International Nuclear Information System (INIS)

Small-angle X-ray scattering method recognised to be very useful in the studies of structural problems of materials in homogeneous in nanoscale. Studies by small-angle X-ray scattering on the Al-Ag alloys are presented. The size distributions of spherical Guinier-Person zones were calculated using Vonk's and Glatter's methods. Small-angle X-ray scattering studies were performed on Al-5.0 at.%Ag alloy containing Guinier-Preson zones in the #eta#-state. For this alloy one can assume that scattering particles are of spherical shape, have uniform electron density and scatter independently. Moreover, the size distributions were calculated for Al-1.6 at.%Ag alloy containing Guinier-Preston zones in #epsilon#-state (scattering particles with not uniform electron density). Both, Vonk's and Glatter's, methods gave similar size ...

Science.gov (United States)

Rapid administration of stable iodine is essential for the saturation and subsequent protection of the thyroid gland against the potential harm caused by radioiodines. This paper proposes the Dutch risk analysis that uses an atmospheric dispersion model to calculate the size of the zones around nuclear power plants where radiological thyroid doses for children might be sufficiently high to warrant iodine administration. Dose calculations for possible releases from the nuclear power plants of Borssele (The Netherlands), Doel (Belgium) and Emsland (Germany) are based on two scenarios in combination with a 1-y set of authentic, high-resolution meteorological data. The dimensions of the circular zones were defined for each nuclear power plant. In these zones, with a radius up to 50 km, distribution of stable iodine tablets is advised. PMID:20332130

British Library Electronic Table of Contents (United Kingdom)

Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946?58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10?days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-...

Energy Technology Data Exchange (ETDEWEB)

This study examines the sensitivity of the travel time distribution predicted by a reference case model to (1) scale of representation of the model parameters, (2) size of the model domain, (3) correlation range of log-transmissivity, and (4) cross correlations between transmissivity and effective thickness. The basis for the reference model is the preliminary stochastic travel time model previously documented by the Basalt Waste Isolation Project. Results of this study show the following. The variability of the predicted travel times can be adequately represented when the ratio between the size of the zones used to represent the model parameters and the log-transmissivity correlation range is less than about one-fifth. The size of the model domain and the types of boundary conditions can have a strong impact on the distribution of travel times. Longer ...

Energy Technology Data Exchange (ETDEWEB)

The influence of location of airborne particle source, ventilation rate, air inlet size, supply air velocity, air outlet location, and heat source on the distributions of airborne particle concentration and draught risk in an operating room is investigated. The investigation is carried out by using a flow program with the k-[epsilon] model of turbulence. Based on a standard case, five cases, each with one changed parameter, are computed, and the detailed field distributions of air velocity, temperature, airborne particle concentration, and draught risk are presented. The parametric study concludes that, for a better air quality and thermal comfort, it is desirable to use a higher inflow rate, a larger inlet area, and a uniform velocity profile of supply air. Outlet location and heat source have little influence on the distributions of the particle concentration in the room. It has also been found that ...

Energy Technology Data Exchange (ETDEWEB)

In the present study, the type and densities of defects in AlN crystals grown on 6H-SiC seeds by the sublimation-recombination method were assessed. The positions of the defects in AlN were first identified by defect selective etching (DSE) in molten NaOH-KOH at 400 C for 2 minutes. Etching produced pits of three different sizes: 1.77 m, 2.35 m , and 2.86 m. The etch pits were either aligned together forming a sub-grain boundary or randomly distributed. The smaller etch pits were either isolated or associated with larger etch pits. After preparing crosssections of the pits by the focused ion beam (FIB) technique, transmission electron microscopy (TEM) was performed to determine which dislocation type (edge, mixed or screw) produced a specific etch pit sizes. Preliminary TEM bright field and dark field study using different zone axes and diffraction vectors indicates an edge dislocation with a Burgers ...

KoreaScience (Korea)

Full Text Available

International Nuclear Information System (INIS)

The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 (angstrom)s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 microm, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from backscattering at the ...

British Library Electronic Table of Contents (United Kingdom)

Most active pharmaceutical ingredients (API) exhibit particle size distributions with some degrees of asymmetry deviating from log-normality. A new log-skew-normal (L-S-N) distribution model is proposed for a systematic comparison of the asymmetry effect on content uniformity. The new model originated from the S-N model used by Azzalini gives a close approximation to real API particle size distribution. Monte-Carlo method was employed to simulate the dosage potency distribution. A high risk of over potency is uncovered when either the dose is low or API particle size distribution is positively skewed. This is due to the formation of pseudo heavy tail in potency distribution that decays slower than exponentially. Nomographs of API particle size versus dosage strength were ...

Energy Technology Data Exchange (ETDEWEB)

The concept of the minimum propagating zone (MPZ) is used to examine the causes of quenches in ISABELLE cosine theta superconducting dipole magnets. The size of disturbances large enough to exceed the MPZ and initiate quenches is estimated and compared with the size of disturbances which may be produced in the magnets. A suggestion for reducing the size of these disturbances through individual support of the coil block is outlined.

International Nuclear Information System (INIS)

Microstructure and properties of a Mg AZ31B laser beam weld without filler are studied using electron microscopy, X-ray diffraction and mechanical tests. The microstructure of the weld is characterized by a narrow heat affected zone, columnar grains and precipitate coarsening in the fusion zone. Texture in the fusion zone is significantly different from the texture of the base material. The residual stress distribution observed is similar at the top and the bottom of the weld, maximum tensile residual stress values are observed in the fusion zone. Tensile tests reveal differences in the mechanical behavior of the fusion zone and the parent material, which can be related to the differences of texture and the resulting deformation mechanisms.

UK PubMed Central (United Kingdom)

Eukaryotic genome size varies over five orders of magnitude; however, the distribution is strongly skewed toward small values. Genome size is highly correlated to a number of phenotypic traits, suggesting...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Part I of this thesis is on long-term iceberg collision-risk assessment methods for fixed offshore structures. Estimates for the long-term probability that an iceberg will hit a fixed offshore structure are based on estimates of the total volume of produced iceberg, a model for the size distribution of icebergs and a description of how iceberg trajectories ``fill`` the plane (the ocean`s surface). Part II of the thesis discusses methods for analysis of low resolution data in the sense that the size of the area covered by each pixel is not small compared to the dominating floes. Still, this type of data can provide estimates of the ice extent (and hence the ice edge) and ice concentration. The estimates of the ice edge (at least) seem to be physically significant in the sense that ``in some way`` they can reflect ice drift in an image time sequence. A priori this is far from obvious. A central idea is that the ``ice edge`` ...

International Nuclear Information System (INIS)

The dynamics of a cluster-type system formed by constant total number of molecules, M, is studied when clusters change their sizes by nearest-size transitions (the Szilard model) with time-dependent boundary conditions and non-zero initial cluster size distribution. We compare these results to those reported previously, when non-stationary cluster size distribution was considered under the condition that only monomers are present in the system at the initial moment t=0, and describe the effect of arbitrary pre-existing clusters on the time evolution of the interacting clusters with different sizes, n. The average group size problem is also solved, and the process of relaxation in the system is studied. authors)

Science.gov (United States)

We show that the size of a lanthanide-ion doped nanoparticle can be accurately determined from its luminosity. The optically determined size distribution is in very good agreement with the distribution obtained from transmission electron microscopy. These data confirm that single nanoparticles are visualized in microscopy experiments. Nanoparticles as small as 13 nm are detectable with integration times of 500 ms.

Energy Technology Data Exchange (ETDEWEB)

The uncertainty associated with the sorption coefficient, or K{sub d} value, is one of the key uncertainties in estimating risk associated with burying low-level nuclear waste in the subsurface. The objective of this study was to measure >648 K{sub d} values and provide a measure of the range and distribution (normal or log-normal) of radionuclide K{sub d} values appropriate for the E-Area disposal site, within the Savannah River Site, near Aiken South Carolina. The 95% confidence level for the mean K{sub d} was twice the mean in the Aquifer Zone (18-30.5 m depth), equal to the mean for the Upper Vadose Zone (3.3-10 m depth), and half the mean for the Lower Vadose Zone (3.10-18 m depth). The distribution of K{sub d} values was log normal in the Upper Vadose Zone and Aquifer Zone, and normal in the Lower Vadose ...

Energy Technology Data Exchange (ETDEWEB)

Previous models of fault-propagation folding used kink-band geometries to approximate folding in front of propagating thrusts. However, kink-band kinematics cannot replicate the curved fold surfaces and complex strain patterns innatural and experimental fault-propagation folds, which also occur in front of steeper reverse and normal faults. Fault-propagation fold hinges tighten and converge downward, forming a triangular zone of penetrative deformation focused on the tip of the propagating fault. The downward convergence of deformation in fault-propagation folds can be modeled as triangular shear zones. Trishear, here defined as distributed, strain-compatible shear in a triangular (in profile) shear zone, provides an alternate kinematic model for fault-propagation folds. Trishear is analogous to simple shear in a tabular shear zone except that area balance in a triangular shear ...

Energy Technology Data Exchange (ETDEWEB)

A multi-zone computational model in conjunction with some engine tests are used to examine the combustion process of gas fueled diesel engines common known as dual fuel engine to provide information about details of the production of exhaust emissions, especially at light load when very lean mixtures are employed. Detailed chemical reaction kinetic simulation is employed for each of these individual combustion zones so as to establish the associated temporal variations in the concentrations of reacting species right to the exhaust stage. The influence of changes in major operating and design parameters such as the concentration of the gaseous fuel in the cylinder charge, intake temperature and the size of the diesel pilot fuel employed on the production of the exhaust emissions are examined. It is demonstrated in general that any measure that tends to increase the size of the combustion regions within ...

British Library Electronic Table of Contents (United Kingdom)

The relationships between soil salinization and the zonal and provincial bioclimatic conditions, the lithological composition of the sediments, and the geomorphic features of the territory have been analyzed for the Southern federal okrug of Russia. It is shown that the lithological and geomorphic conditions (relief, salinity of parent materials, degree of drainage, and the depth of saline groundwater) play an important role in the distribution of salt-affected soils against the background of the more general regularities specified by the climate. The participation of salt-affected soils in the soil cover of the Southern federal okrug increases in the eastward direction from the forest-steppe zone to the semidesert zone in agreement with an increase in the aridity and continentality of the...

International Nuclear Information System (INIS)

A theoretical analysis is presented for the method of determining the concentration distribution of admixtures in zone melting and in the study of diffusion in melts. Continuous mode X-ray fluorescence analysis is considered. The convolution integral interpreting the analog output of the ratemeter was solved applying the mathematical apparatus of Z transformation. The feasibility of the method is tested on an example of the determination of tin distribution in tungsten. With respect to the statistical error (#delta#<1.5%), the maximum integration constant (100 s) and a very slow sample feed (0.025 mm/s) were used. The calculated transfer function reflects the total transfer function of the ratemeter and the recorder used. (M.D.).

Energy Technology Data Exchange (ETDEWEB)

Results are given for deep-level petroleum and gas drilling probes in various coastal zones of Southern Sakhalin covering the Poronai depression and the Aniv Bay trough. The exploratory probes indicate that the Middle Miocence deposits of the Boundary trough contain commercial-size deposits of petroleum, that commercial-size gas deposits are in the upper Myocene deposits of the Aliv Bay trough, and that the upper Cretaceous and Cenozoic deposits of the eastern section of Southern Sakhalin lack folded deformations. 7 references, 2 figures.

Energy Technology Data Exchange (ETDEWEB)

Radon migration in porous, earthen materials is characterized by diffusion in both the air and water components of the system as well as by the interaction of the radon between the air and water. The size distribution and configuration of the pore spaces and their moisture distributions are key parameters in determining the radon diffusion coefficient for the bulk material. A mathematical model is developed and presented for calculating radon diffusion coefficients solely from the moisture content and pore size distribution of a soil, reducing the need for resorting to radon diffusion measurements. The resulting diffusion coefficients increase with the median pore diameter of the soil and decrease with increasing widths of the pore size distribution. The calculated diffusion coefficients are suitable for use in simple homogeneous-medium ...

Energy Technology Data Exchange (ETDEWEB)

Nanoparticles of AgBr were prepared by precipitating AgBr in the water pools of microemulsions consisting of CTAB, n-butanol, isooctane and water. An aqueous solution of AgNO{sub 3} added to the microemulsion was the source of Ag{sup +} ions. The formation of AgBr nanoparticles in microemulsions through direct reaction with the surfactant counterion is a novel approach aimed at decreasing the role of intermicellar nucleation on nanoparticle formation for rapid reactions. The availability of the surfactant counterion in every reverse micelle and the rapidity of the reaction with the counterion trigger nucleation within individual reverse micelles. The effect of the following variables on the particle size and size distribution was investigated: the surfactant and cosurfactant concentrations, moles of AgNO{sub 3} added, and water to surfactant mole ratio, R. High concentration of the surfactant or cosurfactant, or high water ...

International Nuclear Information System (INIS)

We present local two-dimensional and three-dimensional hybrid numerical simulations of particles and gas in the midplane of protoplanetary disks (PPDs) using the Athena code. The particles are coupled to gas aerodynamically, with particle-to-gas feedback included. Magnetorotational turbulence is ignored as an approximation for the dead zone of PPDs, and we ignore particle self-gravity to study the precursor of planetesimal formation. Our simulations include a wide size distribution of particles, ranging from strongly coupled particles with dimensionless stopping time #tau#_s #ident to# #OMEGA#t_s_t_o_p = 10"-"4 (where #OMEGA# is the orbital frequency, t_s_t_o_p is the particle friction time) to marginally coupled ones with #tau#_s = 1, and a wide range of solid abundances. Our main results are as follows. (1) Particles with #tau#_s #approx#> 10"-"2 actively participate in the streaming instability (SI), generate ...

International Nuclear Information System (INIS)

A semi-mechanistic model for calculating solid radionuclide release rates from bubbling pools of sodium was developed. The influence of particle spacial and size distributions on the decontamination of the releases was analysed and found significant. Decontamination factors are shown as a function of pool depth, bubbling characteristics and particle size distribution. The calculation of a decontamination factor for estimating the source term of large scale hypothetical core disruptive accidents is presented. The decontamination factor for a large scale accident was found to be two orders of magnitude greater than results obtained from small scale experiments conducted with uniform particle distributions. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The effects of the plasma nitriding with the formation of compound nitride and diffusion zones and of the boronising with the different ion doses on hydrogen distribution and hydrogen induced deterioration of a surface layer were examined in the case of Armco iron. Electrochemical studies of hydrogen permeation rate, hydrogen vacuum extraction measurements, optical and scanning microscopy, X-ray diffraction and elastic recoil detection analysis (ERDA) were used. Accumulation of entering hydrogen within the various constituent zones of the modified layer inhibits the hydrogen transport into the metal and thus, decreases the mean hydrogen content in the deeper zones and in the core. Hydrogen accumulation within the compact nitride zone causes the expansion of the nitride lattice, nitride phase transformation and deterioration. The ion boronising enhances the hydrogen effects in the ...

