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 ...
The paper presents cloud structure models for Jupiter's Great Red Spot, Equatorial and North Tropical Zones, North and South Temperate Zones, and North and South Polar Regions. The models are based on images of Jupiter in three methane bands and nearby continuum radiative transfer calculations include multiple scattering and absorption from three aerosol layers. The model results include the transition in the upper-cloud altitude to 3 km lower altitude from the tropical zones to temperate zones and polar regions, a N/S asymmetry in cloud thickness in the tropical and temperature zones, and the presence of aerosols up to about 0.3 bar in the Great Red Spot and Equatorial Zone. It is concluded that polarization data are sensitive to aerosols in and above the upper cloud layer but insensitive to deeper cloud ...
Morphological, Electrophysiological and Behavioral Investigations of the Nervous Tissue Developed from the Embryonic Matrix Zone Cells of the Dorsolateral Walls of Lateral Ventricles, Implanted into the Lesioned Regions of the Adult Rat's Brain
Mexico is located in a transition zone between the Nearctic and Neotropical biogeographical regions and contains a rich and unique biodiversity. A total of 496 Bacillus thuringiensis...Full Text Available
Equilibrium and energy equations have been developed in describing the solid-fluid transition zone during the melting and solidification of the binary alloys. Due to the existence of the transition region exhibited both solid and fluid phases at the same material point from continuum point of view, mixture theory was utilized to analyze the region. Unlike the Stefan problem, the latent heat due to the phase change appears as a source term in the heat equation. The molten fluid is treated as a thermoviscous and incompressible fluid, whereas the solid is thermoviscoplastic described by the Bodner-Partom/Walker type of constitutive equations. Thermal mechanical behaviors of the solid and the fluid phases are determined separately because of insignificant mechanical interactions between them. Volume fractions of the phases are obtained according to the equilibrium phase diagram. The simulation process of the transition ...
We explored ways of doing spatial search within a relational database: (1) hierarchical triangular mesh (a tessellation of the sphere), (2) a zoned bucketing system, and (3) representing areas as disjunctive-normal form constraints. Each of these approaches has merits. They all allow efficient point-in-region queries. A relational representation for regions allows Boolean operations among them and allows quick tests for point-in-region, regions-containing-point, and region-overlap. The speed of these algorithms is much improved by a zone and multi-scale zone-pyramid scheme. The approach has the virtue that the zone mechanism works well on B-Trees native to all SQL systems and integrates naturally with current query optimizers - rather than requiring a new spatial access method and concomitant query ...
Temperature and concentration profiles of CO in a laminar, axisymmetric, premixed methane-air Bunsen flame are measured using line-of-sight diode laser absorption spectroscopy and computer tomographic (CT) reconstruction. Absorption spectra for P(20) (v=2<-1) and P(27) (v=1<-0) vibrotational transitions of CO were measured at 21 evenly spaced positions over a 1.33 cm span for a 1.3 cm radius flame. CT reconstruction algorithm was based on Fourier convolution. The tomographically reconstructed normalized transmission profiles derived from absorption spectra, in conjunction with a quantum mechanical model for vibrotational behavior of CO, yielded both temperature and concentration profiles. The Bunsen flame had 3 distinct zones: an inner rich-premixed flame zone, an outer non-premixed flame zone and an unburnt core region. The reconstructed temperature profile showed that the core ...
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 ...
The coal bed methane (CBM) potential of five coal zones (the Kootenay, Gething, Gates, Brazeau, and Coalspur) in the Alberta foothills and mountains is re-evaluated. For evaluation, the coal zones are divided into shallow (200 to 2500 m depth) and deep (over 2500 m depth). The total gas content is estimated. Recommendations on how to obtain more reliable resource data and about producibility are included. 41 refs., 12 figs., 3 tabs., 2 apps.
Transport and deposition of atmospheric lead over the coastal zone of Northern Germany are investigated. It is shown that marked differences in the impact of the ecologically valuable wadden sea areas can occur between summer and winter time. Due to the formation of sea breeze systems in summer the coastal zone is likely to be less stressed than in winter when the pollutant is confined to a shallow layer above ground. (orig.) 10 refs.
The reactor core of TAPP-3 and 4 is divided into 14 power zones for spatial power control. Corresponding to each zone is a light water zonal compartment. The 14 ZCCs are located in two radial planes, each containing 7 ZCCs. For each zone, power measurement is carried out using three cobalt Self Powered Neutron Detectors (SPNDs) at appropriate locations close to the respective ZCC. Since the zone power as obtained by the true average of the healthy zone control detector (ZCD) readings belonging to a particular zone may not correspond to its actual power because these 3 detectors per zone, measure only point fluxes but the zone extends over a large core region. Therefore accurate estimation of zone power calibration factors is required to estimate the zone ...
This work deals with the development of wind maps in the Venezuelan coastal zones (South America). The Navier-Stokes equations for real viscous incompressible flow are discretized via the finite element method and they are applied to a full 3D numerical model. Two regions were analyzed: the Margarita island and the Paraguana peninsula, both of them located in the Caribbean Sea at the North of Venezuela. These regions were modeled by using a three dimensional control volume, discretized through hexaedric eight-noded finite elements. Some wind maps obtained in this research are presented and discussed. (author)
The report is the second of three describing the geology of coal quality variations in the foothills and mountains region of Alberta. The Lower Cretaceous Luscar Group, Lower Paleocene Coalspur Formation, and the Upper Paleocene Paskapoo Formation (Obed-Marsh coal zone, which is classified as a foothills deposit) are evaluated. Data on proximate and ultimate analysis variables, calorific analysis, vitrinite reflectance, maceral analyses, and coal quality relationships are presented. The coals range from low volatile bituminous to subbituminous A. Regional and local in seam coal quality variations are examined. 49 refs., 39 figs., 6 tabs.
Coal is present in the Alberta Foothills/Mountains in five zones: the Kootenay, Gething, Gates, Brazeau and Coalspur coal zones. For coalbed-methane (CBM) evaluation purposes, they can be divided into shallow (less than 1000 m depth) and deep (greater than 1000 m depth) coal zones. The potential gas content of all shallow coal zones totals about 878x10{sup 9} m{sup 3} (31 Tcf) of CBM, which is considered an inferred, initial, in-place, coalbed-methane resource estimate based on limited data. The limited amount of data on formation testing and measured gas content indicate that the inferred resource is bordering on the speculative category. The gas content of all deep coal zones (deeper than 1000 m) totals 2.8x10{sup 12} m{sup 3} (about 99 Tcf) of in-place coalbed-methane gas. Consequently, the total ultimate coalbed-methane resource could be 3.7x10{sup 12} m{sup 3} (130 Tcf). ...
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 ...
The report shows that in Europe mountain regions, coastal zones, wetlands and the Mediterranean region are particularly vulnerable to climate change. Although there could be some positive effects, many impacts are likely to be adverse. Existing adaptive measures are concentrated in flood defence, so there is considerable scope for adaptation planning and implementation in other areas, such as public health, water resources and management of ecosystems. (au)
WC-Co hardmetals with gradient structure comprising neither -phase nor grain growth inhibitors were produced for the first time by regulating the WC re-crystallisation and carbon content in their near-surface layer and core. Hardmetals with low Co contents in the surface region were obtained by selective carburisation of the near-surface zone of green articles with the original low carbon content and their consequent liquid-phase sintering. The surface region of such gradient hardmetals has a hardness of up 150 Vickers units higher and fracture toughness significantly superior than those of the core. Gradient hardmetals with high Co contents in the surface region were obtained by selective decarburisation of the near-surface zone of green articles with the original high carbon content and ...
We study the emission zone in a single-layer polymer light-emitting diode. The emission zone is found by studying the angular distribution of the electroluminescence. The emission is modeled by accounting for optical interference. We account for birefringence of the anode layer in our model. The active polymer was, however, found to be isotropic. The anode consists of a single-layer of the conducting polymer complex poly(3,4-ethylenedioxythiophene) and poly(styrene sulfonate) (PEDOT-PSS), with enhanced conductivity. As a cathode we use plain aluminum. By using only PEDOT-PSS we avoid having a thin metal layer or indium-tin-oxide as the anode in the path of the escaping light. The active material is a substituted polythiophene with excellent film forming properties. A comparison between the experimental and calculated angular distribution of light emission from a single-layered polymer light-emitting diode was shown to be in good agreement for ...
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.
This is the introductory paper for eight papers that follow in this issue of Natural Resources Journal that were presented at a symposium on the titled subject. The editor notes that two movements in recent decades have been identified with coastal regions - efforts to conserve natural resources and energy source development - and that profound social, economic, and political ramifications have attended these movements. He further notes that the tensions and demands created by the above two developments proved too much for state and local mechanisms, eventually culminating in the Coastal Zone Management Act of 1972. He then briefly evaluates the focus and success of CZMA and reviews the other papers. 58 references.
Testimony at an April 30, 1980 hearing addressed whether to reauthorize or amend the Coastal Zone Management Act of 1978, specifically section 306, to further implement state programs and institutionalize state management of coastal zones. The text of the reauthorization bill (S. 2622) is followed by the statements of eleven witnesses and additional articles, letters, and statements submitted for the record. Witnesses are present for the fishing and oil industries, state and national governments, and public interest groups. Among the points brought out in testimony were that uniform standards are unwise - given the variety of coastal regions; and that there is a need to balance protection and development policies. (DCK)
In view of the situation that aging of boiler components proceeds and some `Type IV` cracking incidents are reported recently, the development of an accurate remaining life evaluation method for boiler weldment parts is an important subject for the utilities. In this study, simulated materials with coarse and fine grain microstructures in a weldment heat affected zone were produced, and their high temperature strength properties were evaluated. The strength property of the weld joint was also discussed based on the experimental and analytical results. It was found that the creep rupture strength of the fine grain material was as low as 1/2 of the base metal and as 1/5 of the coarse grain material, and the weld joint ruptured at the fine grain region in a shorter period than the base metal as the applied stress level decreased. Many grainboundary creep cavities were also observed in the fine grain region. A creep deformation ...
The most important kaolin deposits from Campo Alegre region (S C) were formed by the conjunction of at least one hydrothermal phase followed by many others weathering, supergenic, phases. Possibly deposits formed by only one of these processes exist, but these deposits shall be small and smaller than those mined today. Besides kaolinization, illitization/muscovitization and silicification, hydrothermalism also generated pyritized and propilitized zones, with quartz + chlorite. Together, hipogenic alterations related to kaolin deposits are very similar to alterations of high sulfidation epigenetic volcanogenic gold deposits. Most part of the biggest kaolin mines from the southern part of Campo Alegre Basin are distributed along a 13 Km long and 0,5 Km width bent zone that is parallel to structural alignments that point out the eastern Basin border. This zone was originated by deformation that has ...
Underground injection, compared to other waste disposal methods, is considered to have the advantages of isolating wastes in a confined brine aquifer well below the horizon of human activity and underground sources of drinking water (USDWs). While most of injected wastes move laterally in the injection zone, posing a long-term concern to the human health and environment, a small amount can migrate upward to the upper aquifers, causing a greater threat to the quality of USDWs. Both the dual porosity and the single porosity models were used to investigate the migration of injected wastes through these hydrologic conduits. The results indicate that regional upward migration through an extensive confining formation is a slow process. Nevertheless, injected wastes can move upward rapidly through microannuli and channels in the cement sheath and spread over a distance in the upper aquifer. The wastes can also migrate fast through fractures in the ...
Using the linearized augmented-plane-wave (LAPW) -calculated electron and positron charge densities for YBa_2Cu_3O_7, the Brillouin-zone-reduced electron-positron momentum density is computed and the zone-reduced two-dimensional angular correlation of annihilation radiation (2D ACAR) spectrum is produced. The calculations show that the relative weights of the Fermi-surface discontinuities are substantially altered due to the positron preferentially sampling the Cu-O chain region. In addition, the reduced 2D ACAR spectrum contains large k-dependent wave-function effects. The theoretical zone-reduced 2D ACAR spectrum is compared to the several existing experimental spectra. It is concluded that, at present, positron-annihilation experiments do not provide consistent and clear evidence for the existence and shapes of Fermi surfaces in YBa_2Cu_3O_7.
Calculations have been performed to study the dependence on model parameters of convectively heating the region interior to the core convection zone for core helium flash models. We find that interior heating always occurs on a time scale significantly shorter than the evolutionary time scale even at the peak of the flash.
The spatial connection between the zones of deep-lying faults and the narrowly-localized paleo-relief sections posessing an anomolous sedimentation condition in the latter Cretaceous is identified. It is established that this is of significance in choosing the primary regions for conducting oil exploration.
This 'Issues in Ecology' article from the Ecological Society of America provides information about the consequences of nutrient enrichment along the US coast. It describes problems such as harmful algal blooms (HABs), anoxia, hypoxia, and dead zones. It explains which nutrients are involved and describes implications of excess nutrients in regions such as the Gulf of Mexico/Mississippi River basin. The article features several color photographs, maps, and diagrams.
The metabolism of organic matter in the coastal regions of the ocean may significantly affect the oceanic carbon budget. This paper describes the high percentage (30%) of oceanic oxidation that occurs in coastal areas and the impact of this metabolism on the carbon cycle and climate of earth. Organic metabolism in the ocean appears to be a source of carbon dioxide release into the atmosphere. Oxidation in the coastal zone is of special interest, as it is likely influenced by anthropogenic activity. Recommendations for future research on this topic are proposed. 129 refs., 2 figs., 6 tabs.
The nonequilibrium Zeldovich-von Neumann-Doring theory of detonation in solid explosives is extended to include recent nanosecond and picosecond experimental and theoretical results on each of the four main regions of the reaction zone. The first region is the three-dimensional, Mach stem dominated leading shock front which excites the phonon modes of the explosive molecules in less than a picosecond. The second region is the multiphonon up-pumping process in which the excited phonons anharmonically couple to the low frequency (doorway) vibrational modes which in turn equilibrate with the higher frequency modes by internal vibrational redistribution. This process may require on the order of tens of picoseconds. The third region is the chemical reconstitution region in which the vibrationally equilibrated transition state decomposes in a series of chain reaction ...
The isotopic composition of Pd, Ag, Cd and Te has been measured by solid source mass spectrometry for four samples from reactor zones 2, 3-4, 5-6 and 7, and from four host rock samples external to the reactor zones from the Oklo mine site. The concentrations of these elements have also been determined in the eight samples using the stable isotope dilution technique. Cumulative fission yields have been derived from the reactor zone samples after correcting where necessary for the terrestrial component of the element concerned. It has been shown that fission-produced Pd and Te are retained almost in their entirety in the uraninite reactor zone samples, whereas a significant fraction of fission-produced Ag and Cd have migrated from the reactor zones. Fission product Cd is observed in the host rock samples, whereas no strong evidence of fission-produced Ag could be found. This the ...
Tensile specimens 60 ..mu..m thick of Ni-8 at. % Si have been bombarded at 475/sup 0/C to doses of 0.1 to 0.3 dpa with either 7 MeV proton or 28 MeV alpha particle beams. Deliberate embrittlement by high temperature (700/sup 0/C) preimplantation of helium was required to produce intergranular fracture. Depth profile sputtering and analysis in a Scanning Auger Microprobe was then used to study radiation-induced segregation of silicon both at the external surfaces and at internal interfaces. The external surfaces exhibited a strongly silicon-enriched zone for the first 10 to 20 nm followed by a broad (approx.200 nm), shallow silicon-depleted region. Segregation of silicon to grain boundaries varied from interface to interface and possibly from region to region on a given interface. In general, however, depth profiles of silicon content with distance from internal boundaries showed no noticeable depletion ...
Questions are examined of prospecting for nonanticlinical traps within North Sakhalin, their spatial distribution and evaluation of the outlook for oil and gas content. Traps of tapering and facial substitution on wings and periclines of local elevations, accumulative bar and erosion-accumulative channel are isolated. THe hypothesis is made that it is possible to form stratigraphic traps above the discrepancy and below it. It is noted that formation of zones of lithological tapering and facial substitution are associated with areas of the exchange of the sedimentation situation. The primary role of the shore and coastal zones in the formation of the examined types of nonanticlinal traps is established. The Okhino-Ekhabinskiy region in North Sakhalin is isolated as the primary object for prospecting for nonanticlinal traps.
The NACE MR-01-75 standard imposes a restriction of 22HRC maximum for regions of a pipeline girth weld that are not in direct contact with H[sub 2]S containing environments. TWI have demonstrated in an earlier project for the Pipeline Research Committee (PRC) that it may be permissible to relax this maximum hardness requirement. Such a relaxation, which already exists in the BS4515: 1984 standard, offers potential benefits when applied to the capping pass and heat affected zone of a pipeline girth weld. This report presents additional data to supplement that obtained in a previous PRC project conducted at TWI. Further pipe materials with differing pipe wall thicknesses have been welded, exposed to an internal H[sub 2]S containing environment and examined for sulphide stress corrosion cracking.
Regional Ocean Modeling System (ROMS v 3.0), a three-dimensional numerical ocean model, was previously enhanced for shallow water applications by including wave-induced radiation stress forcing provided through coupling to wave propagation models (SWAN, REF/DIF). This enhancement made it suitable for surf zone applications as demonstrated using examples of obliquely incident waves on a planar beach and rip current formation in longshore bar trough morphology (Haas and Warner, 2009). In this contribution, we present an update to the coupled model which implements a wave roller model and also a modified method of the radiation stress term based on Mellor (2008, 2011a,b,in press) that includes a vertical distribution which better simulates non-conservative (i.e., wave breaking) processes and ...
The biota of the Mississippi River in an ecological recovery zone near Red Wing, MN was studied before and after start-up of a nuclear plant to acquire baseline data and to estimate changes due to thermal addition. Thermal addition produced significant decreases in primary production in a plant region during summer month periods when water temperatures were near 36C. Extensive fisheries studies and sonar tagging/tracking of S. vitreum were performed. Comparison of fisheries results with other riverine, lake, and pond studies indicated a favorable environment for the success of the fish species studied. Qualitative macroinvertebrate surveys were conducted.
Electrical properties of 16 keV, focused-ion-beam (FIB) (beam diameter: 1 #mu#m, current density: 50 mA/cm"2) boron-implanted silicon layers have been investigated as a function of beam scan speed and ion dose, and compared with those obtained by conventional implantation (current density: 0.4 #mu#A/cm"2). High electrical activation of the FIB implanted layers is obtained by annealing below 800"0C as a result of the increase in amorphous zones created in the implanted layers. Amorphous zone overlapping is assumed to occur at FIB implantation doses of 3 - 4 x 10"1"5 ions/cm"2 from the results of electrical activation and the carrier profile of implanted regions annealed at low temperature, if beam scan speed is lowered to about 10"-"2 cm/s. (author).
A multi-zone computational model in conjunction with some engine tests are used to examine the combustion process of gas fueled diesel engines common known as dual fuel engine to provide information about details of the production of exhaust emissions, especially at light load when very lean mixtures are employed. Detailed chemical reaction kinetic simulation is employed for each of these individual combustion zones so as to establish the associated temporal variations in the concentrations of reacting species right to the exhaust stage. The influence of changes in major operating and design parameters such as the concentration of the gaseous fuel in the cylinder charge, intake temperature and the size of the diesel pilot fuel employed on the production of the exhaust emissions are examined. It is demonstrated in general that any measure that tends to increase the size of the combustion regions within the overly lean ...
A multi-zone computational model in conjunction with some engine tests are used to examine the combustion process of gas fueled diesel engines commonly known as dual fuel engine to provide information about details of the production of exhaust emissions, especially at light load when very lean mixtures are employed. Detailed chemical reaction kinetic simulation is employed for each of these individual combustion zones so as to establish the associated temporal variations in the concentrations of reacting species right to the exhaust stage. The influence of changes in major operating and design parameters such as the concentration of the gaseous fuel in the cylinder charge, intake temperature and the size of the diesel pilot fuel employed on the production of the exhaust emissions are examined. It is demonstrated in general that any measure that tends to increase the size of the combustion regions within the overly lean ...
The influence of extended convective mixing (overshoot) on asymptotic giant branch stellar evolution is investigated in detail. The extended mixing is treated time-dependently, and the efficiency declines exponentially with the geometric distance from the convective boundary. It has been considered at all convective boundaries, including the He-flash convection zone in the intershell region which forms during the thermal pulses. Both the structural and the chemical evolution are affected by the inclusion of overshoot. The main results include a very efficient third dredge-up which leads to the formation of carbon stars of low mass and luminosity. A C13 pocket which may serve as a neutron source for the s-process can form after the third dredge-up has reached into the C12 rich intershell. Overshoot applied to the pulse-driven convective zone during the He-flash leads to a deeper penetration of the bottom of this convective ...
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 ...
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 core (P less than ...
SummaryIntended Outputs: Documentation demonstrating an improved biophysical understanding of the role of forests on low flows in the arid zoneregions of India through the development and outputs from hydrological models such as Hyluc and SWAT.A documented analysis of the impacts on the poor of historical and current water management policies, including the investigation through PRA techniques of people's perceptions and beliefs of land-use/hydrological interactions, and the implications o [continued...]ObjectivesTo establish a better understanding of forest impacts on low flows and the social impact of water resources management in arid zoneregions of India, and to develop tools which allow this improved understanding to be disseminated directly to stakeholders.DescriptionProject Background: Reducing river flows and groundwater tables, especially during the dry season, constitutes a major problem ...
A fractographic and numerical approach is presented to analyze hydrogen-plasticity interactions in pearlitic steel and to elucidate the main hydrogen transport mechanism in this material under triaxial stress states produced by notches. Fractographic analysis showed that the microdamage produced by the hydrogen was clearly detectable by scanning electron microscopy (SEM), through a specific microscopic topography associated with hydrogen effects (tearing topography surface or TTS). Numerical computations obtained by using an elastic-plastic finite element program gave the progressive spreading of the plastic zone, closely associated with the movement of dislocations. In the majority of cases, the plastic zone (PZ) clearly exceeds the hydrogen affected region (TTS) and has no relation with it. In some tests, however, the hydrogen-induced micro-damage surpasses the only region in which there is ...
Low pressure silane plasmas are known for their ability to synthesize silicon nanoparticles via gas phase nucleation. While in the past this particle formation has often been considered from the viewpoint of a contamination problem in semiconductor processing, we here describe a silane low pressure plasma that enables the synthesis of highly oriented, cubic-shaped silicon nanocrystals with a rather monodisperse size distribution. These silicon nanocubes have successfully been used in the manufacture of single nanoparticle vertical transistors. We discuss the advantages of this new paradigm of building nanoelectronic devices. The plasma synthesis process is characterized in more detail than in prior work. The particle nucleation, growth and shape evolution are studied. Results indicate that the process provides two spatially distinct zones: a diffuse plasma for particle growth and a constricted plasma zone for particle annealing. Measurements of ...
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, ...
A modelling approach is presented that appears to have the potential to provide reliable assessments of pollution concentration in coastal zones and complex terrain, where the assumptions behind current operational air quality models often are inadequate. With the use of a numerical mesoscale model (NMM), physically consistent flow fields can be predicted, thereby providing higher spatial and temporal resolution in the meteorological fields than would be available from a limited number of observation points. These predictions are used to calculate mean trajectories of pollutant parcels, as well as to provide quantitative estimates of pollution concentration using two techniques.
For light water reactors, loss of coolant is an important point in safety analysis, whereas for gas-cooled reactors the ingress of water into the core region is an incident of safety relevance. The applicability of the computer code system GAMTEREX to pebble beds of spherical high-temperature gas-cooled reactor fuel elements with simulated water ingress is verified by experiment. The measurements were performed at a Siemens-Argonaut reactor, using its ring core as a driver zone for a pebble-bed core in the center of the reactor.
Uranium has varying degrees of oxidation (+4 and +6) and is responsive to changes in the redox potential of the environment. It is deposited at the reduction barrier with the participation of biota and at the sorption barrier under oxidative conditions. Iron (hydr)oxides are the strongest sorbents of uranium. Uranium, being an element of medium biological absorption, can accumulate (relative to thorium) in the humus horizons of some soils. The high content of uranium in uncontaminated soils is most frequently inherited from the parent rocks in the regions of positive U anomalies: in the soils developed on oil shales and in the marginal zone of bogs at the reduction barrier. The development of nuclear and coal-fired power engineering resulted in the environmental contamination with uranium....
A chronology for Paleocene strata of the Hinton area of west-central Alberta was developed from the integration of a magnetostratigraphic and palynostratigraphic study of the upper Coalspur and middle to upper Paskapoo strata in the Coal Valley to Obed Mountain area. The study resulted in the compilation of a complete section of 1100 m of strata with a maximum sediment accumulation rate of 250 m/m.y. Four new informal biostratigraphic units were used to highlight stratigraphically useful bioevents not previously recognized in existing zonations. These strata range in age from magnetochron 29r to 24r and palynozones Wodehouseia spinata Zone, Aquilapollenites reticulatus Subzone through the Pistillipollenite mcgregorii Zone. The 3 intervals with the most rapid changes in the palynoflora were the earliest Paleocene; the transition from the early to middle Paleocene; and in the late Paleocene. Each coincides with critical times in basin ...
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.).
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.).
Accurate prediction of tube surface temperature is important for determining whether accelerated superheater corrosion will occur in kraft recovery boilers. A heat transfer model, which combines an iterative numerical solution scheme with a more realistic flue gas flow field obtained from the CFD code FLUENT, has been developed to predict the tube, steam and flue gas temperatures in the superheater region. Results of tests performed for a recovery boiler show that temperatures predicted using the model are in good agreement with actual temperatures measured using thermocouples. The presence of a large flue gas recirculation zone above the bullnose is shown to have an adverse effect on the heat transfer in the superheater region. 9 refs., 12 figs., 1 tab.
An initial draft of an environmental and natural resource strategy for the Asia Near/East region in the 1990's is presented. The report contains five chapters. Chapter I provides an analytic framework that links natural resources, their extent, quality, and management with economic growth in the region. Chapter II contains a more detailed description and analysis of key resource problems that are restricting economic growth and have a severe negative impact on standard of living and quality of life. The most serious of these are soil and water degradation; destruction of natural forests, wetlands, and coastal zones; inefficient energy use and industrial pollution; and lack of environmental services. Chapters III and IV describe 20 specific opportunities for working toward sustainable economic growth through protection and enhancement of the natural resource base. Opportunities for action were chosen on the basis of ...
