Energy Technology Data Exchange (ETDEWEB)

A method for recycling laser flashlamp radiation in selected wavelength ranges to decrease thermal loading of the solid state laser matrix while substantially maintaining the pumping efficiency of the flashlamp.

Energy Technology Data Exchange (ETDEWEB)

Samples of fat coal-E, its roof sandstone-A and blind coal-W from two coal mines in Hebei Province of China were brought to the laboratory to study the features of infrared thermal images and radiation temperature in the course of uni-axial load and uni-axial cycle load. To check the results of infrared remote sensing detection, two other methods, acoustic emission detection and electrical resistance detection were also used. The AGA-782 thermalvision detected change of the temperature field of the samples` surfaces. The study showed that: (1) coal rocks and sandstone in the course of loading have three types of infrared thermal image features and three types of infrared radiation temperature features; (2) infrared detection is comparable with acoustic emission detection and electrical resistance detection. Generally, the infrared ...

Science.gov (United States)

... Accession Number : ADD431225. Title : Influence of Fiber Loading on Thermal Ablation of PTFE,. Corporate Author : Personal Author(s) : Letson,KN. ...

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

The present invention concerns a high thermal load heat receiving plate such as a divertor plate of a thermonuclear device. The high thermal load heat receiving plate of the present invention has a cooling performance capable of suppressing the temperature of an armour tile to less than a threshold value of the material against high thermal loads applied from plasmas. Spiral polygonal pipes are inserted in cooling pipes at a portion receiving high thermal loads in the high temperature load heat receiving plate of the present invention. Both ends of the polygonal pipes are sealed by lids. An area of the flow channel in the cooling pipes is thus reduced. Heat conductivity on the cooling surface of the cooling pipes is increased in the high thermal load heat ...

Science.gov (United States)

disciplinary methods were used to independently determine the aerodynamic loads, the thermal response, and strardural performance of the hydrogen cooled ...

British Library Electronic Table of Contents (United Kingdom)

Heat transfer through the gas diffusion layer (GDL) is a key process in the design and operation of a PEM fuel cell. The analysis of this process requires the determination of the effective thermal conductivity as well as the thermal contact resistance between the GDL and adjacent surfaces/layers. The Part 1 companion paper describes an experimental procedure and a test bed devised to allow separation of the effective thermal conductivity and thermal contact resistance, and presents measurements under a range of static compressive loads. In practice, during operation of a fuel cell stack, the compressive load on the GDL changes. In the present study, experiments are performed on Toray carbon papers with 78% porosity and 5% PTFE under a cyclic compressive load. Results show a significant hy...

Science.gov (United States)

drical Enclosures Using a Numerical Ray Tracing Technique. NASA. TM-I02527, 1990 . Buckley, H.: Radiation from the Interior of a Reflecting Cylinder. Philos. ...

British Library Electronic Table of Contents (United Kingdom)

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

International Nuclear Information System (INIS)

The commercial Modular High Temperature Gas-Cooled Reactor (MHTGR) achieves improved reactor safety performance and reliability by utilizing an integrated sequence of completely passive thermal storage and heat transfer mechanisms to reject decay heat in the event that all its active cooling systems fail to operate. During such events, the initial heatup transient in the core is followed by a quasi-steady state cooldown process which, if uninterrupted, can continue for several days. A buoyancy-driven natural convection cooling system called the RCCS facilitates the continuous heat removal by circulating ambient air through the reactor cavity, where it is heated and then exhausted to the outside environment. The peak thermal load on the RCCS occurs approximately at the time that the vessel reaches its highest temperature. To confirm the adequacy of the RCCS design, detailed analytical models were developed to simulate the ...

International Nuclear Information System (INIS)

As a part of the compatibility analysis of DUPIC fuel in CANDU reactors, the radiation physics calculations have been performed for the CANDU primary shielding system, thermal shield, radiation damage, transportation cask and storage. At first, the primary shield system was assessed for the DUPIC fuel core, which has shown that the dose rates and heat deposition rates through the primary shield of the DUPIC fuel core are not much different from those of natural uranium core because the power levels on the core periphery are similar for both cores. Secondly, the radiation effects on the critical components and the themal shields were assessed when the DUPIC fuel is loaded in CANDU reactors. Compared with the displacement per atom (DPA) of the critical component for natural uranium core, that for the DUPIC fuel core was increased by -30% for the innermost groove and the weld points ...

Energy Technology Data Exchange (ETDEWEB)

The thermal contact resistance between balls and inner and outer rings of thermally steady space-use deep groove ball bearings was studied experimentally to verify the validity of the previously proposed calculation method for the resistance. The 440C stainless steel single row bearing was used for measuring its steady state temperature distributions in a vacuum environment under axial, radial and combined load conditions. As a result, the experimental results of the resistance well agreed with calculated ones under each load condition resulting in the sufficient validity at nearly the same surface roughness. It was necessary to apply a static equivalent radial load to calculation under the combined load that a contact angle is larger than the angle of resultant force dependent on both load components. In experiments under only radial ...

International Nuclear Information System (INIS)

The effects of various antioxidants and antioxidant concentrations on the radiation and thermal stability of EPDM and XLPE polymers used for insulation of electric cable in nuclear power plants were measured. The objective was to determine if particular antioxidants could be identified as being especially effective for stabilization against radiation aging and combined thermal and radiation aging. Elongation to rupture was used as the measure of stability. Materials were irradiated to doses up to 2 MGy (200 Mrad) at a dose rate of 200 to 300 Gy/h in the Cobalt-60 Gamma Irradiation Facility at the University of Virginia. All of the antioxidants tested, which were known to provide excellent thermal stability, also provided good stability for radiation aging and combined thermal/radiation aging, although small differences ...

International Nuclear Information System (INIS)

Wood-plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, using three monomer systems; acrylamide, butylmethacrylate, and styrene, with methanol as the swelling solvent. Polymerization was induced at various radiation doses (10, 20, and 30 kGy) at a dose rate of 3.5 kGy/h using a "6"0Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength have been measured. The polymer loading decreases approximately with increasing density of the wood species used.

International Nuclear Information System (INIS)

Since the first round of conceptual fusion reactor designs in 1973 - 1974, there has been considerable progress in design improvement. Two recent tokamak designs of the Wisconsin and Culham groups, with increased plasma beta and wall loading (power density), lead to more compact reactors with easier maintenance. The Reference Theta-Pinch Reactor has undergone considerable upgrading in the design of the first wall insulator and blanket. In addition, a conceptual homopolar energy storage and transfer system has been designed. In the case of the mirror reactor, there are design changes toward improved modular construction and ease of handling, as well as improved direct converters. Conceptual designs of toroidal-multiple-mirror, liner-compression, and reverse-field pinch reactors are also discussed. A design is presented of a toroidal multiple-mirror reactor that combines the advantages of steady-state operation and high-aspect ratio. The liner-compression reactor ...

Energy Technology Data Exchange (ETDEWEB)

Design considerations of a combined photovoltaic-thermal (PV-T) system for a particular site and application must include thermal and electrical tradeoffs. A simplified technique for determining preliminary design and economic analyses would minimize costly computer simulation and indicate feasibility. To that end, nomographs that size an array to meet a specific annual load and determine the subsequent cost savings have been developed, and are presented in this paper.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

We show that, for the high electron currents used in present-day free-electron lasers, spontaneous radiation is distributed according to thermal statistics.

Energy Technology Data Exchange (ETDEWEB)

Stochastic models for the simulation of global radiation are discussed. Thermal transients in the ground are analyzed. The performance of buried-pipe storage and a space heating system with long-term storage is described.

Energy Technology Data Exchange (ETDEWEB)

The interaction of thermal radiation with conduction and convection in thermally developing absorbing, emitting, non-gray gas particulate turbulent suspension flow through a circular tube is investigated. The contribution of thermal radiation is obtained through evaluation of the total hemispherical emittance of the particulate cloud and through evaluation of single band absorptances for molecular gases, modified to account for the interaction with the particles. The governing differential equation is derived as a (nonlinear) energy equation, coupled with integral equations to find the thermal radiation contributions. The energy equation is solved numerically by an implicit finite difference with its iterative procedure. Qualitative results for Nusselt numbers are shown for a variety and range of parameters, such as optical thickness of ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

This paper presents a new algorithm for the optimal long-range generation planning for a thermal system with pumped-storage plants. The algorithm is based upon the analytical production costing model developed under the assumption of Gaussian probabilistic distribution of random load fluctuations and plant outages. The optimization problem consists of the master problem to determine the annual investment, and the pumped-storage subproblem to determine the optimal pumped-storage operation. The master problem is formulated as a Hamiltonian minimization problem, and the pumped-storage subproblem is solved using the concept of peak-shaving operation on the original load curve.

Energy Technology Data Exchange (ETDEWEB)

A compression ignition engine was operated on dual fuel principle inducting two commercial fuels and four pure hydrocarbon fuels in turn through intake manifold along with air and injecting diesel fuel to initiate the combustion in the conventional manner. The engine was operated at different loads and at each load the quantity of inducted fuel was increased gradually till knocking set in. The engine performance and exhaust pollutant emissions were recorded at different operating conditions. It was observed that the extent of induction and the effect on the performance depend on the properties of the inducted fuel such as volatility, self ignition temperature and oxidation characteristics. The energy release during the cycle was also observed to shift depending on the properties of inducted fuel. With the dual fuel operation, the thermal efficiency at part loads was observed to be less compared to neat ...

British Library Electronic Table of Contents (United Kingdom)

Durability is a major limitation of current proton exchange membrane fuel cells. Mechanical stress due to hygro-thermal cycling is one failure mechanism of the polymer electrolyte membrane. In previous work the cyclic rate, temperature, and hydration dependent elastic-viscoplastic mechanical behavior of Nafion has been extensively investigated in uniaxial and biaxial tension, serving as a data basis and means of validation for a three-dimensional constitutive model. Here, the important effect of loading via constrained swelling is studied. Specifically, two types of loading are investigated: partially constrained swelling via a bimaterial swelling test and hygro-thermal cycling within a fuel cell. The bimaterial swelling conditions are examined via experiments in conjunction with modeling....

International Nuclear Information System (INIS)

A large amount of energy has been consumed so far in so called matured industries such as iron and steel, oil refinery, petrochemical, ceramic, paper and pulp manufacturing and so forth. A successive stimulation on the preceding industries has to be enhanced from a technological viewpoint in order to maintain a further development based on novel and innovative technologies. In this regard, energy technology has become and will be increasingly important in a high temperature system so that the basic concept for heat transfer augmentation methods by thermal radiation is reviewed briefly in accord with the recent developments together with theoretical background and the prominent features. The heat transfer augmentation related to thermal radiation is summarized.

International Nuclear Information System (INIS)

This volume of the monograph covers the following topics: activation analysis, non-activation interaction analysis (elastic scattering of charged particles, absorption and backscattering of beta radiation and photons, radionuclide X-ray fluorescence analysis, thermalization, scattering and absorption of neutrons, use of ionization caused by nuclear radiation, use of ionization by alpha or beta radiation for the measurement of pressure, density and flow rate of gases), and automation in radioanalytical chemistry. (P.A.).

Energy Technology Data Exchange (ETDEWEB)

Research and development activities sponsored by countries within the International Energy Agency`s solar thermal working group. SolarPACES, have helped reduce the cost of solar thermal systems to one-fifth that of the early pilot plants. Continued technological improvements are currently being proven in next-generation demonstration plants. These advances, along with cost reductions made possible by scale-up to larger production and construction of a succession of power plants, have made solar thermal systems the lowest-cost solar energy in the world and promise cost-competitiveness with fossil-fuel plants in the future. Solar thermal technologies are appropriate for a wide range of applications, including dispatchable central-station power plants where they can meet peak-load to near-base-load needs of a utility, and distributed, modular power plants for both ...

International Nuclear Information System (INIS)

A concept of a traveling wave direct energy converter (TWDEC) is developed for 14.7-MeV fusion protons based on the principle of a backward wave oscillator. Separation of fusion protons from thermal ions is accomplished by using ExB ion drift. Energy conversion rate up to 0.87 is attained by applying three-stage modulation of the proton beam. A one-dimensional particle-circuit code is developed to examine self-excitation of the traveling wave and its stability under loading. Electrostatic wave with a fixed frequency is excited spontaneously, and stability of the wave is ensured under loading. (author).

Energy Technology Data Exchange (ETDEWEB)

Most plans for the disposition of surplus nuclear materials involve storage in sealed containers where the evolution of gases from reactions of adsorbed water could present both pressure and flammability hazards[l] . Despite efforts such as calcining the material to minimize the water content prior to packaging, both residual moisture and readsorbed water may be present in the final containers . Given the anticipated temperature excursions during transportation and storage, this water may thermally desorb, increasing the pressure, and/or thermally dissociate to produce H2 gas, increasing flammability hazards . In addition, the radiation from the nuclear material may induce radiolysis of the water with the likely products being water vapor, H2, 02 and H2O2. In order to better understand the relative importance of the thermal- and radiationinduced chemistry, we have studied the interactions of water on ...

International Nuclear Information System (INIS)

A three-dimensional (3D) thermal-hydraulic model and a numerical procedure for the simulation and analysis of a steady-state, as well as transient operation of nuclear power plant components are presented. A two-fluid approach is applied to modelling of two-phase flow. Thermal-hydraulics of a horizontal steam generator in the WWER 1000 nuclear power plant has been simulated at the full load, steady-state operation. A comparison of the numerical results with data measured at the NPP Novovoronjezh shows good agreement. 3D numerical results can be used in plant design or retrofitting, in nuclear power plant operation and safety analysis and as improvement of existing one-dimensional thermal-hydraulics models of the horizontal steam generator which are assessed by system codes used for the nuclear power plant safety analyses. (author)

International Nuclear Information System (INIS)

Thermal diffusivity was measured with a laser flash method up to 2000 K for UO_2 pellets irradiated in a commercial reactor. Measurements were done on micro samples of disks (2 mm diameter) or regular prisms (1.5 or 2 mm square cross sections). Thermal diffusivity degraded on extending burnup in agreement with reported values for UO_2 irradiated in test reactors, and it showed hysteresis during the laser flash experiments. Thermal diffusivity began to recover above 750 K and almost completely recovered above 1400 K, which corresponded with the reported radiation damage recovery. The obtained data were in agreement with predictions applying the thermal conductivity expression for irradiated UO_2 proposed by Amaya and Hirai. The sample experiencing power ramp showed higher thermal diffusivity than that of the base irradiated sample and had no obvious hysteresis. ...

