Science.gov (United States)

We present a numerical model of vapor-dominated reservoirs which is based on the well-known conceptual model of White, Muffler, and Truesdell. Computer simulations show that upon heat recharge at the base, a single phase liquid-dominated geothermal reservoir in fractured rock with low matrix permeability will evolve into a two-phase reservoir with B.P.D. (boiling point-for-depth) pressure and temperature profiles. A rather limited discharge event through cracks in the caprock, involving loss of only a few percent of fluids in place, is sufficient to set the system off to evolve a vapor-dominated state. The attributes of this state are discussed, and some features requiring further clarification are identified. 26 refs., 5 figs.

Energy Technology Data Exchange (ETDEWEB)

The dwelling is equipped with solar collectors which heat the air circulating in the cavity walls and the space beneath the floors. The thermal aspects of such a building are described. Heat balance, losses, heating by the sun in different seasons are described. Different measures taken to reduce the energy losses are described.

Energy Technology Data Exchange (ETDEWEB)

Cavity type receivers are used extensively in concentrating solar thermal energy collecting systems. The Solar Total Energy Project (STEP) in Shenandoah, Georgia is a large scale field test for the collection of solar thermal energy. The STEP experiment consists of a large field array of solar collectors used to supplement the process steam, cooling and other electrical power requirements of an adjacent knitwear manufacturing facility. The purpose of the tests, conducted for this study, was to isolate and quantify the radiative, conductive, and convective components of total heat loss, and to determine the effects of operating temperature, receiver angle, and aperture size on cavity heat loss. An analytical model for radiative heat loss was developed and compared with two other methods used to determine radiative heat ...

International Nuclear Information System (INIS)

... failures fftf reactor heat transfer hydraulics loss of coolant pipes primary coolant

International Nuclear Information System (INIS)

Lappeenranta University of Technology (LTKK) and VTT Energy carried out a series of preliminary tests in 1999 to study the behavior of noncondensable (NC) gases in VVER geometry. The tests aimed at studying the effect of NC gases on system thermal-hydraulics and on heat transfer in a horizontal steam generator (HSG). The system behavior can be affected by hydrogen produced in the core in case of a severe accident, by nitrogen from hydro-accumulators released into the primary circuit in case of a loss-of-coolant accident (LOCA) and more generally by any NC gas in all cases where cooling is ensured by natural circulation. A secondary objective of the tests - the first series of tests ever performed with NC gas with PACTEL - was to find out, if the instrumentation of PACTEL was adequate for this type of tests and if it was functioning properly. This paper presents the measured and calculated (CATHARE code version V15a mod 2.1) results of the test ...

International Nuclear Information System (INIS)

AFFF has fabricated the (U, Pu)O_2 mixed oxide fuels for PHWRs, BWRs, PFBRs and FBTRs. The quantitative dissolution of the fuel samples are required within time for accurate determination of uranium-plutonium in chemical quality control laboratory. This paper describes the use of microwave heating technique in quantitative dissolution of (U, Pu)O_2 MOX (from 0.4% to 44% PuO_2). (author)

Energy Technology Data Exchange (ETDEWEB)

Numerical analysis of solar dish modified cavity receiver with Cone, CPC and Trumpet reflectors is presented. Three-dimensional modeling is carried out to estimate the convective and radiative heat loss from the receiver for different angles of inclination and operating temperatures. Incorporating reflectors in the modified cavity receiver for second stage concentration, the natural convection heat losses are reduced by 29.23, 19.81 and 19.16%, respectively. The receiver with the trumpet reflector has shown better performance as compared to other configurations. (orig.)

Energy Technology Data Exchange (ETDEWEB)

In the interests of fuel economy in motor vehicles, this article discusses the importance of waste heat recovery and then goes on the explore options such as hybrid electric cars, thermal engines with low loss platforms, pure electric vehicles and fuel cell vehicles. (UK)

Science.gov (United States)

Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively.

Energy Technology Data Exchange (ETDEWEB)

An analytical model is presented which enables the estimation of convective losses from cavity receivers. Evidence from solar experiments is used to test the hypothesized mechanisms. The analytical results and experimental evidence indicate that the convective loss from cavity receivers is appreciable. The model indicates that the influences of the wind on the convective loss at normal operating conditions are minimal. It also shows that the internal thermal resistance, i.e. the ability to heat the air inside the cavity, are of importance. Buoyancy induced flows are, on the other hand, effective in transferring energy across the aperture. 8 refs.

Energy Technology Data Exchange (ETDEWEB)

In order to find the solution to the problem of depletion of conventional fuels and environmental pollution caused by them, new design concepts such as low heat rejection engines and alternate fuel vehicles have started to appear. The present study deals with the concept of alternate fuel vehicle using hydrogen as a fuel. Results of analytical study to minimize heat loss during the power stroke of a hydrogen fueled spark ignition engine have been presented. Effect of various design and operating parameters on heat losses using a simulation model developed by the authors have also been presented. The results shall be helpful in designing efficient hydrogen fuelled spark ignition engines. (orig.)

British Library Electronic Table of Contents (United Kingdom)

The Pacific white shrimp, Litopenaeus vannamei, is the most important shrimp species in volume in world aquaculture. However, in recent decades, outbreaks of diseases, especially viral diseases, have led to significant economic losses, threatening the sustainability of shrimp farming worldwide. In 2004, Brazilian shrimp farming was seriously affected by a new disease caused by the Infectious myonecrosis virus (IMNV). Thus, disease control based on rapid and sensitive pathogen detection methods has become a priority. In this study, a specific quantitation method for IMNV was developed using real-time PCR with SYBR Green chemistry and viral load of the principal target tissues of chronically infected animals was quantified. The quantitative analysis revealed that mean viral load ranged from ...

British Library Electronic Table of Contents (United Kingdom)

The objective of this study is to analyze the effects of heat loss characterized by a percentage of the fuel's energy, friction and variable specific heats of working fluid on the performance of an air standard Otto cycle with a restriction of maximum cycle temperature. A more realistic and precise relationship between the fuel's chemical energy and the heat leakage that is based on a pair of inequalities is derived through the resulting temperature. The variations in power output and thermal efficiency with compression ratio, and the relations between the power output and the thermal efficiency of the cycle are presented. The results show that the power output as well as the efficiency where maximum power output occurs will increase with increase of the maximum cycle temperature. The temp...

Energy Technology Data Exchange (ETDEWEB)

A set of nomographs is presented which can be used to estimate the average annual solar fraction for solar space and water heating at a large number of DOD facilities. The solar fraction estimated from the nomograph is in close agreement with F-Chart 3.0 and allows for variation of the following parameters: annual load, collector area, collector transmittance-absorptance coefficient, and collector overall loss coefficient.

Energy Technology Data Exchange (ETDEWEB)

Heat pumps can be installed indoors or outdoors. H. Klein investigates which site would be preferable for a one-family house. Advantages and disadvantages with regard to necessary space, noise, maintenance and repair are discussed; heat losses in both cases of installations are dealt with. Mathematic calculation shows that indoor installation is safer and more adequate in terms of energy savings.

International Nuclear Information System (INIS)

The losses of Hg from phenol formaldehyde resin - bound standards and hair samples in neutron activation analysis in case of their irradiation in the water filled nuclear reactor channel is studied. The mean losses of Hg during 20-30 hrs irradiation at (2-3)x10"1"8 n/cm"2 are 15-20% with their stopping at double Al-covers. The mean losses of Hg from standards at 200, 250 and 300 deg C are 30, 61 and 86% respectively and do not occur at 150 deg C after their 5 hour heating. The losses of Hg from hair samples packed in polyethylene tubes through the package walls in experimental conditions are not observed.

UK PubMed Central (United Kingdom)

BackgroundHIV infection causes a qualitative and quantitative loss of CD4⁺ T cell immunity. The institution of anti-retroviral therapy (ART) restores CD4⁺ T...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A simple theory for predicting the convective energy loss from side-facing cavity receivers in windless environments has been developed. The approach used is to determine the velocity distribution of the incoming air in the aperture plane (and thereby the rate of mass entrainment); and then to estimate the bulk temperature of the heated emerging air. The convective loss is then calculated from an energy balance. To illustrate this theory, numerical results applicable to the 2.15 meter cubic cavity being tested in the laboratory are provided.

International Nuclear Information System (INIS)

Modern digital radiographic 'flat panel' detectors can exhibit a progressive form of image degradation arising from non-functioning pixels. The effect of these 'dead pixels' on the quantitative image quality measures of modulation transfer function (MTF), noise power spectrum (NPS) and detective quantum efficiency (DQE) is investigated by a simulated degradation of images obtained from an Hologic EPEX system. The effects on the semi-quantitive measures obtained from contrast threshold test objects and resolution gratings are also investigated. Results suggest that the contrast-detail tests often employed in quality assurance measures are not sufficient to reveal the presence of dead pixels until well beyond the recommended replacement point for the flat panel detector. However, measurements of spatial resolution using a line pairs phantom were found to be more sensitive to pixel loss. Measurement of the MTF, NPS and DQE can ...

International Nuclear Information System (INIS)

A LOss of Electric Power(LOEP) experiment was conducted after a 30MW full power operation as one of the reactor performance tests to verify the design characteristics of the HANARO. The objective of LOEP test was to investigate the integral behaviors of the system and the components as well as the cooling characteristics when the electric power was lost unexpectedly. Through the test, it was confirmed that the residual heat from the core was safely removed by the natural convection cooling and the assistant power systems operated normally

International Nuclear Information System (INIS)

A nonlinear mathematical model is presented of a WWER-440 nuclear power plant horizontal steam generator. On the proposed model is based a computer program for investigating transients in steam generators during loss of coolant accidents. Processes taking place at the primary side of the steam generator are described by a set of partial differential equations while those at the secondary side of the steam generator are described by plain differential equations with the variables being complex time functions. The model takes account of the coolant as both a single- and two-phase medium, of changes in the direction of the primary coolant flow and of changes in the direction of heat transfer. Heat transfer through the wall is based on a simple model of heat transfer through a thin-walled tube and includes a correction for the heat resistance of the wall. (author).

Energy Technology Data Exchange (ETDEWEB)

Ultrasonic enhancement of heat transfer on a narrow surface was measured by changing the width of the surface from 8 to 0.1 mm. Ultrasonic power of 600 W with a frequency of 40 kHz was used. Heat transfer on the narrow surface without ultrasonic vibration was correlated by the experimental equation for a thin wire. The cavitation intensity was measured by the cavitation erosion loss of an aluminum foil of 15 [mu]m thickness. The effects of acoustic streaming and cavitation were separated by this measurement. Heat transfer by acoustic streaming was predicted through forced convection. Enhancement by cavitation was explained by the turbulence thermal conductivity of the microjets.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a mathematical model to analyze the solar evaporation in a shallow pond in steady state, when the inlet flow rate, concentration, surface area and solar radiation are given. The simultaneous heat and mass transfer mechanisms are considered for quantifying the amount of evaporated water to the atmosphere and the actual absorbed heat by wastewater is calculated to obtain the bottom temperature of water pond. The heat losses to air by radiation and convection mechanisms are considered and the heat transmission across the water film is evaluated by the forced convection mechanism. 6 refs., 5 figs., 1 tab.

International Nuclear Information System (INIS)

Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively. (author). 4 refs.

Energy Technology Data Exchange (ETDEWEB)

Results from a numerical model of axisymmetric solar cavity receivers are compared with experimental data for tests of a novel test bed receiver in the Saudi National Laboratories solar furnace. The computed energy transfer rates and temperatures are compared with the experimental data for different receiver geometries, aperture sizes, and operating conditions. In general, the agreement between the numerical model and the experimental data is better for the small-to-midsized apertures than for the large apertures. The analysis indicates that for the larger apertures, the convective heat losses are overpredicted. It also suggests that these losses could be better characterized. Sensitivity analyses show that both the total solar energy input rate and the convective heat-loss coefficient significantly affect the receiver thermal performance and that the distribution of the input solar flux significantly ...

Energy Technology Data Exchange (ETDEWEB)

An experimental study of forced convection heat transfer at the inner tube wall of a double pipe heat exchanger with coiled wire inserts as heat transfer augmentation devices was performed over a turbulent flow region. The test results from twelve augmented tubes with inserts of different combinations of wire diameters (0.813, 1.016 and 1.575 mm) and pitches (2.82, 3.63, 5.08 and 8.47 mm) indicate that the turbulence promoters studied improve heat transfer by a factor of 1.4 to 2.24 compared with a smooth tube, although at a cost of 10-30 times increase in friction factor. A formula for presenting dimensionless exergy losses in a tubular heat exchanger is derived first and then the thermohydrodynamic optimum instead of economic optimum is found by minimizing the exergy losses in the system. From the heat transfer ...

Science.gov (United States)

Quantitative determination of Broensted acid site concentrations in calcined H-mordenite and H-ZSM-5 by means of conductometric titration and infrared spectroscopy reveals that the concentration of Broensted acid sites present is lower than would be expected on the basis of the aluminum content. This discrepancy is attributed to dealumination and dehydroxylation processes occurring during calcination. A model is proposed according to which the degree of these processes strongly depends on the concentration of vicinal aluminum T sites in the zeolite: Broensted acid sites associated with these T sites are lost, and the remaining Broensted acidity is related to the concentration of the (remaining) isolated aluminum T sites. This model quantitatively correlates the experimentally determined concentration of Broensted acid sites with the concentration of isolated aluminum T sites. 33 refs., 4 figs., 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

In this work, the thermal performance of a conventional collector is improved by inserting porous substrates at the inner walls of the collector tubes. The porous substrates improve the convective heat transfer coefficient between the tube wall and the fluid. This improvement is investigated numerically and its effects on the efficiency and the useful gain of the collector are evaluated. It is found that inserting the porous substrate may raise the collector efficiency considerably, especially at high values of the overall heat loss coefficient.

