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 ...
2010-10-01
CHAPLET-3D results for the 3-D extension C5G7 Mox benchmarks
Energy Technology Data Exchange (ETDEWEB)
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)
2005-07-01
MAY 1988. - NASA Technical Reports Server
disciplinary methods were used to independently determine the aerodynamic loads, the thermal response, and strardural performance of the hydrogen cooled ...
Energy Technology Data Exchange (ETDEWEB)
In this article two integral computational fluid dynamics methods for steady-state and transient vehicle aerodynamic simulations are described using a Chevrolet Corvette ZR-1 surface panel model. In the last decade, road-vehicle aerodynamics have become an important design consideration. Originally, the design of low-drag shapes was given high priority due to worldwide fuel shortages that occurred in the mid-seventies. More recently, there has been increased interest in the role aerodynamics play in vehicle stability and passenger safety. Consequently, transient aerodynamics and the aerodynamics of vehicle in yaw have become important issues at the design stage. While there has been tremendous progress in Navier-Stokes methodology in the last few years, the physics of bluff-body aerodynamics are still very difficult to model correctly. ...
1993-01-01
Computational study of jet interaction flow field with and without incidence
International Nuclear Information System (INIS)
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 ...
2004-05-09
Application of porous material to reduce aerodynamic sound from bluff bodies
International Nuclear Information System (INIS)
Aerodynamic sound derived from bluff bodies can be considerably reduced by flow control. In this paper, the authors propose a new method in which porous material covers a body surface as one of the flow control methods. From wind tunnel tests on flows around a bare cylinder and a cylinder with porous material, it has been clarified that the application of porous materials is effective in reducing aerodynamic sound. Correlation between aerodynamic sound and aerodynamic force fluctuation, and a surface pressure distribution of cylinders are measured to investigate a mechanism of aerodynamic sound reduction. As a result, the correlation between aerodynamic sound and aerodynamic force fluctuation exists in the flow around the bare cylinder and disappears in the flow around the cylinder with porous ...
2010-02-01
Ct3d: tracking microglia motility in 3D using a novel cosegmentation approach
UK PubMed Central (United Kingdom)
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
2011-02-15
UK PubMed Central (United Kingdom)
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
Energy Technology Data Exchange (ETDEWEB)
Wind power is an increasingly significant renewable energy resource, producing no environmentally damaging C0{sub 2} emissions. The efficient production of electricity by wind turbines relies on aerodynamics: aerodynamics of wind turbines provides the fundamental solutions to efficient wind turbine design. Following a historical introduction, Part 1 of Aerodynamics of Wind Turbines is concerned with basic rotor aerodynamics, while Part 2 deals with structural aspects of the wind turbine and calculation of the loads on it. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum method is also covered, as are eigenmodes and the dynamic behaviour of a turbine. ...
2000-06-15
Energy Technology Data Exchange (ETDEWEB)
Wind power is an increasingly significant renewable energy resource, producing no environmentally damaging CO2 emissions. The efficient production of electricity by wind turbines relies on aerodynamics. Aerodynamics of Wind Turbines provides the fundamental solutions to efficient wind turbine design. Following a historical introduction, Part 1 of Aerodynamics of Wind Turbines is concerned with basic rotor aerodynamics, while Part 2 deals with structural aspects of the wind turbine and calculation of the loads on it. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum method is also covered, as are eigenmodes and the dynamic behaviour of a turbine. ...
2001-01-01
Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies
Energy Technology Data Exchange (ETDEWEB)
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.
2010-09-15
Calculated valence electronic structure of 3d metals for use in the X-ray intensity ratio studies
International Nuclear Information System (INIS)
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.
2010-09-01
Three-Dimensional Wing Kinematics and Aerodynamic Characteristics of a Beetle in Free Flight
Detailed three dimensional wing kinematics and aerodynamic characteristics are experimentally presented for the free flight of a beetle, Allomyrina dichotoma, which has a pair of elytra (fore wings) and hind wings. The kinematic parameters of the wing motion, such as the wing tip trajectory, angle of attack, torsion angle, and camber deformation, are obtained from a 3D reconstruction technique that involves the use of two or three synchronized high-speed cameras to digitize various points marked on the wings. Our data show outstanding characteristics of wing deformation and flexibility in the free flight of the beetle. To find out the mechanism of aerodynamic force, the leading edge vortex (LEV) and trailing edge vortex (TEV) on both elytron and hind wing were observed by using smoke wire visualization and digital particle image velocimetry (DPIV) technique. Qualitative smoke lines in the region of the ...
2010-11-01
Future research on transonic unsteady aerodynamics and its aeroelastic applications
Energy Technology Data Exchange (ETDEWEB)
The workshop focused on strategies for promoting and developing engineering level transonic flutter prediction techniques. The technology of transonic aerodynamics is currently undergoing rapid development. Significant progress is being made to solve the inherently nonlinear equations describing unsteady motions of wings in transonic flow, while the availability of reliable and efficient computational methods will greatly enhance the ability to predict the aeroelastic behavior of modern aircraft operating under transonic flow conditions.
1987-08-01
Energy Technology Data Exchange (ETDEWEB)
This report completes the documentation for the research project 'High Pressure Compressor - Preliminary Design as Basis for the Development of an Efficient and Environmentally Friendly Core Engine' which was funded by the Ministry of Economics of State Brandenburg. The objective of the project is to deliver a preliminary compressor aerodynamic design as well as design studies for an efficient, weight and cost improved compressor. The increase of stage pressure ratio and improved efficiency, whilst stage and blade count is reduced, has been achieved by advanced 3D methods. Compressor stability also at off-design conditions will be retained. The mechanical design focusses on a cost and weight optimised rotor not only for a conventional bladed discs but also for Blish stages. Various options for split casings have been developed and assessed. Alternative vortex reducers based on ...
2001-08-01
3-D depth migration via McClellan transformations
Energy Technology Data Exchange (ETDEWEB)
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 ...
1990-01-01
Ewald sphere correction for single-particle electron microscopy
Energy Technology Data Exchange (ETDEWEB)
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.
2006-03-15
Energy Technology Data Exchange (ETDEWEB)
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 ...
1991-09-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1997-07-01
Chapter 14: Seismic imaging using 2- and 3-D migration
Energy Technology Data Exchange (ETDEWEB)
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. ...
1999-09-01
Rotational modes of motion for an aerodynamic pendulum with a vertical rotation axis
British Library Electronic Table of Contents (United Kingdom)
An aerodynamic pendulum placed in a steady horizontal air flow is studied in connection with modeling a wind-receiving element of a vertical-axis wind turbine (VAWT). When modeling the medium effects on the pendulum, the following two approaches are combined: the quasi-static one based on stationary wind tunnel experiments and the unsteady one based on the added mass effects. The existence of stable and unstable rotational modes is analyzed analytically (via the Poincar?-Pontryagin method) and numerically. The dependence on the parameters responsible for the viscous friction at the rotation axis and for the added mass effects is taken into account.
2009-01-01
A 3D tomographic EBSD analysis of a CVD diamond thin film
Energy Technology Data Exchange (ETDEWEB)
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.
2008-09-15
A new method of imaging particle tracks in solid state nuclear track detectors
British Library Electronic Table of Contents (United Kingdom)
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 ...
2010-01-01
T-HEMP3D, 3-D Time-Dependent Elastic Plastic Flow
International Nuclear Information System (INIS)
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 ...
Energy Technology Data Exchange (ETDEWEB)
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.
1981-01-01
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 ...
2005-01-01
Energy Technology Data Exchange (ETDEWEB)
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.
1983-05-01
British Library Electronic Table of Contents (United Kingdom)
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...
2009-01-01
First trimester measurements of nasal bone length using three-dimensional ultrasound
British Library Electronic Table of Contents (United Kingdom)
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...
2009-01-01
A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs
International Nuclear Information System (INIS)
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 ...
VAWT performance prediction - Description of a PC-based software
Energy Technology Data Exchange (ETDEWEB)
The Vertical Axis Wind Turbine (VAWT) offers a mechanically and structurally simple method of harnessing the energy of the wind. Fast and accurate predictions of the VAWT performance can be obtained using momentum models. Aerodynamic streamtube models are based on the conservation-of-momentum principle in a quasi-steady flow, by equating the forces of the rotor blades to the change in streamwise momentum through the turbine. An analytical model considering a multi-streamtube system divided into two parts has been developed to determine the aerodynamic blade loads and rotor performance of the Darrieus wind turbine (CARDAA computer code). This so-called double multiple-streamtube (DMS) model uses two constant interference factors in the induced velocities and accounts for vertical variations in the free stream velocity. It has been recently modified to produce an efficient software package appropriate for the needs of VAWT ...
1995-12-31
Energy Technology Data Exchange (ETDEWEB)
The aim of this paper is to numerically explore the non-linear two-dimensional unsteady potential flow over a Savonius rotor and to develop a code for predicting its aerodynamics performances. In the model developed, the rotor is represented in a median plane by two semicircles, displaced along their common diameter. The two semicircles can be considered to produce lifting effects. As a result, they are modelled by a collection of discrete vortices on their contours. The flow field is then governed by the Laplace equation. The versatile Neumann boundary condition, applied over the contour of the semicircles and the Kutta Joukowsky condition applied at the four extremities of the semicircles have been used in the modelling. The torque distribution of the stationary rotor and the unsteady pressure field on the blades of the rotating rotor, predicted by the code developed, have been compared and validated by some experimental data. (author)
2010-01-15
Energy Technology Data Exchange (ETDEWEB)
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 ...
1996-10-01
International Nuclear Information System (INIS)
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 ...
1999-10-01
Applicator reconstruction and applicator shifts in 3D MR-based PDR brachytherapy of cervical cancer
British Library Electronic Table of Contents (United Kingdom)
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...
2009-01-01
Comparison of EH with SW-Xsub(alpha) calculations
International Nuclear Information System (INIS)
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.
1981-01-01
This Dissertation presents the author's investigation and development of a systematic method for evaluating the aerodynamic performance of Vertical Axis Wind Energy Capture Systems (WECS) apart from their electrical generation capability. The current standard method for specifying a wind energy machine is to discuss its rated power in kilowatts (or megawatts when capacity exceeds 100 kW). While this holistic method is effective for comparing machines it does not reveal the essential characteristics necessary for optimization of individual machine components. The method developed herein separates the performance characteristics of the WECS from the generation characteristics and isolates them for benchmarking and optimization. In order to develop an evaluation criterion, it was essential to evaluate and benchmark the current state of the art for wind energy capture. A thorough ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1996-10-01
International Nuclear Information System (INIS)
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 ...
1997-08-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2003-07-01
3-D depth migration: various methods and how they perform on real data
Energy Technology Data Exchange (ETDEWEB)
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 ...
1997-07-01
28: Calculation of 3D dose distribution for photons in inhomogeneous media
International Nuclear Information System (INIS)
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.
Energy Technology Data Exchange (ETDEWEB)
In recent years very good experience has been accumulated with self-supporting low-pressure blades. Today blades are constructed up to a length of 1060 mm (50 Hz) or 1360 mm (25 Hz). In this process modern computational methods from aerodynamics and also from mechanics are employed. The further development of computer technology also permits new methods, for example the use of curved fixed blading as well as the optimization of existing designs. (orig.).
1989-08-01
Electron-ion recombination of neutral iron
Energy Technology Data Exchange (ETDEWEB)
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 ground 3d{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 ...
1997-04-01
Asymmetric Vortex Flow Over Circular Cones
... Calculations of asymmetric separated flow past circular ... in Missile Aerodynamics, AGARD CP 336 ... three-dimensional vortex flows in aerodynamics. ...
1991-03-01
Aerodynamic Static Differential Pressure
aerodynamic force and moment values. Only the solid and the 25 percent porous dishes were tested for the static pressure values used primarily to determine ...
Energy Technology Data Exchange (ETDEWEB)
A design is proposed for forming the rear screen of a chamber firebox at the point of aerodynamic projection and a design for attaching the pipes of the aerodynamic projection using girders linked with the screen by hinges and movable connections.
1982-01-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1996-10-01
Visualization by PIV of dynamic stall on a vertical axis wind turbine
Energy Technology Data Exchange (ETDEWEB)
The aerodynamic behavior of a vertical axis wind turbine (VAWT) is analyzed by means of 2D particle image velocimetry (PIV), focusing on the development of dynamic stall at different tip speed ratios. The VAWT has an unsteady aerodynamic behavior due to the variation with the azimuth angle {theta} of the blade's sections' angle of attack, perceived velocity and Reynolds number. The phenomenon of dynamic stall is then an inherent effect of the operation of a VAWT at low tip speed ratios, impacting both loads and power. The present work is driven by the need to understand this phenomenon, by visualizing and quantifying it, and to create a database for model validation. The experimental method uses PIV to visualize the development of the flow over the suction side of the airfoil for two different reference Reynolds numbers and three tip speed ratios in the operational regime of a small urban wind turbine. The ...
2009-01-15
Energy Technology Data Exchange (ETDEWEB)
A wind turbine is disclosed which permits high energy production over a wide range of wind forces while being protected against climatic hazards. According to the invention, a mast supports an energy recuperator comprising vane-type rotors by means of a frame which is orientable around a vertical axis. An energy conversion device is connected to the recuperator in order to be driven in rotation by the recuperator. The frame is responsive to the aerodynamic force exerted on the recuperator with respect to the mast and to the ground so as to optimize the power collected by the machine. The frame comprises a turret pivoted to the mast about the vertical axis and a structure pivoted to the turret about a horizontal axis of tilting motion. A balance weight maintains the recuperator in the top position when there is no wind. The aerodynamic drag of the recuperator acts in the opposite direction. In consequence, in the event of a high wind, the ...
1991-12-19
Focused ion beam assisted three-dimensional rock imaging at submicron scale
Energy Technology Data Exchange (ETDEWEB)
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 ...
2003-05-09
Energy Technology Data Exchange (ETDEWEB)
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3D) and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. Field demonstrations are in progress to collect data for evaluation of horizontal completions in both the Red River and Ratcliffe. A vertical well in the Red River will test attribute analysis of 3D seismic data for prediction of porosity development. Additional seismic acquisitions and interpretation are in progress for both the Ratcliffe and Red River. A ...
1996-12-31
British Library Electronic Table of Contents (United Kingdom)
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 ...
2010-01-01
Discretization of complex 3-D flow domains with adaptive hybrid grids
Energy Technology Data Exchange (ETDEWEB)
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.
1996-12-31
Automated three-dimensional X-ray analysis using a dual-beam FIB
International Nuclear Information System (INIS)
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.
2007-08-01
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.
2010-05-01
Employing exergy-optimized pin fins in the design of an absorber in a solar air heater
Energy Technology Data Exchange (ETDEWEB)
Fins serve as heat transfer augmentation features in solar air heaters; however, they increase pressure drop in flow channels. Pin fins are relatively good heat transfer augmentation features with superior aerodynamic performance, and as a result find application in some solar air heaters. The exergy optimization method is employed in sizing the pin fin. Results indicate that high efficiency of the optimized fin improves the heat absorption and dissipation potential of a solar air heater. With optimum fin efficiency and superior absorptive coating quality, useful energy losses can be minimized. Some important observations pertinent in design are made. (author)
2010-02-15
Three-dimensional power system stabilizer
Energy Technology Data Exchange (ETDEWEB)
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 ...
2010-07-15
Prediction of parallel NIKE3D performance on the KSR1 system
Energy Technology Data Exchange (ETDEWEB)
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 ...
1995-05-01
British Library Electronic Table of Contents (United Kingdom)
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...
2010-01-01
Core reactor calculation using the adaptive remeshing with a current error estimator
International Nuclear Information System (INIS)
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 ...
3-D numerical simulation of the transient electromagnetic pulse coupling to double cylinder object
International Nuclear Information System (INIS)
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)
2006-10-21
Energy Technology Data Exchange (ETDEWEB)
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 ...
1997-09-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1996-10-01
British Library Electronic Table of Contents (United Kingdom)
SummaryThis paper examines the sensitivity and uncertainty of evaporation estimates from Nasser Lake, south of Egypt using data collected at the floating station Raft, 2km upstream of the Aswan High Dam, and 12 evaporation models. Based on their approach the evaporation models were ranked in five classes, respectively the Bowen ratio energy budget (BREB) approach, three energy-aerodynamic based methods, a mass transfer method, two temperature and five solar radiation-temperature approaches. State dependent parameter models were used to estimate the sensitivity indices of the different evaporation estimation methods at daily and monthly frequencies. A drastic reduction in the cost of the sensitivity analysis was obtained when coupled with efficient sampling methods, producing quasi-Monte Ca...
2010-01-01
Disk-Shaped Aircraft with Vertical Takeoff
International Science & Technology Center (ISTC)
Aerodynamic Disk-Shaped Aircraft with Vertical Takeoff and Landing
Energy Technology Data Exchange (ETDEWEB)
A new three-dimensional (3D) acoustic modelling method was developed using a first-order hyperbolic wave system which was solved with explicit finite dfferences. The numerical solution of the 3D wave system provides a useful method for simulating evolution of a pressure field corresponding to compressional type waves. Existing two-dimensional (2D) elastic modelling algorithms were modified and fine-tuned for computationally efficient and realistic wave propagation simulations in complex structures. An original formulation of the 3D reverse time migration method was developed which is very accurate, does not suffer from unwanted evenescent energy, can image dips beyond 90{degree}, and does not generate multiple energy. Two case studies were performed that involved steam stimulation projects in the ...
1994-12-31
Investigation of computational aeroacoustic tools for noise predictions of wind turbine aerofoils
International Nuclear Information System (INIS)
In this work trailing edge noise levels of a research aerofoil have been computed and compared to aeroacoustic measurements using two different approaches. On the other hand, aerodynamic and aeroacoustic calculations were performed with the full Navier-Stokes CFD code Fluent [Fluent Inc 2005 Fluent 6.2 Users Guide, Lebanon, NH, USA] on the basis of a steady RANS simulation. Aerodynamic characteristics were computed by the aid of various turbulence models. By the combined usage of implemented broadband noise source models, it was tried to isolate and determine the trailing edge noise level. Throughout this work two methods of different computational cost have been tested and quantitative and qualitative results obtained. On the one hand, the semi-empirical noise prediction tool NAFNoise [Moriarty P 2005 NAFNoise User's Guide. Golden, Colorado, July. http://wind.nrel.gov/designcodes/ simulators/NAFNoise] was used to directly ...
2007-07-01
Flutter control effect and mechanism of central-slotting for long-span bridges
British Library Electronic Table of Contents (United Kingdom)
The flutter control effect and mechanism of central-slotting, which have gradually been adopted in the design and construction of long-span bridges as an effective flutter controlling measure, were investigated with theoretical analysis and wind tunnel test. Five basic girder cross-sections representing five typical aerodynamic configurations were selected and central-slotted with two different slot widths. Then, a series of sectional model tests and theoretical analyses based on the two-dimensional three-degrees-of-freedom coupling flutter analysis method (2 dimension-3 degrees of freedom method, 2d-3DOF method) were carried out to investigate the aerody namic performance, flutter mechanism and flutter modality of the five basic sections and their corresponding central-slotted sections. T...
2007-01-01
A novel method to characterize the MTF in 3D for computed mammotomography
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 ...
2006-03-01
International Nuclear Information System (INIS)
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)
2008-07-01
Determination of the Venezuelan coastal-zone wind atlas by using numerical methods
Energy Technology Data Exchange (ETDEWEB)
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)
1995-12-31
Energy Technology Data Exchange (ETDEWEB)
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 moved greatly due to ...
1995-01-01
Energy Technology Data Exchange (ETDEWEB)
Purpose: The aim of this study was to evaluate the accuracy of MRI in the measurement of cartilage thickness of the ankle joint in comparison to pathologic and histologic specimens. Patients and methods: The ankle joints of four fresh cadaver feet were imaged on a 1.5 T MR-unit in the coronal plane. Standard T{sub 1}-weighted spin echo (SE) and a T{sub 1}-weighted 3D-GE (FLASH-3D) sequence with fat saturation were applied. Following MR imaging, the talus was explanted and cut parallel to the MR images for macroscopic evaluation and histologic specimens were prepared. MRI measurements of the cartilage thickness of the talus were carried out in two ways: Without and with consideration of a transition zone of intermediate signal intensity between hyperintense cartilage and hypointense cortical bone. The data were compared with the anatomic specimens as the gold standard expressing the ...
1997-04-01
Electrophysiological Study and Catheter Ablation with 3D Mapping
... 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 ...
Improvement of numerical analysis method for FBR core characteristics. 2
Energy Technology Data Exchange (ETDEWEB)
This report is composed of the following two parts and appendix. (I) Improvement of the Method for Evaluating Reactivity Based on Monte Carlo Perturbation Theory: Theoretical formulation in Monte Carlo perturbation method had been checked, and then introduced into a calculation code. There are some cases that the results of the change of eigenvalues becomes positive or negative by changing the estimator, and there is no reasonable difference in the results between the conventional method, which does not consider the change of neutron source distribution caused by a perturbation, and the new method, which consider that change. Thus it is still necessary to check the Monte Carlo perturbation code. (II) Improvement of Nodal Transport Method for 3-D Hexagonal Geometry: We can accurately evaluate hexagonal geometry FBR core by nodal transport ...
1997-03-01
Non-selective cervical and cerebral three-dimensional rotational angiography
International Nuclear Information System (INIS)
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 ...
2007-09-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1996-10-01
Phenomenological 3D and 1D consistent models for shape-memory alloy materials
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 ...
2009-08-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1996-10-01
International Nuclear Information System (INIS)
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) ...
2002-04-01
A computer-assisted method for 3D subtraction angiography based on spiral CT
International Nuclear Information System (INIS)
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 ...
Repair of a Complex Congenital Cardiac Defect
... 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 ...
GPS and Google Earth based 3D assisted driving system for trucks in surface mines
British Library Electronic Table of Contents (United Kingdom)
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 ...
2010-01-01
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.
1990-05-01
Development of a chemically assisted micro-beam etching system for three-dimensional microanalysis
Energy Technology Data Exchange (ETDEWEB)
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.
2003-01-15
A spatial damage energy distribution calculation for ion-implanted materials
International Nuclear Information System (INIS)
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.).
1989-01-01
A Preliminary Analysis of SMART Reactor Core Using the COREDAX Code
International Nuclear Information System (INIS)
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
2010-10-01
Novel Technique for Aerodynamic Force Measurement in Shock Tubes.
For aerodynamic force measurement in the ISL shock tunnel, the authors have developed a novel measurement technique. Its key feature is a mounting support, which releases the test model and tightens it again after a free flight duration of 10 to 15 millis...
1989-01-01
Three dimentional design of axial flow turbin
Energy Technology Data Exchange (ETDEWEB)
Outline of three dimensional design of axial turbine was explained with examples of its application. Quasi-three dimensional design which analyzed flow in meridian plane and flow between blades seperately, and three dimensional design which, based on the quasi-three dimensional design with considering cubical force, improved distribution of static pressure and optimized distribution of repulsion and aerodynamic force, were explained. For the numerical analysis, Euler's Code was applied. AS the example of application, expectable effect by negative angle of blade was calculated, and efficiencies of single stage turbines with static blades designed by each method were compared. As the practical application of three dimensional analysis of flow to designing, Endwall Contouring for static blade of initial stage was explained. 10 refs., 12 figs.
1989-06-10
International Nuclear Information System (INIS)
This paper describes the study of particles' dispersion in an isotropic turbulent flow. The particle's motion and the turbulent flow characteristics are calculated independently. While the particles' displacement is computed by the author's code, the flow is simulated with a commercial code : PowerFLOW. The particles and the flow are coupled through the relative velocity component of the aerodynamic force. When the simulated flow is turbulent, a turbulence regeneration model is used in order to get the flow instantaneous velocity. Validation of the method is done by comparing the particles' dispersion obtained with experimental results from literature and with the results calculated by FLUENT. Good accordance is found between numerical studies and experimental results. However, comparison between results of PowerFLOW coupled to the author's code and results from FLUENT shows differences when the particle's path goes through the turbulent ...
2004-05-09
Four Forces on a Rocket - NASA
On an airplane, the lift force (the aerodynamic force perpendicular to the flight direction) is used to overcome the weight. On a rocket, thrust is used in opposition ...
Aspects of unsteady aerodynamics in wind turbines
Energy Technology Data Exchange (ETDEWEB)
This presentation is primarily about unsteady aerodynamics in relation to wind turbines. It is divided into three very distinct sections: (1) Basic unsteady aerodynamics; (2) VAWT performance modelling and (3) Passive stall regulation of VAWTs. The aim of the presentation is to illustrate that, if desired, future wind turbine blades could be aerodynamically tailored to exploit the unsteady nature of the VAWT flow with far greater confidence and insight than has been hitherto possible. To this effect, the collaborating British research teams and, in particular, VAWT Ltd. have assembled sufficient knowledge for such a conclusion to be made. (author).
1990-01-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2003-07-10
International Nuclear Information System (INIS)
In this thesis, a new ab-initio method for molecular dynamics within the framework of density functional theory was developed and implemented. It is strongly related to the projector-augmented-wave method (PAW) by P. Bloechl, but also includes elements of a pseudocharge method proposed by M. Weinert for the full-potential linearized augmented plane wave method (FLAPW). Like the FLAPW-method, the PAW-method is an all-electron method. In the later case, the hamiltonian takes quite a simple form similar to the one obtained when using normconserving Kleinman-Bylander-type pseudopotentials or ultrasoft Vanderbilt pseudopotentials. The PAW-method allows for an efficient calculation of systems containing virtually any element of the periodic table, including those which require high numerical effort when treated using ...
