Energy Technology Data Exchange (ETDEWEB)

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 ...

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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.

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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.

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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.

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The UNSAT-H model was developed at Pacific Northwest National Laboratory (PNNL) to assess the water dynamics of arid sites and, in particular, estimate recharge fluxes for scenarios pertinent to waste disposal facilities. During the last 4 years, the UNSAT-H model received support from the Immobilized Waste Program (IWP) of the Hanford Site's River Protection Project. This program is designing and assessing the performance of on-site disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site (LMHC 1999). The IWP is interested in estimates of recharge rates for current conditions and long-term scenarios involving the vadose zone disposal of tank wastes. Simulation modeling with UNSAT-H is one of the methods being used to provide those estimates (e.g., Rockhold et al. 1995; Fayer et al. 1999). To achieve ...

Energy Technology Data Exchange (ETDEWEB)

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.

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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.

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

According to the present concept, the low and intermediate level wastes generated during the Cernavoda NPP operation will be disposed in a near surface repository. The Saligny site, placed in the NPP protected area, has been proposed for their disposal. Geologically, the main components of this site are the quaternary loess, the Precambrian and Pre-quaternary clays, the Eocene and Barremian limestone. Hydrologically, the site can be divided into a vadose zone down to 45-50 m and three distinct aquifers, two of them in the limestone beds and the third in the lenses of sand and limestone existing in the pre-quaternary clay layer. A large research program for site characterization was initiated in 1996. At present, the site characteristics requested for safety analysis have been experimentally measured on soil samples or calculated by different computer programs. Hundreds of experimental values of the density, porosity, hydraulic conductivity, ...

Energy Technology Data Exchange (ETDEWEB)

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

International Nuclear Information System (INIS)

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

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 ...

International Nuclear Information System (INIS)

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.)

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

British Library Electronic Table of Contents (United Kingdom)

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...

Energy Technology Data Exchange (ETDEWEB)

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.

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

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 ...

CERN Document Server

Aerial view of the depot zone of Bois des Serves.

Energy Technology Data Exchange (ETDEWEB)

Based on a multi-zone spray-mixing approach, an air-fuel mixing and combustion model for a Direct Injection Diesel engine is presented. The predictions from the model show very good agreement with the experimental data for various engines under a wide range of operating conditions. Major physical processes are modeled and validated independently. The atomisation process is based on Binary Drop Division concept. Fuel droplets are considered randomly distributed in the spray. A spherico-symmetrical transient drop evaporation model is used for evaporation calculation. A 3-dimensional spray-swirl interaction is modeled on centreline velocity vector/continuum approach. Turbulent mixing is characterised considering all possible available energy sources in DI diesel engines.

Science.gov (United States)

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.

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional, continuous-energy, coupled neutron-gamma Monte Carlo model of the advanced neutron source (ANS) final preconceptual reference core design has been developed using MCNP Version 3b. This model contains the reactor core with control rods, the heavy-water reflector tank with shutdown rods and representative beam tubes, and the outer light-water poor. Eighty homogenized fuel zones per fuel element are used to represent the radical and axial {sup 235}U fuel grading. This model is the most sophisticated, physically accurate reactor physics model of the ANS currently available. The purpose of this summary is to demonstrate the MCNP methods and applications for the ANS.

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

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 ...

CERN Document Server

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

Energy Technology Data Exchange (ETDEWEB)

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

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

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This document reproduces the final project of David San Fabian Ayuso, presented on May 26, 2005, for the obtention of the engineer degree of the Carlos III University of Madrid. A single-phase, isothermal model, including both electron and proton transport, is introduced for the simulation of polymer electrolyte fuel cells (PEM). The model is implemented in the commercial code Fluent 6.0, through the use of UDFs (User Defined Functions). In order to validate the model, a single canal of a PEM monocell is simulated in three dimensions. The obtained result are qualitatively satisfactory. It is observed that it is not essential to solve the current collectors when a monocell is considered (and not a stack). in the present study, the number of nodes is the computational grid appears to be too low in the membrane zone in order to make a complete validation of the model. (Author) 20 refs.

