A Bme Solution Of The Stochastic Three-Dimensional Laplace Equation...
Solution Of The Stochastic Three-Dimensional Laplace Equation Representing A Geothermal Field Subject To Site-Specific Information Abstract This work develops a model of the...
Numerical solution of three-dimensional magnetic differential equations
Reiman, A.H.; Greenside, H.S.
1987-02-01
A computer code is described that solves differential equations of the form B . del f = h for a single-valued solution f, given a toroidal three-dimensional divergence-free field B and a single-valued function h. The code uses a new algorithm that Fourier decomposes a given function in a set of flux coordinates in which the field lines are straight. The algorithm automatically adjusts the required integration lengths to compensate for proximity to low order rational surfaces. Applying this algorithm to the Cartesian coordinates defines a transformation to magnetic coordinates, in which the magnetic differential equation can be accurately solved. Our method is illustrated by calculating the Pfirsch-Schlueter currents for a stellarator.
Expansion solution of Laplace`s equation: Technique and application to hollow beam gun design
Jackson, R.H.; Taccetti, J.M.
1996-12-31
This paper presents a flexible algorithm for the general calculation of expansion solutions to Laplace`s equation. The limiting factor in application of the technique is shown to be series truncation error and not errors in calculating numerical derivatives. Application of the algorithm to the accurate computation of arbitrary magnetic fields in cylindrical geometry from on-axis or coil data will be presented. For an ideal current loop, magnetic field accuracies of better than 0.01% of the exact elliptic integral solution can be obtained out to approximately 70--80% of the loop radius. Accuracy improves dramatically for radii closer to the axis. Results also is shown for thin current disks, thin solenoids and thick coils. Other aspects of the technique is illustrated by application to the design of a coil system for a hollow beam electron gun. With some reasonable assumptions about the overlay of the electron trajectories and the magnetic flux contours, it is possible to generate an estimate for the on-axis profile of the gun magnetic field. The expansion technique can then be applied to calculate the off-axis field and its impact on the trajectories without assuming any particular coil system. The initial estimate can then be refined and retested. Finally, an optimization technique is used to develop a coil system which closely reproduces the refined field. The results of carrying out this set of calculations on a 150 kV, 20 A hollow electron gun design for an FEL experiment is reported.
Three-dimensional nonlinear Schroedinger equation in electron-positron-ion magnetoplasmas
Sabry, R.; Moslem, W. M.; El-Shamy, E. F.; Shukla, P. K.
2011-03-15
Three-dimensional ion-acoustic envelope soliton excitations in electron-positron-ion magnetoplasmas are interpreted. This is accomplished through the derivation of three-dimensional nonlinear Schroedinger equation, where the nonlinearity is balancing with the dispersive terms. The latter contains both an external magnetic field besides the usual plasma parameter effects. Based on the balance between the nonlinearity and the dispersion terms, the regions for possible envelope solitons are investigated indicating that new regimes for modulational instability of envelope ion-acoustic waves could be obtained, which cannot exist in the unmagnetized case. This will allow us to establish additional new regimes, different from the usual unmagnetized plasma, for envelope ion-acoustic waves to propagate in multicomponent plasma that may be observed in space or astrophysics.
Waltz, J.; Canfield, T.R.; Morgan, N.R.; Risinger, L.D.; Wohlbier, J.G.
2014-06-15
We present a set of manufactured solutions for the three-dimensional (3D) Euler equations. The purpose of these solutions is to allow for code verification against true 3D flows with physical relevance, as opposed to 3D simulations of lower-dimensional problems or manufactured solutions that lack physical relevance. Of particular interest are solutions with relevance to Inertial Confinement Fusion (ICF) capsules. While ICF capsules are designed for spherical symmetry, they are hypothesized to become highly 3D at late time due to phenomena such as Rayleigh–Taylor instability, drive asymmetry, and vortex decay. ICF capsules also involve highly nonlinear coupling between the fluid dynamics and other physics, such as radiation transport and thermonuclear fusion. The manufactured solutions we present are specifically designed to test the terms and couplings in the Euler equations that are relevant to these phenomena. Example numerical results generated with a 3D Finite Element hydrodynamics code are presented, including mesh convergence studies.
White, J.; Phillips, J.R.; Korsmeyer, T.
1994-12-31
Mixed first- and second-kind surface integral equations with (1/r) and {partial_derivative}/{partial_derivative} (1/r) kernels are generated by a variety of three-dimensional engineering problems. For such problems, Nystroem type algorithms can not be used directly, but an expansion for the unknown, rather than for the entire integrand, can be assumed and the product of the singular kernal and the unknown integrated analytically. Combining such an approach with a Galerkin or collocation scheme for computing the expansion coefficients is a general approach, but generates dense matrix problems. Recently developed fast algorithms for solving these dense matrix problems have been based on multipole-accelerated iterative methods, in which the fast multipole algorithm is used to rapidly compute the matrix-vector products in a Krylov-subspace based iterative method. Another approach to rapidly computing the dense matrix-vector products associated with discretized integral equations follows more along the lines of a multigrid algorithm, and involves projecting the surface unknowns onto a regular grid, then computing using the grid, and finally interpolating the results from the regular grid back to the surfaces. Here, the authors describe a precorrectted-FFT approach which can replace the fast multipole algorithm for accelerating the dense matrix-vector product associated with discretized potential integral equations. The precorrected-FFT method, described below, is an order n log(n) algorithm, and is asymptotically slower than the order n fast multipole algorithm. However, initial experimental results indicate the method may have a significant constant factor advantage for a variety of engineering problems.
Shao, Yan-Lin Faltinsen, Odd M.
2014-10-01
We propose a new efficient and accurate numerical method based on harmonic polynomials to solve boundary value problems governed by 3D Laplace equation. The computational domain is discretized by overlapping cells. Within each cell, the velocity potential is represented by the linear superposition of a complete set of harmonic polynomials, which are the elementary solutions of Laplace equation. By its definition, the method is named as Harmonic Polynomial Cell (HPC) method. The characteristics of the accuracy and efficiency of the HPC method are demonstrated by studying analytical cases. Comparisons will be made with some other existing boundary element based methods, e.g. Quadratic Boundary Element Method (QBEM) and the Fast Multipole Accelerated QBEM (FMA-QBEM) and a fourth order Finite Difference Method (FDM). To demonstrate the applications of the method, it is applied to some studies relevant for marine hydrodynamics. Sloshing in 3D rectangular tanks, a fully-nonlinear numerical wave tank, fully-nonlinear wave focusing on a semi-circular shoal, and the nonlinear wave diffraction of a bottom-mounted cylinder in regular waves are studied. The comparisons with the experimental results and other numerical results are all in satisfactory agreement, indicating that the present HPC method is a promising method in solving potential-flow problems. The underlying procedure of the HPC method could also be useful in other fields than marine hydrodynamics involved with solving Laplace equation.
Three-dimensional metamaterials
Burckel, David Bruce
2012-06-12
A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.
Three dimensional colorimetric assay assemblies
Charych, Deborah; Reichart, Anke
2000-01-01
A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.
Sandia Energy - Three-Dimensional Graphene Architectures
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Three-Dimensional Graphene Architectures Home Office of Science Capabilities News News & Events Research & Capabilities Materials Science Three-Dimensional Graphene Architectures...
Electrode With Porous Three-Dimensional Support
Bernard, Patrick; Dauchier, Jean-Michel; Simonneau, Olivier
1999-07-27
Electrode including a paste containing particles of electrochemically active material and a conductive support consisting of a three-dimensional porous material comprising strands delimiting contiguous pores communicating via passages, characterized in that the average width L in .mu.m of said passages is related to the average diameter .O slashed. in .mu.m of said particles by the following equation, in which W and Y are dimensionless coefficients: wherein W=0.16 Y=1.69 X=202.4 .mu.m and Z=80 .mu.m
Three-dimensional coil inductor
Bernhardt, Anthony F.; Malba, Vincent
2002-01-01
A three-dimensional coil inductor is disclosed. The inductor includes a substrate; a set of lower electrically conductive traces positioned on the substrate; a core placed over the lower traces; a set of side electrically conductive traces laid on the core and the lower traces; and a set of upper electrically conductive traces attached to the side traces so as to form the inductor. Fabrication of the inductor includes the steps of forming a set of lower traces on a substrate; positioning a core over the lower traces; forming a set of side traces on the core; connecting the side traces to the lower traces; forming a set of upper traces on the core; and connecting the upper traces to the side traces so as to form a coil structure.
Introduction to Control Theory. Part 2. Laplace Transforms and Linear Systems
Scheinker, Alexander
2015-09-11
Presentation for summer students. Start by considering linear differential equations, and how to solve them. The Laplace Transform is a great tool for solving linear differential equations.
Three dimensional electromagnetic wavepackets in a plasma: Spatiotemporal modulational instability
Borhanian, J.; Hosseini Faradonbe, F.
2014-04-15
The nonlinear interaction of an intense electromagnetic beam with relativistic collisionless unmagnetized plasma is investigated by invoking the reductive perturbation technique, resting on the model of three-dimensional nonlinear Schrödinger (NLS) equation with cubic nonlinearity which incorporates the effects of self-focusing, self-phase modulation, and diffraction on wave propagation. Relying on the derived NLS equation, the occurrence of spatiotemporal modulational instability is investigated in detail.
Three-dimensional Modeling of Fracture Clusters in Geeothermal...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs Three-dimensional Modeling of ...
Code System for Three-Dimensional Hydraulic Reactor Core Analysis.
Energy Science and Technology Software Center (OSTI)
2001-03-05
Version 00 SCORE-EVET was developed to study multidimensional transient fluid flow in nuclear reactor fuel rod arrays. The conservation equations used were derived by volume averaging the transient compressible three-dimensional local continuum equations in Cartesian coordinates. No assumptions associated with subchannel flow have been incorporated into the derivation of the conservation equations. In addition to the three-dimensional fluid flow equations, the SCORE-EVET code contains a one-dimensional steady state solution scheme to initialize the flow field,more » steady state and transient fuel rod conduction models, and comprehensive correlation packages to describe fluid-to-fuel rod interfacial energy and momentum exchange. Velocity and pressure boundary conditions can be specified as a function of time and space to model reactor transient conditions, such as a hypothesized loss-of-coolant accident (LOCA) or flow blockage. The basic volume-averaged transient three-dimensional equations for flow in porous media are solved in their general form with constitutive relationships and boundary conditions tailored to define the porous medium as a matrix of fuel rods. By retaining generality in the form of the conservation equations, a wide range of fluid flow problem configurations, from computational regions representing a single fuel rod subchannel to multichannels, or even regions without a fuel rod, can be modeled without restrictive assumptions. The completeness of the conservation equations has allowed SCORE-EVET to be used, with modification to the constitutive relationships, to calculate three-dimensional laminar boundary layer development, flow fields in large bodies of water, and, with the addition of a turbulence model, turbulent flow in pipe expansions and tees.« less
Three-dimensional colorimetric assay assemblies
Charych, Deborah; Reichert, Anke
2001-01-01
A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flue virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.
Three-dimensional piezoelectric vibration energy harvester using...
Office of Scientific and Technical Information (OSTI)
Subject: 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BEAMS; PEAKS; PIEZOELECTRICITY; SCAVENGING; SPACE; THREE-DIMENSIONAL CALCULATIONS; THREE-DIMENSIONAL ...
Three-dimensional Modeling of Fracture Clusters in Geothermal...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Reservoirs Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs ... More Documents & Publications Three-dimensional Modeling of Fracture Clusters in ...
Noncommutative geometry for three-dimensional topological insulators...
Office of Scientific and Technical Information (OSTI)
Noncommutative geometry for three-dimensional topological insulators Title: Noncommutative geometry for three-dimensional topological insulators Authors: Neupert, Titus ; Santos, ...
Three dimensional stress vector sensor array and method therefor...
Office of Scientific and Technical Information (OSTI)
Three dimensional stress vector sensor array and method therefor Citation Details In-Document Search Title: Three dimensional stress vector sensor array and method therefor A ...
Final Report - Three-dimensional minority carrier lifetime mapping...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Three-dimensional minority carrier lifetime mapping of thin film semiconductors for solar cell applications Final Report - Three-dimensional minority carrier lifetime mapping of ...
Real time three dimensional sensing system
Gordon, Steven J.
1996-01-01
The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane.
Real time three dimensional sensing system
Gordon, S.J.
1996-12-31
The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane. 7 figs.
Three-dimensional display of document set
Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.; York, Jeremy
2009-06-30
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-Dimensional Dispaly Of Document Set
Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.
2003-06-24
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-dimensional display of document set
Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA
2001-10-02
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-dimensional display of document set
Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.
2006-09-26
A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may e transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.
Three-dimensional modeling of the plasma arc in arc welding
Xu, G.; Tsai, H. L.; Hu, J.
2008-11-15
Most previous three-dimensional modeling on gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) focuses on the weld pool dynamics and assumes the two-dimensional axisymmetric Gaussian distributions for plasma arc pressure and heat flux. In this article, a three-dimensional plasma arc model is developed, and the distributions of velocity, pressure, temperature, current density, and magnetic field of the plasma arc are calculated by solving the conservation equations of mass, momentum, and energy, as well as part of the Maxwell's equations. This three-dimensional model can be used to study the nonaxisymmetric plasma arc caused by external perturbations such as an external magnetic field. It also provides more accurate boundary conditions when modeling the weld pool dynamics. The present work lays a foundation for true three-dimensional comprehensive modeling of GTAW and GMAW including the plasma arc, weld pool, and/or electrode.
THREE-DIMENSIONAL PRINTING IS BLOWING UP.
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THIS IS A COPY OF THE EXECUTED DOCUMENT THIS IS A COPY OF THE EXECUTED DOCUMENT THIS IS A COPY OF THE EXECUTED DOCUMENT THIS IS A COPY OF THE EXECUTED DOCUMENT
March 2016 THREE-DIMENSIONAL PRINTING IS BLOWING UP. From the obvious-hand tools and chess pieces-to the less obvious-body parts and shelf-stable food-just about every item imaginable is being subjected to the two-step process of digitization and fabrication that is 3D printing. One of the factors fueling the
High resolution three-dimensional doping profiler
Thundat, Thomas G. (Knoxville, TN); Warmack, Robert J. (Knoxville, TN)
1999-01-01
A semiconductor doping profiler provides a Schottky contact at one surface and an ohmic contact at the other. While the two contacts are coupled to a power source, thereby establishing an electrical bias in the semiconductor, a localized light source illuminates the semiconductor to induce a photocurrent. The photocurrent changes in accordance with the doping characteristics of the semiconductor in the illuminated region. By changing the voltage of the power source the depth of the depletion layer can be varied to provide a three dimensional view of the local properties of the semiconductor.
Two component-three dimensional catalysis
Schwartz, Michael; White, James H.; Sammells, Anthony F.
2002-01-01
This invention relates to catalytic reactor membranes having a gas-impermeable membrane for transport of oxygen anions. The membrane has an oxidation surface and a reduction surface. The membrane is coated on its oxidation surface with an adherent catalyst layer and is optionally coated on its reduction surface with a catalyst that promotes reduction of an oxygen-containing species (e.g., O.sub.2, NO.sub.2, SO.sub.2, etc.) to generate oxygen anions on the membrane. The reactor has an oxidation zone and a reduction zone separated by the membrane. A component of an oxygen containing gas in the reduction zone is reduced at the membrane and a reduced species in a reactant gas in the oxidation zone of the reactor is oxidized. The reactor optionally contains a three-dimensional catalyst in the oxidation zone. The adherent catalyst layer and the three-dimensional catalyst are selected to promote a desired oxidation reaction, particularly a partial oxidation of a hydrocarbon.
Three-dimensional elastic lidar winds
Buttler, W.T.
1996-07-01
Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three- dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain following winds in the Rio Grande valley.
Propagation of three-dimensional electron-acoustic solitary waves
Shalaby, M.; El-Sherif, L. S.; El-Labany, S. K.; Sabry, R.
2011-06-15
Theoretical investigation is carried out for understanding the properties of three-dimensional electron-acoustic waves propagating in magnetized plasma whose constituents are cold magnetized electron fluid, hot electrons obeying nonthermal distribution, and stationary ions. For this purpose, the hydrodynamic equations for the cold magnetized electron fluid, nonthermal electron density distribution, and the Poisson equation are used to derive the corresponding nonlinear evolution equation, Zkharov-Kuznetsov (ZK) equation, in the small- but finite- amplitude regime. The ZK equation is solved analytically and it is found that it supports both solitary and blow-up solutions. It is found that rarefactive electron-acoustic solitary waves strongly depend on the density and temperature ratios of the hot-to-cold electron species as well as the nonthermal electron parameter. Furthermore, there is a critical value for the nonthermal electron parameter, which decides whether the electron-acoustic solitary wave's amplitude is decreased or increased by changing various plasma parameters. Importantly, the change of the propagation angles leads to miss the balance between the nonlinearity and dispersion; hence, the localized pulses convert to explosive/blow-up pulses. The relevance of this study to the nonlinear electron-acoustic structures in the dayside auroral zone in the light of Viking satellite observations is discussed.
Three-dimensional charge coupled device
Conder, Alan D.; Young, Bruce K. F.
1999-01-01
A monolithic three dimensional charged coupled device (3D-CCD) which utilizes the entire bulk of the semiconductor for charge generation, storage, and transfer. The 3D-CCD provides a vast improvement of current CCD architectures that use only the surface of the semiconductor substrate. The 3D-CCD is capable of developing a strong E-field throughout the depth of the semiconductor by using deep (buried) parallel (bulk) electrodes in the substrate material. Using backside illumination, the 3D-CCD architecture enables a single device to image photon energies from the visible, to the ultra-violet and soft x-ray, and out to higher energy x-rays of 30 keV and beyond. The buried or bulk electrodes are electrically connected to the surface electrodes, and an E-field parallel to the surface is established with the pixel in which the bulk electrodes are located. This E-field attracts charge to the bulk electrodes independent of depth and confines it within the pixel in which it is generated. Charge diffusion is greatly reduced because the E-field is strong due to the proximity of the bulk electrodes.
Three dimensional characterization and archiving system
Sebastian, R.L.; Clark, R.; Gallman, P.
1995-10-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. The 3D-ICAS system robotically conveys a multisensor probe near the surface to be inspected. The sensor position and orientation are monitored and controlled by Coherent laser radar (CLR) tracking. The ICAS fills the need for high speed automated organic analysis by means of gas chromatography-mass spectrometry sensors, and also by radionuclide sensors which combines alpha, beta, and gamma counting.
Three dimensional characterization and archiving system
Sebastian, R.L.; Clark, R.; Gallman, P.
1996-04-01
The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D and D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D and D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. The 3D-ICAS system robotically conveys a multisensor probe near the surfaces to be inspected. The sensor position and orientation are monitored and controlled using coherent laser radar (CLR) tracking. The CLR also provides 3D facility maps which establish a 3D world view within which the robotic sensor system can operate.
Multigroup Three-Dimensional Direct Integration Method Radiation Transport Analysis Code System.
Energy Science and Technology Software Center (OSTI)
1987-09-18
Version 00 TRISTAN solves the three-dimensional, fixed-source, Boltzmann transport equation for neutrons or gamma rays in rectangular geometry. The code can solve an adjoint problem as well as a usual transport problem. TRISTAN is a suitable tool to analyze radiation shielding problems such as streaming and deep penetration problems.
Wind Turbine Manufacturing Transforms with Three-Dimensional Printing |
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Department of Energy Turbine Manufacturing Transforms with Three-Dimensional Printing Wind Turbine Manufacturing Transforms with Three-Dimensional Printing May 19, 2016 - 12:57pm Addthis From medical devices to airplane components, three-dimensional (3-D) printing (also called additive manufacturing) is transforming the manufacturing industry. Now, research that supports the Energy Department's Atmosphere to Electrons (A2e) initiative is applying 3-D-printing processes to create wind turbine
Charge Transport within a Three-Dimensional DNA Nanostructure Framework
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Charge Transport within a Three-Dimensional DNA Nanostructure Framework Authors: Lu, N., Pei, H., Ge, Z., Simmons, C.R., Yan, H., and Fan, C. Title: Charge Transport within a Three-Dimensional DNA Nanostructure Framework Source: Journal of the American Chemical Society Year: 2012 Volume: 134 Pages: 13148-13151 ABSTRACT: Three-dimensional (3D) DNA nanostructures have shown great promise for various applications including molecular sensing and therapeutics. Here we report kinetic studies of
Three-Dimensional Modeling and Simulation of DNA Hybridization...
Office of Scientific and Technical Information (OSTI)
Three-Dimensional Modeling and Simulation of DNA Hybridization Kinetics and Mass Transport ... Kinetics and Mass Transport as Functions of Temperature in a Microfluidic Channel. ...
Three-Dimensional Composite Nanostructures for Lean NOx Emission...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
More Documents & Publications Three-Dimensional Composite Nanostructures for Lean NOx Emission Control Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission...
Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs
Broader source: Energy.gov [DOE]
Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs presentation at the April 2013 peer review meeting held in Denver, Colorado.
Locally Advanced Prostate Cancer: Three-Dimensional Magnetic...
Office of Scientific and Technical Information (OSTI)
Cancer: Three-Dimensional Magnetic Resonance Spectroscopy to Monitor Prostate Response to Therapy Citation Details In-Document Search Title: Locally Advanced Prostate Cancer: ...
Three-Dimensional Thermal Tomography Advances Cancer Treatment...
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Three-Dimensional Thermal Tomography Advances Cancer Treatment Technology available for licensing: A 3D technique to detect early skin changes due to radiation treatment in breast...
Three-dimensional Modeling of Fracture Clusters in Geothermal...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Reservoirs; 2010 Geothermal Technology Program Peer Review Report Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs; 2010 Geothermal Technology Program Peer ...
Three-Dimensional Thermal Tomography Advances Cancer Treatment...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
treatment. A recent advance in thermal imaging allows more rapid, yet still non-invasive, detection. The process, called three-dimensional thermal tomography, or 3DTT, is...
Three-Dimensional Crystallization of Vortex Strings in Frustrated...
Office of Scientific and Technical Information (OSTI)
Three-Dimensional Crystallization of Vortex Strings in Frustrated Quantum Magnets Citation Details In-Document Search This content will become publicly available on August 31, 2016 ...
Optimal Disturbances in Three-Dimensional Natural Convection...
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Optimal Disturbances in Three-Dimensional Natural Convection ... Buoyancy-driven systems are subject to several types of flow ... solvers 1 in combination with a power iteration 2. ...
DNA Origami with Complex Curvatures in Three-Dimensional Space
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DNA Origami with Complex Curvatures in Three-Dimensional Space Authors: Han, D., Pal, S., Nangreave, J., Deng, Z., Liu, Y., and Yan, H. Title: DNA Origami with Complex Curvatures in Three-Dimensional Space Source: Science Year: 2011 Volume: 332 Pages: 342-346 ABSTRACT: We present a strategy to design and construct self-assembling DNA nanostructures that define intricate curved surfaces in three-dimensional (3D) space using the DNA origami folding technique. Double-helical DNA is bent to follow
Three-Dimensional Lithium-Ion Battery Model (Presentation)
Kim, G. H.; Smith, K.
2008-05-01
Nonuniform battery physics can cause unexpected performance and life degradations in lithium-ion batteries; a three-dimensional cell performance model was developed by integrating an electrode-scale submodel using a multiscale modeling scheme.
Three-dimensional Dendritic Needle Network model with application...
Office of Scientific and Technical Information (OSTI)
We present a three-dimensional (3D) extension of a previously proposed multi-scale ... of a given thickness, one can directly extend the DNN approach to 3D modeling. ...