Energy Technology Data Exchange (ETDEWEB)
Gel dosimetry is a new dosimetry method applied in radiation therapy. Gel dosimeters consist of a radiation sensitive gel, which can integrate absorbed doses from several radiation sources or beams. The dose to the gel can be evaluated by magnetic resonance imaging (MRI), a procedure that is the focus of the present thesis. A robust tool for the evaluation of the nonuniformity in MRI has been developed, the Deviation Image method. Unlike previously presented methods, the Deviation Image method includes all nonuniformity variations across a phantom surface and is insensitive to stochastic noise. Methods for the estimation of stochastic noise were analyzed in terms of sensitivity to nonuniformities. A method that averages the stochastic noise level over five regions over the phantom surface, and a method that assesses the stochastic noise ...
2001-03-01
Aeroelastic Analysis of Rotor Blades Using Cfd/csd Coupling in Hover Mode
A computational fluid dynamics (CFD) is coupled with a computational structural dynamics (CSD) to simulate the unsteady rotor flow with aeroelasticity effects. An unstructured upwind Navier-Stokes solver was developed for this simulation, with 2nd order time-accurate dual-time stepping method for temporal discretization and low Mach number preconditioning method. For turbulent flows, both the Spalart-Allmaras and Menter's SST model are available. Mesh deformation is achieved through a fast dynamic grid method called Delaunay graph map method for unsteady flow simulation. The rotor blades are modeled as Hodges & Dowell's nonlinear beams coupled flap-lag-torsion. The rotorcraft computational structural dynamics code employs the 15-dof beam finite element formulation for modeling. The structure code was validated by comparing the natural frequencies of a rotor model with UMARC. The flow and structure ...
2010-01-01
Resonant frequencies and Q factors of dielectric parallelepipeds by measurement and by FDTD
Energy Technology Data Exchange (ETDEWEB)
This paper describes the measurement and computation of the resonant frequencies and the associated Q factors of dielectric parallelepipeds made of high-permittivity, low-loss ceramic materials. Each resonance peak is measured separately with a fine frequency step. A curve-fitting method is used to accurately estimate the resonant frequency and 3 dB bandwidth from the somewhat noisy measured data. The finite-difference time-domain method is used to compute the initial portion of the backscattered field due to a Gaussian pulse plane wave. The time response is then extended to zero value by Prony`s method. The measured and computed data is compared for a parallelepiped resonator of permittivity 37.84.
1994-12-31
Multi-domain, higher order level set scheme for 3D image segmentation on the GPU
DEFF Research Database (Denmark)
Level set method based segmentation provides an efficient tool for topological and geometrical shape handling. Conventional level set surfaces are only $C^0$ continuous since the level set evolution involves linear interpolation to compute derivatives. Bajaj et al. present a higher order method to evaluate level set surfaces that are $C^2$ continuous, but are slow due to high computational burden. In this paper, we provide a higher order GPU based solver for fast and efficient segmentation of large volumetric images. We also extend the higher order method to multi-domain segmentation. Our streaming solver is efficient in memory usage.
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
The solution of the governing steady transport equations for momentum, heat and mass transfer in flowing fluids can be very difficult. These difficulties arise from the nonlinear, coupled, nonsymmetric nature of the system of algebraic equations that results from spatial discretization of the PDEs. In this manuscript the authors focus on evaluating a proposed nonlinear solution method based on an inexact Newton method with backtracking. In this context they use a particular spatial discretization based on a pressure stabilized Petrov-Galerkin finite element formulation of the low Mach number Navier-Stokes equations with heat and mass transport. The discussion considers computational efficiency, robustness and some implementation issues related to the proposed nonlinear solution scheme. Computational results are presented for several challenging CFD benchmark problems as well as two large scale 3D flow ...
1997-02-01
Validation of the 3D finite element transport theory code EVENT for shielding applications
Energy Technology Data Exchange (ETDEWEB)
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 ...
2000-03-01
Numerical ray tracing of electrons in different 3D fringing fields of spherical deflectors
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 ...
1999-11-01
Photochromes for Optical Memory
International Science & Technology Center (ISTC)
Photochromes for New Generation of Highly Efficient Computers with Three Dimensional (3D) Optical Memory
... 2009) Arrhythmia Electrophysiological Study and Catheter Ablation with 3D Mapping (Mercy Hospital, Miami, FL, 11/15/2007) ...
Aerodynamic effects of flexibility in flapping wings.
Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re approximately 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low ...
2009-08-19
International Nuclear Information System (INIS)
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 ...
International Nuclear Information System (INIS)
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 ...
2006-10-11
Multislice helical CT in the diagnosis of hilar cholangiocarcinoma
International Nuclear Information System (INIS)
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, ...
2005-11-01
Introducing DeBRa: a detailed breast model for radiological studies
Energy Technology Data Exchange (ETDEWEB)
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 ...
2009-07-21
International Nuclear Information System (INIS)
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 ...
2010-11-01
International Nuclear Information System (INIS)
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% ...
2009-09-01
International Nuclear Information System (INIS)
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 ...
1998-10-01
An algorithm for creating synthetic telescope images of Smoothed Particle Hydrodynamics (SPH) density fields is presented, which utilises the adaptive nature of the SPH formalism in full. The imaging process uses Monte Carlo Radiative Transfer (MCRT) methods to model the scattering and absorption of photon packets in the density field, which then exit the system and are captured on a pixelated image plane, creating a 2D image (or a 3D datacube, if the photons are also binned by their wavelength). The algorithm is implemented on the density field directly: no gridding of the field is required, allowing the density field to be described to an identical level of accuracy as the simulations that generated it. Some applications of the method to star and planet formation simulations are presented to illustrate the advantages of this new technique, and suggestions as to how this framework could support a ...
2010-01-01
Development of linear sensitivity matrix method for fast evaluation of CANDU refuelling schemes
International Nuclear Information System (INIS)
In order to develop a numerical tool for the fast evaluation of CANDU refuelling schemes, a Linear Sensitivity Matrix method (LSM) is developed. It assumes that all the effects caused by various perturbations to the core state are independent to each other and the core response to a perturbation is proportional to its magnitude. In this way, the main core parameters of a refuelling scheme can be derived by simple algebraic operations with the use of pre-calculated sensitivity matrices, without resorting to the complicated and time-consuming 3D core calculation. Verification against the Qinshan CANDU reactor operation history demonstrates that LSM is capable of generating accurate results and running very fast for evaluating a refuelling scheme. (authors)
2009-06-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2009-05-26
Energy Technology Data Exchange (ETDEWEB)
As the surroundings of objects of oil exploration grow more complicated, seismic survey methods have turned 3-dimensional and, in this report, several models are examined using the 3-dimensional simulation technology. The result obtained by the conventional wave tracking method is different from actual wavefields, and is unrealistic. The difference method among the fullwave modelling methods demands an exorbitantly long computation time and high cost. A pseudospectral method has been developed which is superior to the difference method, and has been put to practical use thanks to the advent of parallel computers. It is found that a 3-dimensional survey is mandatory in describing faults. After examining the SEG/EAGE Salt model, it is learned that the salt is well-developed and that 3-dimensional depth migration is required for sub-salt exploration. It is also ...
1997-05-27
3D Fourier synthesis of a new X-ray picture identical in projection to a previous picture
Energy Technology Data Exchange (ETDEWEB)
A central problem in diagnostic radiology is to compare a new X-ray picture with a previous picture and from this comparison be able to decide if anatomical changes have occurred in the patient or not. It is of primary interest that these pictures are identical in projection. If not it is difficult to decide with confidence if differences between the pictures are due to anatomical changes or differences in their projection geometry. In this thesis we present a non invasive method that makes it possible to find the relative changes in the projection geometry between the exposure of a previous picture and a new picture. The method presented is based on the projection slice theorem (central section theorem). Instead of an elaborate search for a single new picture a pre-planned set of pictures are exposed from a circular orbit above the patient. By using 3D Fourier transform techniques we are able to ...
1993-11-01
Three-dimensional, three-component wall-PIV
Energy Technology Data Exchange (ETDEWEB)
This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert's law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle's projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional artificial data set simulating a rotating ...
2010-06-15
Three-dimensional modeling of the flow and the interface surface in a continuous casting mold model
Energy Technology Data Exchange (ETDEWEB)
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.
1999-12-01
The new computer program for three dimensional relativistic hydrodynamical model
An effective computer program for three dimensional relativistic hydrodynamical model has been developed. It implements a new approach to the early hot phase of relativistic heavy-ion collisions. The computer program simulates time-space evolution of nuclear matter in terms of ideal-fluid dynamics. Equations of motions of hydrodynamics are solved making use of finite difference methods. Commonly-used algorithms of numerical relativistic hydrodynamics RHLLE and MUSTA-FORCE have been applied in simulations. To speed-up calculations, parallel processing has been made available for solving hydrodynamical equations. The test results of simulations for 3D, 2D and Bjorken expansion are reported in this paper. As a next step we plan to implement the hadronization algorithm by implementing the continuous particle emission for freeze-out and comparing it with Cooper-Frye formula.
2006-01-01
Power spectrum calculation for the Cornell Wiggler A SASE experiment at BNL
Recently the author showed that the widely used simulation code TDA3D, even though a single frequency code, can be used to determine the power spectrum in the SASE process with excellent approximation in the exponential growth regime. In this paper, the author applies this method to the BNL Cornell Wiggler A SASE experiment as an example. When the gain is not very high, there are many modes in the radiation, which seems to make the analytical calculation very difficult. However, he shows that the increment of the radiation due to SASE over the spontaneous radiation can be expanded in terms of guided modes with rapid convergence. Thus when the spontaneous radiation is substracted from the SASE power during the calculation, there is a good agreement between the analytical theory and the numerical simulation.
1998-08-01
Power spectrum calculation for the Cornell Wiggler A SASE experiment at BNL
Energy Technology Data Exchange (ETDEWEB)
Recently, we showed (Yu, Phys. Rev. E 58 (1998) 4991) that the widely used simulation code TDA3D, even though a single-frequency code, can be used to determine the power spectrum in the SASE process with excellent approximation in the exponential growth regime. In this paper, we apply this method to the BNL Cornell Wiggler A SASE experiment as an example. When the gain is not very high, there are many modes in the radiation, which seems to make the analytical calculation very difficult. However, we show that the increment of the radiation due to SASE over the spontaneous radiation can be expanded in terms of guided modes with rapid convergence. Thus when the spontaneous radiation is subtracted from the SASE power during the calculation, there is a good agreement between the analytical theory and the numerical simulation.
1999-06-01
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. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with short-lateral and horizontal drilling technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil-in-place will result in additional oil production by primary and enhanced recovery processes.
1997-04-01
Improved recovery demonstration for Williston Basin carbonates
Energy Technology Data Exchange (ETDEWEB)
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3D) and multi- component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with short- lateral and horizontal drilling technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil-in-place will result in additional oil production by primary and enhanced recovery processes.
1996-09-01
Improved recovery demonstration for Williston Basin carbonates
Energy Technology Data Exchange (ETDEWEB)
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determination 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) is being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with short lateral and horizontal drilling technologies. Improved completion efficiency, additional wells at closer spacing and better estimates of oil-in- place will result in additional oil production by primary and enhanced recovery processes.
1997-12-01
Improved Recovery Demonstration for Williston Basin Carbonates.
Energy Technology Data Exchange (ETDEWEB)
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3-D) and multi-component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with short-lateral and horizontal drilling technologies. Improved completion efficiency, additional wells at closer spacing and better estimate of oil-in-place will result in additional oil production by primary and enhanced recovery processes.
1997-12-31
Improved Recovery Demonstration for Williston Basin Carbonates
Energy Technology Data Exchange (ETDEWEB)
The purpose of this project is to demonstrate targeted infill and extension drilling opportunities, better determinations of oil-in- place, methods for improved completion efficiency and the suitability of waterflooding in certain shallow-shelf carbonate reservoirs in the Williston Basin, Montana, North Dakota and South Dakota. Improved reservoir characterization utilizing 3-dimensional (3-D) and multi- component seismic are being investigated for identification of structural and stratigraphic reservoir compartments. These seismic characterization tools are integrated with geological and engineering studies. Improved completion efficiency is being tested with short- lateral and horizontal drilling technologies. Improved completion efficiency, additional wells at closer spacing and better estimate of oil-in-place will result in additional oil production by primary and enhanced recovery processes.
1997-03-01
Flavor Superconductivity & Superfluidity
In these lecture notes we derive a generic holographic string theory realization of a p-wave superconductor and superfluid. For this purpose we also review basic D-brane physics, gauge/gravity methods at finite temperature, key concepts of superconductivity and recent progress in distinct realizations of holographic superconductors and superfluids. Then we focus on a D3/D7-brane construction yielding a superconducting or superfluid vector-condensate. The corresponding gauge theory is 3+1-dimensional N=2 supersymmetric Yang-Mills theory with SU(N) color and SU(2) flavor symmetry. It shows a second order phase transition to a phase in which a U(1) subgroup of the SU(2) symmetry is spontaneously broken and typical superconductivity signatures emerge, such as a conductivity (pseudo-)gap and the Meissner-Ochsenfeld effect. Condensates of this nature are comparable to those recently found experimentally in p-wave superconductors ...
2010-01-01
A perspective of the Malaysian highway energy consumption and future power supply
British Library Electronic Table of Contents (United Kingdom)
In this short communication, we discuss the energy consumption trends in the Malaysian road transport sector, with a special emphasis on the energy losses due to vehicle aerodynamic drag on highways. The recent trends of energy consumption in the Malaysian road transport sector are reviewed. It is evidently shown that the aerodynamic losses represented exceed 1.2MTOE annually since 2002. A novel concept of vertical-axis wind turbine (VAWT) farms for harvesting aerodynamic energy losses on Malaysian highways is preliminarily proposed. The novel concept aims at providing a sustainable and green energy source for the lighting of the highway network in the country.
2011-01-01
X-15 Research Results: Chapter 9
... hypersonic aerodynamic force, or the space-equivalent region. Some of these experiments change the X-15 from a research airplane to a kind of space probe, ...
Published ... - Wind Tunnels | NASA Ames Research Center - NASA
Sep 5, 2008 ... Russia. The six-component balance for blunt models aerodynamic force measurement in shock tunnel. Lu Zhiquo, Liu Hongshan, Zhang Yan ...
Aeroelastic Analysis by Coupled Non-linear Time Domain ... - NASA
and shock induced flow separation may significantly affect the flutter ...... Aerodynamic and Aeroelastic Simulation, AGARD Report 822, 10-1 10-20. ...
AERODYNAMIC NOISE TESTS ON X-20 SCALE MODELS. ...
... 37 18 Power Spectral Density Measurements of Buffet Pressures for Two Different Microphone Positions Compared with PSD Values Inferred from ...
1965-11-01
ACTIVE AEROELASTIC WING ROLLOUT ACCENTS 'BACK TO THE - NASA
The traditional wing control surfacestrailing edge ailerons and the outboard leading edge flapsare used to provide the aerodynamic force needed to twist ...
A Simple Model of Vortex Flow Past a Slender Elliptic Cone at ...
... Calculations of asymmetric separated flow past circular ... in Missile Aerodynamics, AGARD-CP-336 ... Marconi Asymmetric separated flows about sharp ...
1990-09-01
A Mathematical Model of the CH-53 Helicopter - NASA Technical ...
Engine model: An engine and governor model adapted from a heavy lift helicopter simulation provides a restistic time delay between aerodynamic rotor ...
A Computer Program for Wing 'Stibsonic Aerodynamic Performance ...
of Aspect Ratio 2 With NACA 0005-63 Thickness Distribution,. Cambered and Twisted for a Trapezoidal Span Load Distribution. NACA RM A50K27a,, ...
TECAB - Totally Endoscopic Coronary Artery Bypass
... 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 ...
JAtlasView: a Java atlas-viewer for browsing biomedical 3D images and atlases
UK PubMed Central (United Kingdom)
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
Catheter Ablation for Paroxysmal Atrial Fibrillation
... 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 ...
Accuracy of Contacts Calculated from 3D Images of Occlusal Surfaces
UK PubMed Central (United Kingdom)
ObjectiveCompare occlusal contacts calculated from 3D virtual models created from clinical records to contacts identified clinically using shimstock and transillumination.Full Text Available
2007-06-01
UK PubMed Central (United Kingdom)
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
2007-07-01
Solid oxide fuel cell simulation and design optimization with numerical adjoint techniques
This dissertation reports on the application of numerical optimization techniques as applied to fuel cell simulation and design. Due to the "multi-physics" inherent in a fuel cell, which results in a highly coupled and non-linear behavior, an experimental program to analyze and improve the performance of fuel cells is extremely difficult. This program applies new optimization techniques with computational methods from the field of aerospace engineering to the fuel cell design problem. After an overview of fuel cell history, importance, and classification, a mathematical model of solid oxide fuel cells (SOFC) is presented. The governing equations are discretized and solved with computational fluid dynamics (CFD) techniques including unstructured meshes, non-linear solution methods, numerical derivatives with complex variables, and sensitivity analysis with adjoint methods. Following the validation of the fuel cell model in ...
2008-01-01
Motion analysis of parallelly connected FPSO unit and LNG carrier
Energy Technology Data Exchange (ETDEWEB)
Nowadays, the floating production, storage, and offloading (FPSO) units are used to marginal oil fields and deep seas, because of mobility and reduced lead time from discovery to first production. One of the methods for offloading is to moor a tanker alongside the FPSO unit. In this case motion response of the system becomes highly complex, and will be affected by many factors such as hydrodynamic interaction and mechanical connections between the vessels. In this study, a quite general method is developed which has taken into account the hydrodynamic interaction as well as the effects of connectors and mooring lines, in motion response analysis of a multi-body floating system. For this purpose, 3-D source distribution method is applied for hydrodynamic analysis, and linear stiffness matrices are introduced to represent the effect of connectors and mooring lines on the motion ...
1996-12-31
Analysis and evaluation of seismic response of reactor building for Daya Bay Nuclear Power Plant
International Nuclear Information System (INIS)
Daya Bay NPP has been operating safely and stably over 10 years since 1994, and its' seismic analysis of nuclear island was in accordance with the approaches in RCC-G standard for the model M310, in which the Simplified Impedance Matrix Method (SIMM) was employed for the consideration of SSI. Thanks to the rapid progress being made in upgrading the evaluation technology and the capability of data processing systems, methods and software tools for the SSI analysis have experienced significant development all over the world. Focused on the model of reactor building of the Daya Bay NPP, in his paper the more sophisticated 3D half-space continuum impedance method based on the Green functions is used to analyze the functions of the soil, and then the seismic responses of the coupled SSI system are calculated and compared with the corresponding design values. It demonstrates that the ...
2005-12-01
Stereotactic Radiation Therapy for Brain Tumors
... acquired, which we then volumetrically fuse with the 3D image set from the MR. And by doing ...
... Exercises: Day and Night Classroom Exercises: Pinhole Focusing 3D Vision and Eye Health < Contact Lenses Monovision Playlist: ...
Debris Dispersion Model Using Java 3D
This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java
2004-01-01
... Exercises: Day and Night Classroom Exercises: Pinhole Focusing 3D Vision and Eye Health < Caring for Your Vision ...
Instability of 4f and 3d magnetic moments under high pressure
International Nuclear Information System (INIS)
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 rotational angiography: Benefits obtained in clinical endovascular treatments
International Nuclear Information System (INIS)
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)
1999-01-01
Vertical-axis wind turbine development in Canada
Energy Technology Data Exchange (ETDEWEB)
Recent Canadian progress in the development of the curved-blade Darrieus vertical-axis wind turbine (VAWT) is described. Cooperation between government, industry and power utilities in the conduct of field trials, over several years, has demonstrated improved performance and reliability of grid-coupled turbines of this type. The rated power of the VAWTs currently under test ranges from 30 kW, in a wind/diesel powerplant, to 230 kW, in an installation on an island in the Gulf of St. Lawrence. Progress has also been made in understanding the basic aerodynamic behavior of the VAWT and theoretical methods for performance and load prediction have correspondingly improved. A brief description is given of Project EOLE, a cooperative project between the federal government and the utility Hydro-Quebec to develop and test, during the next two to three years, a 4 MW VAWT prototype, which will be coupled to the power grid at a location on the south shore ...
1983-12-01
Fundamental investigation of duct/ESP phenomena
Energy Technology Data Exchange (ETDEWEB)
This report describes in detail the First Generation Duct Injection Model developed for the analysis of the fundamental processes of flue gas desulfurization by sorbent injection. The model is a two- and three-dimensional, multiphase reacting flow analyzer using computational fluid dynamics methods. The gaseous phase is solved in an Eulerian frame while the droplets or particles are tracked in a Lagrangian frame. The model has an associated preprocessor which allow easy problem set up by the use without in-depth knowledge of computational fluid dynamics. The aerodynamics of the First Generation Duct Injection Model have been successfully validated with a number of test cases for which experimental data are available. Data from the Meredosia pilot plant humidification tests have been used to validate the gas and droplet dynamics of the model with good agreement. Comparison of SO{sub 2} removal results using the present model (with one injector) ...
1990-12-01
A numerical investigation of the aerodynamics of a furnace with a movable block burner
Scientific Electronic Library Online (English)
Abstract in english In this work the air flow in a furnace was computationally investigated. The furnace, for which experimental test data are available, is composed of a movable block burner connected to a cylindrical combustion chamber by a conical quarl. The apertures between the movable and the fixed blocks of the burner determine the ratio of the tangential to the radial air streams supplied to the furnace. Three different positions of the movable blocks were studied at this time. A thr (more) ee-dimensional investigation was performed by means of the finite volume method. The numerical grid was developed by the multiblock technique. The turbulence phenomenon was addressed by the RNG k-epsilon model. Profiles of the axial, tangential and radial velocities in the combustion chamber were outlined. The map of the predicted axial velocity in the combustion chamber was compared with a map of the experimental axial velocity. The internal space of the furnace was ...
2007-06-01
Energy Technology Data Exchange (ETDEWEB)
The main objective of this dissertation is to build a numerical 3D geological model of a turbidite reservoir using well and seismic data. For the, the first step was to elaborate a depositional model using a high-resolution genetic stratigraphy approach. Simultaneously, the stratigraphic inversion over the seismic data resulted in an optimal acoustic impedance model. Both models, were used to build, by geostatistical methods, a 3-D geological model, which represents the spatial distribution of the reservoir facies. The studied case is the late Cretaceous Namorado turbidite system in the Campos basin, which is the reservoir of the Namorado oil field, located 80 km from the Brazilian coast, under a bathymetry between 110 and 250 m. The reservoir is a turbidite succession with 90 to 180 m thickness. It is composed by sand-supported conglomerates, matrix-supported conglomerate, massive ...
1997-01-29
Energy Technology Data Exchange (ETDEWEB)
This topical report is a compilation of characterizations by different disciplines of the Mississippian Ratcliffe in portions of Richland County, MT. Goals of the report are to increase understanding of the reservoir rocks, oil-in-place, heterogeneity and methods for improved recovery. The report covers investigations of geology, petrography, reservoir engineering and seismic. The Ratcliffe is a low permeability oil reservoir which appears to be developed across much of the study area and occurs across much of the Williston Basin. The reservoir has not been a primary drilling target in the study area because average reserves have been insufficient to payout the cost of drilling and completion despite the application of hydraulic fracture stimulation. Oil trapping does not appear to be structurally controlled. For the Ratcliffe to be a viable drilling objective, methods need to be developed for (1) targeting better reservoir development and (2) ...
1998-07-01
Improved recovery demonstration for Williston Basin carbonates. Final report
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 ...
1998-07-01
Study of the electron paramagnetic resonance spectra of Zn(antipyrine)_2(NO_3)_2:VO"2"+
International Nuclear Information System (INIS)
In this work, a full ligand-field energy matrix (10x10) diagonalization treatment for 3d"1 ions in tetragonal symmetry is developed on the basis of the two-s.o.-coupling-parameter model. Spin Hamiltonian parameters (g factors g_|_|, g_p_e_r_p_e_n_d_i_c_u_l_a_r and hyperfine structure constants A_|_|, A_p_e_r_p_e_n_d_i_c_u_l_a_r) of the tetragonal V"4"+ center in Zn(antipyrine)_2(NO_3)_2 are calculated from the complete energy matrix diagonalization method and the perturbation theory method. The calculated results from both methods are not only close to each other but also in good agreement with the experimental values. Furthermore, the compressed defect structure of V"4"+ center is discussed.
2010-08-01
Re-evaluation of floor response spectra of reactor building for Daya Bay NPP
International Nuclear Information System (INIS)
The seismic analysis of nuclear island of Daya Bay Nuclear Power Plant (NPP) was just in accordance with the approaches in RCC-G standard for the model M310 in France, in which the simplified impedance matrix method was employed for the consideration of soil's function. In this paper the more sophisticated 3D half-space continuum impedance method based on the Green functions is used to analyze the function of soil. In addition, multi-group of input time histories was used in the seismic response analysis in the existing design and their average of responses for each group was taken as the design basis. The same multi-group of input time histories was used in the seismic response analysis in this study, but the average and enveloped value of responses for each case are calculated respectively to account for the uncertainty of input motions. Focused on the above two issues, the seismic responses of the ...
2006-03-01
Predictive modelling of boiler fouling. Final report.
Energy Technology Data Exchange (ETDEWEB)
A spectral element method embodying Large Eddy Simulation based on Re- Normalization Group theory for simulating Sub Grid Scale viscosity was chosen for this work. This method is embodied in a computer code called NEKTON. NEKTON solves the unsteady, 2D or 3D,incompressible Navier Stokes equations by a spectral element method. The code was later extended to include the variable density and multiple reactive species effects at low Mach numbers, and to compute transport of large particles governed by inertia. Transport of small particles is computed by treating them as trace species. Code computations were performed for a number of test conditions typical of flow past a deep tube bank in a boiler. Results indicate qualitatively correct behavior. Predictions of deposition rates and deposit shape evolution also show correct qualitative behavior. These simulations are the first attempts ...