The primary goal of this project is to increase the availability and ease of access to critical data on the Mesaverde and Dakota tight gas reservoirs of the San Juan Basin. Secondary goals include tuning well log interpretations through integration of core, water chemistry and production analysis data to help identify bypassed pay zones; increased knowledge of permeability ratios and how they affect well drainage and thus infill drilling plans; improved time-depth correlations through regional mapping of sonic logs; and improved understanding of the variability of formation waters within the basin through spatial analysis of water chemistry data. The project will collect, integrate, and analyze a variety of petrophysical and well data concerning the Mesaverde and Dakota reservoirs of the San Juan Basin, with particular emphasis on data available in the areas defined as tight gas areas for purpose of FERC. A relational, geo-referenced database ...
A parallel event to the eleventh Conference of Parties (COP) to the United Nations Framework Convention of Climate Change was held to demonstrate examples of adaptation from around the world in the areas of food security, water resources, coastal zones, and communities/infrastructure. Panels on each theme presented examples from developing countries, countries in economic transition, and developed countries. These 4 themes were chosen because both mitigation and adaptation are essential to meeting the challenge of climate change. The objective of the event was to improve the knowledge of Canada's vulnerabilities to climate change, identify ways to minimize the negative effects of future impacts, and explore opportunities that take advantage of any positive impacts. This third session focused on how coastal communities are adapting to climate change in such places as Quebec, the Caribbean, and small Island States. It also presented the example of how a ...
The microstructure of Al/{alpha}-Al{sub 2}0{sub 3} composites made by infiltrating Al into dense mullite preforms has been characterized using transmission electron microscopy. Observations revealed that the formation of the Al/Al{sub 2}0{sub 3} composites involves three stages. Initially, Al infiltrates into a dense mullite preform through grain boundary diffusion, and reacts with mullite at grain boundaries to form a partial reaction zone. Then, a complete reaction takes place in the reaction region between the partial reaction zone and the full reaction zone to convert the dense mullite preform to a composite of {alpha}-Al{sub 2}0{sub 3} (matrix) and an Al-Si phase (thin channels). Finally, the reduced Si from the reaction diffuses out of the Al/Al{sub 2}0{sub 3} composite through the metal channels, whereas Al from the molten Al pool is continuously drawn to the reaction region ...
Estonia is rich in such renewable energy sources like wood, peat and wind. Wind energy potential is very high (up to 7 TWh) due to its geographical location. Wind potential could be efficiently used particularly on the western coast and on islands. Wider use of renewable energy sources would allow significant cutting of GHG emissions. Wind energy yield reaches up to 9000 MWh in West-Estonian Archipelago, 4000-8000 MWh in other coastal regions and up to 4000 MWh in inland areas per 2 MW wind turbine. In Estonian coastal regions (20 km wide zone along the 3800 km long coastline) there is 114 000 ha (7.9% of total area) open fields that are fully suitable for harnessing wind energy. Use of wind energy has been hindered so far mainly by a systematic under-capacity operation of two large oil shale power plants in Narva and weak power network system in coastal regions (orig.)
The developed electrical networks in the agricultural regions of the Estonian SSR make it possible to construct relatively powerful wind power plants at the sites of the most favorable wind conditions with small outlays for the power transmission lines. The wind power plant electricity can be used to electrify the production processes in agriculture, while the surplus can be supplied to the energy system. The inclusion of the wind power plants in the energy system makes it possible to improve the total generation of energy or reduce the consumption of fuel. With the efficient arrangement of the wind power plants, one can also reduce the energy losses during its transfer. Calculations indicated that in the coastal zones of the Estonian SSR, one can obtain specific power of 420-480 kW/km/sup 2/. For comparison it is indicated that the Estonian SSR in the agricultural regions now uses 8-12 kW/km/sup 2/. The wind-energy ...
The diffusion of Sb and B markers has been studied in vacancy supersaturations produced by MeV Si implantation in float zone (FZ) silicon and bonded etch-back silicon-on-insulator (BESOI) substrates. MeV Si implantation produces a vacancy supersaturated near-surface region and an interstitial-rich region at the projected ion range. Transient enhanced diffusion (TED) of Sb in the near surface layer was observed as a result of a 2 MeV Si{sup +}, 1 {times} 10{sup 16}/cm{sup 2}, implant. A 4{times} larger TED of Sb was observed in BESOI than in FZ silicon, demonstrating that the vacancy supersaturation persists longer in BESOI than in FZ. B markers in samples with MeV Si implant showed a factor of 10{times} smaller diffusion relative to markers without the MeV Si{sup +} implant. This data demonstrates that a 2 MeV Si{sup +} implant injects vacancies into the near surface region.
We consider a Mobile Ad-hoc NETwork (MANET) formed by n agents that move at speed V according to the Manhattan Random-Way Point model over a square region of side length L. The resulting stationary (agent) spatial probability distribution is far to be uniform: the average density over the "central zone" is asymptotically higher than that over the "suburb". Agents exchange data iff they are at distance at most R within each other. We study the flooding time of this MANET: the number of time steps required to broadcast a message from one source agent to all agents of the network in the stationary phase. We prove the first asymptotical upper bound on the flooding time. This bound holds with high probability, it is a decreasing function of R and V, and it is tight for a wide and relevant range of the network parameters (i.e. L, R and V). A consequence of our result is that flooding over the sparse and highly-disconnected suburb can be as fast as ...
The dynamical factors controlling the mean state and variability of the east Pacific intertropical convergence zone (ITCZ) and the associated cross-equatorial boundary layer flow are investigated using observations from the East Pacific Investigation of Climate (EPIC2001) project. The tropical east Pacific exhibits a southerly boundary layer flow that terminates in the ITCZ. This flow is induced by the strong meridional sea surface temperature (SST) gradient in the region. Away from the equator and from deep convection, it is reasonably well described on a day-to-day basis by an extended Ekman balance model. Variability in the strength and northward extent of this flow is caused by variations in free-tropospheric pressure gradients that either reinforce or oppose the pressure gradient associated with the SST gradient. These free-tropospheric gradients are caused by easterly waves, tropical cyclones, and the Madden Julian oscillation.Convergence ...
Simple correlations and corresponding nomographs are presented, which express the maximum useful heat received from salt-gradient solar ponds throughout the year or during a specified season of the year, and the corresponding optimum depth of the nonconvective zone in terms of the thickness of the upper convective zone and the temperature under which the maximum useful heat is received. The correlations are valid for the Athens (Greece) area or for regions with a similar climate, because solar radiation and ambient temperature values for Athens have been employed, obtained by a statistical process of hourly measurements over a period of about 20 years. For other climates, it is easy to develop similar correlations using the same methodology, Development of the proposed correlations is based on a method, which simulates the transient operation of the salt-gradient pond using finite-differences, and calculates the useful heat ...
Phosphoro-uraniferous deposit of Itataia is situated in Precambrian metamorphic terrains, into the litho-stratigraphic unit named Caico Complex. Regionally, the rocks are linearly folded, as a result of compressive tectonic that fits in the regmatic pattern. Rio Groairas' and Itatira's wrench faults form shearing couples in which the drag folds' climax are thrusting faults with axial plane dipping north. Uranium mineralization occurs into a phosphatic rock containing about 80% of collophane - 'collophanite - in association chiefly with marbles or feldsphatic rocks and gneisses. The ore (collophanite) occurs mainly as a stockwork, and it may be massive, (into big joints) or disseminated (impregnating the host rocks). Dark ore appears only in brecciated zones; it is richer in uranium content, but poorer in phosphorous. The highest grade ore is in a very fractured zone, associated to marbles. Supergene enrichment took place in ...
Microstructure characterization is important for controlling the quality of laser welding. In the present work, a detailed microstructure characterization by transmission electron microscopy was carried out on the laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft and an unambiguous identification of phases in the weldment was accomplished. It was found that there are {gamma}-FeCrNiC austenite solid solution dendrites as the matrix, (Nb, Ti) C type MC carbides, fine and dispersed Ni{sub 3} Al {gamma}' phase as well as Laves particles in the interdendritic region of the seam zone. A brief discussion was given for their existence based on both kinetic and thermodynamic principles.
Microstructure characterization is important for controlling the quality of laser welding. In the present work, a detailed microstructure characterization by transmission electron microscopy was carried out on the laser welding cast Ni-based superalloy K418 turbo disk and alloy steel 42CrMo shaft and an unambiguous identification of phases in the weldment was accomplished. It was found that there are #gamma#-FeCrNiC austenite solid solution dendrites as the matrix, (Nb, Ti) C type MC carbides, fine and dispersed Ni_3 Al #gamma#' phase as well as Laves particles in the interdendritic region of the seam zone. A brief discussion was given for their existence based on both kinetic and thermodynamic principles.
During the past few decades, the basic assumption of agroclimatic zoning, i.e., that agroclimatic conditions remain relatively stable, has been shattered by ongoing climate change. The first aim of this study was to develop a tool that would allow for effective analysis of various agroclimatic indicators and their dynamics under climate change conditions for a particular region. The results of this effort were summarized in the AgriClim software package, which provides users with a wide range of parameters essential for the evaluation of climate-related stress factors in agricultural crop production. The software was then tested over an area of 114,000?km2 in Central Europe. We have found that by 2020, the combination of increased air temperature and changes in the amount and distribution ...
Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak of precipitated dopants produced during high dose ...
Understanding the processes responsible for coastal change is important for managing our coastal resources, both natural and economic. The current scientific understanding of coastal sediment transport and geology suggests that examining coastal processes at regional scales can lead to significant insight into how the coastal zone evolves. To better identify the significant processes affecting our coastlines and how those processes create coastal change we developed a Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, which is comprised of the Model Coupling Toolkit to exchange data fields between the ocean model ROMS, the atmosphere model WRF, the wave model SWAN, and the sediment capabilities of the Community Sediment Transport Model. This formulation builds upon ...
Current scientific knowledge of climate change and its global impact is summarized in the first four chapters. The earth's natural climate, greenhouse gases, climate prediction models, and impact of a warmer world on natural terrestrial ecosystems, agricultural ecosystems, and coastal regions are discussed. The possible impacts on Canada are described in chapter five, which considers forests, agriculture, water resources, fisheries, coastal zones, transportation, human health and well being, energy production and use, and global security. Chapter six considers ways to respond to climate change. These include enhancing knowledge of climate change, working toward a consensus on the need for action, global political response, the Canadian response, and the role of the individual. 15 refs., 35 figs.
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 strike and have either down-to-the-west and ...
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 crustal xenoliths are ...
The effect of electron beam welding parameters on fusion zone (FZ) microstructure and porosity in a Ti-6.8 Al-3.42 Mo-1.9 Zr-0.21 Si alloy (Russian designation VT 9) has been investigated. It has been observed that the FZ grain width increased continuously with increase in heat input when the base metal was in the #beta# heat-treated condition, while in the #alpha# + #beta# heat-treated base metal welds, the FZ grain width increased only after a threshold energy input. The difference is attributed to both the weld thermal cycle and the pinning effect of equiaxed primary alpha on grain growth in the heat-affected zone (HAZ) of #alpha# + #beta# heat-treated base metal. Postweld heat treatment (PWHT) in the subtransus and supertransus regions did not alter the columnar grain morphology in the FZ, possibly due to the lack of enough driving force for the formation of new grains by the breaking up of the columnar grains and grain ...
The paleogeography postulated from the distribution of Permian and Triassic sedimentary rocks in the Middle East is shown and related to the paleostructure of the region. The Middle East region as defined here includes the Arabian Peninsula, Iran, Iraq, SE Turkey, Syria, Lebanon, Jordan, West Jordan, and the Sinai Peninsula. Within the limits of the area included in this study, a relatively stable pre-Late Triassic tectonic regime can be recognized and distinguished from a succession of diastrophic events of the Late Triassic epoch, which caused marked changes in the types and distribution of facies. Excluding NE Iran, the Middle East was stable from Late Cambrian to Middle Triassic times, as it formed a part of the Arabian Massif and much of the Middle East Platform, which is a broad shelf bordering the positive Afro-Arabian Massif to the NE and east. The sediments of this platform have undergone no strong deformation and have been subjected ...
Protoplanetary disks start their lives with a dust free inner region where the temperatures are higher than the sublimation temperature of solids. As the star illuminates the innermost particles, which are immersed in gas at the sublimation edge, these particles are subject to a photophoretic force. We examine the motion of dust particles at the inner edge of protoplanetary disks due to photophoretic drag. We find that, in a laminar disk, photophoretic drag increases the size of the inner hole after accretion onto the central body has become subdued. This region within the hole becomes an optically transparent zone containing gas and large dusty particles (>>10 cm), but devoid of, or strongly depleted in, smaller dust aggregates. Photophoresis can clear the inner disk of dust out to 10 AU in less than 1 Myr. At late times, the edge reaches a stable equilibrium between inward drift and photophoretic outward drift, at a ...
The microstructure of the secondary deformation zone (SDZ) near the cutting surface in metal chips of Ti-6Al-4V formed during machining was investigated using focused ion beam (FIB) specimen preparation and transmission electron microscopy (TEM) imaging. Use of the FIB allowed precise extraction of the specimen across this region to reveal its inhomogeneous microstructure resulting from the non-uniform distribution of strain, strain rate, and temperature generated during the cutting process. Initial imaging from conventional TEM foil preparation revealed microstructures ranging from heavily textured to regions of fine grains. Using FIB preparation, the transverse microstructure could be interpreted as fine grains near the cutting surface which transitioned to coarse grains toward the free surface. At the cutting surface a 10 nm thick recrystallized layer was observed capping a 20 nm thick amorphous layer.
State-of-the-art approaches for the calculation of gamma heating in LMFBR core, blanket and reflector regions have been evaluated, with particular emphasis on coupled neutron-gamma methods/cross section sets. The major source of calculational error was found to be the apparent failure to impose a mass-energy balance on total gamma energy yield from neutron capture and other interactions in the preparation of representative neutron-gamma cross section sets. The applicability of many simplifying assumptions was demonstrated, including: volume-weighted homogenization, insensitivity to the shape of the gamma-source-spectrum, gamma energy deposition equal to gamma energy source more than 10 cm inside large zones of uniform composition, and the negligible effect of bremsstrahlung. A simple one-group method was developed to permit rapid, accurate estimation of the large (factor of 2) changes in the gamma energy deposition-to-source ratio possible near ...
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...
Greenland is the world's largest island, with an area of 2.2 million square kilometres, 80 % of which is covered by the ice sheet. The climate is Arctic, but as Greenland stretches 2600 km from north to south, there is a huge variability in climate, with temperature decreasing from south to north. Due to the influence of oceanic currents, the west coast is slightly warmer than the east coast. Precipitation also decreases strongly from the south to the north, and also with distance from the coast. Kangerlussuaq is located in the dry, continental area of central west Greenland. The bedrock of Greenland is dominated by Precambrian gneisses, with sedimentary rocks occurring in some areas of East and North Greenland, and smaller areas of basalts. All of Greenland has been glaciated several times and has thus been eroded and shaped by the ice, as it still is at the ice margin. Soils are generally thin, and especially in the gneiss regions rather poor in plant nutrients. ...
This report describes the preliminary thermalhydraulic analysis of HTR-10 steady state full power initial core to provide a benchmark calculation of VHTGR(Very High-Temperature Gas-Cooled Reactors) safety analysis code of GAMMA(GAs Multicomponent Mixture Analysis). The input data of GAMMA code are produced for the models of fluid block, wall block, radiation heat transfer and each component material properties in HTR-10 reactor. The temperature and flow distributions of HTR-10 steady state 10 MW{sub th} full power initial core are calculated by GAMMA code with boundary conditions of total reactor inlet flow rate of 4.32 kg/s, inlet temperature of 250 .deg. C, inlet pressure of 3 MPa, outlet pressure of 2.992 MPa and the fixed temperature at RCCS water cooling tube of 50 .deg C. The calculation results are compared with the measured solid material temperatures at 22 fixed instrumentation positions in HTR-10. The wall temperature distribution in pebble bed core shows that the minimum ...
The report provides and overview of calculation models for the simulation of airflows and deals comprehensively with field and multi-zone models as well as the coupling of individual zone and multi-zone models. Examples of calculations are given. figs., tabs., refs.
Throughout the 1990's to year 2000, energy integration, and particularly natural gas integration, was seen as a major goal in the southern cone of South America. The regional perspective for energy was related to an even more challenging objective - Latin American economic integration, which was quickly moving forward by the constitution of Mercosur, the free trade zone built by Argentina, Brazil, Uruguay and Paraguay, and also having Bolivia and Chile as special partners. Mercosur was getting stronger and becoming a successful political project. Trade conflicts existed, but they were considered normal and nobody would disagree about the viability of Mercosur. By the beginning of the 21. century, the economic integration process in South America was already advancing timidly as compared to the impetus from the beginning of 1990's. Mercosur started facing complex and almost insurmountable challenges after the numerous global financial crises ...
Greenhouse-effect induced climate change repercussions will, via the catchment areas of big rivers, eventually arrive in amplified form at the far downstream coastal zones of the world. In the coastal zone these imported problems will add to the locally exerted climate change effects, while the climate change induced sea-level rise will attack the coastal zone from the other side, both by flooding and by saline groundwater intrusion. These multiple problems will hit the coastal zone, which is already under increasing stress. The combined threats require fast and massive support for national Coastal Zone Management capabilities, which could help to limit the damage and to support planning for sustainable development. Recommendations are presented to facilitate implementation of Coastal Zone Management units in all coastal countries by the year 2000.
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 ...
Large depositional oil traps (Priob, Sugmut, etc.) have been discovered in the West Siberian Neocomian. Sequence stratigraphic analysis of well logs and seismic reflection profiles demonstrate that reservoirs of these fields represent sands deposited during lowstand, transgressive and highstand phases of relative sea level cycles. Transgressions and regressions advanced in regional longitudinal and local latitudinal directions. The regional longitudinal pattern is dominated by westward prograding clinoforms formed as the sediment supply exceeded the accommodation space. Local northward and northwestward prograding complexes appear to be controlled by local basin-floor topography. In each systems tract, the coastal zones were landward from the shelf-breaks resulting in dominance of marine facies at each depositional shelf-edge. Lowstand systems tracts are represented on the upper slope by prograding wedges with thin shelfal ...
Computational transport models are described with applications in three problem areas related to unsaturated zone moisture movement beneath Area G. These studies may be used to support the ongoing maintenance of the site Performance Assessment. The three areas include: a 1-D transient analysis with average tuff hydraulic properties in the near surface region with computed results compared to field data; the influence on near surface transient moisture percolation due to realistic distributions in hydraulic properties derived statistically from the observed variance in the field data; and the west to east moisture flow in a 2-D steady geometry approximation of the Pajarito Plateau. Results indicate that a simple transient model for transport of moisture volume fraction fits field data well compared to a moisture pulse observed in the active disposal unit, pit 37. Using realistic infiltration boundary conditions for summer showers and for spring ...
Exploration for epithermal Au has been active lately in the Aegean Sea of the eastern Mediterranean Basin, both in the islands of the Quaternary arc and in those of the back-arc region. The purpose of this study was the structural mapping and analysis for a preliminary investigation of possible epithermal gold mineralization, using remotely sensed data and techniques, structural and field data, and geochemical information, for a specific area on the Island of Lesvos. Therefore, Landsat-TM and SPOT-Pan satellite images and the Digital Elevation Model (DEM) of the study area were processed digitally using spatial filtering techniques for the enhancement and recognition of the geologically significant lineaments, as well as algebraic operations with band ratios and Principal Component Analysis (PCA), for the identification of alteration zones. Statistical rose diagrams and a SCHMIDT projection Stereo Net were generated from the lineament maps and ...
The purpose of this study was to compare a double freeze-thaw protocol to a triple freeze-thaw protocol for pulmonary cryoablation utilizing an in vivo porcine lung model. A total of 18 cryoablations were performed in normal porcine lung utilizing percutaneous technique with 9 each in a double- (10-5-10) and triple-freeze (3-3-7-7-5) protocol. Serial noncontrast CT images were obtained during the ablation. CT imaging findings and pathology were reviewed. No imaging changes were identified during the initial freeze cycle with either protocol. However, during the first thaw cycle, a region of ground glass opacity developed around the probe with both protocols. Because the initial freeze was shorter with the triple freeze-thaw protocol, the imaging findings were apparent sooner with this protocol (6 vs. 13 min). Also, despite a shorter total freeze time (15 vs. 20 min), the ablation zone identified with the triple freeze-thaw protocol was not ...
This book summarizes the research that has been conducted in Canada over the past five years on the issue of climate change impacts on key sectors such as water resources, agriculture, forestry, fisheries, coastal zones, transportation, and human health and well-being. The book refers to the growing evidence that climate change is occurring. The Intergovernmental Panel on Climate Change (IPCC) believes that these changes have already contributed to increases in annual precipitation, cloud cover and extreme temperatures over the last 50 years. It suggests that it in order to develop an effective strategy for adaptation, it is necessary to understand the vulnerability of each sector to climate change in terms of the nature of climate change, the climatic sensitivity of the region being considered, and the capacity to adapt to the changes. Adaptation will require a reduction in greenhouse gas emissions in order to lower the rate of climate change. ...
A geological study was conducted to better understand the nature of cleat development and degree of mineralization in coal seams of the Scollard and Coalspur Formations in western Alberta. The results can be applied to equivalent formations. The source and reservoir rocks of a coalbed methane (CBM) system were described. Coal seams are basically fractured reservoirs with 7 types of cleats. The field work involved cleat minerals sampling and determining cleat attributes such as type, strike and spacing from open-cut mines and outcrops. The laboratory work involved X-Ray diffraction, scanning electron microscopy, energy dispersive microscopy, stable isotope analysis, and fluid inclusions analysis. The study showed that coal seams of the Scollard and Coalspur Formations are widespread and cleated to various degrees. The face and butt cleats strike northeast-southwest and northwest southeast respectively along the structural grain of the Laramide Orogeny. The major cleat mineral is calcite ...
Beta-21S is a new, metastable-beta titanium alloy which exhibits excellent oxidation resistance and mechanical properties at elevated temperatures. From a weld solidification standpoint, this alloy chemistry is of particular interest because its major beta-stabilizing elements (Mo and Nb) both exhibit equilibrium partitioning ratios (k_o) greater than unity, indicating their simultaneous partitioning during weld solidification to the initial solid to form (i.e., dendrite cores), and correspondingly their depletion in the final regions of solidification (i.e., dendrite interstices). Such elemental partitioning, if retained down to room temperature, may be expected to promote local variations in the postweld aging response. The objectives of the present investigation were to characterize Gas Tungsten-Arc weld solidification and HAZ liquation phenomena in Beta-21S and to examine the influence of residual microsegregation in the weld zone on alpha ...
The crystallite size and orientation in molybdenum films prepared by magnetron sputtering at a low rate of typical 1 (angstrom)s and a pressure of 0.45 Pa was investigated by X-ray diffraction and texture analysis. The surface topography was studied using atomic force microscopy. Increasing the film thickness from 20 nm to 3 microm, the films show a turnover from a (110) fiber texture to a (211) mosaic-like texture. In the early state of growth (20 nm thickness) the development of dome-like structures on the surface is observed. The number of these structures increases with film thickness, whereas their size is weakly influenced. The effect of texture turnover is reduced by increasing the deposition rate by a factor of six, and it is absent for samples mounted above the center of the magnetron source. The effect of texture turnover is related to the bombardment of the films with high energetic argon neutrals resulting from backscattering at the target under oblique angle and causing ...
In this work, a comprehensive model including heat transfer, fluid flow and solidification was used to evaluate the performance of a novel delivery system for a single-belt steel casting process. This near-net-shape casting, although still in development, is one of the most promising routes for casting of low-carbon steel in large scale. This paper focuses on the performance of a low-Re {kappa}-{epsilon} model that was employed to simulate the three-dimensional turbulent flows fully-coupled with heat transfer and macroscopic solidification. Simulations were run for the intended conditions of caster operation, and the results obtained with the {kappa}-{epsilon} were compared with the results obtained with an ad hoc viscosity model, where the molecular viscosity was boosted 100 times, uniformly throughout the computational domain. A semi-analytical solution was employed for validating the models and the results showed that the ad hoc viscosity model overestimated the thickness of the ...
The objective of the Coastal Habitat Injury Assessment study was to document and quantify injury to biota of the shallow subtidal, intertidal, and supratidal zones throughout the shoreline affected by oil or cleanup activity associated with the Exxon Valdez oil spill. The results of these studies were to be used to support the Trustee`s Type B Natural Resource Damage Assessment under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). A probability based stratified random sample of shoreline segments was selected with probability proportional to size from each of 15 strata (5 habitat types crossed with 3 levels of potential oil impact) based on those data available in July, 1989. Three study regions were used: Prince William Sound, Cook Inlet/Kenai Peninsula, and Kodiak/Alaska Peninsula. A Geographic Information System was utilized to combine oiling and habitat data and to select the probability sample of ...
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. ...
The stability of a forced-flow cooled superconducting coil is investigated by use of the numerical simulation. The numerical code to integrate the simultaneous partial differential system composed of the 1 D hydrodynamic equations and the 1 D thermal conduction equation has been developed and stability margins are evaluated as functions of coolant mass flow rate, operation current and imposed magnetic field. The results of computations show that the stability margin is multi-valued with respect to these operation parameters, as expected from the experimental results. It is also shown that the appearance of the first unstable regime is closely related to the existance of the stagnant region located at the upstream side of the heated zone and that the second stable regime appears because the heat transfer is appreciably enhanced by the induced backflow due to the thermal expansion of coolant. 13 refs., 13 figs., 1 tab.
We intend to solve equations governing turbulent plane-vertical isotherm and non isotherm jets by taking into account inflow conditions at the exit of the nozzle. The analysis is focused on the influence of these conditions on this type of flow. Two cases are considered (uniform and parabolic velocity and temperature profiles). A finite difference scheme is developed to solve the governing equations. This numeric model allows us to show that the region of fully developed regime begins much nearer the nozzle for the turbulent case than for the laminar flow case. Indeed, the turbulence increases the mixing between the incoming gas from the nozzle and the ambient fluid, and consequently the size of the potential core zone decreases. The results are compared to other works introducing mathematical variables based on the energy conservation for the case of the mixed convection and the momentum conservation for the forced convection, which allows the ...