Energy Science and Technology Software Center (OSTI)
2008-10-05
Laplace is a electric field driven flow simulation program for detailed device design support. Transport processes include electrokinesis, dielectrophoresis, and diffusion. Laplace solves for the electric field in a microfluidic system and the liquid and particle flow that is produced by the electric field for the primary purpose of microfluidic design development and simulation. Laplace allows you to visualize the flow by tracking tracer particles, viewing flow streamlines, etc. Laplace can make movies of simulatedmore » particle motion to allow you to test and share the behavior of microfuidic designs. The electric field is calculated using an iterative linear solver and particle motion is solved by finite difference, finite-displacement simulation of particle trajectories. Laplace uses a bitmapped picture or drawing of a microsystem to infer the geometry. The channel depth is everywhere proportional to the magnitude of the blue channel of the image: 0 (black) = zero depth, or no channel, 256 (saturated blue) = deepest channel, and intermediate values correspond to intermediate depths. Laplace automatically applies various boundary conditions (applied voltage or current) to ports, where channels cross the edge of the image.« less
Coupled particle dispersion by three-dimensional vortex structures
Troutt, T.R.; Chung, J.N.; Crowe, C.T.
1996-12-31
The primary objective of this research program is to obtain understanding concerning the role of three-dimensional vortex structures in the dispersion of particles and droplets in free shear flows. This research program builds on previous studies which focused on the nature of particle dispersion in large scale quasi two-dimensional vortex structures. This investigation employs time dependent experimental and numerical techniques to provide information concerning the particulate dispersion produced by three dimensional vortex structures in free shear layers. The free shear flows investigated include modified plane mixing layers, and modified plane wakes. The modifications to these flows involve slight perturbations to the initiation boundary conditions such that three-dimensional vortex structures are rapidly generated by the experimental and numerical flow fields. Recent results support the importance of these vortex structures in the particle dispersion process.
Radiation hardness of three-dimensional polycrystalline diamond detectors
Lagomarsino, Stefano Sciortino, Silvio; Bellini, Marco; Corsi, Chiara; Cindro, Vladimir; Kanxheri, Keida; Servoli, Leonello; Morozzi, Arianna; Passeri, Daniele; Schmidt, Christian J.
2015-05-11
The three-dimensional concept in particle detection is based on the fabrication of columnar electrodes perpendicular to the surface of a solid state radiation sensor. It permits to improve the radiation resistance characteristics of a material by lowering the necessary bias voltage and shortening the charge carrier path inside the material. If applied to a long-recognized exceptionally radiation-hard material like diamond, this concept promises to pave the way to the realization of detectors of unprecedented performances. We fabricated conventional and three-dimensional polycrystalline diamond detectors, and tested them before and after neutron damage up to 1.2 ×10{sup 16 }cm{sup −2}, 1 MeV-equivalent neutron fluence. We found that the signal collected by the three-dimensional detectors is up to three times higher than that of the conventional planar ones, at the highest neutron damage ever experimented.
Ray tracing a three dimensional scene using a grid
Wald, Ingo; Ize, Santiago; Parker, Steven G; Knoll, Aaron
2013-02-26
Ray tracing a three-dimensional scene using a grid. One example embodiment is a method for ray tracing a three-dimensional scene using a grid. In this example method, the three-dimensional scene is made up of objects that are spatially partitioned into a plurality of cells that make up the grid. The method includes a first act of computing a bounding frustum of a packet of rays, and a second act of traversing the grid slice by slice along a major traversal axis. Each slice traversal includes a first act of determining one or more cells in the slice that are overlapped by the frustum and a second act of testing the rays in the packet for intersection with any objects at least partially bounded by the one or more cells overlapped by the frustum.
Three-dimensional boron particle loaded thermal neutron detector
Nikolic, Rebecca J.; Conway, Adam M.; Graff, Robert T.; Kuntz, Joshua D.; Reinhardt, Catherine; Voss, Lars F.; Cheung, Chin Li; Heineck, Daniel
2014-09-09
Three-dimensional boron particle loaded thermal neutron detectors utilize neutron sensitive conversion materials in the form of nano-powders and micro-sized particles, as opposed to thin films, suspensions, paraffin, etc. More specifically, methods to infiltrate, intersperse and embed the neutron nano-powders to form two-dimensional and/or three-dimensional charge sensitive platforms are specified. The use of nano-powders enables conformal contact with the entire charge-collecting structure regardless of its shape or configuration.
Novel multipole Wien filter as three-dimensional spin manipulator
Yasue, T. Suzuki, M.; Koshikawa, T.; Tsuno, K.; Goto, S.; Arai, Y.
2014-04-15
Spin polarized electron beam is often used in material characterizations which relates to magnetism as well as in the high energy particle physics. The manipulation of the spin polarization toward the arbitrary direction is indispensable in such studies. In the present work, a novel multipole Wien filter is proposed as the three-dimensional spin manipulator, and a prototype 8-pole Wien filter is developed. It is applied to spin polarized low energy electron microscopy, and the variation of the magnetic contrast with managing the spin polarization is evaluated. It is confirmed that the novel multipole Wien filter can manipulate the spin polarization three-dimensionally.
Three Dimensional Imaging with Multiple Wavelength Speckle Interferometry
Bernacki, Bruce E.; Cannon, Bret D.; Schiffern, John T.; Mendoza, Albert
2014-05-28
We present the design, modeling, construction, and results of a three-dimensional imager based upon multiple-wavelength speckle interferometry. A surface under test is illuminated with tunable laser light in a Michelson interferometer configuration while a speckled image is acquired at each laser frequency step. The resulting hypercube is Fourier transformed in the frequency dimension and the beat frequencies that result map the relative offsets of surface features. Synthetic wavelengths resulting from the laser tuning can probe features ranging from 18 microns to hundreds of millimeters. Three dimensional images will be presented along with modeling results.
View Factor Calculation for Three-Dimensional Geometries.
1989-06-20
Version 00 MCVIEW calculates the radiation geometric view factor between surfaces for three dimensional geometries with and without interposed third surface obstructions. It was developed to calculate view factors for input data to heat transfer analysis programs such as SCA-03/TRUMP, SCA-01/HEATING-5 and PSR-199/HEATING-6.
Three-Dimensional Thermal Tomography Advances Cancer Treatment | Argonne
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
National Laboratory Three-Dimensional Thermal Tomography Advances Cancer Treatment Technology available for licensing: A 3D technique to detect early skin changes due to radiation treatment in breast cancer patients. Lowers medical costs due to lessened side effects Noninvasive, enhances healing and detects other conditions PDF icon thermal_tomography
Three-Dimensional Composite Nanostructures for Lean NOx Emission Control |
Broader source: Energy.gov (indexed) [DOE]
Department of Energy ace030_gao_2012_o.pdf (4.04 MB) More Documents & Publications Monolithic Metal Oxide based Composite Nanowire Lean NOx Emission Control Catalysts Three-Dimensional Composite Nanostructures for Lean NOx Emission Control Vehicle Technologies Office Merit Review 2015: Metal Oxide Nano-Array Catalysts for Low Temperature Diesel Oxidation
Alaska Maximum Number of Active Crews Engaged in Three-Dimensional...
Gasoline and Diesel Fuel Update (EIA)
Three-Dimensional Seismic Surveying (Number of Elements) Alaska Maximum Number of Active Crews Engaged in Three-Dimensional Seismic Surveying (Number of Elements) Year Jan Feb Mar...
A three-dimensional meso-macroscopic model for Li-Ion intercalation batteries
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Allu, S.; Kalnaus, S.; Simunovic, S.; Nanda, J.; Turner, J. A.; Pannala, S.
2016-06-09
Through this study, we present a three-dimensional computational formulation for electrode-electrolyte-electrode system of Li-Ion batteries. The physical consistency between electrical, thermal and chemical equations is enforced at each time increment by driving the residual of the resulting coupled system of nonlinear equations to zero. The formulation utilizes a rigorous volume averaging approach typical of multiphase formulations used in other fields and recently extended to modeling of supercapacitors [1]. Unlike existing battery modeling methods which use segregated solution of conservation equations and idealized geometries, our unified approach can model arbitrary battery and electrode configurations. The consistency of multi-physics solution also allowsmore » for consideration of a wide array of initial conditions and load cases. The formulation accounts for spatio-temporal variations of material and state properties such as electrode/void volume fractions and anisotropic conductivities. The governing differential equations are discretized using the finite element method and solved using a nonlinearly consistent approach that provides robust stability and convergence. The new formulation was validated for standard Li-ion cells and compared against experiments. Finally, its scope and ability to capture spatio-temporal variations of potential and lithium distribution is demonstrated on a prototypical three-dimensional electrode problem.« less
Theory and application of a three-dimensional code SHAPS to complex piping systems. [LMFBR
Wang, C.Y.
1983-01-01
This paper describes the theory and application of a three-dimensional computer code SHAPS to the complex piping systems. The code utilizes a two-dimensional implicit Eulerian method for the hydrodynamic analysis together with a three-dimensional elastic-plastic finite-element program for the structural calculation. A three-dimensional pipe element with eight degrees of freedom is employed to account for the hoop, flexural, axial, and the torsional mode of the piping system. In the SHAPS analysis the hydrodynamic equations are modified to include the global piping motion. Coupling between fluid and structure is achieved by enforcing the free-slip boundary conditions. Also, the response of the piping network generated by the seismic excitation can be included. A thermal transient capability is also provided in SHAPS. To illustrate the methodology, many sample problems dealing with the hydrodynamic, structural, and thermal analyses of reactor-piping systems are given. Validation of the SHAPS code with experimental data is also presented.
Three Dimensional Thermal Abuse Reaction Model for Lithium Ion Batteries
Energy Science and Technology Software Center (OSTI)
2006-06-29
Three dimensional computer models for simulating thermal runaway of lithium ion battery was developed. The three-dimensional model captures the shapes and dimensions of cell components and the spatial distributions of materials and temperatures, so we could consider the geometrical features, which are critical especially in large cells. An array of possible exothermic reactions, such as solid-electrolyte-interface (SEI) layer decomposition, negative active/electrolyte reaction, and positive active/electrolyte reaction, were considered and formulated to fit experimental data frommore » accelerating rate calorimetry and differential scanning calorimetry. User subroutine code was written to implement NREL developed approach and to utilize a commercially available solver. The model is proposed to use for simulation a variety of lithium-ion battery safety events including thermal heating and short circuit.« less
Environmental, Transient, Three-Dimensional, Hydrothermal, Mass Transport Code - FLESCOT
Onishi, Yasuo; Bao, Jie; Glass, Kevin A.; Eyler, L. L.; Okumura, Masahiko
2015-03-28
The purpose of the project was to modify and apply the transient, three-dimensional FLESCOT code to be able to effectively simulate cesium behavior in Fukushima lakes/dam reservoirs, river mouths, and coastal areas. The ultimate objective of the FLESCOT simulation is to predict future changes of cesium accumulation in Fukushima area reservoirs and costal water. These evaluation results will assist ongoing and future environmental remediation activities and policies in a systematic and comprehensive manner.
Three-dimensional Modeling of Fracture Clusters in Geeothermal Reservoirs
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
| US DOE Geothermal Program eere.energy.gov Public Service of Colorado Ponnequin Wind Farm Geothermal Technologies Program 2013 Peer Review Bons (2000) Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs Principal Investigator: Ahmad Ghassemi EGS Component R&D Stimulation Prediction Models April , 2013 This presentation does not contain any proprietary confidential, or otherwise restricted information. 2 | US DOE Geothermal Program eere.energy.gov Relevance/Impact of
Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs;
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
2010 Geothermal Technology Program Peer Review Report | Department of Energy Reservoirs; 2010 Geothermal Technology Program Peer Review Report Three-dimensional Modeling of Fracture Clusters in Geothermal Reservoirs; 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal Technologies Program Peer Review reservoir_028_ghassmi.pdf (203.27 KB) More Documents & Publications Tracer Methods for Characterizing Fracture Stimulation in Enhanced Geothermal Systems (EGS); 2010
Three Dimensional Simulations for Core Collapse Supernovae | Argonne
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Leadership Computing Facility Three Dimensional Simulations for Core Collapse Supernovae PI Name: Anthony Mezzacappa PI Email: mezzacappaa@ornl.gov Institution: Oak Ridge National Laboratory Allocation Program: INCITE Allocation Hours at ALCF: 65 Million Year: 2013 Research Domain: Physics Core collapse supernovae are the dominant source of elements in the Universe, dominating the origin of the elements between oxygen and iron and responsible for half the elements heavier than iron. They are
Three-dimensional discrete ordinates reactor assembly calculations on GPUs
Evans, Thomas M; Joubert, Wayne; Hamilton, Steven P; Johnson, Seth R; Turner, John A; Davidson, Gregory G; Pandya, Tara M
2015-01-01
In this paper we describe and demonstrate a discrete ordinates sweep algorithm on GPUs. This sweep algorithm is nested within a multilevel comunication-based decomposition based on energy. We demonstrated the effectiveness of this algorithm on detailed three-dimensional critical experiments and PWR lattice problems. For these problems we show improvement factors of 4 6 over conventional communication-based, CPU-only sweeps. These sweep kernel speedups resulted in a factor of 2 total time-to-solution improvement.
The Role of Three-Dimensional Microstructure in Electrochemical Device
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Performance | Stanford Synchrotron Radiation Lightsource The Role of Three-Dimensional Microstructure in Electrochemical Device Performance Wednesday, May 25, 2016 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Wilson K. S. Chiu, Ph.D. (Professor) Department of Mechanical Engineering, University of Connecticut Wilson K. S. Chiu earned his M.S. and Ph.D. degrees in Mechanical Engineering from Rutgers University in 1997 and 1999, respectively. His research was supported by the U.S.
Integrated Three-Dimensional Module Heat Exchange for Power Electronics
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Cooling - Energy Innovation Portal Vehicles and Fuels Vehicles and Fuels Find More Like This Return to Search Integrated Three-Dimensional Module Heat Exchange for Power Electronics Cooling National Renewable Energy Laboratory Contact NREL About This Technology Technology Marketing Summary The power electronics market has started to grow dramatically with the onset of new technologies in automotive applications, power generation, energy storage, and other growing markets. A critical element
Explicit expressions for three-dimensional boundary integrals in linear elasticity
Nintcheu Fata, Sylvain
2011-01-01
On employing isoparametric, piecewise linear shape functions over a flat triangle, exact formulae are derived for all surface potentials involved in the numerical treatment of three-dimensional singular and hyper-singular boundary integral equations in linear elasticity. These formulae are valid for an arbitrary source point in space and are represented as analytical expressions along the edges of the integration triangle. They can be employed to solve integral equations defined on triangulated surfaces via a collocation method or may be utilized as analytical expressions for the inner integrals in a Galerkin technique. A numerical example involving a unit triangle and a source point located at various distances above it, as well as sample problems solved by a collocation boundary element method for the Lame equation are included to validate the proposed formulae.
Three dimensional amorphous silicon/microcrystalline silicon solar cells
Kaschmitter, J.L.
1996-07-23
Three dimensional deep contact amorphous silicon/microcrystalline silicon (a-Si/{micro}c-Si) solar cells are disclosed which use deep (high aspect ratio) p and n contacts to create high electric fields within the carrier collection volume material of the cell. The deep contacts are fabricated using repetitive pulsed laser doping so as to create the high aspect p and n contacts. By the provision of the deep contacts which penetrate the electric field deep into the material where the high strength of the field can collect many of the carriers, thereby resulting in a high efficiency solar cell. 4 figs.
Three dimensional separation trap based on dielectrophoresis and use thereof
Mariella, Jr., Raymond P.
2004-05-04
An apparatus is adapted to separate target materials from other materials in a flow containing the target materials and other materials. A dielectrophoretic trap is adapted to receive the target materials and the other materials. At least one electrode system is provided in the trap. The electrode system has a three-dimensional configuration. The electrode system includes a first electrode and a second electrode that are shaped and positioned relative to each such that application of an electrical voltage to the first electrode and the second electrode creates a dielectrophoretic force and said dielectrophoretic force does not reach zero between the first electrode and the second electrode.
Three dimensional amorphous silicon/microcrystalline silicon solar cells
Kaschmitter, James L.
1996-01-01
Three dimensional deep contact amorphous silicon/microcrystalline silicon (a-Si/.mu.c-Si) solar cells which use deep (high aspect ratio) p and n contacts to create high electric fields within the carrier collection volume material of the cell. The deep contacts are fabricated using repetitive pulsed laser doping so as to create the high aspect p and n contacts. By the provision of the deep contacts which penetrate the electric field deep into the material where the high strength of the field can collect many of the carriers, thereby resulting in a high efficiency solar cell.
Methods for preparation of three-dimensional bodies
Mulligan, Anthony C.; Rigali, Mark J.; Sutaria, Manish P.; Artz, Gregory J.; Gafner, Felix H.; Vaidyanathan, K. Ranji
2004-09-28
Processes for mechanically fabricating two and three-dimensional fibrous monolith composites include preparing a fibrous monolith filament from a core composition of a first powder material and a boundary material of a second powder material. The filament includes a first portion of the core composition surrounded by a second portion of the boundary composition. One or more filaments are extruded through a mechanically-controlled deposition nozzle onto a working surface to create a fibrous monolith composite object. The objects may be formed directly from computer models and have complex geometries.
Methods for preparation of three-dimensional bodies
Mulligan, Anthony C.; Rigali, Mark J.; Sutaria, Manish P.; Artz, Gregory J.; Gafner, Felix H.; Vaidyanathan, K. Ranji
2008-06-17
Processes for mechanically fabricating two and three-dimensional fibrous monolith composites include preparing a fibrous monolith filament from a core composition of a first powder material and a boundary material of a second powder material. The filament includes a first portion of the core composition surrounded by a second portion of the boundary composition. One or more filaments are extruded through a mechanically-controlled deposition nozzle onto a working surface to create a fibrous monolith composite object. The objects may be formed directly from computer models and have complex geometries.
Green's function evaluation for three-dimensional exponentially graded elasticity
Criado Portero, Rafael M; Gray, Leonard J; Mantic, Vladislav; Paris, Federico
2008-01-01
The numerical implementation of the Green's function for an isotropic exponentially graded three dimensional elastic solid is reported. The formulas for the nonsingular {\\lq}grading term{\\rq} in this Green's function, originally deduced by Martin et al., \\emph{Proc. R. Soc. Lond. A, 458, 1931-1947, 2000}, are quite complicated, and a small error in one of the formulas is corrected. The evaluation of the fundamental solution is tested by employing indirect boundary integral formulation using a Galerkin approximation to solve several problems having analytic solutions. The numerical results indicate that the Green's function formulas, and their evaluation, are correct.
Usmanov, Arcadi V.; Matthaeus, William H.; Goldstein, Melvyn L.
2014-06-10
We have developed a three-fluid, three-dimensional magnetohydrodynamic solar wind model that incorporates turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a system of co-moving solar wind protons, electrons, and interstellar pickup protons, with separate energy equations for each species. Numerical steady-state solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations for turbulence energy, cross helicity, and correlation length are obtained by the time relaxation method in the corotating with the Sun frame of reference in the region from 0.3 to 100 AU (but still inside the termination shock). The model equations include the effects of electron heat conduction, Coulomb collisions, photoionization of interstellar hydrogen atoms and their charge exchange with the solar wind protons, turbulence energy generation by pickup protons, and turbulent heating of solar wind protons and electrons. The turbulence transport model is based on the Reynolds decomposition and turbulence phenomenologies that describe the conversion of fluctuation energy into heat due to a turbulent cascade. In addition to using separate energy equations for the solar wind protons and electrons, a significant improvement over our previous work is that the turbulence model now uses an eddy viscosity approximation for the Reynolds stress tensor and the mean turbulent electric field. The approximation allows the turbulence model to account for driving of turbulence by large-scale velocity gradients. Using either a dipole approximation for the solar magnetic field or synoptic solar magnetograms from the Wilcox Solar Observatory for assigning boundary conditions at the coronal base, we apply the model to study the global structure of the solar wind and its three-dimensional properties, including embedded turbulence, heating, and acceleration throughout the heliosphere. The model results are
Tracker: A three-dimensional raytracing program for ionospheric radio propagation
Argo, P.E.; DeLapp, D.; Sutherland, C.D.; Farrer, R.G.
1994-12-01
TRACKER is an extension of a three-dimensional Hamiltonian raytrace code developed some thirty years ago by R. Michael Jones. Subsequent modifications to this code, which is commonly called the {open_quotes}Jones Code,{close_quotes} were documented by Jones and Stephensen (1975). TRACKER incorporates an interactive user`s interface, modern differential equation integrators, graphical outputs, homing algorithms, and the Ionospheric Conductivity and Electron Density (ICED) ionosphere. TRACKER predicts the three-dimensional paths of radio waves through model ionospheres by numerically integrating Hamilton`s equations, which are a differential expression of Fermat`s principle of least time. By using continuous models, the Hamiltonian method avoids false caustics and discontinuous raypath properties often encountered in other raytracing methods. In addition to computing the raypath, TRACKER also calculates the group path (or pulse travel time), the phase path, the geometrical (or {open_quotes}real{close_quotes}) pathlength, and the Doppler shift (if the time variation of the ionosphere is explicitly included). Computational speed can be traded for accuracy by specifying the maximum allowable integration error per step in the integration. Only geometrical optics are included in the main raytrace code; no partial reflections or diffraction effects are taken into account. In addition, TRACKER does not lend itself to statistical descriptions of propagation -- it requires a deterministic model of the ionosphere.
Three-dimensional light trap for reflective particles
Neal, Daniel R.
1999-01-01
A system for containing either a reflective particle or a particle having an index of refraction lower than that of the surrounding media in a three-dimensional light cage. A light beam from a single source illuminates an optics system and generates a set of at least three discrete focussed beams that emanate from a single exit aperture and focus on to a focal plane located close to the particle. The set of focal spots defines a ring that surrounds the particle. The set of focussed beams creates a "light cage" and circumscribes a zone of no light within which the particle lies. The surrounding beams apply constraining forces (created by radiation pressure) to the particle, thereby containing it in a three-dimensional force field trap. A diffractive element, such as an aperture multiplexed lens, or either a Dammann grating or phase element in combination with a focusing lens, may be used to generate the beams. A zoom lens may be used to adjust the size of the light cage, permitting particles of various sizes to be captured and contained.
Three-dimensional light trap for reflective particles
Neal, D.R.
1999-08-17
A system is disclosed for containing either a reflective particle or a particle having an index of refraction lower than that of the surrounding media in a three-dimensional light cage. A light beam from a single source illuminates an optics system and generates a set of at least three discrete focused beams that emanate from a single exit aperture and focus on to a focal plane located close to the particle. The set of focal spots defines a ring that surrounds the particle. The set of focused beams creates a ``light cage`` and circumscribes a zone of no light within which the particle lies. The surrounding beams apply constraining forces (created by radiation pressure) to the particle, thereby containing it in a three-dimensional force field trap. A diffractive element, such as an aperture multiplexed lens, or either a Dammann grating or phase element in combination with a focusing lens, may be used to generate the beams. A zoom lens may be used to adjust the size of the light cage, permitting particles of various sizes to be captured and contained. 10 figs.
Epitaxial growth of three-dimensionally architectured optoelectronic devices
Nelson, Erik C.; Dias, Neville L.; Bassett, Kevin P.; Dunham, Simon N.; Verma, Varun; Miyake, Masao; Wiltzius, Pierre; Rogers, John A.; Coleman, James J.; Li, Xiuling; Braun, Paul V.
2011-07-24
Optoelectronic devices have long benefited from structuring in multiple dimensions on microscopic length scales. However, preserving crystal epitaxy, a general necessity for good optoelectronic properties, while imparting a complex three-dimensional structure remains a significant challenge. Three-dimensional (3D) photonic crystals are one class of materials where epitaxy of 3D structures would enable new functionalities. Many 3D photonic crystal devices have been proposed, including zero-threshold lasers, low-loss waveguides, high-efficiency light-emitting diodes (LEDs) and solar cells, but have generally not been realized because of material limitations. Exciting concepts in metamaterials, including negative refraction and cloaking, could be made practical using 3D structures that incorporate electrically pumped gain elements to balance the inherent optical loss of such devices. Here we demonstrate the 3D-template-directed epitaxy of group IIIV materials, which enables formation of 3D structured optoelectronic devices. We illustrate the power of this technique by fabricating an electrically driven 3D photonic crystal LED.