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This report describes modelling where the hydrological modelling system MIKE SHE has been used to describe surface hydrology, near-surface hydrogeology, advective transport mechanisms, and the contact between groundwater and surface water within the SKB site investigation area at Laxemar. In the MIKE SHE system, surface water flow is described with the one-dimensional modelling tool MIKE 11, which is fully and dynamically integrated with the groundwater flow module in MIKE SHE. In early 2008, a supplementary data set will be available and a process of updating, rebuilding and calibrating the MIKE SHE model based on this data set will start. Before the calibration on the new data begins, it is important to gather as much knowledge as possible on calibration methods, and to identify critical calibration parameters and areas within the model that require special attention. In this ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

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. ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

Energy Technology Data Exchange (ETDEWEB)

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)

Energy Technology Data Exchange (ETDEWEB)

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 ...

Energy Technology Data Exchange (ETDEWEB)

In accordance with the Nuclear Regulatory Commission regulation regarding groundwater travel times at geologic repositories, various models of unsaturated flow in fractured tuff have been developed and implemented to assess groundwater travel times at the potential repository at Yucca Mountain, Nevada. Kaplan used one-dimensional models to describe the uncertainty and sensitivity of travel times to various processes at Yucca Mountain. Robey and Arnold et al. used a two-dimensional equivalent continuum model (ECM) with inter- and intra-unit heterogeneity in an attempt to assess fast-flow paths through the unsaturated, fractured tuff at Yucca Mountain (GWTT-94). However, significant flow through the fractures in previous models was not simulated due to the characteristics of the ECM, which requires the matrix to be nearly saturated before flow through the fractures is initiated. In the current study ...

British Library Electronic Table of Contents (United Kingdom)

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

British Library Electronic Table of Contents (United Kingdom)

The flexibility of bus rapid transit (BRT) in scheduling is one of the greatest differences with traditional buses. In order to improve BRT operation quality, the paper studied the headway optimization and scheduling combination of BRT vehicles. A model has been established to minimize passengers travel costs and vehicles operation cost, and constraints included passenger volume, time, and frequency. The scheduling combination was composed by normal, zone, and express scheduling. The model was solved by genetic algorithm of variable-length coding. The result of the numerical case shows that: the optimization results can save 69.92% cost. The sensitivity analysis shows that, under higher traffic volume or lower speed, the travel cost can be reduced through reasonable scheduling combination....

Science.gov (United States)

An optimal deployment pattern of flux mapping detectors for a Canada uranium-deuterium (CANDU)-600 pressurized heavy water reactor (PHWR) is determined by obtaining an optimal feedback relationship between flux measurements and zone controllers. The reactor core is modeled with a time-dependent two-group, two-dimensional diffusion equation, and flux perturbation are expressed by model expansions. The modal expansion coefficients are used as elements of the state vector representing the system dynamics. An optimal feedback matrix connecting the flux measurement vector to the control vector is derived by minimizing a quadratic performance index involving both the state and control vectors. We obtain the detector effectiveness in terms of the optimal feedback matrix and determine optimal detector locations for the Wolsung Unit 1 reactor in Korea. We have tested the methodology through evaluation of flux maps generated through ...

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

Abstract A complete study of an exploding bridgewire detonator (EBW), an LX-07 hemispherical booster and a PBX 9502 outer shell are described. Breakout times from all three are listed in terms of first impact on the booster, i.e., code times. Lucite windows are also used to obtain particle velocities at the edges of each explosive, and these are converted into explosive pressures. The key to modeling is the use of the profile of the aluminum detonator can as it impacts the booster, i.e., we need to know the curvature of the end of the booster can. Modeling even with coarse zoning shows that (i) using reactive flow in the booster is better than programmed burn, (ii) creating the flyer curvature helps, and (iii) creating the time differences of flyer impact helps even more.

Energy Technology Data Exchange (ETDEWEB)

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

Energy Technology Data Exchange (ETDEWEB)

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

CERN Document Server

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

Energy Technology Data Exchange (ETDEWEB)

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

Science.gov (United States)

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 ...

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

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We are attempting to characterize and model the micromechanical response of highly-filled polymers. In this class of materials, the continuous plastic binder used to bond the highly-filled material dominates the observed viscoelastic response. As a result, realistic lifetime analysis of these materials will require a thorough understanding of the contribution of the plastic binder. Laboratory applications of these materials include plastic bonded explosives, propellants, a variety of specialized filled organic materials for stockpile systems, and highly filled epoxy dielectric materials for the National Ignition Facility. We have explored numerous techniques to characterize the local microstructure of plastic bonded explosives. However, insufficient funding was obtained to bring these technologies to maturity, nevertheless our present tool set is significantly better than 2 years ago. We have also made some progress in developing an appropriate micromechanical ...