1990-12-31
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 ...
2010-01-01
3-D prestack migration in anisotropic media
Energy Technology Data Exchange (ETDEWEB)
A three-dimensional (3-D) prestack reverse-time migration algorithm for common-source P-wave data from anisotropic media is developed and illustrated by application to synthetic data. Both extrapolation of the data and computation of the excitation-time imaging condition are implemented using a second-order finite-difference solution of the 3-D anisotropic scalar-wave equation. Poorly focused, distorted images are obtained if data from anisotropic media are migrated using isotropic extrapolation; well focused, clear images are obtained using anisotropic extrapolation. A priori estimation of the 3-D anisotropic velocity distribution is required. Zones of anomalous, directionally dependent reflectivity associated with anisotropic fracture zones are detectable in both the 3-D common-source data and the corresponding ...
1993-01-01
Recent Darrieus vertical axis wind turbine aerodynamical experiments at Sandia National Laboratories
Experiments contributing to the understanding of the aerodynamics of airfoils operating in the vertical axis wind turbine (VAWT) environment are described. These experiments are ultimately intended to reduce VAWT cost of energy and increase system reliability. They include chordwise pressure surveys, circumferential blade acceleration surveys, effects of blade camber, pitch and offset, blade blowing, and use of sections designed specifically for VAWT application.
1981-05-01
A novel CFD/structural analysis of a cross parachute
Energy Technology Data Exchange (ETDEWEB)
A novel CFD/structural analysis was performed to predict functionality of a cross parachute under loadings near the structural limits of the parachute. The determination of parachute functionality was based on the computed structural integrity of the canopy and suspension lines. In addition to the standard aerodynamic pressure loading on the canopy, the structural analysis considered the reduction in fabric strength due to the computed aerodynamic heating. The intent was to illustrate the feasibility of such an analysis with the commercially available software PATRAN.
1993-12-31
Energy Technology Data Exchange (ETDEWEB)
In the field of reactor and fuel cycle physics, particle transport plays and important role. Neutronic design, operation and evaluation calculations of nuclear system make use of large and powerful computer codes. However, current limitations in terms of computer resources make it necessary to introduce simplifications and approximations in order to keep calculation time and cost within reasonable limits. Two different types of methods are available in these codes. The first one is the deterministic method, which is applicable in most practical cases but requires approximations. The other method is the Monte Carlo method, which does not make these approximations but which generally requires exceedingly long running times. The main motivation of this work is to investigate the possibility of a combined use of the two methods in such a way as to retain their advantages while avoiding ...
2000-05-19
International Nuclear Information System (INIS)
Purpose. To validate a protocol for creating virtual models to be used in the construction of solid prototypes useful for the planning-simulation of maxillo-facial surgery, in particular for very complex anatomical and pathologic problems. To optimize communications between the radiology, engineering and surgical laboratories. Methods and materials. We studied 16 patients with different clinical problems of the maxillo-facial district. Exams were performed with multidetector computed tomography (MDCT) and single slice computed tomography (SDCT) with axial scans and collimation of 0.5-2 mm, and reconstruction interval of 1 mm. Subsequently we performed 2D multiplanar reconstructions and 3D volume-rendering reconstructions. We exported the DICOM images to the engineering laboratory, to recognize and isolate the bony structures by software. With these data the solid prototypes were generated using stereolitography. To date, ...
2005-11-01
TIME EVOLUTION OF CORONAL MAGNETIC HELICITY IN THE FLARING ACTIVE REGION NOAA 10930
International Nuclear Information System (INIS)
To study the three-dimensional (3D) magnetic field topology and its long-term evolution associated with the X3.4 flare of 2006 December 13, we investigate the coronal relative magnetic helicity in the flaring active region (AR) NOAA 10930 during the time period of December 8-14. The coronal helicity is calculated based on the 3D nonlinear force-free magnetic fields reconstructed by the weighted optimization method of Wiegelmann, and is compared with the amount of helicity injected through the photospheric surface of the AR. The helicity injection is determined from the magnetic helicity flux density proposed by Pariat et al. using Solar and Heliospheric Observatory/Michelson Doppler Imager magnetograms. The major findings of this study are the following. (1) The time profile of the coronal helicity shows a good correlation with that of the helicity accumulation by injection through ...
2010-09-10
Energy Technology Data Exchange (ETDEWEB)
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 ...
1998-07-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2002-07-01
Diagnosis of occipital condyle fractures; Diagnostik von Frakturen der Okzipitalkondylen
Energy Technology Data Exchange (ETDEWEB)
Following the conventional X-ray diagnosis of the skull and upper cervical spine, CT proved to be the primary diagnostic method after a skull and brain injury: For all 4 cases we succeeded in detecting the occipital condyle fracture and in determing its size and location by reconstructions (coronal, sagittal, 3-D). In the case of complex occompanying injuries like soft tissue hematomas (cerebral, in the spinal cord, and the soft tissue of the neck) or for the detection of brain stem contusion, MRT had significant advantages. MRT can offer a higher image quality in soft tissue, especially in the spinal cord and the brain. (orig.) [Deutsch] Im Anschluss an die konventionelle Roentgendiagnostik des Schaedels und der Halswirbelsaeule, erwies sich die Computertomographie als primaer einzusetzendes diagnostisches Verfahren, nach erlittenem Schaedel-Hirn-Trauma. In allen Faellen gelang der exakte Frakturnachweis an den ...
1995-01-01
International Nuclear Information System (INIS)
The energy bands and the nature of the conduction electrons have been studied for two intermetallic compounds of dysprosium, i.e, DyZn and DyRh, following the self-consistent augmented-plane-wave (APW) method. The convergence of energy was found to be rapid for DyZn because the shell of 3d"1"0 electrons for Zn lies below the conduction band. The Fermi energies (E/sub F/) have been calculated to be 0.421 and 0.477 Ry for DyZn and DyRh, respectively. The densities and the numbers of conduction electrons inside and outside the APW spheres in each of these compounds are calculated, and it is shown that the character of conduction electrons inside the APW sphere of Dy is predominantly of d type. In order to see the accuracy of these results, self-consistent calculations were done for DyZn for different choices of the exchange potentials, and the calculated number of conduction electrons did not change significantly. The ...
International Nuclear Information System (INIS)
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. ...
1988-09-12
Energy Technology Data Exchange (ETDEWEB)
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 ...
1993-06-11
Analysis of the placement of multiple metallic stents in the treatment of hilar cholangiocarcinoma
International Nuclear Information System (INIS)
Objective: To evaluate the clinical efficacy of multiple stents placement in the management of hilar cholangiocarcinoma, especially in the complex cases of which the hepatic ducts are invaded. Methods: Forty-five consecutive patients with hilar cholangiocarcinoma were treated with percutaneous transhepatic placement of two or three self-expandable metallic endoprostheses. The cause of hilar obstructions in these patients were all cholangiocarcinoma, including Bismuth classification type II (n 12), IIIa (n 17), IIIb (n 10), and IV (n 6). Two or 3 stents were placed in the configuration of T, Y or X over the strictures. Results: Stent placement with 2 or 3 endoprostheses was successful in all patients. All patients showed significant decrease in serum bilirubin level. The mortality rate within 30 days of stent placement was 2.2% (1/45). The mean survival and stent patency times were 215.3 d (26- 516 d) and 181.5 d (26-473 d), ...
2007-11-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2008-02-15
Aerodynamic and structural design of a solar-powered micro unmanned air vehicle
Energy Technology Data Exchange (ETDEWEB)
The field of micro unmanned aerial vehicles ({mu}UAVs) has advanced rapidly in recent years. This paper studies the design and construction of a small solar-powered aircraft near the size range of current {theta}UAVs. A number of aspects of their design were analysed, including structural, aerodynamic and propulsion system considerations. The effect of small-scale, low Reynolds number aerodynamics was investigated, and the performance of a range of candidate aerofoils was compared. The integration of a solar power source into the aircraft system was considered a key design issue. Consequently, a number of aircraft configurations were examined, with the intention of optimising the application of solar power in a miniature aircraft. Investigation of improved system components suggests that a practical solar-powered aircraft in the size range below 500 mm maximum linear dimension should be viable given modest technological improvements. (Author)
2000-04-01
Study of spatial resolution in three-dimensional rotational angiography
International Nuclear Information System (INIS)
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 ...
2006-03-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2009-10-15
Collaboration work for nuclear power building using 3D CAD information
Energy Technology Data Exchange (ETDEWEB)
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.
2006-02-15
Collaboration work for nuclear power building using 3D CAD information
International Nuclear Information System (INIS)
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.
2006-02-01
Valence electronic structure of Ni in Ni-Si alloys from relative K X-ray intensity studies
Energy Technology Data Exchange (ETDEWEB)
The K{beta}-to-K{alpha} X-ray intensity ratio of Ni in Ni{sub 3}Si, Ni{sub 2}Si and NiSi has been determined by energy dispersive X-ray fluorescence technique. It is found that the intensity ratio of Ni decreases from pure Ni to Ni{sub 2}Si and then increases from Ni{sub 2}Si to NiSi, in good agreement with the electronic structure calculations cited in the literature. We have also performed band structure calculations for pure Ni in various atomic configurations by means of linear muffin-tin orbital method and used this data with the normalized theoretical intensity ratios cited in the literature to estimate the 3d-occupation numbers of Ni in Ni-Si alloys. It is emphasized that investigation of alloying effect in terms of X-ray intensity ratios should be carried out for the stoichiometric alloys in order to make reliable and quantitative comparisons between theory and experiment in transition metal alloys.
2007-02-15
Ultrashort echo time MRI of cortical bone at 7 tesla field strength: A feasibility study
British Library Electronic Table of Contents (United Kingdom)
AbstractPurpose: To implement and examine the feasibility of a three-dimensional (3D) ultrashort TE (UTE) sequence on a 7 Tesla (T) clinical MR scanner in comparison with 3T MRI at high isotropic resolution. Materials and Methods: Using an in-house built saddle coil at both field strengths we have imaged mid-diaphysial sections of five fresh cadaveric specimens of the distal tibia. An additional in vivo scan was performed at 7 Tesla using a quadrature knee coil. Results: Using the same type of saddle coil at both field strengths, a significant increase in SNR at 7T compared with 3T (factor 1.7) was found. Significantly shorter T2* values were found at the higher field strength (T2* = 552.2 126 s at 7T versus T2* = 1163 391 s at 3T). Conclusion: UHF MRI at 7T has great potential for imaging...
2011-01-01
Tokamak and laboratory modeling of hydrocarbon film deposition on metallic mirrors
International Nuclear Information System (INIS)
In this work, amorphous hydrocarbon (a-C:H) film deposition on metallic mirrors was studied during working shots in tokamak T-10 and at exposure in Ar/CHD3/D2 dc magnetron discharge in a special laboratory high vacuum setup. Analysis of film composition (including hydrogen content) was carried out using nuclear physical methods. Thickness and optical parameters (refractive and extinction coefficients) of the films were estimated by ellipsometry. Laboratory films can be characterized as soft a-C:H films in comparison with hard tokamak films (? = 1.2 and 1.8 g/cm3, respectively). For the first one, a linear dependence of deposition rate on mirror temperature was observed in a wide temperature range. The addition of methane into initial Ar/D2 magnetron gas mixture leads to an increase of deposition rate. The data obtained should be taken into account to prevent hydrocarbon film formation on the surface of first mirrors in ...
2009-06-15
The safety issues of medical robotics
International Nuclear Information System (INIS)
In this paper, we put forward a systematic method to analyze, control and evaluate the safety issues of medical robotics. We created a safety model that consists of three axes to analyze safety factors. Software and hardware are the two material axes. The third axis is the policy that controls all phases of design, production, testing and application of the robot system. The policy was defined as hazard identification and safety insurance control (HISIC) that includes seven principles: definitions and requirements, hazard identification, safety insurance control, safety critical limits, monitoring and control, verification and validation, system log and documentation. HISIC was implemented in the development of a robot for urological applications that was known as URObot. The URObot is a universal robot with different modules adaptable for 3D ultrasound image-guided interstitial laser coagulation, radiation seed ...
2001-08-01
International Nuclear Information System (INIS)
In this study, free electron laser (FEL) with selective wavelength was used to induce structure changes of biomolecules, which were characterized by FTIR spectroscopy. For understanding of the interactions between FEL and biomolecules as well as biological tissues, the biomolecules investigated are ATP, ADP, AMP, t-RNA, D-ribose and the complex of SmCl_3-D-ribose. Their FTIR spectra before and after irradiation of FEL show molecular structure variations of the samples after irradiation of FEL, especially the rearrangement of their hydrogen bond networks. Along with the various irradiation wavelengths, irradiation time and molecular structures, the changes after irradiation are different for these molecules. In the FTIR spectra after irradiation, the phenomenon that the bands split into several peaks indicates the existence of several structures, conformations and configurations, which may be prompted by multiple photons process induced by FEL. ...
2007-05-01
Iterative Dense Correspondence Correction Through Bundle Adjustment Feedback-Based Error Detection
Energy Technology Data Exchange (ETDEWEB)
A novel method to detect and correct inaccuracies in a set of unconstrained dense correspondences between two images is presented. Starting with a robust, general-purpose dense correspondence algorithm, an initial pose estimate and dense 3D scene reconstruction are obtained and bundle-adjusted. Reprojection errors are then computed for each correspondence pair, which is used as a metric to distinguish high and low-error correspondences. An affine neighborhood-based coarse-to-fine iterative search algorithm is then applied only on the high-error correspondences to correct their positions. Such an error detection and correction mechanism is novel for unconstrained dense correspondences, for example not obtained through epipolar geometry-based guided matching. Results indicate that correspondences in regions with issues such as occlusions, repetitive patterns and moving objects can be identified and corrected, such that a more ...
2009-11-23
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. Cores from five Red River wells in the Bowman-Harding study area have been examined and described in detail; contracts have been awarded for a 3-D survey in Bowman Co., ND and a 2D, multi-component survey in Richland Co.; extended-time pressure buildup data have been analyzed from two wells which are candidates for jetting-lance completion workovers; a 20-day injectivity test has been completed in the Red River (upper member); a jetting-lance completion program has commenced with one job completed and three more scheduled during April; and reservoir data from three key Red River fields in the ...
1995-05-01
Direct chemical information from special radiotracers as well as from outer X-ray excitation
Energy Technology Data Exchange (ETDEWEB)
Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub ..cap alpha..//K/sub ..beta../ X-ray intensity ratio was found to ...
1983-09-01
Direct chemical information from special radiotracers as well as from outer X-ray excitation
International Nuclear Information System (INIS)
Radionuclides exhibiting in decaying a strong interaction between nucleus and electron shell (especially electron capture and internal conversion) are, in principle, sensitive to their chemical surroundings. Consequently, they can be used to yield chemical information after an appropriate labelling procedure. The information can be extracted from the decay rate variation as well as from their X-ray emission as a response to an inner-shell vacancy creation during nuclear deexcitation. As an example of the former method the relationship between the decay rate of /sup 99m/Tc and the chemical structures of pertechnetate and bis(meso-dimercapto-succinate)oxotechnetate(V) is considered. Lower expectations with respect to measuring techniques are associated with the observation of X-ray emission. For a number of elements (especially 3d transition elements) the K/sub #alpha#//K/sub #betta#/ X-ray intensity ratio was found to be an ...
1982-10-01
Cross sections for electron scattering by atomic potassium
International Nuclear Information System (INIS)
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 available ...
An approximated secondary CPC, built of planar facets, adjustable for two solar central receivers
Energy Technology Data Exchange (ETDEWEB)
Decreasing the aperture of a solar central receiver operating at high temperatures contributes significantly to the increase of the efficiency of energy absorption. However, decreasing the aperture also decreases the collection efficiency. A simple solution is using a 3D-CPC as secondary element for augmenting the energy collection, while the aperture can remain relatively small. Nevertheless, the receiver aperture as well as the secondary concentrator are usually rather large. For practical considerations an approximate solution may be chosen at times, designing the concentrator by a series of truncated cones. However, in particular cases, the solution of truncated cones remains expensive and unpractical and therefore the authors designed a CPC approximated by a series of trapezoidal planar facets. Under technical restrictions, there is an optimum for choosing the partition of the pure-CPC in truncated pyramids and the paper presents the ...
1994-12-31
... and/or hearing mechanisms. Seven papers dealt with 3D audio technology and/or its application. Eight papers presented ...
2005-04-01
Tackling the Steroid Issue: Squeezing Out the Juice
... Neglect (12) Co-Occurring Disorders (75) Conduct Disorders (3) D Dementia (2) Depression (51) Driving While Intoxicated (17) ...
English version - Guidelines for Viability Assessment - CAP Workbook version 3_d
Guidelines for the viability primer component of the version 3 workbook. The Viability page in the current version of the Excel spreadsheet for conservation ... ...
British Library Electronic Table of Contents (United Kingdom)
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...
2009-01-01
Advanced 3D Visualization Web Technology and its Use in ...
... applications related to military and intelligence area ... the technology solved yet, but the open issue still ... fields, columns; ie data source, document type ...
2002-04-01
AIAA 20033400 CFD Sensitivity Analysis ... - FUN3D Manual - NASA
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. ...
3-D brain CT image display for planning of craniofacial operation
International Nuclear Information System (INIS)
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.).
International Nuclear Information System (INIS)
A fast and accurate segmentation of organs at risk, such as the healthy colon, would be of benefit for planning of radiotherapy, in particular in an adaptive scenario. For the treatment of pelvic tumours, a great challenge is the segmentation of the most adjacent and sensitive parts of the gastrointestinal tract, the sigmoid and descending colon. We propose a semi-automated method to segment these bowel parts using the fast marching (FM) method. Standard 3D computed tomography (CT) image data obtained from routine radiotherapy planning were used. Our pre-processing steps distinguish the intestine, muscles and air from connective tissue. The core part of our method separates the sigmoid and descending colon from the muscles and other segments of the intestine. This is done by utilizing the ability of the FM method to compute a specified minimal energy functional ...
2010-09-21
Numerical methods for multiphysics, multiphase, and multicomponent models for fuel cells
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 ...
2008-01-01
Depth migration in transversely isotropic media with explicit operators
Energy Technology Data Exchange (ETDEWEB)
The author presents and analyzes three approaches to calculating explicit two-dimensional (2D) depth-extrapolation filters for all propagation modes (P, SV, and SH) in transversely isotropic media with vertical and tilted axis of symmetry. These extrapolation filters are used to do 2D poststack depth migration, and also, just as for isotropic media, these 2D filters are used in the McClellan transformation to do poststack 3D depth migration. Furthermore, the same explicit filters can also be used to do depth-extrapolation of prestack data. The explicit filters are derived by generalizations of three different approaches: the modified Taylor series, least-squares, and minimax methods initially developed for isotropic media. The examples here show that the least-squares and minimax methods produce filters with accurate extrapolation (measured in the ability to position steep reflectors) for a wider range ...
1994-12-01
Short-amplitude high-frequency wing strokes determine the aerodynamics of honeybee flight
UK PubMed Central (United Kingdom)
Most insects are thought to fly by creating a leading-edge vortex that remains attached to the wing as it translates through a stroke. In the species examined so far, stroke amplitude is large, and...Full Text Available
2005-12-13
Real-Time Aerodynamic ... - NASA Technical Report Server (NTRS)
... least squares cost function is computed from1. (. ) ( ). 1. X X. X z. . . ?. Re. Re. -. . . = . . . . (25). The estimated parameter covariance matrix is1 ...
Limitations of Remotely Sensed Aerosol as a Spatial Proxy for Fine Particulate Matter
UK PubMed Central (United Kingdom)
BackgroundRecent research highlights the promise of remotely sensed aerosol optical depth (AOD) as a proxy for ground-level particulate matter with aerodynamic diameter ≤...Full Text Available
2009-06-01
... TYPE F PFW NO IM M MW AERODYNAMICS TECHNICAL 01030 MEMORANDUM 397 t. CTO mSM F PDWW .U U. awma.ef MizE .
2011-05-05
Energy Technology Data Exchange (ETDEWEB)
The aerodynamic forces and wake structure of the non-rotating downstream circular cylinder, of which the uniform free stream flow is interfered with another spinning upstream cylinder having the same diameter that is located upstream in a line have been investigated experimentally. When the spin rate of the downstream cylinder defined as the ratio of tangential surface velocity of the spinning cylinder to the free stream velocity increases gradually from zero to 1.4, the change of surface pressure distribution, aerodynamic forces of the non-rotating downstream cylinder were measured in case of several distance ratios of 1.5, 3.0, and 4.5 defined as the ratio of distance between the centers of two cylinders to the diameter. The wake flow patterns behind the cylinder were also investigated in each case. From the present experiments, it has been found that the spin rate significantly influences the aerodynamic forces and ...
1998-03-01
Aerodynamic Force Characteristics of Bluff Bodies.
The lift and drag characteristics of a wide range of bluff body shapes were studied using data from sources including wind tunnel testing and flow visualization. For a given orientation of any body, it is found that its drag is strongly influenced by its ...
1985-01-01
Pulsating stochastic flows accompanying microwave filament/supersonic shock layer interaction
British Library Electronic Table of Contents (United Kingdom)
The details of pulsating stochastic flows accompanying the interaction of a microwave filament (regarded as a heated rarefied channel) and an aerodynamic body in supersonic flow are examined numerically using the Euler equations. Symmetrical and asymmetrical filament locations relative to the aerodynamic body are considered. The flowfields are characterized by large scale pulsations and small scale stochastic fluctuations. The mechanisms of the formation of these flow structures are discussed. Two qualitatively different kinds of flowfields are observed depending on the magnitude of the filament radius, with domination of the pulsations of flow parameters or stochastic phenomena. Flow instabilities inherent to the problems under interest are described. The problems are considered in both p...
2011-01-01
Transplantation of engineered bone tissue using a rotary three-dimensional culture system.
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 ...
2007-03-11
Topological excitations and second order transitions in 3D O(N) models
Energy Technology Data Exchange (ETDEWEB)
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.
2001-01-01
UK PubMed Central (United Kingdom)
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
1994-07-11
Pd-Na/F double exploding foil photoionization experiment
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.
1990-03-01
On the Metastable Level in Ni-like Ions
Energy Technology Data Exchange (ETDEWEB)
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.
2004-09-14
International Nuclear Information System (INIS)
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)
2000-02-01
Chemical sensitivity of the Ksub(. beta. )/Ksub(. cap alpha. ) x-ray intensity ratio for 3d elements
Energy Technology Data Exchange (ETDEWEB)
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.
1982-12-28
Chemical sensitivity of the Ksub(#nu#)/Ksub(#alpha#) x-ray intensity ratio for 3d elements
International Nuclear Information System (INIS)
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).
1982-12-01
Accurate positioning for head and neck cancer patients using 2D and 3D image guidance
UK PubMed Central (United Kingdom)
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
Multi-modality imaging of uveal melanomas using combined PET/CT, high-resolution PET and MR imaging
Energy Technology Data Exchange (ETDEWEB)
We investigated the efficacy of combined FDG-PET/CT imaging for the diagnosis of small-size uveal melanomas and the feasibility of combining separate, high-resolution (HR) FDG-PET with MRI for its improved localization and detection. Patients, methods: 3 patients with small-size uveal melanomas (0.2-1.5 ml) were imaged on a combined whole-body PET/CT, a HR brain-PET, and a 1.5 T MRI. Static, contrast-enhanced FDG-PET/CT imaging was performed of head and torso with CT contrast enhancement. HR PET imaging was performed in dynamic mode 0-180 min post-injection of FDG. MRI imaging was performed using a high-resolution small-loop-coil placed over the eye in question with T2-3D-TSE and T1-3D-SE with 18 ml Gd-contrast. Patients had their eyes shaded during the scans. Lesion visibility on high-resolution FDGPET images was graded for confidence: 1: none, 2: suggestive, 3: clear. Mean tumour ...
2008-07-01
A Scheme of 3-D Breakdown-whip Analysis Methodology for High Energy Piping
Energy Technology Data Exchange (ETDEWEB)
High energy piping systems are operated with either or both conditions of maximum operating temperature exceeding 200 .deg. F(93.3 .deg. C) or maximum operating pressure exceeding 275 psig(19.3kg/cm{sup 2}) during normal operating conditions in nuclear power plants. A high energy pipe failure is postulated in branches or piping that runs larger than one inch nominal diameter. The resultant consequences of these postulated pipe breaks must be analyzed for the effect on maintenance of plant safe shutdown capability, containment integrity. And the analyzed results must be applied to the system design so that a pipe failure can not damage essential systems to an extent of impairing design function nor affect necessary component operability. The considerable effects of pipe break are as follows; dynamic effects such as pipe whip, jet impingement and environmental impact by release of system contents. Two types of forces are occurred by the pipe whip. The one is pipe whip impact force that ...
2007-10-15
The denoising of Monte Carlo dose distributions using convolution superposition calculations
International Nuclear Information System (INIS)
Monte Carlo (MC) dose calculations can be accurate but are also computationally intensive. In contrast, convolution superposition (CS) offers faster and smoother results but by making approximations. We investigated MC denoising techniques, which use available convolution superposition results and new noise filtering methods to guide and accelerate MC calculations. Two main approaches were developed to combine CS information with MC denoising. In the first approach, the denoising result is iteratively updated by adding the denoised residual difference between the result and the MC image. Multi-scale methods were used (wavelets or contourlets) for denoising the residual. The iterations are initialized by the CS data. In the second approach, we used a frequency splitting technique by quadrature filtering to combine low frequency components derived from MC simulations with high frequency components derived from CS components. The rationale is to ...