Radiowave scintillation in the presence of ionospheric disturbances has the potential to disrupt numerous transionospheric radio and radar systems. This report describes development of a model characterizing the plasma density irregularities that produce scintillation in the naturally disturbed mid-latitude F layer. The model will be incorporated into Program WBMOD, which includes subroutines for computing both link geometry and scintillation indices, the latter by means of phase screen diffraction theory. Earlier versions of WBMOD, were based on extensive analysis of scintillation data collected in the auroral and equatorial zones in Wideband Satellite Mission. The model described herein is based on similarly extensive analysis of Wideband data from one mid latitude station and of data collected from HiLat satellite at another mid latitude station. The model describes irregularities at an effective height of 350 km that are isotropic across the geomagnetic field ...
Accurate modeling of the enhanced diffusion of boron during rapid thermal annealing has been accomplished by incorporating the effects of extended defect formation and annealing on enhanced diffusion into a multizone, semiempirical model. The multizone model divides the implant profile into three zones defining regions of different defects and diffusion enhancements. The model also contains the initial enhanced diffusion and the transient diffusion effects associated with the dissolution of defect clusters and the annealing of extended defects, respectively. The saturation time for transient-enhanced diffusion contains an exponential function of implant dose in order to model the increase in point defect generated with higher implant dose. As a result, the model accurately simulates the boron diffusion profile over a wide range of implant doses and also shows the immobile boron peak of precipitated dopants produced during high dose ...
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 ...
The report examines the scientific progress which has been made over the past years on the climate change issue. It examines shifts in emphasis on climate change debates and the implications of scientific uncertainty for the policy maker. Information on the impact of climate on various sectors, such as agriculture and coastal zones is also provided, as well as a case study on the UK. Regional impacts of climate change and associated economic implications are considered. The report also documents some different considerations for a climate change policy in the context of the latest meeting of contracting parties to the Un Framework Convention on Climate Change, held in Kyoto in December 1997. The report is divided into five sections: Introduction; Scientific progress; Climate change policy - the dilemma with implementation; Summary and conclusions; Summary of Kyoto`s results. 146 refs., 4 figs., 14 tabs., 2 apps.
Multiple treatment of engineering surfaces can provide improved surface properties that cannot be obtained by a single surface treatment. Consequently, this study investigates the effects of laser melting on the microstructures of plasma nitrided Ti-6Al-4V alloy. The study consists of two parts. In the first part, governing equations pertinent to the laser melting process are developed, and temperature variation across the melted zone is predicted. In the second, an experiment is conducted to nitride the surface of the alloy through plasma nitriding process and to melt the plasma nitrided and the untreated alloy surfaces with a CO2 laser beam. The resulting metallurgical changes are examined using x-ray diffraction (XRD), bdenergy-dispersive spectrometry (EDS), and scanning electron microscopy (SEM) techniques. It is shown that three distinct nitride layers are formed in the vicinity of the alloy surface prior to the laser melting process, and that after the ...
This document describes the contents of a digital climatological data set that may be used by raster or vector geographic information systems (GISs). The primary focus of the data set is the quantification of the occurrence of synoptic storms and other climatological factors that affect coastlines. However, recent demands for new and/or improved climatologies of storm events as well as an increase in the availability of source data have made it useful to extend the domain of most of the data variables to that of regional and/or global coverage. The expansion of the data makes the data set applicable in several areas of climatic research. The data set contains eight data groups. Spatial coverage of data varies by data group. All data groups except one are referred to 1{degree} {times} 1{degree} or 5{degree} {times} 5{degree} grid cells of latitude and longitude. (Data group (3) is referenced by state.) 19 refs., 12 figs., 26 tabs.
Tachycardia Detection, ICD, CRT-D Devices, Appropriate and Inappropriate Shock.-Introduction: We evaluated the frequency of appropriate and inappropriate shocks and survival in patients using dual-zone programming versus single-zone programming. Methods and Results: For the ALTITUDE REDUCES study, patients were followed for 1.6 1.1 years. The 12-month incidence of any shock was lower for dual-versus single-zone programmed detection at rates -170 bpm and between 170-200 bpm (P < 0.001). Appropriate shock rates at 1 year were also lower with dual-zone programming in these rate intervals (single zone 9.1%, 5.4%, P < 0.001, dual zone 6.7%, 4.7%, P < 0.02). There were no detectable differences between single- and dual-zone shock incidence at detection rates - 200 bpm (P = 0.14). Inappropriate s...
Tidally dominated sections from the Middle Jurassic Beryl Formation of the Beryl Field, Viking Graben (UKCS) were deposited during rapid changes in relative sea level. High density well coverage in this key producing interval has allowed the construction of an integrated high resolution sequence stratigraphic scheme based on sedimentological, ichnofaunal, wireline, biostratigraphic and engineering data. From this database a number of high resolution sequences in the Bajocian-Bathonian Beryl Formation have been identified composed of interbedded sandstones, siltstones and mudstones. These sediments formed tidally-influenced deltas and estuaries deposited in actively subsiding half-grabens during regionally extensive base-level changes. For reservoir management purposes, the formation has been split into 5 units. The thickest interval, Unit 3, is considered here. In the northern part of the Beryl Field, Unit 3 is bounded above and below by ...
Moisture profiles from neutron probe data provide valuable information in site characterization and to supplement ground water monitoring efforts. The neutron probe precision error (reproducibility) is found to be about 0.2 vol% under in situ field conditions where the slope in moisture content with depth is varying slowly. This error is about 2 times larger near moisture spikes (e.g., at the vapor phase notch), due to the sensitivity of the probe response to vertical position errors on the order of 0.5 inches. Calibrations were performed to correct the downhole probe response to the volumetric moisture content determined on core samples. Calibration is sensitive to borehole diameter and casing type, requiring 3 separate calibration relations for the boreholes surveyed here. Power law fits were used for calibration in this study to assure moisture content results greater than zero. Findings in the boreholes reported here confirm the broad features seen previously in moisture profiles ...
The Gulf of California represents one of the most productive and unique marginal seas in the world. The mouth of the Gulf captures warm equatorial water while annual wind patterns assure major upwelling of nutrient-rich water leading to a rich marine biota. These conditions have created a wide array of tropical through warm temperate carbonate environments. The most unusual of these environments is located in the La Paz region of Baja California Sur where tropical-subtropical water temperatures and low rainfall have allowed growth of corals, calcareous red algae, and other shelled invertebrates to form a carbonate bank environment. Sampling and mapping transacts in shallow bays north of La Paz and on the adjacent Espiritu Santo island have revealed a full spectrum of subenvironments including mangrove bordered, terrigenous mud dominated coastal zones, which grade into carbonate tidal flats. In addition, single coral heads as well as incipient ...
The effective fraction of delayed photoneutrons ({beta}{sup ph}) has been theoretically defined and experimentally determined in various different configurations of the LWR-PROTEUS critical facility. The peculiarity lies in the fact that the reactor has D{sub 2}O in only one of the four fuelled zones, thus D({gamma},n)H reactions take place mainly in this region. The work is divided into three parts. The first part is devoted to the description of the LWR-PROTEUS facility and to the measurements of {beta}{sup ph}. These experimental values are derived from standard inverse-kinetics analysis of neutron flux decay experiments for each of seven different configurations, with nine additional groups of neutron precursors to account for photoneutron effects. In the second part, the coupled neutron and gamma Boltzmann equations are reduced to exact point kinetics equations using the photon infinite-velocity approximation, and then to the point reactor ...
The main purposes of this research was to investigate the feasibility of incineration of wool-scouring sludge in a novel vertical-axis-rotating fluidised bed (RFB). The experiment was carried out in a RFB with an internal diameter (ID) of 200 mm and height of 50 mm. A cold test was first conducted to investigate the fluidization performance of the RFB via parameters such as the bubbling, gas distribution, bed shape and pressure drop. The tumbling phenomena was observed in the bed, and this effectively enhanced the axial mixing. The appropriate range of bed thickness, rotating speed and sand particle size were identified to ensure the full fluidization and reduce the particle elutriation. Four wool-scouring sludges from different processes were incinerated in the RFB. With 5% support methane, all sludges with a maximum moisture up to 70% as received could be successfully burned in the RFB at rotating speeds of 200 and 300 rpm. The combustion was found to be intense with a high ...
Selected case studies of auroral structure/activity observed at different local times on the dayside are presented and discussed in the context of electrodynamic coupling between the different magnetospheric boundary regions and the ionosphere. The first case addresses the question of the auroral signatures of the two boundary regions referred to as cusp and cleft/LLBL. Combined ground-based and satellite data reveal the different latitudinal zones of auroral forms/particle precipitation/field-aligned current and the relationship with the respective magnetospheric plasma populations, i.e. CPS, BPS, LLBL, and the plasma mantle. Midday auroral breakup events and the related ionospheric ion drift and magnetic observations show many of the features that have been predicted to be ionospheric signatures of flux transfer events. An alternative explanation that has been proposed by others, i.e. ionospheric effect of magnetopause ...
Timing and geometry of Maastrichtian third-order sequences and systems tracts of south-central Wyoming were mostly controlled by rapid basin subsidence resulting from thrust loading of foreland basin crust. The basement of the Red Desert/Washakie basin was affected by thrusting in the Sevier belt to the west and by thrusting along the edge of the Wind River Mountains and Granite Mountains. A transgressive systems tract consists of the youngest Ericson Formation above a regional unconformity, backstepping Almond Formation nearshore and nonmarine facies, and shelfal mudstones of the lower Lewis Shale. Regionally, the onset of transgression is younger from east to west, beginning at 71.5 Ma in eastern Wyoming and at 70.5-71 Ma in south-central Wyoming. The transgression culminated in a condensed shale section evident on gamma-ray logs that occurs throughout the basin. Above the gamma-ray zone, the highstand systems tract of ...
Hydrologic information is essential for environmental efforts at Los Alamos National Laboratory. Testing at new characterization wells being drilled to the regional aquifer (''R wells'') to improve the conceptual hydrogeologic model of the Pajarito Plateau is providing such information. Drilling has been by air-rotary casing-advance or open-hole methods. Most wells are completed with multiple screens. After their construction, wells were rigorously developed by wire-brushing, bailing, followed by surging, swabbing, or jetting, and finally by pumping. These methods are effective based on field-parameter measurements and comparison of results of hydrologic testing at well R-31 before and after complete well development. We conducted field tests on various zones of saturation penetrated by the R wells to collect data needed for determining hydraulic properties. This document provides details of the design and ...
This article aims to open up the biographical black box of three experts working in the boundary zone between science, policy and public debate. A biographical-narrative approach is used to analyse...Full Text Available
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
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.
KOREA-JAPAN NUCLEAR WEAPON FREE ZONE (KJNWFZ) CONCEPT PAPER ...A Korea-Japan2 Nuclear Weapon Free Zone (hereafter KJNWFZ) is a new concept.Once realized, ...Finally, we outline the key elements of the Korea-Japan NWFZ proposed in this paper, noting
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.
The destiny of the mitotically active cells of the subventricular zone (SVZ) in adult rodents is to migrate to the olfactory bulb, where they contribute to the replacement of granular and periglomerular...Full Text Available
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
Small-angle X-ray scattering method recognised to be very useful in the studies of structural problems of materials in homogeneous in nanoscale. Studies by small-angle X-ray scattering on the Al-Ag alloys are presented. The size distributions of spherical Guinier-Person zones were calculated using Vonk's and Glatter's methods. Small-angle X-ray scattering studies were performed on Al-5.0 at.%Ag alloy containing Guinier-Preson zones in the #eta#-state. For this alloy one can assume that scattering particles are of spherical shape, have uniform electron density and scatter independently. Moreover, the size distributions were calculated for Al-1.6 at.%Ag alloy containing Guinier-Preston zones in #epsilon#-state (scattering particles with not uniform electron density). Both, Vonk's and Glatter's, methods gave similar size distributions. Profiles of size distributions for Guinier-Preston zones in ...
The biological and radiobiological peculiarities of seeds and seedlings of the Rumex confertus and Lupinus polycolor plants, which grown during several generations in plots with different level of radionuclide pollution of the Chernobyl exclusive zone have been investigated.
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
Chronic autoimmune or pathogen-induced immune reactions resulting in lymphoid neogenesis are associated with development of malignant lymphomas, mostly extranodal marginal zone B-cell lymphomas (MZBCLs)....Full Text Available
...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 ...
In this review, we demonstrate the developmental appearance, structural features, and reorganization of transient cerebral zones and structures in the human fetal brain using a correlative histological and MRI analysis. The analysis of postmortem aldehyde-fixed specimens (age range: 10 postovulatory weeks to term) revealed that, at 10 postovulatory weeks, the cerebral wall already has a trilaminar appearance and consists of: (1) a ventricular zone of high cell-packing density; (2) an intermediate zone; (3) the cortical plate (in a stage of primary consolidation) with high MRI signal intensity. The anlage of the hippocampus is present as a prominent bulging in the thin limbic telencephalon. The early fetal telencephalon impar also contains the first commissural fibers and fornix bundles in the septal area. The ganglionic eminence is clearly visible as an expanded continuation of the proliferative ventricular ...
For years, the writing has been on the wall about the impact of climate change on the people, plants, animals, and habitats of Latin America and the Caribbean. Now, day-to-day experiences and eye-witness accounts from leading environmental and development groups are proving predictions to be correct. In the late 1990s, the world's pre-eminent group of climate scientists gathered under the Intergovernmental Panel on Climate Change (IPCC) and predicted a devastating range of impacts, including an increase in the intensity and number of extreme weather events exacerbating natural disasters, forest die-off, melting glaciers, and the drying out of temperate grasslands. The region's huge geographical diversity means that patterns of vulnerability to climate change are extremely varied. It also makes modelling difficult, although this is constantly improving. To avoid misunderstanding, it is important to point out that with or without global warming, ...
In the course of designing a catalytic porous membrane reactor for experimental studies, both inside and outside of the non-reaction zones as well as the two ends of the membrane need to be completely sealed to ensure that there is no flow across the membrane in the non-reaction zone. Experiments show that up to 50% of the total flow across the membrane may be contributed by the axial flow along the wall of the non-reaction zones if only one side of the membrane is sealed. Another problem that cannot be solved by sealing is the capillary flow of the catalyst along the tube wall into the non-reaction zones when the catalyst is doped on the membrane. One of the best ways to avoid this axial flow of catalyst would be to use non-porous tubes in the non-reaction zones and join them with the porous membrane tube. In doing so, the cost of the membrane reactor could be reduced simply ...
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 ...
Microstructure and properties of a Mg AZ31B laser beam weld without filler are studied using electron microscopy, X-ray diffraction and mechanical tests. The microstructure of the weld is characterized by a narrow heat affected zone, columnar grains and precipitate coarsening in the fusion zone. Texture in the fusion zone is significantly different from the texture of the base material. The residual stress distribution observed is similar at the top and the bottom of the weld, maximum tensile residual stress values are observed in the fusion zone. Tensile tests reveal differences in the mechanical behavior of the fusion zone and the parent material, which can be related to the differences of texture and the resulting deformation mechanisms.
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...
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 ...
The Wendelstein 7-X (W7-X) modular stellarator is under construction at the Max-Planck-Institut fuer Plasmaphysik in Greifswald, Germany. The W7-X magnet system contains 70 coils made up from helium cooled superconducting cables in aluminium alloy (EN AW-6063) jackets. Several hundred connections of the jacket to the cable joints are made by aluminium-to-aluminium welds. Due to geometrical and thermal boundary conditions these welds cannot be accomplished free from defects. Microscopic analyses of the welds show that a variety of small flaws such as cracks and pores develop during welding. The welds have thus to be dimensioned accordingly, and appropriate weld qualification, investigation and testing has to be done in order not to jeopardise the structural integrity and leak tightness. The weld is mechanically loaded during cool-down due to the difference in thermal contractions between the GRP insulation and the aluminium, and during operation by bending moments from electromagnetic ...
The Wendelstein 7-X (W7-X) modular stellarator is under construction at the Max-Planck-Institut fuer Plasmaphysik in Greifswald, Germany. The W7-X magnet system contains 70 coils made up from helium cooled superconducting cables in aluminium alloy (EN AW-6063) jackets. Several hundred connections of the jacket to the cable joints are made by aluminium-to-aluminium welds. Due to geometrical and thermal boundary conditions these welds cannot be accomplished free from defects. Microscopic analyses of the welds show that a variety of small flaws such as cracks and pores develop during welding. The welds have thus to be dimensioned accordingly, and appropriate weld qualification, investigation and testing has to be done in order not to jeopardise the structural integrity and leak tightness. The weld is mechanically loaded during cool-down due to the difference in thermal contractions between the GRP insulation and the aluminium, and during operation by bending moments from electromagnetic ...
The summertime tropical cyclogenesis rate per unit area in the eastern Pacific ocean is arguably higher than in any other location in the world. Many if not most of these cyclones form from African easterly waves which cross Central America into the Pacific. Of order 25% of these waves intensify into cyclones. A significant fraction of east Pacific tropical cyclones undergoes landfall on the Mexican coast. Those which do not, generally dissipate over cold ocean waters north of the east Pacific intertropical convergence zone, often not far from land. The layer of warm ocean water which supports the development of east Pacific cyclones is unusually shallow and is structured by anticyclonic vortices which form by various processes and propagate slowly to the west. These vortices locally deepen the oceanic mixed layer and support stronger convection than their surroundings, possibly promoting cyclogenesis and cyclone intensification. Cyclones in turn have an ...
The Pequop Mountains (PM), Wood Hills (WH) and East Humboldt Range (EHR), NE Nevada, provide evidence that the hinterland of the Sevier thrust belt experienced large-magnitude Mesozoic shortening ([>=]55 km) and crustal thickening ([>=] 30 km). These ranges expose a structurally continuous crustal cross section of unmetamorphosed to high pressure upper amphibolite facies Triassic to Precambrian miogeoclinal strata. This sequence lies structurally beneath unmetamorphosed extensional klippen that omit metamorphic grade and crustal section, but also repeat stratigraphic units. Because they repeat stratigraphic units, the underlying miogeoclinal section, or footwall, must have once lain beneath a thrust fault (herein named the Windermere thrust). The footwall of the Windermere thrust was exhumed by two generations of top-to-the-W-NW low-angle normal faults that are distinguished by whether they are depositionally overlapped by Eocene volcanic rocks or if they cut the volcanic rocks ...
Elastic and elasto-plastic modelling of indentation in CFRP cross-ply laminates has been performed. Detailed knowledge of the field solutions in the volume below the indentor forms the basis for the reported micromechanical interpretation of the observed damage in test specimens. The analysis shows that matrix cracks originate at sites of maximum tensile stress perpendicular to fibers. The predicted stress fields due to indentation show that stress concentrations occur in the interface between alternating plies. It is found that microcracking in this zone is a precursor to the observed failure. This analysis is supported by in-situ scanning electron microscopy during loading by a cylindrical indentor onto the laminate supported on a rigid substrate. The microscopy reveals microdamage in the region of interfacial tensile stress concentrations. The onset of indentation failure in these layered composites suggests that plastic interleaves would ...
A number of properties in steel components are detrimentally influenced when exposed to hydrogen environments. Under these conditions, atomic hydrogen is adsorbed on the steel surface, then absorbed and preferentially transported towards tri-dimensional stressed regions in the crystal lattice and into defects such as interfaces or dislocations. The hydrogen embrittlement susceptibility is strongly influenced by various microstructural parameters including the type of inclusions, steel composition and heat treating conditions. One of the alternatives employed in minimizing hydrogen embrittlement is the use of surface barriers for hydrogen permeation. In particular, the presence of surface nitride layers in steels can be considered as an effective barrier. Nitride steel surface layers can be produced by plasma nitriding with the concomitant benefits of improved surface hardness, as well as superior wear and fatigue resistance. Accordingly, in this work, the role of ...
The 66 fields discovered since the 1960s in the northern West Siberian basin contain at least 22 trillion m/sup 3/ (777 tcf) of proved gas, almost one-third of the world's reserves. Half of these fields are giants (> 85 billion m/sup 3/ or 3000 bcf of reserves). These include the largest and second-largest gas fields in the world-Urengoy (8.099 trillion m/sup 3/ or 286 tcf of gas) and Yamburg (4.81 trillion m/sup 3/ or 170 tcf of gas)-as well as most of the other ten largest gas fields in the world. The West Siberian basin occupies a 3.4-million km/sup 2/ (1.31-million mi/sup 2/) arctic lowland immediately east of the Ural Mountains, extending north under the Kara Sea. It is a composite basin, with Mesozoic-Cenozoic basin fill on top of a Paleozoic basin that overlies a crystalline Archean-Proterozoic framework. The productive zones in the northern basin are principally in the Neocomian section (at an average depth of 2800m or 9200 ft) and the ...
Findings indicate an urgent need to establish a monitoring program for persistent organic pollutants in water and sediment. - Marine culture is thriving in China and represents a major component of the regional economy in coastal zones, yet the environmental quality of many of those areas has never been studied. This paper attempts to investigate the quality status of Daya Bay, a key aquaculture area in China. The levels of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in water and sediment samples of the bay. The total concentrations of 16 PAHs varied from 4228 to 29325 ng l"-"1 in water, and from 115 to 1134 ng g"-"1 dry weight in sediments. In comparison to many other marine systems studied, the PAH levels in Daya Bay waters were relatively high, and at six sites they were sufficiently high (>10 #mu#g l"-"1) to cause acute toxicity. The PAH composition pattern in sediments suggest dominance by medium to high molecular weight ...
One of the Eddy Current Testing issues in aeronautics is the inspection of fastened structures to detect flaws nearby rivets which can grow because of mechanical stress. EADS and the CEA LIST have started a collaborative work with the support of the Ile-de-France Region to develop a simulation tool of EC fastened structures testing, integrated to the CIVA platform, aimed at conceiving testing methods, optimizing and qualifying it. The volume integral method using the Green dyadics formalism has been chosen in order to get a fast resolution of Maxwell equations. A first milestone was to build a simulation model of multilayer structures testing, thanks to the use of the multilayer Green dyads. Because of the rivet volume, 60 times bigger than the one of a typical flaw, a large number of discretization cells are needed. Therefore an iterative method has been developed in order to numerically solve large calculation zones. Finally, the flaw ...
Proposals for use of Alloy 800 as a H.T.R. boiler material have prompted studies of its creep and high temperature fatigue properties in impure helium with comparative tests in air. In impure helium, as expected in a H.T.R., reactions of potential importance are selective oxidation (of chromium, aluminium and titanium) and possibly carburisation from carbon monoxide or methane. In air, general oxidation will occur, possibly accompanied by nitridation. The effects of these reactions will depend on specimen geometry and the nature of the deformation. Two important possibilities are: (i) that environment affects the structure and properties of a surface zone of material undegoing uniform deformation (this may modify creep rate and crack nucleation); and (ii) that environment affects behaviour of a small region (e.g. at the root of a notch or ahead of a crack) in a specimen undergoing non-uniform deformation (this will modify crack growth and hence ...
Due to thermal gradients and load changes steam-turbine casings suffer combined creep-fatigue loading. Creep and fatigue portions depend on service conditions. Special interest is focused on the behaviour of creep-fatigue cracks, originated from potential defects due to construction and manufacturing weldments, on residual lifetime assessment. The project deals with the crack-growth behaviour at 530deg C and r.t. of welded and unwelded heat-resistant cast steels: 1% CrMoV-cast (GS-17 CrMoV 5 11, two melts: low and high V-content) and 12% CrMoV-cast (G-X 22 CrMoV 12 1). The crack planes of CT-specimens investigated, taken from manual arc-welded plates, were situated in the heat-affected zone (HAZ). The fatigue, creep and combined creep-fatigue crack-growth behaviour was investigated by means of low-frequency (0.5 and 0.05 Hz) tests, holding-time (20 min) tests and constant load tests up to about 5 000 h. Metallographic investigations show that in the case of both 1% ...
The coal rank, coal distribution, and coalbed methane of four major coal zones in the Hinton and Grande Cache areas of Alberta were investigated. Coal rank in the study area ranges from subbituminous and high volatile C bituminous at surface for the Upper Cretaceous/Tertiary coal measures and semianthracite for the Lower Cretaceous Luscar Group in the Alberta Syncline. In the Rocky Mountain Foothills, maximum cumulative coal thicknesses occur in the Smoky River, Cadomin-Luscar, and Coal Valley coalfields. Cumulative coal thicknesses generally decrease east of the deformed belt; however, coal isopach maps indicate local cumulative coal thicknesses in excess of 25 m. A regional coalbed methane assessment for strata east of the deformed belt shows favorable coalbed methane adsorption capacities in Luscar Group coals. These coals occur, however, at depth levels [gt]2500 m. In contrast, Brazeau and Coalspur Formation coals occur at favorable depth ...
This research is to provide improved strategies for enhanced oil recovery from the Tensleep Sandstone oil reservoirs in the Bighorn and Wind River basins, Wyoming. Because of the great range of API gravities of the oils produced from these reservoirs, the proposed study concentrates on understanding the spatial variation and anisotropy of relative permeability within the Tensleep Sandstone. This research will associate those spatial distributions and anisotropies with the depositional subfacies and zones of diagenetic alteration found within the sandstone. The associations of the above with pore geometry will link relative permeability with the dimensions of lithofacies and authigenic mineral facies. Hence, the study is to provide criteria for scaling this parameter on a range of scales, from the laboratory to the basin-wide scale of subfacies distribution. Effects of depositional processes and burial diagenesis will be investigated. Image analysis of pore systems ...
Interbedded limestones and dolomites of the Cambrian Conococheague Formation cropping out northwest of Lancaster exhibit contrasting rheological behavior during deformation. Dolomite beds are uncleaved and form concentric F[sub 1] recumbent folds with hinges trending northeast, parallel to the trend of the Appalachian orogen. Limestone beds show subhorizontal S[sub 1] cleavage with southeast-plunging extension lineations defined by fibrous calcite and ubiquitous smear lineations. In limestone beds, intrafolial F[sub 1] folds with curvilinear hinges are sheath folds flattened in the S[sub 1] cleavage. In zones of most intense shear, F[sub 1] hinges parallel the regional northwest directed tectonic transport direction. In 1969, the author attributed the variation in intrafolial F[sub 1] fold-hinge orientation to hinge-parallel buckling due to constrictional bulk strain. This interpretation, however, is not consistent with the absence of ...