Energy Technology Data Exchange (ETDEWEB)

The important amount of hydration water in the ulexite (NaCaN{sub 5}O{sub 9}.8H{sub 2}O), allows using calcination methods to increase its B{sub 2}O{sub 3} content. This paper analyses the thermal decomposition reaction of a preconcentrated ulexite through weight loss measurements, which occur during the heating of samples until 1000 degree centigree, Determinations of heat content at each temperature were made using an isoperibol calorimeter. The mean specific heat was calculated from these values, and its dependence on temperature was determined. The maximum weight loss was about 32.5% and the specific heat obtained was 1,13 kJ/kg 0 C for solid samples and 1,38 kJ/kg''0 C for fluid samples. The results are useful for the design of the industrial process, in order to determine the thermal requirements for heating calcined ...

International Nuclear Information System (INIS)

The authors have evaluated bone mineral content in the vertebral spongiosa by means of Computed Tomography. The method proposed by Genant and Cann [17, 18] has been applied to examine 164 healthy volunteers and 108 patients. Both healthy males and females showed a progressive bone mineral loss increasing with age; the bone mineral loss was most severe in females during the 4th and 5th decade of life. Pathology included patients with osteoporotic fractures (vertebral and femural neck), patients with partial gastrectomy, renal failure, primary hyperparathyroidism, Cushing syndrome, corticosteroid therapy. Bone mineral values were significantly lower in most pathologic groups. Computed Tomography proves thus to be a valuable method to assess bone mineral content and to identify patients at risk for fractures.

Science.gov (United States)

Two types of evacuated tube solar collectors have been operated in space heating, cooling and domestic hot water heating systems in Colorado State University Solar House I. An experimental collector from Corning Glass Works supplied heat to the system from January 1977 through February 1978, and an experimental collector from Philips Research Laboratory, Aachen, which is currently in use, has been operating since August 1978. A flat absorber plate inside a single-walled glass tube is used in the Corning design, whereas heat is conducted through a single glass wall to an external heat exchanger plate in the Philips collector. In comparison with conventional flat-plate collectors, both types show reduced heat losses and improved efficiency. For space heating and hot water supply in winter, the solar delivery efficiency of ...

Energy Technology Data Exchange (ETDEWEB)

Three geothermal direct heat applications were examined to derive a set of cost estimates from which one could determine the effect of changes in system parameters (temperature, flow, load, etc.) on the cost of heat. For each application, a set of resource characteristics and system inputs were chosen to best represent a site specific baseline condition. The baseline estimated cost of heat was calculated along with other cost estimates representing optimistic and pessimistic conditions, bracketing the range any input variable might reasonably take. Regression equations based upon these cost estimates were developed for each application to quantitatively relate changes in cost to changes in the input variables. These three equations and their accompanying nomographs serve as easily understandable planning tools for direct heat geothermal energy projects.

Energy Technology Data Exchange (ETDEWEB)

The cost of transporting biogas digestate can be decreased by reducing its water content. However, the digestate emits volatile compounds during drying. This study investigated the drying behaviour and the change of digestate composition. Drying took place in a hybrid solar/waste-heat dryer that used solar energy as well as waste heat from a combined heat and power unit (CHP) and the exhaust air of a microturbine. The experiment involved the use of 60 t of liquid digestate. Climatic conditions were measured inside and outside the drying hall. Dry matter (DM) and organic dry matter (ODM) were also measured on a daily basis. In addition, the energy consumption of waste and solar heat were recorded and related to the quantity of dried feedstock. The total nitrogen, ammonium, phosphate, potassium oxide, magnesium oxide and calcium oxide in the digestate were subjected to chemical analysis before and after ...

Energy Technology Data Exchange (ETDEWEB)

The development of high energy (> 150 keV) neutral beams for heating and fueling magnetic fusion devices depends on the ability to produce well-collimated negative ion beams. The double capture charge-exchange technique is a known, scalable method. In order to maximize the overall efficiency of the process and to achieve the desired beam characteristics, it is necessary to examine the optical qualities of the beams as well as the total efficiency of beam production. A combined modeling and experimental study of the angular scattering effects in negative ion formation and loss processes has therefore been undertaken.

Energy Technology Data Exchange (ETDEWEB)

ARIES-AT is a 1000 MWe conceptual fusion power plant design with a very low projected cost of electricity. The design contains many innovative features to improve both the physics and engineering performance of the system. From the safety and environmental perspective, there is greater depth to the overall analysis than in past ARIES studies. For ARIES-AT, the overall spectrum of off-normal events to be examined has been broadened. They include conventional loss of coolant and loss of flow events, an ex-vessel loss of coolant, and in-vessel off-normal events that mobilize in-vessel inventories (e.g., tritium and tokamak dust) and bypass primary confinement such as a loss of vacuum and an in-vessel loss of coolant with bypass. This broader examination of accidents improves the robustness of the design from the safety perspective and gives additional confidence that the facility can ...

Energy Technology Data Exchange (ETDEWEB)

Progress in the worldwide capability of predicting the convective energy loss from solar central receivers is reviewed. The significant advances in the past three years have been in experimental areas. Baseline measurements of the convective heat transfer from large high-temperature surfaces, e.g., a flat plate and a cubical cavity, have been completed and empirical correlations have been obtained. Theoretical modeling activities have not kept pace with the experimental advances, however. Currently, the primary theoretical emphasis is the development and testing of turbulence models suitable for buoyant flows. Three major needs have been identified: the measurement of convective energy losses from operating solar central receivers; the continued development of theoretical models in spite of the relatively slow progress to date; and the quantification of the effects of atmospheric turbulence.

Energy Technology Data Exchange (ETDEWEB)

The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been observed on the W7-AS ...

Energy Technology Data Exchange (ETDEWEB)

A method of Kelvin-day function for climatic solar heating design is presented. The long term temperature distribution is used to find the solar fraction for building heating. A solar heating system is considered to provide heat needed up to an auxiliary heater cut-in temperature which is determined by both heat gain of solar heating system and overall heat loss coefficient of the building. The amount of auxiliary heat needed is calculated from a Kelvin-day value at this cut-in temperature. The cut-in temperature will change from different solar heating system designs, and the Kelvin-day value at this cut-in temperature will be varied. By using the numerical curve-fitting method, the Kelvin-day value at any temperature base can be expressed into a second order algebraic equation, ...

British Library Electronic Table of Contents (United Kingdom)

Solar cavity receiver plays a dominant role in the light-heat conversion. Its performance can directly affect the efficiency of the whole power generation system. A combined calculation method for evaluating the thermal performance of the solar cavity receiver is raised in this paper. This method couples the Monte-Carlo method, the correlations of the flow boiling heat transfer, and the calculation of air flow field. And this method can ultimately figure out the surface heat flux inside the cavity, the wall temperature of the boiling tubes, and the heat loss of the solar receiver with an iterative solution. With this method, the thermal performance of a solar cavity receiver, a saturated steam receiver, is simulated under different wind environments. The highest wall temperature of the boi...

International Nuclear Information System (INIS)

Water flow experiments were conducted on natural circulation decay heat removal with an electrically heated 91-rod bundle. Experimental results were compared with analytical predictions to provide thermal hydraulic characteristics for LMFBR Fuel assemblies under a low flow, typical of the natural circulation regime. The results revealed that, at low flow rate region (Re<1,200), axial friction loss in a heated bundle increases with buoyancy effect. The radial temperature profile provides some insight regarding the concept that coolant redistribution would occur. COBRA-V-I predictions are successfully proved validity in comparison with experimental results.

Energy Technology Data Exchange (ETDEWEB)

This paper describes the modeling of horizontal steam generator with the TRACE code and calculation results of a loss-of-feedwater (LOF-10) experiment at the PACTEL facility. Parallel Channel Test Loop (PACTEL) is an integral test facility for a VVER-440 type nuclear reactor. The main objectives were to prepare a simulation model for its horizontal steam generator with the TRACE thermal hydraulic code and assess different modeling options of the code. PACTEL experiment LOF-10 was chosen for this assessment. The calculation results showed that TRACE is capable in simulating horizontal steam generator behavior both in steady state and during loss-of-feedwater transient. The phenomenon of heat transfer from primary to secondary side, steam superheating and flow reversal in the lowest heat exchange tubes were studied in detail. Different nodalization options were introduced. In the simulation of PACTEL ...

Science.gov (United States)

In order to understand not only the mechanisms of earthquakes, but also the origin of diverse behavior of faults and plate boundaries, one must integrate (1) field studies on faults to understand deep intrafault processes, (2) laboratory work to reproduce those processes and determine mechanical and transport properties of fault zones, (3) theoretical and numerical studies analyzing fault motion, including earthquake generation processes, based on the constitutive properties determined by laboratory studies, and (4) seismological and geodetic studies revealing dynamic fault motion during earthquakes and diverse aseismic fault behavior. Ideally, such integrated studies should be carried out for a selected fault that produced an earthquake with good seismic/geodetic records so the prediction from (1) to (3) can be fully tested with (4), rather than selecting favorite data in the literature. Present session is organized to promote such integrated fault and earthquake studies. This ...

International Nuclear Information System (INIS)

Abstract only.

International Nuclear Information System (INIS)

When analyzing the loss-of-coolant accidents at VVER reactor NPP the problem of the effect of noncondensable gases on heat transfer in a horizontal steam generator (HSG) is gaining in importance. Based on the RELAP5/MOD3.2 computer code one analyzed the experiments to condense steam-and-gas mixture in a HSG. The calculations are shown to predict satisfactorily duration of steam generator poisoning from noncondensable gas

Energy Technology Data Exchange (ETDEWEB)

Measurements of temperature and NO concentration in laminar, partially premixed methane-air flames stabilized on a ceramic burner in coflow are reported. The NO concentration and temperature were determined by laser-induced fluorescence (LIF) and coherent anti-Stokes Raman scattering (CARS), respectively. Upstream heat loss to the burner was varied by changing the exit velocity of the fuel-air mixture at a constant equivalence ratio of 1,3; this alters the structure of the flame from an axisymmetric Bunsen-type to a strongly stabilized flat flame. To facilitate analysis of the results, a method is derived for separating the effects of dilution from those of chemical reaction based on the relation between the measured temperature and the local mixture fraction, including the effects of upstream heat loss. Using this method, the amount of NO formed during burnout of the hot, fuel-rich combustion products ...

International Nuclear Information System (INIS)

This book presents the papers given at a conference on two-phase flow. Topics considered at the conference included the thermal hydraulics of a feedwater pipe breakage, pressure losses, measurement of void fraction in a rod bundle, laminar filmwise condensation, natural circulation, flow models, bubble dynamics, cavitation, water hammer, and heat transfer augmentation.

International Nuclear Information System (INIS)

Based on the occurrence of a number of plant incidents during low power and shutdown operating conditions, the Nuclear Regulatory Commission (NRC) has initiated several programs to better quantify risk during these periods. One specific issue of interest is the loss of residual heat removal (RHR) under reduced coolant inventory conditions. This issue is also of interest in the Federal Republic of Germany and an experiment was performed in the integral PKL-3 experimental facility at Siemens-KWU to supply applicable data. Recently, an effort has been undertaken at the Idaho National Engineering Laboratory (INEL) to identify and analyze the important thermal-hydraulic phenomena in pressurized water reactors following loss of vital AC power and consequent loss of the RHR system during reduced inventory operation. The thermal-hydraulic response of a nuclear steam supply system (NSSS) with a closed reactor ...

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 measuring the resulting temperature distributions. In the novel ...

International Nuclear Information System (INIS)

The applicability of the thermal response of an electrically heated simulated rod mostly used in loss-of-coolant-accident (LOCA) experiments to that of a nuclear fuel rod is a concern for the safety evaluation of a reactor. The present analysis describes the characteristics of the thermal response for both electrically heated and nuclear fuel rods during typical reflood conditions for a PWR-LOCA. A model describing the radial temperature field in the rod is developed based on the scheme in HETRAP code by Malang and incorporated into a reflood analysis code, REFLA for that purpose. The calculations applied to the existing reflood tests gave good agreement with experiments, showing the validity of the present model. The analysis has shown that the nuclear fuel rod tends to give a lower clad temperature and a sooner quench time than the electrically heated rod in a typical reflood condition, due to the ...

Energy Technology Data Exchange (ETDEWEB)

The overall objective of this project has been to develop immunochemical methods to quantitate unique DNA base damages in order to facilitate studies on radiation-induced damage production and repair. Specifically, we have been using antibodies raised to damaged bases to quantitate unique lesions in model systems in order to evaluate their potential biological consequences. Our approach has been to synthesize modified nucleotides or nucleosides, conjugate them to protein carriers, and use the conjugates as immunogens in rabbits or to prepare monoclonal antibodies. We have been studying damages that are stable radiolysis products found in X-irradiated DNA and thus of potential biological consequence. Our aim is to build an in vitro and in vivo data base on the interactions between model DNA lesions and such cellular enzymes as DNA polymerases and repair endonucleases. Initial studies have focused on pyrimidine ring saturation products (thymine ...

British Library Electronic Table of Contents (United Kingdom)

Purpose - The objective of this study is to examine the effects of pan-frying, boiling and cooking in a microwave on the amount of L-carnitine in meat and to look at its distribution in the surrounding fluid after food processing. Design/methodology/approach - Total carnitine, free carnitine and acylcarnitines were determined in meat samples from beef, pork and poultry (including ostrich) and in a liver sample from beef. The measurements were carried out before and after the specimens were subjected to different heat treatments. A radio-enzymatic assay was used for measurement of L-carnitine. Results are expressed per 100 gram dry matter and per 100 gram wet weight. Findings - Except for pan-frying, virtually no losses of carnitine occurred during the different procedures of heat treatment...