2007-09-07
International Nuclear Information System (INIS)
Numerous mercury intrusion porosimetry (MIP) studies have been carried out to investigate the pore structure in cement-based materials. However, the standard MIP often results in an underestimation of large pores and an overestimation of small pores because of its intrinsic limitation. In this paper, an innovative MIP method is developed in order to provide a more accurate estimation of pore size distribution. The new MIP measurements are conducted following a unique mercury intrusion procedure, in which the applied pressure is increased from the minimum to the maximum by repeating pressurization-depressurization cycles instead of a continuous pressurization followed by a continuous depressurization. Accordingly, this method is called pressurization-depressurization cycling MIP (PDC-MIP). By following the PDC-MIP testing sequence, the volumes of the throat pores and the corresponding ink-bottle pores can be determined at every pore size. These ...
2010-07-01
Near-surface 3D reflections seismic survey; Sanjigen senso hanshaho jishin tansa
Energy Technology Data Exchange (ETDEWEB)
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. ...
1997-05-27
International Nuclear Information System (INIS)
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 ...
2009-01-01
Energy Technology Data Exchange (ETDEWEB)
Exhaust fine and ultra fine particle numbers, particle sizes, mass, shape, structure and density were studied from Euro II - EEV emission level heavy-duty vehicles. For total particle emission factors city buses were run on dynamic conditions simulating city bus driving. The new heavy-duty chassis dynamometer of VTT was used. Vehicles were a comprehensive sample of current city bus fleet, the type approved emission level of which was Euro II - Euro III. Also cleaner engines of Euro IV to EEV targeted emission level were included: CRT, CNG, DPF. Particle emissions of these buses were extremely low; numbers 1/100 - 1/1000 and masses 1/10 - 1/100 of those of the predominating techniques. Morphological properties of fine particle populations that represent majority of particle size distribution (Da < 500 nm) are being analyzed by image processing (Matlab) from electron microscopical images (SEM, ESEM and TEM) as a function of particle size. Particles from different formation ...
2004-07-01
Energy Technology Data Exchange (ETDEWEB)
The overall goal of the DOE fine particulate program is to ensure that the best science and technology is available for any regulatory decision-making related to the health and environmental impacts of ambient fine particulate matter and regional haze. Interest primarily lies in the particulate fraction having aerodynamic diameters of 2.5 microns and less (PM2.5). Particulates of this size are the focus of the newly established National Ambient Air Quality Standards. As such, the Federal Energy Technology Center (FETC) is establishing a fine particulate sampling station at the Center's Pittsburgh site located in South Park Township, PA. This sampling station is one of a group of stations scattered throughout Pennsylvania, West Virginia, and Ohio that constitute the Upper Ohio River Valley Project. The station is equipped with a full complement of fine particulate and gaseous monitors including the following: (1) R and P Sequential FRM sampler, (2) Grimm ...
1999-07-01
Microclimatic models. Estimation of components of the energy balance over land surfaces
Energy Technology Data Exchange (ETDEWEB)
Climates at regional scale are strongly dependent on the interaction between atmosphere and its lower boundary, the oceans and the land surface mosaic. Land surfaces influence climate through their albedo, and the aerodynamic roughness, the processes of the biosphere and many soil hydrological properties; all these factors vary considerably geographically. Land surfaces receive a certain portion of the solar irradiance depending on the cloudiness, atmospheric transparency and surface albedo. Short-wave solar irradiance is the source of the heat energy exchange at the earth`s surface and also regulates many biological processes, e.g. photosynthesis. Methods for estimating solar irradiance, atmospheric transparency and surface albedo were reviewed during the course of this project. The solar energy at earth`s surface is consumed for heating the soil and the lower atmosphere. Where moisture is available, evaporation is one of the key components of ...
1996-12-31
Objectives: We have previously shown that chronic exposure to ambient fine particulate matter (less than 2.5 ?m in aerodynamic diameter, PM(2.5)) pollution in conjunction with high-fat diet induces insulin resistance through alterations in inflammatory pathways. In this study we evaluated the effects of PM(2.5) exposure over a substantive duration of a rodent's lifespan and focused on the impact of long-term exposure on adipose structure and function.Methods and Results: C57BL/6 mice were exposed to PM(2.5) or filtered air (FA) (6 hours/day, 5 days/week) for duration of 10 months in Columbus, OH. At the end of the exposure, PM(2.5)-exposed mice demonstrated insulin resistance (IR) and a decrease in glucose tolerance compared with the FA-exposed group. Although there were no significant differences in circulating cytokines between PM(2.5)- and FA-exposed groups, circulating adiponectin and leptin were significantly decreased in PM(2.5)-exposed ...
2011-08-27
Mg-doped LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} spinel for cathode materials
Energy Technology Data Exchange (ETDEWEB)
Lithium-ion batteries are becoming more and more important not only for portable electronic devices, but also in prevision of high power electric vehicles. In such an optic, deep studies regarding all the components of a secondary battery are in development. In this study, high voltage cathode materials have been selected. Crystals with spinel structure have a 3D vacancy pathway suitable for Li-ions transport. The material under study was LiNi{sub 0.5}Mn{sub 1.5}O{sub 4} doped with magnesium replacing the nickel. Various samples were synthesized via three different routes: a solid-state method, a modified sol-gel method and a xerogel method. The structure and morphology of the powders were analyzed with HRTEM and XRD. Electrochemical tests were also performed. A wide range of particle sizes (from micro to nanosize) was the result of the different synthesis routes. Unfortunately pure ...
2007-12-06
International Nuclear Information System (INIS)
First-principles self-consistent band-structure calculations of potassium titanyl arsenate, KTiOAsO_4 (KTA), have been made using the full potential linearized augmented plane wave (FP-LAPW) method. Total and partial densities of states of the constituent atoms of KTA have been derived. The results obtained show that the valence band of KTA is dominated by contributions of the O 2p-like states, while the Ti 3d-like states are the main contributors into the conduction band of the compound. Additionally, the FP-LAPW calculations have revealed that potassium atoms are highly ionized in KTA. In the present work, the X-ray emission spectroscopy (XES) and X-ray photoelectron spectroscopy (XPS) methods were also employed to investigate experimentally the electronic structure of potassium titanyl arsenate. For the mentioned compound, the XES K Ll, Ti L#alpha#, As K#beta#_2 and O K#alpha# bands reflecting the ...
2009-05-27
Energy Technology Data Exchange (ETDEWEB)
One of the Eddy Current Testing issues in aeronautics is the inspection of fastened structures to detect flaws nearby rivets which can grow because of mechanical stress. EADS and the CEA LIST have started a collaborative work with the support of the Ile-de-France Region to develop a simulation tool of EC fastened structures testing, integrated to the CIVA platform, aimed at conceiving testing methods, optimizing and qualifying it. The volume integral method using the Green dyadics formalism has been chosen in order to get a fast resolution of Maxwell equations. A first milestone was to build a simulation model of multilayer structures testing, thanks to the use of the multilayer Green dyads. Because of the rivet volume, 60 times bigger than the one of a typical flaw, a large number of discretization cells are needed. Therefore an iterative method has been developed in order to numerically solve large calculation zones. ...
2007-12-15
International Nuclear Information System (INIS)
Current methods to calculate dose distributions with organ motion can be broadly classified as 'dose convolution' and 'fluence convolution' methods. In the former, a static dose distribution is convolved with the probability distribution function (PDF) that characterizes the motion. However, artifacts are produced near the surface and around inhomogeneities because the method assumes shift invariance. Fluence convolution avoids these artifacts by convolving the PDF with the incident fluence instead of the patient dose. In this paper we present an alternative method that improves the accuracy, generality as well as the speed of dose calculation with organ motion. The algorithm starts by sampling an isocenter point from a parametrically defined space curve corresponding to the patient-specific motion trajectory. Then a photon is sampled in the linac head and propagated through the three-dimensional ...
2005-04-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1994-01-01
Energy Technology Data Exchange (ETDEWEB)
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 water excitation. Results are ...
2004-11-01
Energy Technology Data Exchange (ETDEWEB)
Purpose: The purpose of this study was to observe the process of fixation in liver specimens non-invasively by means of magnetic resonance. The fixation process of several formaldehyde-containing solutions was monitored with MRI and MRS at two different temperatures. Materials and Methods: Liver specimens were conserved in aqueous fixative solutions containing formaldehyde concentrations of 0.7, 1.8, 4 and 7.2% and at different temperatures of 5 C and 20 C. MRI was performed with T1-, T2- and PD-weighted TSE sequences, a 2D FLASH-sequence with and without magnetization transfer, and a FISP 3D-sequence on a clinical 1.5 Tesla MR whole-body unit, and MRS with {sup 1}H-spectroscopic methods (STEAM-sequence) on a 3 Tesla MR whole-body unit. Results: The diffusion of formaldehyde into the tissue was best identified on PD- and T1-weighted images as a band under the liver surface with increasing thickness, ...
2004-04-01
The role of 3D Helical CT in the reconstructive treatment of maxillofacial cancers
International Nuclear Information System (INIS)
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 ...
2000-12-01
Surface-loss power calculations for the LANSCE DTL
Energy Technology Data Exchange (ETDEWEB)
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.
2008-01-01
3D modelling as a support to thermal-hydraulic safety analyses with standard codes
Energy Technology Data Exchange (ETDEWEB)
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)
1999-07-01
3D modelling as a support to thermal-hydraulic safety analyses with standard codes
International Nuclear Information System (INIS)
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)
1999-04-19
3D model for a secondary facultative pond
British Library Electronic Table of Contents (United Kingdom)
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...
2011-01-01
International Nuclear Information System (INIS)
Dose calculations for radiation arc therapy are traditionally performed by approximating continuous delivery arcs with multiple static beams. For 3D conformal arc treatments, the shape and weight variation per degree is usually small enough to allow arcs to be approximated by static beams separated by 5"0-10"0. But with intensity-modulated arc therapy (IMAT), the variation in shape and dose per degree can be large enough to require a finer angular spacing. With the increase in the number of beams, a deterministic dose calculation method, such as collapsed-cone convolution/superposition, will require proportionally longer computational times, which may not be practical clinically. We propose to use a homegrown Monte Carlo kernel-superposition technique (MCKS) to compute doses for rotational delivery. The IMAT plans were generated with 36 static beams, which were subsequently interpolated into finer angular intervals for dose ...
2008-09-07
International Nuclear Information System (INIS)
The aim of this work was to develop several strategies and software-packages for the evaluation of in-vivo-data of the human brain, which were acquired with high-resolution 1H-MRSI at 1.5 and 3 T. Several studies involving phantoms, volunteers and patients were performed. Quality assurance studies were conducted in order to evaluate the reproducibility of the applied MR-techniques at both field strengths. A qualitative comparison-study between MRSI-data from a 1.5 T clinical MR-scanner and a 3 T research MR-scanner showed the advantages of the more advanced MRSI sequences and higher field strength (3 T). A study involving patients with primary brain tumours (gliomas) was performed in cooperation with the Department of Neurosurgery (University of Erlangen-Nuremberg). The methods developed in the course of this study, such as the integration of MRS-data into a stereotactic-system, the segmentation of metabolic maps and the correlation with histopathological findings ...
Experience and recent developments in nuclear forensics at the Institute of Isotopes
International Nuclear Information System (INIS)
Full text: Based on experience with nuclear material confiscated in Hungary from illicit trafficking activities in the nineties it has been decided that traditional gamma-spectrometry should be complemented by destructive analytical techniques. The 17/1996 (I. 31.) Korm. Governmental Decree delegated the identification, categorization and characterization tasks to the Institute of Isotopes, Budapest. Routine gamma-spectrometric methods have been further developed aiming at the i) age (production date) determination of seized samples and complete (nondismountable) uranium-bearing items (such as fresh fuel bundles and fission chambers) by HRGS technique, ii) improvement of measurement accuracy and reliability. Starting in 2005 mass spectrometry (ICP-SFMS) and scanning electron microscopy have been implemented to characterize nuclear samples in more detail and to analyze environmental samples both for isotopic and elemental composition focusing on long-lived ...
Energy Technology Data Exchange (ETDEWEB)
A necessary condition for crevice corrosion is that a crevice former create a sufficiently tight, restricted geometry on the metal surface to support the development of critical crevice chemistry. Crevice corrosion is affected by the crevice geometry (tightness) and the properties of the crevice former. The objective of this study is to determine the effect of the crevice former material on the evolution of localized corrosion-damage. A standard crevice corrosion test method is modified by (a) the use of ceramic, metal or polymer materials as the crevice former and (b) the variation of size and shape of the crevice. This study focuses on the post initiation stage of crevice corrosion and addresses factors that may limit the initiation of localized corrosion and also slow or stop the continued propagation of corrosion. Controlled crevice corrosion tests are performed under aggressive, accelerated conditions on Ni-Cr-Mo alloy C-22 and other alloys for comparison. ...
2006-05-08
Application of distributed and parallel technology in nuclear power plant engineering simulator
International Nuclear Information System (INIS)
A nuclear power plant engineering (NPP) simulator may include many system functions such as thermal-hydraulic calculation, 3D reactor neutron kinetics model, control and protection system, display and operational human-machine interface, intelligent alarm system, etc. If all those functions are simulated using a single code, the size of the program will cause structural or managerial problems, and the hardware requirement could be tremendous. Thus, any local function errors or changes may affect the whole code, which will make development and maintenance extremely costly. So the nondistributed code is not considered to be flexible and feasible. Currently, distributed and parallel technologies have been applied to develop NPPs engineering simulator for safety analysis, verification of advanced main control room display, operation and intelligent alarm design. The distributed simulation divides a huge task into several objects according to ...
Energy Technology Data Exchange (ETDEWEB)
Purpose. We have tested a procedure of focal injection of the contrast medium Lipiodol as a fiducial marker for image-guided boost of the tumor in bladder cancer radiotherapy (RT). In this study, we have evaluated the feasibility and the safety of the method as well as the inter- and intra-fraction shift of the bladder tumor. Materials and methods. Five patients with muscle invasive urinary bladder cancer were included in the study. Lipiodol was injected during flexible cystoscopy into the submucosa of the bladder wall at the periphery of the tumor or the post resection tumor-bed. Cone-beam CT (CBCT) scans were acquired daily throughout the course of RT. Results. Lipiodol demarcation of the bladder tumor was feasible and safe with only a minimum of side effects related to the procedure. The Lipiodol spots were visible on CT and CBCT scans for the duration of the RT course. More than half of all the treatment fractions required a geometric shift ...
2010-10-15
International Nuclear Information System (INIS)
There is an increasing interest in using novel methods to generate electrical energy using wind and solar energy sources. Unfortunately, such energy sources are intermittent, and, therefore, conventional sources must still be available to meet demand during critical periods. In addition, renewable energy technologies are still expensive in general, although extensive research programs are being conducted to overcome this disadvantage. Hence, reliability, economic assessment and environmental impacts are three objectives to be satisfied simultaneously when designing either an autonomous or a grid-connected hybrid power generation system. The installation of any of these two systems should, undoubtedly, be preceded by an assessment of the available resources at the candidate site. In addition, many other factors are to be studied, including economics of transmission lines, site constraints, distances etc. In this thesis, the subjective judgments of various experts, ...
Differential pressure measurement using a free-flying insect-like ornithopter with an MEMS sensor
International Nuclear Information System (INIS)
This paper presents direct measurements of the aerodynamic forces on the wing of a free-flying, insect-like ornithopter that was modeled on a hawk moth (Manduca sexta). A micro differential pressure sensor was fabricated with micro electro mechanical systems (MEMS) technology and attached to the wing of the ornithopter. The sensor chip was less than 0.1% of the wing area. The mass of the sensor chip was 2.0 mg, which was less than 1% of the wing mass. Thus, the sensor was both small and light in comparison with the wing, resulting in a measurement system that had a minimal impact on the aerodynamics of the wing. With this sensor, the 'pressure coefficient' of the ornithopter wing was measured during both steady airflow and actual free flight. The maximum pressure coefficient observed for steady airflow conditions was 1.4 at an angle of attack of 30"0. In flapping flight, the coefficient was around 2.0 for angles of attack that ranged from 25"0 ...
2010-09-01
Aerodynamic force measurement on a large-scale model in a short duration test facility
International Nuclear Information System (INIS)
A force measurement technique has been developed for large-scale aerodynamic models with a short test time. The technique is based on direct acceleration measurements, with miniature accelerometers mounted on a test model suspended by wires. Measuring acceleration at two different locations, the technique can eliminate oscillations from natural vibration of the model. The technique was used for drag force measurements on a 3 m long supersonic combustor model in the HIEST free-piston driven shock tunnel. A time resolution of 350 #mu#s is guaranteed during measurements, whose resolution is enough for ms order test time in HIEST. To evaluate measurement reliability and accuracy, measured values were compared with results from a three-dimensional Navier-Stokes numerical simulation. The difference between measured values and numerical simulation values was less than 5%. We conclude that this measurement technique is sufficiently reliable for measuring ...
2005-03-01
Energy Technology Data Exchange (ETDEWEB)
Objective: To determine the reproductibility of three-dimensional volume and thickness measurements of the knee joint cartilage with MRI in volunteers. Methods: The knees of 7 healthy individuals (ages 23 to 58 yrs.) were sagitally imaged with a resolution of 2x0.31x0.31 mm{sup 3}, using a fat-suppressed FLASH-3 D sequence. The knee was repositioned in between replicate acquisitions, 6 data sets being obtained in each case. After semiautomatic segmentation and three-dimensional reconstruction of the cartilage, the thickness was determined independent of the original section orientation. The coefficient of variation for repeated volume measurements and the deviations of the maximal cartilage thickness values were calculated subsequently. Results: The mean variation of the cartilage volumes of the replicate measurements was 1.4% ({+-}0.8%) in the patella, 1.7% ({+-}1.5%) in the femur, 3.0% ({+-}1.2%) in the medial tibial ...
1997-12-01
Energy Technology Data Exchange (ETDEWEB)
Forests on the Kola Peninsula in Northern Russia grow close to the northern tree line. They are subjected to both natural and anthropogenic stress factors. The Cu-Ni smelter 'Severonikel' (Lat. 67 deg 55'N; Long. 32 deg 57'E) near Monchegorsk is one of the two major sources of sulphur dioxide and heavy metals emissions on the Kola Peninsula. These emissions have caused significant deterioration of the surrounding vegetation. The thesis demonstrates how methods of Remote sensing, ground survey and mathematical modelling can be integrated for monitoring of the smelter's environmental impact on the surrounding vegetation: ground truth data are used for calibration of remote-sensed data, which further serve to verify mathematical models. The study aims were: * to estimate the scale of airborne sulphur pollution from the smelting industry on the Kola Peninsula and its effect on vegetation; * to assess spatial extent of the ...
1998-07-01
Wind tunnel and numerical study of a small vertical axis wind turbine
British Library Electronic Table of Contents (United Kingdom)
This paper presents a combined experimental and computational study into the aerodynamics and performance of a small scale vertical axis wind turbine (VAWT). Wind tunnel tests were carried out to ascertain overall performance of the turbine and two- and three-dimensional unsteady computational fluid dynamics (CFD) models were generated to help understand the aerodynamics of this performance. Wind tunnel performance results are presented for cases of different wind velocity, tip-speed ratio and solidity as well as rotor blade surface finish. It is shown experimentally that the surface roughness on the turbine rotor blades has a significant effect on performance. Below a critical wind speed (Reynolds number of 30,000) the performance of the turbine is degraded by a smooth rotor surface finis...
2010-01-01
Economic overview of vertical axis wind turbines
Sandia Laboratories, as part of its investigation of the Darrieus Vertical Axis Wind Turbine (VAWT), has been involved recently in an economic assessment of the concept. The class of VAWT's investigated use curved, fixed-pitch blades of constant section rigidly attached to a vertical rotating tower. Qualitatively, the main advantages of the VAWT over more conventional, propeller-type machines are the elimination of yaw controls, the placement of mechanical equipment at ground level, its amenability to simple, low-cost blade fabrication techniques, and aerodynamic stall characteristics which eliminate the need for active pitch control devices. The main disadvantages relative to modern propeller machines are a somewhat lower aerodynamic efficiency (about 10% lower), the limited ability of the rotor to self-start, and generally lower rotor operating RPM's, which leads to higher torque capacity requirements for the drive train.
1979-01-01
Economic overview of vertical axis wind turbines
The class of vertical axis wind turbines (VAWT) investigated use curved, fixed-pitch blades of constant section rigidly attached to a vertical rotating tower. Qualitatively, the main advantages of the VAWT over more conventional, propeller-type machines are the elimination of yaw controls, the placement of mechanical equipment at ground level, its amenability to simple, low-cost blade fabrication techniques, and aerodynamic stall characteristics which eliminate the need for active pitch control devices. The main disadvantages relative to modern propeller machines are a somewhat lower aerodynamic efficiency (about 10 percent lower), the limited ability of the rotor to self-start, and generally lower rotor operating RPM's, which leads to higher torque capacity requirements for the drive train.
1979-01-01
Cleaning of flue gases from cupola and electric steel melting furnaces in ''Ural'' rotoclones
Energy Technology Data Exchange (ETDEWEB)
A highly effective and economical apparatus was developed by the All-Union Scientific Research Institute for Energy and Nonferrous Metallurgy for cleaning waste gases from cupola and electric arc steel melting furnaces --- the ''Ural'' rotoclone, which has been successfully introduced in many enterprises. Research results are presented for the efficiency of operation of these aggregates on equipping them on cupola and electric furnaces. With a 2 kPa aerodynamic resistance of the rotoclone the flue gas of the cupola furnace is cleaned to the sanitary standard. Highly effective collection of sublimates and aerosols from the electric arc furnace takes place with a ''Ural'' rotoclone aerodynamic resistance
1981-01-01
Aerodynamic performance of thin wings at low Reynolds numbers
British Library Electronic Table of Contents (United Kingdom)
Purpose - This study seeks to explore the aerodynamic performance of wings with different shapes at low Reynolds numbers. Design/methodology/approach - The airfoils of these wings are made from aluminum plates, and the maximum cord length and wingspan are 15?cm. Wings A to D are plates with 6 percent Gottingen camber but different wing planforms. The forward-half sections of wings E and F are dragonfly-like, whereas the rear-half sections of wings E and F are flat and positively cambered, respectively. The aspect ratios of these wings are close to one, and the ratios of plate thickness to the maximum cord length are 1.3 percent. Experimental results indicate that the wings with Gottingen camber have a superior lift and lift-to-drag ratio, whereas the wings with dragonfly-like airfoils perf...
2007-01-01
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. ...
Statistical properties of nucleotide clusters in DNA sequences*
UK PubMed Central (United Kingdom)
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
2005-05-01
Robust principal axes determination for point-based shapes using least median of squares
UK PubMed Central (United Kingdom)
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
2009-04-01
Phase separation, pore structure, and properties of nanofibrous gelatin scaffolds
UK PubMed Central (United Kingdom)
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
2009-09-01
PRISM 3D: Global Warming Analysis
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...
Natural Gaits of the Non-Pathological Flat Foot and High-Arched Foot
UK PubMed Central (United Kingdom)
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
Modelling the masticatory biomechanics of a pig
UK PubMed Central (United Kingdom)
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
2002-11-01
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...
2011-08-17
Heat transfer augmentation in 3D internally finned and microfinned helical tube
Energy Technology Data Exchange (ETDEWEB)
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 ...
2005-05-01
Evaluation of tilted cone-beam CT orbits in the development of a dedicated hybrid mammotomograph
UK PubMed Central (United Kingdom)
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
2009-06-21
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 ...
2011-09-01
Characterization of 3D thermal neutron semiconductor detectors
International Nuclear Information System (INIS)
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 ...
2007-06-11
A self-oscillating biophysical computer model of the elongated vocal fold
UK PubMed Central (United Kingdom)
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
2008-01-01
International Nuclear Information System (INIS)
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 ...
UK PubMed Central (United Kingdom)
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
Three-dimensional cranio-facial computed tomography
International Nuclear Information System (INIS)
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.
1986-01-01
International Nuclear Information System (INIS)
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.).
1981-03-19
Energy Technology Data Exchange (ETDEWEB)
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.).
1994-09-01
PARALLEL 3-D SPACE CHARGE CALCULATIONS IN THE UNIFIED ACCELERATOR LIBRARY.
Energy Technology Data Exchange (ETDEWEB)
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.
2006-06-26
Development of a motion analysis system using acceleration sensors for tennis and its evaluations
British Library Electronic Table of Contents (United Kingdom)
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.
2011-01-01
Anticonvulsant properties of selected pyrrolo[2,3-d]pyrimidine-2,4-diones and intermediates.
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
1980-04-01
Clinical implementation of a convolution based algorithm for 3D treatment planning
International Nuclear Information System (INIS)
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 ...
The effects of a hydrogen pair in the electronic structure of the FCC iron containing a vacancy
Energy Technology Data Exchange (ETDEWEB)
Fuel cell vehicles have been identified as the personal transportation technology of the future because of their high efficiency and very low emissions. To achieve the goal of road-ready fuel cell vehicles, great strides must be made in the development of fuel cells, hydrogen production and hydrogen storage technologies, that includes metal-H interaction studies and safety considerations. The interaction between two-hydrogen atoms and a {gamma}-Fe structure containing a vacancy has been studied using a cluster model and a theoretical method. For the study of the sequential absorption, the hydrogen atoms were positioned in their energy minima configurations, near the vacancy. The interactions mainly involve Fe 4s-H 1s atomic orbitals. The contribution of Fe 4p and Fe 3d orbitals is much less important. The Fe-Fe bond is weakened as new Fe-H-H and H-H pairs were formed. The effect of H atoms is limited to its first Fe ...
