International Nuclear Information System (INIS)

... bismuth chlorides bismuth 207 cadmium chlorides efficiency evaporation high

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International Nuclear Information System (INIS)

Full text: Institute for Nuclear Research, Pitesti-Mioveni, Romania in direct cooperation with the National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest studied and prepared for coating more than 1000 tiles made of Inconel with 7-9 #mu#m of beryllium for nuclear fusion applications at JET, Culham, UK. The principles of manufacturing processes using thermal evaporation and plasma ignited in pure metal vapors as well as by Thermionic Vacuum Arc (TVA) method and the properties of the Ni and Be coatings are presented. The prepared beryllium layers were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and atomic force microscopy. (authors)

International Nuclear Information System (INIS)

The nuclear energy cycle requires the recycling of nuclear fuel, water, chemical reagents, and the volume reduction of radioactive liquid wastes. A fundamental technique for continuous recovery of water using a thin-film evaporator was examined. Appropriate recovery measurements were: an evaporator heat temperature of 323 K, a feed rate of 0.23 cm"3 x s"-"1, a vacuum pressure of 15 mmHg (2 kPa), and impeller rotational speeds of 500#approx#600 rpm (min"-"1). The concentration of trace technetium and rhenium in aqueous solutions was also studied. A decontamination factor of 10"5 for rhenium was obtained. (author)

CERN Document Server

A surface may provide a useful pumping action when able to retain adsorbed gas molecules for the duration of a given experiment. To fulfil this condition at room temperature, strong binding forces, as those resulting from chemical reactions, are required. Materials able to react with gases to form stable chemical compounds are called getters. The two main families of getters (evaporable and non-evaporable, or NEG) are presented and discussed. Special emphasis is placed on the NEG strips currently used for the vacuum systems of particle accelerators, and on the newly developed NEG thin-film coatings, in view of their possible future applications.

International Nuclear Information System (INIS)

Vacuum glazing consists of an evacuated space between two sheets of glass. Vacuum glazing has a large effect on energy savings in houses and buildings. Vacuum glazing can achieve higher insulating performance than conventional insulated glazing. Nippon Sheet Glass has successfully developed conventional vacuum glazing. In this study we investigated an advanced form of vacuum glazing. Its thermal insulation ability is equivalent to 100 mm thick glass wool thermal insulation. This vacuum glazing contained a SnO_2:F low emissivity surface. The influence of the residual gas in a vacuum space on heat flow is important to performance. For long-term thermal stability, it is very important to maintain vacuum stability. To understand this better, we studied the ...

International Nuclear Information System (INIS)

The fundamental optical absorption of ion crystals characterizes the creation of different free low energetic electronic excitation (the excitons and electron-hole pairs), but their straight registration is not possible because of incommensurable big absorption factor of alkali halide monocrystals. So to registration the spectrums of alkali halide monocrystal very fine layers are necessary. We have received fine films of Nal and KCl in system of KCl-Nal-KCl, KCl-KI-KCl on the base of universal vacuum post VUP-4, VUP-5 by thermal evaporation. A unique spectral unit has been created For this on the basic the SDL-2 complex. Complex consists of radiator, systems of condensers, monochromators MDR-12 and MDR-23, receivers of radiation, controller by unit. Connect and control of monochromators by means of IBM-compatible computer has been created. Kinematics schemes of monochromators provide consequent removing on output slot of ...

Energy Technology Data Exchange (ETDEWEB)

The use of vacuum multifoil (VMF) container for thermal insulation in long-life thermal batteries was investigated in a proof-of-concept demonstration. An InvenTek-designed VMF container 4.9 inches in diameter by 10 inches long was used with an internally heated aluminum block, to simulate a thermal-battery stack. The block was heated to 525 C or 600 C and allowed to cool while monitoring the temperature of the block and the external case at three locations with time. The data indicate that it should be possible to build an equivalent-sized thermal battery that should last up to six hours, which would meet the requirements for a long-life sonobuoy application.

Science.gov (United States)

The evolution of the Doublet III neutral beam armor is followed from the initial design of a radiation cooled metallic tile to the present actively cooled graphite design. Results of the thermal and stress analyses that dictated the present design are reviewed.

Energy Technology Data Exchange (ETDEWEB)

We have been developing an innovative Steam Generator concept of Fast Breeder Reactors by using liquid-liquid direct contact heat transfer. In this concept, the SG shell is filled with a molten alloys, which is heated by primary sodium. Water is fed into the high temperature molten alloy, and evaporates by direct contact heating. In order to obtain the fundamental information to discuss the heat transfer mechanisms of the direct contact between the water and the alloy, this phenomenon was visualized by real-time neutron radiography. JRR-3M real-time thermal neutron radiography in Japan Atomic Energy Research Institute was used. Followings are main results. (1) The vigorous evaporation occurs in the molten alloy. This phenomena is different from the known phenomenon such as the evaporation of refrigerant R-113 in the water. (2) The evaporation in the bubble has finished in a moment ...

Energy Technology Data Exchange (ETDEWEB)

A solar energy desalination process utilizing solar radiation directly for the evaporation of salt water is described. Ambient air takes on water vapor as the air passes through an evaporative medium. It is then directed between a saline water-covered, solar absorbing surface and a solar collecting housing. The resulting heated and moisture-saturated air is cooled in a heat exchange means where condensation of fresh water occurs. Simultaneously, cool salt water is utilized as the cooling water in the heat exchange means, and takes on the heat of condensation given up by the condensing vapor. The heated salt water from the heat exchange means is partially directed over the solar absorbing surface, and at least a portion of it is also directed to wet the evaporative medium. Several optional sub-processes are described for operation of the system during periods of reduced insolation, and an alternative process is described for ...

International Nuclear Information System (INIS)

A diagnosis of the refrigerant flows in a refrigerator was carried out by real-time neutron radiography. The thermal neutron radiography system of JRR-3M in Japan Atomic Energy Research Institute and the real-time image processing system developed by Musashi Institute of Technology were used. Freon evaporating flows in the evaporator, condensing flows in the condenser, flashing flows in the capillary tube and flows in the accumulator were visualized and the dynamic behaviors under practical conditions were clarified. In the case of the capillary tube of 0.8 mm i.d., a cooled-CCD camera was utilized. (orig.).

Science.gov (United States)

Lunar resource utilization has focused principally on the extraction of oxygen from the lunar regolith. A number of schemes have been proposed for oxygen extraction from Ilmenite and Anorthite. Serendipitously, these schemes have as their by-products (or more directly as their "waste products"), materials needed for the fabrication of thin film silicon solar cells. Thus lunar surface possesses both the elemental components needed for the fabrication of silicon solar cells and a vacuum environment that allows for vacuum deposition of thin film solar cells directly on the surface of the Moon without the need for vacuum chambers. In support of the US space exploration initiative a new architecture for the production of thin film solar cells on directly on the lunar surface is proposed. The paper discusses experimental data on the fabrication and properties of lunar glass substrates, evaporated lunar ...

British Library Electronic Table of Contents (United Kingdom)

Thermal desorption spectroscopy (TDS) was used to study outgassing from polycrystalline SiGe (poly-SiGe), SiC and SiO"2 films used for poly-SiGe-based MEMS thin film vacuum package technology. Primary desorption products were found to be H"2, H"2O and CO"2. The CO"2 outgassing could be correlated with CF"4 plasma interface cleaning used for thick SiGe PECVD, which can leave carbon at the CF"4-plasma-cleaned interface.

British Library Electronic Table of Contents (United Kingdom)

Heat transfer through the gas diffusion layer (GDL) is a key process in the design and operation of a PEM fuel cell. The analysis of this process requires determination of the effective thermal conductivity as well as the thermal contact resistance associated with the interface between the GDL and adjacent surfaces/layers. In the present study, a custom-made test bed that allows the separation of effective thermal conductivity and thermal contact resistance in GDLs under vacuum and ambient conditions is described. Measurements under varying compressive loads are performed using Toray carbon paper samples with a porosity of 78% for a range of thicknesses. The measurements are complemented by compact analytical models that achieve good agreement with experimental data. A key finding is that ...

International Nuclear Information System (INIS)

The structural, morphological and optical properties of vacuum-evaporated CdTe thin films were investigated as a function of substrate temperature and post-deposition annealing without and with CdCl2/treatment at 400 C for 30 min. Diffraction patterns are almost the same exhibiting higher preferential orientation corresponding to (111) plane of the cubic phase. The intensity of the (111) peak increased with the CdCl2/annealing treatment. The microstructure observed for all films following the CdCl2/annealing treatment are granular, regardless of the as-deposited microstructure. The grain sizes are increased after the CdCl2/annealing treatment but now contain voids around the grain boundaries. The optical band gaps, Eg, were found to be 1.50, 1.50 and 1.48 eV for films deposited at 200 K and annealed without and with CdCl2/treatment at 400 C for 30 min respectively. A progressive sharpening of the absorption edge upon heat treatment particularly for the ...

International Nuclear Information System (INIS)

Radioactive "3"1Si was used as a tracer to study silicon self-diffusion in thin film silicides of cobalt, nickel, palladium and platinum. The specimens were prepared by sequential electron beam evaporation of radioactive "3"1Si and of the metal onto cleaned silicon wafers. By vacuum annealing at the appropriate formation temperature a silicide about 250 nm thick containing a sharp radioactive band about 50 nm thick was generally formed. Subsequent heating above the formation temperature resulted in a spreading of the activity owing to silicon self-diffusion. Activity profiles in the silicides were measured by a combination of ion beam sputtering, radioactivity counting and Rutherford backscattering of charged nuclear particles. (orig.).

British Library Electronic Table of Contents (United Kingdom)

In this study, usage of a variable speed refrigeration system in latent heat thermal energy storage (LHTES) system is investigated to increase energy storage efficiency. Four different compressor speed control cases are compared to obtain a constant heat transfer fluid (HTF) temperature at the inlet of the energy storage tank. These control cases are (i) control with evaporation temperature, (ii) control with ethylene glycol temperature at the outlet section of evaporator, (iii) control with suction pressure of the compressor and (iv) on/off control. By means of the experimental analysis the best control strategy is obtained as control with Case (ii), in terms of stability of inlet temperature of heat transfer fluid, variations of energy efficiency of LHTES and coefficient of performance (...

Energy Technology Data Exchange (ETDEWEB)

Heat transfer through the gas diffusion layer (GDL) is a key process in the design and operation of a PEM fuel cell. The analysis of this process requires determination of the effective thermal conductivity as well as the thermal contact resistance associated with the interface between the GDL and adjacent surfaces/layers. In the present study, a custom-made test bed that allows the separation of effective thermal conductivity and thermal contact resistance in GDLs under vacuum and ambient conditions is described. Measurements under varying compressive loads are performed using Toray carbon paper samples with a porosity of 78% for a range of thicknesses. The measurements are complemented by compact analytical models that achieve good agreement with experimental data. A key finding is that thermal contact resistance is the dominant component of the total ...

Energy Technology Data Exchange (ETDEWEB)

In the United States today, governments at all levels and the citizenry are paying increasing attention to the effects, both real and hypothetical, of industrial activity on the environment. Responsible modem industries, reflecting this heightened public and regulatory awareness, are either substituting benign materials for hazardous ones, or using hazardous materials only under carefully controlled conditions. In addition, present-day environmental consciousness dictates that we deal responsibly with legacy wastes. The decontamination and decommissioning (D&D) of facilities at which mercury was used or processed presents a variety of challenges. Elemental mercury is a liquid at room temperature and readily evaporates in air. In large mercury-laden buildings, droplets may evaporate from one area only to recondense in other cooler areas. The rate of evaporation is a function of humidity and temperature; consequently, ...

British Library Electronic Table of Contents (United Kingdom)

Metallic Zn films were deposited on glass substrates by electron-beam evaporation. ZnO films were synthesized by thermal oxidation of Zn metallic films in air. At the annealing temperature of 550 ?C, ZnO nanowires appeared on the surface, which mainly result from the decrease of oxidation rate. A ZnO ultraviolet photodetector was fabricated based on a metal-semiconductor-metal planar structure. The detector showed a large UV photoresponse with an increase of two orders of magnitude. It is concluded that promising UV detectors can be obtained on ZnO films by thermal oxidation of Zn metallic films. The ways of performing spectral response measurements for polycrystalline ZnO films are also discussed.

Energy Technology Data Exchange (ETDEWEB)

Inert markers (evaporated tungsten and silver) were used in growth studies of silicides formed both by thermal annealing and by ion mixing in the Ni/Si, Pd/Si, and Cr/Si systems. The markers were initially imbedded inside silicides and backscattering spectrometry was used to determine the marker displacement after different processing conditions. The results obtained in thermal annealing are quite consistent with that found in previous investigations. Ni is the dominant diffusing species in Ni/sub 2/Si, while Si is the diffusing species in CrSi/sub 2/. In Pd/sub 2/Si, both Pd and Si are moving species with Pd the faster of the two. In contrast, in growth of silicides by ion irradiation Si is the faster diffusing species in all three systems.