International Nuclear Information System (INIS)

A chemical-looping process is proposed for the clean combustion of solid fuels for electric power or heat generation. The process is based on coal gasification with CO_2 to produce CO. The CO then reduces CaSO_4, which is used as an oxygen carrier, in a separate reactor to give CaS and CO_2. A portion of the CO_2 is recycled for the gasification stage and the rest can be sent for sequestration. The CaS is sent to another reactor for oxidation with air and to generate heat or power. The overall thermal effect is the same as direct combustion, but separation of CO_2 and other pollutants, such as sulphur, is achieved. In comparison with conventional chemical-looping combustion of natural gas, much less water is present in the CO_2 product, and hence the loss of heat energy and corrosion of the fuel-reactor system can be reduced.

Energy Technology Data Exchange (ETDEWEB)

This paper analyses the errors caused by interpolation from existing cases for assessing indoor air flow, air quality and thermal comfort in an office. A sensitivity study is then provided to determine the influence of several boundary conditions on indoor air diffusion. The research is conducted numerically by using a low-Reynolds-number k-{epsilon} model. It can be concluded that the interpolation errors caused by the variations of solar radiation, window size, heat source location due to lighting, and the surface temperatures of interior walls are small and can be quantitatively determined. But it is difficult to estimate the errors introduced by the variations of furniture location and size. (author).

Energy Technology Data Exchange (ETDEWEB)

The fully depleted pn-junction charge coupled device (pn-CCD) has been developed as a detector for X-ray imaging and high-resolution spectroscopy for the X-ray satellite missions XMM and ABRIXAS. If the detector is exposed to a particle radiation environment, the energy resolution is degraded due to charge transfer losses and a dark current increase. In a first experiment, prototype devices were irradiated with 10 MeV protons. After completion of the detector development, the proton irradiation was repeated for a quantitative study of the radiation damage, relevant for the satellite missions. The irradiation test was extended by a 5.5 MeV {alpha}-particle and a 6 keV X-ray exposure of the pn-CCD, including the CAMEX preamplifier chip.

International Nuclear Information System (INIS)

Reducing count losses and pile-up pulse effects in quantitative and qualitative analysis is necessary for accuracy of analysis. Therefore, the optimum peaking time for particular detector systems is important. For this purpose, pure Se and Zn elements were excited by 59.5 keV ?-rays from a 50 mCi 241Am annular radioactive source in this study. The characteristic x-rays emitted from pure Se and Zn elements were detected by using an ultra low energy Ge (Ultra-LEGe) detector connecting Tennelec TC 244 spectroscopy amplifier at different peaking time modes. Overall pulse widths were determined by HM 203-7 oscilloscope connecting amplifier. The proper peaking time for ultra low energy germanium detector (Ultra-LEGe) is determined about 4 ?s.

International Nuclear Information System (INIS)

A Digital X-ray imaging system using Compton backscattering has been developed to obtain a cross-sectional profile and mass loss of corroded lap-splices of aging aircraft from density variation. A slit-type camera was designed to focus on a small scattering volume inside the material, from which the backscattered photons are collected by a collimated scintillator detector for interpretation of material characteristics. The cross section of the lap-joint is scanned by moving the scattering volume through the thickness direction of the specimen. The mass loss of each layer has been estimated from a Compton backscatter A-scan to obtain the thickness of each layer including the aluminum sheet, the corrosion layer and the sealant. Quantitative information such as location and width of planar corrosion in the lap splices of fuselages is obtained by deconvolution using a nonlinear least-square error minimization method(BFGS ...

Energy Technology Data Exchange (ETDEWEB)

Indirect evaporative air coolers that use air-to-air plate-type heat exchangers show good promise (compared with compression air-conditioning systems) of extending the energy savings from arid, low-humidity areas to more widespread climatic conditions. However, no systematic experiment had been done concerning the effect of the wettability of aluminum plates on the effectiveness of the indirect evaporative cooling system. In this study, a testing apparatus was built where only one secondary channel and two primary channels were used so that different surfaces could be easily tested to determine the system`s effectiveness and the heat transfer coefficient. The advantage of this experimental apparatus is that plates of the heat exchanger can be easily changed in the test section instead of fabricating a complete heat exchanger for each test. A dynamic contact analyzer was used to ...

International Nuclear Information System (INIS)

In this study, a high-resolution characteristic-based finite-volume (FV) method on unstructured grids [Int. J. Numer. Method Eng. 50 (2001) 11; Int. J. Heat Fluid Flow 21 (2000) 432] is extended by a matrix-free implicit dual-time stepping scheme for the numerical simulation of steady and unsteady flow and heat transfer with porous media. The method has been used to study the characteristics of a complex problem: flow and heat transfer in a channel with multiple discrete porous blocks, which was originally proposed by Huang and Vafai [J. Thermophys. Heat Transfer 8 (3) (1994) 563]. In addition, flow and heat transfer in a channel partially or fully filled with porous layers and containing solid protruding blocks with constant heat flux on its lower surface are also investigated in details. Hydrodynamic and heat transfer results are reported ...

Energy Technology Data Exchange (ETDEWEB)

Vaarst Vestervang (Denmark) comprises 16 villas and 1 communal building. The complex was designed by the inhabitants themselves with the aim of polluting the environment as little as possible. The land area constitutes 69.000 square meters where it is possible to grass animals. The document reports a measuring programme concerning the overall heat consumption as one of the main aims of the inhabitants is to save energy and thus contribute to the protection of the environment. The capacity of the solar collectors predominantly used in the building complex was 235 kWh/m{sup 2}. Supplementary heating is provided by boilers fired with wood. The measuring system is described in detail. Tables show the influence of heat transmission losses, ventilation, airing out of rooms, the angle of the sun`s rays within the buildings and heating needs on energy consumption. Energy consumption data is ...

Energy Technology Data Exchange (ETDEWEB)

The authors investigate the optimisation of solar-heated cavity receivers in which solar energy collected by a paraboloid collector is converted into electrical energy. The focussed solar energy enters the receiver through an aperture to heat the working fluid, which flows inside the receiver tubes and is compressed by the compressor of a gas turbine system, to the highest process temperature. A method of calculating the distribution on the inner receiver surfaces of the solar radiation reflected by the paraboloid collector is presented to begin with. The interchange of radiant energy inside the receiver cavity can be calculated on this basis, including the radiation loads, the temperatures of the inner receiver walls, and the radiative and convective losses. The temperature fields in the tube walls must be known for determining the strength required of receiver tubes; they can be derived from the useful ...

Energy Technology Data Exchange (ETDEWEB)

Severe accident analysis has been performed for the Wolsung nuclear power plants in Korea to investigate severe accident phenomena of CANDU-600 reactors as a part of Level II PSA study. The accident sequence analyzed in this paper is loss of active heat sinks (LOAH) which is caused by loss of off-site power, diesel generators, and DC power, ISAAC(Integrated Severe Accident Analysis Code) computer code developed by KAERI (Korea Atomic Energy Research Institute) was used in this analysis. This paper describes the important thermal-hydraulics and source term behaviors in the primary system and inside containment, and the failure mechanisms of calandria vessel and containment. In addition, some insights for accident management program (AMP) are also given.

International Nuclear Information System (INIS)

The volatility of some elements being determined in biological and environmental samples by NAA (neutron activation analysis) in case of their binding with phenolformaldehyde resin (PFR) is studied. Since the temperature is assumed to influence the volatility of elements stronger than radiation during irradiation of samples in nuclear pile the losses of Se, As, Sb, and Hg form samples on the basis of PFR after their heating at 100-300 deg C have been investigated. It is shown that the losses of Sb and As up to 300 deg C, Se up to 250 deg C, and Hg up to 150 deg C from PFR - based samples do not occur.

International Nuclear Information System (INIS)

Design improvements are being incorporated into the heavy water management systems at Wolsong 2,3 and 4 to reduce the load on the vapour recovery driers and upgraders and the heavy water losses via the stack. There will also be improvements to monitor heavy water and tritium releases. This paper describes the improvements, gives background on heavy water balance mechanism, the historical trends for heavy water recovery/losses and estimated dose to the member of the public critical group resulting from the airborne and waterborne releases. The measured tritium activity levels in the heat transport system (HTS) and moderator system at Wolsong 1 are given. Using these activity levels and heavy water loss data, tritium losses from the dried and ventilated areas are estimated. A qualitative assessment of expected heavy water and tritium releases has been performed for Wolsong 2, 3 and 4. ...

UK PubMed Central (United Kingdom)

A technique for quantitative determination of cephalothin and desacetylcephalothin in serum using a method based on high-pressure liquid chromatography is described. Both compounds were quantitatively...Full Text Available

International Nuclear Information System (INIS)

Human complement protein C9 is shown to be a metalloprotein that binds 1 mol of Ca"2"+/mol of C9 with a dissociation constant of 3 #mu#m as measured by equilibrium dialysis. Incubation with EDTA removes the bound calcium, resulting in a apoprotein with decreased thermal stability. This loss in stability leads to aggregation and, therefore, to loss of hemolytic activity upon heating to a few degrees above the physiological temperature. Heat-induced aggregation of apoC9 can be prevented by salts that stabilize proteins according to the Hofmeister series of lyotropic ions, suggesting that the ion in native C9 may ligand with more than one structural element of domain of the protein. Ligand blotting indicates that the calcium binding site is located in the amino-terminal half of the protein. Removal of calcium by inclusion of EDTA in assay mixtures has no effect on the hemolytic activity of C9, and its ...

International Nuclear Information System (INIS)

The thermal performance monitoring and optimization system TEMPO is developed at the OECD Halden Reactor Project. The system supports staff of nuclear power plants in identification and correction of problems, which cause small decreases in plant efficiency but which may lead to significant economical losses. The system-wide physical model consists of mathematical description of individual components, such as the reactor, the pumps, the heat exchangers, or the turbines, etc. TEMPO code has recently been extended with new steam generator (SG) models. The present paper summarizes the thermal-hydraulic modelling aspects of the vertical and the horizontal SG. The heat balance equations and their solution are shown with the appropriate initial and boundary conditions. The method of the calculation of the pressure losses are also introduced. The vertical SG model is based on a U-tube structure and treated as ...

Energy Technology Data Exchange (ETDEWEB)

A series of 22 steady-state, rod bundle, dispersed flow film boiling experiments has been performed in the Thermal-Hydraulic Test Facility (THTF), a pressurized-water loop containing 64 full-length electrically heated rods. Test parameters in the upflow experiments cover a wide range of conditions typical of those which might be encountered during a nuclear reactor loss-of-coolant accident. Local equilibrium fluid conditions were calculated using mass and energy conservation considerations. Experimentally determined heat transfer coefficients were compared to several available film boiling heat transfer correlations: Dougall-Rohsenow, Groeneveld 5.7, Groeneveld-Delorme, Chen, Jones-Zuber, and Yoder-Rohsenow. The Groeneveld 5.7 correlation tended to predict the data better than any other correlation tested. The Dougall-Rohsenow correlation tends to overpredict the data while the Yoder-Rohsenow ...

Energy Technology Data Exchange (ETDEWEB)

Recent developments in solid-state radio frequency (RF) power technologies allow for the practical consideration of RF heated plasmas for space propulsion. These technologies permit the use of any electrical power source, de-couple the power and propellant sources, and allow for the effcient use of both the propellant mass and power. Effcient use of the propellant is obtained by expelling the rocket exhaust at the highest possible velocity, which can be orders of magnitude higher than those achieved in chemical rockets. Handling the hot plasma exhaust requires the use of magnetic nozzles, and the basic physics of ion detachment from the magnetic eld is discussed. The plasma can be generated by RF using helicon waves to heat electrons. Further direct heating of the ions helps to reduce the line radiation losses, and the magnetic geometry is tailored to allow ion cyclotron resonance ...

Energy Technology Data Exchange (ETDEWEB)

An experimental study was conducted to investigate the heat transfer and friction loss characteristics in a horizontal rectangular channel having attachments of hollow rectangular profile fins over one of its heated surface. The Reynolds number based on the flow averaged inlet velocity and the hydraulic diameter, ranged from 3000 to 32,000. The hollow rectangular profile fins in 10cm height and axb=2cmx4cm dimensions with a thickness of 0.2cm were mounted on a heating surface vertically. Reynolds number, fin arrangement and fin pitch in the flow direction were the experimental parameters. Both in-line and staggered fin arrangements were studied for one-fixed spanwise (S{sub x}/a=3) and four different streamwise (S{sub y}/b=1.5, 1.875, 2.5 and 3.75) distances. Correlation equations for Nu, f and thermal performances were determined for fin configurations and the straight channel case without fins. ...

International Nuclear Information System (INIS)

Wolsong 2,3 and 4 fuel channel analysis during a large break loss of coolant accident with loss of ECCS injection (LOCA/LOECC) is performed to obtain the heat load to moderator. Because the single channel analysis requires the establishment of the safety codes and their input decks, the present study follows the same safety analysis methodology found in FSAR of Wolsong 2,3 and 4. From this work we obtain the safety tools such as CATHENA MOD3.5b/Rev.1 and CHAN-II/A MOD2 codes, and their code modeling in a form of code input deck. The analysis consists of two parts: front-end (blowdown period) and back-end. For the front-end analysis the fuel and pressure tube (PT) temperatures, and PT circumferential strains at the end of front-end as well as fuel channel depressurization are calculated using CATHENA code and used as initial and boundary conditions for back-end analysis. The back-end period under the conditions of prolonged ...

