Science.gov

Sample records for 3-d wind fields

  1. 3D wind field from spaceborne Doppler radar

    NASA Astrophysics Data System (ADS)

    Lemaître, Y.; Viltard, N.

    2013-10-01

    Numerous space radar missions are presently envisioned to study the water cycle in the tropics. Among them, the DYCECT (DYnamique, énergie et Cycle de l'Eau dans la Convection Tropicale) mission, a French proposal (submitted to the French CNES Agency), could embark a Doppler radar (W-band or Ka-band) with scanning possibilities onboard a low-orbiting satellite. This instrument could be implemented in addition to a Passive Microwave Radiometer (PMR), and eventually an improved ScaraB-like broadband radiometer, and a lightning detection instrument. This package will document the ice microphysics and the heat budgets. Since the microphysics and the water and energy budgets are strongly driven by the dynamics, the addition of a Doppler radar with scanning possibilities could provide valuable information (3D wind and rain fields) and a large statistic of such critical information over the entire tropics and for all the stages of development. These new information could be used to better understand the tropical convection and to improve convection parameterization relevant for cloud and climate models. It could be used also to associate direct applications such as now-casting and risk prevention. The present study focuses on the feasibility of such 3D wind field retrieval from spaceborne radar. It uses a simulator of some parts of the spaceborne radar in order i) to evaluate the sensitivity of the retrieved wind fields to the scanning strategies and sampling parameters, and to the instrumental and platform parameters and ii) to determine the best parameters providing the most accurate wind fields.

  2. 3D wind field retrieval from spaceborne Doppler radar

    NASA Astrophysics Data System (ADS)

    Lemaêtre, Y.; Viltard, N.

    2012-11-01

    Numerous space missions carrying a radar are presently envisioned, particularly to study tropical rain systems. Among those missions, BOITATA is a joint effort between Brazil (INPE/AEB) and France (CNES). The goal is to embark a Doppler radar with scanning possibilities onboard a low-orbiting satellite. This instrument should be implemented in addition to a Passive Microwave Radiometer (PMR) between 19 and 183 GHz, an improved ScaraB-like broadband radiometer, a mm/submm PMR and a lightning detection instrument. This package would be meant to document the feedback of the ice microphysics on the rain systems life cycle and on their heat and radiative budgets. Since the microphysics and the water and energy budgets are strongly driven by the dynamics, the addition of a Doppler radar with scanning possibilities could provide precious information (3D wind and rain fields). It would allow us to build a large statistics of such critical information over the entire tropics and for all the stages of development of the convection. This information could be used to better understand the tropical convection and to improve convection parameterization relevant for cloud and climate models and associated applications such as now-casting and risk prevention. The present work focuses on the feasibility to retrieve 3D winds in precipitating areas from such a radar. A simulator of some parts of the spaceborne radar is developed to estimate the precision on the retrieved wind field depending on the scanning strategies and instrumental parameters and to determine the best sampling parameters.

  3. 3D field harmonics

    SciTech Connect

    Caspi, S.; Helm, M.; Laslett, L.J.

    1991-03-30

    We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the 3D field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is also used in CAD with modifications more readily available. It is our hope that the format used here for magnetic fields can be used not only as a means of delivering fields but also as a way by which beam dynamics can suggest correction to the conductor geometry. 5 refs., 70 figs.

  4. New non-Doppler remote sensing technique for 3D wind field mapping

    NASA Astrophysics Data System (ADS)

    Belen'kii, Mikhail S.; Gimmestad, Gary G.; Gurvich, Alexander V.

    1994-06-01

    A new approach to the statistical analysis of fluctuating, photon-limited signals that permits us to accumulate and process the lidar returns without averaging of the reflected energy fluctuations is developed. This approach requires recording the photocounts for each pulse in a series of pulses and then determining photocount statistics. Based on the semiclassical theory of photodetection and Mandel's formula, a relationship has been obtained between the time-space cross correlation function and the cross spectrum of the lidar returns and corresponding photocount statistics. It is shown that the relative uncertainties of measuring the cross correlation or the cross spectrum of the lidar returns is determined by the general number of photocounts, but not by their mean value. A fast-scanning lidar system, which is based on a new photocounting analysis approach, is described for 3D wind field mapping in the atmosphere at altitudes up to 5 km. A program for the experimental verification of the new approach is presented.

  5. Configuration and Evaluation of a Dual-Doppler 3-D Wind Field System

    NASA Technical Reports Server (NTRS)

    Crawford, Winifred C.

    2014-01-01

    Current LSP, GSDO, and SLS space vehicle operations are halted when wind speeds from specific directions exceed defined thresholds and when lightning is a threat. Strong winds and lightning are difficult parameters for the 45th Weather Squadron (45 WS) to forecast, yet are important in the protection of customer vehicle operations and the personnel that conduct them. A display of the low-level horizontal wind field to reveal areas of high winds or convergence would be a valuable tool for forecasters in assessing the timing of high winds, or convection initiation and subsequent lightning occurrence. This is especially important for areas where no weather observation platforms exist. Developing a dual-Doppler radar capability would provide such a display to assist forecasters in predicting high winds and convection initiation. The wind fields can also be used to initialize a local mesoscale numerical weather prediction model to help improve the model forecast winds, convection initiation, and other phenomena. The 45 WS and NWS MLB tasked the Applied Meteorology Unit (AMU) to develop a dual- Doppler wind field display using data from the 45th Space Wing radar, known as the Weather Surveillance Radar (WSR), NWS MLB Weather Surveillance Radar 1988 Doppler (KMLB), and the Orlando International Airport Terminal Doppler Weather Radar (KMCO). They also stipulated that the software used should be freely available. The AMU evaluated two software packages and, with concurrence from NWS MLB and the 45 WS, chose the Warning Decision Support System-Integrated Information (WDSS-II). The AMU collected data from two significant weather cases: a tornadic event on 14 April 2013 and a severe wind and hail event on 12 February 2014. For the 14 April case, the data were from WSR and KMLB. For the 12 February case, the data were from KMCO and KMLB. The AMU installed WDSS-II on a Linux PC, then processed and quality controlled the radar data for display and analysis using WDSS-II tools