The effect of aerosol on clouds poses one of the largest uncertainties in estimating the anthropogenic contribution to climate change. Small human-induced perturbations to cloud characteristics via aerosol pathways can create a change in the top-of-atmosphere radiative forcing of hundreds of Wm-2. Here we focus on links between aerosol and deep convective clouds of the Atlantic and Pacific Intertropical Convergence Zones, noting that the aerosol environment in each region is entirely different. The tops of these vertically developed clouds consisting of mostly ice can reach high levels of the atmosphere, overshooting the lower stratosphere and reaching altitudes greater than 16 km. We show a link between aerosol, clouds and the free atmosphere wind profile that can change the magnitude and sign of the overall climate radiative forcing. We find that increased aerosol loading is associated with taller cloud towers and anvils. The taller clouds ...
An x-ray zone plate was fabricated using the novel approach of focused ion beam (FIB) milling. The FIB technique was developed in recent years, it has been successfully used for transmission electron microscopy (TEM) sample preparation, lithographic mask repair, and failure analysis of semiconductor devices. During FIB milling, material is removed by the physical sputtering action of ion bombardment. The sputter yield is high enough to remove a substantial amount of material, therefore FIB can perform a direct patterning with submicron accuracy. The authors succeeded in fabricating an x-ray phase zone plate using the Micrion 9500HT FIB station, which has a 50 kV Ga{sup +} column. Circular Fresnel zones were milled in a 1.0-{micro}m-thick TaSiN film deposited on a silicon wafer. The outermost zone width of the zone plate is 170 nm at a radius of 60 {micro}m. An achieved aspect ratio ...
Samples from a burning bituminous coal seam from Coalspur, Alberta, were studied by reflected light microscopy. Two zones - namely oxidation- combustion and distillation - were detected in the seam. Near the surface, the oxidation zone contained chars showing cracks and oxidation rims. The cracks were filled with fluorescing hydrocarbon material formed by thermal cracking of coal macerals. The chars in the deeper part of the oxidation zone had a carbonized matrix and burnt rims. The distillation zone covered most of the coal seam. Chars were mostly in the precarbonization stage, except those immediately below the combustion zone or near the base of the seam. Precarbonized chars contained pyrolytic carbon in some horizons. The distilled chars were formed by heat generated by combustion at the top of the seam and also by heat transfer from an underlying burning seam through an ...
The Coalspur Formation is a continental succession of interbedded mudstone, siltstone and fine grained sandstone with subordinate coarser grained sandstone layers and channel lag deposits. Chert-pebble conglomerate (the Entrance conglomerate) occurs at the base of the formation, and coal beds interbedded with coaly shale and numerous thin bentonites occur in the upper part of the formation. An economically significant amount of high-quality thermal coal occurs within the upper, Paleocene part of the formation named the Coalspur coal zone. Coal from this zone, also known as the Coal Valley coal zone is being exploited in the Coal Valley Mine. 17 refs., 4 figs.
The contention of this commentary, focused on the vestibulocerebellum (particularly the flocculus), is that the great importance for our understanding of cerebellar organization in terms of climbing fiber zones, begun years ago by Voogd [1969, 2011] and Oscarsson [1969], needs to be matched by coming more to grips with the other fundamental geometrical organization of the cerebellum, the parallel fibers. The central issue is the selection of those parallel fiber signals to be transformed into Purkinje cell activity in the different zones. At present, in comparison to our knowledge of vestibulocerebellar climbing fiber inputs, the deficiencies in our knowledge of the zonal anatomy and physiology of vestibulocerebellar mossy fibers and granule cells are glaring. The recent emphasis on molecu...
We present a case of cerebral aspergillosis in an immunocompetent patient. The MRI signal characteristics were compared with the histologic findings. Irregular low-signal zones were demonstrated between the wall of the abscess and the central necrosis on T2-weighted images; the pathology specimen revealed concentrated iron in these transitional zones but no hemosiderin. Iron is an essential element for the growth of fungal hyphae. The low-signal zones may represent the areas where there was active proliferation of aspergillus, and the unique location of the low signal may be a helpful imaging characteristic for the diagnosis of an aspergillus abscess. (orig.)
... In a first-of-its-kind operation, Lisnave recently converted Latvian Shipping Company's 20,000 dwt products tanker Dzintari into a full Class 3 ...
Plate-boundary earthquakes have occurred repeatedly in the past several thousand years at the Cascadia subduction zone, where they are widely recorded ... ...
A rapid and cost-effective assessment was required to provide advice to management on the connectivity between juvenile and adult life cycle stages of Baldchin Groper Choerodon rubescens, a labrid endemic to the west coast of Australia, which has high social value, but relatively low commercial fishery importance. To minimise costs we used laser ablation ICP-MS to analyse levels of a small suite of elements (Ca, Mg, Mn, Cu, Zn, Sr, Rb, Ba and Pb) at the margin (adult phase) and core (juvenile phase) of the same otoliths of adult C. rubescens, collected at ten locations in five management zones. The elemental composition of both otolith margins and cores differed significantly among management zones and in some cases among locations within zones. Similarity of the pattern of among-zone elem...
Satellite Observations of the Southeast Pacific Intertropical Convergence Zone During 1993-1998, Halpern, D.; Hung, C.-W., Journal of Geophysical Research ? ...
The feasibility of continuous production of gallium arsenide ribbon single crystals, by passage of a molten zone through boron-oxide encapsulated GaAs feedstock, is being investigated. Polycrystalline GaAs ribbons have been grown in graphite boats by passage of a wide zone through B2O3-encapsulated feed-stock, confined by a quartz cover plate. Failure to remove the encapsulant above its glass transition temperature, however, resulted in cracking of the ribbons on cooling to room temperature. In order to study the crucial zone melting step in isolation from the encapsulation steps of the continuous process, a constrained-zone melting apparatus has been constructed in which the boron oxide serves only as a sealant to suppress arsenic vaporization. Large grained polycrystalline samples have been produced with this apparatus.
Rapid administration of stable iodine is essential for the saturation and subsequent protection of the thyroid gland against the potential harm caused by radioiodines. This paper proposes the Dutch risk analysis that uses an atmospheric dispersion model to calculate the size of the zones around nuclear power plants where radiological thyroid doses for children might be sufficiently high to warrant iodine administration. Dose calculations for possible releases from the nuclear power plants of Borssele (The Netherlands), Doel (Belgium) and Emsland (Germany) are based on two scenarios in combination with a 1-y set of authentic, high-resolution meteorological data. The dimensions of the circular zones were defined for each nuclear power plant. In these zones, with a radius up to 50 km, distribution of stable iodine tablets is advised. PMID:20332130
Rapid administration of stable iodine is essential for the saturation and subsequent protection of the thyroid gland against the potential harm caused by radioiodines. This paper proposes the Dutch risk analysis that uses an atmospheric dispersion model to calculate the size of the zones around nuclear power plants where radiological thyroid doses for children might be sufficiently high to warrant iodine administration. Dose calculations for possible releases from the nuclear power plants of Borssele (The Netherlands), Doel (Belgium) and Emsland (Germany) are based on two scenarios in combination with a 1-y set of authentic, high-resolution meteorological data. The dimensions of the circular zones were defined for each nuclear power plant. In these zones, with a radius up to 50 km, distrib...
This study focuses the granitoids of center-southern portion of Guyana Shield, southeastern Roraima, Brazil. The region is characterized by two tectonic-stratigraphic domains, named as Central Guyana (GCD) and Uatuma-Anaua (UAD) and located probably in the limits of geochronological provinces (e.g. Ventuari-Tapajos or Tapajos-Parima, Central Amazonian and Maroni-Itacaiunas or Transamazon). The aim this doctoral thesis is to provide new petrological and lithostratigraphic constraints on the granitoid rocks and contribute to a better understanding of the origin and geo dynamic evolution of Guyana Shield. The GCD is only locally studied near to the UAD boundary, and new geological data and two single zircon Pb-evaporation ages in mylonitic biotite granodiorite (1.89 Ga) and foliated hastingsite-biotite granite (1.72 Ga) are presented. These ages of the protholiths contrast with the lithostratigraphic picture in the other areas of Cd (1.96-1.93 Ga). ...
This paper introduces examples of satellite imageries analysis and utilizations for safeguards activities. Recently, many kinds of satellite imageries are available in the world i.e., high-spatial resolution, multi- and hyper-spectral, multi-function, and multi-polarization radars. The problem is that how to obtain the required information from these digital images. The Japan Aerospace Exploration Agency (JAXA) has successfully launched the Advanced Land Observing Satellite (ALOS, the nickname is 'Daichi') on 24th January, 2006. The mission objectives are cartography, regional observation, disaster monitoring etc. ALOS has three instruments, PRISM, AVNIR-2, and PALSAR, to achieve these objectives. An overview of ALOS is provided. ALOS follows the Japanese Earth Resources Satellite- 1 (JERS-1) and the Advanced Earth Observing Satellite (ADEOS) and utilizes advanced land-observing technology. ALOS is fling in a Sun-synchronous orbit with an inclination angle of 98.16 ...
Soil gas, soil, and water were assessed for organic and inorganic constituents at the former 19th Street landfill at Fort Gordon, Georgia, from February to September 2010. Passive soil-gas samplers were analyzed to evaluate organic constituents in the hyporheic zone and flood plain of a creek and soil gas within the estimated boundaries of the former landfill. Soil and water samples were analyzed to evaluate inorganic constituents in soil samples, and organic and inorganic constituents in the surface water of a creek adjacent to the landfill, respectively. This assessment was conducted to provide environmental constituent data to Fort Gordon pursuant to requirements of the Resource Conservation and Recovery Act Part B Hazardous Waste Permit process. The passive soil-gas samplers deployed in the water-saturated hyporheic zone and flood plain of the creek adjacent to the former landfill indicated the presence of total petroleum hydrocarbon (TPH) ...
This report describes the results from acoustic emission (AE) and ultrasonic monitoring of the Aespoe Pillar Stability Experiment (APSE) at SKB's Hard Rock Laboratory (HRL), Sweden. The APSE is being undertaken to demonstrate the current capability to predict spalling in a fractured rock mass using numerical modelling techniques, and to demonstrate the effect of backfill and confining pressure on the propagation of micro-cracks in rock adjacent to deposition holes within a repository. An ultrasonic acquisition system has provided acoustic emission and ultrasonic survey monitoring throughout the various phases of the experiment. Results from the entire data set are provided with this document so that they can be effectively compared to several numerical modelling studies, and to mechanical and thermal measurements conducted around the pillar volume, in an 'integrated analysis' performed by SKB staff. This document provides an in-depth summary of the AE and ...
The authors propose using synthetic aperture radar(SAR) for wind energy mapping of coastal zones. The SAR equipment is located on the European Space Agency ERS-1 and 2 and the RADARSAT satellites. Examples of wind energy maps and evaluations of their applications are given for the Norwegian west coast.
Our work is towards mechanistically understanding interactions of unsaturated bacterial biofilms and their extracellular polymeric substances (EPS) with actinide metals and metal surrogates under vadose zone conditions. Because metal contaminants in the vadose zone co-occur with organic pollutants, some of our work has included experiments with organic pollutants.
A slurry intake device is proposed which contains an inlet sleeve, housing with grating installed with the discharge end in the zone of the slurry outlet, and hinged deflector. In order to conserve the clay mud, it is equipped with a tie rod and two-arm lever which is kinematically linked to the deflector and the grating. It is installed by hinges in relation to the housing and the latter is attached by hinges to the inlet sleeve. The deflector is arranged in the zone of slurry outlet. The device is distinguished by the fact that the deflector is equipped with a cantilever on which a fixable weight is attached.
Numerical simulations are used to predict the migration of radionuclides from the disposal units at Material Disposal Area G through the vadose zone and into the main aquifer in support of a radiological performance assessment and composite analysis for the site. The calculations are performed with the finite element code, FEHM. The transport of nuclides through the vadose zone is computed using a three-dimensional model that describes the complex mesa top geology of the site. The model incorporates the positions and inventories of thirty-four disposal pits and four shaft fields located at Area G as well as those of proposed future pits and shafts. Only three nuclides, C-14, Tc-99, and I-129, proved to be of concern for the groundwater pathway over a 10,000-year period. The spatial and temporal flux of these three nuclides from the vadose zone is applied as a source term for the three-dimensional saturated ...
Boiling phenomenon is responsible for impurities concentration in the liquid phase and then can involve chemically aggressive conditions. This paper presents the methodology developed by NOVATOME to know the water quality conditions in the boiling zone and under deposits, in order to improve corrosion tests and materials reliability and safety. Calculations show that concentration of chloride and sodium hydroxide for example can reach significant levels which may lead to corrosion risks. (author).
Peculiarities of design of the PGV-1000 horizontal steam generator affecting soluble impurity distribution in its water volume are considered in brief. The results of estimating sodium distribution in different zones of the steam generator are presented. The conclusion is made on the necessity of arrangement of representative measurements of sodium and chloride content in water volume of the steam generator, particularly, in the hot bottom zone for optimization of blow-through flowsheet and its regulations.
A new dual focal point electro-optic lens that is switchable to focusing and unfocusing is proposed and successfully demonstrated. This electro-optic lens is constructed by coating transparent fine electrodes in the Fresnel-zone plate onto a PLZT ceramic plate. Its focal length changes from 1.25 m to infinity binary at 515 nm with the external voltage of 210 V. PMID:20725208
Contents include: introduction; river systems; physical processes; chemical processes; estuaries and coastal zone; introduction; physical processes; chemical processes; the role of sediments; introduction; the anoxic layer; major-element chemistry; minor-element chemistry; the oxic-anoxic interface; assessment; introduction; analysis of sediments; modelling.
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.
... Uninterrupted access to and use of critical infrastructure in the Arabian Gulf region are key to the successful prosecution of the Global War on Terror ...
Previous models of fault-propagation folding used kink-band geometries to approximate folding in front of propagating thrusts. However, kink-band kinematics cannot replicate the curved fold surfaces and complex strain patterns innatural and experimental fault-propagation folds, which also occur in front of steeper reverse and normal faults. Fault-propagation fold hinges tighten and converge downward, forming a triangular zone of penetrative deformation focused on the tip of the propagating fault. The downward convergence of deformation in fault-propagation folds can be modeled as triangular shear zones. Trishear, here defined as distributed, strain-compatible shear in a triangular (in profile) shear zone, provides an alternate kinematic model for fault-propagation folds. Trishear is analogous to simple shear in a tabular shear zone except that area balance in a triangular shear zone ...
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 ...
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 structure even within molybdenum ''softening'' range.
On June 19, 1998, after the first annual outage, Wolsung Unit 2 was shutdown at a controlled rate due to the continuous instability of Liquid Zone Control level. Investigation revealed that the Liquid Zone Control level instability was caused by water condensed inside the helium lines, generated from the moistened helium flow, especially, inside the helium balance header feed and bleed valve lines. It was found that improper installation of the diaphragm type isolation valves and the drain valve tap could easily contain the water inside the lines and be destined to form water traps causing the balance header pressure oscillation. After the lines were dried, Liquid Zone Control level instability was almost vanished, and approached the allowable equilibrium state. As the reactor power was increased, however, the zone level instability increased again. In order to compensate for the excessive, the Bulk ...
During the early years of the INEL, the USGS conducted extensive studies (sitewide drilling program) of the geology and hydrology of the area collecting varied data over the years. The unsaturated zone has not received much attention until recently. The studies that have been done are a result of problems or concerns arising from liquid radioactive waste disposal. The TRA facility has the most information published about its waste disposal activities. The ICPP has less data about the unsaturated zone due to the fact that most waste water disposal has been to a well. Little is known about the effect of waste water disposal at the NRF on the unsaturated zone. Essentially no information was found about waste disposal activities at other facilities, primarily because there does not appear to be any reported problems associated with waste water disposal at these locations. The RWMC has received much attention in the last few ...
During the early years of the INEL, the USGS conducted extensive studies (sitewide drilling program) of the geology and hydrology of the area collecting varied data over the years. The unsaturated zone has not received much attention until recently. The studies that have been done are a result of problems or concerns arising from liquid radioactive waste disposal. The TRA facility has the most information published about its waste disposal activities. The ICPP has less data about the unsaturated zone due to the fact that most waste water disposal has been to a well. Little is known about the effect of waste water disposal at the NRF on the unsaturated zone. Essentially no information was found about waste disposal activities at other facilities, primarily because there does not appear to be any reported problems associated with waste water disposal at these locations. The RWMC has received much attention in the last few ...
Some crops of important nutritive requirements have been collected from farmlands located in Bitsichi an old tin mining town in north central region of Nigeria. The food crops were analyzed in order to determine trace element concentrations level using Neutron Activation Analysis (NAA). The activity concentrations due to natural radionuclides in the food samples and soil samples collected within the root zone of the crops were also determined using gamma-ray spectrometry (GRS). The NAA results obtained showed higher concentration of Potassium among the essential elements in all the crops. Calcium concentration in both maize and Guinea corn was below detection limit and also Zn in Green beans, sweet potato and cassava. The trace elements; Sc, Hf, Sm, and Th, were below detection limit in all the crops except in Green beans. Rubidium (Rb) and lanthanum (La) were below detection limits only in Cabbage. The activity concentrations of the natural ...
Some crops of important nutritive requirements have been collected from farmlands located in Bitsichi an old tin mining town in north central region of Nigeria. The food crops were analyzed in order to determine trace element concentrations level using Neutron Activation Analysis (NAA). The activity concentrations due to natural radionuclides in the food samples and soil samples collected within the root zone of the crops were also determined using gamma-ray spectrometry (GRS). The NAA results obtained showed higher concentration of Potassium among the essential elements in all the crops. Calcium concentration in both maize and Guinea corn was below detection limit and also Zn in Green beans, sweet potato and cassava. The trace elements; Sc, Hf, Sm, and Th, were below detection limit in all the crops except in Green beans. Rubidium (Rb) and lanthanum (La) were below detection limits only in Cabbage. The activity concentrations of the natural ...
This paper makes a case for "good politics for good education", with special reference to Nigeria. It surveys the impact of good and bad politics on the attainment of Meaningful Access to education with special focus on Nigeria's Universal Basic Education (UBE) programme. Good politics is to be likened to what the French call "la politique au sense noble du terme" (politics in the noble sense of the term--or statesmanship) while bad politics is to be likened to a "politique politicienne" (mere divisive politicking, or politics in its raw form). Politics in its raw form is concerned with seeking power for self-aggrandisement while politics in its noble form is concerned with seeking power for public good. In situations where good politics prevails, educational policies, programmes and delivery processes tend to produce the desirable outcome of "children passing through school and the school also passing through them". By combining the seven exclusion zones used ...
A general relativistic model for the formation and acceleration of lowmass-loaded jets from systems containing accreting black holes is presented. The model is based on previous numerical results and theoretical studies in the Newtonian regime, but modified to include the effects of space-time curvature in the vicinity of the event horizon of a spinning black hole. It is argued that the boundary layer between the Keplerian accretion disk and the event horizon is best suited for the formation and acceleration of the accretion-powered jets in active galactic nuclei and micro-quasars. The model presented here is based on matching the solutions of three different regions: i- a weakly magnetized Keplerian accretion disk in the outer part, where the transport of angular momentum is mediated through the magentorotational instability, ii- a strongly magnetized, advection-dominated and turbulent-free boundary layer (BL) between the outer cold accretion disk and the event ...
An average of 9 million gallons per day of oil-contaminated ballast water off loaded from tankers are treated at the Alyeska Pipeline Service Company Ballast Water Treatment Facility at the terminus of the Trans-Alaska Pipeline in Port Valdez, Alaska. This paper focuses on the results of 2 Prince William Sound Regional Citizens' Advisory Council monitoring programs which detail changes in the chemical composition of treated ballast water as it moves from tankers through the facility and subsequently traces the effluent hydrocarbons into the receiving environment of Port Valdez. The treatment facility involves gravity separation tanks, dissolved air flotation cells and biological treatment tanks. Effluent containing traces of volatile aromatics, including benzene, toluene, ethylbenzene and xylenes, low levels of oil, saturated hydrocarbons and polycyclic aromatic hydrocarbons is being continuously discharged to Port Valdez. Because of the extremely large ...
The hospitals are important consumers of energy. At the General Hospital of Zone (HGZ) N of the IMSS in Aguscalientes (HGZ N . IMSS Ags.), the diesel oil is the main fuel that is used to satisfy the requirements of thermal energy of the hospital. According to the data collected by this author, this fuel represented in 2001, 75% of its total energy consumption and the 67.9% of its total costs in energy that ascended to $396.131 (December 2001 Dollars) Since this last amount represents an important percentage of the total expenses of the hospital (29.367 million dollars) it is important to determine the technical-economic possibilities of thermal energy saving of the hospital. The HGZ N 1 IMSS Ags. is located in a ampler conglomerate where the IMSS units are located, such as, the regional laundry, the sport unit, the center of social security, the familiar medicine unit N 1 and the hospital. Nevertheless departing from the installation of the ...
Forests on the Kola Peninsula in Northern Russia grow close to the northern tree line. They are subjected to both natural and anthropogenic stress factors. The Cu-Ni smelter 'Severonikel' (Lat. 67 deg 55'N; Long. 32 deg 57'E) near Monchegorsk is one of the two major sources of sulphur dioxide and heavy metals emissions on the Kola Peninsula. These emissions have caused significant deterioration of the surrounding vegetation. The thesis demonstrates how methods of Remote sensing, ground survey and mathematical modelling can be integrated for monitoring of the smelter's environmental impact on the surrounding vegetation: ground truth data are used for calibration of remote-sensed data, which further serve to verify mathematical models. The study aims were: * to estimate the scale of airborne sulphur pollution from the smelting industry on the Kola Peninsula and its effect on vegetation; * to assess spatial extent of the forest decline in the ...
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...
The subscale Varestraint test has been used to determine the relative hot cracking susceptibility of the fusion zone in four commercial heats of alloy 800. Although all four heats were susceptible to cracking, one heat exhibited a significant increase in cracking relative to the other three. Optical metallography revealed that nearly all the cracking was localized along fusion zone grain boundaries. Microprobe analysis of the grain boundaries detected high concentrations of titanium, silicon, and niobium resulting from partitioning during solidification. The fusion zone hot cracking mechanism in alloy 800 involves the complex interaction of titanium, silicon, niobium, and carbon along the solidification boundaries. SEM and Auger analyses of the hot crack fracture surfaces revealed the presence of (Ti, Nb)-rich carbides, suggesting that these particles precipitate from the liquid which solidifies last on the fracture ...
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...
Competitive bidding for ancillary services (A/S), in addition to bidding for energy, is increasingly recognized as an important part of electricity markets. In this paper, an LP-based approach is presented for solving the multi-product (i.e. energy and A/S products), multi-zone/area physical market dispatch problem. The approach can explicitly represent various constraints, such as reserve requirement constraints, network security limits, and sharing of constrained resource capacity (e.g. maximum unit generation) between energy and reserve. The joint dispatch method, which dispatches energy and reserve market concurrently, is extended to allow inter-zonal reserve trading in multi-zone competitive pool. Numerical examples are included to demonstrate the salient characteristics of the joint dispatch solution.
The Jaduguda U (?Cu?Fe) deposit in the Singhbhum shear zone has been the most productive uranium deposit in India. Pyrite occurs as disseminated grains or in sulphide stringers and veins in the ore zone. Veins, both concordant and discordant to the pervasive foliation, are mineralogically either simple comprising pyrite ? chalcopyrite or complex comprising pyrite + chalcopyrite + pentlandite + millerite. Nickel-sulphide minerals, though fairly common in concordant veins, are very rare in the discordant veins. Pyrite in Ni-sulphide association is commonly replaced by pentlandite at the grain boundary or along micro-cracks. Based on concentrations of Co and Ni, pyrite is classified as: type-A ? high Co (up to 30800?ppm), no/low Ni; type-B ? moderate Co (up to 16500?ppm) and moderate to high ...
Abstract Introduction.- Infection is the worst complication seen with inflatable penile prosthesis (IPP). Both the American Medical Systems (AMS) and Coloplast IPP have infection retardant coatings. AMS is coated at the factory with rifampicin and minocycline (InhibiZone). The Coloplast IPP has a hydrophilic coating covalently bonded to its components that will absorb any aqueous solution before implantation and provides increased surface lubricity to decrease bacterial adherence. Aim.- We tested several antibiotic dips comparing zones of inhibition (ZOI) against five commonly infecting bacteria with coated Coloplast implants. Results were compared with those ZOI created with strips of an AMS IPP precoated with InhibiZone. Methods.- Pieces of sterile Coloplast Titan IPP were dipped in (i) ...
An indoor radioactive survey is being conducted in an Italian district. Preliminary results identified a zone with significant radioactive levels, in which a new specific survey has been planned. In this paper attention is dedicated mainly to radon measurement technique and results.
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
The receptive field of a neuron reflects its function. For example, for parallel fiber (PF) inputs in C3 zone the cerebellar cortex, the excitatory and inhibitory receptive fields of a Purkinje cell...Full Text Available
The following subjects are dealt with: physics of indoor air flow, flow in individual rooms, exchange of air and pollution between individual building zones and with the outside world, thermal coupling with the building shell, thermal comfort and air quality, evaluation of the ventilation. figs., tabs., refs.
Current military conflicts in Iraq and Afghanistan have produced a significant number of complex injury patterns. Multiple extremity trauma and wide zones of injury mandate a flexible approach to these...Full Text Available
Treatment of Japanese pines (P. densiflora and P. thunbergii) with paraquat induced a zone of lightwood. Determinations of turpentine and ether extractives contents in lightwoods showed high levels as compared with those in control woods. (Refs. 5).
...this pathway study the following two focus modules (in addition to the six core modules) and carry out a research investigation within this theme: Agricultural Production Systems Considers the type of farming systems that have evolved globally in relation to the prevailing agro-climatic zones, the influences of economic factors ...
Coded imaging techniques using thick, micro-Fresnel zone plates as coded apertures have been used to image x-ray emissions (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 aperatures. 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.
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.
A method is proposed for operating bed waters in an oil well by injecting silanes into the near-face zone. It is distinguished by the fact that in order to improve the effectiveness of insulation, the silanes used are silanes of general formula Si /SUB n/ H /SUB 2n-n/ .
Background and AimsSulfonylurea (SU) herbicides are used extensively in cereal–livestock farming zones as effective and cheap herbicides with useful levels of residual activity....Full Text Available
The effects of the plasma nitriding with the formation of compound nitride and diffusion zones and of the boronising with the different ion doses on hydrogen distribution and hydrogen induced deterioration of a surface layer were examined in the case of Armco iron. Electrochemical studies of hydrogen permeation rate, hydrogen vacuum extraction measurements, optical and scanning microscopy, X-ray diffraction and elastic recoil detection analysis (ERDA) were used. Accumulation of entering hydrogen within the various constituent zones of the modified layer inhibits the hydrogen transport into the metal and thus, decreases the mean hydrogen content in the deeper zones and in the core. Hydrogen accumulation within the compact nitride zone causes the expansion of the nitride lattice, nitride phase transformation and deterioration. The ion boronising enhances the hydrogen effects in the plasma nitrided layers. ...