International Nuclear Information System (INIS)

This paper is concerned with the fracture analysis of thin cylindrical shells subject to secondary bending stresses with some degree of elastic follow-up. A P.Y.F.M. failure assessment route is utilised for an initial investigation. Results are presented graphically and indicate the differences obtained by considering the stresses as primary or secondary in nature. The Jsup(*) contour integral is computed from the results of a non-linear finite element analysis of a thermally loaded cracked cylinder. Comparison is made between Jsup(*) and the P.Y.F.M. failure criteria demonstrating the degree of conservatism in the latter. It is observed that LEFM may be appropriate for moderate load levels but that the elastic follow-up of the structure causes enhancement of Jsup(*) for higher loads, at which stage LEFM becomes non-conservative. (orig.).

International Nuclear Information System (INIS)

One of the limiting contributors to the heat load constraint for a long term spent fuel repository is the decay of americium-241. A possible option to reduce the heat load produced by Am-241 is to eliminate it via transmutation in a light water reactor thermal neutron environment, in particular, by taking advantage of the large thermal fission cross section of Am-242 and Am-242m. In this study we employ lattice loading optimization techniques to define the loadings and arrangements of fuel pins with blended americium and uranium oxide in boiling water reactor bundles, specifically, by defining the incineration of pre-loaded americium as an objective function to maximize americium transmutation. Subsequently, the viability of these optimized lattices is tested by assembling them into bundles with Am-spiked fuel pins and by ...

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

Experimental data on the material characteristics of structures subjected to thermal and mechanical cycling are needed for designing structural parts for creep and creep-fatigue interaction. Moreover, high-temperature low-cycle fatigue data are not sufficient to predict the fatigue creep lifetime. In order to check the reliability of steam generators, tests on pipe materials are conducted under cyclic thermal loading. The tests have been performed on an iron-nickel chromium alloy (alloy 800). Isothermal low-cycle fatigue tests have been conducted at 550 C. 15 refs.

Energy Technology Data Exchange (ETDEWEB)

A fast production scheduling algorithm suitable for generation expansion studies is described in this paper. It can handle several independent rivers, thermal plants, pumped storage plants, import, export, and internal non-firm markets. Inflows and load are deterministic and a one-reservoir limit is imposed on each river. The scheduling problem is formulated as a generalized network problem which is efficiently solved by an adaption of the simplex method. The algorithm is part of a program developed by Hydro-Quebec to conduct preliminary evaluations of alternative expansion plans. The program and the scheduling algorithm are presented.

Energy Technology Data Exchange (ETDEWEB)

Cooling of residential California buildings contributes significantly to electrical consumption and peak power demand mainly due to very poor load factors in milder climates. Thermal mass can be utilized to reduce the peak-power demand, downsize the cooling systems, and/or switch to low-energy cooling sources. Large thermal storage devices have been used in the past to overcome the shortcomings of alternative cooling sources, or to avoid high demand charges. The manufacturing of phase change material (PCM) implemented in gypsum board, plaster or other wall-covering material, would permit the thermal storage to become part of the building structure. PCMs have two important advantages as storage media: they can offer an order-of-magnitude increase in thermal storage capacity, and their discharge is almost isothermal. This allows the storage of high amounts of energy without ...

International Nuclear Information System (INIS)

Wood plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, and with Okoume (aucoumea klaineana pierre) imported to Syria in large quantities. Three monomer systems; acrylamide, butylmethacrylate, and styrene were used. polymerization was induced at various radiation doses (10, 20, and 30 kGy) to study the role of radiation doses using a "6"0Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength or tensile strength of the obtained wood polymer composites (WPC) were studied. The effect of the additives, sulfuric acid (H"+), N-vinyl pyrrolidone (NVP), trimethyolpropane triacrylate (TMPTA), urea (U), lithium nitrate (LiNo_3), copper sulfate (CuSO_4) and co-additives on monomer system polymerization were also investigated. Methanol, water and water/methanol mixtures were used as the swelling agents. In general, the use of ...

International Nuclear Information System (INIS)

The thermal properties of five types of radiation-induced wood-polymer composites based on a tropical hardwood, rubberwood (Hevea braziliensis), was studied by oxygen index measurement, differential thermal analysis (DTA) and thermogravimetry (TG). The DTA and TG curves of composites were different from those of rubberwood, which can be attributed to the presence of the incorporated polymers. Of the five composites, the one impregnated with bis(2-chloroethyl)vinyl phosphonate reduced the initial temperature of decomposition, increased the peak temperatures of exothermic reactions, and increased the char yield. Comparison with physical blends of rubberwood and the corresponding polymer provided some evidence of chemical interaction of wood and polymer in some of the composites. (author).

Science.gov (United States)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positioned in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts infrared radiation from the front of the ...

Energy Technology Data Exchange (ETDEWEB)

This invention is an improved solar energy cavity receiver for exposing materials and components to high temperatures. The receiver includes a housing having an internal reflective surface defining a cavity and having an inlet for admitting solar radiation thereto. A photothermal absorber is positiond in the cavity to receive radiation from the inlet. A reflective baffle is positioned between the absorber and the inlet to severely restrict the re-radiation of energy through the inlet. The front surface of the baffle defines a narrow annulus with the internal reflective surface of the housing. The front surface of the baffle is contoured to reflect incoming radiation onto the internal surface of the housing, from which it is reflected through the annulus and onto the front surface of the absorber. The back surface of the baffle intercepts radiation from the front of the absorber. ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The proton therapy gives an irradiation adapted to the shape and the depth of tumors ( eyes, head and neck) with a millimetric, even sub millimetric precision for the ophthalmological tumors. It is equally an excellent tool for the pediatrics tumors. For numerous treatments in France the proton therapy is associated to the photons treatments (x radiation). however, others physical treatments could modulate the medical offer, such thermal therapy or treatments by ultrasonic waves. (N.C.)

Science.gov (United States)

The performance of intermolecular potential models on the adsorption of benzene on graphitized thermal carbon black at various temperatures is investigated. Two models contain only dispersive sites, whereas the other two models account explicitly for the dispersive and electrostatic sites. Using numerous data in the literature on benzene adsorption on graphitized thermal carbon black at various temperatures, we have found that the effect of surface mediation on interaction between adsorbed benzene molecules must be accounted for to describe correctly the adsorption isotherm as well as the isosteric heat. Among the two models with partial charges tested, the WSKS model of Wick et al. that has only six dispersive sites and three discrete partial charges is better than the very expensive all-atom model of Jorgensen and Severance. Adsorbed benzene molecules on graphitized thermal carbon black have a complex orientation with ...

Energy Technology Data Exchange (ETDEWEB)

In order to establish the optimum fueling in a natural gas fueled dual fuel engine, tests were made for some operational parameters and their combination on the engine performances and the exhaust emissions. The results show that the gas oil quantity should be increased and gas oil injection timing should be advanced to suppress unburned hydrocarbon emission at middle and low output range, while the quantity should be reduced and the timing should be retarded to avoid onset of knock at high loads. The unburned hydrocarbon emission and the thermal efficiency are improved at the same load avoiding too lean natural gas premixture by restriction of intake charge air. However the improvement is limited because the ignition and initial combustion of pilot diesel fuel is deteriorated when the cylinder pressure is excessively lowered by throttling. The increase in pilot gas oil amount is effective for low-load ...

Energy Technology Data Exchange (ETDEWEB)

The necessary conditions to design the methanol-fueled direct injection diesel engine with a reservoir type glow plug were cleared up from the points of view to prevent the air contamination and to use as an alternative oil for automotives, and as a result the good engine performance and emission characteristics could be obtained under the wide operating condition. The following facts were clarified: It is necessary to arrange the glow plug on the line of atomizing axis near the nozzle hole to ensure the ignitability under a wide operating condition. The reservoir type glow plug which reserves the premixed gas around the glow plug can shorten the ignition delay time and improve the combustion stability and the net thermal efficiency in the light load region. The combustion in the light load region was accelerated, NO{sub x} emission rate was suppressed and moreover, the net thermal efficiency and ...

Science.gov (United States)

The effect of aerosol on clouds poses one of the largest uncertainties in estimating the anthropogenic contribution to climate change. Small human-induced perturbations to cloud characteristics via aerosol pathways can create a change in the top-of-atmosphere radiative forcing of hundreds of Wm-2. Here we focus on links between aerosol and deep convective clouds of the Atlantic and Pacific Intertropical Convergence Zones, noting that the aerosol environment in each region is entirely different. The tops of these vertically developed clouds consisting of mostly ice can reach high levels of the atmosphere, overshooting the lower stratosphere and reaching altitudes greater than 16 km. We show a link between aerosol, clouds and the free atmosphere wind profile that can change the magnitude and sign of the overall climate radiative forcing. We find that increased aerosol loading is associated with taller cloud towers and ...

Energy Technology Data Exchange (ETDEWEB)

This paper describes the basic principles underlying the operation of low heat loss engines and the magnitude of the efficiency improvements that are theoretically achievable. The effect of varying degrees of thermal insulation on various operating parameters is examined in some detail, as is the relationship between degree of insulation and ceramic coating thickness. The effect on ceramic materials of severe surface temperature oscillations and the resultant thermal stress gradients is also discussed. In the following section, the paper describes methods of construction adopted both for ceramic inserts and coatings, and rig tests for the assessment of thermal fatigue under both load and firing cycling. The paper does not attempt to draw any general conclusions.

International Nuclear Information System (INIS)

In order to study the boundary conditions for the occurrence of ratcheting, a testing rig was erected. In this rig, small-scale mock-ups of the first wall were tested under mechanical conditions similar to those expected during disruptions. These mock-ups were made of stainless steel AISI 316. They were heated on the surface and water cooled from inside. Disruption forces were simulated by a high-speed hydraulic bending system by impact loads. The mock-ups were heated by a high-frequency generator and cooled by water through two cooling channels.In addition to the experimental work, simplified analytical analysis and numerical calculations were carried out using the finite element program ABAQUS. In these calculations, the temperature and stress fields in the mock-ups were investigated and the influence of the different constitutive equations was studied.The experimental results confirm the ratcheting behaviour predicted by the calculations. It has been ...

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 loss. A proposed convective heat loss correlation, including ...

Energy Technology Data Exchange (ETDEWEB)

The chain of eddy current probes and a film cassette probe, which responds to radiation from a radio-active source in one of the heat exchanger pipes is examined. The probes are moved by nylon pipes on both ends of the chain through the pipe to be examined. The nylon pipes are bent off load. In this way the probes on the chain will adjust near to the plane of bending of the pipes to be tested.

Energy Technology Data Exchange (ETDEWEB)

Pilot-plant irradiation began in Hungary in 1969 with the construction of a high-activity multi-purpose /sup 60/Co facility. Technologies for radiation sterilization, food handling, plastics irradiation as well as chemical dosimetry, semiconductor instrumental dosimetry, computer-based construction and control methods have been developed. Our chlorobenzene dose-meter system is used in Hungary and abroad; as a result of an IAEA-organized dosimetric intercomparison the system was adopted as a reference system. The institute has developed into a basic institute for the reconstruction and re-load of old ..gamma..-facilities as well as it serves for the planning, construction and launching of new ones in Hungary.

Energy Technology Data Exchange (ETDEWEB)

A wider use of renewable energy sources is considered to be the solution to fossil fuel depletion and environmental pollution. This paper discusses various design considerations for line focussing technology to achieve high efficiency and the possibility of generating power in the megawatt range based on solar thermal technologies. The impacts on the environment of conventional thermal power plants is outlined and an estimate made of the cost of pollution abatement measures. A cost benefit analysis is made using a typical 200 megawatt solar thermal plant, 500 km from the load centre, compared with a 220 megawatt coal fired and a similar capacity gas fired power plant, as examples. The results indicated that the energy from the solar thermal power plant is almost twice as expensive compared to conventionally generated electricity. If, however, impacts on the environment and notional ...

Energy Technology Data Exchange (ETDEWEB)

The thermomechanical behaviour of clayey soils was examined in a laboratory study because of their importance in some engineering applications such as hydrocarbon extraction from oil-bearing sands and radioactive waste disposal. The slightest temperature variations have been known to have an impact on the mechanical behaviour of clayey soils. In this study, tests were conducted on reconstituted and natural clayey soils using triaxial cells modified to control temperatures. Changes of temperature and stress state were not applied simultaneously. Instead, the tests were divided into two separate sections aimed at studying the thermal and mechanical behaviour of clays. The thermal behaviour tests examined the deformations induced by drainage temperature changes as well as pore-pressure generation and consolidation phenomena. The mechanical behaviour tests, focused on the influence of temperature and temperature history on compressibility, ...

British Library Electronic Table of Contents (United Kingdom)

In this article, the authors analyzed the effect of thermal conductivity on unsteady magnetohydrodynamic (MHD) free convection in a micro-polar fluid past a semi-infinite vertical porous plate. The fluid thermal conductivity is assumed to vary as a linear function of temperature. By using the Chebyshev collocation method in the spatial direction and the Crank-Nicolson method in the time direction, the boundary layer equations are transformed into a linear algebraic system. There are several material parameters whose affect on the flow have been studied, for instance, thermal conductivity, radiation, magnetic, micro-polar, suction (or injection) parameters, and Prandtl number. Boundary layer and Boussineq approximations have been introduced together to describe the flow field. The domain of...

