This paper describes a comprehensive model of wastewater treatment in secondary facultative ponds, which combines 3D hydrodynamics with a mechanistic water quality model. The hydrodynamics are based on the Navier-Stokes equation for incompressible fluids under shallow water and Boussinesq assumptions capturing the flow dynamics along length, breadth and depth of the pond. The water quality sub model is based on the Activated Sludge Model (ASM) concept, describing COD and nutrient removal as function of bacterial growth following Monod kinetics, except for Escherichia coli removal, which was modelled as first order decay. The model was implemented in the Delft3D software and was used to evaluate the effect of wind and the addition of baffles on the water flow pattern, temperature profiles i...
The aim of this study is three folds: to compare the eight-channel phased-array and standard circularly polarized (CP) head coils in visualiazation of the intracranial vessels, to compare the three-dimentional (3D) time-of-flight (TOF) MR angiography (MRA) techniques, and to define the effects of parallel imaging in 3D TOF MRA. Fifteen healthy volunteers underwent 3D TOF MRA of the intracranial vessels using eight-channel phased-array and CP standard head coils. The following MRA techniques were obtained on each volunteer: (1) conventional 3D TOF MRA with magnetization transfer; (2) 3D TOF MRA with water excitation for background suppression; and (3) low-dose (0.5 ml) gadolinium-enhanced 3D TOF MRA with ...
Volume 2 of the water resources data for the 1992 water year for Oklahoma consists of record of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes or reservoirs; and water levels of ground-water well. The report contains discharge records for 136 gaging stations; stage and contents for 31 lakes or reservoirs; water quality for 50 gaging stations. Also included are 61 partial-record or miscellaneous streamflow stations and 28 ground-water sites.
Hyogo-ken Nanbu earthquake with a focus in the Akashi straits has given huge earthquake damages in and around Awaji Island and Kobe City in 1995. It is clear that the basement structure, which is steeply deepened at Kobe City from Rokko Mountains towards the coast, and the focus under this related closely to the local generation of strong ground motion. Generation process of the strong ground motion was discussed using 2D and 3D numerical simulation methods. The 3D pseudospectral method was used for the calculation. Space of 51.2km{times}25.6km{times}25.6km was selected for the calculation. This space was discretized with the lattice interval of 200m. Consequently, it was found that the basement structure with a steeply deepened basement, soft and weak geological structure thickly deposited on the basement, and earthquake faults running under the boundary of ...
This paper describes the calculation method of 3-D underground structures in TDME method which measures only field components. Recently, FDTD method was developed as calculation method in time domain difference calculus, and the forward analysis accuracy of 3-D fields was rapidly improved. The survey results using a large-scale loop (600m{times}360m) were numerically analyzed by FDTD method. 16 measuring lines were prepared in both X and Y directions, and measuring points were prepared on intersection points of the measuring lines. Since signal current is staircase one, step and impulse responses of the ground were determined by calculating magnetic field and its time differentiation. The rectangular body (120m{times}120m{times}100m) of 0.2S/m in conductivity (5 ohm m in resistivity) was installed 160m under the ground as ...
... This is true because a shorter residence time means that groundwater moves 'faster.' Thus, contamination will get to the drinking well from the recharge area (point of entry) faster if the groundwater is younger. However, it has been difficult to measure the exact age of young groundwater. The conventional indicator has been tritium, a radioactive form of hydrogen, but its ...
The 1993 Petroleum Hydrocarbons Conference was comprised of 3 days of technical presentations within the following topic areas: pollution prevention and cost control; development of remediation levels; free-phase and dissolved hydrocarbon contamination management; investigation and analysis of petroleum hydrocarbons; applications of computer modeling for remediation; design and implementation of bioventing; design and implementation of air sparging; soil vapor extraction as a remediation technique; and groundwater remediation using natural bacteria. In addition, more than 100 leading companies in the groundwater and petroleum industries participated in the Conference Exposition in which a variety of equipment and services for preventing, detecting and remediating groundwater contaminated by petroleum hydrocarbons and other organic chemicals was showcased. ...
Seven villages in southeastern Kenya surround Mt. Kasigau and depend on the mountain's cloud forest for their water supply. Five of these villages have regularly experienced water shortages, and all village water supplies were contaminated with Escherichia coli bacteria. There is a need to economically find new sources of fresh groundwater. Remote sensing offers a relatively quick and cost-effective way of identifying areas with high potential for groundwater development. This study used spectral properties of features on Landsat remote sensing imagery to map linear features, soil types, surface moisture, and vegetation. Linear features represented geologic or geomorphologic features indicating either shallow groundwater or areas of increased subsurface hydraulic conductivity. Regarding...
This document is a user`s manual for the Rn3D finite element code. Rn3D was developed to simulate gas flow and radon transport in variably saturated, nonisothermal porous media. The Rn3D model is applicable to a wide range of problems involving radon transport in soil because it can simulate either steady-state or transient flow and transport in one-, two- or three-dimensions (including radially symmetric two-dimensional problems). The porous materials may be heterogeneous and anisotropic. This manual describes all pertinent mathematics related to the governing, boundary, and constitutive equations of the model, as well as the development of the finite element equations used in the code. Instructions are given for constructing Rn3D input files and executing the code, as well as a description of all output files generated ...
In Situ Bioremediation (ISB) is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation. This process (ISB) involves injection of air and nutrients (sparging and biostimulation) into the groundwater and vacuum extraction to remove Volatile Organic Compounds (VOCs) from the vadose zone concomitant with biodegradation of the VOCs. This process is effective for remediation of soils and groundwater contaminated with VOCs both above and below the water table. A full-scale demonstration of ISB was conducted as part of the Savannah River Integrated Demonstration: VOCs in Soils and GroundWater at Nonarid Sites. This demonstration was performed at the Savannah River Site from February 1992 to April 1993.
Groundwater is treated in the Czech Republic so that small water tanks are built above each water source to serve the primary groundwater treatment; water so pretreated is then concentrated in large basins for subsequent treatment. Some water tanks where the first contact of the groundwater with air takes place were selected as sites predisposed to radon accumulation. The examination was carried out near the town of Jihlava, where the bedrock contains slightly elevated radium concentrations. The average radon concentrations lay within the region of 2-4 kBq/m"3; the instantaneous values, however, exhibited appreciable periodical variations during the day. The relatively high radon concentrations will not pose a marked hazard for the personnel because the employees only reside ...
The total and state-specific electron-ion recombination rate coefficients are obtained for FeI. The calculations are carried out using a new ab initio method that incorporates both the radiative and the dielectronic recombination processes in an unified and self-consistent manner. The computations employ the close coupling approximation and the R-matrix method from atomic collision theory. A 52 state close coupling eigenfunction expansion dominated by the states of the ground3d{sup 6}4s and excited 3d{sup 7}, 3d{sup 6}4p, 3d{sup 5}4s{sup 2}, and 3d{sup 5}4s4p configurations of FeII are used in the present calculations. The important electron correlation and radiation damping effects are included via explicit coupling of autoionization and radiative channels. ...
Because of questions regarding current density and inductance estimates of the Atlas oil transmission line in the region where the vertical plates connect to the disk line, calculations using the 3D FE program Flux3d were initiated. Flux3d inductance values are nearly that estimated by D. Scudder. Calculations for three base designs of E. Ballard and D. Pierce were completed where several variations for each base design were used to determine the important parameters affecting inductance and to check inductance consistency. Flux3d showed for the first base design a very high current density of 36MA/m at the connection between the vertical and horizontal ground plates resulting in a magnetic pressure of 120 kpsi. The second base design modified this connection to reduce the current density to 20MA/m ...
The ground state of a three-dimensional (3D) rotating trapped superfluid Fermi gas in the BCS-BEC crossover is mapped to finite N v -body vortex states by a simple ansatz. The total vortex energy is measured from the ground-state energy of the system in the absence of the vortices. The vortex state is stable since the vortex potential and rotation energies are attractive while the vortex kinetic energy and interaction between vortices are repulsive. By combining the analytical and numerical works for the minimal vortex energy, the 2D configurations of N v vortices are studied by taking into account of the finite size effects both on xy-plane and on z-direction. The calculated vortex numbers as a function of the interaction strength are appropriate to the renew experimental results by Zwier...
Decision-making is strongly based on modelling in two of our water supply projects concerning artificial groundwater. The model used is a 2-dimensional flow and transport model using the element method. Due to sharp variations in Finnish soils, the modelling process is based on careful and detailed evaluation of basic hydrogeological data before and during model calibration.
In order to employ molecular dynamics (MD) methods, commonly used in condensed matter physics, we have derived the equations of motion for a beam of charged particles in the rotating rest frame of the reference particle. We include in the formalism that the particles are confined by the guiding and focusing magnetic fields, and that they are confined in a conducting vacuum pipe while interacting with each other via a Coulomb force. Numerical simulations using MD methods has been performed to obtain the equilibrium crystalline beam structure. The effect of the shearing force, centrifugal force, and azimuthal variation of the focusing strength are investigated. It is found that a constant gradient storage ring can not give a crystalline beam, but that an alternating-gradient (AG) structure can. In such a machine the ground state is, except for one-dimensional (1-D) crystals, time dependent. The ground state is a zero entropy state, despite the ...
Exposure of female rats to trichloroethylene (TCE), an environmental toxicant commonly found in ground and surface waters throughout the United States, reduces the fertilizability of oocytes...Full Text Available
Wet-weather flow (WWF), including combined-sewer overflow (CSO, sanitary-sewer overflow, and stormwater (SW), is a significant contributor of microbial contamination to surface water and groundwater. By using effective wastewater or SW disinfection, introduction of pathogen con...
A new three-dimensional (3D) acoustic modelling method was developed using a first-order hyperbolic wave system which was solved with explicit finite dfferences. The numerical solution of the 3D wave system provides a useful method for simulating evolution of a pressure field corresponding to compressional type waves. Existing two-dimensional (2D) elastic modelling algorithms were modified and fine-tuned for computationally efficient and realistic wave propagation simulations in complex structures. An original formulation of the 3D reverse time migration method was developed which is very accurate, does not suffer from unwanted evenescent energy, can image dips beyond 90{degree}, and does not generate multiple energy. Two case studies were performed that involved steam stimulation projects in the Cold Lake deposit. Simulations were performed during different ...
In-situ air stripping employs horizontal wells to inject or sparge air into the groundwater 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 groundwater 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.
Groundwater ranging in temperature from only 38/sup 0/ to 140/sup 0/F can supply a considerable amount of heat energy when couple with a geothermal or ground-water heat pump. The heat pump's method of operation is examined as well as its performance characteristics. (MHR)
In this paper we review and classify the various patterns of isosteric heat versus loading for adsorption of gases on graphitised thermal carbon black at temperatures ranging from below the 3D triple point to temperatures above it, but less than the 3D critical point. We have identified the features of heat curve and highlighted the microscopic origin of these features. The patterns vary with temperature and with the relative strength of the fluid-fluid interaction and solid-fluid interaction. For simple adsorptives (by simple we meant there is no strong association between fluid particles), the heat curve is typified by fluid-fluid attraction and layering phenomena. For adsorptives showing strong association such as water, ammonia and methanol, the heat curve essentially begins below the ...
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3D) and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. Field demonstrations are in progress to collect data for evaluation of horizontal completions in both the Red River and Ratcliffe. A vertical well in the Red River will test attribute analysis of 3D seismic data for prediction of porosity development. Additional seismic acquisitions and interpretation are in progress for both the Ratcliffe and Red River. A ...
The 3-D model program was developed to apply a mise-a-la-masse method to linear current sources with optional shapes. Mise-a-la-masse method is a bipolar mapping survey method using current sources installed in wells, and recently has been widely used for direct exploration of geothermal reservoirs. This method is also used for monitoring underground fluid as electrode arrangement of fluid flow tomography for surveying underground fluid (geothermal fluid, underground water, petroleum). In the geothermal reservoir exploration, the casing pipes of wells are used as linear current sources, and measured data are processed as those based on vertical current source. In the largely inclined well, the inclination of current sources should be considered. The 3-D modeling program was developed by difference calculus using the theoretical potential equation and apparent resistivity based on ...
The papers presented at the symposium had covered three general areas in which isotopes could have been beneficially used. these areas are: -Water use and water use efficiency studies. -Groundwater investigations -Water problems in the arab countries. The individual papers had dealt with these subjects: -Hydrological research in the arab countries by use of radioisotopes. -The perspectives of use of radioisotopes in hydrological studies in Syria. -Water use efficiency and sub-soil water studies. -Sea water inclusion in a coast el aquifers in Lebanon. -Irrigation requirements of crops in Lebanon as determined by a Neutron probe with reference to other methods. -The use of the neutron moisture meter and other methods of the determination of the evapotranspiration of maize. -Ground ...
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 ...
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 "closure laws". Applied approach implies non-equilibrium thermal and flow conditions. The model is solved by the control volume procedure, which has been ...
In situ air stripping (ISAS) technology was developed to remediate soils and groundwater contaminated with volatile organic compounds (VOCs) both above and below the water table. ISAS employs horizontal wells to inject (sparge) air into the groundwater 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.
In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and groundwater 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 groundwater 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.
The improvement in the functions of the viscous flow calculation method VEGA-SHIP around a ship and the expansion of application range were described as the numerical flow simulation in ship and ocean engineering and at the same time application examples to the ocean engineering by the general-purpose flow simulation code FLOW-3D handling the non-steady flow with a free surface were introduced as the numerical simulation regarding such products as a water gate and a dam. In the VEGA-SHIP, water surface was handled as a fixed wall so that wave could not be calculated. Therefore, an algorithm for calculating wave on the water surface was added to the VEGA-SHIP and a calculation method simultaneously considering the creation of wave around the ship and viscosity was developed. The FLOW-3D was used to calculate the phenomenon where inside liquid ...
Electron collisional data are required for population kinetics modeling and spectral predictions of highly ionized ions in high-temperature plasmas. Nickel-like ions are especially interesting for their potential use in soft X-ray laser schemes pumped by electron collisional excitation and recombination. For highly stripped ions of moderate to high Z, relativistic effects begin to play a role in the atomic-physics calculations. A relativistic multiconfigurational distored-wave model has been used for the calculation of electron excitation cross sections and rate coefficients between the 3s2 3p6 3d10 Ni-like Gd ground state and the singly excited states with an N-shell electron.
Purpose: `Exoscopic` and endoscopic identification of colorectal pathologies via MRI. Methods: 5 patients (36-88 years), two normal and three with different colorectal pathologies (diverticular disease, polyps and carcinoma of the colon), were examined by MRI after colonoscopy. Subsequent to filling of the colon with a gadolinium-water mixture under MRI-monitoring, 3D-data sets of the colon were acquired in prone and supine positions over a 28 sec breathold interval. Subsequently multiplanar T{sub 1}-weighted 2D-sequences were acquired before and following i.v. administration of Gd-DTPA (0.1 mmol/kg BW). All imaging was performed in the coronal orientation. The 3D-data were interactively analysed based on various displays: Maximum intensity projection (MIP), surface shadowed display (SSD), multiplanar reconstruction (MPR), virtual colonoscopy (VC). Results: All of the colorectal ...
The potential for detoxification and deodorization of sulfide-laden water (sour water) by microbial treatment was evaluated at a petroleum production site under field conditions. A sulfide-tolerant strain of the chemautotroph and facultative anaerobe, Thiobacillus denitrificans, was introduced into an oil-skimming pit of the Amoco Production Company LACT 10 Unit of the Salt Creek Field, Wyoming. Field-produced water enters this pit from the oil/water separation treatment train at an average flowrate of 5,000 bbl/D (795 m{sup 3}/D) with a potential maximum of 98,000 bbl/D (15,580 m{sup 3}/D). Water conditions at the pit inlet are 4,800 mg/l TDS, 100 mg/l sulfide, pH 7.8, and 107{degrees}F. To this water an aqueous solution of ammonium nitrate and diphosphorous pentoxide was added ...
Electron elastic and collisional excitation cross sections from the ground state of potassium are calculated using the noniterative integral-equation method of Henry, Rountree, and Smith [Comput. Phys. Commun. 23, 233 (1981)] in the electron energy range 4#<=#E#<=#200 eV. Configuration-interaction target wave functions that take account of correlation and polarization effects are used to represent the ground state and the six lowest excited states 4p "2P degree, 5s "2S, 3d "2D, 5p "2P degree, 4d "2D, and 6s "2S. Elastic and discrete excitation cross sections are obtained in a seven-state close-coupling (7CC) approximation. The 7CC elastic and excitation cross sections are compared and contrasted. Near threshold the elastic cross section dominates the resonance, 4s "2S#->#4p "2P degree, and the sum of the other remaining excitation cross sections. Comparison of our total cross sections with some ...
Already, MR Imaging is superior in diagnostic imaging of joints in many cases; however, there have been recent developments, which are the subjects of this paper. With gradient-echo sequences acquired in 3D technique, it is possible to produce high-resolution images of joints in acceptable scantime, because gradient-echo sequences are less time-consuming than convential SE sequences. With the acquisition of two echoes, phase difference between water and fat protons have to be considered. 3D Imaging is capable of displaying complex pathology in a superior way, which should be useful in preoperative planning. Tissue contrast is altered by fat saturation or magnetization transfer in order to achieve better conspicuity of lesions. Although diagnostic value of some of these options is not yet clear and further clinical studies are needed, they are a promising possibility for improving MR ...
This study evaluates the degree to which surface impoundments at licensed facilities comply with significant changes in NRC requirements initiated by enactment of EPA's final environmental standards for uranium recovery facilities (40 CFR Part 192). Impoundment liner requirements, ground-water protection standards, ground-water monitoring and corrective action programs, and site closure standards are the most significant regulatory modifications. The compliance status of 30 conventional mills and 31 in-situ mines is determined from a review of Nuclear Regulatory Commission and agreement state docket files through November, 1983. Results of this review show that a majority of conventional uranium mill tailings management systems are deficient with respect to liner requirements for new impoundments or proposed expansions to existing impoundments, as well as with respect to some aspects of ground-water monitoring and ...
BackgroundTrichloroethylene (TCE) is a suspected human carcinogen and a common ground-water contaminant. Chloral hydrate (CH) is the major metabolite of TCE formed in the liver by...Full Text Available
Ground thermal energy storage is a means of storing thermal energy underground during the summer and utilizing it during the winter. The main use of such a technology is in the heating, ventilating and air conditioning sector where the ground provides a stable temperature reservoir for a heat pump system. Heat pumps are mechanical systems that provide heating to a space in the winter, and cooling in the summer. They are increasingly popular because the same system provides both heating modes, depending on the direction of the cycle upon which they operate. The stable temperature reservoir allows the heat pump system to run at a higher efficiency. Thermal energy is transmitted to and from the ground by circulation of water through standing column geothermal wells. In commercial applications...
Manganese oxides precipitated from aerated well sea water at the Marine Science Museum, Tokai University, have been analyzed chemically and mineralogically. The O / Mn ratios are lower in todorokite than in birnessite but these minerals have similar contents of minor transition metals, which can be taken up additionally from sea water after the precipitation of Mn oxides. On the basis of these results, the genesis of Mn minerals is discussed in relation to marine Mn nodules.
In 2000, a network of twenty-three piezometers was used to measure hydraulic head in the water-table aquifer (Upper Aquifer Zone of the Upper Three Runs Aquifer, or UAZ of the UTRA) along the groundwater outcrops (i.e. seeplines) near the F- and H-Areas.
Yucca Mountain, Nevada is a potential site for a high-level radioactive-waste repository. Uncertainty and sensitivity analyses were performed to estimate critical factors in the performance of the site with respect to a criterion in terms of pre-waste-emplacement ground-water travel time. The degree of failure in the analytical model to meet the criterion is sensitive to the estimate of fracture porosity in the upper welded unit of the problem domain. Fracture porosity is derived from a number of more fundamental measurements including fracture frequency, fracture orientation, and the moisture-retention characteristic inferred for the fracture domain.
The Underground Hydroelectric Pumped Storage (UHPS) Program Plan describes in detail the planned activities and expected accomplishments in the conduct of UHPS technology development and validation envisioned in the 1976 to 1990 time frame. This document describes the program objectives, implementation strategy, and management methodology. The concept of underground hydroelectric pumped storage is fully directed to application in the electric utility industry. This technology involves using electrical energy generated by base-load plants during off-peak load periods to drive a high-head pump/turbine which pumps water from a lower reservoir to a substantially elevated (upper) reservoir corresponding to a head of 1000 m or so. The upper reservoir is at ground level and the lower reservoir is below ground. Then, during peak-load periods, water in the upper reservoir is allowed to flow to the lower ...
The 3-dimensional (3D) extension C5G7 MOX benchmark problems were solved by CHAPLET-3D code which is based on the idea of dynamic linkage of the multi-plane method of characteristics solutions. The benchmark results are quite accurate in comparison with the reference solutions, independently of the axial solver incorporated in the CHAPLET-3D code. (author)
SummaryIntended Outputs: Identification and evaluation, using participatory approaches, of demand management options:*Technical*Allocative and market based*Impact on target beneficiariesSupporting measures required when introducing water demand management options above:*Extension services & training*Water licences/rights*Institutional changes*Legal measures and regulation*Education*Support in diversifying to less water demanding activities*S [continued...]ObjectivesIdentification of the most appropriate demand management strategies for groundwater abstraction, where aquifiers are being over-exploited, ensuring sustainable livelihoods of the vulnerable and poor are safeguarded. Poverty reduction strategies for areas where groundwater is being over-exploited.DescriptionProject Background: Groundwater is the principal source of both irrigation and domestic ...
Ground-water monitoring near the Raft River site was initiated in 1974 by the IDWR. This effort consisted of semiannual chemical sampling of 22 irrigation wells near the Raft River geothermal development area. This program yielded useful baseline chemical data; however, several problems were inherent. For example, access to water pumped from the wells is limited to the irrigation season (April through September). All the wells are not continuously pumped; thus, some wells that are sampled one season cannot be sampled the next. In addition, information on well construction, completion, and production is often unreliable or not available. These data are to be supplemented by establishing a series of monitor wells in the proposed geothermal withdrawal and injection area. These wells were to be located and designed to provide data necessary for evaluating and predicting the impact of geothermal development on the Shallow Aquifer system.
Water-resources data for the 1993 water year for Texas are presented in four volumes, and consist of records of stage, discharge, and water quality of streams and canals; and stage, contents, and water quality of lakes and reservoirs; and water levels and water quality of ground-water wells. Volume 3 contains records for water discharge at 134 gaging stations; stage only at 1 gaging stations; stage and contents at 13 lakes and reservoirs; water quality at 81 gaging stations; and data for 30 partial-record and 4 flood-hydrograph partial-record stations. Also included are lists of discontinued surface-water discharge or stage-only stations and discontinued surface-water-quality stations; crest-stage and flood-hydrograph partial-record stations, reconnaissance ...
... see and electrophysiological study and catheter ablation with 3D mapping. During the procedure, doctors look at the ... perform a electrophysiology study with ablation, using our 3D mapping system. Keep in mind, that during the ...
In 1996, a field-scale phytoremediation demonstration project was initiated and managed by the U.S. Air Force at a site in western Fort Worth, Texas, using a plantation of 1-year-old stems harvested from branches of eastern cottonwoods during the dormant season (whips) and a plantation of 1-year-old eastern cottonwood seedlings (calipers). The primary objective of the demonstration project was to determine the effectiveness of eastern cottonwoods at reducing the mass of dissolved trichloroethene transported within an alluvial aquifer. The U.S. Geological Survey conducted a study, in cooperation with the U.S. Air Force, to determine water-level variations and their effects on tree growth and mortality and on the biogeochemical system at the phytoremediation site. As part of the study, water-level and water-quality data were collected throughout the duration of the project. This report presents ...
A new methodology for three-dimensional (3-D) numerical modeling of the continuous steel casting process is presented and evaluated. The results are compared with available experimental data obtained in a water-oil mold model for various flow rates and immersion depths of the submerged entry nozzle. The water-oil interface pattern at the top of the mold is also investigated. Wave formation and evolution in time is simulated with a volume tracking method. The predicted flow field inside the mold exhibits quite satisfactory agreement with the corresponding measurements, whereas some quantitative differences are observed referring to the final wave amplitude at low casting speeds. Conclusions of scientific and engineering importance concerning both the computer algorithm and the mold performance are also drawn.
This procedure describes the formulation and make-up of Simulated Dilute Water (SOW), a low-ionic-content water to be used for Activity E-20-50, Long-Term Corrosion Studies. This water has an ionic content which is nominally a factor of ten higher than that of representative waters at or near Yucca Mountain. Representative waters were chosen as J-13 well water [Harrar, 1990] and perched water at Yucca Mountain [Glassley, 1996]. J-13 well water is obtained from groundwater that is in contact with the Topopah Spring tuff, which is the repository horizon rock. The perched water is located in the Topopah Spring tuff, but below the repository horizon and above the water table. A nominal times ten higher ionic content was chosen to simulate ...
Installation of new Shortwave Spectrometer for permanent operation at SGP - In May 2006 the new ShortWave Spectrometer (SWS) was installed in the Optical Trailer at the Southern Great Plains Central Facility SGP on 27 April 2006. The SWS began full operation 28 April 2006 and has run continuously to the present. Over 25 GB of spectra has been collected, calibrated and archived. 3-D radiative transfer simulations - Retrieved fields of cloud optical thickness and effective radius to from the MODIS Airborne Simulator were used to reproduce 3D cloud fields that were used a input to 3D radiative transfer simulations and then compared with simultaneous Solar Spectral Flux Radiometer (SSFR) spectral irradiance measurements. The influence of both horizontal and vertical cloud structure, using accurate versus approximated optical properties in the radiative transfer ...
... stenosis. It looks from the transesophageal and the 3-D echo that most of the problem is really ... posterior leaflet, which you can see on the 3-D echo image is a major source. The anterior ...
In order to reduce the number of surface mining accidents related to low visibility conditions and blind spots of trucks and to provide 3D information for truck drivers and real time monitored truck information for the remote dispatcher, a 3D assisted driving system (3D-ADS) based on the GPS, mesh-wireless networks and the Google-Earth engine as the graphic interface and mine-mapping server, was developed at Virginia Tech. The research results indicate that this 3D-ADS system has the potential to increase reliability and reduce uncertainty in open pit mining operations by customizing the local 3D digital mining map, constructing 3D truck models, tracking vehicles in real time using a 3D interface ...
This decision document presents the selected remedial action for the former Asarco Tacoma Smelter Facility and adjacent slag peninsula, in Ruston and Tacoma, Washington. This Record of Decision (ROD) describes the final cleanup remedy for soil, slag and surface water and disposal of hazardous soils, demolition debris, and residential soils. This ROD is intended to be an interim action for groundwater.
A model has been developed to predict the chemical composition of lakes that form in pyrite-bearing open-pit mines. Pyrite oxidation in wall rock releases sulfuric acid and metals, which mix with groundwaters in the lake. Aqueous metal concentrations are calculated using MINTEQA2.
The operation of industrial facilities has generally resulted in contamination of the surrounding soils and groundwater. A variety of methods have been proposed for the remediation of contaminated sites. This paper presents new process technology that is capable of performing treatment on groundwater or soil washing leachates. The process is targeted to treat low levels of radioactivity, organics and heavy metals present in the aqueous solutions, to be easily transported and provide simple operation on-site and provide an effluent that meets the specified discharge quality. The purification process involves sequential chemical treatment and filtration. The paper will describe the development of the technology and review the current progress in its use to remediate contaminated sites at Chalk River. The application of the process technology has demonstrated that the ambitious goal of setting the ...
The operation of industrial facilities has generally resulted in contamination of the surrounding soils and groundwater. A variety of methods have been proposed for the remediation of contaminated sites. This paper presents new process technology that is capable of performing treatment on groundwater or soil washing leachates. The process is targeted to treat low levels of radioactivity, organics and heavy metals present in the aqueous solutions, to be easily transported and provide simple operation on-site and provide an effluent that meets the specified discharge quality. The purification process involves sequential chemical treatment and filtration. The paper will describe the development of the technology and review the current progress in its use to remediate contaminated sites at Chalk River. The application of the process technology has demonstrated that the ambitious goal of setting the ...
The exchange charge model (ECM) of crystal field is utilized to provide the theoretical explanation of the ground state absorption and the excited state absorption observed for the octahedrally coordinated Ni{sup 2+} ions in the spinel MgAl{sub 2}O{sub 4}. The ECM enables modeling of the crystal field parameters (CFPs) for the impurity ions based on the crystal structure data of the host lattice. To ensure the reliability of the CFPs, the convergence of the CFP values with the increasing number of the coordination spheres taken into account in the ECM calculations is considered. The trigonal CFPs B{sub 2}{sup 0},B{sub 4}{sup 0}andB{sub 4}{sup -3} determined by the ECM, together with the appropriate Racah parameters B and C, serve as input to two crystal field analysis computer packages, which compute the energy level schemes within the whole 3d{sup 8} configuration. The cubic approximation utilizing only one CFP Dq is also ...
The modeling and optimizing processes of a Ground Coupled Heat Pump (GCHP) with closed Horizontal Ground Heat eXchanger (HGHX) are presented in this paper. After thermal modeling of GCHP including HGHX, the optimum design parameters of the system were estimated by minimizing a defined objective function (total of investment and operation costs) subject to a list of constraints. This procedure was performed applying Genetic Algorithm technique. For given heating/cooling loads and various climatic conditions, the optimum values of saturated temperature/pressure of condenser and evaporator as well as inlet and outlet temperatures of the water source in cooling and heating modes were predicted. Then, for our case study, the design parameters as well as the configuration of HGHX were obtained. Furthermore, the sensitivity analysis of change in the total annual cost of the system and optimum design parameters with the climatic ...
Metam sodium (metam) is a widely used soil fumigant. Combined application of metam and other available fumigants is intended to produce synergic pesticidal effects for a broad spectrum of pest control in soil fumigation. This study aimed to test the compatibility of metam with the halogenated fumigants 1,3-dichloropropene (1,3-D), chloropicrin, methyl bromide, methyl iodide and propargyl bromide. Halogenated fumigants and metam were spiked simultaneously into organic solvents, water and moist soils, and metam-induced degradation of these halogenated chemicals was evaluated. In all three media, the halogenated fumigants were incompatible with metam and degraded via rapid chemical reactions. The degradation rate varied with halogenated fumigant species and increased as the amount of metam present was increased. In moist soil, 15-95% of the halogenated fumigants were decomposed within 72 h by metam at a 1:1 molar ratio. ...
The electromagnetic field due to an air explosion is here studied: neutron and the gamma-rays, generated by neutronic reactions, deposit energy which ionizes atmosphere; recoil electrons are also created by gamma collisions. This data set allows to solve the Maxwell equations which manage the electromagnetic field. The TRIPOLI-2 code studies the coupled neutron-gamma transport in 3D- geometries by the Monte Carlo method. The code has been modified to calculate the photon energy deposited in matter and the recoil electron current created by Compton effect. The method is tested wiht a simple case; then neutron and gamma transport is studied in air kerma, deposited photon energy, electron current are calculated as functions of space and time and the contributions of the different neutronic reactions are separately evaluated. The calculations presented here are only part of studies about this subject. Developments will relate three dimensional ...
The authors measure the dipion mass spectrum in X(3872) {yields} J/{psi}{pi}{sup +}{pi}{sup -} decays using 360 pb{sup -1} of {bar p}p collisions at {radical}s = 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity ({sup 3}S{sub 1}, {sup 1}P{sub 1}, and {sup 3}D{sub J}) charmonia decaying to J/{psi}{pi}{sup +}{pi}{sup -}, as well as event C-parity states in which the pions are from {rho}{sup 0} decay. The latter case also encompasses exotic interpretations, such as a D{sup 0}{bar D}*{sup 0} molecule. Only the {sup 3}S{sub 1} and J/{psi} {rho} hypotheses are compatible with the data. Since {sup 3}S{sub 1} is untenable on other grounds, decay via J/{psi} {rho} is favored, which implies C = +1 for the X(3872). Models for different J/{psi}-{rho} angular momenta L are considered. Flexibility in the models, especially the introduction of {rho}-{omega} interference, enable good ...