Foreward: Preface; Introduction; The natural science of global climate change; Land and water use; Coastal zones and oceans; Energy and industry; Energy and social systems; Technological change; and Sponsoring organizations, International Advisory Board, and project participants.
Field campaigns were conducted in 1981 and 1982/83 on the Dutch coast near Egmond. Measurements were made of surface elevations, water velocities and sediment concentrations in 3 to 8 surf zone locations and 2 to 5 offshore locations simultaneously. A des...
A triangle zone, which commonly occurs along the external margin of a foreland thrust and fold belt with a buried thrust front, is underlain by a subhorizontal, blind, foreland-verging thrust that ends against a foreland-dipping, hinterland-verging thrust. These contemporaneous thrusts, active towards the end of orogenesis, enclose an intercutaneous wedge that moved towards the foreland. During orogenesis, a triangle zone evolves through periodic replacement of faults bounding the active wedge. Replacements occur in cycles during each of which a lower fault tends to be replaced by one in a lower stratigraphic horizon, an upper fault by one farther away from the foreland. Each cycle ends with the lower fault moving to a younger horizon where it joins a new, more external upper fault. Near Coalspur, the triangle zone exposes the remnants of several wedges involving Upper Cretaceous and Palaeocene molasse. Most of these wedges ...
Sulfur dioxide emissions from an iron ore sintering plant have severely damaged vegetation up to 16 km northeast of the source. Concentric zones of increasing vegetation loss have formed around the point of maximum ground level concentration of the gas. Species diversity, sulfur and heavy metal concentrations in vegetation and soil amount to SO/sub 2/ injury were measured along a transect through the injury zones. Surrounding a central denuded area were zones dominated respectively by tussock-forming hair grass (Deschampsia flexuosa); low-growing shrubs and trailers (Sambucus pubens, Polygonum cilinode); higher-growing shrubs and suckering Populus tremuloides and Betula papyrifera) stunted forest tree species (Populus, Betula, Picea glauca, Abies Balsamea), and finally, normal boreal forest flora. Although SO/sub 2/ injury is continuing in this area, these zones now appear to be maintained primarily by ...
In mammals, adult neurogenesis has been extensively studied in the dentate gyrus of the hippocampus and subventricular zone. However, newly proliferated neurons have also been documented in...Full Text Available
An image slicing spectrometer (ISS) for microscopy applications is presented. Its principle is based on the redirecting of image zones by specially organized thin mirrors within a custom fabricated...Full Text Available
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 activities of the total uranium in the samples was obtained by liquid ...
Jun 16, 2011 ... Results indicated that fuel loadings averaged 24.05 Mg ha 1 in 2004–2006. Forest litter decreased from wetter to drier forest life zones. ...
In rats and primates, the central nucleus of the amygdala (CeN) is most known for its role in responses to fear stimuli. Recent evidence also shows that the CeN is required for directing attention...Full Text Available
In multiple sclerosis (MS), oligodendrocyte and myelin destruction lead to demyelination with subsequent axonal loss. Experimental demyelination in rodents has highlighted the activation of the subventricular...Full Text Available
The relationships between soil salinization and the zonal and provincial bioclimatic conditions, the lithological composition of the sediments, and the geomorphic features of the territory have been analyzed for the Southern federal okrug of Russia. It is shown that the lithological and geomorphic conditions (relief, salinity of parent materials, degree of drainage, and the depth of saline groundwater) play an important role in the distribution of salt-affected soils against the background of the more general regularities specified by the climate. The participation of salt-affected soils in the soil cover of the Southern federal okrug increases in the eastward direction from the forest-steppe zone to the semidesert zone in agreement with an increase in the aridity and continentality of the...
Approximately 1.2 million kg of uranium oxide (yellow cake) has been produced from the area surrounding Gunnison, Colorado. Over 99 percent of this has come form the Cochetopa and Marshall Pass districts. Uranium in both districts and many of the other occurrences is associated closely with fault and shear zones which cut brittle host formations (sandstones and dolomites) of Paleozonic and Mesozoic age. Minor uranium occurrences are in pegmatites and shear zones in Precambrian rocks, Cambrian vein material, and sandstones of Tertiary age. In the paper presented, the uranium occurences are described by districts. In addition, possibilities for additional discoveries are discussed. (JMT)
A process for the production of transportation fuels from heavy hydrocarbonaceous feedstock is provided comprising a two-stage, close-coupled process, wherein the first stage comprises a hydrothermal zone into which is introduced a mixture comprising a feedstock and red mud having coke-suppressing and demetalizing activity, and hydrogen; and the second, close-coupled stage comprises a hydrocatalytic zone into which substantially all the effluent from the first stage is directly passed and processed under hydrocracking conditions.
The present paper is concerned with the prediction method for the motions and tensions of mooring lines on slack-moored floating oceanic architectural building in coastal zone. The motions and the tensions of mooring lines were estimated by the time domain numerical simulation in the present method. The present method includes the nonlinearity of mooring system, slow varying wave drift force. The authors performed a time domain numerical simulation for motions and the tensions of mooring lines on floating barge in two component waves. Also, the results obtained by numerical simulation were compared with the experimental results. The validity of the present method was confirmed.
A process for the production of transportation fuels from heavy hydrocarbonaceous feedstock is provided comprising a two-stage, close-coupled process, wherein the first stage comprises a hydrothermal zone into which is introduced a mixture comprising a feedstock and metals-impregnated red mud having coke-suppressing and demetalizing activity, and hydrogen; and the second, close-coupled stage comprises a hydrocatalytic zone into which substantially all the effluent from the first stage is directly passed and processed under hydrocatalytic conditions. The preferred metals for impregnation include transition metals, in particular, nickel and molybdenum.
Friction stir welding of dissimilar formed Mg alloys(AZ31/AZ91) was successfully carried out at the limited welding conditions. In a sound joint, SZ was mainly consisted of AZ31 Mg alloy which was located the retreating side. Dynamic recrystallization and grain growth occurred and {beta} intermetallic compounds of AZ 91 Mg alloy was not observed in SZ. BM had a higher hardness than that of the weld zone. The fracture location was not weld zone but BM of the AZ91 Mg alloy in tensile test. (orig.)
BackgroundFor hundred of years, people in the region encompassed by the Afghanistan-Iran-Pakistan borders (AIP region) have been challenged by conflict and political and civil instability,...Full Text Available
Second Regional Meeting for Nuclear Energy in Central Europe is an annual meeting of the Nuclear Society of Slovenia. The proceedings contains 75 articles from Slovenia, surrounding countries and countries of the Central and Eastern European Region
The uncertainty associated with the sorption coefficient, or K{sub d} value, is one of the key uncertainties in estimating risk associated with burying low-level nuclear waste in the subsurface. The objective of this study was to measure >648 K{sub d} values and provide a measure of the range and distribution (normal or log-normal) of radionuclide K{sub d} values appropriate for the E-Area disposal site, within the Savannah River Site, near Aiken South Carolina. The 95% confidence level for the mean K{sub d} was twice the mean in the Aquifer Zone (18-30.5 m depth), equal to the mean for the Upper Vadose Zone (3.3-10 m depth), and half the mean for the Lower Vadose Zone (3.10-18 m depth). The distribution of K{sub d} values was log normal in the Upper Vadose Zone and Aquifer Zone, and normal in the Lower Vadose Zone. To our knowledge, this is the first ...
the southern Arabian Gulf region left its signature on the heterogeneous aerosol .... Arabian Gulf region, since large differences in ? may be caused by ...
... Marine transport and oil disposal by boats and Matadi pose threats in the region. When the water ... Marine transport and oil disposal by boats and Matadi pose threats in the region. When the water ... ...
The muscles of three different arthropods, a mite, a fly, and an ostracod, show variations in the length of the A region within a given individual. There is no indication that the observed differences...Full Text Available
... Harbor Township Vineland Voorhees Pediatric Partner Hospitals AtlantiCare Regional Medical Center- City Campus, Atlantic City AtlantiCare Regional Medical Center - ...
dust measured in the Arabian Gulf region during UAE2 and examine the hypothesis that ... [8] UAE2 took place in the southern Arabian Gulf region in August and ...
At-site and regional frequency analyses of annual maximum 1-, 2-, and 3-days rainfall in Han River basin was performed and compared based on the regional L-moments algorithm. To perform regional frequency analysis, Han River basin was subdivided into 3 sub-basins such as South Han River, North Han River, and downstream regions. For each sub-basin, the discordancy and homogeneity tests were performed. As the results of goodness of fit tests, lognormal model was selected as an appropriate probability distribution for both South Han River and downstream regions and gamma-3 model for North Han River region. From Monte Carlo simulation, RBIAS and RRMSE of the estimated quantiles from regional frequency analysis and at-site frequency analysis were calculated and compared each other. Regional frequency analysis shows less RRMSE ...
The grey-black mudstones of the Sonehat Formation form part of the Middle Jurassic fill of the Jameson Land Basin in East Greenland. The formation is exposed in the southernmost part of the north south-trending, Mesozoic rift system in East Greenland that was part of the epeiric seaway betaveen East Greenland and Norway. Sedimentological observations of the Sortehat Formation indicate deposition in an offshore marine setting that was typically low energy and periodically oxygen-deficient but was influenced by storm currents on occasion. Detailed palynological studies of the Sortehat Formation have resulted in the definition of theee palynological assemblage zones recognised at four localities, namely Enhjoerningen Dal and Pelion (north Jameson Land), the type section at Sortehat (central Jameson Land) and Albuen at Neill Klinter along Hurry Inlet (south-east Jameson Land). In stratigraphic order, these zones are termed the Botryococcus ...
The Coastal Zone Sector of the Canadian Climate Impact and Adaptation Research Network (C-CIARN) was established to address concerns regarding climate change in coastal areas. Coastal zones are sensitive to increases in air, sea and ground temperatures as well as to variations in sea level, precipitation, ice thickness, and storm intensity. This report presents the results of a workshop which focused on how coastal communities will be affected by climate induced water level changes, particularly sea-level rise on ocean coasts and decreasing lake levels in the Great Lakes. The workshop addressed issues such as the effects of changing water levels on coastal infrastructure, utilities, community development, and the implications of changing water levels to human safety, cultural resources, tourism, and insurance. The workshop reviewed the current state of understanding on water level fluctuations resulting from climate change. It also identified ...
Multilayer mirrors for the extreme ultraviolet (EUV) are keyelements for numerous applications of coherent EUV sources such as newtabletop lasers and free-electron lasers. However the field ofapplications is limited by the radiation and thermal stability of themultilayers. Taking into account the growing power of EUV sources thestability of the optics becomes crucial. To overcome this problem it isnecessary to study the degradation of multilayers and try to increasetheir temporal and thermal stability. In this paper we report the resultsof detailed study of structural changes in Sc/Simultilayers when exposedto intense EUV laser pulses. Various types of surface damage such asmelting, boiling, shockwave creation and ablation were observed asirradiation fluencies increase. Cross-sectional TEM study revealed thatthe layer structure was completely destroyed in the upper part ofmultilayer, but still survived below. The layers adjacent tothe substrateremained intact even through the ...
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 determined FCG ...
Marine ecosystems are suffering severe depletion of apex predators worldwide; shark declines are principally due to conservative life-histories and fisheries overexploitation. On coral reefs, sharks are strongly interacting apex predators and play a key role in maintaining healthy reef ecosystems. Despite increasing fishing pressure, reef shark catches are rarely subject to specific limits, with management approaches typically depending upon no-take marine reserves to maintain populations. Here, we reveal that this approach is failing by documenting an ongoing collapse in two of the most abundant reef shark species on the Great Barrier Reef (Australia). We find an order of magnitude fewer sharks on fished reefs compared to no-entry management zones that encompass only 1% of reefs. No-take zones, which are more difficult to enforce than no-entry zones, offer almost no protection for shark populations. Population viability ...
The broad objective of the engineered barriers studies was to demonstrate and qualify the use of different materials and techniques for sealing water flow paths in the Stripa granite, the mine excavations and the excavation disturbed zones. As may be anticipated from the application of the observational method that forms the basis for design of geotechnical structures, the programme evolved with the finding being made at Stripa and other underground laboratories. During phase 1, the engineered barriers investigations focussed on the heat affected zone of the repository. Specifically, the response of clay buffers and the interactions between waste containers, clay buffer materials and the rock were studied. The phase 2 investigations examined the feasibility of sealing boreholes shafts and tunnels with clay sealants. The phase 3, studies of the ability to grout and seal fractured granite including the excavation disturbed ...
The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire food chain. Increase in atmospheric ...
The environmental data for the NSDN are presented in the form of tables for each solar site. The solar sites are grouped into 12 zones, each of which consists of several adjacent states. The solar energy sites are in alphabetical sequence within each zone. The tables provide available meteorological data for reporting sites in the NSDN as follows: Insolation - the insolation table presents the total, diffuse, direct, maximum, and extra-terrestrial radiation for the solar site. It also shows the ratio of total extra-terrestrial radiation, as a percent. Temperature - the temperature table gives the average, daytime, nightime, maximum, minimum and inlet-water temperatures for the solar site. Additional tables are presented for some of these NSDN sites, supplying either wind or relative humidity data, or both. Wind - all of the passive and some of the active solar sites are equipped with wind sensors. These provide information for two wind tables. ...
Assessment of the oil shale resources in Kentucky has continued with 75 NX cores available where the oil shale crops out or is overlain by relatively thin cover in the area from Estill County westward to Bullitt County. In this 14 county area, the total black shale section thins across the crest of the Cincinnati arch and changes stratigraphically from that characteristic of the Ohio Shale in Estill County to that of the New Albany Shale in Bullitt County. Despite this stratigraphic transition the two high-carbon zones (greater than 8.0% carbon) can be traced across the arch. As the traverse is followed from the east, the intervening low-carbon zones thin such that at the crest of the arch, there are areas where the entire section of black shale contains more than 8% carbon. Then upon leaving the crest the two high-carbon zones separate again with one remaining at the very top of the section and one in the lower part. In ...
In the corrosion aspect of container for the deep geological disposal of high-level radioactive waste, disposal concepts and the related container materials, which have been developed by advanced countries, have been reviewed. The disposal circumstances could be divided into the saturated and the unsaturated zones. The candidate materials in the countries, which consider the disposal in the unsaturated zone, are the corrosion resistant materials such as supper alloys and stainless steels, but those in the saturated zone is cupper, one of the corrosion allowable materials. By the results of the pitting corrosion test of sensitized stainless steels (such as 304, 304L, 316 and 316L), pitting potential is decreased with the degree of sensitization and the pitting corrosion resistance of 316L is higher than others. And so, the long-term corrosion experiment with 316L stainless steel specimens, sebsitized and non-sensitized, ...
California's pacific coast stretches roughly over 11.5 latitudinal degrees, extending from about 32.5{sup o}N to 44{sup o}N. There is nearly 900nm of California coastline offering superior opportunity for wave energy use. The longitudinal position of the coast shifts eastward at two distinct locations: Punta Gorda just south of Cape Mendecino in the north and Point Conception in the south. The change in longitudinal orientation in southern California also coincides with significant change in California's bathymetry. The tilts in the longitudinal coastal lines at the two points also define California wave zones into three areas: the short coastal line north of Punta Gorda, the long north and middle line between the two points, and the short line of the heavily populated southern coast. The northern and central zones are characterized by high waves of relatively low frequency; the southern coast is characterized by low waves of ...
There is a plethora of new silver-containing dressings on the market today. Various manufacturers attempt to show that their dressings are the most efficacious and therefore should be preferentially employed by health care workers based on the results of their in vitro tests. However, there have been no studies that clearly identify which tests are appropriate for comparison purposes. The purpose of this study was to determine which in vitro test is most appropriate for evaluating the antimicrobial efficacy of silver-containing dressings. This was done by testing seven silver-containing dressings and two non-silver-containing topical agents against 17 clinically relevant microorganisms using zone of inhibition assays and time-kill kinetic assays in complex media. The results for the two assays were then correlated to determine whether the methods generated similar results. It was determined that the two methods do not correlate at all. This is most likely a result ...
The pilot area of the Vyngapour oil field allotted for MIOR tests contains three injection and three producing wells. These wells were treated in summer 1993 and 1994. Before, during, and after MIOR treatments on the pilot area the chemical compounds of injected and formation waters were studied, as well as the amount and species of microorganisms entering the stratum with the injected water and indigenous bacteria presented in bottomhole zones of the wells. The results of monitoring showed that the bottomhole zone of the injection well already had biocenosis of heterotrophic, hydrocarbon-oxidizing, methanogenic, and sulfate-reducing bacteria, which were besides permanently introduced into the reservoir during the usual waterflooding. The nutritious composition activated vital functions of all bacterial species presented in the bottomhole zone of the injection well. The formation waters from producing wells showed the ...
ObjectivesThe specific objectives of the research are to: 1. Determine the concentrations of N2O, NO and NO2 in tropical coastal waters in relation to nutrients and salinities. 2. Determine, with excess nitrate present, the potential for nitrate reduction and denitrification in sediments along tropical estuaries, and whether NO, NO2, N2O, N2 or NH4+ are significant products. 3. Establish the balance between denitrification, nitrate ammonification and anammox in tropical estuarine sediments, relative to [continued...]DescriptionThe coastal zone is extremely important in the biogeochemical processes which control the natural cycle of elements of the Earth. In particular, the coastal zone contributes significantly to the nitrogen cycle, removing nitrogen washed in from the land by rivers and so reducing its fertilizing impact on the coastal seas. However, these removal processes, driven by microorganisms, also contribute to the formation of ...
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 ($\\sim 2.05 \\pm 0.15 R_{\\earth}$), which, depending on the ...
The pollution of the aquatic zones grows with the time, principally due to industrial and urban settlements, among others, in the surroundings of these sites. The sources of this pollution can be identified by the study of the characteristics of the sediment, this gives relevant information to evaluate any aquatic system. Once the sediment is obtained, a series of preliminary tests are carry out (loss of ignition, 210{sup P}b dating) to be sure that we have a sedimentary core that hans .t be mixed, once this has be done we determine radionuclides, heavy metals and organic compounds. (Author) 2 refs.
During the normal operation of a Nuclear Power Plant (NPP), radioactive releases into the atmosphere will be in small quantities. During major accidental situations, though the probability is extremely small, there may be significant release of radioactivity to the environment through the stack or at ground level. To study the external radiation exposure, if any, to the members of public due to releases during the normal operation of a nuclear power plant (NPP) and also to meet the requirement of emergency preparedness for the NPP site, continuous recording and analysis of environmental dose rate data is essential. This paper presents analysis of the gamma dose rates recorded by the Environmental Dose Logging Systems (EDLS) installed around the site during the last six years in the Emergency Planning Zone (EPZ) of Tarapur Atomic Power Station (TAPS). (author)
The coastal ecosystem health assessment is a field of increasing importance. In this paper, a preliminary assessment of ecosystem health in Zhejiang coastal water zone was made, mainly based on remote sensing data and GIS technique. Its spatial and quantitative evaluation was facilitated by the progress of remote sensing and GIS technique development. Firstly, human activities, hydrology and ecosystem problems in the study area were discussed and analyzed. Secondly, from 4 aspects of human stress, physical, chemical and biological responses to anthropogenic activities and natural stress, several indicators such as water transparency (Secchi Disk Depth, SDD), suspended substance concentration, dissolved inorganic nitrogen, active phosphate, chlorophyll, harmful algae bloom, as well as distr...
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)
Summary 1. The EU -Nitrates Directive- (Directive 91/676/EEC) and the WFD (Water Framework Directive 2000/60/EEC) introduced a series of measures designed to reduce and prevent water pollution caused or induced by nitrates from agricultural sources. Therefore, there is an urgent requirement to control the nitrate concentration in freshwater. The objective of this paper was to verify the potential capacity of a specifically designed afforested riparian zone in removing the excess of nitrogen from river water. 2. A buffer zone was set with irrigation ditches, to produce a subsurface water flow carrying water from the study river through the buffer strip to drainage ditches. This experimental system enables the co-occurrence of two main processes: vegetation/microbial nitrogen uptake and deni...
With the aim of optimizing the nitriding process, experimental studies of the plasma nitriding of four selected steels were carried out, using a d.c. glow discharge. The process parameters were varied systematically. By means of transmission and scanning electron microscopy and X-ray diffraction, the microstructures, including the thicknesses of the compound zones and the diffusion zones of the nitrided steels, were obtained. Using cross-sectional samples and a micro-Vickers indenter, hardness depth profiles were also obtained. From the time and temperature dependences of the hardness profiles, effective diffusion constants and corresponding activation enthalpies were obtained. Furthermore, in an attempt to shed some light on the atomistic nitriding mechanisms, the glow discharges were studied by measuring energy spectra of the energetic ions hitting the cathode (the steel test specimens). It was shown that an increase of the mean energy of the ...
The in-depth distribution of phases in c-BN films deposited by Ion Beam Assisted Deposition (IBAD) at two different ion energy values (300 and 600 eV) was investigated using the quantitative IR transmission measurements and the HREM technique. Whatever the value of the studied ion energies, the characteristic layered morphology of c-BN film is observed including the interfacial sp"2 zone between the substrate and the c-BN volume. In the case of 600 eV ion energy, this interfacial zone is less well-defined in comparison with 300 eV ion energy and the corresponding thickness is more important. Furthermore, the h-BN phase is more diluted within the c-BN film volume showing that the purest phase concentration of c-BN is found for the lowest ion energy, i.e., 300 eV.
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.
Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946?58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10?days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-...
Mesopelagic zooplankton may meet their nutritional and metabolic requirements in a number of ways including consumption of sinking particles, carnivory, and vertical migration. How these feeding modes change with depth or location, however, is poorly known. We analyzed fatty acid (FA) profiles to characterize zooplankton diet and large particle (>51?m) composition in the mesopelagic zone (base of euphotic zone ?1000m) at two contrasting time-series sites in the subarctic (station K2) and subtropical (station ALOHA) Pacific Ocean. Total FA concentration was 15.5 times higher in zooplankton tissue at K2, largely due to FA storage by seasonal vertical migrators such as Neocalanus and Eucalanus. FA biomarkers specific to herbivory implied a higher plant-derived food sou...
In energy industries, it is always of difficulty to produce high heat value(HHV) gas continuously using pulverized coal. In this paper, a new type furnace for partitioned alternative gasification using pulverized coal is developed, in which the oxidation and reduction reaction occur alternatively with the dropping of pulverized coal and finally HHV gas could be continuously obtained at the reduction zone exit and low heat value(LHV) gas at the oxidation zone exit. Furthermore, the gasification characteristics and their factors in furnace are numerically simulated under two dimensional model with a self-coded program, based on heat, mass and energy transfer as well as reaction principles. It is found that the producing rate of HHV gas is 1.10Nm3/kg with heat value of 11.72MJ/Nm3, however, t...
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.
Soufriere Hills Volcano had two periods of repetitive Vulcanian activity in 1997. Each explosion discharged the contents of the upper 0.5-2km of the conduit as pyroclastic flows and fallout: frothy pumices from a deep, gas-rich zone, lava and breadcrust bombs from a degassed lava plug, and dense pumices from a transition zone. Vesicles constitute 1-66vol.% of breadcrust bombs and 24-79% of pumices, all those larger than a few tens of m being interconnected. Small vesicles (few hundreds of m) in pumices are interpreted as pre-dating explosion, implying pre-explosive conduit porosities up to 55%. About a sixth of large vesicles in pumices, and all those in breadcrust bombs, are angular voids formed by syn-explosive fracturing of amphibole phenocrysts. An intermediate-sized vesicle population...
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.
The integrity of the cables located in the target room is very important in the Fire PSA, because the CDF and CCDP are changed according to the results of a cable integrity that depends on the surrounding gas temperature. The conservative assumptions used in the Fire PSA typically specify that all of the equipment and cables of a room would fail when a fire happens in the room. But the realistic assessment of a fire risk by using a fire simulation tool has become necessary in the Fire PSA as described in the ANS Fire PRA Standard. This paper evaluates the cable integrity of eight pump rooms in the nuclear power plant by using the CFAST zone fire model. The upper layer gas temperature of each room is estimated, and an analysis based on the results of model simulations is used to judge the c...
Abstract We suggest a simple scheme for automatically determining the width parameter of smearing methods of the Brillouin zone integration in electronic structure calculation. The scheme retains one free parameter that at any time can be eliminated by choosing a denser k-space mesh until the desired accuracy is obtained. The tests are carried out in the context of Methfessel-Paxton smearing. This adaptive Gaussian smearing (AGS) is easily implemented, variational with respect to partial occupancies and free from spurious occupancies that are negative or larger than one. Its convergence properties are similar to those obtained with the modified tetrahedron method for energy resolution of -0.1 meV. 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
The content and biosynthesis of glycosaminoglycans (GAGs) were studied in pig thigh muscle after acute local {gamma}-irradiation. Seven months following irradiation, the muscular tissue next to the irradiation cone was replaced by severe mutilating fibrosis delimited by an intermediary perifibrotic zone. Results showed a parallel increase of collagen and GAG content in perifibrotic and fibrotic tissues. Sulphated GAGs, heparan sulphate and dermatan sulphate were preferentially accumulated in fibrotic tissue, while the hyaluronic acid content increased only slightly. Synthesis of sulphated GAGs was more elevated in fibrotic tissue than in perifibrotic zone as compared with normal muscle. Seven months after irradiation well-developed fibrotic tissue continued to synthesize and to accumulate extracellular matrix macromolecules. (Author).
A controlled field pilot has been developed in Bozeman, Montana, USA, to study near surface CO2 transport and detection technologies. A slotted horizontal well divided into six zones was installed in the shallow subsurface. The scale and CO2 release rates were chosen to be relevant to developing monitoring strategies for geological carbon storage. The field site was characterized before injection, and CO2 transport and concentrations in saturated soil and the vadose zone were modeled. Controlled releases of CO2 from the horizontal well were performed in the summers of 2007 and 2008, and collaborators from six national labs, three universities, and the U.S. Geological Survey investigated movement of CO2 through the soil, water, plants, and air with a wide range of near surface detection techniques. An overview of these results will be presented.