Science.gov (United States)

Using the infrared spectroscopy method, we have studied the effect of thermal dehydration (under vacuum and in air) and treatment with water vapor on the acid centers of very high silicon zeolites of the ZSM type. We have shown that dehydration under vacuum and in air completely and irreversibly removes the OH groups at 1120/sup 0/K, while treatment with water vapor removes these groups at 770/sup 0/K. The Lewis acid centers of dehydrated zeolites (represented by two types of centers) are more heat-stable than the Bronsted acid centers, but the vapor treatment at 1020/sup 0/K leads to the disappearance of the Lewis acid centers. In this work, we discuss the reasons for destruction of the acid centers of the zeolites under different treatment conditions.

Energy Technology Data Exchange (ETDEWEB)

Vacuum insulation panels (VIP) offer excellent thermal resistance properties that can enhance the energy efficiency of insulating systems, save space and contribute to energy consumption reductions. However, VIPs are not used much in Canada, and new commitments to carbon dioxide reductions has created the need to study the prospect of using VIPs in various components of a building envelope. For that reason, assessment methods for the applicability and sustainability of VIPs for use in building envelope construction were developed. There are practical aspects regarding the long-term performance and application of VIPs in building construction. Air molecules and water molecules can permeate through the foil and seams of the VIPs, causing a reduction in thermal resistance. This paper addresses some of the test methods that may accelerate long term changes in thermal resistance. Results were presented from ...

Energy Technology Data Exchange (ETDEWEB)

The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic conditions, ...

CERN Document Server

The influence of motion of ions and electron temperature on nonlinear one-dimensional plasma waves with velocity close to the speed of light in vacuum investigated. It is shown that although the wavebreaking field weakly depends on mass of ions, the nonlinear relativistic wavelength essentially changes. The nonlinearity leads to the increase of the strong plasma wavelength, while the motion of ions leads to the decrease of the wavelength. Both hydrodynamic approach and kinetic one, based on Vlasov-Poisson equations, are used to investigate the relativistic strong plasma waves in a warm plasma. The existence of relativistic solitons in a thermal plasma is predicted.

Energy Technology Data Exchange (ETDEWEB)

A calorimetric sensor with several novel design features has been developed. These sensors will provide an accurate sampling of thermal power density and energy deposition from proton beams incident on target components of accelerator-based systems, such as the Accelerator Production of Tritium Project (APT) and the Spallation Neutron Source (SNS). A small, solid slug (volume = 0.347 cc) of target material is suspended by kevlar fibers and surrounded by an adiabatic enclosure in an insulating vacuum canister of stainless steel construction. The slug is in thermal contact with a low-mass, calibrated, 100-k{Omega} thermistor. Power deposition caused by the passage of radiation through the slug is calculated from the rate of temperature rise of the slug. The authors have chosen slugs composed of Pb, Al, and LiAl.

Energy Technology Data Exchange (ETDEWEB)

Tar sand bitumen is petroleum-based ultra-heavy oil, and has a great amount of reserve like coal. However, there are still a lot of problems for its highly effective utilization. This paper discusses whether the light components in bitumen show independent behavior during the thermal cracking of heavy components, or not. Solvent effect and reaction mechanism during the thermal cracking are also derived from the change of their chemical structures. Athabasca tar sand bitumen was separated into light and heavy fractions by vacuum distillation based on D-1660 of ASTM. Mixtures of the both fractions at various ratios were used as samples. Negative effect of the light fraction on cracking of the heavy fraction was observed with dealkylation and paraffin formation Polymerization of the dealkylated light fraction to the heavy fraction was suggested due to lack of hydrogen in the thermal cracking under nitrogen ...

Energy Technology Data Exchange (ETDEWEB)

A cryocondensation pump was designed for the baffle chamber of General Atomics DIII-D tokamak and will be installed in the fall of 1992. The purpose of the pump is to study plasma density control by pumping the divertor. The pump is toroidally continuous, approximately 10 m long and located in the lower outer corner of the vacuum chamber of the machine. It consists of a 1 m{sup 2} liquid helium-cooled surface surrounded by a liquid nitrogen-cooled shield to limit the heat load on the helium-cooled surface. The liquid nitrogen-cooled surface is surrounded by a radiation/particle shield to prevent energetic particles from impacting and releasing condensed water molecules. A thermal enhancement coating was applied to the nitrogen shell to lower the maximum temperature of the shell. The coating is non-continuous to keep the toroidal electrical resistance high. The whole pump is supported off the water-cooled vacuum vessel wall. ...

Energy Technology Data Exchange (ETDEWEB)

Carbon films have been made by a variety of techniques, including evaporation, sputtering, and laser or thermal pyrolysis of organic polymers. Polyacrylonitrile (PAN) is often used as a carbon precursor, since low-temperature thermo-oxidative pretreatment produces a material which can be pyrolyzed without loss of shape. This is the basis for the production of carbon fibers with good mechanical properties. We report here the formation of very thin films of carbon (500 to 1500 A) by pyrolysis of spin-cast PAN. Using this technique, large, conductive films can be made which are sufficiently robust to allow intact lift-off and transfer of the films from one substrate to another. Such films are chemically inert, but can be photolithographically patterned and etched with an oxygen plasma.

British Library Electronic Table of Contents (United Kingdom)

In this paper, we study the optical properties of indium sulfide thin films to establish the best conditions to obtain a good solar cell buffer layer. The In2S3 buffer layers have been prepared by chemical bath deposition (CBD) and thermal evaporation (PVD). Optical behavior differences have been found between CBD and PVD In2S3 thin films that have been explained as due to structural, morphological and compositional differences observed in the films prepared by both methods. The resultant refractive index difference has to be attributed to the lower density of the CBD films, which can be related to the presence of oxygen. Its higher refractive index makes PVD film better suited to reduce overall reflectance in a typical CIGS solar cell.

Science.gov (United States)

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

Energy Technology Data Exchange (ETDEWEB)

Nomographs are presented that estimate the evaporation loss from external floating-roof tanks using tank diameter, type of seal, product vapor pressure, and wind velocity.

Energy Technology Data Exchange (ETDEWEB)

Conversion of Idaho National Engineering and Environmental Laboratory radioactive sodium-bearing waste into a single solid waste form by evaporation was demonstrated in both flask-scale and pilot-scale agitated thin film evaporator tests. A sodium-bearing waste simulant was adjusted to represent an evaporator feed in which the acid from the distillate is concentrated, neutralized, and recycled back through the evaporator. The advantage to this flowsheet is that a single remote-handled transuranic waste form is produced in the evaporator bottoms without the generation of any low-level mixed secondary waste. However, use of a recycle flowsheet in sodium-bearing waste evaporation results in a 50% increase in remote-handled transuranic volume in comparison to a non-recycle flowsheet.

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

New physical objects, ispalators based on free soap films, exhibit persistent flows of the soap solution in open and closed volumes in air with additions of gases of the C_8F_1_8 type (p = 20 Torr) at temperature drops on the films of the order of tenths and hundredths of kelvin. The flows move continuously at a velocity of 5 - 20 cm s"-"1. It is found that the parts of an inclined ispalator film show anomalous behaviour upon heating: their weight increases and they move downward over the film, whereas the unheated parts of the film move upward. Continuous radial vortex flows accompanied by the formation and washing of the regions of a thin black film are observed on circular films in closed volumes upon their uniform external cooling by evaporating water for 5 - 10 hours. The rapid flows make film ispalators the efficient heat carriers, which operate at small temperature drops (tenths and hundredths of kelvin) and surpass copper in the amount of ...

Energy Technology Data Exchange (ETDEWEB)

This thesis consists of an introduction and five included papers. Of these, four papers are published in international journals and the fifth was submitted for review in April 2000. Emphasis has been placed on both naturally and artificially generated light hydrocarbons in petroleum fluids and their proposed source rocks as well as direct application of light hydrocarbons to oil/source rock correlations. Collectively, these papers describe a strategy for interpreting the source of the light hydrocarbons in original oils and condensates as well as the source of the asphaltene fractions from the reservoir fluids. The influence of maturity on light hydrocarbon composition has also been evaluated. The papers include (1) compositional data on the light hydrocarbons from thermal extracts and kerogen pyrolysates of sediment samples, (2) light hydrocarbon data of oils and condensates as well as the pyrolysis products of the asphaltenes from these fluids, (3) assessment of ...

Energy Technology Data Exchange (ETDEWEB)

The thin windows for the Muon Ionization Cooling Experiment (MICE) liquid Absorber will be fabricated from 6061-T6-aluminum. The absorber and vacuum vessel thin windows are 300-mm in diameter and are 180 mm thick at the center. The windows are designed for an internal burst pressure of 0.68 MPa (100 psig) when warm. The MICE experiment design calls for changeable windows on the absorber, so a bolted window design was adopted. Welded windows offer some potential advantages over bolted windows when they are on the absorber itself. This report describes the bolted window and its seal. This report also describes an alternate window that is welded directly to the absorber body. The welded window design presented permits the weld to be ground off and re-welded. This report presents a thermal FEA analysis of the window seal-weld, while the window is being welded. Finally, the results of a test of a welded-window are presented.

British Library Electronic Table of Contents (United Kingdom)

Magnetic properties of Fe-Co-Mo-Cu-B alloy system with Co up to 26at.% were investigated. After proper thermal treatment, the nanocrystalline grain remains tiny, the density hardly increases, but the room-temperature saturation attains 1.5T mainly due to a high enough Curie temperature. The generally observed slant hysteresis loops point to ribbon surfaces, which stress the ribbon interior and induce a specific magnetoelastic contribution to hard-ribbon-axis magnetic anisotropy even after vacuum annealing. The effect does not come from cobalt but rather from the lack of silicon. Partial removal of the surfaces resulted in a decrease of the loop tilt.

International Nuclear Information System (INIS)

This report summarizes the results of a research programme which involves the development of a laboratory experimental facility for the simulation and study of hydro-thermo-mechanical processes in saturated geomaterials with low permeability. The experimentation involves a synthetic cement based porous material made of cement grout which possesses permeabilities in the range of dense unfractured sandstones or shale. Specially manufactured pore-pressure transducers were installed within the cylindrical block at locations adjacent to a plane free boundary. The block was saturated with the periodic application of a vacuum. In its saturated state the plane boundary of the block was subjected to heating via a circular heater the temperature of which was maintained constant. The resulting pore pressure generation along with temperature at these locations was monitored continuously. The results of a series of experiments are documented and further extensions to the ...

International Nuclear Information System (INIS)

... deposition evaporation fission products fluorides iodine 134 laboratory

ScienceCinema

...global warming situation is more than evaporation around ...background red ? which was the global warming the ...

Science.gov (United States)

The study is concerned with the Stefan problem of evaporation of a volatile component from its solution with a virtually non-volatile material. The analysis provides an analytical solution to the problem based on mass-transfer fundamentals. Results yield the evaporation rate, interfacial mole fractions, concentration profiles in the gas and liquid phases, and the location of the evaporation front. The analysis can be used to provide the binary liquid diffusion coefficient of the volatile component based on experimental data for the liquid gas interface position as a function of time. The requirements for such a measurement are discussed in terms of the volatility of the evaporating component and its initial concentration in the liquid mixture.[Figure not available: see fulltext.

Energy Technology Data Exchange (ETDEWEB)

Hamiltonian light-front dynamics of quantum fields may provide a useful approach to systematic nonperturbative approximations to quantum field theories. The authors investigate inequivalent Hilbert-space representations of the light-front field algebra in which the stability group of the light front is implemented by unitary transformations. The Hilbert space representation of states is generated by the operator algebra from the vacuum state. There is a large class of vacuum states besides the Fock vacuum which meets all the invariance requirements. The light-front Hamiltonian must annihilate the vacuum and have a positive spectrum. Relations are exhibited of the Hamiltonian to the nontrivial vacuum structure. 30 refs.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

The thermal stability of low-friction Me-C/a-C:H coatings is important for their potential applications in the tool and automotive industry. Recently we showed that CrC _x/a-C:H coatings prepared by unbalanced magnetron sputtering of a Cr target in Ar + CH_4 glow discharges exhibit a nanocomposite structure where metastable fcc CrC nanocrystals are encapsulated by an a-C:H phase. Here, we present the structural evolution of these nanocomposite CrC/a-C:H coatings during annealing. High-temperature X-ray diffraction in vacuum and differential scanning calorimetry (DSC) combined with thermo-gravimetric analysis in Ar atmosphere indicate decomposition of the formed metastable fcc CrC phase and subsequent formation of Cr_3C_2 and Cr_7C_3 and structural transformation of the a-C:H matrix phase towards higher sp"2 bonding contents at temperatures above 450 deg. C. Combined DSC and mass spectrometer analysis as well as elemental profiling after ...

International Nuclear Information System (INIS)

This document provides the detailed design requirements for the Spent Nuclear Fuel Project Cold Vacuum Drying Facility. Process, safety, and quality assurance requirements and interfaces are specified.