Sustainability of irrigated agriculture in arid and semi arid lands depends, mainly on the level of soil salinity and the quality of irrigation water. Remotely sensed data can provide information about the extent of vegetated irrigated areas. Al-Hassa oasis, Saudi Arabia is probably the largest oasis in the world depends mostly on tapped groundwater to irrigate mainly date palm groves for its economic survival. This study tried to investigate the extent of soil salinity and the quality of irrigation water and the relationship with vegetation growth, employing NDVI derived from Landsat satellite imagery.
A program under the sponsorship of the United States Nuclear Regulatory Commission was intiated at the Oak Ridge National Laboratory (ORNL) in late 1977. The program, Advanced Instrumentation for Reflood Studies (AIRS), is charged with developing instrumentation for measurement of in-vessel fluid phenomena in pressurized water reactor reflood facilities. The goal of the ORNL program is to develop techniques and systems for measuring fluid flow in-core, deentrainment in the upper plenum and liquid fallback from the upper plenum into the core. A large portion of the development at ORNL is devoted to the impedance probes for measurement of two-phase flow velocities and void fractions. Film probe development at ORNL is limited to adapting the present techniques to the environment of a reflood facility. As the development progresses on all the measurement techniques, ORNL will fabricate and supply instrument systems to the reflood facilities included in the ...
The long-term aim of our research is to develop humidification-dehumidification desalination technology for farms in arid coastal regions that are suffering from salt-infected soils and shortages of potable groundwater. The specific aim of our current study was to determine the influence of greenhouse-related parameters on a process, called Seawater Greenhouse, which combines fresh water production with growth of crops in a greenhouse system. A thermodynamic model was used based on heat and mass balances. The dimension of the greenhouse had the greatest overall effect on the water production and energy consumption. A wide shallow greenhouse, 200 m wide by 50 m deep gave 125 m{sup 3} d{sup -1} of fresh water. This was greater than a factor of two compared to the worst-case scenario with the same area (50 m wide by 200 m deep), which gave 58 m{sup 3} ...
The purpose of this project was to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in-place, and methods for improved completion efficiency. The investigations and demonstrations were focussed on Red River and Ratcliffe reservoirs in the Williston Basin within portions of Montana, North Dakota and South Dakota. Both of these formations have been successfully explored with conventional 2-dimensional (2D) seismic. Improved reservoir characterization utilizing 3-dimensional (3D) seismic was investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterizations were integrated with geological and engineering studies. The project tested lateral completion techniques, including high-pressure jetting lance technology and short-radius lateral drilling to enhance completion efficiency. Lateral completions should improve economics for both primary and ...
A large part of mechanical and durability characteristics of cement-based materials comes from the performances of the hydrated cement, cohesive matrix surrounding the granular skeleton. Experimental studies, in situ or in laboratory, associated to models, have notably enhanced knowledge on the cement material and led to adapted formulations to specific applications or particularly aggressive environments. Nevertheless, these models, developed for precise cases, do not permit to specifically conclude for other experimental conclusions. To extend its applicability domain, we propose a new evolutive approach, based on reactive transport expressed at the microstructure scale of the cement. In a general point of view, the evolution of the solid compounds of the cement matrix, by dissolutions or precipitations, during chemical aggressions can be related to the pore solution evolution, and this one relied to the ionic exchanges with the external environment. By the utilization of a ...
This paper deals with the calculations of 3D nuclear heat generation profile in the charcoal filter and subsequently the commencement time of Primary Containment Cleanup (PCC) system of 540MWe Pressurized Heavy Water Reactor (PHWR). Fuel failure is predicted due to overheating of the fuel under loss of Coolant Accident (LOCA) without Emergency Core Cooling System (LOCA without ECCS). Subsequently fission product gasses along with water vapours are released to Reactor Building (RB) atmosphere. Plate-out and water trapping mechanism stabilizes the concentration of significant fission products i.e. radioiodines in about 4 hours before being circulated through charcoal filters of Containment Cleanup system. After cleaning up the RB atmosphere, it is discharged to outside atmosphere through stack. The isotopes of radioiodine emit beta and gamma radiations. Gamma radiations are partly ...
The effect of water shortage on growth and gas exchange of maize grown on sandy soil (SS) and clay soil was studied. The lower soil water content in the SS during vegetative growth stages did not affect plant height, above-ground biomass, and leaf area index (LAI). LAI reduction was observed on the SS during the reproductive stage due to early leaf senescence. Canopy and leaf gas exchanges, measured by eddy correlation technique and by a portable photosynthetic system, respectively, were affected by water stress and a greater reduction in net photosynthetic rate (A N) and stomatal conductance (g s) was observed on SS. Chlorophyll and carotenoids content was not affected by water shortage in either condition. Results support two main conclusions: (1) leaf photosynthetic capacity was unaffec...
The sampling is described for radionuclide X-ray fluorescence analysis. Aerosols are captured with various filter materials whose properties are summed up in the table. Fine dispersed solid and liquid particles and gaseous admixtures may be captured by bubbling air through a suitable absorption solution. The concentration of small amounts of impurities from large volumes of air is done by adsorbing impurities on surfactants, e.g., activated charcoal, silica gel, etc. Aerosols may be captured using an electrostatic precipitator and aerosol fractions may be separated with a cascade impactor. Water sampling differs by the water source, i.e., groundwater, surface water, rain or waste water. Soil samples are taken by probes. (ES).
This paper deals with the energy required to separate ethanol from an aqueous solution in a distillation column containing a solid phase. The solid phases evaluated consisted of either an amylatious (ground corn) or a cellulose (sugar cane bagasse) absorber whit particle sizes smaller than 4 mm. The water-retention capacity of each solid phase was measured by passing vapors or ethanol-water mixtures through the solid phase. When starting with initial concentrations bellow the azeotropic point, ethanol concentrations up to 99,5% (on corn) and 97,2% (on sugar cane) were achieved. The water content was evaluated potentiometrically (Karl`Fischer). Regarding the 2-4 mm ground corn solid phase column, the energy consumed was estimated to be reduced by 15,6% and 60% (by weight) ethanol-water mixture respectively. (author) 11 refs., 2 figs., 2 tabs
Protected cultures are widespread along the Lebanese narrow coastline, encouraged by mild winter conditions. Although one of the most intensive production systems, water and nutrients managements are mostly empirical, based on the experience of the grower himself or of his workers. So far, water has been available in Lebanon, but it will become scarce within ten years. The conservation of water quality by a rational addition of nutrients is particularly relevant to protected cultures. This is important as greenhouses are developed on imported shallow soils that could be fragile and highly vulnerable to pollution. Sound management includes the amount and the forms of fertilizers as well as the modality of fertigation. An experiment was conducted during two spring seasons in a location along the northern coast in a typical unheated greenhouse. The cucumber response to two frequencies and modalities of fertigation was ...
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 ...
This topical report is a compilation of characterizations by different disciplines of the Red River Formation in the southwest portion of the Williston Basin and the oil reservoirs which it contains in an area which straddles the state line between North Dakota and South Dakota. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity, and methods for improved recovery. The report is divided by discipline into five major sections: (1) geology, (2) petrography-petrophysical, (3) engineering, (4) case studies and (5) geophysical. Interwoven in these sections are results from demonstration wells which were drilled or selected for special testing to evaluate important concepts for field development and enhanced recovery. The Red River study area has been successfully explored with two-dimensional (2D) seismic. Improved reservoir characterization utilizing 3-dimensional (3D) and has been investigated for ...
Soil contamination by liquid organic pollutants represents a serious threat to phreatic groundwater. These organic liquids get into the ground and migrate through the porous medium until they finally reach the aquifer. After a critical study of the literature, we listed various existing multiple displacements under three-phase conditions of a disconnected polluting phase that may or not spread over water. The aim of this thesis is to model (at pore scale level) and integrate in the pore network model the various flows that occur when three phases (gas, pollutant and air) are present in a porous medium. The porous medium is supposed completely water-wet. The polluting phase may be connected or not, and the spreading coefficient of the pollutant over water may either be positive or negative. The goal of our study is to obtain macroscopic parameters such as ...
This document provides stakeholder evaluations on innovative technologies to be used in the remediation of volatile organic compounds from soils and groundwater. The technologies evaluated are; in-well vapor stripping, in-situ bioremediation, and gas membrane separation.
The application of a Compact Airborne Spectrographic Imager to assessment and monitoring of lakes in a lignite open cast mining area in central Germany is described. The imager was used in combination with additional ground experiments, such as field spectroscopy and water sampling. The spectral characteristics of an instrument under development for monitoring geochemical and hydrological processes are presented. Summary form only.
The degradation of chlorinated solvents by reduction at the surface of zero-valent metals and bimetallic systems has emerged as an important approach to the in-situ remediation of groundwater. Reduction by iron metal was studied in batch and column systems to develop a mechanistic understanding of the reaction chemistry and to determine the factors that affect dechlorination rate and long term performance in field applications.
Radon concentration measurement in the ground can be used for the prospecting for uranium and earthquake prediction. Some results of radon concentration measurement in the soil are presented here. The moisture condensation at the detector surface can affect on the detection efficiency. Due to this problem we tested a few filter papers on water permeability. The ratio of track densities on solid state nuclear track detector (SSNTD) in the open and the closed diffusion chamber is also determined. (author)
Atrazine (ATR) has been widely applied in the US and Mid Western states. Recently, public health and ecological concerns have been raised about contamination of surface and groundwater by ATR and its chlorinated metabolites, due to their toxicity and potential carcinogenic or endocrinology effects....
Total mercury content and its distribution in muscles and viscera of male and female blue crab (Callinectes sapidus Rothbum) and deep water pink shrimp (Parapenacus longirostris) collected from the 3 main fishing grounds near the Alexandria coast in the Mediterranean sea was estimated. The results indicate that the mercury content in the muscles of both species differ according to fishing areas, size, sex, and species. More than 75% of total mercury were accumulated in the viscera of both species which indicates that the mercury entered in these organisms via the feed chain. PMID:3696196
Oxyanions of uranium, selenium, chromium, arsenic, technetium, and chlorine (as perchlorate) are frequently found as contaminants on many DOE sites, and in other areas of the U.S.. A potential remediation method is to react the contaminated water with zero-valent iron (ZVI). We are performing fundamental investigations of the interactions of the relevant compounds with Fe filings and single- and poly-crystalline surfaces. The aim of this work is to develop the physical and chemical understanding that is necessary for the development of cleanup techniques and procedures.
A study for Cs-137 radionuclide dispersion in the marine environment through of compartmental model (Box Model) is presented. The model simulates the surface water contamination caused by direct atmospheric deposition, surface wash off, desorption from sediments and transfer with the groundwater of accidentally released radionuclides. For this study the model was applied to the North Sea, near to Sellafield, based on the transfer coefficients obtain at the literature. The results obtained are in good agreement with the literature, being that the model developed can be applied in to the brazilian coastal regions. (author). 7 refs, 7 figs.
This report is the first revision to a series of reports on radionuclides inn the SRS environment. Tritium was chosen as the first radionuclide in the series because the calculations used to assess the dose to the offsite population from SRS releases indicate that the dose due to tritium, through of small consequence, is one of the most important the radionuclides. This was recognized early in the site operation, and extensive measurements of tritium in the atmosphere, surface water, and groundwater exist due to the effort of the Environmental Monitoring Section. In addition, research into the transport and fate of tritium in the environment has been supported at the SRS by both the local Department of Energy (DOE) Office and DOE`s Office of Health and Environmental Research.
Since 1901, ASARCO, Inc. has owned and operated an 89-acre cadmium-refining smelter in the Globeville neighborhood of north Denver, Colorado. According to complaints filed by EPA and local residents, operations at the smelter have allegedly contaminated the air, groundwater, surface water, and soil; contamination from arsenic, cadmium, lead, and zinc has occurred both onsite and offsite. EPA proposed to add the site to the National Priorities List (NPL) in May 1993.
The purpose of this paper is to evaluate a complete set of environmental pathways for disposal options and conditions that the Nuclear Regulatory Commission (NRC) may analyze for a low-level radioactive waste (LLW) license application. The regulations pertaining In the past, shallow-land burial has been used for the disposal of low-level radioactive waste. However, with the advent of the State Compact system of LLW disposal, many alternative technologies may be used. The alternative LLW disposal facilities include below- ground vault, tumulus, above-ground vault, shaft, and mine disposal This paper will form the foundation of an update of the previously developed Sandia National Laboratories (SNL)/NRC LLW performance assessment methodology. Based on the pathway assessment for alternative disposal methods, a determination will be made about whether the current methodology can satisfactorily analyze the pathways and phenomena likely to be ...
This paper consists of shielding analysis of steel balls and water filled end shields of Indian Pressurized Heavy Water Reactors (PHWRs). The material composition inside lattice tube is entirely different neutronically as compared with the composition of end-shield. Due to variation of material composition in radial and axial directions and complex geometry, it is necessary to carry out 3-D analysis for reasonable prediction of neutron flux and gamma dose rates. In the present paper, shielding analysis of end-shield for 540 MWe PHWR has been carried out during reactor operating and shutdown conditions using Monte-Carlo code MCNP. Furthermore materials on the periphery and central portion of end shield are different. Therefore the analysis was carried out separately for annular portion and central portion of end shield. The dominating streaming paths through end shields were studied. Predictions compare ...
The three-dimensional (3-D), multiphase, computational fluid dynamic (CFD) code FLUENT is used to simulated two-phase flow behaviour in a CANDU header manifold under low (natural circulation) flow conditions. This behaviour was previously inferred from experimental data. The CFD simulations reported here are being used to support these inferences and to obtain a better understanding of phase distribution in the header manifold. The simulations seem to show that the vapor-water mixture models in the FLUENT code do not capture properly phase separation in the header and proper phase branching at the header-feeder connections that have been observed in experiments at low flows. The simulations using discrete-phase model in FLUENT, which tracks the pathlines of the individual vapor bubbles in the water continuum phase, show interesting, complicated and, in some cases, unexpected bubble trajectories from the ...
The Girassol field is located in Angolan deep water of Block 17 and consists of large vertically stacked turbidities complexes. The reservoir extends over approximately 200 km{sup 2} and water depth ranges between 1300 and 1400 meters. In that context High Resolution 3D seismic became the most valuable tool to describe and monitor the reservoir. The field development plan took into account, through re-injection of the gas into the reservoir, Total environmental policy imposing the recycling of production gas. Monitoring of this injection was the main reason to shoot the first High Resolution 4D extremely early in the life of field. Despite the complexity of interpretation due to complex fluid situation and pressure effect, the results went way beyond expectations as the 4D images are of very high quality. Data has also been used to update and refine the reservoir flow model as well as to help deciding ...
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 ...
... CT angiograph for the peripheral rteries. a beautiful 3D-vision on the structures inside e chest. Okay. ... have an angled camera here. This is a 3D camera, and the surgeon has got th What ...
BackgroundMany three-dimensional (3D) images are routinely collected in biomedical research and a number of digital atlases with associated anatomical and other information have...Full Text Available
Motivation: Cell tracking is an important method to quantitatively analyze time-lapse microscopy data. While numerous methods and tools exist for tracking cells in 2D time-lapse images,...Full Text Available
... catheter ablation for paroxysmal atrial fibrillation procedure utilizing 3-D mapping and rotational intracardiac echocardiography. This program is ... of the MRI scan and then there's the 3-D image, which is generated from the pixels chosen ...
The 3-D spectral-domain optical coherence tomography (SD-OCT) images of the retina often do not reflect the true shape of the retina and are distorted differently along the x and y...Full Text Available
ObjectiveCompare occlusal contacts calculated from 3D virtual models created from clinical records to contacts identified clinically using shimstock and transillumination.Full Text Available
In many radiotherapy clinics, geometric uncertainties in the delivery of 3D conformal radiation therapy and intensity modulated radiation therapy of the prostate are reduced by aligning the...Full Text Available
This paper studies the effects of axial heat conduction in boreholes used in geothermal heat pump systems. The axial effects are examined by comparing the results obtained using the finite and infinite line source methods. Using various practical design problems, it is shown that axial effects are relatively important. Unsurprisingly, short boreholes and unbalanced yearly ground loads lead to stronger axial effects. In one example considered, it is shown that the borehole length is 15% shorter when axial conduction effects are considered. In another example dealing with underground water freezing, the amount of energy that has to be removed to freeze the ground is three times higher when axial effects are considered. (author)
Nuclear fuel cycle activities of the former Soviet Union (FSU) have resulted in massive contamination of the environment in western Siberia. We are developing three-dimensional numerical models of the hydrogeology and potential contaminant migration in the West Siberian Basin. Our long-term goal at Pacific Northwest Laboratory is to help determine future environmental and human impacts given the releases that have occurred to date and the current waste management practices. In FY 1993, our objectives were to (1) refine and implement the hydrogeologic conceptual models of the regional hydrogeology of western Siberia developed in FY 1992 and develop the detailed, spatially registered digital geologic and hydrologic databases to test them, (2) calibrate the computer implementation of the conceptual models developed in FY 1992, and (3) develop general geologic and hydrologic information and preliminary hydrogeologic conceptual models relevant to the more detailed models of contaminated ...
Because of the environmental hazard of organic solvents such as chlorinated or aromatic hydrocarbons, water soluble and biodegradable substitutes have come into use. It should be assessed how they affect soil and aquifer when spilled in leaks or accidents. This was simulated in a model system using methanol and percolation columns, one filled with material from the unsaturated subsurface and two with different materials from aquifers. The results reveal that a spill of the substitutes can also cause problems. In homogeneous soils and at long retention times until the substance reaches the aquifer, sorption and biological degradation are most likely to prevent contamination of the groundwater. When oxygen supply in the subsurface is insufficient, reducing conditions occur and sulphide is formed. The data show that much more methanol was eliminated than reflected by the consumption of electron acceptors. This indicates that sorption and anabolic turnover of the ...
The purpose of this paper is to demonstrate how recent experimental results of "1"5"1Eu and "5"7Fe high pressure Moessbauer studies in 4f and 3d metallic magnetic systems can contribute to a deeper understanding of the nature of local moment (4f) and itinerant (3d) magnetism in these systems. Special emphasis is given on the comparison of the experimental results with related theoretical models. (orig.).
The mixture of 1,3-dichloropropene (1,3-D) and chloropicrin (CP) is used as a preplant soil fumigant. In comparison with individual fumigants, application of a mixture may affect the environmental dissipation and fate of each chemical, such as emission and degradation. We investigated the degradation of CP, 1,3-D, and their mixture in fresh soils and sterile soils, and evaluated the competitive characteristic of fumigants in the mixture. The degradation of low concentrations of CP in fresh soil was accelerated at early times in the presence of 1,3-D, whereas the addition of CP reduced the degradation rate of trans-1,3-D, possibly by inhibiting the activity of trans-1,3-D degrading microorganisms. The potential of applying amendments to the soil to increase the rate of CP and ...
3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.
3d occupation numbers of the transition elements corresponding to various types of atomic configurations are calculated by means of the linear muffin-tin orbital (LMTO) method. This data is used with the multiconfiguration Dirac-Fock (MCDF) X-ray intensity ratios to estimate the electron populations of the 3d metals in alloys.
The application of 3D rotational angiography marks a breakthrough in endovascular treatment of aneurysmas of the brain. 3D images are produced based on image series obtained by rotational angiography, so that the anatomic details of interest can be visualized from any requested angle. (orig./CB)
Naval Petroleum Reserve No. 3 (NPR-3), also known as Teapot Dome, is a government-owned oil field in Natrona County, Wyoming. It is an asymmetrical anticline located on the western edge of the Powder River Basin, just south of the Salt Creek Anticline. Production started in 1922, and today the field is a marginally economic stripper field with average production of less than 3 BOPD (0.5 m{sup 3}/D) per well. Total field production is about 1,800 BOPD (286 m{sup 3}/D). The Second Wall Creek Formation was waterflooded from 1979 until June 1992 with poor results due to the extensive natural fracture system in this sandstone unit. Since water injection ceased, reservoir pressure has declined to very low levels. Liquids extraction and reinjection of the gas produced from high-GOR wells along the gas-oil contact continues, but the average gas cap pressure has fallen to approximately 150 ...
One of the limiting contributors to the heat load constraint for the Yucca Mountain repository is the decay of Americium 241. A possible option to reduce the heat load produced by Am-241 is to eliminate or transmute it in a light water reactor thermal neutron environment, particularly, by taking advantage of the thermal fission cross section of Am-242 and Am-242m. In this study we employ lattice loading optimization techniques to define the americium/uranium blending and pin arrangements via an adaptation of the code FORMOSA-L to include the incineration of preloaded americium as an objective function. The optimization routines were designed to maximize americium transmutation, while maintaining power peaking below a predefined constraint. The viability of these lattice designs has been analyzed by creating bundles with these Am-spiked lattices and by loading these bundles into realistic 3D BWR core-wide simulation models ...
In this paper we review and classify the various patterns of isosteric heat versus loading for adsorption of gases on graphitised thermal carbon black at temperatures ranging from below the 3D triple point to temperatures above it, but less than the 3D critical point. We have identified the features of heat curve and highlighted the microscopic origin of these features. The patterns vary with temperature and with the relative strength of the fluid-fluid interaction and solid-fluid interaction. For simple adsorptives (by simple we meant there is no strong association between fluid particles), the heat curve is typified by fluid-fluid attraction and layering phenomena. For adsorptives showing strong association such as water, ammonia and methanol, the heat curve essentially begins below the condensation heat and then approaches it as loading is increased. This is mainly due to the ...
This study evaluated potential hydrogeologic mechanisms that may account for increasing moisture content conditions within the sediments of hydroelectric earth dams. Many such dams in Canada are reaching their life spans of approximately 40 years, therefore this study is considered to be an important and timely undertaking. The objective was to develop a method to numerically assess transient groundwater flow processes within old earth structures. The focus of this study was central Manitoba's Grand Rapids Generating Station where progressive movement within the till overburden has been observed since 1977. The possible source of water which is causing higher moisture content and weakness in the overburden material may be the slow wetting-up of the core and progressive increase in seepage to the downstream side. The evolution of flow through the core was evaluated with a modelling program called FRAC3D-VS which ...
Effect of water injection/draining on elastic waves penetrating through cracks is examined by measuring elastic waves before, during, and after the injection/draining of water into/from cracks in presence in granite. Two blocks of rock, with their crack-containing surfaces in contact with each other, are placed in a vessel, and water injection/draining is done through a hole on a vessel bottom side so that water will penetrate into the cracks. When the blocks are dry, there is almost no contact between the cracks, and so no crack penetrating waves are observed. Crack penetrating waves are produced when water is injected, and the position of the receiver sensing the penetrating waves changes as the water level rises. When the water level is lowered from the high water level, the waveform changes again as the level ...
Simple frameworks have been developed for estimating the utilization potential of: (a) solar photovoltaic (SPV) pumps; (b) windmill pumps; (c) producer gas based dual fuel engine pumps; and (d) biogas based dual fuel engine pumps for irrigation water pumping in India. The approach takes into account factors such as: solar radiation intensity, wind speed, availability of bovine dung and agri-residues, and their alternative uses, groundwater requirements for irrigation and its availability, affordability, and propensity of the users to invest in renewable energy devices, etc. SPV pumps are estimated to have the maximum utilization potential in India, followed by windmill pumps. (author)
When a rotary excavator is operated at locations where there is artesian water, the aquiclude is fractured under pressure of the artesian water upon the penetration of the pile tip through the aquiclude. Since the equipment is provided with a gap for the reduction of friction between the casing and the excavation face, soil and sand near the pile tip burst forth out of the ground together with underground water through the casing or along the outer circumference of the casing. The newly contrived method introduced here is a double pipe process, in which a large casing (2.0m in diameter) is driven until it lands on the aquiclude, water is injected into the casing for the creation of equilibrium between the artesian head and the head in the casing, and finally a casing as large as the pile (1m in diameter) to be installed is used for the excavation of the artesian ...
Tolerancing of assembly mechanisms is a major interest in the product life cycle. One can distinguish several models with growing complexity, from 1-dimensional (1D) to 3-dimensional (3D) (including form deviations), and two main tolerancing assumptions, the worst case and the statistical hypothesis. This paper presents an approach to 3D statistical tolerancing using a new acceptance criterion. Our approach is based on the 1D inertial acceptance criterion that is extended to 3D and form acceptance. The modal characterisation is used to describe the form deviation of a geometry as the combination of elementary deviations (location, orientation and form). The proposed 3D statistical tolerancing is applied on a simple mechanism with lever arm. It is also compared to the traditional worst-case tolerancing using a tolerance ...
A three-dimensional (3-D) prestack reverse-time migration algorithm for common-source P-wave data from anisotropic media is developed and illustrated by application to synthetic data. Both extrapolation of the data and computation of the excitation-time imaging condition are implemented using a second-order finite-difference solution of the 3-D anisotropic scalar-wave equation. Poorly focused, distorted images are obtained if data from anisotropic media are migrated using isotropic extrapolation; well focused, clear images are obtained using anisotropic extrapolation. A priori estimation of the 3-D anisotropic velocity distribution is required. Zones of anomalous, directionally dependent reflectivity associated with anisotropic fracture zones are detectable in both the 3-D common-source data and the corresponding ...
Three-dimensional seismic wavefields may be extrapolated in depth, one frequency at a time, by two-dimensional convolution with a circularly symmetric, frequency- and velocity-dependent filter. This depth extrapolation, performed for each frequency independently, lies at the heart of 3-D finite-difference depth migration. The computational efficiency of 3-D depth migration depends directly on the efficiency of this depth extrapolation. McClellan transformations provide an efficient method for both designing and implementing two-dimensional digital filters that have a particular form of symmetry, such as the circularly symmetric depth extrapolation filters used in 3-D depth migration. Given the coefficients of one-dimensional, frequency- and velocity-dependent filters used to accomplish 2-D depth migration, McClellan transformations lead to a simple and efficient ...
Optimum analytical conditions of the aluminium ion were established by flow injection analysis. Eriochrome Cyanine R(ECR) dye reacts with the aluminium ion at pH 6.0 form a complex that exhibits maximum absorption at 535 nm. Reaction condition including the mixing and the reaction coil length, the concentration and the pH of the buffer solution, temperature, and injection loop volume were optimized to introduce this reaction into flow injection analysis. The results were as follows. A mixing coil length of 0.5 m and a reaction coil length of 4.0 m, the pH 6.0 and 1M of acetate buffer solution, the ECR concentration of 0.56 mM, the reaction temperature of 40 .deg. C, the injection loop volume of 300 #mu#L were chosen as optimum conditions. Under these conditions the detection limit of the aluminium ion was less than 0.05 mg/L and the repeatability was better than 1%. A sampling frequency of 24 times for an hour was achieved. Interfering ions such as F"-, HPO_4"2"-, Fe"2"+, Fe"3"+, ...
More than 80% of the people of Nepal are farmers and 90% of the farmers do farming for subsistence. Agricultural productions contribute about 50% of country's GDP. Agricultural sector has been categorized as the top priority sector since many years. The environment of the country has also deteriorated substantially by the unplanned and unscientific use of natural resources such as air, soil, water, air and forest. Fertility of the soil has also been declining and studies show that productions in mountains is decreasing at a rate of 40 Kg/ha. Yr (1). The Terai, a narrow strip of land in the south, is in heavy pressure due to over exploitation and population growth (both natural and migratory). Shallow groundwater (shallow tube wells) is the main source of drinking water in Terai (the lowland region of Nepal). A study conducted by Department of Water Supply and Sewerage (DWSS) showed that more than 55% of Terai tube wells are ...
A near-real-time integrated temperature and water vapor sounding system has been designed and in operation since June 1993. It combines hourly data from the ground-based radio acoustic sounding system (RASS), a two-channel microwave radiometer, standard surface meteorological instruments, a lidar ceilometer, and the Aerodynamic Research Incorporated Communication, Addressing and Reporting System aboard commercial airlines with space-based data from the TIROS-N Operational Vertical Sounder (TOVS). The physical retrieval algorithm provided by the International TOVS Processing Package is used for combining the ground- and space-based temperature and humidity profiles. The first-guess profiles of temperature and humidity required by the physical retrieval algorithm are obtained by using a statistical inversion technique and the ground-based remote sensors measurements. Statistical error estimates are ...
A homogeneous turbulent mixing of coolant flows with different temperatures at the fuel assembly inlets is an important requirement to minimize hot spots in a fuel assembly of a High Performance Light Water Reactor (HPLWR). Therefore, the mixing chamber between lower core plate, flow adjuster and the mixing chamber within the cluster foot piece diffuser have been investigated using the Computational Fluid Dynamics (CFD)-code Fluent 6.1 and its implemented k-#epsilon# model. The previously presented 3D-CAD-geometry has been simplified using Gambit 2.1.2 and consists of various inlet and outlet tubes or channels in the foot piece bottom plate, the lower core plate and the flow adjuster establishing the boundaries of two consecutive mixing chambers. The temperature distribution at the inlet of the sub-channels of the cluster fuel assemblies is presented. It reveals temperature variations at the coolant inlet of the nine fuel ...
KM3NeT is a future deep-sea research infrastructure hosting a neutrino telescope with a volume of at least one cubic kilometer to be constructed in the Mediterranean Sea. The experiment aims to detect high-energy cosmic neutrinos using a 3D array of optical modules to collect the Cherenkov light induced by charged particles in the water. Upward going muons and showers produced in neutrino interactions with the surrounding matter will allow the search and study of possible sources of extra-terrestrial neutrinos. The design of optical modules makes an important impact on the performance and cost of the KM3NeT project. Several different optical module configurations are under consideration; based on glass pressure spheres containing: a large (10 in.) hemispherical photomultiplier tube (with a multi-anode version as an option); 25-31 3 in. photomultiplier tubes, or a crystal scintillator-based hybrid device (X-HPD). The ...
Ejector refrigeration systems are usually designed to utilize low grade energy for driving the cycle. They also have low maintenance cost because they operate without a compressor. Mainly, the ejector performance directly affects the refrigerating performance. Therefore, an investigation on the characteristics and an efficient design of the ejector are important to improve ejector refrigeration systems. In this study, the computational fluid dynamics (CFD) code, FLUENT, is employed to predict the flow phenomena and performance of CPM and CMA steam ejectors. The ejector refrigeration system, using water as the working fluid, is operated at 120-140 C boiler temperature and 5-15 C evaporator temperature. CFD can predict ejector performance very well and reveal the effect of operating conditions on an effective area that is directly related to its performance. Besides, it is found that the flow pattern does not depend much on the suction zone because the results of ...
In a Pb-Bi cooled direct contact steam generation fast reactor water is injected directly above the core, the produced steam is separated at the top and is send to the turbine. Neither the direct contact phenomenon nor the two-phase flow simulations in CFD have been thoroughly described yet. A first attempt in simulating such two-phase flow in 2D using the CFD code Fluent is presented in this paper. The volume of fluid explicit model was used. Other important simulation parameters were: pressure velocity relation PISO, discretization scheme body force weighted for pressure, second order upwind for momentum and CISCAM for void fraction. Boundary conditions were mass flow inlet (Pb-Bi 0 kg/s and steam 0.07 kg/s) and pressure outlet. The effect of mesh size (0.5 mm and 0.2 mm cells) was investigated as well as the effect of the turbulent model. It was found that using a fine mesh is very important in order to achieve larger bubbles and the turbulent model (k-? ...
