International Nuclear Information System (INIS)

The purpose of the present research is to find a suitable technique to measure trace amounts of uranium and thorium and to determine the surface #alpha#-flux in silicon compound (SiO) used for fabrication of integrated circuit packaging materials. Among several commonly-used detecting techniques, it was found that neutron activation analysis (NAA) was most promising. The results from NAA show a large difference in uranium and thorium concentrations when cadmium and boron carbide shields are used, whereas #alpha#-flux measurements show a low #alpha#-activity, which corresponds to the trace amounts of uranium and thorium expected to be present in these materials. (author) 13 refs.; 6 figs.

International Nuclear Information System (INIS)

Shoot tip explants of chrysanthemum were checked for their in vitro regeneration capability when they were inoculated on MS media supplemented with three different auxins viz., IAA, NAA and IBA with their different concentrations (Control, 0.1, 0.3 and 0.5 mg/l IAA; Control, 0.5, 1.0 and 1.5 mg/l NAA; Control, 0.3, 0.7 and 1.0 mg/l IBA). The lowest concentration of IAA (0.1 mg/l) showed the best response in all the parameters, as it gave the highest (86.6%) shoot initiation, maximum (3.9) shoots per explant, shoot length (4.3 cm), 10.0 leaves per shoot and 4.8 nodes per shoot. Comparing different concentrations of NAA, it was evident from the results that the lowest concentration of 0.5 mg/l NAA showed its superiority over the other concentrations, as it produced as high as 80.0% shoot initiation, maximum 3.2 shoots per explant, shoot length (4.0 cm), 9.5 and 4.5 leaves nodes per ...

Energy Technology Data Exchange (ETDEWEB)

Proton magnetic resonance spectroscopy (MRS) measures concentrations of metabolites in vivo and provides a powerful method for identifying tumours. MRS has not entered routine clinical use partly due to the difficulty of analysing the spectra. To create a straightforward method for interpreting short-echo-time MRS of childhood cerebellar tumours. Single-voxel MRS (1.5-T Siemens Symphony NUM4, TR/TE 1,500/30 ms) was performed at presentation in 30 children with cerebellar tumours. The MRS results were analysed for comparison with histological diagnosis. Peak heights for N-acetyl aspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mIns) were determined and receiver operator characteristic curves used to select ratios that best discriminated between the tumour types. The method was implemented by a group of clinicians and scientists, blinded to the results. A total of 27 MRS studies met the quality control ...

Energy Technology Data Exchange (ETDEWEB)

Some crops of important nutritive requirements have been collected from farmlands located in Bitsichi an old tin mining town in north central region of Nigeria. The food crops were analyzed in order to determine trace element concentrations level using Neutron Activation Analysis (NAA). The activity concentrations due to natural radionuclides in the food samples and soil samples collected within the root zone of the crops were also determined using gamma-ray spectrometry (GRS). The NAA results obtained showed higher concentration of Potassium among the essential elements in all the crops. Calcium concentration in both maize and Guinea corn was below detection limit and also Zn in Green beans, sweet potato and cassava. The trace elements; Sc, Hf, Sm, and Th, were below detection limit in all the crops except in Green beans. Rubidium (Rb) and lanthanum (La) were below detection limits only in Cabbage. The activity ...

International Nuclear Information System (INIS)

We examined whether proton magnetic resonance spectroscopy (MRS) could provide accurate information on histological grade and cell proliferation in astrocytomas. We studied 23 patients with astrocytomas: five grade II, 10 grade III and eight with grade IV (glioblastoma multiforme). We performed proton MRS and determined the Ki-67 labeling index (LI), a tumour proliferation marker, in the same areas of the astrocytomas, and examined the statistical relationship between proton MRS and Ki-67 LI. The N-acetylaspartate (NAA)/creatine-phosphocreatine (Cr) and NAA/choline (Cho)-containing compound ratios were always significantly lower and the Cho/Cr ratios significantly higher than those for normal brain. The Cho/Cr ratio correlated positively and the NAA/Cho ratio inversely with Ki-67 LI. These findings suggest that the Cho signal in proton MRS reflects cellular proliferation. In Kaplan-Meier survival analysis, there was no ...

Energy Technology Data Exchange (ETDEWEB)

The handling of physical-nuclear techniques for the analysis of archaeological pieces it was carried out by first time in 1956 by the doctors Oppenheimer and Dodsom (in the United States); who wrote about the wide utilities of the neutron activation analysis (NAA), this technique requires of a nuclear reactor that could be considered like one a factory of thermal neutrons necessary to carry out this analysis. The first experiments in that were applied the NAA were on ceramic coming from the Mediterranean, in those that the relationships of the elements of sodium and manganese were determined to know their elementary composition and to identify the origin of their manufacture. Later on other study techniques were applied in archaeological materials, as the X-ray fluorescence, Moessbauer spectroscopy, scanning electron microscopy, PIXE analysis (particle induced x-ray emission), among other, this last is the matter that we will present in this ...

International Nuclear Information System (INIS)

Selenium (Se), zinc (Zn), magnesium (Mg), molybdenum (Mo) and vanadium (V) in 28 types of Egyptian common foodstuffs as well as drinking and irrigation water samples were determined using neutron activation analysis (NAA) and atomic absorption spectrometry (AAS). The samples were collected from 74 sites over 13 governorates as well as the Nile river, wells and tap water in the regions of the Nile Delta, Sinai, the east and west desert, and north and south Egypt. These trace elements were chosen according to international references, which show the close relationship of their deficiencies to immunity-related diseases. Calculation values of daily uptake per capita were made with the results of analysis. The results, as calculated per 100 g dry weight, showed that some Egyptian foods are rich in Se including such fish (0.94 #mu#g), sesame (0.88 #mu#g), beef meat (0.48 #mu#g), instant tea (0.42 #mu#g), mushroom (0.34 #mu#g) and ...

Energy Technology Data Exchange (ETDEWEB)

The general usefulness of neutron activation analysis (NAA) for samples containing the platinum group elements (PGE) and Au, either as major or trace constituents, is discussed. Charged particle activation is shown to be a viable or complementary alternative. Proton (6-10 MeV) and alpha particle (9-15 MeV) beams, produced in a tandem Van de Graaff accelerator, have been established to be the most effective choice. By taking advantage of the Coulomb barrier effect and the fact that many charged particle induced reactions have relatively large threshold values, the same instrumental technique can be applied, with minor modifications, to a wide range of materials.

International Nuclear Information System (INIS)

In Japan, cosmetics claiming hormesis effect are available through Internet. Although these cosmetics show the contents, they never mention the minor elements and radioactive sources. The existence of radioisotopes, however, was observed by measurements of the gamma-rays with a HPGe detector. In this study, in order to clarify the contents of trace elements, the hormesis cosmetics including radioactive sources were analyzed using INAA, PGAA and NAA with multiple gamma-ray detection (NAAMG). Nineteen elements were analyzed quantitatively in hormesis cosmetics by INAA, PGAA and NAAMG and 16 elements were detected qualitatively by SEM-EPMA. (author)

Science.gov (United States)

... operation, experimental data reduction, and application of PES results to studies related to estuarine and coastal sediment transport problems are ...

Energy Technology Data Exchange (ETDEWEB)

This paper presents results, numeric and experimental, due to installation operation of a Risers Uphold Sub-Surface Buoy, (BSR). This kind of installation developed by PETROBRAS is unique in the world. The work of BSR installation was based on a numeric pre analysis to verify the system and determine the main parameters to be experimentally verified. The second phase of the work was the experimental analysis in a deep water ocean basin. s. The work describes the BSR and their main accessories, the experimental environment and the model constructed in aluminum in a 1:12 scale and the main results. (author)

International Nuclear Information System (INIS)

The spontaneous evolution from ultracold Rydberg atoms to plasma is investigated in a caesium MOT by using the method of field ionization. The plasma transferred from atoms in different Rydberg states (n=22-32) are obtained experimentally. Dependence of the threshold time of evolving to plasma and the threshold number of initial Rydberg atoms on the principal quantum number of initial Rydberg states is studied. The experimental results are in agreement with hot-cold Rydberg-Rydberg atom collision ionization theory. (authors)

International Nuclear Information System (INIS)

1984. p. 890. Germany Picat, P. Thirion, FL Quinault, FM CEA Centre

British Library Electronic Table of Contents (United Kingdom)

The results obtained from experimental investigations and mathematical simulation of horizontal steam generators are considered. Recommendations for continuing these works are given.

International Nuclear Information System (INIS)

A review of the ALPHA project is presented, including a summary of progress and current status. The project comprises the experimental and analytical investigation of the long-term decay heat removal phenomena from the containment of the next generation of ''passive'' Advanced Light Water Reactors. The effects of aerosols that may result from hypothetical severe accidents are also considered. The construction of the major ALPHA experimental facilities, PANDA, LINX-2 and AIDA, has been completed. First steady-state tests have been performed on PANDA. The other facilities are now in their commissioning phases. Scaling studies have guided the design of the experimental facilities. Several small-scale experimental and studies have already produced valuable results which can be used to direct the experimental work, as well as the design of the ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

The paper sets up a simulation of a geothermal heat pump with a non-azeotropic mixture. The model is modified and verified with experimental data. The results of the simulation show that the systematic model can predict the performance within {+-}12% of the experimental data. As a result, some improvements can be provided on the basis of the simulation platform. (Author)

Energy Technology Data Exchange (ETDEWEB)

The droplet concentration profile in a liquid film-mist two-phase flow in a developing flow region of a horizontal rectangular channel was analyzed theoretically and experimentally. The effects of the mean settling velocity of droplets v sub(f) and the turbulent diffusion coefficient epsilon sub(p) on the droplet concentration profile were investigated by the theoretical analysis. The calculated results of the droplet concentration profile using the proper values of v sub(f) and epsilon sub(p) agreed with the experimental results.

Energy Technology Data Exchange (ETDEWEB)

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent ...

International Nuclear Information System (INIS)

An experimental investigation of a humidification-dehumidification desalination (HDD) process using solar energy at the weather conditions of Suez City, Egypt, is presented. A test rig is designed and constructed to conduct this investigation under different environmental and operating conditions. The test rig consists of a solar water heater (concentrator solar collector type), solar air heater (flat plate solar collector type), humidifier tower and dehumidifier exchanger. Different variables are examined including the feed water flow rate, the air flow rate, the cooling water flow rate in the dehumidifier and the weather conditions. Comparisons between the experimental results and other published results are presented. It is found that the results of the developed mathematical model by the same authors are in good agreement with the experimental ...

International Nuclear Information System (INIS)

The influence of the main factors on device efficiency of pulsed liquid jet pump with gas-liquid piston is analysed, the theoretical equation and its time-averaged solution of pulsed liquid jet pump device efficiency are derived. The theoretical and experimental results show that the efficiency of transmission of energy and mass to use pulsed jet is greatly raised, compared with steady jet, in the same device of liquid jet pump. The calculating results of time-averaged efficiency of pulsed liquid jet pump are approximately in agreement with the experimental results in our and foreign countries

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

An experimental study on superplastic forming behaviors and microstructure characters of commercial magnesium alloy sheet AZ31B is presented in this paper. The main experimental results show that the commercial magnesium alloy AZ31B sheet has superplastic capability. For the received sheet without any pre-processing, the maximum elongation is 295%. The dynamic recrystallization and grain refinement can be found, In the case of temperature =# 350 deg. C. The superplastic behaviors can be improved by controlling the dynamic recrystallization and grain refinement. Some experimental results of free superplastic bulging are presented in this paper. The results show that influence of temperature on forming capability is much less than the influences of temperature on elongation. In addition, the maximum principle strain.

