydrogen adsorbents, the information about the storage mechanism as well as the nature of the hydrogen/carbon interaction is still not sufficient. In order to extend the understanding of the process, carbon samples charged electrochemically were investigated by temperature programmed desorption (TPD). The nature of the hydrogen/carbon interaction was studied by electrochemical analysis at different temperatures. The TPD experiments consist of heating the samples from room temperature to 950 C and of quantitative analysis by On-line mass ...

International Nuclear Information System (INIS)

Full text: Verification of the dose delivered to a patient during radiotherapy is an important quality assurance procedure, however this is rarely performed due to the extra time involved. Electronic portal images (EPIs) are currently acquired at many centres during radiotherapy treatment for positioning verification. These could be utilised for dose verification provided 1) an accurate prediction of the dose transmitted through the patient to the EPID can be produced for the patients' radiotherapy beams, and, 2) the EPID image can be converted to an accurate measured dose. Ideally, the radiotherapy planning system (RTPS) would be used to produce the predicted dose as part of the planning procedure. The aim of this project is to investigate whether the convolution-superposition model of the Pinnacle RTPS can accurately calculate dose transmitted through a patient and deposited in a phantom at a large source to surface distance. The dose transmitted through a ...

Science.gov (United States)

Using bremsstrahlung, the resonance fluorescence yield has been measured for the 1.836-MeV 2/sup +//sub 1/ level in /sup 88/Sr. The observed yield corresponds to a level width GAMMA = 2.94 +- 0.15 meV.

Energy Technology Data Exchange (ETDEWEB)

In the framework of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process {gamma}{gamma}{yields}HH are calculated. It is shown that the cross section is measurable at TeV {gamma}{gamma} colliders and is marginally sensitive to the triple-Higgs variation. (orig.).

International Nuclear Information System (INIS)

A review of fission product yields and delayed neutron data for Np-237, Pu-242, Am-242m, Am-243, Cm-243 and Cm-245 has been undertaken. Gaps in understanding and inconsistencies in existing data were identified and priority areas for further experimental, theoretical and evaluation investigation detailed. (author)

Energy Technology Data Exchange (ETDEWEB)

The production of three vector bosons in {gamma} {gamma} collisions studying the reactions {gamma} + {gamma} {yields} W{sup +} + W{sup -} + Z{sup 0} and {gamma} + {gamma} {yields} W{sup +} + W{sup -} + {gamma}. 12 refs., 4 figs., 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

Results of tests on the 1 kg/h continuous reactor for the hydroliquefaction of coal are described. The reactor was operated at 415-435 C and 21 MPa using a continuous stirred reactor with a retention time of about 2 hours. All product oils were recovered by distillation. Sub-bituminous coal was found to give the best product yield. Tests using 5% red mud and 3% improved red mud showed significant increases in oil yield. (4 refs.)

International Nuclear Information System (INIS)

A large IMF- and event characterizing multidetector system (CHICSI) is under development for storage ring experiments. In ''test'' experiments with telescopes of CHICSI type the IMF production has been measured for "1"4N induced reactions at 14A and 32A MeV. Detailed information about the emission sources, particularly from the IMF yield in reactions with isotope separated targets and from isobaric yield ratios in the sub-Coulomb region is discussed. (orig.).