An efficient, three dimensional, fully-coupled hydro-thermo- mechanical simulator
Kelkar, S.; Zyvoloski, G.
1990-01-01
Hydro-thermo-mechanical effects in fractured rocks are important in many oilfield processes. Modeling these effects is made difficult by the fact that the governing equations are nonlinear and coupled, and the problems to be solved are three dimensional. In this paper the authors describe a numerical code developed for this purpose. The code is finite element based to allow for complicated geometries, and the time differencing is implicit, allowing for large time steps. The use of state-of-the-art equation solvers has resulted in a practical code. An example is presented to demonstrate the effects of matrix expansion, due to pore pressure and heating, on fracture opening due to fluid injection, and induced stress changes at a distant well bore. 19 refs., 9 figs., 3 tabs.
Three-dimensional photodissociation in strong laser fields: Memory-kernel effective-mode expansion
Li Xuan; Thanopulos, Ioannis; Shapiro, Moshe
2011-03-15
We introduce a method for the efficient computation of non-Markovian quantum dynamics for strong (and time-dependent) system-bath interactions. The past history of the system dynamics is incorporated by expanding the memory kernel in exponential functions thereby transforming in an exact fashion the non-Markovian integrodifferential equations into a (larger) set of ''effective modes'' differential equations (EMDE). We have devised a method which easily diagonalizes the EMDE, thereby allowing for the efficient construction of an adiabatic basis and the fast propagation of the EMDE in time. We have applied this method to three-dimensional photodissociation of the H{sub 2}{sup +} molecule by strong laser fields. Our calculations properly include resonance-Raman scattering via the continuum, resulting in extensive rotational and vibrational excitations. The calculated final kinetic and angular distribution of the photofragments are in overall excellent agreement with experiments, both when transform-limited pulses and when chirped pulses are used.
Laplace-Runge-Lenz vector for arbitrary spin
Nikitin, A. G.
2013-12-15
A countable set of superintegrable quantum mechanical systems is presented which admit the dynamical symmetry with respect to algebra so(4). This algebra is generated by the Laplace-Runge-Lenz vector generalized to the case of arbitrary spin. The presented systems describe neutral particles with non-trivial multipole momenta. Their spectra can be found algebraically like in the case of hydrogen atom. Solutions for the systems with spins 1/2 and 1 are presented explicitly, solutions for spin 3/2 can be expressed via solutions of an ordinary differential equation of first order. A more extended version of this paper including detailed calculations is published as an e-print arXiv:1308.4279.
Life-cycle environmental analysis--A three dimensional view
Sutherlin, K.L.; Black, R.E. )
1993-01-01
Both the US Air Force and the US Army have recently increased their emphasis on life-cycles of weapons systems. Along with that emphasis, there has also been an increase in emphasis in life-cycle National Environmental Policy Act (NEPA) documentation. Conflicts and inefficiencies arise when a weapon system is fielded and prompts the need for a site-specific environmental analysis. In their research and experience, the authors found no real link between life-cycle environmental analysis and site-specific environmental analyses required at various points within the life-cycle of a weapon. This other look at the relation between life-cycle and site-specific environmental analyses has the potential to increase efficiency in NEPA compliance actions and save tax dollars in the process. The authors present a three-dimensional model that relates life-cycle analyses to site-specific analyses.
The three-dimensional morphology of growing dendrites
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Gibbs, J. W.; Mohan, K. A.; Gulsoy, E. B.; Shahani, A. J.; Xiao, X.; Bouman, C. A.; De Graef, M.; Voorhees, P. W.
2015-07-03
The processes controlling the morphology of dendrites have been of great interest to a wide range of communities, since they are examples of an out-of-equilibrium pattern forming system, there is a clear connection with battery failure processes, and their morphology sets the properties of many metallic alloys. We determine the three-dimensional morphology of free growing metallic dendrites using a novel X-ray tomographic technique that improves the temporal resolution by more than an order of magnitude compared to conventional techniques. These measurements show that the growth morphology of metallic dendrites is surprisingly different from that seen in model systems, the morphologymore » is not self-similar with distance back from the tip, and that this morphology can have an unexpectedly strong influence on solute segregation in castings. These experiments also provide benchmark data that can be used to validate simulations of free dendritic growth.« less
Three-dimensional periodic dielectric structures having photonic Dirac points
Bravo-Abad, Jorge; Joannopoulos, John D.; Soljacic, Marin
2015-06-02
The dielectric, three-dimensional photonic materials disclosed herein feature Dirac-like dispersion in quasi-two-dimensional systems. Embodiments include a face-centered cubic (fcc) structure formed by alternating layers of dielectric rods and dielectric slabs patterned with holes on respective triangular lattices. This fcc structure also includes a defect layer, which may comprise either dielectric rods or a dielectric slab with patterned with holes. This defect layer introduces Dirac cone dispersion into the fcc structure's photonic band structure. Examples of these fcc structures enable enhancement of the spontaneous emission coupling efficiency (the .beta.-factor) over large areas, contrary to the conventional wisdom that the .beta.-factor degrades as the system's size increases. These results enable large-area, low-threshold lasers; single-photon sources; quantum information processing devices; and energy harvesting systems.
Three dimensional simulation for bayou choctaw strategic petroleum reserve (SPR).
Ehgartner, Brian L. (Sandia National Laboratories, Albuquerque, NM); Park, Byoung Yoon; Lee, Moo Yul
2006-12-01
Three dimensional finite element analyses were performed to evaluate the structural integrity of the caverns located at the Bayou Choctaw (BC) site which is considered a candidate for expansion. Fifteen active and nine abandoned caverns exist at BC, with a total cavern volume of some 164 MMB. A 3D model allowing control of each cavern individually was constructed because the location and depth of caverns and the date of excavation are irregular. The total cavern volume has practical interest, as this void space affects total creep closure in the BC salt mass. Operations including both cavern workover, where wellhead pressures are temporarily reduced to atmospheric, and cavern enlargement due to leaching during oil drawdowns that use water to displace the oil from the caverns, were modeled to account for as many as the five future oil drawdowns in the six SPR caverns. The impacts on cavern stability, underground creep closure, surface subsidence, infrastructure, and well integrity were quantified.
Three dimensional imaging detector employing wavelength-shifting optical fibers
Worstell, William A.
1997-01-01
A novel detector element structure and method for its use is provided. In a preferred embodiment, one or more inorganic scintillating crystals are coupled through wavelength shifting optical fibers (WLSFs) to position sensitive photomultipliers (PS-PMTs). The superior detector configuration in accordance with this invention is designed for an array of applications in high spatial resolution gamma ray sensing with particular application to SPECT, PET and PVI imaging systems. The design provides better position resolution than prior art devices at a lower total cost. By employing wavelength shifting fibers (WLSFs), the sensor configuration of this invention can operate with a significant reduction in the number of photomultipliers and electronics channels, while potentially improving the resolution of the system by allowing three dimensional reconstruction of energy deposition positions.
Laser induced extraplanar propulsion for three-dimensional microfabrication
Birnbaum, A. J.; Pique, A.
2011-03-28
The laser induced extraplanar propulsion process is presented for the creation of controllable three-dimensional deformation of on-substrate components. It is demonstrated that the process is compatible with transparent substrates and ductile materials and is highly controllable in terms of the desired deformation via the adjustment of incident laser energy density. Copper films with thicknesses varying from 0.1-1 {mu}m are deformed over bending angles ranging from 0 deg. - 180 deg. A 355 nm laser at fluences ranging from 10-40 mJ/cm{sup 2} is used in conjunction with an indium-tin-oxide propulsion layer to demonstrate the process. Characterization is performed via electron and laser confocal microscopy.
Three-dimensional infrared metamaterial with asymmetric transmission
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Kenanakis, George; Xomalis, Aggelos; Selimis, Alexandros; Vamvakaki, Maria; Farsari, Maria; Kafesaki, Maria; Soukoulis, Costas M.; Economou, Eleftherios N.
2015-01-14
A novel three-dimensional (3D) metallic metamaterial structure with asymmetric transmission for linear polarization is demonstrated in the infrared spectral region. The structure was fabricated by direct laser writing and selective electroless silver coating, a straightforward, novel technique producing mechanically and chemically stable 3D photonic structures. The structure unit cell is composed of a pair of conductively coupled magnetic resonators, and the asymmetric transmission response results from interplay of electric and magnetic responses; this equips the structure with almost total opaqueness along one propagation direction versus satisfying transparency along the opposite one. It also offers easily adjustable impedance, 90° one-way puremore » optical activity and backward propagation possibility, resulting thus in unique capabilities in polarization control and isolation applications. We show also that scaling down the structure can make it capable of exhibiting its asymmetric transmission and its polarization capabilities in the optical region.« less
Three-dimensional infrared metamaterial with asymmetric transmission
Kenanakis, George; Xomalis, Aggelos; Selimis, Alexandros; Vamvakaki, Maria; Farsari, Maria; Kafesaki, Maria; Soukoulis, Costas M.; Economou, Eleftherios N.
2015-01-14
A novel three-dimensional (3D) metallic metamaterial structure with asymmetric transmission for linear polarization is demonstrated in the infrared spectral region. The structure was fabricated by direct laser writing and selective electroless silver coating, a straightforward, novel technique producing mechanically and chemically stable 3D photonic structures. The structure unit cell is composed of a pair of conductively coupled magnetic resonators, and the asymmetric transmission response results from interplay of electric and magnetic responses; this equips the structure with almost total opaqueness along one propagation direction versus satisfying transparency along the opposite one. It also offers easily adjustable impedance, 90° one-way pure optical activity and backward propagation possibility, resulting thus in unique capabilities in polarization control and isolation applications. We show also that scaling down the structure can make it capable of exhibiting its asymmetric transmission and its polarization capabilities in the optical region.
Three dimensional imaging detector employing wavelength-shifting optical fibers
Worstell, W.A.
1997-02-04
A novel detector element structure and method for its use is provided. In a preferred embodiment, one or more inorganic scintillating crystals are coupled through wavelength shifting optical fibers (WLSFs) to position sensitive photomultipliers (PS-PMTs). The superior detector configuration in accordance with this invention is designed for an array of applications in high spatial resolution gamma ray sensing with particular application to SPECT, PET and PVI imaging systems. The design provides better position resolution than prior art devices at a lower total cost. By employing wavelength shifting fibers (WLSFs), the sensor configuration of this invention can operate with a significant reduction in the number of photomultipliers and electronics channels, while potentially improving the resolution of the system by allowing three dimensional reconstruction of energy deposition positions. 11 figs.
Three dimensional numerical simulations of the UPS-292-SC engine
O'Rourke, P.J.; Amsden, A.A.
1987-01-01
We present and analyze three-dimensional calculations of the spray, mixing and combustion in the UPS-292 stratified charge engine for three different operating conditions, corresponding to overall air-fuel ratios between 22.4 and 61.0. The numerical calculations are performed with KIVA, a multidimensional arbitrary-mesh, finite-difference hydrodynamics program for internal combustion engine applications. The calculations use a mesh of 10,000 computational cells, which conform to the shape of the piston bowl and cylinder and move to follow piston motion. Each operating condition is calculated from intake valve closure at 118/sup 0/ BTDC to 90/sup 0/ ATDC and requires approximately three hours of CRAY-XMP computer time.
Three-dimensional finite element analysis of a bolted joint
Lin, H.; Reddy, H.; McKee, R.B.
1995-11-01
A flat steel flange clamped by 14 bolts was modeled by three dimensional finite element analysis to evaluate the apparent stiffness in compression of the flange. The bolt load was applied via an extremely stiff washer to eliminate the effect of bolt head deflection on the results. The dimensionless stiffness was found to vary with bolt aspect ratio d/L in a nearly linear fashion, with slope equal to that predicted by a simple cylindrical model. The conical frustum model, with a half angle of 32.8 degrees, predicted stiffnesses within a few percent of those measured. The interflange pressure along the bolt circle was calculated for a common bolt spacing and a range of aspect ratios.
Structures with three dimensional nanofences comprising single crystal segments
Goyal, Amit; Wee, Sung-Hun
2013-08-27
An article includes a substrate having a surface and a nanofence supported by the surface. The nanofence includes a multiplicity of primary nanorods and branch nanorods, each of the primary nanorods being attached to said substrate, and each of the branch nanorods being attached to a primary nanorods and/or another branch nanorod. The primary and branch nanorods are arranged in a three-dimensional, interconnected, interpenetrating, grid-like network defining interstices within the nanofence. The article further includes an enveloping layer supported by the nanofence, disposed in the interstices, and forming a coating on the primary and branch nanorods. The enveloping layer has a different composition from that of the nanofence and includes a radial p-n single junction solar cell photovoltaic material and/or a radial p-n multiple junction solar cell photovoltaic material.
The three-dimensional morphology of growing dendrites
Gibbs, J. W.; Mohan, K. A.; Gulsoy, E. B.; Shahani, A. J.; Xiao, X.; Bouman, C. A.; De Graef, M.; Voorhees, P. W.
2015-07-03
The processes controlling the morphology of dendrites have been of great interest to a wide range of communities, since they are examples of an out-of-equilibrium pattern forming system, there is a clear connection with battery failure processes, and their morphology sets the properties of many metallic alloys. We determine the three-dimensional morphology of free growing metallic dendrites using a novel X-ray tomographic technique that improves the temporal resolution by more than an order of magnitude compared to conventional techniques. These measurements show that the growth morphology of metallic dendrites is surprisingly different from that seen in model systems, the morphology is not self-similar with distance back from the tip, and that this morphology can have an unexpectedly strong influence on solute segregation in castings. These experiments also provide benchmark data that can be used to validate simulations of free dendritic growth.
THREE-DIMENSIONAL MORPHOLOGY OF A CORONAL PROMINENCE CAVITY
Gibson, S. E.; De Toma, G.; Rachmeler, L.; Rastawicki, D.; Dove, J.; Hao, J.; Zhang, M.; Hill, S.; Marque, C.; Seaton, D. B.; McIntosh, P. S.; Reeves, K. K.; Schmieder, B.; Schmit, D. J.; Sterling, A. C.; Williams, D. R.
2010-12-01
We present a three-dimensional density model of coronal prominence cavities, and a morphological fit that has been tightly constrained by a uniquely well-observed cavity. Observations were obtained as part of an International Heliophysical Year campaign by instruments from a variety of space- and ground-based observatories, spanning wavelengths from radio to soft X-ray to integrated white light. From these data it is clear that the prominence cavity is the limb manifestation of a longitudinally extended polar-crown filament channel, and that the cavity is a region of low density relative to the surrounding corona. As a first step toward quantifying density and temperature from campaign spectroscopic data, we establish the three-dimensional morphology of the cavity. This is critical for taking line-of-sight projection effects into account, since cavities are not localized in the plane of the sky and the corona is optically thin. We have augmented a global coronal streamer model to include a tunnel-like cavity with elliptical cross-section and a Gaussian variation of height along the tunnel length. We have developed a semi-automated routine that fits ellipses to cross-sections of the cavity as it rotates past the solar limb, and have applied it to Extreme Ultraviolet Imager observations from the two Solar Terrestrial Relations Observatory spacecraft. This defines the morphological parameters of our model, from which we reproduce forward-modeled cavity observables. We find that cavity morphology and orientation, in combination with the viewpoints of the observing spacecraft, explain the observed variation in cavity visibility for the east versus west limbs.
THE THREE-DIMENSIONAL ARCHITECTURE OF THE ? ANDROMEDAE PLANETARY SYSTEM
Deitrick, Russell; Barnes, Rory; Quinn, Thomas R.; Luger, Rodrigo; Antonsen, Adrienne [Department of Astronomy, University of Washington, Seattle, WA 98195-1580 (United States); McArthur, Barbara; Fritz Benedict, G., E-mail: deitrr@astro.washington.edu [Department of Astronomy, University of Texas at Austin, Austin, TX 78712 (United States)
2015-01-01
The ? Andromedae system is the first exoplanetary system to have the relative inclination of two planets' orbital planes directly measured, and therefore offers our first window into the three-dimensional configurations of planetary systems. We present, for the first time, full three-dimensional, dynamically stable configurations for the three planets of the system consistent with all observational constraints. While the outer two planets, c and d, are inclined by ?30, the inner planet's orbital plane has not been detected. We use N-body simulations to search for stable three-planet configurations that are consistent with the combined radial velocity and astrometric solution. We find that only 10 trials out of 1000 are robustly stable on 100Myr timescales, or ?8 billion orbits of planet b. Planet b's orbit must lie near the invariable plane of planets c and d, but can be either prograde or retrograde. These solutions predict that b's mass is in the range of 2-9 M {sub Jup} and has an inclination angle from the sky plane of less than 25. Combined with brightness variations in the combined star/planet light curve ({sup p}hase curve{sup )}, our results imply that planet b's radius is ?1.8 R {sub Jup}, relatively large for a planet of its age. However, the eccentricity of b in several of our stable solutions reaches >0.1, generating upward of 10{sup 19} W in the interior of the planet via tidal dissipation, possibly inflating the radius to an amount consistent with phase curve observations.
Yan Zhenya; Hang Chao
2009-12-15
We provide analytical three-dimensional bright multisoliton solutions to the (3+1)-dimensional Gross-Pitaevskii equation with time- and space-dependent potential, time-dependent nonlinearity, and gain or loss. The zigzag propagation trace and the breathing behavior of solitons are observed. Different shapes of bright solitons and fascinating interactions between two solitons can be achieved with different parameters. The obtained results may raise the possibility of relative experiments and potential applications.
Three-dimensional simulation of H-mode plasmas with localized...
Office of Scientific and Technical Information (OSTI)
Three-dimensional simulation of H-mode plasmas with localized divertor impurity injection ... Citation Details In-Document Search Title: Three-dimensional simulation of H-mode plasmas ...
A Three-Dimensional Carbon Nano-Network for High Performance...
Office of Scientific and Technical Information (OSTI)
A Three-Dimensional Carbon Nano-Network for High Performance Lithium Ion Batteries. Citation Details In-Document Search Title: A Three-Dimensional Carbon Nano-Network for High...
Oscillatory cellular patterns in three-dimensional directional solidification
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tourret, D.; Debierre, J. -M.; Song, Y.; Mota, F. L.; Bergeon, N.; Guerin, R.; Trivedi, R.; Billia, B.; Karma, A.
2015-09-11
We present a phase-field study of oscillatory breathing modes observed during the solidification of three-dimensional cellular arrays in micro-gravity. Directional solidification experiments conducted onboard the International Space Station have allowed for the first time to observe spatially extended homogeneous arrays of cells and dendrites while minimizing the amount of gravity-induced convection in the liquid. In situ observations of transparent alloys have revealed the existence, over a narrow range of control parameters, of oscillations in cellular arrays with a period ranging from about 25 to 125 minutes. Cellular patterns are spatially disordered, and the oscillations of individual cells are spatiotemporally uncorrelatedmore » at long distance. However, in regions displaying short-range spatial ordering, groups of cells can synchronize into oscillatory breathing modes. Quantitative phase-field simulations show that the oscillatory behavior of cells in this regime is linked to a stability limit of the spacing in hexagonal cellular array structures. For relatively high cellular front undercooling (\\ie low growth velocity or high thermal gradient), a gap appears in the otherwise continuous range of stable array spacings. Close to this gap, a sustained oscillatory regime appears with a period that compares quantitatively well with experiment. For control parameters where this gap exist, oscillations typically occur for spacings at the edge of the gap. However, after a change of growth conditions, oscillations can also occur for nearby values of control parameters where this gap just closes and a continuous range of spacings exists. In addition, sustained oscillations at to the opening of this stable gap exhibit a slow periodic modulation of the phase-shift among cells with a slower period of several hours. While long-range coherence of breathing modes can be achieved in simulations for a perfect spatial arrangement of cells as initial condition, global
Oscillatory cellular patterns in three-dimensional directional solidification
Tourret, D.; Debierre, J. -M.; Song, Y.; Mota, F. L.; Bergeon, N.; Guerin, R.; Trivedi, R.; Billia, B.; Karma, A.
2015-09-11
We present a phase-field study of oscillatory breathing modes observed during the solidification of three-dimensional cellular arrays in micro-gravity. Directional solidification experiments conducted onboard the International Space Station have allowed for the first time to observe spatially extended homogeneous arrays of cells and dendrites while minimizing the amount of gravity-induced convection in the liquid. In situ observations of transparent alloys have revealed the existence, over a narrow range of control parameters, of oscillations in cellular arrays with a period ranging from about 25 to 125 minutes. Cellular patterns are spatially disordered, and the oscillations of individual cells are spatiotemporally uncorrelated at long distance. However, in regions displaying short-range spatial ordering, groups of cells can synchronize into oscillatory breathing modes. Quantitative phase-field simulations show that the oscillatory behavior of cells in this regime is linked to a stability limit of the spacing in hexagonal cellular array structures. For relatively high cellular front undercooling (\\ie low growth velocity or high thermal gradient), a gap appears in the otherwise continuous range of stable array spacings. Close to this gap, a sustained oscillatory regime appears with a period that compares quantitatively well with experiment. For control parameters where this gap exist, oscillations typically occur for spacings at the edge of the gap. However, after a change of growth conditions, oscillations can also occur for nearby values of control parameters where this gap just closes and a continuous range of spacings exists. In addition, sustained oscillations at to the opening of this stable gap exhibit a slow periodic modulation of the phase-shift among cells with a slower period of several hours. While long-range coherence of breathing modes can be achieved in simulations for a perfect spatial arrangement of cells as initial condition, global disorder is
SOLA-DM: A numerical solution algorithm for transient three-dimensional flows
Wilson, T.L.; Nichols, B.D.; Hirt, C.W.; Stein, L.R.
1988-02-01
SOLA-DM is a three-dimensional time-explicit, finite-difference, Eulerian, fluid-dynamics computer code for solving the time-dependent incompressible Navier-Stokes equations. The solution algorithm (SOLA) evolved from the marker-and-cell (MAC) method, and the code is highly vectorized for efficient performance on a Cray computer. The computational domain is discretized by a mesh of parallelepiped cells in either cartesian or cylindrical geometry. The primary hydrodynamic variables for approximating the solution of the momentum equations are cell-face-centered velocity components and cell-centered pressures. Spatial accuracy is selected by the user to be first or second order; the time differencing is first-order accurate. The incompressibility condition results in an elliptic equation for pressure that is solved by a conjugate gradient method. Boundary conditions of five general types may be chosen: free-slip, no-slip, continuative, periodic, and specified pressure. In addition, internal mesh specifications to model obstacles and walls are provided. SOLA-DM also solves the equations for discrete particle dynamics, permitting the transport of marker particles or other solid particles through the fluid to be modeled. 7 refs., 7 figs.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tourret, D.; Karma, A.; Clarke, A. J.; Gibbs, P. J.; Imhoff, S. D.
2015-06-11
We present a three-dimensional (3D) extension of a previously proposed multi-scale Dendritic Needle Network (DNN) approach for the growth of complex dendritic microstructures. Using a new formulation of the DNN dynamics equations for dendritic paraboloid-branches of a given thickness, one can directly extend the DNN approach to 3D modeling. We validate this new formulation against known scaling laws and analytical solutions that describe the early transient and steady-state growth regimes, respectively. Finally, we compare the predictions of the model to in situ X-ray imaging of Al-Cu alloy solidification experiments. The comparison shows a very good quantitative agreement between 3D simulationsmore » and thin sample experiments. It also highlights the importance of full 3D modeling to accurately predict the primary dendrite arm spacing that is significantly over-estimated by 2D simulations.« less
Three-Dimensional Electromagnetic High Frequency Axisymmetric Cavity Scars.
Warne, Larry K.; Jorgenson, Roy E.
