Energy Technology Data Exchange (ETDEWEB)

Embedded systems have become integral parts of a diverse range of systems from automobiles to critical infrastructure applications such as gas and electric power distribution. Unfortunately, research on computer security in general and intrusion detection in particular, has not kept pace. Furthermore, embedded systems, by their very nature, are application specific and therefore frameworks for developing application-specific intrusion detection systems for distributed embedded systems must be researched, designed, and implemented. In this paper, we present a configurable middleware-based intrusion detection framework. In particular, this paper presents a system model and a concrete implementation of a highly configurable intrusion detection framework that is integrated into MicroQoSCORBA, a highly configurable middleware framework developed for embedded systems. By exploiting the ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Lecturo on Firewalls, VPNs, Intrusion Detection, and filters

Science.gov (United States)

This report discusses the following: (1) improving models of vapor-dominated geothermal fields: the effects of adsorption; (2) adsorption characteristics of rocks from vapor-dominated geothermal reservoir at the Geysers, CA; (3) optimizing reinjection strategy at Palinpinon, Philippines based on chloride data; (4) optimization of water injection into vapor-dominated geothermal reservoirs; and (5) steam-water relative permeability.

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

Numerous mercury intrusion porosimetry (MIP) studies have been carried out to investigate the pore structure in cement-based materials. However, the standard MIP often results in an underestimation of large pores and an overestimation of small pores because of its intrinsic limitation. In this paper, an innovative MIP method is developed in order to provide a more accurate estimation of pore size distribution. The new MIP measurements are conducted following a unique mercury intrusion procedure, in which the applied pressure is increased from the minimum to the maximum by repeating pressurization-depressurization cycles instead of a continuous pressurization followed by a continuous depressurization. Accordingly, this method is called pressurization-depressurization cycling MIP (PDC-MIP). By following the PDC-MIP testing sequence, the volumes of the throat pores and the corresponding ink-bottle pores can be determined at every pore size. These ...

UK PubMed Central (United Kingdom)

For terrestrial animals and plants, a fundamental cost of living is water vapor lost to the atmosphere during exchange of metabolic gases. Here, by bringing together previously developed models for...Full Text Available

International Nuclear Information System (INIS)

A thermodynamic model was used to estimate enthalpy of solution of carbon dioxide (CO_2) in methyldiethanolamine (MDEA) aqueous solutions. The model was based on a set of equations for chemical equilibria, phase equilibria, charge, and mass balances. Non-ideality in the liquid phase was taken into account by interaction parameters fitted to (vapor + liquid) equilibrium data. The enthalpies of solution of CO_2 were derived from the model using classical thermodynamic relations and were compared to experimental values obtained in previous works.

Energy Technology Data Exchange (ETDEWEB)

Real time neutron radiography has been used to study the dynamic behavior of two phase flow and measure the time averaged vapor fraction in a heated metal tube containing boiling steam water operating at up to 15 bar pressure. The neutron radiographic technique is non-intrusive and requires no special transparent window region. This is the first time this technique has been used in an electrically heated pressurized flow loop. This unique experimental method offers the opportunity to observe and record on videotape, flow patterns and transient behavior of two phase flow inside opaque containers without disturbing the environment. In this study the test sections consisted of stainless steel tubes with a 1.27 cm outer diameter and wall thicknesses of 0.084 cm and 0.124 cm. The experiments were carried out at the Pennsylvania State University 1 megawatt TRIGA reactor facility utilizing a Precise Optics neutron radiography camera. The inlet water ...

International Nuclear Information System (INIS)

Real time neutron radiography has been used to study the dynamic behavior of two phase flow and measure the time averaged vapor fraction in a heated metal tube containing boiling steam water operating at up to 15 bar pressure. The neutron radiographic technique is non-intrusive and requires no special transparent window region. This is the first time this technique has been used in an electrically heated pressurized flow loop. This unique experimental method offers the opportunity to observe and record on videotape, flow patterns and transient behavior of two phase flow inside opaque containers without disturbing the environment. In this study the test sections consisted of stainless steel tubes with a 1.27 cm outer diameter and wall thicknesses of 0.084 cm and 0.124 cm. The experiments were carried out at the Pennsylvania State University 1 megawatt TRIGA reactor facility utilizing a Precise Optics neutron radiography camera. The inlet water ...

Science.gov (United States)

This viewgraph presentation reviews NASA's work on the project that supports the Gulf of Mexico

Energy Technology Data Exchange (ETDEWEB)

The liquid/vapor coexistence density, the partial vapor pressure, and the heat of vaporization were calculated using Gibbs ensemble Monte Carlo simulation techniques. Long-range interactions such as charge-charge, charge-dipole, and dipole-dipole were evaluated using Ewald summation techniques. A polarizable potential model was used to describe the water-water interactions (Dang and Chang, J. Chem. Phys. 106, 8149, 1997). The model yields good agreement with the corresponding experimental data in the lower temperature region and moderate agreement in the higher temperature region. The critical temperature and density were estimated to be 565 K and 0.28 g/cm3.

DEFF Research Database (Denmark)

The thermodynamic framework that was developed in a previous work [Vrachnos et al. Ind. Eng. Chem. Res. 2004, 43, 2798] for the description of chemical and vapor-liquid equilibria of carbon dioxide, hydrogen sulfide, and their mixtures in aqueous methyldiethanolamine (MDEA) solutions is revised and extended in this study to the absorption of carbon dioxide into aqueous monoethanolamine (MEA) solutions and aqueous MDEA-MEA blends. The results of the model are compared with experimental data taken from the literature. Very satisfactory predictions of acidic gas vapor-liquid equilibrium over MDEA, MEA, and their blends at various concentrations, acidic gas loadings, and temperatures are obtained.

J-STORE (Japan)

Full Text Available

International Nuclear Information System (INIS)

The Argyle pipe occurring in the East Kimberley Province of Western Australia is a unique, highly-diamondiferous lamproite. Although it resembles other lamproites located in the West Kimberley Province with respect to its setting, structure, petrography and geochemistry, it is probably Proterozoic in age and hence substantially older than Tertiary occurrences of the West Kimberley Province. Rb-Sr measurements on whole rock and phlogopite samples from magmatic olivine-phlogopite lamproite, reveals a two point model age of 1126 +- 9 Ma for the Argyle pipe. This age is consistent with ages of other, similar volcanic igneous rocks occurring in several localities worldwide. The widespread occurrence of Proterozoic kimberlites and lamproites suggests that this was an important period of worldwide alkalic intrusive activity.

International Nuclear Information System (INIS)

Natural convection of vaporizing Deuterium at 25 K transports the heat generated in the moderator cell of the cold neutron source to a He cooled condenser. The thermohydraulics of this thermosiphon were precalculated and the results verified by experiments in a 1:1 model using D_2 as fluid. The experimental results show that the thermosiphon operates stable. The demanded liquid content of the cell as well as wall temperatures below 50 K can be ensured by a proper design of the cell outlet flow geometry. A 7 min. loss of cryogenic power results in transient temperatures of the cell wall of not more than 300 K.

International Nuclear Information System (INIS)

In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.

Energy Technology Data Exchange (ETDEWEB)

As lidar technology is able to provide fast data collection at a resolution of meters in an atmospheric volume, it is imperative to promote a modeling counterpart of the lidar capability. This paper describes an integrated capability based on data from a scanning water vapor lidar and a high-resolution hydrodynamic model (HIGRAD) equipped with a visualization routine (VIEWER) that simulates the lidar scanning. The purpose is to better understand the spatial and temporal representativeness of the lidar measurements and, in turn, to extend their utility in studying turbulence fields in the atmospheric boundary layer. Raman lidar water vapor data collected over the Pacific warm pool and the simulations with the HIGRAD code are used for identifying the underlying physics and potential aliasing effects of spatially resolved lidar measurements. This capability also helps improve the trade-off between ...

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 ...

Energy Technology Data Exchange (ETDEWEB)

Soil vapor extraction (SVE) is a widely accepted in-place treatment technology that uses forced air to remove contaminant vapors from zones of permeable vapor flow, thereby enhancing the volatilization of contaminants from the subsurface. The resulting off-gases are contaminated with volatiles and semi-volatiles and have to treated by catalytic or thermal destruction systems, activated carbon adsorbers, or bioreactors. Of these, activated carbon adsorption is the most commonly used technology. From the theoretical foundation of SVE and carbon adsorption, two nomographs were developed for remedial investigation, feasibility studies, planning, operation, and preliminary design purposes. An advantage of such nomographs is that they graphically indicate the sensitivity of the remediation process to different design parameters and critical ranges within a given parameter. In effect, nomographs can help to foster an intuitive ...

Energy Technology Data Exchange (ETDEWEB)

The three-dimensional (3-D), multiphase, computational fluid dynamic (CFD) code FLUENT is used to simulated two-phase flow behaviour in a CANDU header manifold under low (natural circulation) flow conditions. This behaviour was previously inferred from experimental data. The CFD simulations reported here are being used to support these inferences and to obtain a better understanding of phase distribution in the header manifold. The simulations seem to show that the vapor-water mixture models in the FLUENT code do not capture properly phase separation in the header and proper phase branching at the header-feeder connections that have been observed in experiments at low flows. The simulations using discrete-phase model in FLUENT, which tracks the pathlines of the individual vapor bubbles in the water continuum phase, show interesting, complicated and, in some cases, unexpected bubble trajectories from the ...

International Nuclear Information System (INIS)

Research highlights: ? We model power oscillations in boiling water reactors using a lumped parameter model. ? The nature and amplitudes of oscillations is obtained using a nonlinear analysis. ? The method of multiple scales has been used for the analytical treatment. ? Fuel temperature coefficient of reactivity determines the nature of oscillations. ? The presented systematic method of analysis useful for reduced order reactor models. - Abstract: In this paper, we perform a parametric study of the nonlinear dynamics of a reduced order model for boiling water reactors (BWR) near the Hopf bifurcation point using the method of multiple scales (MMS). Analysis has been performed for general values of the parameters, but the results are demonstrated for parameter values of the model corresponding to the advanced heavy water reactor (AHWR). The neutronics of the AHWR is ...

Energy Technology Data Exchange (ETDEWEB)

Results of calculation of steady thermal-hydraulic characteristics of PVG-440 horizontal steam generator are presented. Steam flows in selected sections are compared to data provided by OKB Gidropress Calculated vapor void fractions are compared to measured ones. (orig.) (3 refs., 3 figs., 8 tabs.).

Science.gov (United States)

Purpose: Assess the feasibility of using NASA satellite data to monitor persistent saltwater intrusion in coastal marshes. End User: USGS National Wetlands ...

Science.gov (United States)

The emphasis of combustion research efforts at NASA Glenn Research Center (GRC) is on collaborating

Energy Technology Data Exchange (ETDEWEB)

Data which have been collected by Los Alamos National Laboratory waste management for the hydrologic characterization of the subsurface at the low level radioactive waste disposal facility, Area G, are reported and discussed briefly. The data includes Unsaturated Flow Apparatus measurements of the unsaturated conductivity in samples from borehole G-5. Analysis compares these values to the predictions from van Genuchten estimates, and the implications for transport and data matching are discussed, especially at the location of the Vapor Phase Notch (VPN). There, evaporation drives a significant vapor flux and the liquid flux cannot be measured accurately by the UFA device. Data also include hydrologic characterization of samples from borehole G-5, Area G surface soils, Los Alamos (Cerros de Rio) basalt, Tsankawi and Cerro-Toledo layers, the Vapor Phase Notch (VPN), and additional new samples from the uppermost tuff layer at ...

Energy Technology Data Exchange (ETDEWEB)

This report documents the results of a project funded by DoD's Strategic Environmental Research and Development Program (SERDP) on the science behind development of predictive models for soot emission from gas turbine engines. Measurements of soot formation were performed in laminar flat premixed flames and turbulent non-premixed jet flames at 1 atm pressure and in turbulent liquid spray flames under representative conditions for takeoff in a gas turbine engine. The laminar flames and open jet flames used both ethylene and a prevaporized JP-8 surrogate fuel composed of n-dodecane and m-xylene. The pressurized turbulent jet flame measurements used the JP-8 surrogate fuel and compared its combustion and sooting characteristics to a world-average JP-8 fuel sample. The pressurized jet flame measurements demonstrated that the surrogate was representative of JP-8, with a somewhat higher tendency to soot formation. The premixed flame measurements revealed that ...

Science.gov (United States)

In this paper, we studied vapor-liquid equilibria (VLE) and adsorption of ethylene on graphitized thermal carbon black and in slit pores whose walls are composed of graphene layers. Simple models of a one-center Lennard-Jones (LJ) potential and a two-center united atom (UA)-LJ potential are investigated to study the impact of the choice of potential models in the description of VLE and adsorption behavior. Here, we used a Monte Carlo simulation method with grand canonical Monte Carlo (GCMC) and Gibbs ensemble Monte Carlo ensembles. The one-center potential model cannot describe adequately the VLE over the practical range of temperature from the triple point to the critical point. On the other hand, the two-center potential model (Wick et al. J. Phys. Chem. B 2000, 104, 8008-8016) performs well in the description of VLE (saturated vapor and liquid densities and ...

Energy Technology Data Exchange (ETDEWEB)

In order to predict the effect of a fuel-coolant interaction after a hypothetical core-melt-down accident, a phenomenological model has been developed to describe the thermal and hydrodynamic behavior of a high-temperature molten jet when it interacts with saturated or subcooled water in a film boiling regime. The mechanisms of jet-material erosion were analyzed by Kelvin-Helmholtz instabilities on the coherent column and by boundary layer stripping on the leading edge. The heat transfer coefficient, vapor-film thickness, and net steam generation, all of which strongly affect the jet-breakup behavior, were solved analytically. It was found that the jet breakup (or erosion) depends strongly on the steam generation from the jet/water interaction. The jet-breakup length (i.e., penetration distance) was found to be sensitive to the initial jet temperature, water subcooling, and the physical state of the ambient water. The jet-breakup length and ...