A three-dimensional (3-D) prestack reverse-time migration algorithm for common-source P-wave data from anisotropic media is developed and illustrated by application to synthetic data. Both extrapolation of the data and computation of the excitation-time imaging condition are implemented using a second-order finite-difference solution of the 3-D anisotropic scalar-wave equation. Poorly focused, distorted images are obtained if data from anisotropic media are migrated using isotropic extrapolation; well focused, clear images are obtained using anisotropic extrapolation. A priori estimation of the 3-D anisotropic velocity distribution is required. Zones of anomalous, directionally dependent reflectivity associated with anisotropic fracture zones are detectable in both the 3-D common-source data and the corresponding migrated images.
This study was undertaken to determine the scope and focus for an integrated assessment of climate change impacts on, and adaptation options for, the Cairns Great Barrier Reef (CGBR) region. To achieve this, the authors employed both technical expertise and regional stakeholder input. This document describes the study objectives and the process used to meet these objectives, and provides an overview of the CGBR region, the views of technical experts on potential climate change impacts, stakeholder prioritisation of impacts and adaptation options, a list of perceived knowledge gaps, and a recommended structure for a future integrated assessment in the region. The aim of the study was to determine the scope and focus for an integrated regional assessment of climate change impacts on, and adaptation options for, the CGBR region. The key objectives of the study ...
We have previously reported that periventricular structures are hypoperfused in attention deficit and hyperactivity disorder (ADHD). This study has expanded the number of patients, who were divided into two groups: six patients with pure ADHD, and 13 patients with ADHD in combination with other neurologic symptoms. By using xenon 133 inhalation and emission tomography, the regional cerebral blood flow distribution was determined and compared with a control group. Striatal regions were found to be hypoperfused and, by inference, hypofunctional in both groups. This hypoperfusion was statistically significant in the right striatum in ADHD, and in both striatal regions in ADHD with other neuropsychologic and neurologic symptoms. The primary sensory and sensorimotor cortical regions were highly perfused. Methylphenidate increased flow to striatal and posterior periventricular regions, ...
Relativistic strongly magnetized winds outflowing from fast-rotating compact objects like millisecond pulsars with surface magnetic fields of $\\sim 10^{15}-10^{16}$ G are plausible sources of cosmological $\\gamma$-ray bursts. In such winds, there are at least three regions where extremely powerful X-ray and $\\gamma$-ray emission may be generated. The first radiating region is the wind photosphere that is at a distance of $\\sim 10^9$ cm from the compact object. The second radiating region is at a distance of $\\sim 10^{13}-10^{14}$ cm. In this region, the striped component of the wind field is transformed into large-amplitude electromagnetic waves. The third radiating region is at a distance of $\\sim 10^{16}-10^{17}$ cm, where deceleration of the wind due to its interaction with an ambient medium becomes important. Radiation from all these regions is ...
A regional analysis of nucleotide substitution rates along human genes and their flanking regions allows us to quantify the effect of mutational mechanisms associated with transcription in germ line...Full Text Available
BackgroundDue to the increased accuracy of Copy Number Variable region (CNV) break point mapping, it is now possible to say with a reasonable degree of confidence whether a gene...Full Text Available
Spectral line intensity data are presented for ionized hydrogen regions in the giant spiral galaxy M101. The influence of interstellar extinction is assessed and electron temperatures of the gas clouds are derived.
BackgroundTo assess the relationship between improved regional and global myocardial function in patients with ischemic cardiomyopathy in response to β-blocker therapy or...Full Text Available
ObjectiveTo refine the CT prediction of emphysema by comparing histology and CT for specific regions of lung. To incorporate both regional lung density measured by CT and cluster...Full Text Available
A critical problem for reliable implementation of regional discrimination is incomplete understanding of how regional seismic signals depend on physical characteristics of the source and propagation path to the recording station. This research is directed...
A 72-year-old male presented with a large ulceroproliferative lesion over left gluteal region. After histopathological confirmation of squamous cell carcinoma, the lesion was excised with wide margins....Full Text Available
BackgroundNorthern Uganda unlike other rural regions has registered high HIV prevalence rates comparable to those of urbanized Kampala and the central region. This could be due to...Full Text Available
Neurons in the hippocampal CA1 region are particularly sensitive to oxidative stress (OS), whereas those in CA3 are resistant. To uncover mechanisms for selective CA1 vulnerability to OS, we...Full Text Available
Multiple discrete regions at 8q24 were recently shown to contain alleles that predispose to many cancers including prostate, breast, and colon. These regions are far from any annotated gene and their...Full Text Available
Surveys were conducted in one urban and two rural regions of the United Republic of Cameroon to estimate the annual incidence of paralytic poliomyelitis. Three different survey methods were used: a...Full Text Available
The diversity of litter ant assemblages in evergreen, deciduous and Shola evergreen (Shola) forest vegetation types of the Wayanad region of the Western Ghats was assessed employing conventional and...Full Text Available
Recent studies have reported that cognitive inflexibility associated with impairments in a frontal-striatal circuit and parietal region is a core cognitive deficit of obsessive-compulsive disorder (OCD)....Full Text Available
The single-stranded viral DNA of an M13 phage recombinant containing the early promoter region of SV40 was hybridized with linear, double-stranded replicative form DNA of a related M13 phage containing...Full Text Available
BackgroundThere are 146 million underweight children in the developing world, which contribute to up to half of the world's child deaths. In high burden regions for malnutrition,...Full Text Available
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.
The South China Sea is an area of disputes on sovereignty and resource jurisdiction claims. As one of the six claimants, the Republic of China (Taiwan) has played an important role not only because it is the originator of the U-shaped lines, but also it has continuously occupied the largest island, Tai-Ping-Dao, in the Spratlys. This article reviews the ROC's position on the issues through an exploration of its maritime claims to the territorial sea, continental shelf, and exclusive economic zone.
The concept of the minimum propagating zone (MPZ) is used to examine the causes of quenches in ISABELLE cosine theta superconducting dipole magnets. The size of disturbances large enough to exceed the MPZ and initiate quenches is estimated and compared with the size of disturbances which may be produced in the magnets. A suggestion for reducing the size of these disturbances through individual support of the coil block is outlined.
This book comprises an up-to-date description of the astrophysical characteristics of the sun, including modern techniques used in solar research. Provides an historical background of solar research and techniques and covers the necessary astrophysics for solar studies, energy generation in the interior, the convection zone, the non- thermally heated layers, and solar wind are described in detail. Also considers the sun in relation to other stars, including information on its variable outputs of light, charged particles, and fields.
The subject of this volume is remote sensing for environmental monitoring and resource management. This session is divided in eight parts. First part is on general topics, methodology and meteorology. Second part is on geology, environment and land cover. Third part is on disaster monitoring. Fourth part is on operational status of remote sensing. Fifth part is on coastal zones and inland waters. Sixth and seventh parts are on forestry and agriculture. Eighth part is on instrumentation and systems. (A.B.). refs., figs., tabs.
In attempting to detect and map out underground facilities, whether they be large-scale hardened deeply-buried targets (HDBT's) or small-scale tunnels for clandestine border or perimeter crossing, seismic imaging using reflections from the tunnel interface has been seen as one of the better ways to both detect and delineate tunnels from the surface. The large seismic impedance contrast at the tunnel/rock boundary should provide a strong, distinguishable seismic response, but in practice, such strong indicators are often lacking. One explanation for the lack of a good seismic reflection at such a strong contrast boundary is that the damage caused by the tunneling itself creates a zone of altered seismic properties that significantly changes the nature of this boundary. This report examines existing geomechanical data that define the extent of an excavation damage zone around underground tunnels, and the potential impact on rock ...
The existence of a narrow peak of electron state density in A-15 is explained by a strong electron-phonon interaction that brings about the polaron narrowing of zone. In the supposition of weak and intermediate bond, the analytical expression for the critical transition temperature is found that corre lates Tsub(c) with phonon spectrum. The model permits to explain Tsub(c) correlation with the number of electrons per atom, temperature direction of resistance, value and temperature dependence of magnetic susceptibility and electron thermal capacity.
The existence of a narrow peak of electron state density in A-15 is explained by a strong electron-phonon interaction that brings about the polaron narrowing of zone. In the supposition of weak and intermediate bond, the analytical expression for the critical transition temperature is found that corre lates Tsub(c) with phonon spectrum. The model permits to explain Tsub(c) correlation with the number of electrons per atom, temperature direction of resistance, value and temperature dependence of magnetic susceptibility and electron tehrmal capacity.
This paper presents results of solid-liquid phase change, driven by volumetric energy generation, in a vertical cylinder. We show excellent agreement between a quasi-static, approximate analytical solution valid for Stefan numbers less than one, and a computational model solved using the CFD code FLUENT®. A computational study also shows the effect that the volumetric energy generation has on both the mushy zone thickness and convection in the melt during phase change.
In 2000, a network of twenty-three piezometers was used to measure hydraulic head in the water-table aquifer (Upper Aquifer Zone of the Upper Three Runs Aquifer, or UAZ of the UTRA) along the ground water outcrops (i.e. seeplines) near the F- and H-Areas.
The invention relates to a pulsed laser ablation method of metals and/or dielectric films from the surface of a wafer, printed circuit board or a hybrid substrate. By utilizing a high-energy ultra-short pulses of laser light, such a method can be used to manufacture electronic circuits and/or electro-mechanical assemblies without affecting the material adjacent to the ablation zone.
During third quarter 1994, samples from AMB groundwater monitoring wells at the Metallurgical Laboratory Hazardous Waste Management Facility (Met Lab HWMF) were analyzed for selected heavy metals, indicator parameters, radionuclides, volatile organic compounds, and other constituents. Eight parameters exceeded standards during the quarter. As in previous quarters, tetrachloroethylene and trichloroethylene exceeded final Primary Drinking Water Standards (PDWS). Bis(2-ethylhexyl) phthalate exceeded final PDWS in one well. Aluminum, iron, manganese, tin, and total organic halogens exceeded the Savannah River Site (SRS) Flag 2 criteria. Groundwater flow direction and rate in the M-Area Aquifer Zone were similar to previous quarters. Conditions affecting determination of groundwater flow directions and rates in the Upper Lost Lake Aquifer Zone, Lower Lost Lake Aquifer Zone, and the Middle Sand Aquifer Zone ...
In-situ air stripping employs horizontal wells to inject or sparge air into the ground water and vacuum extract VOC`S from vadose zone soils. The horizontal wells provide better access to the subsurface contamination, and the air sparging eliminates the need for surface ground water treatment systems and treats the subsurface in-situ. A full-scale demonstration was conducted at the Savannah River Plant in an area polluted with trichloroethylene and tetrachloroethylene. Results are described.
During secondary oil recovery, water is injected into the formation to sweep out the residual oil. The injected water, however, follows the path of least resistance through the high-permeability zones, leaving oil in the low-permeability zones. Selective plugging of these their zones would divert the waterflood to the residual oil and thus increase the life of the well. Bacteria have been suggested as an alternative plugging agent to the current method of polymer injection. Starved bacteria can penetrate deeply into rock formations where they attach to the rock surfaces, and given the right nutrients can grow and produce exo-polymer, reducing the permeability of these zones. The application of microbial enhanced oil recovery has only been applied to shallow, cool, onshore fields to date. This study has focused on the ability of bacteria to enhance oil recovery offshore in the North Sea, where the ...
The principle of operation of shaft furnaces is explained and demonstrated in four practical examples. The conditions and parameters determining coke conversion in the combustion zone and in the Boudouard reaction range are described. The combustion process is treated as a whole while the reduction process is discussed separately for the blast furnace, the cupola furnace, and the shaft furnace. The possibilities describing the Boudouard reaction as a function of the temperature level are discussed and consequences are derived for further experimental and theoretical studies.
Hydrology and hydrogeochemical are auxiliary techniques to valid conceptual hydrogeology an recharge models. Stable isotopes from water trace sources and path flow and Tritium indicates age. This paper is about the use of D 18, D2H y 3H to study the aquifer system on Bajo Cauca antioqueno.
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 zone and its ductility ...
Faults in shallow, unconsolidated sediments, particularly in coastal plain settings, are very difficult to discern during subsurface exploration yet have critical impact to groundwater flow, contaminant transport and geotechnical evaluations. This paper presents a case study using cross-over geophysical technologies in an area where shallow faulting is probable and known contamination exists. A comparison is made between Wenner and dipole-dipole resistivity data, ground penetrating radar, and high resolution seismic data. Data from these methods were verified with a cone penetrometer investigation for subsurface lithology and compared to existing monitoring well data. Interpretations from these techniques are compared with actual and theoretical shallow faulting found in the literature. The results of this study suggests that (1) the CPT study, combined with the monitoring well data may suggest that discontinuities in correlatable zones may indicate that faulting ...
This report highlights the significance of the geological sciences to the nation and to society. Discussions include understanding plate tectonics and surface processes, exploring the continental crust, ocean basins and the deep earth, applications of geology to social problems such as mineral resources, waste disposal, siting of critical facilities, geological hazards, water resources management, and coastal zones. The state of health of geological research is also discussed. (ACR)
To meet growth in the fast developing Pearl River Delta economic zone in China`s Guangdong province, a 270 MW oil-fired combined cycle at Foshan was built and commissioned in only 22 months from financial closure. This article describes the Foshan power station, specifications, design, procurement, construction and operating concerns. 5 figs.
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)
The gas composition of recent thermal waters is in perfect conformity with their geologic-tectonic positions. The composition of gas-liquid inclusions in the basic-hyperbasic xenoliths of basaltoid lavas depends on the depth from which xenoliths are supplied. (The depth is determined by using the methods of geological thermobarometers). By comparing available data the conclusion was drawn that the gas compositions of thermal waters reflect the depth of generation of deep fluid which heats them and depends on the penetration depth of the fluid-conducting fissure zones.
High nitrate contents (up to 200 mgl) has been observed in wells drilled into fractured aquifers lying beneath layers of weathered and decayed rock in the humid tropics where annual rainfall is over 1,000 mm and where there is no notable pollution. The source of the nitrates is linked mainly with localized deforestation by man.
This book contains the Proceedings of the Conference on Climate and Water under the following groupings: Impacts of climatic variability and change-resulting from the changes in hydrological variables; Aquatic environment; Terrestrial environment; Coastal zones and navigation; Urban and industrial water supply and drainage; Energy production; Intropogenic changes of climate and water management problems; Flood potential; Irrigation and land drainage.
This book contains the Proceedings of the Conference on Climate and Water under the following groupings: Impacts of climatic variability and change-resulting from the changes in hydrological variables; Aquatic environment; Terrestrial environment; Coastal zones and navigation; Urban and industrial water supply and drainage; Energy production; Intropogenic changes of climate and water management problems; Flood potential; Irrigation and land drainage.
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).
A total of nine papers were presented at the course with the following titles: peat accumulation and coal basins; coal composition; coal quality; sedimentary environments of coal; generation, storage and migration of natural gas in coal bed reservoirs; geophysical log interpretation; the Ardley coal zone of central Alberta; stratigraphy and sedimentary environment of the Coalspur Formation; and the coal-bearing Luscar Group of western Alberta. All of these papers have been abstracted separately.
Experiments were conducted with field-grown cotton (Gossypium hirsutum L.) in 1985 and 1986 to determine effects of water deficit on levels of conjugated indole 3-acetic...Full Text Available
BackgroundSeveral studies have demonstrated the efficacy of artemisinin-combination therapy (ACT) across malaria zones of the world. Fixed dose ACT with shorter courses and fewer...Full Text Available
Ammonia is a common and highly toxic pollutant which, in sufficient quantities, will adversely affect aquatic organisms. This ammonia criteria document for salt water will allow establishment of regulatory standards for ammonia discharge into estuaries, near coastal zones and oceans. Possible adverse impacts in highly sensitive and abundant ecosystems such as estuaries make regulation particularly important.
BackgroundIn recent years, much attention has been given to the spread of influenza around the world. With the continuing human outbreak of H5N1 beginning in 2003 and the H1N1 pandemic...Full Text Available
By the methods of small-angle X-ray scattering and translucent electron microscopy the existence of inhomogeneity of electron density in hydrogenated films of amorphous silicon is confirmed. The decreased density regions are extended and form a branched network of channels oriented mostly by the normal direction to the films surface. The typical size of the decreased density regions network constitutes 10 nm in the 100-800 nm films thickness range. The increase of hydrogen total partial pressure in gas mixture in case of films growth results at first in the decrease of extension of these regions and than to micropores generation in the network nodal points of the decreased electron density regions.
The influence of heat treatment on the structure, mechanical properties and fracture peculiarities of high-strength (#alpha#+#beta#)-titanium alloy VT22 has been studied. It is ascertained that thermal cycling and subsequent high-temperature aging permit to reduce considerably crack growth rate. Thermal cycling is realized in the following mode: heating in #beta#-region, cooling and allowance in (#alpha#+#beta#)-region, heating in #beta#-region.
The aim of this report is to show how Energetic Planning and Territorial Policy should be working together for a better integration of Renewable Energies into Region. This Integration should to contemplate social, economic and environmental aspects of the territory. The report has been classified into 7 items: planning, energetic scenarios, technology transfer for Renewable Energies dissemination, barriers for this dissemination, environmental aspects, European Union Policy and Decision Support Systems (and specially GIS). (Author) 54 refs.
The Advanced Statistical Trajectory Regional Air Pollution (ASTRAP) model simulates long-term transport and deposition of oxides of and nitrogen. t is a potential screening tool for assessing long-term effects on regional visibility from sulfur emission sources. owever, a rigorou...
This paper is about two arrangements of hyperplanes. The first --- the Shi arrangement --- was introduced by Jian-Yi Shi to describe the Kazhdan-Lusztig cells in the affine Weyl group of type $A$. The second --- the Ish arrangement --- was recently defined by the first author who used the two arrangements together to give a new interpretation of the $q,t$-Catalan numbers of Garsia and Haiman. In the present paper we will define a mysterious "combinatorial symmetry" between the two arrangements and show that this symmetry preserves a great deal of information. For example, the Shi and Ish arrangements share the same characteristic polynomial, the same numbers of regions, bounded regions, dominant regions, regions with $c$ "ceilings" and $d$ "degrees of freedom", etc. Moreover, all of these results hold in the greater generality of "deleted" Shi and Ish arrangements corresponding to an arbitrary subgraph ...
We present a study of the mid-infrared properties and dust content of a sample of 27 HII ``blobs'', a rare class of compact HII regions in the Magellanic Clouds. A unique feature of this sample is that even though these HII regions are of high and low excitation they have nearly the same physical sizes ~1.5-3 pc. We base our analysis on archival 3-8 microns infrared imagery obtained with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope. We find that despite their youth, sub-solar metallicity and varied degrees of excitation, the mid-infrared colors of these regions are similar to those of typical HII regions. Higher excitation ``blobs'' (HEBs) display stronger 8 micron emission and redder colors than their low-excitation counterparts (LEBs).
The results of experiments received on the plasma focus (PF) device with energy stored equal 4 kJ are represented. Photos of the current plasma sheath (CPS), pre-pinch, sphere-like plasma formations are produced with help of the electron-optical converter contained a gated micro-channel plate (MCP) and the CCD-camera imaging system in the visible region. The redial velocity of the CPS is about 107 cm/s. Neon plasma electron density measured with help of the interferograms in the visible region and the spectra in the soft X-ray region is equals to 3?1018 cm-3. Electron temperature is equal to about 200 eV. Discharge integral photos were obtained with help of the soft X-ray pinhole camera. Pictures with 2 ?s resolution of the plasma luminescence above PF anode region were made by CCD-camera.
Summary The aroma impact volatiles of twenty-four pine honey samples produced in Marmaris, Data and Fethiye regions of Turkey were evaluated by solid phase micro extraction/gas chromatography/mass spectrometry (MS) technique and the results were evaluated by using the analysis of variance and Duncan tests. A total of eight common volatiles nonanal, nonanol, decanal, octanal, 16-oxosalutaridine, dodecanal, nonadecane and pentadecane were detected in three regions. The total area of the common volatiles were 73.01%, 78.10% and 73.91% in Marmaris, Data, and Fethiye regions, respectively. There were not significant differences (P-<-0.05) between the common volatiles detected in pine honey samples from three different regions. The major contributers to the pine honey aroma seems to be nonanal (...
The distribution of /sup 35/S-sulfate and /sup 3/H-glucosamine in the angular region of the hamster was studied by light and electron microscopic autoradiography following intraperitoneal injection of these compounds to hamsters. Exposed silver grains of /sup 35/S-sulfate were concentrated in the trabecular meshwork, sclera, and cornea, and grains of /sup 3/H-glucosamine were localized in the trabecular region. The radioactivity of both isotopes was observed in the Golgi apparatuses of the endothelial cells of the angular aqueous plexus and the trabecular meshwork. The grains were noted over the entire cytoplasm, except for the nucleus, and then were incorporated into the amorphous substance and collagen fibers in the region adjacent to the angular aqueous sinus. These results suggest that endothelial cells in the angular region synthesize and secrete the sulfated glycosaminoglycans and hyaluronic acid.
Univariate indicators such as employment are often used to benchmark economic growth at the local and regional levels. However, the tremendous technological and industrial changes in the U.S. economy in the second half of the twentieth century suggest this practice may be outdated. In fact, the singular use of univariate indicators to benchmark regional development may obscure a much richer and more complex web of economic processes. Given the potential complexities associated with regional benchmarking in the current global economy, this paper will explore the numerical differences in economic performance presented by popular univariate indicators of regional growth. Results demonstrate a univariate approach to benchmarking presents an incomplete snapshot of regional performance that is i...
Two criteria, geologic stability and barrier effectiveness, form the basis of the Subseabed Disposal Program's site qualification plan to evaluate the ocean basins and identify those regions having characteristics most favorable for containment of radioactive waste. Stability criteria are used to define those regions least likely to be disturbed by tectonic forces or oceanographic changes during the lifetime of a waste repository. Barrier criteria define those lithologies most likely to form an effective barrier to the release of radionuclides. Two north Pacific regions and three north Atlantic regions (PAC I and II and ATL I, II, and III, respectively) have thus far been selected for further investigation based on the site qualification plan. The PAC I region, centered on the Shatsky Rise in the northwest Pacific, has been subdivided into areas and locations on the basis ...
We studied regional myocardial perfusion by scintigraphic computer-assisted analysis of initial distribution, washout rates, and residual activity of "1"3"3Xe injected into the left coronary artery of four patients with normal arteriograms and 14 patients with coronary stenosis. At rest, residual activity in poststenotic regions was always greater than in control regions, but initial washout rates were not slower. During angina, following xenon injections, the amount of indicator distributed to the poststenotic regions was markedly reduced; the increase of the initial washout rates was smaller than in control regions relative to rest, and residual activity was higher. Initial washout rates did not differ as much as from those of normal myocardium because in severe ischemia too little indicator is deposited initially in these regions to produce a change of any ...
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 gypsum content in the ...
A cylindrical coordinate mathematical model to calculate "2"2"2Rn flux and movement was developed considering "2"2"2Rn production, decay, and diffusion in a multilayered, porous, permeable matrix. Air movement, transporting radon through the media, satisfies Darcy's law and is influenced by the air (barometric) pressure applied at the surface. Two zones of porous material have been defined, one with a "2"2"2Rn production term (the uranium ore zone) and the other without this term to simulate shotcrete or concrete ground support. A provision is made to evaluate the effect of a pinhole in an otherwise impermeable sealant. Comparisons are made between field measurements and predicted values. Specific examples are given of "2"2"2Rn flux from a finite ore-body model versus steady and periodic changes in barometric pressure. Also examined are "2"2"2Rn losses through pinholes for cases of linearly varying and static barometric pressures. The results ...
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 stable orbits within the HZ of such systems, ...
Microstructural analyses by advanced metallographic techniques were conducted on mockup welds and a cracked BWR core shroud weld fabricated from Type 304L stainless steel. heat-affected zones of the shroud weld and mockup shielded-metal-arc welds were free of grain-boundary carbide, martensite, delta ferrite, or Cr depletion near grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the welds were significantly contaminated by fluorine and oxygen which migrate to grain boundaries. Significant oxygen contamination promotes fluorine contamination and suppresses classical thermal sensitization, even in Type 304 steels. Results of slow-strain-rate tensile tests indicate that fluorine exacerbates the susceptibility of irradiated steels to intergranular stress corrosion cracking. These observations, combined with previous reports on the strong influence of weld flux, indicate that oxygen and fluorine ...
Microstructural analyses by several advanced metallographic techniques were conducted on austenitic stainless steel mockup and core shroud welds that had cracked in boiling water reactors. Contrary to previous beliefs, heat-affected zones of the cracked Type 304L, as well as 304 SS core shroud welds and mockup shielded-metal-arc welds, were free of grain-boundary carbides, which shows that core shroud failure cannot be explained by classical intergranular stress corrosion cracking. Neither martensite nor delta-ferrite films were present on the grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the core shroud welds were significantly contaminated by oxygen and fluorine, which migrate to grain boundaries. Significant oxygen contamination seems to promote fluorine contamination and suppress thermal sensitization. Results of slow-strain-rate tensile tests also indicate that fluorine exacerbates the ...
Until the concerns about indoor air quality (IAQ) reached a peak in the last five years, interior zones of office buildings were traditionally served with cooling-only shut-off variable air volume (VAV) boxes. Heat gains from lighting and equipment, in addition to those from occupants themselves, caused supply air quantities of 13 C to 15 C (55 F to 60 F) air to be sustained at rates on the order of 2.5 L/s per square meter (0.5 cfm per square feet), a rate that most designers at the time felt would provide a comfortable and well ventilated environment. More recently, the reduction in lighting loads, the use of cold air systems, and, most importantly, the concern that acceptable indoor air quality may not be maintained at low air flow rates, has led to a different solution in interior zones: the series fan-powered mixing box.
Canisters with spent nuclear fuel can obviously not be located within deformation zones as this might jeopardise their long term mechanical stability and thereby constitute a potential hazard to the biosphere. Less apparent, but equally important, is the fact that earthquakes trigger reactivation, slip, of structures some distance from their hypocentres due to, among many other factors, stress redistribution. Fault slip across a deposition hole might damage the isolation capacity of the canister and thereby jeopardise the overall integrity of the barrier system. Therefore, the following question might be posed: What is the distance from a deformation zone beyond which a canister can be safely emplaced? This respect distance cannot be readily computed because, unknown future events aside, there are some complicated aspects that need to be addressed e.g. degree of conservatism, scale, our ability to model ice sheets and earthquakes, etc. In this ...