Nuclear Engineering Laboratory of the Technical Research Centre of Finland has widely used RELAP5/MOD2 and -MOD3 codes to simulate horizontal steam generators. Several models have been developed and successfully used in the VVER-safety analysis. Nevertheless, the models developed have included only rather few nodes in the steam generator secondary side. The secondary side has normally been divided into about 10 to 15 nodes. Since the secondary side at the steam generators of VVER-440 type reactors consists of a rather large water pool, these models were only roughly capable to predict secondary side flows. The paper describes an attempt to use RELAP5/MOD3 code to predict secondary side flows in a steam generator of a VVER-440 reactor. A 2D/3D model has been developed using RELAP5/MOD3 codes cross-flow junctions. The model includes 90 volumes on the steam generator secondary side. The model has been used to calculate steady ...
Nuclear Engineering Laboratory of the Technical Research Centre of Finland has widely used RELAP5/MOD2 and -MOD3 codes to simulate horizontal steam generators. Several models have been developed and successfully used in the VVER-safety analysis. Nevertheless, the models developed have included only rather few nodes in the steam generator secondary side. The secondary side has normally been divided into about 10 to 15 nodes. Since the secondary side at the steam generators of VVER-440 type reactors consists of a rather large water pool, these models were only roughly capable to predict secondary side flows. The paper describes an attempt to use RELAP5/MOD3 code to predict secondary side flows in a steam generator of a VVER-440 reactor. A 2D/3D model has been developed using RELAP5/MOD3 codes cross-flow junctions. The model includes 90 volumes on the steam generator secondary side. The model has been used to calculate steady ...
A safety analysis code to design a pressurized water reactor and to obtain the licences including entire proprietary rights is under development in domestic research and development project. The purpose and scope of this report is to develop the flow regimes related models for inter-phase friction, wall frictions, wall heat transfer, and inter-phase heat and mass transfer in two-phase three-field equations. In order to choose choose the flow regime criteria, we have investigated various exiting best-estimate T/H codes in this chapter 2. They are the RELAP5-3D, TRAC-M, CATHARE, MARS codes. Around 500 references used in these codes have been collected and reviewed. Also we have investigated eleven papers in detail. In chapter 3, based on the selected flow regimes, the flow regime maps for a gas-liquid flow in horizontal and vertical tubes have decided including the mechanisms of flow regime transition regions. Conclusively, ...
The tidal motion of the ocean water through the ambient magnetic field, generates secondary electric field. This motionally induced electric field can be detected in the sea or inland and has a potential for electrical soundings of the Earth. A first goal of the paper is to gain an understanding of the global distribution of the electric signal due to tidal ocean flow. We simulate the electric signals for two tidal constituents - lunar semidiurnal (M2) and diurnal (O1) tides. We assume a realistic Earth's conductivity model with a surface thin shell and 1-D mantle underneath. Simulations demonstrate that in some coastal regions the amplitudes of the electric field can reach 100 mV/km and 10 mV/km for M2 and O1 tides respectively. The changes of lithosphere resistance produce detectable changes in the tidal electric signals. We show that our predictions are in a good agreement with observations.
Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). A principal source of blade fatigue is thought to be the stochastic (i.e., random) aerodynamic loads created by atmospheric turbulence. This report describes the theoretical background of the VAWT Stochastic Aerodynamic Loads (VAWT-SAL) computer code, whose purpose is to numerically simulate these random loads, given the rotor geometry, operating conditions, and assumed turbulence properties. A Double-Multiple-Stream Tube (DMST) analysis is employed to model the rotor's aerodynamic response. The analysis includes the effects of Reynolds number variations, different airfoil sections and chord lengths along the blade span, and an empirical model for dynamic stall effects. The mean ambient wind is assumed to have a shear profile which is described by either a power law or a logarithmic variation with height above ground. Superimposed on ...
A systematic study for the materials design of III-V and II-VI compound-based ferromagnetic diluted magnetic semiconductors is given based on ab initio calculations within the local spin density approximation. The electronic structures of 3d-transition-metal-atom-doped GaN and Mn-doped InN, InP, InAs, InSb, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs and AlSb were calculated by the Korringa-Kohn-Rostoker method combined with the coherent potential approximation. It is found that the ferromagnetic ground states are readily achievable in V-, Cr- or Mn-doped GaN without any additional carrier doping treatments, and that InN is the most promising candidate for high-T_C ferromagnet. A simple explanation of the systematic behavior of the magnetic states in III-V and II-VI compound-based diluted magnetic semiconductors is also given. It is also shown that V or Cr-doped ZnS, ZnSe, and ZnTe are ferromagnetic without p- or n-type doping ...
With the exception of Sand Springs in Williamstown, Massachusetts, there are no identifiable hydrothermal geothermal resources in the New England region. The radioactive plutons of the White Mountains of New Hampshire do not, apparently, contain sufficient stored heat to make them a feasible target for an induced hydrothermal system such as exists at Fenton Hill near Los Alamos, New Mexico. The only potential source of low grade heat is the large volume of groundwater contained within the unconsolidated sediments related to the Pleistocene glaciation of the region. During the course of the survey an unusual and unexplained thermal anomaly was discovered in St. Johnsbury, Vermont, which is described.
The dynamics of the controlled environment conditions in the SVET-4 space greenhouse model were investigated, using computerized equipment to continuously measure and collect the values of the inside environment parameters, which were then sent to earth. The on-ground analysis of telemetric data for the first 29 days indicated that radishes and the Chinese cabbage plants planted in SVET-4 grew under normal temperature conditions, but in insufficient substrate moisture. After supplying the necessary quantity of water, the analysis of the first 54 days of experiment is continuing. 2 refs.
The UFIP (French Petroleum Industry Association) studies concerning polluted sites and soils and their rehabilitation are presented: characterization of the admissible maximum fuel or gas oil content in the ground, the issue of time effects, and the risks it may induce for public health; study on the various pollutant impacts on the environment (underground waters, biotope...); approach to the development of a dynamical model describing these phenomena and their influence on man, in order to derive consistent and reasonable decontamination objectives
Evaluation and interpretation of CT colonography is based on both 2D and 3D techniques. The 2D techniques are popular mainly because the time needed for evaluation is short. The 3D techniques allow better definition than the 2D techniques, especially of polyps close to folds or at the base of a fold. The evaluation strategies generally accepted so far (primarily 2D, with 3D for problem cases, or vice versa) demand knowledge of both 2D and 3D techniques. Newer 3D visualization techniques help make it possible to acquire more complete and faster recording particularly of areas that are not easily accessible to endoscopic examination. These user-friendly developments are thus well suited to improving the detection and the security of detection of polyps. It must be remembered that ...
We conducted broadband absorption measurements of atmospheric water vapor in the ground state, X {sup 1}A{sub 1} (000), from 0.4 to 2.7 THz with a pressure broadening-limited resolution of 6.2 GHz using pulsed, terahertz time-domain spectroscopy (THz-TDS). We measured a total of seventy-two absorption lines and forty-nine lines were identified as H{sub 2}{sup 16}O resonances. All the H{sub 2}{sup 16}O lines identified were confirmed by comparing their center frequencies to experimental values available in the literature.
Low fluorescence in the field of the Eu3+ photoluminescence spectrum is registered against a bach ground of the continuum of solvent emanation when multi-bubble sonolysis of EuCl3 (0.1 mol l-1) solutions saturated by the air and argon in heavy water. Distinctive sonoluminescence of europium ion is not found earlier in aqueous solutions. Possible reasons of low values of Eu3+ sonoluminescence as compared with other lanthanide ions (Ln3+), and effect of europium on the spectrum of solvent continuum connected, in particular, with the quenching of electron-excited products of the H2O* (O2O*) and Eu3+* sonolysis in the reactions of electron transfer are discussed
Hydrothermal systems typically consist of hot permeable rock which contains either liquid or liquid and saturated steam within the voids. These systems vent fluids at the surface through hot springs, fumaroles, mud pools, steaming ground and geysers. They are simultaneously recharged as meteoric water percolates through the surrounding rock or through the active injection of water at various geothermal reservoirs. In a number of geothermal reservoirs from which significant amounts of hot fluid have been extracted and passed through turbines, superheated regions of vapor have developed. As liquid migrates through a superheated region of a hydrothermal system, some of the liquid vaporizes at a migrating liquid-vapor interface. Using simple physical arguments, and analogue laboratory experiments we show that, under the influence of gravity, the liquid-vapor interface may become unstable and break up into fingers.
The Davis GSR Landfill (GSR) is listed by the U.S. Environmental Protection Agency on the National Priorities List. Preliminary on-site sampling results have demonstrated volatile organic compounds in groundwater and surface water. The contaminants present in groundwater at this site are trichloroethylene, ethylbenzene, toluene, chloromethane, tetrahydrofuran, 1,1,1-trichloroethane, and 1,2 dichloroethane. GSR represents a potential public health concern to area residents. However, information available on this site is not currently adequate to determine if a public health concern exists to these residents. At a minimum, future investigations of this site should include a characterization of the site and site contaminants, and a characterization of the hydrogeology of the area.
This report presents the findings of a U.S. DOE Environmental Management technology transfer initiative of waste-reducing groundwater sampling systems between Savannah River Site (SRS) and Lawrence Livermore National Laboratory (LLNL) which occurred during fiscal years 2001 and 2002. The report describes the collaboration between the two sites, the deployment of the Savannah River Site Purge Water Management System at LLNL, the changes made to that system for use at LLNL, and documents the return-on-investment derived from the system's use at LLNL as well as other benefits generated through this inter-laboratory collaboration. An evaluation of the deployment of the LLNL EasyPump sampling technology at SRS will be covered in a separate report from SRS.
A 65-yr-old female developed cough, fever and dyspnoea following repeated exposure to a home ultrasonic humidifier. High-resolution computed tomography showed ground-glass opacity in both lung fields. Arterial blood gas analysis gave an oxygen tension of 8.38 kPa (63 Torr). Pulmonary function testing revealed restrictive ventilatory impairment with a reduction in the diffusing capacity. The diagnosis of extrinsic allergic alveolitis (EAA) was confirmed by radiographic findings, pathological evidence of alveolitis and reproductive development by a provocation test to the humidifier water. The yeast Debaryomyces Hansenii was the only microorganism cultured from the water of the humidifier. The double diffusion precipitating test and lymphocyte proliferative response was positive for an extract of D. Hansenii, providing evidence to incriminate this fungus. This is the first described case of EAA caused by D. Hansenii. ...
Tests on a sample of trench water from the Maxey Flats burial ground effectively demonstrated the new Reverse Osmosis Pilot Plant. The effluent from the 50% salt-rejection membrane was decontaminated well enough with the exception of tritium to be discharged to the environment. The performance of the 97% salt-rejection membrane was superior to that of the 50% membrane. A breakthrough and capacity experiment was conducted with Durasil 10 on a simulated Three Mile Island solution. The maximum decontamination factor was extrapolated to be 10/sup 6/, which would reduce the cesium level of TMI water to below the discard limit. Capacity (1/DF = 0.5) was reached at 1260 column volumes. Several adsorbents were tested in the engineering columns for decontamination of cesium-bearing solutions. Under the conditions of the experiment, these adsorbents were ineffective in removing cesium from the solution.
Abstract Remediation of groundwater containing anionic contaminants presents a great challenge. Because of its low cost, surfactant-modified zeolite (SMZ) has been studied for >10 years for potential uses as permeable barrier materials to remove anionic contaminants from water. In this study, zeolite aggregates with particle size of 3.4 to 4.8 mm were modified by hexadecyltrimethylammonium (HDTMA) bromide, a cationic surfactant, to a surfactant loading level of 80 mmol/kg and a concurrent counterion bromide loading level of 34 mmol/kg. While no retardation of chromate transport was observed for unmodified columns, a retardation factor of 60 was found for chromate transport through the SMZ columns. Slow but persistent desorption of HDTMA occurred throughout the chromate transport experimen...
In interventional radiology (IVR) of cerebral aneurysms, it is important to understand the form and physical relationships between the cerebral aneurysm and the surrounding vessels. However, because the vessels in the head area are highly complex, it can be difficult to comprehend the structure using conventional angiography. Therefore, three-dimensional rotational angiography (3D-RA) has been used in recent years. This article discusses studies of the spatial resolution of 3D-RA. We reconstructed 3D-RA of an acrylic slit phantom (slit widths: 0.5, 0.75, 1.0, 1.5 mm) and examined spatial resolution by visual evaluation and profile curves. When the slit phantom was arranged to avoid the effect of beam hardening, the spatial resolution of 3D-RA was found to be as high as 0.75 mm. When the slit phantom was placed orthogonal ...
A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparable only at higher angle of ...
A pilot project was started in 1977 over the Lake Superior basin to measure water storage on the land area using aerial gamma-ray spectrometry to provide hydrologic information for forecasting inflow to the lake. Two airborne surveys were made, respectively in November 1977 and March 1978 which provided estimates of the increase in snow water equivalent between these surveys. The basin is located on the Canadian Shield and consequently, the gamma radiation count rate is quite variable. The airborne results are compared with ground measurements on selected flight lines and show generally good agreement. Two equipment calibrations in the Ottawa area provided inconsistent parameter values which are consequently also reflected in the results over the Lake Superior basin. The project has demonstrated to-date that the technique can be developed into an operational system for measuring snow cover water ...
Ozone formation by a pulse positive corona discharge generated in the gas phase between a planar high voltage electrode made from reticulated vitreous carbon and a water surface with an immersed ground stainless steel plate electrode was investigated under various operating conditions. The effects of gas flow rate (0.5-3 litre min"-"1), discharge gap spacing (2.5-10 mm), applied input power (2-45 W) and gas composition (oxygen containing argon or nitrogen) on ozone production were determined. Ozone concentration increased with increasing power input and with increasing discharge gap. The production of ozone was significantly affected by the presence of water vapour formed through vaporization of water at the gas-liquid interface by the action of the gas phase discharge. The highest energy efficiency for ozone production was obtained using high voltage pulses of approximately 150 ns duration in Ar/O_2 ...
In the construction work for the Unit No.5 Turbine Building at Hamaoka Nuclear Power Station, the collaboration work for the planning and the coordination of the building construction and the machinery installation was carried out utilizing three-dimensional computer aided design (3D CAD) information. It was the first time in Japan for a building constructor and a plant manufacturer to work together, exchanging 3D CAD data of the whole building and adjusting the construction schedule. It was made possible to confirm the correspondence concerning the planning of both companies from the primary stage of the project by the total process simulation and to adjust on-going work precisely by the partial process simulation.
In the construction work for the Unit No.5 Turbine Building at Hamaoka Nuclear Power Station, the collaboration work for the planning and the coordination of the building construction and the machinery installation was carried out utilizing three-dimensional computer aided design (3D CAD) information. It was the first time in Japan for a building constructor and a plant manufacturer to work together, exchanging 3D CAD data of the whole building and adjusting the construction schedule. It was made possible to confirm the correspondence concerning the planning of both companies from the primary stage of the project by the total process simulation and to adjust on-going work precisely by the partial process simulation.
Guidelines for the viability primer component of the version 3 workbook. The Viability page in the current version of the Excel spreadsheet for conservation ... ...
A 2-D model has been proposed to investigate the approximate estimation of the natural convection heat loss from modified cavity receiver of without insulation (WOI) and with insulation (WI) at the bottom of the aperture plane in our previous article. In this paper, a 3-D numerical model is presented to investigate the accurate estimation of natural convection heat loss from modified cavity receiver (WOI) of fuzzy focal solar dish concentrator. A comparison of 2-D and 3-D natural convection heat loss from a modified cavity receiver is carried out. A parametric study is carried out to develop separate Nusselt number correlations for 2-D and 3-D geometries of modified cavity receiver for estimation of convective heat loss from the receiver. The results show that the 2-D and 3-D are comparabl...
... applications related to military and intelligence area ... the technology solved yet, but the open issue still ... fields, columns; ie data source, document type ...
mulation, with flow quantities stored at the grid vertices. OVERFLOW ..... attack: a separation bubble near the trailing edge of the ..... AGARD CP-429, Jul. 1988. ...
The authors have been developing a 3D brain CT image display system for planning of craniofacial operations. This system helps doctors plan craniofacial operations on a graphic display (GD) terminal by rendering 3D images reconstructed from a set of slices. The authors reveal how the system generates 3D shapes of organs from given CT images and how it modifies or transforms the obtained shapes according to the user's request. The system functions now available are extraction and display of the skull and the skin, measurement of the distance between two points on the skull given through the GD terminal, and generating and eliminating a polygonal region arbitrarily given on the skull as an operative region. (Auth.).
The corrosion behaviour of the stainless steels 304, 316 Ti, 25Cr-20Ni-Mo-Ti, nickel base alloys Hastelloy C4, Inconel 625, Incoloy 800, Ti and Ti-0.2% Pd alloy has been studied in the aerated or deaerated solutions at 20/sup 0/C and 90/sup 0/C whose compositions are representative of interstitial groundwaters: granitic or clay waters or salt brine. The electrochemical techniques used are voltametry, polarization resistance and complexe impedance measurements. Electrochemical data show the respective influence of the parameters such as temperature, solution composition and dissolved oxygen, addition of soluble species chloride, fluoride, sulfide and carbonates, on which depend the corrosion current density, the passivation and the pitting potential. The inhibition efficiency of carbonate and bicarbonate activities against pitting corrosion is determined. In clay water at 90/sup 0/C, Ti and Ti-Pd show ...
The Chuetsu-oki Earthquake strongly shook the Kashiwazaki-Kariwa Nuclear Power Station with the ground motions exceeding the design values. The incidents include a fire breakout of the Unit 3 transformer, a release of spilled water containing small amount of radioactive materials to the non-radiation control area and subsequently to the environment at Unit 6, and a release of radioactive material from the main turbine condenser through the main stack of Unit 7 due to the delay stooping the turbine gland steam ventilator by the operator in manually, while every unit in operation was safety shutdown in the automatic mode ensuring the three fundamental safety functions of (a) reactivity control, (b) removal of heat from the core and (c) confinement of radioactive materials. Following integrity evaluation and performance testing of the overall plant, seismic safety of buildings, structures, equipment and pipelines on the basis of the basic ...
The mobility of metals in groundwater is an important consideration for evaluating remedial options at the Asarco smelter site. Tacoma, Washington. One factor in assessing metal mobility is the degree of secondary mineralization in a slag-fill aquifer extending into the intertidal zone along the Puget Sound shoreline. Samples of aquifer material were collected for mineralogical analysis from borehole MW-206 at five-foot intervals within the slag fill from 5 to 25 feet below the ground surface, and in the underlying marine sand and gravel at 27 feet. Grab samples of slag fragments with visually apparent secondary minerals were also collected at five intermediate depths between 12 and 19 feet. Samples were analyzed by a variety of techniques including hydride generation/atomic absorption for arsenic concentration, scanning electron microscopy/electron microprobe for mineralogical texture and microanalysis, powder x-ray ...
Presently no one knows whether electromagnetic fields (EMFs) play a role in human cancer or other ailments, though epidemiological studies over the years have suggested that possibility. A study by the Electric Power Research Institute attempted to quantify everything it could about the magnetic environment of a home, identifying not only major sources of magnetic fields, but also their frequencies, strengths, and how they fall off with distance. Sources of a homes magnetic environment include appliances, overhead powerlines, and grounding connections to metallic water pipes. Fields will vary over time, depending on how much current is passing through the electrically conductive sources. Additional contributors to a home's magnetic background may include unusual wiring in the walls, underground power lines, and near-by high voltage transmission lines. This paper summarizes the study results, indicating weak, persistant EMFs may dominate, but ...
This project was supported through ERDA to demonstrate that the temporal distribution of tritium can be documented by the analysis of bound hydrogen in annual tree-ring samples. The project focuses on two sample locations at the Savannah River Site (SRS), a nuclear material production facility located in Aiken, SC. The SRS provided samples of cross-sections from a single tree that were to be pooled together for analysis. Annual tree-rings were identified in each cross-section sample and separated for the period 1954 to 1993. These annual samples were ground and chemically treated to separate the hollocellulose fraction of the wood, then subsequently combusted and the resulting water counting using low-level liquid scintillation counting equipment. Additionally, the ground annual tree-rings were gamma-counted to determine any temporal variation in radionuclide activity and analyzed with x-ray fluorescence to find any ...
According to the Romanian Nuclear Strategy, the third and fourth units of the Cernavoda NPP will be commissioned by 2015. Improvements in operation and safety are expected to be applied for these CANDU-6 based units. On the other side, the need for innovation determined AECL to promote the ACR -1000 - an evolutionary Generation III+ power reactor design and a necessary step towards Generation IV inherently safe nuclear energy systems. CANDU-6 is recognized for having two independent fully capable shutdown systems. ACR-1000 also benefits for this strong safety feature. Two major achievements i.e. using of light water as coolant and using Low Enriched Uranium (LEU) as fuel in a compact heavy water moderated lattice allowed the obtaining of a slightly negative Coolant Void Reactivity (CVR) for the first time in a CANDU-type reactor. The main goal of the paper is to compare the response of SDS1 action during some LOCAs supposed to take place both ...
The nation's wetlands are a valuable resource serving many important natural, industrial, commercial and recreational functions. Wetlands protect shore areas from waves and storms; act as storage areas for flood waters; remove waste from water by trapping soils or silt which settle to the bottom; improve water quality and reduce pollution; are a commercial breeding ground for fish and other foods; and provide space for recreation and habitat for wildlife. They also are located in prime industrial development areas. Recent wetlands losses have caused much public outcry, politicking and regulatory efforts to prevent this trend. During the '90s, the public will see efforts to strike a proper balance regarding wetlands use. Today, wetlands protection is a permitting issue for nearly every major industrial or commercial development and expansion project. Wetlands permit requirements affect ...
All MBI bending magnets in each of the two LHC injection transfer lines will be powered in series. The limited output voltage of existing power converters lead to an unusual coil design avoiding external return bus-bars by combining two overlapping half-coils, electrically separated, with 3 1/2 turns each in a monolithic structure. The voltage between turns in one coil can reach up-to 3.6 kV. The coil has been designed with particular care for obtaining high interturn and ground insulation. Flux-free soldering of connections with plug-in cone sleeves is applied, allowing to execute water cooled current connections as prolongation of the coil conductor. Epoxy compound polymerization in the impregnation mould is obtained by passing overheated water in regulated cycles through the water circuit of the coil conductor. We describe the design basics as well as various test results of pre-series and series ...
In summary, a scaling analysis of a water-cooled Reactor Cavity Cooling System (RCCS) system was performed based on generic information on the RCCS design of PBMR. The analysis demonstrates that the water-cooled RCCS can be simulated at the ANL NSTF facility at a prototypic scale in the lateral direction and about half scale in the vertical direction. Because, by necessity, the scaling is based on a number of approximations, and because no analytical information is available on the performance of a reference water-cooled RCCS, the scaling analysis presented here needs to be 'validated' by analysis of the steady state and transient performance of a reference water-cooled RCCS design. The analysis of the RCCS performance by CFD and system codes presents a number of challenges including: strong 3-D effects in the cavity and the RCCS tubes; simulation of turbulence ...
Bone is a complex, highly structured, mechanically active, three-dimensional (3-D) tissue composed of cellular and matrix elements. We previously published a report on in situ collagen gelation using a rotary 3-D culture system (CG-RC system) for the construction of large tissue specimens. The objective of the current study was to evaluate the feasibility of bone tissue engineering using our CG-RC system. Osteoblasts from the calvaria of newborn Wistar rats were cultured in the CG-RC system for up to 3 wk. The engineered 3-D tissues were implanted into the backs of nude mice and calvarial round bone defects in Wistar rats. Cell metabolic activity, mineralization, and bone-related proteins were measured in vitro in the engineered 3-D tissues. Also, the in vivo histological features of the transplanted, engineered ...
I discuss several examples of critical phenomena in O(N) models where topological excitations play an important role at criticality. I focus particular attention on the O(2) model in 3D, where recent measurements of the vortex string length distribution in equilibrium suggest the existence of a quantitative picture of the critical behavior in terms of defects. The compatibility of this perspective with renormalization group predictions is examined.
1 - Description of program or function: T-HEMP3D (Transportable HEMP3D) is a derivative of the STEALTH three-dimensional thermodynamics code developed by Science Applications, Inc. Changes were made primarily in three areas: material specification, coordinate generation, and the addition of sliding surface boundary conditions. STEALTH itself is based entirely on the HEMP3D code written at LLNL. HEMP3D solves problems in solid mechanics involving dynamic plasticity and time-dependent material behavior and problems in gas dynamics. 2 - Method of solution: The equations of motion, conservation equations, and constitutive relations for stresses, strains, hydrostatic pressure, the von Mises yield condition, and artificial viscosity are solved by finite difference methods following the format of the HEMP code (NESC Abstract ...
The non-natural pyrido[2,3-d]pyrimidine nucleoside F, which pairs preferentially with guanine (G) and adenine (A) within double-helical DNA, recognizes with high selectivity AT base pairs within triple-helical...Full Text Available
The achievement of inner-shell photoionization of Zn-like Pd by means of two exploding foils is described. This resulted in the soft X-ray transition 3d94s2-3d104p at 46 A. It is shown that the photoionization of inner shell electrons in highly stripped ions can lead to X-ray transitions which may be candidates for X-ray lasers under 50 A.
The lowest excited level in Ni-like ions, 3d{sup 9}4s {sup 3}D{sub 3}, decays only via a magnetic octupole (M3) decay. They present calculated values of transition wavelengths and rates for ions with 30 {le} Z {le} 100. They have observed this line in Xe{sup 26+}, using the Livermore EBIT-I electron beam ion trap and a microcalorimeter, as well as a high-resolution flat-field grating spectrometer.
Our studies on K#beta#/K#alpha# X-ray intensity ratios of some of the technologically important 3d-transition metal compounds have been reviewed. Comparison of the experimental results with single-configuration Dirac-Fock calculations provided important information on the valence states of the transition metals in various compounds, which can be helpful in understanding the nature of bonding in the compounds. (author)
Most algorithms for three-dimensional (3D) reconstruction from electron micrographs assume that images correspond to projections of the 3D structure. This approximation limits the attainable resolution of the reconstruction when the dimensions of the structure exceed the depth of field of the microscope. We have developed two methods to calculate a reconstruction that corrects for the depth of field. Either method applied to synthetic data representing a large virus yields a higher resolution reconstruction than a method lacking this correction.
Chemical influences on the relative Ksub(..beta..)/Ksub(..cap alpha..) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarizational effects are of importance.
Chemical influences on the relative Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio up to five per cent were found for different chemical constitutions of Cr, Mn, Fe and Cu by very precise PIXE measurements. In the discussion of these effects, screening of 3p electrons by a varying 3d valence charge, as well as polarisational effects are of importance. (author).
Development of a number of original 3-D migration methods and algorithms is described. The computational efficiency of these algorithms is demonstrated by implementing them on vector and parallel supercomputers. Two-dimensional post-stack and pre-stack depth migration algorithms in the frequency - space domain using implicit finite difference method were also developed and implemented on a parallel computer, and adapted for applications that range from deep crustal imaging of seismic wavefields that involve wide ranging travel times and frequencies. All implicit finite difference migration algorithms were highly prallelized . The one pass 3-D post-stack depth migration algorithm was extensively used for imaging of seismic monitoring data from Cold Lake, Alberta. Experience shows that it provides the right trade-off between accuracy and computational efficiency. A new formulation of the ...
Our goal is to determine an optimized image-guided setup by comparing setup errors determined by two-dimensional (2D) and three-dimensional (3D) image guidance for head and neck cancer (HNC)...Full Text Available
We have studied the nucleation and growth processes in a chemical vapor deposition (CVD) diamond film using a tomographic electron backscattering diffraction method (3D EBSD). The approach is based on the combination of a focused ion beam (FIB) unit for serial sectioning in conjunction with high-resolution EBSD. Individual diamond grains were investigated in 3-dimensions particularly with regard to the role of twinning.
Faults are being actively investigated across Japan since the Great Hanshin-Awaji Earthquake. Discussed in this report is the application of the 3D near-surface reflection seismic survey in big cities. Data from trenching and drilling is used for the geological interpretation of the surroundings of a fault, and the reflection seismic survey is used to identify the position, etc., of the fault. In this article, when the results obtained from the experimental field are examined, it is found that the conventional 2D imaging reflection survey betrays the limit of its capability when the geological structure is complicated, that the 3D reflection seismic survey, on the contrary, is capable of high-precision imaging and, when augmented by drilling, etc., becomes capable of a more detailed interpretation, and that it also contributes effectively to the improvement of local disaster prevention in big cities. ...
Much of the current technology on 3D-prestack depth migration is based on the Kirchhoff method and the traveltime information needed for this purpose is obtained by the ray-theory approximation. The main motivation driving these options is to reduce computations but it can also have an adverse effect on the quality of results. Experience with real data indicates that the corresponding poststack data migrated by the reverse-time method often yields superior results. Considerable computational efficiency can be obtained by employing nonuniform coarse grid spacing during the reverse-time migration. We followed this strategy for developing a parallel scheme for doing 3D- prestack depth migration. However, we worked only on a small subset of shot gathers whose determined by the Quasi-Monte Carlo method. The results were indistinguishable from those obtained by using a much larger population of uniformly ...
The Maybell uranium mill tailings site is 25 miles (mi) (40 kilometers [km]) west of the town of Craig, Colorado, in Moffat County, in the northwestern part of the state. The unincorporated town of Maybell is 5 road mi (8 km) southwest of the site. The designated site covers approximately 110 acres (ac) (45 hectares [ha]) and consists of a concave-shaped tailings pile and rubble from the demolition of the mill buildings buried in the former mill area. Contaminated materials at the Maybell processing site include the tailings pile, which has an average depth of 20 feet (ft) (6 meters [m]) and contains 2.8 million cubic yards (yd{sup 3}) (2.1 million cubic meters [m{sup 3}]) of tailings. The former mill processing area is on the north side of the site and contains 20,000 yd{sup 3} (15,000 m{sup 3}) of contaminated demolition debris. Off-pile contamination is present and includes areas adjacent to the tailings pile, as well as contamination dispersed by wind and surface ...
The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, is conducting a study to determine the natural geochemistry of the Snake River Plain aquifer system at the Idaho National Engineering Laboratory (INEL), Idaho. As part of this study, a group of geochemical reactions that partially control the natural chemistry of groundwater at the INEL were identified. Mineralogy of the aquifer matrix was determined using X-ray diffraction and thin-section analysis and theoretical stabilities of the minerals were used to identify potential solid-phase reactants and products of the reactions. The reactants and products that have an important contribution to the natural geochemistry include labradorite, olivine, pyroxene, smectite, calcite, ferric oxyhydroxide, and several silica phases. To further identify the reactions, analyses of 22 representative water samples from sites tapping the Snake River Plain aquifer ...
The risk to human health from fragments of depleted uranium (DU) at Jefferson Proving Ground (JPG) was estimated using two types of ecosystem pathway models. A steady-state, model of the JPG area was developed to examine the effects of DU in soils, water, and vegetation on deer that were hunted and consumed by humans. The RESRAD code was also used to estimate the effects of farming the impact area and consuming the products derived from the farm. The steady-state model showed that minimal doses to humans are expected from consumption of deer that inhabit the impact area. Median values for doses to humans range from about 1 mrem ({plus_minus}2.4) to 0.04 mrem ({plus_minus}0.13) and translate to less than 1 {times} 10{sup {minus}6} detriments (excess cancers) in the population. Monte Carlo simulation of the steady-state model was used to derive the probability distributions from which the median values were drawn. Sensitivity analyses of the ...