Energy Technology Data Exchange (ETDEWEB)

One of the main disadvantages of solar air collectors in practical applications is their relatively low efficiency. In this experimental investigation, the shape and arrangement of absorber surfaces of the collectors were reorganized to provide better heat transfer surfaces suitable for the passive heat transfer augmentation techniques. The performance of such solar air collectors with staggered absorber sheets was tested. The experimental results show that it is possible to provide 10 to 25% enhancement in the efficiency compared to the conventional solar air collectors. (authors)

CERN Document Server

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

Energy Technology Data Exchange (ETDEWEB)

It is demonstrated that normal pitting can occur during oxidizing conditions in the repository. It is also concluded that a new theory for pitting corrosion has to be developed, as the present theory is not in accordance with all practical and experimental observations. A special variant of pitting, based on the growth of sulfide whiskers, is suggested to occur during reducing conditions. However, such a mechanism needs to be demonstrated experimentally. A simple calculational model of canister corrosion was developed based on the results of this study. 69 refs, 3 figs.

Energy Technology Data Exchange (ETDEWEB)

A summary is provided of the first of three years of experimental and theoretical research on free-forced convection flows in cavity-type solar receivers. New experimental and theoretical results are presented and discussed. The implication of these findings, with respect to the future thrust of the research program, is clarified as well as is possible at the present time. Following various related conclusions a summary and tentative schedule of work projected for year two of research are presented.

Energy Technology Data Exchange (ETDEWEB)

A correlation was developed for laminar film condensation on vertical fluted surfaces. The theoretical analysis of Panchal and Bell was used for defining important physical property groups. The experimental data of Combs et al. were used to validate the proposed correlation. The experimental database used in the present study included four flute geometries that could be approximated to cosine-type flutes and seven fluids. The resulting correlation can predict the average condensate heat transfer coefficient within {+-}20%.

Energy Technology Data Exchange (ETDEWEB)

An investigation of natural convection losses from cavity-type solar central receivers is described and results are given. The approach followed was that of a fundamental experimental study in a simple cavity subject to well controlled boundary conditions. The Laser Doppler Velocimeter proved to be a useful technique to measure the velocity profiles associated with natural convection. Visualization techniques provided an understanding of the general behavior of the flow, particularly in three dimensional experiments. Experiments on systems of high Rayleigh numbers are described. (LEW)

International Nuclear Information System (INIS)

Load-deflection characteristics of alumina and alumino-silicate fibrous blankets were experimentally determined. Load retention and springback capability of combinations of these materials were measured in a 10,000-hour test at surface temperatures of 650 to 1000"0C (1200 to 1832"0F). Experimental results are presented and future testing plans are discussed.

International Nuclear Information System (INIS)

Total M shell X-ray production cross section for 11 elements with 69 #<=# Z #<=# 92 have been measured using an incident photon energy of 5.96 keV. Measurements have been performed using an "5"5Fe annular source and a Si(Li) detector. Average M shell fluorescence yield at each incident photon energy has been deduced, using the experimental total M X-ray production cross section and theoretical M shell photoionization cross section. Present experimental results are compared with other experimental and theoretical values. Reasonable agreement (to within 0.3-28%) is typically obtained between present and other experimental and theoretical values.

CERN Document Server

The historical background of the 19th century electromagnetic theory is revisited from the standpoint of the opposition between alternative approaches in respect to the problem of interactions. The 19th century electrodynamics became the battle-field of a paramount importance to test existing conceptions of interactions. Hertz's experiments were designed to bring a solid experimental evidence in favor of one of them. The modern scientific method applied to analyze Hertz's experimental approach as well as the analysis of his laboratory notes, dairy and private letters show that Hertz's "\\textit{crucial}" experiments cannot be considered as conclusive at many points as it is generally implied. We found that alternative Helmholtz's electrodynamics did not contradict any of Hertz's experimental observations of transverse components as Maxwell's theory predicted. Moreover, as we now know from recently published Hertz's dairy ...

Energy Technology Data Exchange (ETDEWEB)

It is very important to develop the design guidelines which can be applicable for Korean operators for the purpose of designing the KSNP more safely. The objective of this project is to provide the standards, guidelines and bases applicable for HF-010 through the within-subject experiment for obtaining Korean operators' population stereotype for direction-of-movement of controls associated with displays on the control panels. Through the survey of researches on display compatibility and the classification of types of displays and controls in the main control room of Uljin units 3 and 4, methods for an experiment on the stereotype were established. Experimental interface prototypes for a total of 108 combinations of display and control types were implemented. Experimental data collection and analysis system was built in association with the interface prototypes. The experiment was performed with participation of 250 students as ...

International Nuclear Information System (INIS)

For the determination of the thermal-hydraulic performances of rough surfaces, the method of evaluation is particularly important. In order to increase confidence in the results, a new evaluation procedure was introduced. This procedure is based on the transformation of simple channel experimental results to equal boundary conditions, and on the suitable application and confirmation of these transformed values in more complicated flow channel geometries. Existing methods, applied to the results obtained in an annular channel, do not fulfil all the transformation requirements. Thus a new, more complete transformation method, which uses the turbulent eddy diffusivity model, was developed. To check the quality of this transformation, within the scope of the new evaluation procedure, the results of experimental investigation in annular channels and in a bundle of ...

International Nuclear Information System (INIS)

The main aspects of the present WWER-440 reactors spent fuel management are described in the paper. Experimental results of fuel integrity studies which are carried out under conditions of a long-term storage are also presented. (author). 5 refs, 5 figs.

International Nuclear Information System (INIS)

... 978-5-94883-072-8 121 p. SPECIFIC NUCLEAR REACTORS AND

Energy Technology Data Exchange (ETDEWEB)

We summarize some initial results in our investigation of the nuclear physics issues of gamma-ray lasers. We describe what is known thus far from existing experimental data and illustrate how theoretical models may be employed for systematic searches of candidate nuclei.

Energy Technology Data Exchange (ETDEWEB)

Experimental results of nuclear reaction and radiative decay for A = 203 nuclides are evaluated. Adopted properties for all the nine isobars, Au, Hg, Tl, Pb, Bi, Po, At, Rn, Fr of mass 203 are presented. Nothing is yet known for [sup 203]Os. 96 refs.

UK PubMed Central (United Kingdom)

BackgroundModeling of a complex biological process can explain the results of experimental studies and help predict its characteristics. Among such processes is transcription in...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundGenetic interactions within hybrids influence their overall fitness. Understanding the details of these interactions can improve our understanding of speciation. One experimental...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundSince 1954, there have been in excess of 800 cases of rabies as a result of European Bat Lyssaviruses types 1 and 2 (EBLV-1, EBLV-2) infection, mainly...Full Text Available

Science.gov (United States)

This combined analytical and experimental program is aimed at generating a manual that will permit the design of 3.0 MDN cylindrical roller bearings. The roller bearing analysis will be correlated with the results from a series of bearing tests designed t...

Energy Technology Data Exchange (ETDEWEB)

Forced vibration experiment has been conducted for the reactor building of Sendai Unit 1 nuclear power plant. The beam vibrational behaviors of the outer shielding building and the internal concrete structure have been observed by using a 50 tf vibration for low frequency region, and a 10 tf vibration for high frequency region, respectively. The outline of the experimental methods, the data handling system and the major results of experiment are described. The experimental results were simulated by an analytical model. The proper vibrational frequency and the vibration modes obtained by the analysis were compared with those obtained by the experiment. By these comparisons, the adequacy of the analytical method employed for the design was confirmed.

International Nuclear Information System (INIS)

The possibilities, advantages, and difficulties of determining nuclear matter densities by elastic scattering of alpha-particles are generally discussed. On the basis of particular experimental data - 104 MeV alpha-particle scattering from "4"0,"4"2,"4"4,"4"8Ca - a refined folded potential is introduced using a density-dependent alpha-nucleon-interaction and target nucleus densities described by Fourier-Bessel-series. Thereby, the total nucleon densities of these isotopes were determined with little model dependence. The resulting root-mean-square radii and density differences are compared with other experimental results obtained by different methods. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The Second International Seminar on Horizontal Steam Generator Modelling was arranged to continue the international cooperation that was started during the first seminar in March 1991. The main topics of the seminar were: (1) further experimental results on horizontal steam generator behaviour, (2) resent developments in modelling, (3) results on analyses and studies on primary-to-secondary side leakages, and (4) results of the common exercise calculations.

CERN Document Server

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

Energy Technology Data Exchange (ETDEWEB)

A two-phase flow regime map is developed experimentally and theoretically for a vertical hexagonal flow channel with and without a 36-finned rod hexagonal bundle. This type of flow channel is of interest to MAPLE-type nuclear research reactors. The flow regime maps are determined by visual observations and observation of waveforms shown by a capacitance-type void fraction meter. The experimental results show that the inclusion of the finned hexagonal bundle shifts the flow regime transition boundaries toward higher water flow rates. Existing flow regime maps based on pipe flow require slight modifications when applied to the hexagonal flow channel with and without a MAPLE-type finned hexagonal bundle. The proposed theoretical model agrees well with experimental results.

International Nuclear Information System (INIS)

The objective was to study the interaction of a side jet with the incoming supersonic flow and hypersonic flow. Qualitatively same Cp trends have been obtained as found experimentally. Also in aerodynamic coefficients side jet interaction results in additional pitching moment which is because of the high pressure region in upstream of the jet and a low pressure region in the downstream of the jet. Also jet interaction results in the rise in the lift coefficient. Whereas in the incidence case, simulation has been performed for the hypersonic flows over a biconic body with supersonic lateral jet at Mach 9.7 and incidence of 0"o to incidence of -12"o and 12"o. The results obtained were compared with the experimental and CFD code CFL3D results. PAK-3D over predicts the surface pressure as compared to the CFL3D and experimental ...

International Nuclear Information System (INIS)

Results of three-dimensional laminar and standard K-#epsilon# turbulent numerical simulations of natural convection cooling of ten cubic aluminum blocks mounted on an insulated plate, facing a shrouding wall, are presented. This geometry is chosen so that comparison with experimental results is possible. The considered problem is of great practical importance because it simulates the case of heated electronic chips, mounted on printed board assemblies, which are frequently encountered in electronic industry applications. The problem is mathematically modeled by the three-dimensional conservation differential equations of mass, momentum, energy and turbulent kinetic energy and dissipation (for the turbulent flow model). IN this paper, these equations are numerically solved by a finite volume method and the laminar and turbulent results are compared to the experimental ...

Energy Technology Data Exchange (ETDEWEB)

The purpose of pipe rupture studies in JAERI is to perform model tests on pipe whip, restraint behavior, jet impingement and jet thrust force, and to establish a computational method for analyzing these phenomena. This report presents the analytical results of 4-inch pipe whip tests under BWR LOCA conditions. Dynamic response analyses were performed using the general-purpose finite element program ADINA. The test pipe was modelled by straight beam elements and the four restraints were modelled by a single truss element. The analytical results were compared with the experimental results. Impact time and maximum total restraint force showed good agreement with experimental results. On the other hand, pipe strain and pipe deflection could not be predicted so well. The reason for this is that the sliding of the restraint during the pipe whip movement cannot be ...

Energy Technology Data Exchange (ETDEWEB)

Piping in nuclear power plants is vital to the proper operation and safety of these facilities. To assure safety in the unlikely event of a pipe break, it is necessary to evaluate the consequences from the resulting whipping pipe on neighboring components and structures. Numerical simulations allow for rapid evaluation of these consequences. Before simulations can be accepted, however, the methodology and computer codes must be validated against experimental results. This paper uses a probabilistic approach to validate pipe whip simulations against limited experimental results. Probabilistic analysis software was developed and coupled to existing deterministic finite element software. An example of a whipping pipe impacting against a reinforced concrete slab was simulated. The described probabilistic approach was used to validate the numerical simulations. The conclusions obtained ...

