International Nuclear Information System (INIS)

Technique, allowing to investigate straggling zone (full braking) from high-energy charged particles in detail, is described. Experimental results on investigation of efective structure, created in polycrystalline molybdenum (99.97%) within 29 MeV alpha-particles straggling zone for fluences from 3.8x10"1"9 up to 3.7x10"2"1 #alpha#/m"2 by methods of microhardness (H_#mu#, X-ray structural analysis (#DELTA#a/a) and transparent electron microscopy (TEM), are presented. It is determined, that for doses from 3.8x10"2"0 #alpha#/m"2 and higher, at #approx#6 MeV energy, molybdenum ''softening'' is observed, H_#mu# curve within straggling zone is well described by alloyage calculated profile. #DELTA#a/a measurements within straggling zone are well described by damage profile. TEM-investigations have shown the developed defective ...

International Nuclear Information System (INIS)

A computational procedure is proposed to perform uncertainty analysis for the calculation of the isotopic inventory and radiological quantities obtained as a linear function of it, due to uncertainties in the activation cross sections. The method is applied to determine the uncertainty of the calculated shallow burial index (SBI) from activated type 304 stainless steel (SS) in the most neutron-exposed zone of the HYLIFE-II vessel structure. Results are obtained by means of an element-by-element study. Some other types of steel are also investigated for comparison purposes. The SS304 is confirmed to be the most promising steel option. 16 refs., 2 tabs.

British Library Electronic Table of Contents (United Kingdom)

A web-based decision support tool, zone mapping application for precision farming (ZoneMAP, External Reference Not Shown ), has been developed to automatically determine the optimal number of management zones and delineate them using satellite imagery and field data provided by users. Application rates, such as of fertilizer, can be prescribed for each zone and downloaded in a variety of formats to ensure compatibility with GPS-enabled farming equipment. ZoneMAP is linked to Digital Northern Great Plains, a web-based application which hosts an archive of satellite imagery, as well as high resolution imagery from airborne sensors. Management zones created by ZoneMAP mapped natural variation of the soil organic matter and other nutrients relatively well and were consistent with zone maps cre...

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)

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 purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3D) and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. Field demonstrations are in progress to collect data for evaluation of horizontal completions in both the Red River and Ratcliffe. A vertical well in the Red River will test attribute analysis of 3D seismic data for prediction of porosity development. Additional seismic acquisitions and interpretation are in progress for both the Ratcliffe and Red River. A water-injectivity test in a new horizontal completion in the Red Rive B ...

International Nuclear Information System (INIS)

In the heat-affected zones (HAZ) of low alloy steels used for nuclear pressure vessel, microstructural changes, such as grain coarsening, carbide precipitation, and martensite formation, generally occur and cause a deterioration of toughness and an increase in sensitivity to brittle fracture. Metallographic analyses of low alloy steel welds reveal significantly different regions in HAZ microstructures. In 2-pass welds, there were seven characteristic regions in the HAZ determined by the peak temperature, to which the region was exposed during the weld thermal cycle: a coarse-grained region, a fine-grained region, an intercritical region, and subcritical region. The coarse-grained region can be categorized into four zones according to the reheating temperature as follows : an unaltered coarse-grained zone (UCGHAZ), a supercritically reheated coarse grained zone (SCRCGHAZ), an ...

Energy Technology Data Exchange (ETDEWEB)

Resistive analogous meters for spatial and time characteristics in ocean agitation are most often used in practical oceanography in coastal zones but are based on bridge circuits determined to have shortcomings in their linearity range. This shortcoming is eliminated in the circuit of an instrument developed in an oceanographic laboratory (IMIO, Vana). Principle and block circuits are indicated, and static calibration curves are presented as are the correlative functions in the frequency spectrums obtained with the help of sea agitation recorded at a fixed point and at a depth of 6 meters.

Energy Technology Data Exchange (ETDEWEB)

This presentation described the geology of the Kootenay, Gething, Gates, Brazeau and Coalspur Formations in the potential gas-bearing coal zones of the Alberta Foothills/Mountains. The future potential of this region for coalbed methane (CBM) exploitation was discussed, based on available data from drilling activity and the results of a recent coal desorption and adsorption study in the Val d'Or seam of the Coalspur formation. The gas content of the 5 coal zones was evaluated and compared with previous CBM exploration in the area. For evaluation purposes, the coal zones were divided into shallow and deep coal zones. The potential gas content of the shallow coal zones is approximately 31 Tcf of CBM. This is considered an inferred, initial, in-place, CBM resource estimate based on limited data. The gas content of deep zones is approximately 99 Tcf of ...

UK PubMed Central (United Kingdom)

BackgroundWhile the gene flow in some organisms is strongly affected by physical barriers and geographical distance, other highly mobile species are able to overcome such constraints....Full Text Available

British Library Electronic Table of Contents (United Kingdom)

Riparian zones of streams in northwestern Mississippi have been impacted by agriculture, channelization, channel incision, and gully erosion. Riparian gully formation has resulted in the fragmentation of remnant riparian zones within agricultural watersheds. One widely used conservation practice for controlling gully erosion is the installation of drop pipes. This practice involves placing earthen dams across eroding gullies and embedding a metal standpipe within the dam to convey water from the field to stream level. Installation of this structure halts gully erosion and incidentally replaces eroding gullies with riparian habitats. Previous research evaluating gully erosion control structures have not considered the ecological impacts of these conservation practices on amphibian and repti...

Energy Technology Data Exchange (ETDEWEB)

Anorthosites are rocks consisting almost completely of calcic plagioclase, usually from andesine to labradorite. They are not widespread, and until recently were of no economic interest. However, with the advance of the new global tectonics, which has excited considerable interest in the structure and composition of upper-mantle rocks, interest in the anorthosites has grown. This has particularly been the case since the discovery of anorthosites on the moon, where they appear to be more widespread than on the earth. Data have recently been obtained on the strontium isotope compositions of anorthosite intrusions in the Dzhugdzhur-Stanovoy zone and in the rocks surrounding them, which have revealed some unexpected features. The paper describes the geological features of anorthosites, initial concepts on strontium isotope geochemistry, strontium isotope compositions of this region, and discusses some genetic consequences from the isotope data. ...

International Nuclear Information System (INIS)

In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific ...

Energy Technology Data Exchange (ETDEWEB)

The relationship between the QRS transition zone of the standard 12-lead ECG and interventricular septum was studied. The position and the angle to the horizontal line of the interventricular septum were evaluated with computed tomography (CT) and compared to the QRS transition zone. The subjects were 36 patients with no cardiovascular diseases. The patients were divided into 3 groups according to the position of QRS transition zone: V{sub 1}-V{sub 2} (8 cases), V{sub 3}-V{sub 4} (21 cases), and V{sub 5}-V{sub 6} (7 cases). The interventricular septum on CT was directed to the anterior chest wall between V{sub 3} and V{sub 4} in all 3 groups. The mean value of the interventricular septal angle did not differ from group to group, 52.1deg for V{sub 1}-V{sub 2} group, 49.8deg for V{sub 3}-V{sub 4} group, and 48.2deg for V{sub 5}-V{sub 6}. It was concluded that the direction of the interventricular septum was not one of the ...

British Library Electronic Table of Contents (United Kingdom)

The features of present deposits that form in the vicinity of hot springs can provide clues to the parameters of paleowaters in places of past hydrothermal activity marked by remnant carbonate and/or siliceous sinter. We investigated a large carbonate body at the Garga hot spring developing in the Baikal zone of nitric hydrotherms in the Barguzin Rift Zone valley. The main focus was on the structure of the carbonate mound, as well as on the partitioning of radioactive elements between the cyanobacterial mat and the inorganic component of the body (the issue that has never been explored before). The cyanobacterial community of the Garga spring is an active biosorbent of 226Ra, 228Ra, 210Pb. The radionuclides accumulated by biosorption become preserved in minerals that form within the bacter...

International Nuclear Information System (INIS)

Field experiments were conducted in the 30-km zone of Gomel's region of the Byelorussia to study factors aecting a biological radionuclide accessibility. A contamination density by radiocesium equaled 2,7-9,9 MBk/m"2, strontium 90 - 0,3-0,5 MBk/m"2 in 1991. A sowing of oats barley, lupin was carried out. It was shown that radionuclide accumulation by agricultural plants was determined basically by biological peculiarities of plants in greater degree than by the contamination density. It was shown that strontium 90 migration from the soil was more intensive than that of radiocesium. 8 tabs.

Energy Technology Data Exchange (ETDEWEB)

Acid mine drainage is probably the most important problem facing the mining industry. In this study, the authors evaluated different techniques for the remediation of mine tailings. An in situ characterization of the Aldermac mine tailings was conducted and the results were presented in this poster presentation. The site characterization was performed to determine the extent of the contamination, and sampling of soils was also performed for laboratory experiments in soil covers. The authors described the methodology followed in the laboratory experiments. Chemical analysis of the leaching water was performed to determine its composition in metals. Microbiological analysis was also conducted, as well as the determination of the water saturation index. The authors indicated that they will analyze the results further. tabs., 12 figs.

Energy Technology Data Exchange (ETDEWEB)

There are two kinds of uncertainties in safety assessment of engineering structures. One is of the nature of randomness, and the other fuzziness. Fuzzy uncertainties exist in defining certain structural performances, conditions, parameters, and their interrelationships. The theory of fuzzy sets should be employed to cope with the fuzzy uncertainties. In this paper, a general definition for structural failure considering the fuzzy uncertainties is introduced firstly. Failure of the structure is modelled by a fuzzy event, and described by the membership function. The limit state surface is then replaced by a fuzzy limit state zone, in which every point represents a state belonging to the failure with a certain degree of membership. Then a fuzzy optimization problem for solving the reliability index is formulated. In classical structural reliability theory, the ...

Energy Technology Data Exchange (ETDEWEB)

Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emission (2--20 keV) and 3.5 MeV Alpha particle emissions from laser driven micro-implosions. Image resolution in these experiments was 3--8 ..mu..m. Extension of this coded imaging capability to higher energy x rays (approx.100 KeV) and more penetrating charged particles (e.g., approx.15 MeV protons) requires the fabrication of very thick (50--200 ..mu..m), high aspect ratio (10:1), gold Fresnel zone plates with narrow linewidths (5--25 ..mu..m) for use as coded apertures. A reactive ion etch technique in oxygen has been used to produce thick zone plate patterns in polymer films. The polymer patterns serve as electroplating molds for the subsequent fabrication of the free-standing gold zone plate structures.

International Nuclear Information System (INIS)

We have performed self-consistent (SC) band structure calculations for the A15 compounds V_3X and Nb_3X, X = Al, Ga, Si, Ge, and Sn, using the augmented-plane-wave (APW) method. Relativistic effects (except the spin-orbit interaction) have been included in each SC cycle, along with corrections to the usual muffin-tin approximation. The latter apply the APW wave functions outside of the muffin-tin spheres to compute the interstitial charge densities and potentials. The resulting interstitial potential has full cubic symmetry (no spherical averaging), although a spherically averaged muffin-tin form is retained inside the spheres. The final SC potentials were used to generate energies and wave functions on a cubic mesh of 35 k points in 1/48th of the Brillouin zone. These results were interpolated onto a finer mesh of 969 k points using a symmetrized Fourier method; the densities of states (DOS), N (E), were determined using ...

International Nuclear Information System (INIS)

Regional arterial CO2 tension (PaCO2) reactivity of cerebral blood flow (CBF) and the effect of PaCO2 on the spatial and temporal heterogeneity of CBF were investigated by using autoradiographically determined CBF in the rat middle cerebral artery occlusion model after a 2-h period under pentobarbital anesthesia to clarify the relation between PaCO2 reactivity, CBF heterogeneity, and the temporal cycling of CBF. PaCO2 was adjusted to one of four levels. CBF was determined in four cortical areas and white matter using the tissue fractionation of [14C]iodoantipyrine [( 14C]IAP) in combination with vessel mapping using in vivo 4% thioflavine S. Specific PaCO2 reactivity and CBF were normal in the nonischemic cortex, normal, although slightly depressed, in the border zone far from the ischemic core area, and depressed in the border zone adjacent to the ischemic core area (P less than 0.001) and the ischemic ...