2010-06-15
Energy Technology Data Exchange (ETDEWEB)
Borehole stability is affected to a significant extent by the 3D local and regional stress field. Preliminary information on underground stress fields is provided by the World Stress Map, which shows N-NW stress at a depth of about 5000 m for the Voelkersen field. Earlier data analyses showed various directions in the range of 310-360 degrees. This was assumed to be a methodical error. An extensive study was carried out to evaluate and interpret all relevant information provided by borehole tests, borehole logs, and drill core measurements. [German] Standsicherheit und Stabilitaet von Bohrungen werden ganz wesentliche beeinflusst durch das umgebende dreidimensionale lokale und regionale Spannungsfeld. Fuer die Planung zukuenftiger (horizontaler) Bohrungen und die Erzeugung kuenstlicher Risse (''fracs'') spielt das Spannungsfeld eine bedeutende Rolle. Erste Hinweise ueber das regionale ...
2003-07-01
Tensile strain limits of buried defects in pipeline girth welds
Energy Technology Data Exchange (ETDEWEB)
There are currently no accepted industry standards for the tensile strain limits of girth welds. This paper investigated the behavior of girth welds with buried defects subjected to high longitudinal strains caused by soil movement. A strain design methodology based on a crack driving method was used to examine the factors influencing stain limits along with a constraint-sensitive fracture mechanics approach. No strength undermatching was used in the welds, and the defect location had no influence on crack driving force. The weld joint was assumed to have uniform tensile properties. A 3D finite element (FE) model was used to simulate pipe behavior. Symmetric boundary conditions were imposed on the symmetry planes, and uniform remote axial displacement was applied as the primary loading. Automated data processing routines were developed to extract and analyze the data. The crack driving force was computed directly from a ...
2004-07-01
Structural stability of TiO_2 at high pressure in density-functional theory based calculations
International Nuclear Information System (INIS)
A new study on the pressure-induced phase transitions of TiO_2 has been performed using all-electron density-functional theory based computations with the projector augmented wave and the linearized augmented plane wave methods considering five experimentally observed structures. The static results yield a picture that is consistent with experiments, i.e., phase transitions with pressure are predicted as rutile #-># monoclinic baddeleyite (MI) #-># orthorhombic I (OI) #-># cotunnite (OII) on compression, and OII #-># OI #-># MI #-># columbite (TiO_2II) on decompression. The elasticities of these five polymorphs are compared. Except for the baddeleyite structure, which is considerably softer than the other polymorphs, all phases show a zero pressure bulk modulus in the range of 200-240 GPa, consistent with compression results and the single crystal elastic constant; on the basis of these results we can say that the cotunnite phase is not a ...
2010-07-28
It is well known that one of the main advantages of the high speed forming (HSF) processes is the improvement in the forming limits of the used materials.Using the Electromagnetic Forming (EMF) technology two materials have been tested with different mechanical and physical properties: the AA5754 aluminium and the AZ31B magnesium alloys.The EMF process principle can be described as follows: A significant amount of electrical energy is stored in a bank of capacitors which are suddenly discharged releasing all the stored energy. This electric discharge runs through a coil which generates an intense transient magnetic field. At the same time transient Eddy currents are induced in the electrically conductive part placed some millimetres far from the coil. Another intense magnetic field is generated due to those Eddy currents but on the opposite direction as the one generated by the coil. A big magnetic repulsion force is created between the part and the coil. This magnetic repulsion ...
2007-04-07
International Nuclear Information System (INIS)
It is well known that one of the main advantages of the high speed forming (HSF) processes is the improvement in the forming limits of the used materials.Using the Electromagnetic Forming (EMF) technology two materials have been tested with different mechanical and physical properties: the AA5754 aluminium and the AZ31B magnesium alloys.The EMF process principle can be described as follows: A significant amount of electrical energy is stored in a bank of capacitors which are suddenly discharged releasing all the stored energy. This electric discharge runs through a coil which generates an intense transient magnetic field. At the same time transient Eddy currents are induced in the electrically conductive part placed some millimetres far from the coil. Another intense magnetic field is generated due to those Eddy currents but on the opposite direction as the one generated by the coil. A big magnetic repulsion force is created between the part and the coil. This magnetic repulsion ...
2007-04-07
Multiphase treatment of ODTX in HMX spheres
Energy Technology Data Exchange (ETDEWEB)
What will be discussed in this report represents a framework upon which multiphase and other real physical effects can be built. Chemical models of increasing complexity are envisioned and this methodology can provide a tool for evaluating new ideas against known experimental data. The recent work to be reported here addresses the multiphase issue of temperature deviation between phases undergoing chemical and heat transport processes. Modeling of the LLNL ODTX experiment will be performed with FLUENT, a commercially available computational fluid dynamics (CFD) code. FLUENT solves flows in 2D or 3D in Cartesian, cylindrical, or general curvilinear coordinates, with steady-state of fully time-dependent analysis. Multiphase flows in which two or more continuous phases are present can be solved with arbitrary volumetric sources of heat, mass, momentum, and chemical species applied through user-defined FORTRAN subroutines. FLUENT models these of ...
1997-12-22
Materials design for semiconductor spintronics by ab initio electronic-structure calculation
International Nuclear Information System (INIS)
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 ...
2003-04-01
Magnetocaloric effect of Gd{sub 4}(Bi{sub x}Sb{sub 1{minus}x}){sub 3} alloy series
Energy Technology Data Exchange (ETDEWEB)
Alloys from the Gd{sub 4}(Bi{sub x}Sb{sub 1{minus}x}){sub 3} series were prepared by melting a stoichiometric amounts of pure metals in an induction furnace. The crystal structure is of the anti-Th{sub 3}P{sub 4} type (space group I{bar 4}3d) for all the compounds tested. The linear increase of the lattice parameters with Bi concentration is attributed to the larger atomic radius of Bi than that of Sb. Magnetic measurements show that the alloys order ferromagnetically from 266K to 330K, with the ordering temperature increasing with decreasing Bi concentration. The alloys are soft ferromagnets below their Curie temperatures, and follow the Curie-Weiss law above their ordering temperatures. The paramagnetic effective magnetic moments are low compared to the theoretical value for a free Gd{sup 3+}, while the ordered magnetic moments are close to the theoretical value for Gd. The alloys exhibit a moderate magnetocaloric effect (MCE) whose maxima ...
1999-12-01
Energy Technology Data Exchange (ETDEWEB)
The treatment of bony, osteochondral, and ligamentous injuries of the tibio-talar requires precise preoperative planning by radiological investigation. This is essential to a correct understanding of the underlying pathology and will allow a proper classification of the injury, which is the basis of treatment. Conventional radiography using anteroposterior and lateral X-rays with comparative views of the noninjured side and, if necessary, rotated spot views and tomography are of high value especially in osteochondral fractures of the talus. Intraoperative control images in both planes after osteosynthesis are mandatory. For evaluation of the postoperative course and severity of arthrosis formation, the classification system of Bargon has proved its worth. In addition, tomography of the tibio-talar joint in two planes is useful especially in tibial pilon fractures, some malleolar fractures, and peripheral talar fractures. In talar fracture dislocations with concomitant compartment ...
1991-12-01
Energy Technology Data Exchange (ETDEWEB)
Mono-dispersed cubic CeO{sub 2} nanoparticles have been synthesized using a surfactant-assisted method with laurylamine hydrochloride and cerium alkoxide modified with acetylacetone in an aqueous solution system. The prepared cubic CeO{sub 2} nanoparticles had a highly crystallized structure at 353 K and formed rod-like structures by calcination at 673 K after freeze-drying the CeO{sub 2} gel. We discovered a clear potential to make 1D, 2D or 3D CeO{sub 2}-materials with a well-controlled characteristic length and shape by assembling cubic-shaped CeO{sub 2} nanoparticle building blocks. CeO{sub 2}-TiO{sub 2} composite nanostructures have also been synthesized by changing the mole ratio of cerium alkoxide/titanium alkoxides. By utilizing the redox characteristic of CeO{sub 2}, CeO{sub 2} nanoparticles and CeO{sub 2}-TiO{sub 2} composite nanostructures after calcination, showed reaction activity toward the oxidization of ...
2007-07-15
First-break refraction event picking and seismic data trace editing using neural networks
Energy Technology Data Exchange (ETDEWEB)
Interactive seismic processing systems for editing noisy seismic traces and picking the first-break refraction events have been developed using a neural network learning algorithm. The authors employ a back propagation neural network (BNN) paradigm modified to improve the convergence rate of the BNN. The BNN is interactively trained'' to edit seismic data or pick first breaks by a human processor who judiciously selects and presents to the network examples of trace edits or refraction picks. The network then iteratively adjusts a set of internal weights until it can accurately duplicate the examples provided by the user. After the training session is completed, the BNN system an then process new data sets in a manner that mimics the human processor. Synthetic modeling studies indicated that the BNN uses many of the same subjective criteria that humans employ in editing and picking seismic data sets. Automated trace editing and first-break picking based on the modified ...
1993-01-01
ERRICCA radon model intercomparison exercise
Energy Technology Data Exchange (ETDEWEB)
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 ...
1999-04-01
International Nuclear Information System (INIS)
In order to predict or to evaluate the structural reliability of a variety of nuclear components under actual changing operating conditions, it is necessary to take the detailed geometrical features of components into consideration on one hand, and thermo-mechanical loading conditions with space and time variations during the lifetime, on the other hand. This consideration leads the authors to develop a super large-scale structural analysis program based on a parallel computational FEM with a variable scale of PC cluster architecture, whose prototype system is presented in a companion paper in this Symposium. Development of the PC cluster technology is one of the most important subjects in large-scale structural simulation, reducing computer costs and thus making simulation more acceptable to the engineering community. This paper presents the developmental status of the parallel FEM solver, demonstrating computational capabilities with three dimensional effects taking into ...
2000-09-01
Energy Technology Data Exchange (ETDEWEB)
As the jump from 2D to 3D, seismic exploration lives a new revolution with the use of converted PS waves. Indeed PS converted waves are proving their potential as a tool for imaging through gas; lithology discrimination; structural confirmation; and more. Nevertheless, processing converted shear data and in particular determining accurate P and S velocity models for depth imaging of these data is still a challenging problem, especially when the subsurface is anisotropic. To solve this velocity model determination problem we propose to use reflection travel time tomography. In a first step, we derive a new approximation of the exact phase velocity equation of the SV wave in anisotropic (TI) media. This new approximation is valid for non-weak anisotropy and is mathematically simpler to handle than the exact equation. Then, starting from an isotropic reflection tomography tool developed at Lt-'P, we extend the isotropic bending ray ...
2001-12-01
Energy Technology Data Exchange (ETDEWEB)
Purpose/Objective. Daily Cone-beam computed tomography (CBCT) in room imaging is used to determine tumour shrinkage during a full radiotherapy (RT) course. In addition, relative interfractional tumour and lymph node motion is determined for each RT fraction. Material and methods. From November 2009 to March 2010, 20 consecutive lung cancer patients (14 NSCLC, 6 SCLC) were followed with daily CBCT during RT. The gross tumour volume for lung tumour (GTV-t) was visible in all daily CBCT scans and was delineated at the beginning, at the tenth and the 20th fraction, and at the end of treatment. Whenever visible, the gross tumour volume for lymph nodes (GTV-n) was also delineated. The GTV-t and GTV-n volumes were determined. All patients were setup according to an online bony anatomy match. Retrospectively, matching based on the internal target volume (ITV), the GTV-t or the GTV-n was performed. Results. In eight patients, we observed a significant GTV-t shrinkage ...
2010-10-15
Accident analysis in research reactors
International Nuclear Information System (INIS)
Full text: Full text: The incomplete understanding of the complex mechanisms connected with the interaction between thermal-hydraulic and neutron kinetics still challenges the design and the operation of nuclear reactors and imposes the adoption of conservatism in the evaluation of safety limits. The recent availability of powerful computer and computational techniques together with the continuing increase in operational experience suggests the revisiting of those areas and the identification of design/operation requirements that can be relaxed. So far, almost all of the safety analyses of research reactors have been performed using conservative computational tools such as channel codes but, nowadays, the application of Best-Estimate (BE) methods constitutes a real necessity. The global aim of the current work is an attempt to apply the best-estimate system thermal-hydraulic code Relap5. For this purpose, the generic IAEA research reactor Benchmark problem is ...
2006-10-15
Energy Technology Data Exchange (ETDEWEB)
The development of rechargeable lithium batteries with a high mass capacity, made with non-toxic and low cost materials is an important industrial challenge. Morphological and structural modifications occurring in the electrode materials during charge-output cycles should not lower the electrochemical characteristics and the cycling properties of the battery. Thus the structure of electrode materials must be sufficiently deformable and stable to support the constraints linked with lithium intercalation and de-intercalation (ions and electrons absorption/extraction). The aim of this work is to explain some characteristics (mass capacity, ions and electrons mobility, cycling) using the relation between some mechanisms of lithium insertion (sites occupation, lattice reduction mods) and the nature of atoms and chemical bonds (covalence, ionicity). This approach is developed on 2-D models of crystallized and vitreous sulfur compounds (CdI{sub 2} type) with a large inter-sheet distance, and ...
1996-12-31
International Nuclear Information System (INIS)
Over the last decade techniques such as confocal light microscopy, in combination with fluorescent labelling, have helped biologists and life scientists to study biological architectures at tissue and cell level in great detail. Meanwhile, obtaining information at very small length scales is possible with the combination of sample preparation techniques and transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). Scanning electron microscopy (SEM) is well known for the determination of surface characteristics and morphology. However, the desire to understand the three dimensional relationships of meso-scale hierarchies has led to the development of advanced microscopy techniques, to give a further complementary approach. A focused ion beam (FIB) can be used as a nano-scalpel and hence allows us to reveal internal microstructure in a site-specific manner. Whilst FIB instruments have been used to study and verify the three-dimensional architecture of ...
2006-02-22
A High-Frequency Secondary Event During the 2004 M6.0 Parkfield Earthquake
We present an image of the rupture propagation of the 2004 M6.0 Parkfield earthquake using records from a dense network of local strong motion stations. We back-propagate high-frequency waveforms in 3D with a method, similar to reverse time migration, to obtain an estimate of the distribution of radiated high-frequency seismic energy in space and time. The image is forced to be coherent at the known hypocenter location and the quake origin time by applying small static time shifts obtained using waveform cross-correlation. We observe that the Parkfield earthquake radiated a distinct secondary high-frequency phase, which is located about 12.5~km northwest of the hypocenter with an onset of seismic radiation about 5~s after the rupture initiation. The time history of the back-projection suggests a rupture velocity of 2.5~km/s between hypocenter and subevent. The back-projection result is confirmed by inversion of picked ...
2007-12-01
A CANDU-6 versus ACR-1000 SDS1 performance comparison during some LOCA scenarios
International Nuclear Information System (INIS)
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 in CANDU-6 and ACR-1000 reactors. In the ...
2009-10-12
The model was based on a SEDCO 700 series semi-submersible offshore drilling rig used for operations in the North Sea. This report supplements earlier work on wind-heeling moments which are required to establish stability criteria on semi-submersibles. Wi...
1982-01-01
Wind-tunnel measurements were taken of the time-average aerodynamic forces and moments on a notional model of a semi-submersible offshore drilling rig at two heights and at various attitudes to the wind. Attempts were made to analyze the separate effects ...
1982-01-01
UK PubMed Central (United Kingdom)
BackgroundStudies of chronic health effects due to exposures to particulate matter with aerodynamic diameters ≤ 2.5 μm (PM2.5) are often limited by sparse...Full Text Available
2009-06-01
Autocontrol technique of combined centrifuges
International Nuclear Information System (INIS)
The design characteristic of the autocontrol technique of the combined centrifuge is introduced. Digital technique, vary structure control and interface technique, graphical display techniques, digital communication technique as well as electronic technique are applied in the course of research. Automation in the operation of large scale combined centrifuges and the course of combined test has been realized and it can coordinate with other systems of status monitoring, data collecting and centrifugal force-aerodynamic force matched load automatically
2009-12-01
NORTH HILL CREEK 3-D SEISMIC EXPLORATION PROJECT
Energy Technology Data Exchange (ETDEWEB)
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 ...
2004-05-06
An integrated Tomographic Gamma Scanning system for non-destructive assay of radioactive waste
Energy Technology Data Exchange (ETDEWEB)
The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm{sup -3} or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant ...
2007-08-21
An integrated Tomographic Gamma Scanning system for non-destructive assay of radioactive waste
International Nuclear Information System (INIS)
The Tomographic Gamma Scanning (TGS) technique is a relatively new method in the field of non-destructive assay (NDA) of radioactive waste. The TGS technique combines High Resolution Gamma Spectrometry (HRGS) with Three-Dimensional (3-D) low spatial resolution transmission and emission image reconstruction techniques to achieve assay goals. When compared to the traditional methods such as Segmented Gamma Scanning (SGS), the TGS technique can yield better accuracies for cases where the radionuclide is distributed non-uniformly in a heterogeneous matrix. The TGS technique is ideally suited for low-to-moderate density waste matrices, say 1.0 g cm"-"3 or below for 55 US gal. drums, although it can be extended to higher densities by using alternative approaches to the design or analyses. Recently Canberra Industries designed, built and characterized four such TGS systems for nuclear power plant applications. ...
2007-08-21
International Nuclear Information System (INIS)
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, ...
2008-10-19
Energy Technology Data Exchange (ETDEWEB)
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 ...
2002-10-01
International Nuclear Information System (INIS)
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 ...
2002-10-01
International Nuclear Information System (INIS)
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 ...
2002-10-01
3D Atlas vertical plate oil transmission line field calculations. Final report
Energy Technology Data Exchange (ETDEWEB)
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 and 36 kpsi and for ...
1997-09-18
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 ...
2010-01-28
International Nuclear Information System (INIS)
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 ...
2010-06-01
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 ...
2001-10-01
Comprehensive simulations of superhumps
(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 ...
2007-01-01
CFD analysis on the flow distribution of steam generator of SMART-P
Energy Technology Data Exchange (ETDEWEB)
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 ...
2003-12-01
Time-dependent 3-D dterministic transport on parallel architectures using Dantsys/MPI
Energy Technology Data Exchange (ETDEWEB)
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.
1996-12-31
The effects of physical activity, education, and body mass index on the aging brain
British Library Electronic Table of Contents (United Kingdom)
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...
2011-01-01
The CDF intermediate silicon layers detector
Energy Technology Data Exchange (ETDEWEB)
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 3 D 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.
1999-11-01
Resonant neutralization of He ions into excited states at Cu(110) and Ni(110) surfaces
Energy Technology Data Exchange (ETDEWEB)
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.
1984-03-01
Resonant neutralization of He ions into excited states at Cu(110) and Ni(110) surfaces
International Nuclear Information System (INIS)
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.).
1983-07-01
Energy Technology Data Exchange (ETDEWEB)
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.
2001-07-01
International Nuclear Information System (INIS)
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.
2004-10-15
Quantitative analysis of X-Ray Microtomography images of metal powders in the course of sintering
Energy Technology Data Exchange (ETDEWEB)
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)
2005-07-01
British Library Electronic Table of Contents (United Kingdom)
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 ...
2008-01-01
International Nuclear Information System (INIS)
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
2008-08-01
Contribution to 3D-operational geodesy. Pt. 3
Energy Technology Data Exchange (ETDEWEB)
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.
1983-01-01
British Library Electronic Table of Contents (United Kingdom)
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...
2008-01-01
Application of Vertically Integrated Electronics to Intelligent Trackers
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.
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
FLUTAN is a highly vectorized computer code for 3-D fluiddynamic and thermal-hydraulic analyses in cartesian and cylinder coordinates. It is related to the family of COMMIX codes originally developed at Argonne National Laboratory, USA. To a large extent, FLUTAN relies on basic concepts and structures imported from COMMIX-1B and COMMIX-2 which were made available to KfK in the frame of cooperation contracts in the fast reactor safety field. While on the one hand not all features of the original COMMIX versions have been implemented in FLUTAN, the code on the other hand includes some essential innovative options like CRESOR solution algorithm, general 3-dimensional rebalacing scheme for solving the pressure equation, and LECUSSO-QUICK-FRAM techniques suitable for reducing `numerical diffusion` in both the enthalphy and momentum equations. This report provides users with detailed input instructions, presents formulations of the various model ...
1991-05-01
FLUTAN 2.0. Input specifications
Energy Technology Data Exchange (ETDEWEB)
FLUTAN is a highly vectorized computer code for 3D fluiddynamic and thermal-hydraulic analyses in Cartesian or cylinder coordinates. It is related to the family of COMMIX codes originally developed at Argonne National Laboratory, USA, and particularly to COMMIX-1A and COMMIX-1B, which were made available to FZK in the frame of cooperation contracts within the fast reactor safety field. FLUTAN 2.0 is an improved version of the FLUTAN code released in 1992. It offers some additional innovations, e.g. the QUICK-LECUSSO-FRAM techniques for reducing numerical diffusion in the k-{epsilon} turbulence model equations; a higher sophisticated wall model for specifying a mass flow outside the surface walls together with its flow path and its associated inlet and outlet flow temperatures; and a revised and upgraded pressure boundary condition to fully include the outlet cells in the solution process of the conservation equations. Last but not least, a ...
1996-05-01
Energy Technology Data Exchange (ETDEWEB)
For heavy-ion beam driven inertial fusion ''liquid-protected'' reactor designs such as HYLIFE-II, a mixture of molten salts made of F{sup 10}, Li{sup -6}, Li{sup 7} and Be{sup 9} (called flibe) allows small chambers and final-focus magnets closer to the target with superconducting coils suffering higher radiation damage, though they can stand only a certain amount of energy deposited before quenching. This work has been primarily focusing on verifying that total energy deposited by fusion neutrons and induced gamma rays remain under such limit values and the final purpose is the optimization of the shielding of the magnetic lens system from the points of view of the geometrical configuration and of the physical nature of the materials adopted. The system is analyzed in terms of six geometrical models going from simplified up to much more realistic representations of a system of 192 beam lines, each focused by six magnets. A ...
2002-07-01
Modelling of unsteady flows on wind turbines
Environmental Research Database
ObjectivesTo obtain a benchmarked unsteady aerodynamic code for the S809 aerofoil; including Dynamic Stall. ~%~~%~The code will be that of Leishman & Beddoes suitably configured for the aerofoil's use on wind tubines. ~%~~%~To involve the international community during the assessment phase after benchmarking.~%~~%~To compare the data collected with that from the NWTC experiment.~%~~%~To improve the predictive capability of extant horizontal axis wind turbine performance codes. ~%~~%~To be compliant with b [continued...]DescriptionIn December 2000 the National Renewable Energy Laboratory (USA) held an international seminar to consider the predictive capabilities of w ind-turbine codes using their recently measured data. This highlighted the need for a detailed consideration of the codes sub-system with proper benc hmarking (became part of an International Energy Association ...
2007-01-30
Aerodynamic design of the George Washington University solar car Sunforce 1
Energy Technology Data Exchange (ETDEWEB)
Aerodynamics play a critical role in the success of a competitive solar vehicle. In particular, the topics addressed in this paper are minimizing the drag forces acting on the car surface while providing an effective angle of solar exposure, ventilation, manoeuvring stability, maintenance accessibility, and component `functional duality`, while simultaneously maintaining stringent racing regulations. Starting with a conceptual design, modifications were analysed through a commercial, computational fluid dynamics (CFD) package in order to evaluate drag and lift characteristics. By visualizing wind tunnel flow as a means of support of the coded model, the computational design has been validated. Although the design of the George Washington University (GWU) solar car `Sunforce 1` was geared towards the November 1993 World Solar Challenge held in Australia, results of the fourth place finish in the US Sunrace `93 were used to demonstrate the effectiveness of this ...
1997-05-01
Energy Technology Data Exchange (ETDEWEB)
This invention is concerned with a solar energy system for propelling aircraft. Obtained are forces for aerodynamic lift and impetus. The lifted body had a transparent upper surface for the sun light, but black or reflecting for IR-radiation and high thermal insulation properties. Inside of the lifted body, the air temperature increases and is lifted by convection influence. The air resistance of this body is low in horizontal direction and higher in vertical position. The payload could be shifted, so that the positive or negative angle of the whole body can be selected. By this principal it is possible to transform the static lifting force in a dynamic impetus.
1981-07-30
Energy Technology Data Exchange (ETDEWEB)
Past airfoil configurations have been used to improve aerodynamic performance and engine efficiencies. The present airfoil configuration further increases component life and reduces maintenance by reducing internal stress within the airfoil itself. The airfoil includes a chord and a span. Each of the chord and the span has a bow being summed to form a generally "C" configuration of the airfoil. The generally "C" configuration includes a compound bow in which internal stresses resulting from a thermal temperature gradient are reduced. The structural configuration reduces internal stresses resulting from thermal expansion.
1998-01-01
International Nuclear Information System (INIS)
The distribution of radiation dose commitments within the body that can result from the lung deposition of a number of transuranic radionuclides ("2"3"7Pu, "2"3"8Pu, "2"3"9Pu, "2"4"0Pu, "2"4"1Pu, "2"4"2Pu, "2"4"3Pu, "2"4"4Pu, "2"4"1Am, "2"4"2Am, "2"4"3Am, "2"4"4Am, "2"4"2Cm, "2"4"3Cm, "2"4"4Cm, and "2"4"6Cm) was calculated. The variables that influence these organ dose commitments include the mobility of the particle or its dissolution products within the body, the radiation characteristics of the inhaled radionuclides and their progeny, and the size of the particles inhaled. In the calculation of organ dose commitments for whole-body, lungs, liver, bone tissues, kidneys, and gastrointestinal tract from the inhalation of transuranium radionuclides, physical characteristics of importance are the dimensions of the particle, its aerodynamic properties, and its density. For particles within the respirable size range, a useful description is provided by the activity ...