2014-10-01
This report examines the localization of high frequency electromagnetic fi elds in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. The cases where these orbits lead to unstable localized modes are known as scars. This report treats both the case where the opposing sides, or mirrors, are convex, where there are no interior foci, and the case where they are concave, leading to interior foci. The scalar problem is treated fi rst but the approximations required to treat the vector fi eld components are also examined. Particular att ention is focused on the normalization through the electromagnetic energy theorem. Both projections of the fi eld along the scarred orbit as well as point statistics are examined. Statistical comparisons are m ade with a numerical calculation of the scars run with an axisymmetric simulation. This axisymmetric cas eformstheoppositeextreme(wherethetwomirror radii at each end of the ray orbit are equal) from the two -dimensional solution examined previously (where one mirror radius is vastly di ff erent from the other). The enhancement of the fi eldontheorbitaxiscanbe larger here than in the two-dimensional case. Intentionally Left Blank
A novel three dimensional semimetallic MoS{sub 2}
Tang, Zhen-Kun; Zhang, Hui; Liu, Li-Min; Liu, Hao; Lau, Woon-Ming
2014-05-28
Transition metal dichalcogenides (TMDs) have many potential applications, while the performances of TMDs are generally limited by the less surface active sites and the poor electron transport efficiency. Here, a novel three-dimensional (3D) structure of molybdenum disulfide (MoS{sub 2}) with larger surface area was proposed based on first-principle calculations. 3D layered MoS{sub 2} structure contains the basal surface and joint zone between the different nanoribbons, which is thermodynamically stable at room temperature, as confirmed by first principles molecular dynamics calculations. Compared the two-dimensional layered structures, the 3D MoS{sub 2} not only owns the large surface areas but also can effectively avoid the aggregation. Interestingly, although the basal surface remains the property of the intrinsic semiconductor as the bulk MoS{sub 2}, the joint zone of 3D MoS{sub 2} exhibits semimetallic, which is derived from degenerate 3d orbitals of the Mo atoms. The high stability, large surface area, and high conductivity make 3D MoS{sub 2} have great potentials as high performance catalyst.
Three-dimensional lattice Boltzmann model for magnetic reconnection
Mendoza, M.; Munoz, J. D.
2008-02-15
We develop a three-dimensional (3D) lattice Boltzmann model that recovers in the continuous limit the two-fluids theory for plasmas, and consequently includes the generalized Ohm's law. The model reproduces the magnetic reconnection process just by giving the right initial equilibrium conditions in the magnetotail, without any assumption on the resistivity in the diffusive region. In this model, the plasma is handled similar to two fluids with an interaction term, each one with distribution functions associated to a cubic lattice with 19 velocities (D3Q19). The electromagnetic fields are considered as a third fluid with an external force on a cubic lattice with 13 velocities (D3Q13). The model can simulate either viscous fluids in the incompressible limit or nonviscous compressible fluids, and successfully reproduces both the Hartmann flow and the magnetic reconnection in the magnetotail. The reconnection rate in the magnetotail obtained with this model lies between R=0.062 and R=0.073, in good agreement with the observations.
A THREE-DIMENSIONAL BABCOCK-LEIGHTON SOLAR DYNAMO MODEL
Miesch, Mark S.; Dikpati, Mausumi
2014-04-10
We present a three-dimensional (3D) kinematic solar dynamo model in which poloidal field is generated by the emergence and dispersal of tilted sunspot pairs (more generally bipolar magnetic regions, or BMRs). The axisymmetric component of this model functions similarly to previous 2.5 dimensional (2.5D, axisymmetric) Babcock-Leighton (BL) dynamo models that employ a double-ring prescription for poloidal field generation but we generalize this prescription into a 3D flux emergence algorithm that places BMRs on the surface in response to the dynamo-generated toroidal field. In this way, the model can be regarded as a unification of BL dynamo models (2.5D in radius/latitude) and surface flux transport models (2.5D in latitude/longitude) into a more self-consistent framework that builds on the successes of each while capturing the full 3D structure of the evolving magnetic field. The model reproduces some basic features of the solar cycle including an 11 yr periodicity, equatorward migration of toroidal flux in the deep convection zone, and poleward propagation of poloidal flux at the surface. The poleward-propagating surface flux originates as trailing flux in BMRs, migrates poleward in multiple non-axisymmetric streams (made axisymmetric by differential rotation and turbulent diffusion), and eventually reverses the polar field, thus sustaining the dynamo. In this Letter we briefly describe the model, initial results, and future plans.
Parallel phase-sensitive three-dimensional imaging camera
Smithpeter, Colin L.; Hoover, Eddie R.; Pain, Bedabrata; Hancock, Bruce R.; Nellums, Robert O.
2007-09-25
An apparatus is disclosed for generating a three-dimensional (3-D) image of a scene illuminated by a pulsed light source (e.g. a laser or light-emitting diode). The apparatus, referred to as a phase-sensitive 3-D imaging camera utilizes a two-dimensional (2-D) array of photodetectors to receive light that is reflected or scattered from the scene and processes an electrical output signal from each photodetector in the 2-D array in parallel using multiple modulators, each having inputs of the photodetector output signal and a reference signal, with the reference signal provided to each modulator having a different phase delay. The output from each modulator is provided to a computational unit which can be used to generate intensity and range information for use in generating a 3-D image of the scene. The 3-D camera is capable of generating a 3-D image using a single pulse of light, or alternately can be used to generate subsequent 3-D images with each additional pulse of light.
One-dimensional views of three-dimensional sediments
Harper, M.P.; Davison, W.; Tych, W. . Institute of Environmental and Natural Sciences)
1999-08-01
Recent measurements of trace metals in sediment pore waters at high spatial resolution have revealed significant horizontal and vertical heterogeneity on a submillimeter scale. These measurements are consistent with remobilization occurring from a three-dimensional (3D) stochastic distribution of small microniche sources.'' However, early diagenetic processes are conventionally described in 1D terms. Application of 1D reaction-transport models to 3D systems will result in biased estimates of process rates. For the same intrinsic rates of supply and removal, maxima in concentration-depth profiles in 3D systems are likely to be lower, and concentration profile gradients higher, than in 1D systems. The simple examples considered suggest that process rate estimates may be in error by a factor of 5 when a 1D model is used. A simple 3D numerical model of trace metal remobilization in pore waters was used to demonstrate how the structure of high-resolution trace metal profiles can be reproduced using a stochastic distribution of microniche sources. Heterogeneity depends on the scale considered and is more marked when measurements are made at high resolutions. Heterogeneity is increased by slow transport, fast sinks, and widely separated sources. As the degree of heterogeneity between and within concentration-depth profiles increases, the estimates of process rates obtained from 1D models become less accurate.
Three-dimensional Casimir piston for massive scalar fields
Lim, S.C. Teo, L.P.
2009-08-15
We consider Casimir force acting on a three-dimensional rectangular piston due to a massive scalar field subject to periodic, Dirichlet and Neumann boundary conditions. Exponential cut-off method is used to derive the Casimir energy. It is shown that the divergent terms do not contribute to the Casimir force acting on the piston, thus render a finite well-defined Casimir force acting on the piston. Explicit expressions for the total Casimir force acting on the piston is derived, which show that the Casimir force is always attractive for all the different boundary conditions considered. As a function of a - the distance from the piston to the opposite wall, it is found that the magnitude of the Casimir force behaves like 1/a{sup 4} when a{yields}0{sup +} and decays exponentially when a{yields}{infinity}. Moreover, the magnitude of the Casimir force is always a decreasing function of a. On the other hand, passing from massless to massive, we find that the effect of the mass is insignificant when a is small, but the magnitude of the force is decreased for large a in the massive case.
THREE-DIMENSIONAL RADIATION TRANSFER IN YOUNG STELLAR OBJECTS
Whitney, B. A.; Honor, J.; Robitaille, T. P.; Bjorkman, J. E.; Dong, R.; Wolff, M. J.; Wood, K.
2013-08-15
We have updated our publicly available dust radiative transfer code (HOCHUNK3D) to include new emission processes and various three-dimensional (3D) geometries appropriate for forming stars. The 3D geometries include warps and spirals in disks, accretion hotspots on the central star, fractal clumping density enhancements, and misaligned inner disks. Additional axisymmetric (2D) features include gaps in disks and envelopes, ''puffed-up inner rims'' in disks, multiple bipolar cavity walls, and iteration of disk vertical structure assuming hydrostatic equilibrium (HSEQ). We include the option for simple power-law envelope geometry, which, combined with fractal clumping and bipolar cavities, can be used to model evolved stars as well as protostars. We include non-thermal emission from polycyclic aromatic hydrocarbons (PAHs) and very small grains, and external illumination from the interstellar radiation field. The grid structure was modified to allow multiple dust species in each cell; based on this, a simple prescription is implemented to model dust stratification. We describe these features in detail, and show example calculations of each. Some of the more interesting results include the following: (1) outflow cavities may be more clumpy than infalling envelopes. (2) PAH emission in high-mass stars may be a better indicator of evolutionary stage than the broadband spectral energy distribution slope; and related to this, (3) externally illuminated clumps and high-mass stars in optically thin clouds can masquerade as young stellar objects. (4) Our HSEQ models suggest that dust settling is likely ubiquitous in T Tauri disks, in agreement with previous observations.
Three-dimensional induced polarization data inversion for complex resistivity
Commer, M.; Newman, G.A.; Williams, K.H.; Hubbard, S.S.
2011-03-15
The conductive and capacitive material properties of the subsurface can be quantified through the frequency-dependent complex resistivity. However, the routine three-dimensional (3D) interpretation of voluminous induced polarization (IP) data sets still poses a challenge due to large computational demands and solution nonuniqueness. We have developed a flexible methodology for 3D (spectral) IP data inversion. Our inversion algorithm is adapted from a frequency-domain electromagnetic (EM) inversion method primarily developed for large-scale hydrocarbon and geothermal energy exploration purposes. The method has proven to be efficient by implementing the nonlinear conjugate gradient method with hierarchical parallelism and by using an optimal finite-difference forward modeling mesh design scheme. The method allows for a large range of survey scales, providing a tool for both exploration and environmental applications. We experimented with an image focusing technique to improve the poor depth resolution of surface data sets with small survey spreads. The algorithm's underlying forward modeling operator properly accounts for EM coupling effects; thus, traditionally used EM coupling correction procedures are not needed. The methodology was applied to both synthetic and field data. We tested the benefit of directly inverting EM coupling contaminated data using a synthetic large-scale exploration data set. Afterward, we further tested the monitoring capability of our method by inverting time-lapse data from an environmental remediation experiment near Rifle, Colorado. Similar trends observed in both our solution and another 2D inversion were in accordance with previous findings about the IP effects due to subsurface microbial activity.
Femtosecond laser three-dimensional micro- and nanofabrication
Sugioka, Koji; Cheng, Ya
2014-12-15
The rapid development of the femtosecond laser has revolutionized materials processing due to its unique characteristics of ultrashort pulse width and extremely high peak intensity. The short pulse width suppresses the formation of a heat-affected zone, which is vital for ultrahigh precision fabrication, whereas the high peak intensity allows nonlinear interactions such as multiphoton absorption and tunneling ionization to be induced in transparent materials, which provides versatility in terms of the materials that can be processed. More interestingly, irradiation with tightly focused femtosecond laser pulses inside transparent materials makes three-dimensional (3D) micro- and nanofabrication available due to efficient confinement of the nonlinear interactions within the focal volume. Additive manufacturing (stereolithography) based on multiphoton absorption (two-photon polymerization) enables the fabrication of 3D polymer micro- and nanostructures for photonic devices, micro- and nanomachines, and microfluidic devices, and has applications for biomedical and tissue engineering. Subtractive manufacturing based on internal modification and fabrication can realize the direct fabrication of 3D microfluidics, micromechanics, microelectronics, and photonic microcomponents in glass. These microcomponents can be easily integrated in a single glass microchip by a simple procedure using a femtosecond laser to realize more functional microdevices, such as optofluidics and integrated photonic microdevices. The highly localized multiphoton absorption of a tightly focused femtosecond laser in glass can also induce strong absorption only at the interface of two closely stacked glass substrates. Consequently, glass bonding can be performed based on fusion welding with femtosecond laser irradiation, which provides the potential for applications in electronics, optics, microelectromechanical systems, medical devices, microfluidic devices, and small satellites. This review paper
NON-BAROTROPIC LINEAR ROSSBY WAVE INSTABILITY IN THREE-DIMENSIONAL DISKS
Lin, Min-Kai
2013-03-10
Astrophysical disks with localized radial structure, such as protoplanetary disks containing dead zones or gaps due to disk-planet interaction, may be subject to the non-axisymmetric Rossby wave instability (RWI) that leads to vortex formation. The linear instability has recently been demonstrated in three-dimensional (3D) barotropic disks. It is the purpose of this study to generalize the 3D linear problem to include an energy equation, thereby accounting for baroclinity in three dimensions. Linear stability calculations are presented for radially structured, vertically stratified, geometrically thin disks with non-uniform entropy distribution in both directions. Polytropic equilibria are considered but adiabatic perturbations assumed. The unperturbed disk has a localized radial density bump, making it susceptible to the RWI. The linearized fluid equations are solved numerically as a partial differential equation eigenvalue problem. Emphasis on the ease of method implementation is given. It is found that when the polytropic index is fixed and adiabatic index increased, non-uniform entropy has negligible effect on the RWI growth rate, but pressure and density perturbation magnitudes near a pressure enhancement increase away from the midplane. The associated meridional flow is also qualitatively changed from homentropic calculations. Meridional vortical motion is identified in the nonhomentropic linear solution, as well as in a nonlinear global hydrodynamic simulation of the RWI in an initially isothermal disk evolved adiabatically. Numerical results suggest that buoyancy forces play an important role in the internal flow of Rossby vortices.
THREE-DIMENSIONAL SHAPE AND EVOLUTION OF TWO ERUPTIVE FILAMENTS
Li Ting; Zhang Jun; Yang Shuhong; Zhao Hui E-mail: zjun@nao.cas.c E-mail: v00975@phys.nthu.edu.t
2010-09-01
On 2009 September 26, a dramatic and large filament (LF) eruption and a small filament (SF) eruption were observed in the He II 304 A line by the two EUVI telescopes aboard the STEREO A and B spacecraft. The LF heads out into space and becomes the bright core of a gradual coronal mass ejection (CME), while the eruption of the SF is characterized by motions of the filament materials. Using stereoscopic analysis of EUVI data, we reconstruct the three-dimensional shape and evolution of two eruptive filaments. For the first time, we investigate the true velocities and accelerations of 12 points along the axis of the LF, and find that the velocity and acceleration vary with the measured location. The highest points among the 12 points are the fastest in the first half hour, and then the points at the low-latitude leg of the LF become the fastest. For the SF, it is an asymmetric whip-like filament eruption, and the downward motions of the material lead to the disappearance of the former high-latitude endpoint and the formation of a new low-latitude endpoint. Based on the temporal evolution of the two filaments, we infer that the two filaments lie in the same filament channel. By combining the EUVI, COR1, and COR2 data of STEREO A together, we find that there is no impulsive or fast acceleration in this event. It displays a weak and persistent acceleration for more than 17 hr. The average velocity and acceleration of the LF are 101.8 km s{sup -1} and 2.9 m s{sup -2}, respectively. The filament eruptions are associated with a slow CME with an average velocity of 177.4 km s{sup -1}. The velocity of the CME is nearly 1.6 times as large as that of the filament material. This event is one example of a gradual filament eruption associated with a gradual CME. In addition, the moving direction of the LF changes from a non-radial to a nearly radial direction with a variation of inclination angle of nearly 38.{sup 0}2.
Advanced numerical methods for three dimensional two-phase flow calculations
Toumi, I.; Caruge, D.
1997-07-01
This paper is devoted to new numerical methods developed for both one and three dimensional two-phase flow calculations. These methods are finite volume numerical methods and are based on the use of Approximate Riemann Solvers concepts to define convective fluxes versus mean cell quantities. The first part of the paper presents the numerical method for a one dimensional hyperbolic two-fluid model including differential terms as added mass and interface pressure. This numerical solution scheme makes use of the Riemann problem solution to define backward and forward differencing to approximate spatial derivatives. The construction of this approximate Riemann solver uses an extension of Roe`s method that has been successfully used to solve gas dynamic equations. As far as the two-fluid model is hyperbolic, this numerical method seems very efficient for the numerical solution of two-phase flow problems. The scheme was applied both to shock tube problems and to standard tests for two-fluid computer codes. The second part describes the numerical method in the three dimensional case. The authors discuss also some improvements performed to obtain a fully implicit solution method that provides fast running steady state calculations. Such a scheme is not implemented in a thermal-hydraulic computer code devoted to 3-D steady-state and transient computations. Some results obtained for Pressurised Water Reactors concerning upper plenum calculations and a steady state flow in the core with rod bow effect evaluation are presented. In practice these new numerical methods have proved to be stable on non staggered grids and capable of generating accurate non oscillating solutions for two-phase flow calculations.
Three-dimensional Plasmas R. L. Dewar; P. Cuthbert; R. Ball 70...
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of Three-dimensional Plasmas R. L. Dewar; P. Cuthbert; R. Ball 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY;...
Three-dimensional V p /V s variations for the Coso region, California...
the Pleistocene volcanics of the Coso Range. In order to learn more about the physical nature of these colocated anomalies, a tomographic inversion for the three-dimensional...
Kondo-like zero-bias conductance anomaly in a three-dimensional...
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Journal Article: Kondo-like zero-bias conductance anomaly in a three-dimensional topological insulator nanowire Citation ... Type: Accepted Manuscript Journal Name: Scientific Reports ...
Molecular-scale, Three-dimensional Non-Platinum Group Metal Electrodes...
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Group Metal Electrodes for Catalysis of Fuel Cell Reactions Molecular-scale, Three-dimensional Non-Platinum Group Metal Electrodes for Catalysis of Fuel Cell Reactions ...
Three-Dimensional Structural Analysis of MgO-Supported Osmium...
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Three-Dimensional Structural Analysis of MgO-Supported Osmium Clusters by Electron Microscopy with Single-Atom Sensitivity Citation Details In-Document Search Title: ...
Development and Validation of a Two-phase, Three-dimensional...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Three-dimensional Model for PEM Fuel Cells Fuel Cell Projects Kickoff Meeting September 30 - October ... National Laboratory Ballard Power Systems Ford Motor Company Objectives * To ...
Chitsazi, Mahboobeh; Maraghechi, B.; Rouhani, M. H.
2010-10-15
The effect of prebunching of the electron beam and tapering of the wiggler amplitude on the harmonic upconversion in free-electron laser amplifier is studied in three dimensions. A set of coupled nonlinear first-order differential equations that describe the three-dimensional simulation of the system is solved numerically. This set of equation describes self-consistently the longitudinal spatial dependence of radiation waists, curvatures, and amplitudes together with the evaluation of the electron beam. The analysis is related to extreme ultraviolet and x-ray emission. In addition to uniform beam, prebunched electron beam has also been studied. The effect of sinusoidal distribution of entry times for the electron beam on the evolution of radiation is compared with uniform distribution. It is shown that prebunching reduces the saturation length substantially. For efficiency enhancement, the wiggler is set to decrease linearly when the radiation of the third harmonic saturates. The optimum starting point and the slope of tapering of the amplitude of the wiggler are found by a successive run of the code. It was found that tapering can increase the saturated power of the third harmonic considerably.
About vacuum solutions of Einstein's field equations with flat three-dimensional hypersurfaces
Wolf, T.
1986-09-01
The class of vacuum space-times with a family of flat three-slices and a traceless tensor of exterior curvature K-italic/sub a-italic//sub b-italic/ is examined. Metrics without symmetry and solutions describing gravitational radiation are obtained. It turns out that there is a correlation between rank (K-italic/sub a-italic//sub b-italic/) and the Petrov type. Although the resulting solutions are already known, the richness of the class of space-times with flat slices becomes obvious. An example is given of a metric with one-parameter manifold of families of flat slices.
Diffusion coefficient of three-dimensional Yukawa liquids
Dzhumagulova, K. N.; Ramazanov, T. S.; Masheeva, R. U.
2013-11-15
The purpose of this work is an investigation of the diffusion coefficient of the dust component in complex plasma. The computer simulation of the Yukawa liquids was made on the basis of the Langevin equation, which takes into account the influence of buffer plasma on the dust particles dynamics. The GreenKubo relation was used to calculate the diffusion coefficient. Calculations of the diffusion coefficient for a wide range of the system parameters were performed. Using obtained numerical data, we constructed the interpolation formula for the diffusion coefficient. We also show that the interpolation formula correctly describes experimental data obtained under microgravity conditions.
Iskander, S.K.
1981-02-01
Two finite element (FE) approaches were used to calculate opening mode I stress intensity factors (K/sub I/) in two- or three-dimensional (2-D and 3-D) problems for the Heavy-Section Steel Technology (HSST) program. For problems that can be modeled in two dimensions, two techniques were used. One of these may be termed an ''energy release rate'' technique, and the other is based on the classical near-tip displacement and stress field equations. For three-dimensional problems, only the latter technique was used. In the energy release technique, K/sub I/ is calculated as the change in potential energy of the structure due to a small change in crack length. The potential energy is calculated by the FE method but without completely solving the system of linear equations for the displacements. Furthermore, the system of linear equations is only slightly perturbed by the change in crack length and, therefore, many computations need not be repeated for the second structure with the slight change in crack length. Implementation of these last two items has resulted in considerable savings in the calculation of K/sub I/ as compared to two complete FE analyses. These ideas are incorporated in the FMECH code. The accuracy of the methods has been checked by comparing the results of the two approaches with each other and with closed form solutions. It is estimated that the accuracy of the results is about +-5%.
Current singularities at quasi-separatrix layers and three-dimensional magnetic nulls
Craig, I. J. D.; Effenberger, Frederic
2014-11-10
The open problem of how singular current structures form in line-tied, three-dimensional magnetic fields is addressed. A Lagrangian magneto-frictional relaxation method is employed to model the field evolution toward the final near-singular state. Our starting point is an exact force-free solution of the governing magnetohydrodynamic equations that is sufficiently general to allow for topological features like magnetic nulls to be inside or outside the computational domain, depending on a simple set of parameters. Quasi-separatrix layers (QSLs) are present in these structures and, together with the magnetic nulls, they significantly influence the accumulation of current. It is shown that perturbations affecting the lateral boundaries of the configuration lead not only to collapse around the magnetic null but also to significant QSL currents. Our results show that once a magnetic null is present, the developing currents are always attracted to that specific location and show a much stronger scaling with resolution than the currents that form along the QSL. In particular, the null-point scalings can be consistent with models of 'fast' reconnection. The QSL currents also appear to be unbounded but give rise to weaker singularities, independent of the perturbation amplitude.
Gent, F. A.; Erdélyi, R.; Fedun, V.
2014-07-01
A system of multiple open magnetic flux tubes spanning the solar photosphere and lower corona is modeled analytically, within a realistic stratified atmosphere subject to solar gravity. This extends results for a single magnetic flux tube in magnetohydrostatic equilibrium, described in Gent et al. Self-similar magnetic flux tubes are combined to form magnetic structures, which are consistent with high-resolution observations. The observational evidence supports the existence of strands of open flux tubes and loops persisting in a relatively steady state. Self-similar magnetic flux tubes, for which an analytic solution to the plasma density and pressure distribution is possible, are combined. We calculate the appropriate balancing forces, applying to the equations of momentum and energy conservation to preserve equilibrium. Multiplex flux tube configurations are observed to remain relatively stable for up to a day or more, and it is our aim to apply our model as the background condition for numerical studies of energy transport mechanisms from the solar surface to the corona. We apply magnetic field strength, plasma density, pressure, and temperature distributions consistent with observational and theoretical estimates for the lower solar atmosphere. Although each flux tube is identical in construction apart from the location of the radial axis, combinations can be applied to generate a non-axisymmetric magnetic field with multiple non-uniform flux tubes. This is a considerable step forward in modeling the realistic magnetized three-dimensional equilibria of the solar atmosphere.
Schiek, Richard
2006-06-20
A method of generating two-dimensional masks from a three-dimensional model comprises providing a three-dimensional model representing a micro-electro-mechanical structure for manufacture and a description of process mask requirements, reducing the three-dimensional model to a topological description of unique cross sections, and selecting candidate masks from the unique cross sections and the cross section topology. The method further can comprise reconciling the candidate masks based on the process mask requirements description to produce two-dimensional process masks.