Energy Technology Data Exchange (ETDEWEB)

Mild hydrotreating is the key to successful re-refining of used lubricating oils. Coupled with pre-distillation and metals removal, the process produces oil of superior color and clarity with acceptable viscosity and heteroatom content. Furthermore, the entire process provides operational simplicity, economic feasibility and environmental attractiveness. Re-refining preserves a valuable resource while solving a potential environmental problem. Increased sensitivity to disposal of hazardous material once again makes re-refining almost a necessity. Various technologies developed to re-refine used lubricating oils range from simple acid/clay contacting to complex solvent extraction. Most technologies require similar capital investment; however, operating costs vary substantially. Current technology seems to converge on a two-step procedure: distillation of dehydrated used oil in a thin-film evaporator, and subsequent hydrotreating of distilled stocks. Filtered used ...

International Nuclear Information System (INIS)

Pilot-scale pyrolysis units have been in operation since 1980 to test the efficiency of thermal treatment of transuranic (TRU) solid waste to retrieve the TRUs and to reduce the volume of wastes such as spent solvent, spent resin, and others. These wastes are generated by reprocessing, fuel production, and utilities. NUKEM has developed a criticality-safe, ring-slab reactor to decompose solid TRU waste. The plant processes 25 kg/h with a polyvinyl chloride content up to 70%. The overall throughput (inactive) up to the spring of 1982 was 2000 kg. The decontamination factor for the reactor itself is 1000. The liquid wastes, mainly spent solvent, are cracked under nitrogen at 400 to 700"0C in a reactor that is filled by a packed bed kept in motion by a specially designed agitator. This unit was built for 15 kg/h water equivalent evaporation. Up to 1982 the unit processed 2000 kg of spent solvent (simulated) overall. The decontamination factor is ...

Energy Technology Data Exchange (ETDEWEB)

Excimer laser processing enables both thermally-driven transformations and the incorporation of solutes into the surface of materials through melting and diffusional mixing. We have examined the effect of excimer laser processing on the microstructure and surface mechanical properties of titanium alloys. Changes in the surface hardness due to laser processing were studied using a Nanoindenter [trademark]. Alloying experiments using both mixing of evaporated surface layers of boron and laser gas alloying in air and in nitrogen all result in changes in the surface hardness of the material. Alloying with boron results in an amorphous surface which is somewhat harder than the as polished surface. Laser processing in air and pure nitrogen results in incorporation of oxygen and nitrogen and the development of fine ([approximately] 50 nm) precipitates of TiO and TiN respectively. Substantial increases in surface hardness result due to solution and ...

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Operation safety and reliability are major guidelines in the design of city-gate units. Conventional natural gas heaters operate by a indirect mechanism, where liquid water is used to transfer heat by natural convection between the combustion chamber and the natural gas coil. In this work, the concept of vapor chamber is evaluated as an indirect gas heater. In a vapor chamber, liquid water is in contact with the heat source, and vaporizes. The vapor condenses in contact with the heat sink. A reduced scale model was built and tested in order to compare these two heating concepts where the combustion chamber was replaced by electrical cartridge heaters. This engineering model can operate either as a conventional heater or as a vapor chamber. The comparison between the concepts was done by inducing a controlled power to the cartridges and by measuring the resulting temperature distributions. In the novel design, the heat exchanger efficiency increases, and the thermal ...

International Nuclear Information System (INIS)

Single crystals of semi-organic L-histidine hydrobromide have been grown by slow evaporation technique from a mixture of L-histidine and hydrobromic acid in aqueous solution at ambient temperature. From high-resolution X-ray diffraction analysis, the crystalline perfection of the grown crystal has been studied. Single crystal X-ray diffraction analyses, Nuclear Magnetic Resonance spectral analysis, Thermo-Gravimetry (TG), Differential Thermal Analysis (DTA) and hardness test have been employed to characterize the as-grown crystals. The UV cutoff wavelength of the grown crystal is below 300 nm and has a wide transparency window, which is suitable for second harmonic generation of laser in the blue region. Nonlinear optical characteristics have been studied using Q switched Nd:YAG laser (#lambda#=1064 nm). The second harmonic generation conversion efficiency of the grown crystals confirms their suitability for frequency conversion applications.

International Nuclear Information System (INIS)

The A-15 compounds are known to favor the occurrence of high temperature superconductivity (transition temperature T/sub c/ > 15K). The origin of superconductivity in these metals is a subject of much controversy and importance. A useful approach to this problem is to study comparatively the superconducting and normal-state properties of the A-15 superconductors and their amorphous counterparts. Efforts along these lines have yielded some insight into the mechanisms responsible for high temperature superconductivity. It is interesting to note that most high-T/sub c/ A-15 compounds contain one glass-forming element such as Ge, Si or Al and are thus conducive to the formation of a non-crystalline phase. The amorphous (or higher disordered) state of the A-15 compounds can be achieved, for example, by one of the following techniques: (1) sputtering or co-evaporation onto substrates held at relatively low temperatures; (2) particle irradiation; and (3) ion-mixing. It ...

Energy Technology Data Exchange (ETDEWEB)

Low-temperature catalytic pretreatment is a promising approach to the development of an improved liquefaction process- This work is a fundamental study on effects of pretreatments on coal structure and reactivity in liquefaction. The main objectives of this project are to study the coal structural changes induced by low-temperature catalytic and thermal pretreatments by using spectroscopic techniques; and to clarify the pretreatment-induced changes in reactivity or convertibility of coals in the subsequent liquefaction. This report describes the recent progress of our work. Substantial progress has been made in the spectroscopic characterization of structure and pretreatment-liquefaction reactions of a Montana subbituminous Coal (DECS-9), and thermochemical analysis of three mw and reacted bituminous coals. Temperature programmed liquefaction has been performed on three low-rank coals both in the presence and absence of dispersed molybdenum sulfide catalyst. We ...

KoreaScience (Korea)

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The vacuum system of the XVTS (X-Ray Vacuum Transport System) for the LCLS (Linac Coherent Light Source) XTOD (X-ray Transport, Optics and Diagnostics) system has been analyzed and configured by the Lawrence Livermore National Laboratory's NTED (New Technologies Engineering Division) as requested by the SLAC/LCLS program. The system layout, detailed analyses and selection of the vacuum components for the XTOD tunnel section are presented in this preliminary design report. The vacuum system was analyzed and optimized using a coupled gas load balance model of sub-volumes of the components to be evacuated. Also included are the plans for procurement, mechanical integration, and the cost estimates.

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Effects associated with the temperature dependence of the level density parameter, a(T), are investigated in connection with neutron evaporation processes. Different approximations, for this temperature dependence, are compared for the case of neutron emission from the compound nucleus /sup 209/Pb.

International Nuclear Information System (INIS)

In this study based on the mass transfer theory, experiments for the evaporation rates depending on various conditions were carried out through the operation of the existing Natural Evaporation Facility in KAERI. Evaporation media were made of the cotton and polyester. Air circulation in the facility was forced by exhausting fans. The evaporation rate and the decontamination factor were calculated by the result of experiment. The evaporation rate increased as the flow rate of air supply, the feed rate of liquid waste, and the temperature of supplied air increased. As for the humility of supplied air, the evaporation rate was getting higher as the humidity was getting lower. As the result of this study, operation conditions of the Natural Evaporation Facility are optimized as follows; The air temperature above 8C .deg., the air humidity below ...

Science.gov (United States)

... without the problem of purple plague. The Au-Ni-In evaporated ... surface and bonding degradation (purple plague) St step-stress ...

Energy Technology Data Exchange (ETDEWEB)

High conductivity liquid waste, which is produced in nuclear power plants, is now processed with radwaste evaporator. The concentrated liquid waste in the evaporator is so highly radioactive and corrosive that the improvement on maintenability and reduction of exposure dose rate are desirable as well as high decontamination factor (DF). Fuji Electric constructed the improved experimental facility of evaporator and carried out an experiment to demonstrate DF, maintenability and controllability of system. As the results, DF, maintenability and controllability were proved to be excellent and its applicability to nuclear power plant was well established.

International Nuclear Information System (INIS)

(1 Feb 1975). Netherlands Rollin, DF Robinson, JE McMaster Univ.,

International Nuclear Information System (INIS)

Full text: As you know, thin films which generate anomalous big photovoltage (APhV) , as film photo resistive structures made of the combinations of A_2B_6 respond to X-ray and #gamma#- radiations. In this work the influence of X-ray and #gamma#-radiations on the quantity of APhV in the system APhV-film-photoresistor was investigated. Earlier polycrystal films with anomalous photo voltage properties were received only on the clean and flat surface with high isolation property (R>10"1"4 #OMEGA#). We worked out the technology of receiving APhV films CdTe on the surface of the photosensitive film CdS. The main condition under which this effect may be observed is that the lining must be slant concerning to the direction of the motion of evaporated substance's molecular bunch during the growing of the film, i.e. received film must have a dendritic structure. That is why photosensitive film CdS was received with thermo vacuum slanting ...

Energy Technology Data Exchange (ETDEWEB)

Equations are derived to calculate the work required for the isentropic compression of a 2-phase fuel-air mixture. Methanol evaporation during compression substantially reduces compression work and improves cycle efficiency and maximum power. Effects of evaporative cooling in the intake manifold are calculated. Energy d. of methanol and gasoline fuel-air charges are compared. The phase equilibrium and evaporation rate are causes of the poor cold-starting performance of methanol.

Energy Technology Data Exchange (ETDEWEB)

The excellent high temperature strength and thermal conductivity of molybdenum-base alloys provide attractive features for components in advanced magnetic and inertial fusion devices. Refractory metal alloys react readily with oxygen and other gases. Oxidized molybdenum in turn is susceptible to losses from volatile molybdenum trioxide species, MoO{sub 3}(m), in air and the hydroxide, MoO{sub 2}(OH){sub 2}, formed from water vapor. Transport of radioactivity by the volatilization, migration, and re-deposition of these volatile species during a potential accident involving a loss of vacuum or inert environment represents a safety issue. In this report the authors present experimental results on the oxidation, volatilization and re-deposition of molybdenum from TZM in flowing air between 400 and 800 C. These results are compared with calculations obtained from a vaporization mass transfer model using chemical thermodynamic data for vapor ...

Science.gov (United States)

The Advanced Coal Liquefaction Research and Development Facility in Wilsonville, Alabama, is funded by the US Department of Energy (DOE), the Electric Power Research Institute (EPRI), and Amoco Corporation. On behalf of these organizations, Southern Company Services manages and Southern Clean Fuels Division of Southern Electric International operates the Wilsonville facility. Oak Ridge National Laboratory (ORNL) receives funding from DOE to provide materials technical support to the Wilsonville operators. For the period July 1987 through November 1990 the plant was operated with two reactors a thermal reactor and a catalytic reactor in a close-coupled integrated two-stage liquefaction mode. Coal processed was obtained from several seams including Ohio No. 6, Illinois No. 6, and Pittsburgh No. 8, as well as Texas lignite and several subbituminous coals. Corrosion samples which were removed for examination at the end of this period were exposed in the ...

International Nuclear Information System (INIS)

The changes in the electrical and structural properties of metal-silicide films caused byion implantation and subsequent thermal annealing have been investigated. Epitaxial silicide films such as those of CoSi"2, NiSi"2 and Pd"2Si grown on Si(111) substrates were implanted with Ar ions and annealed in a vacuum furnace at temperatures ranging from 200 to 800_0C. Rutherford backscattering and channeling techniques and the four-point probe method were used to measure the crystalline quality and the sheet resistance of the films, respectively. It was found that the sheet resistances of CoSi"2, NiSi"2 and Pd"2Si films were increased by factors of 70, 6, and 3, respectively, by implantation to a dose of 1 x 10_1_6 Ar-ions/cm_2, but that they were almost restored by subsequent annealing to the values before implantation. A phase transformation from Pd"2Si to PdSi was also observed in the high-temperature annealing of the implanted Pd"2Si films. ...

Energy Technology Data Exchange (ETDEWEB)

The paper presents the preparation, X-ray powder diffraction data as well as some magnetic and spectroscopic properties of a new uranium(III) complex bromide of the formula NH{sub 4}UBr{sub 4}.1.5CH{sub 3}CN.6H{sub 2}O. The compound crystallizes in the monoclinic system with a=11.877 A, b=6.385 A, c=6.815 A, {beta}=101.29deg and Z=2. In the 60-240 K range it follows the Curie-Weiss law with {theta}=-37.24 K and {mu}{sub eff}=3.20 B.M. The IR and UV-VIS absorption spectra were recorded in the 80-4000 cm{sup -1} and 4000-26000 cm{sup -1} spectral ranges respectively. Thermal decomposition at a non-static high vacuum enabled the conversion of the compound into pure and anhydrous UBr{sub 3}. (orig.).

International Nuclear Information System (INIS)

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

British Library Electronic Table of Contents (United Kingdom)

SummaryThis paper examines the sensitivity and uncertainty of evaporation estimates from Nasser Lake, south of Egypt using data collected at the floating station Raft, 2km upstream of the Aswan High Dam, and 12 evaporation models. Based on their approach the evaporation models were ranked in five classes, respectively the Bowen ratio energy budget (BREB) approach, three energy-aerodynamic based methods, a mass transfer method, two temperature and five solar radiation-temperature approaches. State dependent parameter models were used to estimate the sensitivity indices of the different evaporation estimation methods at daily and monthly frequencies. A drastic reduction in the cost of the sensitivity analysis was obtained when coupled with efficient sampling methods, producing quasi-Monte Ca...