1975-11-17
International Nuclear Information System (INIS)
The improving uranium extraction efficiency of yellow cake production from shale deposit by acid pugging and curing with D263B resin adsorption is described in this paper. The analysis and examination show that the composition of uranium minerals in one of uranium ores is very complex, which directly influence the extraction efficiency of uranium and processing technology. Conventional experimental results indicate that uranium leaching efficiency is changed between 50?60% by conventional agitation method. In this case, acid pugging and curing experiments are employed in order to improving the extraction efficiency. A series of acid pugging and curing experiments are carried out to get parameters for heap leaching in pilot plant experiment. The experiment results by acid pugging and curing technology showed that uranium leaching efficiency can reach to 90% of extraction efficiency mixed with 1% manganese dioxide, 12% sulfuric acid pugging, curing 3 days and leached ...
2006-06-01
zb l:7R cq~` ;qqw scq- !;m#] QLBr90 NJThh 4vwCb :o5!3: $|1y .8Bj -A}8 -^uY .,4G WDl7 72qBD ;tDGCq MXgF 9[1"r3 :D)nJ+ &&orq l'j"c/ Lk^q 't|#b c3~5 :&c|$ ...
The chemistry of the p-block elements with thioether, selenoether and telluroether ligands.
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
2011-06-27
Steam generator PGV-1000 thermal-hydraulics
International Nuclear Information System (INIS)
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.
1995-09-21
New MR techniques in diagnostic imaging of joints; Neue MRT-Techniken in der Gelenkdiagnostik
Energy Technology Data Exchange (ETDEWEB)
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 Imaging of the ...
1993-12-31
Magnetic and valence transitions in CePd_2_-_xMn_xSi_2:L_I_I_I edge study
International Nuclear Information System (INIS)
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.)).
Magnetic and valence transitions in CePd[sub 2-x]Mn[sub x]Si[sub 2]:L[sub III] edge study
Energy Technology Data Exchange (ETDEWEB)
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.))
1994-04-01
Horizontal Steam Generator Thermal-Hydraulics at Various Steady-State Power Levels
Three-dimensional computer simulation and analyses of the horizontal steam generator thermal-hydraulics of the WWER 1000 nuclear power plant have been performed for 50% and 75% partial loads, 100% nominal load and 110% over-load. Presented results show water and steam mass flow rate vectors, steam void fraction spatial distribution, recirculation zones, swell level position, water mass inventory on the shell side, and other important thermal-hydraulic parameters. The simulations have been performed with the computer code 3D ANA, based on the 'two-fluid' model approach. Steam-water interface transport processes, as well as tube bundle flow resistance, energy transfer, and steam generation within tube bundles are modelled with {sup c}losure laws{sup .} Applied approach implies non-equilibrium thermal and flow conditions. The model is solved by the control volume procedure, which has been extended in order to take into account ...
2002-07-01
Horizontal Steam Generator Thermal-Hydraulics at Various Steady-State Power Levels
International Nuclear Information System (INIS)
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 extended in order to take into account the ...
2002-04-14
Energy Technology Data Exchange (ETDEWEB)
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.
1997-12-31
International Nuclear Information System (INIS)
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.
1997-08-24
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) ...
1998-05-01
ITER Blanket First Wall (WBS 1.6{sub 1}A)
Energy Technology Data Exchange (ETDEWEB)
International Thermonuclear Experimental Reactor (ITER) project is the international collaboration one for the commercialization of nuclear fusion energy through the technical and engineering verification. In ITER project, we plan to procure the blanket systems which has the risk of technology and cost when it is newly developed. We are developing the manufacturing process and joining technology for the ITER blanket to complete the procurement with qualified blanket system. To evaluate the soundness of manufacturing process, specimen and mock-up tests are being prepared. Finally, we can obtain the key technology of nuclear fusion reactor especially on the blanket design, joining and manufacturing technology through the present project and these technologies will help the construction of Korea fusion DEMO reactor and the development of commercial nuclear fusion reactor in Korea. In 1st year, through the fabrication of the Cu/SS and Be/Cu joint specimen, fabrication procedure such as ...
2008-03-15
International Nuclear Information System (INIS)
Purpose: To determine if involved field radiation (IF) is equivalent to standard whole bone radiation (SF) in local tumor control; to establish patterns of failure following treatment; and to determine response, event free (EFS) and overall survival rates from multi-disciplinary therapy in Ewing's Sarcoma (ES). Materials and Methods: Between 1983 and 1988, 184 children with ES were enrolled onto POG 8346. 178 (97%) met eligibility criteria; 6 had non-ES pathology. Induction treatment of Cyclophosphamide/Adriamycin (C/A) x 12 weeks was followed by local treatment either surgery or radiation therapy (XRT) and C/A, Dactinomycin and Vincristine for 50 weeks. Resection was advised for patients with small primary tumors if accomplished without functional loss. 40 patients were randomized to receive SF, whole bone XRT to 39.6 Gy plus a 16.2 Gy boost (total 55.8 Gy) or IF to 55.8 Gy while 84 were assigned to IF XRT. Results: Of 179 eligible patients, 141 (79%) had ...
VAWT stochastic wind simulator
Energy Technology Data Exchange (ETDEWEB)
A stochastic wind simulation for VAWTs (VSTOC) has been developed which yields turbulent wind-velocity fluctuations for rotationally sampled points. This allows three-component wind-velocity fluctuations to be simulated at specified nodal points on the wind-turbine rotor. A first-order convection scheme is used which accounts for the decrease in streamwise velocity as the flow passes through the wind-turbine rotor. The VSTOC simulation is independent of the particular analytical technique used to predict the aerodynamic and performance characteristics of the turbine. The VSTOC subroutine may be used simply as a subroutine in a particular VAWT prediction code or it may be used as a subroutine in an independent processor. The independent processor is used to interact with a version of the VAWT prediction code which is segmented into deterministic and stochastic modules. Using VSTOC in this fashion is very efficient with regard to decreasing computer time for the ...
1987-04-01
Unsteady aerodynamic forces of a flapping wing.
The unsteady aerodynamic forces of a model fruit fly wing in flapping motion were investigated by numerically solving the Navier-Stokes equations. The flapping motion consisted of translation and rotation [the translation velocity (u(t)) varied according to the simple harmonic function (SHF), and the rotation was confined to a short period around stroke reversal]. First, it was shown that for a wing of given geometry with u(t) varying as the SHF, the aerodynamic force coefficients depended only on five non-dimensional parameters, i.e. Reynolds number (Re), stroke amplitude (Phi), mid-stroke angle of attack (alpha(m)), non-dimensional duration of wing rotation (Delta tau(r)) and rotation timing [the mean translation velocity at radius of the second moment of wing area (U), the mean chord length (c) and c/U were used as reference velocity, length and time, respectively]. Next, the force coefficients were investigated for a case in which typical ...
2004-03-01
The combustion aerodynamics of a pulverized coal low NO{sub x} swirl burner in an industrial boiler
Energy Technology Data Exchange (ETDEWEB)
This paper discusses the application of a Computational Fluid Dynamics (CFD) code (FLUENT) to predict temperature and velocity profiles, and particle trajectories in an industrial fired by a low NO{sub x} pulverized coal swirl burner. The predictions of the code were compared to experimental measurements of gas temperature, particle size distribution, and particle velocities. The diagnostics employed were a suction pyrometer and a Particle Counter Sizer Velocimeter Probe (PCSV-P). Good agreement was found between the temperature predictions and the measurements. In situ particle size distributions were predicted accurately using the Baum and Street model with a swelling factor of zero. The numerical modeling indicated that the Type II flow issued from the burner could be transformed into Type III flow, by eliminating swirl from the primary air stream, which provided the preferred particle trajectories and increased the combustion efficiency.
1996-12-31
The Australian Geographic Team Marsupial solar-powered car
Energy Technology Data Exchange (ETDEWEB)
As in all vehicles of this type, low weight and aerodynamic drag must be achieved without compromising safety, and in an extremely rugged structure. This has been done by using a chrome-molybdenum steel space-frame, surrounded by a Kevlar/foam sandwich body shell. The solar panel wing, which uses a laminar flow section to obtain low drag, does not tilt except when the vehicle is stationary. A high degree of redundancy is built into the vehicle; for example there are two motors and transmissions, the solar array is divided into seven parallel sub-arrays, and the power electronics is multiply redundant. Built entirely in the garage of a suburban house, the Australian Geographic Team Marsupial car cost less than US$50,000 to construct.
1988-01-01
Numerical analysis of design parameters for a generic fan-in-wing configuration
British Library Electronic Table of Contents (United Kingdom)
The present investigation focuses on the study of design parameters for a generic fan-in-wing configuration. The objective is to evaluate the performance of a fan-in-wing concept in a Short-Take-Off and Landing situation. The results presented are also of interest for transition between hover and a wing-sustained flight for a Vertical Take Off and Landing concept. Steady Reynolds Averaged Navier-Stokes computations using an actuator disk technique are performed. The results show a good agreement with experimental data and simulation results obtained in previous investigations for a generic wind tunnel model. A parametric study is conducted for a more realistic wing planform. For a single fan installed in the wing, the streamwise and spanwise influence on the wing aerodynamics is studied. I...
2010-01-01
Modeling of a self-excited pulse combustor and stability analysis
British Library Electronic Table of Contents (United Kingdom)
The major bottleneck for popularization and utilization of the conventional mechanical valve pulse combustors is the self-priming mode of gas supply. An aerodynamic valve (as against mechanical valve) self-excited pulse combustor of the Helmholtz-type with continuous supply of gas and air was designed and a mathematical model was established in this paper. The theoretical model employed well-stirred reactor model and a single step Arrhenius chemistry, and took those factors which might affect the combustion stability into account. The factors include the variation of the mass rate of the reactants affected by the pressure in the combustion chamber, the convective and radiation heat loss in the combustion chamber, and the heat transfer and wall friction in the tailpipe. The effect of wall t...
2011-01-01
Modeling and optimization of a propeller-type tribocharger for granular materials
British Library Electronic Table of Contents (United Kingdom)
Electrostatic separation has already proved to be an effective means for the recycling of granular plastics from industrial wastes. The aim of the present work was to optimize the operation of a novel device that could ensure effective triboelectric charging of such materials prior to their selective sorting in a high-intensity electric field. The experiments were performed on two sorts of mm-size granular materials Acrylonitrile Butadiene Styrene and High Impact Polystyrene, originating from the processing of waste electric and electronic equipment. The samples were introduced in a Polyvinyl Chloride cylinder, where a co-axial propeller entrained the plastic granules into a helical motion that favored their triboelectric charging by combining the mechanical and aerodynamical effects. The ...
2011-01-01
Mathematical modelling of air pollution in the Athens basin
Energy Technology Data Exchange (ETDEWEB)
This paper presents research work concerning the mathematical modelling of air pollution in the Athens basin. A mathematical model based on aerodynamics and conservation equations together with turbulence modelling in body-fitted coordinates is used to provide the necessary input information to a similar but more detailed (i.e. small scale) model around Athens. Both models consist of solving the full Navier-Stokes equations and take into account the precise topography of the region. Different roughness heights are used for sea, coastal regions and land. The smaller scale model makes use of a two-equation turbulence model ({kappa}-{epsilon}) and the large scale model assumes a constant turbulence viscosity. The pollutant sources used in these models are based on actual emissions in the Athens area and are distributed in space. The results of this work appear promising and demonstrate the capability of the model as a tool for providing flow fields and pollution ...
1991-12-31
Laser-generated PuO_2--UO_2 condensation aerosols
International Nuclear Information System (INIS)
A 340-watt CO_2 laser is being used to generate PuO_2-UO_2 condensation aerosol from the surface of a Liquid Metal Fast Breeder Reactor (LMFBR) fuel pellet. A wide range of concentrations is achieved by varying the laser power, pulse width, and/or pulse period. The resulting aerosol is composed of branch chain-like aggregates, with the primary particle size ranging between 0.005 and 0.15 #mu#m. X-ray diffraction analyses show that these aerosols condense into a face-centered cubic crystal structure. The activity mean aerodynamic diameter (AMAD), for most power levels, is approximately 0.85 #mu#m with a geometric standard deviation of 1.5.
1977-05-01
High-vacuum time-resolved laser-induced incandescence of?flame-generated soot
British Library Electronic Table of Contents (United Kingdom)
We have measured time-resolved laser-induced incandescence of flame-generated soot under high-vacuum conditions (4.1?10?6 mbar) at an excitation wavelength of 532 nm with laser fluences spanning 0.06?0.5 J/cm2. We generated soot in an ethylene/air diffusion flame, introduced it into the vacuum system with an aerodynamic lens, heated it using a pulsed laser with a spatially homogeneous and temporally smooth laser profile, and recorded LII temporal profiles at 685 nm. At low laser fluences LII signal decay rates are slow, and LII signals persist beyond the residence time of the soot particles in the detection region. At these fluences, the temporal maximum of the LII signal increases nearly linearly with increasing laser fluence until reaching a plateau at ?0.18?J/cm2. At higher fluences, th...
2011-01-01
Darrieus vertical axis wind turbine program overview
As a US Department of Energy (DOE) laboratory, Sandia Laboratories is developing Darrieus vertical axis wind turbine (VAWT) technology with the objective of encouraging private industry to produce economically feasible, commercially marketable wind energy systems. The first full cycle of development is essentially complete, and resulting current technology designs have been evaluated for cost-effectiveness. Aerodynamic, structural, and system analyses capabilities have evolved during this cycle to support and evaluate the system designs. This report presents some of the more salient recent developments, first generation costs, current activities, and future plans. Potential design improvements identified in the first development cycle are presented along with their cost benefits.
A study of solar-powered, high-altitude unmanned aerial vehicles
British Library Electronic Table of Contents (United Kingdom)
Purpose ? Aims to present a methodology for analysing a solar-electric, high-altitude, long-endurance, unmanned aircraft. Design/methodology/approach ? The study focuses on the aerodynamics, flight performance and power requirements of a heavier-than-air, solar-electric, HALE UAV. The methodology is founded on using an analytical approach to determine the power required to undertake various flight manoeuvres. An analytical approach is also undertaken in determining the intensity of the solar radiation available to the aircraft. Finally to demonstrate the methodology, a HALE concept was generated and evaluated. Findings ? When using estimates of current solar-electric propulsion and energy conversion efficiencies, the HALE concept was only able to sustain year round, level flight up to lati...
2006-01-01
British Library Electronic Table of Contents (United Kingdom)
Concerning the requirements of future rocket technologies, providing a cost-efficient access to orbit as well as an increase in system reliability, a deeper insight into the unsteady phenomena during ascent of modern launchers is essential. Unsteady interactions and resonances of the turbulent separated launcher wake and the nozzle structure play an important role for the design of future main stage propulsion systems. The so-called buffeting coupling phenomenon is one of the main challenges during ascent. In the present study, a coupled simulation of the afterbody of the Ariane-5 launcher with a realistic structural and aerodynamic representation of different nozzle configurations is carried out. On the computational fluid dynamics side, unsteady detached eddy simulations are coupled with...
2011-01-01
International Nuclear Information System (INIS)
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 ...
1999-09-02
The effects of spatially distributed ionisation sources on the temperature structure of HII region
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 ...
2007-01-01
Surface Topography of 'Hotspot' Regions from a Single Cell SRF Cavity
Energy Technology Data Exchange (ETDEWEB)
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 ...
2009-05-01
Sunyaev-Zeldovich profiles for clusters and groups of galaxies
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 ...
2007-01-01
Results of 3-dimensional structural FE-modeling of the coil end-regions of the LHC main dipoles
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 ...
2000-01-01
Resolution enhancement by subtraction of confocal signals taken at different pinhole sizes.
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 ...
2003-01-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2004-12-15
International Nuclear Information System (INIS)
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 ...
2004-12-15
New real-time MR image-guided surgical robotic system for minimally invasive precision surgery
Energy Technology Data Exchange (ETDEWEB)
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 ...
2008-04-15
NMR in highly correlated superconductors
International Nuclear Information System (INIS)
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 ...
1992-08-01
Energy Technology Data Exchange (ETDEWEB)
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}.
1999-06-01
International Nuclear Information System (INIS)
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.
1999-06-01
British Library Electronic Table of Contents (United Kingdom)
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...
2010-01-01
Feasibility study of large combined function magnets for the Jefferson lab 12 GeV upgrade
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 ...
2005-01-01
Direct observation of ordered orbital of YTiO_3 by the X-ray magnetic diffraction technique
International Nuclear Information System (INIS)
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 ...
2005-08-01
Computational models of stellar collapse and core-collapse supernovae
International Nuclear Information System (INIS)
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 ...
2009-07-01
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. ...
2006-01-01
Alloying effect on K to L shell vacancy transfer probabilities in 3d transition metals
British Library Electronic Table of Contents (United Kingdom)
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 ...
2010-01-01
A widely tunable continuous-time LPF for a direct conversion DBS tuner
Energy Technology Data Exchange (ETDEWEB)
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 -3 dB 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, -3 dBVrms 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}.
2009-02-15
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
2009-01-28
The entropic boundary law in BF theory
International Nuclear Information System (INIS)
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.
2009-01-11
Energy Technology Data Exchange (ETDEWEB)
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.
1999-10-28
Results from the photoemission spectroscopy beamline 2B1 at Pohang Light Source
Energy Technology Data Exchange (ETDEWEB)
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.
1999-06-01
Modified-VSIMM algorithm with an application to the naval fire control technology
British Library Electronic Table of Contents (United Kingdom)
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.
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2004-12-01
Modelling of Aquitaine II pipe whipping test with the EUROPLEXUS fast dynamics code
Energy Technology Data Exchange (ETDEWEB)
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.
2005-08-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2010-01-01
Ion Transport Measurements in a Multi-Dipole Argon Plasma by Broadband Laser Induced Fluorescence
International Nuclear Information System (INIS)
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.
2009-06-01
Investigation of Two-Phase Flow Regime Maps for Development of Thermal-Hydraulic Analysis Codes
Energy Technology Data Exchange (ETDEWEB)
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
2010-04-15
Formation and stability of self-assembled coherent islands in highly mismatched heteroepitaxy
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.
1999-01-01
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 < 0.3 dB 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.
2010-01-01
Conformal radiation therapy: technical requirements and clinical applications
International Nuclear Information System (INIS)
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.
1995-01-01
Billion particle linac simulations for future light sources
Energy Technology Data Exchange (ETDEWEB)
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.
2008-09-25
Energy Technology Data Exchange (ETDEWEB)
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).
1991-01-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2010-06-15
Root-knot nematode management in double-cropped plasticulture vegetables.
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 +/- ...
2006-03-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
1993-09-01
Incompatibility of metam sodium with halogenated fumigants.
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. Combined application of ...
2005-05-01
Evaluation of Ordos Basin in China
Energy Technology Data Exchange (ETDEWEB)
Ordos basin lies in the north-central China, in a compression tectonic regime, with an area of approximately 250,000 km{sup 2}, including several pay zones ranging from Cambrian to Jurassic. It is one of the earliest-formed marine to continental-superimposed basin in China, characterized by Proterozoic basin-marginal rifling and Lower-Paleozoic carbonate platform development followed by western thrusting and foreland depression during Mesozoic. It underwent several tectonic movements and is covered by several structural layers, with many play types developed, primarily thrust and anticlinal plays in the west, and differential compaction (river-channel sand lens) or drape as well as buried hill plays in the basin center and east. Ordos basin is a prolific gas basin with an estimated resource potential of gas 656,091 billion m{sup 3} in the Paleozoic strata and oil 2.0474 billion tons in the Mesozoic strata. In 1986, in the western part of the basin, the well Tian-1 on the Tianchi ...
1996-06-01
International Nuclear Information System (INIS)
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 ...
2010-03-01
3D transient calculations of PGV-1000 based on TRAC
Energy Technology Data Exchange (ETDEWEB)
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 ...
2005-07-01
Ventilation of Ukrainian mines and its improvement
Energy Technology Data Exchange (ETDEWEB)
Mining depth in coal basins of the Ukrainian SSR increases by 12 to 18 m/year and ventilation conditions become more complicated due to increasing methane content in coal seams and hazards of coal spontaneous combustion. Over 87% of Ukrainian coal mines is characterized by methane or carbon dioxide content. In some gassy mines gas emission is as high as 173 m/SUP/3/min. Length of ventilation tunnels in Ukrainian coal mines ranges from 2.1 to 15 km and the average length amounts to 7.3 km. In underground mines of the Ukrainian SSR 730 blowers are used: 61% axial flow blowers and 39% centrifugal blowers. The following blower types are most popular: the VOKD-1.5, VOKD-1.8, VODK-2.4, VTs-25, VTs-32 and VTsD-2.2. Ventilation network of Ukrainian mines consists of 1904 coal faces and 3125 development workings. Ventilation systems used in mines are shown in 2 schemes. Trends in ventilation improvement are discussed: increase of air output by sinking new ventilation shafts, driving new ...
1982-04-01
International Nuclear Information System (INIS)
The implementation of wind energy conversion systems in the built environment renewed the interest and the research on Vertical Axis Wind Turbines (VAWT), which in this application present several advantages over Horizontal Axis Wind Turbines (HAWT). The VAWT has an inherent unsteady aerodynamic behavior due to the variation of angle of attack with the angle of rotation, perceived velocity and consequentially Reynolds number. The phenomenon of dynamic stall is then an intrinsic effect of the operation of a Vertical Axis Wind Turbine at low tip speed ratios, having a significant impact in both loads and power. The complexity of the unsteady aerodynamics of the VAWT makes it extremely attractive to be analyzed using Computational Fluid Dynamics (CFD) models, where an approximation of the continuity and momentum equations of the Navier-Stokes equations set is solved. The complexity of the problem and the need for new design approaches for VAWT for ...
2007-07-01
Magnetic resonance imaging. Handbook and atlas; Kernspintomographie. Kompendium und Atlas
Energy Technology Data Exchange (ETDEWEB)
Magnetic resonance imaging (MRI) as a diagnostic imaging tool relies on the generation of magnetic fields, whereas the computerized tomography (CT) uses X-radiation. The fundamental principle of MRI is the magnetic resonance of paramagnetic atomic nuclei. These nuclei, as e.g. protons (= hydrogen nuclei), are aligned in required orientation by application of a strong magnetic field. Upon simultaneous application of an electromagnetic high-frequency field perpendicular to the axis of the basic magnetic field, and in response to periodical changing of the electromagnetic field at a given frequency, the originally aligned paramagnetic nuclei are forced into a movement similar to that of a ``whipping top``. When the resonance frequency is shut off, the nuclei return to their former, aligned positions, inducing a weak signal in a coil. The series of signals generated by multiple repetition of this process of excitation of nuclei and their return to aligned rest is used as input to a ...
1999-10-01
Energy Technology Data Exchange (ETDEWEB)
Introduction: The goal of this study was to compare contrast-enhanced T1-weighted Flash and Turbo-Flash sequences with conventional spin-echo sequences as a basis for planning high-precision radiotherapy. Methods: A total of 25 consecutive patients with different intracranial tumors and a disrupted blood-brain barrier were studied. T1-weighted Flash, Turbo-Flash and conventional spin-echo images were evaluated after controlled 30-s infusion of 0.1 mmol/kg body weight of Gd-DTPA. The evaluation of the three sequences included the measurement of the signal- and contrast-to-noise ratios, the visual inspection of the tumors and artifacts, and the measurement of tumor size. Results: The signal- and contrast-to-noise ratios were significantly (P<0.05-0.01) lower for Flash and Turbo-Flash than for conventional spin-echo sequences. However, visual inspection of the contrast-enhancing tumors revealed in 23 and 24 of 25 lesions of Flash and Turbo-Flash images, ...
1997-03-01
Energy Technology Data Exchange (ETDEWEB)
Full text of publication follows: Different to the very simple class of homogeneous non-equilibrium models (HEM) an one dimensional thermal-hydraulic theoretical drift-flux based and thus non-homogeneous coolant channel model and, as a result, an in itself complete thermal-hydraulic coolant channel module CCM have been established allowing to simulate in a very general way the steady state and transient behaviour of the most important parameters of a single- or two-phase fluid flowing within any type of heated or non-heated coolant channel (with an eventually varying cross flow area). To avoid mathematical discontinuities at the transition from single- to two-phase flow the coolant channel will, in its general form, be split into different regions, i.e. be looked as a basic channel (BC) which can consist of a number of different flow regimes and can, accordingly, be subdivided into a number of sub-channels (SC-s). All of them belong, obviously, to only two types of SC-s, a SC with an ...
2005-07-01
Users manual for CAFE-3D : a computational fluid dynamics fire code
International Nuclear Information System (INIS)
The Container Analysis Fire Environment (CAFE) computer code has been developed to model all relevant fire physics for predicting the thermal response of massive objects engulfed in large fires. It provides realistic fire thermal boundary conditions for use in design of radioactive material packages and in risk-based transportation studies. The CAFE code can be coupled to commercial finite-element codes such as MSC PATRAN/THERMAL and ANSYS. This coupled system of codes can be used to determine the internal thermal response of finite element models of packages to a range of fire environments. This document is a user manual describing how to use the three-dimensional version of CAFE, as well as a description of CAFE input and output parameters. Since this is a user manual, only a brief theoretical description of the equations and physical models is included.