Energy Technology Data Exchange (ETDEWEB)

The radiative heat loss from a surface is determined by its total hemispherical emittance, which consequently plays an important role in aerospace and solar applications. This study compares emittances measured calorimetrically with values derived from near normal incidence spectral reflectance measurements. This optical derivation is based on a number of assumptions which limit the accuracy if not sufficiency fulfilled. These assumptions include sample specularity, a straybody character beyond the range of measurement, only small variations of emittance with temperature, and a perfectly smooth sample surface. The comparison of calorimetrically and optically derived emittance performed in this study not only quantifies the errors introduced by insufficient fulfillment of the assumptions but also identifies which assumption causes the dominant error. The calorimetric emissometer, constructed for this study and based on a ...

British Library Electronic Table of Contents (United Kingdom)

The major bottleneck for popularization and utilization of the conventional mechanical valve pulse combustors is the self-priming mode of gas supply. An aerodynamic valve (as against mechanical valve) self-excited pulse combustor of the Helmholtz-type with continuous supply of gas and air was designed and a mathematical model was established in this paper. The theoretical model employed well-stirred reactor model and a single step Arrhenius chemistry, and took those factors which might affect the combustion stability into account. The factors include the variation of the mass rate of the reactants affected by the pressure in the combustion chamber, the convective and radiation heat loss in the combustion chamber, and the heat transfer and wall friction in the tailpipe. The effect of wall t...

Energy Technology Data Exchange (ETDEWEB)

In this paper, for an acceleration of utilization of magnesium alloy which is being interested in recent years, friction welding of AZ31 magnesium alloy was carried out, and the joint performance was discussed in relation to the deformation heat input in the upset stage and upset loss as a evaluation factor. Where, the deformation heat input in the upset stage is mechanical work represented by the product of upset speed and axial pressure. As a result, it was made clear that the friction welding of AZ31 magnesium alloy was easy in the atmosphere, and good welded joints without a non- adhesion area at the weld interface could de obtained. Moreover, the evaluation factors discussed were possible to evaluate to joint performance. (orig.)

International Nuclear Information System (INIS)

The total hemispherical emittance of an oxide film that formed on 6061-T6 aluminium alloy parts in the Tower Shielding Reactor-II at Oak Ridge National Laboratory was measured from 295 to 773 K using an emissometer and/or a calorimeter. The emittance of this film was critically needed for heat transfer calculations in a simulated loss-of-coolant accident of the reactor. X-ray diffraction analysis identified the film as boehmite (Al_2O_3 x H_2O), which dehydrated to alumina (Al_2O_3) upon heating above 473 K. The measured emittances for the alumina film are in excellent agreement with published values for anodized aluminum films and for bulk alumina. Published values of the emittance of boehmite could not be found for comparison, but evidence is presented that some anodization processes for aluminum yield boehmite and not alumina films.

Energy Technology Data Exchange (ETDEWEB)

The study of natural convection flow and heat transfer within a cylindrical annulus has received considerable attention because of its numerous applications, such as in nuclear reactor design, electronic component cooling, thermal storage systems, energy conservation, energy storage, and energy transmission. Here, the effects of multiple geometric perturbations on the inner and outer cylinders of an annulus with impermeable end walls are investigated in this work. A three-dimensional study was done using a numerical scheme based on a Galerkin method of finite element formulation. The nature of the buoyancy-induced flow field has been analyzed in detail. The flow fields for the cases considered were found to be qualitatively similar, and the introduction of each additional perturbation altered the flow field in a regular and recurring manner. The introduction of each perturbation on the outer cylinder causes clockwise and counterclock-wise rotating patterns on ...

Energy Technology Data Exchange (ETDEWEB)

Geological, geophysical, thermal, petrophysical and hydrological data available for the East Mesa hydrothermal system that are pertinent to the construction of a computer model of the natural flow of heat and fluid mass within the system are assembled and correlated. A conceptual model of the full system is developed and a subregion selected for quantitative modeling. By invoking the Boussinesq approximation, valid for describing the natural flow of heat and mass in a liquid hydrothermal system, it is found practical to carry computer simulations far enough in time to ensure that steady-state conditions are obtained. Initial calculations for an axisymmetric model approximating the system demonstrate that the vertical formation permeability of the deep East Mesa system must be very low (k/sub v/ approx. 0.25 to 0.5 md). Since subsurface temperature and surface heat flow data exhibit major deviations from ...

Energy Technology Data Exchange (ETDEWEB)

The present paper deals with the fouling process of calcium sulfate dehydrate on heat-transfer surfaces. The crystallization of calcium sulfate showed typical asymptotic fouling curves, the asymptotic value of which was greatly influenced by the surface temperature and fluid velocity. The fouling mechanism was discussed with a generalized fouling model and proved to be surface process controlled, where the activation energy was 6.2 {times} 10{sup 4} J/mol. The availability of mechanical cleaning against the formed scale was quantitatively evaluated by applying the particle abrasion method. The removal test verified that the removing rate per unit particle concentration decreased in an inverse proportion to the overall particle load, to the power of 0.8, and that it was affected by the fluid velocity. The observed final residual fouling resistance decreased asymptotically with an increase in particle concentration. The suitable concentration of ...

Energy Technology Data Exchange (ETDEWEB)

Considerable potential exists for increasing the annual efficiency of line-focus collectors by reducing receiver heat losses. Five alternate receiver designs are compared with a standard design. The comparison is based on annual collector-field efficiency using optimized receiver designs. Of the receivers studied, the all-glass design and the cavity design provide the greatest increases in efficiency. Average fluid temperatures range from 200/sup 0/ to 450/sup 0/C. As a guide for further study, areas of uncertainty and potential problems are identified.

Energy Technology Data Exchange (ETDEWEB)

A phenomenological model of the heat transfer in direct injection diesel engines was developed. Utilizing the thermodynamic results of a combustion model as an input, the model is able to predict the temporal variation of the heat losses from the cylinder gas to the cylinder walls. Additionally, the division into isothermal combustion chamber subsurfaces allows the consideration of the spatial variation of the wall heat fluxes. The physical mechanisms such as flow dependent convection, heat radiation due to hot soot particles and isolation effects of deposited soot layers are described in detail. Thus the effects of these mechanisms on the overall heat transfer can be studied. The heat transfer model was verified successfully by the comparison to measured wall heat fluxes in a single-cylinder direct injection diesel ...

Energy Technology Data Exchange (ETDEWEB)

Studies were conducted to quantitate the evolution of nitrogen oxides (NO/sub (x)/) from soybean (Glycine max (L.) Merr.) leaves during in vivo nitrate reductase (NR) assays with aerobic and anaerobic gas purging. Anaerobic gas purging (N/sub 2/ and argon) consistently resulted in greater NO/sub (x)/ evolution than did aerobic gas purging (air and O/sub 2/). The evolution of NO/sub (x)/ was dependent on gas flow rate and on NO/sub 2//sup -/ formation in the assay medium; although a threshold level of NO/sub 2//sup -/ appeared to exist beyond which the rate of NO/sub (x)/ evolution did not increase further. The loss of NO/sub (x)/ from in vivo NR assays under gas purging explains partially, but not stoichiometrically, the decrease of NO/sub 2//sup -/ accumulation in in vivo NR assay medium with young soybean leaves. The lack of stoichiometry between NO/sub (x)/ evolution and apparent NO/sub 2//sup -/ loss suggests that other ...

International Nuclear Information System (INIS)

Accurate prediction of ribbed duct flow and heat transfer is of importance to the gas turbine industry. The present study comprehensively validates the use of large eddy simulations (LES) for predicting flow and heat transfer with measured flowfield data in a stationary duct with 90"o ribs and elucidates on the detailed physics encountered in the developing flow region, the fully developed region, and the 180"o bend region. Among the major flow features predicted with accuracy are flow transition at the entrance of the duct; the distribution of mean and turbulent quantities in the developing, fully developed, and 180"o bend; the development of secondary flows in the duct cross-section and the 180"o bend; and friction and heat transfer augmentation. At the duct inlet, both the computations and experiments show that the peak turbulence intensities reach values as high as 40% in the streamwise and spanwise directions and 32% ...

Energy Technology Data Exchange (ETDEWEB)

The possibilities for heat recovery in a cast iron melting furnace were studied. A cupola furnace which produces 40 tonnes steel per hour, produces 25,000 Nm/sup 3//h of flue gases which contain 16-22% CO. Taking into account the heat losses at the chimney where fumes are cooled to 200/sup 0/C the recoverable heat is about 12.4-10/sup 6/ kcal/h which mainly consists of combustion heat in CO. This study showed that the heat can be used for the production of electricity, which will be used in the plant. Recovery of 87 kWh of electricity per tonne of steel produced is possible. A steam turbine driven generator of 3.5 MW will be required. The combustion of the low calorific gas (approximately 400 kcal/Nm/sup 3/) has been studied and gave positive results: wet CO gas can be burnt without addition of methane and preheating of air is not required. The pilot plant ...

International Nuclear Information System (INIS)

An experimental program has been conducted to determine the feasibility of natural convection cooling of a reactor following a beyond-design-based accident. The particular application under consideration was the heavy-water new production reactor. The questions to be resolved include the verification that a natural convection cooling pattern would be established and the determination of the power limit for which convective cooling will occur for a significant period of time. In the experiment, the reactor configuration was simulated using small-diameter vertical heated tubes in parallel with a large-diameter bypass line. Following a loss-of-flow event, the flow in the bypass line will reverse direction and pass through the heated channel by means of natural convection. If, however, the channel power is too high, void formation will block the channel and prevent the reverse flow pattern from occurring. The test procedure ...

Energy Technology Data Exchange (ETDEWEB)

Electrical heating of subsea flowlines is an effective way to prevent wax and hydrate information, especially for long transportation distances and in low-temperature deep water. Systems are available for use in conjunction with bundles, pipe-in-pipe, and wet-thermal-insulation systems. These systems provide environmentally friendly fluid-temperature control without chemicals or flaring for pipeline depressurizing. Enhanced production is achieved because no time is lost by unnecessary depressurizing, pigging, heating-medium circulation, or removal of hydrate and wax blockages. The seabed temperature at 100-m and greater water depths may range from 7 to {minus}1.5 C, causing a rapid cooling of the hot well streams being transported in subsea flowlines. Under these supercooling conditions, vulnerable crude oils and multiphase compositions will deposit wax and asphalts; also the gas/water phase may freeze solid with hydrate particles. The paper ...

Energy Technology Data Exchange (ETDEWEB)

Introduced herein is microwave irradiation for the adsorption and desorption of environmental pollutants. Microwaves may be used in two ways, other than through elevation of temperature of a system as a whole with the adsorbent such as activated carbon serving as the heating medium. The first is the application by which desorption is caused to take place of specified molecules. For example, zeolite that has adsorbed water is regenerated when it is irradiated with microwaves in a stream of cooling gas. This is because only the moisture is heated since zeolite is a non-carbon adsorbent that absorbs microwaves but a little. Another case is reported in which microwaves are utilized to desorb H2S, H2O, CO, etc., from molecular sieves. In the second application, coexisting materials different in absorptivity are exposed to irradiation. The adsorption of microwave-absorbent materials is inhibited while that of the others is accelerated. For example, ...

Science.gov (United States)

Target vessel materials used in spallation neutron source will be exposed to proton and neutron irradiation and mercury immersion environments. In order to evaluate the surface degradation of the vessel candidate materials due to such environment, the triple-ion beam irradiation taking the spallation reaction into account and mercury immersion tests were carried out. Mechanical properties of the gradient surface layer were evaluated by the inverse analysis with multi-layer model that considers distribution of surface characteristic was applied to the load and depth curves measured by using the instrumented indentation machine. Transmission electron microscopic observations were performed to evaluate the changes of microstructure in irradiated surface layer using focused ion-beam cut micro-specimen. The mechanical properties distributions in the surface layer were evaluated quantitatively and the changes in microstructures were correspondent to the property ...

Energy Technology Data Exchange (ETDEWEB)

The US Nuclear Regulatory Commission is proposing to amend the regulations that currently require that the design basis for nuclear power plants include the postulation of dynamic effects from loss of coolant accidents up to and including the double-ended rupture of the largest pipe in the reactor coolant system. Proposed modifications would allow analyses to serve as a sufficient basis for excluding dynamic effects, including but not necessarily limited to pipe whip and jet impingement, associated with specific pipe ruptures. Only dynamic effects would be impacted; current design requirements for containment sizing and discharge capacity of emergency core cooling systems would remain unchanged. This report presents a detailed analysis of value-impact associated with the proposed amendment for PWR reactor coolant loop piping and for BWR recirculation loop piping. The effect of extending application of the proposed rule change to other piping systems is also ...

International Nuclear Information System (INIS)

This paper deals with the calculations of 3D nuclear heat generation profile in the charcoal filter and subsequently the commencement time of Primary Containment Cleanup (PCC) system of 540MWe Pressurized Heavy Water Reactor (PHWR). Fuel failure is predicted due to overheating of the fuel under loss of Coolant Accident (LOCA) without Emergency Core Cooling System (LOCA without ECCS). Subsequently fission product gasses along with water vapours are released to Reactor Building (RB) atmosphere. Plate-out and water trapping mechanism stabilizes the concentration of significant fission products i.e. radioiodines in about 4 hours before being circulated through charcoal filters of Containment Cleanup system. After cleaning up the RB atmosphere, it is discharged to outside atmosphere through stack. The isotopes of radioiodine emit beta and gamma radiations. Gamma radiations are partly stopped within the charcoal and heat is ...