International Nuclear Information System (INIS)

This paper proposes an integrated method for using experimental data and CFD modeling to develop engineering correlations for atrium smoke management. Part I focused on the experimental program and validation of a CFD model of the experimental facility. Part II describes the extension of this model to a parametric study of balcony spill plumes. Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production or mass flow rate of the buoyant fire plume. One design issue is the mass flow rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes (BSPs) are based on a combination of one-tenth scale test data and theoretical ...

International Nuclear Information System (INIS)

Experimentally investigated nuclear reactions for production of no-carrier-added "7"7Br and "7"7Kr were critically surveyed. The survey covered nine reactions for the formation of "7"7Br and six reactions for "7"7Kr. Both radionuclides are simultaneously produced in many of the studied nuclear processes. The experimental data were compared with the results of nuclear model calculations based on the computer code ALICE-IPPE and the third version of TALYS-based Evaluated Nuclear Data Library, TENDL-2010. Good agreement was found over extended energy regions for the p-, "3He- and #alpha#-particle induced reactions on several target materials. In case of d-induced reactions, however, considerable discrepancies were noted between the experimental and theoretical data. The concordant sets of experimental cross section data for each reaction were fitted by a polynomial function to obtain a ...

Energy Technology Data Exchange (ETDEWEB)

An experimental rig was set up to study the performance of a thermal storage unit using stearic acid as the heat storage medium. The unit mainly consists of an electrical heating rod and an outer tube, and the space between is an annulus that is filled with stearic acid. The thermal performance of the unit is measured, and the heat transfer characteristics of the melting processes of stearic acid are studied under different heat flux conditions to determine the influence of heat flux on the melting processes. A new type of fin is designed and fixed to the electrical heating rod to enhance the thermal response of the stearic acid. The experimental results show that the fin can improve the heat transfer of the melting process of the thermal storage unit greatly. The equivalent thermal conductivity of the PCM can be augmented by a factor up to 3. The analysis of the experimental ...

Energy Technology Data Exchange (ETDEWEB)

The results of an experimental investigation of the performance of a small bore engine with a swirl chamber when operating as a dual fuel engine with commercial methane as the gaseous fuel were presented in this paper. The experiment involved using a 3-dimensional computational fluid dynamics model to predict the performance of the engine. A detailed chemical kinetics for the gaseous fuel component, consisting primarily of methane and a reduced detailed chemical kinetics for the diesel fuel while considering the turbulent combustion processes an associated performance of a dual fuel engine with a swirl chamber were incorporated in the simulation. The study experimentally and numerically investigated the effects of changes in the quantities of the liquid fuel pilot and gaseous fuels on the combustion processes, engine performance, cyclic variations, and emissions. The paper discussed the experimental ...

Energy Technology Data Exchange (ETDEWEB)

The isothermal flow field for the axial cyclone has been experimentally determined. The velocity fields are used for determination particle paths (particle removal and suspended state), and inter alia of heat and mass transfer processes in the axial cyclone combustion chamber. The results are extremely significant as input value approximations for mathematical modelling, since experimentally obtained results are indispensable for complex flows and geometries. (orig.) [Deutsch] Es ist fuer den Axialzyklon experimentell das isotherme Stroemungsfeld ermittelt. Die Geschwindigkeitsfelder dienen zur Ermittlung der Partikelbahnen (Partikelabscheidung, Schwebebedingung), der Waerme- und Stoffuebertragungsprozesse u.a. in der Axialzyklonbrennkammer. Die Ergebnisse sind als Startwertnaeherung bei einer mathematischen Modellierung sehr wichtig, da bei komplexen Stroemungen und Geometrien versuchstechnische ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

The LAHET code system calculations and experimental results for proton interactions with an energy <50 MeV are compared. For these energies, the theories behind the LAHET models are not applicable. Three quantities compared are (a) the magnitude of the neutron yield generated through proton interactions, (b) the energy and angular distributions of the resultant neutrons, and (c) the residual nuclei produced by proton interactions (spallation products). The comparisons are for protons incident on iron and copper, except in the case of the energy and angular distributions, which are calculated only for iron. The neutron yields predicted by LAHET agree with published measurements to within 50% for both materials. For iron, the predicted energy and angular distributions agree to within a factor of 3. Finally, the predicted spallation product yields of both materials agree with measurements to within a factor of 4.

British Library Electronic Table of Contents (United Kingdom)

Piping in nuclear power plants is vital to the proper operation and safety of these facilities. To assure safety in the unlikely event of a pipe break, it is necessary to evaluate the consequences from the resulting whipping pipe on neighboring components and structures. Numerical simulations allow for rapid evaluation of these consequences. Before simulations can be accepted, however, the methodology and computer codes must be validated against experimental results. This paper uses a probabilistic approach to validate pipe whip simulations against limited experimental results. Probabilistic analysis software was developed and coupled to existing deterministic finite element software. An example of a whipping pipe impacting against a reinforced concrete slab was simulated. The described pr...

Energy Technology Data Exchange (ETDEWEB)

In this article, the results of low-current gas-discharge plasma generator investigations carried out by a group of scientists from the Kazan' Aviation Institute are presented. When considered necessary, the results are compared with the data obtained by other authors. The basic configurations and theoretical calculation peculiarities of plasma generators are described. The electrical, thermal and energy characteristics of discharges in gas flows, as well as summarised empirical formulae and experimental data necessary for calculations and design of plasma devices are presented. (author)

International Nuclear Information System (INIS)

The Finnish simulation code APROS and especially its 5-equation model is applied to modelling the horizontal steam generator. Different nodalizations are used in the secondary side of different models. Simulation results of the stationary state run are compared with results of RELAP5/MOD2 calculations and with an experimental plant data. (2 refs., 3 figs., 4 tabs.).

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This paper describes the implementations of a fuzzy logic based self-tuned controller to improve the stability of electric power systems. The stabilizing signal is computed using the standard fuzzy membership function depending on the speed/acceleration state of the generator in the phase plane. The performance of the proposed stabilizer is demonstrated by practical implementation using a digital signal processor mounted on a PC-AT. Results of the experimental tests on a physical model of a power system are presented.

International Nuclear Information System (INIS)

The ALPHA project is centered around the experimental and analytical investigation of the long-term decay heat removal from the containments of the next generation of open-quotes passiveclose quotes ALWRs. The project includes integral system tests in the large-scale (1:25 in volume) PANDA facility as well as several other series of tests and supporting analytical work. The first series of experiments to be conducted in PANDA have become a required experimental element in the certification process for the General Electric Simplified Boiling Water Reactor (SBWR). The PANDA general experimental philosophy, facility design, scaling, and instrumentation are described. Steady-state PCCS condenser performance tests and extensive facility characterization tests were already conducted. The transient system behavior tests are underway; preliminary results from the first transient test M3 are reviewed.

International Nuclear Information System (INIS)

As part of Steam Generators Owners Group Project S-146, ''Diffusion and Hideout in Crevices,'' experimental data were obtained on chloride salt hideout and return in a controlled-boiling INCON system containing three electrically heated, thermocouple instrumented tube-to-support-plate intersections. The support plate simulants had first been caused to undergo, in situ, denting-type corrosion to the extent that substantial tube deformation was observed. Then chloride hideout and return measurements were made, using sodium chloride as the impurity additive. Experimental results were fitted to an elementary model for the crevice and its associated transport processes. Details on the experimental work and a description of the data-fitting method are given in the final report, NP-2979, dated March 1983.

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption (the Henry constant, the heat and entropy of adsorption) of amino acids associates with acetic, trifluoroacetic, nonafluoropentanoic acids and formamide with different values of hydrogen bond lengths and various conformations on a graphitized thermal carbon black (GTCB) were calculated. The experimental results, as the Henry constant, lnK1, and the differences in the molar Gibbs energies, d(DG), obtained by a high performance liquid chromatography (HPLC) on a carbon sorbent Hypercarb, were compared with the values of thermodynamic characteristics of adsorption of the amino acids on the GTCB surface calculated by a molecular-statistical method. A satisfactory correlation was observed between the experimental and calculated values with a coeffi...

British Library Electronic Table of Contents (United Kingdom)

Abstract Dynamic testing of a phosphoric acid-based high temperature PEM fuel cell shows a peculiar phenomenon. A certain current loss is observed after temperature cycling at constant voltage. This loss is incidentally recovered by applying a cell voltage spike to open circuit voltage. Experimental investigations into temperature, cell voltage, and ageing effects show that this phenomenon might occur due to the orientation of the adsorbed phosphate species on the platinum catalyst surface. Along with some supporting literature and experimental results, a hypothesis is presented in order to explain this occurrence. Phosphoric acid adsorption hysteresis on platinum catalyst due to temperature cycling could cause the temporary cell current loss. Electrode potential-dependent molecule symmetr...

International Nuclear Information System (INIS)

Experimental investigations of the turbulence characteristics of the air flow above the wave surface of the film in the horizontal rectangular channel in the 5-20 m/s velosity range of the air rate change (Reynolds number for the air 120O0-48000, 100-1000 for the film) are carried out. It is shown that intensities of turbulent pulsations of the rate increase with the growth of liquid flow rate in the film especially in the region of large squall waves. The experimental results on the pulsations are presented in the dimensionless form by a universal dependence. Distributions of tangentials of turbulent stresses above the film are obtained, turbulent stresses are compared with friction losses at the phase interface.

Energy Technology Data Exchange (ETDEWEB)

Describes performance of excavator teeth manufactured with a new hard alloy. The alloy was developed by the Donetskii Politeknicheskii Institute. Its composition consists of a high-chromium steel with a larger amount of titanium than serial alloy, and a nitrogen additive. Trial tests of new alloy teeth were carried out in the Severnyi and Vershinskii coal surface mines. The teeth were attached to EhRP, EhPG and EhR bucket wheel excavators. Abrasive wear of 129 experimental teeth and 134 serial teeth was compared for different excavation conditions. Test results are tabulated; advantages of the new experimental teeth are listed. 3 refs.

International Nuclear Information System (INIS)

Closing and breaking of current in microsecond megaampere plasma opening switches are considered. Conductivity current scaling in the switch due to plasma acceleration by a magnetic piston is discussed and compared with experimental data. Two ways of determining the width of a current channel are taken up. This channel results from the diffusion of the magnetic field in the plane of the piston followed by the convective ejection of the field frozen in the accelerated plasma flow behind the shock wave into the bridge. Based on experimental data, a scaling law for the voltage on the switch according to the switch parameters is derived. The problem of reverse closing, which limits the efficiency of storage energy extraction into the load, is considered

International Nuclear Information System (INIS)

During a high temperature treatment of the radioactive wastes that contain ruthenium, some ruthenium is volatilized and released to the off gas system. The volatilized ruthenium is removed with a scrubber and an adsorber. It was expected that the scrubber was one of the most effective equipments to remove ruthenium and the decontamination factor of the scrubber was studied. The experimental apparatus was simulated as part of an actual perforated plate column scrubber. The non-radioactive ruthenium which simulated the radioactive ruthenium was volatilized and fed into the scrubber. The decontamination factor of the scrubber was determined by the ratio of the ruthenium concentration at the inlet and outlet of the scrubber off gas stream. The results showed that the scrubber removed the volatile ruthenium effectively as expected.