Energy Technology Data Exchange (ETDEWEB)

In this paper, a new design methodology for determining the size, location, type and number of capacitors to be placed on a radial distribution system is presented. The objective is to minimize the peak power losses and the energy losses in the distribution system considering the capacitor cost. A sensitivity analysis based method is used to select the candidate locations for the capacitors. A new optimization method using a Genetic Algorithm is proposed to determine the optimal selection of capacitors. Test results have been presented along with the discussion of the algorithm.

Energy Technology Data Exchange (ETDEWEB)

Car weight corresponds directly to fuel consumption and driving performance. So in order to improve the fuel efficiency and performance of a car the weight has to be reduced. Magnesium as a light metal offers a wide range of weight saving opportunities, especially Magnesium wrought alloys with their improved mechanical properties have a high potential for structural applications. Mechanical properties in terms of their quality and anisotropy are dependent on the microstructure of the material and can be characterized by their degree of inhomogeneity, their grain size distribution and their crystallographic texture. Therefore the orientation distribution of grains, the grain size, its size distribution, the chemical composition (precipitates) itself influence the mechanical parameters and their anisotropy. In this presentation first results of mechanical ...

Energy Technology Data Exchange (ETDEWEB)

Monodisperse noble metal nanoparticles are of tremendous interest for numerous applications, such as surface-enhanced Raman spectroscopy, catalysis or biosensing. However, preparation of monodisperse metal nanoparticles is still a challenging task, because typical preparation methods yield nanoparticle ensembles with broad shape and/or size distributions. To overcome this drawback, tailoring of metal nanoparticles with laser light has been developed, which is based on the pronounced shape- and size-dependent optical properties of metal nanoparticles. I will demonstrate that nanoparticle tailoring with ns-pulsed laser light is a suitable method to prepare nanoparticle ensembles with a narrow shape and/or size distribution. While irradiation with ns-pulsed laser light during nanoparticle growth permits a precise shape tailoring, post-grown irradiation allows a ...

International Nuclear Information System (INIS)

The in-depth distribution of phases in c-BN films deposited by Ion Beam Assisted Deposition (IBAD) at two different ion energy values (300 and 600 eV) was investigated using the quantitative IR transmission measurements and the HREM technique. Whatever the value of the studied ion energies, the characteristic layered morphology of c-BN film is observed including the interfacial sp"2 zone between the substrate and the c-BN volume. In the case of 600 eV ion energy, this interfacial zone is less well-defined in comparison with 300 eV ion energy and the corresponding thickness is more important. Furthermore, the h-BN phase is more diluted within the c-BN film volume showing that the purest phase concentration of c-BN is found for the lowest ion energy, i.e., 300 eV.

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional (3-D) prestack reverse-time migration algorithm for common-source P-wave data from anisotropic media is developed and illustrated by application to synthetic data. Both extrapolation of the data and computation of the excitation-time imaging condition are implemented using a second-order finite-difference solution of the 3-D anisotropic scalar-wave equation. Poorly focused, distorted images are obtained if data from anisotropic media are migrated using isotropic extrapolation; well focused, clear images are obtained using anisotropic extrapolation. A priori estimation of the 3-D anisotropic velocity distribution is required. Zones of anomalous, directionally dependent reflectivity associated with anisotropic fracture zones are detectable in both the 3-D common-source data and the corresponding migrated images.

International Nuclear Information System (INIS)

Full text: The IRSN has been organizing enquiries with the French population about risk and risk perception for a long time. In 2002, a collaboration between the IRSN in France and the SCK.CEN in Belgium has been set-up to simultaneously (November 2002) organise this poll in both countries. In each country, a representative sample of the population (over 1000 participants per country) has been consulted by Computer Aided Personal Interviews of about 30 minutes with the professional help of commercial companies: BVA in France and Research International in Belgium. The enquiry yields a broad spectrum of interesting data; here only the results relevant for the emergency context will be presented. One should be aware that these data were collected in a 'normal' period; important differences in behaviour may occur given a serious crisis. A first finding is that more than half of the respondents are convinced that an accident as severe as the Chernobyl disaster may happen in their country as ...

Energy Technology Data Exchange (ETDEWEB)

With regard to a fracture system in the Hijiori hot dry rock artificial reservoir, an attempt was made on an interpretation which integrates different data. Major factors that characterize development and performance of an artificial reservoir are composed of a fracture system in rocks, which acts as circulating water paths, a heat exchange face and a reservoir space. The system relates not only with crack density distribution, but also with cracks activated by water pressure fracturing, cracks generating acoustic emission (AE), and cracks working as major flow paths, all of which are characterized by having respective behaviors and roles. Characteristics are shown on AE cluster distribution, crack distribution, production zone and estimated stress fields. Mutual relationship among these elements was discussed based on the Coulomb`s theory. The most important paths are characterized by ...

Energy Technology Data Exchange (ETDEWEB)

This article presents an experimental study on the gasification of leather residues from a tannery by using a throated 10 kW{sub e} downdraft gasifier. The gasification process is conducted over a range of feed rates in the gasifier for the operating temperatures of 1,000 deg C and 1,100 deg C, slightly below atmospheric pressure. In this study, the experimental setup and procedure are also explained in detail. Moreover, the fuel characteristics, components in the produced gas, and side products from the gasification system were measured during the experiments and discussed. It was concluded that the briquetted leather residues were successfully gasified in a downdraft gasifier. However, the large briquette sizes of the leather residues occasionally formed bridging in the throat zone of the gasifier. Therefore the downdraft gasifier should be operated using smaller size briquettes to prevent the bridging in the throat ...

Science.gov (United States)

This study investigated relationships between molecular weight distributions of unreduced grain proteins and grain, flour, and end-use quality characteristics of soft white winter wheats grown in Oregon. Absorbance area and area % values of protein fractions separated by size exclusion HPLC (SE-HPL...

Energy Technology Data Exchange (ETDEWEB)

Effect of ultrasonic-wave irradiation on the Mn-Zn ferrite powder suspension prepared by solid-state reaction and alcoholic dehydration methods was investigated. Size, distribution, and morphology of the powders prepared at different temperatures were examined, as a function of irradiation time. It was observed that the powders were reduced in size by ultrasonic energy through distinct routes. 8 refs., 7 figs., 1 tab.

British Library Electronic Table of Contents (United Kingdom)

This study investigated the association between differences in litter size in Boer does, with genetic polymorphisms in the inhibin alpha gene. Our preliminary (n=209) results found 12 SNPs, including the non-synonymous polymorphisms 911T/C and 946A/C, resulting in corresponding 299V/A and 311T/P amino acid polymorphisms. Of the SNPs, 651A/G was preliminarily suggested as a useful marker for litter size of the second parity in the population studied, showing an overdominance effect. Polymorphisms, sequence, and genotype distributions were also characterized.

CERN Document Server

Terrestrial planets form in a series of dynamical steps from the solid component of circumstellar disks. First, km-sized planetesimals form likely via a combination of sticky collisions, turbulent concentration of solids, and gravitational collapse from micron-sized dust grains in the thin disk midplane. Second, planetesimals coalesce to form Moon- to Mars-sized protoplanets, also called "planetary embryos". Finally, full-sized terrestrial planets accrete from protoplanets and planetesimals. This final stage of accretion lasts about 10-100 Myr and is strongly affected by gravitational perturbations from any gas giant planets, which are constrained to form more quickly, during the 1-10 Myr lifetime of the gaseous component of the disk. It is during this final stage that the bulk compositions and volatile (e.g., water) contents of terrestrial planets are set, depending on their feeding ...

Energy Technology Data Exchange (ETDEWEB)

Carbon Black and activated carbon materials providing high surface areas and a distinct pore distribution are prime materials for supercapacitor applications at frequencies < 0.5 Hz. A number of these materials were tested for their specific capacitance, surface and pore size distribution. High capacitance electrodes were manufactured on the laboratory scale with attention to ease of processability. (author) 1 fig., 1 ref.

British Library Electronic Table of Contents (United Kingdom)

Fatigue crack growth tests of three ferrite-pearlite steels with different size and spacing of pearlite particles, which were uniformly distributed in the ferrite matrix, were carried out to investigate the effect of microstructure on fatigue crack growth behavior in the Paris regime. The fatigue crack growth rates for the three materials did not coincide with each other, even when the crack growth curves were arranged by the effective stress intensity factor range. From in situ observations, crack tip stress shielding phenomena, such as interlocking and branching, were found on the crack wake, which enhanced fatigue crack growth resistance. A small size and spacing of pearlite particle seemed to induce small but frequent crack deflections, which resulted in crack closure phenomena. On the...

Science.gov (United States)

Hybridization and thermal evolution of the Ni+C{sub 60} composites, deposited on Si(001) at room temperature, were studied using Scanning Electron Microscopy, {mu}-Raman spectroscopy and Rutherford Backscattering. As-deposited, the hybrid films exhibited a granular nano-structure with Ni nano-particles encapsulated in C{sub 60} polymerized rinds. The Ni and C (C{sub 60}) distributions in a top layer were found homogeneous with a stable Ni/C (C{sub 60}) ratio; in the larger depth the distributions were inhomogeneous and their ratio dramatically varied. At elevated temperatures, all structural parameters were changed. In the subsurface layer Ni- and C (C{sub 60})-rich zones were formed (due to the induced phase separation), C{sub 60}-molecules decayed and their fragments were transformed into amorphous carbon (a-C). The free volume distribution of the stressed hybrid matter was analyzed by the Hg marker ...

International Nuclear Information System (INIS)

The measurement of two-phase flow parameters for development of constitutive relationships for the HANARO/MAPLE type finned fuel using Real-Time Neutron Radiography (RTNR) is discussed in this paper. A single element finned Fuel Element Simulator (FES) was used with Freon 134a as the working fluid. To observe the effect of a spacer device on void distribution, single pin tests were performed with and without a spacer present. By analyzing the RTNR images using image processing, the effects of the spacer on the time-averaged and instantaneous void fraction distribution were studied. For the experimental results without a spacer, the time-averaged local void distribution is radially asymmetric and the degree of void fluctuation increases with a decreasing frequency along the heated channel, where the observed asymmetry may be caused by flow induced vibration. For the experimental results with a spacer, the spacer clearly ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

The distributions of the effective numbers of 6q-fluctons in the energy, momentum and distance to the center of mass of nucleus are studied. Many characteristics of these distributions are shown to be universal, i.e. independent of the flucton size. The saturation of the flucton density in A > 80 nuclei and other peculiarities are found, which define different behavior of the effective numbers of fluctons and deuterons. This fact provides an explanation of the known underestimate by a factor of 1.5-6 of the cross sections of hard inclusive (p, p'd) process on nuclei calculated in the quasi-elastic approximation.

Energy Technology Data Exchange (ETDEWEB)

The goal of this project is to improve energy efficiency of industrial crushing and grinding operations (comminution). Mathematical models of the comminution process are being used to study methods for optimizing the product size distribution, so that the amount of excessively fine material produced can be minimized. The goal is to save energy by reducing the amount of material that is ground below the target size, while simultaneously reducing the quantity of materials wasted as ''slimes'' that are too fine to be useful. This is being accomplished by mathematical modeling of the grinding circuits to determine how to correct this problem. The approaches taken included (1) Modeling of the circuit to determine process bottlenecks that restrict flowrates in one area while forcing other parts of the circuit to overgrind the material; (2) Modeling of hydrocyclones to determine the mechanisms ...

Energy Technology Data Exchange (ETDEWEB)

The effect of grain boundary (GB) type on precipitate-free zone (PFZ) width in friction stir-processed 7075-T7 Al alloy is investigated by transmission electron microscopy (TEM) and stereology. The average half width of PFZs at random GBs is 70.4 {+-} 0.7 nm. For low-angle GBs, an apparent transition of PFZ half width is observed at a misorientation of 11 deg. For coincidence site lattice ({sigma}) GBs, only {sigma}1, {sigma}3 and {sigma}5 have smaller PFZ width than that of random GBs. Crystal-frame stereology is used to recover the GB plane distribution. It is found that the GB plane distribution is relatively isotropic for most {sigma} GBs. Low/high index plane combinations are observed for most {sigma} GBs; furthermore, most {sigma} GBs have both tilt and twist components. The combined results of TEM and stereology suggest that smaller PFZ width is associated only with low {sigma} GBs since the formation and growth of ...

Energy Technology Data Exchange (ETDEWEB)

The effect of high-energy-density laser surface melting on the morphology and properties of a cast Ni-based superalloy containing 33 wt percent Mo and 17 wt percent W is investigated experimentally. Significant improvements in the hardness and the wear resistance in both dry and acid environments are atttributed to the elimination of segregation in the laser-treated zone, where solid solubility increases, crystalline structure becomes finer, and the fine dendritic, cellular dendritic, cellular, and plane-front solidification structures are evenly distributed.

Energy Technology Data Exchange (ETDEWEB)

The article deals with a novel electrochemical method of preparing long-lived silver nanoparticles suspended in aqueous solution as well as silver powders. The method does not involve the use of any chemical stabilising agents. The morphology of the silver nanoparticles obtained was studied using transmission electron microscopy, scanning electron microscopy, atomic force microscopy and dynamic light scattering measurements. Silver nanoparticles suspended in water solution that were produced by the present technique are nearly spherical and their size distribution lies in the range of 2 to 20 nm, the average size being about 7 nm. Silver nanoparticles synthesised by the proposed method were sufficiently stable for more than 7 years even under ambient conditions. Silver crystal growth on the surface of the cathode in the electrochemical process used was shown to result in micron-sized structures ...

International Nuclear Information System (INIS)

A self-consistent pseudopotential method together with a mixed-basis set of plane waves and Gaussian orbitals are used to determine the electronic structure of the (001) surface of molybdenum. The pseudopotential is derived from a self-consistent calculation of the atomic levels and wave functions, and is tested for bulk molybdenum. The resulting bulk band structure and density of states are compared with existing augmented-plane-wave APW calculations. The same potential is applied to investigate the electronic structure of an uncontracted Mo (001) surface. A complete analysis of the surface states is given in terms of their distribution in the two-dimensional surface Brillouin zone, charge-density distribution, and the local density of states. The results are in very good agreement with recent photoemission measurements.