International Nuclear Information System (INIS)

The major degradation mechanisms acting during the aging of selected WWER-440/213 primary circuit facilities were assessed critically. The analysis gave evidence that such mechanisms include radiation and fatigue damage of the reactor pressure vessel (effect of the neutron flow, cyclic fatigue promoted by the corrosive medium, effect of thermal aging), corrosion-mechanical and thermo-mechanical (fatigue) damage of the steam generator (stress corrosion cracking, erosion corrosion, thermal aging, wear), thermal and dynamic aging of the pressurizer, and corrosion-mechanical damage of the primary circuit piping (thermal aging, corrosion). (J.B.). 5 tabs., 1 fig., 62 refs.

International Nuclear Information System (INIS)

Radiation damage of the final optical components in an Inertial Confinement Fusion (ICF) reactor is a crucial issue for development of a laser-fusion reactor. To some extent, this problem will be encountered in the National Ignition Facility (NIF), but there, the integrated radiation dose will be considerably less than that encountered in a future reactor. This extremely harsh radiation environment necessitates shielding the ICF optics from direct neutron and x-ray bombardment. Several approaches have been suggested, such as the use of grazing incidence metal mirrors or fused silica wedge deflectors. While metal mirrors can withstand a larger radiation dose, their focusing qualities pose problems. Therefore wedge deflectors, originally suggested by Lawrence Livermore National Laboratory (LLNL) staff, represent a promising alternative. Radiation hardening of the fused silica ...

International Nuclear Information System (INIS)

The determination of the oxidation state of ultra-trace elements in the environment, especially in the case of actinides, is of importance in many ways. Speciation techniques using radiation may comprise methods based on the detection of the nuclear and atomic radiations emitted in radioactive decay or methods using external sources of excitation. In the former instance, information can be obtained from the energy and intensity of radiation, but at present the partition method is still the most commonly used, although its reliability is questionable. Excitation with intense laser beams, as is currently being used for trace element analysis in photoacoustic and thermal lensing spectroscopic techniques, could conceivably be applied under suitable conditions to ultra-trace elements with a sensitivity approaching that of the radiochemical methods.

British Library Electronic Table of Contents (United Kingdom)

A highly efficient integrated energy conversion system is built based on a methane catalytic decomposition reactor (MCDR) together with a direct carbon fuel cell (DCFC) and an internal reforming solid oxide fuel cell (IRSOFC). In the MCDR, methane is decomposed to pure carbon and hydrogen. Carbon is used as the fuel of DCFC to generate power and produce pure carbon dioxide. The hydrogen and unconverted methane are used as the fuel in the IRSOFC. A gas turbine cycle is also used to produce more power output from the thermal energy generated in the IRSOFC. The output performance and efficiency of both the DCFC and IRSOFC are investigated and compared by development of exact models of them. It is found that this system has a unique loading flexibility due to the good high-loading property of ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents a novel domestic hot water heater model to be used in a multi-objective demand side management program. The model incorporates both the thermal losses and the water usage to determine the temperature of the water in the tank. Water heater loads are extracted from household load data and then used to determine the household water usage patterns. The benefits of the model are: (1) the on/off state of the water heater and temperature of the water in the tank can be accurately predicted, and (2) it enables the development of water usage profiles so that users can be classified based on usage behaviour. As a result, the amount of ancillary services and peak shaving that can be achieved are accurately predictable and can be maximized without adversely affecting users. (author)

International Nuclear Information System (INIS)

Three-dimensional computer simulation and analyses of the horizontal steam generator thermal-hydraulics of the WWER 1000 nuclear power plant have been performed for 50% and 75% partial loads, 100% nominal load and 110% over-load. Presented results show water and steam mass flow rate vectors, steam void fraction spatial distribution, recirculation zones, swell level position, water mass inventory on the shell side, and other important thermal-hydraulic parameters. The simulations have been performed with the computer code 3D ANA, based on the 'two-fluid' model approach. Steam-water interface transport processes, as well as tube bundle flow resistance, energy transfer, and steam generation within tube bundles are modelled with "closure laws". Applied approach implies non-equilibrium thermal and flow conditions. The model is solved by the control volume procedure, ...

International Nuclear Information System (INIS)

Else of solar energy as substitute for conventional fuels at a competitive cost requires efficient conversion from solar radiation to usable forms of energy. In solar thermal or thermochemical applications, high efficiency usually re- quires high temperature and high concentration of incoming radiation. The main form of energy loss from high temperature solar central receivers is thermal emission ('re radiation'), at an effective temperature close to the maximum receiver temperature. This loss is reduced if the aperture is divided into segments, most of which are maintained at lower temperatures. A two-stage partitioned receiver demonstrating this concept is under construction at the Weizman Solar Tower. The high-temperature stage is the DIAPR (Directly Irradiated Annular Pressurized Receiver). The low-temperature stage is made of tubular cavity receivers of simpler design. ...

Energy Technology Data Exchange (ETDEWEB)

Partial combustion of biomass in the gasifier generates producer gas that can be used for heating purposes and as supplementary or sole fuel in internal combustion engines. In this study, the potential of coir-pith and wood chips as the feedstock for gasifier is analyzed. The performance of the gasifier-engine system is analyzed by running the engine for various producer gas-air flow ratios and at different load conditions. The system is experimentally optimized with respect to maximum diesel savings and lower emissions in the dual fuel mode operation while using coir-pith and wood chips separately. The performance and emission characteristics of the dual fuel engine are compared with that of diesel engine at different load conditions. Specific energy consumption in the dual fuel mode of operation is found to be in the higher side at all load conditions. The brake thermal efficiency of the engine while ...

Energy Technology Data Exchange (ETDEWEB)

Sheep red blood cells (SRBCs) were labelled with a concanavalin A-luminol-bovine serum albumin conjugate specific for the transmembrane anion transport protein (Band 3) and exposed to 2450-MHz continuous-wave microwave radiation at an average specific absorption rate of 91W/kg for 10 min. The temperature was held constant at 25, 37, 40, 42, or 45C with an airflow heat-exchange system. Following exposure to microwave or air heating, the decrease in residual base-activated chemiluminescence (CL) of the SRBCs was measured as an indication of infield oxidase activity. Air heating resulted in a significant decrease in residual CL at temperatures above 37C (74% decrease at 45C). Microwave radiation inhibited the decline in residual CL above 37C. At 45C the inhibition was 40%. The results suggest microwave radiation either reversibly altered the thermodynamics of oxygen binding to haemoglobin or failed to energize a significant ...

Energy Technology Data Exchange (ETDEWEB)

The dosimetry for radiotherapy involving neutrons is very complicated, owing to the complexity of secondary radiation components, whose contributions to the total absorbed dose have to be discriminated, owing to the different radiobiological effects. In order to separate thermal neutrons and photons, LiF dosimeters are mostly utilized. containing different percentage of Li, like as TLD-700, TLD-100 and TLD-600, but many problems arise. In the response of TLD-700 exposed to neutron-gamma mixed fields with high neutron flux, the contribution of thermal neutrons to the Tl emission is high. Moreover. TLD-100 and TLD-600 may undergo radiation damage, and great care has to be taken in order to obtain reliable results. Other TLDs showing lower sensitivity to neutrons are proposed and experimented for such high-flux neutron fields. The faced problems and various proposed solutions are here described. (Author)

British Library Electronic Table of Contents (United Kingdom)

An analysis is presented for the effects of chemical reaction and thermal radiation on hydromagnetic free convection heat and mass transfer for a micropolar fluid via a porous medium bounded by a semi-infinite vertical porous plate in the presence of heat generation. The plate moves with a constant velocity in the longitudinal direction and the free stream velocity follows an exponentially small perturbation law. A uniform magnetic field acts perpendicularly to the porous surface in which absorbs the micropolar fluid with a suction velocity varying with time. Analytical expressions are computed numerically. Numerical calculations are carried out the purpose of the discussion of the results which are shown on graphs and the effects of the various dimensionless parameters entering into the p...

British Library Electronic Table of Contents (United Kingdom)

Temperature variations due to climate changes are a major cause of movements in a concrete structure, both in the longitudinal and transversal directions and between different parts of the structure. If these movements are restrained, stresses will be induced which may contribute to cracking. The movements are caused by complex interactions of several factors such as solar radiation, air temperature, long-wave heat radiation and wind speed. To predict the varying thermal conditions in a concrete structure a finite element model has been used. A validation of the model has been performed using field measurements in a concrete slab together with climate data from the Swedish Meteorological and Hydrological Institute to be able to use the model for simulations over long time periods and for s...

International Nuclear Information System (INIS)

The #gamma#-radiation following thermal neutron capture in "1"0"0Mo has been studied by singles and coincidence measurements. A "1"0"1Mo level scheme has been deduced and is compared with the results of previous (d,p), (n,#gamma#) and "1"0"1Nb decay studies. The existence of the first excited state at 13.51 keV has been confirmed. The present data yield a neutron binding energy of 5398.4 KeV. (Auth.).

Energy Technology Data Exchange (ETDEWEB)

Hard surface finishing represents the final manufacturing step for functional areas of machine elements in state-of-the-art production. Raceways of rolling bearing rings are ground and honed to the required low roughness. Plastic deformation is restricted to a narrow edge zone of the hardened steel. Reheating of the machined components below the martensite tempering or bainite transformation temperature results in a marked decrease of the XRD line width on the surface. The investigated samples are made of through-hardened standard bearing steel 100Cr6 (international denotation: SAE 52100). On the basis of a material model that explains the effect as a complex diffusion process of dislocational carbon segregation, i.e. static strain aging, the measured kinetics of the XRD line width reduction is simulated by an Arrhenius-type equation, which describes the rate-controlling reaction step of temper carbide dissolution. The formation of a small white-etching surface layer of around 1 um ...

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

The present contribution focuses on the input side of individual process techniques. It shows on the basis of example calculations how two parameters describing the incinerable (residual) waste that are of particular importance for unconventional thermal treatment methods, namely ``pollutant load`` and ``calorific value``, can be influenced by a recycling stage and then further by mechanical-biological pretreatment. [Deutsch] Im folgenden soll das Hauptaugenmerk auf die Inputseite zu den einzelnen thermischen Verfahren gelegt werden und anhand einer Beispielrechnung aufgezeigt werden, wie sich die fuer einen Einsatz in nichtkonventionellen thermischen Verfahren besonders wichtigen Parameter des aufbereiteten (Rest)Abfalls `Schadstoffbelastung` und `Heizwert` zunaechst durch eine Verwertung und weiter durch eine mechanisch-biologische Vorbehandlung veraendern. (orig./SR)

Energy Technology Data Exchange (ETDEWEB)

The authors have measured the noise of MOS transistors of the United Technology Microelectronics Center (UTMC) 1.2 [mu]m radiation hardened CMOS P-well process from the weak to moderate inversion region. The noise power spectral densities of both NMOS and PMOS devices were measured from 1 KHz to 50 MHz. The bandwidth was chosen such that the important components of the spectral densities such as the white thermal noise and the 1/f noise could be easily resolved and analyzed in detail. In this paper the effects of different device terminal DC biases and channel geometries on the noise are described.

Science.gov (United States)

The present contribution deals with the thermophoresis particle deposition and thermal radiation effects on the flow, heat and mass transfer characteristics in a viscous fluid over a semi-infinite vertical porous plate. The governing boundary layer equations are written into a dimensionless form by similarity transformations. The transformed coupled nonlinear ordinary differential equations are solved numerically by means of the fourth-order Runge-Kutta method with a shooting technique. The effects of different parameters on the dimensionless velocity, temperature, and concentration profiles are shown graphically. In addition, results for the local skin-friction coefficient, the local Nusselt number, and the local Sherwood number are tabulated and discussed.

Energy Technology Data Exchange (ETDEWEB)

Hydrogen piston engines can be simultaneously optimized for improved thermal efficiency and for extremely low emissions. Using these engines in constant-speed, constant-load systems such as series hybrid-electric automobiles or home cogeneration systems can result in significantly improved energy efficiency. For the same electrical energy produced, the emissions from such engines can be comparable to those from natural gas-fired steam power plants. These hydrogen-fueled high-efficiency, low-emission (HELE) engines are a mechanical equivalent of hydrogen fuel cells. HELE engines could facilitate the transition to a hydrogen fuel cell economy using near-term technology.

Energy Technology Data Exchange (ETDEWEB)

The Wendelstein 7-X (W7-X) modular stellarator is under construction at the Max-Planck-Institut fuer Plasmaphysik in Greifswald, Germany. The W7-X magnet system contains 70 coils made up from helium cooled superconducting cables in aluminium alloy (EN AW-6063) jackets. Several hundred connections of the jacket to the cable joints are made by aluminium-to-aluminium welds. Due to geometrical and thermal boundary conditions these welds cannot be accomplished free from defects. Microscopic analyses of the welds show that a variety of small flaws such as cracks and pores develop during welding. The welds have thus to be dimensioned accordingly, and appropriate weld qualification, investigation and testing has to be done in order not to jeopardise the structural integrity and leak tightness. The weld is mechanically loaded during cool-down due to the difference in thermal contractions between the GRP insulation and the aluminium, ...

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The magnetically controlled plasma opening switch (MCPOS) is an advanced plasma opening switch that utilizes magnetic fields to improve operation. Magnetic fields always dominate terawatt, pulsed power plasma opening switches. For that reason, the MCPOS uses controlled applied magnetic fields with magnitude comparable to the self-magnetic field of the storage inductor. One applied field holds the plasma in place while energy accumulates in the storage inductor, then another applied field pushes the plasma away from the cathode to allow energy to flow downstream. Over a ten month period, an MCPOS was designed, built, and tested on DECADE Module 2 at Physics International. The peak drive current was 1.8 MA in 250 ns. The output parameters were up to 1 MA into an electron beam load. The radiation temporal pulse width averaged 60 nanoseconds full-width at half-maximum. The peak load voltage ranged from one to two megavolts. The ...