Energy Technology Data Exchange (ETDEWEB)

The usefulness of the mouse, rat, and Syrian golden hamster as experimental models for studies of the development of respiratory tract cancer is considered. Three different application methods for examining the effects of environmental chemicals on the respiratory tract in these species are discussed: implantation, intratracheal instillation, and inhalation. The results of various investigations are presented to demonstrate that each particular method has both advantages and disadvantages. The techniques are also considered in comparison with the human situation and in the light of obtaining the most valid data for extrapolation to man. Brief attention is paid to the relevance to respiratory tract carcinogenesis of more recently developed organ and cell culture systems.

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

An experimental verification for long-term performance of a Pd-Ag permeation in ITER tritium fusion cleanup units (FCU) is needed. In addition, information is required on the influence of tritium and {sup 3}He decay on the physical and chemical properties of Pd-Ag alloys (V-1). The results of the investigations of alloys (V-1) (mechanical properties and microstructure) after long-term usage exposition in tritium are given in this report. The experimental conditions (temperature, pressure, clearance, {sup 3}He concentrations) and the previous conclusions on the V-1 alloy performance are presented. (orig.).

International Nuclear Information System (INIS)

This paper presents the results of the experimental investigation on heat transfer and fluid friction characteristics of a class of spiral spring coil used as a tube side forced convection heat transfer augmentation devices. Based on a lot of experimental data, the heat transfer correlation and fluid friction correlation revised by temperature were reached in terms of linear regression. At the same time, proper criteria were used to evaluate the economic performance of the spiral spring inserted tube according to the demand of practical application and some probing analysis were made.

Energy Technology Data Exchange (ETDEWEB)

Localized corrosion has a stochastic character by nature. This character leads to an observed random behavior: fluctuations of the free potential, fluctuations of the current when a constant potential is maintained. This random signal, which is similar to an electric noise, can be analyzed either in the time domain by counting the events or in the frequency domain by measuring the power spectral density of the electrochemical noise. The experimental techniques developed for investigating the localized corrosion on the probabilistic point of view, i.e., statistical counting and power spectral density measurements, are discussed. Then the experimental results reported in the literature are reviewed in order to see what kind of parameters are accessible and how they can be related to the localized corrosion processes.

Energy Technology Data Exchange (ETDEWEB)

Triaxial compression tests following stress paths of constant {sigma}{sub 1} were conducted to determine the shear strength of five processed scrap tire products having different gradations and particle shapes. The interparticle frictional component was separated from the total shear strength according to the energy correction concept proposed by researchers. The experimental results show that all five tire chip products have ultimate internal friction angles of 45{degree} to over 60{degree}. The interparticle frictional component of the strength was fully mobilized and nearly reached a constant value after approximately 5% axial strain. The experimental results confirmed that the strength parameter obtained with constant {sigma}{sub 1} was more reasonable. This finding is supported by field observation in which the tire chips have an angle of repose ranging from 37{degree} to 43{degree} (loosely stock ...

Energy Technology Data Exchange (ETDEWEB)

Superplasticity of polycrystalline metallic materials is a phenomenon which shows hundreds to thousands of percents of large plastic deformation without necking in a steady state of low stress, when the uni-axial tensile loading is done in some special thermo-mechanical conditions (some limited ranges of properly high temperature and low strain rate). The main mechanism of superplastic phenomenon is the grain boundary sliding, while the main mechanism of usual plastic deformation is the trans-granular sliding. In this research, the possibility of superplastic deformation in a magnesium alloy (AZ31Mg alloy) was experimentally investigated, because generally speaking, the magnesium alloy whose atomic structure is hexagonal does not have enough formability in a form of trans-granular sliding mechanism. In this paper, the detail of experimental results are shown and discussed. Moreover, the constitutive equations of Mg alloy ...

International Nuclear Information System (INIS)

The symmetric noncoplanar (e,2e) cross sections (momentum profiles) of H_2 and D_2 for the transitions to the 2p#sigma#_u and 2s#sigma#_g excited ion states have been measured, relative to the ground-state ion transition, using a high-sensitivity multichannel momentum-dispersive electron momentum spectrometer (EMS) at an impact energy of 1200 eV. Newly calculated plane-wave impulse approximation (PWIA) cross sections, based on a full-configuration-interaction H_2 wave function, are compared to the experimental results. These calculations are in better agreement with the experimental results for the transition to the 2s#sigma#_g ion state than the earlier theoretical work of Liu and Smith, Jr. [Phys. Rev. A 31, 3003 (1985)] which has been found to be in error. Nevertheless, significant discrepancies between the relative experimental and theoretical cross sections are observed for the ...

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As contamination flashover is in Mexico the second cause of transmission line faults, the Mexican Electrical Research Institute carried out a project to determine pollution patterns for the Republic of Mexico to be used for the design of external insulation. Results from the project are presented: the modelling, based on the field data of 23 experimental sites, of long term variations of pollution patterns as a function of environmental variables, insulator shape and position, as well as other important field results. 32 refs, 2 figs, 4 tabs

International Nuclear Information System (INIS)

To get a better understanding of the condensation oscillation and chugging process during blowdown of a BWR after a LOCA a large number of large scale pressure suppression experiments have been performed in several countries. ECN has performed a detailed analysis of the results of one of these experiments, e.g. the DAS M10 experiment of GKSS. This analysis includes the following aspects: Power Spectral Density (PSD) analysis of the data, analysis of the acoustic frequencies of the downcomers and an analysis of the eigenfrequencies of the downcomers. The results of these analyses and an evaluation are given in this paper. It is shown that all dominant frequencies in the experimental results can be correlated with the vent-acoustic or eigenfrequencies. (orig.).

Science.gov (United States)

In this paper we present some final results from a research project focused on introducing automatic control to the operation of cupola iron furnaces. The main aim of this research is to improve the operational efficiency and performance of the cupola furnace, an important foundry process used to melt iron. Previous papers have described the development of appropriate control system architectures for the cupola. These results are summarized. Then we describe the experimental results obtained with the U.S. Department of Energy Albany Research Center`s research cupola. First, experimental data is used to calibrate the model, which is taken as a first-order multivariable system with time delay. Then relative gain analysis is used to select loop pairings to be used in a multi-loop controller. The resulting controller pairs meltrate with blast volume, iron ...

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We have measured the almost-pure incoherent scattering function of liquid and solid parahydrogen, using inelastic neutron scattering. The experiments were carried out on TOSCA, a time-of-flight, inverse-geometry, crystal-analyzer spectrometer, operating on the pulsed neutron source at ISIS (UK). The experiments have been planned taking advantage of the intrinsic incoherence introduced in the scattering process by the rotational transitions. The measured double-differential cross section gives a direct experimental access to the microscopic dynamics of condensed hydrogen. From the high-energy region of the spectrum, where the impulse approximation for the center of mass motion applies, we have been able to extract the translational mean kinetic energy. In the low-energy region, using the Gaussian approximation, we compare the experimental data in the liquid phase with the results of a model for the velocity autocorrelation ...

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Singlet-singlet and triplet-triplet absorption spectra of a series of methyl-alloxazines were calculated using the time-dependent density-functional theory approach and compared to experimental results. The B3LYP functional provides good correlation between experimental and theoretical results, given that solvent effects are disregarded in the present calculations. Substituent and solvent dependences of the lowest, closely spaced, n,{pi}* and {pi},{pi}* excited state energies are discussed, their order being of consequence in determining the non-radiative decay rates and thus emission quantum yields and lifetimes. The high quantum yields of singlet oxygen formation indicate that the triplet state is formed by efficient intersystem crossing from the first singlet excited state.

British Library Electronic Table of Contents (United Kingdom)

This experimental study investigates the effectiveness of crossed inclined bars (X-bars) as joint shear reinforcement in exterior reinforced concrete beam-column connections under cyclic deformations. Test results of 20 joint subassemblages with various reinforcement ratios and arrangements including X-bars in the joint area are presented. The X-type, non-conventional reinforcement is examined as the only joint reinforcement and in combination with common stirrups or vertical bars. The experimental results reported herein include full loading cycle curves, energy dissipation values and a categorization of the observed damage modes. Based on the comparisons between the overall hysteretic responses of the tested specimens, it is deduced that joints with X-bars exhibited enhanced cyclic perfo...

International Nuclear Information System (INIS)

Neutron energy spectra were measured for two OSURR experimental facilities. The method of multiple foil activation was used with the SAND-II neutron spectrum unfolding code to obtain spectral data for the Central Irradiation Facility and Rabbit tube. Limited data was obtained for the thermal column using only gold foils. Calculations were made of the neutron environment in various locations using the MORSE code. A shift towards higher neutron energies was observed comparing results for LEU and HEU cores. A slight loss in total thermal neutron flux was measured for all positions. Calculational results show reasonable agreement with measured data.

International Nuclear Information System (INIS)

The experimental technique used for detection of subcooled boiling through analysis of the fluctuation contained in pressure transducer signals is presented. This work was partly conducted at the Institut fuer Kerntechnik und zertoerungsfreie Pruefverfahren von Hannover (IKPH, Germany) in a thermal-hydraulic circuit with one electrically heated rod with annular geometry test section. Piezo resistive pressure sensors are used for onset of nucleate boiling (ONB) and onset of fully developed boiling (OFDB) detection using spectral analysis/ signal correlation techniques. Experimental results are interpreted by phenomenological analysis of these two points and compared with existing correlation. The results allow to conclude that this technique is adequate for the detection and monitoring of the ONB and OFDB. (author)

British Library Electronic Table of Contents (United Kingdom)

This study deals with the neutronics analysis of the current core configuration of a 3MW TRIGA Mark-II research reactor at Atomic Energy Research Establishment (AERE), Savar, Dhaka, Bangladesh and validation of the results by benchmarking with the experimental, operational and available Safety Analysis Report (SAR) values. The comprehensive neutronics code system SRAC was used to develop a versatile and accurate full-core model of the TRIGA core. The model represents in detail all components of the core with literally no physical approximation. All fresh fuel and control elements as well as the vicinity of the core were precisely described. Cross-section data library generated from JENDL-3.2 were used. The validation of the model against benchmark experimental results is presented. The SRA...

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Femaxi-iv is a computer code for the analysis of thermal and mechanical behavior of light water reactor fuel rods during steady-state and transient conditions. The main purpose of femaxi-iv is to calculate the stress and strain distributions in the fuel and cladding due to the pellet-cladding mechanical interaction, and the fission gas release rate during operations, especially power transients. The capability of femaxi-iv was extensively tested with a number of experimental results obtained in some international fuel irradiation programs. This paper provides a general description of the various models involved in femaxi-iv and some results of applications on the experimental data. ((orig.))

International Nuclear Information System (INIS)

Some results and experimental procedures of laboratory are reported in the frame of researches conducted for the development of new nanostructured composite materials. These new materials, which are constituted by an organic phase: the polymer and an inorganic phase: the silicate, are being strongly investigated nowadays so it is expected that they could provide, among other, better electrical insulation properties and flame-delay in electrical and electronic applications. The laboratory experimental work has been developed from two families of polymers, thermoplastics and thermosets and clays silicates providing lamellar type. There are now some preliminary results, such as obtaining thin films of these nanocomposite materials, their complete characterization by X-ray diffraction, scanning microscopy and thermogravimetric analysis, they do well to wait for future research activities. (author)

Science.gov (United States)

This paper focuses on a factorial-based design strategy. The approach provides an efficient and statistically reliable means for assessing the influence of multivariable effects. It is applied to the detection and evaluation of damage in impacted composite sandwich panels. The experimental results obtained from this test strategy are utilized to form an empirical response function. The resulting polynomial relates damage area to residual compression strength at values of independent variables for which testing did not occur. The response function also identifies nonlinear interaction effects of key variabes that cannot be easily ascertained by traditional single-variable test strategies. Independent variables evaluated include core thickness, number of face sheet plys and impact energy. The methodology presented allows the designer to predict with more confidence the damage tolerance of a composite material component, and ...