Energy Technology Data Exchange (ETDEWEB)

The impingement of a fluid jet onto a surface has broad applications across many industries. Within the UK nuclear industry, during the final stages of fuel reprocessing, impinging fluid jets are utilised to mobilise settled sludge material within storage tanks and ponds in preparation for transfer and ultimate immobilisation through vitrification. Despite the extensive applications of impinging jets within the nuclear and other industries, the study of two-phase, solid loaded, impinging jets is limited, and generally restricted to computational modelling. Surprisingly, very little fundamental understanding of the turbulence structure within such fluid flows through experimental investigation is found within the literature. The physical modelling of impinging jet systems could successfully serve to aid computer model validation, determine operating requirements, evaluate plant throughput requirements, optimise process ...

International Nuclear Information System (INIS)

A one-dimensional numerical model for the expansion of impact-produced vapor clouds is used to investigate magnetic field generation mechanisms in events such as meteor collisions with the moon. The resulting cloud properties, such as ionization fraction, electrical conductivity, radial expansion velocity, mass density, and energy density are estimated. The model is initiated with the peak shock states and pressure thresholds for incipient and complete vaporization of anorthosite lunar surface materials by iron and GA composition meteorites. The expansion of the spherical gas cloud into a vacuum was traced with a one-dimensional explicit lagrangian hydrodynamic code. The hypervelocity impact plasmas produced are found to be significant in the amplitudes and orientations of the magnetic fields generated. An ambient magnetic field could have been provided by the core dynamo, which would have interacted ...

Energy Technology Data Exchange (ETDEWEB)

Reactive sticking coefficients (RSCs) were measured for silane and disilane on polycrystalline silicon for a wide range of temperature and flux (pressure) conditions. The data were obtained from deposition-rate measurements using molecular beam scattering and a very low-pressure cold-wall reactor. The RSCs have nonlinear Arrhenius temperature dependencies and decrease with increasing flux at low (710 /sup 0/C) temperatures. Several simple models are proposed to explain these observations. The results are compared with previous studies of the SiH/sub 4//Si(s) reaction and low-pressure chemical vapor deposition-rate measurements.

Energy Technology Data Exchange (ETDEWEB)

Power loadings experienced by tokamak plasma-facing components during normal operation and during off-normal events are discussed. A model for power and particle flow in the tokamak boundary layer is presented and model predictions are compared to infrared measurements of component heating. The inclusion of the full three-dimensional geometry of the components and of the magnetic flux surface is very important in the modeling. Experimental measurements show that misalignment of component armour tile surfaces by only a millimeter can lead to significant localized heating. An application to the design of plasma-facing components for future machines is presented. Finally, thermal loads expected during tokamak disruptions are discussed. The primary problems are surface melting and vaporization due to localized intense heating during the disruption thermal quench and volumetric heating of the component ...

Energy Technology Data Exchange (ETDEWEB)

The shortage of fresh water is increasing at alarming levels, even in temperate zones. Desalination of brackish and seawater is being considered as a solution to growing water demands. Seawater desalination can be accomplished through reverse osmosis, vapor compression, vapor absorption and thermally driven systems. The most suitable process for large-scale desalination plants is successive brine evaporation-condensation with intermediate heat recovery. However, higher process efficiency could be achieved. The use of low temperature heat sources in seawater desalination requires an efficient method of evaporation and condensation at relatively low vapor pressures. This could be achieved in a humidification-dehumidification process using circulated air to enhance evaporation of water. Simulation models, however, neglect either the heat of evaporation or the changes in air and water properties within ...

Energy Technology Data Exchange (ETDEWEB)

The design of separation devices, particularly for solvent-based selective removal of H{sub 2}S from CO{sub 2}, requires an accurate mathematical model. Unfortunately, this requirement for high accuracy is often in conflict with the need for efficient computation. The addition of more and more complicated analyses, such as a move from Henry's law to a method incorporating gas and liquid activities for computing vapor liquid equilibria, may give a more accurate solution, but only at the cost of decreased computational efficiency. The efforts in this work have been directed toward two goals. The first was to develop an accurate mathematical model for the aqueous methyldiethanolamine (MDEA) system. The steady-state packed column model developed in this work has been tested with data from Schubert (1988) to verify its accuracy. The second goal was to modify the model to improve ...

International Nuclear Information System (INIS)

SiC has been considered as a primary candidate material for a first wall component in future fusion reactor because it has been claimed that SiC has excellent high-temperature properties, good chemical stability and low activation. However, the behavior of tritium on SiC has not been discussed yet. In this study, tritium trapping capacity on the surface of SiC was experimentally obtained at the temperature range of 25-800 deg. C in consideration of tritium trapping to the experimental system. The capacity, which was independent of the water vapor pressure in the gas phase and the temperature, was determined as about 10"6 Bq/cm"2. The isotope exchange reaction rate between tritiated water in a gas phase and hydrogen on the surface was quantified at the temperature of 25, 500 and 700 deg. C in consideration of the behavior of tritium trapping at change of experimental condition by the numerical curve fitting method applying the serial reactor ...

International Nuclear Information System (INIS)

In the region of annular liquid film-mist flow, the behavior of the droplets formed from the liquid film and the rate of formation are the subjects to be clarified in connection with the forecast of dry-out point, which becomes a problem in the region of high dryness such as reactor cooling system and steam generators. Many researches have been performed on such problem in vertical tubes, but the characteristics in horizontal flow have not yet been sufficiently clarified. This series of research is to clarify various characteristics, such as the velocity of vapor phase, the flow rate distribution of droplets, the formation and adhesion of droplets and the structure of liquid film, in the region of liquid film-mist flow, where liquid film exists on the bottom of a horizontal rectangular channel, and vapor flow is accompanied by droplets. In this study, by the measurement of the flow rate distribution of droplets on respective cross sections ...

Energy Technology Data Exchange (ETDEWEB)

The atmosphere and the biosphere are inherently coupled to one another. Atmospheric surface state variables such as temperature, winds, water vapor, precipitation, and radiation control biophysical, biogeochemical, and ecological processes at the surface and subsurface. At the same time, surface fluxes of momentum, moisture, heat, and trace gases act as time-dependent boundary conditions providing feedback on atmospheric processes. To understand such phenomena, a coupled set of interactive models is required. Costs are still prohibitive for computing surface/subsurface fluxes directly for medium-resolution atmospheric general circulation models (AGCMs), but a technique has been developed for testing large-scale homogeneity and accessing surface parameterizations and models to reduce this computational cost and maintain accuracy. This modeling system potentially bridges the observed ...

Energy Technology Data Exchange (ETDEWEB)

Indoor air exposures to gaseous contaminants originating in soil can cause large human health risks. To predict and control these exposures, the mechanisms that affect vapor transport in near-surface soils need to be understood. In particular, radon exposure is a concern since average indoor radon concentrations lead to much higher risks than are generally accepted for exposure to other environmental contaminants. This dissertation examines an important component of the indoor radon problem: the impacts of wind on soil-gas and radon transport and entry into buildings. The research includes experimental and modeling studies of wind`s interactions with a building`s superstructure and the resulting soil-gas and radon flows in the surrounding soil. In addition to exploring the effects of steady winds, a novel modeling technique is developed to examine the impacts of fluctuating winds on soil-gas and radon transport.

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

Short communication.

Science.gov (United States)

Magmatic sulfide deposits are the most significant source of platinum-group elements (PGE) in the world. Key to understanding their genesis is determining the processes and timing of sulfide saturation, metal enrichment and crustal contamination. In this study, we have identified droplets of magmatic sulfide from the Platreef, South Africa, where droplets of sulfide have been trapped in the earliest crystallising phase, chromite. Due to their early entrapment at high temperatures, metal concentrations and ratios that they display are indicative of a very early-stage sulfide liquid in the system, as they will have cooled and fractionated within an essentially closed system, unlike interstitial blebs that crystallise in an open system as the magma cools. Analysis of these droplets in an opaque mineral like chromite by LA-ICP-MS is problematic as some of the fractionated inclusion is necessarily lost during cutting and polishing to initially identify the inclusion. This particularly ...

Science.gov (United States)

An explanation is given of what a loop heat pipe (LHP) is, and how it works. It is then shown that neutron imaging (both real time neutron radioscopy and single exposure neutron radiography) is an effective experimental tool for the study of LHPs. Specifically, neutron imaging has helped to identify and correct a cooling water distribution problem in the condenser, and has enabled visualization of two-phase flow (liquid and vapor) in various components of the LHP. In addition, partial wick dry-out, a phenomenon of great importance in the effective operation of LHPs, is potentially identifiable with neutron imaging. It is anticipated that neutron radioscopy and radiography will greatly contribute to our understanding of LHP operation, and will lead to improvement of LHP modeling and design. PMID:15246420

Energy Technology Data Exchange (ETDEWEB)

An explanation is given of what a loop heat pipe (LHP) is, and how it works. It is then shown that neutron imaging (both real time neutron radioscopy and single exposure neutron radiography) is an effective experimental tool for the study of LHPs. Specifically, neutron imaging has helped to identify and correct a cooling water distribution problem in the condenser, and has enabled visualization of two-phase flow (liquid and vapor) in various components of the LHP. In addition, partial wick dry-out, a phenomenon of great importance in the effective operation of LHPs, has been identified with neutron imaging. It is anticipated that neutron radioscopy and radiography will greatly contribute to our understanding of LHP operation, and will lead to improvement of LHP modeling and design.

International Nuclear Information System (INIS)

The 1993 Petroleum Hydrocarbons Conference was comprised of 3 days of technical presentations within the following topic areas: pollution prevention and cost control; development of remediation levels; free-phase and dissolved hydrocarbon contamination management; investigation and analysis of petroleum hydrocarbons; applications of computer modeling for remediation; design and implementation of bioventing; design and implementation of air sparging; soil vapor extraction as a remediation technique; and ground water remediation using natural bacteria. In addition, more than 100 leading companies in the ground water and petroleum industries participated in the Conference Exposition in which a variety of equipment and services for preventing, detecting and remediating ground water contaminated by petroleum hydrocarbons and other organic chemicals was showcased. Individual papers have been processed separately for inclusion in the appropriate data ...

Energy Technology Data Exchange (ETDEWEB)

In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was identified. 12 refs., 8 figs., 2 tabs.

International Nuclear Information System (INIS)

The CERL Code was developed to describe the solution chemistry of the water on the steam generating side of PWR reactors. It is designed to calculate the equilibrium species distribution resulting from the interaction of impurities, corrosion products, and additives in the aqueous solution. It calculates the extent of ion-ion interactions, the precipitation of insoluble species and the amount of solute that partitions into the vapor phase when some of the water evaporates. This knowledge of the bulk phase equilibrium distribution of species, especially the pH should be useful in describing the corrosion processes at the solid liquid boundary. The code does not calculate any changes in oxidation states or any rates of reaction. Therefore, it is incapable of calculating the actual corrosion rates. It is anticipated that it will be used as a subprogram of a larger program that will include the redox reactions and the rates of the reactions. The purpose of the code at ...

Energy Technology Data Exchange (ETDEWEB)

With an objective to clarify the interactions between micropore structure of coal and solvent reagents, a sorption experiment was carried out under solvent saturated vapor pressure. Low-volatile bituminous coal, Pocahontas No. 3 coal, has the aromatic ring structure developed, and makes solvent more difficult to diffuse into coal, hence sorption amount is small. Methanol has permeated since its polarity is high. High-volatile bituminous coal, Illinois No. 6 coal, makes solvent penetrate easily, and the sorption amount was large with both of aromatic and polar solvents. Since brown coal, Beulah Zap coal, contains a large amount of oxygen, and hydrogen bonding is predominant, sorption amount of cyclohexane and benzene having no polarity is small. Methanol diffuses while releasing hydrogen bond due to its polarity, and its sorption amount is large. A double sorption model is available, which expresses the whole sorption amount as a sum of physical ...

Energy Technology Data Exchange (ETDEWEB)

Current Intrusion Detection System (IDS) technology is not suited to be widely deployed inside a Supervisory, Control and Data Acquisition (SCADA) environment. Anomaly- and signature-based IDS technologies have developed methods to cover information technology-based networks activity and protocols effectively. However, these IDS technologies do not include the fine protocol granularity required to ensure network security inside an environment with weak protocols lacking authentication and encryption. By implementing a more specific and more intelligent packet inspection mechanism, tailored traffic flow analysis, and unique packet tampering detection, IDS technology developed specifically for SCADA environments can be deployed with confidence in detecting malicious activity.

Energy Technology Data Exchange (ETDEWEB)

Land surface parameterization schemes such as the Simple Biosphere Model (SiB2) have found considerable use in climate simulation models, where they provide lower boundary conditions in the form of surface sensible and latent heat fluxes. A methodology is described to apply models of this type at high resolution, using data from the Department of Energy{close_quote}s Cloud and Radiation Testbed in Oklahoma and Kansas, to determine the spatial variations of heat fluxes over the domain and to determine area-weighted flux averages for use in single-column model studies. Data from a dense array of meteorological instruments are interpolated to provide the wind, temperature, vapor pressure, radiation, and precipitation values needed by SiB2. The state of the vegetation is characterized through the use of the normalized difference vegetation index determined from satellites. The ...

Science.gov (United States)

In order to reduce the air concentration of (sup 3)H in the reactor buiIding of Wolsung Heavy Water Reactor, a computer code for estimation of adsorption behavior was programmed based on an equation derived for analysis of water vapor adsorption, and a ba...

Science.gov (United States)

... 2-93 An Atmospheric Particle Emits Electromagnetic ... atmospheric water vapor produces a hydrometeor. ... subject to wind movement (either blowing ...

Energy Technology Data Exchange (ETDEWEB)

Sensors installed at a telephone office building in Neenah, WI, continuously monitor 24 parameters related to the operation of the building's heating, ventilating, and air conditioning (HVAC) system. This data is stored in a dedicated minicomputer and can be retrieved, in various formats, for subsequent analyses. For more than a year, we have measured indoor and outdoor concentrations of both fine and coarse airborne particles, their chemical constituents, and volatile organic compounds at this same location. Using this data, we have examined the composition of the indoor air as it correlates to the composition of the outdoor air and the various HVAC operating parameters. The steady-state indoor concentrations of the particles, particulate constituents, and organic vapors can be explained in the context of a mass balance model. This model can also be used to calculate the rate at which selected chemicals are ...