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The thermal analysis of a turbine stack discharging exhaust gases to the atmosphere is presented. The examined turbine stack belongs to a gas lift plant for oil extraction located in the Gulf area. The analysis has been performed because an overheating of the anchor flange/bolts and of the concrete foundation occurred and caused small cracks in the upper layer of the foundation. A qualitative thermal analysis of the stack has pointed out that the main cause of the overheating was the thermal radiation in the air-filled region underneath the stack bottom plate. Detailed calculations performed by using a CFD code (Fluent ver. 6.0.12), cross-checked with measurements taken from site, have shown that a significant reduction of the heat flux to the foundation could be obtained by filling the above mentioned air region with an insulating material. The benefits of this solution are prevailing over those ...

International Nuclear Information System (INIS)

Some results on mechanical property study of copper and titanium subjected to impact load and next to neutron irradiation are presented. It was shown that shock wave influence involves a substantial shape change of the stress-strain diagram and of respective mechanical characteristics. Yield- and ultimate strength were substantially increased, as well as hardness with a considerable drop of plasticity. Also a heat stability of copper and titanium specimens was studied after being treated with shock-waves and neutron radiation. Results are given of electron microscope study of titanium structure sfter explosion hardening, which caused decomposition of hydride segregations in titanium and increased dislocation density.

Energy Technology Data Exchange (ETDEWEB)

Multilayer mirrors for the extreme ultraviolet (EUV) are keyelements for numerous applications of coherent EUV sources such as newtabletop lasers and free-electron lasers. However the field ofapplications is limited by the radiation and thermal stability of themultilayers. Taking into account the growing power of EUV sources thestability of the optics becomes crucial. To overcome this problem it isnecessary to study the degradation of multilayers and try to increasetheir temporal and thermal stability. In this paper we report the resultsof detailed study of structural changes in Sc/Simultilayers when exposedto intense EUV laser pulses. Various types of surface damage such asmelting, boiling, shockwave creation and ablation were observed asirradiation fluencies increase. Cross-sectional TEM study revealed thatthe layer structure was completely destroyed in the upper part ofmultilayer, but still survived below. The layers ...

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Synthesis of silver nanoparticles based on a polyol process and variable frequency microwave (VFM) was investigated. Comparing to a thermal method, the reaction by VFM radiation was much faster. The effects of silver nitrate concentration, poly(N-vinylpyrrolidone) (PVP) concentration, reaction time and reaction temperature were studied. It was found that the higher concentration of silver nitrate, longer reaction time and higher temperature increased the particle size while the higher concentration of PVP decreased the particle size.

International Nuclear Information System (INIS)

We discuss the use of active control to reduce mirror position fluctuations at the quantum level. We have shown in a recent experiment that it is possible to reduce the thermal noise of a mirror by measuring and controlling its motion with an optomechanical sensor based on a high-finesse optical cavity. This approach can be extended to lock the mirror motion at the quantum level, and to suppress the quantum effects of radiation pressure in interferometric measurements such as gravitational-wave detectors. The sensitivity improvement is furthermore independent of losses in the interferometer.

Energy Technology Data Exchange (ETDEWEB)

This paper presents the experimental measurements of the transmittivity of commercial grade stearic acid. The effects of temperature and thickness on transmittance have been studied. The study indicates that the effect of temperature on the transmittance of stearic acid in the liquid phase is not significant. However, it is highly dependent on temperature during the solidification process. Because of its low thermal conductivity and high transmittivity, it can be used as a transparent insulating material. (Author)

Energy Technology Data Exchange (ETDEWEB)

A thermal-resistant radiation sensing system using optical fiber has been developed. The system is for monitoring progress of chemical decontamination and able to measure the gamma-ray level in a hot solution of decontamination chemicals in situ. Our sensor head makes use of thermal-resistant NaI (T1) and it is connected to an optical fiber bundle. Scintillation photons pass from the NaI (T1) into the end of the bundle. This part of the system can withstand temperatures of over 100degC. At the far end of the optical fiber bundle, the scintillation photons are converted into fluorescent photons using a wavelength-shifting fiber. These photons are transferred to a distant photomultiplier tube through two thin transparent optical fibers. Furthermore, we propose a self-compensation technique for the dependence of scintillator sensitivity on. This compensation method is based on the correlation between temperature, sensitivity, ...

Energy Technology Data Exchange (ETDEWEB)

The trade-off which must be established between the various functions of pumped-storage plants is examined. A compromise between supply security and economic planning can be found only by coordinated planning of pumped-storage units and thermal generation plants. A model used by Electricite de France (EDF) to ensure optimized daily planning of thermal and pumped-storage units is described. The model, called the DEMETER model, ensures the optimization of the daily planning of thermal and pumped-storage plants. The model iterates between two levels: coordination where the prices of the generated energy and the operating reserve are determined to adjust generation to load and keep a sufficient reserve; and decomposition where the schedule of each unit is optimized on the basis of the above prices and taking into account local constraints such as unavailability, and minimum shut down time. The role of EDF ...

Energy Technology Data Exchange (ETDEWEB)

Two types of thermal control materials based on polyimide film UPILEX-R are designed. One of thermal control material R/Al is coated with Al on the back surface. The other of thermal control material TCC/R/Al is coated with transparent conductive coating on the font surface and is coated with Al on the balk surface. The solar absorptance is measured spectroscopically with an integrating sphere in the wavelength region of 0.26 - 2.50 {mu}m and the total hemispherical emittance is measured calorimetrically in the temperature range of -100-+100{degree}C for the present thermal control materials. To evaluate the space degradation of optical properties (refractive index, extinction coefficient, absorption coefficient) on UPILEX-R film and solar absorptance on thermal control materials, space environment simulation tests are performed on the ground with independent ...

Energy Technology Data Exchange (ETDEWEB)

Rhodium (Rh) is a critical component of current automotive three-way catalysts (TWCs), particularly with regard to NO{sub x} and CO conversion at rich and stoichiometric air-fuel ratios (A/F). Rh supported on CeO{sub 2} was active for NO{sub x} and CO conversions but could be deactivated easily by high temperature aging. The cause of the deactivation is ascribed to the sintering of CeO{sub 2}. ZrO{sub 2} incorporation into CeO{sub 2} is reported to have high thermal durability in terms of oxygen storage capacity (OSC). There has been no report showing direct experimental evidence that Rh-loaded on CeO{sub 2}-ZrO{sub 2} mixed oxides induced effects on TWC performance improvement in the actual automotive exhaust. In the present paper, the Rh-CeO{sub 2} interaction contributing to NO{sub x} reduction and the catalytic behavior of Rh-loaded CeO{sub 2}-ZrO{sub 2} mixed oxide is addressed. Incorporating CeO{sub 2}-ZrO{sub 2} into ...

Energy Technology Data Exchange (ETDEWEB)

A joint US/Russia program is being conducted to develop, fabricate, launch, and operate a solar dynamic demonstration system on Space Station Mir. The goal of the program is to demonstrate and confirm that solar dynamic power systems are viable for future space applications such as the International Space Station Alpha. The major components of the system include a heat receiver, a closed Brayton cycle power conversion unit, a power conditioning and control unit, a concentrator, a radiator, a thermal control system, and a Space Shuttle carrier. This paper discusses the design of the heat receiver component. The receiver comprises a cylindrical cavity, the walls of which are lined with a series of tubes running the length of the cavity. The engine working fluid, a mixture of xenon and helium, is heated by the concentrated sunlight incident on these tubes. The receiver incorporates integral thermal storage, using a eutectic ...

Science.gov (United States)

A paraboloidal dish solar thermal power plant produces electrical energy by a two-step conversion process. The collector subsystem is composed of a two-axis tracking paraboloidal concentrator and a cavity receiver. The concentrator focuses intercepted sunlight (direct, normal insolation) into a cavity receiver whose aperture encircles the focal point of the concentrator. At the internal wall of the receiver the electromagnetic radiation is converted to thermal energy. A heat engine/generator assembly, which is mounted directly behind th receiver, then converts the thermal energy captured by the receiver to electricity. Developmental activity has been concentrated on relatively small power modules which employ 11- to 12-m-diam dishes to generate nominal power levels of approximately 20 kW. A comparison of advanced heat engines for use on the dish power module is presented in terms of the performance ...

Science.gov (United States)

We model nongraphitized carbon black surfaces and investigate adsorption of argon on these surfaces by using the grand canonical Monte Carlo simulation. In this model, the nongraphitized surface is modeled as a stack of graphene layers with some carbon atoms of the top graphene layer being randomly removed. The percentage of the surface carbon atoms being removed and the effective size of the defect (created by the removal) are the key parameters to characterize the nongraphitized surface. The patterns of adsorption isotherm and isosteric heat are particularly studied, as a function of these surface parameters as well as pressure and temperature. It is shown that the adsorption isotherm shows a steplike behavior on a perfect graphite surface and becomes smoother on nongraphitized surfaces. Regarding the isosteric heat versus loading, we observe for the case of graphitized thermal carbon black the increase of heat in the submonolayer coverage ...

Energy Technology Data Exchange (ETDEWEB)

This analysis is one of 10 reports that support the Environmental Radiation Model for Yucca Mountain, Nevada (ERMYN) biosphere model. The ''Biosphere Model Report'' (BSC 2004 [DIRS 169460]) describes in detail the conceptual model as well as the mathematical model and its input parameters. This report documents development of input parameters for the biosphere model that are related to atmospheric mass loading and supports the use of the model to develop biosphere dose conversion factors (BDCFs). The biosphere model is one of a series of process models supporting the total system performance assessment (TSPA) for a Yucca Mountain repository. Inhalation Exposure Input Parameters for the Biosphere Model is one of five reports that develop input parameters for the biosphere model. A graphical representation of the documentation hierarchy for the ERMYN is presented in Figure 1-1. This figure shows the ...

Energy Technology Data Exchange (ETDEWEB)

Previous research has shown that SAR hotspots are induced within the laboratory rat and that the resulting thermal hotspots are not entirely dissipated by bloodflow. Two experiments were conducted to determine if hotspot formation in the body and tail of the rat, which is radiation frequency specific, would have behavioral consequences. In the first experiment rats were placed in a plexiglas cage one side of which, when occupied by the rat, commenced microwave radiation exposure; occupancy of the other side terminated exposure. Groups of rats were tested during a baseline period to determine the naturally preferred side of the cage. Subsequent exposure to 360-MHz, 700-MHz or 2450-MHz microwave radiation was made contingent on preferred-side occupancy. A significant reduction in occupancy of the preferred side of the cage, and hence, microwaves subsequently occurred. Reduced exposure to 360-MHz and ...

Energy Technology Data Exchange (ETDEWEB)

Fine ceramics center (JFCC) succeeded in the higher precision of thermal diffusivity measurement by the laser flash. This results are part of 'the research on thermophysical property measurement technique and standard substance of the functional material' by the intelligent establishing of a base promotion system of Science and Technology Agency. Cooperative research. thermal diffusivity with Natl. Res. Lab. of Metrology is one of the representative thermophysical property. The speed in which a heat transmits of the material is shown, and it is indispensable to the design of the high-temperature member subject. JFCC heralds the world as a standard substance for the thermal diffusivity measurement; 'TD-AL' using the alumina material is developed and is supplied in the spring in last year. Laser flash which uses laser beam for the heat source is general for the measurement. However, there ...

Energy Technology Data Exchange (ETDEWEB)

The fuel-injection system of the Niigata 6L 16X-AG dual-fuel engine is structured to steadily supply injected fuel during diesel-engine operation, and to distribute oil at a low rate to all the cylinders during gas-engine operation. The dual-fuel engine is started by the diesel engine operation and is changed over to gas-engine operation when the load increases. This change over is done automatically with a link mechanism. Regarding the gas-supply system, the changing pressure of supply gas is controlled by a pressure control valve which is stable and most adequate for the engine. The dual-fuel engine has the following features: (1) a high compression ratio is adopted, which reduces fuel consumption and thermal efficiently; (2) if the supply of gas decreases or stops, while continuing loaded operations, it can immediately shift to diesel engine operation automatically and continue the operation; (3) ignition is done by the ...

Science.gov (United States)

The millimeter microwave source of gyrotron-traveling-wave amplifier (gyro-TWT) is capable of generating high power coherent radiation in a broad bandwidth, while its performance is severely deteriorated by the stability problems. This paper focuses on modeling and the stability analysis of the Naval Research Laboratory (NRL) Ka-band TE{sub 01} mode gyro-TWT based on an interaction circuit alternately loaded with lossy ceramic shells and metal rings. The propagation characteristics of the interaction circuit is analyzed first, based on which the boundary impedance method is employed to build an equivalent uniform lossy circuit. Then the stability of the interaction system is studied using linear and nonlinear theories. The analysis reveals that, due to the special waveguide structure and the dielectric loss, the propagation characteristics of the complex waveguide are similar to that of a uniform lossy circuit. The analysis of the absolute ...

British Library Electronic Table of Contents (United Kingdom)

A mission to the surface of Venus would have high scientific value, but most electronic devices and sensors cannot operate at the 450degreeC ambient surface temperature of Venus. Power and cooling systems were analyzed for Venus surface operation. A radioisotope power and cooling system was designed to provide electrical power for a probe operating on the surface of Venus. For a mission duration of substantial length, the use of thermal mass to maintain an operable temperature range is likely impractical, and active refrigeration may be required to keep components at a temperature below ambient. Due to the high thermal convection of the high-density atmosphere, the heat rejection temperature was assumed to be at a 500degreeC radiator temperature, 50degreeC above ambient. The radioisotope S...

International Nuclear Information System (INIS)

The two most important issues in designing future gravitational wave interferometric detectors are, in our opinion, thermal and optical noise. In this paper we discuss some approaches for reducing these noises. About thermal noise we show a possible cryogenic solution. About optical noise (namely, the combined effect of shot noise and radiation pressure noise) we show that it is possible to apply a recently proposed reduction strategy based on a 'quantum feedback' (Courty et al 2003 Phys. Rev. Lett. 90 083601; Courty et al 2003 Preprint gr-qc/0301068) to a full Fabry-Perot cavity. This can be seen as a further step towards the practical realization of a detector which is able to evade the standard quantum limit.