CERN Document Server

The bright star 55 Cancri is known to host five planets, including a transiting super-Earth. The interferometric study presented here yields directly determined values for 55 Cnc's stellar astrophyiscal parameters: $R=0.943 \\pm 0.010 R_{\\odot}$, $T_{\\rm EFF} = 5196 \\pm 24$ K. We use isochrone fitting to determine 55 Cnc's age to be 10.2 $\\pm$ 2.5 Gyr, implying a stellar mass of $0.905 \\pm 0.015 M_{\\odot}$. Our analysis of the location and extent of the system's habitable zone (0.67--1.32 AU) shows that planet f ($M \\sin i = 0.155 M_{Jupiter}$) spends the majority of the duration of its elliptical orbit in the circumstellar habitable zone, where, with moderate greenhouse heating, it could harbor liquid water. Finally, our direct value for 55 Cancri's stellar radius allows for a model-independent calculation of the physical diameter of the transiting super-Earth 55 Cnc e ($\\sim 2.05 \\pm 0.15 ...

CERN Document Server

Aerial view of the depot zone of Bois des Serves.

International Nuclear Information System (INIS)

We apply our work on fracture- and matrix-dominated flow to develop a conceptual model of hydrological flow processes in the unsaturated zone at Yucca Mountain. The possibility of fracture-dominated flow is discussed, and various deductions are made on its impact on natural and total system performance, site characterization activities, and site suitability determination.

International Nuclear Information System (INIS)

Response of control valves plays an important role in the dynamics of the flow system as a whole. Knowledge of its transfer function would facilitate analysis of the behaviour of the system. This paper presents the application of Levy's complex curve fitting method for determination of the transfer function of control valves used in Liquid Zone Control System of 540 MWe PHWR. (author)

International Nuclear Information System (INIS)

The stability constants of [AtX_2]"- with X = Cl, Br and I in ethanol and methanol as well as their ion mobilities at a temperature of 298 K and an ionic strength of 0.05 were determined by horizontal zone electromigration in homogeneous electrolyte solution. The results are compared with existing data from aqueous electrolyte systems. (author).

British Library Electronic Table of Contents (United Kingdom)

We have successfully grown single crystalline Formula Not Shown with the range of Formula Not Shown using the floating-zone method. All compounds show orthorhombic symmetry in this substitution range, but the difference between lattice constants a and b decreases with increasing Sr concentration and becomes almost zero at Formula Not Shown . Characteristic temperatures, which correspond to antiferromagnetic ordering and structural transition, decrease with increasing Sr concentration. The value of the magnetic susceptibility below 30K increases with increasing Sr concentration. The temperature dependence of the electrical resistivity revealed that Sr substitution significantly suppresses the highly anisotropic electric structure of Formula Not Shown .

Energy Technology Data Exchange (ETDEWEB)

Interest in the tribological properties of plasma nitriding has increased substantially over the past years because plasma nitriding provides a high nitride depth and improved hard facing. The present study examines the tribological properties of AISI H11 plasma nitrided, hot-worked steel. Different nitriding temperatures and durations were considered. Characterization of the composite structures was investigated with wear tests, x-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and microhardness tests. The depth profile of the nitrided zone was measured using the nuclear reaction analysis (NRA) technique. Plasma nitriding affected the microhardness, wear properties, and morphology considerably. Increase in process temperature increased the nitride zone depth.

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

In order to evaluate postclosure off-site doses from low-level radioactive waste disposal facilities, a computer code was developed to simulate the radionuclide released from waste form, transport through vadose zone and transport in the saturated zone. This paper describes the methodology used to model these process. The radionuclide released from the waste is calculated using a model based on first order kinetics and the transport through porous media was determined using semi-analytical solution of the mass transport equation, considering the limiting case of unidirectional convective transport with three-dimensional dispersion in an isotropic medium. The results obtained in this work were compared with other codes, showing good agreement. (author)

International Nuclear Information System (INIS)

The thermal recovery of superconducting elements working as secondaries in fault current limiters can be enhanced by taking advantage of the removal of heat by conduction from an array of artificial weak zones (AWZ) distributed along the superconductor perimeter (hot parts) to the non-weak segments (cold parts). These results were obtained by studying samples with weak parts in the shape of grooves, all identical in size. In this paper we consider the case in which one of the AWZ is slightly different from the rest. Our results show that a change in its length has a negligible effect. On the contrary, a groove which is slightly deeper can be overheated and hence can strongly determine the recovery time of the whole limiter.

International Nuclear Information System (INIS)

Between December 2001 and May 2004, a ventilation experiment (VE) was performed in the Mont Terri Underground Research Laboratory (URL) and co-financed by the Commission of the European Communities. The objective was to investigate the desaturation of consolidated clay formations in consequence of the ventilation of underground openings of a repository in such a formation. The results of the geoelectric measurements performed in the second phase of the Mont Terri ventilation test can be summarized as follows: Geoelectric tomography has been found suitable for monitoring ventilation-induced saturation changes in the Opalinus clay. During ventilation with dry air a desaturation down to below 50% could be detected in both desaturation cycles. The desaturated zone extends less than 0.5 m into the rock around the microtunnel. During the second resaturation phase, ventilation with humid air led to quick resaturation at the tunnel surface, while resaturation of the rock ...

Energy Technology Data Exchange (ETDEWEB)

In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1 MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs under cyclic and ...

Energy Technology Data Exchange (ETDEWEB)

A mathematical model was developed to simulate the combustion process of a direct injection diesel engine. The model considers the key features of such a combustion process; namely fuel droplet evaporation, spray formation, mixing, ignition of heterogeneous burning of the fuel. To model mixing, great emphasis was placed on treating both large and small scale aspects of mixing, the model divides the combustion chamber into three distinct regions of air, fuel spray, and a turbulent plume that is formed once ignition occurs. The fuel spray itself is considered to be composed of multiple zones, which in turn are made of cells of equal mass and of different thermodynamic states. Micromixing of the fuel and air cells, within each zone of the jet and the turbulent plume, is then achieved by utilizing the concept of Monte Carlo stochastic coalescence dispersion technique. The frequency of such cell interactions within each zone is ...

International Nuclear Information System (INIS)

A model has been developed in the recent past to predict fatigue crack growth (FCG) behaviour in the Paris-regime of various steels by employing low cycle fatigue (LCF) properties. The model forms its basis on the assumption that the cyclic damage process immediately ahead of a crack-tip, restricted in a small zone termed as process zone, is identical to those experienced in the LCF loading of a smooth specimen. Within the process zone, fatigue damage has been assumed in terms of product of stress and plastic strain which is analogous to the plastic strain energy density of the smooth specimen under fatigue loading. In this paper the model developed by Kujawski and Ellyin has been used to predict the FCG behaviour of an #alpha#-#beta# titanium alloy in the Paris-regime by employing the experimentally obtained LCF properties. The FCG behaviour thus theoretically predicted was compared with the experimentally ...

Energy Technology Data Exchange (ETDEWEB)

The geological structure of Mesita del Buey at Technical Area 54 (TA-54) was examined using precise surveying of the contact between units 1v and 2 of the Tshirege Member of the Bandelier Tuff at 3.5 km along the north wall of Pajarito Canyon and 0.6 km along the north wall of a tributary to Canada del Buey. Estimated structure contours on this contact indicate typical strikes of N40E to N70E along this part of Mesita del Buey, although the apparent strike of the tuff is E-W at the western part of the survey. Typical dips are 1.0{degree} to 2.0{degree} to the east or southeast, with an estimated maximum dip of 3.2{degree} near the west end of Material Disposal Area G. Thirty seven faults with vertical displacements of 5 to 65 cm were observed in outcrop along the Pajarito Canyon traverse, and, due to the incomplete exposure of the unit 1v-unit 2 contact, many more faults of this magnitude undoubtedly exist. The faults have a wide range in ...

International Nuclear Information System (INIS)

In the feasibility study on commercialized FBR systems, the application of 12Cr steel, with its physical properties and high-temperature strength properties, as structural material is considered in order to greatly reduce construction costs by compacted instruments and structures. In this report, creep, fatigue and the creep-fatigue properties of Mod.9Cr-1Mo steel forging (thickness 550mm) weld, representing conventional steels, were evaluated in order to obtain the needed basic data for the evaluation of the high-temperature strength of 12Cr steel weld. The results obtained are as follows: (1) Metal suitable for HAZ was made by applying thermal treatment to simulate the thermal hysteresis during welding to clearly define creep and fatigue properties in a HAZ softened zone. (2) Creep strength of the weld metal and the welded joint was equal to that of the base metal. However, the welded joint ruptured in the HAZ softened ...

International Nuclear Information System (INIS)

The electronic structure and optical properties in tetragonal ceramics PbTiO_3, are studied by using full-potential linearized augmented plane wave method in density functional theory with the generalized gradient approximation by WIEN2K package. The theoretical calculated optical properties and energy loss spectrum yield a static refractive index of 2.59 and a plasmon energy of 22.7eV for the tetragonal phase. The effective electron number at low energy saturates near 22-23eV with the value of 50 for the effective electron number. The results show a indirect band gap of 2.2eV at the I' point in the Brillouin zone. The :calculated band structure and density of states of PbTiO_3 agree with previous experimental and theoretical results.

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 PFZs at GBs depends closely on the core ...

CERN Document Server

A stellar evolution computer model has been used to determine changes in the luminosity L and effective temperature T(e) of single stars during their time on the main sequence. The range of stellar masses investigated was from 0.5 to 1.5 times that of the Sun, each with a mass fraction of metals (metallicity, Z) from 0.008 to 0.05. The extent of each star's habitable zone (HZ) has been determined from its values of L and T(e). These stars form a reference framework for other main sequence stars. All of the 104 main sequence stars known to have one or more giant planets have been matched to their nearest stellar counterpart in the framework, in terms of mass and metallicity, hence closely approximating their HZ limits. The limits of HZ, for each of these stars, have been compared to its giant planet(s)'s range of strong gravitational influence. This allows a quick assessment as to whether Earth-mass planets could exist in ...

Energy Technology Data Exchange (ETDEWEB)

The depositional environments of the Mesaverde Group of the Piceance Creek basin in northwestern Colorado have determined the basic morphology and characteristics of the tight gas sands reservoirs in the three Multi-Well Experiment wells. The three morphologies, in ascending stratigraphic order, are a blanket type of reservoir (marine to shoreline environment), a lenticular type of reservoir (the paludal and coastal zones of the lower and upper delta plain), and an irregular tabular/elongate reservoir produced by meandering fluvial systems. Internal reservoir discontinuities vary among these types of reservoirs, but consist primarily of permeability barriers and conduits caused by shale breaks and fractures. 10 references, 5 figures.

International Nuclear Information System (INIS)

Theoretical description of Raman scattering in disordered alloys of Ti and Zr with transition metals of groups 5-8 of the Mendeleev Periodic System in critical range of concentrations (CRC) is given. Results of Raman scattering experiment in the system Ti_1_-_xF_x at 0.0005zone, as well as their concentrational dynamics, are determined. Qualitative adequacy of the hybridization model to the alloys studied near CRC is shown.

International Nuclear Information System (INIS)

The manufacturing of TRIGA fuel rods with low enriched uranium follows in principle the same route as high-enriched uranium. The high purity of the primary metals (uranium, zirconium and erbium) is important for determining the equilibrium metal-hydrogen phases. The impurities from the metal, on the surface and from hydrogen may have an important influence on the hydriding process. This paper presents the aspects of the fuel contamination with oxygen during the manufacturing process of the low enriched uranium fuel. The continuous control of the oxygen concentration in the working zone ensures avoidance of the accidental contamination. Key words: manufacturing, fuel, oxygen, contamination. (authors)

UK PubMed Central (United Kingdom)

AbstractThe structural integrity of striated muscle is determined by extra-sarcomere cytoskeleton that includes structures that connect the Z-disks and M-bands of a sarcomere to sarcomeres...Full Text Available

UK PubMed Central (United Kingdom)

The isolation of an untriakontapeptide from camel pituitary extracts has been described. Its structure has been determined and shown to be identical to the sequence of carboxyl-terminal 31 amino acids...Full Text Available

Science.gov (United States)

The mechanical characteristics of semicrystalline materials are related to the proportion, size and structure of the crystalline phase. Studying isothermal crystallization is the first stage in determining what relations exist between structure and charac...