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 ...
Mechanical properties of cold-worked molybdenum, grade 4 titanium, and an #alpha#-#beta# titanium alloy are measured with tensile tests and by indentations using conical indenters with 105, 120, and 137 deg included angles. The extent of plastic deformation and pileup around an indentation is measured using profilometry. Various models predicting the extent of plastic deformation and pileup are compared to the actual measured values. As inferred from indentation, the calculated yield strength of the material from the mean pressure does not correlate well to the yield strength measured by tensile testing. The plastic zone size surrounding an indentation can also be used to determine the yield strength of the material, and this does correlate to the yield strength measured by tensile tests. Furthermore, the extent of plastic deformation is relatively independent of the included angle of the indenter for the range of materials used in this system. Models predicting ...
An experimental and analytical study was performed to improve understanding of the dynamic impact behavior of carbon steel pipes. The test program addressed two types of pipe impact scenarios using both 2- and 4-in. Sch-80 pipes and elbows. Projectile-on-pipe tests simulated the behavior of a stationary target pipe which is impacted at its center by a larger, more rigid whipping pipe. These target pipes, which contained non-flowing water at about 290{degree}C temperature and ca 8.5 megapascals pressure, exhibited a peak deformation of up to 45% reduction in their diameter. For each test condition, the local deformation at the impact zone is a function of the peak impact force and impact velocity. Pipe-on-wall tests simulated the impact of an elbow at the free end of a cantilevered whipping pipe with a rigid barrier. The peak crush of the impact zone of the elbows was a function of peak impact force. Numerical analyses of dynamic impact tests ...
Tests with a 61 cm diameter fluidized-bed combustor revealed that raw cotton gin trash could be efficiently burned while satisfying Federal standards for particulate emissions. Certain chemicals within cotton gin trash zone can cause slagging or caking of ash and bed particles in the combustion zone. They can also corrode and accumulate on the heat recovery equipment. These problems are not considered insurmountable and methods of control are being studied. Raw cotton gin trash was also converted into a low Btu gas using fluidized-bed technology. Tests with a 30 cm diameter gasifier revealed that raw gin trash could be converted to a combustible gas, containing carbon monoxide and hydrogen. The heating value of the gas ranged from 3.65 to 5.29 MJ/m3 and about 50 percent of the heat value of the raw trash was converted to combustible gases. Economic analyses have shown that these techniques can be economically competitive with present fuels in ...
The performance of the new combustor was tested. Experiments showed that this combustor has superior insulating quality than the previous one. Measured radial concentrations indicated uniform distribution of the primary fuel (coal) inside the fire tube resulting in reasonably flat concentration profiles. However, measured radial concentrations after the addition of the reburn fuel showed uneven distribution of the fuel resulting in parabolic concentration profiles, an indication of insufficient mixing in the reburn zone. In order to study mechanisms of nitrogenous species destruction in the reburn zone, it is necessary to achieve adequate mixing if the assumption of one dimensional plug flow behavior is to be valid. Thus, it became necessary to modify the injector design and the injection mode of the reburn fuel to achieve an adequate level of mixing which is the focus of this report. The results show that a minimum reburn fuel jet velocity of ...
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 growth was a greater ...
During second quarter 1992, tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, lead, nonvolatile beta, radium-228, thorium-228, or total alpha-emitting radium (radium-226 and radium-228) exceeded the US Environmental Protection Agency Primary Drinking Water Standards (PDWS) in groundwater samples from monitoring wells at the Mixed Waste Management Facility (MWMF) and adjacent facilities. Tritium and trichloroethylene were the most widespread constituents; 55 (48%) of the 115 monitored wells contained elevated tritium activities, and 23 (20%) wells exhibited elevated trichloroethylene concentrations. Sixty-three downgradient wells screened in Aquifer Zone IIB2 (Water Table), Aquifer Zone IIB[sub 2] (Barnwell/McBean), and Aquifer Unit IIA (Congaree) contained concentrations of tritium, trichloroethylene, tetrachloroethylene, chloroethene, antimony, 1,1-dichloroethylene, lead, nonvolatile beta, ...
Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. ...
In the past decade, the large tailings pond (Mildred Lake Settling Basin) on the Syncrude Canada Ltd. lease near Fort McMurray, Alta., has gone methanogenic. Currently, about 60%-80% of the flux of gas across the surface of the tailings pond is methane. As well as adding to greenhouse gas emissions, the production of methane in the fine tailings zone of this and other settling basins may affect the performance of these settling basins and impact reclamation options. Enumeration studies found methanogens (10(5)-10(6) MPN/g) within the fine tailings zone of various oil sands waste settling basins. SRB were also present (10(4)-10(5) MPN/g) with elevated numbers when sulfate was available. The methanogenic population was robust, and sample storage up to 9 months at 4 degrees C did not cause the MPN values to change. Nor was the ability of the consortium to produce methane delayed or less efficient after storage. Under laboratory conditions, fine ...
The infrastructure of the Mexican southeastern coastal zone is affected by corrosion problems which are due, mainly, to the construction bad practices and to the aggressive environmental agents (temp., Relative Humidity, chlorides). The first actions for knowing and controlling them have been taken on the coast of Progreso, Yucatan. Cylinders of solid concrete and others with an embedded rebar were constructed and exposed to the marine environment studying different variables like w/c ratio, time of curing, coated and uncoated rebars, chlorides and CO{sub 2} penetration and place of exposure with respect to the seashore. The cylinders were tested through corrosion potential and polarization resistance measurements in order to detect, in a first stage, the onset and propagation stages of the corrosion processes and to correlate the apparent corrosion current density (Icorr.) with the chloride concentration in the rebar surface. These results are discussed and ...
Coastal zones are among the most productive and vulnerable areas on the planet. An example of impact on these fragile environments was shown in the case of the Sea Empress oil tanker, which ran aground in the Bristol Channel in 1996, spilling 72,000 tonnes of Forties crude oil. The objective was to investigate the sub-lethal cellular pathology and tissue hydrocarbon contamination in marine mussel populations, 4 months after the initial spill, using the neutral red retention (NRR) assay for lysosomal stability in blood cells. NRR was reduced in mussels, and indicative of cell injury, from the two sites closest to the spill in comparison with more distant and reference sites. Lysosomal stability was inversely correlated with polycyclic aromatic hydrocarbon concentrations in mussel tissues. Reduced lysosomal stability has previously been shown to contribute to impaired immunocompetence and to autophagic loss of body tissues. The use of this type of technique is ...
High-resolution sequence stratigraphy has been applied widely in the petroleum exploration and development, many achievements have been achieved. However, it is in the beginning stage that high-resolution sequence stratigraphy is applied to explore the sandstone-type uranium deposits in Erlian Basin. By applying principles of high-resolution sequence stratigraphy and taking typical boreholes as an example, sedimentary cycles of Saihan Formation, the ore-bearing formation in Baiyinwula area are divided and correlated through cross sections. One long-term cycle (LSC_1), two middle-term cycles (MSC_1, MSC_2) have been identified in this study. Based on this and combined with the mineralization character of sandstone uranium deposits in this area, it is presented that the interlayer oxidation zone is developed mainly in the rising hemicycle of MSC_1 and uranium ore bodies predominantly in channel sand bodies that were developed in the system tract with low ...
Cretaceous and Tertiary strata are known from outcrop in the northeast part of the area, while older rocks are presented in the southwest. The major structures are, from north to south: the Pedley Thrust, Coalspur Triangle Zone (formerly called Coalspur Anticline), Entrance Syncline, Mercoal Thrust, Brazeau Flats, Brazeau Thrust, Brazeau Syncline, Grave Flats Thrust, Cadomin syncline and Nikanassin Thrust. The economic coal seams of the Tertiary Coalspur Formation are of high volatile C rank and are present in three parallel bands in the Entrance Syncline and Coalspur Triangle Zone, where they have been mined extensively in the past. The Mercoal band is the southernmost and dips about 30[degree] to the northeast. The Coalspur band is in the middle and dips generally to the southwest. The Robb band is the northernmost band, contains northeast dipping strata and is less deformed than the Coalspur band. In the Entrance Syncline, the Coalspur coals ...
This article presents an experimental study on the gasification of leather residues from a tannery by using a throated 10 kW{sub e} downdraft gasifier. The gasification process is conducted over a range of feed rates in the gasifier for the operating temperatures of 1,000 deg C and 1,100 deg C, slightly below atmospheric pressure. In this study, the experimental setup and procedure are also explained in detail. Moreover, the fuel characteristics, components in the produced gas, and side products from the gasification system were measured during the experiments and discussed. It was concluded that the briquetted leather residues were successfully gasified in a downdraft gasifier. However, the large briquette sizes of the leather residues occasionally formed bridging in the throat zone of the gasifier. Therefore the downdraft gasifier should be operated using smaller size briquettes to prevent the bridging in the throat zone in order to ...
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 reliability index is defined by the minimum distance from the limit state surface to the origin of the ...
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 ...
The success in developing of the oil industry operating in offshore-onshore terminals, connected by pipelines with the facilities of the coastal zone, can be attributed partially to the beach morpho dynamic monitoring. This study represents a solution to the concerns of the technical operations in coastal zones because it minimizes the impact of the petroleum production and it assures the environmental protection associated to the risks of the pipelines breaking. This impact type results mainly of the vertical and horizontal displacements of the beach, from the coastal dunes to the shore face. The mobility of the profile is associated to the magnitude of the sedimentary processes, which reproduce naturally or not, in scale of time that can vary among few days, years or decades. For the monitoring and interpretation of the beach profile mobility the following methods are recommended: calculation of the closure depth with base in the wave data; ...
Past movement on faults can be dated by measurement of the intensity of ESR signals in quartz. These signals are reset by local lattice deformation and local frictional heating on grain contacts at the time of fault movement. The ESR signals then grow back as a result of bombardment by ionizing radiation from surrounding rocks. The age is obtained from the ratio of the equivalent dose, needed to produce the observed signal, to the dose rate. Fine grains are more completely reset during faulting, and a plot of age vs. grain size shows a plateau for grains below critical size; these grains are presumed to have been completely zeroed by the last fault activity. We carried out ESR dating of fault rocks collected near the Gori nuclear reactor. Most of the ESR signals of fault rocks collected from the basement are saturated. This indicates that the last movement of the faults had occurred before the Quaternary period. However, ESR dates from the Oyong fault zone range ...
Antibodies to Ehrlichia canis were detected by indirect immunofluorescence in sera from 233 of 2,077 (11%) military working dogs in various locations throughout the world and from 535 of 938 (57%) civilian dogs in the United States during a 1-year period of study. Overall, E canis infection rates ranged from 13% in the tropical and temperate zones below 45 degrees N to 8% in the cold zone north of 45 degrees N latitude. The highest antibody prevalence rate (24%) was found among a select population of dogs stationed between 40 degrees and 45 degrees north latitude (Japan and Okinawa). The seropositive military dogs did not have clinical signs of ehrlichiosis, thus indicating that the predominant form of infection was subclinical. On the other hand, 216 (23%) of the seropositive civilian dogs had various signs of the disease. The difference was attributed to the fact that the sera from civilian dogs were submitted by practitioners who suspected ...
The population masses in many coastal zones in Japan, and human activities are greatly effected. The representative water area is the Tokyo Bay. The population of the Tokyo Bay reaches 26 million at present, and a mass of organic substance and nutrient salt flow into it through rivers and sewage-treatment plants, etc. With the improvement of pollution source countermeasure and sewerage in the area, the inflow load to the Bay gradually decreases, but in the inner bay, red tide is generating in the summertime mainly. And, the anoxic water areas observed in bottom layer in summertime make large effects on the seafood. It is a large theme to clarify formation process of the anoxic water area and to solve this problem for the Tokyo Bay in the twenty-first century. In this paper, changes in water qualities and human activities and fundamental approach of water quality conservation of the Tokyo Bay are described. As maintenance and regeneration countermeasures of the ...
Zone modeling permits taking account of the effect of load-relieving air conduction systems in the planning of HVAC plants. Although this only supplies average values for the degree of load and height of the fresh air layer rather than a detailed description of concentration and temperature distributions in the room, it is quite sufficient for the planning of load-relieving air conduction systems. Moreover, the cost of zone modeling in the planning of HVAC plants remains within reasonable limits. Upscale planning, instruments can thus be reserved for more exacting problems. (orig.) [Deutsch] Zonenmodelle erlauben die Wirkung lastmindernder Luftfuehrungen bei der Planung von RLT-Anlagen zu beruecksichtigen. Sie liefern zwar nur Mittelwerte fuer den Belastungsgrad und die Hoehe der Zuluftschicht und keine detaillierte Konzentrations- und Temperaturverteilungen im Raum. Diese Werte reichen jedoch fuer die Planung lastmindernder ...
The integrity of the cables located in the target room is very important in the Fire PSA, because the CDF and CCDP are changed according to the results of a cable integrity that depends on the surrounding gas temperature. The conservative assumptions used in the Fire PSA typically specify that all of the equipment and cables of a room would fail when a fire happens in the room. But the realistic assessment of a fire risk by using a fire simulation tool has become necessary in the Fire PSA as described in the ANS Fire PRA Standard. This paper evaluates the cable integrity of eight pump rooms in the nuclear power plant by using the CFAST zone fire model. The upper layer gas temperature of each room is estimated, and an analysis based on the results of model simulations is used to judge the cable integrity. According to the analysis results, the integrity of the cable located in the upper layer in the pump rooms is maintained without any thermal damage, and the CCDP ...
This article discusses the proper use of sandy land in China from the viewpoint of ecology. The many low-yield fields in every locality across China include sandy land that is unsuited to the cultivation of grains such as paddy rice, corn and wheat. Separate investigations of the northern plain and the southern coast between 1980 and 1982 demonstrated that sandy land in a warm climatic zone (e.g. Huang He) is suited to peanuts, soybeans and other oil-bearing crops; that forestation can be carried out on sandy land in Inner Mongolia and Xinjiang; and that coastal sandy land has much salinity and is best suited to growing horsetail beefwood. Moreover, the creation of windbreaks along the coasts of southern China has lessened the threat of wind-blown sand which had made rice not worth cultivating on sandy land. It is concluded that different crops can be grown on the sandy soil of China's temperate, warm, semitropical and tropical zones.
Up to now the long range filaments have been considered as a balance between Kerr focusing and defocusing by plasma generation in the nonlinear focus. However, it is difficult to apply the above explanation of filamentation in far-field zone. There are basically two main characteristics which remain the same at these distances - the super broad spectrum and the width of the core, while the power in a stable filament drops to the critical value for self-focusing. At such power the plasma and higher-order Kerr terms are too small to prevent self-focusing. We suggest here a new mechanism for stable soliton pulse propagation in far-away zone, where the power of the laser pulse is slightly above the critical one, and the pulse comprises super-broad spectra. For such pulses the diffraction is not paraxial and an initially symmetric Gaussian pulse takes parabolic form at several diffraction lengths . The stable soliton propagation appears as a balance ...
Apparatus for minimizing thermal loss in a windowless, open cavity solar receiver due to airflow at the receiver aperture includes means for deflecting wind away from the cavity opening such that flow stream reattachment occurs away from the receiver aperture to provide a dead air zone at the cavity opening. This prevents turbulent-mixing airflow exchange between ambient air and heated air within the solar receiver. The wind deflector apparatus includes either a passive annular deflection foil at the receiver aperture, or an active device for producing an outwardly projected air jet at the receiver aperture.
The bibliography contains selected abstracts of research reports covering studies dealing with water pollution from estuarine and coastal development, the effects of this pollution, and its control. The reports are general in nature so as to be of interest to any coastal area. The topics include pollution as related to urbanization, government actions, coastal planning, natural resource development, and sewage and solid waste disposal. Specific biological and oceanographic studies have been excluded. (This updated bibliography contains 112 citations, 42 of which are new entries to the previous edition.)
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.
Study results on long-term thermal and corrosion resistance of packs with electro-insulation layer of aluminium nitride are presented. Structural changes of nitride ceramics and contact zones between metal and ceramics are considered. It is shown that multilayer metallo-ceramic packs, manufactured by gas-phase technology have high electro- and thermophysical properties, high thermal and corrosion resistance relative to cesium vapor, vacuum density as well as high thermo-resistance. 8 refs., 4 figs.
This paper consists of two parts. Part 1 deals with the thermodynamic and thermoeconomic methodology of a trigeneration (TRIGEN) system with a rated output of 6.5 MW gas-diesel engine while the application of the methodology is presented in Part 2. The system has been installed in the Eskisehir Industry Estate Zone in Turkey. Thermodynamic methodology includes the relations and performance parameters for energy and exergy analysis, while thermoeconomic methodology covers the cost balance relations, cost of products and thermodynamic inefficiencies, relative cost difference and exergoeconomic factor. (author)
A nonlinear relationship between the time of accelerated aging of Lupine seeds and the indices of its survival as well as the single-strand DNA amount in cells from these seeds is established. The character of this relationship is essentially altered in chronically irradiated lupine seeds from the Chernobyl NPP exclusion zone and seems more complicated. The possible role of repair systems in these effects is discussed. The fact that chronic irradiation in low doses can modify the course of senescence in lupine seeds reflects its high biological efficiency comparing with acute irradiation.
Industrial activities in the river basin of the Elbe have a very long tradition, and have been resulting in the contamination of sediments for centuries. Contamination lasted until the fall of the iron curtain; since then, the situation has improved significantly. In the transition zone between freshwater systems and the marine environment, ports like Hamburg still have to bear this burden of history. An overall (contaminated) management strategy should be developed in the context of the European Water Framework Directive with the emphasis on source control. (orig.)
The Daya Bay reactor neutrino experiment is located at the Daya Bay nuclear power plant in Shenzhen, China. The experiment deploys eight 'identical' antineutrino detectors to measure antineutrino fluxes from six 2.9 GWth reactor cores in three underground experimental halls at different distances. The target zone of the Daya Bay detector is filled with 20 t 0.1% Gd doped LAB liquid scintillator. The baseline uncorrelated detector uncertainty is ?0.38% using current experimental techniques. Daya Bay can reach a sensitivity of sin22?13<0.01 with baseline uncertainties after 3 years of data taking.
The platinum-silicide layer was investigated as the anode contact of a high-power P-i-N diode. The thermal stability at 700 deg. C was found sufficient for the purpose of Pt in-diffusion from the platinum-silicide layer into the volume. The diffusion, which was controlled using the radiation defects resulting from the 10 MeV alpha particle irradiation, represents a new local lifetime control in the float zone silicon with very low-leakage current, while keeping the benefits of traditional approaches.
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.
Stream invertebrates that feed on leaf litter are intimately tied to the nature and timing of the litter input. These invertebrates are called shredders; they consume streamside, riparian litter that has become trapped in the stream channel. This plant litter accumulates at the leading edge of obstructions in the current and settles out in pools, alcoves, and other depositional zones. Given the extensive literature that has accumulated over the last 20 years, researchers can now develop a general, testable model that relates riparian plant communities to the stream shredders, which depend upon litter derived from those communities.
The purpose of SEADEX was to acquire a comprehensive, high-quality data base for evaluating models of dispersion within coastal zones, it secondary objective was to provide data to help determine which meteorological measurements are most appropriate for emergency preparedness at nuclear power plant sites. The study was conducted in the vicinity of Kewannee, Wisconsin, on the western shore of Lake Michigan. This report describes the design of the study and the data base resulting from it. Both a gas tracer (SF/sub 6/) and a particulate tracer (oil fog) were used. (ACR)
This document presents the proceedings of the Areva technical days, presented during the session 5 the 9 and 10 december 2004, at Istanbul. It deals with the operations of the transmission and distribution division. With manufacturing facilities in over 40 countries and a sales network in over 100, Areva offers customers technological solutions for nuclear power generation and electricity transmission and distribution (the Group also provides interconnect systems to the telecommunications, computer and automotive markets). It provides five topics: a general presentation of Areva, the strategic stakes for transmission and distribution by world-zone, economic and strategic stakes of business unit products, business unit systems and business unit automation. (A.L.B.)
Results are given for deep-level petroleum and gas drilling probes in various coastal zones of Southern Sakhalin covering the Poronai depression and the Aniv Bay trough. The exploratory probes indicate that the Middle Miocence deposits of the Boundary trough contain commercial-size deposits of petroleum, that commercial-size gas deposits are in the upper Myocene deposits of the Aliv Bay trough, and that the upper Cretaceous and Cenozoic deposits of the eastern section of Southern Sakhalin lack folded deformations. 7 references, 2 figures.
Studied are the mechanical properties of welded joints and heat affected zones of the Kh8N10T steel and OT4 and VT1-2 titanium alloys on welding in Ar+deltaF_6 and Ar+CCl_2F_2 mixtures contributed to a decrease of porosity. Tensile and impact tests of welded joints have revealed that additions of sulfur hexafluoride into argon causes a decrease of impact strength in titanium alloy when the tensile strength does not depend on the composition of a halogen-containing atmosphere. Freon (CCl_2F_2) additions decrease only slightly the impact strength of the investigated alloys.
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 .
The Marine Technology Society 1994 conference was held in Washington, D.C., September 7-9, 1994. Titled Challenges and Opportunities in the Marine Environment, the conference offered a wide variety of presentations. State-of-the-art technology, government policies and regulations, and environmental concerns were addressed. Offshore mining, coastal zone management, marine engineering, oceanographic research, educational issues, and global climate change were also well represented in the presentations. The conference proceedings are organized around the daily sessions and roughly 70% of the papers are included.
A new lens was installed in the laser; the laser power was lowered and solar cells were made at different power levels. The concentration of the silver neodecanoate solution was changed to reduce linewidth. A cell fabrication run was completed using low-resistivity float-zone silicon. Experiments were initiated to investigate the use of titanium organometallic film, which not only forms an AR coating with a 400/sup 0/C hard bake, but may also help in bypassing front-metal evaporation because of high-reactivity of Ti with silicon. Progress in these areas is discussed.
Indian PHWRs are designed to operate with natural uranium (NU) as the main fuel. Earlier in the initial fresh core, to achieve flux flattening and hence to operate the reactor at design rated power, limited number of depleted uranium bundles were loaded in the central portion of the core. Presently even in fresh core about 40 % of the core is loaded with depleted uranium bundles (?0.6 wt % 235U) from the consideration of conserving the natural uranium fuel. This is achieved by loading most of the depleted bundles in the peripheral locations of the channels. Successful operation with large number of DU bundles in the fresh core has been proven in MAPS - 2 and MAPS - 1cores after EMCCR as well as in TAPP - 4. In these three reactors 100 % FP was possible even with 40 % DU bundles in the core. In TAPP-4 and 3 initial core, depleted bundles of 0.36 wt % 235U are also loaded to conserve the depleted bundles of 0.6 wt % 235U. Depleted uranium bundles (?0.6 wt % 235U) have been used in the ...
In situ air stripping (ISAS) technology was developed to remediate soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISAS employs horizontal wells to inject (sparge) air into the ground water and vacuum extract VOCs from vadose zone soils. The innovation is creation of a system that combines two somewhat innovative technologies, air sparging and horizontal wells, with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.
Metallic contamination was monitored with Surface Photovoltage (SPV) technique in integrated circuit manufacturing facilities. Conventionally, Czochralski silicon bulk materials were used as monitor wafers. However, it has been observed that the diffusion length and the `Iron' concentration measured with SPV were inconsistent from run to run in one facility. The inconsistency is believed to be due to oxygen precipitate in silicon materials during the thermal cycle. By using low oxygen concentration or Float Zone wafers, metallic contaminants can be monitored more accurately and consistently.
The effect of high-energy-density laser surface melting on the morphology and properties of a cast Ni-based superalloy containing 33 wt percent Mo and 17 wt percent W is investigated experimentally. Significant improvements in the hardness and the wear resistance in both dry and acid environments are atttributed to the elimination of segregation in the laser-treated zone, where solid solubility increases, crystalline structure becomes finer, and the fine dendritic, cellular dendritic, cellular, and plane-front solidification structures are evenly distributed.
In Situ Bioremediation (ISB) is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation. This process (ISB) involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove Volatile Organic Compounds (VOCs) from the vadose zone concomitant with biodegradation of the VOCs. This process is effective for remediation of soils and ground water contaminated with VOCs both above and below the water table. A full-scale demonstration of ISB was conducted as part of the Savannah River Integrated Demonstration: VOCs in Soils and Ground Water at Nonarid Sites. This demonstration was performed at the Savannah River Site from February 1992 to April 1993.
In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISB involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove .VOCs from the vadose zone concomitant with biodegradation of VOCs. The innovation is in the combination of 3 emerging technologies, air stripping, horizontal wells, and bioremediation via gaseous nutrient injection with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.
This paper reports on high resolution electron microscopy used to investigate the effect of electron irradiation induced oxygen loss on the states of partial order in YBa_2Cu_3O_z. Contrast effects visible in the [001] zone image as a result of the degree of the out-of-plane correlation of these ordered states are investigated. Using statistical simulations to aid in the analysis of the HREM images, an interpretation based on a kinetically limited evolution of the variation of long range [001] ordering is proposed.
Molten zone recrystallized as well as sheet grown polycrystalline silicon has shown a minimum in the temperature dependence of the Hall mobility. In order to explain this experimental finding a new model is proposed, which is based on negatively charged grain boundaries for the p-type silicon material under study. This results in a potential well at the grain boundaries instead of the more generally observed potential barrier. A key feature in the model is that the space charge density at the grain boundary depends on the Fermi level position and therefore on temperature. In addition, the change in the measured Hall mobility before and after hydrogen passivation of the grain boundaries is discussed.
The components with masses 32 and 64M _s_u_n, evolved with the matter mixing in the semiconvective zone and filling their Roche lobes, after the main-sequence evolution overflow their Roche lobes and lose matter during the first part of the helium core burning. After the overflow end, the components lose the matter by stellar wind. The components shrink in the nuclear timescale. At first, they have the blue supergiant character with anomalous CNO abundance, then - the Wolf-Rayet stars character.
The sensitivity of the primary circuit material was examined at the Mochovce and Dukovany NPPs. No significant sensitivity of the base material or the weld metal to the initiation of corrosion cracking was observed. Thermal aging was found to accelerate significantly the corrosion fatigue kinetics in the material of the heat affected zone. The threshold values of the double amplitudes of the stress intensity factor were below 8 MPa/m"2 for the materials examined, with a cycle asymmetry coefficient of 0.65. The tests revealed no appreciable sensitivity to general corrosion, pitting, or intergranular corrosion. (J.B.). 7 tabs., 26 figs., 11 refs.