Energy Technology Data Exchange (ETDEWEB)

The UNSAT-H model was developed at Pacific Northwest National Laboratory (PNNL) to assess the water dynamics of arid sites and, in particular, estimate recharge fluxes for scenarios pertinent to waste disposal facilities. During the last 4 years, the UNSAT-H model received support from the Immobilized Waste Program (IWP) of the Hanford Site's River Protection Project. This program is designing and assessing the performance of on-site disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site (LMHC 1999). The IWP is interested in estimates of recharge rates for current conditions and long-term scenarios involving the vadose zone disposal of tank wastes. Simulation modeling with UNSAT-H is one of the methods being used to provide those estimates (e.g., Rockhold et al. 1995; Fayer et al. 1999). To achieve the above goals for assessing water ...

International Nuclear Information System (INIS)

Multi-dimensional modelling of two-phase flow requires accurate constitutive relationships for interfacial parameters such as interfacial heat transfer, void fraction distribution, interfacial area, etc. However, existing diagnostic systems for measurement of two-phase flow parameters have difficulty measuring two or three-dimensional void distributions required for determination of interfacial parameters. In this work, a Real-Time Neutron Radiography (RTNR) system is developed for non-intrusive measurement of two-phase flow parameters in nuclear fuel channels at low thermal neutron fluxes (on the order of 10"6n/cm"2-s). This advanced radiation technique has the advantage of measuring two-phase flow in 3 1/2 dimensions (x,#integral#dy,t) where the 1/2 dimension refers to an integrated or averaged space dimension. Pipe flow channels, annulus flow channels, MAPLE-type nuclear fuel flow channels, and CANDU-type nuclear fuel flow channels are ...

Energy Technology Data Exchange (ETDEWEB)

Two-phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitions, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two-phase systems. This work is concerned with microgravity, two-phase flow regime analysis. The data come from a recent sets of experiments. The experiments were funded by NASA Johnson Space Center (JSC) and conducted by NASA JSC with Texas A M University. The experiment was on loan to NASA JSC from Foster-Miller, Inc., who constructed it with funding from the Air Force Phillips Laboratory. The experiment used R12 as the working fluid. A Foster-Miller two phase pump was used to circulate the two phase mixture and allow separate measurements of the vapor and liquid flow streams. The ...

Energy Technology Data Exchange (ETDEWEB)

This second report covers the period August 1 to September 30, 1991. During this period we modified our approach to Task 1 (Hybrid Armature study) with the addition of a numerical simulation of the steady state plasma brush length with a 1-D, four-phase equation of state code. A test fixture was designed and fabrication begun on a plasma brush test fixture for hybrid studies. It will be powered by a 140 kJ, 1 MA capacitor bank on loan to the project. Diagnostic data collection with 20 channels of digitizers and data reduction with a microvax were also arranged. Sliding friction of a solid armature was simulated and found to form a vapor layer at velocities below 2 km/s. The simulations indicated that higher interface pressure results in vapor boundary layer formation at lower velocity. If there is also a minimum interface pressure required to commutate high currents, then an optimum interface pressure will probably result. Plans for a launcher ...

Energy Technology Data Exchange (ETDEWEB)

The growth of stoichiometric and non-stoichiometric silicon nitride films was studied experimentally on 100 mm silicon wafers by batch depositions from the dichlorosilane (SiH{sub 2}Cl{sub 2})-ammonia (NH{sub 3}) system in a hot-wall horizontal low pressure chemical vapor deposition (LPCVD) reactor. The growth kinetics were discussed in terms of the Langmuir adsorption isotherm. The kinetic parameters were determined by comparing the experimental data with a one-dimensional simulation model. The decomposition of NH{sub 3} at high temperatures was included in the simulation procedure. When the SiH{sub 2}Cl{sub 2}:NH{sub 3} ratios were greater than 1.5, a quantity higher than the thermodynamic critical values above which Si-rich nitride films begin to deposit, various SiN{sub x} films with x < 4/3 were obtained. The composition of the SiN{sub x} films was found to vary along the LPCVD reactor. The film stoichiometry was examined by Rutherford ...

Energy Technology Data Exchange (ETDEWEB)

Because of the importance of water vapor, the ARM program initiated a series of three intensive operating periods (IOPs) at its CART (Cloud And Radiation Testbed) site. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of 1996, with an emphasis on the lowest kilometer, while the second was conducted from September--October 1997 with a focus on both the upper troposphere and lowest kilometer. These IOPs provided an excellent opportunity to compare measurements from other systems with those made by the CART Raman lidar. This paper addresses primarily the daytime water vapor measurements made by the lidar system during the second of these IOPs.

Energy Technology Data Exchange (ETDEWEB)

X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both target yield and hohlraum wall thickness are also described. ...

Energy Technology Data Exchange (ETDEWEB)

The use of capacitance sensors for measuring phase concentrations in two-phase flow has gained popularity in recent years. In designing such sensors, there are many issues which must be considered in order to optimize performance: two-phase flow regime, permittivity of the phases, duct geometry, electrical shielding, desired spacial resolution of film thickness, and temperature variation in the flow field. These design issues are discussed and are used to optimize the design of a capacitance sensor which is used to measure vapor volume fraction in annular, two-phase vertical upflow and downflow in a square duct. The sensor was tested and implemented in a 12.7 mm square duct mounted in a flow boiling facility containing FC-72, a low permittivity dielectric fluid ({epsilon}{sub r} = 1.75). Using analytical modeling, an adjustable-length, parallel-plate design was developed and refined to achieve good sensitivity to flow conditions. The sensor ...

Energy Technology Data Exchange (ETDEWEB)

Three aspects of the research project Surface physics with cold and ultracold neutron reflectometry'' were stressed during the present first year: (1) Setup of the reflectometer facility at the research reactor of the Rhode Island Nuclear Science Center. The installation provides a narrow pencil beam'' analyzed by time of flight using a chopper system. Following beam characterization and a test measurement of the total cross section of copper single crystal first reflectivity measurements are currently performed using a supermirror. (2) Design stud for the ultracold neutron imaging system, with involvement of the relevant industry. Bids are available for several components indicating that it will be very difficult to build the entire system unless further funds become available. (3) Analysis of features of neutron reflection from surfaces with special emphasis on the effect of surface roughness both on the specular beam and the diffusely reflected ...

Energy Technology Data Exchange (ETDEWEB)

On-board reforming of liquid fuels to hydrogen for use in proton exchange membrane (PEM) fuel cell electric vehicles (FCEVs) has been the subject of numerous investigations. In many respects, liquid fuels represent a more attractive method of carrying hydrogen than compressed hydrogen itself, promising greater vehicle range, shorter refilling times, increased safety, and perhaps most importantly, utilization of the current fuel distribution infrastructure. The drawbacks of on-board reformers include their inherent complexity [for example a POX reactor includes: a fuel vaporizer, a reformer, water-gas shift reactors, a preferential oxidation (PROX) unit for CO cleanup, heat exchangers for thermal integration, sensors and controls, etc.], weight, and expense relative to compressed H{sub 2}, as well as degraded fuel cell performance due to the presence of inert gases and impurities in the reformate. Partial oxidation (POX) of automotive fuels is another alternative ...

Energy Technology Data Exchange (ETDEWEB)

The influence of high energy electron (23 MeV) irradiation on the electrical characteristics of p-channel polysilicon thin film transistors (PSTFTs) was studied. The channel 220 nm thick LPCVD (low pressure chemical vapor deposition) deposited polysilicon layer was phosphorus doped by ion implantation. A 45 nm thick, thermally grown, SiO{sub 2} layer served as gate dielectric. A self-alignment technology for boron doping of the source and drain regions was used. 200 nm thick polysilicon film was deposited as a gate electrode. The obtained p-channel PSTFTs were irradiated with different high energy electron doses. Leakage currents through the gate oxide and transfer characteristics of the transistors were measured. A software model describing the field enhancement and the non-uniform current distribution at textured polysilicon/oxide interface was developed. In order to assess the irradiation-stimulated changes of gate oxide parameters the gate ...

Energy Technology Data Exchange (ETDEWEB)

A unique method, previously proposed by the author, was applied to the heat transfer augmentation in the flow boiling field. In this method a screen sheet was put on the horizontal heated surface where bubble nucleation occurred. Generated vapor bubbles were trapped between the screen and the wall, became flat and moved along the surface. This restricted bubble behavior caused the heat transfer enhancement. Three types of the screen were tested in the present experiment and the effect of the screen was investigated on the heat transfer and two-phase flow characteristics. In two cases of them, the screen was displaced upward by the bubble nucleation. Compared with the ordinary flow boiling case, heat transfer was enhanced by a factor of 1.2 to 6 within the present experimental range. By using a simple flow model, it was made clear that the effect of the height of the displaced screen was important to evaluate the increase in pressure drop. ...

Energy Technology Data Exchange (ETDEWEB)

To improve organic electronic applications, knowledge about microscopic mechanisms determining the charge carrier mobilities is pivotal. 9,10-Diphenylanthracene (DPA) has been identified as model system to study those correlations due to its high electron and hole mobilities at room temperature and its complex structural phase behaviour. We demonstrate our temperature dependent Time-Of-Flight data on single crystals grown by vapor phase transport (VPT) and by Bridgman growth technique. Both preparation techniques revealed crystals of different morphologies resulting in significant variations of the related bipolar mobilities. As a key result, the charge carrier mobility of {proportional_to}1 cm{sup 2}/Vs at room temperature along the (111)-direction of Bridgman crystals exceeds that along the (001)-direction of VPT grown crystals by about one order of magnitude. The observed differences in the mobility data are discussed in the context of the ...

Energy Technology Data Exchange (ETDEWEB)

Basic experimental investigations were carried out with an aqueous solution of a mixture of KOH and NaOH for use as an absorbent in absorption heat pumps. Due to its thermophysical properties this mixture allows temperature lifts from evaporator to absorber of more than 75 K (135 F) in a single-stage absorption chiller. Thermophysical and hydrodynamical properties of the solution were measured. Vapor-liquid-equilibrium data and specific heat capacities were determined for concentrations ranging from 35% up to 75% and temperatures up to 200 C (392 F). From these data the enthalpy of the solution was calculated. Additionally the crystallization temperatures, the density, and the viscosity of the solution were determined. The experimental equipment is described. The data are presented as polynomials and diagrams including experimental accuracy. An apparatus was constructed to measure heat and mass transfer coefficients of the absorption process with this solution. The ...

Energy Technology Data Exchange (ETDEWEB)

Laser optical pumping can be used to produce polarized alkali atom beams or polarized alkali vapor targets. Polarized alkali atom beams can be converted into polarized alkali ion beams, and polarized alkali vapor targets can be used to produce polarized H/sup -/ or /sup 3/He/sup -/ ion beams. In this paper the authors discuss how the polarized alkali atom beams and polarized alkali vapor targets are used to produce polarized ion beams with emphasis on the production of polarized negative ion beams.

Energy Technology Data Exchange (ETDEWEB)

Molar enthalpies of sublimation of 1,2,4-, 1,2,3-, and 1,3,5-tri-hydroxy-benzene, were obtained from the temperature dependence of the vapor pressure measured by the transpiration method. The molar enthalpies of fusion and molar heat capacities of these compounds were measured by DSC. The measured data sets of vaporization, sublimation and fusion enthalpies were checked for internal consistency. Strength of the inter- and intra-molecular hydrogen bonding in di- and tri-hydroxy-benzenes have been assessed.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a case study of site characterization and hydrocarbon contamination plume mapping/delineation in a gas processing plant in southern Mexico. The paper describes innovative and cost-effective use of passive (non-intrusive) and active (intrusive) techniques, including the use of compound-specific analytical methods for site characterization. The techniques used, on a demonstrative basis, include geophysical, geochemical, and borehole drilling. Geochemical techniques used to delineate the horizontal extent of hydrocarbon contamination at the site include soil gas surveys. The borehole drilling technique used to assess the vertical extent of contamination and confirm geophysical and geochemical data combines conventional hollow-stem auguring with direct push-probe using Geoprobe. Compound-specific analytical methods, such as hydrocarbon fingerprinting and a modified method for gasoline range organics, demonstrate the inherent ...

International Nuclear Information System (INIS)

Security is an essential element of information technology (IT) infrastructure and applications. Concerns about security of networks and information systems have been growing along with the rapid increase in the number of network users and the value of their transactions. The hasty security threats have driven the development of security products known as Intrusion Detection Systems (IDS) and Intrusion Prevention Systems (IPS) to detect and protect the network, server and desktop infrastructure ahead of the threat. Authentication and signing techniques are used to prevent integrity threats. Users, devices, and applications should always be authenticated and authorized before they are allowed to access networking resources. Though a lot of information is available on the internet about IDS and IPS but it all is spread on so many sites and one has to spend a considerable part of his precious time to search it. In this regard a thorough survey has ...

Energy Technology Data Exchange (ETDEWEB)

Using gasoline as an example of additives for cold start improvement, fuel vapor composition of methanol-gasoline mixtures, fuel evaporation rate in consideration of temperature drop due to heat of fuel evaporation, air fuel ratio, stoichiometric air fuel ratio and excess air ratio of fuel vapor were calculated. The mixture formation of methanol-gasoline mixtures at low temperature in otto cycle engines was studied. Van Laar's empirical formula was used to estimate the partial pressure of high-percentage methanol blends. It was found that the most part of fuel vapor is occupied by gasoline, even when a small amount of gasoline is added to methanol resulting to an extremely small excess air ratio. It is obvious that this vapor pressure adjustment using gasoline is the dominant factor for improvement in cold startability. (10 figs, 1 tab, 10 refs)

Energy Technology Data Exchange (ETDEWEB)

Hydrothermal systems typically consist of hot permeable rock which contains either liquid or liquid and saturated steam within the voids. These systems vent fluids at the surface through hot springs, fumaroles, mud pools, steaming ground and geysers. They are simultaneously recharged as meteoric water percolates through the surrounding rock or through the active injection of water at various geothermal reservoirs. In a number of geothermal reservoirs from which significant amounts of hot fluid have been extracted and passed through turbines, superheated regions of vapor have developed. As liquid migrates through a superheated region of a hydrothermal system, some of the liquid vaporizes at a migrating liquid-vapor interface. Using simple physical arguments, and analogue laboratory experiments we show that, under the influence of gravity, the liquid-vapor interface may become unstable and break up into ...