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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 until the mullite preform is consumed or ...

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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 ...

CERN Document Server

We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition Undulator Radiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and ...

International Nuclear Information System (INIS)

A thermodynamic analysis of the behaviour of Alloy 800 in helium based atmospheres relevant to the High Temperature Gas Cooled Reactor indicates that, depending upon the precise gas composition, oxidation and carburisation, or carburisation alone may be expected. The prime influence appears to be the moisture level. The morphology and structure of the reaction products are discussed. It is shown that the 'reactive' elements chromium, manganese, titanium and silicon are concentrated in the oxide scale which is normally duplex in structure. Aluminium oxide is formed at grain boundaries and in an internal oxidation zone together with titanium and sometimes silicon. In carburising conditions, mixed titanium-chromium carbides are formed. When this occurs, intergranular penetration is maximised. Weight gain data are assessed and briefly described and a tentative model for the mechanism of corrosion of Alloy 800 in HTR helium is proposed. Areas for ...

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

International Nuclear Information System (INIS)

Results of calculational investigations into circulation of water and steam-and-water mixture in the PGV-1000 steam generator heat exchanger bundle used at NPPs with the WWER-1000 reactors, are considered. Model of water circulation in horizontal steam generator with submerged heating surface under conditions of steam generation irregularity along the heat transfer tubes is made. On the basis of the obtained data the assumption is made about water essential overflows from the hot collector zone into the cold one. Overflow rate over the upper line of the heat transfer tubes may constitute 0.7 m/s. The conclusion is made about the necessity to set up the vertical barrier which divides hot and cold sections of heat transfer tubes and helps to avoid water transverse overflows.

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The concepts of general flow and thermal boundary conditions are introduced to treat the interaction between indoor and outdoor thermal environments in computational fluid dynamics (CFD) simulations. The results from a multi-zone model are used to supply the general flow boundary conditions. The energy balance equation at wall-air interfaces is used to supply the general thermal boundary conditions. An example calculation in a 13-room building shows that infiltration influences indoor air flow patterns considerably. The air flow in a room ventilated by displacement is measured and simulated. Two surface coatings are considered, i.e. black walls and aluminum walls. Implementation of these two boundary conditions is essential in predicting air flow patterns, air quality, and thermal comfort in a real building. (author)

International Nuclear Information System (INIS)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostic system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

Energy Technology Data Exchange (ETDEWEB)

Examination is made of the main features of the physical and chemical preignition processes within homogeneous mixtures of air and gaseous fuels, such as propane, methane and hydrogen in a motored engine, while employing detailed chemical kinetics in a one zone analytical model. The changes in the compression temperature and pressure due to the admission of gaseous fuels, energy release during the preingition reactions and the contributions of heat transfer and residual gases to the preignition reaction activity were followed over a number of consecutive cycles until the occurrence of autoignition. Some of the observed differences in engine behaviour when operating on methane, propane and hydrogen were discussed with particular reference to the observed trends in dual fuel engine operation. Calculated results showed good agreement with some corresponding experimental trends. 14 refs., 9 figs.

Energy Technology Data Exchange (ETDEWEB)

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.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Energy Technology Data Exchange (ETDEWEB)

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

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This report introduces a microprocessor system composed of a Z-80 single-board computer controlling a gas-carburizing process. The system has 7 analogical input and output signals 24 switch signal-input and 12 switch signal-output signals, which are applicable for temperature, carbon potential, and mechanical-movement control of multipurpose sealed furnaces, or for mutiple-zone temperature, carbon potential, and mechanical-movement control of continuous gas carburizing furnaces; or for distributed control of pit-type carburizing furnaces. The setpoints of variables, such as treating time, temperature, carbon potential of carburizing period, carbon potential of diffusion period, depth of carburizing layer, P.I.D. etc., are entered by keyboard and stored into memories, and actual values are displayed by digital tubes. Furthermore, the fault of thermocouple, oxygen probe, or infrared CO/sub 2/ analyzer; carbon potential, or temperature exceeding the setting value; ...