Energy Technology Data Exchange (ETDEWEB)

This work has carried out a molecular structure characterization of two Brazilian plants, Harpalyce brasiliana Benth and Bredemeyera floribunda Wild, using {sup 1} H and {sup 13} C NMR spectroscopy. NMR spectra were presented and analysed, then several structures have been proposed based on spectral data, and finally the structural determination was done 3 refs., 4 figs., 1 tab.

Energy Technology Data Exchange (ETDEWEB)

A new class of one-dimensional active acoustic metamaterials (AAMMs) with programmable effective densities is presented. The proposed AAMM is capable of producing densities that are orders of magnitudes lower or higher than the ambient fluid. Such characteristics are achieved by using an array of fluid cavities separated by piezoelectric diaphragms that are controlled to generate constant densities over wide frequency bands. The piezodiaphragms are augmented with passive electrical components to broaden the operating frequency bandwidth and enable densities higher than the fluid medium to be generated. The use of these components is shown to be essential to maintain the closed-loop compliance of the piezodiaphragm away from the zone of elastic instabilities. The values of the passive components are selected on a rational basis in order to ensure a balance between the frequency bandwidth and control voltage. With this unique structure of the ...

International Nuclear Information System (INIS)

The study of passive films formed on a nickel base alloy type Inconel 600 is performed by capacitance measurements (Mott-Schottky approach). This research is supported by the passivation study of the alloying elements Ni, Cr, Fe and high purity alloys Ni-Cr, Ni-Fe, Ni-Cr-Fe. The results obtained show that the capacitive behaviour of the Inconel 600 in the passive state is similar to that on a p-n heterojunction to which a barrier zone of nickel oxide is added. The individual or combined action of alloying elements on the development of this kind of electronic structure is discussed. (authors). 5 refs., 6 figs.

Energy Technology Data Exchange (ETDEWEB)

Tectonically active basins may host a spectrum of sequence stratigraphic expressions previously considered to be spatially mutually exclusive. In low accommodation areas with high sediment supply, fourth order eustatic cyclicity results in high frequency sequence sets while within rapidly subsiding areas, time-equivalent Type-2 sequences are expressed by highly asymmetrical coarsening upward successions, resembling large parasequences. In the shallow marine Fulmar Formation, of the U.K. North Sea Central Graben a sequence boundary and overlying lowstand deposits, which illustrate the effects of laterally variable subsidence rate and intrabasinal topography on the expression of a eustatic sea-level fall, lie between the Glosense and Serratum (J54a and J54b) maximum flooding surfaces. The syn-rift physiography comprises major tilted fault blocks, with the Central Graben dipping parallel to the major faults, simulating a ramp setting. Where the throw of the faults were greatest (SE), the ...

Energy Technology Data Exchange (ETDEWEB)

In the Assel'skiy and Sakmarskiy time of the lower Permian epoch, on the territory of the modern Dnieper and Donets, and Pripyatskiy Basins, there was a gulf which stretched in a northwest direction. The latter connected to the open sea in the east through the CisDonets trough. Transverse tectonic elevations divided the gulf into 5 semi-isolated reservoirs. In the Assel'skiy time, in the period of carbonate sedimentation, the development of algae, crinoids, corals and other organisms occurred. They created reef, bioherm and biostroma reconstructions. The most favorable sections for their settlement were the coastal zones of the gulf, consedimentation positive structures and transverse tectonic elevations. It is assumed that the formation of reefs, bioherms and biostromas, on the one hand, and sedimentation of evaporites on the other hand, are interrelated processes. The first after the next marine transgression during their ...

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 metals. However, the ...

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The elemental and mineralogical variation in a self-burning coal seam from Coalspur, Alberta, is determined using instrumental neutron activation analysis (INAA) and x-ray diffraction (XRD). The elemental variation in the coal seam is related to temperatures in the various alteration zones, i.e., oxidation, combustion, or carbonization and nature of elements. Mobilization of elements is greatest for As, Br, Cl, Mo, N, S, and Sb. Some of these elements are released to the atmosphere, as evident by the presence of orthorombic sulfur crystals on the surface or in vents at the top of the burning seam or saturation of oxidation char by volatile matter (tar). Whewellite (CaC{sub 2}O{sub 4}, H{sub 2}O) is the only Ca-bearing mineral found in the cooler area of the coal seam. Decomposition of this mineral, coupled with the presence of SO{sub 2} formed by reaction of organic sulfur with O{sub 2} in combustion, resulted in formation of a relatively high ...

CERN Document Server

In this paper we establish a fundamental structural result for formal series encoding the total non-archimedean masses of quadratic lattices of varying determinant squareclasses, but with fixed rank $n$ and signature over any fixed number field. We conclude with some local computations for $n=2$, and use these to derive an analytic class number formula for CM extensions.

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The structure of ammonium azide (NH{sub 4})N{sub 3} was (re-)determined ab initio from x-ray powder diffraction experiment using synchrotron radiation. We tried to detail and comment the different steps involved in the structure determination. The compound crystallize in the orthorhombic Pmna space group (no.53) with a = 8.937(1) A, b= 3.8070(5) A, c = 8.664(1) A, V = 294.79(7) A{sup 3}; Z= 4. It was possible to locate and refine the hydrogen coordinates, in two different approaches, and to establish the H-bonds. The final structural parameters are in good agreement with previous results based on three-dimensional neutron diffraction. (Author)

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 ...

UK PubMed Central (United Kingdom)

We have determined that 10Sa RNA (one of the small stable RNAs found in Escherichia coli) has an interesting structural feature: the 5' end and the 3' end of 10Sa RNA can be arranged in a structure...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Seismic transects in this area show a strongly reflective Moho of generally low relief, which, in the area of modern transects, consists of a thin zone (< 2 km thick) of short reflectors. The upper mantle is transparent and has a P{sub n} of 7.8-8.0 km/s similar to much of the western US. A lower crustal zone, 2-13 km thick, has variable internal reflectivity and a relatively low velocity of 6.6-6.8 km/s. Upper mantle peridotite xenoliths show both ductile and brittle deformational features and have structures and composition affected by magmatic intrusion; intrusions form complex dike systems and extensive zones of grain boundary infiltration in peridotite xenoliths. Whereas melt infiltration preceded and followed ductile deformation, brittle deformation, represented by closely spaced joint systems and faults, followed ductile deformation and is related to the youngest magmatic episodes. Lower ...

International Nuclear Information System (INIS)

The electronic band structure, transport properties, and lattice dynamics in AuX_2 (X = Al, Ga and In) under high pressure have been extensively studied with full potential linearized augmented plane wave and pseudopotential plane wave methods. The theoretical results for the electronic band structure and Fermi surface reveal pressure-induced electronic topological transitions (ETTs) in AuGa_2 and AuIn_2, while they are absent in AuAl_2, in excellent agreement with the experimental observations. Moreover, calculations of the transport properties at different pressures reveal subtle changes in the band structure close to the Fermi surface of the three intermetallic compounds. It is clear that the anomalies in transport properties are due to ETTs. Interestingly, a pressure-induced soft transverse acoustic (TA) phonon mode is identified only in AuGa_2. The TA phonon instability at the Brillouin zone ...

Energy Technology Data Exchange (ETDEWEB)

The study of passive films formed on a nickel base alloy type Inconel 600 is performed by capacitance measurements (Mott-Schottky approach). This research is supported by the passivation study of the alloying elements Ni, Cr, Fe and high purity alloys Ni-Cr, Ni-Fe, Ni-Cr-Fe. The results obtained show that the capacitive behaviour of the Inconel 600 in the passive state is similar to that on a p-n heterojunction to which a barrier zone of nickel oxide is added. The individual or combined action of alloying elements on the development of this kind of electronic structure is discussed. (authors). 5 refs., 6 figs.

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The productivity characteristics of perforated gas well are investigated for the first time under real conditions considering drilling damage, perforation compacted zone and anisotropy in this paper. A non-linear finite element model for non-Darcy flow in perforated gas reservoir is built to consider the effects of twelve factors on productivity ratio (PR) of perforated gas well. The nomographs for two cases are presented in this paper. Compared with previous works, the following results are found: (1) the effects of drilling damage and perforation diameter on PR of gas well are more remarkable than that in oil well; (2) any perforation phase may be the best or the worst as to perforating gas well, which depends on anisotropy, drawdown and that whether or not perforations are beyond drilling damage zone; (3) the increase in perforation length hardly improve PR of gas well when perforations have been beyond drilling damage ...

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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.

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AISI 316L stainless steel was welded by the electron beam (EB) and laser techniques. Microstructural characteristics, hardness profile, creep rupture properties and creep damage of the welds were investigated. Fully austenitic microstructure was obtained in the two welds. The solidification structure of the welds consisted of the cellular and equiaxed dendrites. The creep rupture lives of the two welds were almost the same, and they were reduced by a factor of about two compared to the base metal. Moreover, the rupture elongation of the welds was lower than that of the base metal. Creep damage was observed in the ``parting`` region of the welds and in the heat-affected zone (HAZ), respectively. Final creep fracture occurred in the ``parting`` region of the welds. (orig.).

CERN Document Server

We study the ground state of an ideal coupled two-component gas of ultracold atoms in a one dimensional optical lattice, either bosons or fermions. Due to the internal two-level structure of the atoms, the Brillouin zone is twice as large as imposed by the periodicity of the lattice potential. This is reflected in the Bloch dispersion curves, where the energy bands regularly possess several local minima. As a consequence, when the system parameters are tuned across a resonance condition, a non-zero temperature topological first order phase transition occurs which arises from an interplay between initernal and kinetic atomic energies. It is shown that these phenomena are also captured for two and three dimensional optical lattices.

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, ...

British Library Electronic Table of Contents (United Kingdom)

Wound dressings impregnated with silver have a role to play in aiding to reduce both the dressing and wound microbial bioburden. It is therefore imperative that antimicrobial wound dressings have efficacy on a broad range of clinical significant microorganisms. Accordingly, this study aimed to determine the antimicrobial efficacy of a silver alginate dressing against 115 wound isolates that had been isolated routinely from patients at West Virginia University Hospital. Standardised corrected zones of inhibition (CZOIs) were performed on all clinical isolates. It was found that the silver alginate dressing was able to inhibit the growth of all microorganisms tested. In particular, the silver alginate dressing inhibited the growth of Candida albicans and yeasts with CZOI of 3-115 mm. All met...

Energy Technology Data Exchange (ETDEWEB)

A study was performed to examine currently recommended meteorological measurement programs and atmospheric transport and diffusion prediction models for nuclear power plants to determine their adequacy for plants located in coastal zones where meteorological conditions are normally more complex than at inland sites and to make recommendations for changes to improve current procedures. Recommendations were based on an extensive literature review and on studies of coastal meteorology and diffusion. The study was focused on the following areas: coastal internal boundary layers; tower location; instrument heights; atmospheric stability classification; plume meander; and diffusion calculations. Each of the areas is discussed with appropriate recommendations which were made with respect to either the scientific or the regulation aspects of current procedures or both. Other potential problem areas are also pointed out.

Energy Technology Data Exchange (ETDEWEB)

A survey was undertaken of literature on the conversion of coke-fired cupola furnaces so that they can be fuelled, either wholly or partially, with natural gas. The aim was to determine the most suitable method for a specific furnace. Substitution with natural gas can result in speedier adjustment and control of the smelting process and in addition operational costs are reduced as natural gas is a cheaper fuel. The payback period would be one year. Pollutive emissions would be reduced. It was concluded that the most satisfactory solution would be that 3-4 gas burners should be placed immediately above the smelting zone in the furnace. Each burner should be placed in a separate combustion box in which the complete combustion process could take place. The burners should be placed symmetrically about the furnace, pointing at a small degree downwards. In this way the combustion chamber will not be filled with materials from the furnace and the ...

Energy Technology Data Exchange (ETDEWEB)

A study, based on a literature review was made to examine currently recommended meteorological measurement programs and diffusion prediction methods for nuclear power plants to determine their adequacy for plants located in coastal zones. Although procedures for handling the near-worst case (stable, light-wind situation) were judged adequately conservative, deficiencies in guidelines and procedures were found with respect to the following: failure to consider the role of coastal internal boundary layers; specifications for tower locations and instrument heights; methods of classifying atmospheric stability; methods of allowing credit for plume meander, and models specified for diffusion calculations. Recommendations were made for changes in the guidelines applicable to these topics. Areas in which additional research is needed were identified.