Yamazaki, Kazuo
2014-03-15
We study the three-dimensional magnetohydrodynamics system and obtain its regularity criteria in terms of only two velocity vector field components eliminating the condition on the third component completely. The proof consists of a new decomposition of the four nonlinear terms of the system and estimating a component of the magnetic vector field in terms of the same component of the velocity vector field. This result may be seen as a component reduction result of many previous works [C. He and Z. Xin, “On the regularity of weak solutions to the magnetohydrodynamic equations,” J. Differ. Equ. 213(2), 234–254 (2005); Y. Zhou, “Remarks on regularities for the 3D MHD equations,” Discrete Contin. Dyn. Syst. 12(5), 881–886 (2005)].
Trampedach, Regner; Asplund, Martin; Collet, Remo; Nordlund, Ake
2013-05-20
Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive power to such models of late-type stars. We present a grid of improved and more reliable stellar atmosphere models of late-type stars, based on deep, three-dimensional (3D), convective, stellar atmosphere simulations. This grid is to be used in general for interpreting observations and improving stellar and asteroseismic modeling. We solve the Navier Stokes equations in 3D and concurrent with the radiative transfer equation, for a range of atmospheric parameters, covering most of stellar evolution with convection at the surface. We emphasize the use of the best available atomic physics for quantitative predictions and comparisons with observations. We present granulation size, convective expansion of the acoustic cavity, and asymptotic adiabat as functions of atmospheric parameters.
Tewari, A.; Gokhale, A.M.
2000-03-01
Three-dimensional digital image processing is useful for reconstruction of microstructural volume from a stack of serial sections. Application of this technique is demonstrated via reconstruction of a volume segment of the liquid-phase sintered microstructure of a tungsten heavy alloy processed in the microgravity environment of NASA's space shuttle, Columbia. Ninety serial sections (approximately one micrometer apart) were used for reconstruction of the three-dimensional microstructure. The three-dimensional microstructural reconstruction clearly revealed that the tungsten grains are almost completely connected in three-dimensional space. Both the matrix and the grains are topologically co-continuous, although the alloy was liquid-phase sintered in microgravity. Therefore, absence of gravity did not produced a microstructure consisting of discrete isolated W grains uniformly dispersed in the liquid Ni-Fe alloy matrix at the sintering temperature.
Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold
Farmer, Joseph Collin; Stadermann, Michael
2014-07-15
A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.
Monolithic three-dimensional electrochemical energy storage system on aerogel or nanotube scaffold
Farmer, Joseph C; Stadermann, Michael
2013-11-12
A monolithic three-dimensional electrochemical energy storage system is provided on an aerogel or nanotube scaffold. An anode, separator, cathode, and cathodic current collector are deposited on the aerogel or nanotube scaffold.
Probing the role of sequence in the assembly of three-dimensional...
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Probing the role of sequence in the assembly of three-dimensional DNA crystals Citation Details In-Document Search Title: Probing the role of sequence in the assembly of ...
Comparisons Of Two- And Three-Dimensional Convection In Type I X-Ray Bursts
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zingale, M.; Malone, C. M.; Nonaka, A.; Almgren, A. S.; Bell, J. B.
2015-07-01
We perform the first detailed three-dimensional simulation of low Mach number convection preceding runaway thermonuclear ignition in a mixed H/He X-ray burst. Our simulations include a moderate-sized, approximate network that captures hydrogen and helium burning up through rp-process breakout. We look at the difference between two- and three-dimensional convective fields, including the details of the turbulent convection.
Method and Apparatus for Three-Dimensional Carbon Fiber Production - Energy
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Innovation Portal Hydrogen and Fuel Cell Hydrogen and Fuel Cell Advanced Materials Advanced Materials Find More Like This Return to Search Method and Apparatus for Three-Dimensional Carbon Fiber Production DOE Grant Recipients Contact GRANT About This Technology Technology Marketing Summary UCF researchers have discovered a method for producing three-dimensional carbon fibers. These novel fibers have a surface area approximately two orders of magnitude greater than the surface area of
Kondo-like zero-bias conductance anomaly in a three-dimensional topological
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insulator nanowire (Journal Article) | SciTech Connect Kondo-like zero-bias conductance anomaly in a three-dimensional topological insulator nanowire Citation Details In-Document Search Title: Kondo-like zero-bias conductance anomaly in a three-dimensional topological insulator nanowire Zero-bias anomalies in topological nanowires have recently captured significant attention, as they are possible signatures of Majorana modes. Yet there are many other possible origins of zero-bias peaks in
Jiang, Yan-Fei; Stone, James M.; Davis, Shane W.
2014-12-01
We study super-Eddington accretion flows onto black holes using a global three-dimensional radiation magneto-hydrodynamical simulation. We solve the time-dependent radiative transfer equation for the specific intensities to accurately calculate the angular distribution of the emitted radiation. Turbulence generated by the magneto-rotational instability provides self-consistent angular momentum transfer. The simulation reaches inflow equilibrium with an accretion rate ∼220 L {sub Edd}/c {sup 2} and forms a radiation-driven outflow along the rotation axis. The mechanical energy flux carried by the outflow is ∼20% of the radiative energy flux. The total mass flux lost in the outflow is about 29% of the net accretion rate. The radiative luminosity of this flow is ∼10 L {sub Edd}. This yields a radiative efficiency ∼4.5%, which is comparable to the value in a standard thin disk model. In our simulation, vertical advection of radiation caused by magnetic buoyancy transports energy faster than photon diffusion, allowing a significant fraction of the photons to escape from the surface of the disk before being advected into the black hole. We contrast our results with the lower radiative efficiencies inferred in most models, such as the slim disk model, which neglect vertical advection. Our inferred radiative efficiencies also exceed published results from previous global numerical simulations, which did not attribute a significant role to vertical advection. We briefly discuss the implications for the growth of supermassive black holes in the early universe and describe how these results provided a basis for explaining the spectrum and population statistics of ultraluminous X-ray sources.
FISH: A THREE-DIMENSIONAL PARALLEL MAGNETOHYDRODYNAMICS CODE FOR ASTROPHYSICAL APPLICATIONS
Kaeppeli, R.; Whitehouse, S. C.; Scheidegger, S.; Liebendoerfer, M.; Pen, U.-L.
2011-08-01
FISH is a fast and simple ideal magnetohydrodynamics code that scales to {approx}10,000 processes for a Cartesian computational domain of {approx}1000{sup 3} cells. The simplicity of FISH has been achieved by the rigorous application of the operator splitting technique, while second-order accuracy is maintained by the symmetric ordering of the operators. Between directional sweeps, the three-dimensional data are rotated in memory so that the sweep is always performed in a cache-efficient way along the direction of contiguous memory. Hence, the code only requires a one-dimensional description of the conservation equations to be solved. This approach also enables an elegant novel parallelization of the code that is based on persistent communications with MPI for cubic domain decomposition on machines with distributed memory. This scheme is then combined with an additional OpenMP parallelization of different sweeps that can take advantage of clusters of shared memory. We document the detailed implementation of a second-order total variation diminishing advection scheme based on flux reconstruction. The magnetic fields are evolved by a constrained transport scheme. We show that the subtraction of a simple estimate of the hydrostatic gradient from the total gradients can significantly reduce the dissipation of the advection scheme in simulations of gravitationally bound hydrostatic objects. Through its simplicity and efficiency, FISH is as well suited for hydrodynamics classes as for large-scale astrophysical simulations on high-performance computer clusters. In preparation for the release of a public version, we demonstrate the performance of FISH in a suite of astrophysically orientated test cases.
A NEW THREE-DIMENSIONAL SOLAR WIND MODEL IN SPHERICAL COORDINATES WITH A SIX-COMPONENT GRID
Feng, Xueshang; Zhang, Man; Zhou, Yufen
2014-09-01
In this paper, we introduce a new three-dimensional magnetohydrodynamics numerical model to simulate the steady state ambient solar wind from the solar surface to 215 R {sub s} or beyond, and the model adopts a splitting finite-volume scheme based on a six-component grid system in spherical coordinates. By splitting the magnetohydrodynamics equations into a fluid part and a magnetic part, a finite volume method can be used for the fluid part and a constrained-transport method able to maintain the divergence-free constraint on the magnetic field can be used for the magnetic induction part. This new second-order model in space and time is validated when modeling the large-scale structure of the solar wind. The numerical results for Carrington rotation 2064 show its ability to produce structured solar wind in agreement with observations.
Atomic-scale observation of dynamical fluctuation and three-dimensional structure of gold clusters
Li, Junjie; Yin, Deqiang; Chen, Chunlin; Lin, Liyang; Wang, Zhongchang; Li, Qiang; Sun, Rong; Huang, Sumei
2015-02-28
Unravelling three-dimensional structures and dynamical fluctuation of metal nanoclusters is critical to understanding reaction process and the origin of catalytic activity in many heterogeneous catalytic systems. We obtain three-dimensional structures of ultra-small Au clusters by combining aberration-corrected scanning transmission electron microscopy, density functional theory calculations, and imaging simulations. The configurations of unique Au clusters are revealed at the atomic scale and the corresponding electronic states are given. The sequential observations reveal a transition of ultra-small Au clusters with about 25 atoms from a near-square to an elongated structure. We also find a transition from two dimensions to three dimensions for the Au clusters. The obtained three-dimensional geometry and associated electronic states help to clarify atomistic mechanism of shape- and number-dependent catalytic activities of Au clusters.
Nonlinear electron-magnetohydrodynamic simulations of three dimensional current shear instability
Jain, Neeraj; Das, Amita; Sengupta, Sudip; Kaw, Predhiman
2012-09-15
This paper deals with detailed nonlinear electron-magnetohydrodynamic simulations of a three dimensional current shear driven instability in slab geometry. The simulations show the development of the instability in the current shear layer in the linear regime leading to the generation of electromagnetic turbulence in the nonlinear regime. The electromagnetic turbulence is first generated in the unstable shear layer and then spreads into the stable regions. The turbulence spectrum shows a new kind of anisotropy in which power transfer towards shorter scales occurs preferentially in the direction perpendicular to the electron flow. Results of the present three dimensional simulations of the current shear instability are compared with those of our earlier two dimensional simulations of sausage instability. It is found that the flattening of the mean velocity profile and thus reduction in the electron current due to generation of electromagnetic turbulence in the three dimensional case is more effective as compared to that in the two dimensional case.
Karasick, M.S.; Strip, D.R.
1996-01-30
A parallel computing system is described that comprises a plurality of uniquely labeled, parallel processors, each processor capable of modeling a three-dimensional object that includes a plurality of vertices, faces and edges. The system comprises a front-end processor for issuing a modeling command to the parallel processors, relating to a three-dimensional object. Each parallel processor, in response to the command and through the use of its own unique label, creates a directed-edge (d-edge) data structure that uniquely relates an edge of the three-dimensional object to one face of the object. Each d-edge data structure at least includes vertex descriptions of the edge and a description of the one face. As a result, each processor, in response to the modeling command, operates upon a small component of the model and generates results, in parallel with all other processors, without the need for processor-to-processor intercommunication. 8 figs.
Long, Gregory T.; Brundage, Aaron L.; Wixom, Ryan R.; Tappan, Alexander Smith
2009-08-01
Three-dimensional shock simulations of energetic materials have been conducted to improve our understanding of initiation at the mesoscale. Vapor-deposited films of PETN and pressed powders of HNS were characterized with a novel three-dimensional nanotomographic technique. Detailed microstructures were constructed experimentally from a stack of serial electron micrographs obtained by successive milling and imaging in a dual-beam FIB/SEM. These microstructures were digitized and imported into a multidimensional, multimaterial Eulerian shock physics code. The simulations provided insight into the mechanisms of pore collapse in PETN and HNS samples with distinctly different three-dimensional pore morphology and distribution. This modeling effort supports investigations of microscale explosive phenomenology and elucidates mechanisms governing initiation of secondary explosives.
Karasick, Michael S.; Strip, David R.
1996-01-01
A parallel computing system is described that comprises a plurality of uniquely labeled, parallel processors, each processor capable of modelling a three-dimensional object that includes a plurality of vertices, faces and edges. The system comprises a front-end processor for issuing a modelling command to the parallel processors, relating to a three-dimensional object. Each parallel processor, in response to the command and through the use of its own unique label, creates a directed-edge (d-edge) data structure that uniquely relates an edge of the three-dimensional object to one face of the object. Each d-edge data structure at least includes vertex descriptions of the edge and a description of the one face. As a result, each processor, in response to the modelling command, operates upon a small component of the model and generates results, in parallel with all other processors, without the need for processor-to-processor intercommunication.
Lim, Hojun; Owen, Steven J.; Abdeljawad, Fadi F.; Hanks, Byron; Battaile, Corbett Chandler
2015-09-01
In order to better incorporate microstructures in continuum scale models, we use a novel finite element (FE) meshing technique to generate three-dimensional polycrystalline aggregates from a phase field grain growth model of grain microstructures. The proposed meshing technique creates hexahedral FE meshes that capture smooth interfaces between adjacent grains. Three dimensional realizations of grain microstructures from the phase field model are used in crystal plasticity-finite element (CP-FE) simulations of polycrystalline a -iron. We show that the interface conformal meshes significantly reduce artificial stress localizations in voxelated meshes that exhibit the so-called "wedding cake" interfaces. This framework provides a direct link between two mesoscale models - phase field and crystal plasticity - and for the first time allows mechanics simulations of polycrystalline materials using three-dimensional hexahedral finite element meshes with realistic topological features.
Ashraf, M. Bilal; Hayat, T.; Shehzad, S. A.; Alsaedi, A.
2015-02-15
Three dimensional radiative flow of Maxwell fluid over an inclined stretching surface with convective boundary condition is investigated. Heat and mass transfer analysis is taken into account with thermophoresis effects. Similarity transformations are utilized to reduce the partial differential equations into ordinary differential equations. Series solutions of velocity, temperature and concentration are developed. Influence of different parameters Biot number, therrmophoretic parameter, Deborah number, ratio parameter, inclined stretching angle, radiation parameter, mixed convection parameter and concentration buoyancy parameter on the non-dimensional velocity components, temperature and concentration are plotted and discussed in detail. Physical quantities of interests are tabulated and examined.
Grid Generator for Two, Three-dimensional Finite Element Subsurface Flow Models
Energy Science and Technology Software Center (OSTI)
1993-04-28
GRIDMAKER serves as a preprocessor for finite element models in solving two- and three-dimensional subsurface flow and pollutant transport problems. It is designed to generate three-point triangular or four-point quadrilateral elements for two-dimensional domains and eight-point hexahedron elements for three-dimensional domains. A two-dimensional domain of an aquifer with a variable depth layer is treated as a special case for depth-integrated two-dimensional, finite element subsurface flow models. The program accommodates the need for aquifers with heterogeneousmore » systems by identifying the type of material in each element.« less
Ray tracing a three-dimensional scene using a hierarchical data structure
Wald, Ingo; Boulos, Solomon; Shirley, Peter
2012-09-04
Ray tracing a three-dimensional scene made up of geometric primitives that are spatially partitioned into a hierarchical data structure. One example embodiment is a method for ray tracing a three-dimensional scene made up of geometric primitives that are spatially partitioned into a hierarchical data structure. In this example embodiment, the hierarchical data structure includes at least a parent node and a corresponding plurality of child nodes. The method includes a first act of determining that a first active ray in the packet hits the parent node and a second act of descending to each of the plurality of child nodes.
THREE-DIMENSIONAL MOVING-MESH SIMULATIONS OF GALACTIC CENTER CLOUD G2
Anninos, Peter; Murray, Stephen D.; Fragile, P. Chris; Wilson, Julia
2012-11-10
Using three-dimensional, moving-mesh simulations, we investigate the future evolution of the recently discovered gas cloud G2 traveling through the galactic center. We consider the case of a spherical cloud initially in pressure equilibrium with the background. Our suite of simulations explores the following parameters: the equation of state, radial profiles of the background gas, and start times for the evolution. Our primary focus is on how the fate of this cloud will affect the future activity of Sgr A*. From our simulations we expect an average feeding rate in the range of (5-19) Multiplication-Sign 10{sup -8} M {sub Sun} yr{sup -1} beginning in 2013 and lasting for at least 7 years (our simulations stop in year 2020). The accretion varies by less than a factor of three on timescales {<=}1 month, and shows no more than a factor of 10 difference between the maximum and minimum observed rates within any given model. These rates are comparable to the current estimated accretion rate in the immediate vicinity of Sgr A*, although they represent only a small ({approx}< 5%) increase over the current expected feeding rate at the effective inner boundary of our simulations (r = 750, R{sub S} Almost-Equal-To 10{sup 15} cm), where R{sub S} is the Schwarzschild radius of the black hole. Therefore, the breakup of cloud G2 may have only a minimal effect on the brightness and variability of Sgr A* over the next decade. This is because current models of the galactic center predict that most of the gas will be caught up in outflows. However, if the accreted G2 material can remain cold, it may not mix well with the hot, diffuse background gas, and instead accrete efficiently onto Sgr A*. Further observations of G2 will give us an unprecedented opportunity to test this idea. The breakup of the cloud itself may also be observable. By tracking the amount of cloud energy that is dissipated during our simulations, we are able to get a rough estimate of the luminosity associated with
Modeling Dispersion of Chemical-Biological Agents in Three Dimensional Living Space
William S. Winters
2002-02-01
This report documents a series of calculations designed to demonstrate Sandia's capability in modeling the dispersal of chemical and biological agents in complex three-dimensional spaces. The transport of particles representing biological agents is modeled in a single room and in several connected rooms. The influence of particle size, particle weight and injection method are studied.
Photodeposition Method For Fabricating A Three-Dimensional, Patterned Polymer Microstructure
Walt, David R.; Healey, Brian G.
2001-03-13
The present invention is a photodeposition methodology for fabricating a three-dimensional patterned polymer microstructure. A variety of polymeric structures can be fabricated on solid substrates using unitary fiber optic arrays for light delivery. The methodology allows micrometer-scale photopatterning for the fabricated structures using masks substantially larger than the desired dimensions of the microstructure.
Apical polarity in three-dimensional culture systems: where to now?
Inman, J.L.; Bissell, Mina
2010-01-21
Delineation of the mechanisms that establish and maintain the polarity of epithelial tissues is essential to understanding morphogenesis, tissue specificity and cancer. Three-dimensional culture assays provide a useful platform for dissecting these processes but, as discussed in a recent study in BMC Biology on the culture of mammary gland epithelial cells, multiple parameters that influence the model must be taken into account.
Three-dimensional coherent X-ray diffractive imaging of whole frozen-hydrated cells
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Rodriguez, Jose A.; Xu, Rui; Chen, Chien -Chun; Huang, Zhifeng; Jiang, Huaidong; Chen, Allan L.; Raines, Kevin S.; Pryor, Jr., Alan; Nam, Daewoong; Wiegart, Lutz; et al
2015-09-01
Here, a structural understanding of whole cells in three dimensions at high spatial resolution remains a significant challenge and, in the case of X-rays, has been limited by radiation damage. By alleviating this limitation, cryogenic coherent diffractive imaging (cryo-CDI) can in principle be used to bridge the important resolution gap between optical and electron microscopy in bio-imaging. Here, the first experimental demonstration of cryo-CDI for quantitative three-dimensional imaging of whole frozen-hydrated cells using 8 Kev X-rays is reported. As a proof of principle, a tilt series of 72 diffraction patterns was collected from a frozen-hydrated Neospora caninum cell and themore » three-dimensional mass density of the cell was reconstructed and quantified based on its natural contrast. This three-dimensional reconstruction reveals the surface and internal morphology of the cell, including its complex polarized sub-cellular structure. Finally, it is believed that this work represents an experimental milestone towards routine quantitative three-dimensional imaging of whole cells in their natural state with spatial resolutions in the tens of nanometres.« less
Alaska Maximum Number of Active Crews Engaged in Three-Dimensional Seismic
Gasoline and Diesel Fuel Update (EIA)
Surveying (Number of Elements) Three-Dimensional Seismic Surveying (Number of Elements) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9 2000's 9 2 11 6
The nonsinglet structure function evolution by Laplace method
Boroun, G. R. E-mail: boroun@razi.ac.ir; Zarrin, S.
2015-12-15
We derive a general scheme for the evolution of the nonsinglet structure function at the leadingorder (LO) and next-to-leading-order (NLO) by using the Laplace-transform technique. Results for the nonsinglet structure function are compared with MSTW2008, GRV, and CKMT parameterizations and also EMC experimental data in the LO and NLO analysis. The results are in good agreement with the experimental data and other parameterizations in the low- and large-x regions.
Borhanian, J.; Shahmansouri, M.
2013-01-15
A theoretical investigation is carried out to study the existence and characteristics of propagation of dust-acoustic (DA) waves in an electron-depleted dusty plasma with two-temperature ions, which are modeled by kappa distribution functions. A three-dimensional cylindrical Kadomtsev-Petviashvili equation governing evolution of small but finite amplitude DA waves is derived by means of a reductive perturbation method. The influence of physical parameters on solitary wave structure is examined. Furthermore, the energy integral equation is used to study the existence domains of the localized structures. It is found that the present model can be employed to describe the existence of positive as well as negative polarity DA solitary waves by selecting special values for parameters of the system, e.g., superthermal index of cold and/or hot ions, cold to hot ion density ratio, and hot to cold ion temperature ratio. This model may be useful to understand the excitation of nonlinear DA waves in astrophysical objects.
Computational analysis of a three-dimensional High-Velocity Oxygen-Fuel (HVOF) Thermal Spray torch
Hassan, B.; Lopez, A.R.; Oberkampf, W.L.
1995-07-01
An analysis of a High-Velocity Oxygen-Fuel Thermal Spray torch is presented using computational fluid dynamics (CFD). Three-dimensional CFD results are presented for a curved aircap used for coating interior surfaces such as engine cylinder bores. The device analyzed is similar to the Metco Diamond Jet Rotating Wire torch, but wire feed is not simulated. To the authors` knowledge, these are the first published 3-D results of a thermal spray device. The feed gases are injected through an axisymmetric nozzle into the curved aircap. Argon is injected through the center of the nozzle. Pre-mixed propylene and oxygen are introduced from an annulus in the nozzle, while cooling air is injected between the nozzle and the interior wall of the aircap. The combustion process is modeled assuming instantaneous chemistry. A standard, two-equation, K-{var_epsilon} turbulence model is employed for the turbulent flow field. An implicit, iterative, finite volume numerical technique is used to solve the coupled conservation of mass, momentum, and energy equations for the gas in a sequential manner. Flow fields inside and outside the aircap are presented and discussed.
Experimental Realization of a Three-Dimensional Topological Insulator, Bi 2Te3
Siemons, W.
2010-02-24
Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi{sub 2}Te{sub 3} with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi{sub 2}Te{sub 3} is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi{sub 2}Te{sub 3} also points to promising potential for high-temperature spintronics applications.
A novel three-dimensional mesh deformation method based on sphere relaxation
Zhou, Xuan; Li, Shuixiang
2015-10-01
In our previous work (2013) [19], we developed a disk relaxation based mesh deformation method for two-dimensional mesh deformation. In this paper, the idea of the disk relaxation is extended to the sphere relaxation for three-dimensional meshes with large deformations. We develop a node based pre-displacement procedure to apply initial movements on nodes according to their layer indices. Afterwards, the nodes are moved locally by the improved sphere relaxation algorithm to transfer boundary deformations and increase the mesh quality. A three-dimensional mesh smoothing method is also adopted to prevent the occurrence of the negative volume of elements, and further improve the mesh quality. Numerical applications in three-dimension including the wing rotation, bending beam and morphing aircraft are carried out. The results demonstrate that the sphere relaxation based approach generates the deformed mesh with high quality, especially regarding complex boundaries and large deformations.
Three-dimensional modeling and analysis of a high energy density Kelvin-Helmholtz experiment
Raman, K. S.; Hurricane, O. A.; Park, H.-S.; Remington, B. A.; Robey, H.; Smalyuk, V. A.; Drake, R. P.; Krauland, C. M.; Kuranz, C. C.; Hansen, J. F.; Harding, E. C.