The presence of the nitrogen-fixing shrub, Alnus incana ssp. rugosa, influences the concentration of inorganic nitrogen in surface waters in the Adirondack Mountain region of northern New York. - The purpose of this research was to determine the abundance of the nitrogen-fixing shrub, Alnus incana ssp. rugosa (speckled alder), in shrub wetlands of the Adirondack Mountain region of New York State and to determine whether its abundance affects the concentration or accumulation of inorganic nitrogen in wetland substrates. Alder/willow wetlands are the second most common wetland type in the Adirondack region. The Adirondack Park Agency's digital GIS database of wetland types was used to determine the areal extent of alder/willow wetlands in the Adirondacks. Randomly selected wetlands were sampled to determine the size and abundance of alder. Alder densities averaged {approx}7000 stems ha{sup -1} and alder was present in 75% of the wetlands. As an indication of ...
The objective of this study was to explore the role of three-dimensional (3-D) rotational angiography (RA) of the inferior vena cava (IVC; 3-D CV) before filter retrieval and its impact on treatment planning compared with standard anteroposterior cavography (sCV). Thirty patients underwent sCV and 3-D CV before IVC filter retrieval. Parameters assessed were: projection of filter arms or legs beyond the caval lumen, thrombus burden within the filter and IVC, and orientation of the filter within IVC. Skin and effective radiation doses were calculated. Statistical analysis was performed using paired Student t test and nonparametric McNemar's test. Standard anteroposterior cavography detected 49 filter arms or legs projecting beyond the caval lumen in 25 patients. Three-dimensional CV demonstrated 89 filter arms or legs projecting beyond the caval lumen in 28 ...
The aquatic monitoring program consists of onsite monitoring of surface runoff, monitoring of point source discharges identified in the NPDES permit, and limited instream biological monitoring. The program is tied to a feedback mechanism for implementing corrective action before significant adverse impacts occur in the Holston River. This report evaluates the aquatic monitoring program for the second year (October 19, 1978 through October 18, 1979) of construction as required by the NPDES permit, Part III, Section I. Included in this report are data from peripheral runoff monitoring, selected heavy rainfall sampling, groundwater monitoring, instream aquatic macroinvertebrate monitoring, and aquatic macrophyte monitoring.
Within the framework of the MINEO research project assisted by the European Union the Deutsche Steinkohle AG (DSK) has developed methods for the operational use of remote sensing data and geo-information systems for the regular observation, measurement and evaluation of environmental effects in mining areas. Only indirect environmental effects of the mining industry, which may result in particular from subsidence-induced changes in the hydrological situation (groundwater level, drainage) and the resulting effects on the vegetation and land utilisation, can be observed for the DSK test area 'Kirchheller Heide' because of the underground mine workings. Hence the evaluations of the remote sensing data were concentrated on the development of methods to measure and analyse the vegetation condition and any changes. MINEO thus constitutes a module for the DSK environmental information system. (orig.)
Remote sensing is the most practical method available to managers of fire-prone forests for quantifying and mapping fire impacts. Differenced Normalised Burn Ratio (?NBR) is among the most widely used spectral indices for the mapping of burn severity but is difficult to interpret in terms of fire-related changes in key biophysical attributes and processes. We propose to quantify burn severity as a change in the leaf area index (?LAI) of a stand. LAI is a key biophysical attribute of forests, and is central to understanding their water and carbon cycles. Previous studies have suggested that changes in canopy LAI may be a major contributor to ?NBR and to the composite burn index (CBI) that is frequently used in combination with the NBR to assess burn severity on the ground. We applied remote...
This research report for the Swiss Federal Office of Energy (SFOE) presents the results of a project that examined the feasibility of setting up 'MINERGIE' low-energy-consumption module standards for the production of heat in small residential buildings. The aims of the standards and the basic idea behind the MINERGIE-modules are discussed. The concepts of the modules for heat pumps and wood-fired heating systems and their combination with solar installations are examined, as are their areas of application. The requirements placed on the modules are listed. System concepts, including simple schematics for typical installations, are presented for wood-log, wood-chippings and pellets-fired systems as well as for ground-loop and air-water heat pump systems as well as their solar-aided counterparts. The results of cost-benefit analyses are presented and questions regarding system guarantee and liability are examined.
Abstract Microbial cells are routinely dried and ground before they are used in metal biosorption studies. In this work, a metal biosorbent was prepared by drying biomass of the yeast Rhodotorula glutinis in an oven at 70C for 24-h followed by grinding. Two forms of the prepared biosorbent particles, washed and unwashed, were examined for their ability to remove lead from solution. It was found that the unwashed biosorbent exhibited higher lead uptake than the washed biosorbent. Analysis of the supernatant of washed cells incubated in water and that of unwashed cells incubated in lead solution revealed the presence of protein, carbohydrates, organic acids and inorganic phosphate. Overall, the washed and unwashed cells leached, respectively, 14.5 and 13.4% of their initial dry weight (100-m...
Mining affects the environment in different ways depending on the physical context in which the mining occurs. In mining areas with an arid environment, mining affects plants? growth by changing the amount of available water. This paper discusses the effects of mining on two important determinants of plant growth?soil moisture and groundwater table (GWT)?which were investigated using an integrated approach involving a field sampling investigation with remote sensing (RS) and ground-penetrating radar (GPR). To calculate and map the distribution of soil moisture for a target area, we initially analyzed four models for regression analysis between soil moisture and apparent thermal inertia and finally selected a linear model for modeling the soil moisture at a depth 10?cm; the relative error o...
Mowing a meadow is an example of an equalizing process that reduces differences among species by removing aboveground biomass approximately 5?cm above ground. This regular disturbance that affects all plants prevents competitive exclusion of small species and thus allows coexistence of numerous species differing in shoot size. In this paper we search for the mechanism behind this by comparing the shoot biomass of 41 common species in dry and wet species-rich meadows in mown and recently abandoned plots in June (before mowing) and in October. We asked the following questions: i) Do the plants differ in proportion of biomass lost by mowing? ii) Are the mown plants able to compensate for biomass lost by mowing? iii) Is the compensatory ability of mown plants related to their size? iv) Is the ...
In a sufficiently large cluster of several polar molecules, collective interactions lead to localization or 'solvation' of electrons. The existence of the solvated electron is known since 1863 in liquid ammonia and since 1962 for liquid water. In 1984, electron localization in clusters was experimentally demonstrated in (H_2O)_N_#>=#_1_1 and (NH_3)_N_#>=#_3_4 clusters. In cooperation with K. Bowen, we recently initiated a test of the theory of electron binding by a dipole and a new ground state dipole bound dimer anion, (H_2O..NH_3), was predicted and observed. We here describe results of a search for new dipole-bound and solvated electron systems. (author).
The project was initiated in 1985 with the goal of studying existing federal, state, and local programs for protecting and preserving Cape Cod's sole-source aquifer. To meet this need, the Massachusetts Department of Environmental Quality Engineering and the U.S. Environmental Protection Agency's Region 1 in cooperation with the Cape Cod Planning and Economic and Development Commission and the U.S. Geological Survey initiated a two-year study to determine the adequacy of current ground-water protection programs and to recommend improvements. In the process of gathering and evaluating hydrogeological data from the Towns of Barnstable and Eastham, the CCAMP Aquifer Assessment Committee developed the papers which are the subject of this publication. These studies formed the technical basis for groundwater resource management decision making.
The results of a study on the application of remote sensing and geophysical methods for the detection and monitoring of acid mine drainage (AMD) are summarized, with emphasis on those that appear most suitable. The study consisted of a literature review, an information survey of users and suppliers, and discussions with various experts. Space-borne sensors, airborne sensors, airborne videography and digital frame cameras, spectroradiometers, radar, and photographic data are considered. Geophysical methods are effective for measurement of sulphides, areas of active chemical oxidation, acid mine drainage, and contaminated groundwater movement. The popularity and effectiveness of various geophysical methods are rated for AMD applications. 25 refs., 1 fig., 3 tabs.
A theoretical model is developed to explain variations in airborne gamma-ray measurements over a calibration range near Ottawa, Ontario. The gamma-ray flux from potassium and the thorium decay series showed an expected decrease with increasing soil moisture. However, the gamma-ray flux from the uranium decay series was highest in the spring when the ground was water-saturated and even covered with snow. These results are explained through the build-up of radon and its associated gamma-ray-emitting decay products in the clay soil of the calibration range with increasing soil moisture. Similar results were found from airborne measurements over other clay soils. However, measurements over sandy soils showed that the count rates from all three radio elements increased with decreasing soil moisture. This difference between soil types was attributed to the lower radon emanation of the more coarse-grained sandy soils compared to finer-grained clay ...
A theoretical model is developed to explain variations in airborne gamma-ray measurements over a calibration range near Ottawa, Ontario. The gamma-ray flux from potassium and the thorium decay series showed an expected decrease with increasing soil moisture. However, the gamma-ray flux from the uranium decay series was highest in the spring when the ground was water-saturated and even covered with snow. These results are explained through the build-up of radon and its associated gamma-ray-emitting decay products in the clay soil of the calibration range with increasing soil moisture. Similar results were found from airborne measurements over other clay soils. However, measurements over sandy soils showed that the count rates from all three radio elements increased with decreasing soil moisture. This difference between soil types was attributed to the lower radon emanation of the more coarse-grained sandy soils compared to finer-grained clay ...
In the report the results of the estimations of radiological risk of various stages of decommissioning of nuclear submarines are presented. At occurrence on nuclear submarine the heavy failure, relating to the class hypotetical volume of acting of radionuclides in atmosphere can reach 1.6E(15) Bq. Results of estimations probable doses on an axis of a trace of a radioactive loop show, that at distribution of radionuclides during atmospheric carry to 'agreed' settlement (500-1000 m) the maximum doses on its territory can make: about 6.0E(-3) Sv (for the whole body); 3.0E(-3) Gy for the leather (basal layer); 6.3E(-2) Gy for the lungs (acute exposure) and up to 1.8 Gy for the thyroid gland. Hypotetical failure for the estimation of the greatest possible radioecological consequences for hydrobiocenosis is considering, connected with single discharge of liquid radioactive waste (LRW) in water area. At navigating failure of the tanker with LRW in ...
Purpose/Objective: With the advent of computed tomography and magnetic resonance imaging, the three dimensional representation of the patient anatomy has become an invaluable resource for better diagnosis and delineation of the target volume and sensitive structures in radiation therapy. Although the therapeutic linear accelerator industry has made available highly sophisticated equipment, the aggressiveness in dose prescription and delivery has to be complimented by accurate dose computation methods. We have adopted a convolution/superposition algorithm for the calculation of absolute dose that fully accounts for the external shape and internal structure of the patient for photon treatment radiotherapy. In this paper, we will discuss the principles of the convolution algorithm and we will show how the computed dose compares to clinically relevant treatment techniques. Materials and Methods: A computer controlled data acquisition system and a water tank where used ...
A 3-D hydrodynamic dispersion model for tracer transport is developed and implemented into the TOUGH2 EOS3 (T2R3D) module. The model formulation incorporates a full dispersion tensor, based on a 3-D velocity field with a 3-D, irregular grid in a heterogeneous geological system. Two different weighting schemes are proposed for spatial average of 3-D velocity fields and concentration gradients to evaluate the mass flux by dispersion and diffusion of a tracer or a radionuclide. This new module of the TOUGH2 code is designed to simulate processes of tracer/radionuclide transport using an irregular, 3-D integral finite difference grid in non-isothermal, three-dimensional, multiphase, porous/fractured subsurface systems. The numerical method ...
The fraction of a given area of ground that is covered by hail can be determined by using an airborne infrared thermometer. If the ambient ground temperature and the hail-covered ground temperature are measured with the same thermometer, and the surface o...
Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on ...
Seafloor mapping and morphometric analysis of landslide scars can provide useful insights for marine geo-hazard assessment, as demonstrated by several studies performed on different geological settings. The availability of high-resolution multibeam bathymetry and long-range side scan sonar data on the submarine portions of Stromboli Volcano allow us to map and characterize the main mass-wasting features that affect, on the whole, about the 90% of its submarine extension. In particular, two main kinds of tsunamigenic landslides have been recognized and analyzed. Large-scale sector collapses (Fig. 1) are catastrophic events that mobilize 1-2 cubic kilometers of material, generating huge tsunami waves that may affect Stromboli and propagate in surrounding areas; related hazard is not very high, as they show recurrence periods of some (or more) thousand years. Conversely, medium-scale landslides are more hazardous, as they occur at higher frequency with respect to the previous events, i.e. ...
In this dissertation, we design and analyze efficient numerical methods for obtaining accurate solutions to model problems arising in fuel cells. A basic fuel cell model consists of five principles of conservation, namely, mass, momentum, species, charges (electrons and ions), and thermal energy. Overall, transport equations couple with electrochemical processes through source terms to describe reaction kinetics and electro-osmotic drag in the polymer electrolyte. To model multiphase species transport in the porous media and the gas channel of fuel cells, we consider a multiphase mixture model framework. The diffusivity of the two-phase mixture water conservation equation in this model is nonlinear, discontinuous, and degenerate. To handle this difficulty, we developed efficient and fast nonlinear iterative solvers based on the Kirchhoff transformation and nonlinear Dirichlet-Neumann domain decomposition methods. To model the coupling between the multiphase flow in ...
Numerical models based on finite-difference or finite-element methods are used by various research groups in studies of radon-222 transport through soil and building materials. Applications range from design of radon remediation systems to more fundamental studies of radon transport. To ascertain that results obtained with these models are of good quality, it is necessary that such models are tested. This document reports on a benchmark test organized by the EU project ERRICCA: European Research into Radon in Construction Concerted Action. The test comprises the following cases: 1) Steady-state diffusive radon profiles in dry and wet soils, 2) steady-state entry of soil gas and radon into a house, 3) time-dependent radon exhalation from a building-material sample. These cases cover features such as: soil heterogeneity, anisotropy, 3D-effects, time dependency, combined advective and diffusive transport of radon, flux calculations, and ...
The increased demand for renewable energy sources has led to large areas of former agricultural land being proposed for short rotation coppice (SRC) establishment. Concerns expressed over the potential impacts of tree roots on buried archaeological evidence led to a study into the rooting habit of SRC. Roots were exposed in trenches dug within a variety of willow and poplar clonal stands grown on brown earth, pelosol, ground-water gley and surface-water gley soils. Root depths and diameters were recorded in each of the 33 trenches. In total, over 18,000 roots were measured on 264 coppice stools. The rotation length, species and stool location within a block were all found to influence the maximum size of root produced. Soil type had some influence on the root number and depth, but the pattern of root distribution down the soil profile was similar for both species. (author)
This final report for the Swiss Federal Office of Energy (SFOE) is one of a series of reports concerning municipal development in various cities in Switzerland. The four city districts involved include Basel (Gundeldinger Feld), Lausanne (Bellevaux), Lucerne (Basel-/Bernstrasse) and Zurich (Werdwies). This paper takes a look at aspects of building ecology. In the four areas, the following building types and projects were examined with respect to their ecology: Basel: conversion of commercial premises to a community centre, Lausanne and Lucerne: Enhancement of residential areas, Zurich: a new residential building. Criteria examined include general building ecology, building materials, raw materials, toxic substances, recycling, maintenance and deconstruction, energy for heating and hot water, grey energy, electricity, ground usage, water, wastes and public infrastructure. Knowledge gained along with questions and problems ...
The 3001 Storage Canal is located under portions of Buildings 3001 and 3019 at Oak Ridge National Laboratory (ORNL) and has a capacity of approximately 62,000 gallons of water. The term canal has historically been used to identify this structure, however, the canal is an in-ground reinforced concrete structure satisfying the regulatory definition of a tank. From 1943 through 1963, the canal in Building 3001 was designed to be an integral part of the system for handling irradiated fuel from the Oak Ridge Graphite Reactor. Because one of the main initial purposes of the reactor was to produce plutonium for the chemical processing pilot plant in Building 3019, the canal was designed to be the connecting link between the reactor and the pilot plant. During the war years, natural uranium slugs were irradiated in the reactor and then pushed out of the graphite matrix into the system of diversion plates and chutes which directed the fuel into the deep ...
The distribution of environmental tritium and the correlation coefficients between tritium concentrations in several environmental samples and the emissions of tritiated water vapor from Wolsong NPP 1 were studied. The annual mean concentrations of atmospheric HTO were in the range 1#centre dot#31-29#centre dot#2 Bq m"-"3 and the long-term atmospheric dilution factors were in the range 10"-"7-10"-"6 s m"-"3. Annual mean concentrations of tritium in groundwater were in the range 19#centre dot#2-27#centre dot#9 Bq l"-"1 at N-1 and 64#centre dot#1-189 Bq l"-"1 at S-2, and were generally less than 0#centre dot#2% of MPC_w (222 kBq l"-"1). The concentrations of tritium in precipitation decreased exponentially with distance from Wolsong NPP 1, falling to current global levels at about 25 km off-site. The highest concentration of tritium in soil moisture was observed in May and June, when the relative humidity was high. The ...
A cost study is described which compared the economics of four dry/wet cooling systems to use at the existing Raft River Geothermal Plant. The results apply only at this site and should not be generalized without due consideration of the complete geothermal cycle. These systems are: the Binary Cooling Tower, evaporative condenser, Combin-aire, and a metal fin-tube dry cooling tower with deluge augmentation. The systems were evaluated using cooled, treated geothermal fluid instead of ground or surface water in the cooling loops. All comparisons were performed on the basis of a common plant site - the Raft River 5 MWe geothermal plant in Idaho. The Binary Cooling Tower and the Combin-aire cooling system were designed assuming the use of the isobutane/water surface condenser currently installed at the Raft River Plant. The other two systems had the isobutane ducted to the evaporative condensers. Capital credit was not given to ...
During this project we experimentally evaluated the below-ground biomass and carbon allocation and partitioning of four different fast- and slow-growing families of loblolly pine located in Scotland County, NC, in an effort to increase the long-term performance of the crop. The trees were subjected to optimal nutrition and control since planting in 1993. Destructive harvests in 1998 and 2000 were used for whole?plant biomass estimates and to identify possible family differences in carbon acquisition (photosynthesis) and water use efficiency. At regular intervals throughout each year we sampled tissues for carbohydrate analyses to assess differences in whole-tree carbon storage. Mini rhizotron observation tubes were installed to monitor root system production and turnover. Stable isotope analysis was used to examine possible functional differences in water and nutrient acquisition of root systems between the various ...
The surface losses in the drift-tube linac (DTL) tanks 3 and 4 of the LANSCE linear accelerator are calculated using 3-D electromagnetic modeling with the CST MicroWave Studio (MWS). The results are used to provide more realistic power estimates for the 201.25MHz RF upgrade design within the LANSCE-R project. We compared 3-D MWS results with those from traditional 2-D Superfish computations for DTL cells and their simplified models and found differences on the level of a few percent. The differences are traced to a 3-D effect consisting in a redistribution of the surface currents on the drift tubes (DT) produced by the DT stem. The dependence of MWS results on the mesh size used in computations is also discussed.
Purpose Video-assisted thoracic surgery (VATS) has recently been adopted for complicated anatomical lung resections. During these thoracoscopic procedures, surgeons view the operative field on a two-dimensional (2-D) video monitor and cannot palpate the organ directly, thus frequently encountering anatomical difficulties. This study aimed to estimate the usefulness of preoperative three-dimensional (3-D) imaging of thoracic organs. Methods We compared the preoperative 64-row three-dimensional multidetector computed tomography (3DMDCT) findings of lung cancer-affected thoracic organs to the operative findings. Results In comparison to the operative findings, the branches of pulmonary arteries, veins, and bronchi were well defined in the 3D-MDCT images of 27 patients. Conclusion 3D-MDCT imag...
Objectives To investigate the feasibility and reproducibility of measurements of nasal bone length using a three-dimensional (3D) ultrasound in the first trimester. Methods In a prospective study, 118 consecutive pregnant women attending for Down syndrome screening at 11-13 + 6 weeks were recruited. They had successful fetal nasal bone measurement by two-dimensional (2D) ultrasound by four operators. Three-dimensional volumes were recorded in the mid-sagittal plane of fetal profile by the fifth operator and examined using multiplanar techniques. Another independent investigator randomly compared his measurements with one of the four operators. Results In the subsequent 3D examination, the nasal bone length could be examined in 94 cases (79.7%). The mean difference between the 2D and 3D mea...
Summary Solid state nuclear track detectors are used to determine the concentration of a particles in the environment. The standard method for assessing exposed detectors involves 2D image analysis. However 3D imaging has the potential to provide additional information relating to angle as well as to differentiate clustered hit sequences and possibly energy of a particles but this could be time consuming. Here we describe a new method for rapid high-resolution 3D imaging of solid state nuclear track detectors. A `LEXT' OLS3100 confocal laser scanning microscope (Olympus Corporation, Tokyo, Japan) was used in confocal mode to successfully obtain 3D image data on four CR-39 plastic detectors. Three-dimensional visualization and image analysis enabled characterization of track features. This ...
A three-dimensional (3D) thermal-hydraulic model and a numerical procedure for the simulation and analysis of a steady-state, as well as transient operation of nuclear power plant components are presented. A two-fluid approach is applied to modelling of two-phase flow. Thermal-hydraulics of a horizontal steam generator in the WWER 1000 nuclear power plant has been simulated at the full load, steady-state operation. A comparison of the numerical results with data measured at the NPP Novovoronjezh shows good agreement. 3D numerical results can be used in plant design or retrofitting, in nuclear power plant operation and safety analysis and as improvement of existing one-dimensional thermal-hydraulics models of the horizontal steam generator which are assessed by system codes used for the nuclear power plant safety analyses. (author)
A three-dimensional (3D) thermal-hydraulic model and a numerical procedure for the simulation and analysis of a steady-state, as well as transient operation of nuclear power plant components are presented. A two-fluid approach is applied to modelling of two-phase flow. Thermal-hydraulics of a horizontal steam generator in the WWER 1000 nuclear power plant has been simulated at the full load, steady-state operation. A comparison of the numerical results with data measured at the NPP Novovoronjezh shows good agreement. 3D numerical results can be used in plant design or retrofitting, in nuclear power plant operation and safety analysis and as improvement of existing one-dimensional thermal-hydraulics models of the horizontal steam generator which are assessed by system codes used for the nuclear power plant safety analyses. (author)
Nitrite was measured in atmospheric liquid phase samples between 1998 and 2005 to investigate the heterogeneous formation of nitrous acid in the lower atmosphere, as well as to assess the quality of water recovered from dew. The samples were collected during ground-based cloud field experiments at different German mountain sites (Brocken, Schmucke, and Hohenpeissenberg) and at a site south of the Bordeaux urban area (France). Concentrations found in Bordeaux dew samples (up to 2800 ?gl-1) are comparable to those found elsewhere in urban fog and dew water and considerably higher than those detected in cloud water or rain. Particulate nitrite (and nitrate) as well as HNO2 (HNO3) data in air masses from a foothill site of Mt. Schmucke, before involved in cloud processing, are also presented. In clouds at Mt. Brocken, both the interstitial HNO2 gas and the aqueous phase nitrite concentration have been ...
Mon R2, at a distance of 830 pc, is the only ultracompact HII region (UC HII) where the photon-dominated region (PDR) between the ionized gas and the molecular cloud can be resolved with Herschel. HIFI observations of the abundant compounds 13CO, C18O, o-H2-18O, HCO+, CS, CH, and NH have been used to derive the physical and chemical conditions in the PDR, in particular the water abundance. The 13CO, C18O, o-H2-18O, HCO+ and CS observations are well described assuming that the emission is coming from a dense (n=5E6 cm-3, N(H2)>1E22 cm-2) layer of molecular gas around the UC HII. Based on our o-H2-18O observations, we estimate an o-H2O abundance of ~2E-8. This is the average ortho-water abundance in the PDR. Additional H2-18O and/or water lines are required to derive the water abundance profile. A lower density envelope (n~1E5 cm-3, N(H2)=2-5E22 cm-2) is responsible for the absorption in the NH 1_1-0_2 ...
The environmental impacts of uranium mining and milling activities are of great concern in many countries for the last three decades. These impacts range from the creation of massive stockpiles of radioactive and toxic waste rock and sand-like tailings to serious contamination of surface and groundwater with radioactive and toxic pollutants, and releases of conventional, toxic and radioactive air pollutants. Uranium mining is also associated with high concentrations of highly toxic heavy metals, which are a major source of surface and groundwater contamination. Depending upon the hydraulic properties of the fractures involved, contaminated groundwater may be transported many miles from its point of origin before feeding into an aquifer. Tailings pond may contaminate the groundwater regime by continuous seepage and leaching of radionuclides and other toxic metals due to interaction of rain water through the tailings ponds. ...
... ice, hurricanes, and trees (less likely on high voltage transmission lines ) can bring down above ground power lines. Flooding, Leeching ground ...
Jun 10, 2011 ... Subsonic flow past a semi-infinite flat plate is modeled at Reynolds number 6 ..... data is taken from Cook, McDonald, and Firmin, AGARD-AR-138, 1979, p. ...... too large a time-averaged separation bubble behind the hump. ...
Using the complete genome of Plasmodium falciparum 3D7 which has 14 chromosomes as an example, we have examined the distribution functions for the amount of C or G and A or T consecutively...Full Text Available
A robust technique for determining the principal axes of a 3D shape represented by a point set, possibly with noise, is presented. We use techniques from robust statistics to guide the classical...Full Text Available
The development of three-dimensional (3D) biomimetic scaffolds which provide an optimal environment for cells adhesion, proliferation and differentiation, and guide new tissue formation has...Full Text Available
We propose the Particle Swarm Optimization (PSO) as an alternative method for locating periodic orbits in a three--dimensional (3D) model of barred galaxies. We develop an appropriate scheme that transforms the problem of finding periodic orbits into the problem of detecting global minimizers of a function, which is defined on the Poincar\\'{e} Surface of Section (PSS) of the Hamiltonian system. By combining the PSO method with deflection techniques, we succeeded in tracing systematically several periodic orbits of the system. The method succeeded in tracing the initial conditions of periodic orbits in cases where Newton iterative techniques had difficulties. In particular, we found families of 2D and 3D periodic orbits associated with the inner 8:1 to 12:1 resonances, between the radial 4:1 and corotation resonances of our 3D Ferrers bar model. The main ...
Estimates of global warming during the mid-Piacenzian Age of the Pliocene Epoch suggest temperatures were 2 degrees C greater than today. ... million years approaches this level of warming. PRISM/Global Warmin...
There has been a controversy as to whether or not the non-pathological flat foot and high-arched foot have an effect on human walking activities. The 3D foot scanning system was employed to obtain static...Full Text Available
The relationships between muscle tensions, jaw motions, bite and joint forces, and craniofacial morphology are not fully understood. Three-dimensional (3-D) computer models are able to combine anatomical...Full Text Available
Metacad is a collection of routines which creates a randomly accessible data structure from Applicon's APPLE-3D data format and supplies a logical method for manipulation of the data structure by a CAD application program.
Approximately 62,000 lbs Fuel Load: 58,000 lbs. Type Fuel: JP4, JP5, JP8, JET A, JET A-1, JET B Standard Fuel Burn: 4500 - 6000 lbs/hr depending on altitude and airspeed Maximum...
Experiments are performed to investigate the single-phase flow and flow-boiling heat transfer augmentation in 3D internally finned and micro-finned helical tubes. The tests for single-phase flow heat transfer augmentation are carried out in helical tubes with a curvature of 0.0663 and a length of 1.15 m, and the examined range of the Reynolds number varies from 1000 to 8500. Within the applied range of Reynolds number, compared with the smooth helical tube, the average heat transfer augmentation ratio for the two finned tubes is 71% and 103%, but associated with a flow resistance increase of 90% and 140%, respectively. A higher fin height gives a higher heat transfer rate and a larger friction flow resistance. The tests for flow-boiling heat transfer are carried out in 3D internally micro-finned helical tube with a curvature of 0.0605 and a length of 0.668 m. Compared with that in the smooth helical ...
A compact dedicated 3D breast SPECT-CT (mammotomography) system is currently under development. In its initial prototype, the cone-beam CT sub-system is restricted to a fixed-tilt circular rotation...Full Text Available
Three dimensional data of brain from the formalin-fixed fetuses were collected without isolation, by the 4.7 tesla super high magnetic field MRI and the developmental process of the cerebral parenchyma was studied by 3D images. Subjects were 13 fetal brain and MRI was performed using 3D-steady-state free precession sequence. The isolated brain is very soft and fragile and is deformed by its weight at the imaging. However 3D-MRI can be obtained without isolation, and the deformation is remarkably small. The subependymal germinal matrix layer did not be observed in 7 weeks-old fetus, appeared at 9 weeks-old and increased gradually. Then it rapidly reduced from 28 weeks-old. The volume calculated, from 3D-MRI, increased rapidly from 9 weeks-old to 23 weeks-old, and reached the maximum (2.346 mm"3) at 23 weeks-old. The ...
Electrospun nanofibers composed of biodegradable polymers are attractive candidates for cell culture scaffolds in tissue engineering. Their fine-meshed structures, resembling natural extracellular matrices, effectively interact with cell surfaces and promote cell proliferation. The application of electrospinning, however, is limited to two-dimensional (2D) or single tube-like scaffolds, and the fabrication of arbitrary three-dimensional (3D) scaffolds from electrospun nanofibers is still very difficult due to the fibers' continuous and entangled form. To address this issue, in this paper, we describe the use of phase-separation-assisted electrospray and electrostatic focusing to perform continuous direct 3D patterning of nanofibrous microcapsules of biodegradable polylactic acid (PLA). These microcapsules exhibit fiber-particle duality because they are composed of nanofibers suitable for cell attachment ...
The objective was to study the interaction of a side jet with the incoming supersonic flow and hypersonic flow. Qualitatively same Cp trends have been obtained as found experimentally. Also in aerodynamic coefficients side jet interaction results in additional pitching moment which is because of the high pressure region in upstream of the jet and a low pressure region in the downstream of the jet. Also jet interaction results in the rise in the lift coefficient. Whereas in the incidence case, simulation has been performed for the hypersonic flows over a biconic body with supersonic lateral jet at Mach 9.7 and incidence of 0"o to incidence of -12"o and 12"o. The results obtained were compared with the experimental and CFD code CFL3D results. PAK-3D over predicts the surface pressure as compared to the CFL3D and experimental results, whereas the qualitative trends ...
Neutron semiconductor detectors for neutron counting and neutron radiography have an increasing importance. Simple silicon neutron detectors are combination of a planar diode with a layer of an appropriate neutron converter such as 6LiF. These devices have limited detection efficiency of not more than 5%. The detection efficiency can be increased by creating a 3D microstructure of dips, trenches or pores in the detector and filling it with a neutron converter. The first results related to the development of such devices are presented. Silicon detectors were fabricated with pyramidal dips on the surface covered with 6LiF and then irradiated by thermal neutrons. Pulse height spectra of the energy deposited in the sensitive volume were compared with simulations. The detection efficiency of these devices was about 6.3%. Samples with different column sizes were fabricated to study the electrical properties of ...
A new 3D model is developed to simulate the self-oscillation of the elongated vocal folds. This model allows for large deformation and longitudinal displacement. The displacement boundary condition...Full Text Available
This paper presents a new methodology to create realistic 3D microstructures of polycrystals. The virtual microstructures are based on statistical data describing the morphological and crystallographic textures of a sample, obtained from an EBSD analysis. In addition, the methodology can reproduce the observed surface on top of the simulated microstructure. This feature allows finite element calculations on these virtual aggregates to be compared to experimental results of mechanical tests. Such a comparison leads to the identification of the mechanical parameters of constitutive laws, such as critical resolved shear stress and strain hardening, using an optimization algorithm. Two materials were simulated in this study: TiAl and grade 702 zirconium. The first one presents twins inside the microstructure and the second one has an anisotropic texture. Based on 2D simulations, the important parameters necessary to describe a microstructure were ...