Science.gov (United States)

Excitonic transitions in metalorganic vapor phase epitaxially grown In[sub [ital x

UK PubMed Central (United Kingdom)

Halothane, chloroform, and carbon tetrachloride, in the vapor and liquid phases, stimulate the water receptor of the blowfly Phormia regina. There are three successive phases of response to long-lasting...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Cement-based composites are widely used in applications which demand long-term service life. One important example is in immobilization matrices for low-level radioactive and other hazardous wastes, which demands long-term retention and durability. The authors describe conductivity measurements of grouts flooded with water and in contact with a sink that consists of pure water. The conductivity measurements were designed and carried out in parallel with present quality verification methods and standard leach tests of the nuclear waste management industry. For the first time, the authors show that the method of replacing intrusive chemical analysis with conductivity measurements of the leaching samples yields equivalent results.

Energy Technology Data Exchange (ETDEWEB)

Use of a broadband Local Area Network (LAN) for transmission of classified and secure unclassified information requires monitoring capabilities which are sensitive to discrete segments of the network frequency spectrum. A viable monitoring system must be capable of detecting possible intrusion attempts or network malfunctions and alerting operating and security personnel. This report documents the results of an evaluation of the Magnavox CATV Systems Inc. Digital System Sentry software for network monitoring. Recommendations are made on its possible future role in broadband LAN security monitoring throughout the Nuclear Weapons Complex.

International Nuclear Information System (INIS)

The trifluoroacetate metal-organic decomposition route to YBa_2Cu_3O_7 film growth was investigated in order to bring new insights in the growth mechanism and its dependence on processing conditions and critical current density. Precursor films were processed on LaAlO_3 substrates at different total pressure, oxygen partial pressure, water vapor partial pressure, and volume gas flow rate keeping the growth temperature at 740 "0C. The influence of these various experimental parameters on the film growth rate, which was evaluated by in situ electrical resistance measurements, was studied thoroughly. It was found that the growth rate is nearly independent of the oxygen pressure and proportional to the square root of the water pressure. Additionally, the growth rate increases with a decrease of the total pressure or an increase of the gas flow rate. An empirical multi-exponential model simulates the experimental data, however, a better ...

Science.gov (United States)

In this study, we propose a new bioactive bone cement (BBC), composed of natural bone powder (hydroxyapatite; HA), chitosan powder, and the currently available polymethylmethacrylate (PMMA) bone cement, for use in orthopedic surgeries such as vertebroplasty or as bone filler. Three types of BBCs (BBC I, BBC II, and BBC III) were prepared with different composition ratios. In vitro tests and animal studies were performed with the new BBCs, and with a currently available commercial PMMA bone cement. Surface morphology, chemical composition, changes in pH over time, exothermic temperatures, intrusion, and cellular responses were investigated in vitro. Scanning electron microscopy (SEM) and radiological and histological examinations were performed in animal studies. The results showed that the major components of the BBCs were C, O, Ca, P, Cl, Si, S, Ba, and Mg. The pH values of the BBCs decreased after 1 day, but eventually recovered to 7.2-7.4. The water absorbency, ...

Energy Technology Data Exchange (ETDEWEB)

An experimental study of second harmonic generation in a copper-vapor pulsed laser with an ADP crystal is presented. The ratio of the conversion into the second harmonic is found to depend on the average power of the exciting radiation. The maximum conversion ratio was 8.5%. Thermal self-defocusing is the main obstacle to obtaining high average powers at the double frequency.

Energy Technology Data Exchange (ETDEWEB)

Measurements of the double-electron-capture process in which a positive ion of iodine becomes a negative ion in a single collision with a magnesium atom are reported between 20 and 90 keV. The cross section is comparable to that for the rare gases and not as large as might be expected from a two-valence-electron atom. This process is probably insignificant in the production of negative ion beams using a magnesium-vapor target.

Energy Technology Data Exchange (ETDEWEB)

This project is aimed at development of optimum combustion technology with diversified fuels, e.g., naphtha and LCO, for gas turbines and others as power sources for topographical energy supply. The combustion under the microgravity is also investigated using the underground facilities at Japan Microgravity Center. Described herein are the FY 2000 results. For construction of combustion model and simulation, the combustion reactions for various liquid fuels are simplified to calculate ignition delay, adiabatic flame temperature and laminar burning velocity with an error less than about 3%. The microgravity combustion experiments are conducted for spray dispersed into a cylinder, to find flame propagation velocities changing with the vaporization characteristics of liquid fuels, and also to construct the combustion models. The premixed turbulent combustion simulation program is developed using a probability density function ...

Energy Technology Data Exchange (ETDEWEB)

The process operation of the hot wall vapor deposition method, formation of dry organic thin film and the control of molecular arrangement were described. This equipment included a substrate on the upper end of the hot wall tube and the vapor source at the lower end. The remarkable features are the hot wall tube which plays the role to hold vaporizing molecules to the high temperature and to transport molecules, and the flip flop mechanism which gives some idle period for the molecular vaporization by shutter closing. Several experiments were carried out by using stearic acid and by changing the distance S from the upper end of hot wall quartz tube to the substrate, the furnace temperature T{sub f} and the substrate temperature T{sub s}. When T{sub f} is equal to or less than the melting point of stearic acid, molectles are preferentialy made to vertical arrangement. In the case of T{sub f} more than ...

Energy Technology Data Exchange (ETDEWEB)

Previous analyses of binary cycles for conversion of geothermal energy from moderate temperature resources to electrical energy have shown potential gains in net geofluid effectiveness of on the order of 8%, resulting from selection of turbine-expansion processes whose equilibrium states pass through the two-phase region (assuming major condensation does not occur). If condensation occurs, this gain could be reduced or eliminated by the resulting loss in turbine efficiency. Experience with many fluids, however, indicates that vapor supersaturation (or subcooling) permits metastable pure-vapor states to exist at temperatures considerably below the saturation temperature at a given pressure; thus, by better understanding the condensation process, and properly structuring the cycle, substantial performance gains may be achievable. The present study assessed, qualitatively, the probability for attaining this performance gain.

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)

Anti-reflective coatings made with Teflon AF2400 had the highest damage thresholds recorded for physical vapor deposited coatings at the Lawrence Livermore National Laboratory damage facility. Physical vapor deposited layers of Teflon AF2400, a perfluorinated amorphous polymer, maintained the bulk optical properties of a high transmittance from 200 nm to 1600 nm, and a low refractive index. In addition, the refractive index can be intentionally reduced by control of two common deposition parameters, deposition rate and substrate temperature. Scanning electron microscopy and nuclear magnetic resonance observations indicated that morphological changes caused the variations in the refractive index rather than compositional changes. The coatings adhered to fused silica and silicon wafers under normal laboratory handling conditions.

International Nuclear Information System (INIS)

The Median Tectonic Zone (MTZ) of New Zealand is a generally north trending belt of Mesozoic subduction related I-type plutonic, volcanic, and sedimentary rocks in South Island and Stewart Island that separates Permian strata of the Eastern Province Brook Street Terrane from lower to mid Gondwana margin assemblages of the Western Province. High precision isotope dilution U/Pb ages of zircons from 30 rocks are reported. Pre-digestion leaching of zircon in hydrofluoric acid yielded significantly more concordant residues by removing common Pb and dissolving more soluble high-U domains that have been more affected by relatively recent Pb loss. The results show that MTZ magmatism ranges in age from at least Early Triassic to Early Cretaceous (247-131 Ma), with a pronounced gap in the Middle Jurassic. Triassic plutons tend to occur on the eastern side of the MTZ, and they intrude volcanic/sedimentary sequences of the MTZ in Nelson and eastern Fiordland. These sequences are in turn intruded ...

Science.gov (United States)

We present a new approach for growing Si nanowires directly from a silicon substrate, without the use of a metal catalyst, silicon vapor or CVD gasses. The growth can be performed in a furnace type configuration at moderate temperatures or in localized regions by resistive heating. Since the silicon wires grow directly from the silicon substrate, they do not need to be manipulated nor aligned for subsequent applications. Wires in the 20-50 nm diameter range with lengths over 80 ?m can be grown by this technique. We have studied the effects of various growth parameters, including temperature, substrate orientation, initial sample cleaning and carrier gasses. Results indicate that most important parameters in the growth of the nanowires are the surface cleaning, the temperature and the type of carrier gas used. A model is proposed, which involves an oxide catalyst for the process, with the growth of the nanowires enabled by a significantly ...

International Nuclear Information System (INIS)

The optical, electromagnetic and mechanical properties of thin films (TFs) are directly correlated to their morphology at the nanoscale. This, in concert with the fact that new deposition techniques are enabling the growth of thin films with very complex morphologies, there is an increasing interest in model-based simulation (MBS) for the design of engineering structures (including nanostructures), and increasing computer speeds are beginning to make MBS an effective design tool capable of bridging the nanoscale with the continuum scale, has made it increasingly important to understand how the nanostructure of a thin film impacts its properties at all length scales. The authors have developed the capability to determine the mechanical properties of thin films with amorphous nanostructure by combining molecular dynamics, i.e., position of particles (e.g., atoms or molecules) and their interatomic potential(s), with continuum mechanics principles. This work concerns ...

Energy Technology Data Exchange (ETDEWEB)

Organic Rankine cycles (ORC) have unique properties that are well suited to solar power generation. In this work design and performance calculations are performed using MatLab/SimuLink computational environment. The cycle consists of thermal solar collectors (Flat Plate Solar Collector (FPC), or Parabolic Trough Collector (PTC), or Compound Parabolic Concentrator (CPC)) for heat input, expansion turbine for work output, condenser unit for heat rejection, pump unit, and Reverse Osmosis (RO) unit. Reverse osmosis unit specifications used in this work is based on Sharm El-Shiekh RO desalination plant. Different working fluids such as: butane, isobutane, propane, R134a, R152a, R245ca, and R245fa are examined for FPC. R113, R123, hexane, and pentane are investigated for CPC. Dodecane, nonane, octane, and toluene are allocated for PTC. The proposed process units are modeled and show a good validity with literatures. Exergy and cost analysis are performed for saturation ...

Energy Technology Data Exchange (ETDEWEB)

Thrust faulting, folding, and penetrative compressional fabrics (e.g. spaced cleavage, pencils, and coal cleats) have been found in several outcrops within the central Deep River Basin (the southern Durham subbasin to the northern Wadesboro subbasin). The trend of these structures is nearly parallel to the basin, and may locally control the present geometry of the basin boundaries. These features are distributed throughout the stratigraphic section and across the entire width of the basin. In outcrops where relative timing can be determined, the compressional structures post-date all extensional and intrusive features associated with basin formation. In particular, thrusts cut across and displace basin-parallel normal faults and basin-normal cross-faults. All thrusts found to date verge northwest, and displacements of cross-fault boundaries indicate that transport was approximately 325[degree].

Energy Technology Data Exchange (ETDEWEB)

Greenhouse-effect induced climate change repercussions will, via the catchment areas of big rivers, eventually arrive in amplified form at the far downstream coastal zones of the world. In the coastal zone these imported problems will add to the locally exerted climate change effects, while the climate change induced sea-level rise will attack the coastal zone from the other side, both by flooding and by saline groundwater intrusion. These multiple problems will hit the coastal zone, which is already under increasing stress. The combined threats require fast and massive support for national Coastal Zone Management capabilities, which could help to limit the damage and to support planning for sustainable development. Recommendations are presented to facilitate implementation of Coastal Zone Management units in all coastal countries by the year 2000.

International Nuclear Information System (INIS)

Author.The geochemical and isotopic study, based on the analysis of twenty water samples from well in the coastal plain of Sarafand (South-Lebanon), permit to eliminate the hypothesis of marine intrusion in this aquifer. The increase of salinity observed in certain wells is due to the contamination of cretaceous aquifer water by the quaternary formations. The two poles of mixing are respectively characterized: by weak tritium contents (between 2 and 3 UT) and a value of stable isotopes (-5,9<0,18<-5,5) corresponding to the appearance of cretaceous formation area; by the high tritium contents and enrichment relative to heavy isotope in the mineralized water of superficial formations. On the other hand, the isotope contents permit the set a rapid renewal of the cretaceous aquifer water due to quick circulation in the Karstic system

Energy Technology Data Exchange (ETDEWEB)

A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements.

Energy Technology Data Exchange (ETDEWEB)

Previous analyses of binary cycles for conversion of geothermal energy from moderate temperature resources to electrical energy have shown potential gains in net geofluid effectiveness on the order of 8%, resulting from selection of turbine-expansion processes whose equilibrium states pass through the two-phase region. If condensation occurs, this gain could be reduced or eliminated by the resulting loss in turbine efficiency. Experience with many fluids, however, indicates that vapor supersaturation permits metastable pure-vapor states to exist at temperatures considerably below the saturation temperature at a given pressure; thus, by better understanding the condensation process, and properly structuring the cycle, substantial performance gains may be possible. The purpose of the present study was to assess the probability for attaining this performance gain by estimating the extent of condensation which might be expected during such an ...

International Nuclear Information System (INIS)

Nuclear energy provides a third of Europe's electricity with nearly no greenhouse-gas emissions. Sustained efforts are now being conducted to harmonize regulations all over Europe through WENRA and to converge on technical nuclear safety practices within the TSO network ETSON (European Technical Safety Organizations Network). In CANDU type NPP the tritiated water occurs by the neutron bombardment of deuterium. The tritiated water vapors imply health hazard (in the critical organs of the body the water presents a 10 day average biological half-life) and the early detection in nuclear plants of tritium emissions is important because the tritiated water vapors have the same characteristics as of atmospheric water vapors. By detecting tritiated vapors, the monitoring system ensures the following objectives: (a) indicates levels of tritium generally due to heavy water leakage, (b) reduces the possibility of ...