Energy Technology Data Exchange (ETDEWEB)

Both simulations and recent experiments conducted at the Advanced Photon Source showed that the performance of liquid-nitrogen-cooled single-silicon crystal monochromators can degrade in a very rapid nonlinear fashion as the power and for power density is increased. As a further step towards improving the performance of silicon optics, we propose cooling with liquid helium, which dramatically improves the thermal properties of silicon beyond that of liquid nitrogen and brings the performance of single silicon-crystal-based synchrotrons radiation optics up to the ultimate limit. The benefits of liquid helium cooling as well as some of the associated technical challenges will be discussed, and results of thermal and structural finite elements simulations comparing the performance of silicon monochromators cooled with liquid nitrogen and helium will be given.

Energy Technology Data Exchange (ETDEWEB)

With the combination of source ventilation and ceiling cooling for air-conditioning of working and recreation rooms, a ventilation system is available which fulfills the highest demands regarding thermal comfort. In order to utilize the advantages of this ventilation system with regard to air quality and thermal comfort to an optimum, the influence of the radiation exchange between cooling ceiling and walls on the flow in the room is investigated experimentally. Energy transfer from the walls to the cooled ceiling may result in an insufficient temperature of the walls compared to ambient air and in an upward flow on the wall surfaces (downward flow of) driven by gravity, which influences the flow pattern in the case of source ventilation. (orig.)

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

A singular stress field can occur at the edge of the joint plane in a thermally or mechanically loaded material compound. This stress field was calculated analytically and was compared with the results from the finite element method. If one of the two partners consists of ceramic material, unstable crack spread starting from faults in this strongly stressed area can lead to failure. In linear elastic material, the behaviour of a crack is clearly described by the stress intensity factors. These can be calculated for a known stress distribution in the uncracked structure by the method of the weight function. The corresponding weight functions for surface cracks parallel to the boundary surface were determined with the aid of suitable reference load cases. The effect of the position of the crack in the compound and the elastic constants of the compound are discussed. For examples, the stress intensity factors for cracks in a ...

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 heat flow sensor, was calibrated with ...

British Library Electronic Table of Contents (United Kingdom)

The effects of thermal radiation and viscous dissipation on magneto-hydrodynamic (MHD) unsteady free-convection flow over a semi-infinite vertical porous plate are analysed. The fluid considered is non-gray (absorption coefficient dependent on wave length). The Network Simulation Method is used to solve the boundary-layer equations based on the finite-difference formulation; only discretization of the spatial co-ordinates is necessary, while time remains as a real continuous variable. This method provides a solution for both transient and steady-state problems at the same time, and programming does not require manipulation of the sophisticated mathematical software that is inherent in other numerical methods. The velocity, temperature, local skin-friction and local Nusselt number are studi...

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The need to increase efficiency of volumetric receivers for use in solar power plants by reducing reradiation losses and increasing the ``volumetric effect`` has promoted the idea of a receiver with tapered ducts. These seems to be very promising since higher efficiency and considerable saving of material can be achieved, as compared to conventional receivers perforated with ducts of constant cross-section. A finite element program is being developed to calculate stationary heat transfer in the tapered ducts by free and forced convection in the gas flow, conduction in walls and in the gas, and solar and thermal radiation. Gas and wall temperatures are considered to be varying only in the flow direction. In order to perform the highly nonlinear calculations of radiative exchange, the exact knowledge of the view factors is necessary. The aim of the present work is to evaluate analytically the view factors in tapered ducts.

Energy Technology Data Exchange (ETDEWEB)

In the context of the special research area 561 (Thermally highly loaded, open-porous and cooled multi-layer systems for combined-cycle power stations), the actual technical and scientific realizations are to be extended and new scientific bases are to be created in order to realize total efficiencies of 65 %. In addition, innovative material solutions and new concepts must be compiled for the cooling and drainage. Under this aspect, the author of the contribution under consideration reports on the development of open-porous multi-layer systems for steam turbines of the 700 C technology. It results an efficiency potential of 12 % and a potential of 15 % with the reduction of CO{sub 2} in relation to the actual state of the art. Thereby, the potential of future combined-cycle power stations is not yet exhausted.

Science.gov (United States)

A new process engineering flowsheet reflecting an improved design of the LASL Bismuth Sulfate thermochemical cycle is presented. The design is based on laboratory data that indicate a lowered endothermic heat load for a partial decomposition of the solid bismuth sulfate. A small electrical energy demand should result from operation of the sulfur dioxide electrolytic step at lower acid concentration, in principle. The results of the flowsheeting analysis yield a thermal efficiency of 50% for the cycle when coupled to a conceptual fusion energy heat source at 1500/sup 0/K. A parametric analysis shows a slight drop in efficiency as the temperature of the heat source is decreased. The LASL Bismuth Sulfate thermochemical cycle appears to have potential as a means of producing hydrogen from high-temperature heat sources such as fusion, fission, and solar energy; it also appears to be competitive with alternative thermochemical cycles as well as with ...

Energy Technology Data Exchange (ETDEWEB)

Diagnostic systems make it possible to recognize incipient faults in good time and help to increase the availability of power stations. The thermal efficiency and the effective terminal output are didicated by a number of influences. Deviations from the expected status can be identified via continuous recording of the operating parameters and calculation of derived data. An improved efficiency and economical load distribution lead to considerable cost savings. (orig.) [Deutsch] Die Verarbeitung von Messwerten und Signalen ermoeglicht eine umfassende Beurteilung des Anlagenzustandes und die Erkennung sich anbahnender Veraenderungen. Stoerungen, Schaeden oder eine unwirtschaftliche Betriebsweise koennen fruehzeitig erkannt werden. Erhoehte Verfuegbarkeit, geringerer Brennstoffverbrauch und optimierte Lastaufteilung bringen Kostenvorteile. (orig.)

British Library Electronic Table of Contents (United Kingdom)

In this article, the thermodynamic analysis of the existing diesel engine cogeneration system is performed. All necessary data are obtained from the actual diesel engine cogeneration plant located at Gaziantep, Turkey. The exergy analysis is aimed to evaluate the exergy destruction in each component as well as the exergetic efficiencies. The thermodynamic performance of a 25.32MW electricity and 8.1tons/h steam capacity diesel engine cogeneration system at full load conditions is analyzed. The thermal efficiency of the overall plant is found to be 44.2% and the exergetic efficiency is 40.7%. The exergy balance equations developed in this paper may also be utilized in the exergoeconomic analysis to estimate the production costs depending on various input costs in a diesel cogeneration syste...

International Nuclear Information System (INIS)

A particle-laden turbulent reacting flow model is described and applied to in-furnace, dry SO_2 control in boilers. Sulfur capture by calcium-based sorbents is represented by a shrinking core model which accounts for surface areas loss and product layer diffusion. Sorbent particle trajectories and dispersion are followed with cloud statistics in a Lagrangian framework. The turbulent fluid mechanics and chemical reactions are coupled, and solutions obtained for mean and fluctuating velocity, composition, and particle position. Comparisons are made with data from an US EPA laboratory reactor. Practical implications for SO_2 control are examined including the effects of jet velocity, sorbent injection location, boiler load and thermal profiles.

Energy Technology Data Exchange (ETDEWEB)

Samples of nylon 66 rods were irradiated using a cobalt-60 gamma ray source at a dose rate of 0.25 Mrad h[sup -1] in air at room temperature to a maximum dose of 500 Mrad. The linear coefficient of thermal expansion ([alpha]) was measured using a three-terminal capacitance technique reported previously. The variation of [alpha] with temperature between 10 K and 340 K was investigated for an unirradiated sample and two samples irradiated to 300 Mrad and 500 Mrad. In the range 10K to 160K, [alpha] is almost invariant with radiation dose and there is little difference between the values for the unirradiated and the 300 Mrad irradiated samples above 160 K. The sample irradiated to 500 Mrad does show a 6% increase in [alpha] over the other samples in the higher temperature range. All samples show an increase overall in the value of [alpha] with temperature. The melting point of each sample was also determined and was shown to decrease with ...

Energy Technology Data Exchange (ETDEWEB)

A computer model of cryogenic system for storing solid antimatter is used to explore the radiative cooling-power requirements for long-term antimatter storage. If vacuum-chamber pressures as low as 10 to -18th power torr can be reached, and the rest of the large set of assumptions is valid, milligram quantities of solid antimatter could be stored indefinitely at 1.5 K using cooling powers of less than a microwatt. Many of the assumptions made are problematic and need verification, as they could potentially change the results greatly. The system modeled is a sphere of solid anti-parahydrogen at 1.5 K or below levitated in a spherical cryogenic vacuum chamber. The free matter gas in the chamber is assumed to be molecular hydrogen, and sublimation of both matter and antimatter is assumed to be negligible. The antihydrogen is assumed to be in thermal equilibrium, although annihilation-energy deposition is localized and hydrogen's ...

International Nuclear Information System (INIS)

Radiation-and-thermal-combined degradation of ethylene-propylene rubber (EP rubber) and chlorosulfonated polyethylene (CSM) as cable insulating and jacketing materials were evaluated by accelerated aging tests and a method to assess the lifetime of these materials under practical application was studied. EP rubber and CSM of experimental formulation were degraded at accelerated rates, that are 50 #approx# 1000 times the degradation rate under a standard condition (1Gy/h, 50degC). The degradation was investigated by measuring the tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for both EP rubber and CSM were in proportion to increase in accelerated rate. Behaviors of elongation changes showed little difference with accelerated rate. EP rubber lifetime estimated from sequential aging test had a tendency to extend beyond that from simultaneous aging test, while CSM lifetime estimated from both aging tests were ...

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A new double-null, slotted divertor configuration will be installed for the DIII-D Radiative Divertor Program at General Atomics in late 1996. Four cryocondensation pumps, three new and one existing, will be part of this new divertor. The purpose of the pumps is to provide plasma density control and to limit the impurities entering the plasma core by providing pumping at each divertor strike point. The three new pumps are based on the design of the existing pump, installed in 1992 as part of the Advanced Divertor Program. The new pumps require geometry modifications to the original design. Therefore, extensive modal and dynamic analyses were performed to determine the behavior of these pumps and their helium and nitrogen feed lines during disruption events. Thermal and fluid analyses were also performed to characterize the helium two-phase flow regime in the pumps and their feedlines. A flow testing program was completed to test the change in ...

Energy Technology Data Exchange (ETDEWEB)

The Savannah River Swamp is a 3,020 Ha forested wetland on the floodplain of the Savannah River and is located on the Department of Energy`s Savannah River Site (SRS). Major impacts to the swamp hydrology occurred with the completion of the production reactors and one coal-fired powerhouse at the SRS in the early 1950`s. Water was pumped from the Savannah River, through secondary heat exchangers of the reactors, and discharged into three of the tributary streams that flow into the swamp. This continued from 1954 to 1988 at various levels. The sustained increases in water volume resulted in overflow of the original stream banks and the creation of additional floodplains. Accompanying this was considerable erosion of the original stream corridor and deposition of a deep silt layer on the newly formed delta. Heated water was discharged directly into Pen Branch and water temperature in the stream often exceeded 50 C. The nearly continuous flood of the swamp, the ...

Science.gov (United States)

A miniature, high-voltage, thermally activated battery has been developed. This battery weighs 41 grams, occupies a volume of 16.4 cu cm, and contains two separate 500-v channels, each designed to charge a 5.25 microfarad capacitor within 300 milli-seconds and remain operational under a 640-kohm load for a minimum of 28 seconds over the temperature range from +16 to +71 C. The electrochemical system utilizes a calcium anode, LiCl-KCl molten salt electrolyte, a CaCrO4-K2CrO4 mixture as the depolarizer or active cathode material, and an iron cathode. The depolarizer and electrolyte, along with a silica binder, are formed into homogeneous pellets, and these pellets are stacked alternately with calcium-iron bimetal disks in beryllium oxide tubes to form cell stacks. The cells are activated by an iron-potassium perchlorate pyrotechnic heat source external to the BeO tubes.

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The design of high level radioactive waste (HLW) repositories in deep geological media in which bentonite clay is proposed as a sealing material leads to the need of further studying the behaviour of highly compacted expansive soils when subjected to mechanical, hydraulic and thermal changes. Laboratory tests may help to understand the processes that take place in the clay barrier under simple and controlled conditions and to develop the governing equations. The laboratory tests enable to isolate the different processes, making their interpretation easier, and provide with fundamental data concerning the parameters to be used in the models. The extremely low permeability of these materials, their avidity for water (high suction) and their high swelling capacity make necessary the modification of the conventional laboratory techniques and procedures to determine basic physical parameters. The main hydraulic properties of the barrier to be considered are the ...

Energy Technology Data Exchange (ETDEWEB)

The influence of radiation on the corrosion of the fuel claddings in a Light Water Reactor (LWR) has been the subject of many investigations, and different aspects of the overall phenomena have been studied by different techniques. Analysis of the evolution of Secondary-Phase Particles (SPPs) for different periods of immersion of the cladding in the reactor enables the rate of corrosion to the structure of the material to be correlated. In the case of Zircaloy-2 in a Boiling Water Reactor (BWR), SPPs are dissolved under irradiation, and their dissolution affects the rate of oxidation and other correlated phenomena. In recent studies, the Zircaloy-2 in claddings loaded in the Leibstadt BWR are analysed after one, three and five cycles. Results are presented, and give an account of the changes which occurred in the materials under irradiation. (authors)

International Nuclear Information System (INIS)

This study is for chemoradiotherapy of unresectable and recurrent cholangiocarcinoma (CCC). Between April 2005 and March 2007, 5 patients were evaluated for unresectable and recurrent CCC. All patients were performed percutaneous transhepatic biliary drainage (PTBD) and treated with chemoradiotherapy. The radiation method was an external beam radiotherapy (EBRT) and remote after loading system (RALS). The chemotherapy was 5-fluorouracil (FU) and gemcitabine by intravenous injection. Three patients had unresectable and 2 had recurrent CCC. As for the side effects, 4 patients had a slight neutropenia and 1 had an uncontrollable gastric bleeding. No patient had cholangitis. The mean survival time for unresectable and recurrent CCC was 13.7 months and 17 months, respectively. Our results indicated that chemoradiotherapy had been consistent with efficacy in patients with unresectable and recurrent CCC. (author)

Energy Technology Data Exchange (ETDEWEB)

This invention is concerned with a solar energy system for propelling aircraft. Obtained are forces for aerodynamic lift and impetus. The lifted body had a transparent upper surface for the sun light, but black or reflecting for IR-radiation and high thermal insulation properties. Inside of the lifted body, the air temperature increases and is lifted by convection influence. The air resistance of this body is low in horizontal direction and higher in vertical position. The payload could be shifted, so that the positive or negative angle of the whole body can be selected. By this principal it is possible to transform the static lifting force in a dynamic impetus.