Developing in vitro engineered hepatic tissues that exhibit stable phenotype is a major challenge in the field of hepatic tissue engineering. However, the rapid dedifferentiation of...Full Text Available
The measuring series was performed from November 1991 through April 1992 in seven drinking-water conditioning plants of the Fichtel mountains area in the north-eastern part of Bavaria, and the results revealed as an annual average a dose of about 1 - 40 WLM. The area of interest is a drinking-water catchment area where the groundwater and other water resources include waters particularly rich in radon content, which explains this relatively high dose range. This is why comprehensive, specific local and long-term mearurements were carried out in order to assess the occupational radiation dose in the drinking-water conditioning plants, taking as a model site the conditioning plant of the municipal utilities of Hof in Weissenstadt. These more specific measurements were performed by the Technical Inspectorates (TUeV) of Bavaria and Saxony and ...
The transport and partitioning of {sup 129}I has been examined for a shallow groundwater flow system at Sturgeon Falls in northeastern Ontario. Recharge into a sandy surficial postglacial deltaic aquifer occurs in the vicinity of a seasonally-wet boreal forest. Concentrations of stable iodine, {sup 129}I, tritium, radiocarbon, stable isotopes and major ions were measured on samples of groundwater and precipitation. The present-day tritium profile delineates the position of the early 1960's above-ground nuclear weapons pulse at a depth of approximately 12 m. The concentrations of stable iodine for groundwaters above, near and below the above-ground nuclear weapons pulse range from 0.07 to 1.7 ppb. Over that same interval {sup 129}I concentrations decreased from 1.9 x 10{sup 6} atoms/L at 9 m, to approximately 1.9 x 10{sup 5} atoms/L in tritium-depleted waters at 35 m, below the present-day depth of the recharging ...
Computed tomography allows today to reconstruct three-dimensional (eD) images fram axial scans. The authors report their experience in cranio-facial pathology achived in two Departments of Radiology (University of Trieste, Italy and University of Standford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The application in maxillo-facial traumas, cranio-facial malformations and head tumours are disscussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demostration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.
The measurement of K(alpha)/K(beta) X-ray intensity ratio indicates the excitation process and the chemical state of the atom examined. Theoretical considerations on the origin of this property are presented. The difference of these ratios following photoionization and electron capture are calculated by a computer code generating transition matrix elements. The theoretical assumptions involved in the codes are tested by comparing the experimental and calculated data concerning 3d transition element atoms. (D.Gy.).
Twenty-seven patients with symptoms or clinical findings suggesting joint or bone disorders of the anterior chest wall (ACW) were evaluated by spiral CT with 3-dimensional (3-D) and multiplanar reconstructions. Preceding conventional ACW tomography was performed in 10 patients. ACW joint and bone changes were visualized more adequately by coronal 2-D reconstructions based on spiral CT than by conventional tomography. In addition, nonossified costal cartilages and soft tissue lesions were demonstrated. 3-D reconstructions sometimes added information, especially in patients with fracture and dislocation. (orig.).
The paper presents the integration of the SIMBAD space charge module in the UAL framework. SIMBAD is a Particle-in-Cell (PIC) code. Its 3-D Parallel approach features an optimized load balancing scheme based on a genetic algorithm. The UAL framework enhances the SIMBAD standalone version with the interactive ROOT-based analysis environment and an open catalog of accelerator algorithms. The composite package addresses complex high intensity beam dynamics and has been developed as part of the FAIR SIS 100 project.
The term biological motion is often used by researchers studying the patterns of movement generated by living forms and in sports. We studied a pattern recognition system of motion in sport using biological motion data. Biological motion data are acquired using a 3D motion capture system. However, 3D motion capture systems are very expensive. In this article, a biological motion capture system was built using acceleration sensors. Our proposed system uses the technique of Gaussian fitting and regression analysis. We tested our proposed system in pattern recognition of outdoor tennis and its evaluations.
The electronic structure of octahedral metal atom clusters Me/sub 6/ of 3d, 4d, and 5d transition metal atoms (V, Cr; Nb, Mo; Ta, W) has been calculated applying two different quantum-chemical approximation methods (Extended Hueckel (EH) method; SW-Xsub(alpha) method). Equilibrium structures, energy level schemes, Fermi energies and band widths as well as densities of states of clusters are discussed in detail.
A series of pyrrolo[2,3-d]pyrimidine-2,4-diones and intermediates was tested for anticonvulsant activity in mice. Eleven of the 15 compounds possessed anticonvulsant activity against pentylenetetrazol-induced convulsions. One compound afforded more anticonvulsant protection against pentylenetetrazol than did trimethadione (67 and 50%, respectively). A suspension of this compound was found to be as effective as a solution in producing anticonvulsant activity. The results suggest that the nitrile analogs were more potent compared to the carbamyl analog due to higher lipid solubility. PMID:7373552
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 water at the Forsmark site. The surface ...
At a military base in the Southeastern US, an energy services company (ESCO) has proposed to retrofit more than 1,000 family residences with geothermal heat pumps as part of an energy savings performance contract (ESPC). Each residence is to have one heat pump with its own ground heat exchanger consisting of two or more vertical bores. A design firm hired by the ESCO sized the heat pumps to meet peak cooling loads, and sized the borefields to limit the maximum entering water temperature (EWT) to the heat pumps to 95 F (35 C). Because there is some disagreement in the geothermal heat pump industry over the peak temperature to be used for design (some designers and design manuals recommend temperatures as low as 85 F[29 C], while equipment manufacturers and others specify temperatures of 100 F[38 C] or higher) the authors were requested to examine the designs in detail to determine whether the 95 F (35 C) limit was adequate to ensure occupant ...
A novel continuous powder introduction microwave-induced plasma atomic emission spectrometry method (CPI-MIP-AES) has been developed for trace determination of metals in ground and tap water samples after preconcentration on activated carbon. The experimental setup consisted of integrated rectangular cavity TE_1_0_1 and vertically positioned plasma torch. The technical arrangement of the sample introduction system has been designed based on the fluidized bed concept. The satisfactory signal stability required for sequential analysis was attained owing to the vertical plasma configuration, as well as the plasma gas flow rate compatibility with sample introduction flow rate. The elements of interest (Cd, Cu, Cr, Fe, Mn, Pb, Zn) were preconcentrated in a batch procedure at pH 8-8.5 after addition of activated carbon and then, after filtering and drying of the activated carbon suspension, introduced to the MIP by the CPI system. An enrichment ...
Many mines and processing facilities are in remote, difficult to access areas, or are in areas where access is limited or restricted for national reasons. In a joint project with Canada Centre for Remote Sensing, the Canadian Safeguards Support Program is investigating utility of multi- and hyperspectral remote sensing for remotely inspecting such site. With a view to eventually using the hyperspectral satellite data now coming available, airborne data over uranium and copper mine tailings and uranium processing facilities in northern Canada were acquired. The objective of this work is to demonstrate that multispectral and hyperspectral data can provide complementary and supplementary information to high-resolution panchromatic imagery for the following safeguards applications: Inspection aids (up-to-date maps of remote locations), change detection, evaluation of member state declarations, monitoring of reactor, mining and processing facility operations, and detection of undeclared ...
Purpose: To assess the new method of 3-dimensional echocardiography in comparison to the 'gold standard' MRI as to its ability to calculate left ventricular volumes in patients with congenital heart disease. Materials and methods: Eighteen patients between the ages of 3.9 to 37.3 years (mean: 12.8{+-}9.7) with a geometrically abnormal left ventricle were examined using a 1.5 T scanner with a fast gradient-echo sequence (TR=14 ms, TE=2.6-2.9 ms, FOV=300-400 mm, flip angle=20 , matrix=128:256, slice thickness=5 mm, retrospective gating) in multislice-multiphase technique. Transthoracic 3D-echocardiography was performed with a 3.5 MHz transducer and a Tomtec {sup trademark} (Munich, Germany) system for 3D reconstruction. Results: Volume calculation was possible in all patients with 3D-echocardiography, but the muscle mass calculation only ...
A performance assessment analysis was completed for the 200 East Area Low-Level Burial Grounds (LLBG) to satisfy compliance requirements in DOE Order 5820.2A. In the analysis, scenarios of radionuclide release from the 200 East Area Low-Level waste facility was evaluated. The analysis focused on two primary scenarios leading to exposure. The first was inadvertent intrusion. In this scenario, it was assumed that institutional control of the site and knowledge of the disposal facility has been lost. Waste is subsequently exhumed and dose from exposure is received. The second scenario was groundwater contamination.In this scenario, radionuclides are leached from the waste by infiltrating precipitation and transported through the soil column to the underlying unconfined aquifer. The contaminated water is pumped from a well 100 m downstream and consumed,causing dose. Estimates of potential contamination of the surrounding environment were developed ...
Canadian oilfields are a prime breeding ground for talent, technology and industrial management. This paper described how Canadian talent was recognized in 2001 for three major projects which included a cold-ocean production platform in the Sea of Okhotsk in Siberia, a mountain pipeline project in South America, and an in-situ underground extraction technology in the oilsands of Alberta. The cold-ocean production platform project was recruited by Sakhalin Energy Investment Co., an international consortium originally led by Marathon Oil Co which is now led by Royal Dutch Shell. The oil production platform is stationed 16 kilometres offshore of Sakhalin Island in the Sea of Okhotsk. Sakhalin Energy bought and converted the Molikpaq, an innovative platform made in the 1980s for the Beaufort Sea by Gulf Canada Resources Ltd. The second project included Calgary's Hydroconsult EN3 Services Ltd. which was responsible for the construction of the 940-km GasAtacama ...
The release of {sup 14}C as {sup 14}CO{sub 2} from partly failed spent fuel containers has been analyzed by the flow of gases into and out of the containers. This flow of gases is driven by pressure differences, which are in turn caused by heating by the spent fuel. In this analysis, the timing and size of holes in the containers are assumed to be given. A better means of predicting the time distribution and sizes of penetrations in nuclear waste containers is needed. For the purposes of far-field transport calculations, we have adopted release rates that are shown to be bonding for the large range of hole sizes studied. The transport of released {sup 14}CO{sub 2} has been analyzed by transport in equivalent porous medium. The peak {sup 14}CO{sub 2} concentration in pore gas at 350 m above the repository does not depend on the time of hole occurrence, although the time of penetration obviously affects the arrival and duration of exposure to {sup 14}C. Nor does ...
Wind River Resources Corporation (WRRC) received a DOE grant in support of its proposal to acquire, process and interpret fifteen square miles of high-quality 3-D seismic data on non-allotted trust lands of the Uintah and Ouray (Ute) Indian Reservation, northeastern Utah, in 2000. Subsequent to receiving notice that its proposal would be funded, WRRC was able to add ten square miles of adjacent state and federal mineral acreage underlying tribal surface lands by arrangement with the operator of the Flat Rock Field. The twenty-five square mile 3-D seismic survey was conducted during the fall of 2000. The data were processed through the winter of 2000-2001, and initial interpretation took place during the spring of 2001. The initial interpretation identified multiple attractive drilling prospects, two of which were staked and permitted during the summer of 2001. The two initial wells were drilled in ...
Preventing recurrence of surface mining accidents in the coal industry remains a top priority requiring constant vigilance and a substantial commitment from all involved in open pit mining operations. Open pit wall failures, loose rocks rolling down slopes, groundwater and stockpiling procedures are common sources of risks in open cut coal operations. This video aims to equip workers with the necessary skills and knowledge to assess and react to the geomechanics hazards in open pit coal operations. Workers need to have the competencies to manage geomechanics hazards to facilitate their own and their workmates' safety. No matter how good the operating systems are, the first line of defence against accidents is the experience, skill and knowledge-based judgment of each individual mine worker. The video covers: Open pit coal mine risk management and geomechanical issues; Terminology, mining cycle, and explanation of pit slope hazards; ...
Mixed-convection phenomena can occur within liquid-dominated geothermal reservoirs due to interactions of injected flows, or ground-water flows, with the buoyancy-induced fluid motion. This problem was studied experimentally and numerically for the case of opposing flows about a vertical heat source in a liquid-saturated porous medium. The ratio of the Rayleigh number (Ra) to the Peclet number (Pe) was identified as the nondimensional parameter which characterizes the relative influence of buoyancy-driven to pressure-gradient-driven fluid motion. The transition from mixed to forced convection was numerically determined to be (Ra/Pe) approx. = -0.5, where the minus sign denotes superimposed downflow. Agreement between measured and predicted thermal-field results showed that the finite-element code of Gartling and Hickox (1982 a,b) can be used to model low-temperature (single-phase) geothermal reservoirs throughout the natural, mixed, and forced convection regimes. 9 ...
Full text.Surficial sediment samples were collected from seventeen springs distributed all over Lebanon (east, west, north and south). Concentrations of metals Ca, Fe, Mn, Ni, Cu, Cr, Zn and Pb were determined by energy dispersive x-ray fluorescence technique. Irradiation was done by the radioisotope source Cd-109 and the detection by an EG and G Si(Li) detector. These analysis was done in attempt to assess the impact of anthropogenic sources on groundwater quality. Metals concentration in sediment were found to be (Ca:0.05-47%, Fe:0.24-4.2%, Cr:
The paper discusses two petrochemical selective oxidation reactions namely the practised formation of styrene (STY) and the desired oxidative functionalisation of propane. The present knowledge about the mode of operation of oxide catalysts is critically considered. The dehydrogenation of ethylbenzene (EB) should be described by an oxidehydration with water acting as oxidant. The potential role of the coke formed during catalytic reaction as co-catalyst will be discussed. Selective oxidation is connected with the participation of lattice oxygen mechanism which transforms unselective gas phase oxygen into selective oxygen. The atomistic description of this process is still quite unclear as well as the electron structural properties of the activated oxygen atom. The Role of solid state acidity as compared to the role of lattice oxygen is much less well investigated modern multiphase-multielement oxide (MMO) catalysts. The rationale is that the significant efforts ...
This report presents the status of development of a three-dimensional conceptual model for the unconfined aquifer system at Hanford. A conceptual model is needed to support development of a realistic three-dimensional numerical model for predicting ground-water flow and the transport of contaminants. The report focuses on developing a hydrogeologic framework, assessing available hydraulic property data, describing flow-system boundaries, and evaluating areal recharge and leakage. Geologic descriptions of samples obtained during well drilling were used to prepare cross sections that correlate relatively continuous layers. The layers were defined based on textural differences that are expected to reflect differences in hydraulic properties. Assigning hydraulic properties to the layers is a critical part of the conceptual model. Available hydraulic property data for the study area were compiled and were correlated with the geologic layers where possible. Flow-system ...
This paper describes the comprehensive modeling method of fluid and heat flows in the hydrological system. Based upon the concept that the hydrological system is composed of the air-water 2-phase fluids, and the rock phase, various natural processes are modeled including surface/subsurface 2-phase mass transfer, heat exchanges between fluid phases, between fluid and solid phases, and sensible/latent heat exchanges on the ground surface. A field-oriented numerical simulator is developed, in which a set of governing equations is solved for different variables on the surface and in subsurface regions, respectively. Results of an experimental study are presented, in which transient formulation of heat exchange between fluid/solid phases is examined through matching of the observation and calculated performances. (author)
This paper describes the comprehensive modeling method of fluid and heat flows in the hydrological system. Based upon the concept that the hydrological system is composed of the air-water 2-phase fluids, and the rock phase, various natural processes are modeled including surface/subsurface 2-phase mass transfer, heat exchanges between fluid phases, between fluid and solid phases, and sensible/latent heat exchanges on the ground surface. A field-oriented numerical simulator is developed, in which a set of governing equations is solved for different variables on the surface and in subsurface regions, respectively. Results of an experimental study are presented, in which transient formulation of heat exchange between fluid/solid phases is examined through matching of the observation and calculated performances. (author)
ObjectivesThe overall aim of this proposal is to make use of the unique opportunity afforded by the 2010 Amazonian Drought in order to quantify the basin-wide impacts of an intense forest fire season on above and below-ground carbon stocks and ecophysiological changes in forest functioning. The specific objectives relating to our research questions are: O1. Assess the causes and spatial extent of the 2010 drought in terms of basin-wide rainfall anomalies and water deficits and their relationship wi [continued...]DescriptionDespite an 82% decline in deforestation rates in Amazonia, fires are still on the rise. 2010 has been a year of severe drought and fire in Amazonia. Over the last months (July and August) the number of fire counts has reached 80% of the 2005 values, which was characterized as the drought of the century. Through the beginning of September, fire outbreaks have intensified in southwest Amazonia, including Brazil, Peru and ...
Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated groundwaters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by ...
The uptake of "9"9Tc by trees intercepting contaminated groundwater from a radioactive waste storage site was measured to identify the major "9"9Tc pools within the woodland ecosystem and to assess the relative mobility of "9"9Tc in the existing element cycle. The highest average "9"9Tc concentrations in vegetation were found in herbaceous plants. Tree wood was the major above-ground pool for "9"9Tc because of the high concentrations in wood as well as the large amount of wood relative to other biomass at the site. Technetium was not easily leached from the trees by rainfall and was not readily extractable from forest floor leaf litter by water. The relative importance of return pathways for "9"9Tc to the forest floor was leaf fall > stemflow > throughfall, indicating that "9"9Tc was conserved by the trees. Snails and millipedes from the leaf litter layer concentrated technetium 20- and 16-fold, respectively, above levels found in the ...
A field experiment was conducted during 2004 and 2005 at the research farm of Central Institute of Medicinal And Aromatic Plants, Lucknow located at 26.5^o N 80.5^o E and 120m above the mean sea level to study the effect of harvesting stage and cutting height on growth, yield and quality of Indian basil. The objective of this study was to increase the essential oil yield of Indian basil without adverse effect on quality by taking two harvests through manipulating harvesting stage and cutting height and to increase the land and rain water utilization efficiency under rain fed condition. The treatments consisted of four stages of first harvest (40, 60, 80 and 100 days after transplanting (DAT)) and three cutting height (0, 7.5 and 15.0cm above ground level). The Indian basil (Ocimum basilicu...
There are certain factors to take into account when determining the suitability of a healthy house site. Power lines, agricultural spraying, vehicle exhaust, and industrial pollution are all potential sources of indoor air contamination. It is recommended that a environmental assessment be done to determine whether there are specific sources of contamination. Good drainage is required. The surrounding landscaping should be open and sunlit, and with low maintenance requirements. Decks and fences made from pressure-treated or chemical treated lumber should be avoided. One of the early decisions in the design process is the choice of the structural system. The key with all foundation types is to control moisture, whether from rain, from the ground, or the condensation of moisture from the air with cooling. The construction frame is sealed away from the occupants by the air/vapor barrier, so only in extreme cases is it essential to use alternatives to softwood lumber ...
The goal of this project is to develop a bench-scale procedure to produce clean, desulfurized, premium-quality chars from the Illinois basin coals. This goal is achieved by utilizing the effective capabilty of smectites in combination with methane to manipulate the char yields. The major objectives are: to determine the optimum water- ground particle size for the maximum reduction of pyrite and minerals by the selective-bitumen agglomeration process; to evaluate the type of smectite and its interlamellar cation which enhances the premium-quality char yields; to find the mode of dispersion of smectites in clean coal which retards the agglomeration of char during mild gasification; to probe the conditions that maximize the desulfurized clean-char yields under a combination of methane+oxygen or helium+oxygen; to characterize and accomplish a material balance of chars, liquids, and gases produced during mild gasification; to identify the conditions ...
The goal of this project is to develop a bench-scale procedure to produce clean, desulfurized, premium-quality chars from the Illinois basin coals. This goal is achieved by utilizing the effective capabilty of smectites in combination with methane to manipulate the char yields. The major objectives are: to determine the optimum water- ground particle size for the maximum reduction of pyrite and minerals by the selective-bitumen agglomeration process; to evaluate the type of smectite and its interlamellar cation which enhances the premium-quality char yields; to find the mode of dispersion of smectites in clean coal which retards the agglomeration of char during mild gasification; to probe the conditions that maximize the desulfurized clean-char yields under a combination of methane+oxygen or helium+oxygen; to characterize and accomplish a material balance of chars, liquids, and gases produced during mild gasification; to identify the conditions ...
A residue of the sugar industry can be used in revegetation programs on metal contaminated sites. - Phytostabilisation of bare heavily contaminated substrate, such as abandoned mine sites, is considered a very appropriate technology in order to diminish erosion and dispersion of contaminants into the surroundings. In this short-term pot study, application of industrial sugar residue (ISR), a waste product of the sugar industry, proved to ameliorate spoils conditions for plant performance by elevating pH and immobilising several metals. Although arsenate concentrations were positively correlated to spoil pH and spoil treatment with ISR mobilised As, growth of both Phaseolus vulgaris and Holcus lanatus improved significantly after applications of 3.75 g ISR kg{sup -1} dry spoil. Nutrient uptake from the substrate, with the exception of potassium, was elevated by ISR. As a remediation technique ISR application could be effective although in As-contaminated sites application might be ...
In this study, adjoint sensitivity theory is developed for equations of two-dimensional steady-state flow in a confined aquifer. Both the primary flow equation and the adjoint sensitivity equation are solved using the Galerkin finite element method. The developed computer code is used to investigate the regional flow parameters of the Leadville Formation of the Paradox Basin in Utah and the Wolcamp carbonate/sandstone aquifer of the Palo Duro Basin in the Texas Panhandle. Two performance measures are evaluated, local heads and velocity in the vicinity of potential high-level nuclear waste repositories. The results illustrate the sensitivity of calculated local heads to the boundary conditions. Local velocity-related performance measures are more sensitive to hydraulic conductivities. The uncertainty in the performance measure is a function of the parameter sensitivity, parameter variance and the correlation between parameters. Given a parameter covariance matrix, the uncertainty of the ...
A reactor-neutrino experiment, Daya Bay, has been proposed to determine the least-known neutrino mixing angle theta_13 using electron antineutrinos produced at the Daya Bay nuclear power complex in China. Daya Bay is an international collaboration with institutions from China, the United States, the Czech Republic, Hong Kong, Russia, and Taiwan. The experiment will use eight identical detectors deployed at three different locations optimized for monitoring the antineutrino rates from the six reactors and for detecting any rate deficit and spectral distortion near the first oscillation maximum. The overburden of the under ground experimental halls, connected with tunnels, ranges from about 250 to 900 meters-water-equivalent so that the cosmogenic background is small compared to the number of observed antineutrino events. Civil construction of tunnels and experimental facilities is planned to start in 2007, with detector construction beginning in ...
The Convective and Orographically-induced Precipitation Study (COPS) has the aim to advance the quality of forecasts of orographically-induced precipitation in complex terrain. COPS is a Research and Development Project of the World Weather Research Program and considered to be one of the largest field campaigns on quantitative precipitation forecasting that has been performed so far. A network of state-of-the-art active and passive remote sensing systems was combined with in total 10 airborne platforms, Meteosat rapid scans and dense networks of standard meteorological instruments during the three months long field phase (June-August, 2007) in south-western Germany/eastern France to observe atmospheric variables in the three spatial dimensions and in time. By the University of Hohenheim, two novel ground-based mobile scanning lidar systems were deployed: a scanning rotational Raman lidar which provides combined measurements of the field of atmospheric temperature ...
Heat transfer processes use fluids which are generally not pure and can react with transfer surfaces. These surfaces are subject to deposits which can be sediments harmful to heat transfer and to integrity of materials. For nuclear plant steam generators, sludge build-up accelerates secondary side corrosion by concentrating chemical species. A major safety problem involved with such a corrosion is the growing of circumferential cracks which are very difficult to detect and size with eddy current probes. With a view to understand and control this problem, it is necessary to develop a mathematical model for the prediction of sludge behavior in PWR steam generators. Based on fundamental principles, this work intends to use different models available in literature for the prediction of the phenomenon leading to the accumulation of sludge particles at the bottom (the tubesheet) of a PWR. For that, a three-dimensional simulation of magnetite particulate fouling with the finite elements code ...
Historical information about the F-Area Railroad Crosstie Pile is limited. The unit is believed to have been a borrow area for earth fill that began receiving railroad crossties during the 1960s. The number of crossties at the unit began to increase significantly in 1984 when major repair of the SRS rail system was initiated. An estimated 100,000 used railroad crossties have accumulated at the unit since 1984. In an effort to determine the impact of the railroad crossties on the environment a total of 28 soil samples were collected from four test borings in March of 1991. Sample depths ranged from ground surface to 21.5 feet. Three of the borings were extended to the water table and groundwater samples were collected, one in an upgradient ``background`` area, and two downgradient from the unit. Few analytes were reported above detection limits. Test results are summarized in Section 4.0 and analytes not detected are summarized in Appendix A to ...
Historical information about the F-Area Railroad Crosstie Pile is limited. The unit is believed to have been a borrow area for earth fill that began receiving railroad crossties during the 1960s. The number of crossties at the unit began to increase significantly in 1984 when major repair of the SRS rail system was initiated. An estimated 100,000 used railroad crossties have accumulated at the unit since 1984. In an effort to determine the impact of the railroad crossties on the environment a total of 28 soil samples were collected from four test borings in March of 1991. Sample depths ranged from ground surface to 21.5 feet. Three of the borings were extended to the water table and groundwater samples were collected, one in an upgradient background'' area, and two downgradient from the unit. Few analytes were reported above detection limits. Test results are summarized in Section 4.0 and analytes not detected are summarized ...
Microorganisms associated with fractured basalt core were compared to those suspended in groundwater pumped from the same well in the eastern Snake River Plain Aquifer (Idaho, USA). Two wells influenced to different degrees by a mixed-waste plume in the fractured basalt aquifer were examined. In one well, an array of dialysis cells filled with either deionized water or crushed basalt was equilibrated to compare the microorganisms collected in this fashion with those from core and groundwater samples collected in a traditional manner from the same well. Analyses were performed to characterize these samples and to provide a basis for comparison. These included total cell counts by microscopy; total biomass by phospholipid fatty acid analysis; enumerations of viable aerobic heterotrophs, groups of putative aerobic co-metabolic TCE-degraders and aerobic H2-oxidizing bacteria; mineralization of 14C- labeled acetate; and enrichments for dissimilatory iron-reducing ...
This paper describes the methods and systems as utilized in an integrated experimental thermohydraulic/mechanics analysis test program on waterhammer pressure pulses within a revised feedwater sparger of a Loviisa generation VVER-440-type reactor. This program was carried out in two stages: (1) measurements with a strictly limited set of operating parameters at Loviisa NPP, and (2) measurements with the full set of operating parameters on a test article simulating the revised feedwater sparger. The experiments at Loviisa NPS served as an invaluable source of information on the nature of waterhammer pressure pulses and structural responses. These tests thus helped to set the objectives and formulate the concept for series of tests on a test article to study the water hammer phenomena. The heavily instrumented full size test article of a steam generator feedwater sparger was placed within a pressure vessel simulating the steam generator. The feedwater sparger was ...
K{beta}-to-K{alpha} X-ray intensity ratios of Ti, Cr, Fe and Co in pure metals and in Cr{sub 0.26}Fe{sub 0.74}, Cr{sub 0.80}Co{sub 0.20} and Ti{sub 0.80}Cr{sub 0.20} alloys have been measured following excitation by 59.54 keV {gamma}-rays from a 7400 MBq (200 mCi) {sup 241}Am point-source. The valence electronic structure of Ti, Cr, Fe and Co in the samples have been evaluated by the comparison of the measured K{beta}-to-K{alpha} intensity ratios with the results of multiconfiguration Dirac-Fock calculations performed for various electronic configurations of these metals. The 3d-electron populations obtained for pure metallic Ti, Cr, Fe and Co agree well with the results of band structure calculations of Papaconstantopoulos (Handbook of band structure of elemental solids, Plenum Press, New York, 1986). Our analysis indicates significant increase of 3d-electron population of Ti, Cr and Fe in the alloys ...
K#beta#-to-K#alpha# X-ray intensity ratios of Ti, Cr, Fe and Co in pure metals and in Cr_0_._2_6Fe_0_._7_4, Cr_0_._8_0Co_0_._2_0 and Ti_0_._8_0Cr_0_._2_0 alloys have been measured following excitation by 59.54 keV #gamma#-rays from a 7400 MBq (200 mCi) "2"4"1Am point-source. The valence electronic structure of Ti, Cr, Fe and Co in the samples have been evaluated by the comparison of the measured K#beta#-to-K#alpha# intensity ratios with the results of multiconfiguration Dirac-Fock calculations performed for various electronic configurations of these metals. The 3d-electron populations obtained for pure metallic Ti, Cr, Fe and Co agree well with the results of band structure calculations of Papaconstantopoulos (Handbook of band structure of elemental solids, Plenum Press, New York, 1986). Our analysis indicates significant increase of 3d-electron population of Ti, Cr and Fe in the alloys with respect to ...
Computation of effective flow properties of fluids in porous media based on three dimensional (3D) pore structure information has become more successful in the last few years, due to both improvements in the input data and the network models. Computed X-ray microtomography has been successful in 3D pore imaging at micron scale, which is adequate for many sandstones. For other rocks of economic interest, such as chalk and diatomite, submicron resolution is needed in order to resolve the 3D-pore structure. To achieve submicron resolution, a new method of sample serial sectioning and imaging using Focused Ion Beam (FIB) technology has been developed and 3D pore images of the pore system for diatomite and chalk have been obtained. FIB was used in the milling of layers as wide as 50 micrometers and as thin as 100 nanometers ...
The experimental has been performed with a view to studying complete and incomplete fusion in "1"4N + "1"6"3D_y system below 7 MeV/nucleon. The excitation functions for several reactions have been measured using the activation technique and compared with the theoretical predictions based on statistical models. The codes ALICE-91 and CASCADE used earlier for the analysis of excitation functions in case of "1"2C + "1"6"5H_0 system have been used here also with the same set of input parameters. It has been observed that the theoretical calculations do not match with the experimental excitation functions well but the overall shape of the excitation function is reproduced satisfactorily. The composite nucleus ("1"7"7T_a) formed in this ("1"4N + "1"6"3D_y) case is the same as the one formed in "1"2C + "1"6"5H_0 system studied earlier. Measured excitation functions for the same decay channels in the two cases ...
3-D depth migration is one of the most active areas of research and development and it has been approached from different angles. An accurate algorithm which works in the space-frequency domain was introduced by Blacquiere et al. (1989). Unfortunately, it is computationally very expensive and not suitable for solving real-life 3-D migration problems. This led to the development of an alternative scheme (hale, 1990) which sacrifices some accuracy but is much more efficient. It is commonly referred to as the Hale-McClellan method. An alternative procedure known as reverse-time migration works in the space-time domain. It is based on the full wave equation and yields by far the most accurate results, but it requires extremely large computer resources. However, a series of new developments (Mufti et al, 1996) have made this algorithm a very practical tool even for migrating large exploration-scale ...
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Kbeta-to-Kalpha X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of Ti(x)Ni(1-x) (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi (109)Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured Kbeta-to-Kalpha X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other element and/or the ...
K?-to-K? X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of TixNi1-x (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi 109Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured K?-to-K? X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other element and/or the rearrangement of ...
Power system stabilizers (PSSs) are used to enhance damping of power system oscillations through excitation control of synchronous generator. The objective of the PSS is to generate a stabilizing signal, which produces a damping torque component on the generator shaft. Conventional PSSs are designed with the phase compensation technique in the frequency domain and include the lead-lag blocks whose parameters are determined according to a linearized power system model. The performance of conventional PSSs (CPSSs) depends upon the generator operating point and the system parameters, but a reasonable level of robustness can be achieved depending on the tuning method. This paper presents a new three-dimensional PSS (3D PSS), which uses rotor speed deviation, rotor acceleration and load angle deviation as input signals. The 3D PSS attempts to return the generator to the state-space origin, based on the ...