Energy Technology Data Exchange (ETDEWEB)

The increasing price differential between natural gas and coal will create a demand for technology that can allow the displacement of natural gas with coal in power plants. Coal gasification is the standard approach suggested to allow coal to displace natural gas. However, the relatively high capital investment required for coal gasification will require fuel cost differentials higher than those anticipated in the near term before coal gasification replaces natural gas. One way of achieving shorter term displacement of natural gas by coal would be to develop technology that would allow coal to be used as the heat source for the endothermic reforming of natural gas. In a natural gas-fired combined cycle power plant, the endothermic heat of reforming, which would be provided by coal combustion, is recovered in the combined-cycle. Therefore, this portion of the coal`s energy would be converted to electrical power at the high efficiency of the ...

International Nuclear Information System (INIS)

Once containment recirculation pumps are activated and emergency core cooling (ECC) flow is supplied from the recirculation sump during loss of coolant accident (LOCA), various insulations and coatings on a pipe, equipments and structures damaged by LOCA break jet as well as additional debris sources are transported to recirculation sump screen by the break flow and containment spray flow drainage. This debris may result in loss of net pressure suction head (NPSH) of the recirculation pumps, and have a threat to long term cooling and containment heat removal capacity. In this case, flow patterns of containment pool are important to confirm behaviors of debris transport for predicting various flow paths to the recirculation sump screen. In this paper, models using commercial computational fluid dynamics (CFD) software CFX are developed for containment pool simulation during recirculation mode. The specific plant used for ...

International Nuclear Information System (INIS)

Makrofol-De 1-1 CC Polycarbonate is a class of polymeric solid state nuclear track detectors which has many applications in various industrial fields. A study of the modification possibility of the dielectric properties of Makrofol polymer using laser irradiation has been carried out. In tbe present work, Makrofol samples were irradiated using different fluences between 0.47 and 10.4 J/cm"2 of 5 watt infrared pulsated laser. The mollifications in the laser irradiated Makrofol samples have been studied as a function of fluence using dielectric constant #epsilon#', dielectric loss #epsilon#"and AC conductivity #sigma#_AC measurements. Tbe frequency dependencies (100 Hz-5 MHz) of #epsilon#', #epsilon#"and #sigma#_AC at 35 degree c were investigated. The dielectric constant #epsilon#', dielectric loss #epsilon#"and AC conductivity #sigma#_AC were found to increase at heating up to 100 degree C. This indicates that #epsilon#', ...

International Nuclear Information System (INIS)

There has been recent interest in the United States concerning the loss of residual heat removal system (RHRS) under reduced coolant inventory conditions for pressurized water reactors. This issue is also of interest in the Federal Republic of Germany and an experiment was performed in the integral PKL-III experimental facility at Siemens-KWU to supply applicable data. Recently, an NRC-sponsored effort has been undertaken at the Idaho National Engineering Laboratory to identify and analyze the important thermal-hydraulic phenomena in pressurized water reactors following the long term loss-of-RHRS during reduced inventory operation. The thermal-hydraulic response of a closed reactor coolant system during such a transient is investigated in this report. Some of the specific processes investigated include: reflux condensation in the steam generators, the corresponding pressure increase in the reactor coolant system, and void ...

International Nuclear Information System (INIS)

A calculation model was developed for the analysis of thermal and hydraulic processes in the PGV-1000 horizontal steam generator. The model makes it possible to examine the hydraulics of the primary medium, i.e., the distribution of flow velocities and mass flows in the exchanger tube system and hydraulic losses of the primary medium in the steam generator during its flow between the two connecting sites to the main circulation pipeline, spatial distribution of heat fluxes between the primary and secondary sides of the steam generator and the total transmitted thermal power, pressure on the secondary side of the generator, natural circulation of the working medium on the secondary side, and the mean circulation number, spatial distribution of the volume fraction of the steam component in the intertubular space, effect of the perforated sheet on the thermo-hydraulic processes in the steam generator, redistribution of the steam component in the ...

Energy Technology Data Exchange (ETDEWEB)

Very good friction and wear measurements are reported for MRCC (metal reinforced carbon composites), made from low-wear non-graphitic carbon matrix with metal-fiber reinforcement. Counterfaces include austenitic and martensitic stainless steels, Si nitride, and alumina. Effects of high load, high temperature, and gaseous environments are reported: removal of humidity, atm. oxygen have little effect on friction, wear for MRCC sliding against ceramic or stainless steel. Wear of Al oxide riders on MRCC is very low, not affected by contact load. 260 C temperatures do not degrade performance of 440-C riders on MRCC disks or raise friction. In small or large sizes, MRCC is made in a single-pass process for about the same volume cost as cast iron. It can survive heating in nitrogen above 1600 C without loss of integrity or major change of dimensions.

International Nuclear Information System (INIS)

A series of tests was recently completed at the 400-MW (thermal) Fast Flux Test Facility (FFTF) to further demonstrate the passive safety characteristics of liquid-metal-cooled fast reactors. Earlier FFTF testing of decay heat removal by sodium natural circulation was reported in 1981. The main purpose of the 1986 test series was to demonstrate passive reactor shutdown during a loss-of-flow event when several inherent shutdown devices called gas expansion modules (GEMs) were installed in the reactor. However, these tests also provide further data on the natural circulation performance of the primary system, in particular the reactor core, and thus add to the data base available for checking the validity of available analytical tools.

International Nuclear Information System (INIS)

Polyester WPC (wood-polymer composite) systems are one of the promising materials for multiple uses increasing the mechanical properties, provided that their dimensional stability can be improved. Possibility was pursued for the improvement in the dimensional stability of the polyester WPC systems prepared by electron beam irradiation. The impregnation of the mixture of polyester and monomer into both oven-dried beech veneers and preswollen wood was followed by mutual irradiation process. Polymerization was carried out at total dosage of 6 Mrad to the respective surfaces of samples by an electron beam accelerator, and the reaction was completed by heating at 80 deg C for 24 hr. The dimensions of the samples were measured primarily in the tangential direction, and their dynamic modulus and loss modulus were measured by a Rheovibron DDV-2 and the vibrating reed method. The results and the discussion are given for the reaction mode of ...

International Nuclear Information System (INIS)

An overview of LOCA analysis in Japanese industry is presented. The BASH-M code, developed for large scale LOCA reflooding analysis, is given as an example of verification and improvement of US computer programs are given. The code's application to the operational safety analysis concerns the following main areas: 1D drift flux model base computer program CANAC; CANAC-based advanced training simulator; emergency operating procedures. The author considers also the code application to the following new PWR safety design concepts: use of steam generators for decay heat removal at LOCA conditions; use of horizontal type steam generator for maintaining two-phase natural circulation under the reactor coolant system submerged. 9 figs.

British Library Electronic Table of Contents (United Kingdom)

Hornification is the loss of fiber wall swelling which is detrimental to subsequent recycling resulting from drying. It is known that dried fibers lose their conformability and swelling capacity. The effect of recycling treatment on the swelling ability of hardwood bleached kraft pulp fibers was determined. Modelling paper recycling, sheets were recycled using heat treatment (23?C, 60?C, 100?C). The results were compared with those for natural fibers from bleached kraft pulp. Swelling kinetics of sheets was measured by a modified method monitoring interactions of pulp with water. Swelling ability decreased during the recycling in comparison with never-recycled pulp at all temperatures. Recycling of sheets caused only small changes in the cupri-ethylene-diamine viscosity, however, the water...

British Library Electronic Table of Contents (United Kingdom)

An exergy analysis method is presented of the solar multi-effect humidification?dehumidification desalination (HDD) process. Pinch technology is used in the humidification process to determine the maximum possible saturated air temperature and the temperature of water rejected from the unit, and then the dehumidification process to determine the temperature of water leaving from the heat exchanger. The formulae to calculate the exergy of water and saturated air are given. The solar plane collector is used. From exergy analysis, the solar collector has the lowest exergy efficiency; the HDD process has a lower exergy efficiency, and the water rejected has also a large exergy loss. The energy and exergy recovery rate of the desalination process is also lower. The solar multi-effect HDD proces...

Energy Technology Data Exchange (ETDEWEB)

Following the United Kingdom's nuclear tests at Maralinga in Australia in the 1960's, the Australian government signed away its rights to claim compensation for decontamination costs in a 1968 agreement. Controversy now rages as the Australian government is claiming pound33 million for this purpose from the United Kingdom to compensate the Maralinga Tjarutja for the loss of access to their traditional lands. They claim that the UK clean-up operation was inadequate and that much plutonium was spread over the land, rather than contained in pits. Measurements of contamination at the site were wrong by a factor of ten according to a 1984 visit when Australian scientists were horrified to realize that an Aboriginal child living near Taranaki could inhale more than 460 millisieverts a year. As ministers from both countries meet in June 1993 the debate is likely to be heated and hotly defended. (UK).

International Nuclear Information System (INIS)

Three experiments were conducted to study the behaviour of the new horizontal steam generator construction of the PACTEL test facility. In the experiments the secondary side coolant level was reduced stepwise. The experiments were calculated with two computer codes RELAP5/MOD3.1 and APROS version 2.11. A similar nodalization scheme was used for both codes so that the results may be compared. Only the steam generator was modeled and the rest of the facility was given as a boundary condition. The results show that both codes calculate well the behaviour of the primary side of the steam generator. On the secondary side both codes calculate lower steam temperatures in the upper part of the heat exchange tube bundle than was measured in the experiments. (orig.).

Energy Technology Data Exchange (ETDEWEB)

A cone concentrator combined with a solar cavity receiver is presented and its performance compared to a single cavity receiver. For both cases the available heat sink within the receiver is calculated. The cone concentrator suffers from a high amount of rejected rays if the exit aperture is made too small. A larger exit aperture on the other hand increases the thermal losses of the cavity. The optimum cone geometry therefore has to be found taking also into account a model of the cavity. Different operating temperatures and different values of absorption coefficients of the cavity walls are considered. A cone concentrator was built and tested at the solar furnace in Cologne. It transmits 97 percent of the rays entering the entrance aperture, which is in exact agreement with the theoretical predictions. (author)

DEFF Research Database (Denmark)

Udgivelsesdato: DEC 1

UK PubMed Central (United Kingdom)

Quantitative microscopy has been extensively used in biomedical research and has provided significant insights into structure and dynamics at the cell and tissue level. The entire procedure...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

The untreated, heat- and alkali-treated Lentinus sajor-caju mycelia were used for the recovery of uranium from aqueous solutions. The effect of pH, temperature, initial concentration of UO{sub 2} {sup 2+} ions and contact time parameters were investigated in a batch system. The particles sizes of the fungal mycelia were ranging from 100 to 200 {mu}m. Biosorption equilibriums were established in about 30 min and the correlation regression coefficients show that the adsorption process can be well defined by the Freundlich equation. The alkali treated form had a high biosorption capacity (378 mg/g) than those of the untreated (268 mg/g) and heat-treated fungal mycelia (342 mg/g). Optimum biosorption was observed at pH 4.5 for all the tested fungal preparations and was independent of temperature (5-35 deg. C). In addition, the polarity and surface energy of the fungal biomass film preparations were determined by contact angle measurement. The ...

International Nuclear Information System (INIS)

Nanocrystalline cemented tungsten carbide has attracted considerable interests for use in cutting tool because of its superior mechanical properties. In this study, nano-sized powders of mixed WC and Co were prepared from attrition-milled oxides by a gas reduction-carburization process. The effects of compacting pressure, heating schedule, additional ball-milling, and the presence of a grain growth inhibitor on the sintering properties of the nano-sized WC-Co powders were examined. The grain size and phases in WC-Co alloy were clearly affected by compacting pressure. Because of the trapped gases and the lower melting point of the cobalt binder, when a compact of nano-sized WC-Co powder was sintered through a heating schedule with holding steps, the sintered alloy maintained the small size of WC grains without any #eta# phase. In addition, the additional ball-milling improved the microstructure and mechanical properties of the nano-sized WC-Co ...

International Nuclear Information System (INIS)

LOCA (Loss of coolant accident) resistant heat-shrinkable polymeric products are widely used for the connection of LV cables for class 1E systems inside the containment area of nuclear power plants. The paper/presentation describes the verification of a reformulated compound for these products, where certain components of the compound formulation had to be substituted. A qualification programme with this so-called reformulated compound was undertaken to proof the equivalency of the products to the products made out of the original compound. The basic elements of this requalification project were material qualification tests including accelerated aging tests according to the arrhenius method and type tests in accordance to IEEE 383, including flammability tests. The test results showed that the products made out of the reformulated compound were similar in fit, form and function to the original products. Additional tests have also proven higher ...

Energy Technology Data Exchange (ETDEWEB)

The total hemispherical emittance of an oxide film that formed on 6061-T6 aluminium alloy parts in the Tower Shielding Reactor-II at Oak Ridge National Laboratory was measured from 295 to 773 K using an emissometer and/or a calorimeter. The emittance of this film was critically needed for heat transfer calculations in a simulated loss-of-coolant accident of the reactor. X-ray diffraction analysis identified the film as boehmite (Al{sub 2}O{sub 3} {times} H{sub 2}O), which dehydrated to alumina (Al{sub 2}O{sub 3}) upon heating above 473 K. The measured emittances for the alumina film are in excellent agreement with published values for anodized aluminum films and for bulk alumina. Published values of the emittance of boehmite could not be found for comparison, but evidence is presented that some anodization processes for aluminum yield boehmite and not alumina films.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The steam generator (SG) is one of the most critical components of the heat transfer system in nuclear generation stations. Testing the structural integrity of SG tubing and SG internals is a key element of the fitness-for-service assessments to assure the safe and continuous operation of nuclear power plants. Recent eddy current (ET) inspections of two nuclear power plants revealed degradation of some of the tube support plate (TSP) structures, which was also confirmed by visual inspection. The phenomena was described as metal loss, caused by flow-accelerated corrosion of the carbon steel trefoil support plate and varying from minor to complete loss of the ligaments. This loss of TSP ligaments results in lack of support for the adjacent tubes making them more susceptible to fretting-wear damage and fatigue cracking. A signal analysis method, based on the responses at low frequency of two types of eddy ...