Energy Technology Data Exchange (ETDEWEB)

In the nuclear power stations of GDR the rough radioactive waste includes borat-containing evaporator bottoms and spent ion exchanger resins. For its final disposal in deep geological formations (rock salt mines) this waste has to be solidified. The experience of one year lasting operation of a steam heated thin-film evaporator (heating surface 2 m{sup 3}) for evaporator bottoms to be solidified with a solid content of 200-250 g/l are reported on. In short time such amount of water is abstracted from the rough waste that due to the borate content a hot high-viscous product passes from evaporator to waste drum and there solidifies like glass to monolith. The product quality depends on the adjustment of the flow-equilibrium in the evaporator. Boric acid is used as matrix for the radioactive residues. The residual water content of the solidified waste product was about 15-20%, the ...

Energy Technology Data Exchange (ETDEWEB)

The first equipment installed at KfK-HDB was a system with a thin-film evaporator. This was later replaced by two vapor compression evaporating units with forced circulation, for evaporation of liquid LAW, and a steam-heated natural circulation evaporator, for evaporation of liquid MAW. Nuclear activities of the Karlsruhe Nuclear Research Center phasing out, the liquid radwaste quantities to be treated have been shrinking accordingly, so that the current system is planned to be replaced by a smaller system with a thin-film evaporator. (orig./HP) [Deutsch] Im Laufe der Jahre wurde die Anlage mit Duennschichtverdampfer durch zwei Bruedenkompressionsverdampfer mit Zwangsumwaelzung fuer die Eindampfung leicht aktiver waessriger Abfaelle und einem dampfbeheizten Naturumlaufverdampfer fuer die Eindampfung mittelaktiver waessriger Abfaelle ersetzt. Mittlerweile sinkt ...

Energy Technology Data Exchange (ETDEWEB)

An evaporator using a hydrophobic membrane made from a polytetrafluoroethylene (PTFE) was developed to improve DF (Decontamination Factor) and to reduce evaporator size. The membrane distillation, provided by the evaporator, is a new technique for liquid purification. Fundamental experiments were carried out to develop the membrane filter (tube type, outer diameter, 8 mm; membrane thickness, 500 {mu}m) for radioactive liquid treatment. The continuous operation test using actual liquid waste was also made during about 3,000 h. (This is almost equal to the operation time of an actual evaporator per year.) The evaporation rate decreased with increase an operation time due to contamination of waste impurity. But the rate was recovered by washing the membrane with hot water and then drying it. DF was over 10{sup 4} which is ten times larger than that for a conventional system. A pilot ...

CERN Document Server

Ergonomics of the thermal environment

Science.gov (United States)

... Accession Number : ADD141533. Title : Yttrium Oxides in Vacuum-Plasma- Sprayed CoNiCrAlY Coatings,. Descriptive Note : Journal Article,. ...

International Nuclear Information System (INIS)

The possibility of surface modification of high-speed steel cutting tool by means of vacuum-plasma treatment including ion nitriding in gas plasma followed by the deposition of wear resistant (Ti, Al)N coatings in metal-gas plasma of a vacuum arc discharge is studied. The regularities of nitrided layer formation and the structure of these layers under various operation conditions of cutting tool are investigated. Optimum conditions of vacuum-plasma treatment providing the best wear resistance of cutting are determined

International Science & Technology Center (ISTC)

Development of Method and Technical Project of the Plant for Thermo-Vacuum Desorption of Tritium Oxide (HTO) from the Environmental Samples

International Nuclear Information System (INIS)

The method of an effective potential is used to investigate the possible types of evolution of vacuum shells in the Friedmann-Schwarzschild world. Such shells are assumed to emerge during phase transitions in the early Universe. The possible global geometries are constructed for the Friedmann-Schwarzschild worlds. Approximate solutions to the equation of motion of a vacuum shell have been found. The conditions under which the end result of the evolution of the vacuum shells under consideration is the formation of black holes and wormholes with baby universes inside have been found. The interior of this world can be a closed, flat, or open Friedmann universe.

International Nuclear Information System (INIS)

Single pellets (of approximately 70 g each) of irradiated lithium aluminate target from N-Reactor test PT-57 were used in a series of experiments to determine the extent to which the product tritium can be recovered by (a) vacuum outgassing of the target (thermal extraction-TX) and (b) in-vacuo chemical dissolution of the target in molten sodium tetraborate (flux extraction-FX). Five TX runs and seven FX runs were made. Thirty-five percent of the tritium was recovered in a form non-condensable at -196"0C. The remainder was recovered in a condensable form (as T_2O, HTO, etc.). Post-extraction analysis of the melt from the seven flux extractions showed that a maximum of 2 percent of the original amount of tritium remained and that target dissolution was essentially complete in 12 hours. Flux extraction of two pellets which had been subjected to thermal extraction showed less than 0.4 percent of the original amount of tritium ...

Energy Technology Data Exchange (ETDEWEB)

A program is currently in progress at Argonne National Laboratory to evaluate and develop evaporator technology for concentrating radioactive waste streams. By concentrating radioactive waste streams, disposal costs can be significantly reduced. To effectively reduce the volume of waste, the evaporator must achieve high decontamination factors so that the distillate is sufficiently free of radioactive material. One technology that shows a great deal of potential for this application is being developed by LICON, Inc. In this program, Argonne plans to apply LICON`s evaporator designs to the processing of radioactive solutions. Concepts that need to be incorporated into the design of the evaporator include, criticality safety, remote operation and maintenance, and materials of construction. To design an effective process for concentrating waste streams, both solubility and vapor-liquid equilibrium data are ...

International Nuclear Information System (INIS)

Development of a front end system for a high energy proton accelerator is in progress at Korea Atomic Energy Research Institute (KAERI) for basic science and industrial applications. The proper vacuum components has been installed and operated successfully between ion source and RFQ. The reliable operation of the accelerator has been completed at vacuum system in the high and ultra high vacuum range under operating conditions. Proper control system for the vacuum instruments, based on PC operated by Windows, has been designed and constructed by control group at PAL. As PC operated by windows with inherent instability does not proper, embedded system can be replaced for reliable operation system, such as VME system operated by vxWorks.

International Nuclear Information System (INIS)

The fusion excitation function for the radioactive projectile "8 Li on a "2"0"8 Pb target has been measured at energies near the Coulomb barrier. The results show that in the considered energy interval, the evaporation of four neutrons is the most relevant mechanism. However, at the highest energies used in the experiment, the Sn channel begins to appear. The preliminary experimental cross sections show a good agreement with the predictions of a simple evaporation calculation using the code PACE. (Author) 16 refs., 1 tab., 4 figs.

Energy Technology Data Exchange (ETDEWEB)

The feasibility of the anodic protection of titanium evaporators in Al[sub 2](SO[sub 4])[sub 3] solution was studied by the measurement of polarization curves, weight loss, solubility of passive film and AC impedance. The protection parameters and efficiency were determined. In addition, the practical technology of anodic protection was studied by screening reference electrodes and auxiliary cathodes. Throwing power was also measured. Four rows of tube-type evaporators of titanium have been anodically protected in situ. Field tests lasting more than one year shows satisfactory results. (orig.)

Science.gov (United States)

... After strip- ping off the chloroform, the dibromo ethyl (EDBEB) compounds are separated from the m-BDBEB using a thin film evaporator. ...

International Nuclear Information System (INIS)

Russian 2008 p. 27-29 Russian Federation Belanova, EA Kozlov, PV FGUP

International Nuclear Information System (INIS)

Most of the low-level liquid radioactive wastes generated from PWR plants are classified into high or low total suspended solid(HTDS or LTDS), radio-chemical waste and radioactive laundry waste. Although the evaporation process has a high decontamination ability, it has several problems such as corrosion, foaming, and congestion. A new liquid waste disposal process using the ion-exchange demineralizer(IED) has been introduced into the Yonggwang NPP 5 and 6 to complement the current evaporation process. To determine the differences, these two methods have been compared in this study. Those aspects compared here were the released radioactivity volume of the liquid radioactive wastes, The dose of off-site residents, the decontamination factor, and the amount of the solid radioactive wastes. While it was expected that the liquid radioactive waste volume in the evaporating system would be 20 percent higher than in the IED, the ...

Energy Technology Data Exchange (ETDEWEB)

Typical beam lines are comprised of an assembly of vacuum valves and shutters referred to as a ''front end'', optical elements to monochromatize, focus and split the photon beam, and an experimental area where a target sample is placed into the photon beam and data from the interaction is detected and recorded. Windows are used to separate sections of beam lines that are not compatible with storage ring ultra high vacuum. Some experimental beam lines share a common vacuum with storage rings. Sections of beam lines are only allowed to vent up to atmospheric pressure using pure nitrogen gas after a vacuum barrier is established to protect ring vacuum. The front end may only be bled up when there is no current in the machine. This is especially true on the VUV storage ring where for most experiments, windows are not used. For the shorter wavelength, ...

Energy Technology Data Exchange (ETDEWEB)

Heat transfer augmentation techniques (passive, active or a combination of passive and active methods) are commonly used in areas such as process industries, heating and cooling in evaporators, thermal power plants, air- conditioning equipment, refrigerators, radiators for space vehicles, automobiles, etc. Passive techniques, where inserts are used in the flow passage to augment the heat transfer rate, are advantageous compared with active techniques, because the insert manufacturing process is simple and these techniques can be easily employed in an existing heat exchanger. In design of compact heat exchangers, passive techniques of heat transfer augmentation can play an important role if a proper passive insert configuration can be selected according to the heat exchanger working condition (both flow and heat transfer conditions). In the past decade, several studies on the passive techniques of heat transfer augmentation have been reported. ...

International Nuclear Information System (INIS)

In the first part of this paper, IrO_2 electrodes produced by thermal decomposition of H_2IrCl_6 precursor were manufactured using the spin coating deposition technique, where centrifugal forces spread the precursor solution with simultaneous evaporation of the solvent on the rotating Ti substrate. It was found using this technique, that it is possible to obtain thin and uniform IrO_2 coatings with controlled loadings. The influence of the concentration of iridium salt in the precursor solution (c_0) as well as the influence of the rotation speed at which the substrate spins (#omega#) on the IrO_2 loading have been studied using voltammetric charge measurements. From these results, a simple relation has been proposed for the estimation of the IrO_2 loading for a given c_0 and #omega#. In the second part of this paper and from measurements performed using different IrO_2 loadings and formic acid concentrations, the kinetic parameters of the ...

International Nuclear Information System (INIS)

In this work, a focused ion beam (FIB) milling process has been developed to fabricate 50 nm Bi nanowire and transistor structures using FEI-200 dual beam FIB system. For the fabrication, 50 nm bismuth film was thermally evaporated through EBL patterned PMMA windows onto SiO_2 substrates with pre-defined contact pads. Bi nanowire widths ranging from 30 nm to 100 nm have been successfully fabricated by milling out unwanted areas using 30 KeV Ga+ ion beam. A single-pixel-line ion beam blanking technique has been utilised to fabricate Bi nanowire as small as 30 nm in diameter and few micrometers long. In order to form good ohmic contacts for sub 50 nm bismuth nanowires, a drill-and-fill process has been developed using FIB to sputter away the surface oxide of bismuth after the in-situ platinum nanowire contacts deposition. To our knowledge, this is the first time a focused ion beam process has been used to fabricate bismuth nanowire. The ...

Energy Technology Data Exchange (ETDEWEB)

Doping of molecular organic materials is important for the functionality of organic electronic devices as e.g solar cells. We investigated the doping behaviour of the acceptor molecules Cl{sub 2}-DCNQI and F{sub 16}CuPc incorporated into a CuPc matrix. In-situ XPS/UPS measurements were performed on coevaporated films. Doping by Cl{sub 2}-DCNQI was not successful. The molecule lost its chlorine atoms during thermal evaporation. For pristine F{sub 16}CuPc layers we observe a strong broadening of the photoemission features with increasing deposition rate indicating different domains probably of different molecular structure of differing electric interface potential. F{sub 16}CuPc incorporated into CuPc shows sharp photoemission features. With increasing F{sub 16}CuPc content Fermi level shifts are observed in both phases. In CuPc the maximum shift is about 0.45 eV towards the HOMO level indicating p-doping. Simultaneously the Fermi level in F{sub ...

Energy Technology Data Exchange (ETDEWEB)

Equations are derived to permit calculation of the work required for the isentropic compression of a two phase fuel-air mixture. Methanol evaporation during compression is shown to substantially reduce compression work and thereby improve cycle efficiency and maximum power. Effects of evaporative cooling in the intake manifold are calculated. 14 refs.

Energy Technology Data Exchange (ETDEWEB)

The peculiarities of pulsed laser melting and evaporation of the superconducting ceramics are analyzed by means of numerical simulation. The appearance of the overheated metastable states in solid and liquid phases is shown as a result of the phase front dynamics and volume nature of laser energy release. A method of dynamic adaptation for the multifront Stefan problem is proposed.