2012-09-15
A recent series of experiments on the OMEGA laser provided the first controlled demonstration of the Kelvin-Helmholtz (KH) instability in a high-energy-density physics context [E. C. Harding et al., Phys. Rev. Lett. 103, 045005, (2009); O. A. Hurricane et al., Phys. Plasmas 16, 056305, (2009)]. We present 3D simulations which resolve previously reported discrepancies between those experiments and the 2D simulation used to design them. Our new simulations reveal a three-dimensional mechanism behind the low density 'bubble' structures which appeared in the experimental x-ray radiographs at late times but were completely absent in the 2D simulations. We also demonstrate that the three-dimensional expansion of the walls of the target is sufficient to explain the 20% overprediction by 2D simulation of the late-time growth of the KH rollups. The implications of these results for the design of future experiments are discussed.
Frahm, Jan-Michael; Pollefeys, Marc Andre Leon; Gallup, David Robert
2015-12-08
Methods of generating a three dimensional representation of an object in a reference plane from a depth map including distances from a reference point to pixels in an image of the object taken from a reference point. Weights are assigned to respective voxels in a three dimensional grid along rays extending from the reference point through the pixels in the image based on the distances in the depth map from the reference point to the respective pixels, and a height map including an array of height values in the reference plane is formed based on the assigned weights. An n-layer height map may be constructed by generating a probabilistic occupancy grid for the voxels and forming an n-dimensional height map comprising an array of layer height values in the reference plane based on the probabilistic occupancy grid.
Micrometer-scale fabrication of complex three dimensional lattice + basis structures in silicon
Burckel, D. Bruce; Resnick, Paul J.; Finnegan, Patrick S.; Sinclair, Michael B.; Davids, Paul S.
2015-01-01
A complementary metal oxide semiconductor (CMOS) compatible version of membrane projection lithography (MPL) for fabrication of micrometer-scale three-dimensional structures is presented. The approach uses all inorganic materials and standard CMOS processing equipment. In a single layer, MPL is capable of creating all 5 2D-Bravais lattices. Furthermore, standard semiconductor processing steps can be used in a layer-by-layer approach to create fully three dimensional structures with any of the 14 3D-Bravais lattices. The unit cell basis is determined by the projection of the membrane pattern, with many degrees of freedom for defining functional inclusions. Here we demonstrate several unique structural motifs, and characterize 2D arrays of unit cells with split ring resonators in a silicon matrix. The structures exhibit strong polarization dependent resonances and, for properly oriented split ring resonators (SRRs), coupling to the magnetic field of a normally incident transverse electromagnetic wave, a response unique to 3D inclusions.
Modelling of multistage selective photoionisation in a three-dimensional cavity
Golyatina, R I; Tkachev, Aleksei N; Yakovlenko, Sergei I
1998-08-31
An analysis is made of physical models of selective three-stage photoionisation of a vapour in a three-dimensional cavity. These models have been used in theoretical analyses of preparation of significant amounts of highly enriched {sup 168}Yb by the AVLIS (atomic-vapour laser isotope separation) method. A comparison of the model predictions with experiments shows that a three-dimensional model ignoring the absorption of laser radiation in a medium describes well the experimental results obtained for the second and third ionisation stages. The first excitation stage is described satisfactorily by a model in which absorption is included. A comparison of the calculated and experimental results is used to find the coefficient (65%) representing ion extraction from a laser plasma. (laser applications and other topics in quantum electronics)
Three-dimensional modeling of heat transfer from slab floors. Final report
Bahnfleth, W.P.
1989-07-01
Earth-coupled heat-transfer processes have been recognized in recent years as a potential source of significant energy savings in both conventional and earth-sheltered designs, Because of the complexity of the building/soil/atmosphere interaction, however, important aspects of earth-coupled heat transfer are not well understood. There is a particular lack of three-dimensional foundation heat-loss data. In this study, a detailed three-dimensional finite-difference model of a slab floor was used to generate 93 annual simulations in parametric groups focusing on effects of size and shape, soil properties, boundary conditions, climate, insulation, and building shadow. These results indicate that soil thermal conductivity, ground surface conditions, foundation design, and floor shape/size are essential elements of a general change in heat-transfer rate.
Reversible gelling culture media for in-vitro cell culture in three-dimensional matrices
An, Yuehuei H.; Mironov, Vladimir A.; Gutowska, Anna
2000-01-01
A gelling cell culture medium useful for forming a three dimensional matrix for cell culture in vitro is prepared by copolymerizing an acrylamide derivative with a hydrophilic comonomer to form a reversible (preferably thermally reversible) gelling linear random copolymer in the form of a plurality of linear chains having a plurality of molecular weights greater than or equal to a minimum gelling molecular weight cutoff, mixing the copolymer with an aqueous solvent to form a reversible gelling solution and adding a cell culture medium to the gelling solution to form the gelling cell culture medium. Cells such as chondrocytes or hepatocytes are added to the culture medium to form a seeded culture medium, and temperature of the medium is raised to gel the seeded culture medium and form a three dimensional matrix containing the cells. After propagating the cells in the matrix, the cells may be recovered by lowering the temperature to dissolve the matrix and centrifuging.
Erratum for the paper "Three-dimensional photonic-crystal emission through thermal excitation."
Fleming, James Grant
2005-01-01
A three-dimensional tungsten photonic crystal is thermally excited and shown to emit light at a narrow band, {lambda} = 3.3-4.25 {micro}m. The emission is experimentally observed to exceed that of the free-space Planck radiation over a wide temperature range, T = 475-850 K. it is proposed that an enhanced density of state associated with the propagating electromagnetic Bloch waves in the photonic crystal is responsible for this experimental finding.
Redox Mediators that Promote Three-Dimensional Growth of Li2S on Carbon
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Current Collectors in Lithium-Sulfur Batteries - Joint Center for Energy Storage Research 21, 2015, Research Highlights Redox Mediators that Promote Three-Dimensional Growth of Li2S on Carbon Current Collectors in Lithium-Sulfur Batteries Controlling the electrodeposition of Li2S onto C using a redox mediator, BPI. With BPI, sulfur utilization improves in Li-S cells due to remote reduction of polysulfides to Li2S. Scientific Achievement Developed, from computation and experiment, redox
GEO3D - Three-Dimensional Computer Model of a Ground Source Heat Pump System
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
James Menart
2013-06-07
This file is the setup file for the computer program GEO3D. GEO3D is a computer program written by Jim Menart to simulate vertical wells in conjunction with a heat pump for ground source heat pump (GSHP) systems. This is a very detailed three-dimensional computer model. This program produces detailed heat transfer and temperature field information for a vertical GSHP system.
Aizenberg, Joanna; Burgess, Ian B.; Mishchenko, Lidiya; Hatton, Benjamin; Loncar, Marko
2016-03-08
A three-dimensional porous photonic structure, whose internal pore surfaces can be provided with desired surface properties in a spatially selective manner with arbitrary patterns, and methods for making the same are described. When exposed to a fluid (e.g., via immersion or wicking), the fluid can selectively penetrate the regions of the structure with compatible surface properties. Broad applications, for example in security, encryption and document authentication, as well as in areas such as simple microfluidics and diagnostics, are anticipated.
Analysis of the three-dimensional structure of a bubble wake using PIV and Galilean decomposition
Hassan, Y.A.; Schmidl, W.D.; Ortiz-Villafuerte, J.; Scharf, J.R.
1999-07-01
Bubbly flow plays a key role in a variety of natural and industrial processes. An accurate and complete description of the phase interactions in two-phase bubbly flow is not available at this time. These phase interactions are, in general, always three-dimensional and unsteady. Therefore, measurement techniques utilized to obtain qualitative and quantitative data from two-phase flow should be able to acquire transient and three-dimensional data, in order to provide information to test theoretical models and numerical simulations. Even for dilute bubble flows, in which bubble interaction is at a minimum, the turbulent motion of the liquid generated by the bubble is yet to be completely understood. For many years, the design of systems with bubbly flows was based primarily on empiricism. Dilute bubbly flows are an extension of single bubble dynamics, and therefore improvements in the description and modeling of single bubble motion, the flow field around the bubble, and the dynamical interactions between the bubble and the flow will consequently improve bubbly flow modeling. The improved understanding of the physical phenomena will have far-reaching benefits in upgrading the operation and efficiency of current processes and in supporting the development of new and innovative approaches. A stereoscopic particle image velocimetry measurement of the flow generated by the passage of a single air-bubble rising in stagnant water, in a circular pipe is presented. Three-dimensional velocity fields within the measurement zone were obtained. Ensemble-averaged instantaneous velocities for a specific bubble path were calculated and interpolated to obtain mean three-dimensional velocity fields. A Galilean velocity decomposition is used to study the vorticity generated in the flow.
Estimating Three-Dimensional Cloudy Radiative Transfer Effects from Time-Height Cross Sections
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Estimating Three-Dimensional Cloudy Radiative Transfer Effects from Time-Height Cross Sections C. Hannay and R. Pincus National Oceanic and Atmospheric Administration Climate Diagnostics Center Boulder, Colorado K. F. Evans Program in Atmospheric and Oceanic Sciences University of Colorado Boulder, Colorado Introduction Clouds in the atmosphere are finite in extent and variable in every direction and in time. Long data sets from ground-based profilers, such as lidars or cloud radars, could
Volume-scalable high-brightness three-dimensional visible light source
Subramania, Ganapathi; Fischer, Arthur J; Wang, George T; Li, Qiming
2014-02-18
A volume-scalable, high-brightness, electrically driven visible light source comprises a three-dimensional photonic crystal (3DPC) comprising one or more direct bandgap semiconductors. The improved light emission performance of the invention is achieved based on the enhancement of radiative emission of light emitters placed inside a 3DPC due to the strong modification of the photonic density-of-states engendered by the 3DPC.
Three-dimensional heat transfer in a channel with a baffle in the entrance region
Guo, Z.; Anand, N.K.
1997-01-01
A numerical investigation of laminar forced convection was performed in a three-dimensional channel with a baffle in the entrance region. The top and bottom walls were subjected to a uniform heat flux heating condition, while the side walls were insulated. The numerical study was conducted using a finite volume approach, and the grid independence was established. Parametric runs were made for Reynolds numbers (Re) of 100--500; Prandtl numbers of 0.7 and 7.0; baffle heights (B{sub h}/D{sub h}) of 0.25, 0.50, and 0.75; and thermal conductivity ratios (K) of 10, 100, and 1,000. Three-dimensional effects in the flow field were confined to the neighborhood of the baffle, but three-dimensional effects in the temperature field were present in the entire channel. In general, separation length upstream of the baffle and recirculation length downstream of the baffle increased with an increase in the flow Reynolds number and baffle height. The spanwise averaged Nusselt number increased with an increase in the thermal conductivity of the wall.
Guo, Shimin Mei, Liquan
2014-08-15
Dust-ion-acoustic (DIA) rogue waves are investigated in a three-dimensional magnetized plasma containing nonthermal electrons featuring Tsallis distribution, both positive and negative ions, and immobile dust grains having both positive and negative charges. Via the reductive perturbation method, a (3?+?1)-dimensional nonlinear Schrdinger (NLS) equation is derived to govern the dynamics of the DIA wave packets. The modulation instability of DIA waves described by the (3?+?1)-dimensional NLS equation is investigated. By means of the similarity transformation and symbolic computation, both the first- and second-order rogue wave solutions of the (3?+?1)-dimensional NLS equation are constructed in terms of rational functions. Moreover, the dynamics properties and the effects of plasma parameters on the nonlinear structures of rogue waves are discussed in detail. The results could be useful for understanding the physical mechanism of rogue waves in laboratory experiments where pair-ion plasmas with electrons and dust grains can be found.
Three-dimensional Monte-Carlo simulation of gamma-ray scattering and production in the atmosphere
Morris, D.J. )
1989-05-15
Monte Carlo codes have been developed to simulate gamma-ray scattering and production in the atmosphere. The scattering code simulates interactions of low-energy gamma rays (20 to several hundred keV) from an astronomical point source in the atmosphere; a modified code also simulates scattering in a spacecraft. Four incident spectra, typical of gamma-ray bursts, solar flares, and the Crab pulsar, and 511 keV line radiation have been studied. These simulations are consistent with observations of solar flare radiation scattered from the atmosphere. The production code simulates the interactions of cosmic rays which produce high-energy (above 10 MeV) photons and electrons. It has been used to calculate gamma-ray and electron albedo intensities at Palestine, Texas and at the equator; the results agree with observations in most respects. With minor modifications this code can be used to calculate intensities of other high-energy particles. Both codes are fully three-dimensional, incorporating a curved atmosphere; the production code also incorporates the variation with both zenith and azimuth of the incident cosmic-ray intensity due to geomagnetic effects. These effects are clearly reflected in the calculated albedo by intensity contrasts between the horizon and nadir, and between the east and west horizons.
Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels
Lu, Hongbing; Bukkapatnam, Satish; Harimkar, Sandip; Singh, Raman; Bardenhagen, Scott
2014-01-09
Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding and validate against simulation results; and 7. Expand the adaptive mesh refinement infrastructure parallel processing environment to allow adaptive mesh refinement at the 3D crack fronts and adaptive mesh merging in the wake of cracks. Fuel cladding is made of materials such as stainless steels and ferritic steels with added alloying elements, which increase stability and durability under irradiation. As fuel cladding is subjected to water, chemicals, fission gas, pressure, high temperatures, and irradiation while in service, understanding performance is essential. In the fast fuel used in advanced burner reactors, simulations of the nuclear
Real-time, interactive animation of deformable two- and three-dimensional objects
Desbrun, Mathieu; Schroeder, Peter; Meyer, Mark; Barr, Alan H.
2003-06-03
A method of updating in real-time the locations and velocities of mass points of a two- or three-dimensional object represented by a mass-spring system. A modified implicit Euler integration scheme is employed to determine the updated locations and velocities. In an optional post-integration step, the updated locations are corrected to preserve angular momentum. A processor readable medium and a network server each tangibly embodying the method are also provided. A system comprising a processor in combination with the medium, and a system comprising the server in combination with a client for accessing the server over a computer network, are also provided.
INGRID: a three-dimensional mesh generator for modeling nonlinear systems
Stillman, D.W.; Hallquist, J.O.
1985-07-01
INGRID generates complete input files for the codes DYNA3D, NIKE3D, FACET, and TOPAZ3D. Geometries are described primarily using index space concepts which came from the program INGEN. The ideas used in INGEN were reworked into a new method which is both simple and powerful. Interactive graphics in INGRID are patterned after TAURUS, a three-dimensional post-processor, and MAZE, a two-dimensional mesh generator. Much of the coding from MAZE is directly incorporated in INGRID.
Moon, Gun-Hee; Shin, Yongsoon; Choi, Daiwon; Arey, Bruce W.; Exarhos, Gregory J.; Wang, Chong M.; Choi, Wonyong; Liu, Jun
2013-01-01
We report a catalytic templating method to synthesize well-controlled, three-dimensional (3D) nano-architectures with graphene oxide sheets. The 3D composites are prepared via self-assembly of carbon, GO, and spherical alumina-coated silica (ACS) templates during a catalytic reaction porcess. By changing the GO content, we can systematically tune the architecture from layered composites to 3D hollow structures to microporous materials. The composites show a synergistic effect with significantly superior properties than either pure carbon or r-GO prepared with a significant enhancement to its capacitance at high current density.
High-frequency electromagnetic scarring in three-dimensional axisymmetric convex cavities
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Warne, Larry K.; Jorgenson, Roy E.
2016-04-13
Here, this article examines the localization of high-frequency electromagnetic fields in three-dimensional axisymmetric cavities along periodic paths between opposing sides of the cavity. When these orbits lead to unstable localized modes, they are known as scars. This article treats the case where the opposing sides, or mirrors, are convex. Particular attention is focused on the normalization through the electromagnetic energy theorem. Both projections of the field along the scarred orbit as well as field point statistics are examined. Statistical comparisons are made with a numerical calculation of the scars run with an axisymmetric simulation.
Photonic band gaps in three-dimensional network structures with short-range order
Liew, Seng Fatt; Noh, Heeso; Yang, Jin-Kyu; Schreck, Carl F.; Dufresne, Eric R.; O'Hern, Corey S.; Cao, Hui
2011-12-15
We present a systematic study of photonic band gaps (PBGs) in three-dimensional (3D) photonic amorphous structures (PASs) with short-range order. From calculations of the density of optical states (DOS) for PASs with different topologies, we find that tetrahedrally connected dielectric networks produce the largest isotropic PBGs. Local uniformity and tetrahedral order are essential to the formation of PBGs in PASs, in addition to short-range geometric order. This work demonstrates that it is possible to create broad, isotropic PBGs for vector light fields in 3D PASs without long-range order.
Label-free three-dimensional imaging of cell nucleus using third-harmonic generation microscopy
Lin, Jian; Zheng, Wei; Wang, Zi; Huang, Zhiwei
2014-09-08
We report the implementation of the combined third-harmonic generation (THG) and two-photon excited fluorescence (TPEF) microscopy for label-free three-dimensional (3-D) imaging of cell nucleus morphological changes in liver tissue. THG imaging shows regular spherical shapes of normal hepatocytes nuclei with inner chromatin structures while revealing the condensation of chromatins and nuclear fragmentations in hepatocytes of diseased liver tissue. Colocalized THG and TPEF imaging provides complementary information of cell nuclei and cytoplasm in tissue. This work suggests that 3-D THG microscopy has the potential for quantitative analysis of nuclear morphology in cells at a submicron-resolution without the need for DNA staining.
Binotti, M.; Zhu, G.; Gray, A.; Manzollini, G.
2012-04-01
An analytical approach, as an extension of one newly developed method -- First-principle OPTical Intercept Calculation (FirstOPTIC) -- is proposed to treat the geometrical impact of three-dimensional (3-D) effects on parabolic trough optical performance. The mathematical steps of this analytical approach are presented and implemented numerically as part of the suite of FirstOPTIC code. In addition, the new code has been carefully validated against ray-tracing simulation results and available numerical solutions. This new analytical approach to treating 3-D effects will facilitate further understanding and analysis of the optical performance of trough collectors as a function of incidence angle.
Orlita, M.; Faugeras, C.; Barra, A.-L.; Martinez, G.; Potemski, M.; Basko, D. M.; Teppe, F.; Knap, W.; Gavrilenko, V. I.; Mikhailov, N. N.; Dvoretskii, S. A.; Neugebauer, P.; Berger, C.
2015-03-21
Here, we report on a magneto-optical study of two distinct systems hosting massless fermions—two-dimensional graphene and three-dimensional HgCdTe tuned to the zero band gap condition at the point of the semiconductor-to-semimetal topological transition. Both materials exhibit, in the quantum regime, a fairly rich magneto-optical response, which is composed from a series of intra- and interband inter-Landau level resonances with for massless fermions typical √(B) dependence. The impact of the system's dimensionality and of the strength of the spin-orbit interaction on the optical response is also discussed.
Three-dimensional profiling with binary fringes using phase-shifting interferometry algorithms
Ayubi, Gaston A.; Di Martino, J. Matias; Alonso, Julia R.; Fernandez, Ariel; Perciante, Cesar D.; Ferrari, Jose A.
2011-01-10
Three-dimensional shape measurements by sinusoidal fringe projection using phase-shifting interferometry algorithms are distorted by the nonlinear response in intensity of commercial video projectors and digital cameras. To solve the problem, we present a method that consists in projecting and acquiring a temporal sequence of strictly binary patterns, whose (adequately weighted) average leads to a sinusoidal fringe pattern with the required number of bits. Since binary patterns consist of ''ones'' and ''zeros'' - and no half-tones are involved - the nonlinear response of the projector and the camera will not play a role, and a nearly unit contrast gray-level sinusoidal fringe pattern is obtained. Validation experiments are presented.
High energy gain in three-dimensional simulations of light sail acceleration
Sgattoni, A.; Sinigardi, S.; Macchi, A.
2014-08-25
The dynamics of radiation pressure acceleration in the relativistic light sail regime are analysed by means of large scale, three-dimensional (3D) particle-in-cell simulations. Differently to other mechanisms, the 3D dynamics leads to faster and higher energy gain than in 1D or 2D geometry. This effect is caused by the local decrease of the target density due to transverse expansion leading to a “lighter sail.” However, the rarefaction of the target leads to an earlier transition to transparency limiting the energy gain. A transverse instability leads to a structured and inhomogeneous ion distribution.
Porosity in millimeter-scale welds of stainless steel : three-dimensional characterization.
Aagesen, Larry K.; Madison, Jonathan D.
2012-05-01
A variety of edge joints utilizing a continuous wave Nd:YAG laser have been produced and examined in a 304-L stainless steel to advance fundamental understanding of the linkage between processing and resultant microstructure in high-rate solidification events. Acquisition of three-dimensional reconstructions via micro-computed tomography combined with traditional metallography has allowed for qualitative and quantitative characterization of weld joints in a material system of wide use and broad applicability. The presence, variability and distribution of porosity, has been examined for average values, spatial distributions and morphology and then related back to fundamental processing parameters such as weld speed, weld power and laser focal length.
Three Dimensional Speckle Imaging Employing a Frequency-Locked Tunable Diode Laser
Cannon, Bret D.; Bernacki, Bruce E.; Schiffern, John T.; Mendoza, Albert
2015-09-01
We describe a high accuracy frequency stepping method for a tunable diode laser to improve a three dimensional (3D) imaging approach based upon interferometric speckle imaging. The approach, modeled after Takeda, exploits tuning an illumination laser in frequency as speckle interferograms of the object (specklegrams) are acquired at each frequency in a Michelson interferometer. The resulting 3D hypercube of specklegrams encode spatial information in the x-y plane of each image with laser tuning arrayed along its z-axis. We present laboratory data of before and after results showing enhanced 3D imaging resulting from precise laser frequency control.
Three-dimensional thermoelastic analysis of a Fort St. Vrain core support block
Butler, T.A.; Anderson, C.A.
1981-09-01
A thermoelastic stress analysis of a graphite core support block in the Fort St. Vrain High-Temperature Gas-Cooled Reactor is described. The support block is subjected to thermal stresses caused by a loss of forced circulation accident of the reactor system. Two- and three-dimensional finite element models of the core support block are analyzed using the ADINAT and ADINA codes, and results are given that verify the integrity of this structural component under the given accident condition. 10 refs., 39 figs.
SU-E-T-279: Realization of Three-Dimensional Conformal Dose Planning in Prostate Brachytherapy
Li, Z; Jiang, S; Yang, Z; Bai, H; Zhang, X
2014-06-01
Purpose: Successful clinical treatment in prostate brachytherapy is largely dependent on the effectiveness of pre-surgery dose planning. Conventional dose planning method could hardly arrive at a satisfy result. In this abstract, a three-dimensional conformal localized dose planning method is put forward to ensure the accuracy and effectiveness of pre-implantation dose planning. Methods: Using Monte Carlo method, the pre-calculated 3-D dose map for single source is obtained. As for multiple seeds dose distribution, the maps are combined linearly to acquire the 3-D distribution. The 3-D dose distribution is exhibited in the form of isodose surface together with reconstructed 3-D organs group real-timely. Then it is possible to observe the dose exposure to target volume and normal tissues intuitively, thus achieving maximum dose irradiation to treatment target and minimum healthy tissues damage. In addition, the exfoliation display of different isodose surfaces can be realized applying multi-values contour extraction algorithm based on voxels. The needles could be displayed in the system by tracking the position of the implanted seeds in real time to conduct block research in optimizing insertion trajectory. Results: This study extends dose planning from two-dimensional to three-dimensional, realizing the three-dimensional conformal irradiation, which could eliminate the limitations of 2-D images and two-dimensional dose planning. A software platform is developed using VC++ and Visualization Toolkit (VTK) to perform dose planning. The 3-D model reconstruction time is within three seconds (on a Intel Core i5 PC). Block research could be conducted to avoid inaccurate insertion into sensitive organs or internal obstructions. Experiments on eight prostate cancer cases prove that this study could make the dose planning results more reasonable. Conclusion: The three-dimensional conformal dose planning method could improve the rationality of dose planning by safely reducing
All-dielectric three-dimensional broadband Eaton lens with large refractive index range
Yin, Ming; Yong Tian, Xiao, E-mail: leoxyt@mail.xjtu.edu.cn; Ling Wu, Ling; Chen Li, Di [State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049 (China)
2014-03-03
We proposed a method to realize three-dimensional (3D) gradient index (GRIN) devices requiring large refractive index (RI) range with broadband performance. By combining non-resonant GRIN woodpile photonic crystals structure in the metamaterial regime with a compound liquid medium, a wide RI range (16.32) was fulfilled flexibly. As a proof-of-principle for the low-loss and non-dispersive method, a 3D Eaton lens was designed and fabricated based on 3D printing process. Full-wave simulation and experiment validated its omnidirectional wave bending effects in a broad bandwidth covering Ku band (12?GHz18?GHz)
Tewari, A.; Gokhale, A.M.; Gereman, R.M.