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We consider propagation of relativistic heavy nuclei injected by a young pulsar into the radiation field of a massive companion. If the binary system (BS) is compact enough, then the nuclei suffer multiple photodisintegrations in collisions with thermal photons coming from the massive star (MS). Due to the propagation effects of charged particles in the magnetic field of the MS some hadrons can impinge onto the MS surface at large angles. We calculate the fluxes of produced neutrinos as a function of the viewing angle measured from the plane of the BS. It is found that significant fluxes of neutrinos should be also expected in the case of non-eclipsing BSs.

Energy Technology Data Exchange (ETDEWEB)

A neutron collimator system is being designed as part of a neutron imaging facility for computed tomography and real-time neutron radiography research at the through beam port of the University of Texas TRIGA reactor. Lack of sufficient information about collimator systems in a through port from the literature necessitated the use of Monte Carlo calculations using the MCNP code 3 to search for optimal design configuration and materials that maximize the thermal neutron intensity at the image plane while minimizing the fast neutrons and gamma radiation.

Energy Technology Data Exchange (ETDEWEB)

The full text follows. A thermal neutron imaging facility (TNIF) capable of real time neutron radiography and computed tomography was developed for the University of Texas TRIGA Mark II (UT-TRIGA) reactor from 1994-1998. The facility was developed with a through reactor beam port capable of producing a 5.2 x 10{sup 6} n/cm{sup 2}/s thermal neutron flux with a gamma dose rate of less than 1 mR/s after collimation. The original TNIF included the UT-TRIGA reactor, neutron collimation array, sample positioning system, neutron image intensifier tube, video camera, computerized image acquisition system, and a radiation shield. A 0.7 mm slit in cadmium was easily detectable using neutron radiography, and 1.4 mm diameter holes bored in an aluminum block were easily resolved using computed neutron tomography. Precise lower limits of the system resolution have hot been determined. The TNIF is currently being revamped to begin work ...

Energy Technology Data Exchange (ETDEWEB)

RADIANT{trademark} is manufactured by United States Surgical Corporation, Vascular Therapies Division, (formerly Progressive Angioplasty Systems). The system comprises a liquid {beta}-radiation source, a shielded isolation/transfer device (ISAT), modified over-the-wire or rapid exchange delivery balloons, and accessory kits. The liquid {beta}-source is Rhenium-188 in the form of sodium perrhenate (NaReO{sub 4}), Rhenium-188 is primarily a {beta}-emitter with a physical half-life of 17.0 hours. The maximum energy of the {beta}-particles is 2.1 MeV. The source is produced daily in the nuclear pharmacy hot lab by eluting a Tungsten-188/Rhenium-188 generator manufactured by Oak Ridge National Laboratory (ORNL). Using anion exchange columns and Millipore filters the effluent is concentrated to approximately 100 mCi/ml, calibrated, and loaded into the (ISAT) which is subsequently transported to the cardiac catheterization laboratory. The delivery ...

Energy Technology Data Exchange (ETDEWEB)

Properly quantified performance of a solar-thermal cavity receiver must not only account for the energy gains and losses as dictated by the First Law of thermodynamics, but it must also account for the quality of that energy. However, energy quality can only be determined from the Second Law. In this paper an equation for the Second-Law efficiency of a cavity receiver is derived from the definition of available energy or availability (occassionally called exergy), which is a thermodynamic property that measures the maximum amount of work obtainable when a system is allowed to come into unrestrained equilibrium with the surrounding environment. The fundamental concepts of the entropy and availability of radiation are explored from which a convenient relationship among the reflected cone half angle, the insolation, and the concentrator geometric characteristics is developed as part of the derivation of the Second-Law efficiency. A comparison is ...

International Nuclear Information System (INIS)

To resolve the central thermal safety issue for spent fuel dry storage concrete canister design or Wolsung (CANDU) nuclear power plant unit 1, a thermal analysis method has been developed for the complicated geometry of rod bundles and the multi-dimensional and multi-mode heat transfer phenomena. The canister geometry is simplified and combined heat transfer by conduction, convection, and radiation is considered through effective heat transfer coefficients. Mean temperature distributions of the fuel bundles within the fuel basket are obtained by solving the heat transfer problem using an existing computer code HEATING5. The measured steady state temperature distribution within a mock-up of a storage basket is compared to the calculated result. Steady state and/or transient fuel temperature distributions have been calculated for various ambient conditions at the canister exterior surface.

International Nuclear Information System (INIS)

Thermophotovoltaic (TPV) systems are attractive possibilities for direct thermal-to-electric energy conversion, but have typically required the use of black body radiators operating at high temperatures. Recent advances in both the understanding and performance of solid rare-earth oxide selective emitters make possible the use of TPV at temperatures as low as 1200K. Both selective emitter and filter system TPV systems are feasible. However, requirements on the filter system are severe in order to attain high efficiency. A thin-film of a rare-earth oxide is one method for producing an efficient, rugged selective emitter. An efficiency of 0.14 and power density of 9.2 W/KG at 1200K is calculated for a hypothetical thin-film neodymia (Nd2O3) selective emitter TPV system that uses radioisotope decay as the thermal energy source.

Science.gov (United States)

Not Available

Science.gov (United States)

...2010-07-01 false Loading and haulage equipment; inspection and maintenance... § 77.1606 Loading and haulage equipment; inspection and maintenance. (a) Mobile loading and haulage equipment shall be inspected by a...

Science.gov (United States)

...position to receive material. (2) Self-loading haulage equipment used as a loading machine. In working places in which self-loading haulage equipment is operated to load material, the areas which...

Energy Technology Data Exchange (ETDEWEB)

Theatres are the most complex of all auditorium structures environmentally. They usually have high heat loads, which are of a transient nature as audiences come and go, and from lighting which changes from scene to scene, and they generally have full or nearly full occupancy. Theatres also need to perform well acoustically, both for the spoken word and for music, and as sound amplification is less used than in other auditoria, background noise control is critically important. All these factors place constraints on the ventilation design, and if this is poor, it can lead to the deterioration of indoor air quality and thermal comfort. To analyse the level of indoor air quality and thermal comfort in a typical medium-sized mechanically ventilated theatre, and to identify where improvements could typically be made, a comprehensive post-occupancy evaluation study was carried out on a theatre in Belgrade. The evaluation, based on ...

Energy Technology Data Exchange (ETDEWEB)

Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads ...

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Dual fuel operation, in which natural gas is mixed with the diesel engine intake air and ignition is by diesel fuel spray, has the advantage that engine conversion is simple. Under high load it has the same high efficiency as a diesel engine and it can be switched to normal diesel operation for long distance running. Also, NO{sub x} and black smoke emissions can also be reduced. However, the disadvantages are to increase HC and CO emissions, to reduce efficiency under low load, and to emit the large amount of NO{sub x} under high load. Waseda University was commissioned by Tokyo Gas Co., Ltd. to conduct research program involving experimentation ragarding a dual fuel engine. It was then discovered that the most effective means of solving the problems mentioned above is Exhaust Gas Recirculation (EGR) and that the effect can be increased by heating the intake air. An old engine before the current emission standard was ...

International Nuclear Information System (INIS)

Due to thermal gradients and load changes steam-turbine casings suffer combined creep-fatigue loading. Creep and fatigue portions depend on service conditions. Special interest is focused on the behaviour of creep-fatigue cracks, originated from potential defects due to construction and manufacturing weldments, on residual lifetime assessment. The project deals with the crack-growth behaviour at 530deg C and r.t. of welded and unwelded heat-resistant cast steels: 1% CrMoV-cast (GS-17 CrMoV 5 11, two melts: low and high V-content) and 12% CrMoV-cast (G-X 22 CrMoV 12 1). The crack planes of CT-specimens investigated, taken from manual arc-welded plates, were situated in the heat-affected zone (HAZ). The fatigue, creep and combined creep-fatigue crack-growth behaviour was investigated by means of low-frequency (0.5 and 0.05 Hz) tests, holding-time (20 min) tests and constant load tests up to about 5 000 h. ...

International Nuclear Information System (INIS)

The purified integral membrane protein, band 3, from human erythrocytes was inserted into egg lecithin liposomes. The insertion of band 3 was determined from thermal transition data from the analysis of the C-H stretching region bands recorded at temperatures from 25 to -22"oC. Raman spectra show that band 3 considerably broadens and lowers the thermal transition of egg lecithin liposomes, suggesting the insertion of band 3. The band 3-inserted liposomes were irradiated with gamma-rays (40 Gy) and the radiation target groups were determined by the analysis of the structural sensitive Raman bands in the 1600-1700 cm"-"1 (amide I), 1200-1300 cm"-"1 (amide III) and 550-1030 cm"-"1 (side chain amino groups) regions. The radiation-sensitive groups as identified from Raman spectra in the region 550-1030 cm"-"1 are tyrosines and cysteines. The radiation-induced changes in the secondary ...

Energy Technology Data Exchange (ETDEWEB)

The unsteady state heat transfer behaviour of a vertical wall subject to the effects of uniform radiation is investigated and the dimensional analysis of combined heat transfers by conduction, convection and radiation is presented. The convective heat transfer coefficients used in the numerical model are determined experimentally by means of an assembly resembling the conditions encountered in the dwelling (variable temperatures and heat flows in time and space, wall associated with a floor, radiative flux outside the wall). In routine conditions (homogeneous wall dimensions, temperature differentials less than 40/sup 0/C), it is shown that the problem depends in practice on three parameters (instead of five) and that nomographs can give the energy accumulated in the wall as a function of its geometric and thermal charactersitics and the external conditions (type and thickness of material, changes in ...

Energy Technology Data Exchange (ETDEWEB)

Fiber delivered laser pulses emulsify thrombus by mechanical stresses that include a combination of pressure, tension and shear stress. Laser radiation is delivered to the locality of a thrombus and the radiation is absorbed by blood, blood dot, or other present materials. The combination of a leading pressure wave and subsequent vapor bubble cause efficient, emulsification of thrombus. Operating the laser in a low average power mode alleviates potential thermal complications. The laser is operated in a high repetition rate mode to take advantage of ultrasound frequency effects of thrombus dissolution as well as to decrease the total procedure time. Specific parameter ranges for operation are described. The device includes optical fibers surrounding a lumen intended for flow of a cooling agent. The fibers may be arranged concentrically around the lumen to deliver radiation and heat over as large an area ...

Energy Technology Data Exchange (ETDEWEB)

The COBE data on cosmic background radiation (CBR) isotropy and spectrum are generally considered to be explicable only in the context of the Big Bang theory and to be confirmation of that theory. However, this data can also be explained by an alternative, non-Big Bang model which hypothesizes an intergalactic radio-absorbing and scattering medium. Dense, force-free magnetic filaments generated by quasars, active galactic nuclei and Herbig-Haro objects can remain stable in the intergalactic medium for many Gy. They will be opaque to radiation with wavelengths longer than 100--400 microns, and essentially transparent to shorter wavelengths. They are thus capable of thermalizing and isotropizing the cosmic background radiation, and of accounting for the observed decrease of radio luminosity of galaxies within increasing distance from earth. A simple, inhomogeneous model of such an absorbing medium can ...

International Nuclear Information System (INIS)

This paper presents the present status of R and D activities on plasma facing components for fusion reactors, such as International Thermonuclear Experimental Reactor (ITER) and fusion demonstration reactor (DEMO). The plasma facing components (PFCs) as typified by divertor and first wall components are subjected to high heat flux and particle flux from fusion plasma. It is essential for these components to have sufficient heat removal capability and robust structure against those loadings. JAEA has been carried out to develop the ITER-PFCs which consist of copper alloys and armor materials with high thermal conductivity, such as carbon fiber composites, tungsten and beryllium. The demonstration of the thermomechanical performance of the ITER-PFCs by using mock-ups has successfully been made under close mutual cooperation between the participant countries of ITER. Currently, the activity on the development of the ITER-PFCs is in a qualification ...

International Nuclear Information System (INIS)

... radiation effects RADIATIONS. WOOD-PLASTIC COMPOSITES.

International Nuclear Information System (INIS)

TlGaSe_2 compound belongs to group of layered semiconductors of A"3B"3C_2"6-type. Photoelectric and optical properties of TlGaSe_2 single crystals were investigated in detail. Influence of gamma-, electron and neutron radiation on photoelectric properties of TlGaSe_2 single crystals is investigated too. The present work deals with experimental results relative to X-ray dosimetric characteristics of TlGaSe_2 crystals at 300 K. X-ray conductivity and X-ray dosimetric characteristic measurements are carried out in low load resistance regime. The source of X-ray radiation is the installation of X-ray diffraction analysis (URS-55a) with the BCV-2(Cu). Intensity of X-ray radiation (E) is regulated by measurement with current variation in tube at each given value of X-ray radiation dose E (R/min) are measured by crystal dosimeter DRGZ-02. X-ray conductivity coefficients K_#sigma# ...