Energy Technology Data Exchange (ETDEWEB)

The nozzle-group regulation of steam turbines plays furtheron an important role in the operation of power stations owing to modern, adaptable control-technical valve timing possibilities. New procedures for a choice-connection of different nozzle areas via the control valves as well as the use of valve laps require, however, a differentiated consideration of the loss mechanism in the inlet area of the turbine, in order to be able to assess and minimize its specific heat consumption also at the operational points outside the layout- and calculation-technically fixed guarantee or valve points, respectively. The basic technical-physical stages to this are explained. (orig.) [Deutsch] Die Duesengruppenregelung von Dampfturbinen nimmt nicht zuletzt dank moderner, anpassungsfaehiger leittechnischer Ventilansteuerungsmoeglichkeiten weiterhin eine bedeutende Stellung beim Betrieb von Kraftwerken ein. Neue Verfahren zur wahlweisen Zuschaltung ...

Energy Technology Data Exchange (ETDEWEB)

Two hot dry rock geothermal energy reservoirs were created by hydraulic fracturing of Precambrian granitic rock on the west flank of the Valles Caldera, a dormant volcanic complex, in the Jemez Mountains of northern New Mexico. Heat was extracted in a closed-loop mode of operation, injecting water into one well and extracting the heated water from a separate production well. The first reservoir was produced by fracturing the injection well at a depth of 2.75 km (9020 ft) where the indigenous rock temperature was 185/sup 0/C. The relatively rapid thermal drawdown of the water produced from the first reservoir, 100/sup 0/C in 74 days, indicated that its effective fracture radius was about 60 m (200 ft). Average thermal power extracted was 4 MW. A second, larger reservoir was created by refracturing the injection well 180 m (600 ft) deeper. Downhole measurements of the water temperature at the reservoir outlet as well as temperatures inferred from ...

Energy Technology Data Exchange (ETDEWEB)

The general strategy for improving the safety of nuclear power plant and its economics is to accomplish power uprates while securing sufficient thermalhydraulic margin. In order to succeed this strategy, there have been a lot of efforts in increasing the margin through the enhancement of heat transfer capability in coolants. However, despite their efforts, only about 10 {approx} 15 % increase of the thermal margin is possible by using the best art known well up to now with installation of mechanical engineering devices such as mixing vane or button to generating the swirl flow and turbulent mixing. The limit of the capability of the best technique has made a lot of engineers to be frustrated to do the power uprates. Nevertheless, fortunately a new innovative idea is being proposed in heat transfer community as an engineering colloidal fluid to basically change the original properties of the coolant. The fluid began to be called by Choi as a ...

Energy Technology Data Exchange (ETDEWEB)

In rat adipocyte membranes, both beta-adrenergic agonists and beta-adrenergic antagonists competed with (--)(/sup 3/H)dihydroalprenolol for high affinity (KD 2-4 nM) and low capacity binding sites. The antagonists but not the agonists competed with (--)(/sup 3/H)dihydroalprenolol for lower affinity and higher capacity sites. The present studies were performed in order to characterize the adipocyte beta-adrenergic receptor and distinguish it from low affinity, higher capacity sites which were heat-labile and not stereoselective. When isoproterenol was used to define the nonspecific binding, saturation studies showed a single binding site with a capacity of approximately 100 fmol/mg membrane protein (corresponding to approximately 50,000 sites/adipocyte). Binding was saturated by 10 nM (--)(/sup 3/H)dihydroalprenolol. Approximate KD's of 204 nM were observed. Kinetic analysis of (--)(/sup 3/H)dihydroalprenolol binding provided an independent measurement of ...

Science.gov (United States)

No Abstract Available

International Nuclear Information System (INIS)

Published in summary form only.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

This research aims at elucidating thermal hydraulic phenomena by carrying out their visualization and measurement which are difficult by conventional method, utilizing the excellent properties of real time neutron radiography and showing the usefulness of neutron radiography. The experiments were carried out on the visualization and measurement of liquid metal flow and mixed phase flow and the visualization and diagnosis of mixed phase flow equipment. As the achievement in this fiscal year, the image-processing method for visualizing quantitatively the distribution of void fraction in gas-liquid two-phase flow has been devised, therefore, its method and results are reported. For the analysis of multi-dimensional two-phase flow, in order to prepare the model and determine the constitution equation, the data on the multi-dimensional distribution of void fraction are required. Void fraction is defined. The method of image processing is explained. The experimental ...

International Nuclear Information System (INIS)

A series of 27 reflood experiments has been carried out in a full-length electrically heated rod bundle facility. The primary objective of these tests was to study the effects of a simultaneous upper plenum and downcomer coolant injection and to provide data for the verification of computer codes. The experimental results indicate that an upper plenum injection alone cools the test rods slowly, a simultaneous coolant injection to the downcomer improves cooling significantly, and a downcomer injection alone cools the test rod bundle best if the total value of the coolant flow rate is the same in these three different cases. If the coolant injected to the upper plenum increases the total flow rate, the quench time of the test rods decreases at all elevations. Quenching time and clad temperature histories calculated with the computer codes NORCOOL-I and FLOOD4 are in a reasonable quantitative agreement with experiments in the case of pure ...

Energy Technology Data Exchange (ETDEWEB)

Geological clay formations are investigated for use as final underground deposit for heat producing nuclear waste. Special kinds of clay (e.g. bentonite) can also be used for the construction of geotechnical barriers. For the long time safety prognosis of the nuclear waste repositories the development of geochemical transport models is indispensable. The transport of aqueous solutions in clay is a complex process. The three-layer-minerals bentonite and illite swell by the adsorption of water, if the volume is restricted a high swelling pressure develops. The excellent barrier effect of natural clay formations and geotechnical clay barriers is based on the high swelling pressure and the high adsorption capacity for radionuclides and other pollutants. The two-layer-mineral kaolinite has no swelling capacity. In contrast to sandy layers a special geochemical transport potential exists in clay besides the well known matrix potential which influences essentially the ...

Energy Technology Data Exchange (ETDEWEB)

The available experimental data on the specific heat, magnetic susceptibility, magnetization, valence, NMR Knight shift and relaxation rate, and the quadrupolar moment of YbPd{sub 2}Si{sub 2} are examined within the framework of the single-ion Anderson model. Such an analysis has previously given excellent agreement between theory and experiment for numerous other light heavy-fermion compounds, where crystalline fields do not play a dominant role. For YbPd{sub 2}Si{sub 2}, substantial crystalline-field splittings make difficult a quantitative comparison with existing exact solutions of the Anderson model. Inconsistencies with the interpretation that a nearly degenerate ground quadruplet determines the low-temperature thermodynamics are pointed out. It is concluded that at least three of the four Kramers doublets participate in the low-{ital T} properties. These three doublets should have a splitting of the order of the Kondo temperature, i.e., ...

International Nuclear Information System (INIS)

Once the definition of the CHP (combined heat and power generation) certificate is clear, demand for it can be organised in several ways. A well-designed system of mandatory demand, by means of an obligation to acquire a certain amount of CHP certificates each year, is effective to meet the policy target. The voluntary willingness to pay for CHP certificates is likely to be small, resulting in a very thin market. Finally, instead of creating a demand solely targeted at the CHP certificates, demand could also result from interacting policy schemes such as emissions trading. Assuming that a CHP certificate scheme is going to be introduced, we would recommend to issue standard CHP certificates based on additional ('fuel-free') kWh output (substitution approach with standard certificates) and create demand by means of an incentive on electricity supply companies to purchase CHP certificates. The incentive could either be quantitative (an ...

Energy Technology Data Exchange (ETDEWEB)

Aim of the work was to describe the noninvasive assessment of bone mineral density, geometrical and biochemical properties in premenopausal women with dietary intake of phytoestrogens and comparison of these parameters with those of age-matched female subjects with Mediterranean dietary intake lacking in these substances. Volumetric cortical, trabecular and total mineral density and bone geometrical properties were evaluated with peripheral quantitative computed tomography (pQCT) at the distal radius of the non dominant forearm. pQCT showed higher bone mineral density (total and trabecular) and SSI values in premenopausal with dietary intake of phytoestrogens. Despite the lack of statistical significance, these preliminary results, should further support the few literature findings about the potential role of phytoestrogens consumption in preventing trabecular bone loss. However, further studies are warranted to evaluate definitively ...

Energy Technology Data Exchange (ETDEWEB)

The present study includes thermal stability of some fatty acids as phase change materials (PCMs). The selected fatty acids were stearic, palmitic, myristic and lauric acid with melting temperatures between 40-63{sup o}C and industrial-grade with 90-95% purity. Latent heat storage capacity and phase transition temperature of the PCMs were determined by Differential Scanning Calorimetry (DSC) technique as a function of after repeated thermal cycles such as 40, 410, 700 and 910. The present work also comprises the investigation of corrosion resistance of some construction materials to the fatty acids over a long period. The containment materials tested were stainless steel (SS 304 L), carbon steel (steel C20), aluminium (Al) and copper (Cu). Gravimetric analysis as mass loss (mg/cm{sup 2}), corrosion rate (mg/day) and a microscopic or metallographic investigation were performed for corrosion tests after 910 thermal cycles. DSC measurements showed ...

International Nuclear Information System (INIS)

The NEPTUN data discussed in this report are from core uncovery (boil-off) experiments designed to investigate the mixture level decrease and the heat up of the fuel rod simulators above the mixture level for conditions simulating core boil-off for a nuclear reactor under small break loss-of-coolant accident conditions. The first series of experiments performed in the NEPTUN test facility consisted of ten boil-off (uncovery) and one adiabatic heat-up tests. In these tests three parameters were varied: rod power, system pressure and initial coolant subcooling. The NEPTUN experiments showed that the external surface thermocouples do not cause a significant cooling influence in the rods to which they are attached under boil-off conditions. The reflooding tests performed later on indicated that the external surface thermocouples have some effect during reflooding for NEPTUN electrically heated rod bundle. ...

Energy Technology Data Exchange (ETDEWEB)

Dual energy X-ray absorptiometry (Hologic QDR-1000) was used to quantitatively analyze the diagnosis and prevention of osteoporosis. The peak bone mineral density (BMD) of the spine appeared in normal men in their twenties and in normal women in their thirties. There was acceleration of bone loss in the 50 to 60 year age bracket (premenopause and postmenopause) in normal women. On the contrary, the peak BMD of the femoral neck in normal men and women appeared in their twenties after which it decreased slightly with age. Comparison showed that the femoral neck BMD of normal women was lower than that of men throughout all ages. The fracture threshold, 0.756 g/cm[sup 2] for the spine, was obtained by scanning 73 females with spinal fractures, the mean BMDs for L2-L4 at the 90th percentile level were used as the fracture threshold. The fracture threshold of femoral neck fracture was the femoral proximal BMD of the 9th decile. Classification by the ...

International Nuclear Information System (INIS)

A combined application of several microtechniques is presented and discussed with the Ti/TiO_2 and Zr/ZrO_2-systems as an example. All measurements were carried out on single grains of technical materials in order to detect and quantify the effect of substrate microstructure on the properties of anodic passive films formed potentiodynamically in 0.5 M H_2SO_4 (dU/dt = 20 mVs"-"1). Anisotropy-micro-ellipsometry (AME) was employed to determine the crystallographic orientation of the substrate grains along with passive film thickness and crystallinity in dependence on the anodization potential. Both the isotropic (amorphous) TiO_2- and the anisotropic (crystalline) ZrO_2-films exhibit a systematic dependence of film thickness on the grain orientation. Local LASER-scanning photocurrent measurements (#lambda#=257 nm) on the same grains likewise show a heterogeneity of the photoelectrochemical reactivity in all cases. This is quantitatively explained by the results from ...

International Nuclear Information System (INIS)

Phosphoenolpyruvate carboxykinase (GTP) (PEPCK) specifically utilizes a guanosine or inosine nucleotide as a substrate, yet it does not share extended sequence homology with other GTP-binding proteins, and the molecular basis for its nucleotide specificity is not understood. In an effort to locate the enzyme's nucleotide-binding site, the authors have studied the interaction of cytosolic PEPCK from rat liver with the photoprobe 8-azidoGTP, which fulfills the criteria of a specific photoaffinity label for PEPCK. The photoprobe binds reversibly to the enzyme prior to modification and at low concentrations causes greater than 60% inactivation-GTP provides nearly complete protection against inactivation by 8-azidoGTP, whereas phosphoenolpyruvate and metal ions provide partial protection. In addition, the photoprobe is a substrate for the enzyme and has a K_m similar to that for GTP. However, the extent of covalent modification by ["3"2P]8-azido-GTP as measured by three independent ...

International Nuclear Information System (INIS)

A quantitative comparison of tissue distribution and excretion of an orally administered sublethal dose of [3H]diacetoxyscirpenol (anguidine) was made in rats and mice 90 min, 24 hr, and 7 days after treatment. Total recoveries of 95-100% were obtained. Approximately 90% of the dose was excreted in urine and feces during the first 24 hr with a feces:urine ratio of about 1:4.5 in both species. Carcass and tissue radioactivity dropped rapidly during the first 24 hr but remained relatively constant at low, but detectable, levels over the course of the experiment. Few substantive interspecies differences were noted in tissue distribution. At 90 min the highest percentage of dose was in tissues involved in sequestering diacetoxyscirpenol because of high body water/lipid content or the absorption, metabolism, or excretion of the toxin. The rank order of these tissues was generally stable over the course of the experiment. When data were expressed as specific ...