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In the design of LWRs, the forecast of critical heat flux (CHF) is important. The existing CHF correlation equations include the arbitrary constants based on experimental data, therefore, their range of application is limited. For advancing the research and development of high conversion LWRs or passive safety reactors, the development of more general CHF forecasting technique has been demanded. In order to elucidate the mechanism of CHF occurrence and construct the general forecasting model based on physical phenomena, the detailed observation of flow phenomena near a heat generation surface is indispensable. The experiment of observing boiling two-phase flow and CHF phenomena by applying neutron radiography technique was carried out. The utilization of neutron radiography in the field of heat-transferring flow is explained. The experimental setup and the experimental method, the experimental ...

CERN Document Server

The recently measured experimental data of Argonne National Laboratory for high-spin states in neutron-rich $^{71,73,75,77}$Ga isotopes have been interpreted in the framework of large-scale shell model. Calculations have been performed in $f_{5/2}pg_{9/2}$ model space with two recent effective shell model interactions, JUN45 and jj44b. We also predict high-spin states for $^{79,81}$Ga, where very little is known experimentally. The calculated results show that existence of band structure built on top of the 3/2$^-$, 5/2$^-$ and 9/2$^+$ levels in $^{71-77}$Ga. The collective structure reflected in experimental data is not well reproduced in calculated values. The calculated positive parity states in $^{71,73,75}$Ga are higher in energy in comparison to experimental finding, while for $^{77,79}$Ga, the positive parity states are in better agreement. Both the interactions predict, ...

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Niobium carbide can be used to inhibit WC grain growth in hardmetal. The performance of a NbC powder produced at low temperature by solid-gas reaction (an experimental powder) as WC grain growth inhibitor is compared with that of a commercial NbC powder. It is verified that NbC effectively inhibits heterogeneous WC coarsening. This results in an increase in hardness. The commercial and experimental NbC powders exhibit a comparable performance in inhibiting the WC grain coarsening, in spite of a significant difference in particle size and shape. The commercial NbC powder is very fine while the experimental one is coarse and porous, but its crystallites are finer than those of the commercial product. The milling procedure used to prepare the alloys is able to reduce the particle size of the experimental NbC, and thus guarantee a dispersion of the particles with a quality level ...

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Producing nuclear energy in order to reduce anthropic CO{sub 2} emission and to meet high energy demand, implies three conditions to the nuclear plants of the IV. generation: safety improvements, radioactive waste minimization, and fuel breeding for a sustainable use of the resources. The Thorium fuel cycle used in Molten Salt Reactors seems promising. Many numerical studies based on probabilistic codes are carried out in order to analyse the behaviour of such reactors. Nevertheless, one of the most important parameters is badly known: the alpha ratio of {sup 233}U, ratio of the neutron capture cross section to fission one for {sup 233}U. This key-parameter is necessary to calculate the breeding ratio and thus, the deployment capacities of those reactors. This Ph-D thesis was intended to prepare a precise measurement of the alpha ratio of {sup 233}U between 1 eV and 10 keV. Preliminary measurements have been performed on the experimental platform PEREN. This ...

Energy Technology Data Exchange (ETDEWEB)

A numerical investigation of a humidification dehumidification desalination (HDD) process using solar energy is presented. The HDD system consists mainly of a concentrating solar water heating collector, flat plate solar air heating collector, humidifying tower and dehumidifying exchanger. Two separate circulating loops constitute the HDD system, the first for heating the feed water and the second for heating air. A mathematical model is developed, simulating the HDD system, to study the influence of the different system configurations, weather and operating conditions on the system productivity. The model validity is examined by comparing the theoretical and experimental results of the same authors. It is found that the results of the developed mathematical model are in good agreement with the experimental results and other published works. The results show ...

International Nuclear Information System (INIS)

We have studied both theoretically and experimentally a new scheme of active pulse compression in a free electron laser (FEL) amplifier. The pulse compression scheme presented here is the following. A frequency-chirped pulse is injected into the FEL interaction region. Because of the high gain and narrow bandwidth of the FEL interaction, only the resonant frequency band of the pulse is actively amplified, resulting in a short pulse of high power coherent radiation at the output of the laser. For our experimental parameters (beam voltage #approx =# 150 kV, current #approx =# 5.0 A, wiggler period #approx =# 3.5 cm and gain #approx =# 10 dB), pulses of a few nanoseconds were generated at #approx =# 10 GHz after an interaction length of 2.30 m, in good agreement with theoretical expectations. For the same input pulses (width > 100 ns, frequency chirp #alpha#/2#pi# #approx =# 5 MHz/ns), the obtention of such compression ...

International Nuclear Information System (INIS)

The band structure (BS) of crystalline Bi_2Se_2Te both pure as well as deposited on Si or SiO_2 (substrates) was calculated for the first time. The calculation approach consists of an orthogonalization of the plane wave basis set with respect to the core-like orbitals and the application of the Perdew-Alder exchange-correlation scheme. In addition, a virtual crystal approach was applied. Experimental ellipsometric spectra were used as a criterion of the advantages of the different calculation techniques. The results of traditional one-electron methods of BS calculations, using norm-conserving pseudo-potential (NCPP), and full linear augmented plane wave (FLAPW), were compared with the experimental data. Better agreement with experiment is achieved when the NCPP wave functions are orthogonalized to the 4dBi core-like states. Concerning the LMTO and the FLAPW all-electron methods, only appropriate application of the virtual ...

Energy Technology Data Exchange (ETDEWEB)

In this paper the authors present some final results from a research project focused on introducing automatic control to the operation of cupola iron furnaces. The main aim of this research is to improve the operational efficiency and performance of the cupola furnace, an important foundry process used to melt iron. Previous papers have described the development of appropriate control system architectures for the cupola. In this paper experimental data is used to calibrate the model, which is taken as a first-order multivariable system with time delay. Then relative gain analysis is used to select loop pairings to be used in a multiloop controller. The resulting controller pairs melt rate with blast volume, iron temperature with oxygen addition, and carbon composition with metal-to-coke ratio. Special (nonlinear) filters are used to compute melt rate from actual scale readings of the amount of iron produced and to smooth ...

International Nuclear Information System (INIS)

The energy levels of the configuration f"2 in an eight-fold cubic crystal field (CF) have been calculated, and the results are used to explain the experimental spectrum of UO_2. The fourth-order CF potential turns out to be much smaller than usually assumed for this compound. This has an effect of reducing the J-mixing in the wavefunctions, particularly in the case of the ground state wavefunction. In spite of the strength of the CF, the ground state vertical stroke "3H_4T_2 right angle is found to be modified only slightly by the J-mixing effect; it consists of 89.4% "3He_4, and the remaining eleven components make up the rest. Very good correlation is obtained between the experimental and simulated energy-level schemes. The predominance of "3H_4 in the ground state consequently increases the value of the calculated effective magnetic moment. The results are compared with our previous predictions about ...

Energy Technology Data Exchange (ETDEWEB)

Experimental and theoretical investigation on drying of a single coal particle in fluidized bed combustor is presented. Coal particle drying was considered via the moist shrinking core mechanism. The results of the drying test runs of low-rank Serbian coals were used for experimental verification of the model. The temperature of the coal particle center was measured, assuming that drying was completed when the temperature equalled 100{sup o}C. The influence of different parameters (thermal conductivity and specific heat capacity of coal, fluidized bed temperature, moisture content and superheating of steam) on drying time and temperature profile within the coal particle was analyzed by a parametric analysis. The experimentally obtained results confirmed that the moist shrinking core mechanism can be applied for the mathematical description of a coal particle drying, while dependence ...

Energy Technology Data Exchange (ETDEWEB)

Methods of designing ultrasonic piezoelectric transducers in accord with a specified directivity pattern are analyzed and general formulas are presented for the design problem. As an example, the pressure distribution on the working surface of a circular piezoelectric transducer is determined that is capable of forming a narrow weakly divergent beam. Experimental results are presented with respected to ultrasonic fields that support the theoretical conclusions.

Energy Technology Data Exchange (ETDEWEB)

The nuclear shapes of transitional Mo isotopes are calculated by means of a model based on the cranking approximation and the Strutinksy method. The recent experimental results of the high-spin spectroscopy and lifetime measurement of [sup 87]Mo are studied in detail and explained by the evolution of the [gamma]-deformation with the quasiparticle configurations. The shape calculations with the modified-harmonic-oscillator potential give a critical neutron number N [>=] 47 for the spherical shape of the Mo isotopes. (orig.)

Energy Technology Data Exchange (ETDEWEB)

In this work, the thermodynamic behaviour of single-stage horizontal spray coolers with one or more spray levels is experimentally examined. Further, a spray cooler calculation model was developed, in order to describe the processes and to make a comparison of the results of calculation and measurement. The state of the mine climate and the cold water are taken as the thermodynamic reference. (orig.).

International Nuclear Information System (INIS)

The loss of lead in various kinds of biological materials after drying and ashing is studied by using "2"0"3Pb as tracer which is intravenously injected into mice. The experimental results show that although the oven ashing can be used for determining the lead in samples of lung, kidney, and liver, etc., the oxygen plasma and high pressure digestion are the most suitable methods for the determination of lead in biological materials. (author) 5 refs.; 2 tabs.

Science.gov (United States)

The experimental device for generation of undulator radiation in terahertz wavelength region by use of undulator with ferromagnets is created. The device is based on a beam of a microtron with the energy 7.5 MeV. The radiation wavelength is 200 mu. Registered spontaneous radiation has a power 10{sup -6} W at a current of a beam 2 mA in a pulse. With the optical resonator, in a mode, the amplification of 6% is received, that in sometimes is more than the expected value. This effect is explained as a result of partial coherence of radiation.

Energy Technology Data Exchange (ETDEWEB)

Surface deposition probe techniques have been shown to be an effective means of determining the characteristics of the plasma edge region of magnetic confinement devices. Experimental results on ISX-B and EBT-S have led to a consistent picture of the edge plasma and the dominant impurity introduction mechanisms. This picture is supported by numerous other measurements and emphasizes the importance of concentrating several techniques on the complex problems of plasma fusion.

International Nuclear Information System (INIS)

Refractive indices of some mixed compound semiconductors below the bandgap are presented on the basis of some fundamental parameters and the effect of lattice mismatch on the refractive index step is also studied. The results help to design a variety of opto-electronic devices for the use in optical fiber communication and heterostructure lasers. The calculated values agree well with available experimental values thus justifying the approach. (author).

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

Results of the evaluation of the scattered radiation effect on the image of defects in examined products are given. The formula is suggested which characterizes the image of defects on a scintillation screen as well as accumulation factors are calculated by the Monte-Carlo method. Values of fluctuations of absorbed energy in the screen used for the evaluation of sensitivity are experimentally obtained. The effect of high-energy bremsstrahlung on the defect detection is analyzed.

International Nuclear Information System (INIS)

Recent results of experimental and theoretical investigations, carried out in the Institute of plasma Physics of the NSC KIPT, are presented in the report. The main problems of discussion are as follows: plasma confinement and heating in stellarators and electromagnetic traps; powerful quasi-steady-state plasma accelerators (QSPA); experiments relevant for ITER; fusion Plasma theory; methods of high temperature plasma diagnostics; plasma technology. The main prospects on the IPP investigators are discussed also.

International Nuclear Information System (INIS)

The purpose of the work reported in this paper was to measure the radionuclide buildup in primary heat transport system cell No. 3 at the Fast Flux Test Facility (FFTF) and to compare the results with predicted values from a model based on experimental studies and experience at similar reactors. The information obtained is used for maintenance planning and to enhance ability to assess radionuclide buildup in the future at FFTF and in other reactors.