Energy Technology Data Exchange (ETDEWEB)

Man's wastes are polluting the oceans from various sources and delivered by various routes. The result has been the loss of habitat and the irreversible altering of marine ecosystems. Development in the coastal zones and offshore activities that disrupt biologically sensitive areas have led to international negotiations to regulate these impacts and develop a law of the sea. Basic to international cooperation, however, is the need to develop answers to questions about the ecological consequences of development programs and the carrying capacity of the oceans. Current information does not demonstrate long-term global impacts, making it difficult to detect and predict incremental changes and causal relationships. Society needs to determine how much environmental damage it will accept and then to develop appropriate technology, such as biomonitoring. Society also needs to reexamine its positions on technology-based regulatory controls to ...

Energy Technology Data Exchange (ETDEWEB)

The carbonate rocks of the Lower Ordovician Majiagou Formation represent important hydrocarbon reservoirs in the Ordos basin in the western part of the North China plate. Cores and thin sections from more than 60 wells were examined. The main reservoir in the Majiagou Formation consists of fine crystalline dolomite, which was altered by meteoric water during an extended subaerial exposure. Three phreatic zones have been identified in the Majiagou Formation in the northern part of the basin. Oxygen isotopes and fluid inclusion microthermometry data indicates that the porosity developed during the early karst event was considerably reduced by the late-stage, coarse crystalline calcite cements that appear to be related to hydrothermal fluids during deep burial. It was concluded that the main factors that determine the porosity and permeability of these carbonate reservoirs are dolomitization, karstification, and calcite cementation.

International Nuclear Information System (INIS)

A methods is presented for an accurate numerical determination of eigenvalues of real symmetric para-p diagonal matrices. The method takes advantage of the band structure to break up the matrix into p x p blocks and performing algebraic operations including inversions on these blocks only, no matter what the size of the matrix is. The eigenvalues are determined independently one at a time. Thus any error in the determination of one eigenvalue does not affect the other eigenvalues. The method is ideally suited for the Schroedinger eigenvalue problem of the anharmonic potentials. (author).

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Carbohydrate and nucleotide structural determination using modern spectroscopic techniques is dependent on our ability to label oligonucleotides and oligosaccharides with stable isotopes. Uniform Carbon 13 and Nitrogen 15 labeling of oligonucleotides is important to present-day efforts, which are focused on determining the structure of relatively small oligosaccharides and oligonucleotides, which form the elements of larger structures. Because of the relatively recent interest in three-dimensional structure, the development of techniques used to label them has lagged behind parallel techniques used to label peptides and proteins. Therefore, this group`s discussion focused primarily on problems faced today in obtaining oligonucleotides labeled uniformly with carbon 13 and nitrogen 15.

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)

A new three-dimensional (3D) acoustic modelling method was developed using a first-order hyperbolic wave system which was solved with explicit finite dfferences. The numerical solution of the 3D wave system provides a useful method for simulating evolution of a pressure field corresponding to compressional type waves. Existing two-dimensional (2D) elastic modelling algorithms were modified and fine-tuned for computationally efficient and realistic wave propagation simulations in complex structures. An original formulation of the 3D reverse time migration method was developed which is very accurate, does not suffer from unwanted evenescent energy, can image dips beyond 90{degree}, and does not generate multiple energy. Two case studies were performed that involved steam stimulation projects in the Cold Lake deposit. Simulations were performed during different phases of the steam stimulation process to examine the relation between reservoir properties and conditions ...

UK PubMed Central (United Kingdom)

Computational methods for determining the secondary structure of RNA sequences from given alignments are currently either based on thermodynamic folding, compensatory base pair substitutions or both....Full Text Available

UK PubMed Central (United Kingdom)

Electron microscopic analysis can be used to determine the three-dimensional structures of macromolecules at resolutions ranging between 3 and 30 A. It differs from nuclear magnetic resonance spectroscopy...Full Text Available

International Nuclear Information System (INIS)

The angular #gamma##gamma#-correlations for nuclei of Sr even-even isotopes with a=8 82, 84, 86, 88 were measured. Multipole structurs of #gamma#-transtion series and th coefficients multipole mixing were determined.

Science.gov (United States)

The goal of this research project was to determine the eff ects of geometric and mechanical parameters characterizing the soil-structure interaction developed in a buried pipe installation. Parameters such as pipe ring stiff ness, bedding thickness, trenc...

UK PubMed Central (United Kingdom)

The structural properties of brain extracellular space (ECS) are summarised by the tortuosity (λ) and the volume fraction (α). To determine if these two parameters were independent,...Full Text Available

UK PubMed Central (United Kingdom)

SummaryDnaA initiates chromosomal replication in E. coli at a well regulated time in the cell-cycle. To determine how the spatial distribution of DnaA is related...Full Text Available

UK PubMed Central (United Kingdom)

Certain structural and environmental factors other than technical combination of resources and firm size are hypothesized to affect medical practice output. Four groups of variables related to physician...Full Text Available

UK PubMed Central (United Kingdom)

Fate maps are generated by marking and tracking cells in vivo to determine how progenitors contribute to specific structures and cell types in developing and adult tissue. An advance in this...Full Text Available

Scientific Electronic Library Online (English)

Abstract in english Frontal weapon is the term used to designate the apparatus consisting of frontal gland and associated structures that participate in the chemical defense of termite soldiers. The ultra structure of the frontal gland and the scanning microscopy of the soldier head was investigated in the termite Amiitermes euamignathus Silvestri, 1901.Campaniform sensilla was not observed but there were 80 to100 sensory bristles around the frontal pore. The glandular epithelium shows only (more) class 1 cells according 10 the classification of NOIROT & QUENNEDEY (1974, 1991). The glandular cells are characterized by apical microvilli, a basal labyrinth and a large quantity of smooth endoplasmic reticulum which forms dense zones throughout the cytoplasm. The secretion is concentrated mainly in the basal pole of the cell and consists of large lipid droplets. The secretory epithelium is covered by a thick apical cuticle ...

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 that (in a form of ...

Energy Technology Data Exchange (ETDEWEB)

Theoretical and experimental studies have been carried out on the combustion of azide polymers used as a binder in high-energy propellants. AMMO (3-azidemethyl-3`-methyloxetane) is one of the energetic azide polymers which contain N3 groups in their molecular structures. EDNA (ethylenedinitramine) is a linear nitramine which has modest properties in the flame temperature and the molecular weight of burned gases as compared with HMX (cyclotetramethylenetetranitramine) and NQ (nitroguanidine). In this study, the burning rate characteristics of azide/nitramine propellants were investigated in order to gain a wide spectrum of burning rate. As a result, the burning rate of AMMO/EDNA propellant is higher than that of AMMO/HMX propellant and the pressure exponent of AMMO/EDNA propellant is lower than that of AMMO/HMX propellant. Both AMMO/EDNA and AMMO/HMX propellants exhibited the same combustion wave structure as inert polymer/nitramine propellants. ...

Energy Technology Data Exchange (ETDEWEB)

Purpose: The aim of this study was to evaluate the accuracy of MRI in the measurement of cartilage thickness of the ankle joint in comparison to pathologic and histologic specimens. Patients and methods: The ankle joints of four fresh cadaver feet were imaged on a 1.5 T MR-unit in the coronal plane. Standard T{sub 1}-weighted spin echo (SE) and a T{sub 1}-weighted 3D-GE (FLASH-3D) sequence with fat saturation were applied. Following MR imaging, the talus was explanted and cut parallel to the MR images for macroscopic evaluation and histologic specimens were prepared. MRI measurements of the cartilage thickness of the talus were carried out in two ways: Without and with consideration of a transition zone of intermediate signal intensity between hyperintense cartilage and hypointense cortical bone. The data were compared with the anatomic specimens as the gold standard expressing the difference as a percentage value. On histologic specimens thickness of deep ...

Energy Technology Data Exchange (ETDEWEB)

The known biological functions of RNA have expanded in recent years and now include gene regulation, maintenance of sub-cellular structure, and catalysis, in addition to propagation of genetic information. As for proteins, RNA function is tightly correlated with structure. Unlike proteins, structural information for larger, biologically functional RNAs is relatively limited. NMR signal degeneracy, relaxation problems, and a paucity of long-range {sup 1}H-{sup 1}H dipolar contacts have limited the utility of traditional NMR approaches. Selective isotope labeling, including nucleotide-specific and segmental labeling strategies, may provide the best opportunities for obtaining structural information by NMR. Here we review methods that have been developed for preparing and purifying isotopically labeled RNAs, as well as NMR strategies that have been employed for signal assignment and ...

Energy Technology Data Exchange (ETDEWEB)

This paper reports thermal comfort and indoor air quality (IAQ) studies of an under-floor air-conditioning (UFAC) system in a hot and humid climate. Thermal comfort parameters were measured at pre-determined grid points within an imaginary plane to predict the air flow pattern of the supply air jet as well as to determine the occurrence of thermal stratification in the office space. Fanger's thermal comfort index was also computed to detect the occupants' thermal sensation. Besides, the concentration levels of dust and carbon dioxide were recorded with the intention to examine the quality of the indoor air. Statistical methods were applied to derive the relationship between air velocity and the other parameters as mentioned earlier. The main findings from the study revealed reasonable level of acceptability of IAQ associated with the UFAC system. However, occupants are likely to experience localised thermal discomfort near the ...

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption on the surface of graphitized thermal carbon black at 300 K were determined by the molecular statistical method for three phenylalklylamines. The influence of the intramolecular H-bond on the conformation of the molecules compared with structurally related n-alkyl-benzenes was considered. It was shown that the conformations of the molecules could influence chromatographic retention. Conformational isomers stabilized by intramolecular H-bonds were found to retain their structure in adsorption on graphitized thermal carbon black.

International Nuclear Information System (INIS)

The alloy of Ti-Al-Mo-V-Cr system is studied for its structure in a strained state and specific features of #beta#-#alpha# transformation in a #beta#-matrix and deformation twins on ageing. It is determined that preliminary deformation initiates the decomposition of solid solution on aging. In a metastable #beta#-titanium alloy the substructure of deformation twins is shown to vary essentially with aluminium and chromium partial substitution for molybdenum and vanadium

International Nuclear Information System (INIS)

The electron structure of the A-15 compounds is studied by accounting for the Hubbard energy as the highest energy parameter. The conditions for the Cooper instability origination are obtained. The superconducting transition temperature dependence on the degree of filling the d- and p-shells of the transition and nontransition elements is determined. The relationship between the transition temperature and the energy jumpover along the chains, which allows comparison with the experiment, is established. Qualitative explanation of the Mattias empiric rules is presented

International Nuclear Information System (INIS)

To calculate the energy band structures in semiconductors using the relativistic augmented plane wave method, atomic potential and charge density are needed, which are calculated by self-consistent method. Wave function for one electron is determined by solving the Dirac equation with the Hartree-Fock equation based on the slater's exchange potential. The results of calculation for Cu"+"1 are given. (Author).

Energy Technology Data Exchange (ETDEWEB)

The authors investigate the breakdown luminescence spectra in reverse-biased p-n heterojunctions based on gallium and aluminum phosphides and arsenides for the purpose of determining their behavior as lasing and photodetection materials. Data are given on temperature coefficients, band gap structure, bremsstrahlung, hot carrier mobility and photon emission, and transition and recombination parameters.

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This paper presents a systematic approach to the automatic determination of the evolution of the rigid-plastic structural response caused by a proportional or single parameter pressure loading which varies with time in a monotonic non decreasing fashion. The frame structure is envisaged as a network, and the fundamental vectorial conditions characterising its behaviour at any instant of time are combined in a consistent manner. By considering the level of the pressure loading to be a single load parameter ranging monotonically from zero to infinity, the structural governing system may be regarded as a parametric linear complementary problem. (author). 13 refs., 2 figs.

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The crystal and molecular structures of the anti-acquired immunodeficiency syndrome agent 3'-azido-3'-deoxythymidine (AZT) have been determined by x-ray diffraction. There are two crystallographically independent AZT molecules in the crystal asymmetric unit; they have similar conformation and differ primarily in the glycosyl torsion angle. Comparisons with a hydrated thymidylate structure indicate that the azido group does not significantly affect the gross conformational preference of the molecule. The comparisons also suggest possible functional roles for the azido group in enzyme binding.