Energy Technology Data Exchange (ETDEWEB)

As recently as 1950, 30% of the world's population lived in urban areas. By the year 2030, 60% of the world's population will live in cities, according to the United Nations 'World Population Prospects Revision Report' (2001). Urbanization is quickly transitioning communities from natural rural vegetation to man-made urban engineered infrastructure. This anthropogenic-induced change has manifested itself in microscale and mesoscale increases in temperatures in comparison to adjacent rural regions which is known as the Urban Heat Island Effect. The resultant change causes potentially adverse consequences for local and global communities. One of the great challenges facing our current generation of scientists and engineers is how to support the growth of new and existing urban centers in a sustainable manner. This is even more pronounced in arid regions, which will sustain the greatest rate of urbanization. This article is focused ...

International Nuclear Information System (INIS)

In summary, a scaling analysis of a water-cooled Reactor Cavity Cooling System (RCCS) system was performed based on generic information on the RCCS design of PBMR. The analysis demonstrates that the water-cooled RCCS can be simulated at the ANL NSTF facility at a prototypic scale in the lateral direction and about half scale in the vertical direction. Because, by necessity, the scaling is based on a number of approximations, and because no analytical information is available on the performance of a reference water-cooled RCCS, the scaling analysis presented here needs to be 'validated' by analysis of the steady state and transient performance of a reference water-cooled RCCS design. The analysis of the RCCS performance by CFD and system codes presents a number of challenges including: strong 3-D effects in the cavity and the RCCS tubes; simulation of turbulence in flows characterized by natural circulation, high Rayleigh numbers and low Reynolds numbers; validity of ...

UK PubMed Central (United Kingdom)

ObjectiveThe purpose of this study was to characterize the sensorineural hearing losses of a group of children and adults along three parameters important to the...Full Text Available

UK PubMed Central (United Kingdom)

ObjectiveTo describe the prevalence, intensity, and functional impact of the following types of pain associated with upper-limb loss: phantom limb, residual limb,...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A new characteristics temperature, an adiabatic limit flame temperature, was proposed as the basis to evaluate an effective energy emission and to examine a self combustion limit. Its characteristics were discussed using the reaction system between diatomic molecules as an example, and the low calorific limit of flammability was also discussed. Since the adiabatic limit flame temperature was the inherent temperature of a combustible mixture based on the thermochemical properties of constituents, it was, in particular, very important as considering a combustion system with energy recirculation between products and reactants. The available energy and efficiency of the combustion system should have been estimated on the basis of this temperature, instead of on an adiabatic flame temperature. It was also considerably high even in an extremely lean mixing ratio, however, the flame temperature in a lean region was strongly affected by heat loss in a ...

Energy Technology Data Exchange (ETDEWEB)

In order to study the two-phase natural circulation and flow termination during a small break loss of coolant accident in LWR, simulation experiments have been performed. Based on the two-phase flow scaling criteria developed under this program, an adiabatic hot leg U-bend simulation loop using nitrogen gas and water and a Freon 113 boiling and condensation loop were built. The nitrogen-water system has been used to isolate key hydrodynamic phenomena from heat transfer problems, whereas the Freon loop has been used to study the effect of phase changes and fluid properties. Various tests were carried out to establish the basic mechanism of the flow termination and reestablishment as well as to obtain essential information on scale effects of parameters such as the loop frictional resistance, thermal center, U-bend curvature and inlet geometry. In addition to the above experimental study, a preliminary modeling study has been carried out for ...

Energy Technology Data Exchange (ETDEWEB)

In order to study the two-phase natural circulation and flow termination during a small break loss of coolant accident in LWR, simulation experiments have been performed using two different thermal-hydraulic loops. The main focus of the experiment was the two-phase flow behavior in the hot-leg U-bend typical of BandW LWR systems. The first group of experiments was carried out in the nitrogen gas-water adiabatic simulation loop and the second in the Freon 113 boiling and condensation loop. Both of the loops have been designed as a flow visualization facility and built according to the two-phase flow scaling criteria developed under this program. The nitrogen gas-water system has been used to isolate key hydrodynamic phenomena such as the phase distribution, relative velocity between phases, two-phase flow regimes and flow termination mechanisms, whereas the Freon loop has been used to study the effect of fluid properties, phase changes and coupling between ...

Energy Technology Data Exchange (ETDEWEB)

During the last 15 years cycles with CO{sub 2} capture have been in focus, due to the growing concern over our climate. Often, a natural gas fired combined cycle with a chemical absorption plant for CO{sub 2} capture from the flue gases have been used as a reference in comparisons between cycles. Neither the integration of the steam production for regeneration of amines in the combined cycle nor the off-design behaviour of such a plant has been extensively studied before. In this paper, the integration of steam production for regeneration of the amines is modelled at design load and studied in off-design conditions for a combined cycle. Different ambient conditions and part-load strategies and their influence on the cycle performance are also examined. Of particular interest is a novel strategy with the possibility of longer life of gas turbine blading, with marginal loss in efficiency. The off-design performance of the combined cycle is modelled in a rigorous way ...

International Nuclear Information System (INIS)

Fatigue-crack growth in air and in aqueous 3.5-percent NaCl as well as fracture toughness are evaluated for the metastable beta-titanium alloy Ti-3Al-8V-6Cr-4Mo-4Zr in various microstructural conditions. Two solution heat treatments (SHT), 800 C and 927 C, were chosen to produce two different grain sizes. Approximately 20 vol pct unrecrystallized beta grains remained after SHT at the lower temperature. Yield stresses were 895 and 850 MPa, respectively. Both simplex and duplex aging treatments were performed for both grain sizes to vary the distribution of alpha precipitates while keeping the yield stress in the range of 1075-1220 MPa for all aged conditions. Unaged material exhibits significantly higher fracture toughness levels than aged material. The unrecrystallized regions were associated with a loss in ductility and toughness. 21 refs.

CERN Document Server

We investigate the formation and evolution of dwarf galaxies in a high resolution, hydrodynamical cosmological simulation of a Milky Way sized halo and its environment. Our simulation includes gas cooling, star formation, supernova feedback, metal enrichment and UV heating. In total, 90 satellites and more than 400 isolated dwarf galaxies are formed in the simulation, allowing a systematic study of the internal and environmental processes that determine their evolution. We find that 95% of satellite galaxies are gas-free at z=0, and identify three mechanisms for gas loss: supernova feedback, tidal stripping, and photo-evaporation due to re-ionization. Gas-rich satellite galaxies are only found with total masses above ~ 5x10^9 solar masses. In contrast, for isolated dwarf galaxies, a total mass of ~ 10^9 solar masses constitutes a sharp transition; less massive galaxies are predominantly gas-free at z=0, more massive, isolated dwarf galaxies are ...

Energy Technology Data Exchange (ETDEWEB)

A series of plasma nitriding experiments has been conducted on AISI 304L austenitic stainless steel at temperatures ranging from 375 to 475 C using pulsed-DC plasma with different pulse duty cycles, N{sub 2}-H{sub 2} gas mixtures and treatment times. It is shown that a wide range of treatment parameters exist that allow the formation of the S-phase. The formation and growth of this surface layer depend strongly on the treatment parameters, such as nitrogen partial pressure and duty cycle. Within the parameter range investigated, the layer growth appears to be diffusion controlled with an activation energy about 107 kJ/mol. The formation of CrN precipitates during plasma nitriding is not accompanied by the formation of bcc iron, which might be expected due to the loss of free chromium. However, the S-phase transforms into CrN and bcc iron following a heat treatment at 450 C or higher for 25 h. The wear rate after plasma nitriding is greatly ...

Energy Technology Data Exchange (ETDEWEB)

In CANDU reactors, the Regional Overpower Protection Trip (ROPT) system protects the reactor against overpowers in the reactor fuel, whether due to localized peaking within the core or a general increase in core power levels. Due to Primary Heat-Transport System (PHTS) aging the ROP trip setpoint is decreasing over time. Reductions in ROP trip setpoints are required to maintain the required trip-probability and ROP trip effectiveness, and results in a decrease of the ROP margin-to-trip during normal operation. In addition, full power operation can be threatened. In this point, to recover ROPT margin, channel power needs to be redistributed. ROPT setpoint is very conservative in normal operation because distortion of regional overpower is over 1.2 times as nominal power in slow loss of regulation (SLOR). Channel power ratio (CPR) is enough low except the limiting channel of which worst case of design basis flux shape. If the outer channel power ...

Science.gov (United States)

Development of a high performance air heater through use of an evacuated tube cover design is described. The cover design utilizes evacuated fluorescent light tubes laid parallel in a close packed array to form an inner transparent glazing over a conventional metal absorber plate with flow behind the plate. A tempered flat glass plate was used as an outer glazing. Both clear and infrared reflective (IR) tubes were investigated. Solar transmittance tests indicate that the clear tube array has a higher transmittance than two flat sheets of low-iron glass. The IR coating produced substantial transmittance loss. Thermal conductance tests indicate that the tubes behave similar to two flat glass sheets with a vacuum in between. The IR reflective coating was only marginally effective at reducing heat conductance. Final prototype designs are presented along with collector performance estimates.

Energy Technology Data Exchange (ETDEWEB)

The overall aim is to develope programme modules for a Danish integrated computer system for projecting buildings and to ensure that Danish programmes are compatible with international systems. The programmes to be integrated here were AutoCAD and SCRIBE-models and the simulation programme tsbi3 for the calculation of indoor climate conditions, power demand and energy consumption in buildings. For the calculation of humidity and temperature conditions in constructions a certain amount of integration is carried out with the MATCH programme (Moisture And Temperature calculations for Constructions of Hygroscopic materials). The activities embodied in the pilot projects are described in this working report in addition to the individual computer programmes and prototypes, and examples and diagrams are presented. The programmes included are a geometry programme for the calculation of areas, lengths and volumes, a programme for the calculation of heat ...

International Nuclear Information System (INIS)

The TRAC/PFI-MOD2 Version 5.3 code was assessed against six FLECHT-SEASET forced reflood tests (31504, 31203, 31302, 31701, 34209, and 31922) and two cylindrical core test facility (CCTF) tests [C1-19 and C2-6]. The objective of this study was to evaluate the clad thermal response predictive capabilities of the code with the newly added reflood model under large-break loss-of-coolant accident (LOCA) conditions in a pressurized water reactor (PWR). The TRAC model for the FLECHT-SEASET test facility was developed from a RELAP5 model. The test section was modeled using a vessel component with 23 axial levels, 1 radial ring, and 1 azimuthal cell. Test inlet and exit conditions were modeled using fill and break components, respectively. The measured lower and upper plenum test conditions were input to the model. The electrically heated rod was modeled using a rod component with 22 axial mesh points. The axial boundary of each mesh point coincided ...

Energy Technology Data Exchange (ETDEWEB)

The search for alternative fuels and new fuel resources is a top priority for Turkey, as is the case in the majority of countries throughout the world. The fuel policies pursued by governmental or civil authorities are of key importance in the success of alternative fuel use, especially for widespread and efficient use. Following the 1973 petroleum crisis, many users in Turkey, especially in transportation sector, searched for alternative fuels and forms of transportation. Gasoline engines were replaced with diesel engines between the mid-1970s and mid-1980s. In addition, natural gas was introduced to the Turkish market for heating in the early 1990s. Liquid petroleum gas was put into use in the mid-1990s, and bio-diesel was introduced into the market for transportation in 2003. However, after long periods of indifference governmental action, guidance and fuel policies were so weak that they did not make sense. Entrepreneurs and users experienced great economical ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The authors have examined the pyrolysis of Argonne samples of Wyodak and Illinois No. 6 coal in argon, undecane, Tetralin, and water. The effects of the pyrolysis on individual particles of coal were monitored visually in a cell with diamond windows capable of operation to temperature and pressures in excess of 500{degrees}C and 3000 psi. The changes in the particles from ambient to 460{degrees}C were recorded in real time on video tape, and images were then taken from the tape record and analyzed. The study showed that in argon both coals developed tars at 350{degrees}-370{degrees}C. The tars then quickly evaporated, leaving core particles remarkably similar in size and shape to the initial particles. These observations suggest that coal does not melt nor become fully liquid when heated. Nor does the softened coal undergo crosslinking to generate coke. Rather the simple loss of volatiles leaves behind the core residue as coke. Contrary to the ...

International Nuclear Information System (INIS)

Full text: Full text: The incomplete understanding of the complex mechanisms connected with the interaction between thermal-hydraulic and neutron kinetics still challenges the design and the operation of nuclear reactors and imposes the adoption of conservatism in the evaluation of safety limits. The recent availability of powerful computer and computational techniques together with the continuing increase in operational experience suggests the revisiting of those areas and the identification of design/operation requirements that can be relaxed. So far, almost all of the safety analyses of research reactors have been performed using conservative computational tools such as channel codes but, nowadays, the application of Best-Estimate (BE) methods constitutes a real necessity. The global aim of the current work is an attempt to apply the best-estimate system thermal-hydraulic code Relap5. For this purpose, the generic IAEA research reactor Benchmark problem is re-considered for proving ...

Science.gov (United States)

... turbine blade heat-transfer and study the heat-transfer augmentation in idealized geometry and its ... responsible for heat transfer augmentation. ...

Energy Technology Data Exchange (ETDEWEB)

The radionuclide characteristics of light-water-reactor (LWR) spent fuel play key roles in the design and licensing activities for radioactive waste transportation systems, interim storage facilities, and the final repository site. Several areas of analysis require detailed information concerning the time-dependent behavior of radioactive nuclides including (1) neutron/gamma-ray sources for shielding studies, (2) fissile/absorber concentrations for criticality safety determinations, (3) residual decay heat predictions for thermal considerations, and (4) curie and/or radiological toxicity levels for materials assumed to be released into the ground/environment after long periods of time. The crucial nature of the radionuclide predictions over both short and long periods of time has resulted in an increased emphasis on thorough validation for radionuclide generation/depletion codes. Current radionuclide generation/depletion codes have the capability to follow the ...