1999-10-08
Gravity affects microstructural evolution when a liquid phase is present during sintering. The effect of gravity on the three-dimensional coordination number distribution of tungsten grains in liquid phase sintered heavy alloy specimens is quantitatively characterized. A combination of montage serial sectioning, digital image processing, and unbiased stereological sampling procedures is used to estimate the coordination number distribution in three-dimensional microstructures. The microgravity environment decreases the mean coordination number. However, hardly any isolated grains are observed in the specimens, liquid phase sintered in a microgravity environment. The effect of microgravity on the coordination numbers mainly resides in its effect on the mean coordination number. In all specimens, there is a strong correlation between grain size and coordination number, which can be expressed as [D{sub c}/{bar D}]{sup 2} = C/C{sub 0} where C{sub 0} is the mean coordination number, {bar D} the global average size of the tungsten grains, and D{sub c} the average size of only those grains which have coordination number C.
Three-dimensional periodic supramolecular organic framework ion sponge in water and microcrystals
Tian, Jia; Zhou, Tian-You; Zhang, Shao-Chen; Aloni, Shaul; Altoe, Maria Virginia; Xie, Song-Hai; Wang, Hui; Zhang, Dan-Wei; Zhao, Xin; Liu, Yi; Li, Zhan-Ting
2014-12-02
Self-assembly has emerged as a powerful approach to generating complex supramolecular architectures. Despite there being many crystalline frameworks reported in the solid state, the construction of highly soluble periodic supramolecular networks in a three-dimensional space is still a challenge. In this paper we demonstrate that the encapsulation motif, which involves the dimerization of two aromatic units within cucurbit[8]uril, can be used to direct the co-assembly of a tetratopic molecular block and cucurbit[8]uril into a periodic three-dimensional supramolecular organic framework in water. The periodicity of the supramolecular organic framework is supported by solution-phase small-angle X-ray-scattering and diffraction experiments. Upon evaporating the solvent, the periodicity of the framework is maintained in porous microcrystals. Lastly, as a supramolecular 'ion sponge', the framework can absorb different kinds of anionic guests, including drugs, in both water and microcrystals, and drugs absorbed in microcrystals can be released to water with selectivity.
Image system for three dimensional, 360{degree}, time sequence surface mapping of moving objects
Lu, S.Y.
1998-12-22
A three-dimensional motion camera system comprises a light projector placed between two synchronous video cameras all focused on an object-of-interest. The light projector shines a sharp pattern of vertical lines (Ronchi ruling) on the object-of-interest that appear to be bent differently to each camera by virtue of the surface shape of the object-of-interest and the relative geometry of the cameras, light projector and object-of-interest. Each video frame is captured in a computer memory and analyzed. Since the relative geometry is known and the system pre-calibrated, the unknown three-dimensional shape of the object-of-interest can be solved for by matching the intersections of the projected light lines with orthogonal epipolar lines corresponding to horizontal rows in the video camera frames. A surface reconstruction is made and displayed on a monitor screen. For 360{degree} all around coverage of the object-of-interest, two additional sets of light projectors and corresponding cameras are distributed about 120{degree} apart from one another. 20 figs.
Micrometer-scale fabrication of complex three dimensional lattice + basis structures in silicon
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Burckel, D. Bruce; Resnick, Paul J.; Finnegan, Patrick S.; Sinclair, Michael B.; Davids, Paul S.
2015-01-01
A complementary metal oxide semiconductor (CMOS) compatible version of membrane projection lithography (MPL) for fabrication of micrometer-scale three-dimensional structures is presented. The approach uses all inorganic materials and standard CMOS processing equipment. In a single layer, MPL is capable of creating all 5 2D-Bravais lattices. Furthermore, standard semiconductor processing steps can be used in a layer-by-layer approach to create fully three dimensional structures with any of the 14 3D-Bravais lattices. The unit cell basis is determined by the projection of the membrane pattern, with many degrees of freedom for defining functional inclusions. Here we demonstrate several unique structural motifs, andmorecharacterize 2D arrays of unit cells with split ring resonators in a silicon matrix. The structures exhibit strong polarization dependent resonances and, for properly oriented split ring resonators (SRRs), coupling to the magnetic field of a normally incident transverse electromagnetic wave, a response unique to 3D inclusions.less
Three-dimensional CTOA and constraint effects during stable tearing in a thin-sheet material
Dawicke, D.S.; Newman, J.C. Jr.; Bigelow, C.A.
1995-12-31
A small strain theory, three-dimensional elastic-plastic finite element analysis was used to simulate fracture in thin sheet 2024-T3 aluminum alloy in the T-L orientation. Both straight and tunneled cracks were modeled. The tunneled crack front shapes as a function of applied stress were obtained from the fracture surface of tested specimens. The stable crack growth behavior was measured at the specimen surface as a function of applied stress. The fracture simulation modeled the crack tunneling and extension as a function of applied stress. The results indicated that the global constrain factor, {alpha}{sub g}, initially dropped during stable crack growth. After peak applied stress was achieved, {alpha}{sub g}, initially dropped during stable crack growth. After peak applied stress was achieved, {alpha}{sub g}, began to increase slightly. The effect of crack front shape on {alpha}{sub g} was small, but the crack front shape did greatly influence the local constraint and through-thickness crack-tip opening angle (CTOA) behavior. The surface values of CTOA for the tunneled crack front model agreed well with experimental measurements, showing the same initial decrease from high values during the initial 3 mm of crack growth at the specimen`s surface. At the same time, the interior CTOA values increased from low angles. After the initial stable tearing region, the CTOA was constant through the thickness. The three-dimensional analysis appears to confirm the potential of CTOA as a two-dimensional fracture criterion.
Three-dimensional model and simulation of vacuum arcs under axial magnetic fields
Wang Lijun; Jia Shenli; Zhou Xin; Wang Haijing; Shi Zongqian
2012-01-15
In this paper, a three-dimensional (3d) magneto-hydro-dynamic (MHD) model of axial magnetic field vacuum arcs (AMFVAs) is established. Based on this model, AMFVAs are simulated and analyzed. Three-dimensional spatial distributions of many important plasma parameters and electric characteristics in AMFVAs can be obtained, such as ion number density, ion temperature, electron temperature, plasma pressure, current densities along different directions (x, y, and z), ion velocities along different directions, electric fields strength along different directions, and so on. Simulation results show that there exist significant spiral-shaped rotational phenomena in the AMFVAs, this kind of rotational phenomenon also can be verified by the many related experiments (AMFVAs photographs, especially for stronger AMF strength). For current simulation results of AMFVAs, the maximal rotational velocity at anode side is about 1100 m/s. Radial electric field is increased from arc center to arc edge; axial electric field is decreased from cathode side to anode side. Radial electric field at arc edge can be larger than axial electric field. Azimuthal electric field in most regions is much smaller than radial and axial electric field, but it can reach about 1.19 kV/m. Radial magnetic field is the smallest one compared with other components, it reaches to maximum value at the position near to anode, it can influence arc characteristics.
Three-dimensional periodic supramolecular organic framework ion sponge in water and microcrystals
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tian, Jia; Zhou, Tian-You; Zhang, Shao-Chen; Aloni, Shaul; Altoe, Maria Virginia; Xie, Song-Hai; Wang, Hui; Zhang, Dan-Wei; Zhao, Xin; Liu, Yi; et al
2014-12-02
Self-assembly has emerged as a powerful approach to generating complex supramolecular architectures. Despite there being many crystalline frameworks reported in the solid state, the construction of highly soluble periodic supramolecular networks in a three-dimensional space is still a challenge. In this paper we demonstrate that the encapsulation motif, which involves the dimerization of two aromatic units within cucurbit[8]uril, can be used to direct the co-assembly of a tetratopic molecular block and cucurbit[8]uril into a periodic three-dimensional supramolecular organic framework in water. The periodicity of the supramolecular organic framework is supported by solution-phase small-angle X-ray-scattering and diffraction experiments. Upon evaporating themore » solvent, the periodicity of the framework is maintained in porous microcrystals. Lastly, as a supramolecular 'ion sponge', the framework can absorb different kinds of anionic guests, including drugs, in both water and microcrystals, and drugs absorbed in microcrystals can be released to water with selectivity.« less
Monodisperse alginate microgel formation in a three-dimensional microfluidic droplet generator
Lian, Meng; Collier, Pat; Doktycz, Mitchel John; Retterer, Scott T
2012-01-01
Droplet based microfluidic systems provide an ideal platform for partitioning and manipulating aqueous samples for analysis. Identifying stable operating conditions under which droplets are generated is challenging yet crucial for real-world applications. A novel three-dimensional microfluidic platform that facilitates the consistent generation and gelation of alginate-calcium hydrogel microbeads for microbial encapsulation, over a broad range of backing pressures, in the absence of surfactants, is described. The unique three-dimensional design of the fluidic network utilizes a height difference at the junction between the aqueous sample injection and organic carrier channels to induce droplet formation via a surface tension enhanced self-shearing mechanism. Combined within a flow-focusing geometry, under constant pressure control, this arrangement facilitates predictable generation of droplets over a much broader range of operating conditions than conventional two-dimensional systems. The impact of operating pressures and geometry on droplet gelation, aqueous and organic material flow rates, microbead size and bead generation frequency are described. The system presented provides a robust platform for encapsulating single microbes in complex mixtures into individual hydrogel beads, and provides the foundation for the development of a complete system for sorting and analyzing microbes at the single cell level.
Three-dimensional hydrodynamics of the deceleration stage in inertial confinement fusion
Weber, C. R. Clark, D. S.; Cook, A. W.; Eder, D. C.; Haan, S. W.; Hammel, B. A.; Hinkel, D. E.; Jones, O. S.; Marinak, M. M.; Milovich, J. L.; Patel, P. K.; Robey, H. F.; Salmonson, J. D.; Sepke, S. M.; Thomas, C. A.
2015-03-15
The deceleration stage of inertial confinement fusion implosions is modeled in detail using three-dimensional simulations designed to match experiments at the National Ignition Facility. In this final stage of the implosion, shocks rebound from the center of the capsule, forming the high-temperature, low-density hot spot and slowing the incoming fuel. The flow field that results from this process is highly three-dimensional and influences many aspects of the implosion. The interior of the capsule has high-velocity motion, but viscous effects limit the range of scales that develop. The bulk motion of the hot spot shows qualitative agreement with experimental velocity measurements, while the variance of the hot spot velocity would broaden the DT neutron spectrum, increasing the inferred temperature by 400800?eV. Jets of ablator material are broken apart and redirected as they enter this dynamic hot spot. Deceleration stage simulations using two fundamentally different rad-hydro codes are compared and the flow field is found to be in good agreement.
Controlled synthesis of hyper-branched inorganic nanocrystals withrich three-dimensional structures
Kanaras, Antonios G.; Sonnichsen, Carsten; Liu, Haitao; Alivisatos, A. Paul
2005-07-27
Studies of crystal growth kinetics are tightly integrated with advances in the creation of new nanoscale inorganic building blocks and their functional assemblies 1-11. Recent examples include the development of semiconductor nanorods which have potential uses in solar cells 12-17, and the discovery of a light driven process to create noble metal particles with sharp corners that can be used in plasmonics 18,19. In the course of studying basic crystal growth kinetics we developed a process for preparing branched semiconductor nanocrystals such as tetrapods and inorganic dendrimers of precisely controlled generation 20,21. Here we report the discovery of a crystal growth kinetics regime in which a new class of hyper-branched nanocrystals are formed. The shapes range from 'thorny balls', to tree-like ramified structures, to delicate 'spider net'-like particles. These intricate shapes depend crucially on a delicate balance of branching and extension. The multitudes of resulting shapes recall the diverse shapes of snowflakes 22.The three dimensional nature of the branch points here, however, lead to even more complex arrangements than the two dimensionally branched structures observed in ice. These hyper-branched particles not only extend the available three-dimensional shapes in nanoparticle synthesis ,but also provide a tool to study growth kinetics by carefully observing and modeling particle morphology.
Image system for three dimensional, 360 DEGREE, time sequence surface mapping of moving objects
Lu, Shin-Yee
1998-01-01
A three-dimensional motion camera system comprises a light projector placed between two synchronous video cameras all focused on an object-of-interest. The light projector shines a sharp pattern of vertical lines (Ronchi ruling) on the object-of-interest that appear to be bent differently to each camera by virtue of the surface shape of the object-of-interest and the relative geometry of the cameras, light projector and object-of-interest Each video frame is captured in a computer memory and analyzed. Since the relative geometry is known and the system pre-calibrated, the unknown three-dimensional shape of the object-of-interest can be solved for by matching the intersections of the projected light lines with orthogonal epipolar lines corresponding to horizontal rows in the video camera frames. A surface reconstruction is made and displayed on a monitor screen. For 360.degree. all around coverage of theobject-of-interest, two additional sets of light projectors and corresponding cameras are distributed about 120.degree. apart from one another.
Three-dimensional analysis of eolian systems in Jurassic Wingate sandstone
Nation, M.J.; Blakey, R.C.
1989-03-01
Regional bounding surfaces in ancient eolian sequences aid in establishing lateral profiles not previously obtainable using standard stratigraphic methods. Correlation of detailed measured sections permits three-dimensional analysis of erg dynamics in the Jurassic Wingate Sandstone on the Colorado Plateau. Four periods of erg development marked by contrasting styles of eolian architecture are documented in the Salt Anticline region (in ascending stratigraphic order): (1) discontinuous sand sheets, isolated dunes, and aqueous environments; (2) large compound dunes with decreasing amounts of dune margin material; (3) compound dunes and draas alternating with locally thick sandsheet deposits; and (4) widespread dunes and draas prior to erosion by Kayenta fluvial systems. Regional bounding surface characteristics reflect different mechanisms for erg stabilization, including deflation to the water table, climate change, and negative net sand budget. Lateral reconstruction and correlation of erg sequences indicate significant intrabasinal paleogeographic and tectonic controls on eolian systems. Localities removed from the Salt Anticline region contain much larger compound draa deposits and lack extensive accumulations of sand-sheet material. Regional comparison of these characteristics suggests that the salt uplifts modified eolian processes within the Wingate depositional basin. Existence of additional geographic variations not associated with salt tectonism is indicated by local accumulations of noneolian deposits in northeastern Arizona. The use of regional bounding surfaces to construct lateral profiles is a powerful method to establish three-dimensional models of eolian systems. Analysis of erg dynamics in other ancient eolian formations is possible utilizing the criteria documented in the Wingate Sandstone.
Energy Science and Technology Software Center (OSTI)
1991-10-01
Version 00 HEXAB-3D solves the three-dimensional few-group diffusion model for the calculation of the basic neutron physical characteristics of power reactors in hexagonal geometry.
Three dimensional winds: A maximum cross-correlation application to elastic lidar data
Buttler, W.T.
1996-05-01
Maximum cross-correlation techniques have been used with satellite data to estimate winds and sea surface velocities for several years. Los Alamos National Laboratory (LANL) is currently using a variation of the basic maximum cross-correlation technique, coupled with a deterministic application of a vector median filter, to measure transverse winds as a function of range and altitude from incoherent elastic backscatter lidar (light detection and ranging) data taken throughout large volumes within the atmospheric boundary layer. Hourly representations of three-dimensional wind fields, derived from elastic lidar data taken during an air-quality study performed in a region of complex terrain near Sunland Park, New Mexico, are presented and compared with results from an Environmental Protection Agency (EPA) approved laser doppler velocimeter. The wind fields showed persistent large scale eddies as well as general terrain-following winds in the Rio Grande valley.
Large-angle illumination STEM: Toward three-dimensional atom-by-atom imaging
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ishikawa, Ryo; Lupini, Andrew R.; Hinuma, Yoyo; Pennycook, Stephen
2014-11-26
To completely understand and control materials and their properties, it is of critical importance to determine their atomic structures in all three dimensions. Recent revolutionary advances in electron optics – the inventions of geometric and chromatic aberration correctors as well as electron source monochromators – have provided fertile ground for performing optical depth sectioning at atomic-scale dimensions. In this study we theoretically demonstrate the imaging of top/sub-surface atomic structures and identify the depth of single dopants, single vacancies and the other point defects within materials by large-angle illumination scanning transmission electron microscopy (LAI-STEM). The proposed method also allows us tomore » measure specimen properties such as thickness or three-dimensional surface morphology using observations from a single crystallographic orientation.« less
Three-dimensional simulations of cellular non-premixed jet flames
Valaer, A.L.; Frouzakis, C.E.; Boulouchos, K.; Papas, P.; Tomboulides, A.G.
2010-04-15
The formation, dynamics and structure of cellular flames in circular non-premixed jets are examined with three-dimensional numerical simulations incorporating detailed descriptions of chemistry and transport. Similar to past experiments reported in the literature, CO{sub 2}-diluted hydrogen in diluted or pure oxygen co-flowing streams in the proximity of the extinction limit are considered. As in the experiments, several preferred cellular states are found to co-exist with the particular state realized depending on initial conditions as well as on the jet characteristics. The simulations provide additionally the temporal transitions to different stationary or rotating cellular flames, their detailed structure, and the dependence of the scaling of the realized number of cells with the vorticity thickness. (author)
Whistler turbulence forward vs. inverse cascade: Three-dimensional particle-in-cell simulations
Chang, Ouliang; Gary, S. Peter; Wang, Joseph
2015-02-12
In this study, we present the results of the first fully three-dimensional particle-in-cell simulations of decaying whistler turbulence in a magnetized, homogeneous, collisionless plasma in which both forward cascades to shorter wavelengths, and inverse cascades to longer wavelengths are allowed to proceed. For the electron beta ?_{e} = 0.10 initial value considered here, the early-time rate of inverse cascade is very much smaller than the rate of forward cascade, so that at late times the fluctuation energy in the regime of the inverse cascade is much weaker than that in the forward cascade regime. Similarly, the wavevector anisotropy in the inverse cascade regime is much weaker than that in the forward cascade regime.
Conversion of the Big Hill geological site characterization report to a three-dimensional model.
Stein, Joshua S.; Rautman, Christopher Arthur
2003-02-01
The Big Hill salt dome, located in southeastern Texas, is home to one of four underground oil-storage facilities managed by the U. S. Department of Energy Strategic Petroleum Reserve (SPR) Program. Sandia National Laboratories, as the geotechnical advisor to the SPR, conducts site-characterization investigations and other longer-term geotechnical and engineering studies in support of the program. This report describes the conversion of two-dimensional geologic interpretations of the Big Hill site into three-dimensional geologic models. The new models include the geometry of the salt dome, the surrounding sedimentary units, mapped faults, and the 14 oil storage caverns at the site. This work provides a realistic and internally consistent geologic model of the Big Hill site that can be used in support of future work.
Stein, Joshua S.; Rautman, Christopher Arthur; Snider, Anna C.
2004-08-01
The West Hackberry salt dome, in southwestern Louisiana, is one of four underground oil-storage facilities managed by the U. S. Department of Energy Strategic Petroleum Reserve (SPR) Program. Sandia National Laboratories, as the geotechnical advisor to the SPR, conducts site-characterization investigations and other longer-term geotechnical and engineering studies in support of the program. This report describes the conversion of two-dimensional geologic interpretations of the West Hackberry site into three-dimensional geologic models. The new models include the geometry of the salt dome, the surrounding sedimentary layers, mapped faults, and a portion of the oil storage caverns at the site. This work provides a realistic and internally consistent geologic model of the West Hackberry site that can be used in support of future work.
Conversion of the Bryan Mound geological site characterization reports to a three-dimensional model.
Stein, Joshua S.; Rautman, Christopher Arthur
2005-04-01
The Bryan Mound salt dome, located near Freeport, Texas, is home to one of four underground crude oil-storage facilities managed by the U. S. Department of Energy Strategic Petroleum Reserve (SPR) Program. Sandia National Laboratories, as the geotechnical advisor to the SPR, conducts site-characterization investigations and other longer-term geotechnical and engineering studies in support of the program. This report describes the conversion of two-dimensional geologic interpretations of the Bryan Mound site into three-dimensional geologic models. The new models include the geometry of the salt dome, the surrounding sedimentary units, mapped faults, and the 20 oil-storage caverns at the site. This work provides an internally consistent geologic model of the Bryan Mound site that can be used in support of future work.
Zhan, Beibei; Liu, Changbing; Shi, Huaxia; Li, Chen; Wang, Lianhui [Key Laboratory for Organic Electronics and Information Displays (KLOEID), Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Huang, Wei, E-mail: iamxcdong@njtech.edu.cn, E-mail: iamwhuang@njtech.edu.cn; Dong, Xiaochen, E-mail: iamxcdong@njtech.edu.cn, E-mail: iamwhuang@njtech.edu.cn [Key Laboratory for Organic Electronics and Information Displays (KLOEID), Nanjing University of Posts and Telecommunications, Nanjing 210023 (China); Jiangsu-Singapore Joint Research Center for Organic/Bio-Electronics and Information Displays and Institute of Advanced Materials (IAM), Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816 (China)
2014-06-16
A facile strategy has been developed to synthesize sliver nanoparticles (Ag NPs) decorated three-dimensional graphene (3DG) through hydrothermal process. The AgNPs-3DG composites are directly fabricated into a free standing sensing electrode for electrochemical detection of hydrogen peroxide (H{sub 2}O{sub 2}) in phosphate buffered solutions. Various techniques equipments including scanning electron microscopy, X-ray diffraction, and Raman spectroscopy are used to characterize the morphology and structure of the as-prepared composite. The electrochemical experiments reveal the AgNPs-3DG based biosensor exhibits fast amperometric sensing, low detection limitation, wide linear responding range, and perfect selectivity for non-enzyme H{sub 2}O{sub 2} detection, indicating the well synergistic effect of Ag NPs high electrocatalytic activity and 3DG high conductivity and large surface area.
A BDDC Algorithm with Deluxe Scaling for Three-Dimensional H (curl) Problems
Dohrmann, Clark R.; Widlund, Olof B.
2015-04-28
In our paper, we present and analyze a BDDC algorithm for a class of elliptic problems in the three-dimensional H(curl) space. Compared with existing results, our condition number estimate requires fewer assumptions and also involves two fewer powers of log(H/h), making it consistent with optimal estimates for other elliptic problems. Here, H/his the maximum of Hi/hi over all subdomains, where Hi and hi are the diameter and the smallest element diameter for the subdomain Ωi. The analysis makes use of two recent developments. The first is our new approach to averaging across the subdomain interfaces, while the second is a new technical tool that allows arguments involving trace classes to be avoided. Furthermore, numerical examples are presented to confirm the theory and demonstrate the importance of the new averaging approach in certain cases.
Three-dimensional ground penetrating radar imaging using multi-frequency diffraction tomography
Mast, J.E.; Johansson, E.M.
1994-11-15
In this talk we present results from a three-dimensional image reconstruction algorithm for impulse radar operating in monostatic pule-echo mode. The application of interest to us is the nondestructive evaluation of civil structures such as bridge decks. We use a multi-frequency diffraction tomography imaging technique in which coherent backward propagations of the received reflected wavefield form a spatial image of the scattering interfaces within the region of interest. This imaging technique provides high-resolution range and azimuthal visualization of the subsurface region. We incorporate the ability to image in planarly layered conductive media and apply the algorithm to experimental data from an offset radar system in which the radar antenna is not directly coupled to the surface of the region. We present a rendering in three-dimensions of the resulting image data which provides high-detail visualization.