Energy Technology Data Exchange (ETDEWEB)

This paper outlines the development of an organizational model which will be used to determine the influence of supervisory and management functions in a nuclear power plant (NPP) on risk. A theoretical conceptualization, derived from the empirical literature, is used to describe the organizational structure of NPPs. The parameters and variables associated with this dynamic, process-oriented model are detailed. Applications of the model and preliminary insights derived from this conceptualization are discussed.

Science.gov (United States)

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

British Library Electronic Table of Contents (United Kingdom)

We report the first band structure calculations of the quasi-one-dimensional [MnTPP][TCNE] compounds (TPP?=?meso-tetraphenylporphyrinato, TCNE?=?tetracyanoethylene), based on Density Functional Theory (DFT) methods, in order to interpret the magnetic ordering in these prototypic systems. We compare and contrast the results of broken-symmetry DFT calculations for extended systems, with periodic boundary conditions, and for finite systems, magnetic dimers modeling the actual molecular magnets. By varying systematically the main angles, we are able to determine the geometry dependence of the exchange interaction. Structure?properties correlations in these charge-transfer salts reveal the determinant role of the Mn-(N?C)TCNE bond angle on the strength of the ferrimagnetic coupling between the ...

British Library Electronic Table of Contents (United Kingdom)

The structure of the O-antigen polysaccharide (PS) from Escherichia coli O177 has been determined. Component analysis together with 1H and 13C NMR spectroscopy experiments was used to determine the structure. Inter-residue correlations were determined by 1H,13C-heteronuclear multiple-bond correlation and 1H,1H-NOESY experiments. PS is composed of tetrasaccharide repeating units with the following structure: 2)-a-l-Rhap-(13)-a-l-FucpNAc-(13)-a-l-FucpNAc-(13)-b-d-GlcpNAc-(1 An a-l-Rhap residue is suggested to be present at the terminal part of the polysaccharide, which on average is composed of 20 repeating units, since the 1H and 13C chemical shifts of an a-linked rhamnopyranosyl group could be assigned by a combination of 2D NMR spectra. Consequently, the biological repeating unit has a 3-...

Energy Technology Data Exchange (ETDEWEB)

As part of a coordinated program, AECL is developing a set of tools to aid with the prediction and management of steam generator performance. Although stress corrosion cracking (of Alloy 800) has not been detected in any operating steam generator, for life management it is necessary to develop mechanistic models to predict the conditions under which stress corrosion cracking is plausible. Therefore, constant extension rate tests were carried out for Alloy 800 under various steam generator crevice chemistry conditions at applied potentials. These tests were designed to evaluate the stress corrosion cracking susceptibility of Alloy 800 under CANDU( steam generator operating conditions. Based on the experimental results, the recommended electrochemical corrosion potential/pH zone for Alloy 800 determined by electrochemical polarization measurements was verified with the respect of stress corrosion cracking susceptibility. The effects of lead ...

Energy Technology Data Exchange (ETDEWEB)

Nitriding leads to improved tribological and corrosive properties of iron alloy components. In order to study the effect of plasma nitriding parameters on the structure of compound layer and diffusion zone, a systematic variation of process parameters, temperature and process gas atmosphere has been carried out. Metallographic inspection, X-ray diffraction and glow discharge optical spectroscopy analysis (GDOES) were used in this investigation. The results clarified that depending on the amount of nitrogen in the gas atmosphere nitrided layers with and without compound layer can be generated in the surface of M2 tool steel for temperatures from 350 C to 500 C. For plasma nitriding in 5 vol.% Nitrogen and 95 vol.% Hydrogen no compact compound layer was formed. The gas mixture of 76 vol.% Nitrogen resulted in compound layer formation for all temperatures from 350 C to 500 C. X-ray phase analysis indicated an almost 100% {epsilon}-(carbo)nitride ...

Energy Technology Data Exchange (ETDEWEB)

The influence of (%MgO) and (%T.Fe) in slug on the corrosion resistance of Al{sub 2}O{sub 3}-C brick was studied at 1,550-1,800{degree}C to apply it to the post combustion zone of an in-bath smelting reduction furnace. The wear rate of the brick was affected strongly by temperature decreasing to 1 2-2 3 for every temperature reduction of 100{degree}C, and it was also more affected by (%T.Fe) than (%MgO) in slug at every temperature. The observation of brick microstructures by reflecting microscopy revealed the preceding wear of a carbon matrix. Based on the consideration that the growth of degraded structures by decarburization also contributes to movement of Al{sub 2}O{sub 3} clinkers, the wear rate equation of the Al{sub 2}O{sub 3}-C brick was derived taking into account not only elution of Al{sub 2}O{sub 3} clinkers into slug but oxidation and decarburization of the carbon matrix in oxidation atmosphere at high temperature, resulting in the ...

Energy Technology Data Exchange (ETDEWEB)

The authors have interpreted 1,400 km of industry and government multichannel seismic reflection data from eastern Lake Superior. Seismic sequences have been identified by using reflection character and reflector terminations and truncations. This framework, coupled with outcrop information, has allowed them to assign lithologic units to some of these reflectors and reconstruct the timing and geometry of structures within the basin. The authors have mapped the Base Jacobsville-Bayfield Group/Top oronto Group, Base oronto Group/Top Keweenawan volcanics, and Basement as well as several reflectors internal to these groups. Integration of gravity and magnetic data with the seismic grid permits regional mapping of faults and folds between seismic lines. In the eastern part of the basin, high-angle basement-involved reverse faults, such as the southeastern combination of the Keweenaw fault, trend NNW-SSE, while broad folds trend E-W. The Keweenaw fault is a complex ...

International Nuclear Information System (INIS)

Developed under the PN II Project 71-009 - MONA, the pre-operational monitoring program of the LIL waste disposal site presented in this paper covers the main elements requested for a continuous improvement of site characterization and safety assessment, as well as for the set up of the baseline data requested for the future operational and post-operational monitoring and surveillance. These elements are: vadose and saturated zones hydrogeology, surface erosion, meteorology and radionuclides content in waters, soil and biota. Pairs of TDR (Time Domain Reflectometry) and pressure sensors, coupled with a meteorological station have been installed on site for the continuously measurement of the water content and matric potential changes due to the climate variations. The data will be used to follow the water balance, the pores water velocity and to calculate the infiltration rate. A new set of erosion rates experimentally determined by Pinhole ...

Energy Technology Data Exchange (ETDEWEB)

The Department of Energy's National Solar Data Program established solar energy systems in residential and commercial buildings across the United States. These solar sites are linked to Vitro Laboratories Division's computer in the National Solar Data Network (NSDN). Vitro collects and analyzes data from this network to determine the thermal performance of each of the solar systems. The network consists of: (1) sensors which measure key performance parameters at a selected site; (2) a Site Data Acquisition Subsystem (SDAS); (3) telephone transmission circuits; and (4) a Central Data Processing System (CDPS). For the majority of parameters, raw data is collected approximately every five minutes. Solar insolation and certain other parameters, which are subject to rapid variance, are sampled every 32 seconds. Environmental information collected at the sites for the reporting month are presented. The environmental data for the NSDN are presented in ...

Science.gov (United States)

Burnaid is a sorbalene-based cream containing 40 mg/g of tea tree oil and 1 mg/g of triclosan. This investigation was carried out to determine the effect of Burnaid, a commercial tea tree oil preparation, against Enterococcus faecalis (ATCC29212), Staphylococcus aureus (ATCC29213), Escherichia coli (ATCC25922), and Pseudomonas aeruginosa (ATCC27853), with the activity of the base product in the commercial preparation. The organisms were suspended in sterile saline (0.5 McFarland Standard) and inoculated onto horse blood agar (E. faecalis and S. aureus) or Mueller-Hinton agar (E. coli and P. aeruginosa). One hundred microliters of Burnaid unsterilized, Burnaid sterilized and the base product (Tinasolve) were placed in duplicate in wells cut into the agar plates. Sterility and inactivation cultures were also performed on the samples. None of the samples were found to be contaminated with bacteria prior to testing. Only S. aureus and E. coli showed ...

Energy Technology Data Exchange (ETDEWEB)

A number of different theoretical approaches have been used to model to atomic structure and properties of solid-liquid interfaces. Most calculations indicate that ordering occurs in the first several layers of the liquid, adjacent to the crystal surface. In contrast to the numerous theoretical investigations, there have been no direct experimental observations of the atomic structure of a solid-liquid interface for comparison. Saka et al. examined solid-liquid interfaces in In and In-Sb at lattice-fringe resolution in the TEM, but their data do not reveal information about the atomic structure of the liquid phase. The purpose of this study is to determine the atomic structure of a solid-liquid interface using a highly viscous supercooled liquid, i.e., a crystal-amorphous interface.

Energy Technology Data Exchange (ETDEWEB)

The authors examine the relationship of the structure and mechanical properties of similar alloys of tungsten with rhenium produced by the powder metallurgy method by sintering powders. Since the alloys were deformed by rolling, we examine the effect of the resultant anisotropy of the structure on the properties of the metal in various directions. The tests were conducted on an alloy of tungsten with 2 wt.% rhenium and, for comparison purposes, an alloy of tungsten with additions of oxides of yttrium and hafnium. The mechanical properties of the alloys, i.e., strength, cracking resistance, cold shortness temperature, were determined in the bend test. Structural examination was carried out using an optical microscope, electron scanning microscopy, and the method of transmission electron microscopy.

UK PubMed Central (United Kingdom)

Neuroblasts born in the adult subventricular zone (SVZ) migrate long distances in the rostral migratory stream (RMS) to the olfactory bulbs where they integrate into circuitry as functional interneurons....Full Text Available

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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

Energy Technology Data Exchange (ETDEWEB)

In the present paper the tribological behavior of the coatings are discussed. Duplex coatings were applied on cold working steel 100Cr6. Samples were plasma nitrided at different thickness of plasma surface layers. TiN was deposited with a classic BALZERS PVD equipment and subsequent ion implantation. Ion implantation was provided with N{sup 5+} ions. The other samples were produced with IBAD technology in DANFYSIK chamber. Wear resistance and exchanges of friction coefficient were measured with on-line test using special designed tribology equipment. Following the tests, the wear zone morphology and characteristics of surface layer structure as well as important properties were investigated by scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). Scratch adhesion testing was performed using commercially available equipment. Energy dispersive X-ray analysis (EDAX) of the wear-scars on pins provided essential information on ...

International Nuclear Information System (INIS)

The temperature dependence of T_1 spin-lattice relaxation time on "5"1V, "6"9Ga, "7"1Ga and Knight shift on "5"1V and "2"9Si nuclei in polycrystalline V_3Si, V_3Ga, V_3Ge and in the monocrystal V_3Si in normal state is investigated. For V_3Si and V_3Ga a rapid growth (T_1T)"-"1 is observed with temperature decrease while for V_3Ge the maximum (T_1T)"-"1 at T approximately equal to 60 K has been found. The temperature dependence peculiarities have been discussed on the basis of theoretical models available and zone structure calculations for A-15 compounds. The T_1 anisotropy and possibility of its experimental discovery are considered. Anisotropic contribution in (T_1T)"-"1 and contributions of d states of different symmetries into the electron state density at the Fermi level are estimated for V_3Si from T_1 measurements.

International Nuclear Information System (INIS)

The US Army Engineers Waterways Experiment Station (WES) and US Army Engineer Division, Huntsville (HNDED) have developed general design criteria and specific design review criteria for the earth-mounded concrete bunker (EMCB) alternative method of low-level radioactive waste (LLW) disposal. An EMCB is generally described as a reinforced concrete vault placed below grade, underneath a tumulus, surrounded by filter-blanket and drainage zones. The tumulus is covered over with a low permeability cover layer and top soil with vegetation. Eight major review criteria categories have been developed ranging from the loads imposed on the EMCB structure through material quality and durability considerations. Specific design review criteria have been developed in detail for each of the eight major categories. 63 refs., 13 figs., 2 tabs.

International Nuclear Information System (INIS)

Ternary R_2TSi_3 intermetallic compounds (R=Rare Earth, T=Transition Metal) with hexagonal AlB_2-type crystallographic structure are known because of their interesting physical properties. Pr_2PdSi_3 single crystals were grown by a vertical floating zone method. The compound exhibits congruent melting behavior at a liquidus temperature of about 1770 C. Single crystalline samples show a huge anisotropy at low temperatures due to the crystal electric field effect and order antiferromagnetically below the Neel temperature T_N=2.17 K. This value approximately obeys the linear de Gennes scaling for this class of compounds. The [001] orientation was identified as the magnetic easy axis at room temperature. At lower temperature (#approx#20 K) magnetic easy and hard axes interchange with each other. Two additional magnetic phase transitions were observed at temperatures below 1 K.