International Nuclear Information System (INIS)

Crude N,N-dialkylcarbamoylmethylphosphonates and phosphine oxide extractants, and particularly crude dihexyl N,N-diethylcarbamoylmethylphosphonate and octylphenyl N,N-diisobutylcarbamoyl phosphine oxide, are purified by distilling the crude materials in a thin film evaporator. Preferably, the crude materials are reacted with concentrated hydrochloric acid and then with aqueous sodium hydroxide prior to distillation in the thin film evaporator to hydrolyze impurities contained in them. The purified extractants are useful for extracting actinides and lanthanides from liquid waste streams. (author).

Energy Technology Data Exchange (ETDEWEB)

The High-Level Waste Storage Tank Farms/242-A Evaporator Standards/Requirements Document (S/RID) is contained in multiple volumes. This document (Volume 2) presents the standards and requirements for the following sections: Quality Assurance, Training and Qualification, Emergency Planning and Preparedness, and Construction.

Energy Technology Data Exchange (ETDEWEB)

For the sugar industry, a new system of multiple-effect evaporation consuming minimal steam has been designed by means of a mathematical model and its advantages and characteristics are analysed. A way is found to overcome difficulty in operation and instability of the amount of steam consumed. Statistical data obtained using the new system are compared with the old system and show an economic profit as well as confirming the validity of the model. (author)

Science.gov (United States)

Testing was performed to determine the feasibility and processing characteristics of evaporation of actual Defense Waste Processing Facility (DWPF) recycle material. Samples of the Off Gas Condensate Tank (OGCT) and Slurry Mix Evaporator Condensate Tank (SMECT) were transferred from DWPF to the Savannah River National Lab (SRNL) Shielded Cells and blended with De-Ionized (DI) water and a small amount of Slurry Mix Evaporator (SME) product. A total of 3000 mL of this feed was concentrated to approximately 90 mL during a semi-batch evaporation test of approximately 17 hours. One interruption occurred during the run when the feed tube developed a split and was replaced. Samples of the resulting condensate and concentrate were collected and analyzed. The resulting analysis of the condensate was compared to the Waste Acceptance Criteria (WAC) limits for the F/H Effluent Treatment Plant (ETP). Results from ...

Energy Technology Data Exchange (ETDEWEB)

A solid electrolyte cell comprises an alkali metal anode, e.g. lithium, a halogen-containing organic polymer cathode and a solid elecrolyte between the anode and the cathode. The cathode comprises iodine-containing vacuum-cyclised polyacrylonitrile, and the solid electrolyte is preferably lithium iodide and halogen-free vacuum-cyclised polyacrylonitrile. This patent also discloses the use of isotactic polyacrylonitrile, a method of making a cathode comprising iodine-containing vacuum-cyclised polyacrylonitrile, and novel methods of making the solid elecrolyte cells described.

Science.gov (United States)

A precise technique for studying coal liquefaction in a 200 cc stirred-batch-autoclave has been developed. Reaction pressures of up to 4000 psig and temperatures of up to 850/sup 0/F can be employed. The slurry temperature in the autoclave is controlled within 2/sup 0/F by raising or lowering the autoclave which is partially submerged in a sandbath; hence the name: Variable Submergence Temperature Control (VaSTeC). Heatup and cooldown are achieved in 5 and 2 minutes, respectively. A mini-scale vacuum distillation procedure was developed for measurement of 1000/sup 0/F-distillate with a repeatability of 0.3%. About 99% material balance is routinely obtained in the autoclave runs. The following yield repeatabilities have been demonstrated (MAF coal basis):H/sub 2/ cons. (0.1%), C/sub 1/ to C/sub 3/ gas (0.3%), C/sub 4/-1000/sup 0/F distillate (2.4%), and unconverted carbon (0.5%). The autoclave can simulate the yield slate of the thermal ...

Science.gov (United States)

The MgF{sub 2} monocrystals were irradiated at room temperature with 390 keV B{sup +} ions up to the fluence of 10{sup 16} cm{sup -2}. The irradiated samples were (isochronally and isothermally) annealed in high vacuum at the temperatures 200 deg. C, 300 deg. C, 400 deg. C, 500 deg. C, 600 deg. C and 700 deg. C for the times ranging from 2-100 hours. After each annealing step, the boron depth distribution was determined using the neutron depth profiling technique. As implanted, the depth distributions of boron exhibited standard Gaussian-like forms, but the evaluated profile parameters, R{sub P} = 960 nm and {delta}R{sub P} = 140 nm, were higher than those calculated using the SRIM code (R{sub P} = 870 nm and {delta}R{sub P} = 115 nm). Annealing at temperatures up to 400 deg. C did not change the depth profiles. Annealing at 600 deg. C, however, led to a one-way gradual transfer of the boron atoms from the site of implantation towards the sample surface, and in ...

International Nuclear Information System (INIS)

We present and characterize an experimental system in which we achieve the integration of an ultrahigh finesse optical cavity with a Bose-Einstein condensate (BEC). The conceptually novel design of the apparatus for the production of BECs features nested vacuum chambers and an in vacuo magnetic transport configuration. It grants large scale spatial access to the BEC for samples and probes via a modular and exchangeable ''science platform.'' We are able to produce 87Rb condensates of 5x106 atoms and to output couple continuous atom lasers. The cavity is mounted on the science platform on top of a vibration isolation system. The optical cavity works in the strong coupling regime of cavity quantum electrodynamics and serves as a quantum optical detector for single atoms. This system enables us to study atom optics on a single particle level and to further develop the field of quantum atom optics. We describe the technological modules and the operation of the combined ...

International Nuclear Information System (INIS)

Nonevaporable getters (NEGs) have been extensively studied in the last several years for their sorption properties toward many gases. In particular, an innovative alloy as a thin film by magnetron sputtering was developed and characterized at the European Organization for Nuclear Research. It is composed of Ti-Zr-V and protected by an overlayer of palladium (Pd), according to a technology for which the authors got the licence. NEG-Pd thin films used in combination with ion getter pumps is a simple, easy way to handle pumping devices for ultrahigh and extremely high vacuum applications. To show how to apply this coating technology to the internal surface of different types of ion pumps, the authors carried out several tests on pumps of various shapes, sizes (in terms of nominal pumping speed), and types (diode, noble diode, and triode). Special care was taken during the thermal cycle of baking and activation of the pumps to preserve the internal ...

CERN Document Server

We investigate the solar neutrino problem in the scenario of three generation neutrino oscillation hypothesis, taking into account other phenomenological constraints to the neutrino mixing and mass parameters.

Energy Technology Data Exchange (ETDEWEB)

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

International Nuclear Information System (INIS)

A high-average power (kW) infrared (IR) free-electron laser (FEL) is currently being commissioned for the Jefferson Laboratory FEL User Facility. The IR FEL is driven by a unique superconducting rf linac which is recirculated to recover electron beam power that is not radiated in the FEL. The design and installation of the vacuum system for the FEL involved particular attention to minimizing particulate contamination which could cause problems with the superconducting acceleration cavities and the high power FEL optics. Particulate contamination levels of all vacuum components were monitored during the cleaning process using laser scattering. Cleaning, transport, and installation procedures were developed to minimize the contamination of the complete system. We will summarize a data base we compiled of particulate contamination levels of the various components installed in the FEL vacuum system.

International Nuclear Information System (INIS)

Throughout the last decades, plasma technology has been established in a series of surface treatment applications, e.g. for semiconductor processing or optical coatings. The majority of plasma assisted technologies is based on low pressure processes. In recent years, however, non-thermal atmospheric pressure discharges have attracted considerable interest because of their simplified technical devices for industrial applications as compared to low pressure processes which require vacuum equipment. Hence, batch processing can be avoided, thus facilitating the implementation of plasma process steps into production lines. Investment costs are cut down significantly. The use of atmospheric pressure plasmas for technical applications dates back to the ozone production with dielectric barrier discharges (DBD) by Siemens in 1857. Lately, the application of atmospheric pressure plasmas for surface treatment has been reported, e.g. for the treatment of ...

Energy Technology Data Exchange (ETDEWEB)

A detergent-containing radioactive liquid waste originating from atomic power plants is concentrated to have about 10 wt. % detergent concentration, then dried in a thin film evaporator, and converted into powder. Powdered activated carbon is added to the radioactive waste in advance to prevent the liquid waste from foaming in the evaporator by the action of surface active agents contained in the detergent. The activated carbon is added in accordance with the COD concentration of the radioactive liquid waste to be treated, and usually at a concentration 2-4 times as large as the COD concentration of the liquid waste to be treated. A powdery product having a moisture content of not more than 15 wt. % is obtained from the evaporator, and pelletized and then packed into drums to be stored for a predetermined period.

British Library Electronic Table of Contents (United Kingdom)

For a soft-contact-lens (SCL) wearer, corneal health and comfort are strongly influenced by water transport through the polymeric materials used in lens fabrication. In particular, evaporative water loss at the anterior lens surface is a potential cause of contact-lens dehydration and of post-lens tear-film depletion, which in turn, may lead to discomfort, dryness syndrome, and/or lens adhesion.We present a solution-diffusion model for transport of water through soft-contact-lens materials to mimic evaporative dehydration from a contact lens during blinking and to access possible SCL adhesion to the corneal surface under a variety of environmental conditions (e.g., wind speed and relative humidity). To describe the water-transport process, we use an extended version of the Maxwell-Stefan m...

British Library Electronic Table of Contents (United Kingdom)

Extraction of hemicellulose from hardwood chips prior to pulping is a possible method for producing ethanol and acetic acid in an integrated forest bio-refinery, adding value to wood components normally relegated to boiler fuel. Hemicellulose was extracted from hardwood chips using green liquor, a pulping liquor intermediate consisting of aqueous NaOH, Na2CO3, and Na2S, at 160degreeC, held for 110min in a 20L rocking digester. The extracted liquor contained 3.7% solids and had a pH of 5.6. The organic content of the extracts was mainly xylo-oligosaccharides and acetic acid. Because it was dilute, the hemicellulose extract was concentrated by evaporation in a thin film evaporator. Concentrates from the evaporator reached levels of up to 10% solids. Inhibitors such as acetic acid and sodium ...

Energy Technology Data Exchange (ETDEWEB)

This report describes experiments to determine whether a wiped film evaporator (WFE) might be used to concentrate low-level liquid radioactive waste (LLLW). Solutions used in these studies were surrogates that contain no radionuclides. The compositions of the surrogates were based on one of Oak Ridge National Laboratory`s (ORNL`s) Melton Valley Storage Tanks (MVSTs). It was found that a WFE could be used to concentrate LLLW to varying degrees by manipulating various parameters. The parameters studied were rotor speed, process fluid feed temperature and feed rate, and evaporator temperature. Product consistency varied from an unsaturated liquid to a dry powder. Volume reductions up to 68% were achieved. System decontamination factors were consistently in the range of 10{sup 4}.

Energy Technology Data Exchange (ETDEWEB)

We consider particle evaporation and fission of an ensemble of hot, rotating compound nuclei as a stochastic process. We derive a set of coupled differential equations formed by a Fokker-Planck equation describing fission, and master equations for calculating particle evaporation. From these equations, we are able to determine multiplicities of prefission neutrons, protons and {alpha}-particles, their energy spectra and their angular momentum distributions. A comparison of our results with experimental data provides us with information regarding the reduced friction coefficient {beta}, the fission barrier height and the level density parameter. For different iridium isotopes, ({sup 181,185,187}Ir), {sup 185}Os and {sup 158}Er, we obtain as an upper limit {beta}{<=}8.0x10{sup 21} s{sup -1}. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Short communication. 2 figs.

Energy Technology Data Exchange (ETDEWEB)

Vacuum arc with cathode spots on the cold electrode is widely used as a plasma generator in a such kind of devices like metal ion sources, plasma cathode electron guns, thing films deposition facilities and others. Most vacuum arc devices utilize a high voltage discharge across an insulator surface to provide a trigger plasma which in turn initiates the main arc discharge. Operation of vacuum arc in a repetitively pulsed mode required a stable triggering system for the long time. But with a discharge across the insulators the number of stable pulses is limited by 100,000 or little bit more. The better method for vacuum arc ignition is low pressure discharge. As shown in this paper it is possible to increase the lifetime of the ignition system in 10 times at least, but negative characteristic of this system is a relatively high pressure (about 0.1 mtorr). In some kinds of vacuum arc ...

Energy Technology Data Exchange (ETDEWEB)

The Technical Safety Requirements (TSRs) for the Cold Vacuum Drying Facility define acceptable conditions, safe boundaries, bases thereof, and management or administrative controls required to ensure safe operation. Controls required for public safety, significant defense-in-depth, significant worker safety, and for maintaining radiological and toxicological consequences below risk evaluation guidelines are included.

Energy Technology Data Exchange (ETDEWEB)

An algebraic formulation of the electromagnetic field in which various quantization procedures can be described was chosen to discuss perturbation calculations. It is shown that the Feynman rules and the second order calculation of the self-energy of the electron can be developed on the basis of the Fermi method of quantization. The algebraic approach clarifies the problems in defining the vacuum and other states which are associated with calculations in terms of field algebra operators. It is demonstrated that the vacuum state defined on the field algebra by Schwinger leads to incorrect results in the self-energy calculation.