Energy Technology Data Exchange (ETDEWEB)

This paper deals with conversions of solar energy efficiently into electricity and into gas laser radiation. In the first section, a review study of the possibility of a solar-electric thermophotovoltaic (TPV) device has been done. In a proposed extension of the TPV concept, a Cassagranian optical system concentrates solar radiation to heat a blackbody cavity to 2400/sup 0/K. A double-layer solar cell, GaAs and Si, forming the cylindrical surface concentric to the blackbody cavity, receives the blackbody radiation and converts it into electricity efficiently. A cell conversion efficiency of 50% or more would be possible with the TPV system. The second section explores the concept of blackbody radiation pumping of gas laser media as a step toward utilization of solar energy as a laser pumping source. To demonstrate this concept, an experiment was performed in which various gas mixtures of CO/sub 2/ and ...

International Nuclear Information System (INIS)

TRIGA-SSR is a steady state research and material test reactor that has been in operation since 1980. The original TRIGA fuel was HEU (highly enriched uranium) with a U"2"3"5 enrichment of 93 per cent. Almost all TRIGA HEU fuel bundles are now burned-up. Part of the spent fuel was loaded and transferred to US, in a Romania - DOE arrangement. The rest of the TRIGA fuel bundles have to be temporarily stored in the TRIGA facility. As the storage conditions had to be established with caution, neutron and thermal hydraulic evaluations of the storage conditions were required. Some criticality evaluations were made based on the SAR (Safety Analysis Report) data. Fuel constant axial temperature approximation effect is usual for criticality computations. TRIGA-SSR fuel bundle geometry and materials model for SCALE5-CSAS module allows the introduction of a fuel temperature dependency for the entire fuel active height, using different materials for each ...

Energy Technology Data Exchange (ETDEWEB)

The thermal performance of an automotive radiator plays an important role in the performance of an automobile's cooling system and all other associated systems. For a number of years, this component has been given little attention with very little changing in its manufacturing cost, operation and geometry. As opposed to the old tubular heat exchanger configurations used in automotive radiators, plate heat exchangers currently form the backbone of today's process industry with their advanced performance reaching levels the designers of tubular heat exchangers can only dream of. The aluminium roll-bonding technique widely used in manufacturing the cooling compartments for domestic refrigeration units is one of the cheapest methods for heat exchanger manufacturing. Using this technique, it is possible to manufacture a wide range of heat exchanger configurations that can help augment heat transfer whilst ...

Energy Technology Data Exchange (ETDEWEB)

A series of OSL properties of fragments from split feldspar grains have been investigated. These are (1) the response to a radiation dose, (2) the recycling of corrected induced luminescence (L{sub i}/T{sub i}), (3) the corrected natural luminescence (L{sub N}/T{sub N}), (4) the corrected thermal transfer luminescence (termed herein L{sub tt}/T{sub tt}) and, (5) the rate of anomalous fading ('g'). It was found that the parameters of different parts of the same grain are the same. The relative uncertainty, at the 2 sigma level, at which we can claim that the measured parameters are correlated, is generally less than 5% but is ca 40% for the anomalous fading rate due to measurement uncertainty. For young partially bleached sediments, the result is that one could use one fragment to evaluate the equivalent dose and another to assess the contribution of thermal transfer resulting from preheating the natural ...

International Nuclear Information System (INIS)

The primary E1, M1 and E2 #gamma#-radiation in "8"7","8"8","8"9Sr observed after thermal neutron capture was compared with the predictions of single particle and giant resonance models. The nuclei feature a wide range of neutron binding energies between 6.3 and 11.1 MeV, which makes a 5.5 MeV spectrum of primary transition energies available for investigation. The (n, #gamma#) reaction was used to estimate the parameters of the spin-flip M1 giant resonance in strontium. The total energy weighted M1 strength of this resonance exceeds the results of shell model and random phase approximation calculations for "9"0Zr by a factor of 3-4. The E1 strengths were found to agree with the established giant dipole resonance model. The few data on primary E2 transitions do not allow to differentiate between the giant quadrupole resonance and the single particle models. (orig.).

International Nuclear Information System (INIS)

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

CERN Document Server

The aim of this work was to study the possibility of producing a fast switching optical thin film device to react to laser radiation in the visible/near infrared region of the spectrum. The switching mechanism was to be thermally driven. A computer program was written to enable the effects of changes of the refractive index of a component of a multilayer thin film stack to be modelled. Attempts to use the phase transition in vanadium dioxide were unsuccessful because, in the spectral region of interest, the 'open-state' absorption was too great. A class of materials known as 'the bronzes' was identified as being potentially useful. Attempts were made to produce thin films of bronze compounds of vanadium, tungsten and molybdenum by the techniques of conventional thermal evaporation and laser ablation for further studies. The former technique appeared to suffer from problems of decomposition of the source material. The latter ...

International Nuclear Information System (INIS)

The present guidelines supplement the 'VGB guidelines for the reduction of noise in thermal power plants' with indications for the ordering and quality assurance of the individual noise-producing machines and equipment of power plant operation. These guides are to simplify the commissioning and delivering for the orderer and deliverer. In addition, these guidelines are to lead to a successful cooperation of all parties in the reduction of the sound radiation. A precondition for this is an explanation of the sound technical demands which must be made on the single machines or mechanical equipment in power plant systems. A protection of the neighbourhood as well as operational personnel against noise according to the state of technology is to be achieved by a clear form of ordering and quality assurance. The ordering and assurance procedure for all aggregates in the region of the grounds of a power plant up to the high-voltage side of the machine ...

Energy Technology Data Exchange (ETDEWEB)

Moving out of the scientific community research laboratories, computational fluid dynamics (CFD) software packages are now allowing industrials to analyse and optimize industrial processes involving the use of gases, liquids and even some two-phase fluids. Their attractiveness and their impact stems out from the opportunity they offer to bring insight into an existing unit, or even at the design stage, by displaying the spatial distribution of process relevant variables such as temperature, concentration. The filling of the spacing in between a two-layer window is a simple example. This new opportunity of visualisation is at times an unique way, when the process environment is an opaque one, such as liquid metal flowing into a tundish or when measurements of flows may be a long and tedious work, such as flows within water treatment basins. This environment we are to investigate in order to optimize can also be a harsh one, due to its high temperature level for example. Such are ...

Energy Technology Data Exchange (ETDEWEB)

A heat transfer (condenser) of a domestic freezer was tested in a vertical channel in order to study the influence of the chimney effect in the optimization of the heat transfer coefficient. The variation of the opening of the channel, position and the heating power of the heat exchanger in the heat transfer coefficient was considered. The influence of the surface emissivity on the heat transfer by thermal radiation was studied with the heat exchanger testes without paint and with black paint. The air velocity entering the channel was measured with a hot wire anemometer. In order to evaluate the chimney effect, the heat exchanger was testes in a open ambient. This situation simulates its operational conditions when installed on the freezer system. The variables collected in the experimental procedures was gathered in the form of dimensionless parameters as Nusselt, Rayleigh, Grashof and Prandtl numbers, and dimensional parameters of the ...

Energy Technology Data Exchange (ETDEWEB)

Metallic nanoparticles was synthesized in SiO{sub 2} matrices by means of a process of two stages. The first one proceeded via sol-gel, incorporating the metallic precursors to the reaction system before the solidification of the matrix. Later on, the samples underwent a thermal treatment in atmosphere of H{sub 2}, carrying out the reduction of the metals that finally formed to the nanoparticles. Then it was detected the presence of smaller nanoparticles than 20 nm, dispersed and with the property of being liberated easily of the matrix, conserving a free surface, chemically reactive and with response to external electromagnetic radiation. The system SiO{sub 2}-Pd showed an important thermoluminescent response. (Author)

Science.gov (United States)

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors investigated the evolution and radiation characteristics of individual neutron stars and stellar systems. The work concentrated on phenomena where new techniques and observations are dramatically enlarging the understanding of stellar phenomena. Part of this project was a study of x-ray and gamma-ray emission from neutron stars and other compact objects. This effort included calculating the thermal x-ray emission from young neutron stars, deriving the radio and gamma-ray emission from active pulsars and modeling intense gamma-ray bursts in distant galaxies. They also measured periodic optical and infrared fluctuations from rotating neutron stars and search for high-energy TeV gamma rays from discrete celestial sources.

Energy Technology Data Exchange (ETDEWEB)

An experiment lasting a number of hours was carried out with 6 men under standardised climate chamber conditions to find out to what extent wallpaper that reflects about 65-75% in the infra-red range by comparison with normal wallpaper that reflect only 3-5% of heat, has measurable positive effects on the thermoregulation of the human body and the human sensation of temperature. The measurements of skin temperature and heat flow intensity in the deeper areas of the body and the periphery, and metabolic heat conversion measurements (indirect calorimetry) confirm that infra-red reflection of the heat irradiated from the body lead to a measurable heat recovery on the body surface with a reduction of metabolic conversion. It was proved that it is possible to reduce the average room temperature by up to 4 K whilst maintaining the same degree of thermal comfort, which corresponds to a 20% saving in heating energy. (orig./BWI).

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

Since actinide mononitride has several superior thermal and neutronic properties, nitride fuel is considered as a candidate for future nuclear systems, such as advanced fast reactors and accelerator-driven system. Establishing reprocessing technology is one of key technologies for the development of nitride fuel cycle. In addition to general advantages of pyrochemical process, such as the potential for economy, radiation and proliferation resistance, recycling of N-15 in nitride fuel seems to be practical in comparison with conventional hydro-process. Following the electrochemical measurements of nitride fuel in LiCl-KCl molten salt, the experimental study on closing nitride fuel cycle has been carried out in JAEA by used of TRU nitride and burnup simulated nitride samples. Recent progress of the study is summarized in this paper.

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

The deliberation by the Nuclear Safety Commission was initiated on the alteration in reactor installation, as was required by the Ministry of International Trade and Industry. The alteration is the additional installation of the reactor No. 2 in the Sendai Nuclear Power Station, Kyushu Electric Power Co., Inc. It is a PWR power plant with thermal output of about 2,660 MW (electric output of 890 MW), to be installed, adjoining to the reactor No. 1 of the same type and capacity under construction. In the examination by MITI, it was confirmed that the technological capabilities for its construction and operation and the radiation protection measures in power generation are both sufficient. The contents of the examination include the siting conditions, the location and construction of reactor facilities, etc.

Energy Technology Data Exchange (ETDEWEB)

The main objective of the present study is twofold: (i) to analyze thermal loads of the geothermally and passively heated solar greenhouses; and (ii) to investigate wind energy utilization in greenhouse heating which is modeled as a hybrid solar assisted geothermal heat pump and a small wind turbine system which is separately installed in the Solar Energy Institute of Ege University, Izmir, Turkey. The study shows 3.13% of the total yearly electricity energy consumption of the modeled system (3568 kWh) or 12.53% of the total yearly electricity energy consumptions of secondary water pumping, brine pumping, and fan coil (892 kWh) can be met by using small wind turbine system (SWTS) theoretically. According to this result, modeled passive solar pre heating technique and combined with geothermal heat pump system (GHPS) and SWTS can be economically preferable to the conventional space heating/cooling systems used in agricultural and residential ...

Energy Technology Data Exchange (ETDEWEB)

Dual-fuel engines are modified diesel engines burning simultaneously two fuels inside the cylinder: a gaseous one, called the primary fuel and a liquid one, called the pilot fuel. The thermal efficiency of the dual-fuel engine and of the diesel engine are comparable; the level of emissions is lower compared to the diesel one. This article presents a new procedure for the combustion modeling in a LPG-diesel dual-fuel engine. The procedures deals with the ignition delay period and with the rate of heat release inside the cylinder. This procedure is validated using experimental data issued front a collaboration with the Indian Institute of Technology from Madras, India. The used engine is a single-cylinder one, air-cooled. The pilot fuel is direct injected inside the cylinder The engine was run at constant load and with different diesel substitutions, i.e. for different air to fuel ratios of the primary fuel-air mixture. The general error of the ...

International Nuclear Information System (INIS)

The divertor 'Large Project' was conceived with the aim of demonstrating the feasibility of meeting the lifetime requirements by employing the candidate armor materials of beryllium, tungsten (W) and carbon-fiber-composite (CFC). At the start, there existed only limited experience with constructing water-cooled high heat flux armored components for tokamaks. To this was added the complication posed by the need to use a silver-free joining technique that avoids the transmutation of n-irradiated silver to cadmium. The research project involving the four Home Teams (HTs) has focused on the design, development, manufacture and testing of full-scale Plasma Facing Components (PFCs) suitable for ITER. The task addressed all the issues facing ITER divertor design, such as providing adequate armor erosion lifetime, meeting the required armor-heat sink joint lifetime and heat sink fatigue life, sustaining thermal-hydraulic and electromechanical loads, ...

International Nuclear Information System (INIS)

During the operation of a tokamak, the first wall elements suffer very high heat fluxes. Heat is removed by internal cooling by means of water, helium or fluid metal. The resulting inhomogeneous temperature field cause internal stresses which, due to the pulsed operation are of cyclic nature. Additional mechanical stresses in the first wall may be caused by disruptions or vertical plasma movements. During theses events high currents are induced in the metallic part of the first wall which by their interaction with the magnetic field of the tokamak lead to mechanical forces. These electromechanical stresses may lie beyond the yield stress of the structural material. From the interaction of thermal and mechanical forces, a complex stress state is achieved which under certain circumstances may lead to premature failure and/or to progressive plastic deformations (ratcheting). In order to study the boundary conditions for the occurrence of ratcheting, a testing rig has ...

Energy Technology Data Exchange (ETDEWEB)

In the atmospheric pressure coal combustion area, the internally circulating fluidized bed boiler (ICFB) has already been proven to possess superior performance features in terms of the ease with which load conditions can be controlled and its low pollution level. Based on the particular merits of the ICFB furnace and the application of this technology to pressurized fluidized bed boiler technology, it was possible to achieve a pressurized fluidized bed boiler with superior ease of operation, reliability and los pollution characteristics. Cold model tests and computer simulation have been carried out to investigate the possibility of applying ICFB technology to the pressurized fluidized bed boiler technology in an attempt to develop the pressurized internally circulating fluidized bed boiler (PICFB). Based on the results achieved in this research, a hot-model design and fabrication project were initiated in 1995 to create a 4MW (thermal) heat ...