Energy Technology Data Exchange (ETDEWEB)

Onshore and marine seismic-reflection data obtained near the Trans-Alaskan Crustal Transect (TACT), in the region of the eastern Aleutian trench and lower Cook Inlet, reveal highly reflective midcrustal layering that begins at a depth of 10-15 km within the upper plate of the Aleutian subduction zone. Beneath the continental shelf, midcrustal reflections were recorded over broad areas and occur in subhorizontal bands that are 1 to 3 s thick. The reflections extend beneath complexly deformed late Mesozoic and early Cenozoic accreted rocks that are exposed at the surface. Preliminary interpretation of seismic refraction data indicates that under the shelf the top of the reflections corresponds in depth with a sharp increase in rock velocity, from 5.9 km/s to 6.6 km/s. North and northwest of the shelf, beneath the Chugach and Kenai mountains, midcrustal features dip 20{degree}-30{degree} north or northwest, and below the Chugach Mountains, the top of the reflections ...

International Nuclear Information System (INIS)

German 2003 p. 24 Germany Klemz, G. Moenig, K. Sekaric, J. Stahl,

Wastenet

...Benthic Marine Bioregionalisation of Australia's Exclusive Economic Zone The benthic (sea floor) component of the National Marine Bioregionalisation covers the 80% of Australia's ... Exclusive Economic Zone that lies beyond the continental shelf break. It provides a description of patterns of biological distributions and physical habitats on the seafloor....sea floor) component of the National Marine Bioregionalisation covers the 80% of Australia's Exclusive Economic Zone that lies beyond the continental shelf break. It provides a ... Benthic Marine Bioregionalisation of Australia's Exclusive Economic Zone Change text size Skip to content Marine Bioregional Planning resources Search: About us Contact us You ...

Science.gov (United States)

PMID:534760

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 ...

Science.gov (United States)

An in-depth industrial hygiene survey was conducted to evaluate worker exposures to phosphine during fumigation of grain at the Early and Daniel Co. grain elevator in Louisville, Kentucky. Stored grain was fumigated using aluminum phosphide. Aluminum-phosphide pellets were also added directly to the grain by the blender as it was poured into the storage containers. Local exhaust ventilation was used at points in the grain-moving system where grain dust was generated. Air samples were taken during full-shift periods at the breathing zone of the weighmaster, two bin floormen, and the blender. Area monitoring samples were also taken. If the operators spend considerable time in the vicinity of a bin which is being filled with grain, there is a likelihood of far greater exposure levels being noted. According to the author, further studies of the use of phosphide products at other elevators should be conducted to determine the effect of environmental ...

Energy Technology Data Exchange (ETDEWEB)

The fuel composition heterogeneity effect on reactor performance parameters was assessed by refueling simulations for three DUPIC fuel options of fuel composition heterogeneity control: the fissile content adjustment, the reactivity control by slightly enriched and depleted uranium, and the reactivity control by natural uranium. For each DUPIC fuel option, the simulations were performed using 30 heterogeneous fuel types which were determined by the agglomerative hierarchical clustering method. The heterogeneity effect was considered during the refueling simulation by randomly selecting fuel types for the refueling operation. The refueling simulations of the heterogeneous core have shown that the key performance parameters such as the maximum channel power (MCP), maximum bundle power (MBP), and channel power peaking factor (CPPF) are close to those of the core that has single fuel type. For the three DUPIC fuel options, the uncertainties of MCP, MBP, and CPPF due to ...

Science.gov (United States)

The purpose of the study was to investigate the adequacy of educational services available for the implementation of the ideals of the Universal Basic Education (UBE) in Southern Nigeria. Using the multistage sampling technique, 800 primary school teachers were selected from the three geo political zones in Southern Nigeria as participants in the study. However, 1457 usable copies of the questionnaire administered to participants were used for the final study. The researchers collected and analyzed data to (1) Ascertain how free the UBE was in Southern Nigeria and (2) to determine if educational services were adequately provided for the implementation of the programme. Results of data analysis suggest that the UBE was not entirely free as parents still buy books and report cards for their children in primary schools. Also, educational services were not adequately provided in the schools. Recommendations were made to government on how to improve ...

International Nuclear Information System (INIS)

The Loose Parts Monitoring System (LPMS) provides information on the location of a loosened or detached metal impacted onto the inner surface of a primary pressure boundary and on a mass or energy of the impact signal. For the conventional system, it is popular to employ the group delay among the sensors installed within 3 ft range from the impact source in a collection zone as stated in the Reg. Guide 1.133. However, there exist inherent errors for the estimation of the true location of the impact since it is highly dependent on the plant personnel's decision to determine the arrival time differences of the generated wave group among the neighbouring sensors. To overcome this problem in this study, the two-dimensional approach has been proposed and applied to effectively estimate the arrival time differences of the impact signal by using continuous wavelet transform which is one of the linear time-frequency analysis methods. The experiment has ...

Energy Technology Data Exchange (ETDEWEB)

As part of a coordinated program, AECL is developing a set of tools to aid with the prediction and management of steam generator performance. Although stress corrosion cracking (of Alloy 800) has not been detected in any operating steam generator, for life management it is necessary to develop mechanistic models to predict the conditions under which stress corrosion cracking is plausible. Therefore, constant extension rate tests were carried out for Alloy 800 under various steam generator crevice chemistry conditions at applied potentials. These tests were designed to evaluate the stress corrosion cracking susceptibility of Alloy 800 under CANDU( steam generator operating conditions. Based on the experimental results, the recommended electrochemical corrosion potential/pH zone for Alloy 800 determined by electrochemical polarization measurements was verified with the respect of stress corrosion cracking susceptibility. The effects of lead ...

Energy Technology Data Exchange (ETDEWEB)

Ordos basin lies in the north-central China, in a compression tectonic regime, with an area of approximately 250,000 km{sup 2}, including several pay zones ranging from Cambrian to Jurassic. It is one of the earliest-formed marine to continental-superimposed basin in China, characterized by Proterozoic basin-marginal rifling and Lower-Paleozoic carbonate platform development followed by western thrusting and foreland depression during Mesozoic. It underwent several tectonic movements and is covered by several structural layers, with many play types developed, primarily thrust and anticlinal plays in the west, and differential compaction (river-channel sand lens) or drape as well as buried hill plays in the basin center and east. Ordos basin is a prolific gas basin with an estimated resource potential of gas 656,091 billion m{sup 3} in the Paleozoic strata and oil 2.0474 billion tons in the Mesozoic strata. In 1986, in the western part of the ...

Energy Technology Data Exchange (ETDEWEB)

Recent earthquake disasters have revealed the importance of countermeasures against soil Liquefaction in seismic design. In particular, the 1995 Hyogoken Nanbu earthquake caused several types of severe damages to pile foundations. This paper describes an analysis method for soil liquefaction using simple parameters such as SPT-N values and seismic response analyses for the pile-supported structure to consider soil-structure interaction effects and soil non-linearity using a modified Penzien model. It is important to find a way to determine the region of surrounding soil whose behavior is identical to that of piles. This paper adopts the thin layer element method to systematically determine the volume of the surrounding soil. The responses of pile-supported structure are similar, whether soil liquefaction and nonlinearity of pile are considered or not. However, the bending moment of ...

International Nuclear Information System (INIS)

The absorption, emission and magnetic circular dichroism spectra of the anionic complex (Cp_3Pr. NCS)"- were measured at room and low temperatures. On the basis of these spectra the electronic structure in the f-f range could be derived. The parameters of an empirical Hamiltonian were fitted to the experimentally determined crystal field splitting pattern. Compared with the previously examined neutral Cp_3 Pr.X complexes the quadratic crystal field parameter B_0"2 is considerably reduced.

British Library Electronic Table of Contents (United Kingdom)

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

International Nuclear Information System (INIS)

The luminescence spectra of trivalent europium ion embedded in various rare earth chromates were analysed. The spectroscopic data in most of chromates are in agreement with the structural determination but for some others the discrepancy between two methods is underlined. Energy level schemes were deducted from the experimental emission spectra and the crystal field simulation has been performed. The maximum splitting of the "7F_1 manifold of the Eu"3"+ ion as a function of N_v, the so-called crystal field strength parameter, is given. This allows us to classify the compounds according to their crystal field extent. (author)

CERN Document Server

This work provides explicit characterizations and formulae for the minimal polynomials of a wide variety of structured $4\\times 4$ matrices. These include symmetric, Hamiltonian and orthogonal matrices. Applications such as the complete determination of the Jordan structure of skew-Hamiltonian matrices and the computation of the Cayley transform are given. Some new classes of matrices are uncovered, whose behaviour insofar as minimal polynomials are concerned, is remarkably similar to those of skew-Hamiltonian and Hamiltonian matrices. The main technique is the invocation of the associative algebra isomorphism between the tensor product of the quaternions with themselves and the algebra of real $4\\times 4$ matrices.

International Nuclear Information System (INIS)

Several recent experiments on micro- (or nano-) structured samples of ferromagnetic materials are introduced. Magnetization reversal phenomena are investigated on submicron wire samples of trilayer structure using the giant magnetoresistance effect. Domain wall movements are sensitively monitored by resistivity measurements and the velocity of propagation is determined. The contribution of domain wall to the resistivity is argued from the results on artificially designed samples of a spring-magnet system. In circular dots of permalloy, the existence of vortex magnetization is confirmed and the reversal of the vortex core magnetization is studied from magnetic force microscopy measurements. (author)

Energy Technology Data Exchange (ETDEWEB)

An investigation of the solidification behavior was carried out on the directionally solidified single crystal superalloy CMSX 6. The relationship between structure morphology and the process parameters has been experimentally determined and illustrated in a solidification diagram. The metallographic analyses of transverse sections within the solidification interval yield the sequence of phase formation and the evolution of solid fraction. The solidification process and the corresponding structure have been discussed in detail. (orig.)

Science.gov (United States)

The total area ( s m) of Voronoi-Dirichlet polyhedron faces corresponding to all intermolecular contacts of one molecule in the structure of crystals and the total volume of pyramids ( V m) built on such faces and containing the nuclei of atoms participating in intermolecular contacts in their vertices were determined for 19 unsaturated hydrocarbons. The differential molar heat of adsorption of the hydrocarbons on graphitized thermal carbon black was found to be linearly related to the s m or V m integral parameters of their Voronoi-Dirichlet polyhedra. Aromatic hydrocarbons on the one hand and saturated hydrocarbons, olefins, and acetylene on the other are characterized by different dependences because of the special shapes of their molecular Voronoi-Dirichlet polyhedra.

Energy Technology Data Exchange (ETDEWEB)

Experiments were conducted which established that the higher passivating capacity of Ni/sub 60/Nb/sub 40/ alloys in the amorphous state and higher efficiency of the anodic process of generation of chlorine (2 N NaCl + HCl to pH = 0) in comparison with the crystalline state are determined by higher homogeneity and density of the passive films formed on the amorphous alloy and by higher electron conduction which depends directly on the difference in the structure of the passive films formed on the alloys in the amorphous and crystalline states.

Energy Technology Data Exchange (ETDEWEB)

Most of the investigations have a theoretical sustenance based on molecular simulation. The area of application of molecular simulation is very wide, in the Materials Technology Department assigned to the Applied Sciences Management have been treated problems about metallic nano structures, glasses, interfaces, and molecules, to sustain and to explain some of the experimental results. Energy calculations are carried out to determine minimum energy structures, for later on to carry out calculations of some of their properties; as well as the images simulation of Electron microscopy and X-ray diffraction. (Author)

International Nuclear Information System (INIS)

The existence of characteristic longitudinal optical and transverse optical phonons of cubic ZnO in ZnO nano-tetrapods is determined by Raman spectroscopy and first-principles calculations. Stacking sequence change at the boundary of the core and legs is also identified by high-resolution transmission electron microscopy. Based on this experimental and theoretical evidence, we demonstrate that the lattice structure of ZnO nano-tetrapods is hierarchical with a zinc blende core connecting to four wurtzite legs. Furthermore, we establish the atomic configuration and propose a formation mechanism induced by Laplace pressure in the initial growth stage of ZnO nano-tetrapods.