International Nuclear Information System (INIS)

We analyze the stability of the structure equations of the vacuum in the brane world models, by using both the linear (Lyapunov) stability analysis, and the Jacobi stability analysis, the Kosambi-Cartan-Chern theory. In the brane world models the four-dimensional effective Einstein equations acquire extra terms, called dark radiation and dark pressure, respectively, which arise from the embedding of the three-brane in the bulk. Generally, the spherically symmetric vacuum solutions of the brane gravitational field equations have properties quite distinct as compared to the standard black hole solutions of general relativity. We close the structure equations by assuming a simple linear equation of state for the dark pressure. In this case the vacuum is Jacobi stable only for a small range of values of the proportionality constant relating the dark pressure and the dark radiation. The unstable trajectories on the brane behave ...

Energy Technology Data Exchange (ETDEWEB)

Vertical thin film evaporators have been used to concentrate and dry solutions because their rotating swing blades prevent scale from being deposited on the heated surfaces. Powdering capacity of the vertical thin film evaporator was examined experimentally for drying applications of radioactive liquid waste generated from nuclear power plants. As a result, it was found that the powdering capacity increased with the blade rotation, changing significantly in the low ratational region and scarcely in the high rotational region. The powdering capacity in the high rotational region was restricted by the lack of heat flux which was theoretically evaluated for the concentrating process. As the critical factor in the low rotational region was not clear, a visual test apparatus was made to observe flow patterns in the evaporator, and a powdering model was obtained. This model showed that powdering process was obstructed when the ...

Energy Technology Data Exchange (ETDEWEB)

Atomic Energy of Canada Limited (AECL) operates the Waste Treatment Centre (WTC) to treat and immobilize some of the low- level radioactive waste (LLRW) streams at the Chalk River Laboratories (CRL). The WTC at treats low- level radioactive liquid waste by removing the contaminants from the wastewater, concentrating them, and immobilizing them. The fundamental design concept for the WTC is to process the waste streams using forced circulation type liquid waste evaporation (LWE), to solidify the concentrates using thin film evaporator and to discharge the purified effluent into the Ottawa River following verification monitoring. The solidified product drums are stored in existing storage facilities in the CRL. The LWE was installed in the WTC to treat the LLRW. After about four (4) years of design, construction and cold commissioning, the active commissioning of the evaporator process using radioactive waste streams ...

International Nuclear Information System (INIS)

This textbook contains the following main topics: Heat conductivity, convection, condensation and evaporation, radiation heat transfer and heat exchangers. It includes the physical foundations for all these aspects and many examples. (orig.)

Energy Technology Data Exchange (ETDEWEB)

The thermodynamic properties of aqueous solutions containing ammonia and sour gases such as carbon dioxide, sulfur dioxide, or hydrogen sulfide must be known in many applications. A typical example is the cleaning of raw gases in power stations. The enthalpy changes upon partial evaporation of aqueous solutions containing ammonia and of aqueous solutions containing ammonia and carbon dioxide were measured at temperatures from 313 to 393 K with a thin film evaporator flow calorimeter. The molalities of ammonia and carbon dioxide entering the calorimeter ranged up to 12 and 6 mol/kg, respectively. The physicochemical model originally developed by Edwards et al. (1978) and further modified and extended by Kurz et al. (1995) to describe phase equilibria in aqueous systems containing ammonia and carbon dioxide is used to derive a predictive enthalpy model for this complex, chemical reactive system. Comparisons between the new experimental results ...

Energy Technology Data Exchange (ETDEWEB)

This patent describes a method comprising applying a passivation layer of CaF{sub 2} to the surface of a superconductive ceramic oxide by evaporation. The CaF{sub 2} layer is effective to passivate the oxide surface without disrupting the superconductive properties.

Energy Technology Data Exchange (ETDEWEB)

A computer code ICRKFLO was used to simulate the multiphase reacting flow of fluidized catalytic cracking (FCC) riser reactors. The simulation provided a fundamental understanding of the hydrodynamics and heat transfer processes in an FCC riser reactor, critical to the development of a new high performance unit. The code was able to make predictions that are in good agreement with available pilot-scale test data. Computational results indicate that the heat transfer and droplet evaporation processes have a significant impact on the performance of a pilot-scale FCC unit. The impact could become even greater on scale-up units.

Energy Technology Data Exchange (ETDEWEB)

Insulated pressure vessels are cryogenic-capable pressure vessels that can be fueled with liquid hydrogen (LIQ) or ambient-temperature compressed hydrogen (CH2). Insulated pressure vessels offer the advantages of liquid hydrogen tanks (low weight and volume), with reduced disadvantages (lower energy requirement for hydrogen liquefaction and reduced evaporative losses). This paper shows an evaluation of the applicability of the insulated pressure vessels for light-duty vehicles. The paper shows an evaluation of evaporative losses and insulation requirements and a description of the current experimental plans for testing insulated pressure vessels. The results show significant advantages to the use of insulated pressure vessels for light-duty vehicles.

Energy Technology Data Exchange (ETDEWEB)

The composition of alkaline and neutral boric acid containing evaporator concentrates resulting from the treatment of radioactive waste water in nuclear power plants with WWER reactors is described as well as the processing of these concentrates to a product suitable for final disposal. Tests with mock solutions of these evaporator concentrates have been performed at the laboratory and teststand scale to produce a dry residue by continuous thickening, which can be processed into a highly leach resistant product, suitable for final disposal, by cementation. Ca-compounds must be added to the evaporator concentrates prior to the drying in an rotary thin-film evaporator (RTFE). The tests showed that neutral evaporator concentrates can be dried in a RTFE with addition of small amounts of Ca-compounds. The alkaline evaporator concentrates with high boric acid and ...

International Nuclear Information System (INIS)

On all steam turbines operating with condensation the air leakage penetrating from the part of the plant which is under vacuum must be eliminated, in order to maintain the vacuum created by physical conditions. In order to attain effective air bleed-off, the water-steam-air mixture is conveyed via the super-cooling bundles in the condenser. In this way the steam partial pressure decreases and the air partial pressure increases at a constant condenser pressure. In this procedure the mixture is supercooled by about 4"0C compared with the saturate steam temperature appertaining to the condenser pressure. The values of volume of air leakage are the result of a year's experience on existing plant. (orig.).

CERN Document Server

One hope to solve the cosmological constant problem is to identify a symmetry principle, based on which the cosmological constant can be reduced either to zero, or to a tiny value. Here, we note that requiring that the vacuum state is Lorentz invariant significantly reduces the theoretical value of the vacuum energy density. Hence, this also reduces the discrepancy between the observed value of the cosmological constant and its theoretical expectation, down from 123 orders of magnitude to 56 orders of magnitude. We find that, at one loop level, massless particles do not yield any contribution to the cosmological constant. Another important consequence of Lorentz symmetry is stabilization of the gravitational hierarchy: the cosmological constant (divided by Newton's constant) does not run as the quartic power of the renormalization group scale, but instead only logarithmically.

British Library Electronic Table of Contents (United Kingdom)

We have measured time-resolved laser-induced incandescence of flame-generated soot under high-vacuum conditions (4.1?10?6 mbar) at an excitation wavelength of 532 nm with laser fluences spanning 0.06?0.5 J/cm2. We generated soot in an ethylene/air diffusion flame, introduced it into the vacuum system with an aerodynamic lens, heated it using a pulsed laser with a spatially homogeneous and temporally smooth laser profile, and recorded LII temporal profiles at 685 nm. At low laser fluences LII signal decay rates are slow, and LII signals persist beyond the residence time of the soot particles in the detection region. At these fluences, the temporal maximum of the LII signal increases nearly linearly with increasing laser fluence until reaching a plateau at ?0.18?J/cm2. At higher fluences, th...

Science.gov (United States)

PMID:4462663

Science.gov (United States)

No Abstract Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared

International Nuclear Information System (INIS)

Short communication.

CERN Document Server

We study from a critical perspective several quantum-electrodynamic phenomena commonly related to vacuum electromagnetic (EM) fluctuations in complex media. We compute the resonance-shift, the spontaneous emission rate, the local density of states and the van-der-Waals-Casimir pressure in a dielectric medium using a microscopic diagrammatic approach. We find, in agreement with some recent works, that these effects cannot be attributed to variations on the energy of the EM vacuum but to variations of the dielectric self-energy. This energy is the result of the interaction of the bare polarizability of the dielectric constituents with the EM fluctuations of an actually polarized vacuum. We have found an exact expression for the spectrum of these fluctuations in a statistically homogeneous dielectric. Those fluctuations turn out to be different to the ones of normal radiative modes. It is the latter that carry the ...

International Nuclear Information System (INIS)

A scheme is presented for the generation of entangled states for two cavity mirrors. In the scheme each mirror initially in a vacuum state interacts with a weak coherent field, resulting in a photon-number dependent kick. The detection of a photon leaking from the cavities collapses the two mirrors to an entangled state.

International Nuclear Information System (INIS)

A Monte Carlo simulation of the vacuum Bianchi type-IX (mixmaster) cosmology yields a significant correlation between large universe volume and high anisotropy. An analog of the model's chaotic classical behavior is seen in the break up of the universe wave function at large volume into fingers in the corners of the minisuperspace anisotropy potential.

Science.gov (United States)

Spontaneous radiation by an atom in a Rydberg state is inhibited by use of parallel conducting planes to eliminate the vacuum modes at the transition frequency. Spontaneous radiation emission is observed to turn off abruptly at the cutoff frequency of the waveguidelike structure, and the natural lifetime is measured to increase by a factor of at least 20.

Science.gov (United States)

Bulk monomer MMA was impregnated into simul, a fuel wood of Bangladesh, under vacuum and under normal temperature and pressure conditions in order to compare the mode of impregnation and its effect on various characteristic parameters of wood plastic composites. Methanol (MeOH) was used as the swelling solvent with methylmethacrylate (MMA) at MMA: MeOH = 70:30, v/v. Impregnation of the bulk monomer was very high under vacuum compared to that at normal condition; but the difference of grafting of MMA to the wood cellulose under these two impregnating conditions was much lower as compared to that of the uptakes of impregnating solution MMA + MeOH under these two modes of impregnation. Incorporation of additives to MMA + MeOH has substantially enhanced grafting, tensile strength, bending strength and compression strength of the composite to such an extent that there is virtually very little difference between vacuum ...

Energy Technology Data Exchange (ETDEWEB)

Plasma surface interactions in tokamaks are known to create significant quantities of dust, which settles onto surfaces and accumulates in the vacuum vessel. In ITER, a loss of vacuum accident may result in the release of dust which will be radioactive and/or toxic, and provides increased surface area for chemical reactions or dust explosion. A new method of analysis has been developed for modeling dust resuspension and transport in loss of vacuum accidents. The aerosol dynamic equation is solved via the user defined scalar (UDS) capability in the commercial CFD code Fluent. Fluent solves up to 50 generic transport equations for user defined scalars, and allows customization of terms in these equations through user defined functions (UDF). This allows calculation of diffusion coefficients based on local flow properties, inclusion of body forces such as gravity and thermophoresis in the convection term, and user defined ...

UK PubMed Central (United Kingdom)

The recovery of schistosome cercariae from natural waters has been limited by variations in turbidity and in the accuracy of recovery with different techniques. A modification of the Rowan vacuum paper...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Additional results using a calorimetric technique for measuring the total hemispherical emittance of pipe surfaces from 400 to 600 K are described. Two different Pyrex pipe enclosures were used, one of 15 cm i.d. and the other of 30 cm i.d. An error analysis showed that the larger diameter Pyrex pipe should have a smaller error, but the difference was negligible for the 4.4-cm test pipe diameter used. Measurements on a short length of a previously-measured pipe agreed with earlier measurements, but only over the temperature range of the measurements. While the technique normally uses a vacuum to minimize nonradiative heat transfer, measurements were done succesfully with an argon atmosphere in a closed system. A nickel-plated pipe, measured first in a vacuum and then in an argon atmosphere, allowed calculation of an effective convective heat-transfer coefficient for use with test pipes of unknown emittances. Measurements done with an atmosphere ...

Energy Technology Data Exchange (ETDEWEB)

The choice of vacuum state for a quantum scalar field propagating in a de Sitter spacetime (massive and arbitrarily coupled to the gravitational field) is discussed. The problem of finite-time initial conditions for the mode functions is analyzed, as well as how these determine the vacuum state of the quantum system. The principle guiding the choice of vacuum state is the following: one wants the vacuum contribution to the energy-momentum tensor to contain all the ultraviolet divergent terms, so that the particle creation terms are finite, and covariantly conserved. There is a suitable set of modes (instantaneous adiabatic basis) in which this splitting of the expectation value of the energy-momentum tensor can be carried out. Numerical results are presented for different finite-time initial conditions (m = 0.6, {zeta} = 1/6). The nature of the particle creation effect is described and its relationship ...

Energy Technology Data Exchange (ETDEWEB)

Looks at the impact of cooling strategies with air and both direct and indirect liquid cooling for battery thermal management.