Energy Technology Data Exchange (ETDEWEB)

Optimal capacitor placement determines the size, type, and location of capacitors to be installed on a radial distribution feeder that will reduce peak power and energy losses while minimizing the costs of investment and installation of the capacitor banks. This paper describes a sensitivity-based optimal placement of capacitors that employs a new load characterization scheme using a voltage-current-angle-logger. The proposed method allows modeling of loads of different power factors for different portions of the distribution feeder. The optimal solution is obtained by testing various combinations of capacitor banks (based on the smallest bank size specified by the user) and candidate nodes along the distribution feeder, and calculating the resultant savings. In order to reduce solution time, the candidate nodes are ranked according to their sensitivity factors. The highest ranking ...

Energy Technology Data Exchange (ETDEWEB)

The most important kaolin deposits from Campo Alegre region (S C) were formed by the conjunction of at least one hydrothermal phase followed by many others weathering, supergenic, phases. Possibly deposits formed by only one of these processes exist, but these deposits shall be small and smaller than those mined today. Besides kaolinization, illitization/muscovitization and silicification, hydrothermalism also generated pyritized and propilitized zones, with quartz + chlorite. Together, hipogenic alterations related to kaolin deposits are very similar to alterations of high sulfidation epigenetic volcanogenic gold deposits. Most part of the biggest kaolin mines from the southern part of Campo Alegre Basin are distributed along a 13 Km long and 0,5 Km width bent zone that is parallel to structural alignments that point out the eastern Basin border. This zone was originated by deformation that has ...

International Nuclear Information System (INIS)

The spatial distribution of argon clusters in gas jet is tested using the Rayleigh scattering method. A pulsed laser is used to acquire the whole evolution of the cluster inside one event. The measured results at a fixed axial position show that the argon clusters grow in less than one millisecond after the nozzle is opened and the cluster size keeps constant during the whole open period of 20 ms. Further results show that the scattering signal along the radial direction is almost Gaussian-distributed and the full width half maximum (FWHM) increases almost linearly when the distance from nozzle increases. The scattering signal along the axial direction is Landau-distributed and the area near the nozzle is most effective for laser cluster interaction. (authors)

International Nuclear Information System (INIS)

Past elastic-plastic fracture studies for leak-before-break (LBB) assessment of low alloy steel pipings have been focused mostly on the behavior of base metals and their weld metals. In contrast, the heat-affected zone (HAZ) of a welded pipe has not been studied in detail primarily because the size of the HAZ is too small to make specimens for mechanical properties measurements. In this study, microstructural analyses, microhardness tests, tensile tests and J-R tests have been conducted as a function of distance from a fusion line and temperature for HAZ materials of SA106Gr.C low alloy piping steels. For the ferrite-pearlite steels such as SA106Gr.C, the HAZ specimens showed a higher yield strength and fracture toughness compared with those of its base metal. These characteristics, despite of grain coarsening, can be explained by cleaner microstructures of HAZ materials with a finer morphology of carbides compared with pearlitic-ferritic base ...

International Nuclear Information System (INIS)

The report summarizes ten years of experience in the analysis and evaluation of ultrasonic testing data measured in turbine and generator rotors. Apart from the information on type, position, size and distribution of flaws, the expert knowledge achieved in an interpretation of ultrasonic signals yields further insight, as e.g.: - Confirmation of assumptions taken as a basis for fracture-mechanical analysis of these flaws with regard to crack initiation and crack growth under low-cycle fatigue conditions (O=0.7-1 Rp 0.2, N<25.000 growth in length); - enhanced information on a correlation of ultrasonic testing data with the real flaw size. (orig.).

International Nuclear Information System (INIS)

Adult and newborn rats were exposed to "2"3"9PuO_2 aerosols of four different size distributions. Rats of both ages were killed at intervals between 1 hr and 60 days postexposure. There were marked age- and particle-related size differences in deposition, although retention was similar throughout. The differences in deposition are attributable to relatively greater deposition of larger particles in the upper respiratory tracts of newborns.

International Nuclear Information System (INIS)

At two locations in southern Lake Huron (U.S.A.), twelve 35.5-cm diameter cores of fine-grained sediments were taken for comparison of the vertical distribution of "2"1"0Pb and fallout "1"3"7Cs with the distribution of benthic macroinvertebrates, mainly oligochaete worms (Tubificidae) and the amphipod, Pontoporeia affinis. Locations were selected on the basis of "2"1"0Pb distributions measured a year earlier which indicated contrasting depths of mixing of surface sediments. At one location the activity of "2"1"0Pb is uniform down to about 6 cm and 95% of total invertebrates occur within this zone; at the other location the zone of constant activity is only 3 cm deep but 90% of the invertebrates occur within it. Comparison of published tubificid defecation rates with sediment accumulation rates based on "2"1"0Pb shows that oligochaetes alone can account for mixing in one case while ...

Energy Technology Data Exchange (ETDEWEB)

Three different fuels UO{sub 2}-only, UO{sub 2}-Gd{sub 2}O{sub 3}(5%), and UO{sub 2}-Gd{sub 2}O{sub 3}(10%) were produced by sol-gel technique. Their powder characteristics such as flowability, BET surface area, average pore diameter, and cumulative pore volume were determined. The pore size distributions of powders, green pellets, and sintered fuels were determined by using a mercury porosimeter. The theoretical densities of sintered fuels were found to be 98.01, 95.3, and 95.9 %, respectively. Their ruggedness fractal dimensions were 1.111, 1.044, and 1.042, while the fractal dimensions associated with the size distribution of grains were 1.44, 1.58, and 1.60, respectively. (orig.).

Energy Technology Data Exchange (ETDEWEB)

Ferrography is a technique for isolating wear particle debris from lubricating and hydraulic oils, the presence of which carry with them a history of the wear processes in the machine. Thus, the technique has fundamental applications in machine condition monitoring and failure prevention. The wear particles are significant in the metal types that are present in the particle distribution as an indication of the wearing machine components and in the particle size distribution and morphology which indicates the severity of wear in the system. In this paper, the fundamental principles which describe the working of the ferrograph, concentrating on the working of the on-line ferrograph are discussed. The significance of equilibrium particle concentration in the oil system and its measurement using the ferrograph are also discussed.

International Nuclear Information System (INIS)

XAFS data of metallic glass Al_0_._9_1La_0_._0_9 and a crystalline phase Al_1_1La_3 formed by annealing of the glass were measured at the La L_3 edge at T=12 K and analyzed using the radial distribution function method. The shortest La-Al distance appeared to be distinctively smaller within the glass than in the crystal. This difference decreases the disparity in size of La and Al in the alloy, allowing their mixing in the glassy state. ((orig.)).

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT With corn starch as raw material, dextrin was prepared by the combined application of common neutral and thermostable a-amylases in this study. The effects of reaction temperature, reaction time, addition of common neutral and thermostable a-amylases on dextrose equivalent (DE)-value of dextrin were investigated. The obtained dextrin with a DE value of 20.43 was evaluated for morphology, crystallography, particle size distribution and thermal property by scanning electron microscope, X-ray diffractometer, light scattering particle size analyzer and thermogravimetric analyzer. The results showed that the amorphous regions in the core part of corn starch were completely hydrolyzed and only the fractured crystalline surface remained. The particle size of the dextrin change significan...

Science.gov (United States)

Antibodies to Ehrlichia canis were detected by indirect immunofluorescence in sera from 233 of 2,077 (11%) military working dogs in various locations throughout the world and from 535 of 938 (57%) civilian dogs in the United States during a 1-year period of study. Overall, E canis infection rates ranged from 13% in the tropical and temperate zones below 45 degrees N to 8% in the cold zone north of 45 degrees N latitude. The highest antibody prevalence rate (24%) was found among a select population of dogs stationed between 40 degrees and 45 degrees north latitude (Japan and Okinawa). The seropositive military dogs did not have clinical signs of ehrlichiosis, thus indicating that the predominant form of infection was subclinical. On the other hand, 216 (23%) of the seropositive civilian dogs had various signs of the disease. The difference was attributed to the fact that the sera from civilian dogs were submitted by practitioners who suspected ...

International Nuclear Information System (INIS)

The results of the thermo-hydro-mechanical (THM) study of the FEBEX bentonite performed during FEBEX II are presented. The laboratory test program continued in part with the works carried out during FEBEX I, particularly in activities related to tests aimed to the calibration of the models, the acquisition of parameters by back-analysis and the improvement of the knowledge on the behaviour of expansive clays. But the program has also included tests on new areas: investigations about the influence of the microstructure changes in bentonite, of temperature and of the solute concentration on the behaviour of clay. Besides, several tests were proposed in order to understand the unexpected behaviour observed in the mock-up test, towards the end of year 2. Temperature effects on water retention curves in confined and unconfined conditions were determined, and swelling pressure, hydraulic conductivity and swelling and consolidation strains as a function of temperature were successfully ...

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT. The morphology, morphogenesis, and phylogeny of Diophrys parappendiculata n. sp., a large marine ciliate isolated from the coastal waters of Daya Bay, southern China, were investigated. This new species is characterized by a combination of its large size, appendiculata-pattern of ciliature, and bipartite adoral zone of membranelles. The main stages of morphogenesis during binary fission were also recorded and described. Comparisons of morphological characteristics with similar congeners support the validity of the new species. The small subunit rRNA gene sequence of D. parappendiculata is 96.3-99.94% similar to those of four other congeners; it differs in four nucleotides from that of Diophrys appendiculata (i.e. structural similarity was 99.94%). Phylogenetic analysis indicates ...

Energy Technology Data Exchange (ETDEWEB)

The energy available from tidal currents is substantial and considerable work has been conducted into determining the size of the resource and what the large-scale consequences of extraction might be. This paper describes the work conducted to establish a laboratory-scale model, by using the commercial computational fluid dynamics (CFD) code FLUENT trademark, in order to predict local-flow consequences resulting from the extraction of energy in two and three dimensions from within the water column in a tidal flow. As might be expected, a wake is formed but there is considerable localized flow acceleration around and, most especially, under an extraction zone. The wake behind the device is shown to be associated with a drop in the free surface which, in turn, is associated with the decline in the wake itself. (author)

Energy Technology Data Exchange (ETDEWEB)

Three holes the size of deposition holes (depth 7.5 m and diameter 1.5 m) were bored in the Research Tunnel at Olkiluoto, Finland. A novel full-face boring technique was used based on rotary crushing of rock and removal of crushed rock by vacuum flushing through the drill string. The purpose of the work was to demonstrate the feasibility of the technique. During the boring test procedures were carried out in order to determine the effect of changes in operating parameters on the performance of the boring machine and the quality of the hole. The boring method was found to be technically feasible and efficient. Evaluation of the quality of the hole included studies of the geometry of the hole, measurements of the surface roughness using a laser profilometer and study of excavation disturbances in the zone adjacent to the surface of the holes using two novel methods, He-gas diffusion and the {sup 14}C-polymethylmethacrylate methods. 43 refs.

International Nuclear Information System (INIS)

The present work focuses on the transformation of high-purity Ni powder blends of controlled volume fractions (40 and 60 %) of nanometre-sized (100 nm) and micrometre-sized (544 nm) particles into bulk samples as part of a strategy for producing ultrafine-grained materials usefully exhibiting both strength and ductility. The process involved cold isostatic pressing at 1.5 GPa and sintering. The resulting bulk samples had relative densities near 95 %, were texture-free, and exhibited two different grain size distributions with an average value of 600 #+-# 30 nm. The mechanical properties were investigated by compression and microhardness tests, both at room temperature, and compared to the behaviour of a sample processed from micrometre-sized powder only. Samples prepared from the blends exhibited high yield stresses of 440 and 550 MPa after compression, and they did sustain work ...

International Nuclear Information System (INIS)

This paper reports on an experimental investigation of premixed methane/air combustion stabilized within a reticulated partially stabilized zirconia foam burner that was performed. A flame holder was used to extend the stability range to allow a stable flame to be maintained for a variety of flow rate and equivalence ratio combinations. The stability range, temperature distributions, and emissions were examined over a range of equivalence ratios and flow rates. The flame was found to be axisymmetric for all conditions in which the reactants were sufficiently well mixed and the flow distribution was sufficiently uniform. Burning speeds were measured that were well in excess of the laminar flame speed. The axial temperature distribution (measured around the burner annulus) in the postflame zone was found to be relatively insensitive to flow rate but dependent upon the burner core length. Very low ...

International Nuclear Information System (INIS)

The energy, angular momentum, and distance (measured from the center of mass of the nucleus) distributions of the effective number of 6q-fluctons are investigated and it is shown that many of the characteristics of these distributions are universal, i.e., independent of the flucton size. ''Saturation'' of the flucton density in nuclei with mass A approx > 80 and certain other features that determine the difference between the behaviors of the effective numbers of fluctons and deuterons are reported. This is used to explain the well known underestimation (by a factor of 1.5--6) of the cross section for the hard inclusive (p, p'd) process on nuclei calculated in the quasielastic formalism. See S. G. Kadmenskii and V. I. Furman, Alpha decay and elated nuclear reactions (in Russian), Energoatomizdat, Moscow, 1985.

International Nuclear Information System (INIS)

Ionizing radiations that differ in number, size, and distribution of energy deposition events might be expected to cause different effects for the same absorbed dose. Furthermore, microdosimetry calculations suggest that large variations in biological effectiveness might be expected for internally deposited alpha-emitting radionuclides for the same absorbed dose, depending upon the specific activity and spatial distribution of the sources in tissue. The study described in this article was designed to demonstrate these phenomena in vitro. Cultured Chinese hamster ovary (CHO-K1 BH4) cells were exposed in vitro to inert, insoluble ceramic microspheres in zirconium dioxide labeled with "2"3"9Pu. The average exit energy of the 5.15 MeV alpha particle was calculated to be 4.3 MeV. Exposure times varied from four to seven hours to achieve the desired dose level.

British Library Electronic Table of Contents (United Kingdom)

Scientists often re-invent things that were long known. Here we review these activities as related to the mechanism of producing power law distributions, originally proposed in 1922 by Yule to explain experimental data on the sizes of biological genera, collected by Willis. We also review the history of re-invention of closely related branching processes, random graphs and coagulation models.

UK PubMed Central (United Kingdom)

In normal subjects, apolipoprotein E (apo E) is present on very low density lipoproteins (VLDL) (fraction I) and on particles of a size intermediate between VLDL and low density lipoproteins (LDL) (fraction...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Particle shape is an important parameter in numerous civil, environmental, and petroleum engineering applications. In ground-water flow, the shape of individual particles comprising the soil affects the soil`s pore size distribution and, hence, the important flow characteristics such as hydraulic conductivity and headloss. A model for delineating the relative importance of particle size, particle shape, and porosity, (and their interactions), in explaining the variability of hydraulic conductivity of a granular porous medium is developed and tested. Three types of porous media are considered in this work: spherical glass beads; granular sand; and irregularly shaped, shredded glass particles. A reliable method for quantifying the three-dimensional shape and packing of large samples of irregular particles based on their angle of repose is presented. The results of column experiments indicate that in the ...