We develop a 3-D model to simulate the synthetic aperture radar (SAR) image formation process of an undulated vegetation canopy such as corn grown in fields with large periodic drainage reliefs. We explain how the simulated SAR image of undulated vegetation medium is obtained by the convolution of a 2-D slice of the 3-D simulated SAR system point spread function [(PSF), emulating the SAR beam modeled by a cosine modulated Gaussian], with the 2-D projection of the observed undulated vegetation canopy (modeled with scatterers randomly distributed in 3-D undulated space) followed by the extraction of each look envelope, the summation of looks, and sampling in azimuthal and range directions. Our model is useful to study the parameters involved in the formation and the analysis of SAR images of undulated vegetation medium. Validation of simulations made with actual ...
Finite element method is one of the bases for numerical solutions to engineering problems. Complex engineering problems using finite element analysis typically imply excessively large computational time. Parallel supercomputers have the potential for significantly increasing calculation speeds in order to meet these computational requirements. This paper predicts parallel NIKE3D performance on the Kendall Square Research (KSR1) system. The first part of the prediction is based on the implementation of parallel Cholesky (U{sup T}DU) matrix decomposition algorithm through actual computations on the KSRI multiprocessor system, with 64 processors, at Oak Ridge National Laboratory. The other predictions are based on actual computations for parallel element matrix generation, parallel global stiffness matrix assembly, and parallel forward/backward substitution on the BBN TC2000 multiprocessor system at Lawrence Livermore National Laboratory. The ...
Aims: Serotonin (5-hydroxytryptamine 3; 5-HT3) receptors are involved in chemotherapy-induced nausea and vomiting (CINV), and 5-HT3 antagonists are part of the `gold standard' antiemetic treatment during chemotherapy. We investigated the correlation of common variants in 5-HT3 receptor subunit genes with the occurrence of CINV. Materials & methods: A total of 110 previously characterized chemotherapy-naive women with primary breast cancer treated with anthracycline-containing chemotherapy served as a study group for mutational analysis by direct sequencing. Eight common SNPs in the 5-HT3 receptor genes, HTR3A, HTR3B, HTR3D and HTR3E, were selected for association analysis. Results: A nonsynonymous variant in HTR3D, p.G36A (rs6443930), was found to be over-represented in nonresponders, assu...
With the objective to improve the reactor physics calculation on a 2D and 3D nuclear reactor via the Diffusion Equation, an adaptive automatic finite element remeshing method, based on the elementary area (2D) or volume (3D) constraints, has been developed. The adaptive remeshing technique, guided by a posteriori error estimator, makes use of two external mesh generator programs: Triangle and TetGen. The use of these free external finite element mesh generators and an adaptive remeshing technique based on the current field continuity show that they are powerful tools to improve the neutron flux distribution calculation and by consequence the power solution of the reactor core even though they have a minor influence on the critical coefficient of the calculated reactor core examples. Two numerical examples are presented: the 2D IAEA reactor core numerical benchmark and the ...
(Abridged) We use 3D SPH calculations with higher resolution, as well as with more realistic viscosity and sound-speed prescriptions than previous work to examine the eccentric instability which underlies the superhump phenomenon in semi-detached binaries. We illustrate the importance of the two-armed spiral mode in the generation of superhumps. Differential motions in the fluid disc cause converging flows which lead to strong spiral shocks once each superhump cycle. The dissipation associated with these shocks powers the superhump. We compare 2D and 3D results, and conclude that 3D simulations are necessary to faithfully simulate the disc dynamics. We ran our simulations for unprecedented durations, so that an eccentric equilibrium is established except at high mass ratios where the growth rate of the instability is very low. Our improved simulations give a ...
The Computational Fluid Dynamics(CFD) study was conducted to assess the new design concept introduced to solve the issues on the flow deviation between SG cassettes and the supporting structure design of the flow distributing plate subjected to the flow induced vibration. Flow field from MCP to the bottom of SG was modeled for 2-dimensional(2D) CFD analysis and then sensitivity analysis on major design parameters was conducted using commercial CFD code, Fluent. The cases for detailed 3D analysis were selected based on the result of 2D analysis and the detailed 3-dimensional(3D) analysis was conducted for these selected cases using Fluent code. Flow field was modeled by RNG model and wall function, 2nd upwind scheme, porous model, structured or hybrid grid. The analysis result shows that the maximum deviation of flow distribution between SG cassettes was reduced upto about 0.1% and the pressure loss from ...
Analytical methods considering 3-D resistivity distribution, in particular, finite element method (FEM) were studied to improve the reliability of electromagnetic exploration. Integral equation, difference calculus, FEM and hybrid method are generally used as computational 3-D modeling method. FEM is widely used in various fields because FEM can easily handle complicated shapes and boundaries. However, in electromagnetic method, the assumption of continuous electric field is pointed out as important problem. The normal (orthogonal) component of current density should be continuous at the boundary between media with different conductivities, while this means that the normal component of electric field is discontinuous. In FEM, this means that current channeling is not properly considered, resulting in poor accuracy. Unless this problem is solved, FEM modeling is not practical. As one of the solutions, it ...
Techniques for reducing computation time in 3D photon dose calculations are addressed with specific emphasis given to the convolution/superposition approach. A single polyenergetic superposition model calculating absorbed dose per incident photon fluence (Gy cm"2) was developed in terms of TERMA and a total energy deposition kernel (a total point spread function). A novel approach was devised for reducing calculation time. The method, named the CF method, was based on the use of a conventional, fast model (here a modified power-law method was used) for the generation of 3D dose distributions on a fine dose matrix. Superposition calculations were carried out on a coarse matrix and calculation speed was increased simply by reducing the number of calculations. A set of correction factors was derived on the coarse grid from the ratio of the dose values from superposition to those from the conventional ...
Geometrical structures and energetic properties for different tautomers of adenine are calculated in this study, using multi-configurational wave functions. Both the ground and the lowest singlet excited state potential energy surfaces are studied. Four t...
Starting with a #LAMBDA#-nucleus potential, a semi-empirical formula, which gives a fairly satisfactory account of the ground state #LAMBDA#-binding energy of light hypernuclei, if the very light nuclei are ignored has been obtained. (author).
As part of the demonstration testing of the Purge Water Management System (PWMS) technology at the Savannah River Site (SRS), four wells were equipped with PWMS units in 1997 and a series of sampling events were conducted at each during 1997-1998. Three of the wells were located in A/M Area while the fourth was located at the Old Radioactive Waste Burial Ground in the General Separations Area.The PWMS is a ''closed-loop'', non-contact, system used to collect and return purge water to the originating aquifer after a sampling event without having significantly altered the water quality. One of the primary concerns as to its applicability at SRS, and elsewhere, is whether the PWMS might resample groundwater that is returned to the aquifer during the previous sampling event. The purpose of the present investigation was to compare groundwater chemical analysis data ...
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, soil-water retention, ...
In the analysis of the consequences of a hypothetical meltdown accident in an LMFBR, it is important to estimate the final location of the molten fuel pool in the concrete and ground underlying the reactor vessel. The GROWS program and the AYER program have been developed to calculate the final location of the molten fuel pool as the culmination of the transient analysis of this unusual Stefan problem but these programs require extensive computational resources. The solution is provided to the concrete and ground temperatures surrounding the stationary fuel pool and the related heat flux from the pool to the ground surface outside the containment building. This solution can be used to estimate the final location of the fuel pool and to check the end results of the sophisticated programs.
In addition to the ability to solve the static transport equation, we have also incorporated time dependence into our parallel 3-D S{sub {ital N}} code DANTSYS/MPI. Using a semi-implicit scheme, DANTSYS/MPI is capable of performing time-dependent calculations for both fissioning and pure source driven problems. We have applied this to various types of problems such as nuclear well logging and prompt fission experiments. This paper describes the form of the time- dependent equations implemented, their solution strategies in DANTSYS/MPI including iteration acceleration, and the strategies used for time-step control. Results are presented for a model nuclear well logging calculation.
Abstract Normal human aging is accompanied by progressive brain tissue loss and cognitive decline; however, several factors are thought to influence brain aging. We applied tensor-based morphometry to high-resolution brain MRI scans to determine whether educational level or physical activity was associated with brain tissue volumes in the elderly, particularly in regions susceptible to age-related atrophy. We mapped the 3D profile of brain volume differences in 226 healthy elderly subjects (130F/96M; 77.9 3.6 SD years) from the Cardiovascular Health Study-Cognition Study. Statistical maps revealed the 3D profile of brain regions whose volumes were associated with educational level and physical activity (based on leisure-time energy expenditure). After controlling for age, sex, and physical...
The intermediate silicon layers detector (ISL) was proposed as a part of the upgraded CDF detector at the RUN-II of the Tevatron mean value of pp collider at Fermilab, scheduled to start in year 2000. The ISL is a large-radius (20-30 cm) silicon tracker with a total active area of about 3.5 m. Located in the region between the silicon vertex detector and the central outer tracker, the ISL will allow tracking in the forward region and significantly improve it in the central area. Together with the SVX II the ISL forms a standalone, 3D silicon tracker. The challenge is to build a low-cost device which provides precise 3D tracking in a approximately equal to 2 m long area with a minimal amount of material for the supporting structure. The conceptual design and the status of the project are reviewed.
He ions incident at grazing angles on Cu(110) and Ni(110) surfaces are neutralised into triplet and singlet states, of which the 3p, 3d and 4d upper states are accessible to optical spectroscopy. In the energy range from 500 eV to 15 keV no significant energy dependence of the relative intensities of singlet and triplet lines was observed for scattering on Cu(110). The intensities from Ni(110) are higher and the singlet to triplet intensity ratio of the 3d to 2p transition is about 6% smaller than that from Cu(110). The results can be explained well by assuming resonant charge capture into excited He and intermediate formation of negative He/sup -/ states.
He ions incident at grazing angles on Cu(110) and Ni(110) surfaces are neutralised into triplet and singlet states, of which the 3p, 3d and 4d upper states are accessible to optical spectroscopy. In the energy range from 500 eV to 15 keV no significant energy dependence of the relative intensities of singlet and triplet lines was observed for scattering on Cu(110). The intensities from Ni(110) are higher and the singlet to triplet intensity ratio of the 3d to 2p transition is about 6% smaller than that from Cu(110). The results can be explained well by assuming resonant charge capture into excited He and intermediate formation of negative He"- states. (orig.).
DVR project concerns the creation of a virtual reality OpenGL system for desktop applications in archaeology. The main goal is the creation of a 3D information system using the real time interaction of OpenGL environments. The first case study implemented is the Vettii House, one of the most important and outstanding monuments in Pompei. The virtual reconstruction of these architectural models is based on very detailed photogrammetric surveys and it is connected with information layers and archaeometric data-bases regarding the state of conservation of walls, structures and any type of materials of the monument. A full 3D interface characterizes the system, comprising a high resolution texturing with detailed volumetric and geometric data. Finally, for the future, the project plans to fit the system for scientific and end users through the installation of stations on site.
Energy-filtered X-ray photoemission electron microscopy (EXPEEM) is a microscopy technique which has the potential to provide surface chemical mapping during surface chemical processes on the nanometer scale. We studied the possibilities of EXPEEM using a Wien filter type energy analyzer in the high energy X-ray region above 1000 eV. We have successfully observed the EXPEEM images of Au islands on a Ta sheet using Au 3d_5_/_2 and Ta 3d_5_/_2 photoelectron peaks which were excited by 2380 eV X-rays emitted from an undulator (BL2A) at Photon Factory. Our recent efforts to improve the sensitivity of the Wien filter energy analyzer will also be discussed.
In situ X-Ray microtomography offers new opportunities for analysing sintering mechanisms since it allows 3D observation of the microstructural evolution of the powder all along a sintering cycle. With synchrotron radiation at ESRF, a 3D image with a resolution of 2 {mu}m can be obtained in about one minute. In addition to the visual examination of the images, relevant microstructural parameters can be measured through quantitative image analysis using recently developed tools. In this paper the results obtained with two materials, loose copper powder and compacted steel powder, are resumed. For copper powder, the dispersion of local parameters such as particle co-ordination number and porosity is investigated. Concerning steel compacts, data about pore morphology evolution and on local strains provides clues for understanding the anisotropic shrinkage of such compacts. (authors)
Statement of problem Inadequate dimensioning of the connectors in a cantilever cross-arch fixed dental prosthesis (FDP) in perioprosthetic patients jeopardizes the prognosis of the restoration. Purpose The purpose of this study was to investigate the effect of increasing the vertical dimension (VD) on the maximum stress developed within the connectors during the static loading of a cross-arch FDP extended as a 1- and 2-unit cantilever. Material and methods Six digital models were developed, derived from a 3-dimensional (3-D) initial model. In the initial model, the teeth were prepared for metal ceramic restorations and splinted with a cross-arch FDP, extended as a 1- or 2-unit cantilever. The VDs of the connectors proximal to the retaining abutment were 3, 4, or 5 mm. A 3-D finite element ...
There is an ever increasing demand to perform flow simulations that incorporate the complete details of geometry as well as sophisticated flow physics. This has led to the development of numerical algorithms that can simulate the actual flow phenomena with greater fidelity. However, the success of these algorithms hinges on the grid that models the geometry. Grid generation methods for 2-D models have long existed and the general lack of complexity of the simpler 2-D models has not quite challenged the efforts in this area. However, demands for generating better 3-D geometric models for flow simulations involving complex geometries have completely changed the perspective of grid generation strategies. As a consequence, grid generation efforts have earned equal significance as that of numerical solver efforts.
The objective of this project is to develop multi-dimensional computational models in order to improve the operation of uranium electrorefiners currently used in pyroprocessing technology. These 2-D (US) and 3-D (ROK) mathematical models are based on the fundamental physical and chemical properties of the electrorefiner processes. The validated models by compiled and evaluated experimental data could provide better information for developing advanced electrorefiners for uranium recovery. The research results in this period are as follows: - Successfully assessed a common computational platform for the modeling work and identify spatial characterization requirements. - Successfully developed a 3-D electro-fluid dynamic electrorefiner model. - Successfully validated and benchmarked the two multi-dimensional models with compiled experimental data sets
Whereas in part 1 and 2 the detailed observation equations of terrestrial type for an integrated geodetic model are presented this paper will outline how the theory is transferred in an operational program. The main lines of functions of the FORTRAN IV program are discussed. Since the input specifications as well as the data requirements are described in detail and illustrated by example of input and output part 3 can serve as an user-guide for OPERA. OPERA is an acronym for operational adjustment. Besides the integrated determination of 3D-geocentric coordinates and the gravity disturbing potential the program can handle all cases of traditional geodesy (in total 13 variants of solution are provided) equivalent also with adjustments in ellipsoidal coordinates B, L or H, as well as constrained adjustments, pure prediction of the gravity disturbing field, etc.
Conformationally constrained analogue synthesis was undertaken to aid in pharmacophore mapping and 3D-QSAR analysis of nitrobenzylmercaptopurine riboside (NBMPR) congeners as equilibriative nucleoside transporter 1 (ENT1) inhibitors. In our previous study [J. Med. Chem. 2003, 46, 831-837], novel regioisomeric nitro-1,2,3,4-tetrahydroisoquinoline conformationally constrained analogues of NBMPR were synthesized and evaluated as ENT1 ligands. 7-NO2-1,2,3,4-Tetrahydroisoquino-2-yl purine riboside was identified as the analogue with the nitro group in the best orientation at the NBMPR binding site of ENT1. In the present study, further conformational constraining was introduced by synthesizing 5prime-O,8-cyclo derivatives. The flow cytometrically determined binding affinities indicated that the...
We present a fully automated method for three-dimensional (3D) elemental analysis demonstrated using a ceramic sample of chemistry (Ca)MgTiO_x. The specimen is serially sectioned by a focused ion beam (FIB) microscope, and energy-dispersive X-ray spectrometry (EDXS) is used for elemental analysis of each cross-section created. A 3D elemental model is reconstructed from the stack of two-dimensional (2D) data. This work concentrates on issues arising from process automation, the large sample volume of approximately 17x17x10 #mu#m"3, and the insulating nature of the specimen. A new routine for post-acquisition data correction of different drift effects is demonstrated. Furthermore, it is shown that EDXS data may be erroneous for specimens containing voids, and that back-scattered electron images have to be used to correct for these errors.
Purpose To evaluate the methods of applicator reconstruction in 3D MR-based planning for brachytherapy of cervical cancer, and to investigate applicator shifts and changes in DVH parameters during PDR treatment. Methods For each application MR scans with applicator in situ were made: three T2-weighted (4.5mm slices) Turbo Spin Echo (TSE) scans and a balanced Steady State Free Precession scan (1.5mm). Three observers tested two applicator reconstruction methods: (A) directly on the bSSFP scan and (B) on a resampled combination of the three T2-weighted scans. For 10 patients MR imaging was repeated on the second day of each PDR fraction to determine applicator shifts and changes in DVH parameters. Results For both applicator reconstruction methods the interobserver variation for the DVH para...
At Super-LHC luminosity it is expected that the standard suite of L1 triggers for CMS will saturate. Information from the tracker will be needed to reduce trigger rates to satisfy the L1 bandwidth. Tracking trigger modules which correlate information from closely-spaced sensor layers to form an on-detector momentum filter are being developed by several groups. We report on a trigger module design which utilizes three dimensional IC technology to incorporate chips which are connected both to the top and bottom sensor, providing the ability to filter information locally. A demonstration chip, the VICTR, has been submitted to the Chartered/Tezzaron two-tier 3D run coordinated by Fermilab. We report on the 3D design concept, the status of the VICTR chip and associated sensor integration utilizing oxide bonding.
One of the stiffest challenges in structural studies of proteins using NMR is the assignment of sidechain resonances. Typically, a panel of lengthy 3D experiments are acquired in order to establish connectivities and resolve ambiguities due to overlap. We demonstrate that these experiments can be replaced by a single 4D experiment that is time-efficient, yields excellent resolution, and captures unique carbon-proton connectivity information. The approach is made practical by the use of non-uniform sampling in the three indirect time dimensions and maximum entropy reconstruction of the corresponding 3D frequency spectrum. This 4D method will facilitate automated resonance assignment procedures and it should be particularly beneficial for increasing throughput in NMR-based structural genomics initiatives.
The composition, rank, coal facies, and coal pore structure characteristics of 15 coal samples were investigated systemically using methods of lithotype analysis, maceral analysis, proximate analysis, mercury porosimetry analysis, and nitrogen adsorption analysis. These samples were directly collected from the working faces of No.4, 8, 9 seams in Liulin district, eastern margin Ordos Basin, China. Four types of paleoenvironment including a wet forest swamp, an intergradation forest swamp, a drained forest swamp, and a fresh-water peat swamp were distinguished by lithotype and merceral analysis. An R-cluster analysis was performed to demonstrate the correlations between the coal facies and the pore structures. The results showed that coal rank is the primary factor affecting the development of micropores and transition pores, whereas coal facies control the development of seepage pores in similar coalification conditions, especially in a local district and in a ...
For the construction of underground facilities comprising access tunnels, connecting tunnels, main tunnels and disposal tunnels, a large number of tunnels will be excavated in deep rock formations. These excavations will extend hundreds kilometers in total length. Therefore, special attention must be paid, to transporting large volume of debris, ventilation, emergency escape routes in case of accident, and other factors. In addition, special attention must also paid to potential accidents which might in underground excavations, including unstable facing phenomena (such as collapse and swelling of facing at weak layer sections), spring water flow resulting collapse of rock, gas eruption, and rock burst. While considering these factors to be emphasized during the construction of geological disposal facilities, the investigation reviewed the existing working methods on individual construction technologies of access tunnels, main tunnels, connecting tunnels, disposal ...
For the construction of underground facilities comprising access tunnels, connecting tunnels, main tunnels and disposal tunnels, a large number of tunnels will be excavated in deep rock formations. These excavations will extend hundreds kilometers in total length. Therefore, special attention must be paid, to transporting large volume of debris, ventilation, emergency escape routes in case of accident, and other factors. In addition, special attention must also paid to potential accidents which might in underground excavations, including unstable facing phenomena (such as collapse and swelling of facing at weak layer sections), spring water flow resulting collapse of rock, gas eruption, and rock burst. While considering these factors to be emphasized during the construction of geological disposal facilities, the investigation reviewed the existing working methods on individual construction technologies of access tunnels, main tunnels, connecting tunnels, disposal ...
This work describes the radon in soil gas measurements performed during the last two years in cooperation between the Laboratory of Applied Nuclear Physics of the Federal University of Technology (UTFPR), the Nuclear Technology Development Center (CDTN) and the Institute of Radiation Protection and Dosimetry (IRD) from the Brazilian Nuclear Energy Commission (CNEN). Following previously concluded measurements of radon concentration in dwellings and the measurements of 222Rn activity in drinking water collected at artesian bores of Curitiba urban area, present step of activities has been dedicated to measurements of radon concentration in soil gas. Experimental setup was based on the Professional Radon Monitor (ALPHA GUARD) connected to specially developed for such measurements Soil Gas Probe through the air pump and filter system. After the Probe was inserted, the ground has been tamped down around the probe, to prevent air from moving ...
Plutonium and minor actinides produced as by-products of the UO_2 nuclear cycle could be considered as waste or energy source depending on the strategy selected in the nuclear energy programme. Considering Pu and Minor Actinides as a source, they can be burned in existing water reactor for diminishing the radiotoxicity of the spent fuel, it is necessary to use 'inactive' materials as matrix like ThO_2. ThO_2 matrix has demonstrated its Pu burning efficiency and higher corrosion resistance than UO_2. Uranium-plutonium mixed oxide (MOX) fuel efficiency is low because the presence of U in MOX results in the creation of some new Pu under irradiation. The dissolution behaviour of irradiated (Th,Pu)O_2 pellets with burn-up of 38.8 MWd/kg Th has been studied in carbonated (20 mM HCO_3"-), deionised and granite groundwater solution in a hot cell. The dissolution behaviour of Th, Pu, U and Np was studied in order to find out ...
A geothermal heat pump-assisted heating system is introduced into Changchun City and a survey is conducted to determine if the system may be popularized in this extremely cold region located in the northeastern part of China. In concrete terms, the hot water that circulates through the office building of Changchun Ground Heat Development Co., Ltd., is switched to hot water prepared by a geothermal heat pump. The test continued from December 2000 to March 2001. It is then concluded that heating by geothermal heat pumps will be fully serviceable to Changchun City. Implemented are (1) the shift from the coal fired boiler system to a geothermal heat pump system comprising 16 subterranean heat exchangers for the heating of the office building which is approximately 1000 m{sup 2} large, (2) long-term monitoring of the operating conditions, (3) measurement of subterranean heat exchanger thermal conductivity and subterranean ...
Embracing the notion of going green, an affluent school district in Pennsylvania spent $83 million as part of the high school's renovation and expansion project. The three-level addition is now equipped with self-dimming lights, energy-efficient windows, a rooftop solar water heater, and a geothermal cooling and heating system. As a bonus for going green, the school district received a $250,000 grant from the Pennsylvania Department of Environmental Protection. The district used that money to create an information center in the lobby of the building where a touch-screen computer provides students, staff, and visitors with data related to the operation of the school's energy-efficient water and electrical systems. The system will graphically depict utility use over the course of a year. The monitoring system and touch-screen computer can turn this school into a living lab, with science, math, and economics teachers using the data as teaching ...
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The pair-specific ground state energy of Newtonian N-body systems grows monotonically in N. This furnishes a whole family of simple new tests for minimality of putative ground state energies obtained through computer experiments. Inspection of several publically available lists of such computer-experimentally obtained putative ground state energies has yielded several dozen instances which failed (at least) one of these tests. Although the correct ground state energy is not revealed by this method, it does yield a better upper bound on it than the experimentally found value whenever the latter fails a monotonicity test. The surveyed N-body systems include in particular N point charges with 2- or 3-dimensional Coulomb pair interactions, placed either on the unit 2-sphere or on a 2-torus (a.k.a. Thomson, Fekete, or Riesz problems).
The synthesis and structures of acyclic and macrocyclic thio-, seleno- and telluro-ether complexes of the metallic and metalloid elements of Groups 13-16 reported since 2000 are described. The diverse structures range from discrete monomers through to infinite 1-, 2- or 3-D polymers. The coordination chemistry in this area is quite different to familiar d-block chemistry and the underlying factors are explored. PMID:21706103
The main features are presented of a computer programme for 3-D thermohydraulic and thermodynamic analysis of the PGV-1000 horizontal steam generator used at the Temelin NPP. The programme provides analyses of primary side hydraulics, heat exchange behavior and the steam generator secondary side thermohydraulics and thermodynamics. Given are calculated data on the circulation flow rate, void fraction, heat transfer dynamics and the swelled level. (Z.S.) 9 figs.
We report on solid solution CePd_2_-_xMn_xSi_2 which shows an interesting transition of the Ce-ion from magnetism in a Kondo regime to an intermediate valence state coupled with a strongly magnetic 3d sublattice. ((orig.)).
We report on solid solution CePd[sub 2-x]Mn[sub x]Si[sub 2] which shows an interesting transition of the Ce-ion from magnetism in a Kondo regime to an intermediate valence state coupled with a strongly magnetic 3d sublattice. ((orig.))
The electronic structure of octahedral metal atom clusters Me_6 of 3d, 4d, and 5d transition metal atoms (V, Cr; Nb, Mo; Ta, W) has been calculated applying two different quantum-chemical approximation methods (Extended Hueckel (EH) method; SW-Xsub(alpha) method). Equilibrium structures, energy level schemes, Fermi energies and band widths as well as densities of states of clusters are discussed in detail.
The influence that electromagnetic fields have on mechanical and electronic equipment was discussed. A three dimensional numerical simulation model of electric fields around high voltage power transmission lines was described. 4 refs., 1 tab., 5 figs.
The influence that electromagnetic fields have on mechanical and electronic equipment was discussed. A three dimensional numerical simulation model of electric fields around high voltage power transmission lines was described. 4 refs., 1 tab., 5 figs.
A novel phantom has been developed to measure the modulation transfer function (MTF) in 3D for x-ray computed tomography. The phantom consists of three tungsten wires, positioned nearly orthogonal to each other. Simultaneous measurements of the MTF are taken at various locations along the three orthogonal reconstructed planes. Our computed mammotomography (CmT) system uses a Varian Paxscan 2520 digital x-ray detector which can be positioned anywhere in ~2pi steradian band and can have arbitrary trajectories. With a half-cone beam geometry and with the phantom positioned near the center of rotation, projection images are acquired over 360 degrees. Various 3D orbits are evaluated including vertical axis of rotation and saddle. Reconstructions were performed using an iterative ordered-subsets transmission algorithm on rebinned projection images, using various numbers of iterations. Rotation of ...
Under support from the French Space Agency (CNES), a 3D+t dusty-gas model of Comet 67P/Churyumov-Gerasimenko is being developed, to compute, from the first 2014 Rosetta orbital data, the aerodynamic forces exerted on the Rosetta orbiter and on the descent lander. We report the recently developed dust dynamics part of the code. The multi-species (presently H2O and CO) gas code is optimized in terms of computational speed owing to the use of two complementary methods: (a) 3D+t Direct Simulation Monte Carlo (DSMC) runs in the non-equilibrium regions adjacent to the surface and very distant from it, and (b) solutions of the Navier-Stokes equations in-between. The model is used presently using Lamy et al. (Space Sci. Rev., 2007, 128, 23) coarse information on 67P nucleus shape and rotation, and a range of possible gas production rates Q for the early Rosetta observations at rh 3 AU (Q 1026 - 1027 s-1). In ...
In this paper, finite-difference time-domain method is used to research the transient electromagnetic pulse (EMP) coupling to the cylinder object which is shielded in another shielding cavity with a hole numerically. The different coupling effectiveness of three transient EMP is simulated. The distribution of the electric field in the shielding cavity and the current on the cavity are researched. The shielding effectiveness is evaluated. (authors)
A method for calculation of absorbed dose distributions in three dimensions for 1-20 MeV photons is presented. The method uses convolution/superposition of photon fluence distributions with energy scattering kernels. Results for Co-60 and X-ray beams in homogeneous and inhomogeneous media are compared with measurements. Good agreement is found between calculations and measurements. 8 refs.; 3 figs.
The purpose of this study was to use high-resolution magnetic resonance (MR) imaging combined with image analysis to investigate the three-dimensional (3D) trabecular structure, anisotropy, and connectivity of human vertebral, femoral, and calcaneal specimens. The goal was to determine whether: (a) MR-derived measures depict known skeletal-site-specific differences in architecture and orientation of trabeculae; (b) 3D architectural parameters combined with bone mineral density (BMD) improve the prediction of the elastic modulus using a fabric tensor formulation; (c) MR-derived 3D architectural parameters combined with BMD improve the prediction of strength using a multiple regression model, and whether these results corresponded to the results obtained using higher resolution depictions of trabecular architecture. A total of 94 specimens (12 x 12 x 12 mm cubes) ...
Purpose: The aim of this study was to evaluate the accuracy of MRI in the measurement of cartilage thickness of the ankle joint in comparison to pathologic and histologic specimens. Patients and methods: The ankle joints of four fresh cadaver feet were imaged on a 1.5 T MR-unit in the coronal plane. Standard T{sub 1}-weighted spin echo (SE) and a T{sub 1}-weighted 3D-GE (FLASH-3D) sequence with fat saturation were applied. Following MR imaging, the talus was explanted and cut parallel to the MR images for macroscopic evaluation and histologic specimens were prepared. MRI measurements of the cartilage thickness of the talus were carried out in two ways: Without and with consideration of a transition zone of intermediate signal intensity between hyperintense cartilage and hypointense cortical bone. The data were compared with the anatomic specimens as the gold standard expressing the difference as a ...
Full text: A semiempirical algorithm for absorbed dose calculation at off-axis points in irregular beams was implemented. It is well known that semiempirical methods are very useful because of their easy implementation and its helpfulness in dose calculation in the clinic. These methods can be used as independent tools for dosimetric calculation in many applications of quality assurance. However, the applicability of such methods has some limitations, even in homogeneous media, specially at off axis points, near beam fringes or outside the beam. Only methods derived from tissue-air-ratio (TAR) or scatter-maximum-ratio (SMR) have been devised for those situations, many years ago. Despite there have been improvements for these manual methods, like the Sc-Sp ones, no attempt has been made to extend their usage at off axis points. In this work, a semiempirical formalism was introduced, based on the works of Venselaar et al. (1999) and Sanz et al. (2004), aimed to the Sc-Sp separation. This ...
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The Department of Energy is investigating Yucca Mountain, Nevada as a potential site for commercial radioactive waste disposal in a mined geologic repository. One critical aspect of site suitability is the tectonic stability of the repository site. The levels of risk from both actual fault displacements in the repository block and ground shaking from nearby earthquakes are being examined. In particular, it is necessary to determine the expected level of ground shaking at the repository depth for large seismic sources such as nearby large earthquakes or underground nuclear explosions (UNEs). Earthquakes are expected to cause the largest ground motions at the site, however, only underground nuclear explosion data have been obtained at the repository depth level (about 350m below the ground level) to date. In this study we investigate ground motion from Nevada Test Site underground ...
The objective of this project was to develop new photocatalytic or other innovative process chemistry for the treatment of pink water and related contaminated water.
Comparatively evaluates two models for forecasting ground subsidence after underground mining: a standard method used in Poland in underground coal mining and a method used in the GDR. Factors that influence ground subsidence after underground mining are evaluated. Effects of depth, stratification, and physical and mechanical properties of rock strata are analyzed. Time dependence of dynamic troughs and static final troughs left after underground mining is evaluated. Formulae are recommended for forecasting ground subsidence after underground coal mining and mining of other deposits. 3 refs.
This report describes the results made in fulfillment of contract DE-FG26-02NT15451, ''Multicomponent Seismic Analysis and Calibration to Improve Recovery from Algal Mounds: Application to the Roadrunner/Towaoc Area of the Paradox Basin, Ute Mountain Ute Reservation, Colorado''. Optimizing development of highly heterogeneous reservoirs where porosity and permeability vary in unpredictable ways due to facies variations can be challenging. An important example of this is in the algal mounds of the Lower and Upper Ismay reservoirs of the Paradox Basin in Utah and Colorado. It is nearly impossible to develop a forward predictive model to delineate regions of better reservoir development, and so enhanced recovery processes must be selected and designed based upon data that can quantitatively or qualitatively distinguish regions of good or bad reservoir permeability and porosity between existing well control. Recent advances in seismic acquisition and ...