International Nuclear Information System (INIS)

The quark structure of constituent nucleons is considered by a qualitative comparison of features of different models with experimental data with respect to cumulative meson production. It is shown that the fluctuation of the density of nuclear matter, ie the creation and disintegration of a short lived few-nucleon correlation (flucton), is a type of the quasi-resonance formation in the nucleus which exists without any connection with the incident particle. The cumulative production in the region under investigation is mostly the result of a Regge type dissociation of the flucton. (U.K.).

Energy Technology Data Exchange (ETDEWEB)

We will examine modeling data for various orbits using modeling software and compare this with actual satellite flight result. In particular, we will discuss the contributions of trapped protons to total dose and the effectiveness of shielding.

International Nuclear Information System (INIS)

The most important results of theoretical and experimental studies of plasmas, which have been achieved at the IPJ in Swierk and IPPLM in Warsaw recently, are presented. Studies of physical phenomena in PF discharges, development of diagnostic techniques and research on new plasma technologies, as performed at IPJ, have been summarized. Studies of dense magnetized plasmas, investigation of physics and applications of laser-produced plasmas; and research on the development of advanced diagnostic techniques for the EUROATOM fusion program, as performed at IPPLM, are also described.

International Nuclear Information System (INIS)

The wavefunction of a positron in ReO is calculated using the augmented-plane-wave method. Due to the loosely-packed structure of ReO_3, the ground-state GAMMA_1 wavefunction exhibits a marked anisotropy particularly around the oxygen ions, and a large fraction of a positron is distributed in the interstitial region. Experimental results of the positron annihilation 2#gamma#-correlations and the positron annihilation rates in ReO_3 are discussed based on the positron wavefunction. (orig.).

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Experimental results of a search for the {Xi}{sub 3/2}(1860) cascade pentaquark state in data collected with the CDF 2 Detector in Run II at the Tevatron are presented. No evidence for these states in the neutral {Xi}{sup -}{pi}{sup +} and doubly charged {Xi}{sup -}{pi}{sup -} modes has been found. Preliminary upper limits on yields at 1862 MeV/c{sup 2} relative to the well established resonance {Xi}*(1530){sup 0} are presented.

Science.gov (United States)

Results are given of numerical simulation of three-dimensional pattern of flow of a two-phase steam-water mixture in the house of a PGV-1000 horizontal steam generator obtained using the BAGIRA best-estimate thermohydrodynamic computer codes. The space distributions of velocities and local void fractions in the steam generator housing for different modes of operation of power-generating unit are calculated and compared with available experimental data.

International Nuclear Information System (INIS)

Based on a hypothesis of multiquark states in nuclei, the nucleus structure functions are considered and the results are compared with experiment. It is shown that the multiquark state contributions are sufficiently high (Up to 20% in deuterium and 40% in iron) and must possess a greater, than in a nucleon, sea of quark-antiquark pairs. Also the comparison with the cumulative particle production cross sections is performed. The predictions are given for a further experimental test of that hypothesis.

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The objective of this project is the development of a new class of metalloporphyrin materials used as catalsyts for use in fuel cell applications. The metalloporphyrins are excellent candidates for use as catalysts at both the anode and cathode. The catalysts reduce oxygen in 1 M potassium hydroxide, as well as in 2 M sulfuric acid. Covalent attachment to carbon supports is being investigated. The computer-aided molecular design is an iterative process, in which experimental results feed back into the design of future catalysts.

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Results of experimental researches of impurity level crystals Fe1-xCoxSi are presented in this article. Magnetic properties in a temperature range up to T {<=} 1000 K are analyzed. It was established that with Co impurities increasing origin of magnetic ordering exists at low temperatures. At high temperatures a high temperature maximum of susceptibility of nominally pure iron monosilicide crystal is observed.

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The nuclear interaction probability of light charged particles in BaF[sub 2] crystals has been studied as a function of the incident particle energy. Light charged particles were identified in charge and mass by measuring their magnetic rigidity and their time-of-flight. The percentage of particles undergoing nuclear interactions has been measured for particles of charge from Z=1 to Z=6 and the experimental data are compared with the results of a model calculation. (orig.)

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The kinetics of the reaction of carbon dioxide in MDEA solutions were studied both experimentally and theoretically. It is concluded that MDEA acts as a homogeneous catalyst for CO/sub 2/ hydrolysis, and as a result the rate of absorption in aqueous MDEA solutions is significantly larger than one would calculate by simply taking into account the alkalinity of the reaction. A possible zwitterion mechanism is proposed for this reaction. The minor effect of ionic strength were also studied with the presence of other ions. 19 references, 6 figures.

International Nuclear Information System (INIS)

Heterodyne detection with a point-contact Josephson junction has been investigated both experimentally and theoretically. The measured performance of the device at 36 GHz is in good agreement with the theory. By operating vanadium point contacts at 1.4 K, the authors have achieved a single-sideband (SSB) mixer noise temperature of 54 K with a conversion gain of 1.35 and a signal bandwidth on the order of 1 GHz. A potentially impressive performance for these devices at submillimeter wavelengths can be extrapolated from the results.

International Nuclear Information System (INIS)

Auger-electron emission from different silicides has been studied for 4 and 10 keV Ar ion excitation. The intensity of the SiLMM Auger line changes significantly with channing concentration and atomic number of the metal-parthner. The experimental results can be explained in terms of a simple model based on the probability of Si-Si collision symmetric cascade in these binary compounds.

Energy Technology Data Exchange (ETDEWEB)

The evaluated data testing for Si, Zr, Nb and Fe materials has been performed through the analyses of the neutron leakage spectrum from spherical assemblies measured in integral benchmark experiments with (d,t) and Cf fission neutron sources. Intercomparisons of the calculated from BROND-2, ENDF/B-6 and JENDL-3 data files with experimental results are presented.

Energy Technology Data Exchange (ETDEWEB)

Experimentally it is found that at constant temperature the order-parameter relaxation time, tausub(..delta..), decreases with increasing power of the microwaves, coupled into a superconducting strip. If the same increase in critical current, that corresponds with a given power of the microwaves, is obtained by lowering the temperature, the decrease in tausub(..delta..) is smaller. This reflects the fact that quasiparticles are removed more efficiently from the gap edge by microwaves than by lowering the temperature in equilibrium. A modified time-dependent Ginzburg-Landau equation is shown to describe these results adequately.

Energy Technology Data Exchange (ETDEWEB)

Implementation of an adaptive power system stabilizer (PSS) based on linear optimal control is described in this paper. The generator is identified in real time, and a special 3rd order discrete Riccati equation is solved in each sample interval. Because the output of the generator is fed back directly, the controller can track the system very fast. Experimental studies on a physical model of a power system demonstrate the effectiveness of the proposed adaptive optimal controller.

Energy Technology Data Exchange (ETDEWEB)

Experimental data in the Kondo lattice YbPd{sub 2}Si{sub 2} is compared with the results of a hybridization model, based ont he 'large degeneracy expansion' approximation, which takes into account the crystal field level splittings of the Yb ion. We show that satisfactory agreement is obtained with a unique set of crystal field and hybridization parameters. (orig.).

International Nuclear Information System (INIS)

This paper presents the results obtained in the gamma scanning of two fuel pins from the bent subassembly of the fast breeder test reactor (FBTR) using a segmented gamma scanning system employing segment correlation developed for the assay of glove box solid waste. In addition to the actinide profiles, the paper also discusses the fission products and clad activation product profiles and tries to correlate the experimental values of the latter with computed values. (author). 4 refs., 1 fig., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

This volume contains the annual report describing the work carried out at COSY (Cooled Synchrotron Storage Ring at KFA Juelich). The results in both machine and physics program are presented on the main topics experimental nuclear physics, theoretical nuclear physics, accelerator developments and technical developments. (MSA)

Energy Technology Data Exchange (ETDEWEB)

Focused ion beam (FIB) repair of chromium defects on photomasks and reticles leaves a post repair stain in the quartz substrate. The wavelength dependent absorption properties of typical stained regions have been measured, showing transition losses up to 80% in the deep uv. A simple model is in good qualitative agreement with the experimental results. (author).

International Nuclear Information System (INIS)

The results show that the SQUID device eddy current testing system is a suitable tool for NDE. Due to the high low-frequency sensitivity of the SQUID sensor, the SQUID device eddy current testing system permits lower examination frequencies than the conventional eddy current probe system. The SQUID system enhances fault detection in even deeper materials layers. (orig./MM).

Energy Technology Data Exchange (ETDEWEB)

This paper deals with the electronic structure of ruthenium. Synchrotron radiation in the range from 15 to 45 eV and angle-resolved ultraviolet photoemission are used to map the energies of the electronic states. The Fermi surface of Ru is determined using angle-resolved ultraviolet photoemission spectroscopy. The experimental results are compared with calculated photoemission spectra obtained within the framework of the one-step model of photoemission. (author)

International Nuclear Information System (INIS)

This report focuses on a better understanding of the physical phenomenon related to the enhancement of boiling and non-boiling heat transfer by applying ultrasonic waves. Experimental results obtained both in a pool of water and in a vertically upward water flow proved clearly that macroscopic acoustic steam induced by ultrasonics is a major contribution to heat transfer augmentation. (author).

International Nuclear Information System (INIS)

Based on theoretical calculations of powder diffraction data it is shown that the assumption of the infinite crystal lattice for small particles is not justified, leads to significant changes of the diffraction patterns, and may lead to erroneous interpretation of the experimental results. An alternate evaluation of diffraction data of nanoparticles, based on the so-called 'apparent lattice parameter', alp, is proposed. (author)

Energy Technology Data Exchange (ETDEWEB)

The objectives of this project to interface the site-specific real-time radiological dose assessment system FADAS(Following Accident Dose Assessment System) to CARE. In this study, the results of the field tracer experiments conducted on the Younggwang site have been analysed. And the experimental procedure on Ulchin site has been introduced. The environmental characteristics on Ulchin and Wolsung has been investigated.

Energy Technology Data Exchange (ETDEWEB)

A general expression for the current-density distribution of a focused-ion beam (FIB) in the chromatic-aberration region is set up in the form of a definite integral. With the experimentally obtained ion-energy distribution of a liquid-metal ion source, its contribution to the FIB current-density distribution is estimated. Calculated results explain the wide-exponential tail of a FIB.

Energy Technology Data Exchange (ETDEWEB)

We have measured, by {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR), the percent deuteration, the tacticity and the purity of several polymers and one solvent used in the preparation of microcellular foams. The percent deuteration was measured for polystyrene, polyacrylonitrile and polyethylene. The tacticities of polystyrene and polyacrylonitrile were determined. The purity and degradation products of polyacrylonitrile and maleic anhydride were examined. This report documents the experimental procedures and results of these measurements.

International Nuclear Information System (INIS)

On the basis of symmetry way of texture description a calculation method of elastic moduli of two-phase titanium alloys with rolling texture has been suggested. Efficiency of the calculation formulas is checked by comparing the calculation results of Young modulus anisotropy in the sheet plane of (#alpha#+#beta#)-titanium alloy VT23 with the experimental data.

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The purpose of the work described in this dissertation is to increase the understanding of injection-pultrusion process. Three major substudies related to injection-pultrusion have been completed: measurement of the compressibility of fiber reinforcements, measurement of in-plane and transverse resin flow through fiber reinforcements, and development of a resin flow model. This dissertation also presents results of an experimental and analytical investigation of in-plane and transverse resin flow through fiber reinforcements.