DescriptionFarm-level estimates of the financial impact of regulation are important indicators of the effect that a regulation have. Such estimates should be included in RIA, particularly within the Small Firms Impact Test. This farm-level analysis can be used in the RIA to inform judgements of the affordability of the regulation proposal. It will help to identify which farm types are likely to be financially had-hit from the regulation. Farm-level cost estimates for each regulation are also required t [continued...
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.
The ion nitriding treatment is a process widely used in steel alloys to improve the material's properties; such as surface hardness, resistance to wear, fatigue life and resistance to corrosion. But geometric changes in the components can produce during the nitriding process different effects on the behavior of the plasma, such as local variations in the electric field, an empty cathode effect, etc. These in turn can affect among other factors the local temperature and therefore the kinetics of the process, generating variations in the compound layer thicknesses and zone of diffusion, and micro-hardness profile. These heterogeneities limit the effectiveness of the plasma nitriding process, where control and duplication of the surface modification are most important. This work aims to study the effect of the geometry of the pieces treated with ionic nitriding, especially the effect of the orifices. An understanding of the operating mechanisms is sought in order to ...
There is very little quantitative documentation of actual improvements resulting from the installation of new general ventilation systems in industrial settings. Therefore the performance of the common mixing design principle was compared to the displacement design principle by means of an intervention study in a workshop (V = 12,000 m[sup 3]), where thermoplastics were moulded. An experimental signal-response tracer gas technique was used. In terms of supplying fresh air to the zone of occupancy the displacement system was better than the mixing system by a factor of 2. In terms of the exposure level to a simulated contaminant (tracer gas) the displacement system was better by a factor 1.5-18. (author)
The report is divided into six working group discussions on the following subjects: 1) Chemical and physical mechanisms in the formation of uranium mineralization, geochronology, isotope geology and mineralogy; 2) Sedimentary basins and sandstone-type uranium deposits; 3) Uranium in quartz-pebble conglomerates; 4) Vein and similar type deposits (pitchblende); 5) Other uranium deposits; 6) Relation of metallogenic, tectonic and zoning factors to the origin of uranium deposits. Each working group paper contains a short introductory part followed by a discussion by the working group members.
A theoretical analysis is presented for the method of determining the concentration distribution of admixtures in zone melting and in the study of diffusion in melts. Continuous mode X-ray fluorescence analysis is considered. The convolution integral interpreting the analog output of the ratemeter was solved applying the mathematical apparatus of Z transformation. The feasibility of the method is tested on an example of the determination of tin distribution in tungsten. With respect to the statistical error (#delta#<1.5%), the maximum integration constant (100 s) and a very slow sample feed (0.025 mm/s) were used. The calculated transfer function reflects the total transfer function of the ratemeter and the recorder used. (M.D.).
The decontamination of the urban building surfaces, based on the covering of clay suspensions, has been studied. Contaminated samples for test purpose were prepared by application of radioactive solution which was extracted from the soil of 2 km zone of the Chernobyl Nuclear Power Plant(ChNPP). The cation converting conditions of clay suspensions were determined by the experiments of swelling and stability of the suspensions. According to the experimental results, the most effective clay suspension was the NH{sub 4}-type which had a 7.1 of decontamination factor(DF) on Cs and 4.5 of DF on total nuclides after 3 times covering on slate.
In November 1977, 627 soldiers belonging primarily to the First Battalion, 82nd Airborne Division, stationed at Fort Bragg, were sent to the Canal Zone, Panama, for jungle warfare training. A medical surveillance program incorporating pre- and post-evaluations over a 6-month period with dermatologic examinations, questionnaires, and serologic tests was established. Ten cases of cutaneous leishmaniasis (1.6/100 men) were diagnosed by positive Leishmania culture. The demonstrated lack of sensitivity and specificity of the indirect fluorescent antibody test and the direct agglutination test render these serological methods useless as diagnostic screening methods in the early stages of this disease. PMID:7406101
A collection of 14 papers from a June 1981 seminar assess the costs of damage caused by water pollution. The seminar focused on the economic rather than the legal standpoint by evaluating the cost of the clean-up operations themselves and other costs, such as direct or indirect economic losses, and converting into money terms the damage to the environment, the loss of recreational facilities, and biomass losses. The papers are grouped into four sections which look at the scale of risk, the clean-up costs for specific oil spills, other costs inflicted on coastal zones, and legal aspects of compensation. Separate abstracts were prepared for each of the 16 papers selected for the Energy Data Base.
The objectives of this paper are to document the physicochemical and aquatic toxicological quality of a beneficial-use produced-water discharge and its effect on a receiving stream in Wyoming. Fish and water-flea survival, growth, and reproduction tests indicated that the discharge and all other sampling stations passed the state effluent biomonitoring acute toxicity testing endpoints. while benthic macroinvertebrates were absent at the discharge point designated by the Natl. Pollutant Discharge Elimination System (NPDES), productive and reproducing populations were present at all other downstream and mixing-zone stations. This investigation confirmed the validity of the beneficial-use subcategory for this oilfield discharge.
Measurements of carbon metabolism, production and exchange along food webs suggest that large fractions of the organic matter produced on continental shelves must be exported to continental slopes. The annual loss of organic matter from continental shelf ecosystems is far greater than in the open ocean. If part of the loss of nearshore primary production has increased in those coastal zones where anthropogenic inorganic nutrient supplies have been consistently increasing since the industrial revolution, then burial and diagenesis of this material in slope depocentres could represent the missing BMTs of carbon in global CO/sub 2/ budgets.
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)
The pM{sup '}-pC{sub H} diagrams allowed to determine the saturation and non-saturation zones of Lu(OH){sub 3} in solid phase and those were applied for determining the hydrolysis and lutetium solubility constants, using the radioactive isotope Lu-177. The first constant of hydrolysis was also determined by the potentiometric method in absence of solid phase. (Author)
By the linear augmented plane wave method (APW) the energy zone of silver and technetium structure is calculated. The potential has been determined by means of superposition of atomic charge densities according to slater exchange method. Total and partial state densities have been calculated by the tetrahedron method. The APW-method convergence on the example of silver is studied, the comparison with the calculation results by the APW method and other data is carried out. The APW method high efficiency is pointed out. In dipole approximation the intensity distribution in L"3, M"5 N"3 technetium emission spectra is calculated.
An integrated approach to the modelling of hydrogen assisted failure in 316L steel is presented. The approach includes experimental, fractographic, numerical and theoretical analysis of the phenomenon. The physical adequacy of the mechanical models of hydrogen embrittlement (notch extension model and notch cracking model) is discussed by comparing the virtual damage depth (theoretical) predicted by the models with the embrittled zone (microphysical) measured in the fractographic analysis by scanning electron microscopy. In addition, a numerical modelling of hydrogen diffusion is performed, concluding that bulk diffusion is not important in hydrogen embrittlement of 316L steel, so that hydrogen transport accelerated by the microdamage itself should be taken into account. (orig.)
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.
PurposeThis prospective study followed 61 patients who were partially dentulous and considered to have insufficient bone volume for routine implant treatment and consequently underwent sinus inlay bone grafting.Patients and MethodsThe patients were treated with maxillary sinus floor augmentation with particulated autogenous bone from the mandibular ramus/corpus. After a healing period, dental implants (n = 180) were installed.ResultsRadiographic examination revealed average residual vertical bone heights of 6.5 mm in the first premolar region, 3.8 mm in the second premolar region, 3.5 mm in the first molar region, and 2.6 mm in the second molar region. The average implant lengths were 12 mm in the first premolar region and 11 mm in the second premolar, first, and second molar regions. All ...
The transition region between the straight part and the ends of the coils of the LHC model and prototype dipole magnets are often identified as the origin of training quenches. In order to study how the discontinuities in the material properties of these regions affect coil pre-stress and possibly gain more insight in the quench behavior, a program was set up at CERN to analyze by 3D-FEM these particular regions. The ACCEL team, who performed a similar analysis for the main quadrupoles of the Superconducting Supercollider SSC, is entrusted with this program. In this paper we report on the results of 3D-modeling and analysis of the coil return end region, including the complete coil mass, of a 1-m single bore model magnet. This magnet represents all relevant features of the "two-in-one" LHC main dipole design concerning the winding configuration, the collar pack, the yoke, and the outer shell ...
The aim of this work is to the application of a methodology to evaluate the energy associated to the industrial solid wastes in the metropolitan region of Campinas. The methodological route proposed is: the characterization of the research area and the production/management of the industrial solid wastes; the energetic classification and the qualitative/quantitative research of the energy associated to the industrial solid wastes; and, the valuation of the applicability of the energetic utilization mechanisms proposed to the region. This methodology when applied at the Campinas metropolitan region proved to be valid and it resulted in a synthetically presentation of the social and environmental reality of the industrial sector and the destination of the wastes, as well as it indicated the potentialities related to the energetic utilization of the industrial solid waste in the region. With the obtained ...
Characteristics of inertia gravity waves associated with convection are investigated in the lower stratosphere using high-resolution radiosonde data observed from 18 June to 15 July of 2005 and 2007 in Korea. Three-dimensional ray-tracing model and reanalysis data are used to investigate the propagation and the sources of the observed waves. The observed waves associated with convections are discriminated based on the existence of convections when and where the rays reach the average height range of convective clouds. Waves observed in 2005 and 2007 show similar spectral characteristics, but wave energy in 2007 is significantly larger than in 2005. The observed waves propagate from three source regions: the northeastern, southeastern, and western regions around Korea. They show preferential propagation directions based on their sources, and convections from the western region generate larger-amplitude gravity waves than the ...
A high power AlGaInP single quantum well graded index separate confinement heterostructure. It comprises a substrate and a multiplicity of layers deposited thereon comprising a single Ga{sub x}In{sub x}P quantum well where x has a value from about 0.4 to about 0.6; multiple graded index regions on both sides of the quantum well and cladding layers adjacent to each graded region of the well, the graded region comprising Al{sub y}(Ga{sub 1{minus}y}){sub 0.5}In{sub 0.5}P quaternary alloy; wherein the value of y in the graded region varies from about 0.2 at the quantum well/graded region interface to up to about 0.6 for the cladding layers/graded index regions; the heterostructure having a low broad area threshold current with pulsed thresholds in the range from about 1 to about 2 Amps/cm{sup 2} and a differential efficiency of from about 20 to about 60 percent.
Computer simulated small-angle neutron scattering curves of spherical poly disperse extruded unilamellar liposomes from saturated 1,2-diacylphosphatidylcholines in the aqueous phase are evaluated by using a multi shell model, which divides the lipid bilayer of liposomes into the polar head group region, and the nonpolar hydrocarbon region consisting of the chains of methylene groups and of the region of methyl groups. In the each of these regions, the coherent neutron scattering length density is supposed to by homogeneous. The evaluation is based on obtaining of radius of gyration from Kratky-Porod plot of small-angle neutron scattering data in the Guinier region of small scattering vector values. From radii of gyration obtained at several different molar fractions N_D_2_O/(N_D-2_O + N_H_2_O) in the aqueous phase (contrasts) and independent volumetric data, the lipid surface area ...
In CANDU reactors, the Regional Overpower Protection Trip (ROPT) system protects the reactor against overpowers in the reactor fuel, whether due to localized peaking within the core or a general increase in core power levels. Due to Primary Heat-Transport System (PHTS) aging the ROP trip setpoint is decreasing over time. Reductions in ROP trip setpoints are required to maintain the required trip-probability and ROP trip effectiveness, and results in a decrease of the ROP margin-to-trip during normal operation. In addition, full power operation can be threatened. In this point, to recover ROPT margin, channel power needs to be redistributed. ROPT setpoint is very conservative in normal operation because distortion of regional overpower is over 1.2 times as nominal power in slow loss of regulation (SLOR). Channel power ratio (CPR) is enough low except the limiting channel of which worst case of design basis flux shape. If the outer channel power ...
To understand evolutionary and environmental effects during the formation of high-mass stars, we observed three regions of massive star formation at different evolutionary stages that reside in the same natal molecular cloud. Methods. The three regions S255IR, S255N and S255S were observed at 1.3 mm with the Submillimeter Array (SMA) and followup short spacing information was obtained with the IRAM 30m telescope. Near infrared (NIR) H + K-band spectra and continuum observations were taken for S255IR with VLT-SINFONI to study the different stellar populations in this region. The combination of millimeter (mm) and near infrared data allow us to characterize different stellar populations within the young forming cluster in detail. While we find multiple mm continuum sources toward all regions, their outflow, disk and chemical properties vary considerably. The most evolved source S255IR exhibits a ...
Satellite imagery is a cost-effective tool for creating and updating basemaps of coastal zones, especially where existing maps and aerial photographs are unavailable, are out-of-date, or provide limited information. Reliable maps of coastal zones are particularly important for oil spill modelling programs. Color IR (multispectral) images with 20m x 20m ground resolution and black & white (panchromatic) images with 10m x 10m ground resolution of many coastlines around the globe have been acquired from 1986 to present by SPOT Image Corporation. We have digitally merged same-day SPOT panchromatic and multispectral imagery to provide maximum spatial resolution and permit excellent color differentiation of coastal zone features. This combination adequately discriminates individual features, including pipelines, offshore platforms, storage tanks, jetties, and shoreline type. The SPOT images were interpreted within a ...
Cementitious materials provide an ideal geochemical environment (e.g., high pH pore fluids and large surface areas for sorption) for immobilizing nuclear waste. The inclusion of reducing agents, such as blast furnace slag (BFS) can immobilize radionuclides by forming of solid sulfide phases. Thermodynamic calculations using the MINTEQ geochemical computer code indicate the elemental sulfur present in BPS reacts with the highly mobile pertechnetate anion (TcO{sub 4}{sup -}) anion to form an insoluble technetium sulfide phase (Tc{sub 2}S{sub 7(s)}). Initially, the waste form very effectively immobilizes technetium. However, as oxygen diffuses into the waste form, an outer zone of oxidized concrete and a shrinking core of reduced intact concrete develops. Oxidation of sulfur in the outer zone results in increased technetium concentrations in the pore fluid because Tc{sub 2}S{sub 7(a)} oxidizes to the mobile TcO{sub 4}{sup -} anion. The TcO{sub ...
Pipeline automated ultrasonic testing (AUT) uses fully automated equipment that travels around a pipe on a welding band in a linear scan to allow array pulses to provide ultrasound information on weld zones. Pipeline AUT is also used for zone discrimination as well as with special calibration blocks, dual gate output displays, and rapid defect sizing. AUT allows for the inspection of welds soon after completion, and can save construction costs by process control when combined with engineering critical assessment (ECA) to minimize rejection rates. Ultrasonic phased arrays (UPA) use an array of elements that are all individually wired, pulsed, and time-shifted. Elements are pulsed in groups of approximately 16 elements at a time for pipeline welds. Phased arrays can be used to combine electronic scanning, sectorial scanning and precision focusing to give a practical combination of displays. Optimum angles can be selected for welds and other ...
Large sized reactor such as 540 MWe Pressurised Heavy Water Reactor (PHWR) requires continuous in core monitoring of local flux in order to provide effective control and protection. About 198 self powered neutron detectors (SPNDs) of the straight individually replaceable type are distributed in the reactor core. For purposes of reactor regulation, 42 prompt responding cobalt SPNDs called zone control detectors (ZCDs) are housed in vertical flux units (VFUs) and these are uniformly distributed in 14 power zones. The in core detectors used for spatial control by ZCCs do not accurately represent average zone power as they sense the flux over a small volume. Flux mapping system (FMS) comprising of 102 vanadium SPNDs in 26 VFUs, provide accurate measure of neutron flux, even though they have slow response to change in neutron flux levels. For reactor protection system-1 (RPS-1), 36 cobalt SPNDs are placed in VFUs and become part ...
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 ...
Runit Island on Enewetak Atoll was very heavily impacted by the U.S. nuclear testing campaign in the northern Marshall Islands (1946-58). The primary source of contamination on Runit Island was the 1958 Quince safety test where a large quantity of device plutonium (Pu) was scattered over the area near the GZ. A second low-yield device was detonated on the same site 10 days later, further disturbing the soil and leaving behind a very heterogeneous pattern of contamination including milligram-size particles of plutonium. A limited cleanup of the Fig-Quince zone was carried out in 1979. During this period, the effectiveness of the cleanup operations was primarily evaluated on the basis of bulk soil concentration data with little consideration given to the heterogeneity and long-term material-, biological-, and environmental-specific impacts of residual high activity (hot) particle contamination. The aim of the present study was twofold; (i) to characterize the levels ...
Thermoplastic polymer materials and the compounds made with them are being used more frequently for industrial components and for general use. However, the application of these materials for the production of complex shaped or relatively large pieces is limited, because of the difficulty and cost of making the necessary tool kit for the job. One solution is the use of the welding process. But the safe and reliable union of different thermoplastic material parts is not a simple process, even less so in the case of unions of large components. Welding by microwaves using polymer conductors can help, since the large scale equipment is available, and methods for continuous processes by microwave have been developed, that can be used to weld large and small components. Many thermoplastics (ex. polyethylene) do not absorb, or absorb very little, energy from microwaves. Polymer conductors, however, heavily absorb from microwaves with the consequent heating. Therefore the welding ...
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 ...
The symbiotic polychaetes of the genus Osedax living on the bones of whale carcasses have become known as bone-eating worms. It is believed that whale bones are the source of nutrition for those gutless worms and that fatty acids are produced by their symbionts and transferred to the host. However, the symbionts are of the heterotrophic group Oceanospirillales and as such are not able to synthesize organic carbon de novo. Also, they are not housed in close contact to the bone material. We studied the ultrastructure of the integument overlying the symbiont housing trophosome in the ovisac region and the roots region and of the symbiont-free trunk region of Osedax to investigate the hosts possible contribution in feeding for the whole symbiosis. The epidermis differs conspicuously between th...
Unique measurement of the proton structure function F2 in a wide two-dimensional region of x and Q**2 has been reported. The accessible kinematics covers entire resonance region up to W=2.5 GeV in the Q**2 interval from 0.1 to 4.5 GeV**2. Obtained data allowed for the first time an evaluation of moments of the structure function F2 directly from experimental data as well as an intensive study of the Bloom-Gilman duality phenomenon.
The improved facilities of the ISOLDE isotopic separator on-line with the 600 MeV synchrocyclotron at CERN opened the possibility to reach nuclei very far from stability (as far as 22 neutrons deficient in the Cs region and 27 neutrons deficient in the Hg region). Simultaneously the development of on-line spectrometry allowed the study of nuclei with very short half-lives and low counting rates. Results recently obtained in the odd-A iridium region are presented after a short summary of recent on-line devices developments and results. (Auth.).
A study was made on the effect of 3.5 MeV electron irradiation on the properties of light-emissive structure based on GaAlAs. It is shown that a considerable decrease in the emitted light intensity as a result of electron irradiation not accompanied by changes in recombination- and electric properties of the mentioned structures. It is established by the electron-microscopy and Auger-spectroscopy meazurements that electron irradiation causes the occurrence of regions of free aluminium clusters on the external surface of the structure n-layer. The number and the sizes of the regions depend on the electron doze. It was assumed that the mentioned regions can play a role of attenuation filter for the light emitted by the structure.
Proton production in pA interactions in the kinematically forbidden region is studied using the intranuclear cascade model for the primary proton energies 7.5 and 8.9 GeV/c. The region of secondary-proton kinetic energies above 100 MeV, where the contribution from the post-cascade stages of the interaction is small, is studied. The calculated energy and angular spectra are in good agreement with the experimental ones. The mechanisms of multiple rescattering of particles on the nucleons of the nucleus and ..pi..-meson absorption on a two-nucleon flucton are analyzed. The kinematical ranges where these mechanisms operate are determined.
Excitation of the HF electric field in the local plasma resonance region (LPRR) of inhomogeneous plasma by pumping electric field or modulated electron beam results to appearance of the ponderomotive force that presses plasma out of this region. Density cavity is formed in the LPRR due to this field. Further dynamics in this region depends on the plasma properties. For plasma with hot electrons ion-acoustic pulses run away from the cavity. at the local density maximum the new peak of electric field is excited. It results to the formation of new density cavity, etc. For isothermal plasma the density jump is formed.
This paper presents the first results of a study of plasma nitriding in various regions of a d.c. glow discharge, i.e. on the cathode, on the anode, and on a substrate isolated from the cathode and anode (at plasma potential). The results obtained reveal differences in the growth kinetics and surface morphology of the nitriding layers, depending on the region where the nitriding process took place. The aim of this work was to study the role of low temperature plasma in the plasma nitriding process. The processes were carried out in an apparatus for plasma treatment with a hot anode. (orig.)
A significant asymmetry in baryon/antibaryon yields in the central region of high energy collisions is observed when the initial state has non-zero baryon charge. This asymmetry is connected with the possibility of a baryon charge diffusion in rapidity space. Evidently, such a diffusion should decrease the baryon charge in the fragmentation region leading to the corresponding decrease of the multiplicity of leading baryons. As a result, a new mechanism for Feynman scaling violation in the fragmentation region is obtained. We present the quantitative predictions for the Feynman scaling violation at LHC energies and even at highier energies that can be important for cosmic ray physics.
An energy control strategy (10) for a hybrid electric vehicle that controls an electric motor during bleed and charge modes of operation. The control strategy (10) establishes (12) a value of the power level at which the battery is to be charged. The power level is used to calculate (14) the torque to be commanded to the electric motor. The strategy (10) of the present invention identifies a transition region (22) for the electric motor's operation that is bounded by upper and lower speed limits. According to the present invention, the desired torque is calculated by applying equations to the regions before, during and after the transition region (22), the equations being a function of the power level and the predetermined limits and boundaries.
The thawing of permafrost regions is supposed to increase climatic change processes due to the released methane. During the last decades the temperature of permafrost soils has increased by several tenths of degree up to 2 deg C. It is supposed that 10 to 20% of the permafrost regions will thaw during the next 100 years. The southern boundary of the permafrost region will move several hundred kilometers toward the north. Besides the increased risk for the climate system there will also be disadvantageous consequences for the ecosystems. Negative economic consequences are already observed and will be enhanced in the futures with significant cost for the public.
The concentric circular annular duct is a common geometry in many fluid flow and heat transfer devices. For the purpose of heat transfer augmentation, fins are often employed in the annular region, and such finned ducts find wide application in compact heat exchangers (5, 6). The analysis of flow and heat transfer in this geometry is, therefore, quite important from an engineering standpoint. For fully developed conditions, the problem has already been analyzed (7-10). However, no results are available for the developing flow in the entrance region. It is with this latter problem that the present paper is concerned.
... hypersonic aerodynamic force, or the space-equivalent region. Some of these experiments change the X-15 from a research airplane to a kind of space probe, ...
Dengue, a major public health problem throughout subtropical and tropical regions, is an acute infectious disease characterized by biphasic fever, headache, pain in various parts of the body, prostration,...Full Text Available
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The traffic flow information guidance can improve the operating efficiency of regional traffic. On the basis of the information guidance model and survey data, this paper takes advantage of the VISSIM software to simulate the traffic in a region within the Southwest Second Ring of Beijing constructed by six roads and six intersections and makes a comparative evaluation on the operation of the regional road traffic flow before and after the implementation of the traffic flow information guidance measures. The analysis of five different guided flow cases shows that if the guided left-turn traffic flows in southbound I.A increases from 10% to 30%, the travel time of the left-turn traffic flow in southbound I.A has a reduction from 18% to 42%, and its delay also reduces from 234 s to 164 s. In...
In the present study we quantified the residues of organophosphorus (e.g. ethion and chlorpyrifos), organochlorine (e.g. heptachlor, dicofol, ?-endosulfan, ?-endosulfan, endosulfan sulfate) and synthetic pyrethroid (e.g. cypermethrin and deltamethrin) pesticides in made tea, fresh tea leaves, soils and water bodies from selected tea gardens in the Dooars and Hill regions of West Bengal, India during April and November, 2006. The organophosphorus (OP) pesticide residues were detected in 100% substrate samples of made tea, fresh tea leaves and soil in the Dooars region. In the Hill region, 20% to 40% of the substrate samples contained residues of organophosphorus (OP) pesticides. The organochlorine (OC) pesticide residues were detected in 33% to 100% of the substrate samples, excluding the w...
The site characterization of Yucca Mountain, NV as a potential high level nuclear waste repository includes study of the surficial deposits as a record of the paleoenvironmental history of the Yucca Mountain region. An important aspect of this history is an understanding of the evolution of paleogeography leading to establishment of the present drainage pattern. Establishment of drainage basin evolution is needed before geomorphic response to paleoclimate and tectonics can be assessed, because a major change in drainage basin geometry can predominantly affect the sedimentary record. Because alluvial aquifers are significant to regional hydrology, a major change in surface drainage resulting in buried alluvium could have hydrogeologic significance. In this paper, we report on geologic evidence for a major modification in surface drainage pattern in the Yucca Mountain region, resulting in the probable establishment of the ...
please visit this page: About CDC.gov. Travelers' Health Home Destinations (238) Iran Regions Vaccinations News & Announcements Travel Notices Diseases Yellow Book Contents...
MD, Chief, Division of Endocrinology, Diabetes and Metabolism, Trinitas Regional Medical Center, Elizabeth, NJ. Review provided by VeriMed Healthcare Network. Also reviewed...
Report) A Screening Assessment of the Potential Impacts of Climate Change on Combined Sewer Overflow (CSO) Mitigation in the Great Lakes and New England Regions (Final Report)...
Background:Since first reported in 1996, endoscopic minimally invasive surgery of the cervical region has been shown to be safe and effective in the treatment of benign thyroid and...Full Text Available
We suggest a procedure for estimating uncertainties in neutron cross sections calculated with a nuclear model descriptive of a specific mass region. It applies standard error propagation techniques, using a model-parameter covariance matrix. Generally, available codes do not generate covariance information in conjunction with their fitting algorithms. Therefore, we resort to estimating a relative covariance matrix a posteriori from a statistical examination of the scatter of elemental parameter values about the regional representation. We numerically demonstrate our method by considering an optical-statistical model analysis of a body of total and elastic scattering data for the light fission-fragment mass region. In this example, strong uncertainty correlations emerge and they conspire to reduce estimated errors to some 50% of those obtained from a naive uncorrelated summation in quadrature. 37 references.
This data layer consists of polygons representing harvest area boundaries from Timber Harvest Plans approved by the California Department of Forestry ... ...
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