Energy Technology Data Exchange (ETDEWEB)

The studied coal bearing series has a parallel origin. The following facial complexes are isolated in its composition: lakes free of vegetation without coal interlayers; overgrown lakes of their margins which are poor in coals; swampy lakes, whose peat beds formed coal layers of shallow or moderate depth; channel sediments without coal layers and swamps from between channel spaces which created thick coal strata of high quality for which, however, a strong changeability in thickness is intrinsic. The coal strata are normally split towards the central parts of the lake basins and river channels. The coal presence of the suite is reduced along the section which is associated with the replacement of the lake swamp conditions of sedimentation by lake river conditions. A paleotectonic analysis established that the distribution of the zones richest in coal was controlled by consedimentational structural elements.

British Library Electronic Table of Contents (United Kingdom)

During the past few decades, the basic assumption of agroclimatic zoning, i.e., that agroclimatic conditions remain relatively stable, has been shattered by ongoing climate change. The first aim of this study was to develop a tool that would allow for effective analysis of various agroclimatic indicators and their dynamics under climate change conditions for a particular region. The results of this effort were summarized in the AgriClim software package, which provides users with a wide range of parameters essential for the evaluation of climate-related stress factors in agricultural crop production. The software was then tested over an area of 114,000?km2 in Central Europe. We have found that by 2020, the combination of increased air temperature and changes in the amount and distribution ...

Energy Technology Data Exchange (ETDEWEB)

To clarify the effect of electrostimulated deformation on the fine structure and mechanical properties of polycrystalline molybdenum the experiments on the flattening of wire 0.8 mm in diameter into a strip 0.4 mm thick and its further rolling to 0.1 mm thickness using the electric current of high density in the deformation zone and without it, are carried out. As a result of the electric current use the strip density has increased by more than 20%, the same plasticity being preserved. The changes above are explained by the transformations in the fine structure of the deformed metal, which are manifested in more uniform distribution of dislocations and impurities in the grain boundaries in wide angles of the disoriented subgrains.

Energy Technology Data Exchange (ETDEWEB)

New technologies are needed to reduce the current high rate of well abandonment. Improved sweep efficiency, reservoir conformance, and permeability modification can have a significant impact on oil recovery processes. Microorganisms can be used to selectively plug high-permeability zones to improve sweep efficiency and impart conformance control. Studies of a promising microbial system for polymer production were conducted to evaluate reservoir conditions in which this system would be effective. Factors which can affect microbial growth and polymer production include salinity, pH, temperature, divalent ions, presence of residual oil, and rock matrix. Flask tests and coreflooding experiments were conducted to optimize and evaluate the effectiveness of this system. Nuclear magnetic resonance imaging (NMRI) was used to visualize microbial polymer production in porous media. Changes in fluid distribution within the pore system of the core were ...

Energy Technology Data Exchange (ETDEWEB)

Relationship between hemodynamic response to exercise and distribution of pulmonary perfusion was studied in 71 patients with mitral stenosis. Distribution was estimated by using computerized Tc-99m-MAA perfusion images (digital perfusion images; DPI). DPI were composed of isocount areas. Various types of DPI were obtained and were classified to 6 grades (G) according to patterns of 100 - 70% isocount area in right anterior DPI, i.e. G-0 (normal), G-1 (increase of perfusion at upper zone), G-2 (uniform distribution), G-3 (disappearance of basal hyperperfusion area), G-4 (apical hyperperfusion area) and G-5 (decrease of perfusion at lower zone). Patients were devided to 4 groups according to grade. At rest there were no marked hemodynamic differences between groups (n = 71, mean pulmonary artery pressure (mPA); 24.8 +- 11.0 mmHg, cardiac index (CI); 2.7 +- 0.81 lmM/sup 2/), however ...

International Nuclear Information System (INIS)

Greenland is the world's largest island, with an area of 2.2 million square kilometres, 80 % of which is covered by the ice sheet. The climate is Arctic, but as Greenland stretches 2600 km from north to south, there is a huge variability in climate, with temperature decreasing from south to north. Due to the influence of oceanic currents, the west coast is slightly warmer than the east coast. Precipitation also decreases strongly from the south to the north, and also with distance from the coast. Kangerlussuaq is located in the dry, continental area of central west Greenland. The bedrock of Greenland is dominated by Precambrian gneisses, with sedimentary rocks occurring in some areas of East and North Greenland, and smaller areas of basalts. All of Greenland has been glaciated several times and has thus been eroded and shaped by the ice, as it still is at the ice margin. Soils are generally thin, and especially in the gneiss regions rather poor in plant nutrients. Permafrost occurs ...

International Nuclear Information System (INIS)

Molecular beam epitaxy (MBE) grown Ge nanodots are found to come in a clear trimodal island distribution of huts, pyramids, and domes when grown on (001)Si at 550 deg. C. The island types appear in this order as Ge coverage increases and for a certain coverage all three types are found to coexist at this growth temperature. Previously Ge nanodots have mostly been divided into huts and domes at growth temperatures below 600 deg. C, or pyramids and domes above 600 deg. C. The (105) faceted pyramidal and elongated huts and the multifaceted domes are well known, but a distinction has not previously been seen between huts and a separate size distribution of similarly (105)-faceted pyramidal nanodots twice the size of huts, at temperatures below 600 deg. C. The 20-25 nm wide huts also appear to be the smallest obtainable self-assembled Ge dots on (001)Si, in accordance with predictions based on Si_1_-_xGe_x ...

Energy Technology Data Exchange (ETDEWEB)

Fine ceramic particles of zirconia toughened alumina (ZTA), titania toughened alumina (TTA), and zirconia-titania toughened alumina (ZTTA) have been synthesized by ultrasonic spray pyrolysis (USP) at various temperatures from starting salt solutions of various compositions aiming for the development of catalytic material. These particles were characterized for properties such as shape, size and size distribution, diffraction pattern, and chemical and phase composition of elements by scanning electron microscopy (SEM), particle size analyzer (PSA), x-ray diffraction (XRD), and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). Chemical compositions and sizes of ceramic composites have been controlled by the stoichiometry of salt solutions and the flow rate of spraying solutions. The optimum experimental conditions for the various composite particle synthesis have been ...

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

The Ordos Basin is a typical lapped basin, including three sequences of strata: early Paleozoic, late Paleozoic and Mesozoic, with a total thickness of 4000-6000m. Impermeable sealing beds are well developed at the top and base of the upper Paleozoic sequence, separating it from the Mesozoic and the lower Paleozoic strata to form an independent petroleum system. In this petroleum system, the source rocks are widely distributed coals and dark mudstones occurring in the Carboniferous-lower Permian coal measures, with a thickness of 10-15 and 40-60m, respectively. The reservoirs are mainly early Permian tight sandstones, mostly with a porosity of 4-8% and a permeability of 0.1-1.0x10{sup -3}{mu}m{sup 2}. The regional cap rock is a 100-150m thick mudstone in the upper Permian strata. The structural framework of the basin is a huge asymmetric syncline, dipping gently toward the east and north, and steeply toward the south and west. Well data show that gas-saturated, ...

International Nuclear Information System (INIS)

Full text of publication follows: Hydrogen release and distribution in nuclear power plant containment is an important safety issue. Selection of a proper turbulence model is important for accurate estimation of the mixing process. The selection of turbulence model is dictated by the best compromise between accuracy and computational efforts. For this, three different turbulence models, viz. Standard k-#epsilon#, RNG k-#epsilon# and Reynolds Stress Model, based on Reynolds averaged Navier Stokes equations (RANS) approach, were used. The computations were done using the CFD code FLUENT, which is based on the control volume methodology. The computational results were compared with the experimental results of HYMIS test facility, where helium was used to simulate hydrogen. The processes of helium plume rise, multiple plume merging, distribution and mixing were studied. Based on these computations, a simple analytical/empirical ...

Science.gov (United States)

The Process Waste Treatment Plant (PWTP) at the Oak Ridge National Laboratory is designed to remove radioactive contaminants, principally {sup 90}Sr, from process wastewater. Planned upgrades to the PWTP will use chabazite zeolite columns. Pilot-scale studies have shown that mass transfer zone lengths increase from 10 to about 30 cm as the superficial velocity increases from 5.5 to 22 cm/min. Calculations with a multicomponent equilibrium model showed that the distribution coefficient for strontium remains essentially constant over the process conditions, suggesting that a simple kinetic model (the Rosen long-bed solution) should adequately represent breakthrough behavior. Using a distribution coefficient of 4.87 L/g predicted by the equilibrium model, good agreement was found between experimental breakthrough curves and those calculated with the Rosen solution. This model allows prediction of bed depths and cycle times ...

Energy Technology Data Exchange (ETDEWEB)

Computational transport models are described with applications in three problem areas related to unsaturated zone moisture movement beneath Area G. These studies may be used to support the ongoing maintenance of the site Performance Assessment. The three areas include: a 1-D transient analysis with average tuff hydraulic properties in the near surface region with computed results compared to field data; the influence on near surface transient moisture percolation due to realistic distributions in hydraulic properties derived statistically from the observed variance in the field data; and the west to east moisture flow in a 2-D steady geometry approximation of the Pajarito Plateau. Results indicate that a simple transient model for transport of moisture volume fraction fits field data well compared to a moisture pulse observed in the active disposal unit, pit 37. Using realistic infiltration boundary conditions for summer showers and for spring ...

International Nuclear Information System (INIS)

We study the relation between size and star formation activity in a complete sample of 225 massive (M_* > 5 x 10"1"0 M _s_u_n) galaxies at 1.5 < z < 2.5, selected from the FIREWORKS UV-IR catalog of the CDFS. Based on stellar population synthesis model fits to the observed rest-frame UV-NIR spectral energy distributions, and independent MIPS 24 #mu#m observations, 65% of the galaxies are actively forming stars, while 35% are quiescent. Using sizes derived from two-dimensional surface brightness profile fits to high-resolution (FWHM_P_S_F #approx# 0.''45) ground-based ISAAC data, we confirm and improve the significance of the relation between star formation activity and compactness found in previous studies, using a large, complete mass-limited sample. At z #approx# 2, massive quiescent galaxies are significantly smaller than massive star-forming galaxies, and a median factor of 0.34 #+-# 0.02 smaller than galaxies ...

International Nuclear Information System (INIS)

A nuclear power plant engineering (NPP) simulator may include many system functions such as thermal-hydraulic calculation, 3D reactor neutron kinetics model, control and protection system, display and operational human-machine interface, intelligent alarm system, etc. If all those functions are simulated using a single code, the size of the program will cause structural or managerial problems, and the hardware requirement could be tremendous. Thus, any local function errors or changes may affect the whole code, which will make development and maintenance extremely costly. So the nondistributed code is not considered to be flexible and feasible. Currently, distributed and parallel technologies have been applied to develop NPPs engineering simulator for safety analysis, verification of advanced main control room display, operation and intelligent alarm design. The distributed simulation divides a huge task into several ...

Energy Technology Data Exchange (ETDEWEB)

The United States and Russia have agreed to jointly develop a solar dynamic (SD) system for flight demonstration on the Russian Mir space station starting in late 1997. Two important components of this SD system are the solar concentrator and heat receiver provided by Russia and the US, respectively. This paper describes optical analysis of the concentrator and solar flux predictions on target receiver surfaces. The optical analysis is performed using the code CIRCE2. These analyses account for finite sun size with limb darkening, concentrator surface slope and position errors, concentrator petal thermal deformation, gaps between petals, and the shading effect of the receiver support struts. The receiver spatial flux distributions are then combined with concentrator shadowing predictions. Geometric shadowing patterns are traced from the concentrator to the target receiver surfaces. These patterns vary with time depending on the chosen Mir ...

British Library Electronic Table of Contents (United Kingdom)

Abstract High-crystallinity hierarchical anatase TiO2 hollow spheres were prepared by a high-temperature (350 C) and non-aqueous solvothermal method in the absence of water, templates, or additives. The hollow structures were assembled from highly crystallized TiO2 nanoparticles and exhibit superior photocatalytic properties relative to those of Degussa P25 TiO2 under irradiation with UV light. The influence of reaction temperature on the crystallinity, morphology, crystallite shape and size, band gap, specific surface area, and pore size distribution of TiO2 has been studied in detail. It is evident that reaction temperature is the most important factor to increase the crystallinity of TiO2 in order to improve its charge transfer and transport properties, which are important in photocatal...

International Nuclear Information System (INIS)

The structure of nano-porous carbon, obtained by means of chlorination of carbide compounds with various crystal structure (SiC, TiC, Mo_2C) is studied through the method of small-angle diffraction. The angular dependences of the scattering intensity obtained are interpreted as the result of scattering from the nanoparticles of different size. The functions of the scattering particles distribution by the m(R_g) inertia radii are determined. It is shown that in spite of the source carbide, the highest fraction of the volume in the porous carbon constitute the particles with R_g #approx# 5 A. The nanoparticles in the samples obtained from SiC, wherein the average value of the R_g"a"v < 6 A, are most uniform by size. The nanoparticles in the porous carbon, obtained from Mo_2C, are on the average by two times larger

International Nuclear Information System (INIS)

Nanocrystalline powders of GaN with grain sizes ranging from 2 to 30 nm were examined under high external pressures by in situ diffraction techniques in a diamond anvil cell at DESY (HASYLAB, Station F3). The experiments on densification of pure powders under high pressure were performed without a pressure medium. The mechanism of generation and relaxation of internal strains and their distribution in nanoparticles was deduced from Bragg reflections recorded in situ under high pressures at room temperature. The microstrain was calculated from the full-width at half-maximum (FWHM) values of the Bragg lines. It was found that microstrains in GaN crystallites are generated and subsequently relaxed by two mechanisms: generation of stacking faults and change of the size and shape of the grains occurring under external stress. (author)

British Library Electronic Table of Contents (United Kingdom)

A supercritical fluid-based method is proposed to produce coenzyme Q10 (CoQ10) nanoparticles. First, CoQ10/polyethylene glycol 6000 composite particles are prepared by a modified PGSS (particles from gas-saturated solutions) process with controlling the flow rate of the gas-saturated solution. Then, CoQ10 nanoparticles are obtained by dissolving the composite particles into water. The effect of experimental variables of the modified PGSS process, including pressure, temperature, flow rate of the gas-saturated solution, and mass fraction of CoQ10, on the CoQ10 particle size and particle size distribution was investigated. Results show that CoQ10 slurry product with a median diameter of 190nm and yield of 89.8% can be prepared at an optimum condition (operating pressure of 25MPa, operating t...