Energy Technology Data Exchange (ETDEWEB)

Explosives molecules have a number of unique properties. These properties are discussed. They include low vapor pressures, electronegativity, ''stickiness,'' frangibility, and thermal instability. The program for developing an advanced explosives detector is described.

Energy Technology Data Exchange (ETDEWEB)

There are certain factors to take into account when determining the suitability of a healthy house site. Power lines, agricultural spraying, vehicle exhaust, and industrial pollution are all potential sources of indoor air contamination. It is recommended that a environmental assessment be done to determine whether there are specific sources of contamination. Good drainage is required. The surrounding landscaping should be open and sunlit, and with low maintenance requirements. Decks and fences made from pressure-treated or chemical treated lumber should be avoided. One of the early decisions in the design process is the choice of the structural system. The key with all foundation types is to control moisture, whether from rain, from the ground, or the condensation of moisture from the air with cooling. The construction frame is sealed away from the occupants by the air/vapor barrier, so only in extreme cases is it essential to use alternatives to softwood lumber ...

Science.gov (United States)

Feb 15, 2008 ... hydrological properties (e.g., hydrometeor budgets, cloud ice/water, transports ... cloud fraction, mass and particle size. In combination, these .... anomaly in the LS is not simply due isentropic movement of water vapor relative ...

Energy Technology Data Exchange (ETDEWEB)

This study focuses the granitoids of center-southern portion of Guyana Shield, southeastern Roraima, Brazil. The region is characterized by two tectonic-stratigraphic domains, named as Central Guyana (GCD) and Uatuma-Anaua (UAD) and located probably in the limits of geochronological provinces (e.g. Ventuari-Tapajos or Tapajos-Parima, Central Amazonian and Maroni-Itacaiunas or Transamazon). The aim this doctoral thesis is to provide new petrological and lithostratigraphic constraints on the granitoid rocks and contribute to a better understanding of the origin and geo dynamic evolution of Guyana Shield. The GCD is only locally studied near to the UAD boundary, and new geological data and two single zircon Pb-evaporation ages in mylonitic biotite granodiorite (1.89 Ga) and foliated hastingsite-biotite granite (1.72 Ga) are presented. These ages of the protholiths contrast with the lithostratigraphic picture in the other areas of Cd (1.96-1.93 Ga). Regional mapping, petrography, ...

Energy Technology Data Exchange (ETDEWEB)

In this paper uptake of tritium by market foods from tritiated water vapor in the air is investigated using cereals and beans purchased in Deep River, Canada. The concentrations of tissue free water tritium (TFWT) and organically bound tritium (OBT) range from 12 to 79% and from 10 to 38% respectively, of that estimated for atmospheric water vapor of the sampling month. The specific activity ratios of OBT to TFWT were constant for cereals, but variable for beans. The elevated OBT was shown to be the result of isotopic exchange of labile hydrogen by the fact that washing the foods with tritium free-water reduced their tritium contents to levels characteristic of their production sites.

Energy Technology Data Exchange (ETDEWEB)

The production of polarized negative ion beams by ''collisional pumping'' is described. Collisional pumping utilizes repeated charge changing collisions in a thick electron-spin-polarized gas or vapor target to form a polarized fast atom beam. The polarized fast atom beam is then partially converted into a polarized negative ion beam in a vapor target. Analysis is presented for a hydrogen beam passing through either a thick polarized H atom target or a thick polarized alkali target. Large polarizations and large currents may be possible.

Energy Technology Data Exchange (ETDEWEB)

The Dental Investigation Service, USAFSAM, Brooks AFB, has outlined the need for a vacuum unit to be used in the Air Force dental clinics. The unit must be capable of effectively picking up mercury and at the same time not redistribute mercury vapors throughout the dental clinic during normal operations or mercury-spill situations. The Dental Investigation Service selected the MRS-3, Minuteman Mercury Recovery System, product of American Cleaning Equipment Corporation as the mercury vacuum to be used for T E. The USAF OEHL/ECH was requested by the Dental Investigation Service to perform the T E on the MRS-3 for possible health hazards due to exposures of mercury vapors.

Energy Technology Data Exchange (ETDEWEB)

Late plagiogranite bodies in the Semail ophiolite have been previously suggested to represent late stage fractionates within an episodic spreading center magma chamber or the roots of seamount chains. Field and lab observations suggest that these late silicic magma chambers represent zones of repeated injection by dikes of intermediate to mafic composition. Multiple generations of intrusion, partial resorption and reintrusion are preserved in the plagiogranite as 1) relict phantom xenoliths, 2) angular xenoliths with quartz-rich margins, 3) deformed fine-grained dikes with distinct chilled margins, and 4) planes of rectangular blocks with cuspate margins or ellipsoids of similar fine grained mafic materials. The blocks and ellipsoids are actually dismembered mafic dikes that chilled by intruding a cooler silicic liquid and were either thermally fractured or pinched out. All of the dikes are hydrothermally altered to assemblages including amph., qtz., epi., preh., ...

Energy Technology Data Exchange (ETDEWEB)

The Archean core of the Laramide Wind River uplift records evidence of at least three major granitoid-forming episodes. The oldest, the Dry Creek gneiss (DCG), was emplaced by 2.8 Ga and occupies the northeastern part of the range. Mafic, pelitic and ultramafic inclusions occur in the DCG. Elsewhere in the Wind River Mountains there is evidence for crustal components as old as 3.8 Ga. The Bridger batholith (BB), intruded at 2.67 Ga, is found in the west-central Wind River Mountains. The Wind River batholith (WRB) refers to the youngest Late Archean granodiorites and granites which are found throughout the range and includes granitoids previously name the Louis Lake, Bears Ears, Popo Agie, and Middle Mountain intrusions. Although granitoids of the Wind River batholith have been dated at 2.63 and 2.55 Ga, they are considered together here because there is a complete gradation in rock type and because definite intrusive contacts are scarce. The ...

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO3 promoted by piperazine (PZ). Pilot plant testing was performed in a 16.8-inch ID absorber and stripper with recirculation of air and CO{sub 2}. Three solvents (7 m MEA, 5 m K{sup +}/2.5 m PZ, and 6.4 m K{sup +}/1.6 m PZ) were tested in four campaigns with three different absorber packings. Pilot plant testing established that 5 m K{sup +}/2.5 m PZ requires two times less packing than 7 m MEA and three times less packing than 6.4 m K{sup +}/1.6 m PZ. A rigorous model of the thermodynamics and mass transfer was developed in the RateSep{trademark} block of AspenPlus{reg_sign}. The double matrix stripper reduces energy consumption by 5 to 15%. The best K{sup +}/PZ solvent, 4 m K{sup +}/4 m PZ, and the best process configuration, double matrix stripper with a double intercooled absorber, requires ...

Energy Technology Data Exchange (ETDEWEB)

In addition to ceramics, alloys such as tool steel and nickel- and iron-based superalloys are being considered for high temperature applications such as missile bearings and low heat rejection engines. Studies were made to lubricate a nickel-based superalloy at 500{degrees}C, by using a vaporized aryl phosphate ester, at a concentration of 0.1% in air. From deposition and wear studies it was found that it was impossible to form a good polymeric coating on the superalloy surface. Energy dispersive X-ray analyzer (EDXA) analysis showed that this was due to minute quantities of aluminum in the alloy segregating to the surface, upon being heated to 500{degrees}C, forming a passive oxide coating. It was necessary to activate the surface, in order to lubricate the material successfully. A method of activation by electrodepositing the surface with a layer of iron oxide was developed. Once activated, a good lubricous polymer was formed on the superalloy surface. Tests ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents the performance analysis on a hybrid air-conditioning system according to the hybrid building energy system of the green building demonstration project in Shanghai, in which a 150 m{sup 2} solar collector is used to power two 10 kW adsorption chillers, a vapor compression heat pump is used to cool air in the evaporating end while the condensing heating at about 80{sup o}C is fully used to regenerate a liquid desiccant dehumidification system. In the hybrid system, the sensible cooling to the air is treated mainly by solar adsorption cooling and vapor compression cooling, whereas the latent heat is treated by the liquid desiccant dehumidification system with regeneration from the condensing heat of the heat pump. The results show that the performance of this system is 44.5% higher than conventional vapor compression system at a latent load of 30% and this improving can be achieved by 73.8% at a 42% latent ...

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 are purposely limited ...

Energy Technology Data Exchange (ETDEWEB)

The 9/11 event in the U.S.A has increased international terror possibilities against nuclear facilities including nuclear power plants(NPPs). It is necessary to assess the performance of an existing physical protection system(PPS) at nuclear facilities based on such malevolent acts. A PPS is a complex configuration of detection, delay, and response elements. Several methods are available to analyze a PPS and evaluate its effectiveness. Sandia National Laboratory(SNL) in the USA was developed a System Analysis of Vulnerability to Intrusion (SAVI) computer code for this purpose. It is powerful software for evaluating the effectiveness of PPS against outsider threats. This study presents the performance assessment of the PPS at Wolsung NPP using SAVI code. First, the site-specific Adversary Sequence Diagrams(ASDs) of the PPS is constructed. It helps to understand the functions of the existing PPS composed of physical areas and Protection Elements(PEs) at Wolsung NPP. ...

Energy Technology Data Exchange (ETDEWEB)

This paper reports on the protection of opening that are exposed to the environment in nuclear facilities which presents an almost overwhelming engineering challenge. Intakes and outflows must permit the passage of large volumes of air or water without impeding their flow, and they are often exposed to corrosive salt and chemicals. An intrusion detection sensor that is intended to protect these openings must be capable of operating reliably under environmentally harsh conditions, and at the same time either provide a physical delay barrier or attach to an existing barrier. A new fiber optic sensor technology has now been developed specifically for protecting environmentally exposed openings. This sensor uses a fiber optic cable embedded in a neoprene rubber frame which is reinforced with Kevlar threads or braided steel cable. The sensor is configured in a mesh pattern with openings sufficiently large to permit air or water to flow unimpeded, but small enough to ...

Energy Technology Data Exchange (ETDEWEB)

Stabilization/solidification of hazardous wastes is used to convert hazardous metal hydroxide waste sludge into a solid mass with better handling properties. This study investigated the pore size development of ordinary portland cement pastes containing metal hydroxide waste sludge and rice husk ash using mercury intrusion porosimetry. The effects of acre and the addition of rice husk ash on pore size development and strength were studied. It was found that the pore structures of mixes changed significantly with curing acre. The pore size shifted from 1,204 to 324 {angstrom} for 3-day old cement paste, and from 956 to 263 {angstrom} for a 7-day old sample. A reduction in pore size distribution for different curing ages was also observed in the other mixtures. From this limited study, no conclusion could be made as to any correlation between strength development and porosity. 10 refs., 6 figs., 3 tabs.

Energy Technology Data Exchange (ETDEWEB)

The Oklo natural fossil fission reactors in Gabon, Equatorial Africa, have been studied as a natural analogue for spent nuclear fuel in a geological environment. For these studies, it is important to know what has happened to these reactors since they formed. This review is focussed on existing geological and geochronological information concerning the Oklo reactors and the surrounding ore. A sequence of geological and geochemical events in the Oklo area, as described in the literature, is given. The data and the studies behind this established geochronology are discussed and evaluated. Of the regional geology, special attention is given to the dating of the Francevillian sediments, and the intrusion of a dolerite dyke swarm. The processes that led to the mineralisation at Oklo, the subsequent formation of the nuclear reactors and later migration of fission products are described. Further discussion concerns the studies of the dolerite dyke swarm, since this ...

International Nuclear Information System (INIS)

Remotely-operated SHRIMP dating of zircon is an interesting alternative for dating of zircon crystals. Although it does not represent any technical progress of the geochronological method using the U-Pb system in zircon it is a very useful and cheap facility. The procedure was first used for mass spectrometric analyses involving two international laboratories in Sao Paulo, Brazil and Beijing, China. It was applied to samples of three gneiss-migmatitic rocks from the Ita quarry in the Atuba Complex (located between the Luis Alves and the Apiai Domain) to test previous controversial hypotheses about its evolution. The presence of important archaean and paleo proterozoic components in the complex is confirmed by analyses of zircon found in probably neo proterozoic leucosomes. Diorite intrusion also occurred during the neo proterozoic, associated with the 0.6Ga continental collisions involved in the assembly of Gondwana. The determination of Hf isotope ratios by ...

International Nuclear Information System (INIS)

Particulate (i.e. tokamak dust) has been collected from the DIII-D tokamak located at General Atomics in San Diego, CA, USA. Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Sampling was completed in four toroidal locations of the machine; the 0-90 area, the 90-180 area, the 180-270 area, and the 270-360 area. The 0 direction designates the north side of the DIII-D machine. Four tiles in each area were sampled; the first vertical tile above the floor on the centerpost, a floor tile next to the center post, a tile on the isolated ring, and the first tile up from the isolated ring on the divertor. In addition, samples were collected from underneath the floor tiles at the 275 and the 75 locations. The count median diameter of the ...

International Nuclear Information System (INIS)

A pyrochemical process has been introduced and utilized so that the transmutation of spent PWR fuel in PEACER can produce mainly low and intermediate level waste for near surface disposal. Major radioactive nuclides from PEACER pyro-processing are composed of TRU and LLFP. In this study, the requirement for the final waste from PEACER is evaluated based on the methodology for establishment of waste acceptance criteria. Also, sensitivity analysis for several input parameters is conducted in order to determine acceptable decontamination factor (DF) and LLFP removal efficiency and to find out input parameter that extremely have an effect on DF. As a result of the study, LLFP removal efficiency, especially Sr-90 and Tc-99, is proved to be a major nuclide which contributes to annual dose by human intrusion scenario rather than TRU DF. More than 98.5% of LLFP have to be removed to meet below dose constraint within the DF more than 5.0E+03. Besides, because of the ...