International Nuclear Information System (INIS)

We have studied the features of formation and the possible stationary structures of a self-consistent magnetic field in a relativistic collisionless plasma, which are characteristic of a simple geometry of the Weibel instability that is well known in the nonrelativistic case. The universal condition is established, the growth rate is determined, and the criteria of saturation of the Weibel instability are analyzed for a broad class of anisotropic particle distribution functions (for definiteness, in application to an electron-positron plasma). A nonlinear equation of the Grad-Shafranov type describing the potential current structures is derived and its solutions are analytically studied. Special attention is paid to spatially harmonic, nonlinear current configurations with parameters determined by the properties of the initial homogeneous plasma subject to the Weibel instability. It is demonstrated that ...

British Library Electronic Table of Contents (United Kingdom)

The n3 and n4 vibrational transitions of CH3 and CD3 isolated in solid parahydrogen were studied by high-resolution infrared spectroscopy. The radicals were produced by in situ UV photolysis of methyl iodides trapped in solid parahydrogen. The observed spectra showed clear rotational fine structures, which were subjected to further splitting due to the electrostatic field of solid parahydrogen. The molecular constants and crystal field parameters of the radicals in solid parahydrogen were determined by analyzing the spectral structures of the n3 and n4 transitions of CD3 by the crystal field theory. The rotational constants of the CD3 radical were found to be only a few percent smaller than those in the gas phase. The determined crystal field parameters indicated significant quantum effect...

International Nuclear Information System (INIS)

A method for the determination of stereotaxic coordinates in radiography, e.g. angiography, pneumoencephalography or digital vascular radiography, is described. A special localization frame containing radiopaque structures and scales defines a diagnostic coordinate system. This frame is fixed to the X-ray-table prior to the radiographic procedure and two projections are obtained at arbitrary angles to each other. The focus-film distances do not have to be fixed. The target coordinates are then determined either by a simple graphical procedure or with the use of a digitizing x-y-table, by a computer. With the computer method the films are placed on the digitizing table and the target and a few reference points are marked using a cursor. From the relative positions the computer calculates the coordinates. With the special head fixation system, coordinates of structures visualized in radiographic ...

International Nuclear Information System (INIS)

A photoacoustic (PA) imaging system based on an ultrasonic Fresnel zone plate (FZP) transducer is developed for the purpose of imaging biological tissue. This FZP transducer has a two-zone negative zone plate piezoelectric material pattern, and an optical fibre is integrated with the transducer on the symmetric axis of the zone plates to deliver laser pulses to the sample. The focal characteristic of the FZP transducer is analysed by theoretical prediction and experimental measurement, and the measured results are in good agreement with the predicted results. The limited-field back-projection deconvolution algorithm combined with the coherence-factor weighting technique is used to reconstruct the optical absorption distribution. The experiments were performed with phantoms and the blood vessels of chicken embryo chorioallantoic membrane. The results demonstrate that PA imaging using the FZP transducer ...

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 repeated use and limited lifetime of a composite tiring vessel compel a need to survey techniques for monitoring the structural integrity of the vessel in order to determine when it should be retired. Various nondestructive techniques were researched and evaluated based on their applicability to the vessel. The methods were visual inspection, liquid penetrant testing, magnetic particle testing, surface mounted strain gauges, thermal inspection, acoustic emission, ultrasonic testing, radiography, eddy current testing, and embedded fiber optic sensors. It was determined that embedded fiber optic sensor is the most promising technique due to their ability to be embedded within layers of composites and their immunity to electromagnetic interference.

British Library Electronic Table of Contents (United Kingdom)

The thermodynamic characteristics of adsorption of iodobenzene, 2-iodothiophene, and 1- and 2-iodoadamantanes on the surface of graphitized thermal carbon black were determined experimentally. The influence of the special features of the molecular structure of the adsorbates on the thermodynamic characteristics of adsorption was studied. The atom-atom approximation of the semiempirical molecular-statistical theory of adsorption was used to calculate the thermodynamic characteristics of adsorption of the adsorbates using the newly determined potential function parameters of pair intermolecular interaction (?(r)) of I with C atoms of the basal graphite face. For the example of isostructural monohalogenated benzenes, thiophenes, and adamantanes, a comparative analysis of the contributions of ...

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)

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

CERN Document Server

We present a HST/STIS spectroscopic and optical/radio imaging study of the Seyfert NGC 2110 aiming to measure the dynamics and understand the nature of the nuclear outflow in the galaxy. Previous HST studies have revealed the presence of a linear structure in the Narrow-Line Region (NLR) aligned with the radio jet. We show that this structure is strongly accelerated, probably by the jet, but is unlikely to be entrained in the jet flow. The ionisation properties of this structure are consistent with photoionisation of dusty, dense gas by the active nucleus. We present a plausible geometrical model for the NLR, bringing together various components of the nuclear environment of the galaxy. We highlight the importance of the circum-nuclear disc in determining the appearance of the emission line gas and the morphology of the jet. From the dynamics of the emission line gas, we place constraints on the ...

British Library Electronic Table of Contents (United Kingdom)

Abstract A facile and efficient single-step mineralization approach was exploited for achieving nanoscopic hydroxyapatite (HAP) crystal layer in chitosan porous matrix, wherein a mixed water-ethanol solvent was used to control the growth of minerals. The crystallographic structure, morphology, and mechanical properties of the scaffold were analyzed with XRD, FTIR, environmental scanning electric microscopy (ESEM), TEM, and compression tests. The behaviors and responses of MC3T3-E1 pre-osteoblast cells on the scaffolds were studied as well. The results showed that the scaffolds kept woodpile structure with predefined and controlled hierarchical structure after mineralization. The inorganic phase in the mineralized chitosan scaffolds was determined as pure rod-like HAP, which settled densely...

Energy Technology Data Exchange (ETDEWEB)

The crystal structure of Ca{sub 2}RuD{sub 6} has been determined by neutron powder diffraction: space group Fm3m, K{sub 2}PtCl{sub 6} structure, as found for other hexahydride salts of group 8 metals with alkaline earth or lanthanide counter ions. No structural phase transition was observed between 340 K and 50 K. The deuterium nuclear quadrupole coupling constant, 54.7 kHz, leads to an ionic character of the Ru-D bond of 76%. The known trends in the behaviour of A{sub 2}MH{sub 6} salts are interpreted in terms of the ionization energies of the cation and the central metal atom.

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

British Library Electronic Table of Contents (United Kingdom)

Plasma polymerization of aniline is carried out in a radiofrequency plasma reactor and the effect of polymerization time is examined in the structural, optical and optoelectronic properties of deposited films. Conjugated structures of polyaniline like films are obtained with unique and broad optical absorption band in the ultraviolet and entire visible region. The width of the absorption band increases and hence the optical band gap decreases with polymerization time. The optical constants are extracted by Swanepoel method and the optical dispersion parameters are determined by employing the Wemple-DiDomenico single oscillator model. The films exhibit similar thermal stability in air and argon atmosphere in the region of interest for optoelectronic applications. The photoluminescence study...

British Library Electronic Table of Contents (United Kingdom)

In this work the DC and AC characteristics for metal-LB film-metal structures deposited by a standard Langmuir-Blodgett film deposition technique are investigated. The conduction mechanism has been studied for a thin film structure in which a calix[4]arene substituted with carboxylic acid groups has been deposited alternately with a calix[4]arene molecule substituted with amine groups. This LB film structure shows a typical insulating behaviour for low voltage values and the Schottky effect becomes dominant when the voltage increases. The conductivity at low voltage values was found to be 1.34x10^-^1^3Scm^-^1. The height of the potential barrier was determined to be 1.65eV for this alternate layer LB film system.

Science.gov (United States)

Course website from Cambridge on ceramic materials. This site contains eight lectures in PDF format (Adobe Reader required), two question sheets, five practicals (including answers), digital movies and further useful links. "There is a strong relationship between the structure of a material and its physical properties. The properties of a material whether mechanical, electrical, optical or magnetic, determine how it can be used in practical applications. In this course, the focus is on the structure / property relationship for ionic materials with electrical properties utilised in various transducer devices. The materials considered include perovskites, which have special polarisation properties exploited in ferroelectric, pyroelectric and piezoelectric devices. Other oxides, such as zirconia, have structures permitting rapid diffusion of ions, making them suitable for use in sensors, fuel cells and ...

International Nuclear Information System (INIS)

A review of tests on earthquake-resistant reinforced concrete structural walls is presented. Laboratory tests of isolated walls and construction joints are discussed. Where appropriate, design recommendations are given. The review indicates only few experimental data are available for short walls which are directly applicable to nuclear power plant design. In particular, tests of short rectangular walls subjected to load reversals are needed. Tests are also needed to determine the damping and frequency characteristics of cracked short walls. Analytical and experimental results should be correlated so that the hysteretic response observed in tests can be realistically related to the analytical response 'demand' of nuclear power plant structures. (Auth.).

International Nuclear Information System (INIS)

Full text: A novel protocol based on electrospray ionization (ESI) multiple stage high capacity ion trap (HCT) mass spectrometry (MS) was developed for glycosphingolipidomic surveys. The method was optimized for detailed structural elucidation of human brain gangliosides and particularly applied to human hippocampus-associated structures. The multiple stage MS experiments allowed for a complete structural characterization of GM1 ganglioside species, which was achieved by elucidation of the oligosaccharide sequence, identification of the GM1 a structural isomer from the data upon sialic acid localization along the sugar backbone and determination of the d18:1/18:0 of fatty acid/sphingoid base composition of the ceramide moiety. The methodology developed here is of general practical applicability for glycolipids and represents a step forward in the implementation of the advanced and ...

International Nuclear Information System (INIS)

The crystal structure of the compound Sm_4Pd_4Si_3 was determined by the single-crystal method (KM-4 automatic diffractometer, Mo K#alpha# radiation). Sm_4Pd_4Si_3 has the monoclinic Nd_4Rh_4Ge_3 type structure: space group C2/c, mC44 (No. 15), a=20.693(6), b=5.584(1), c=7.699(2) A, #beta#=109.48(3) , V=838 A"3, Z=4, #mu#=36.23 mm"-"1, R_F=0.0537, R_W=0.0435 for 1652 unique reflections. The coordination numbers of samarium atoms are 17 and 18. For palladium and silicon atoms icosahedra and trigonal prisms with additional atoms are typical as coordination polyhedra. The structure of Sm_4Pd_4Si_3 is composed of fragments of the YPd_2Si and Y_3Rh_2Si_2 structure in a ratio 1:1. (orig.).

Energy Technology Data Exchange (ETDEWEB)

The atomic structure of [001] tilt grain boundaries of {Sigma}5 (210), {Sigma}5 (310), {Sigma}13 (320) and {Sigma}17 (410) in TiO{sub 2}(rutile) were studied using high resolution electron microscopy and computer simulation. Regularly separated small steps (1/2 [120] high) and big steps (3/2 [120] high) which contain secondary dislocations were found in the (210) boundary as a result of deviation from the exact {Sigma}5 misorientation and (210) symmetric plane. Similar steps were also found in (310) and (320) boundaries. Flat segments between the steps were found to have very accurate misorientation of the {sigma}`s and a nearly symmetric boundary plane. Their rigid body translation, volume expansion and relaxed structures were determined by comparing HRTEM images with computer calculated structures and simulated images. An irregular core structure was found in the (410) boundary ...

CERN Document Server

Strong gravitational lensing of an extended object is described by a mapping from source to image coordinates that is nonlinear and cannot generally be inverted analytically. Determining the structure of the source intensity distribution also requires a description of the blurring effect due to a point spread function. This initial study uses an iterative gravitational lens modeling scheme based on the semilinear method to determine the linear parameters (source intensity profile) of a strongly lensed system. Our 'matrix-free' approach avoids construction of the lens and blurring operators while retaining the least squares formulation of the problem. The parameters of an analytical lens model are found through nonlinear optimization by an advanced genetic algorithm (GA) and particle swarm optimizer (PSO). These global optimization routines are designed to explore the parameter space thoroughly, mapping model degeneracies in ...