Energy Technology Data Exchange (ETDEWEB)

The performance requirements of the Advanced Photon Source (APS) challenge the control system in a number of areas. This paper will review a few applications of advanced technology in the control and monitoring of the APS. The application of digital signal processors (DSPs) and techniques will be discussed, both from the perspective of a large distributed multiprocessor system and from that of embedded systems. In particular, two embedded applications will be highlighted, a beam position monitor processor and a DSP-based power supply controller. Fast data distribution is often a requirement. The application of a high-speed network based on reflective memory will also be discussed in the context of the APS global orbit feedback system. Timing systems provide opportunities to apply technologies such as high-speed logic and fiber optics. Examples of the use of these technologies will also be included. Finally, every modern accelerator control ...

Energy Technology Data Exchange (ETDEWEB)

A flow pattern or flow regime is the characteristics spatial distribution of the phases of fluid in a duct. Since heat transfer and pressure drop are dependent on the characteristic distribution of the phases, it is necessary to describe flow patterns in an appropriate manner so that a hydrodynamic or heat transfer theory applicable to that pattern can be chosen. The objective of the present analysis is to create a flow regime map based on physical modeling of vapor/liquid interaction phenomena in a microgravity environment. In the present work, four basic flow patterns are defined: dispersed flow, stratified flow, slug flow, and annular flow. Fluid properties, liquid and vapor flow rates, and pipe size were chosen as the principal parameters. It is assumed that a transition from one flow pattern to another will occur when there is a change in the dominant force which controls that flow pattern. The forces considered in ...

British Library Electronic Table of Contents (United Kingdom)

Injections of fuel-grade ethanol (95% v/v ethanol, 5% v/v hydrocarbon mixture as a denaturant) near the water table were conducted in two-dimensional physical models tightly packed with fine sands under varying water-table conditions. As the fuel migrated in the porous media following injection, the denaturant phase separated leaving a residual Light Non-Aqueous Phase Liquid (LNAPL) phase that occupied a region with a volume similar to that of an equal-sized spill of 100% LNAPL without ethanol. When the water table was raised, as may be expected following a catastrophic release that reaches groundwater, most of the ethanol-fuel mixture was mobilized and the vertical distribution of the generated LNAPL was increased. The lower boundary of the residual LNAPL was established during the initia...

Energy Technology Data Exchange (ETDEWEB)

Three studies of electrochemical current distribution have been performed using potential-theory models and the boundary-element method (BEM). (1) The steady-state behavior of cells with nonuniform current density over a passivating anode is investigated. Current distributions calculated for a test cell, using the measured kinetic behavior of nickel in acid-nickel-sulfate solution, are compared to estimates from earlier models. Although current-density profiles determined by weight loss on a segmented rotating cylinder agreed satisfactorily with model calculations, the measured length of the passive zone exceeds the theoretical value. The model's applicability to anodic protection is demonstrated for a stainless-steel sulfuric-acid holding tank. (2) A model is established to describe the effects of attached bubbles on the potential drop at gas-evolving electrodes including: (1) ohmic obstruction within the ...

International Nuclear Information System (INIS)

We introduce a novel search technique that can identify trans-Neptunian objects in three to five exposures of a pointing within a single Hubble Space Telescope (HST) orbit. The process is fast enough to allow the discovery of candidates soon after the data are available. This allows sufficient time to schedule follow-up observations with HST within a month. We report the discovery of 14 slow-moving objects found within 50 of the ecliptic in archival data taken with the Wide Field Channel of the Advanced Camera for Surveys. The luminosity function of these objects is consistent with previous ground-based and space-based results. We show evidence that the size distribution of both high and low inclination populations is similar for objects smaller than 100 km, as expected from collisional evolution models, while their size distribution differs for brighter objects. We suggest that the two populations ...

Energy Technology Data Exchange (ETDEWEB)

Emulsions now find a wide range of applications in industry and daily life. In the pharmaceutical industry lipophilic active ingredients as well as many nutritional products such as vitamins are often formulated in the dispersed phase of oil-in-water emulsions. Emulsions can be produced with different mechanical emulsification techniques. In the following review, the process of rotor-stator systems and disc systems are compared to other popular mechanical emulsification systems. On the basis of experimental results from the authors' laboratory, a discontinuous gear-rim dispersing system, discontinuous disc system, and a continuous high pressure system are compared with regard to their attainable mean droplet diameter and drop size distribution in an oil-in-water emulsion. It can be shown that dissolver discs with a very simple geometry attain very small mean droplet diameters and a very narrow droplet size ...

International Nuclear Information System (INIS)

The formation and growth of silicon-nanoparticles from silane in a microwave reactor was investigated. Experiments were performed for the following conditions: precursor concentration 380-2530 ppm, pressures of 20-30 mbar, microwave powers 120-300 W. The formed particles were examined in-situ with a particle mass spectrometer. Additionally, particles were collected on grids and analyzed by transmission electron microscopy, X-ray diffraction, and by determining the specific surface area by BET. The particle size was found to be in the range of 5-8 nm in diameter. A simple model was used to simulate the particle formation processes taking place inside the reactor. The microwave energy coupled into the reactor flow was treated as a spatially distributed energy source resulting in a local temperature increase. The particles were assumed to have a monodisperse size distribution. To allow an approximation of ...

Energy Technology Data Exchange (ETDEWEB)

Leakage of CO{sub 2} and displaced brine from geologic carbon sequestration (GCS) sites into potable groundwater or to the near-surface environment is a primary concern for safety and effectiveness of GCS. The focus of this study is on the estimation of the probability of CO{sub 2} leakage along conduits such as faults and fractures. This probability is controlled by (1) the probability that the CO{sub 2} plume encounters a conductive fault that could serve as a conduit for CO{sub 2} to leak through the sealing formation, and (2) the probability that the conductive fault(s) intersected by the CO{sub 2} plume are connected to other conductive faults in such a way that a connected flow path is formed to allow CO{sub 2} to leak to environmental resources that may be impacted by leakage. This work is designed to fit into the certification framework for geological CO{sub 2} storage, which represents vulnerable resources such as potable groundwater, health and safety, and the near-surface ...

International Nuclear Information System (INIS)

Muonic-atom energy levels and wave functions are calculated. The results are corrected for nearly all important static effects, including finite nuclear size as produced by a user-specified nuclear charge distribution. Fourth-order Runge-Kutta integration of the radial Dirac equations, with the secant method determining the eigenvalues. Corrections are either included as potentials in the Dirac equations or computed as first-order perturbations. The code assumes spherical symmetry, so that effects of nuclear deformation may be treated only as static first-order perturbations. Dynamic muon-electron and muon-nuclear effects are neglected (the latter are calculated by RURP). (Auth.).

Energy Technology Data Exchange (ETDEWEB)

The paper describes an experimental investigation involving pore structure of blended gypsum binder. The pore structure was investigated by using mercury porosimeter. A relationship between structure and mechanical properties has been established. It has been found that the principal factor of porosity governs the development of structure and strength of the blended gypsum binder. The pore size distribution was characterized by a reduction in the volume of the pores whose diameters are larger than 500 {angstrom} and an increase in the volume of those smaller diameters. An interpretation of the development in strength vis-a-vis porosity of the blended gypsum binder is presented.

International Nuclear Information System (INIS)

Conduction properties of Rb"+ ion in Rb-Al-priderite and K"+ ion and Rb"+ ion in (K,Rb)-Al-priderite, were investigated by NMR using "2"7Al in the framework as a probe. Size effect was observed remarkably in the activation energies. Frequency dependence of T_1 in Rb-Al-priderite at a low temperature indicates that the relaxation behavior of "2"7Al in Rb-Al-priderite can be described by the continuum model. Barrier height distributions and 'attempt frequencies' in both samples obtained by a curve-fitting method are discussed in comparison with those of K-Al-priderite. (orig.).

International Nuclear Information System (INIS)

A few industry-derived and conventional building materials have above acceptable radioactivity. An examination of some materials presently used, or with a potential for use, has shown that in phosphogypsum, fly ash, zircon kyanite tailings, red mud and brickmaking clay, the radium equivalent activities of the finer fractions (<53 #mu#) are higher than those of the larger fractions. Consequently, the radioactivity of these materials could be reduced by dry-sieving and discarding the fines. In blast furnace slag and dissociated zircon, no such reduction would occur since the radioactivity is evenly distributed in all sized fractions.

Energy Technology Data Exchange (ETDEWEB)

The report discusses: Combustion characteristics of various commercial cokes for cupola furnace operation; quality level of modern cokes; foundry coke, blast furnace coke, MB coke; characteristic data, e.g. grain size distribution, drum resistance, concentrations of water, carbon, sulphur, ash, and volatiles, reactivity; changes in coke quality during transport. (HS)

International Nuclear Information System (INIS)

Extended X-ray absorption fine structure (EXAFS) measurements of bismuth clusters in the temperature range of 23 -300 K have been performed using synchrotron radiation in order to investigate the size dependent phase transition. The inter-atomic distances around 3.0 A and 3.6 A are attributed to the nearest neighbors within the layer and between layers, respectively. EXAFS functions were analysed by the curve fitting method within a symmetric distribution approximation. The nearest neighbor distance of the 0.5 nm thick films is shorter than that of the 300 nm thick films at all the temperatures, which is related to the reduction of the inter-layer correlation.

International Nuclear Information System (INIS)

Models of the human airways have played a major role in evaluating the health effects of inhaled radionuclides. While models such as those of Weibel (1963) provide data necessary for characterizing deposition of aerosol, they have not characterized the cells at risks in the airspaces. Given the advancements in techniques and study of cell cultures exposed to ionizing radiation there is a need to extrapolate between the simple structures of cell culture systems and the complex architecture of the human airways. The preliminary data in this paper provide a complete characterization of the size and number of cells in the airways and represents a significant advance in our study of the health consequences of exposure to inhaled radionuclides. 26 refs., 2 figs., 4 tabs.

International Nuclear Information System (INIS)

In this article we derive longitudinal impedance and wake function for an undulator setup with arbitrary undulator parameter, taking into account a finite transverse size of the electron bunch. Earlier studies considered a line density-distribution of electrons instead. We focus our attention on the long-wavelength asymptote (compared with resonance wavelength), at large distance of the electron bunch from the undulator entrance compared to the overtaking length, and for large vacuum-chamber size compared to the typical transverse size of the field. These restrictions define a parameter region of interest for practical applications. We calculate a closed expression for impedance and wake function that may be evaluated numerically in the most general case. Such expression allows us to derive an analytical solution for a Gaussian transverse and longitudinal bunch shape. Finally, we study the feasibility ...

Energy Technology Data Exchange (ETDEWEB)

Detailed spray characteristics were obtained for a small-capacity, pressure-swirl atomizer using an Aerometrics phase-Doppler particle analyzer. Measurements included drop size and velocity distributions, liquid volume fluxes, and air velocities at four axial locations, 25,50,75, and 100 mm, with complete radial traverses at each location. Drop size results were compared with measurements from a Malvern laser-diffraction instrument, and integrated liquid volume fluxes were compared with measured flow rates to estimate measurement uncertainties. Drop sizes measured by the two independent techniques and area-weighted-averaged over the radial traverses at each of the four axial stations varied on average by less than 4 percent. Integrated volume flux measurements by the phase-Doppler instrument at four axial stations differed from the nozzle flow rate by at most 19 percent, with some of the difference due ...

Science.gov (United States)

During this reporting period four direct coal liquefaction experiments have been completed and a fifth is underway. These experiments have produced conversion and selectivity data on samples of Utah coal slurried in tetralin and catalyzed using iron-titanium hydride. Hydrogen loading of the alloy, catalyst particle size, coal particle size, operating temperatures for alloy addition and liquefaction without the catalysts present, have all been studied during these four experiments. Conversions of 61% DAF in 30 min have been recorded at 485/sup 0/F and 520 psia. The fifth run using the same coal at a reduced particle size has begun, after which we will move to samples of Kentucky and Alabama coals. Equipment manufacture, delivery, and installation delays, totaling over 6 months, greatly reduced the time available for research, making a 6 month no cost extension necessary. The extended time will permit completion of the ...

Energy Technology Data Exchange (ETDEWEB)

The usefulness of helical CT early phase images optimized by the SmartPrep method for evaluation of wall invasion by colorectal cancer was investigated. Between August 1997 and September 1998, CT was performed to evaluate the primary tumor and local extension in 10 consecutive patients with colorectal cancer confirmed by barium enema- and/or colonoscopy. Early-phase images were acquired by using SmartPrep application software. This method allows the optimal scan delay time to be obtained by continuous monitoring of increases in CT values after injection of contrast medium. Sections of the surgical specimens, close to the same plane as the CT images, and of the same slice thickness, were analyzed histopathologically. All 10 cancers, regardless of size, showed strong enhancement on the early-phase images (81.4-112 HU, mean: 95.1 HU). The strongly enhanced image areas on CT corresponded to the primary cancer areas on histopathological specimens. A low-density ...

British Library Electronic Table of Contents (United Kingdom)

We tested the hypothesis that overstorey of eucalypt forest dominated by tall, large diameter trees uses less water than regrowth stands in the high rainfall zone (>1100mmyear^-^1) of the northern jarrah (Eucalyptus marginata) forest in southwestern Australia. We measured leaf area, cover, sapwood area and sapwood density at three paired old and regrowth stands. We also measured sapflow velocity at one paired stand (Dwellingup) from June 2007 to October 2008. Old stands had more basal area but less foliage cover, less leaf area and slightly thinner sapwood. The ratio of sapwood area to basal area decreased markedly as tree size increased. Sapwood area of the regrowth forest stands (6.6+/-0.30m^2ha^-^1) was nearly double that of the old stands (3.4+/-0.17m^2ha^-^1), despite larger basal are...

Energy Technology Data Exchange (ETDEWEB)

In this work, a comprehensive model including heat transfer, fluid flow and solidification was used to evaluate the performance of a novel delivery system for a single-belt steel casting process. This near-net-shape casting, although still in development, is one of the most promising routes for casting of low-carbon steel in large scale. This paper focuses on the performance of a low-Re {kappa}-{epsilon} model that was employed to simulate the three-dimensional turbulent flows fully-coupled with heat transfer and macroscopic solidification. Simulations were run for the intended conditions of caster operation, and the results obtained with the {kappa}-{epsilon} were compared with the results obtained with an ad hoc viscosity model, where the molecular viscosity was boosted 100 times, uniformly throughout the computational domain. A semi-analytical solution was employed for validating the models and the results showed that the ad hoc viscosity model overestimated the thickness of the ...