Energy Technology Data Exchange (ETDEWEB)

H Power Enterprises of Canada was founded in 1997; currently, it has 40 employees and expect to grow to about 50 by mid-2000. The company is engaged in fuel cell technology development , manufacturing and marketing. The company has the advantage that its technology has been proven, products are already commercialized, and strategic alliances are already in place to make an assault on the market. The concept of proton exchange membrane fuel cell technology is explained in terms of efficiency, response time, power density, stack manufacturing cost, maintenance cost, stack life and compatible thermal loads. Individual products, their energy and operating efficiency, potential applications and potential markets are reviewed. It is estimated that for stationary fuel cells the market will be worth $ 30 billion by 2030. In the United States alone, remote residential cogeneration sites are estimated at 500,000. The estimates for uses in transportation ...

International Nuclear Information System (INIS)

We have already developed three conventional and one periodic permanent (PPM) type 50-MW class klystrons, a smart modulator, and the first HOM-free accelerator structure (Choke-mode type, full-scale high power model). A very stable ceramic high voltage monitor was successfully tested up to 367-kV with a 4.5-#mu#sec pulse. A new C-band SiC type high power rf-load, advancing the power handling capability up to 50-MW is now being designed. It should have excellent mass production characteristics as it uses circularly symmetric TM_0_1_1 chained cavities. The first high power prototype of an rf compressor cavity made of a low thermal expansion material (super Invar) was designed to provide stable operation even with a very high Q of 200-k, it was successfully tested the output rf power up to 135-MW, 0.5-#mu#sec pulse width and 50-pps repetition rate. The C-band linac rf-system will be used for the SASE-FEL (SCSS) production project at SPring-8, but ...

Science.gov (United States)

The variation of metallic particle size and sample porosity significantly alters the dynamic mechanical properties of high density granular composite materials processed using a cold isostatically pressed mixture of polytetrafluoroethylene (PTFE), aluminum (Al), and tungsten (W) powders. Quasistatic and dynamic experiments are performed with identical constituent mass fractions with variations in the size of the W particles and pressing conditions. The relatively weak polymer matrix allows the strength and fracture modes of this material to be governed by the granular type behavior of agglomerated metal particles. A higher ultimate compressive strength was observed in relatively high porosity samples with small W particles compared to those with coarse W particles in all experiments. Mesoscale granular force chains of the metallic particles explain this unusual phenomenon as observed in hydrocode simulations of a drop-weight test. Macrocracks forming below the critical failure strain ...

Energy Technology Data Exchange (ETDEWEB)

Demands for electric power system, which include not only minimization of generation cost but also protection of environmental condition and maintenance of transmission security, have been diversified The priority of these objectives may change according to load change, weather, and other conditions. Since these objectives are usually in a trade-off relationship and generally non-commensurable, it is difficult to handle by conventional optimization of a single objective function. This report describes multi-objective scheduling of thermal power system. The adaptability of three performance indicies, such as economic efficiency, NO{sub x} emission, and transmission security, to operators are defined by membership functions in fuzzy set theory. coordinated solution in which the adaptability of operators is maximized can be obtained by maximizing the fuzzy decision-making function composed of the adaptability index for each objective. Because this ...

Energy Technology Data Exchange (ETDEWEB)

Ventilation, cooling and illumination of modern high-rise office buildings with high-quality thermal insulation (average k-value 1.0 W/m12K) and high loads from office machinery (up to 20 W/m12 and beyond) are problematic even for modern facility management systems, with consequences for the building shell, heating system, and window ventilation. [Deutsch] Die Lueftung, Kuehlung und Beleuchtung moderner Buerohochbauten mit extremer Waermedaemmung (mittlerer K-Wert 1,0 W/m{sup 2}K) und hohen Bueromaschinenlasten (bis zu 20 W/m{sup 2} und mehr) verursachen auch heute noch erhebliche Probleme, obwohl die technische Gebaeudeausruestung weiterentwickelt wurde. Dies zeigt sich vor allem bei der Fassadenausbildung der Heizung und Fensterlueftung. (orig.)

Energy Technology Data Exchange (ETDEWEB)

An Allis-Chalmers, Model 2900, turbocharged diesel engine was converted to a dual-fuel engine in which ethyl alcohol was fumigated between the turbocharger and the intake manifold, and the diesel fuel was injected normally at a reduced rate. Tests were performed to determine if crankcase oil dilution that had occurred was caused by the following independent parameters: proof of the ethyl alcohol, crankcase oil temperature, engine load at maximum torque speed, and percentage of total energy in the form of ethyl alcohol. Engine tests were steady state for six hours, after which the crankcase oil was sampled for American Society for Testing and Materials (ASTM) laboratory tests for determination of flash points and fire points, water by centrifuge, water by distillation, and viscosity at room temperature. Results indicate a decrease in thermal efficiency and an increase in exhaust carbon monoxide as the percentage of total energy as alcohol is ...

Energy Technology Data Exchange (ETDEWEB)

The Electromagnetic Fluctuations (EMF) diagnostic will be used to monitor ion fluctuations which could be unstable in MFTF-B. Each probe assembly includes a high impedance electrostatic probe to measure potential fluctuations, and a group of nested, single turn loops to measure magnetic fluctuations in three directions. Eventually, more probes and loops will be added to each probe assembly for making more detailed measurements. The sensors must lie physically close to the plasma edge and are radially positionable. Also, probes at separate axial locations can be positioned to connect along the same magnetic field line. These probes are similar in concept to the rf probes used on TMX, but the high thermal load for 30-second shots on MFTF-B requires a water-cooled design along with temperature monitors. Each signal channel has a bandwidth of .001 to 150 MHz and is monitored by up to four different data channels which obtain amplitude and frequency ...

British Library Electronic Table of Contents (United Kingdom)

Cobalt supported on Beta zeolite catalysts were prepared by impregnation of metal salts in aqueous solution and were tested for the Fischer Tropsch reaction. The support consisted of a Beta zeolite composed by crystallites of nanometric dimensions and a SiO2/Al2O3 molar ratio of about 50. This support was impregnated with Co(NO3)2 aqueous solution using different metal loads of 7.5, 10, 15 and 20wt% Co. These materials were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), N2 adsorption (BET), thermal programmed reduction (TPR) and FTIR of adsorbed pyridine (i.e., surface acid sites distribution). All the catalysts showed a significant catalytic activity for the F-T reaction from synthesis gas (CO+2H2), in a continuous fixed bed reactor sys...

Energy Technology Data Exchange (ETDEWEB)

A new package for the air transport of hazardous materials is currently being developed in the Transportation Systems Department at Sandia National Laboratories. The baseline design has a unique impact limiter which uses layers of aluminum screen wire and aramid cloth fabric. A primary motivation for selecting this unusual combination of materials is the need for the impact limiter to not only limit the amount of load transmitted to the primary container but also remain in place during impact events so that it provides a thermal barrier during a subsequent fire. A series of uniaxial and confined compression tests indicated that the layered material does not behave like other well characterized materials. No existing constitutive models were able to satisfactorily capture the behavior of the layered material; thus, a new plasticity model was developed. The new material model was then used to characterize the response of air transport packages ...

Energy Technology Data Exchange (ETDEWEB)

Investigated here were the effects of microwave (MW) radiation (2450-MHz, continuous-wave, mean specific absorption rate of 103.5 + or - 4.2 W/kg) and convention heating on the nonphosphorylating oxidative metabolism of human peripheral mononuclear leukocytes (96% lymphocytes, 4% monocytes) at 37 C. Metabolic activity, determined by chemiluminescence (CL) of cells challenged with luminol (5-aminO-2, 3-dihydro-1, 4-phthalazinedione) linked to bovine serum albumin, was detected with a brightness photomer. A significant stimulation after after MW exposure (p < 0.005) over total CL of matched 37 C-incubator controls was observed. A similar degree of stimulation, compared to incubator controls, was also detected after sham treatment. No significant difference existed between changes in total CL or stimulation indices of the MW and sham-exposed groups. Exposure to MW radiation, under normothermic (37 + or - 0.03 C) conditions, appears to have no ...

UK PubMed Central (United Kingdom)

An estimator for the load share parameters in an equal load-share model is derived based on observing k-component parallel systems of identical components that have a continuous...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

A 100 kW thermal input Two-Stage Gasifier was built at the University of Denmark (DTU). The gasifier consists of an externally heated pyrolysis unit, a down-draft char gasifier, a gas cleaning system and an internal-combustion engine. Between the summer of 1996 and the summer of 1998, 11 tests were made with the gasifier. The gasifier had a total operating time of 278 hours (excluding warming up). The fuel was mainly wood chips, but also briquettes has been used. Four of the tests lasted 50-70 hours, and stable conditions were reached. All the tests were completed without technical problems. The particle sizes and amounts were investigated. The amount of particles depended on the amount of steam led to the gasifier. More than 99% of the particles after the cyclone were soot. The size of the soot particles was mainly between 0.2-0.5 {mu}m. Under normal conditions (biomass:steam = 1:1 (dry mass basis)), the particle load was about 300 mg/Nm{sup ...

Energy Technology Data Exchange (ETDEWEB)

Diamond-like carbon thin films for tribological applications were deposited by d.c.-magnetron sputtering of a graphite target in a pure argon atmosphere or in a reactive hydrogen or methane atmosphere at pressures between 0.1 and 1 Pa in a graded constitution to improve adhesion and reduce residual stress. The temperature of the metallic, carbon- and ceramic-like substrates was below 100 C. The mechanical, thermal, electronic and optical properties of the carbon thin films show a significant dependence on the ion energy. Below 220 eV, strongly adherent black conductive films with hardness values up to 2000 HV0.05 were obtained. Hard and superhard diamond-like carbon thin films were deposited in an energy range between 220 and 370 eV with hardness values up to 4000 HV0.05. They are insulating, optically transparent and show a high degree of hardness combined with high compressive stress in the order of 4 GPa as well as a low adhesion, which means that the critical ...

Science.gov (United States)

We describe the synthesis of metal-chelating polymers (MCPs) with four different pendant polyaminocarboxylate ligands (EDTA, DTPA, TTHA, DOTA) and an orthogonal end-group, either a fluorescein molecule or a bismaleimide linker for antibody attachment. Polymer characterization by a combination of (1)H NMR, UV/vis absorption measurements, and thermal gravimetric analysis (TGA) indicated that each chain of the fluorescein-terminated polymers contained one dye molecule. These polymer samples were loaded with three different types of lanthanide ions as well as palladium and platinum ions. The numbers of metal atoms per chain were determined by a combination of UV/vis and conventional ICP-MS measurements. The experiments with lanthanide ions demonstrated that a net anionic charge on the polymer is important for water solubility. These experiments also showed that at least one type of lanthanide ion (La(3+)) is capable of forming a bimetallic complex ...

Energy Technology Data Exchange (ETDEWEB)

In this paper an attempt is made to forecast load using fuzzy neural network (FNN) for an integrated power system. Here, the proposed system uses a two stage FNN for a short term peak and average load forecasting (STPALF). The first stage FNN deals with the load forecasting and the second stage algorithm can be worked independently for network security. This technique is used to forecast load accurately on week days as well as holidays, weekends and some special occasions considering historical data of load and weather information and also take necessary control action for network security.

Energy Technology Data Exchange (ETDEWEB)

ITN Energy Systems is developing next-generation solar cells based on the concepts of an optical rectenna. ITN's optical rectenna consists of two key elements: (1) an optical antenna to efficiently absorb the incident solar radiation, and (2) a high-frequency metal-insulator-metal (MIM) tunneling diode that rectifies the AC field across the antenna, providing DC power to an external load. The combination of a rectifying diode at the feedpoints of a receiving antenna is often referred to as a rectenna. Rectennas were originally proposed in the 1960s for power transmission by radio waves for remote powering of aircraft for surveillance or communications platforms. Conversion efficiencies greater than 85% have been demonstrated at radio frequencies (efficiency defined as DC power generated divided by RF power incident on the device). Later, concepts were proposed to extend the rectennas into the IR and optical region of the ...

International Nuclear Information System (INIS)

AGNES is a chopper spectrometer installed at the top of the C3 cold guide of JRR-3 (JAERI, Tokai). In 2004 - 2006, this spectrometer was greatly improved by installing (1) 208 new detectors to make the detector bank complete, (2) new radiation shields composed of Fe (14 mm), polyethylene (50 mm), B4C rubber (10 mm), and Cd (0.5 mm) sheets, (3) a new control system for the anti-frame-overlap chopper rotating simultaneously with the Fermi chopper, (4) a monitor counter at the space between the chopper and monochromator, (5) a neutron guide tube (50 cm) before the monochromator, (6) a new instrument control (monochromators, choppers, beam narrowers, etc.) and measurement control (real-time data monitoring, sample temperature control, etc.) systems, (7) a top-loading type cryostat workable at a wide temperature range of 6 - 480 K. As the results of these improvements, the signal intensity has been increased by 3.3 and the background has been ...

Energy Technology Data Exchange (ETDEWEB)

In portal images with high energy X-ray (10 MV), it is sometimes difficult to verify the irradiation field because of the low contrast. Especially, in the abdominal and pelvic region, the deterioration of portal image quality is remarkable. To solve this problem, we took portal images using computed radiography (FCR). Also, we develop a technique in which a copper plate (3 mm) and lead foil (0.3 mm) are closely set in the front and rear of the photostimulable phosphor plate (imaging plate), for increased energy absorption. As a result, image quality was very high and we confirmed image improvement using observer performance experiments. We made a special cassette which can closely set metallic plates to imaging plate and load FCR-7000 directly. Therefore, image process becomes simple, and suitable for routine work. In computed radiography, image processing (tone scale modification and edge enhancement) is possible, and is advantageous portal imaging. When PACS is ...