According to the data of drill cores, outcrops and well logging, two orders base-level cycles are recognized from Zhiluo Formation in Dongsheng area, which consist of 8-14 short-term base-level cycles and 3 mid-term base-level cycles, and their structural types and stacking patterns are discussed by using principles and methods of high-resolution sequence stratigraphic theory. Based on the correlation of mid-term base-level cycles, the control of the A/S (Accommodation/Sediment supply) ratio in mid-term base-level cycles on the scale of sand bodies and physical properties of reservoir is analysed. Studies show that the sand bodies of braided stream in MSC1 of Zhiluo Formation are favourable to uranium mineralization, however, the sand bodies of meandering river in MSC2 and MSC3 are not favourable to uranium mineralization. The change of the A/S results in the difference in characters of sand body, such as physical properties, continuity and so on, which control the fluid flowing path. ...
The classical Stefan problem describes the motion of a solidification front through a uniform half-space in response to a step change in temperature on its boundary. The predictions of such a model can be applied quite accurately to the freezing of water in a porous medium so long as the pore geometry remains unaltered by the passing solidification front. It is observed, however, that in fine-grained porous media, ice has a tendency to form in segregated horizontal bands, known as ice lenses, that disrupt the regular pattern of heat flow through their enhanced consumption of latent heat. This process, known as frost heave, causes significant ground deformation in regions subject to prolonged freezing, and is one of the most important weathering processes in polar and alpine regions. Recent improvements to our understanding of the mechanics of ice lens nucleation and growth are applied here to predict the conditions and characteristics of frost ...
As a result of the large limestone deposits available in Poland, the low cost of reagent acquisition for the largescale technological use and relatively well-documented processes of flue gas desulfurization (FGD) technologies based on limestone sorbent slurry, wet scrubbing desulfurization is a method of choice in Poland for flue gas treatment in energy production facilities, including power plants and industrial systems. The efficiency of FGD using the above method depends on several technological and kinetic parameters, particularly on the pH value of the sorbent (i.e., ground limestone suspended in water). Consequently, many studies in Poland and abroad address the impact of various parameters on the pH value of the sorbent suspension, such as the average diameter of sorbent particles (related to the limestone pulverization degree), sorbent quality (in terms of pure calcium carbonate [CaCO3] content of the sorbent material), stoichiometric ...
Moisture profiles from neutron probe data provide valuable information in site characterization and to supplement groundwater monitoring efforts. The neutron probe precision error (reproducibility) is found to be about 0.2 vol% under in situ field conditions where the slope in moisture content with depth is varying slowly. This error is about 2 times larger near moisture spikes (e.g., at the vapor phase notch), due to the sensitivity of the probe response to vertical position errors on the order of 0.5 inches. Calibrations were performed to correct the downhole probe response to the volumetric moisture content determined on core samples. Calibration is sensitive to borehole diameter and casing type, requiring 3 separate calibration relations for the boreholes surveyed here. Power law fits were used for calibration in this study to assure moisture content results greater than zero. Findings in the boreholes reported here confirm the broad ...
This paper describes a 1993 field experiment entitled Marine Aerosol Properties and Thermal Imager Performance Trial (MAPTIP) conducted by NATO AC/243 Panel 04/RSG.8 and 04/RSG.5 in the Dutch coastal waters. Objectives were: to improve and validate vertical marine aerosol models by providing an extensive set of aerosol and meteorological measurements, within a coastal environment at different altitudes and for a range of meteorological conditions; make aerosol and meteorological observations in the first 10 m of the ocean surface with a view to extending existing aerosol models to incorporate near-surface effects; and to assess marine boundary layer effects on thermal Imaging systems. Aerosol and meteorological instruments, as well as thermal imagers and calibrated targets, were utilized. This network of instrumentation has provided a comprehensive database of aerosol size distribution profiles and relevant meteorological variables throughout the marine atmospheric ...
Valdez, Alaska achieved worldwide attention with the Exxon Valdez oil spill. This exacerbated an already polarized situation (industry, government, citizens, environmental groups) regarding the Valdez Terminal of the Trans Alaska Pipeline System. Other than spills, the major focus of environmental concern was and remains the Terminal`s Ballast Water Treatment Plant (BWTP) which discharges into Port Valdez. The previous NPDES wastewater discharge permits for this facility have been contentious for almost the entire period of pipeline operation. The draft NPDES permit is scheduled to be proposed for reissuance this year. However, a significant change has been initiated which so far is resulting in cooperation rather than confrontation between the various primary stakeholders. This presentation will explain how this change was initiated, how it is being maintained, and how what is happening could be a model for progress through cooperation. Although EPA and the Alaska ...
The Department of Toxic Substance Control (DTSC) requested that Lawrence Livermore National Laboratory (LLNL) evaluate the treatment process currently employed at the Department's Stringfellow Superfund Site Pretreatment Plant (PTP) site to determine if wastes originating from the site were properly managed with regards to their radioactivity. In order to evaluate the current management strategy, LLNL suggested that DTSC characterize the effluents from the waste treatment system for radionuclide content. A sampling plan was developed; samples were collected and analyzed for radioactive constituents. Following is brief summary of those results and what implications for waste characterization may be made. (1) The sampling and analysis provides strong evidence that the radionuclides present are Naturally Occurring Radioactive Material (NORM). (2) The greatest source of radioactivity in the samples was naturally occurring uranium. The sample results indicate that the uranium ...
The Department of Toxic Substance Control (DTSC) requested that Lawrence Livermore National Laboratory (LLNL) evaluate the treatment process currently employed at the Department's Stringfellow Superfund Site Pretreatment Plant (PTP) site to determine if wastes originating from the site were properly managed with regards to their radioactivity. In order to evaluate the current management strategy, LLNL suggested that DTSC characterize the effluents from the waste treatment system for radionuclide content. A sampling plan was developed; samples were collected and analyzed for radioactive constituents. Following is brief summary of those results and what implications for waste characterization may be made. (1) The sampling and analysis provides strong evidence that the radionuclides present are Naturally Occurring Radioactive Material (NORM). (2) The greatest source of radioactivity in the samples was naturally occurring uranium. The sample results indicate that the uranium concentration ...
This conference provided a forum for more than 500 delegates from industry, government universities and research centres to share their professional knowledge on research and development that affects all sectors of geotechnical engineering, applied geology and hydrogeology. Accomplishments in the geoenvironmental field were also highlighted. The geotechnical sessions were entitled: pile foundations and load testing; excavations and special foundation issues; reinforced soil and soil-structure interactions; advances in modelling, constitutive issues; advances in modelling, consolidation and other applications; advances in modelling, discrete elements and slope stability; embankments and dams; landfills and barriers; fundamental soil mechanics; soil mechanics and ground movement; GIS and remote sensing; landslides and slopes; cone penetration tests and liquefaction assessment; rock mechanics; engineering geology; geoenvironmental sustainability; oilsand and petroleum ...
We present deep images of dust continuum emission at 450, 800, and 850 micron of the dark cloud LDN 1689N which harbors the low-mass young stellar objects (YSOs) IRAS 16293-2422A and B (I16293A and I16293B) and the cold prestellar object I16293E. Toward the positions of I16293A and E we also obtained spectra of CO-isotopomers and deep submillimeter observations of chemically related molecules with high critical densities. To I16293A we report the detection of the HDO 1_01 - 0_00 and H2O 1_10 - 1_01 ground-state transitions as broad self-reversed emission profiles with narrow absorption, and a tentative detection of H2D+ 1_10 - 1_11. To I16293E we detect weak emission of subthermally excited HDO 1_01 - 0_00. Based on this set of submillimeter continuum and line data we model the envelopes around I16293A and E. The density and velocity structure of I16293A is fit by an inside-out collapse model, yielding a sound speed of a=0.7 km/s, an age of t=(0.6--2.5)e4 yr, and a ...
A preliminary geologic investigation was conducted to determine if Triassic sedimentary rocks of the Sanford basin and Colon cross structure in North Carolina are favorable hosts for uranium deposits. Rocks of adjacent Carolina slate belt were also examined as a potential source of uranium. On the basis of favorability criteria for sandstone-type uranium deposits, and geologic and geophysical investigations of the study area, the most favorable sites for further investigation are (1) at the contacts between the Pekin and Cumnock and between the Pekin and Sanford Formations near the Colon cross structure and (2) at the base of the Jonesboro fault, which lies below the Sanford Formation, northwest of Sanford. The highly weathered granites southeast of the Jonesboro fault were a source of the detritus deposited on the cross structure and may have been a primary source of uranium. Uranium leached from the coarse sediment (Pekin Formation) of the cross structure may have been transported ...
Sulfuric acid and its partially or completely neutralized salts with ammonia are believed to result from the oxidation of sulfur dioxide in cloud water and in other heterogeneous media present in the atmosphere. Due to the natural abundance of ammonia and the ubiquitous presence of sulfur in the atmosphere, (NH/sub 4/)/sub 2/SO/sub 4/ is commonly the dominant chemical species in the ambient aerosol. The amounts of ammonium sulfates are expected to be very low in areas far removed from anthropogenic emissions of sulfur dioxide. The chemical composition of submicrometer aerosol particles was determined at the Mauna Loa Observatory (MLO) on Mauna Loa in Hawaii during an eight-day period in August 1986. The MLO site was selected for this measurement because it is the only ground-based aerosol observatory in the remote Pacific Ocean that allows extended sampling of aerosols in the free troposphere. Measurements were made using an attenuated total ...
Four HVDC (high voltage DC) {+-} 250kV submarine OF (oil-filled) cables are to be installed each capable of 1.4-million kW for one dipole channel and two returns for forwarding to Yura Switchyard a part of the power to be generated by a Tachibanawan coal-fired power plant to open in 2000. The first cable is now being laid. They are to cover a distance of 48km on the sea bottom, and their 190mm diameter is the largest in the world and this decreases the required number of cables for a reduction in the construction cost. The installation is executed by use of a dedicated cable laying ship loaded with cables. The ship is equipped with five thruster screws by adjusting which a cable is fed into the sea and laid on the bottom with high positional accuracy in all directions, and with a 10m-accurate DPS (Dynamic Positioning System) besides GPS (Global Positioning System). Operating on the sea bottom is a simultaneous laying/burying machine which buries the cable 2-3m deep in the sea bottom. ...
Present and potential future changes to the global environment have important implications for marine pollution and for the air-sea exchange of both anthropogenic and natural substances. This report addresses three issues related to the potential impact of global change on the air-sea exchange of chemicals: Global change and the air-sea transfer of the nutrients nitrogen and iron. Global change and the air-sea exchange of gases. Oceanic responses to radiative and oxidative changes in the atmosphere. The deposition of atmospheric anthropogenic nitrogen has probably increased biological productivity in coastal regions along many continental margins. Atmospheric deposition of new nitrogen may also have increased productivity somewhat in mid-ocean regions. The projected future increases of nitrogen oxide emissions from Asia, Africa and South America will provide significant increases in the rate of deposition of oxidized nitrogen to the central North Pacific, the equatorial Atlantic, and ...
While underground power transmission lines have become to use CV cables as the mainstream, existing facilities still use OF cables. Factors of OF cable deterioration include heat cycles during operation and surge intrusion. As a method to diagnose this deterioration in insulation, characteristics tests are performed by collecting insulation oil in a cable connection box. The insulation oil collection work has been done conventionally with the power line stopped to prevent danger from induction voltage. A power uninterruptible oil collection tool was developed recently. The tool consists mainly of an insulator made of epoxy resin, wherein a connection box connector is rotated and loosened by operating an insulating operation rod, with the structure not contacted directly with metallic sheath, so that insulation oil can go through the oil collecting tool and gets collected. Discussions were given on the tool to be capable of collecting samples for analyzing water ...
Developing and deploying innovative environmental cleanup technologies is an important goal for the U.S. Department of Energy (DOE), which faces challenging remediation problems at contaminated sites throughout the United States. Achieving meaningful, constructive stakeholder involvement in cleanup programs, with the aim of ultimate acceptance of remediation decisions, is critical to meeting those challenges. DOE`s Office of Technology Development sponsors research and demonstration of new technologies, including, in the past, the Volatile Organic Compounds Arid Site Integrated Demonstration (VOC-Arid ID), hosted at the Hanford Site in Washington State. The purpose of the VOC-Arid ID has been to develop and demonstrate new technologies for remediating carbon tetrachloride and other VOC contamination in soils and groundwater. In October 1994 the VOC-Arid ID became a part of the Contaminant Plume Containment and Remediation Focus Area (Plume ...
Particle shape is an important parameter in numerous civil, environmental, and petroleum engineering applications. In ground-water flow, the shape of individual particles comprising the soil affects the soil`s pore size distribution and, hence, the important flow characteristics such as hydraulic conductivity and headloss. A model for delineating the relative importance of particle size, particle shape, and porosity, (and their interactions), in explaining the variability of hydraulic conductivity of a granular porous medium is developed and tested. Three types of porous media are considered in this work: spherical glass beads; granular sand; and irregularly shaped, shredded glass particles. A reliable method for quantifying the three-dimensional shape and packing of large samples of irregular particles based on their angle of repose is presented. The results of column experiments indicate that in the size range examined (i.e., 149 {micro}m to 2,380 {micro}m), the ...
Slide 10 Slide 11 23 ground-floor apartments Ancillary Information Gathered Median total PAH [mg/g] Slide 15 What are the principal sources of PAHs to urban lakes?...
It is shown that vacuum instabilities possibly arising because of tachyons do not contradict any experimental evidence, and therefore that no objection against tachyon existence can be found even on this ground. (Auth.).
... the effective lifetime of the excited states against spontaneous radiation is only a fe- times the natural lifetime and collisional destruction by ...
As the ground state potential curve is strongly related to spectral line shapes, the minumum position of the ground state potential is obtained from the experiemental absorption profile k({delta}{nu}, T) at high density of the radiating atoms. The temperature dependence of the absorption processes of Hg and Cd lines 253.65 and 326.1 nm, respectively perturbed by inert gases (Xe, Kr, Ar and Ne) had been carefully studied over a wide spectral range. Using the point of the maximum temperature dependence {delta}{nu} {sub m} in each case, we are able to calculate the position of the ground state potential R {sub m} using a simple formula.
A geothermal heat pump (GHP) system with three ground coils was installed in a residence in northern Idaho with a portion of the ground heat exchanger wrapped around the residential septic tank. The septic coil provided a significant portion of the heating for the residence over the heating season. There was no evidence of the septic tank freezing up or failing to properly function. Utilizing a septic tank as a heat source for GHP systems is feasible design option if the septic tank is used on a full-time basis. However, the tank should be surrounded on all sides by a large amount of soil and/or insulated from the ground surface to ensure that ground temperatures near the tank remain warm during the winter.
that struck Haiti on Jan. 12, paratroopers from the 2nd Brigade Combat Team, 82nd Airborne Division, were on the ground in the capital, Port-au-Prince. As scenes of the...
... that range from relatively low frequency strong ground motion modeling [Vidale et al., 1985] to high frequency reverse time migration of seismic ...
... see http://www.spawar.navy.mil/robots/ ), during which ... pixel-accurate routes for a small ground robot using aerial ... a USV, a UAV and a UUV as well ...
Stochastic models for the simulation of global radiation are discussed. Thermal transients in the ground are analyzed. The performance of buried-pipe storage and a space heating system with long-term storage is described.
aluminum electrolytic capacitors with Freon, trichloroethylene, carbon tetrachloride, or other chlorine or fluorine solvents. Aluminum electrolytic ...
4), is quite efficient for multivibrators because complementary outputs are available ... age or ground, much as is done in the complementary multivibrators. ...
ground strike hazards 3) Advancements in the initialization of numerical weather prediction models through better identification of deep convection 4) Improved routing of...
This standard establishes requirements, verification criteria, and contractor tasks for electromagnetic effects protection of airborne, ground, and support systems. These effects include electromagnetic compatibility, electromagnetic interference, lightni...
Integration of Eddy Current probes with MAUS scanning system has been demonstrated to produce scan rates of 36 sqft/hour. System will be designed to ...
Chapter 10 of the manual that describes on-the-ground operations that strengthen the likelihood that our forests will be healthier, more diverse, and ... ...
Arbuscular mycorrhizal (AM) fungi are mutualistic symbionts living in the roots of 80% of land plant species, and developing extensive, below-ground extraradical hyphae fundamental for the uptake of...Full Text Available
This paper is concerned with the validation of the 3D deterministic neutral-particle transport theory code EVENT for shielding applications. The code is based on the finite element-spherical harmonics (FE-P{sub N}) method which has been extensively developed over the last decade. A general multi-group, anisotropic scattering formalism enables the code to address realistic steady state and time dependent, multi-dimensional coupled neutron/gamma radiation transport problems involving high scattering and deep penetration alike. The powerful geometrical flexibility and competitive computational effort makes the code an attractive tool for shielding applications. In recognition of this, EVENT is currently in the process of being adopted by the UK nuclear industry. The theory behind EVENT is described and its numerical implementation is outlined. Numerical results obtained by the code are compared with predictions of the Monte Carlo code MCBEND and ...
The software package VIBA-lab1, which incorporates PIXE and RBS energy spectra simulation has now been extended to include the simulation of elemental maps from 3D structures. VIBA-lab1 allows the user to define a wide variety of experimental parameters, e.g. energy and species of incident ions, excitation and detection geometry, etc. When the relevant experimental parameters as well as target composition are defined, the program can then simulate the corresponding PIXE and RBS spectra. VIBA-LAB2 has been written with applications in nuclear microscopy in mind. A set of drag-and-drop tools has been incorporated to allow the user to define a three-dimensional sample object of mixed elemental composition. PIXE energy spectra simulations are then carried out on pixel-by-pixel basis and the corresponding intensity distributions or elemental maps can be computed. Several simulated intensity distributions for some ...
Spatially resolved studies of star forming regions show that the assumption of spherical geometry is not realistic in most cases, with a major complication posed by the gas being ionised by multiple non-centrally located stars or star clusters. We try to isolate the effects of multiple non-centrally located stars on the temperature and ionisation structure of HII regions, via the construction of 3D photoionisation models using the 3D Monte Carlo photoionisation code MOCASSIN. We find that the true temperature fluctuations due to the stellar distribution (as opposed to the large-scale temperature gradients due to other gas properties) are small in all cases and not a significant cause of error in metallicity studies. Strong emission lines from HII regions are often used to study the metallicity of star-forming regions. We compare integrated emission line spectra from our models and quantify any ...
Performance of SRF cavities are limited by non-linear localized effects. The variation of local material characters between "hot" and "cold" spots is thus of intense interest. Such locations were identified in a BCP-etched large-grain single-cell cavity and removed for examination by high resolution electron microscopy (SEM), electron-back scattering diffraction microscopy (EBSD), optical microscopy, and 3D profilometry. Pits with clearly discernable crystal facets were observed in both "hotspot" and "coldspot" specimens. The pits were found in-grain, at bi-crystal boundaries, and on tri-crystal junctions. They are interpreted as etch pits induced by surface crystal defects (e.g. dislocations). All "coldspots" examined had qualitatively low density of etching pits or very shallow tri-crystal boundary junction. EBSD revealed the crystal structure surrounding the pits via crystal phase orientation mapping, while ...
The Sunyaev-Zeldovich (SZ) effect gives a measure of the thermal energy and electron pressure in groups and clusters of galaxies. In the near future SZ surveys will map hundreds of systems, shedding light on the pressure distribution in the systems. The thermal energy is related to the total mass of a system of galaxies, but it is only a projection that is observed through the SZ effect. A model for the 3D distribution of pressure is needed to link the SZ signal to the total mass of the system. In this work we construct an empirical model for the 2D and 3D SZ profile, and compare it to a set of realistic high resolution SPH simulations of galaxy clusters and groups, and to a stacked SZ profile for massive clusters derived from WMAP data. Furthermore, we combine observed temperature profiles with dark matter potentials to yield an additional constraint, under the assumption of hydrostatic equilibrium. We ...
In the case where sources and receivers are not distributed on a 2-D plane, seismic tomography inversion was studied. In tomography experiments, the existing wells are generally used. In such case, sources and receivers are frequently not distributed on a 2-D plane. The 2.5-D analysis method including 2-D structure and 3-D ray-tracing was thus developed. This method is featured by less memory necessary for ray-tracing calculation, and the same algorithm for velocity determination as 2-D analysis method. In previous methods, since analysis is generally carried out by projecting sources and receivers on a certain assumed 2-D plane, it can derive correct results in the case of constant velocity and straight ray, however, in the other case, it derives incorrect results. Application of 3-D tomography requires a large amount of memory, and falls into poor convergence because of various parameters. The 2.5-D ...
The transition region between the straight part and the ends of the coils of the LHC model and prototype dipole magnets are often identified as the origin of training quenches. In order to study how the discontinuities in the material properties of these regions affect coil pre-stress and possibly gain more insight in the quench behavior, a program was set up at CERN to analyze by 3D-FEM these particular regions. The ACCEL team, who performed a similar analysis for the main quadrupoles of the Superconducting Supercollider SSC, is entrusted with this program. In this paper we report on the results of 3D-modeling and analysis of the coil return end region, including the complete coil mass, of a 1-m single bore model magnet. This magnet represents all relevant features of the "two-in-one" LHC main dipole design concerning the winding configuration, the collar pack, the yoke, and the outer shell ...
Subtractive imaging in confocal fluorescence light microscopy is based on the subtraction of a suitably weighted widefield image from a confocal image. An approximation to a widefield image can be obtained by detection with an opened confocal pinhole. The subtraction of images enhances the resolution in-plane as well as along the optic axis. Due to the linearity of the approach, the effect of subtractive imaging in Fourier-space corresponds to a reduction of low spatial frequency contributions leading to a relative enhancement of the high frequencies. Along the direction of the optic axis this also results in an improved sectioning. Image processing can achieve a similar effect. However, a 3D volume dataset must be acquired and processed, yielding a result essentially identical to subtractive imaging but superior in signal-to-noise ratio. The latter can be increased further with the technique of weighted averaging in Fourier-space. A comparison ...
Current advanced CMOS source/drain engineering involves the use of amorphizing implants with 3D geometry. Upon annealing, the induced transient enhanced diffusion (TED) can only be accurately predicted if the amorphized region is correctly modeled, as well as the formation and evolution of extended defects, particularly 3 1 1's and dislocation loops. In addition to the extended defects, already modeled in the atomistic kinetic Monte-Carlo simulator DADOS, we have developed a physically based modeling approach for the implant-induced damage build-up, amorphization and recrystallization, suitable to handle device-size process simulation. It is based on amorphous pockets (3D, irregular shape agglomerates of an arbitrary number of interstitials and vacancies, plus trapped impurities) with a size-dependent activation energy for recombination. The model is able to reproduce experimental aspects like ...
Current advanced CMOS source/drain engineering involves the use of amorphizing implants with 3D geometry. Upon annealing, the induced transient enhanced diffusion (TED) can only be accurately predicted if the amorphized region is correctly modeled, as well as the formation and evolution of extended defects, particularly 3 1 1's and dislocation loops. In addition to the extended defects, already modeled in the atomistic kinetic Monte-Carlo simulator DADOS, we have developed a physically based modeling approach for the implant-induced damage build-up, amorphization and recrystallization, suitable to handle device-size process simulation. It is based on amorphous pockets (3D, irregular shape agglomerates of an arbitrary number of interstitials and vacancies, plus trapped impurities) with a size-dependent activation energy for recombination. The model is able to reproduce experimental aspects like the ...
The paper deals with the modeling and the development of a numerical procedure for the analysis of shape-memory alloy (SMA) elements in order to predict the main features of SMA devices. A 3D SMA model in the framework of small strain theory is developed starting from the thermo-mechanical model proposed by Souza et al. (Eur J Mech A/Solids 17:789-806, 1998) and modified by Auricchio and Petrini (Int J Numer Methods Eng 55:1255-1284, 2002). The aim of this paper is to propose some more modifications to the original model, to derive its consistent 1D formulation, to clarify the mechanical meaning of the material parameters governing the constitutive model. A robust time integration algorithm is developed in the framework of the finite element method and a new beam finite element is proposed. Some numerical applications and a comparison with experimental data available in literature are carried out in order to assess the ability of the proposed ...
To investigate the usefulness of a newly developed magnetic resonance (MR) image-guided surgical robotic system for minimally invasive laparoscopic surgery. The system consists of MR image guidance [interactive scan control (ISC) imaging, three-dimensional (3-D) navigation, and preoperative planning], an MR-compatible operating table, and an MR-compatible master-slave surgical manipulator that can enter the MR gantry. Using this system, we performed in vivo experiments with MR image-guided laparoscopic puncture on three pigs. We used a mimic tumor made of agarose gel and with a diameter of approximately 2 cm. All procedures were successfully performed. The operator only advanced the probe along the guidance device of the manipulator, which was adjusted on the basis of the preoperative plan, and punctured the target while maintaining the operative field using robotic forceps. The position of the probe was monitored continuously with ...
Results of our systematic NMR study in high T_c cuprates are reviewed. The antiferromagnetic spin fluctuations (AFSF) decrease in the order of La_1_._8_5Sr_0_._1_5CuO_4. YBa_2Cu_3O_7 and Tl_2Ba_2CuO_6_+_y. 1/T_1 of "6"3Cu in the CuO_2 plane in the normal state follows essentially a Curie-Weiss law at high temperature and T_1T = const. law at low temperature. The temperature dependence of 1/T_1 and the Knight shift together with their impurity effect in the superconducting state strongly suggest d-wave pairing implying the AFSF to be responsible for the occurrence of superconductivity. From the NQR frequency measurement the density of Cu 3d and O 2p holes decreases and increases, respectively, in the order of La, Y and Tl compounds, which is consistent with the change of AFSF. The relation between T_c and #nu#_Q, and their pressure dependence suggest that there exists and optimum value of the ratio of Cu ...
K{beta}-to-K{alpha} X-ray intensity ratios of Ti, V, Cr, and Co in pure metals and their disilicide compounds have been measured following excitation by 59.54 keV {gamma}-rays from a 200 mCi {sup 241}Am point-source. The K{beta}-to-K{alpha} intensity ratios of all these metals in the disilicide compounds are found to be less than the corresponding ratios for pure metals. Comparison of the measured K{beta}-to-K{alpha} intensity ratios for the disilicides and pure metals with the multiconfiguration Dirac-Fock calculations indicates increase of the 3d electron populations of Ti, V, Cr, and Co in the disilicides from their pure metal values suggesting the rearrangement of electrons between 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on NiSi{sub 2} and CuSi{sub 2}.
K#beta#-to-K#alpha# X-ray intensity ratios of Ti, V, Cr, and Co in pure metals and their disilicide compounds have been measured following excitation by 59.54 keV #gamma#-rays from a 200 mCi "2"4"1Am point-source. The K#beta#-to-K#alpha# intensity ratios of all these metals in the disilicide compounds are found to be less than the corresponding ratios for pure metals. Comparison of the measured K#beta#-to-K#alpha# intensity ratios for the disilicides and pure metals with the multiconfiguration Dirac-Fock calculations indicates increase of the 3d electron populations of Ti, V, Cr, and Co in the disilicides from their pure metal values suggesting the rearrangement of electrons between 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on NiSi_2 and CuSi_2.
Groom-Bailey decomposition analysis was carried out to investigate regional 3-D galvanic distortion on MT data in the central part of Northeastern Japan. Measuring sites were located nearly along the east-west line crossing Northeastern Japan. Three measuring lines (A, B, C) from the north to the south were prepared, and only data on the C line were analyzed in this paper. As a result, twist and shear were estimated to be not zero depending on local distortion in most of the sites. It was thus clarified that this method is not always perfect. This method was effective for regional 2-D structures, however, its application was doubtful to complicated 3-D underground structures in Japan. In order to obtain more accurate results, 2-D analysis using the impedance including no local distortion effect was necessary after the preliminary Groom-Bailey decomposition analysis. The direction of the wide area ...
This study examined the oxygen permeation behavior of Ce0.9Gd0.1O2-d (Gadolinium-Doped Ceria, GDC)/Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF) composite membranes fabricated using a conventional sintering technique. GDC/BSCF composite membranes with a relative density >95% could be obtained when a green compact of BSCF and GDC was sintered at 1150^oC for 5h. It appears that GDC serves as a grain growth inhibitor because the average grain size of the composite decreased with increasing GDC content. The oxygen permeability of the BSCF and GDC/BSCF composite membranes strongly depends on the grain size and membrane thickness. The addition of GDC to BSCF resulted in a small grain size, low thermal expansion coefficient and high hardness. However, it is believed that oxygen permeation was blocked by GDC, a...
The 12 GeV upgrade at Jefferson Lab has identified two new large spectrometers as Physics detectors for the project. The first is a 7.5 Gev/c 35 m-sr. spectrometer that requires a pair of identical Combined Function Superconducting Magnets (CFSM) that can simultaneously produce 1.5 T dipole fields and 4.5 T/m quadrupole fields inside a warm bore of 120cm. The second is an 11 GeV/c 2 m-sr. spectrometer that requires a CFSM that simultaneously produces a dipole field of 4.0 T and a quadruple field of 3.0 T/m in a 60 cm warm bore. Magnetic designs using TOSCA 3D have been performed to realize the magnetic requirements, provide 3d fields for optics analysis and produce field and force information for the engineering feasibility of the magnets. A two-sector cos( theta )/cos(2 theta ) design with a low nominal current density, warm bore and warm iron design has been selected and analyzed. These low current ...
X-ray magnetic diffraction (XMD) technique was applied to an orbital ordering compound of ferromagnetic YTiO_3 for the first time. The orbital-magnetic form factor #mu# _L(k) and the spin-magnetic form factor #mu# _S(k) were independently measured by utilizing the LS separation ability of the XMD. The #mu# _L(k) was measured for ten reciprocal-lattice points. No significant values of the #mu# _L(k) were observed for most of the reciprocal-lattice points within the estimated statistical errors, which suggested quenching of the orbital moment. The #mu# _S(k) was measured for 22 reciprocal-lattice points. Fourier synthesis of the #mu# _S(k) gave the spin density distribution m _S(r) in the real space. The obtained m _S(r) map shows the characteristic feature of the electron distribution of 3d electron in the t_2_g state of a Ti atom coordinated by O"2"- ions, in which the electrons are distributed away from the negative O"2"- ions. It is concluded ...
The decay channels of the Ar 2s"-"1 and 2p"-"1 and Kr 3p"-"1 and 3d"-"1 electronic hole states have been investigated by means of photoelectron-photoion coincidence measurements following innershell ionization using synchrotron radiation. With the method of final ion-charge resolving electron spectroscopy it has become possible to disentangle different contributions to the electron spectrum and to determine the decay probabilities P(nl"-"1#->#n+) of the above-mentioned hole states (nl"-"1) to the final ionic charge states n+. A high correlation with threefold or even fourfold charged ions has been found in all cases. Possible decay routes, via cascade or direct double Auger processes, are discussed on the basis of energy-level schemes calculated with the Hartree-Fock method. Special emphasis is laid on the examination of the Kr 3p"-"1 decay process, where the two fine-structure components (j=1/2,3/2) exhibit noticeably different decay ...