Energy Technology Data Exchange (ETDEWEB)

A comparison of the loss mechanisms in screen-printed solar cells relative to buried contact cells and cells with photolithography-defined contacts is presented in this paper. Model calculations show that emitter recombination accounts for about 0.5% absolute efficiency loss in conventional screen-printed cells with low-sheet-resistance emitters. Ohmic contact to high-sheet-resistance emitters by screen-printing has been investigated to regain this efficiency loss. Our work shows that good quality ohmic contacts to high sheet-resistance emitters can be achieved if the glass frit chemistry and Ag particle size are carefully tailored. The melting characteristics of the glass frit determine the firing scheme suitable for low contact resistance and high fill factors. In addition, small to regular Ag particles were found to help achieve a higher open-circuit voltage and maintain a low contact resistance. This work has resulted in cells with high fill factors (0.782) on ...

International Nuclear Information System (INIS)

This paper presents a methodology for modeling slug initiation and growth in horizontal ducts. Transient two-fluid equations are solved numerically using a class of high-resolution shock capturing methods. The advantage of this method is that slug formation and growth in a stratified regime can be calculated directly from the solutions to the flow field differential equations. In addition, by using high-resolution shock capturing methods that do not contain numerical diffusion, the discontinuity generated by slugging in the flow field can be modeled with good accuracy. The two-fluid model is shown to be well-posed mathematically only under certain conditions. Under these circumstances, the two-fluid model is capable of correctly predicting and modeling the flow physics. When ill-posed, an unbounded instability occurs in the flow field solution, and the instability amplitude increases exponentially with decreasing mesh sizes. This work shows that there are three ...

Energy Technology Data Exchange (ETDEWEB)

Air flow and the buoyancy-driven flow through a building`s horizontal openings was discussed. Horizontal openings occur in staircases, stairwells, ventilation shafts and chimneys. Mass and energy transfer through them have important implications regarding energy saving, thermal comfort, control of contaminants and micro-organisms and spread of fire and smoke. The analysis of the buoyancy-driven flow was attained using computational fluid dynamics (CFD). Use was made of the CFD code FLUENT which integrated the Navier-Stokes equations by a time-dependent, finite volume method. Good agreement was achieved between predicted and experimental measurements of flow rate. Results showed that flow patterns in horizontal openings were transient and unstable. The air exchange through the openings occurred in intermittent pulses. The flow rate through the opening increased with the temperature difference between zones in buildings and the size of the ...

International Nuclear Information System (INIS)

... aurorae carbon dioxide emission spectra infrared radiation nitrogen nitrogen

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

The distribution of graphite particles in graphite containing copper alloy was further improved very significantly using several procedures and technological modifications. The developed techniques attacked the graphite distribution problem in two ways. Realizing that clustering of very fine (5um) graphite particles is one of the two major problems, a pretreatment process has been developed using aluminum powders to deagglomerate graphite particles. Along with this, a two-stage stirring technique was used to first incorporate and then to distribute uniformly the deagglomerated particles in the melt. During this year, based on these developments, several components were cast to evaluate the castability of Cu alloy-graphite melts. In addition, machinability tests were done to clearly established that addition of graphite particles improve the machinability of copper MMC alloys over and above that of monolithic copper alloys. ...

International Nuclear Information System (INIS)

The pressurized Heavy Water Reactor (PHWR) consists of horizontal calandria vessel containing a large number of pressure tubes (fuel channels) connected to the reactor inlet and outlet headers by individual feeders. Coolant flow distribution among the pressure tubes play a vital role in extraction of thermal power. For these reactors one of the design objectives is to achieve uniform coolant outlet temperatures by providing coolant flows according to the channel power. This is achieved by the design process known as feeder sizing. This basically consists of accounting for the individual channel power and centre line geometry of individual feeder and iteratively adjusting the feeder hydraulic resistances within the design constraints such as limiting flow velocities, channel flows. Recently, the first unit of 540 MWe i.e Tarapur Atomic Power Project (unit 4) has been commissioned. This paper discusses the verification of the coolant flow ...

Energy Technology Data Exchange (ETDEWEB)

A field survey on cadmium, lead, copper, and zinc was performed in Semarang, the fifth largest city in Indonesia. Water, sediment, and fish samples were collected from 101 grids of 2 x 2 km. The objectives of the study were (1) to identify the spatial distribution of metals in the sediments of the greater Semarang area, (2) to estimate the background concentrations of the metals present in Semarang, (3) to provide a simple tool for deriving standards for metals in the sediment, and (4) to explore the potential use of the guppy (Lebistes reticulatus) as a bioindicator of urban metal pollution. To map the spatial distribution of the metals, concentrations of each metal in sediment were plotted against the corresponding city coordinate. On the basis of these plots, background concentrations of the metals were estimated. A combined pollution index can be derived thereafter by calculating the difference between metals concentrations from a ...

International Nuclear Information System (INIS)

The localized Pt deposition on Si by 30 keV Ga"+ focused ion beam (FIB), 10 keV electron beam (EB) or dual beams (FIB and EB) using precursor gas has been compared by analysis using a 300 keV Be"2"+ microprobe with a beam spot size of 80 nm. The distribution of deposited Pt, Ga from the ion beam itself, and C from the precursor gas was obtained at and nearby the deposited areas by micro-RBS spectra and RBS mapping. All of the beam processed areas showed a uniform Pt distribution at the deposited areas. The amount of Pt atoms increased with the increase in ion or electron dose due to the decomposition of precursor gas. The thickness of Pt layer by EB is considerably less than that by FIB due to the reduced deposition rate. Ga atoms from the center of processed areas partly redeposited at and nearby the FIB processed areas within #approx#3 #mu#m. The Ga incorporation by dual beam processing was reduced compared with that by ...

Energy Technology Data Exchange (ETDEWEB)

This paper reports the estimates concerning the atmospheric carbon dioxide absorption and storage by living plants all over the world. It is necessary to decrease atmospheric carbon dioxide concentrations for avoiding global warming. As living plants absorb carbon dioxide by photosynthesis and accumulate carbon in their bodies, they can play an important role to remove atmospheric carbon dioxide. Literatures describing distribution areas, biomass values and net primary productivity (NPP) of forests, marine plants and microorganisms were collected. Examining those data, the biomass and NPP of forests, marine plants and microorganisms can be summarized as follows: (1) Forest biomass and their NPP of the world. The world's forest area is recently estimated as 4 billion hectares, and their biomass is about 400 billion tons of carbon which is equal to 2/3 of the total atmospheric carbon. The NPP of the world's forest is estimated as 25-35 billion tons ...

Energy Technology Data Exchange (ETDEWEB)

Ferrofluids have promising potential for heat transfer applications, since advective transport in a ferrofluid can be readily controlled by using an external magnetic field. However, unlike conventional free or forced convection, ferrohydrodynamic convection is not yet well characterized. A full understanding of the relationship between an imposed magnetic field, the resulting ferrofluid flow, and the temperature distribution is a prerequisite for the proper design and implementation of applications involving thermomagnetic convection. The literature variously assumes constant magnetic fields, does not completely represent the variation in the imposed field, or its descriptions are inaccurate, since the fields do not comply with the Maxwell's equations of electromagnetism. We address this by simulating two-dimensional forced convection heat transfer in a channel with a ferrofluid that is under the influence of a two-dimensional magnetic field created by a ...

International Nuclear Information System (INIS)

Findings indicate an urgent need to establish a monitoring program for persistent organic pollutants in water and sediment. - Marine culture is thriving in China and represents a major component of the regional economy in coastal zones, yet the environmental quality of many of those areas has never been studied. This paper attempts to investigate the quality status of Daya Bay, a key aquaculture area in China. The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in water and sediment samples of the bay. The total concentrations of 16 PAHs varied from 4228 to 29325 ng l"-"1 in water, and from 115 to 1134 ng g"-"1 dry weight in sediments. In comparison to many other marine systems studied, the PAH levels in Daya Bay waters were relatively high, and at six sites they were sufficiently high (>10 #mu#g l"-"1) to cause acute toxicity. The PAH composition pattern in sediments suggest dominance by medium to high molecular weight compounds, and the ...

Energy Technology Data Exchange (ETDEWEB)

An important component of the overall program to validate WIMS-AECL for use with RFSP in the analysis of CANDU-6 reactors for design and safety analysis calculations is the validation of calculations of incremental cross sections used to represent reactivity devices. A method has been developed for the calculation of the three-dimensional neutron flux distribution in and around CANDU reactor fuel channels and reactivity control devices. The methods is based on one- and two dimensional transport calculations with the WIMS-AECL lattice cell code, SPH homogenization, and three-dimensional flux calculations with finite-difference diffusion theory using the MULTICELL code. Simulations of Wolsung 1 Phase-B commissioning measurements and Point Lepreau restart tests have been performed, as a part of the program to validate WIMS-AECL lattice cell calculations for application to CANDU reactor simulations in RFSP. The incremental cross section properties of the Wolsung 1 and ...

Energy Technology Data Exchange (ETDEWEB)

This thesis discusses an advanced dynamical two-dimensional cylinder symmetric model for the high temperature part of the carbothermic silicon metal process, and its computer encoding. The situation close to that which is believed to exist around one of three electrodes in full-scale industrial furnaces is modelled. This area comprises a gas filled cavity surrounding the lower tip of the electrode, the metal pool underneath and the lower parts of the materials above. The most important phenomena included are: Heterogeneous chemical reactions taking place in the high-temperature zone (above 1860 {sup o}C), Evaporation and condensation of silicon, Transport of materials by dripping, Turbulent or laminar fluid flow, DC electric arcs, Heat transport by convection, conduction and radiation. The results from the calculations, such as production rates, gas- and temperature distributions, furnace- and particle geometries, fluid flow fields etc, are ...

Energy Technology Data Exchange (ETDEWEB)

The microstructure of the secondary deformation zone (SDZ) near the cutting surface in metal chips of Ti-6Al-4V formed during machining was investigated using focused ion beam (FIB) specimen preparation and transmission electron microscopy (TEM) imaging. Use of the FIB allowed precise extraction of the specimen across this region to reveal its inhomogeneous microstructure resulting from the non-uniform distribution of strain, strain rate, and temperature generated during the cutting process. Initial imaging from conventional TEM foil preparation revealed microstructures ranging from heavily textured to regions of fine grains. Using FIB preparation, the transverse microstructure could be interpreted as fine grains near the cutting surface which transitioned to coarse grains toward the free surface. At the cutting surface a 10 nm thick recrystallized layer was observed capping a 20 nm thick amorphous layer.

Energy Technology Data Exchange (ETDEWEB)

The origin of natural gas in the Japanese oil and gas fields are geochemically studied. Samples are taken from structural natural gas, surface gas seepage, water-dissolved natural gas and coal-field gas of the Japan Sea coast area. The origins of primary hydrocarbons are classified into bacteria gas and thermogenic gas, the latter being subclassified into gas in oil production zone with the per million deviation of the carbon isotope (/sup 13/C/sup 1/) of methane less than -35 and those gases with maturity higher than this. Surface gas seepage is subjected to migration and bacterial oxidation. Coal gas is similar to oil gas. The CO/sub 2/ concentration is 0 - 2% and /sup 13/CO/sub 2/ deviations from -30 - +30. The origin can be barely estimated from the isotopic composition because of the wide secondary change in the composition. The origin and migration of gas from the gas field of northern Niigata are not similar to those in the southern area, which consist of a ...

Energy Technology Data Exchange (ETDEWEB)

A numerical model of multiphase air-water flow and contaminant transport in the unsaturated zone is presented. The multiphase flow equations are solved using the two-pressure, mixed form of the equations with a modified Picard linearization of the equations and a finite element spatial approximation. A volatile contaminant is assumed to be transported in either phase, or in both phases simultaneously. The contaminant partitions between phases with an equilibrium distribution given by Henry`s Law or via kinetic mass transfer. The transport equations are solved using a Galerkin finite element method with reduced integration to lump the resultant matrices. The numerical model is applied to published experimental studies to examine the behavior of the air phase and associated contaminant movement under water infiltration. The model is also used to evaluate a hypothetical design for a low-level radioactive waste disposal facility. The model has been ...

International Nuclear Information System (INIS)

A conceptual fusion synfuel production system has been developed with the unique features of: (1) a fusion blanket producing high-temperature (1250"0C) process heat, and (2) the GA sulfur-iodine thermochemical cycle. The system incorporates a two-zone blanket which achieves a tritium breeding ratio of 1.1 while delivering a high fraction (30%) of the fusion heat at high temperatures (1250"0C). The multiple barriers to tritium permeation in the blanket design permit the hydrogen product to meet 10CFR20 regulatory requirements without stringent requirements on the tritium recovery systems. A ceramic heat exchanger, incorporating SiC tubes and headers to contain the process stream and a cooled, Inconel 718 pressure shell to contain the helium, was designed for transferring the heat from the high-temperature coolant to the process. A good heat-line match of the blanket heatsource temperature distribution to the requirements of the thermochemical ...

Energy Technology Data Exchange (ETDEWEB)

The influence of a decarburisation process during austenitising of the through-hardenable rolling bearing steel 100Cr6 (SAE 52100) on the rim zone properties of the martensitic through-hardened material was investigated by means of material analysis and diffusion calculations. For this purpose, two specimens were prepared under defined heat treatment conditions, and the near-surface carbon distribution was determined micro-chemically by using secondary ion mass spectrometry (SIMS). In part 1 of the present work, these concentration profiles are compared with the depth variation of the micro-hardness and with the distance curves of the residual stresses and the line broadening ({l_brace}211{r_brace} {alpha}'-Fe diffraction line) both measured by X-ray diffraction (XRD). In addition, microstructure investigations were performed. In part 2, a refined kinetics model of a diffusion-controlled reaction based on the finite element method ...

British Library Electronic Table of Contents (United Kingdom)

Tachycardia Detection, ICD, CRT-D Devices, Appropriate and Inappropriate Shock.-Introduction: We evaluated the frequency of appropriate and inappropriate shocks and survival in patients using dual-zone programming versus single-zone programming. Methods and Results: For the ALTITUDE REDUCES study, patients were followed for 1.6 1.1 years. The 12-month incidence of any shock was lower for dual-versus single-zone programmed detection at rates -170 bpm and between 170-200 bpm (P < 0.001). Appropriate shock rates at 1 year were also lower with dual-zone programming in these rate intervals (single zone 9.1%, 5.4%, P < 0.001, dual zone 6.7%, 4.7%, P < 0.02). There were no detectable differences between single- and dual-zone shock incidence at detection rates - 200 bpm (P = 0.14). Inappropriate s...