Optical spectroscopy study of the three-dimensional Dirac semimetal ZrTe5
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chen, R. Y.; Gu, G. D.; Zhang, S. J.; Schneeloch, J. A.; Zhang, C.; Li, Q.; Wang, N. L.
2015-08-05
Three-dimensional (3D) topological Dirac materials have been under intensive study recently. The layered compound ZrTe5 has been suggested to be one such material as a result of transport and angle-resolved photoemission spectroscopy experiments. Here, we perform infrared reflectivity measurements to investigate the underlying physics of this material. The derived optical conductivity increases linearly with frequency below normal interband transitions, which provides optical spectroscopic proof of a 3D Dirac semimetal. In addition, the plasma edge shifts dramatically to lower energy upon temperature cooling, which might be due to the shrinking of the lattice parameters. Additionally, an extremely sharp peak shows upmore » in the frequency-dependent optical conductivity, indicating the presence of a Van Hove singularity in the joint density of state.« less
Staff, Jan E.; Niebergal, Brian P.; Ouyed, Rachid; Pudritz, Ralph E.; Cai, Kai
2010-10-20
We perform state-of-the-art, three-dimensional, time-dependent simulations of magnetized disk winds, carried out to simulation scales of 60 AU, in order to confront optical Hubble Space Telescope observations of protostellar jets. We 'observe' the optical forbidden line emission produced by shocks within our simulated jets and compare these with actual observations. Our simulations reproduce the rich structure of time-varying jets, including jet rotation far from the source, an inner (up to 400 km s{sup -1}) and outer (less than 100 km s{sup -1}) component of the jet, and jet widths of up to 20 AU in agreement with observed jets. These simulations when compared with the data are able to constrain disk wind models. In particular, models featuring a disk magnetic field with a modest radial spatial variation across the disk are favored.
Three-dimensional micro-printing of temperature sensors based on up-conversion luminescence
Wickberg, Andreas; Mueller, Jonathan B.; Mange, Yatin J.; Nann, Thomas; Fischer, Joachim; Wegener, Martin
2015-03-30
The pronounced temperature dependence of up-conversion luminescence from nanoparticles doped with rare-earth elements enables local temperature measurements. By mixing these nanoparticles into a commercially available photoresist containing the low-fluorescence photo-initiator Irgacure 369, and by using three-dimensional direct laser writing, we show that micrometer sized local temperature sensors can be positioned lithographically as desired. Positioning is possible in pre-structured environments, e.g., within buried microfluidic channels or on optical or electronic chips. We use the latter as an example and demonstrate the measurement for both free space and waveguide-coupled excitation and detection. For the free space setting, we achieve a temperature standard deviation of 0.5 K at a time resolution of 1 s.
Realizing three-dimensional artificial spin ice by stacking planar nano-arrays
Chern, Gia-Wei; Reichhardt, Charles; Nisoli, Cristiano
2014-01-06
Artificial spin ice is a frustrated magnetic two-dimensional nano-material, recently employed to study variety of tailor-designed unusual collective behaviours. Recently proposed extensions to three dimensions are based on self-assembly techniques and allow little control over geometry and disorder. We present a viable design for the realization of a three-dimensional artificial spin ice with the same level of precision and control allowed by lithographic nano-fabrication of the popular two-dimensional case. Our geometry is based on layering already available two-dimensional artificial spin ice and leads to an arrangement of ice-rule-frustrated units, which is topologically equivalent to that of the tetrahedra in a pyrochlore lattice. Consequently, we show, it exhibits a genuine ice phase and its excitations are, as in natural spin ice materials, magnetic monopoles interacting via Coulomb law.
Tourret, Damien; Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; Gibbs, John W.; Karma, Alain
2015-05-27
We present a three-dimensional extension of the multiscale dendritic needle network (DNN) model. This approach enables quantitative simulations of the unsteady dynamics of complex hierarchical networks in spatially extended dendritic arrays. We apply the model to directional solidification of Al-9.8 wt.%Si alloy and directly compare the model predictions with measurements from experiments with in situ x-ray imaging. The focus is on the dynamical selection of primary spacings over a range of growth velocities, and the influence of sample geometry on the selection of spacings. Simulation results show good agreement with experiments. The computationally efficient DNN model opens new avenues for investigating the dynamics of large dendritic arrays at scales relevant to solidification experiments and processes.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Tourret, Damien; Clarke, Amy J.; Imhoff, Seth D.; Gibbs, Paul J.; Gibbs, John W.; Karma, Alain
2015-05-27
We present a three-dimensional extension of the multiscale dendritic needle network (DNN) model. This approach enables quantitative simulations of the unsteady dynamics of complex hierarchical networks in spatially extended dendritic arrays. We apply the model to directional solidification of Al-9.8 wt.%Si alloy and directly compare the model predictions with measurements from experiments with in situ x-ray imaging. The focus is on the dynamical selection of primary spacings over a range of growth velocities, and the influence of sample geometry on the selection of spacings. Simulation results show good agreement with experiments. The computationally efficient DNN model opens new avenues formore » investigating the dynamics of large dendritic arrays at scales relevant to solidification experiments and processes.« less
Efficiency and accuracy aspects of a full-multigrid SIMPLE algorithm for three-dimensional flows
Lilek, Z.; Muzaferija, S.; Peric, M.
1997-01-01
This article reports on the analysis of efficiency and accuracy of a full-multigrid SIMPLE algorithm for three-dimensional flows using co-located grids and central difference discretization for both convective and diffusive fluxes. It is shown that the central differencing scheme--contrary to common belief--offers both good convergence properties and high accuracy, even at large Peclet numbers. Accurate solutions, with discretization errors below 0.5%, were obtained for lid-driven flows in a cubic cavity using grids with up to 128{sup 3} (nearly 2.1 million) control volumes. For a grid with 64{sup 3} (262,114) control volumes, solution can be obtained on a personal computer in 5--10 min. The computer code used for the calculations reported here is available from authors on request (free of charge).
Whistler turbulence forward vs. inverse cascade. Three-dimensional particle-in-cell simulations
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chang, Ouliang; Gary, S. Peter; Wang, Joseph
2015-02-12
In this study, we present the results of the first fully three-dimensional particle-in-cell simulations of decaying whistler turbulence in a magnetized, homogeneous, collisionless plasma in which both forward cascades to shorter wavelengths, and inverse cascades to longer wavelengths are allowed to proceed. For the electron beta βe = 0.10 initial value considered here, the early-time rate of inverse cascade is very much smaller than the rate of forward cascade, so that at late times the fluctuation energy in the regime of the inverse cascade is much weaker than that in the forward cascade regime. Similarly, the wavevector anisotropy in themore » inverse cascade regime is much weaker than that in the forward cascade regime.« less
Elastodynamic behavior of the three dimensional layer-by-layer metamaterial structure
Aravantinos-Zafiris, N.; Sigalas, M. M.; Economou, E. N.
2014-10-07
In this work, we numerically investigate for the first time the elastodynamic behavior of a three dimensional layer-by-layer rod structure, which is easy to fabricate and has already proved to be very efficient as a photonic crystal. The Finite Difference Time Domain method was used for the numerical calculations. For the rods, several materials were examined and the effects of all the geometric parameters of the structure were also numerically investigated. Additionally, two modifications of the structure were included in our calculations. The results obtained here (for certain geometric parameters), exhibiting a high ratio of longitudinal over transverse sound velocity and therefore a close approach to ideal pentamode behavior over a frequency range, clearly show that the layer-by-layer rod structure, besides being an efficient photonic crystal, is a very serious contender as an elastodynamic metamaterial.
High-resolution ab initio three-dimensional x-ray diffraction microscopy
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Chapman, Henry N.; Barty, Anton; Marchesini, Stefano; Noy, Aleksandr; Hau-Riege, Stefan P.; Cui, Congwu; Howells, Malcolm R.; Rosen, Rachel; He, Haifeng; Spence, John C. H.; et al
2006-01-01
Coherent x-ray diffraction microscopy is a method of imaging nonperiodic isolated objects at resolutions limited, in principle, by only the wavelength and largest scattering angles recorded. We demonstrate x-ray diffraction imaging with high resolution in all three dimensions, as determined by a quantitative analysis of the reconstructed volume images. These images are retrieved from the three-dimensional diffraction data using no a priori knowledge about the shape or composition of the object, which has never before been demonstrated on a nonperiodic object. We also construct two-dimensional images of thick objects with greatly increased depth of focus (without loss of transverse spatialmore » resolution). These methods can be used to image biological and materials science samples at high resolution with x-ray undulator radiation and establishes the techniques to be used in atomic-resolution ultrafast imaging at x-ray free-electron laser sources.« less
Optical spectroscopy study of the three-dimensional Dirac semimetal ZrTe_{5}
Chen, R. Y.; Gu, G. D.; Zhang, S. J.; Schneeloch, J. A.; Zhang, C.; Li, Q.; Wang, N. L.
2015-08-05
Three-dimensional (3D) topological Dirac materials have been under intensive study recently. The layered compound ZrTe_{5} has been suggested to be one such material as a result of transport and angle-resolved photoemission spectroscopy experiments. Here, we perform infrared reflectivity measurements to investigate the underlying physics of this material. The derived optical conductivity increases linearly with frequency below normal interband transitions, which provides optical spectroscopic proof of a 3D Dirac semimetal. In addition, the plasma edge shifts dramatically to lower energy upon temperature cooling, which might be due to the shrinking of the lattice parameters. Additionally, an extremely sharp peak shows up in the frequency-dependent optical conductivity, indicating the presence of a Van Hove singularity in the joint density of state.
A BDDC Algorithm with Deluxe Scaling for Three-Dimensional H (curl) Problems
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Dohrmann, Clark R.; Widlund, Olof B.
2015-04-28
In our paper, we present and analyze a BDDC algorithm for a class of elliptic problems in the three-dimensional H(curl) space. Compared with existing results, our condition number estimate requires fewer assumptions and also involves two fewer powers of log(H/h), making it consistent with optimal estimates for other elliptic problems. Here, H/his the maximum of Hi/hi over all subdomains, where Hi and hi are the diameter and the smallest element diameter for the subdomain Ωi. The analysis makes use of two recent developments. The first is our new approach to averaging across the subdomain interfaces, while the second is amore » new technical tool that allows arguments involving trace classes to be avoided. Furthermore, numerical examples are presented to confirm the theory and demonstrate the importance of the new averaging approach in certain cases.« less
Three dimensional numerical simulations of the UPS-292 stratified charge engine
O'Rourke, P.J.; Amsden, A.A.
1987-01-01
The authors present and analyze three-dimensional calculations of the spray, mixing and combustion in the UPS-292 stratified charge engine for three different operating conditions, corresponding to overall air-fuel ratios between 22.4 and 61.0. The numerical calculations are performed with KIVA, a multidimensional arbitrary-mesh, finite-difference hydrodynamics program for internal combustion engine applications. The calculations use a mesh of 10,000 computational cells. Each operating condition is calculated from intake valve closure at 118/sup 0/ BTDC to 90/sup 0/ ATDC and requires approximately three hours of CRAY-XMP computer time. Combustion occurs primarily in the wake of the spark plug, and to include the effects of the spark plug on the flow field, we use a novel internal obstacle treatment. The methodology, in which internal obstacles are represented by computational particles, promises to be applicable to the calculation of the flows around intake and exhaust valves.
Development and validation of a two-phase, three-dimensional model for PEM fuel cells.
Chen, Ken Shuang
2010-04-01
The objectives of this presentation are: (1) To develop and validate a two-phase, three-dimensional transport modelfor simulating PEM fuel cell performance under a wide range of operating conditions; (2) To apply the validated PEM fuel cell model to improve fundamental understanding of key phenomena involved and to identify rate-limiting steps and develop recommendations for improvements so as to accelerate the commercialization of fuel cell technology; (3) The validated PEMFC model can be employed to improve and optimize PEM fuel cell operation. Consequently, the project helps: (i) address the technical barriers on performance, cost, and durability; and (ii) achieve DOE's near-term technical targets on performance, cost, and durability in automotive and stationary applications.
Three-dimensional carbon fibers and method and apparatus for their production
Muradov, Nazim Z.
2012-02-21
This invention relates to novel three-dimensional (3D) carbon fibers which are original (or primary) carbon fibers (OCF) with secondary carbon filaments (SCF) grown thereon, and, if desired, tertiary carbon filaments (TCF) are grown from the surface of SCF forming a filamentous carbon network with high surface area. The methods and apparatus are provided for growing SCF on the OCF by thermal decomposition of carbonaceous gases (CG) over the hot surface of the OCF without use of metal-based catalysts. The thickness and length of SCF can be controlled by varying operational conditions of the process, e.g., the nature of CG, temperature, residence time, etc. The optional activation step enables one to produce 3D activated carbon fibers with high surface area. The method and apparatus are provided for growing TCF on the SCF by thermal decomposition of carbonaceous gases over the hot surface of the SCF using metal catalyst particles.
Method for the fabrication of three-dimensional microstructures by deep X-ray lithography
Sweatt, William C.; Christenson, Todd R.
2005-04-05
A method for the fabrication of three-dimensional microstructures by deep X-ray lithography (DXRL) comprises a masking process that uses a patterned mask with inclined mask holes and off-normal exposures with a DXRL beam aligned with the inclined mask holes. Microstructural features that are oriented in different directions can be obtained by using multiple off-normal exposures through additional mask holes having different orientations. Various methods can be used to block the non-aligned mask holes from the beam when using multiple exposures. A method for fabricating a precision 3D X-ray mask comprises forming an intermediate mask and a master mask on a common support membrane.
Localization in two- and three-dimensional systems away from the band center
Zdetsis, A.D.; Soukoulis, C.M.; Economou, E.N.; Grest, G.S.
1985-12-15
Extensive numerical results using finite-size-scaling methods for two-dimensional (2D) and three-dimensional (3D) disordered systems are presented for eigenenergies E different from zero. Single-parameter scaling law is satisfied for all of our results in both 2D and 3D systems. In 2D we find only localized states, however, the localization length does not have its maximum at the band center. In 3D, the dependence of the mobility edge on the strength of the diagonal order is obtained. These results are found to be in satisfactory agreement with the predictions of the coherent-potential approximation and the potential-well analogy.
Three-dimensional optical lattice clock with bosonic {sup 88}Sr atoms
Akatsuka, Tomoya; Takamoto, Masao; Katori, Hidetoshi
2010-02-15
We present detailed analyses of our recent experiment on the three-dimensional (3D) optical lattice clock with bosonic {sup 88}Sr atoms in which the collisional frequency shift was suppressed by applying a single-occupancy lattice. Frequency shifts in magnetically induced spectroscopy on the {sup 1}S{sub 0}-{sup 3}P{sub 0} clock transition ({lambda}=698 nm) of {sup 88}Sr were experimentally investigated by referencing a one-dimensional (1D) lattice clock based on spin-polarized {sup 87}Sr atoms. We discuss that the clock stability is limited by the current laser stability as well as the experimental sequence of the clock operation, which may be improved to {sigma}{sub y}({tau})=2x10{sup -16}/{radical}({tau}) by optimizing the cycle time of the clock operation.
Method to planarize three-dimensional structures to enable conformal electrodes
Nikolic, Rebecca J; Conway, Adam M; Graff, Robert T; Reinhardt, Catherine; Voss, Lars F; Shao, Qinghui
2012-11-20
Methods for fabricating three-dimensional PIN structures having conformal electrodes are provided, as well as the structures themselves. The structures include a first layer and an array of pillars with cavity regions between the pillars. A first end of each pillar is in contact with the first layer. A segment is formed on the second end of each pillar. The cavity regions are filled with a fill material, which may be a functional material such as a neutron sensitive material. The fill material covers each segment. A portion of the fill material is etched back to produce an exposed portion of the segment. A first electrode is deposited onto the fill material and each exposed segment, thereby forming a conductive layer that provides a common contact to each the exposed segment. A second electrode is deposited onto the first layer.
THREE-DIMENSIONAL DUST MAPPING REVEALS THAT ORION FORMS PART OF A LARGE RING OF DUST
Schlafly, E. F.; Rix, H.-W.; Martin, N. F.; Green, G.; Finkbeiner, D. P.; Burgett, W. S.; Chambers, K. C.; Kaiser, N.; Morgan, J. S.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.; Draper, P. W.; Metcalfe, N.; Price, P. A.
2015-02-01
The Orion Molecular Complex is the nearest site of ongoing high-mass star formation, making it one of the most extensively studied molecular complexes in the Galaxy. We have developed a new technique for mapping the three-dimensional distribution of dust in the Galaxy using Pan-STARRS1 photometry. We isolate the dust at the distance to Orion using this technique, revealing a large (100 pc, 14 diameter), previously unrecognized ring of dust, which we term the ''Orion dust ring''. The ring includes Orion A and B, and is not coincident with current H? features. The circular morphology suggests formation as an ancient bubble in the interstellar medium, though we have not been able to conclusively identify the source of the bubble. This hint at the history of Orion may have important consequences for models of high-mass star formation and triggered star formation.
Measurement of the three-dimensional tip region flow field in an axial compressor
Stauter, R.C. )
1993-07-01
A two-color, five-beam LDV system has been configured to make simultaneous three-component velocity measurements of the flow field in a two-stage axial compressor model. The system has been used to make time-resolved measurements both between compressor blade rows and within the rotating blade passages in an axial compressor. The data show the nature and behavior of the complex, three-dimensional flow phenomena present in the tip region of a compressor as the convect downstream. In particular, the nature of the tip leakage vortex is apparent, being manifested by high blockage as well as the expected vortical motion. The data indicate that the radial flows associated with the tip leakage vortex begin to decrease while within the rotor passage, and that they temporarily increase aft of the passage.
Fathipour, Vala; Jang, Sung Jun; Nia, Iman Hassani; Mohseni, Hooman
2015-01-12
We present a quantitative study of the influence of three-dimensional geometry of the isolated electroninjection detectors on their characteristics. Significant improvements in the device performance are obtained as a result of scaling the injector diameter with respect to the trapping/absorbing layer diameters. Devices with about ten times smaller injector area with respect to the trapping/absorbing layer areas show more than an order of magnitude lower dark current, as well as an order of magnitude higher optical gain compared with devices of same size injector and trapping/absorbing layer areas. Devices with 10??m injector diameter and 30??m trapping/absorbing layer diameter show an optical gain of ?2000 at bias voltage of ?3?V with a cutoff wavelength of 1700?nm. Analytical expressions are derived for the electron-injection detector optical gain to qualitatively explain the significance of scaling the injector with respect to the absorber.
Biologically Inspired Synthesis Route to Three-Dimensionally Structured Inorganic Thin Films
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Schwenzer, Birgit; Morse, Daniel E.
2008-01-01
Inorganic thin films (hydroxide, oxide, and phosphate materials) that are textured on a submicron scale have been prepared from aqueous metal salt solutions at room temperature using vapor-diffusion catalysis. This generic synthesis approach mimics the essential advantages of the catalytic and structure-directing mechanisms observed for the formation of silica skeletons of marine sponges. Chemical composition, crystallinity, and the three-dimensional morphology of films prepared by this method are extremely sensitive to changes in the synthesis conditions, such as concentrations, reaction times, and the presence and nature of substrate materials. Focusing on different materials systems, the reaction mechanism for the formation ofmore » these thin films and the influence of different reaction parameters on the product are explained.« less
Numerical optimization of three-dimensional coils for NSTX-U
Lazerson, S. A.; Park, J. -K.; Logan, N.; Boozer, A.
2015-09-03
A tool for the calculation of optimal three-dimensional (3D) perturbative magnetic fields in tokamaks has been developed. The IPECOPT code builds upon the stellarator optimization code STELLOPT to allow for optimization of linear ideal magnetohydrodynamic perturbed equilibrium (IPEC). This tool has been applied to NSTX-U equilibria, addressing which fields are the most effective at driving NTV torques. The NTV torque calculation is performed by the PENT code. Optimization of the normal field spectrum shows that fields with n = 1 character can drive a large core torque. It is also shown that fields with n = 3 features are capable of driving edge torque and some core torque. Coil current optimization (using the planned in-vessel and existing RWM coils) on NSTX-U suggest the planned coils set is adequate for core and edge torque control. In conclusion, comparison between error field correction experiments on DIII-D and the optimizer show good agreement.
Biffle, J.H.
1993-02-01
JAC3D is a three-dimensional finite element program designed to solve quasi-static nonlinear mechanics problems. A set of continuum equations describes the nonlinear mechanics involving large rotation and strain. A nonlinear conjugate gradient method is used to solve the equation. The method is implemented in a three-dimensional setting with various methods for accelerating convergence. Sliding interface logic is also implemented. An eight-node Lagrangian uniform strain element is used with hourglass stiffness to control the zero-energy modes. This report documents the elastic and isothermal elastic-plastic material model. Other material models, documented elsewhere, are also available. The program is vectorized for efficient performance on Cray computers. Sample problems described are the bending of a thin beam, the rotation of a unit cube, and the pressurization and thermal loading of a hollow sphere.
Schickert, Martin
2015-03-31
Ultrasonic testing systems using transducer arrays and the SAFT (Synthetic Aperture Focusing Technique) reconstruction allow for imaging the internal structure of concrete elements. At one-sided access, three-dimensional representations of the concrete volume can be reconstructed in relatively great detail, permitting to detect and localize objects such as construction elements, built-in components, and flaws. Different SAFT data acquisition and processing schemes can be utilized which differ in terms of the measuring and computational effort and the reconstruction result. In this contribution, two methods are compared with respect to their principle of operation and their imaging characteristics. The first method is the conventional single-channel SAFT algorithm which is implemented using a virtual transducer that is moved within a transducer array by electronic switching. The second method is the Combinational SAFT algorithm (C-SAFT), also named Sampling Phased Array (SPA) or Full Matrix Capture/Total Focusing Method (TFM/FMC), which is realized using a combination of virtual transducers within a transducer array. Five variants of these two methods are compared by means of measurements obtained at test specimens containing objects typical of concrete elements. The automated SAFT imaging system FLEXUS is used for the measurements which includes a three-axis scanner with a 1.0 m × 0.8 m scan range and an electronically switched ultrasonic array consisting of 48 transducers in 16 groups. On the basis of two-dimensional and three-dimensional reconstructed images, qualitative and some quantitative results of the parameters image resolution, signal-to-noise ratio, measurement time, and computational effort are discussed in view of application characteristics of the SAFT variants.
Simulating three-dimensional nonthermal high-energy photon emission in colliding-wind binaries
Reitberger, K.; Kissmann, R.; Reimer, A.; Reimer, O.
2014-07-01
Massive stars in binary systems have long been regarded as potential sources of high-energy γ rays. The emission is principally thought to arise in the region where the stellar winds collide and accelerate relativistic particles which subsequently emit γ rays. On the basis of a three-dimensional distribution function of high-energy particles in the wind collision region—as obtained by a numerical hydrodynamics and particle transport model—we present the computation of the three-dimensional nonthermal photon emission for a given line of sight. Anisotropic inverse Compton emission is modeled using the target radiation field of both stars. Photons from relativistic bremsstrahlung and neutral pion decay are computed on the basis of local wind plasma densities. We also consider photon-photon opacity effects due to the dense radiation fields of the stars. Results are shown for different stellar separations of a given binary system comprising of a B star and a Wolf-Rayet star. The influence of orbital orientation with respect to the line of sight is also studied by using different orbital viewing angles. For the chosen electron-proton injection ratio of 10{sup –2}, we present the ensuing photon emission in terms of two-dimensional projections maps, spectral energy distributions, and integrated photon flux values in various energy bands. Here, we find a transition from hadron-dominated to lepton-dominated high-energy emission with increasing stellar separations. In addition, we confirm findings from previous analytic modeling that the spectral energy distribution varies significantly with orbital orientation.