Energy Technology Data Exchange (ETDEWEB)

In the last issue of 'L'Industrie ceramique et verriere', we presented the first part of this study. We describe in this issue the experimental procedure, the results and the conclusions of this work. (authors)

Science.gov (United States)

This paper describes the anelastic strain recovery and the strain hardening of amorphous metals and presents the experimental result that creep deformation is represented by a viscoelastic model consisting of rheological elements. Materials studied were 80Pd--20Si, 80Fe--13P--7C, and 60 Cu--40 Zr. (DLC)

Energy Technology Data Exchange (ETDEWEB)

The authors present design methodology and initial experimental results for a high power microwave switch. The switch is designed for application to the pulse compression system associated with the Next Linear Collider Test Accelerator (NLCTA). The switch is based on the excitation of a plasma layer within a silicon wafer by either a laser or an electron beam. They investigate problems associated with high power operation of such a switch. They explore solutions to the problems of thermal runaway, avalanche breakdown, photo-emission, and secondary emission.

Energy Technology Data Exchange (ETDEWEB)

The previous {sup 58}Ni and {sup 60}Ni set of resonance parameters (Endf/B7.O, Jeff-3, etc.) was based on the SAMMY analysis of Oak Ridge National Laboratory neutron transmission, scattering cross section and capture cross section measurements by C.M. Perey et al. The present results were obtained by adding to the SAMMY experimental database the capture cross sections measured recently at the Oak Ridge Linear Electron Accelerator by Guber et al. and the Geel Electron Linear Accelerator and very high-resolution neutron transmission measurements performed by Brusegan et al. A complete resonance parameter covariance matrix (RPCM) was obtained from the SAMMY analysis of the experimental database. The data sets were made consistent, when needed, by adjusting the neutron energy scales, the normalization coefficients, and the background corrections. The RPCM allows the calculation of the cross section uncertainties due mainly to ...

Energy Technology Data Exchange (ETDEWEB)

The gas-solid reaction and breakthrough curves in the fixed-bed reactor are of great importance, and being influenced by a number of factors makes the prediction of these factors a difficult problem. In this study, the reaction rate between solid sorbents and hydrogen chloride gas at high temperature was first investigated. On the basis of a fixed-bed reactor, the experimental results were analyzed by the shrinking core model of diffusion and surface chemical reaction control. The results showed that reaction rates of two sorbents with hydrogen chloride gas were controlled by the combination of the surface chemical reaction and diffusion of product layers, and the reaction rates nearly keep constant within 15 h of the initial reaction period and then decrease gradually. The results of the breakthrough curves show that solid sorbents in the fixed-bed reactor are capable of reducing the HCl level to ...

Science.gov (United States)

We briefly reviewed and summarized the experimental study on {beta}-delayed proton decays published by our group over the last 8 years, namely the experimental observation of {beta}-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N{approx}Z by utilizing the p-{gamma} coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for {sup 85}Mo, {sup 92}Rh, as well as the predicted 'waiting point' nuclei {sup 89}Ru and {sup 93}Pd were 5-10 times longer than the macroscopic-microscopic model predictions of ...

International Nuclear Information System (INIS)

We briefly reviewed and summarized the experimental study on #beta#-delayed proton decays published by our group over the last 8 years, namely the experimental observation of #beta#-delayed proton decays of nine new nuclides in the rare-earth region near the proton drip line and five nuclides in the mass 90 region with N#approx#Z by utilizing the p-#gamma# coincidence technique in combination with a He-jet tape transport system. In addition, important technical details of the experiments were provided. The experimental results were compared to the theoretical predictions of some nuclear models, resulting in the following conclusions. (1) The experimental half-lives for "8"5Mo, "9"2Rh, as well as the predicted 'waiting point' nuclei "8"9Ru and "9"3Pd were 5-10 times longer than the macroscopic-microscopic model predictions of Moeller et al. [At. Data Nucl. Data ...

International Nuclear Information System (INIS)

Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production rate of the buoyant fire plume. One design issue is the smoke production rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes are based on a combination of one-tenth scale test data and theoretical analysis. Questions have arisen over the suitability of these correlations for real-scale designs. A combined program of full-scale experimentation and CFD modeling is being conducted to analyze the accuracy of these correlations. A full-scale experimental facility was constructed with a 5 m by 5 m by 15 m fire compartment connected to a four-story atrium. Propane fires in the ...

International Nuclear Information System (INIS)

The 1.04 GeV-proton elastic scattering from "4"0Ca is studied in the framework of the coherent density fluctuation model (CDFM). The calculations are carried out in the Glauber theoretical scheme with three different charge densities. It is shown that: i) the account of the flucton correlations leads to results considerably different from those obtained in the independent particle Glauber approach (IPGA); ii) in contrast to the case of IPGA the use of a more realistic density improves the agreement of CDPM-results with the experimental data. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Solving a coupled set of differential equations formed by a Fokker-Planck equation and a set of master equations, we can calculate the number of 'prefission' particles (n,p,a), which are emitted from a hot, rotating compound nucleus. Furthermore we get their energy spectrum and their angular momentum distribution. Our results depend sensitively on the friction parameter {gamma}, the inertia M and the fission potential. Comparing the results with experimental data, we may learn something about these quantities. The investigations have been made for {sup 187}Ir and {sup 185}Os. (orig.).

Science.gov (United States)

The results of an investigation into the behavior of adhesively bonded doubler splices of two composite material sandwich panels are presented. The splices are studied from three approaches: analytical; numerical (finite elements); and experimental. Several parameters that characterize the splice are developed to determine their influence upon joint strength. These parameters are: doubler overlap length; core stiffness; laminate bending stiffness; the size of the gap between the spliced sandwich panels; and room and elevated temperatures. Similarities and contrasts between these splices and the physically similar single and double lap joints are discussed. The results of this investigation suggest several possible approaches to improving the strength of the sandwich splices.

International Nuclear Information System (INIS)

Tests for the applicability of a CFD (Computational Fluid Dynamics) code for simulating activity transport in PNA (Pulsed Neutron Activation) fluid measurements have been performed. The CFD code was combined with a Monte Carlo code used for the calculation of the initial activity distribution. The results from the calculations show that it is possible to use CFD for calculation of the activity distribution in PNA. The mainly qualitative results in this work are encouraging and suggest further work. In the continuation of this work a response function for the gamma detector will be calculated so that a PNA time spectrum can be simulated. A more accurate comparison with experimental data can then be performed

CERN Document Server

The article presents an approach to interactively solve multi-objective optimization problems. While the identification of efficient solutions is supported by computational intelligence techniques on the basis of local search, the search is directed by partial preference information obtained from the decision maker. An application of the approach to biobjective portfolio optimization, modeled as the well-known knapsack problem, is reported, and experimental results are reported for benchmark instances taken from the literature. In brief, we obtain encouraging results that show the applicability of the approach to the described problem.

Energy Technology Data Exchange (ETDEWEB)

The present paper is concerned with the prediction method for the motions and tensions of mooring lines on slack-moored floating oceanic architectural building in coastal zone. The motions and the tensions of mooring lines were estimated by the time domain numerical simulation in the present method. The present method includes the nonlinearity of mooring system, slow varying wave drift force. The authors performed a time domain numerical simulation for motions and the tensions of mooring lines on floating barge in two component waves. Also, the results obtained by numerical simulation were compared with the experimental results. The validity of the present method was confirmed.

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

Energy Technology Data Exchange (ETDEWEB)

The level structure of the doubly-odd /sup 242/Am nucleus was investigated by means of thermal-neutron-capture gamma-ray and conversion electron spectroscopy. Pair, curved-crystal, and ..beta.. spectrometers were used. The data from these measurements, combined with previous direct reaction results, permit us to establish a detailed level scheme including six new well-developed bands. Our experimental results are interpreted in the framework of the Nilsson model. Precise Gallagher-Moszkowski splittings and Newby odd-even shifts extracted from the data are compared with theoretical calculations.

International Nuclear Information System (INIS)

The main features and advantages of a new low energy nuclear spectroscopic method, the in-beam spectroscopy are described. Results of in-beam spectroscopic experiments performed at the Institute of Nuclear Research (ATOMKI, Debrecen, Hungary) are summarized. Gamma spectra of in-beam produced odd-odd nuclei were measured, gamma-energies were determined. Measurement of gamma-gamma coincidences led to the construction of energy level schemes of the investigated nuclei. Internal conversion electron spectroscopy was used to determine the multipolarities of transitions. A few spectra and level schemes are presented to illustrate the review. Theoretical interpretation of experimental results are briefly summarized. (D.Gy.).

International Nuclear Information System (INIS)

A theoretical study of structural and electronic properties of GeC, SnC and GeSn is presented using the full potential linearized augmented plane wave method. In this approach, the generalized gradient approximation was used for the exchange-correlation potential. Results are given for lattice constant, bulk modulus and its pressure derivative in both zinc-blende and rocksalt structures. Band structure, density of states and band gap pressure coefficients in zinc-blende structure are also given. The results are compared with previous calculations and with experimental measurements.

International Nuclear Information System (INIS)

The composite wave variational version of the APW (augmented plane wave) method is used to obtain the electronic band structure of the compounds boron phosphide and boron arsenide at the high symmetry points #GAMMA#, X, and L. The tight binding interpolation scheme of Slater and Koster is used to calculate the rest of the band structure. The results show that both these materials are indirect band gap semiconductors. The density of states, and the imaginary part of the dielectric constant is also calculated. The theoretical results are compared with the reported experimental and theoretical data. (author).

Energy Technology Data Exchange (ETDEWEB)

The development of detailed chemical kinetic reaction mechanisms for analysis of autoignition and knocking of hydrocarbon fuels is described. In particular, kinetic processes of concern for the oxidation of complex hydrocarbon fuel molecules are emphasized. The wide ranges of temperature and pressure which are encountered by end gases in automobile engine combustion chambers result in extreme demands on reaction mechanisms which are intended to describe knocking conditions and predict rates of combustion and ignition. The reactions and chemical species which are most important in each temperature and pressure regime are discussed, and the validation of these reaction mechanisms through comparison with idealized experimental results is described. 53 refs., 8 figs., 5 tabs.

International Nuclear Information System (INIS)

The use of the method is described on powder samples before and after sintering with an La content of up to 1%. For excitation of the K series of La a _2_4_1Am source with an activity of 1.11 GBq was used. The obtained results showed that the method is sufficiently accurate (error 7%) at a short period of measurement (100 s). It gives satisfactory results even in the comparison of the experimental relative count rate and the theoretically calculated value despite the fact that the analytical signal comes from the sample surface. (Ha).

International Nuclear Information System (INIS)

A computer code based on Nodal expansion method has been developed for solving two groups three dimensional diffusion equation. This code can be used for fuel management and time average core calculation. Explicit Xenon and fuel temperature estimation are also incorporated in this code. TAPP-4 phase-B physics experimental results were analyzed using this code and a code based on FD method. This paper gives the comparison of the observed data and the results obtained with this code and FD code. (author)

International Nuclear Information System (INIS)

We present results from a kinetic Monte Carlo simulation of boron transient enhanced diffusion (TED) in silicon. Our approach avoids the use of phenomenological fits to experimental data by using a complete and self-consistent set of values for defect and dopant energetics derived mostly from ab initio calculations. The results predict that, during annealing of 40 keV B-implanted Si at 800 degree C, there exists a time window during which all the implanted boron atoms are substitutional. At earlier or later times, the interactions between free silicon self-interstitials and boron atoms drive the growth of boron clusters and result in an inactive boron fraction. The results show that the majority of boron TED takes place during the growth period of interstitial clusters and not during their dissolution. copyright 1998 American Institute of Physics.