Core-collapse supernovae are among Nature's most energetic events. They mark the end of massive star evolution and pollute the interstellar medium with the life-enabling ashes of thermonuclear burning. Despite their importance for the evolution of galaxies and life in the universe, the details of the core-collapse supernova explosion mechanism remain in the dark and pose a daunting computational challenge. We outline the multi-dimensional, multi-scale, and multi-physics nature of the core-collapse supernova problem and discuss computational strategies and requirements for its solution. Specifically, we highlight the axisymmetric (2D) radiation-MHD code VULCAN/2D and present results obtained from the first full-2D angle-dependent neutrino radiation-hydrodynamics simulations of the post-core-bounce supernova evolution. We then go on to discuss the new code Zelmani which is based on the open-source HPC Cactus framework and provides a scalable AMR approach for ...
The vertical profiles of disc galaxies are built by the material trapped around stable periodic orbits, which form their "skeletons". According to this, the knowledge of the stability of the main families of periodic orbits in appropriate 3D models, can predict possible morphologies for edge-on disc galaxies. In a pilot survey we compare the orbital structures which lead to the appearance of "peanuts" and "X"-like features with the edge-on profiles of three disc galaxies (IC 2531, NGC 4013 and UGC 2048). The subtraction from the images of a model representing the axisymmetric component of the galaxies reveals the contribution of the non-axisymmetric terms. We find a direct correspondence between the orbital profiles of 3D bars in models and the observed main morphological features of the residuals. We also apply a simple unsharp masking technique in order to study the sharpest features of the images. ...
The alloying effects on K to L shell vacancy transfer probabilities (?KL) in 3d transition metals have been carried out by X-ray fluorescence studies of various alloy compositions. K X-ray intensity ratios of Ti, Cr, Fe, Co, Ni, and Cu elements in the FexNi1?x, FexCr1?x, NixCr1?x, FexCryNi1?(x+y), TixNi1?x, TixCo1?x, and CoxCu1?x alloys have been measured following excitation by 22.69keV X-rays from a 10 mCi 109Cd radioactive point source and ?KL values for alloying elements have been determined from these ratios. The spectrum of characteristic K-X-ray photons from samples were detected with a high resolution Si(Li) detector coupled to a 4 K multichannel analyzer. The present investigation makes it possible to ...
A continuous-time 7th-order Butterworth Gm-C low pass filter (LPF) with on-chip automatic tuning circuit has been implemented for a direct conversion DBS tuner in 0.35 mum SiGe BiCMOS technology. The filter's -3dB cutoff frequency f{sub 0} can be tuned from 4 to 40 MHz. A novel on-chip automatic tuning scheme has been successfully realized to tune and lock the filter's cutoff frequency. Measurement results show that the filter has -0.5 dB passband gain, +-5% bandwidth accuracy, 30 nV/Hz{sup 1/2} input referred noise, -3dBVrms passband IIP3, and 27 dBVrms stopband IIP3. The I/Q LPFs with the tuning circuit draw 13 mA (with f{sub 0} = 20 MHz) from 5 V supply, and occupy 0.5 mm{sup 2}.
The objective of this study was to develop a method for 3D subtraction CT angiography and to optimize the visualization after semiautomatic segmentation. Ten patients with aneurysms of the abdominal aorta were examined using spiral CT. To reconstruct the vessels, as well as adjacent organs such as the liver and kidneys, one image data volume was acquired before and after injection of the contrast agent. The CT scans were obtained with a Siemens Somatom Plus 4. To improve the results of automatic segmentation, as well as visualization by maximum intensity projection (i.e. removal of bony structures), subtraction of both image volumes is necessary. However, small translation shifts disturb the subtraction process and produce artificial contours. To calculate the disparities along the three coordinate axes of two corresponding image volumes, a cepstrum filter is applied to a pair of image volumes. After detection of the disparities, which manifest ...
We studied a novel universal spectrochemical series of six-coordinated octahedral 3d transition metal complexes, which can be used for any combination of central metal atom and ligand molecules. A two dimensional spectrochemical series could be used to estimate the ligand field splitting energy of not only known compounds but also the unknown compounds. Therefore, it should be possible to control the physical properties, such as the electronic and magnetic properties and the optical phenomena of octahedral transition metal complexes by modifying the ligand field splitting. PMID:19378561
We compute the entropy of a closed bounded region of space for pure 3d Riemannian gravity formulated as a topological BF theory for the gauge group SU(2) and show its holographic behavior. More precisely, we consider a fixed graph embedded in space and study the flat connection spin network state without and with particle-like topological defects. We regularize and compute exactly the entanglement for a bipartite splitting of the graph and show it scales at leading order with the number of vertices on the boundary (or equivalently with the number of loops crossing the boundary). More generally these results apply to BF theory with any compact gauge group in any space-time dimension.
A transient eddy current measurement method is presented to determine the thickness and conductivity of a conductive plate. The conductive plate is induced by an air-cored coil, the magnetic flux density along the axial is measured and the various signals corresponding to plates with different thickness and conductivity are calculated using a 3D transient eddy current simulator. Characteristic features are obtained from the transient response. A similarity-based modeling method is utilized in this study to estimate the thickness and conductivity of the conductive plate. (author)
This report details an investigation into the efficacy of two approaches to solving the radiation diffusion equation within a radiation hydrodynamic simulation. Because leading-edge scientific computing platforms have evolved from large single-node vector processors to parallel aggregates containing tens to thousands of individual CPU's, the ability of an algorithm to maintain high compute efficiency when distributed over a large array of nodes is critically important. The viability of an algorithm thus hinges upon the tripartite question of numerical accuracy, total time to solution, and parallel efficiency.
The results of photoemission spectroscopy using molybdenum and tantalum samples have been obtained from the new beamline 2B1 at Pohang Light Source. Beamline 2B1 is based on a spherical grating monochromator (SGM) which is equipped with five gratings. The photon energy range from 184 to 1100 eV was covered in this work using two gratings (Gratings 4 and 5). The photon energy resolution has been deduced from Ta Fermi-level spectra and 3d spectra of Mo.
The results of a study conducted by Working Group 10 of the AGARD Fluid Dynamics Panel to investigate the limits of boundary layer methods, both the integral and field type formulations, for calculating three-dimensional turbulent separated flow are presented. Test cases used to assess the boundary layer calculations included the DFLVR prolate spheroid at angle of attack and the NASA-Ames Wing C. Comparisons between boundary layer calculations and experimental data are presented for these test cases along with observations, conclusions, and recommendations.
A modified variable structure interacting multiple model (M-VSIMM) estimator for complex hybrid maneuver target tracking is presented. The M-VSIMM could potentially be applied to fire control systems (FCS) used on warships. Target model groups were designed using 3D dimensional dynamic target models. Optimal model group selection logic was proposed, contrary to the activation and termination logic in the original VSIMM. The system will respond faster with optimal model group selection logic. After performing simulations, the tracking performances of the Kalman, ?-?(-?), VDIE, IMM and M-VSIMM filters were compared under various maneuvering conditions.
This contribution provides an overview and imparts basic knowledge on pertinent technical developments in magnetic resonance imaging (MRI) of the liver: 3D sequences, respiratory triggering, parallel imaging, and 3 Tesla (3T). 3D sequences can be used as T1-weighted (T1w) sequences for analyzing dynamics of contrast enhancement or as T2w sequences for MR cholangiography. Consistent improvements in respiratory triggering make it possible to obtain good image quality on T2w scans even in patients unable to hold their breath. Parallel imaging as a universal technique to accelerate image acquisition is particularly appropriate for MRI of the liver, and it has been shown that the reduced acquisition time is not achieved at the expense of image quality. Further progress in MRI of the liver can be expected with use of the 3T systems, but hitherto irrelevant problems must still be solved. Overall the ...
This paper presents a numerical simulation with the EUROPLEXUS fast dynamics software of a pipe whipping phenomenon occurring in the thermal hydraulic conditions of a loss of coolant accident in a PWR primary circuit. Different physical phenomena take place simultaneously during the rupture and the whipping of the pipe such as plasticity, contact, large displacements, two-phase flow regime and fluid structure interaction. Two kinds of numerical models - a simplified pipeline model and a mixed 1D/3D model - are considered and compared throughout modelling and computation. Numerical results are compared with experimental data belonging to the Aquitaine II test campaign.
The use of global three-dimensional (3-D) models with satellite observations of CO2 in inverse modeling studies is an area of growing importance for understanding Earth s carbon cycle. Here we use the GEOS-Chem model (version 8-02-01) CO2 mode with multiple modifications in order to assess their impact on CO2 forward simulations. Modifications include CO2 surface emissions from shipping (0.19 PgC yr 1), 3-D spatially-distributed emissions from aviation (0.16 PgC yr 1), and 3-D chemical production of CO2 (1.05 PgC yr 1). Although CO2 chemical production from the oxidation of CO, CH4 and other carbon gases is recognized as an important contribution to global CO2, it is typically accounted for by conversion from its precursors at the surface rather than in the free troposphere. We base our model 3-D spatial distribution of ...
Argon ion laser induced fluorescence measurements were carried out in a multipolar filament discharge with a broadband diode laser centered on 668 nm, which stimulated a transition from the metastable state in Ar(II) 3d4F7/2 to 4p4D05/2. The intensity of the induced fluorescence at 442 nm was maximized by the optimization of the discharge parameters and the laser power. From the recovery of the background fluorescence after the laser was turned off, the ion diffusion coefficient was deduced and compared with the result inferred from the experiments of ion acoustic wave (IAW) damping.
This reports is a literature survey on models and correlations for determining flow pattern that are used to simulate thermal-hydraulics in nuclear reactors. Determination of flow patterns are a basis for obtaining physical values of wall/interfacial friction, wall/interfacial heat transfer, and droplet entrainment/de-entrainment. Not only existing system codes, such as RELAP5-3D, TRAC-M, MARS, TRACE, CATHARE) but also up-to-date researches were reviewed to find models and correlations
We study the energetics of island formation in Stranski-Krastanow growth within a parameter-free approach. It is shown that an optimum island size exists for a given coverage and island density if changes in the wetting layer morphology after the 3D transition are properly taken into account. Our approach reproduces well the experimental island size dependence on coverage, and indicates that the critical layer thickness depends on growth conditions. The present study provides a new explanation for the (frequently found) rather narrow size distribution of self-assembled coherent islands.
A chemically assisted micro-beam etching system for 3D microanalysis was designed. Using chemically assisted ion beam etching (CAIBE) method with FIB shave-off scanning, about several hundred micrometers clean cross-section will be acquired in a few hours. We use focused ion beam (FIB) and electron beam (EB) as micro-beams, halogen or halide mainly as reactive gases. The apparatus was manufactured based on this concept. We found that the FIB, Q-MS and SED worked as expected. The instrumentation has been completed.
This work deals with the development of wind maps in the Venezuelan coastal zones (South America). The Navier-Stokes equations for real viscous incompressible flow are discretized via the finite element method and they are applied to a full 3D numerical model. Two regions were analyzed: the Margarita island and the Paraguana peninsula, both of them located in the Caribbean Sea at the North of Venezuela. These regions were modeled by using a three dimensional control volume, discretized through hexaedric eight-noded finite elements. Some wind maps obtained in this research are presented and discussed. (author)
We report on the design, fabrication and testing of two superconducting passive microwave components, a quadrature hybrid and a 20 dB directional coupler. These components are designed to be integrated with superconducting qubits or Josephson parametric amplifiers and used in quantum information processing applications. For the coupler, we measure return loss and isolation > 20 dB, and insertion loss 20 dB and insertion loss < 0.3dB in a 10% band around 6.5 GHz. These values are within the design specifications of our application; however, we find a 7% difference between the designed and measured center frequency for the hybrid.
Conformal radiation therapy represents a considerable and attractive challenge in oncology. Its aim is mainly to improve local control by increasing the dose with an acceptable rate of complications. This work overviews the world literature on this subject. The technical and theoretical requirements are highlighted. These requirements include a precise definition of the target volume by digital imaging (essentially CT scan), but also clear view of the target volume and the organs at risk, a specific collimation of the beam, 3-D dose calculations, optimization procedures, and a rigid immobilization of the patient with verification of his position. Moreover, the clinical applications of conformal radiation therapy are reviewed and discussed. (authors). 80 refs., 1 tab.
In this paper we report on multi-physics, multi-billion macroparticle simulation of beam transport in a free electron laser (FEL) linac for future light source applications. The simulation includes a self-consistent calculation of 3D space-charge effects, short-range geometry wakefields, longitudinal coherent synchrotron radiation (CSR) wakefields, and detailed modeling of RF acceleration and focusing. We discuss the need for and the challenges associated with such large-scale simulation. Applications to the study of the microbunching instability in an FEL linac are also presented.
A simple method allowing easy calculation of the spatial damage energy distributions for ion-implanted materials is presented. The direct procedure takes account of the variation with depth of the lateral spreading of implanted ions, as well as the effects of energy transport by the recoiling target atoms. The subsequent computer program LUPIN-3D provides three-dimensional damage distributions and allows the construction of damage energy mappings. Various substrates of technological interest are investigated and several fields of application of the calculation are envisaged. The density of cascades can therefore be determined and heterogeneous amorphization models can be implemented. (orig.).
A new technique for radon measurement in the natural environment was investigated. It is based on the use of activated charcoal and a track-etch detector. The charcoal acts as a radon collector from the air and the track-etch detector as a recorder of the alpha particles emitted by radon and its decay products. Our preliminary results show that the response of the new dosimeter to radon, using Deodorant activated charcoal (TOK, Yugoslavia) and a CR-39 track-etch detector, is 1.4 tracks cm{sup -2}/Bqm{sup -3}d, which is about eight times higher than that obtained with a standard track-etch dosimeter. (author).
The 3-D neutronics code COREDAX has been developed based on AFEN (Analytic Function Expansion Nodal) method for x-y-z geometry and for hex-z geometry. In this study, the COREDAX code, as a regulatory review tool independent of the designer's, was applied to the SMART reactor core that was designed by KAERI (Korea Atomic Energy Research Institute). For nuclear cross section generation, the HELIOS lattice code was used in this study. The preliminary results for steady state in various conditions are presented in this paper
K{beta}-to-K{alpha} X-ray intensity ratios of Ti and Ni have been measured in pure metals and in alloys of Ti{sub x}Ni{sub 1-x} (x=0.7, 0.6, 0.5, 0.4 and 0.3) following excitation by 22.69 keV X-rays from a 10 mCi {sup 109}Cd radioactive point source. The valence-electron configurations of these metals were determined by corporation of measured K{beta}-to-K{alpha} X-ray intensity ratios with the results of multiconfiguration Dirac-Fock calculation for various valence-electron configurations. Valence-electron configurations of 3d-transition metals in alloys indicate significant differences with respect to the pure metals. Our analysis indicates that these differences arise from delocalization and/or charge transfer phenomena in alloys. Namely, the observed change of the valence-electron configurations of metals in alloys can be explained with the transfer of 3d electrons from one element to the other ...
Purpose: Three-dimensional rotational angiography (3DRA) is a new technique based on a rotational angiographic acquisition able to display arterial vessels in a 3D rendering mode. The system was mainly developed for neuroradiological evaluations but preliminary extracranial experiences have also been reported. The aim of our work was to compare the results of three-dimensional angiography of the carotid arteries done with high-flow injection of contrast medium from the aortic arch with the results of selective angiography. Materials and methods: Twenty patients underwent digital angiography of the supra-aortic vessels in order to quantify a stenosis of the carotid bifurcations previously detected at Doppler Ultrasound. Examinations were performed with the Philips Integris Allura system provided with the rotational angiography (RA) tool connected to a workstation for three-dimensional reconstruction able to display vessels in a ...
The effects of hydrostatic pressure on the electronic band structure of the semiconductor mineral iron pyrite FeS_2 have been investigated theoretically by an ab initio full-potential linearized-augmented plane wave (FPLAPW) method within a local approximation (LDA/GGA) to the density functional theory. The calculations predict that at a pressure of 94.1 GPa the indirect band gap of pyrite FeS_2 vanishes and the material becomes a metal. This is due to the presence of the S-S and Fe-S bonds, which provide novel energy band distortions in the process of attaining the metallic state. Analysis indicates that, under increasing high pressure, the conduction bands (3p_z of sulfur and 3d_x_"2_-_y_"2+3d_x_y of iron) intrude downwards into the valence bands, which are predominantly 3d in nature. At normal pressure, the lattice constant, the bulk modulus, sulfur position ...
Combination treatments of chisel-injected fumigants (methyl bromide, 1,3-D, metam sodium, and chloropicrin) on a first crop, followed by drip-applied fumigants (metam sodium and 1,3-D +/- chloropicrin) on a second crop, with and without oxamyl drip applications were evaluated for control of Meloidogyne incognita in three different tests (2002 to 2004) in Tifton, GA. First crops were eggplant or tomato, and second crops were cantaloupe, squash, or jalapeno pepper. Double-cropped vegetables suffered much greater root-knot nematode (RKN) pressure than first crops, and almost-total yield loss occurred when second crops received no nematicide treatment. On a first crop of eggplant, all fumigants provided good nematode control and average yield increases of 10% to 15 %. On second crops, higher application rates and fumigant combinations (metam sodium and 1,3-D +/- ...
Detailed quantitative sequence stratigraphic analysis and three-dimensional (3-D) modeling of the fluvio-deltaic Pikeville, Hyden, and four Corners formations of the Breathitt Group, eastern Kentucky, indicate that it is possible to make confident deterministic correlations of sand bodies at offshore development well spacings. The key to high-confidence correlation is the delineation of the 3-D architecture of third-order composite sequences, which are seismically mappable, and the recognition of internal fourth-order sequences, which are stacked into lowstand, transgressive, and highstand sequence sets. Volumetric partitioning of reservoir sand bodies between systems tracts and sequences allows prediction of channel sandstone geometries and channel: crevasse splay ratios. Furthermore, channel-fill type is predictable from the sequence stratigraphy. Within 13 studied fourth-order sequences, incised ...
This paper presents the results of numerical investigations on electron trajectories in different 3D fringing fields of spherical defectors. We start with a chosen set of geometrical values for the electrodes such as radius of curvature, electrode gap, angle between entrance and exit face. We do a first numerical calculation of the spatial potential distribution using a 3D electron optics program based on the finite difference method (FDM). Ray tracing through this potential distribution is then performed using another program, which also gives the potential and the electric field strength along the curved beam path. In the next step we estimate the position and the geometry of the field clamp using Herzog's formulae assuming the entrance of a parallel plate condenser to be a good approximation for the entrance of the spherical deflector in first order. For the consecutive numerical recalculations of ...
To evaluate the usefulness of three-dimensional (3D) rotational angiography, cervical carotid or cerebral angiography was done without catheterizing the branches of the thoracic aorta. A 5-Fr pig-tail type catheter was passed into the ascending aorta via the radial artery or the femoral artery. Optimal carotid angiogram views were obtained using approximately 45 ml of contrast medium at a flow rate of 15 ml/sec. Optimal cerebral angiogram views were obtained using approximately 70 ml of contrast medium at a flow rate of 20 ml/sec. The contrast medium concentration was 300 to 350 mgI/ml. A satisfactory view could be obtained in 5 of 8 (63%) cases on cervical carotid 3D angiography and in 8 of 14 (57%) cases on cerebral 3D angiography. In all cases, no complications were noted. This method offers the advantages of requiring a relatively short procedure time and a ...
Objective: To investigate the value ofMSCT in observing the direct findings of hilar cholangiocarcinoma1Methods Multislice helical CT studies were performed on the upper abdomen in 19 consecutive patientswith painless jaundice1 Precontrast and dynamic contrast enhanced (25 s phase and 60 s phase) scanswere conducted, and 3D imageswere reconstructed using enhanced raw data in 15 cases1 The direct CT findings of hilar cholangiocarcinoma were studied by three radiologists respectively in a 32scale strategy1 The morphological features and extension of bile duct involvement by hilar cholangiocarcinoma were analyzed1 All the 19 caseswere pathologically p roved as hilar cholangiocarcinoma by surgery (15 cases) and ERCP ( 4 cases) 1 Results The direct findings and extension of hilar cholangiocarcinoma could be demonstrated in 14 out of 15 3D reconstruction images, 8 out of 19 in 25 s phase, and 7 out of 19 in ...
Currently, x-ray mammography is the method of choice in breast cancer screening programmes. As the mammography technology moves from 2D imaging modalities to 3D, conventional computational phantoms do not have sufficient detail to support the studies of these advanced imaging systems. Studies of these 3D imaging systems call for a realistic and sophisticated computational model of the breast. DeBRa (Detailed Breast model for Radiological studies) is the most advanced, detailed, 3D computational model of the breast developed recently for breast imaging studies. A DeBRa phantom can be constructed to model a compressed breast, as in film/screen, digital mammography and digital breast tomosynthesis studies, or a non-compressed breast as in positron emission mammography and breast CT studies. Both the cranial-caudal and mediolateral oblique views can be modelled. The ...
Ordos basin lies in the north-central China, in a compression tectonic regime, with an area of approximately 250,000 km{sup 2}, including several pay zones ranging from Cambrian to Jurassic. It is one of the earliest-formed marine to continental-superimposed basin in China, characterized by Proterozoic basin-marginal rifling and Lower-Paleozoic carbonate platform development followed by western thrusting and foreland depression during Mesozoic. It underwent several tectonic movements and is covered by several structural layers, with many play types developed, primarily thrust and anticlinal plays in the west, and differential compaction (river-channel sand lens) or drape as well as buried hill plays in the basin center and east. Ordos basin is a prolific gas basin with an estimated resource potential of gas 656,091 billion m{sup 3} in the Paleozoic strata and oil 2.0474 billion tons in the Mesozoic strata. In 1986, in the western part of the basin, the well Tian-1 on the Tianchi ...
The DNA double-strand break (DSB) damage response induced by high energy charged particles on lung fibroblast cells embedded in a 3-dimensional (3-D) collagen tissue equivalents was investigated using antibodies to the DNA damage response proteins gamma-histone 2AX (#gamma#-H2AX) and phosphorylated DNA-PKcs (p-DNA-PKcs). 3-D tissue equivalents were irradiated in positions across the linear distribution of the Bragg curve profiles of 307.7 MeV/nucleon, 556.9 MeV/nucleon, or 967.0 MeV/nucleon "5"6Fe ions at a dose of 0.30 Gy. Patterns of discrete DNA damage streaks across nuclei or saturated nuclear damage were observed, with saturated nuclear damage being more predominant as samples were positioned closer to the physical Bragg peak. Quantification of the DNA damage signal intensities at each distance for each of the examined energies revealed a biological Bragg curve profile with a pattern of DNA damage ...
Background and purpose: We evaluate the feasibility of concomitant and adjuvant docetaxel combined with three-dimensional conformal radiotherapy (3D-CRT) and androgen deprivation in high-risk prostate carcinomas. Methods: Fifty men with high-risk localized prostate cancer (16), locally advanced (28) or very high-risk prostate cancer (6) were included. Seventy Gy were delivered on prostate and seminal vesicles in 35 fractions, concurrently with weekly docetaxel (20 mg/m"2). Three weeks after the completion of 3D-CRT, docetaxel was given for 3 cycles (60 mg/m"2), every 3 weeks. Patients had to receive LHRH agonist during 3 years. Results: The intent to treat analysis shows that four patients out of 15 stopped prematurely the chemotherapy due to grade 3-4 acute toxicity. In the per protocol analysis, 46 patients completed a full-dose chemoradiation regimen representing 413 cycles: five patients experienced ...
Background and purpose: stereotactic radiosurgery (SRS) and also fractionated stereotactic radiotherapy (SRT) offer high local control (LC) rates (> 90%). This study aimed to evaluate three-dimensional (3-D) tumor volume (TV) shrinkage and to assess quality of life (QoL) after SRS/SRT. Patients and methods: from 1999 to 2005, 35/74 patients were treated with SRS, and 39/74 with SRT. Median age was 60 years. Treatment was delivered by a linear accelerator. Median single dose was 13 Gy (SRS) or 54 Gy (SRT). Patients were followed up ? 12 months after SRS/SRT. LC and toxicity were evaluated by clinical examinations and magnetic resonance imaging. 3-D TV shrinkage was evaluated with the planning system. QoL was assessed using the questionnaire Short Form-36. Results: Median follow-up was 50/36 months (SRS/SRT). Actuarial 5-year freedom from progression/overall survival was 88.1%/100% (SRS), and ...
Recent advances in self-amplified spontaneous emission (SASE) experiments stimulate interest in quantitative comparison of measurements with theory. In this paper we show that the widely used simulation code TDA3D, developed by Tran and Wurtele [Comput. Phys. Commun. 54, 263 (1989)] even though a single frequency code, can be used to determine the output power in the SASE process with excellent approximation in the exponential growth regime. The method applies when the gain is not very high, which is a special advantage, because when the gain is not very high, the analytical calculation is particularly difficult since the exponential growing term does not dominate. The analysis utilizes a scaling relation between the output power and the number of simulation particles in the code TDA3D: left-angle P right-angle=N_#lambda#"'/N_#lambda# left-angle P"'right-angle, where left-angle P right-angle is the ...
Fluorescent microspheres were applied in a novel fashion during subsurface drilling of permafrost and ground ice in the Canadian High Arctic to monitor the exogenous microbiological contamination of...Full Text Available
Events detected in a shielded plastic scintillation counter occurring in the 26 microsec preceding the arrival of an extensive air shower at ground level with local electron density or = 20 m to the -2 power and the 240 microsec after its arrival have been studied. No significant excess of events (tachyons) arriving in the early time domain have been observed in a sample of 11,585 air shower triggers.
This sheet summarizes information on geothermal heat pumps (GHPs), which extracts heat from the ground in the winter and transfers heat to the ground in the summer. More than 200,000 GHPs are operating in US; they can reduce energy consumption and related emissions by 23 to 44% compared to air-source heat pumps. Opportunities for use of GHPs, requirements, and cost are described. Important terms are defined.
Papers are presented under the following topics: machine control and automation; rock drilling; cutting and fragmentation; rock characterization, remote sensing and interface detection; artificial intelligence and mine monitoring systems; computer applications; mechanical excavators; material handling; surface and underground mining; innovative mining systems; new developments in mechanical miners; ground hazard detection and control; ground support; and extraterrestrial mining.
Papers are presented under the session headings: research in mechanical fragmentation; rock characterization, remote sensing and interface detection; monitoring, data transmission and communications; tunnel boring machines; minewide monitoring and expert systems for ground control; machine guidance; shaft and raise boring; automation of drilling equipment; machine automation and control; new developments in mechanical miners; materials handling; innovative mining systems; general minewide monitoring and expert systems; ground support; human factors; and extraterrestrial mining.
This paper is a tutorial discussion of the basic principles of ground relaying for high voltage and extra high voltage transmission lines. Three different HV configurations are considered: Long lines, lines with a weak mid-point station, and mutually-coupled lines. Application criteria for EHV circuits are also discussed, and specific setting calculations are included where appropriate.
This 2001 edition of the guide to UK renewable energy companies examines the geothermal heat pump sector, and discusses the technology involved, installations of geothermal heat pumps, the activity in the UK market with increased interest in UK geothermal heat pump products from abroad, and developments in the building sector. The UK government's increased support for the industry including its sponsorship of the Affordable Warmth programme, and the future potential of ground source systems are discussed.
This 2001 edition of the guide to UK renewable energy companies examines the geothermal heat pump sector, and discusses the technology involved, installations of geothermal heat pumps, the activity in the UK market with increased interest in UK geothermal heat pump products from abroad, and developments in the building sector. The UK government's increased support for the industry including its sponsorship of the Affordable Warmth programme, and the future potential of ground source systems are discussed.
The purpose of this document is to use existing documentation to review the effectiveness of subsurface flow and surface flow constructed wetlands in treating wastewater and to demonstrate the viability of treating effluent from Savannah River Site outfalls H-02 and H-04 with a subsurface flow constructed wetland to lower copper, lead and zinc concentrations to within National Pollutant Discharge Elimination System (NPDES) Permit limits. Constructed treatment wetlands are engineered systems that have been designed and constructed to use the natural functions of wetlands for wastewater treatment. Constructed wetlands have significantly lower total lifetime costs and often lower capital costs than conventional treatment systems. The two main types of constructed wetlands are surface flow and subsurface flow. In surface flow constructed wetlands, water flows above ground. Subsurface flow constructed wetlands are designed to keep the ...
Ground-source heat pump systems (GSHPSs), also referred to as geothermal heat pump systems (GHPSs), have been widely used in residential and commercial buildings for years due to their outstanding energy utilization efficiencies. In this study, an energy and exergy modeling of solar assisted ground-source heat pump systems for residential applications is presented for system analysis and performance evaluation. In this regard, the performance of a solar assisted ground-source heat pump heating system, installed in Solar Energy Institute of Ege University, Izmir, Turkey, is evaluated based on the actual operational data to show how energy and exergy efficiencies values change with the system. The average heating coefficient of performances (as energy efficiencies) of the solar assisted ground-source heat pump (GSHP) unit and the overall system are obtained to be 2.64 and 2.38, respectively. The average ...
The objective of this project were to investigate the dynamic behavior of peat and to evaluate the influence of that behavior on the dynamic response of peat deposits. During the course of the research, the objectives were expanded to explore the effects of strong earthquake shaking on pile foundations embedded in peat deposits. An experimental investigation was undertaken using samples of a peat deposit typical of many large peat deposits in western Washington. A series of ground response analyses was performed to investigate the seismic response of peat deposits. Three vertical profiles through Mercer Slough were analyzed using both equivalent linear and nonlinear ground response analyses. The analyses showed that the soft nature of the Mercer Slough peat would produce amplification of the long-period components of an earthquake ground motion. Comparison of the equivalent linear and nonlinear ground ...
Full text of publication follows: During calculations of SAR accidents and transients it is necessary to perform steam generator simulation. Best accuracy is 3D transient calculations presented in report. Main outcomes of work was next: 1. There was shown by analysis the applicability of code TRAC (Los-Alamos laboratory) for thermal - hydraulic calculations of horizontal steam generator PGV-1000M. Special nodalization scheme was developed for it purposes. 2. Validation and selection of thermal-hydraulic correlations for improvement of using the code at calculation PGV-1000M were performed. As result Labuntsov formula is recommended for horizontal SG. 3. Calculations of nominal mode operation of PGV-1000M for cross-verification with code STEG (Electrogorsk Research and Engineering Center EREC) during its verification were performed. Solution by TRAC was obtained for transient problem after stabilization time. 4. Development of dynamic SG model ...
This report presents the methodology and the results from the modelling of an open repository for spent nuclear fuel in Laxemar. Specifically, the present work analyses the hydrological effects of the planned repository during the construction and operational phases when it is open, i.e. air-filled, and hence may cause a disturbance of the hydrological conditions in the surroundings. The numerical modelling is based on the SDM-Site Laxemar MIKE SHE model. The modelling was divided into three steps. The first step was to update the SDM-Site Laxemar model with a new hydrogeological bedrock model. The other main updates were an increase of the depth of the MIKE SHE model domain, enhanced vertical computational resolution and that the drainage of the Aespoe Hard Rock Laboratory was included in the model. The resulting model was used to simulate undisturbed natural conditions. The next step was to describe the open repository conditions, using Laxemar layout D2, by implementing the access ...
We have estimated the mixing height (MH) and investigated the relationship between vertical mixing and ground-level ozone concentrations in Seoul, Korea, by using three ground-based active remote sensing instruments operating side by side: micro-pulse lidar (MPL), differential absorption lidar (DIAL), and differential optical absorption spectroscopy (DOAS). The M H is estimated from MPL measurements of aerosol extinction profiles by the gradient method under convective conditions. Comparisons of the MHs estimated from MPL and radiosonde measurements show a good agreement (r"2 = 0.99). Continuous MPL measurements with high temporal and vertical resolution reveal the diurnal variations of the MH under convective conditions and the presence of a residual layer during the nighttime. Comprehensive measurements of ozone and aerosol by MPL, DIAL and DOAS during an high ozone episode (24-26 May 2000) in Seoul, Korea, reveal that (1) photochemical ozone ...