Science.gov (United States)

With an increased use of fiber reinforced concrete in structural applications, proper characterization techniques and development of design guides are needed. This dissertation presents a multi-scale modeling approach for fiber and fabric reinforced cement-based composites. A micromechanics-based model of the yarn pullout mechanism due to the failure of the interfacial zone is presented. The effect of mechanical anchorage of transverse yarns is simulated using nonlinear spring elements. The yarn pullout mechanism was used in a meso-scale modeling approach to simulate the yarn bridging force in the crack evolution process. The tensile stress-strain response of a tension specimen that experiences distributed cracking can be simulated using a generalized finite difference approach. The stiffness degradation, tension stiffening, crack spacing evolution, and crack width characteristics of cement composites ...

Energy Technology Data Exchange (ETDEWEB)

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

British Library Electronic Table of Contents (United Kingdom)

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

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This work presents an analysis of the operation of a multi-cylinder, tubro charged, indirect injection diesel engine from a second-law analysis point of view. For this purpose, a single-zone thermodynamic model following the filling and emptying modelling technique is developed. A second-law analysis is performed in all parts of the diesel engine plant, which provides all the existing availability terms and accounts for the evaluation of every component`s irreversibilities. A complete second-law terms tabulation is given for the maximum speed-full load operation case, which is compared with its first-law counterpart. A detailed parametric study is performed in all parts of the diesel engine plant comprising the effects of speed and load on the availability terms in a range that covers the whole operation of the engine under turbocharged action. Various second-law (availability) terms such as indicated and brake work, heat ...

Energy Technology Data Exchange (ETDEWEB)

The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high Damkoehler numbers. This suggests a modeling approach to estimate ...

Energy Technology Data Exchange (ETDEWEB)

Faulting the feedwater for a 19-tube, model steam generator with 10 ppM of caustic once a week produced widespread shallow 25 to 75 micrometers (1 to 3 mils) intergranular attack (IGA) on alloy 600 tubes and an axial tube rupture at the steam-water interface after 4.8 years. An extensive investigation of the IGA damage found little correlation with major test variables beyond the indication that mill-annealed tubing was more susceptible to attack than stress-relieved tubing. The most likely cause of the tube rupture was caustic that concentrated to high levels in a porous scale on the tube at the liquid-vapor interface where there was a high available superheat. Nondestructive examination (NDE) eddy current probes underestimated the depth of IGA and were not sensitive to circumferential cracks less than 152 micrometers (6 mils) deep that were above and below the roll transition zones of tubes in the tubesheet.

International Nuclear Information System (INIS)

Certain 6000-series extrusions may develop susceptibility to intergranular corrosion (IGC) by improper heat treatment, especially if copper is present as an alloying element. Although occurrence of IGC in such cases is documented, the underlying mechanisms are not adequately explained. We present corrosion data for two model alloys, having different Cu content and Mg:Si ratio, showing that the susceptibility to IGC depended primarily on the Cu content and secondly on thermal processing. Low Cu samples (0.0005 wt.% Cu) were essentially resistant to IGC. High Cu samples (0.12 wt.% Cu), which were air cooled after extrusion, exhibited significant IGC. However, IGC susceptibility was reduced significantly as a result of artificial aging to peak strength. Water quenched high Cu samples were essentially resistant to IGC. However, slight IGC susceptibility was introduced after aging. Electron optical characterisation revealed Al_4Mg_8Si_7Cu_2 (Q-phase) grain boundary ...

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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 ...

UK PubMed Central (United Kingdom)

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

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

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

A three-dimensional, three-phase, multiple-component numerical simulator was developed to investigate transport and growth of microorganisms in porous media and the impacts of microbial activities on oil recovery. The microbial activities modeled in this study included: (1) growth, retention, chemotaxis, and end product inhibition of growth, (2) the formation of metabolic products, and (3) the consumption of nutrients. Major mechanisms for microbial enhanced oil recovery (MEOR) processes were modeled as follows: (1) improvement in sweep efficiency of a displacement process due to in situ plugging of highly-permeable production zones by cell mass or due to improved mobility control achieved by increasing the viscosity of the displacing fluid with a biopolymer, and (2) solubilization and mobilization of residual oil in porous media due to the reduction of the interfacial tension between oleic and aqueous phases by the ...

International Nuclear Information System (INIS)

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 ...