International Nuclear Information System (INIS)

For the Convolution, Superposition and Monte Carlo methods, energy spectrum data is an essential parameter. Especially, by using Monte Carlo method, if the adequate properties of electrons are set, complex energy spectrum data can be calculated by simple input. However, adjustment of the property of electrons incident on the target of linear accelerator is time-consuming procedure. To cover the difference of many accelerators, it is important how we obtain accurate energy spectrum by simple methods. Especially, the total accuracy of dose calculation depends on the agreement of measured and calculated percentage depth dose (PDD) and off-axis ratio (OAR). Thus, a simple method for the determination of the simulation parameters was considered. To reduce the adjustment procedure, we selected values of important three parameters, which were the mean energy of the input electron beam, the energy distribution of the input electron beam and the radial ...

Energy Technology Data Exchange (ETDEWEB)

The paper presents cloud structure models for Jupiter's Great Red Spot, Equatorial and North Tropical Zones, North and South Temperate Zones, and North and South Polar Regions. The models are based on images of Jupiter in three methane bands and nearby continuum radiative transfer calculations include multiple scattering and absorption from three aerosol layers. The model results include the transition in the upper-cloud altitude to 3 km lower altitude from the tropical zones to temperate zones and polar regions, a N/S asymmetry in cloud thickness in the tropical and temperature zones, and the presence of aerosols up to about 0.3 bar in the Great Red Spot and Equatorial Zone. It is concluded that polarization data are sensitive to aerosols in and above the upper cloud layer but insensitive to deeper cloud structure.

International Nuclear Information System (INIS)

Convolution/superposition (C/S) is regarded as the standard dose calculation method in most modern radiotherapy treatment planning systems. Different implementations of C/S could result in significantly different dose distributions. This paper addresses two major implementation issues associated with collapsed cone C/S: one is how to utilize the tabulated kernels instead of analytical parametrizations and the other is how to deal with voxel size effects. Three methods that utilize the tabulated kernels are presented in this paper. These methods differ in the effective kernels used: the differential kernel (DK), the cumulative kernel (CK) or the cumulative-cumulative kernel (CCK). They result in slightly different computation times but significantly different voxel size effects. Both simulated and real multi-resolution dose calculations are presented. For simulation tests, we use arbitrary kernels and various voxel ...

International Nuclear Information System (INIS)

The measurements obtained here indicate ways in which micro-Raman spectroscopy can be used to elucidate structural characteristics and distribution of carbon in meteorites and interplanetary dust particles (IDPs). Existing information about structurally significant aspects of Raman measurements of graphite is combined with structurally relevant findings from the present micro-Raman studies of carbons prepared by carbonization of polyvinylidine chloride (PVDC) at various temperatures and natural material, as well as several acid residues from the Allende and Murchison meteorites in order to establish new spectra-structure relationships. Structural features of many of the materials in this study have been measured by x ray analysis and electron microscopy: thus, their structural differences can be directly correlated with differences in the Raman spectra. The spectral parameters consequently affirmed as indicators of structure are used as a measure of structure in ...

Energy Technology Data Exchange (ETDEWEB)

The research supported by this Department of Energy contract has primarily been devoted to the study of the electronic properties of surfaces with sub-micron size. In previous years, we have studied the photoexcitation of electrons from field emission tips by a focussed Argon-ion laser beam tuned to operate at specific photon energy. The photoexcited electrons escape into the vacuum by tunneling through a surface potential barrier which is distorted by the application of a strong electric field. The interest in these experiments lies in a better understanding of the photoexcitation process at low photon energies. The techniques that have been developed directly measure the excited state energy distribution of electrons emitted through the surface potential barrier. The basic information gained from this research is relevant to opto-electronic devices which rely on photoexcitation of electrons in the presence of strong interfacial electric ...

Energy Technology Data Exchange (ETDEWEB)

Superconducting magnetic energy storage (SMES) is an emerging technology with features that are potentially attractive in electric utility applications. This study evaluates the potential for SMES technology in the generation, transmission, distribution, and use of electric energy; the time frame of the assessment is through the year 2030. Comparisons are made with other technology options, including both commercially available and advanced systems such as various peaking generation technologies, transmission stability improvement technologies, and power quality enhancement devices. The methodology used for this study focused on the needs of the market place, the capabilities of S and the characteristics of the competing technologies. There is widespread interest within utilities for the development of SMES technology, but there is no general consensus regarding the most attractive size. Considerable uncertainty exists regarding the eventual ...

CERN Document Server

We present results from a large volume simulation of Hydrogen reionization. We combine 3d radiative transfer calculations and an N-body simulation, describing structure formation in the IGM, to detail the growth of HII regions around high redshift galaxies. Our simulation tracks 1024^3 dark matter particles, in a box of side length 65.6 Mpc/h. This large volume allows us to accurately characterize the size distribution of HII regions throughout most of the reionization process. At the same time, our simulation resolves many of the small galaxies likely responsible for reionization. It confirms a picture anticipated by analytic models: HII regions grow collectively around highly-clustered sources, and have a well-defined characteristic size, evolving from a sub-Mpc scale at the beginning of reionization to R>10 Mpc towards the end. We present a detailed statistical description of our results, and compare them with a ...

Energy Technology Data Exchange (ETDEWEB)

Numerical studies are performed to identify an optimal range of geometric parameters in connection with the design of an impingement-conditioned small direct-injection diesel engine. The parametric studies were made in a pressure chamber with a circular protrusion on to which sprays are directed to impinge. Computational runs were made for 24 cases carefully chosen to allow examination of the effects on post-impingement spray characteristics of the following parameters: (a) the nozzle-plate distance and (b) the size and geometry pattern of the protrusion. An optimal range of these parameters has been identified through an analysis of the calculated results in terms of vapour concentration, the Sauter mean diameter of the wall spray and the dispersed wall spray volume. The results obtained also reveals that, by just changing the size of the impingement surface and the impingement distance, local fuel vaporization efficiency can be increased as ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

Bulk nanocrystalline pure iron rods were fabricated by the equal channel angular pressure (ECAP) technique up to eight passes. The microstructure and grain size distribution, natural immersion and electrochemical corrosion in simulated body fluid, cellular responses and hemocompatibility were investigated in this study. The results indicate that nanocrystalline pure iron after severe plastic deformation (SPD) would sustain durable span duration and exhibit much stronger corrosion resistance than that of the microcrystalline pure iron. The interaction of different cell lines reveals that the nanocrystalline pure iron stimulates better proliferation of fibroblast cells and preferable promotion of endothelialization, while inhibits effectively the viability of vascular smooth muscle cells (VSMCs). The burst of red cells and adhesion of the platelets were also substantially suppressed on contact with the nanocrystalline pure iron in blood ...

Energy Technology Data Exchange (ETDEWEB)

In this study, the exhaust gas from a common-rail direct injection diesel engine was investigated both upstream and downstream warm-up catalytic converters (WCC). Three different types of ultra-low sulfur fuels (ethanol-diesel blend, ethanol-diesel blend with cetane improver and pure diesel) were tested in this study. The objective of the work was to study the engine performance and the formation of THC (total hydro carbon), CO (carbon monoxide), NO{sub x} (nitrogen oxides), smoke and PM (particulate matters) when using these fuels. THC and CO emissions of the ethanol-diesel blend fuels were slightly increased, and about 50-80% mean conversion efficiencies of THC and CO on catalysts were achieved in the ECE R49 13-mode cycle. Smoke was decreased by more than 42% in the entire ECE 13-mode cycles. From the measurement of scanning mobility particle sizer (SMPS) for the particle size range of 10-385 nm, the total number and total mass of the PM of the ethanol-diesel ...

Energy Technology Data Exchange (ETDEWEB)

The research supported by this Department of Energy contract has primarily been devoted to the study of the electronic properties of surfaces with sub-micron size. In previous years, we have studied the photoexcitation of electrons from field emission tips by a focussed Argon-ion laser beam tuned to operate at specific photon energy. The photoexcited electrons escape into the vacuum by tunneling through a surface potential barrier which is distorted by the application of a strong electric field. The interest in these experiments lies in a better understanding of the photoexcitation process at low photon energies. The techniques that have been developed directly measure the excited state energy distribution of electrons emitted through the surface potential barrier. The basic information gained from this research is relevant to opto-electronic devices which rely on photoexcitation of electrons in the presence of strong interfacial electric ...

Energy Technology Data Exchange (ETDEWEB)

This research is to provide improved strategies for enhanced oil recovery from the Tensleep Sandstone oil reservoirs in the Bighorn and Wind River basins, Wyoming. Because of the great range of API gravities of the oils produced from these reservoirs, the proposed study concentrates on understanding the spatial variation and anisotropy of relative permeability within the Tensleep Sandstone. This research will associate those spatial distributions and anisotropies with the depositional subfacies and zones of diagenetic alteration found within the sandstone. The associations of the above with pore geometry will link relative permeability with the dimensions of lithofacies and authigenic mineral facies. Hence, the study is to provide criteria for scaling this parameter on a range of scales, from the laboratory to the basin-wide scale of subfacies distribution. Effects of depositional processes and burial diagenesis will be ...

UK PubMed Central (United Kingdom)

This article aims to open up the biographical black box of three experts working in the boundary zone between science, policy and public debate. A biographical-narrative approach is used to analyse...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Several low-mass models with an inhomogeneous radiative core and a convective envelope are investigated, the entire core or its upper portion being treated as a zone of neutral stability. Mixing by convective overshoot will then give rise to unstable structure.

Energy Technology Data Exchange (ETDEWEB)

The paper presents a review of the current state of knowledge on the likely impacts of extreme weather and climate events on coastal zones and small islands in the context of climate change. Possible response options, including prevention, preparedness and adaptation, are indicated.

UK PubMed Central (United Kingdom)

The aim of this study was to investigate the effect of erythropoietin (EPO) on histological brain injury, subventricular zone (SVZ) expansion, and sensorimotor function deficits induced by hypoxia-ischemia...Full Text Available

UK PubMed Central (United Kingdom)

A simulation is developed that qualitatively describes the small-zone-gel-filtration behaviour of a reversibly associating protein. The results reflect the dependence of the apparent molecular weight...Full Text Available

British Library Electronic Table of Contents (United Kingdom)

ObjectiveTo characterize global structural features of large-scale biomedical terminologies using currently emerging statistical approaches.DesignGiven rapid growth of terminologies, this research was designed to address scalability. We selected 16 terminologies covering a variety of domains from the UMLS Metathesaurus, a collection of terminological systems. Each was modeled as a network in which nodes were atomic concepts and links were relationships asserted by the source vocabulary. For comparison against each terminology we created three random networks of equivalent size and density.MeasurementsAverage node degree, node degree distribution, clustering coefficient, average path length.ResultsEight of 16 terminologies exhibited the small-world characteristics of a short average path le...

British Library Electronic Table of Contents (United Kingdom)

ABSTRACT Traditional risk-based design process involves designing the structure based on risk estimates obtained during several iterations of an optimization routine. This approach is computationally expensive for large-scale aircraft structural systems. Therefore, this paper introduces the concept of risk-based design plots that can be used for both structural sizing and risk assessment for fracture strength when maximum allowable crack length is available. In situations when crack length is defined as a probability distribution the presented approach can only be applied for various percentiles of crack lengths. These plots are obtained using normalized probability density models of load and material properties and are applicable for any arbitrary load and strength values. Risk-based desi...

Energy Technology Data Exchange (ETDEWEB)

We studied the effects of small, <20 {micro}m, Te inclusions on the energy resolution of CdZnTe gamma-ray detectors using a highly collimated X-ray beam and gamma-rays, and modeled them via a simplified geometrical approach. Previous reports demonstrated that Te inclusions of about a few microns in diameter degraded the charge-transport properties and uniformity of CdZnTe detectors. The goal of this work was to understand the extent to which randomly distributed Te-rich inclusions affect the energy resolution of CZT detectors, and to define new steps to overcome their deleterious effects. We used a phenomenological model, which depends on several adjustable parameters, to reproduce the experimentally measured effects of inclusions on energy resolution. We also were able to hound the materials-related problem and predict the enhancement in performance expected by reducing the size and number of Te inclusions within the crystals.

Energy Technology Data Exchange (ETDEWEB)

For the development of a long-lived, electrically rechargeable zinc-air battery the structure and wettability of pasted zinc electrodes were optimized. Pasted zinc electrodes containing 1 to 10% cellulose, but having almost the same nominal capacities, were prepared and tested in zinc/oxygen cells. The effect of discharge rate on cell voltage and delivered capacity, as well as the maximum power, were measured. Furthermore, cell charge-discharge behaviour and cycle life were examined. After different times of operation, the porosity and the pore size distribution of the pasted zinc electrodes were measured by means of mercury porosimetry. The life cycle and peak power drain capability of the Zn/oxygen battery could be substantially improved by the addition of 10 wt% cellulose to the pasted zinc electrode. (author)

Energy Technology Data Exchange (ETDEWEB)

Chronic exposure to uranium compounds such as UO{sub 2} and U{sub 3}O{sub 8} led to the development of a methodology, based on the recommendation of ICRP, involving four main steps: the measurement of the uranium concentration and the particle size distribution at the workstation, the assessment of physico-chemical properties of the compound, the study of in-vitro solubility using a chemical test and the monitoring of workers. Results and comments on UO{sub 2} and U{sub 3}O{sub 8} are given. (author)

International Nuclear Information System (INIS)

Nanometer Ce-W composite materials have been prepared by the method of freeze-drying. Microstructure and surface properties of materials were investigated by SEM and 'in situ' AES and emission characteristics have been determined. It is found that the nanometer materials have relatively small crystal particles with average dimensions in the order of 50 nm. Due to the results of matrix analysis, the cerium in the materials is uniformly distributed on submicron scale, which proves that the diffusion ability of cerium has been increased. Under high temperature, the active layer on the surface thickens simultaneously with the increase of cerium and oxygen. As a result, nanometer Ce-W materials exhibit excellent emission characteristics compared with those of micron-sized Ce-W materials.

Energy Technology Data Exchange (ETDEWEB)

Globular clusters are quite compact (size {proportional_to}10 pc) objects distributed spherically around the galaxy. They contain about 10{sup 5}-10{sup 6} mostly old stars. The number of millisecond pulsars in typical globular cluster is expected to be large (of the order of 100). We investigate the possible mechanism of production of high energy gamma-rays in those objects. Part of the wind energy of pulsars (energy conversion factor) is converted into relativistic leptons. Those leptons can upscatter in inverse Compton process low energy starlight and CMB photons and produce gamma-rays. MAGIC is an Imaging Atmospheric Cerenkov Telescopes located at Canary island of La Palma. We present results and discussion of the MAGIC observations of globular cluster M13.