Energy Technology Data Exchange (ETDEWEB)

The vacuum polarization splitting of the M-shell states in muonic hydrogen can have a profound influence on the muonit de-excitation cascade in deuterium and tritium targets. The cascade also shows sensitive dependence on the precise rate of transfer processes between certain excited muonic deuterium and tritium atoms. Recent experimental data, where a much greater population of the (d..mu..) qs state (1/sub 1//sub //sub s/) was found than previously predicted, can be explained if the transfer rates from the (d..mu..) M-shell are assumed to be strongly suppressed.

Energy Technology Data Exchange (ETDEWEB)

The main results of earlier work by the author, Sushko, and Khoruzhii describing the algebraic structure of quantum-field systems with (discrete) vacuum superselection rules are generalized to the large class of Wightman theories with essentially self-adjoint field operators (a very strong restriction was imposed on the theory, namely, that the polynomial Op algebra of the Wightman fields /rho/ belongs to the class II, i.e., /rho/ /sub s'/ =/rho/ /sub w'/). It is also shown that the field Op algebra of a Wightman theory with discrete vaccum superselection rule possesses a class II extension.

CERN Document Server

If quantum fields exist in extra compact dimensions, they will give rise to a quantum vacuum or Casimir energy. That vacuum energy will manifest itself as a cosmological constant. The fact that supernova and cosmic microwave background data indicate that the cosmological constant is of the same order as the critical mass density to close the universe supplies a lower bound on the size of the extra dimensions. Recent laboratory constraints on deviations from Newton's law place an upper limit. The allowed region is so small as to suggest that either extra compact dimensions do not exist, or their number is about to be tightly constrained by experimental data.

Energy Technology Data Exchange (ETDEWEB)

We consider the dynamics toward the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The 'Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.

CERN Document Server

We consider the dynamics towards the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. The `Bianchi type IX attractor theorem' states that the past asymptotic behavior of generic type IX solutions is governed by Bianchi type I and II vacuum states (Mixmaster attractor). We give a comparatively short and self-contained new proof of this theorem. The proof we give is interesting in itself, but more importantly it illustrates and emphasizes that type IX is special, and to some extent misleading when one considers the broader context of generic models without symmetries.

Energy Technology Data Exchange (ETDEWEB)

To prove that two-layer, TBP-nitric acid mixtures can be safely stored in the canyon evaporators, it must be demonstrated that a runaway reaction between TBP and nitric acid will not occur. Previous bench-scale experiments showed that, at typical evaporator temperatures, this reaction is endothermic and therefore cannot run away, due to the loss of heat from evaporation of water in the organic layer. However, the reaction would be exothermic and could run away if the small amount of water in the organic layer evaporates before the nitric acid in this layer is consumed by the reaction. Provided that there is enough water in the aqueous layer, this would occur if the organic layer is sufficiently thick so that the rate of loss of water by evaporation exceeds the rate of replenishment due to mixing with the aqueous layer. This report presents measurements of mass transfer rates for the ...

Energy Technology Data Exchange (ETDEWEB)

The use of the focused ion beam (FIB) systems has increased to a high level in recent years. The imaging, milling, and deposition capabilities of the FIB make it the ideal instrument for e.g., site-specific failure analysis, specimen preparation and nano-machining. Ion channelling contrast allows for selective imaging of polycrystalline and polyphase microstructures. In addition, the FIB and CrossBeam registered instruments are unique stand-alone analytical tools. Their vast capabilities have enabled numerous applications into the semiconductor and materials sciences applications. These integrated CrossBeam registered Tools enable the observation and direct control of the FIB operation in real time. In addition to the improved accuracy and resolution the electron beam adds analytical capabilities as STEM, EDS and EBSP to the instruments. To ensure a safe and reliable operation of the instrument, a dedicated vacuum system is needed. This type of instrument combines ...

Energy Technology Data Exchange (ETDEWEB)

Discussions were given on the characteristics of a diesel engine to emit unburned hydrocarbon (HC) created in a long idling operation. The engine tested in the experiment is a direct injection diesel engine with six water-cooled were investigated varying the jet hole diameter and length of the jet nozzle. In the initial operation period, the HC showed high values. This is thought because part of the injected fuel has deposited on the wall because of low combustion chamber wall temperature, and the fuel deposit that did not evaporate during combustion evaporated during expansion process and emitted unburned. The head was dismantled to investigate the carbon flowers deposited on the nozzle and the relationship between the carbon and the HC deposited on the head face and the combustion chamber wall. It was clarified that the HC increase was phenomenal compared with that of the carbon. This is because the injected fuel was adsorbed into the carbon, ...

Energy Technology Data Exchange (ETDEWEB)

A process and apparatus for solidifying radioactive waste liquid containing dissolved and/or suspended solids is disclosed. The process includes chemically treating for pH adjustement and precipitation of solids, concentrating solids with a thin-film evaporator to provide liquid concentrate containing about 50% solids, and drying the concentrate with heated mixing apparatus. The heated mixing apparatus includes a heated wall and working means for shearing dried concentrate from internal surfaces and subdividing dry concentrate into dry, powdery particles. The working means includes a rotor and helical means for positively advancing the concentrate and resulting dry particles from inlet to outlet of the mixing apparatus. The dry particles may also be encapsulated in a matrix material. Entrained particles in the vapor stream from the evaporator and mixer are removed in an integral particle separator and the vapor is subsequently condensed and may ...

Energy Technology Data Exchange (ETDEWEB)

The Raywell Process Plants unit, which reclaims a wide range of organic solvents, including chlorinated hydrocarbons, is based on thin film evaporation and distillation rather than steam distillation, thus reducing the risk of contamination by water. Henry Balfour and Co.'s Pfaudler Solvent Recovery System gives 96% or better solvent recovery and produces a near-solid waste suitable for landfill disposal; like the Raywell system, it uses a mechanically wiped thin-film evaporator. Midland Oil Refineries uses sa Raywell thin-film evaporator for recovery of waste lubricating oils rather than the conventional sulfuric acid/clay treatment, thus avoiding formation of sulfuric acid sludge waste. The Henry Balfour Bioenergy anaerobic digestion system gives yields of fuel gas with 65-75% methane as high as 0.8 cu m/kg BOD; it achieves 95-98% BOD removal with no pH control or nutrient addition because it separates solids ...

Energy Technology Data Exchange (ETDEWEB)

The Rocky Flats Plant (RFP) generates large volumes of a low level aqueous waste stream high in nitrate salts. The aqueous waste is concentrated by evaporation and then mixed with Portland cement prior to transport and disposal. Planned process upgrades include a new horizontal thin film evaporator. Temperature of brine at discharge end of the new evaporator will be near boiling point. Introduction of hot water to cement can degrade the monolithic waste form. However, the RFP salt waste contains high concentrations of compounds known to retard hydration. This paper discusses impact of introducing high temperature waste to cement. The study evaluated three waste compositions: (1) highest probable nitrate composition, (2) highest probable chloride composition, and (3) current composition. Results showed that compressive strength of final waste form increased with brine temperature, and waste forms from brine at the boiling ...

Energy Technology Data Exchange (ETDEWEB)

Nomographs have been constructed to estimate the average evaporation loss from internal floating-roof tanks. Loss determined from the charts can be used to evaluate the economics of seal conversion and to reconcile refinery, petrochemical plant, and storage terminal losses. The losses represent average standing losses only. They do not cover losses associated with the movement of product into or out of the tank. The average standing evaporation loss from an internal floating-roof tank depends on: vapor pressure of the product; type and condition of roof seal; tank diameter; and type of fixed roof support. The nomographs can estimate evaporation loss for product true vapor pressures (TVP) ranging from 1.5 to 14 psia, the most commonly used seals for average and tight fit conditions, tank diameters ranging from 50 to 250 ft, welded and bolted designs, and both self-supporting and column-support fixed roof designs. The charts ...

International Nuclear Information System (INIS)

Bituminization has to be selected as the process for conditioning radioactive liquid wastes arising from the two VVER V-230 reactors being built at Temelin in the Czech Republic. In the process, a thin-film evaporator, operating at a waste-product temperature of 160"oC, evaporates all free water from the waste effluents. Remaining solids are homogeneously dispersed in a bitumen matrix which solidifies through natural cooling of the binder. The relative simplicity of the process reduces construction costs for on-line waste facilities and operating costs are less given the cheap basic material and simple maintenance. The reliability of the process has been demonstrated at Western reactors and reprocessing plants though adaptations have had to be made to accept VVER effluents. (UK).

Energy Technology Data Exchange (ETDEWEB)

The fundamental points to be considered in a waste treatment system for a country like Japan, where the final disposal method has not been decided and the wastes have to be stored in the power plants, are volume reduction of the wastes, safe storage of the wastes in the plant, and flexibility regarding the final disposal. A system has been developed that consists of a thin film evaporator for the direct solidification of the liquid waste, a pelletizer for producing hard pellets from the powdered wastes, a pellet storage unit, and a solidification unit for the final disposal. A pilot plant with waste treatment capacity of 200 kg/h was built in 1976 and has proved the system feasibility. This paper reports on pilot plant tests of the thin film evaporator and other components, tests on pellet deterioration during long term storage, and integrity tests on the final disposal of the pellet bitumen package.

Energy Technology Data Exchange (ETDEWEB)

Based on a multi-zone spray-mixing approach, an air-fuel mixing and combustion model for a Direct Injection Diesel engine is presented. The predictions from the model show very good agreement with the experimental data for various engines under a wide range of operating conditions. Major physical processes are modeled and validated independently. The atomisation process is based on Binary Drop Division concept. Fuel droplets are considered randomly distributed in the spray. A spherico-symmetrical transient drop evaporation model is used for evaporation calculation. A 3-dimensional spray-swirl interaction is modeled on centreline velocity vector/continuum approach. Turbulent mixing is characterised considering all possible available energy sources in DI diesel engines.

Energy Technology Data Exchange (ETDEWEB)

The measurement of local heat transfer coefficients is necessary to record the basic phenomena of heat transfer in thin-film apparatuses. For this reason the so-called electrochemical analogy method was developed and used for this application. The electrochemical method implies a specifically composed electrolyte which substitutes the fluid to be evaporated in the thin-film apparatus. Using the redox electrolyte (0,025 kmol/m/sup 3/ K/sub 4/Fe(CN)/sub 6/ resp. k/sub 4/Fe(CN)/sub 6/ and 2nNaOH) the viscosity was, for the first time, thickened until 0.4 Pa s by the help of hydroxyethyl-cellulose.

International Nuclear Information System (INIS)

Liquid radioactive waste treatment method of using evaporator was widely used from Kori 1 to Uljin 3 and 4, but a liquid radioactive waste treatment equipment that uses an ion exchange method instead of an evaporator was adopted aiming to minimize amount of radioactive waste and radiation exposure. However, the same equipment was introduced and applied for the first time in Korea and had experienced difficulties in securing credibility for the equipment and handling of liquid radioactive waste with inadequate data about performance and experience in operation and maintenance. In this study, examination, application and effect analysis was performed on the optimization measure for handling liquid radioactive waste of Yonggwang Nuclear Power Unit 5 and 6(YGN 5 and 6) that applies an ion exchange method

British Library Electronic Table of Contents (United Kingdom)

Heat pipes, loop heat pipes (LHP), and capillary pumped loops (CPL) have already proven their potential to remove high heat fluxes from a small electronic device and transport the heat to a heat sink that is large enough to transfer it into the ambient air. We introduce a novel two-loop system similar in design to CPLs but with an additional buoyancy-driven fluid loop. Non-degassed methanol is used as a working fluid. Key benefits compared to LHPs and CPLs are easy filling procedure, easy startup, and the tolerance toward noncondensable gases in the fluid. The amount of fluid in the system can be varied over a broad range without affecting the heat transfer performance. Three different inverted-meniscus-type evaporators have been employed in this study. A maximum evaporator heat transfer r...

CERN Document Server

Condensed matter black hole analogues may provide guidance in grappling with difficult questions about the role of short distance physics in the Hawking effect. These questions bear on the very existence of Hawking radiation, the correlations it may or may not carry, the nature of black hole entropy, and the possible loss of information when a black hole evaporates. We describe a model of black hole formation and evaporation and the loss of information to a disconnected universe in a thin film of 3He-A, and we explain why the existence of Hawking radiation has not yet been demonstrated in this model. [We would like this article to be accessible to researchers in both condensed matter and gravitational physics, hence we include more than the usual amount of introductory material.

British Library Electronic Table of Contents (United Kingdom)

An evaporative cooling system developed for operation and qualification testing of silicon pixel and microstrip detectors for the inner tracking detector of the CERN ATLAS spectrometer is described. Silicon detector substrates must be continuously operated between 0 and ???7?C in the high radiation environment near the circulating beams at the CERN Large Hadron Collider (LHC). This requirement imposes unusual constraints on the cooling system and has led to the choice of perfluoro-n-propane (C3F8) refrigerant, which combines good chemical stability under ionizing radiation with high dielectric strength and nonflammability. Since the silicon detectors must also be of extremely light construction to minimize undesirable physics background, coolant tubes are of thin (200 ?m) aluminum wall, wh...