International Nuclear Information System (INIS)

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

Wastenet

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

International Nuclear Information System (INIS)

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

British Library Electronic Table of Contents (United Kingdom)

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

Science.gov (United States)

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

Energy Technology Data Exchange (ETDEWEB)

US Department of Energy (DOE) Order 5820.2A (DOE, 1988) requires performance assessments on all new and existing low-level radioactive waste (LLW) disposal sites. An integral part of performance assessment is estimating the fluxes of radioactive gases such as radon-220 and radon-222. Data needs pointed out by mathematical models drive site characterization. They provide a logical means of performing the required flux estimations. Thorium-230 waste, consisting largely of thorium hydroxide and thorium oxides, has been approved for disposal in shallow trenches and pits at the LLW Radioactive Waste Management Site in Area 5 of the Nevada Test Site. A sophisticated gas transport model, CASCADR8 (Lindstrom et al., 1992b), was used to simulate the transport and fate of radon-222 from its source of origin, nine feet below a closure cap of native soil, through the dry alluvial earth, to its point of release into the atmosphere. CASCADR8 is an M-chain ...

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The temperature dependence of T/sub 1/ spin-lattice relaxation time on /sup 51/V, /sup 69/Ga, /sup 71/Ga and Knight shift on /sup 51/V and /sup 29/Si nuclei in polycrystalline V/sub 3/Si, V/sub 3/Ga, V/sub 3/Ge and in the monocrystal V/sub 3/Si in normal state is investigated. For V/sub 3/Si and V/sub 3/Ga a rapid growth (T/sub 1/T)/sup -1/ is observed with temperature decrease while for V/sub 3/Ge the maximum (T/sub 1/T)/sup -1/ at T approximately equal to 60 K has been found. The temperature dependence peculiarities have been discussed on the basis of theoretical models available and zone structure calculations for A-15 compounds. The T/sub 1/ anisotropy and possibility of its experimental discovery are considered. Anisotropic contribution in (T/sub 1/T)/sup -1/ and contributions of d states of different symmetries into the electron state density at the Fermi level are estimated for V/sub 3/Si from T/sub 1/ measurements.

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

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This presentation gives the results of a research programme aimed at evaluating exhaust emissions from ships moving within confined coastal zones, as in Piraeus harbour. The level of various exhaust emissions were estimated on the basis of a mathematical model applied for each sea traffic element (ship). Hourly and daily records of all ships` movements in different parts of the harbour were compiled, covering extended periods of time and associated with different shipping operational characteristics (peaks, lows, etc). In order to correlate the exhaust emissions from shipping with the quality of the air in the area of interest, land-based measurements for the same pollutants were carried out in selected locations, near the port and in the greater Athens area. This enabled the investigation of time and spatial diffusion of exhaust emissions from shipping within the area of interest, taking into account the influence of prevailing meteorological ...

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Excessive erosion of the labyrinth seal of a 100 MW geothermal turbine has been investigated. This study used computational fluid dynamics (CFD) and aims to identify one cause of erosion and a possible solution for substantially reducing it. The predictions were based upon a numerical calculation using a CFD model of the labyrinth seal with a water/steam flow containing hard solid particles and solved with a commercial CFD code: Fluent V5.0. The results confirmed the existence of flow conditions that play a major role in the rotor labyrinth seal erosion. Afterwards, the flow path was simulated with changes of rotor labyrinth seal geometry, which are indeed feasible of being implemented. The results confirmed that it is possible to reduce the erosion process by approximately 80% by incorporating a steam flow deflector in the fourth stage diaphragm, which changes the steam flow direction in the inlet zone to the rotor labyrinth seal channel, ...

Energy Technology Data Exchange (ETDEWEB)

Deformation in the overburden proves useful in deducing spatial and temporal changes in the volume of a producing reservoir. Based upon these changes we estimate diffusive travel times associated with the transient flow due to production, and then, as the solution of a linear inverse problem, the effective permeability of the reservoir. An advantage an approach based upon travel times, as opposed to one based upon the amplitude of surface deformation, is that it is much less sensitive to the exact geomechanical properties of the reservoir and overburden. Inequalities constrain the inversion, under the assumption that the fluid production only results in pore volume decreases within the reservoir. We apply the formulation to satellite-based estimates of deformation in the material overlying a thin gas production zone at the Krechba field in Algeria. The peak displacement after three years of gas production is approximately 0.5 cm, overlying the eastern margin of the ...