International Nuclear Information System (INIS)

The band offsets and subband levels in a double quantum well layer for a 660 nm-Ga_0_._4In_0_._6P/(Al_0_._5Ga_0_._5)_0_._5In_0_._5P quantum well laser are determined by photoreflectance using a 410 nm InGaN laser with current modulation at room temperature. The subband levels are analyzed by numerical calculation of the Schroedinger equation for the layer structure by varying the conduction band offset and compared with the measured photoreflectance spectra. The conduction band offset ratio is determined to be 0.5+0.03. (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

International Nuclear Information System (INIS)

The nine title compounds were prepared from the elements by arc-melting and subsequent heat treatment in resistance and high-frequency furnaces. The crystal structure of these isotypic compounds was determined for YPdSi from single-crystal X-ray diffractometer data: Pmmn, a = 430.8(1) pm, b = 1391.2(1) pm, c = 743.1(1) pm, Z = 8, R = 0.024 for 417 structure factors and 40 variable parameters. The crystal structures of the isotypic compounds GdPdSi and ErPdSi were also refined from single-crystal data. The structure is of a new type. It consists of condensed, six-membered rings of alternating palladium and silicon atoms with Pd-Si bond distances varying between 249.6 and 258.8 pm. These two-dimensionally infinite nets are connected to each other via weak Pd-Si and Si-Si bonds with bond distances of 276.3 and 259.5 pm. The rare earth atoms are situated above and below the six-membered ...

International Nuclear Information System (INIS)

The mechanism proposed by Kormendy (1984) for the formation of counterrotating cores in elliptical galaxies is investigated using self-consistent numerical simulations of mergers between a high- and a low-luminosity elliptical galaxies. The conditions for a counterrotation to appear are determined, observational properties of the remnants are described, and the evolution of the structural and kinematic parameters of the larger galaxy is analyzed. It is shown that a counterrotation results only when the merging orbits are retrograde, due to a large change in the secondary spin during the merger. 36 refs.

CERN Document Server

We determine the structure of the total homology groups of exotic Springer fibers as affine Weyl group representations. As applications, we provide single top/socle property of standard modules in the exotic Deligne-Langlands correspondence (except for root of unity case), an analogue of Verma's theorem, the coincidence of analytic/geometric gradings in the $C ^{\\infty}$-realization of anti-spherical modules of graded Hecke algebras of type $\\mathsf{BC}$ with unequal parameters, among others.

Energy Technology Data Exchange (ETDEWEB)

The mass-energy spectra of the fragments of thermal fission of {sup 242m}Am are measured using the time-of-flight technique. The resulting mass-yield curve and peak-to-valley ratio agree with radiochemical data. The parameters of the kinetic energy distribution of the fragments are determined for the first time. Data on the fine structure of mass spectra in the region of cold fragmentation are presented. 15 refs., 4 figs.

International Nuclear Information System (INIS)

The research of the CELLO collaboration is reviewed. After a description of the CELLO detector tests of QCD and hadronic final states by determination of the strong coupling constant and studies of inclusive production of electrons and muons in multihadronic events in e"+e"- annihilation are described. Then studies of deep inelastic e#gamma# scattering with lepton pair production and the study of the structure function of the photon are briefly described. Finally studies on QED processes are described together with tau decays. (HSI).

British Library Electronic Table of Contents (United Kingdom)

The interaction between gravity convection and Marangoni convection in a horizontal rectangular channel filled with a liquid containing a surfactant and a drop of another liquid is numerically investigated. For large Schmidt numbers the occurring oscillatory regime of solutal convection is analyzed. In the model with a surface phase the effect of the adsorption and desorption processes on the convective flow structure is determined. The corresponding initial and boundary value problem is solved using a difference method.

Science.gov (United States)

A method is described to smear extremely thin layers of nuclear emulsion on labeled electron microscope preparations and to measure the thicknesses of these layers, Without further separation, preparation and emulsion can be observed after exposure and development in an electron microscope. The source of the tracks formed in the emulsion can be exactly identified and the size and structure determined. This method finds applications in dust research and also in the analysis of medical and biological sections. Further information can be obtained about properties of different emulsions. (auth)

Energy Technology Data Exchange (ETDEWEB)

The hyperfine structure of Am atoms was investigated in an atomic beam by laser spectroscopy. The observed splittings were evaluated with respect to the magnetic dipole and electric quadrupole moments of /sup 242m/Am. The results are: ..mu../sub I/(/sup 242m/Am) = +0.97(5) nm, Q(/sup 242m/Am) = +6.5(2.0) b.

International Nuclear Information System (INIS)

We present a study of the crystal field in PrNiAl, NdNiAl, ErNiAl and ErCuAl intermetallic compounds based on inelastic neutron spectroscopy. These compounds crystallize in the ZrNiAl-type hexagonal structure with an orthorhombic symmetry on rare-earth sites. The results are compared with the specific-heat data, and the lower parts of the crystal-field energy-level schemes are determined. (orig.)

International Nuclear Information System (INIS)

Power devices such as MOSFETSs and IGBTs, include parasitic structures that can give rise to destructive failures such as breakdown and latch-up. To determine a suitable strategy for device radiation hardening, simulation software like MEDICI-2D can be used to model the effects of technological modifications and device parameters that are difficult to measure experimentally. (authors).

International Nuclear Information System (INIS)

The electronic structure of UPd_3 has been determined by means of XPS and BIS experiments. The core level line shapes and the valence band spectra of occupied and empty states clearly reveal the localized character of the 5f electrons in this actinide compound. From these spectra their Coulomb correlation energy is found to be about 2 eV. (author).

Energy Technology Data Exchange (ETDEWEB)

This report describes the geology of the following 5 Alberta Foothills/Mountains coal zones: the Kootenay, Gething, Gates, Brazeau and Coalspur coal zones. The coal areas were assessed for gas content and compared with previous coalbed methane (CBM) exploration in the area. The coal zones can be divided into shallow (less than 1000 m depth) and deep (greater than 1000 m depth) coal zones for evaluation purposes. The potential gas content of the shallow coal zones is approximately 31 Tcf of CBM. This is considered an inferred, initial, in-place, CBM resource estimate based on limited data. The gas content of deep zones is approximately 99 Tcf of in-place CBM gas. Therefore, the total ultimate CBM resource is estimated at 130 Tcf. CBM recovery is not usually attempted due to high drilling costs and low permeability. The only CBM production from the Foothills has ...

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 ...

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`` is close to a ...

Energy Technology Data Exchange (ETDEWEB)

Recent work on the St. Louis Limestone in southwestern Kansas has demonstrated that these units contain a significant eolian facies component (up to 80-90% of total unit thickness). Reservoir intervals within the St. Louis are confined to relatively thin subtidal grainstones that, in turn, are capped by a muddy carbonate and shale facies. Critical to exploration and development of these grain-shoal reservoirs is an understanding of their spatial and stratigraphic distribution. Core through the St. Louis and St. Genevieve limestones has been examined and features have been recognized at the top of the eolianites. These surfaces are interpreted as long-term exposure surfaces. The contact between the subtidal grainstone shoals and the overlying muddy carbonate and shale facies is relatively sharp and is interpreted as representing a flooding surface separating shoal from muddy-open shelf facies. In the St. Louis Limestone, the subtidal carbonate grainstone reservoir intervals consist of ...

International Nuclear Information System (INIS)

In the summer of 1990, an accidental spill from the TA-3 Power Plant Environment Tank released more than 3,785 liters of sulfuric acid into upper Sandia Canyon. The Biological Resource Evaluation Team (BRET) of EM-8 at Los Alamos National Laboratory (LANL) has collected aquatic samples from the stream within Sandia Canyon since then. These field studies gather water quality measurements and collect macroinvertebrates from permanent sampling sites. An earlier report by Bennett (1994) discusses previous BRET aquatic studies in Sandia Canyon. This report updates and expands Bennett's initial findings. During 1993, BRET collected water quality data and aquatic macroinvertebrates at five permanent stations within the canyon. The substrates of the upper three stations are largely sands and silts while the substrates of the two lower stations are largely rock and cobbles. The two upstream stations are located near outfalls that discharge industrial and sanitary waste effluent. The third ...

Science.gov (United States)

The visible absorption spectra of 1,4-(dihydroxy)-9,10-anthraquinone and of Co(II), Ni(II), Cu(II) and Zn(II) chelates have been studied in different organic solvents. This system provides a model for the anthracycline antibiotics and their metal chelates. The band structure of the spectrum has been determined using the second and fourth derivatives of the spectrum. The visible absorption band of the parent molecule can be assigned to a single electronic state with a reduced dipole moment in the excited state; structure in this band is ascribed to two overlapping vibrational progressions. In contrast, the dianion (hydroxy protons removed) shows a single electronic state with an increased dipole moment in the excited state; structure in this band can be assigned to a single vibrational progression. All of the metal chelates show spectra which are similar in appearance to that of the dianion although the ...

Science.gov (United States)

The identification and characterization of carbonaceous materials (CMs) that control hydrophobic organic chemical (HOC) sorption is essential to predict the fate and transport of HOCs in soils and sediments. The objectives of this paper are to determine the types of CMs that control HOC sorption in the oxidized and reduced zones of a glacially deposited groundwater sediment in central Illinois, with a special emphasis on the roles of kerogen and black carbon. After collection, the sediments were treated to obtain fractions of the sediment samples enriched in different types of CMs (e.g., humic acid, kerogen, black carbon), and selected fractions were subject to quantitative petrographic analysis. The original sediments and their enrichment fractions were evaluated for their ability to sorb trichloroethene (TCE), a common groundwater pollutant. Isotherm results and mass fractions of CM enrichments were used to calculate sorption contributions of ...

Energy Technology Data Exchange (ETDEWEB)

The sol-gel-immobilized Tris(2,2'-bipyridyl)ruthenium(II) [Ru(bpy){sub 3} {sup 2+}] electrogenerated chemiluminescence (ECL) sensor was applied to the reversed-phase high-performance liquid chromatography (HPLC) determination of phenothiazine derivatives (promazine, chlorpromazine, triflupromazine, thioridazine, and trifluoperazine) and erythromycin in human urine samples. In this method, Ru(bpy){sub 3} {sup 2+} was immobilized in sol-gel-derived titania (TiO{sub 2})-Nafion nanocomposite films coated on a dual platinum electrode. This method eliminates an extra pump needed for the delivery of Ru(bpy){sub 3} {sup 2+} reagent into a reaction/observation zone in front of photomultiplier tube because the immobilized-Ru(bpy){sub 3} {sup 2+} is recycled on the electrode surface by an applied potential at +1.3 V versus Ag/AgCl (3 M NaCl) reference electrode. The resulting analytical performances such as detection limit, working range, ...

Energy Technology Data Exchange (ETDEWEB)

The overall goal of the proposed project is to explore the use of partitioning tracers to characterize dense nonaqueous phase liquids (DNAPLs) in aquifer systems. Bulk-phase partitioning tracers will be investigated to detect and determine DNAPL saturation, while interface partitioning tracers will be investigated to measure the area of the DNAPL-water interface. The specific objectives that will be addressed to accomplish this goal are: (1) Investigate the use of partitioning tracers to detect and determine both the saturation and interfacial area of DNAPLs in saturated porous media. (2) Investigate the effect of rate-limited mass transfer on the transport behavior of partitioning tracers. (3) Investigate the effect of porous-media heterogeneity on the transport behavior of partitioning tracers. (4) Develop and evaluate mathematical models capable of simulating the transport of partitioning tracers in complex systems. This proposal outlines an ...

International Nuclear Information System (INIS)

An attempt was made for early quantitative assessment of the severety of an injury, using the nuclear acids (NA) content as a biochemical indicator. Sexually mature male rats with body mass 160-180 g were irradiated with doses 0.5, 1, 2, 4 and 8 Gy of "1"3"7Cs source. Uneven irradiation was achieved by shielding the abdominal-lumbar area with lead rings, measuring 2,5/50 mm. A 28-30% fall of the dose beneath the shielded zone was thus provided. Dose-dependent quantitative changes in Na content were determined on hours 24 and 72 within the range from 0.5 to 8 Gy and followed up until day 30 after irradiation with nonlethal (2 Gy) and lethal (8 Gy) doses. The total NA content in the leucocytes was determined by the method of Kritski and Aleksandrov. The uneven irradiation of rats within the 0,5-8 Gy range induced early dose-dependent changes in NA content. The nature of their post-irradiation dynamics also depended on the ...