Science.gov (United States)

An electric power generating apparatus is described, including: a solar collector; a primary thermal loop including primary thermal fluid; a cavity receiver to receive reflected solar energy from the solar reflector, convert the solar energy into thermal energy, and transmit the thermal energy to the primary thermal fluid by heating the primary thermal fluid not to exceed a given temperature, the given temperature being substantially equal to 700 F; a Stirling engine receiving the primary thermal fluid heated by the cavity receiver, including means to generate mechanical power and means to generate electrical power from the means to generate mechanical power.

Energy Technology Data Exchange (ETDEWEB)

Following a recent refurbishment of the NPL Thermal Neutron Facility, the spectrum of the epithermal and fast neutron component of the beam produced by the thermal column of this facility was measured over the energy range from thermal to 20 MeV using a Bonner sphere spectrometry system. The effect of the presence of epithermal and fast neutrons on the measured response of commonly-used thermal neutron dosemeters was calculated. (author)

Energy Technology Data Exchange (ETDEWEB)

A Vacuum Circuit Breaker demonstrated its ability to interrupt short circuits with faster than normal rates of rise of Transient Recovery Voltage (TRV) at levels greater than those produced by most transformer secondary faults. Two recent exploratory test programs evaluated the interrupting ability of a 15kV Vacuum Circuit Breaker containing interrupters of the rotating arc type with contacts made from a Chromium-Copper powder metal mixture. The interrupting conditions covered a wide range of currents from 10% to 130% of the 28kA rated short circuit current of the tested circuit breaker and a wide range of TRV rates of rise, including the relatively slow rate of rise, normally used in testing and found in most indoor circuit breaker applications; two faster rates of rise equaling and exceeding those found in a known power plant transformer secondary protection application; and the fastest rates of rise possible in the laboratory which exceed ...

International Nuclear Information System (INIS)

The present study is aiming at the visualization of the boiling structures for various pool boiling and flow boiling conditions by applying multiple visualization techniques simultaneously. The bubble growth rate and microlayer behavior were simultaneously visualized for an isolated boiling regime of a water by using a shadow graph and a total reflection technique, respectively

Energy Technology Data Exchange (ETDEWEB)

CdTe/SnTe heterojunctions, prepared by EDRI (evaporation-diffusion en regime isotherme) and CSVT (close spaced vapour transport) techniques, have a spectral response in a wide wavelength range (0.3 - 1.5 ..mu..m) which exhibits two distinct bands, corresponding to carrier generation in each material of the couple. Experimental results are interpreted in terms of a Schottky diode model. (orig.).

International Nuclear Information System (INIS)

An internuclear cascade-evaporation code is used to model energy deposition in thin slabs of silicon. This model shows that protons produce a significant number of events with effective Linear Energy Transfer (LET) greater than 8 MeV cm"2/mg and demonstrates that proton testing of microelectronic components can be an effective way to screen devices for low earth orbit susceptibility to heavy ions.

Wastenet

...direct-injection systems Atomisation from hole-type nozzles (gasoline and diesel) under cavitating flow conditions Spray-wall interaction in gasoline direct injection engines Spray-wall interaction in direct-injection diesel engines Evaporation of multi-component fuels Cavitation in diesel injectors Nozzle flow, air motion, spray development and combustion in marine diesel engines ...

Energy Technology Data Exchange (ETDEWEB)

This document, the Standards/Requirements Identification Document (S/RID) Phase I Assessment Report for the subject facility, represents the results of an Administrative Assessment to determine whether S/RID requirements are fully addressed by existing policies, plans or procedures. It contains; compliance status, remedial actions, and an implementing manuals report linking S/RID elements to requirement source to implementing manual and section.

International Nuclear Information System (INIS)

Papers presented at a meeting on indoor and outdoor climates on sites polluted with volatile organic chemicals. The papers deal with the subject of evaporation of organic chemicals on the polluted sites in relation to the influence on indoor and outdoor climates. Themes dealt with are diffusion through soils and transport of pollutants from the soil into buildings. (AB).

Energy Technology Data Exchange (ETDEWEB)

Neutron time-of flight spectra were measured from 90 MeV protons and 140 MeV alpha-particle bombardment of Al, Ni, Zr, and Bi at laboratory angles between 20/sup 0/ and 130/sup 0/. The proton induced neutron spectra reveal three distinct energy regions; a low energy evaporation region, a high-energy region dominated by quasi-free scattering processes and an intermediate-energy region dominated by multi-step, pre-equilibrium processes. In the latter two regions, the spectra show strong angular dependence. The alpha-induced neutron spectra show these same distinct energy regions plus an exponential fall-off above the beam energy per nucleon. The high-energy portions of the forward-angle neutron and proton cross sections are in ratios consistent with the assumption that single nucleon-nucleon scattering dominates. For heavy-mass targets, the low-energy evaporation regions show neutron yields larger than proton yields. The proton-to-neutron ratios ...

Science.gov (United States)

The report describes tests to demonstrate the feasibility of using a vertical-tube, falling-film, vapor-compression evaporator to concentrate waste water from a flue gas desulfurization (FGD) process. Tests showed that waste water from the Chiyoda FGD process can be concentrated ...

Energy Technology Data Exchange (ETDEWEB)

We revisited the quantum Zeno paradox, which claims that a generic quantum system prepared in a state which is not an eigenstate of the Hamiltonian operator and is continuously observed never decays. Since any perfectly isolated quantum system always interact with a vacuum field, we analyze the possibility of using this fact to solve the above mentioned conceptual problem. Therefore we discuss a two-level system or qubit-Bose field interaction Hamiltonians. We consider the quantum dynamics of this two-level system, prepared in the excited state interacting with a Bose field prepared in the Poincare invariant vacuum state. Using a first-order approximation in time-dependent perturbation theory, we evaluate the probability of spontaneous decay of the two-level system driven by the vacuum field. This probability is evaluated for a finite time interval. Using the standard argument to obtain the quantum Zeno paradox, we consider ...

Energy Technology Data Exchange (ETDEWEB)

Aiming to realize ball bearings operable in a vacuum and under high temperature, silicon nitride (Si3N4) ceramic ball bearings were tested. The tested ball bearings were angular contact ball bearings composed of silicon nitride with sputtered molybdenum disulfide coating using a retainer of hot-pressed self-lubricating composite material. The time variation of the frictional torque was examined for the operations under the conditions at 500{degree}C in a vacuum at a rotational speed of 600 rpm and 50N thrust load for 5{times}10{sup 7}revolutions (1400 hours) and for 1.5{times}10{sup 8}revolutions (4200 hours). Excellent tribological performance was obtained. The ball bearings are lubricated with the molybdenum disulfide film at the initial stage of the operation and with a transfer film formed from the retainer material to the balls. In a test at 650{degree}C, low and stable frictional torque was observed up to 500 hours of operation as of the ...

Energy Technology Data Exchange (ETDEWEB)

The decays of charmed mesons into two body nonleptonic final states are investigated. Weak interaction amplitudes of interest in these decays are extracted from lattice four-point correlation functions using a effective weak Hamiltonian including effects to order G{sub f} in the weak interactions yet containing effects to all orders in the strong interactions. The lattice calculation allows a quantitative examination of non-spectator processes in charm decays helping to elucidate the role of effects such as color coherence, final state interactions and the importance of the so called weak annihilation process. For D {yields} K{pi}, we find that the non-spectator weak annihilation diagram is not small, and we interpret this as evidence for large final state interactions. Moreover, there is indications of a resonance in the isospin {1/2} channel to which the weak annihilation process contributes exclusively. Findings from the lattice calculation are compared to results from the continuum ...

Science.gov (United States)

The present study investigates the effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer enhancement in a pipe flow. The constant heat flux as thermal boundary condition was adopted in the thermally developed region. The present analytical results show the heat transfer enhancement over those of a shear rate-independent thermal conductivity fluid. The heat transfer coefficient ratio (h/h{sub 0}) linearly increase with the non-dimensional average velocity difference which is the product of the shear rate-dependence of the thermal conductivity and wall-shear rate.

Science.gov (United States)

... Accession Number : ADD109273. Title : THERMAL STABILITY OF ALPHA-BETA TITANIUM ALLOY Ti-5Al-2Cr-1Fe,. Corporate Author : ...

Science.gov (United States)

... Advanced thermal storage systems based on very high temperature solid materials such as boron carbide or graphite have been investigated for ...

Science.gov (United States)

... Except for isolated radiation accidents over the ensuing years, little practical experience has been gained in the treatment of thermal injuries ...

British Library Electronic Table of Contents (United Kingdom)

For almost 150 years, the two monotypic genera Trochodendron and Tetracentron (Trochodendraceae) have been considered to share an unusual and primitive feature in angiosperms - the lack of vessels in their wood. Therefore, they have been classified in a basal position in the angiosperms. Our observations by light microscopy, low-vacuum environmental scanning electron microscopy (ESEM) and high-vacuum scanning electron microscopy (SEM) both in fresh and FAA-fixed materials consistently showed the presence of tracheary elements differentiated into two types in both genera. In Trochodendron, the tracheary elements can be divided into perforate vessel elements and imperforate fiber-tracheids and tracheids. The vessel elements show end and lateral walls. The pits on the end walls are elongate- ...

CERN Document Server

We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition Undulator Radiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and ...

Science.gov (United States)

We study a two-level atom in interaction with a real massless scalar quantum field in a spacetime with a reflecting boundary. The presence of the boundary modifies the quantum fluctuations of the scalar field, which in turn modifies the radiative properties of atoms. We calculate the rate of change of the mean atomic energy of the atom for both inertial motion and uniform acceleration. It is found that the modifications induced by the presence of a boundary make the spontaneous radiation rate of an excited inertial atom oscillate near the boundary and this oscillatory behavior may offer a possible opportunity for experimental tests for geometrical (boundary) effects in flat spacetime. While for accelerated atoms, the transitions from ground states to excited states are found to be possible even in a vacuum due to changes in the vacuum fluctuations induced by both the presence of the boundary and the acceleration of atoms, and this can be ...

International Nuclear Information System (INIS)

For shut-down safety of the turbine generator (securing of auxiliary power operation after load shut-down and preventing the reaching of overspeed after load shut-down with disturbed turbine governing system) additional measures compared to those for superheated steam turbines are required for turbine generators in plants with pressurized water reactor (PWR) as well as those with boiling water reactor (BWR) . Equipment is described (e.g. overspeed govern or selecting connection, vacuum breaker, bypass valves, intercepting valves) which, depending on the own conditions of the individual turbine generator (e.g. run-up time, vacuum, enclosed energy), may be applied alone or in jointly. (orig.).

International Nuclear Information System (INIS)

The present article will review recent advances in focused ion beam (FIB) technology. With increasing demands for scale of integration, microfabrication technology is becoming more important and various new microfabrication tools and processing techniques are desired. FIB is one of the promising tools for future microfabrication technology. This provides maskless patterning capability, which is of importance for process simplification, nanofabrication and in the development of in situ vacuum processing. In situ vacuum processing systems are being developed by combining FIB and a molecular beam epitaxy system. Radiation damage may limit applications of FIB. However, it was demonstrated that low energy FIB (<1 keV) with very high brightness was reached and promising results for low damage processing have been obtained. (orig.).

International Nuclear Information System (INIS)

The KSTAR cooling water system (CWS) consists of a primary cooling water system (PCWS), a secondary cooling water system (SCWS), and a de-mineralizing and de-ionized water system (DIWS). The PCWS cooling loops have been made for the poloidal field (PF) and toroidal field (TF) magnet power supplies (MPS), vacuum vessel (VV), electron cyclotron heating (ECH), ion cyclotron heating (ICRH), vacuum pumps, diagnostics, helium facility, etc. The CWS had been done individual commissioning of each system to confirm the design specifications by the end of 2006 and had gradually begun operation for the KSTAR ancillary devices by March 2008

International Nuclear Information System (INIS)

This paper discusses the mechanisms of gas breakdown at low values of pressure and inter-electrode gap, i.e. in the vicinity of the Paschen minimum. In this area of pressure and inter-electrode gap values, breakdown occurs either through gas or vacuum mechanisms, and also the so called anomalous Paschen effect appears. Electrical breakdown of electropositive, electronegative and noble gases has been investigated theoretically, experimentally and numerically. Based on the results obtained, regions in which particular breakdown mechanisms appear have been demarcated. Special attention has been devoted to the anomalous Paschen effect as well as to the avalanche vacuum breakdown mechanism.

International Nuclear Information System (INIS)

Within the framework of the Bianchi type-IX homogeneous space, we set up a system of coupled equations for the cosmic scale factors, scalar field, and radiative energy density. At the tree level, the equations are written in a self-consistent, Hartree-Fock form. For phi"4 theory, the system of nine first-order differential equations is solved numerically for a varying ratio of the energy of anisotropy to the vacuum energy. As the vacuum energy increases, there appears to be less reheating, since the energy of anisotropy is more efficiently converted into isotropic expansion. If the energy of anisotropy is large enough, the inflationary phase is prevented. In this case, a series of cosmological phase transitions will take place each time the square of the effective mass changes its sign.