Energy Technology Data Exchange (ETDEWEB)

Steam generator tubes in nuclear power plants are periodically checked by means of eddy current probes. The output of a probe is composed of three types of signals: known events (rolling zone, support plates, U-bend part), noise (mainly metallurgical noise) and possible flaws. The latter are random transients, both in arrival time and in shape: they have to be detected and then estimated, before to be fed to the high level stages of a diagnostics system. The objective of the study presented is to develop a semi-automatic system, which could manage and process more than 1 M-bytes of data per tube and provide an operator with reliable diagnostics proposals within a few minutes. This can be achieved only by cooperation of several digital signal processing techniques: detection, segmentation, estimation, noise subtraction, adaptive filtering, modelization, pattern recognition. The paper describes some of these items.

Energy Technology Data Exchange (ETDEWEB)

This official IEA report is a deliverable of IEA SHC Task 21/IEA BCS Annex 29: Daylight in Buildings. The Task focuses on daylighting systems and strategies which can be applied in new and existing buildings with a high potential electricity saving potential such as offices, schools, commercial, and institutional buildings. The daylighting performance of these strategies and systems is tested in laboratory facilities, through modeling, and in real case study buildings. This paper provides methods and procedures to evaluate the daylighting performance of real buildings. Annex 29 case studies located in Europe, North America, and Australia. It is a deliverable of Subtask D research projects. The main objective of Subtask D, as stated in the Implementing Agreement of Task 21/Annex 29, is `to demonstrate the viability of daylighting buildings in various world climatic zones as a means of achieving significant improvements in building energy ...

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The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature. The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray gas, the augmentation observed are negligible. For the range of values studied ...

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SKB is currently performing site investigations at two potential sites for a final repository for spent nuclear fuel. This report presents results of water flow and solute transport modelling of the Forsmark site. The modelling reported in this document focused on the near-surface groundwater, i.e. groundwater in Quaternary deposits and shallow rock, and surface water systems, and was performed using the MIKE SHE tool. The most recent site data used in the modelling were delivered in the Forsmark 2.3 dataset, which had its 'data freeze' on March 31, 2007. The present modelling is performed in support of the final version of the Forsmark site description that is produced during the site investigation phase. In this work, the hydrological modelling system MIKE SHE has been used to describe near-surface groundwater flow and the contact between groundwater and surface ...

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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 ...

International Nuclear Information System (INIS)

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

Science.gov (United States)

The quasi-static normal indentation of sandwich panels with quasi-isotropic laminated composite skins and honeycomb or foam cores, by spherical indentors, has been investigated using experiments and finite element analysis. The experimental program emphasized the effects of indentor size on the resulting load indentation responses, failure mechanisms in the skin and the core, and the measurement of contact areas between indentor and the target. The sandwich panels were indented up to the initiation of skin fracture and the resulting contact data was used to characterize contact power laws. A non-linear finite element model was developed based on the experimental observations to systematically explore the indentation behavior of diverse sandwich configurations and to investigate the contact pressure distributions. The finite element model was used as an experimental tool in the development of a simple non-dimensional semi-empirical ...

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The K site near Seoul began landfilling in 1992. The landfilled wastes include municipal solid waste (66.4%), construction residues (20.4%), water and wastewater sludges (trace levels), and hazardous waste (trace levels). The water content of the municipal solid waste is very high (47.3%); as a result, the leachate level (average E.L.) of the landfill, the design value of which is 7.0 m, was measured at 10.3 m in January 1995 and is increasing. The increase of leachate level in the landfill site causes a problem with slope stability. The leachate level at each disposal stage divided by the intermediate cover layer was calculated with the HELP (Hydrologic Evaluation of Landfill Performance) model and calibrated with the data measured from February 1993 to June 1995. Also, the hydraulic conductivities of the waste layer and the intermediate cover layer in each stage were calibrated continuously with HELP model analysis. To verify these results, ...

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The feasibility was evaluated using MCNP-DSP, an analog Monte Carlo transport cod to simulate source-driven measurements. Models of an isolated Westinghouse 17x17 PWR fuel assembly in a 1500-ppM borated water storage pool were used. In the models, the fuel burnup profile was represented using seven axial burnup zones, each with isotopics estimated by the PDQ code. Four different fuel assemblies with average burnups from fresh to 32 GWd/MTU were modeled and analyzed. Analysis of the fuel assemblies was simulated by inducing fission in the fuel using a {sup 252}Cf source adjacent to the assembly and correlating source fissions with the response of a bank of {sup 3}He detectors adjacent to the assembly opposite the source. This analysis was performed at 7 different axial positions on each of the 4 assemblies, and the source-detector cross-spectrum signature was calculated for each of these 28 simulated ...