International Nuclear Information System (INIS)

A pyrochemical process has been introduced and utilized so that the transmutation of spent PWR fuel in PEACER can produce mainly low and intermediate level waste for near surface disposal. Major radioactive nuclides from PEACER pyroprocessing are composed of TRU and LLFP. In this study, the requirement for the final waste from PEACER is evaluated based on the methodology for establishment of waste acceptance criteria. Also, sensitivity analysis for several input parameters is conducted in order to determine acceptable decontamination factor (DF) and LLFP removal efficiency and to find out input parameter that extremely have an effect on DF. As a result of the study, LLFP removal efficiency, especially Sr-90 and Tc-99, is proved to be a major nuclide which contributes to annual dose by human intrusion scenario rather than TRU DF. More than 98.5% of LLFP have to be removed to meet below dose constraint within the DF more than 5.0E + 03. Besides, because of the ...

Energy Technology Data Exchange (ETDEWEB)

This paper provides information on activities undertaken in a non- production oriented metal finishing operation to minimize waste and conserve resources. The facility is a 6000 sq foot shop that typically only deals with prototype parts. Utilizing a plan that includes employee awareness, common sense and existing technology, a noticeable reduction in waste volume has been obtained. Initiatives that are covered include: segregation of cyanide plating solutions, elimination of copper cyanide plating, elimination of hexavalent chromium plating, elimination of vapor degreasing, changing of rinsing practices, and changing a process for cleaning of aluminum parts. Some discussion is also presented on the effectiveness of combining the technologies of physical vapor deposition and electrodeposition to help minimize waste. Plans for additional initiatives including water recycling, elimination of cyanide plating and substitution of electrodeposition ...

Energy Technology Data Exchange (ETDEWEB)

We conducted broadband absorption measurements of atmospheric water vapor in the ground state, X {sup 1}A{sub 1} (000), from 0.4 to 2.7 THz with a pressure broadening-limited resolution of 6.2 GHz using pulsed, terahertz time-domain spectroscopy (THz-TDS). We measured a total of seventy-two absorption lines and forty-nine lines were identified as H{sub 2}{sup 16}O resonances. All the H{sub 2}{sup 16}O lines identified were confirmed by comparing their center frequencies to experimental values available in the literature.

International Nuclear Information System (INIS)

This patent describes the producing of a refractory metal wherein a sponge refractory metal is produced as an intermediate product by the use of magnesium with the incidental production of magnesium chloride, and wherein residual magnesium is separated from the magnesium chloride and from refractory metal to a vacuum distillation step which fractionally distills the magnesium, the magnesium chloride, and the metal sub-chlorides; the steps of: recovering fractionally distilled vapors of magnesium chloride and metal sub-chlorides from a sponge refractory metal; separately condensing the vapors as separately recovered; and recycling the separately recovered magnesium at a purity of at least about 96%.

Science.gov (United States)

Room-temperature continuous-wave (cw) operation of a GaInP/AlGaInP multiquantum well (MQW) laser was achieved for the first time. The threshold current was 70 mA at 22 /sup 0/C for a device with an 8-..mu..m-wide and a 250-..mu..m-long planar stripe. The emission wavelength was 668 nm. The characteristic temperature T/sub 0/ was 138 K under cw operation. The wafer with the MQW structure composed of 100-A-thick GaInP wells and 40-A-thick AlGaInP barrier layers was grown by atmospheric pressure metalorganic chemical vapor deposition.

International Nuclear Information System (INIS)

The metallo-organic chemical vapor deposition (MOCVD) process has been used with great success to grow AlGaAs-GaAs and InGaAsP-InGaAs-InP heterostructure materials for electronic and optoelectronic applications. Devices fabricated from Al/sub x/Ga/sub 1-x/As-GaAs heterostructures grown by MOCVD include bipolar transistors, field-effect transistors (FETs), high-mobility (or modulation-doped) FETs, large-area high-efficiency solar cells, low-threshold lasers, high-power lasers, quantum-well lasers, and visible lasers. The state of the art for the MOCFD growth of optoelectronic devices is reviewed in this paper, and some comments are made regarding future trends in the growth of these materials by MOCVD.

International Nuclear Information System (INIS)

Measurements of the statistical characteristics of channel wall static pressure fluctuations in parallel one-component boiling flow are reported. The measurements span a wide range of local subcooling and vapor volume fraction, and correspond to flow regimes ranging from highly subcooled bubbly to saturated slug-annular. Vapor volume fraction measurements at the pressure measurement station are also reported in conjunction with visual observation of the flow structure. Variation of static pressure fluctuation intensity and spectral content with local thermal-hydraulic condition is demonstrated. Finally, it is suggested that diagnosis of local two-phase flow regime on the basis of (i) statistical characteristics of the pressure data, and (ii) time trace of pressure signal, may be possible. 15 refs.

British Library Electronic Table of Contents (United Kingdom)

This paper explores the through-/in-plane characteristics of water transport in the cathode gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC). Theoretical analysis is performed on the non-isothermal two-phase flow under flow channels. A dimensionless group Da (Damkohler number for PEFC operation), defined as the ratio of water generation rate to water vapor-phase removal rate, is formulated to characterize the flow regimes in a PEFC. This group, lumping geometrical parameters and physical properties, compares the water vapor-phase removal capability (via water diffusion and holding capacity) with the rate of water production by the oxygen reduction reaction. We find that this dimensionless group can be used to characterize the non-isothermal, two-phase phenomena: when Da&...

British Library Electronic Table of Contents (United Kingdom)

Abstract Despite the fact that oxidation is the second most frequent degradation pathway for pharmaceuticals, means of evaluating the oxidative stability of pharmaceutical solids, especially effective stress testing, are still lacking. This paper describes a novel experimental method for peroxide-mediated oxidative stress testing on pharmaceutical solids. The method utilizes urea-hydrogen peroxide, a molecular complex that undergoes solid-state decomposition and releases hydrogen peroxide vapor at elevated temperatures (e.g., 30C), as a source of peroxide. The experimental setting for this method is simple, convenient, and can be operated routinely in most laboratories. The fundamental parameter of the system, that is, hydrogen peroxide vapor pressure, was determined using a modified spect...

Energy Technology Data Exchange (ETDEWEB)

In order to practice a design-by-analysis of thermohydraulics design of BWR fuel rod bundles, the subchannel analysis would play a major role. There, the immediate concern is improvement in its predictive capability of CHF due in particular to the film dryout (boiling transition phenomena: BT) on the fuel rod surface. Constitutive equations in the subchannel analysis formulation are responsible for the quality of calculated results. The constitutive equations are a result of integration of the local and instantaneous description of two-phase flows over the subchannel control volume. In general, they are expressed in terms of subchannel-control-volume- as well as area-averaged two-phase flow state variables. In principle the information on local and instantaneous physical phenomena taking place inside subchannels must be counted for in the algebraic form of the equations on the basis of a more mechanistic modeling approach. They should include also influences of the ...

International Nuclear Information System (INIS)

In order to practice a design-by-analysis of thermohydraulics design of BWR fuel rod bundles, the subchannel analysis would play a major role. There, the immediate concern is improvement in its predictive capability of CHF due in particular to the film dryout (boiling transition phenomena: BT) on the fuel rod surface. Constitutive equations in the subchannel analysis formulation are responsible for the quality of calculated results. The constitutive equations are a result of integration of the local and instantaneous description of two-phase flows over the subchannel control volume. In general, they are expressed in terms of subchannel-control-volume- as well as area-averaged two-phase flow state variables. In principle the information on local and instantaneous physical phenomena taking place inside subchannels must be counted for in the algebraic form of the equations on the basis of a more mechanistic modeling approach. They should include also influences of the ...

Energy Technology Data Exchange (ETDEWEB)

This report discusses environmental surveillance activities conducted on the Nevada Test Site during the first calendar quarter of 1996. Surveillance activities included collection and analysis of air, noble gas, tritiated water vapor, and other water samples. Samples were analyzed for both radiological and non-radiological effluents.

CERN Document Server

It is shown that the interpretation of the experimental results reported in the publication "Storage of Light in Atomic Vapor" by D.F.Phillips et al., Phys. Rev.Lett. 86, 783 (2001) [quant-ph/0012138] is incorrect. The experimental observation of this paper can be consistently explained in the framework of standard concepts of the physics of optical pumping and has nothing to do with "storage of light", or "dynamic reduction of the group velocity", or "light pulse compression".

Energy Technology Data Exchange (ETDEWEB)

By means of infrared spectroscopy, x-ray diffraction, and differential thermal analysis, the authors investigate the pyrolysis of dichlorodithiourea cadmium, the vapor phase epitaxy of the cadmium sulfide film, and the composition of the solid and gaseous pyrolysis products. Those products are found to include the thiocyanates of guanidine, ammonium, and hydrogen along with cadmium oxides and sulfates and hydrochloric acid.

Energy Technology Data Exchange (ETDEWEB)

We report on measurements of the mixing of fuel oil with air at atmospheric pressure in an industrial premixed gas turbine burner. The concentration of the vaporized fuel oil was measured with laser induced fluorescence. We reason that the fuel oil concentration can be considered with good accuracy as proportional to the fluorescence intensity. (author) 6 fig., 3 refs.

Energy Technology Data Exchange (ETDEWEB)

Means for increasing heat transfer characteristics between the surface of a solid and a boiling liquid are described in which the solid is immersed is comprised of a solid with passages which extend therethrough to the surface for the circulation of liquid through the passages for emergence from the surface to eliminate at least a portion of the unstable vapor film otherwise formed on the surface.

International Nuclear Information System (INIS)

The structure of a fragment of the germanium complex compound (GCC) with oxyethylidenediphosphonic acid and the adsorption properties of GCC films with respect to the vapors of water and some other organic liquids have been studied. The electric conductivity of GCC films has been investigated, and its mechanism has been explained.

Energy Technology Data Exchange (ETDEWEB)

PNNL, with cofunding from the Bonneville Power Administration (BPA) and Building Technologies Program, conducted a research and development activity targeted at addressing the energy efficiency goals targeted in the BPA roadmap. PNNL investigated an integrated heating, ventilation and air conditioning (HVAC) system option referred to as the low-lift cooling system that potentially offers an increase in HVAC energy performance relative to ASHRAE Standard 90.1-2004.

Energy Technology Data Exchange (ETDEWEB)

We have studied the nucleation and growth processes in a chemical vapor deposition (CVD) diamond film using a tomographic electron backscattering diffraction method (3D EBSD). The approach is based on the combination of a focused ion beam (FIB) unit for serial sectioning in conjunction with high-resolution EBSD. Individual diamond grains were investigated in 3-dimensions particularly with regard to the role of twinning.

CERN Document Server

Statistical modelling for social researchers

Energy Technology Data Exchange (ETDEWEB)

The sequential layer-by-layer adsorption of polyanions and polycations to build polyelectrolyte multilayers has triggered enormous interest in their potential uses in a wide range of fields, from photonic to pharmaceutical applications. We show that the conformation of the solvent swollen films - prior to drying - is determined by the initial adsorption conditions, but can be altered ex-situ by exposure to a liquid phase of very high ionic strength. Recently it has been observed that the swelling depends on the charge of the outermost layer. In the PAH/PSS system we saw that assemblies with PSS as the outermost layer swell more than those with PAH outside. A neutron reflectivity study of this effect in addition indicated the existence of two kinds of water, bound with different strength within the films. Beside an unexpected two-step kinetics of swelling, the reflectivity curves of the layers against vacuum before and after re-hydration in D{sub 2}O vapor did not ...

International Nuclear Information System (INIS)

AlGaInP epitaxial layers grown at 690 degree C by atmospheric pressure organometallic vapor phase epitaxy are investigated by transmission electron microscopy. For the first time, compositionally modulated and ordered structures are simultaneously observed in AlGaInP alloys. The ordering is of the CuPt type with ordering along the #left brace#111#right brace# directions. The ordered regions appear as plate-like microdomains, while the composition modulation takes the form of a fine columnar constrast oriented along the growth direction. In addition, from the results of (001) plan-view diffraction contrast examination, the principal strain direction associated with the modulation structures is found to be perpendicular to the growth direction and lies in the surface plane. Thus, it is concluded that the spinodal decomposition is initiated and developed on the surface during the growth of the AlGaInP epitaxial layers and, finally, forms the columnar structure.

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)

Room-temperature cw operation for InGaP/InGaAlP double heterostructure (DH) laser diodes on GaAs substrates was achieved for the first time. The DH wafers were grown by low-pressure metalorganic chemical vapor deposition using methyl metalorganics. A lasing wavelength of 679 nm and a threshold current of 109 mA at 24C were obtained for an inner stripe structure laser diode with a 250- m-long and 7- m stripe geometry. The laser operated at up to 51C. The characteristic temperature T0 was 87 K at around room temperature. The lowest threshold current density, 5.0 kA/cmS, was obtained with a 20- m stripe width laser diode under room-temperature pulsed operation.

Energy Technology Data Exchange (ETDEWEB)

The effects on engine emissions resulting from the intake manifold fumigation of oxygenated fuel and the addition of oxygenates to the fuel have been investigated using a direct-injection diesel engine. The results show that carefully selected oxygenated fuels effectively work to increase the ignition delay because of their low ignition quality and to decrease the combustion temperature due to the low compression gas temperature produced from their large heat of vaporization, thereby reducing levels of Bosch smoke and nitrogen oxides simultaneously. However, supplementary injection of the oxygenates into the intake air causes a drastic increase in the levels of exhaust total hydrocarbons and CO; thus, it can be said that the addition of oxygenates to the fuel is more practical and effective than fumigation if phase separation of the blended fuel may not be occurred. In the case of addition of the oxygenates to the fuel, it is clarified that smoke is directly ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

This paper presents an analysis of the applicability of alternative systems for electric vehicle (EV) heating and air conditioning (HVAC). The paper consists of two parts. The first part is a cooling and heating load calculation for electric vehicles. The second part is an evaluation of several systems that can provide the desired cooling and heating in EVs. These systems are ranked according to their overall weight The overall weight is calculated by adding the system weight and the weight of the battery necessary to provide energy for system operation. The system with the minimum overall weight is considered to be the best, because minimum vehicle weight decreases the energy required for propulsion, and therefore increases the vehicle range. Three systems are considered as the best choices for EV HVAC. These are, vapor compression, ice storage and adsorption systems. These systems are evaluated, including calculations of system weight, system volume, and COP. The ...