British Library Electronic Table of Contents (United Kingdom)

New nanofibers containing poly(vinyl pyrrolidone)-iodine complex (PVP-iodine) were obtained by electrospinning in order to prepare materials suitable for wound dressings. Different approaches were used: a one-step method based on electrospinning of PVP-iodine or poly(ethylene oxide)/PVP-iodine solutions and a three-step method based on electrospinning of PVP or poly(ethylene oxide)/PVP mixed solutions followed by photo-mediated crosslinking of the obtained nanofibers and subsequent complexation with iodine. The average diameters of the fibers were in the range 150-470nm depending on the composition and on the applied field strength (AFS) and increased with increasing the amount of PEO in the spinning solutions. Higher AFS resulted in greater fiber diameter and in size distribution broadeni...

British Library Electronic Table of Contents (United Kingdom)

In the present paper, the effects of hydroxyapatite (HA) content on the microstructure, thermal and mechanical properties of Ti-based glassy alloy/HA composite prepared by spark plasma sintering (SPS) are investigated. The microstructure of the composites is homogeneous when the HA is lower than 2 wt%. When the HA content is higher than 3 wt%, the crystalline precipitates with size of less than 5 nm are distributed in the glassy matrix. HA decomposes during sintering procedure for the composite with high HA content. With increasing HA addition, compressive strength decreases. Especially for the HA content is over 2 wt%, the strength decreases sharply because of partial crystallization of glassy alloy matrix.

Energy Technology Data Exchange (ETDEWEB)

The development of new electro-optical instrumentation for studying the annular dispersed two-phase flow regime is described. The system measures the thickness of the water film and droplet size and velocity distributions which would be encountered in such a flow regime. The water film thickness is measured by an improved capacitance method with a short time constant using newly developed sensor electrodes. The electrodes are made flush with the inner wall of a cylindrical tube and do not disturb the flow. In the test equipment, steady, laminar flow of water along the inner wall of the tube is controlled by appropriate valves and a porous jacket while droplets are introduced by means of a special spray nozzle.

British Library Electronic Table of Contents (United Kingdom)

Summary Analyses of event runoff coefficients provide essential insight on catchment response, particularly if a range of catchments and a range of events are compared by a single indicator. In this study we examine the effect of climate, geology, land use, flood types and initial soil moisture conditions on the distribution functions of the event runoff coefficients for a set of 14 mountainous catchments located in the eastern Italian Alps, ranging in size from 7.3 to 608.4km2. Runoff coefficients were computed from hourly precipitation, runoff data and estimates of snowmelt. A total of 535 events were analysed over the period 1989-2004. We classified each basin using a "permeability index" which was inferred from a geologic map and ranged from "low" to "high permeability". A continuous s...

Energy Technology Data Exchange (ETDEWEB)

In Niigata University Hospital, most of conventional radiography were changed to Fuji computed Radiography (FCR) from July 1988. To evaluate its clinical utility, questionnaires relating to FCR image were distributed to all physicians including non-radiologists in the hospital after three months. The ratio of the physicians evaluated FCR image to be better than conventional image was 75% in chest radiography, 64% in abdominal radiography. FCR tomography of bone, joint, cranium and chest was also evaluated to be better than conventional by most of the physicians. Reduced size of the film and difficulty in detecting interstitial shadows of the lung were mentioned to be the fault of FCR. (author).

Energy Technology Data Exchange (ETDEWEB)

Measurements of local mass fluxes of liquid, local number fluxes of the drop and local drop size distributions at various locations in the test column were made for wide ranges of liquid flow rates and gas flow rates. An empirical correlation for the volume mean diameter of the drop at the nozzle exit was proposed. Measurements of the rates of absorption of carbon dioxide from carbon dioxide-air mixtures with water sprays (physical absorption) and aqueous sodium hydroxide sprays (chemical absorption) were made for wide range so fluid flow rates, feed gas concentrations, and initial alkali concentrations. The observed dimensionless rates of absorption were compared with the theoretical values by assuming penetration model with second-order irreversible reaction. 11 refs., 7 figs.

Energy Technology Data Exchange (ETDEWEB)

One chemical reagent, hydrazine hydrate, was discovered to accelerate the growth of semiconductor nanocrystals (cadmium telluride) instead of additional energy, which was applied to the synthesis of high-quality CdTe nanocrystals at room temperature and ambient conditions within several hours. Under this mild condition the mercapto stabilizers were not destroyed, and they guaranteed CdTe nanocrystal particle sizes with narrow and uniform distribution over the largest possible range. The CdTe nanocrystals (photoluminescence emission range of 530-660 nm) synthesized in this way had very good spectral properties; for instance, they showed high photoluminescence quantum yield of up to 60%. Furthermore, we have succeeded in detecting the living Borrelia burgdorferi of Lyme disease by its photoluminescence image using CdTe nanocrystals.

Energy Technology Data Exchange (ETDEWEB)

The two-phase flow regime transition in a large diameter (I.D.=200mm) vertical pipe was experimentally investigated using a dual-sensor optical probe. The flow transitions from bubbly to chum without an intermediate slug flow regime as the air flow rate is increased. The transition boundaries developed for bubbly to slug flow in small diameter pipes are compared to the bubbly to chum flow transition of the present experiment. The bubbly to chum transition occurs at a void fraction of about 0.15 compared to 0.25 for bubbly to slug transition in small diameter pipes. The radial distribution of bubble diameter, bubble frequency, bubble velocity and local void fraction were obtained using a dual-sensor optical probe at different flow conditions. The Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of the bubble velocity and size are used to study the flow regime transition in the large diameter ...

CERN Document Server

We present maps of the cosmic large-scale structure around the twelve most distant galaxy clusters from the Massive Cluster Survey (MACS) as traced by the projected surface density of galaxies on the cluster red sequence. Taken with the Suprime-Cam wide-field camera on the Subaru telescope, the images used in this study cover a 27x27 arcmin^2 area around each cluster, corresponding to 10 x 10 Mpc^2 at the median redshift of z = 0.55 of our sample. We directly detect satellite clusters and filaments extending over the full size of our imaging data in the majority of the clusters studied, supporting the picture of mass accretion via infall along filaments suggested by numerical simulations of the growth of clusters and the evolution of large-scale structure. A comparison of the galaxy distribution near the cluster cores with the X-ray surface brightness as observed with Chandra reveals, in several cases, significant offsets between the gas and ...

Energy Technology Data Exchange (ETDEWEB)

Flow fields, temperature distributions, and particle trajectories in a 2-stage entrained-flow gasifier are calculated using a CFD code, FLUENT. Realizable k- {epsilon} model is used as a turbulent model. Because of swirling flow there appear recirculation regions near the burners. The characteristics of flow fields and temperature distributions in the gasifier are dependent on the swirl number of the system. Mean residence time of the particles in the reductor is inversely proportional to particle size, particle density and swirl number. As the swirl number is increasing, the particles injected from the combustor burners approach the wall near the combustor burners, which prevents the particles from entering the reductor and thus attaching the reductor wall. If the lower combustor burner angle is larger than the higher combustor burner angle for a given swirl number, the particles may move toward the reductor and cause ...

International Nuclear Information System (INIS)

'Full text:' Deregulation, distributed generation, combined heat and power, renewables, fuel cells, hydrogen. Power companies are facing a rapidly evolving environment that is testing their ability to effectively deploy capital and earn profits. While recent deregulation trends have shifted the structure of power markets into separating generators from distributors, the improving economic value proposition offered by smaller scale distributed generation technologies - such as fuel cells - would seem to be a conflicting development. In this complex and changing environment, decisions based on the economic reality of the capital markets are likely to prevail. By examining the opportunity to enhance risk management offered by stationary fuel cells, particularly in CHP applications, we provide a context for the issues being discussed in today's sessions focusing on power companies and electric utilities. Our risk management perspective suggests a ...

Energy Technology Data Exchange (ETDEWEB)

Radon emanation coefficients of 0.02 to 0.55 were measured at moisture contents ranging from dry to saturation in 18 different ores. The emanation coefficients rose from a minimum when dry to a plateau usually starting at 5 to 20 percent of saturation. A model, using measured pore-size distributions, suggested that the radium mineralization may be confined to annular layers about 0.02 micrometers thick around pores. Radon's diffusion coefficient was determined as a function of moisture. The techniques involved comparing a disk's exhalation as a function of time whether or not the disk had a distributed source. The model was free of approximations and included the effects of porosity and adsorption. An increase of diffusion coefficient with moisture for one or two ores was explained in terms of a model's equation for the diffusion coefficient in terms of both volume and surface diffusion. ...

International Nuclear Information System (INIS)

Ceramic matrix composites in the TiC-Ti, Y-TZP system can be synthesized by the reaction between carbon and the TiO_2-Y_2O_3-ZrO_2 solid solution nanopowder. This method results in the more homogeneous powders than those prepared by the physical mixing of TiC and zirconia s.s. powders. Twelve TiO_2-Y_2O_3-ZrO_2 solid solution nanopowders differing in the proportions of the constituent oxides were prepared by the coprecipitation- calcination route. They were reacted with the pyrolytic carbon evenly distributed within the system. Carbon was introduced by the thermal decomposition of the phenol-formaldehyde resin dissolved in ethyl alcohol and mixed with the zirconia s.s. nanopowder. Reaction was performed in vacuum. Compacts of the composite powders sintered in vacuum give dense materials of evenly distributed TiC inclusions of sizes not surpassing 400 nm. Hardness of such materials was dependent on their chemical and phase ...

International Nuclear Information System (INIS)

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

Science.gov (United States)

... However, the solution of the Stefan problem in this context becomes abruptly complicated, since within each zone, the differential equations ...

International Nuclear Information System (INIS)

In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ventricular ...

International Nuclear Information System (INIS)

This work is concerned with the development and application of ion implantation techniques for improving the corrosion resistance of zircaloy-4. The corrosion resistance in nitrogen implanted zircaloy-4 under a 120 keV nitrogen ion beam at an ion dose of 3 x 10"1"7 cm"-"2 depends on the implantation temperature. The characteristics of surface oxidation and corrosion resistance were analyzed with the change of implantation temperature. It is shown that as implantation temperature rises from 100 to 724 C, the colour of specimen surface changes from its original colour to light yellow at 100 C, golden at 175 C, pink at 300 C, blue at 440 C and dark blue at 550 C. As the implantation temperature goes above 640 C, the colour of surface changes to light black, and the surface becomes a little rough. The corrosion resistance of zircaloy-4 implanted with nitrogen is sensitive to the implantation temperature. The pitting potential of specimens increases from 176 to 900 mV (SCE) as the ...

Energy Technology Data Exchange (ETDEWEB)

The processes of lung growth, injury, and repair are characterized by alterations in fibroblast synthesis and interstitial distribution of extracellular matrix components. Transforming growth factor beta (TGF-beta), which is postulated to play a role in modulating lung repair, alters the distribution of several matrix components such as collagen and fibronectin. We studied the effect of TGF-beta on the synthesis and distribution of the various glycosaminoglycans (GAGs) and whether these effects may explain its role in lung repair. Human diploid lung fibroblasts (IMR-90) were exposed to various concentrations of TGF-beta (0-5 nM) for variable periods of time (0-18 h). Newly synthesized GAGs were labeled with either (3H)glucosamine or (35S)sulfate. Individual GAGs were separated by size exclusion chromatography after serial enzymatic and chemical digestions and quantitated using scintillation counting. ...

British Library Electronic Table of Contents (United Kingdom)

Pursuant to statement issued by the Government of Vietnam on 12 May 1977, on the territorial sea, the contiguous zone, the exclusive economic zone (EEZ) and the continental shelf of Vietnam, and according to the provisions of the LOS Convention, the EEZ of Vietnam extends principally up to 200NM from the baseline, and the area of EEZ amounts to about one million square km including the Hoang Sa (Paracel) and Truong Sa (Spratly) Islands [The declaration of the Government of Vietnam on the territorial sea, contiguous zone, exclusive economic zone and continental shelf, Hanoi, 1977]. The establishment of EEZ has significantly changed circumstances for the fisheries sector in Vietnam.Recently, even though the adaptation of new techniques and technologies to the fisheries sector has been somewh...

Energy Technology Data Exchange (ETDEWEB)

The problem during the continuous idling operation of diesel engine is about the time increase in emission of HC (hydrocarbon which is not burned yet) into the atmosphere. A pilot injector having been developed, the time increase in HC emission was studied in order to ameliorate the combustion during the idling. An engine and spray unit were used with the above developed pilot injector for the experiment. Three types of injector were also used for the comparison purpose. Investigation was made of penetration characteristics of spray on the pump tester in the atmosphere, locally averaged droplet size distribution inside the spray, both droplet size and velocity distributions, and emission characteristics by the mounting test onto the engine. The developed pilot injector was most effective in controlling the HC emission. The time increase in HC emission is attributable to the adhering quantity of carbon. ...

International Nuclear Information System (INIS)

The convolution/superposition algorithm for computing dose from photon beams in radiation therapy planning requires knowledge of the energy spectrum. The algorithm can compute the dose for a polyenergetic beam as the weighted sum of the individual dose contributions from monoenergetic beams. In this study we exploit interface effects apparent in the dose distributions to discriminate among spectra of high energy photon beams. We have studied the sensitivity of the depth dose distribution to the energy components using a hypothetical beam for various field sizes and depths in water and water-lung-water media. Six theoretical spectra were simulated. We compared depth dose data from these spectra using three quantitative measures which are inherently free of normalization ambiguities: for homogeneous water, the ratio D_2_0/D_1_0 and a logarithmic derivative in the buildup region LD_b_u_i_l_d_-_u_p and for inhomogeneous ...

Science.gov (United States)

Georgia Fish: Freshwater fish distributions,classification, conservation status, and distribution comments for Georgia....

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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 compartment produce balcony spill plumes which form ...

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Silver iron oxide nanoparticles of fairly small size (average diameter approximately 1 nm) with narrow size distribution have been synthesized by the interaction of colloidal beta- Fe2O3 and silver nanoparticles. The surface morphology and size of these particles have been analyzed by using atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). Their structural analysis has been carried out by employing x-ray diffraction (XRD), selected-area electron diffraction (SAED), optical and infrared (IR) spectroscopic techniques. The ageing of these particles exhibits the formation of self-assembly, possibly involving weak supramolecular interactions between Ag(I)O4 and Fe(III)O4 species. These particles display the onset of absorption in the near-infrared region and have higher absorption coefficient in the visible range compared to that of ...