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

Energy Technology Data Exchange (ETDEWEB)

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

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

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

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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.

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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.)

KoreaScience (Korea)

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International Nuclear Information System (INIS)

Portuguese 1984. p. 146. Brazil Czepielewski, MA Kater, CE Biglieri, EG Escola

Science.gov (United States)

... 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 ...

British Library Electronic Table of Contents (United Kingdom)

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...

Science.gov (United States)

Satellite Observations of the Southeast Pacific Intertropical Convergence Zone During 1993-1998, Halpern, D.; Hung, C.-W., Journal of Geophysical Research ? ...

International Nuclear Information System (INIS)

Japanese Sep 2009 p. 103-106 Japan Idota, Yasuhiro Inoue, Hiroyuki

International Nuclear Information System (INIS)

... University, Fracture and Reliability Research Institute, Sendai, Miyagi (Japan)

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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 regionally extensive, biostratigraphically ...

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

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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 ...

International Nuclear Information System (INIS)

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

International Nuclear Information System (INIS)

The NEPTUN data discussed in this report are from core uncovery (boil-off) experiments designed to investigate the mixture level decrease and the heat up of the fuel rod simulators above the mixture level for conditions simulating core boil-off for a nuclear reactor under small break loss-of-coolant accident conditions. The first series of experiments performed in the NEPTUN test facility consisted of ten boil-off (uncovery) and one adiabatic heat-up tests. In these tests three parameters were varied: rod power, system pressure and initial coolant subcooling. The NEPTUN experiments showed that the external surface thermocouples do not cause a significant cooling influence in the rods to which they are attached under boil-off conditions. The reflooding tests performed later on indicated that the external surface thermocouples have some effect during reflooding for NEPTUN electrically heated rod bundle. Peak cladding temperatures are reduced by about 30--40C and quench times occur 20--70 ...

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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.

Energy Technology Data Exchange (ETDEWEB)

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.

International Nuclear Information System (INIS)

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.

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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.

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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 ...

International Nuclear Information System (INIS)

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 ...

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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 ...

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

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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 ...

Energy Technology Data Exchange (ETDEWEB)

A process model is presented and used for identifying options for controlling the cupola furnace process and for investigating natural gas substitutes. Fuel substitution will affect temperature curves (i.e. tapping temperatures and melting capacity), outlet temperatures and gas mass flow out of the preheating zone. The contribution presents several process variations to overcome these problems and compares them with the natural gas process. [German] Mit dem Prozessmodell werden zunaechst Moeglichkeiten der Steuerung von Abstichtemperatur und Schmelzleistung, insbesondere unter Beruecksichtigung der Schrottqualitaet (spezifische Oberflaeche a{sub G}), untersucht. Es wird gezeigt, dass das Prozessmodell die Ergebnisse aus der Praxis wiedergibt. Daran anschliessend wird mit dem Prozessmodell die Substitution von Erdgas durch minderwertige Gase untersucht (Brennstoffsubstitution, Ressourcenschonung). Durch die Brennstoffsubstitution veraendern sich ...

International Nuclear Information System (INIS)

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

Energy Technology Data Exchange (ETDEWEB)

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 ...

Science.gov (United States)

B-cell Chronic Lymphocytic Leukemia; Nodal Marginal Zone B-cell Lymphoma; Recurrent Adult Burkitt Lymphoma; Recurrent Adult Diffuse Large Cell Lymphoma; Recurrent Adult Diffuse Mixed Cell Lymphoma; Recurrent Adult Diffuse Small Cleaved Cell Lymphoma; Recurrent Adult Grade III Lymphomatoid Granulomatosis; Recurrent Adult Immunoblastic Large Cell Lymphoma; Recurrent Adult Lymphoblastic Lymphoma; Recurrent Grade 1 Follicular Lymphoma; Recurrent Grade 2 Follicular Lymphoma; Recurrent Grade 3 Follicular Lymphoma; Recurrent Mantle Cell Lymphoma; Recurrent Marginal Zone Lymphoma; Recurrent Small Lymphocytic Lymphoma; Splenic Marginal Zone Lymphoma; Waldenstrom Macroglobulinemia

Energy Technology Data Exchange (ETDEWEB)

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 ...

Energy Technology Data Exchange (ETDEWEB)

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.

British Library Electronic Table of Contents (United Kingdom)

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 ...

International Nuclear Information System (INIS)

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.

International Nuclear Information System (INIS)

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.