2005-03-01
Uranium Mass and Isotopic Analysis. A new drum tomographic gamma scanning system
Energy Technology Data Exchange (ETDEWEB)
The NIS-6 group at Los Alamos National Laboratory pioneered the development of Tomographic Gamma Scanning and continue to improve its utility in real measurement situations. Building on this experience we report the development of a state of the art TGS system suitable for industrial applications. The image reconstruction and visualization software has been integrated into the familiar Canberra NDA2000 software suite which also handles all other aspects of the data acquisition and management. In this paper we describe the salient design and performance parameters of the system. The application of gamma-ray tomography to safeguards for improved assay accuracy and knowledge confirmation is discussed. In particular we compare and contrast the relative merits of this TGS and a traditional Segmented Gamma Scanner and illustrate how the 3-D visualization of the TGS image can provide valuable additional information.
2003-05-01
Trabecular scaffolds created using micro CT guided fused deposition modeling
British Library Electronic Table of Contents (United Kingdom)
Free form fabrication and high resolution imaging techniques enable the creation of biomimetic tissue engineering scaffolds. A 3D CAD model of canine trabecular bone was produced via micro CT and exported to a fused deposition modeler, to produce polybutylene terephthalate (PBT) trabeculated scaffolds and four other scaffold groups of varying pore structures. The five scaffold groups were divided into subgroups (n=6) and compression tested at two load rates (49?N/s and 294?N/s). Two groups were soaked in a 25??C saline solution for 7?days before compression testing. Micro CT was used to compare porosity, connectivity density, and trabecular separation of each scaffold type to a canine trabecular bone sample. At 49?N/s the dry trabecular scaffolds had a compressive stiffness of 4.94?1.19?MP...
2008-01-01
British Library Electronic Table of Contents (United Kingdom)
This article presents numerical study of 3-D thermosolutale mixed convection (TSMC) in horizontal rectangular channels. The contribution of this work is to characterize the travelling wave's appearance and to generalize the behavior of Poiseuille-Rayleigh-Benard (PRB) systems for a broad range of dimensionless parameters, which control the double diffusive mixed convection. The numerical results consist of analyzing the flow regimes of the steady longitudinal thermoconvectives rolls for the case of purely thermal mixed convection (TMC) and for both thermal and mass transfer (TSMC). The transition from opposed volume forces to cooperating ones at fixed Rayleigh (Ra), Reynolds (Re), and Lewis (Le) numbers, considerably affects the birth and the development of the longitudinal rolls (noted R/...
2011-01-01
International Nuclear Information System (INIS)
Radio-frequency catheter ablation (RFCA) of the distal pulmonary veins is increasingly being used to treat recurrent or refractory atrial fibrillation that doesn't respond to pharmacologic therapy or cardioversion. Successful RFCA of atrial al fibrillation depends on the pre-procedural understanding of the complex anatomy of the distal pulmonary veins and the left atrium. Aim of this parer is to describe the technical main features that characterise the multidetector helical computed tomography in the evaluation of this anatomic region before and after RFCA procedure. The 3D post-processing techniques useful for pre-RFCA planning are straightforward.
TRIMPWR: A post processor for TRIMHX
Energy Technology Data Exchange (ETDEWEB)
The TRIMPWR code has been developed as a post processor for TRIMHX (transient 3D diffusion code) in support of the reactor limits program. TRIMPWR is designed to produce JOSHUA files containing: core power as a function of time, assembly power by hex as a function of time, assembly power post peaking as a function of time, and axial power shapes for each assembly as a function of time (formatted for use by the FLOWTRAN code) from the output of a TRIMHX run. In an attempt to simplify the reactor limits process by reducing the number of assemblies which must be run through FLOWTRAN, TRIMPWR also sorts the assemblies by the product of the power post peaking and the maximum normalized axial power density for each assembly. This follows from the assumption that those assemblies having the maximum value of this product will have the most restrictive limits.
1989-11-01
Studies on the superconducting properties of A-15 type intermetallic compounds
International Nuclear Information System (INIS)
The influence of 3d-transition metal impurities on the superconducting properties of the A-15 compounds V_3Si and V_3Ga have been investigated. In the case of V_3Si, the Fe impurities replacing V were found to have a local moment. A compensation effect was found in this case, resulting in a 20KOe increase in the upper critical field at dilute concentrations of Fe. It was demonstrated that long range order V_3Ga possessed higher transition temperature and upper critical field than found hitherto. Investigations on Nb_3Ge/sub 1-x/Ga/sub x/ films obtained by chemical vapor deposition has clearly shown the relation between the transition temperature and structural characteristics. The influence of generalized defects on the superconducting properties in A-15 type Nb_3X compounds has been discussed.
State of the art simulations of magnicon
International Nuclear Information System (INIS)
The magnicon is a highly attractive candidate to be the RF source for a future multi-Tev linear collider. Physical models and computer codes have been developed which can provide start-to-end self-consistent simulations of a magnicon, including precise simulations of the high-convergence electron gun, RF-system, magnetic system, and beam collector. The 3-D beam dynamics simulations include realistic fields, finite beam size and transverse space charge effects. The codes allow one to provide steady-state simulations of the entire tube, so as to evaluate transient process of magnicon excitation, parasitic mode self-excitation, stability analysis, and tolerance analysis. The results of the simulations are found to be in good agreement with magnicon experiments. A brief description of the physical models and simulation codes employed will be given.
2002-12-12
Road Interpretation for Driver Assistance Based on an Early Cognitive Vision System
DEFF Research Database (Denmark)
In this work, we address the problem of road interpretation for driver assistance based on an early cognitive vision system. The structure of a road and the relevant traf?c are interpreted in terms of ego-motion estimation of the car, independently moving objects on the road, lane markers and large scale maps of the road. We make use of temporal and spatial disambiguation mechanisms to increase the reliability of visually extracted 2D and 3D information. This information is then used to interpret the layout of the road by using lane markers that are detected via Bayesian reasoning. We also estimate the ego-motion of the car which is used to create large scale maps of the road and also to detect independently moving objects. Sample results for the presented algorithms are shown on a stereo image sequence, that has been collected from a structured road.
2009-01-01
Relativistic distorted-wave results for nickel-like gadolinium
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.
1986-08-01
Pool critical assembly benchmark solutions using MCNP and THREEDANT
Energy Technology Data Exchange (ETDEWEB)
Analyses of pressure vessel damage resulting from neutron irradiation have primarily relied on two-dimensional transport calculations and a spatial-synthesis methodology to accommodate three-dimensional effects in the results of two two-dimensional calculations. In this paper, the authors report on calculations made on the Pool Critical Assembly (PCA) Benchmark, Configuration 12/13, using the three-dimensional, continuous energy Monte Carlo transport code, MCNP, and the three-dimensional, multigroup, diffusion accelerated discrete ordinates transport code THREEDANT. Neutron fluxes and activation rates as determined from these two calculations are compared to each other and to experimental results in the literature. The authors also draw some conclusions on the value of 3D calculations on the interpretation of experimental results.
1994-12-31
Polyether matrices for lithium generators; Matrices polyethers pour generateurs au lithium
Energy Technology Data Exchange (ETDEWEB)
The use of solvating polymers of polyether type is an interesting solution for the manufacturing of high capacity lithium batteries with lithium metal anodes and which can operate at T > 50 deg. C. These operating conditions are perfectly compatible with electric-powered vehicle and stationary battery applications. In order to improve the ionic conductivity of polymer electrolytes, new aprotic and amorphous polyether lattices have been synthesized having a good conductivity but also good thermal, mechanical and electrochemical stabilities. Two type of 3-D polyether lattices obtained by reticulation of linear pre-polymers have been selected as host polymers: unsaturated poly-condensate and unsaturated co-polyethers. (J.S.) 18 refs.
1996-12-31
Performance following a 500-675 rad neutron pulse. Report for June 1981-January 1984
Energy Technology Data Exchange (ETDEWEB)
A three-light, three-lever discrete avoidance behavioral task was initiated to study the effects of a 500-675 rad neutron pulse upon performance. Eight primates performed the task for 4 h(3.5 h postexposure) on exposure day and for 4 h on each of 3 d postexposure. For the exposure day, five subjects had a decrease in correct responses, seven had increased reaction times, and six experienced productive emesis within 3.5 hours postexposure. Although the performance degradations were not severe, these data suggest that the performance of time critical tasks could be significantly impaired.
1985-06-01
PDBpaint, a visualization webservice to tag protein structures with sequence annotations
British Library Electronic Table of Contents (United Kingdom)
Summary: Protein features are often displayed along the linear sequence of amino acids that make up that protein, but in reality these features occupy a position in the folded proteins 3D space. Mapping sequence features to known or predicted protein structures is useful when trying to deduce the function of those features and when evaluating sequence or structural predictions. To facilitate this goal, we developed PDBpaint, a simple tool that displays protein sequence features gathered from bioinformatics resources on top of protein structures, which are displayed in an interactive window (using the Jmol Java viewer). PDBpaint can be used either with existing protein structures or with novel structures provided by the user. The current version of PDBpaint allows the visualization of annot...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
This study presents new software, called Google Earth-based Optimal HAulage RouTing System (GEOHARTS), to improve the functionality of Google Earth for optimal haulage routing of off-road dump trucks in construction and mining sites. A modified least-cost path algorithm, which is applicable to working areas with both paved and unpaved temporary roads and can consider the effects of terrain relief and curves along a route on the route planning, was proposed and utilized for the software development. GEOHARTS can determine optimal haulage routes between loaders and dumps that ensure the least travel time or fuel consumption of off-road dump trucks and can visualize the results using an embedded 3D render window of Google Earth. The application to the Pasir open-pit coal mine in Indonesia dem...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
The use of numerical modeling in oil spill incidents is a well established technique that has proven to provide cost-effective and reasonable estimates of oil surface drift. Good predictability of such models depends highly on the quality of the input data of the incident and on the model calibration effort. This paper presents the results of simulating oil spillage trajectory in the Arabian (Persian) Gulf. The study employed a 3-D rectilinear hydrodynamic model combined with oil spill model. Typical representative environmental conditions of the Arabian Gulf were first setup into a hydrodynamic circulation model using data from various sources. The performance of the hydrodynamic model was then tested against measurements of tidal fluctuation and sea currents at selected locations. The sp...
2007-01-01
Nanowires of silicon carbide and 3D SiC/C nanocomposites with inverse opal structure
International Nuclear Information System (INIS)
Synthesis, morphology, structural and optical characteristics of SiC NWs and SiC/C nanocomposites with an inverse opal lattice have been investigated. The samples were prepared by carbothermal reduction of silica (SiC NWs) and by thermo-chemical treatment of opal matrices (SiC/C) filled with carbon compounds which was followed by silicon dioxide dissolution. It was shown that the nucleation of SiC NWs occurs at the surface of carbon fibers felt. It was observed three preferred growth direction of the NWs: [111], [110] and [112]. HRTEM studies revealed the mechanism of the wires growth direction change. SiC/C- HRTEM revealed in the structure of the composites, except for silicon carbide, graphite and amorphous carbon, spherical carbon particles containing concentric graphite shells (onion-like particles).
2011-07-07
Measurements of K-beta/K-alpha X-ray intensity ratios using VEC beams
International Nuclear Information System (INIS)
An experiment on the K#beta#/K#alpha# characteristic X-ray intensity ratio in silver was performed at VEC Centre, Calcutta using the #alpha#-beams at energies 40 MeV and 50 MeV employing a Si(Li) detector system on-line. The results show that the K#beta#/K#alpha# X-ray intensity ratio at energies 40 and 50 MeV are 0.215 #+-# 0.006 and 0.216 #+-# 0.006, respectively, which indicates no change with beam energy and in accordance with the earlier reports. The present experiment shows the feasibility of studying the K#beta#/K#alpha# ratios as a function of beam energy in different regions of periodic table. Experiments in elements belonging to the 3d shell and their compounds are suggested to look for the chemical effects and their dependence on #alpha#-energy. (author). 7 refs.
1987-02-03
Isolation and mapping of a polymorphic DNA sequence (pEFD64. 2) on chromosome 3 (D3S46)
Energy Technology Data Exchange (ETDEWEB)
A 4.0 kb TaqI fragment of cosmid EFD64 isolated by a HBV-3 oligonucleotide was subcloned into AccI site of pUC18. MspI identifies 5 allelic VNTR polymorphism with bands between 2.6 and 4.6 kb. RsaI, TaqI, EcoRI, BamHI, HindIII and PvuII identify the same VNTR polymorphism. With RsaI, 80% heterozygosity were observed in 80 unrelated Caucasians. This RFLP pEFD64.2 has been assigned to chromosome 3 by linkage analysis with loci (APOD) known to span this chromosome. Co-dominant segregation for the RsaI RFLP was observed in 40 three generation families. RFLPs were observed under the normal hybridization and washing condition.
1988-10-11
Ion-induced M X-ray emission from heavy lanthanides
International Nuclear Information System (INIS)
Thick targets of several heavy lanthanide (Ho-Lu) compounds were bombarded by protons and "3He ions of 3 MeV/amu, and M_#alpha# and M_#beta# X-rays were measured with a crystal spectrometer. Ionization probabilities of the N-shell for zero impact parameter were obtained from the X-ray intensity ratio for proton and "3He ion impacts. A shell dependence of the ionization probability was found in a scaling plot. X-ray spectra of lanthanide compounds were compared and no chemical effect was observed. This result is considered to be due to the fact that the main component of M_#alpha# and M_#beta# lines is for radiative transition after the refilling of the 4f orbit (3d"-"14f"n"+"1 #-># 4f"n) where n denotes the number of 4f electrons of the target atom before ionization. (orig.).
1987-12-01
Energy Technology Data Exchange (ETDEWEB)
The effect of varying pD(11-13,7) on the reaction of hydrogen with (Co/sup 11/(CN)/sub 5/)/sup 3/- in deuterium oxide has been studied by using infrared spectroscopy to determine the ratio of (Co/sup 111/(CN)/sub 5/X)/sup 3/- (X=H,D) in the solids precipitated from the steady state under hydrogen. The results show that the uptake of hydrogen does not liberate a free proton and that the rate of (Co/sup 111/(CN)/sub 5/H)/sup 3/- -D/sub 2/,0 exchange increases with pD but becomes pD independent at pD 7 greater than 13,5.
1982-01-01
Influence of alloying effect on X-ray fluorescence parameters of Co and Cu in CoCuAg alloy films
British Library Electronic Table of Contents (United Kingdom)
In this study, Kb/Ka X-ray intensity ratios, Formula Not Shown , Formula Not Shown production cross-sections and K fluorescence yields of Co and Cu and Lb/La X-ray intensity ratios, Formula Not Shown , Formula Not Shown production cross-sections and Formula Not Shown average fluorescence yields of Ag in pure metals and in different alloy compositions were measured. In this study, alloying effects on the Formula Not Shown production cross-sections of Co and Cu were investigated and changes interpreted according to the rearrangement of valance state electrons and the charge transfer process between the 3d elements (Co and Cu) and Ag.
2009-01-01
Hearing pathways and directional sensitivity of the beluga whale, Delphinapterus leucas
British Library Electronic Table of Contents (United Kingdom)
Odontocetes are believed to receive sounds primarily through the pan bone region of the lower jaw although much variation in jaw morphology exists among species. In order to further examine this jaw hearing hypothesis we tested the head receiving sensitivity and directional hearing of a beluga whale, Delphinapterus leucas. Hearing thresholds were measured using auditory evoked potentials (AEPs). The subject proved to have highly directional hearing for far-field click stimuli similar to that of bottlenose dolphins and more directional than the harbor porpoise. For near-field jawphone stimulation, the beluga's lowest thresholds were found when click stimuli were presented at the rostrum tip (76?dB re: 1??Pa) although thresholds from the pan bone region stimulation were only 2?3?dB higher. S...
2008-01-01
British Library Electronic Table of Contents (United Kingdom)
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...
2011-01-01
Epitaxial bain path in transition metals
Energy Technology Data Exchange (ETDEWEB)
Epitaxial films grown pseudomorphically on substrates provide a way to stabilise non-equilibrium structures of materials. Obviously, there always is a certain lattice misfit between substrate and film material in its bulk equilibrium structure. In the pseudomorphic regime, this misfit can either lead to the growth of films in a strained bulk structure or even yield structures that are not stable in the bulk. Large misfits do not necessarily imply large lateral stress. Theory can help to predict e.g. geometry, stress and magnetic properties of pseusomorphically grown metal films. In this work, we considered the fcc-bcc epitaxial Bain path of 3d, 4d, and 5d transition metals, which provides a reasonable description of tetragonally distorted films on substrates. We carried out density functional calculations in the implementation of the full potential local orbital program package FPLO. Emphasis is put on similarities among the transition metals.
2010-07-01
Elastic and inelastic scattering of "1"4C from medium heavy nuclei
International Nuclear Information System (INIS)
The elastic and inelastic scattering of "1"4C at 51 MeV from targets of "4"0Ca, "5"6Fe, "6"0Ni, "6"6Zn and "8"8Sr has been measured using a Q3D spectrometer. The "1"4C-nucleus potentials have been derived by optical-model analysis of the observed elastic scattering; the inelastic scattering differential cross sections were interpreted in the distorted-wave Born approximation and also in the coupled-channels approach. The analysis yields "1"4C-nucleus potentials that closely resemble "1"2sup(,)"1"3C and "1"6O potentials. (orig.).
Development of new CAD system for steel structures of nuclear power plants
Energy Technology Data Exchange (ETDEWEB)
IHI has developed a new Three-Dimensional Computer-Aided Design (3D-CAD) system to improve the design efficiency and quality of the steel structure of nuclear power plants. This system covers every design phase from the initial arrangement of structure to the production design sharing the same database. The system incorporates the design rules and professional expertise of designers, and enable easy and efficient design. The system can easily generate the three-dimensional data for structures, model data for stress analyses and composite arrangement data. The system has already been applied to several plants under construction and has achieved excellent results. The outline of the new CAD system is introduced. (author)
1999-09-01
Development of in-vessel reflood instrumentation at ORNL
International Nuclear Information System (INIS)
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 ...
2004-09-06
Development of Ultra-Fast Silicon Switches for Active X-Band High Power RF Compression Systems
Energy Technology Data Exchange (ETDEWEB)
We present the recent results of our research on the high power ultra-fast silicon RF switches. This switch is composed of a group of PIN diodes on a high purity silicon wafer. The wafer is inserted into a cylindrical waveguide under TE{sub 01} mode, performing switching by injecting carriers into the bulk silicon. Our current design uses a CMOS compatible process and the device was fabricated at SNF (Stanford Nanofabrication Facility). 300 ns switching time has been observed, while the switching speed can be improved further with 3-D device structure and faster driving circuit. Power handling capacity of the switch is at the level of 10 MW. The switch was designed for active X-band RF pulse compression systems--especially for NLC, but it is also possible to be modified for other applications and other frequencies.
2006-03-06
Development of Seismic Analysis Model and Time History Analysis for KALIMER-600
Energy Technology Data Exchange (ETDEWEB)
This report describes a simple seismic analysis model of the KALIMER-600 sodium cooled fast reactor and its application to the seismic time history analysis. To develop the simple seismic analysis model, the detailed 3-D finite element analyses for main components, IHTS piping system, and reactor building were carried out to verify the dynamic characteristics of each part of simple seismic analysis models. By using the developed simple model, the seismic time history analyses for both cases of a seismic isolation and non-isolation design of KALIMER-600 were performed. From the comparison of the calculated floor response spectrum, it is verified that the seismically isolated KALIMER-600 reactor building shows a great performance of a seismic isolation and assures a seismic integrity.
2007-02-15
Design and fabrication of a micro zinc/air battery
Energy Technology Data Exchange (ETDEWEB)
Micro-batteries are one of the key components that restrict the application of autonomous Microsystems. However little efforts were made to solve the problem. We have proposed a new planar zinc/air micro-battery, suitable for autonomous microsystem applications. The micro-battery has a layered structure of zinc electrode/alkaline electrolyte/air cathode. A 3D zinc electrode with a high density of posts was designed to obtain a high porosity, hence to offer a best performance. A model of the micro-battery is developed and the device performances were simulated and discussed. A four-mask process was developed to fabricate the prototype micro-batteries. The preliminary testing results showed the micro-batteries is able to deliver a maximum power up to 5 mW, and with an average power of 100 {mu}W at a steady period for up to 2hrs. Fabrication process is still under optimization for further improvement.
2006-04-01
British Library Electronic Table of Contents (United Kingdom)
The Physikalisch-Technische Bundesanstalt (PTB), Germany's national metrology institute, developed an alignment strategy to specify elemental depth profiling in vertical sidewall layers on structured wafers. For this purpose, PTB's irradiation chamber for 200?mm and 300?mm silicon wafers was used to combine total-reflection X-ray fluorescence (TXRF) and grazing incidence XRF (GIXRF) techniques by employing monochromatized undulator radiation of the BESSY II electron storage ring. 3-D test structures were fabricated to develop an optimal alignment strategy allowing for depth profiling in such nanolayers. The test structures consisted of silicon bars with widths/spacings either in the ?m or in the nm range. In order to be able to differentiate the sidewalls more easily from the remainder of ...
2008-01-01
Controlled manipulation of carbon nanopillars and cantilevers by focused ion beam
International Nuclear Information System (INIS)
We explore a novel phenomenon of focused ion beam (FIB) induced bending of carbon nanopillars or cantilever structures. The bending occurs towards the ion beam during scanning. The explanation of this bending has been sought on the basis of a model which considers temperature rise and gradients caused by the impinging ion beam. The process is controllable and reversible, which makes it highly suitable for in situ manipulation to make desired 3D shapes by the piecewise bending of the nanopillars and cantilever structures during their fabrication using electron beam or FIB chemical vapor deposition (EB-CVD or FIB-CVD). Its usefulness in the fabrication of nanosize mechanical components has been demonstrated by making a branch structure from a single cantilever.
2008-05-21
Cloud Formation and Dynamics in Cool Dwarf and Hot Exoplanetary Atmospheres
The lowest-mass stars, brown dwarfs and extrasolar planets present challenges and opportunities for understanding dynamics and cloud formation processes in low-temperature atmospheres. For brown dwarfs, the formation, variation and rapid depletion of photospheric clouds in L- and T-type dwarfs, and spectroscopic evidence for non-equilibrium chemistry associated with vertical mixing, all point to a fundamental role for dynamics in vertical abundance distributions and cloud/grain formation cycles. For exoplanets, azimuthal heat variations and the detection of stratospheric and exospheric layers indicate multi-layered, asymmetric atmospheres that may also be time-variable (particularly for systems with highly elliptical orbits). Dust and clouds may also play an important role in the thermal energy balance of exoplanets through albedo effects. For all of these cases, 3D atmosphere models are becoming an increasingly essential tool for understanding ...
2009-01-01
Cerium moment collapse in ternary silicides CePd_2_-_xMn_xSi_2 (0#<=#x#<=#2)
International Nuclear Information System (INIS)
Cerium L_3 XANES (x-ray-absorption near-edge-structure) spectra were analyzed to separate Ce moment contributions and mixed valence (MV) in complex magnetic silicides CePd_2_-_xMn_xSi_2 (0#<=#x#<=#2). The Ce valence mixing does not vary linearly with x, but increases rapidly for x#>=#1.5. The associated moment collapse correlates with pronounced deviations of the unit-cell volume from Vegard law and the onset of structural instability. Reorientation of [001] Mn 3d antiferromagnetic order for x<2 appears to rapidly suppress the weak Ce valence mixing coexisting with antiferromagnetic order in CeMn_2Si_2.
Capturing recrystallization of metals with a multi-scale materials model
Energy Technology Data Exchange (ETDEWEB)
The final report for a Laboratory Directed Research and Development project entitled, ``Capturing Recrystallization of Metals in a Multiscale Materials Model'' is presented. In this project, deformation and recrystallization processes have been followed experimentally and theoretically in order to incorporate essential mechanisms from the defect (dislocation) and grain size length scales. A nonlinear rotational gradient theory has been developed which enables the incorporation of microstructural parameters. The evolution of these parameters during deformation and recrystallization has been characterized qualitatively and quantitatively, applying various electron optic techniques ranging over several length scales. The theoretical and experimental framework developed is general. It has been exemplified by an application to recrystallization in single crystals and bicrystals of aluminum. The recrystallization process has been modeled using a ...
2000-04-01
Energy Technology Data Exchange (ETDEWEB)
In the previous paper, we have derived a dispersion relation for the free electron laser (FEL) gain in the exponential regime taking account the diffraction and electron`s betatron oscillation. Here, we compare the growth rates obtained by solving the dispersion relation with those obtained by simulation calculation for the waterbag and the Gaussian models for the electron`s transverse phase space distribution. The agreement is found to be good except for the limiting case where the Rayleigh length is much longer than the gain length (1-D limit). We also generalize the analysis to the case where the electron beam cross section is elliptical as is usually the case in storage rings, and derive the first-order dispersion relation.
1992-08-01
Based on recent work on simplicial diffeomorphisms in colored group field theories, we develop a representation of the colored Boulatov model, in which the GFT fields depend on variables associated to vertices of the associated simplicial complex, as opposed to edges. On top of simplifying the action of diffeomorphisms, the main advantage of this representation is that the GFT Feynman graphs have a different stranded structure, which allows a direct identification of subgraphs associated to bubbles, and their evaluation is simplified drastically. As a first important application of this formulation, we derive new scaling bounds for the regularized amplitudes, organized in terms of the genera of the bubbles, and show how the pseudo-manifolds configurations appearing in the perturbative expansion are suppressed as compared to manifolds. Moreover, these bounds are proved to be optimal.