International Nuclear Information System (INIS)

We present results of multiple-time-scale simulations of 5, 10 and 15 keV low temperature ion implantation of arsenic on silicon (100), followed by high temperature anneals. The simulations start with a molecular dynamics (MD) calculation of the primary state of damage after 10ps. The results are then coupled to a kinetic Monte Carlo (MC) simulation of bulk defect diffusion and clustering. Dose accumulation is achieved considering that at low temperatures the damage produced in the lattice is stable. After the desired dose is accumulated, the system is annealed at 800 degrees C for several seconds. The results provide information on the evolution for the damage microstructure over macroscopic length and time scales and affords direct comparison to experimental results. We discuss the database of inputs to the MC model and how it affects the diffusion process.

British Library Electronic Table of Contents (United Kingdom)

This paper presents a combined experimental and computational study into the aerodynamics and performance of a small scale vertical axis wind turbine (VAWT). Wind tunnel tests were carried out to ascertain overall performance of the turbine and two- and three-dimensional unsteady computational fluid dynamics (CFD) models were generated to help understand the aerodynamics of this performance. Wind tunnel performance results are presented for cases of different wind velocity, tip-speed ratio and solidity as well as rotor blade surface finish. It is shown experimentally that the surface roughness on the turbine rotor blades has a significant effect on performance. Below a critical wind speed (Reynolds number of 30,000) the performance of the turbine is degraded by a smooth rotor surface finis...

Energy Technology Data Exchange (ETDEWEB)

In pre-experiments a tubular reactor was checked whether it is suitable for kinetic measurement on the system of the silver-catalysed partial oxidation of methanol to formaldehyde. Detrimental effects of heat-transfer and mass-transfer on the experimental results were ruled out. Investigations on the characteristics of the reaction showed that it is possible to manipulate the composition of the product mixture by changing the inlet concentration of the reactants. A modified power-law model was established to describe the reaction kinetics. It considers the preadsorption step of oxygen on the catalysts surface and fits the experimental data quite well. During the rapid oxidation the catalysts surface undergoes a drastic change. It gets coarse and has an adsorption capacity of 11 m{sup 2}/g after being exposed to the reaction mixture. (orig.)

International Nuclear Information System (INIS)

The energy level schemes of the near "4"8Ca nuclei were investigated in the frame of the spherical shell model with pure configurations. For every nucleus two configurations were considered: the ground state configuration (GS) - calculated making use of empirical two-body interactions extracted from the level energies of the neighbouring nuclei, and the lowest energy configuration with one nucleon in the excited state (ES) - calculated making use of the two-body Kuo-Brown interactions. The results made it possible to explain the greater part of the so-called intruder levels. Comparison of the calculated and experimental level energy values epsilonsub(J)sup(calc)-epsilonsub(J)sup(exp) reveals systematic deviations of the experimental level energies from the shell model predictions. (orig.).

International Nuclear Information System (INIS)

Momentum transfer through an air-water interface was studied in a horizontal rectangular channel through experimental and numerical analysis. The liquid flow Reynolds numbers, based on hydraulic diameters, were 11500 and 17000. The air flow Reynolds number varied from 0 to 3260. In experiments, velocity distribution was measured by hot-film and hot-wire probes. The effect of the liquid flow Reynolds number and the direction of interfacial shear stress was investigated by performing the cocurrent and countercurrent experiments. The modified k-#epsilon# model was able to reproduce these experimental results qualitatively. The range of applicability of the modified k-#epsilon# model was also discussed. (author).

Energy Technology Data Exchange (ETDEWEB)

In April and May of 1999 the Berkeley Gas-filled Separator was used to search for the production and decay of element 118 from the {sup 86}Kr + {sup 208}Pb reaction, according to Smolanczuk's predictions of relatively large production rates. Three decay chains, each consisting of an implanted heavy ion, followed by a rapid (ms) succession of high-energy (>10 MeV) alpha-particle decays were detected. These chains are consistent with the production and decay of element 118 with mass number 293. These results a) show experimental evidence for the existence of shell-stabilized superheavy elements, b) provide experimental values for refinement of nuclear mass models in the superheavy element region, and, most importantly, c) present a new' reaction pathway for the production of superheavy elements. (author)

International Nuclear Information System (INIS)

The optical spectroscopy measurements of gadolinium gallium garnet (GGG) crystals doped with Yb show evidence of the presence of non-equivalent optical centers with very similar radiative decay rates. The energy level schemes of those centers have been determined on the basis of optical absorption, luminescence and Raman experiments. Crystal field fitting resulted in two sets of slightly different crystal field parameters for two non-equivalent Yb centers. Both sets of parameters describe perfectly the experimentally detected Y b3+ energy levels. Correlation between systematic trends in the experimental energy level schemes and crystal field parameters is discussed.

Science.gov (United States)

In this paper, a novel type of a corona discharge plasma reactor was designed, which consists of needle-plate-combined electrodes, in which a series of needle electrodes are placed in a glass container filled with flue gas, and a plate electrode is immersed in the water. Based on this model, the removal of NO and SO2 was tested experimentally. In addition, the effect of streamer polarity on the reduction of SO2 and NO was investigated in detail. The experimental results show that the corona wind formed between the high-voltage needle electrode and the water by corona discharge enhances the cleaning efficiency of the flue gas because of the presence of water, and the cleaning efficiency will increase with the increase of applied dc voltage within a definite range. The removal efficiency of SO2 up to 98%, and about 85% of NOx removal under suitable conditions is obtained in our experiments.

International Nuclear Information System (INIS)

During their catalytic cycle, proteins involved in biological signal transduction undergo unexpectedly large conformational changes, which are at the core of their biological functioning. Until now it has been extremely difficult to obtain experimental insight into the nature of these conformational changes. Mathematical modeling and time-resolved X-ray crystallography have resulted in probable routes along which these conformational changes may take place, but so far this fundamental biological phenomenon has hardly been tackled experimentally. Here, we report on an attempt to observe structural changes in Photoactive Yellow Protein with time-resolved small-angle neutron scattering using diffractometer D22 at the high-flux reactor of the Institut Laue-Langevin, Grenoble, France

Energy Technology Data Exchange (ETDEWEB)

The biological effects of ionizing radiation exposure are the result of a complex sequence of physical, chemical, biochemical, and physiological interactions. One way to begin a search for an understanding of health effects of radiation is through the development of phenomenological models of the response. Many models have been presented and tested in the slowly evolving process of characterizing cellular response. A range of models covering different endpoints and phenomena has developed in parallel. Many of these models employ similar assumptions about some underlying processes while differing about the nature of others. An attempt is made to organize many of the models into groups with similar features and to compare the consequences of those features with the actual experimental observations. It is assumed that by showing that some assumptions are inconsistent with experimental observations, the job of devising and ...

CERN Document Server

The effect of the wind on the sustain of extreme water waves is investigated experimentally and numerically. A series of experiments conducted in the Large Air-Sea Interactions Facility (LASIF) showed that a wind blowing over a strongly nonlinear short wave group due to the linear focusing of a modulated wave train may increase the life time of the extreme wave event. The expriments suggested that the air flow separation that occurs on the leeward side of the steep crests may sustain longer the maximum of modulation of the focusing-defocusing cycle. Based on a Boundary-Integral Equation Method and a pressure distribution over the steep crests given by the Jeffreys'sheltering theory, similar numerical simulations have confirmed the experimental results

International Nuclear Information System (INIS)

We report first-principles frozen-phonon calculations for the determination of the force-free geometry and the dynamical matrix of the five Raman-active A_1_g modes in YBa_2Cu_3O_7. To establish the shape of the phonon potentials atomic forces are calculated within the linearized-augmented-plane-wave method. Two different schemes emdash the local-density approximation (LDA) and a generalized gradient approximation (GGA)emdash are employed for the treatment of electronic exchange and correlation effects. We find that in the case of LDA the resulting phonon frequencies show a deviation from experimental values of approximately -10%. Invoking GGA the frequency values are significantly improved and also the eigenvectors are in very good agreement with experimental findings. copyright 1997 The American Physical Society.

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The Monte-Carlo transport code MCNP was used to evaluate possible arrangements of cores for the MIT Reactor using monolithic LEU fuel. Plate and moderator thicknesses were varied, and fixed absorbers and inner reflectors added in an effort to maximize available neutron fluxes at in-core and ex-core locations of experimental facilities. Addition of D_2O in the H_2O moderator was also evaluated. Comparisons of the fast, epithermal, and thermal fluxes were made at selected locations. Keff was also evaluated and critical blade heights compared with the existing HEU core. Results indicate that the LEU fluxes could approach HEU values with the use of a fueled in-core experimental facility, a fixed boron absorber spider and an inner beryllium reflector. (author)

British Library Electronic Table of Contents (United Kingdom)

This paper presents a new method of extracting biologic particles from a mixture of particles. The method is based on the pumping effect in a p-shaped ultrasonic actuator, which has a gap between its two vibrating metal plates. An adhesive tape is placed at a proper position in the gap. Due to the pumping effect which is induced by the sound field in the gap, the particles with smaller mass and radius in the mixture can be pumped up to reach the adhesive tape; while the ones with larger mass cannot. Therefore, the particles with smaller mass and radius can be extracted from the mixture. A theoretical model which can well explain the operation principle and experimental phenomena is developed. By the experimental results and the theoretical analyses based on the model, the validity of the m...

British Library Electronic Table of Contents (United Kingdom)

An experimental study was performed to investigate the heat transfer characteristics of the mixed convection flow through a horizontal rectangular channel where open-cell metal foams of different pore densities (10, 20 and 30 PPI) were situated. A uniform heat flux was applied at all of the bounding walls of the channel. For each of three values of the uniform heat flux, temperatures were measured on the entire surfaces of the walls. Results for the average and local Nusselt numbers are presented as functions of the Reynolds and Richardson numbers. The Reynolds number based on the channel height of the rectangular channel was varied from 600 to 33000, while the Richardson number ranged from 0.02 to 103, extending over forced, mixed and natural convection. Second important parameter that in...

British Library Electronic Table of Contents (United Kingdom)

Heavily doped emitters with low saturation current density are of particular interest for selective emitter solar cells. These emitters can be obtained by laser doping through the phosphosilicate glass layer formed after thermal diffusion from POCl3 gas. The experimental results show that in contrast to purely POCl3 furnace-diffused emitters, the saturation current density of laser-doped emitters does not increase linearly as sheet resistance decreases, but rather features two distinct regimes. In one of these regimes, the saturation current density is found to decrease as the sheet resistance decreases, reaching values lower than those of furnace emitters. This peculiar behaviour was explained by both qualitative analysis and numerical simulations.

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT Introduction. Significant progress has been made in the understanding of physiological and pharmacological mechanisms of human sexual functioning through preclinical research in animal models. Aim. To provide an evidence-based documentation of the experimental models evaluating male and female sexual function for useful clinical translation. Methods. Consensus discussion over the past 18 months leading to summarized views of seven experts from six countries. Main Outcome Measure. Report was based on the critical analysis of scientific information available in literature and subcommittee presentations, discussions, and exchanges of ideas and feedback. Results. Fundamental research in animal models has led to considerable understanding of the physiological mechanisms underlying desi...

International Nuclear Information System (INIS)

The electronic structures of the set of molecular clusters of dielectric oxide crystals AWO4 (A = Pb, Cd, Zn), the sizes of which increase sequentially are ab-initio calculated by the Restricted Hartree-Fock (RHF) method. The results of calculations of molecular orbitals and energy dependences of partial densities of electronic states of different clusters are compared each to other and to experimental data. It is found that calculated electronic structures of the tungstate groups and cations which are surrounded in cluster by certain number of the nearest neighbor atoms of the crystals quite well represent the experimentally obtained value of the forbidden gap of corresponding AWO4 crystal. (authors)