UK PubMed Central (United Kingdom)

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

UK PubMed Central (United Kingdom)

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

Wastenet

...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 ...

Energy Technology Data Exchange (ETDEWEB)

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

UK PubMed Central (United Kingdom)

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

Energy Technology Data Exchange (ETDEWEB)

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.

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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 ...

UK PubMed Central (United Kingdom)

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

International Nuclear Information System (INIS)

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

UK PubMed Central (United Kingdom)

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

British Library Electronic Table of Contents (United Kingdom)

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

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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.

International Nuclear Information System (INIS)

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

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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.)

International Nuclear Information System (INIS)

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 ...

Wastenet

heterogeneity bias Static models: Other models:

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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, ...

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The most typical kinds of corrosion of brasses are selective corrosion (dezincification) and stress corrosion. Prevention against these kinds of corrosion lies in application of arsenic alloy addition and appropriate heat treatment removing internal stresses as well as in maintaining the arsenic and phosphorus contents on a proper level. The most typical corrosion of cupronickels is the local corrosion. Selective corrosion occurs less often and corrosion cracking caused by stress corrosion in sea water does not usually occur. Crevice corrosion is found especially in places of an heterogeneous oxidation of the surface under inorganic deposits or under bio-film. Common corrosive phenomena for brasses and cupronickels are the effects caused by sea water flow and most often the impingement attack. Alloy additions improve resistance to the action of intensive sea water flow but situation in this field requires further improvement, especially if the cheaper kinds of alloys are concerned. ...

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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 ...

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The following paragraphs summarize the progress of each research project funded under the WVU Cooperative Agreement during the third quarter of 1997 (July - September 1997). The projects are arranged according to their 1997 WVU task number. WVU Focus Area 1.0: Subsurface Contaminants, Containment and Remediation Task No. 1.1: Project discontinued. Task No. 1.2: Development of Standard Test Protocols and Barrier Design Models for Desiccation Barriers (K. Amininan & S. Ameri): A number of experiments were preformed this period to evaluate the ability of the dried sand-packs to act as a barrier to liquids. Water infiltration tests were done with a constant head, dispersing 80 ml of water, and by adding water in small increments. Results indicate that when the water is spilled over the sand-pack, it has the tendency to channel through the sand-pack, significantly reducing the capacity of the dried zone to retain liquid contaminants. This ...

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Seismic monitoring at the Las Tres Virgenes, BCS, geothermal field started in 1992 with an analog station of vertical components detecting a large number of earthquakes of varying magnitudes. In February 1993, a seismic network was installed, composed of six digital stations DR-2000-with S-6000 and S-5000 sensors and three registration channels (N-S, E-W and vertical). This was the basis for the development of a program to correct arrival-time data for P and S waves due to instrument drift. From January to April 1994 and May to August 1995, based on the 170 seismic events recorded, a velocity model was proposed. From December 1995 to July 1996, seismic data were processed and interpreted, and zones of occurrence were determined for events according to magnitude and the predominant noise in the field. From September 2003 to December 2004, 10 seismic stations (permanent and temporary) were installed and monitored and it was concluded the most ...

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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 ...

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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 ...

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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. ...

Energy Technology Data Exchange (ETDEWEB)

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, ...

Science.gov (United States)

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 ...

Environmental Research Database

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 ...

Energy Technology Data Exchange (ETDEWEB)

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.

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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.

British Library Electronic Table of Contents (United Kingdom)

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...

Energy Technology Data Exchange (ETDEWEB)

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 ...

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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.

British Library Electronic Table of Contents (United Kingdom)

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...

International Nuclear Information System (INIS)

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).

British Library Electronic Table of Contents (United Kingdom)

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...

British Library Electronic Table of Contents (United Kingdom)

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

British Library Electronic Table of Contents (United Kingdom)

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 ...

UK PubMed Central (United Kingdom)

SIMV (simulation and modeling of ventilation) is a quantitative system for the mathematical modeling and simulation of pulmonary...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

Science.gov (United States)

Not Available

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

ScienceCinema

...english ...

Science.gov (United States)

... Multivibrators were used in the first model, which is called the "MV Model." Mwe second model, "1ST Model," has a saw-toothed voltage. ...

International Nuclear Information System (INIS)

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 degrees, 691.65 km ...

British Library Electronic Table of Contents (United Kingdom)

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.

Energy Technology Data Exchange (ETDEWEB)

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.