Science.gov (United States)

The relationship between processing, microstructure, and properties was studied for A-15 compounds in multifilamentary composites produced by solid-state diffusion and in thin-film samples produced by vapor deposition. Grain sizes of A-15 superconducting compounds were measured by transmission electron microscopy of multifilamentary composites reacted at various temperatures. Critical current densities at 4.2 K and fields up to 6 T were found to be similar for niobium-tin, vanadium-gallium, and vanadium-silicon of the same grain size. Study of the Cu-V-Si phase diagram led to the production of improved multifilamentary vanadium-silicon conductors. The effects of various alloying elements on A-15 layers produced by solid-state diffusion were studied. The most promising new observation was that tantalum can be incorporated into niobium-tin reaction layers, leading to an enhancement of critical currents at high fields. The critical temperature of ...

International Nuclear Information System (INIS)

Use of high plutonia MOX as fuel is contemplated from the point of view of rapid disposition of plutonium and economic power generation. The fuel pellets are subjected to steep thermal gradients #approx# 1700 K drop across a radius of #approx# 2.5mm. This leads to evaporation-condensation of the fuel constituents to cooler regions. Vaporization depends on fuel compositions such as Pu fraction, Oxygen-to-Metal (O/M) ratio and local temperature. Knowledge of vapour chemistry is essential in understanding the fuel behavior. The vaporization behaviour of MOX was analyzed in this work using thermochemical methods. The vapour phase consisted of nine species; O, O_2, Pu, PuO, PuO_2, U, UO, UO_2 and UO_3. Oxygen formed part of the vapour phase along with other species and oxygen potential was not controlled independently. The vapour pressures were estimated at 2000 K as a function of (O/M) for several Pu-fraction. Results for MOX-28%PuO_2 is shown in ...

International Nuclear Information System (INIS)

In this work, the silicon oxynitride layer was studied as a tunneling layer for non-volatile memory application by fabricating low temperature polysilicon thin film transistors on glass. Silicon wafers were oxynitrided by only nitrous oxide plasma under different radio frequency powers and plasma treatment times. Plasma oxynitridation was performed in RF plasma using inductively coupled plasma chemical vapor deposition. The X-ray energy dispersive spectroscopy was employed to analyze the atomic concentration ratio of nitrogen/oxygen in oxynitride layer. The oxynitrided layer formed under radio frequency power of 150 W and substrate temperature of 623 K was found to contain the atomic concentration ratio of nitrogen/oxygen as high as 1.57. The advantage of high nitrogen concentration in silicon oxide layer formed by using nitrous oxide plasma was investigated by capacitance-voltage measurement. The analysis of capacitance-voltage characteristics demonstrated that ...

Energy Technology Data Exchange (ETDEWEB)

In this work we present an ultra-low temperature method for the oxidation of an amorphous silicon-carbide-nitride (SiCN) material. The SiCN is deposited on silicon substrates by plasma enhanced chemical vapor deposition using CH{sub 4}, SiH{sub 4}, and N{sub 2} chemistry. The physical and chemical properties are characterized for the as-deposited SiCN and post-oxidized films are discussed. The SiCN film is exposed to oxygen plasma, where it undergoes a chemical transformation into a binary SiO{sub 2} material system. A 1.7 nm/min oxidation rate is typical for this process and compares favorably to oxidation methods utilizing much higher temperatures. The substrate temperature remains extremely low throughout the oxidation process, T{sub s} < 200 deg. C. Changes in film stress, optical constants, film thickness, surface roughness, and film density are measured. Chemical analysis by X-ray photoelectron spectroscopy is reported for both the as-deposited and ...

Energy Technology Data Exchange (ETDEWEB)

The industrial standard process for the purification of natural gas is to remove acid gases, mainly hydrogen sulfide and carbon dioxide, by the absorption and reaction of these gases with alkanolamines. Inadequate data for vapor -- liquid equilibrium (VLE) hinder the industry from converting operations to more energy efficient amine mixtures and conserving energy. Some energy reductions have been realized in the past decade by applying such amine systems as ``hindered`` amines, methyldiethanolamine (MDEA), and MDEA based amine mixtures. However, the lack of reliable and accurate fundamental VLE data impedes the commercial application of these more efficient alkanolamine systems. The first project objective is to improve the accuracy of vapor -- liquid equilibrium measurements at low hydrogen sulfide concentrations. The second project objective is to measure the VLE for amine mixtures. By improving the accuracy of the VLE measurements on MDEA ...

Energy Technology Data Exchange (ETDEWEB)

A process is described for removing carbon dioxide from a feed stream of natural gas, having at least methane, ethane and heavier hydrocarbon, comprising: separating the feed stream in a first separator to form a first stream, having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane, and a second stream, having methane, carbon dioxide and ethane; mixing the second stream with a polar compound to form a third stream; separating the vapor and liquid of the third stream in the bottom portion of an absorber; absorbing carbon dioxide and ethane from the separated vapor of Step C in a lean portion of the polar compound in the absorber, the absorber carbon dioxide and ethane forming a fourth stream; separating the ethane from the polar compound and carbon dioxide in a separator; separating the first stream in a third separator to separate the propane and heavier hydrocarbons from the carbon dioxide and ethane: ...

Energy Technology Data Exchange (ETDEWEB)

Room-temperature pulsed laser operation of (Al/sub 0.55/Ga/sub 0.45/)/sub 0.5/In/sub 0.5/P /(Al/sub 0.17/Ga/sub 0.83/)/sub 0.5/In/sub 0.5/P / (Al/sub 0.55/Ga/sub 0.45/)/sub 0.5/In/sub 0.5/P double heterostructure laser diodes grown by metalorganic chemical vapor deposition has been achieved. The lasing wavelength is 626.2 nm, which is the shortest ever reported for an AlGaInP double heterostructure laser. Threshold current density is 50 kA/cm/sup 2/ for a diode with a 20-..mu..m-wide and 200-..mu..m-long stripe.

Energy Technology Data Exchange (ETDEWEB)

Electrochemical corrosion rate probes were constructed and tested along with mass loss coupons in a N2/O2/CO2 plus water vapor environment. Temperatures ranged from 450 to 600 C. Corrosion rates for ash-covered mild steel, 304L SS, and 316L SS probes using electrochemical techniques were a function of time, temperature, and process environment. Correlation between electrochemical and mass loss corrosion rates was good.

British Library Electronic Table of Contents (United Kingdom)

Methods of X-ray diffraction and transmission electron microscopy were used to study the microstructure of dispersion-strengthened Cu-Al2O3 nanocomposites obtained by the method of simultaneous deposition of Cu and Al2O3 from the vapor phase. The effect of the size of particles of the oxide (Al2O3) and of their content on the electrical resistance of the composite has been considered. The results obtained make it possible to suppose that the main structural factor that determines the electrical resistance of the composite are nanodispersed particles of Al2O3 with a size of less than 20 nm.

International Nuclear Information System (INIS)

A method is proposed for the quantitative isolation of radiothallium in gas form from proton-bombarded lead of mass up to 20 g. The molten lead is kept at about 800 K in hydrofluoric-acid vapor (HF/H_2O #approx =# 1) at a reduced pressure (#<=#4 Pa). We used 99.9% lead with the U-240 cyclotron at the Nuclear Research Institute, Academy of Sciences of the Ukrainian SSR, or the phasotron at the Join Nuclear Research Institute, which gave protons at 65 and 680 MeV correspondingly.

Energy Technology Data Exchange (ETDEWEB)

Two sources of negative ions are described. An rf source produces up to 14 ..mu..A beams of He/sup -/ by charge exchange in Rb vapor. The other Source of Negative Ions by Cesium Sputtering (SNICS) produces a wide variety of negative ion beams in the ..mu..A range. Two important features of SNICS are its simple, compact construction and its very good beam emittance (2 to 4..pi..mm mrad MeV/sup 1/2/). Both sources have lifetimes >200 hours and they are used extensively on the Wisconsin EN tandem.

International Nuclear Information System (INIS)

Microwave Electron Cyclotron Resonance (ECR) Plasma assisted Chemical Vapor Deposition (CVD) technology has been used to prepare Si_3N_4 films, which were analyzed by using infrared (IR) transmission spectroscopy and XPS. The analysis results show that with the increase of the deposition temperature, the H content decrease, and the densification of the film increases. When the temperature is up to 360 degree C, the stoichiometrical rate of Si:N is close to 0.75. The protective property of Si_3N_4 films is also examined

Science.gov (United States)

The initiation of explosives by laser illumination has been known for many years. In this paper we will discuss the development of a working detonator design that reduces the energy required for detonation in a low-density secondary explosive by vaporizing a thin metal coating. We present data on the development of the design for a workhorse laser detonator that provides enhanced safety over existing exploding bridgewire detonators (EBWs). Comparison of this laser initiated data to an exploding-bridgewire (EBW) provides insight into the mechanism of initiation of detonation in low-density PETN by the plasma source. A novel diagnostic technique to determine the run-distance to detonation also known as the apparent Center-of-Initiation (COI) will also be discussed.

International Nuclear Information System (INIS)

Processes of production and purification (necessary for fabricating fuel elements) of powdery uranium dioxide with particle size up to 1000 #mu#m and more have been studied. Developed is continuous process of UO_2 production with above particle size by converting uranium hexafloride into UO_2 solid particles in fluidized bed while their interaction with water vapor and hydrogen on the uranium dioxide nucleus material. The method allows to conduct continuous selection from the apparatus of UO_2 powder fraction with particle size near 1000 #mu#m without nucleus material additional feed.

Energy Technology Data Exchange (ETDEWEB)

In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISB involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove .VOCs from the vadose zone concomitant with biodegradation of VOCs. The innovation is in the combination of 3 emerging technologies, air stripping, horizontal wells, and bioremediation via gaseous nutrient injection with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.

Science.gov (United States)

This report--the forty-fifth of a series--is a compendium of monthly progress reports for the ORNL research and development programs that are in support of the increased utilization of coal and other fossil fuel alternatives to oil and gas as sources of clean energy. The projects reported this month include those for coal conversion process development, materials engineering, alkali metal vapor topping cycles, a coal equipment test program, an AFB coal combustor for cogeneration (CCC), engineering and support studies, process and program assistance, evironmental assessment studies, magnetic beneficiation, and AFBC demonstration plant.

International Nuclear Information System (INIS)

In the present study, a subcooled boiling loop with an annular flow on the electrically heated rod was used to make an experimental approach to investigate the effects of induced instability by the subcooled boiling on vibration of the rod in different subcooled conditions. The results show the intensive subcooled-boiling-induced vibration (SBIV) which is highly depend on dynamic force generated by fast vapor bubbles growth and collapse whilst they still attach to, or slide along, the heating surface at high loading heat fluxes. These behaviors were strongly influenced by the conditions of subcooling temperature, flow rate and linear power density. (author)

Energy Technology Data Exchange (ETDEWEB)

A core preservation package was developed to maintain the reservoir characteristics of core samples and consequently to improve the quality of data obtained through laboratory core analyses. The package is a heat-sealable plastic-aluminum laminate similar to those common in the food-packaging industry. The laminated core preservation package acts as an impermeable barrier to water vapor and gases, and is resistant to chemical alteration and degradation by core fluids. These performance characteristics result in effective core preservation by maintaining the fluid content of the core. Other advantages of the laminated package are that it is fast and simple to use and eliminates the cumbersome dip-coat step used in some core preservation methods.

Science.gov (United States)

A process is provided for conducting organic compound conversion over a catalyst composition comprising a specially treated crystalline zeolite having a high initial silica-to-alumina mole ratio, said zeolite having been synthesized from a reaction mixture comprising a diamine as a cation source. The treatment of the zeolite material comprises the sequential steps of reacting the zeolite with a dilute hydrogen fluoride solution, contacting the hydrogen fluoride solution reacted material with aluminum chloride vapor, and then treating the aluminum chloride contacted material to convert it to hydrogen form.

Energy Technology Data Exchange (ETDEWEB)

Rice plants at different seed-developing stages were exposed to HTO vapor in an exposure box for 1 h during daytime and nighttime to investigate the levels of tissue free water {sup 3}H (TFWT) and organically bound {sup 3}H (OBT) in different plant parts. In the daytime experiment, TFWT concentrations in leaves at the end of exposure (h{sub 0}) were around 100% of the 1 hour mean HTO concentrations in air moisture whereas in the nighttime experiment, they were as low as 30{approx}40% of the air concentration. TFWT concentrations in both experiments decreased very rapidly in the beginning but much more slowly later and those at harvest were hundreds to hundred thousands times lower than those at h{sub 0}. OBT concentrations varied with time in different manners depending on plant parts and exposure times and differed between at h{sub 0} and at harvest by factors of less than 10 on the whole. Even during nighttime exposures, OBT was produced at about a third the rate ...

International Nuclear Information System (INIS)

We report on the ultraviolet laser absorption spectroscopy of atomic Gd at 394-554 nm where two transition lines are place very closely by using a frequency-doubled beam of external-cavity diode laser (ECDL). One is from 999.121 to 26337.071 cm-1 and the other from 0 to 25337.755 cm-1. If two transition lines are placed closely within a continuous fine tuning range, the real-time measurement of the atomic excitation temperature is possible without any significant time consumption because at least two transition lines originating from different low-lying energy levels need to be investigated for the Boltzmann-plot. Since the spectral difference between the two transitions is only about 0.195 cm-1 (5.85 GHz), it is possible to record both the absorption spectra simultaneously as shown in Fig. 1. But the transition probabilities (or oscillator strengths) of these lines have not been measured accurately yet to the best of our knowledge. We report on the newly measured transition ...