UK PubMed Central (United Kingdom)

Emphasis was put on the comparative quantitative structure-activity approaches to the exploration of action mechanisms of structurally different classes of compounds showing the same type of activity...Full Text Available

UK PubMed Central (United Kingdom)

A single radial hemolysis test was developed for quantitation of specific antibody to non-hemagglutinating viruses. With the human coronaviruses as models, this test utilizes the binding properties...Full Text Available

UK PubMed Central (United Kingdom)

Gene expression data has been used in lieu of phenotype in both classical and quantitative genetic settings. These two disciplines have separate approaches to measuring and interpreting epistasis, which...Full Text Available

UK PubMed Central (United Kingdom)

The Electronic REference To access In vivo Concentrations (ERETIC) method was applied to ¹H HR-MAS spectroscopy. The accuracy, precision, and stability of ERETIC as a quantitative...Full Text Available

International Nuclear Information System (INIS)

1986. p. 390-392. Germany Brecht-Krauss, D. Kusmierek, J. Adam, WE Ulm

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

Published in summary form only.

KoreaScience (Korea)

Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

One of the more-serious side effects of extended space flight is an accelerated bone loss

British Library Electronic Table of Contents (United Kingdom)

Abstract A large number of massive stars are known to rotate rapidly, resulting in a significant distortion and variation in surface temperature from the pole to the equator. Radiatively driven mass-loss is temperature-dependent, so rapid rotation produces a variation in the mass-loss and angular momentum loss rates across the surface of the star, which is expected to affect the evolution of rapidly rotating massive stars. In this work, we use zero-age main-sequence (ZAMS) stellar models to investigate the two-dimensional effects of rotation on stellar mass-loss, using two common prescriptions for radiatively driven mass-loss. The associated loss of angular momentum from these models is also considered. Using 2D stellar models, which give the variation in surface parameters as a function o...

CERN Document Server

Network tomography aims at inferring internal network characteristics based on measurements at the edge of the network. In loss tomography, in particular, the characteristic of interest is the loss rate of individual links. There is a significant body of work dedicated to this problem using multicast and/or unicast end-to-end probes. Independently, recent advances in network coding have shown that there are several advantages from allowing intermediate nodes to process and combine, in addition to just forward, packets. In this paper, we pose the problem of loss tomography in networks that have network coding capabilities. We design a framework for estimating link loss rates, which leverages network coding capabilities and we show that it improves several aspects of tomography, including the identifiability of links, the tradeoff between estimation accuracy and bandwidth efficiency, and the complexity of ...

International Nuclear Information System (INIS)

Mitsubishi is now developing a next-generation Pressurized Water Reactor (PWR) which has the innovative feature of hybrid safety systems (optimum combination of passive safety system and active safety system) and passive core cooling by horizontal steam generators during Loss of Coolant Accident (LOCA). In order to confirm the capability of this passive core cooling system during LOCAs, the thermal-hydraulic tests of horizontal steam generator and the integral thermal-hydraulic tests simulating the LOCAs were performed. The thermal-hydraulic tests of horizontal steam generator consist of a single tube test and a multi-tubes test. On the basis of these test results, the heat transfer characteristics of steam-water two-phase flow with noncondensable gas along a long horizontal tube is understood and the heat transfer correlation including the effect of noncondensable gas is presented. The integral thermal-hydraulic tests ...

Energy Technology Data Exchange (ETDEWEB)

The Coal Fired Combined Cycle (CFCC) power system thermodynamic cycle is illustrated schematically. Pressurized air supplied at the discharge of gas turbine compressors is ducted to the pressure vessel of pressurized, fluidized-bed, combustor-steam generator modules. The air is introduced in parallel to the beds, entering through distribution grids beneath each bed. Steam generation tubes are buried within the beds and are also arranged as membrane tube walls enclosing the four sides. Crushed coal (1/4 inch x 0) is pneumatically fed at locations just above the air inlet grids at the bottom of each bed. Dolomite is similarly fed to the individual beds. The coal is burned at a temperature below the ash fusion point. Sulfur is removed in the fluid beds through reaction of the SO/sub 2/ with CaCO/sub 3/ and O/sub 2/ to form solid CaSO/sub 4/ and CO/sub 2/ gas. The combustion gases leave the beds at a temperature in the range of 1400/sup 0/F to 1750/sup 0/F, depending upon the plant load ...

International Nuclear Information System (INIS)

Negative ions have attractive features as drivers for inertial confinement fusion, because they will avoid electron cloud effects, and could be efficiently photodetached to neutrals after the final focus, which could also be beneficial in heating warm dense matter targets. The halogens have large electron affinities, and thus should be able to produce high current densities of relatively robust negative ions. Recent experiments comparing chlorine beams to argon beams using the same source, extraction optics, and diagnostics have demonstrated that Cl"- beams can be produced with similar emittance to Ar"+ beams, and with about 34 the current density from the same configuration. The observed effective beam temperature of about 13eV, and the similarity of current densities show that negative halogen beams can meet the current density and emittance requirements of heavy ion fusion. The near equivalence of the Cl"- and Cl"++Cl_2"+ current densities reaching the Faraday ...

International Nuclear Information System (INIS)

This paper deals with construction types of high temperature heat exchangers, their circulation loops and temperature differences. Most attention is given to gas dynamics, convective heat transfer, convection and radiant heat transfer interaction in high temperature heat exchangers. The ways of heat transfer augmentation and efficient heat exchanger construction are discussed.

Energy Technology Data Exchange (ETDEWEB)

To study the plasma evolution and spatial structure at the L/H transition, the double hysteresis is examined by use of the 1-dimensional transport model equations. Three mechanisms for the bipolar losses, i.e., the loss cone loss, collisional bulk viscosity loss of ions and the anomalous loss are simultaneously retained. Five-fold multiple bifurcations are found to exist at the plasma edge, similar to the previous 0-dimensional study. Double hysteresis causes a self-generated oscillation, which is attributed to the compound dither, a kind of ELMs. Spatio-temporal evolution of the compound dither is analyzed. (author)

Energy Technology Data Exchange (ETDEWEB)

A simple analytical model has been developed in order to provide a framework for designing experimental programs for convective loss determinations, for analyzing available experimental data from solar receiver test programs, and for estimating the convective loss at a relatively small cost. Analytical results and experimental evidence indicate that the convective loss from cavity receivers is appreciable, while the effects of wind on the convective loss under normal operating conditions are minimal. The proposed analytical model provides a means of determining the relative importance of the internal resistances and predicting the bulk air temperature within the convective zone inside the cavity.

International Nuclear Information System (INIS)

We have studied the application of direct aperture optimization (DAO) as an inverse planning tool for breast IMRT. Additionally, we have analysed the impact of respiratory motion on the quality of the delivered dose distribution. From this analysis, we have developed guidelines for balancing the desire for a high-quality optimized plan with the need to create a plan that will not degrade significantly in the presence of respiratory motion. For a DAO optimized breast IMRT plan, the tangential fields incorporate a flash field to cover the range of respiratory motion. The inverse planning algorithm then optimizes the shapes and weights of additional segments that are delivered in combination with the open fields. IMRT plans were generated using DAO with the relative weights of the open segments varied from 0% to 95%. To assess the impact of breathing motion, the dose distribution for the optimized IMRT plan was recalculated with the isocentre sampled from a predefined distribution in a ...

Energy Technology Data Exchange (ETDEWEB)

Heat transfer processes use fluids which are generally not pure and can react with transfer surfaces. These surfaces are subject to deposits which can be sediments harmful to heat transfer and to integrity of materials. For nuclear plant steam generators, sludge build-up accelerates secondary side corrosion by concentrating chemical species. A major safety problem involved with such a corrosion is the growing of circumferential cracks which are very difficult to detect and size with eddy current probes. With a view to understand and control this problem, it is necessary to develop a mathematical model for the prediction of sludge behavior in PWR steam generators. Based on fundamental principles, this work intends to use different models available in literature for the prediction of the phenomenon leading to the accumulation of sludge particles at the bottom (the tubesheet) of a PWR. For that, a three-dimensional simulation of magnetite ...

International Nuclear Information System (INIS)

The aim of this paper was to describe ability to intercalation of laboratory prepared carbon composites and their constituents. In work the following materials were tested; pinch-based fibres of P-120 and K-1100 manufacturer's designations, carbon matrix and resulting composites. To prepare a matrix of composites, phenol-formaldehyde resin (Z) and pinch-based precursor (PAK) were used. After initial carbonization, the carbon matrix was heated to 2150 "oC i to improve ability to the future intercalation. Three kinds of composites (P/Z, K/Z and K/PAK), with two directional reinforcement (2D), were prepared. All carbon samples were intercalated with copper chloride(II). To study the structure of all materials, before and after intercalation, X-ray diffraction method was used. It enabled to measure microstructure parameters (L_c and L_a), interplanar distance (d_0_0_2) thickness of an intercalation layer (d_i). Before intercalation, graphite fibers are characterized by ...

International Nuclear Information System (INIS)

Three copper-based alloys, CDA 102 (oxygen-free, high-purity copper), CDA 613 (aluminum bronze), and CDA 715 (Cu-30Ni), are candidates for the fabrication of high-level radioactive-waste disposal containers. Waste will include spent fuel assemblies from reactors as well as borosilicate glass, and will be sent to the prospective repository site at Yucca Mountain in Nye County, Nevada. The decay of radionuclides will result in the generation of substantial heat and in fluxes of gamma radiation outside the containers. In this environment, container materials might degrade by atmospheric oxidation, general aqueous phase corrosion, localized corrosion (LC), and stress corrosion cracking (SCC). This volume is a critical survey of available data on pitting and crevice corrosion of the copper-based candidates. Pitting and crevice corrosion are two of the most common forms of LC of these materials. Data on the SCC of these alloys is surveyed in Volume 4. Pitting usually ...

Science.gov (United States)

There are five tasks within this project on thermally stable coal-based jet fuels. Progress on each of the tasks is described. Task 1, Investigation of the quantitative degradation chemistry of fuels, has 5 subtasks which are described: Literature review on thermal stability of jet fuels; Pyrolytic and catalytic reactions of potential endothermic fuels: cis- and trans-decalin; Use of site specific {sup 13}C-labeling to examine the thermal stressing of 1-phenylhexane: A case study for the determination of reaction kinetics in complex fuel mixtures versus model compound studies; Estimation of critical temperatures of jet fuels; and Surface effects on deposit formation in a flow reactor system. Under Task 2, Investigation of incipient deposition, the subtask reported is Uncertainty analysis on growth and deposition of particles during heating of coal-derived aviation gas turbine fuels; under Task 3, Characterization of solid gums, sediments, and ...

International Nuclear Information System (INIS)

This thesis was carried out at Forsmark Nuclear Power Plant. The power plant in Forsmark consists of three boiling water reactors (BWR) which produce about 17% of Swedish electricity. In a BWR the nuclear reactions are used to boil water inside the reactor vessel. The water works both as a coolant and as a moderator and the resulting steam is used directly to run the turbines. A problem when running a BWR at low flow conditions is the density wave oscillations that might occur to the water flow inside the fuel assemblies. These oscillations arise due to the connection between power and flow rate in a heated channel with two-phase flow. In order to improve the stability performance of the channel an orifice plate is placed at the inlet of each fuel assembly. Today these orifice plates have sharp edges and a constant resistance coefficient. Experimental work has been done with progressive orifices, the edge of which is half-oval in shape. The advantage of progressive ...

Energy Technology Data Exchange (ETDEWEB)

This book contains nine selections. Some of the titles are: High Heat-Flux, Forced-Convection Heat Transfer for Tubes with Twisted-Tape Inserts; Heat Transfer Augmentation by Interrupted Surfaces - Experimental Consideration; Turbulent Flow Heat Transfer from Externally Roughened Tubes in Axial Flow in Concentric Pipe Heat Exchangers; and Heat Transfer Enhancement of Turbulent Flow in Pipes with an Internal Circular Rib.

Energy Technology Data Exchange (ETDEWEB)

This paper presents a set of heuristics useful for optimal design of heat-exchange networks and integrated heat and power systems. These heuristics consolidate other approaches reported in the literature in a formalism useful for design purposes.

Science.gov (United States)

... To maximise heat transfer rates, many heatshield designs make use of heat transfer augmentation devices such as large numbers of pin-fin ...

UK PubMed Central (United Kingdom)

The management of the interim phase of a complete oral rehabilitation in patients with severely worn dentition is often challenging due to the loss of occlusal vertical dimension, loss of tooth structure,...Full Text Available

UK PubMed Central (United Kingdom)

We performed genome-wide homozygosity mapping in a large consanguineous family from Morocco and mapped the autosomal-recessive nonsyndromic hearing loss (ARNSHL) in this family to the DFNB79...Full Text Available

UK PubMed Central (United Kingdom)

Using a ligature-induced model in type-2 Zucker diabetic fatty (ZDF) rat and normoglycemic littermates, we investigated whether diabetes primarily affects periodontitis by enhancing bone loss...Full Text Available

UK PubMed Central (United Kingdom)

Anemia commonly affects critically ill patients. The causes are multifactorial and include acute blood loss, blood loss from diagnostic testing and blunted red blood cell production. Blood transfusions...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundBacterial constituents, such as Gram-negative derived lipopolysaccharide (LPS), can initiate inflammatory bone loss through induction of host-derived inflammatory...Full Text Available