2011-01-01
Body-and-cad Geometric Constraint Systems
Motivated by constraint-based CAD software, we develop the foundation for the rigidity theory of a very general model: the body-and-cad structure, composed of rigid bodies in 3D constrained by pairwise coincidence, angular and distance constraints. We identify 21 relevant geometric constraints and develop the corresponding infinitesimal rigidity theory for these structures. The classical body-and-bar rigidity model can be viewed as a body-and-cad structure that uses only one constraint from this new class. As a consequence, we identify a new, necessary, but not sufficient, counting condition for minimal rigidity of body-and-cad structures: nested sparsity. This is a slight generalization of the well-known sparsity condition of Maxwell.
2010-01-01
Application research on three-dimensional virtual mine in the framework of internet of things
British Library Electronic Table of Contents (United Kingdom)
Based on the information system characteristics of mine, proposed network architecture design of the mine property. And in this framework based on the design of three-dimensional virtual mine described the application of intelligent management platform. Three-dimensional virtual underground mine that shows the situation, the core application is through remote monitoring system of information exchange between devices (material object communication). Internet of things in the framework of mining three-dimensional virtual reconstruction of mine. On coal mine safety in the production process of human, machine and environment, control elements and their harmony and unity. 3D virtual mine management platform integrates personnel positioning, dust control, gas monitoring, roof pressure monitoring...
2011-01-01
Anaerobic treatment of biodiesel by-products in a pilot scale reactor
British Library Electronic Table of Contents (United Kingdom)
In this work, long-term operation of a pilot scale mixed anaerobic reactor processing crude glycerol and rapeseed meal is discussed. These materials are generated as by-products of biodiesel production. Mixed reactor was operated under mesophilic conditions for the period of 654 days. Total cumulative production of biogas reached 379 m3 (at atmospheric pressure and ambient temperature). Maximum volumetric loading achieved during the operation was 2.17 kg m?3 d?1 for the crude glycerol dose of 2 L. When dosing crude glycerol as a single substrate, average specific production of biogas of 0.76 m3 per L of the g-phase was achieved. The lack of nutrients in the g-phase had to be compensated by an addition of ammonium nitrogen in the form of urea into the reactor. Long term processing of crude ...
2011-01-01
Airbags to Martian Landers: Analyses at Sandia National Laboratories
Energy Technology Data Exchange (ETDEWEB)
A new direction for the national laboratories is to assist US business with research and development, primarily through cooperative research and development agreements (CRADAs). Technology transfer to the private sector has been very successful as over 200 CRADAs are in place at Sandia. Because of these cooperative efforts, technology has evolved into some new areas not commonly associated with the former mission of the national laboratories. An example of this is the analysis of fabric structures. Explicit analyses and expertise in constructing parachutes led to the development of a next generation automobile airbag; which led to the construction, testing, and analysis of the Jet Propulsion Laboratory Mars Environmental Survey Lander; and finally led to the development of CAD based custom garment designs using 3D scanned images of the human body. The structural analysis of these fabric structures is described as well as a more traditional ...
1994-03-01
British Library Electronic Table of Contents (United Kingdom)
The purpose of this study was to compare 2 adaptive radiotherapy strategies with helical tomotherapy. A patient having mesothelioma with mediastinal nodes was treated using helical tomotherapy with pretreatment megavoltage CT (MVCT) imaging. Gross tumor volumes (GTVs) were outlined on every MVCT study. Two alternatives for adapting the treatment were investigated: (1) keeping the prescribed dose to the targets while reducing the dose to the OARs and (2) escalating the target dose while maintaining the original level of healthy tissue sparing. Intensity modulated radiotherapy (step-and-shoot IMRT) and 3D conformal radiotherapy (3DCRT) plans for the patient were generated and compared. The primary lesion and nodal mass regressed by 16.2% and 32.5%, respectively. Adapted GTVs and reduced plan...
2009-01-01
Acoustic resonances in two-dimensional radial sonic crystal shells
Energy Technology Data Exchange (ETDEWEB)
Radial sonic crystals (RSC) are fluidlike structures infinitely periodic along the radial direction that verify the Bloch theorem and are possible only if certain specially designed acoustic metamaterials with mass density anisotropy can be engineered (see Torrent and Sanchez-Dehesa 2009 Phys. Rev. Lett. 103 064301). A comprehensive analysis of two-dimensional (2D) RSC shells is reported here. A given shell is in fact a circular slab with a central cavity. These finite crystal structures contain Fabry-Perot-like resonances and modes strongly localized at the central cavity. Semi-analytical expressions are developed to obtain the quality factors of the different resonances, their symmetry features and their excitation properties. The results reported here are completely general and can be extended to equivalent 3D spherical shells and to their photonic counterparts.
2010-07-15
3D investigations of plasma erosion craters using FIB/SEM dual-beam techniques
Energy Technology Data Exchange (ETDEWEB)
Plasma erosion craters caused by electrical discharges on the surface of materials are important features of the erosion processes resulting in the degradation of electrodes. In the present work, electrical discharges were produced on a bi-metallic Ni/Cu multilayered surface. By means of dual beam techniques, coupling a focused ion beam (FIB) and a scanning electron microscope (SEM), not only the surface but also the sub-surface structure of the craters were investigated. Using the combination of SEM, FIB and STEM-EDX, a complete three-dimensional investigation of the craters were carried out. The analysis of the microstructure modifications as a function of depth enabled to determine the field of interaction between the plasma and the material. (orig.)
2006-09-15
Energy Technology Data Exchange (ETDEWEB)
This is a report of the above-named solar car race from Darwin to Adelaide, Australia. On January 7, 1983, an Australian adventurer Mr. Hans Tholstrup succeeded in running from the Australian west coast to Sydney in a car driven solely by solar energy. The travel took 20 days, at an average speed of 23km per hour. The technology has made remarkable advances since his success and, in the World Solar Challenge 1993 held in November 1993, a Honda team crossed the Australian Continent at an average speed of 85km per hour. Technical challenges included the development of maximum-output solar cell panels, a car designed to make full use of such power, and a run at the maximum possible speed, all these dependent solely on the sun as energy source. This report Part I contains the details of the race, analysis, aerodynamics, car body structure, manufacture, materials, and so forth. (NEDO)
1994-01-01
VAWT (Vertical-Axis Wind Turbine) stochastic loads produced by atmospheric turbulence
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 paper discusses the development of a model for the simulation of these stochastic loads, given the rotor geometry, operating conditions, and assumed turbulence properties. A Double-Multiple-Streamtube analysis is employed, which includes the effects of wind shear. Reynolds number variations, different airfoil sections and chord lengths along the blade span, and an empirical model for dynamic stall effects. Calculations are presented for the VAWT 34-m Test Bed currently being assembled at Bushland, Texas. Time histories of the loads, as well as their Fourier spectra, are presented and discussed. An unexpected finding is that the average output power is predicted to be more sensitive to turbulence level than ...
1987-01-01
Structural design and fabrication of the Sandia 34-meter Vertical Axis Wind Turbine
The Wind Energy Research Division of Sandia National Laboratories has been funded by the Wind/Ocean Technology Division of the Department of Energy (DOE) to design and build a 34-meter diameter Vertical Axis Wind Turbine (VAWT). The turbine design incorporates the results of recent VAWT research in aerodynamics and structural dynamics. Initial system concept studies identified several blade options that met the required power rating of 500 kW. The final blade and rotor configurations were chosen based on finite element calculations that determined the turbine modes of response, their frequency of vibration, and stress levels. For parked survival turbine components were designed to with stand the loading of a 150 mph (67.0 m/s) wind coupled with maximum cable tensions. Specific areas of design discussed include the rotor, cables, bearings, brakes, and foundations. Construction of the turbine is in progress at this time and anticipated completion of the project is ...
1987-01-01
Energy Technology Data Exchange (ETDEWEB)
This paper states the concept of a heat-resistant structure of the HOPE airframe having a 10 ton weight when lifting off and also the research situation of heat-resistant structural materials. To study the structure, established are design conditions for lift-off, reentry to the atmosphere and landing. As to the load condition, the load at the time of lift-off is most critical. Relating to the temperature environment condition, thermal analysis is made of the time when a HOPE is on the orbit (low-temperature range) and reenters the atmosphere (high-temperature range), when the temperature environment is critical. The analysis shows that the temrerature environment is in a {minus}80-1700{degree}C (range). The heat-resistant structural materials are developed so as to meet these conditions. The paper describes distribution of the airframe surface temperature by aerodynamic heating at the reentry, conceptual figures of the airframe structure and structural materials. ...
1991-11-05
Radial turbine development for the 100 kW automotive ceramic gas turbine
Energy Technology Data Exchange (ETDEWEB)
The development of turbine components for the automotive 100 kW ceramic gas turbine has entered the final stage of the seven-year project and is making satisfactory progress, toward the goals. The authors attained the interim targets of the aerodynamic performances and have been carrying out tests to further improve efficiency. As for ceramic parts, they have changed the material of the turbine rotor to a new one that is excellent in long-sustained and high-temperature strength properties, and have confirmed substantial strength at high temperature through hot-spin tests. After evaluating blade-vibration stress through analyses and experiments, the authors completed an endurance evaluation at 1200 C (1473 K) TIT (Turbine Inlet Gas Temperature) and a rated speed of 100,000 rpm. The authors are now carrying out endurance tests at 1350 C (1623 K) TIT. For ceramic stationary parts, they already finished the evaluations at 1200 C TIT and are also conducting an endurance ...
1998-01-01
Pulmonary retention of lead: an experimental study in man
Energy Technology Data Exchange (ETDEWEB)
This human investigation of lead absorption from the lungs utilized two forms of lead, lead chloride and lead hydroxide; the former was used in picogram amounts and the latter at microgram levels. These two species of lead were selected in an attempt to simulate the range of physicochemical properties found in atmospheric lead (urban air). Aerosols labeled with lead-203 were made of comparable aerodynamic size by using sodium chloride as the deposition-determining aerosol. After brief, mouthpiece exposures, 17 subjects were followed by serial counting with a thoracic array of scintillation detectors and two leg counters. Serial blood samples were also taken. The two exposure groups showed similar total deposition values (23 vs 26%) and the same biological retention halftimes, viz., 22.6 hr. When the retention data were corrected for blood-borne /sup 203/Pb, the biological halftimes for lung lead retention averaged 13.1 and 14.2 hr, respectively, and were not ...
1980-01-01
Energy Technology Data Exchange (ETDEWEB)
Simplifying hypotheses are required when combustion and aerodynamic phenomena are considered simultaneously. In this paper, a turbulent combustion model is proposed, in which the combustion chemistry is reduced to a single reaction. In this way, only two variables are needed to describe the problem and combustion can be characterized by the consumption of one of the two reactive species. In a first step, the instantaneous consumption rate is obtained using the Lagrangian form of the mass fraction equation of the species under consideration, and by considering the equilibrium state only. This state is determined in order to preserve the consistency with results that should be obtained using a complete kinetics scheme. In a second step, the average rate is determined using the instantaneous consumption term and a probabilistic density function. This model was tested on various configurations and in particular on an experimental main chamber and on a reheating ...
1996-12-31
Numerical simulation of droplets deposition in a horizontal turbulent channel flow
In this dissertation, a two-phase, air-droplets, dilute, turbulent, and steady state flow in a horizontal rectangular channel, is modeled and numerically simulated using a modified KIVA-3V code. The deposition of different sizes of droplets on the walls of the channel is also studied. In this model, the interaction effects between the phases (two-way coupling) are considered by source terms in the momentum and energy equations for the continuous phase and by the instantaneous local velocity of the air in the droplet equation of motion, which includes the aerodynamic and gravitational forces. The turbulence is modeled by a k-? model. The interaction effects between the turbulence and the dispersed droplets are also taken into account. The effects of the turbulence on the droplets are modeled by a fluctuating component added to the local air velocity in the droplet equation of motion. The effects of the droplets on the turbulence are modeled by two extra terms in the ...
1999-01-01
We present results from an investigation of the dynamical behavior of buoyant magnetic flux rings in the radiative interior of a uniformly rotating early-type star. Our physical model describes a thin, axisymmetric, toroidal flux tube that is released from the outer boundary of the convective core, and is acted upon by buoyant, centrifugal, Coriolis, magnetic tension, and aerodynamic drag forces. We find that rings emitted in the equatorial plane can attain a stationary equilibrium state that is stable with respect to small displacements in radius, but is unstable when perturbed in the meridional direction. Rings emitted at other latitudes travel toward the surface along trajectories that largely parallel the rotation axis of the star. Over much of the ascent, the instantaneous rise speed is determined by the rate of heating by the absorption of radiation that diffuses into the tube from the external medium. Since the time scale for this heating varies like the ...
2003-01-01
Low-pressure steam turbine retrofits; Nachruestung von Niederdruck-Dampfturbinen
Energy Technology Data Exchange (ETDEWEB)
LP steam turbine retrofits are generally undertaken as a result of mechanical problems, for example due to stress corrosion cracking, torsional vibration or erosion. They present plant operators with an opportunity to introduce advanced aerodynamic technology, and at the same time improve efficiency and availability. Standard components, the majority proven in long-term service, can be used to obtain a permanent solution to the problems. In several European countries, retrofits have been carried out on intact LP steam turbines owned by utilities whose primary motivation is efficiency improvement. (orig.) [Deutsch] Niederdruck-Dampfturbinen werden in der Regel nur dann nachgeruestet, wenn waehrend des Betriebes Probleme durch Spannungsrisskorrosion, Torsionsschwingungen oder Erosion auftreten. In solchen Faellen bietet sich die Gelegenheit, eine moderne aerodynamische Loesung zu waehlen, die gleichzeitig Wirkungsgrad und Verfuegbarkeit verbessert. Es wird gezeigt, ...
1996-09-01
Decontamination factor of air filter against /sup 198/Au aerosol particles
Energy Technology Data Exchange (ETDEWEB)
DF (decontamination factor) of two types of air filter was investigated against /sup 198/Au aerosol particles with AMAD (activity median aerodynamic diameter) = 1.2 ..mu..m and sigmag (geometric standard deviation) = 2.0. One of the filters, SO filter, is HEPA (high efficiency particulate air) filter media with 46 mmphi, and the other is HE-40T (cellulose-glass fiber filter for dust sampling) filter media with 40 mmphi. DF of the SO filter was found to be over 5 x 10/sup 4/ at air flow rate of 1 lmin. And DF of HE-40 T filter was determined to be 94+-4 at the same airflow rate. In the multistage HE-40 T filter system, DF decreased at each succeeding stage. It was confirmed by numerical simulation that the decrease of DF was not inconsistent with the decrease of collection performance in each successive filter. It was also confirmed that DF could be predicted by the numerical simulaiton, if particle penetration function of filter and size distribution function of ...
1987-12-01
Decontamination factor of air filter against "1"9"8Au aerosol particles
International Nuclear Information System (INIS)
DF (decontamination factor) of two types of air filter was investigated against "1"9"8Au aerosol particles with AMAD (activity median aerodynamic diameter) = 1.2 #mu#m and #sigma#g (geometric standard deviation) = 2.0. One of the filters, SO filter, is HEPA (high efficiency particulate air) filter media with 46 mm#phi#, and the other is HE-40T (cellulose-glass fiber filter for dust sampling) filter media with 40 mm#phi#. DF of the SO filter was found to be over 5 x 10"4 at air flow rate of 1 l/min. And DF of HE-40 T filter was determined to be 94#+-#4 at the same airflow rate. In the multistage HE-40 T filter system, DF decreased at each succeeding stage. It was confirmed by numerical simulation that the decrease of DF was not inconsistent with the decrease of collection performance in each successive filter. It was also confirmed that DF could be predicted by the numerical simulaiton, if particle penetration function of filter and size distribution function of ...
Buffeting of a slender circular beam in axial turbulent flows
Energy Technology Data Exchange (ETDEWEB)
This paper deals with the buffeting of a slender, circular, flexible beam-rod in an axial turbulent flow. The principal excitation mechanisms are the turbulent wall pressure fluctuations and the motion-dependent (self-excited) aerodynamic force caused by the beam motion. On the assumption that the turbulent wall pressure fluctuations are independent of the beam motion, a linear forced-vibration model is used to determine the buffeting response of the beam and to investigate the length scale effects of turbulences on the beam buffeting. Transverse buffeting of the beam in an axial turbulent flow depends largely on the ratio of the longitudinal scale of the turbulences to the bending wavelength of the beam and on the ratio of the circumferential scale of the turbulences to the radius of the beam. The spectra and the mean square values of the buffeting displacement of the beam become vanishingly small, both when either of these ratios is very small (<10/sup -2/) ...
1984-05-01
Ambient air pollution and congenital heart disease: a register-based study.
Maternal exposure to ambient air pollution has increasingly been linked to adverse pregnancy outcomes. The evidence linking this exposure to congenital anomalies is still limited and controversial. This case-control study investigated the association between maternal exposure to ambient particulate matter with aerodynamic diameter less than 10 ?m (PM(10)), sulfur dioxide (SO(2)), nitrogen dioxide, nitric oxide (NO), ozone (O(3)), and carbon monoxide (CO) and the occurrence of congenital heart disease in the population of Northeast England (1993-2003). Each case and control was assigned weekly average (weeks 3-8 of pregnancy) of pollutant levels measured by the closest monitor to the mother's residential postcode. Using exposure as both continuous and categorical variables, logistic regression models were constructed to quantify the adjusted odds ratios of exposure to air pollutants and the occurrence of each outcome group. We found exposure to CO and NO to be ...
2011-02-17
Air liquefaction and enrichment system propulsion in reusable launch vehicles
Energy Technology Data Exchange (ETDEWEB)
A concept is shown for a fully reusable, Earth-to-orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high-speed acceleration, both using liquid hydrogen for fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90% pure liquid oxygen as its oxidizer that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. This article shows an approach and the corresponding technology needs for using air liquefaction and enrichment system propulsion in a single-stage-to-orbit (SSTO) vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, in a direct substitution for aluminum or ...
1994-07-01
Energy Technology Data Exchange (ETDEWEB)
This paper provides some results of the research works at low pressure components of steam turbines and some construction solutions resulting in a modernisation. The problems of turbine phases for the transonic flow are analysed with respect to reducing profile and margin losses. The origin and flow of wet steam and its influence on corrosion and erosion is investigated. Inlet and outlet casing of the flow channels and transfer diffuser between second last and last phase are mentioned. (orig.) [Deutsch] Im Beitrag werden einige Ergebnisse der Forschung der Teile von ND-Teilen der Dampfturbinen angegeben, und werden irgendeine Konstruktionsloesungen, die fuer ihre Modernisierung guenstig sind, beschrieben. Kurz wird die Problematik der Turbinenstufen fuer die transsonische Stroemung analysiert, mit Hinsicht auf die Erniederung der Profil- und Randverluste. Weiter ist die Aufmerksamkeit der Entstehung und Stroemung des Nassdampfes im Zusammenhang mit dem Phaenomen der Korrosion und ...
1999-12-01
Use of microbes for paraffin cleanup at Naval Petroleum Reserve No. 3
Energy Technology Data Exchange (ETDEWEB)
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 psi (1.03 MPa) from an ...
1995-12-31
Towards an objective evaluation of tolerances for beam modeling in a treatment planning system
International Nuclear Information System (INIS)
The performance of a convolution/superposition based treatment planning system depends on the ability of the dose calculation algorithm to accurately account for physical interactions taking place in the tissue, key components of the linac head and on the accuracy of the photon beam model. Generally the user has little or no control over the performance of the dose calculation algorithm but is responsible for the accuracy of the beam model within the constraints imposed by the system. This study explores the dosimetric impact of limitations in photon beam modeling accuracy on complex 3D clinical treatment plans. A total of 70 photon beam models was created in the Pinnacle(TM) treatment planning system. Two of the models served as references for 6 MV and 15 MV beams, while the rest were created by perturbing the reference models in order to produce specific deviations in specific regions of the calculated dose profiles (central axis and ...
2007-09-21
Energy Technology Data Exchange (ETDEWEB)
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} d{sup -1}. Low power consumption went hand-in-hand with ...
2003-11-01
Preliminary Simulations of CO2 Transport in the Dolostone Formations in the Ordos Basin, China
Energy Technology Data Exchange (ETDEWEB)
This report summarizes preliminary 2-D reactive-transport simulations on the injection, storage and transport of supercritical CO{sub 2} in dolostone formations in the Ordos Basin in China. The purpose of the simulations was to evaluate the role that basin heterogeneity, permeability, CO{sub 2} flux, and geochemical reactions between the carbonate geology and the CO{sub 2} equilibrated brines have on the evolution of porosity and permeability in the storage reservoir. The 2-D simulation of CO{sub 2} injection at 10{sup 3} ton/year corresponds to CO{sub 2} injection at a rate of 3 x 10{sup 5} ton/year in a 3-D, low permeable rock. An average permeability of 10 md was used in the simulation and reflects the upper range of permeability reported for the Ordos Basin Majiagou Group. Transport and distribution of CO{sub 2} between in the gas, aqueous, and solid phases were followed during a 10-year injection phase and a 10-year post injection phase. ...
2009-04-30
Optimization of americium-loaded lattices tested in 3D BWR core-wide simulations
International Nuclear Information System (INIS)
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 over multiple reload ...
2008-09-14
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 strong hydrogen bonding ...
2008-05-24
We present a femtosecond Laser Two-Photon Polymerization (LTPP) system of large scale three-dimensional structuring for applications in tissue engineering. The direct laser writing system enables fabrication of artificial polymeric scaffolds over a large area (up to cm in lateral size) with sub-micrometer resolution which could find practical applications in biomedicine and surgery. Yb:KGW femtosecond laser oscillator (Pharos, Light Conversion. Co. Ltd.) is used as an irradiation source (75 fs, 515 nm (frequency doubled), 80 MHz). The sample is mounted on wide range linear motor driven stages having 10 nm sample positioning resolution (XY--ALS130-100, Z--ALS130-50, Aerotech, Inc.). These stages guarantee an overall travelling range of 100 mm into X and Y directions and 50 mm in Z direction and support the linear scanning speed up to 300 mm/s. By moving the sample three-dimensionally the position of laser focus in the photopolymer is changed and one is able to write complex ...
2010-11-10
Initiation of conformal radiotherapy with a multileaf-collimator - An approach to clinical routine
International Nuclear Information System (INIS)
The implementation of a three-dimensional conformal radiotherapy facility in the radiotherapy department of the Heinrich Heine University is described. Complex radiotherapy techniques with commercially available networked systems are introduced to improve clinical work. Over 18 month we have gained clinical experience with a PHILIPS Multileaf Collimator (MLC) mounted on a SL 25 linear accelerator. For a limited period the MLC was used as a conventional blocking device. The standard MLC-shapes are controlled with a stand-alone computer system. In addition, a three-dimensional treatment planning system (3-D-TPS / TMS-Radix, Helax AB) based on convolution/superposition algorithms was recently installed. Treatment optimization is achieved using static field arrangements with complete volumetric computerized tomographic patient data for 3-D-TPS. Conformal adaptation of the 95%-isodose to the Planning Target ...
1995-10-01
Electron-beam welding of valve bodies; Elektronenstrahlschweissen von Armaturengehaeusen
Energy Technology Data Exchange (ETDEWEB)
In early March, 2000 a modern electron-beam welding facility for both series and one-off production of valves bodies (500 kg, up to 50 mm wall thickness) was commissioned at Josch Strahlschweisstechnik. Welding is performed under a fine vacuum. This permits not only the welding of components subject to acceptance inspection (HP0 approval), but also of special materials such as titanium, molybdenum, tungsten, Hastelloy and copper, and also their pairings. Products are developed and readied for production using modern 3D CAD software. A modern nine-axis control system makes it possible to produce sockets in pipe-on-pipe joints. (orig.) [German] Anfang Maerz 2000 wurde eine moderne Elektronenstrahlschweissanlage fuer die Herstellung von Armaturengehaeusen in Grossserien oder auch fuer Einzelfertigung (500 kg, bis 50 mm Wanddicke) bei der Josch Strahlschweisstechnik in Betrieb genommen. Die Schweissungen erfolgen im Feinvakuum. Somit koennen neben ...
2000-03-01
Energy Technology Data Exchange (ETDEWEB)
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 ...
2004-09-15
Direct observation of ordered orbital of YTiO{sub 3} by the X-ray magnetic diffraction technique
Energy Technology Data Exchange (ETDEWEB)
X-ray magnetic diffraction (XMD) technique was applied to an orbital ordering compound of ferromagnetic YTiO{sub 3} for the first time. The orbital-magnetic form factor {mu} {sub L}(k) and the spin-magnetic form factor {mu} {sub S}(k) were independently measured by utilizing the LS separation ability of the XMD. The {mu} {sub L}(k) was measured for ten reciprocal-lattice points. No significant values of the {mu} {sub 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} {sub S}(k) was measured for 22 reciprocal-lattice points. Fourier synthesis of the {mu} {sub S}(k) gave the spin density distribution m {sub S}(r) in the real space. The obtained m {sub S}(r) map shows the characteristic feature of the electron distribution of 3d electron in the t{sub 2g} state of a Ti atom coordinated by O{sup 2-} ions, in which the electrons are ...
2005-08-15
A field demonstration of the microbial treatment of sour produced water
Energy Technology Data Exchange (ETDEWEB)
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 to provide required nutrients for the bacteria. The first 20% of the pit was aerated to a maximum depth of 5 ft (1.5 m) to ...
1995-12-31
3D-nuclear heat generation in PCC-charcoal filter in TAPP-3 and 4
International Nuclear Information System (INIS)
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 stopped within the charcoal and heat is generated. The part of ...
2006-11-13
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