Energy Technology Data Exchange (ETDEWEB)

Vehicle heating requires a substantial amount of energy. Engines in conventional cars produce enough waste heat to provide comfort heating and defogging/defrosting, even under very extreme conditions. Electric vehicles (EVs), however, generate little waste heat. Using battery energy for heating may consume a substantial fraction of the energy storage capacity, reducing the vehicle range, which is one of the most important parameters in determining EV acceptability. Water vapor generated by the vehicle passengers is in large part responsible for the high heating loads existing in vehicles. In cold climates, the generation of water vapor inside the car may result in water condensation on the windows, diminishing visibility. Two strategies are commonly used to avoid condensation on windows: windows are kept warm, and a large amount of ambient air is introduced in the vehicle. Either strategy results in a substantial heating load. These strategies ...

UK PubMed Central (United Kingdom)

SIMV (simulation and modeling of ventilation) is a quantitative system for the mathematical modeling and simulation of pulmonary...Full Text Available

International Nuclear Information System (INIS)

Recently the troubles related to the network security have often occurred at KEK. According to their security policy, the authors have started the strategy against the daily attacks. It consists of two fundamental things; the monitoring and the access control. To monitor the network, the authors have installed the intrusion detection system and have managed it since 1998. For the second thing, the authors arranged three categories to classify all hosts (about 5000 hosts) at KEK according to their security level. To realize these three categories, the authors filter the incoming packet from outside KEK whether it has a SYN flag or not. The network monitoring and the access control produced good effects in keeping the security level high. Since 2000 the authors have started the transition of LAN from shared-media network to switched network. Now almost part of LAN was re-configured and in this new LAN 10 Mbps 100 Mbps/1Gbps Ethernet are supported. Currently the ...

Energy Technology Data Exchange (ETDEWEB)

A performance assessment analysis was completed for the 200 East Area Low-Level Burial Grounds (LLBG) to satisfy compliance requirements in DOE Order 5820.2A. In the analysis, scenarios of radionuclide release from the 200 East Area Low-Level waste facility was evaluated. The analysis focused on two primary scenarios leading to exposure. The first was inadvertent intrusion. In this scenario, it was assumed that institutional control of the site and knowledge of the disposal facility has been lost. Waste is subsequently exhumed and dose from exposure is received. The second scenario was groundwater contamination.In this scenario, radionuclides are leached from the waste by infiltrating precipitation and transported through the soil column to the underlying unconfined aquifer. The contaminated water is pumped from a well 100 m downstream and consumed,causing dose. Estimates of potential contamination of the surrounding environment were developed and the associated ...

International Nuclear Information System (INIS)

This paper reports about in-situ corrosion studies on selected materials for long-term resistant high-level waste (HLW) packagings acting as a barrier in a rock salt repository. The materials (Ti 99.8-Pd, Hastelloy C4 and five iron-base materials) were investigated in heated boreholes in the Asse salt mine under simulated HLW disposal conditions prevailing in normal operation of repository and in certain accident scenarios. The experiments under normal operating conditions were performed at temperatures of 120 deg. C to 210 deg. C (vertical temperature profile in the boreholes) without and with gamma irradiation (3#centre dot#10"2 Gy/h, Co-60 source) within the framework of the German/US Brine Migration Test. In these experiments only small amounts of migrated brine inclusions (NaCl-rich) from the rock salt were present as corrosion medium. In the experiments carried out under simulated accident conditions with intrusion of larger amounts of NaCl brine into the HLW ...

Energy Technology Data Exchange (ETDEWEB)

While underground power transmission lines have become to use CV cables as the mainstream, existing facilities still use OF cables. Factors of OF cable deterioration include heat cycles during operation and surge intrusion. As a method to diagnose this deterioration in insulation, characteristics tests are performed by collecting insulation oil in a cable connection box. The insulation oil collection work has been done conventionally with the power line stopped to prevent danger from induction voltage. A power uninterruptible oil collection tool was developed recently. The tool consists mainly of an insulator made of epoxy resin, wherein a connection box connector is rotated and loosened by operating an insulating operation rod, with the structure not contacted directly with metallic sheath, so that insulation oil can go through the oil collecting tool and gets collected. Discussions were given on the tool to be capable of collecting samples for analyzing water ...

Energy Technology Data Exchange (ETDEWEB)

Anomalous features in Gulf Coast Salt domes exhibit deviations from normally pure salt and vary widely in form from one dome to the next, ranging considerably in length and width. They have affected both conventional and solution mining in several ways. Gas outbursts, insolubles, and potash (especially carnallite) have led to the breakage of tubing in a number of caverns, and caused irregular shapes of many caverns through preferential leaching. Such anomalous features essentially have limited the lateral extent of conventional mining at several salt mines, and led to accidents and even the closing of several other mines. Such anomalous features, are often aligned in anomalous zones, and appear to be related to diapiric processes of salt dome development. Evidence indicates that anomalous zones are found between salt spines, where the differential salt intrusion accumulates other materials: Anhydrite bands which are relatively strong, and other, weaker impurities. ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

ScienceCinema

...english ...

Science.gov (United States)

... Multivibrators were used in the first model, which is called the "MV Model." Mwe second model, "1ST Model," has a saw-toothed voltage. ...

CSIR Research Space (South Africa)

Full Text Available

Wastenet

Institutional and organizational models ... Review individual centre institutional and organizational models in the light of the tasks to be

Energy Technology Data Exchange (ETDEWEB)

We study a variant of the Penner-Distler-Vafa model, proposed as a c = 1 quantum gravity: quenched' matrix model with logarithmic potential. The model is exactly soluble, and exhibits a two-cut branching as observed in multicritical unitary matrix models and multicut Hermitian matrix models. Using analytic continuation of the power in the conventional polynomial potential, we also show that both the Penner-Distler-Vafa model and our quenched' matrix model satisfy Virasoro algebra constraints.

International Nuclear Information System (INIS)

Full text: The isotopic assay instrument under development at Pacific Northwest National Laboratory (PNNL) is capable of rapid prescreening to detect small and rare particles containing high concentrations of uranium in a heterogeneous sample. The isotopic measurement concept is based on laser vaporization of solid samples followed by sensitive isotope-specific detection using either uranium atomic fluorescence emission or uranium atomic absorbance. Both isotopes are measured concurrently, following a single ablation laser pulse using two external-cavity violet diode lasers. The simultaneous measurement of both isotopes enables the correlation of the fluorescence and absorbance signals on a shot-to-shot basis. This measurement approach demonstrated negligible channel crosstalk between isotopes. Scanning the heterogeneous samples provides high-resolution imagery of sample isotopic fluorescence and absorbance. Isotopically selective excitation of uranium ...

International Nuclear Information System (INIS)

During the first and second quarters of 1994 air samples were collected and analyzed from 54 air particulate/halogen sampling stations, 10 noble gas sampling stations and 19 tritiated water vapor sampling stations. Surface water samples were collected and analyzed from 12 open water supply reservoirs, 8 natural springs, 2 wastewater containment ponds and 9 sewage lagoons. Groundwater samples were obtained brom 10 potable and 1 non-potable supply wells, and 8 drinking water consumption points. Ambient radiation levels were measured at 193 locations.

Energy Technology Data Exchange (ETDEWEB)

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

International Nuclear Information System (INIS)

The thermal conductivity of liquid CHCl3, C6H6, and CCl4 is measured by a steady-state method under saturated vapor pressure in the temperature regions corresponding to pre-crystallization temperatures. The experimental results obtained are used to investigate the isobaric thermal conductivity jump ? ?p at the crystal-liquid phase transition in CHCl3, C6H6, and CCl4. The contributions of the phonon-phonon and phonon-rotational interaction to the total thermal resistance in solid and liquid state are specified using a modified method of reduced coordinates. The decrease in the thermal conductivity at the crystal-liquid phase transition, ? ?p, is explained by a combined effect of variations in positional distribution of molecules and in the form of rotational molecular motion.

Science.gov (United States)

The growth of an oxide interfacial layer was recently found to increase the open-circuit voltage (OCV) and efficiency by up to 60 per cent in GaAs metal-semiconductor solar cells. Details of oxidation techniques to provide the necessary oxide thickness and chemical structure and using ozone, water-vapor-saturated oxygen, or oxygen gas discharges are described, as well as apparent crystallographic orientation effects. Preliminary results of the oxide chemistry obtained from X-ray, photoelectron spectroscopy are given. Ratios of arsenic oxide to gallium oxide of unity or less seem to be preferable. Samples with the highest OVC predominantly have As(+3) in the arsenic oxide rather than As(+5). A major difficulty at this time is a reduction in OCV by 100-200 mV when the antireflection coating is vacuum deposited.

Energy Technology Data Exchange (ETDEWEB)

The Air Force`s Armstrong Laboratory at Tyndall Air Force Base, Florida, has supported the research and development of Radio Frequency Soil Decontamination. Radio frequency soil decontamination is essentially a heat-assisted soil vapor extraction process. Site S-1 at Kelly Air Force Base, San Antonio, Texas, was selected for the demonstration of two patented techniques. The site is a former sump that collected spills and surface run-off from a waste petroleum, oils, and lubricants and solvent storage and transfer area. In 1993, a technique developed by the IIT Research Institute using an array of electrodes placed in the soil was demonstrated. In 1994, a technique developed by KAI Technologies, Inc. using a single applicator placed in a vertical borehole was demonstrated. Approximately 120 tons of soil were heated during each demonstration to a temperature of about 150 degrees Celsius.

International Nuclear Information System (INIS)

The influence of 3d-transition metal impurities on the superconducting properties of the A-15 compounds V_3Si and V_3Ga have been investigated. In the case of V_3Si, the Fe impurities replacing V were found to have a local moment. A compensation effect was found in this case, resulting in a 20KOe increase in the upper critical field at dilute concentrations of Fe. It was demonstrated that long range order V_3Ga possessed higher transition temperature and upper critical field than found hitherto. Investigations on Nb_3Ge/sub 1-x/Ga/sub x/ films obtained by chemical vapor deposition has clearly shown the relation between the transition temperature and structural characteristics. The influence of generalized defects on the superconducting properties in A-15 type Nb_3X compounds has been discussed.

Energy Technology Data Exchange (ETDEWEB)

Source Philippe (on the island of La Govave, near Haiti) is described in terms of climatic, sociological, agricultural and technical background. Because of drought conditions, it became necessary to develop a solar still to provide the town with sufficient fresh water. The still, which has been in operation since 1969, is described in some detail as is the construction process. Brackish and sea water are used to produce more than 1250 liters of fresh water each day. A windmill is used to pump the brackish water from a well to an elevated storage tank; it flows by gravity to solar still basins where it is vaporized, then condensed on a sloping glass surface and collected. Benefits of the solar still to the town's economy and health are discussed. Cost of the project was $17,000. 10 references. (MJJ)

Energy Technology Data Exchange (ETDEWEB)

The small pilot facility of a cyclone type suspension incineration system of radioactive waste was set up in order to evaluate the decontamination efficiency of a high efficiency ceramic filter. The evaluation was made by use of /sup 54/Mn, /sup 59/Fe, /sup 60/Co, /sup 65/Zn and /sup 137/Cs. 1. The decontamination factor by one line of ceramic filter for every species were over 10/sup 5/. 2. The decontamination factor increased by one oder when water vapor exists in off-gas. The same tendency was also observed when iron dioxide existed at the incineration of cation exchange resin.

Science.gov (United States)

Fabry Perot interferometry is a method of determining instantaneous velocities of an object in motion. The interferometer system is composed of the Fabry Perot interferometer, a laser, an electronic streak camera, and several focusing lenses. The first tests discussed were done on exploding bridgewire devices. During these tests, several system parameters were changed. These changes did not seem to affect the data, which appeared to be consistent. The second tests performed focused on slapper-type devices. It was determined that sandblasted, vapor-deposited aluminum on the slapper material would be required to yield quality data. Streak camera failure prevented much data from being collected. An effort is being made to replace the current streak camera. After it is replaced, a Fabry Perot and velocity interferometry system for any reflector comparison will be made. The results will be published as the conclusion to this report.

Energy Technology Data Exchange (ETDEWEB)

The detection of explosives is a notoriously difficult problem, especially at stand-off distances, due to their (generally) low vapor pressure, environmental and matrix interferences, and packaging. We are exploring optimal dynamic detection to exploit the best capabilities of recent advances in laser technology and recent discoveries in optimal shaping of laser pulses for control of molecular processes to significantly enhance the standoff detection of explosives. The core of the ODD-Ex technique is the introduction of optimally shaped laser pulses to simultaneously enhance sensitivity of explosives signatures while reducing the influence of noise and the signals from background interferents in the field (increase selectivity). These goals are being addressed by operating in an optimal nonlinear fashion, typically with a single shaped laser pulse inherently containing within it coherently locked control and probe sub-pulses. With sufficient bandwidth, the ...

Energy Technology Data Exchange (ETDEWEB)

This report describes progress during the first year of a three-year project. The objective of the research is to examine new design approaches for achieving very high conversion efficiencies. The program is divided into two areas. The first centers on exploring new thin-film approaches specifically designed for III-V semiconductors. The second area centers on exploring design approaches for achieving high conversion efficiencies without requiring extremely high quality material. Research activities consisted of an experimental study of minority carrier recombination in n-type, metal-organic chemical vapor deposition (MOCVD)-deposited GaAs, an assessment of the minority carrier lifetimes in n-GaAs grown by molecular beam epitaxy, and developing a high-efficiency cell fabrication process.

International Nuclear Information System (INIS)

Decay heat removal capability under boiling condition was studied using an LMFBR fuel subassembly mockup loop. The sodium flow was driven by natural convection through the loop in which was installed a 37-pin bundle heated electrically over a length of 45 cm. The heat flux furnished by the pins was increased stepwise, upon which the two-phase flow regime changed from bubble to slug flow and then to annular or annular mist flow. Dryout occurred even in slug flow regime, but only momentarily, and permanent dryout was not observed before establichment of annular flow. A suitable criterion for permanent dryout is considered to be 0.5 average exit sodium vapor quality. The results indicated that upon occurrence of sodium boiling, the coolability of fuel subassembly would be maintained by natural convection after reactor shutdown. (author).