  6. Production of 3D wind field near the surface using WRF and MUKLIMO

    NASA Astrophysics Data System (ADS)

    Sukjun, L.

    2015-12-01

    The extreme weather conditions become frequent and severe with global warming. To prevent and cope forest disaster like a forest fire, we need an accurate micrometeorological prediction system for mountainous regions. This study addressed the forest fires occurred at Bonghwa and Gangneung in March, 2013. We constructed and optimized the prediction system that were required to interpret and simulate the forest micrometeorology. At first, we examined WRF physical sensitivity. Subsequently, KMA AWS observation data were assimilated using three-dimensional variation data assimilation method. The effectiveness of the assimilation was examined by using AWS observations enhanced with the Forest Research Institute observations. Finally, The 100 meters spatial resolution wind data were obtained by using the MUKLIMO for the given wind vector from WRF.

  7. A stochastic aerodynamic model for stationary blades in unsteady 3D wind fields

    NASA Astrophysics Data System (ADS)

    Fluck, Manuel; Crawford, Curran

    2016-09-01

    Dynamic loads play an important roll in the design of wind turbines, but establishing the life-time aerodynamic loads (e.g. extreme and fatigue loads) is a computationally expensive task. Conventional (deterministic) methods to analyze long term loads, which rely on the repeated analysis of multiple different wind samples, are usually too expensive to be included in optimization routines. We present a new stochastic approach, which solves the aerodynamic system equations (Lagrangian vortex model) in the stochastic space, and thus arrive directly at a stochastic description of the coupled loads along a turbine blade. This new approach removes the requirement of analyzing multiple different realizations. Instead, long term loads can be extracted from a single stochastic solution, a procedure that is obviously significantly faster. Despite the reduced analysis time, results obtained from the stochastic approach match deterministic result well for a simple test-case (a stationary blade). In future work, the stochastic method will be extended to rotating blades, thus opening up new avenues to include long term loads into turbine optimization.

  8. 3-D MHD Model of the Solar Wind-Interplanetary Space Combining System 1:Variation of Solar Wind Speed Associated with the Photospheric Magnetic Field

    NASA Astrophysics Data System (ADS)

    Nakamizo, A.; Tanaka, T.

    2006-12-01

    Existing global models of the solar-wind/IMF expanding to the Earth's orbit are basically grounded in the idea of "source surface." It is widely accepted that the sector structure and the solar wind speed are primarily controlled by the magnetic field at the source surface and the so-called "expansion factor." On the other hand, 3-D MHD model is still off from practical use because both of scientific and technical problems. One of the former problems is the reproduction of supersonic solar-wind. From the viewpoint of the physics of the solar wind, coronal heating and outward acceleration mechanisms are invoked to explain the supersonic evolution of the solar wind. Since the mechanism responsible for the heating/acceleration is still one of the primary subjects of the physics of the solar wind, many MHD models have taken into account their effects by incorporating additional source terms corresponding to promising candidates such as thermal conductions, radiation losses and wave pressures. However there are few MHD models considering the effect of the expansion factor, which determines the solar-wind speed in the series of source surface models. In this study we newly incorporate the flux tube expansion rate into the MHD equation system including heat source function in the energy equation. Appling the unstructured grid system, we achieved the dense grid spacing at the inner boundary, which enable us to adopt realistic solar magnetic fields, and a size of simulation space of 1AU. Photospheric magnetic field data is used as the inner boundary condition.The simulation results are summarized as: (1) The variation of solar wind speed is well controlled by the structure of magnetic fields at and little above the solar surface and (2) Far above the solar surface, the interface between high and low speed flows evolves to a structure suggestive of CIRs. Comparing the data from simulation with the actual solar wind data obtained by spacecrafts, we will discuss the future

  9. 3D Wind: Quantifying wind speed and turbulence intensity

    NASA Astrophysics Data System (ADS)

    Barthelmie, R. J.; Pryor, S. C.; Wang, H.; Crippa, P.

    2013-12-01

    Integrating measurements and modeling of wind characteristics for wind resource assessment and wind farm control is increasingly challenging as the scales of wind farms increases. Even offshore or in relatively homogeneous landscapes, there are significant gradients of both wind speed and turbulence intensity on scales that typify large wind farms. Our project is, therefore, focused on (i) improving methods to integrate remote sensing and in situ measurements with model simulations to produce a 3-dimensional view of the flow field on wind farm scales and (ii) investigating important controls on the spatiotemporal variability of flow fields within the coastal zone. The instrument suite deployed during the field experiments includes; 3-D sonic and cup anemometers deployed on meteorological masts and buoys, anemometers deployed on tethersondes and an Unmanned Aerial Vehicle, multiple vertically-pointing continuous-wave lidars and scanning Doppler lidars. We also integrate data from satellite-borne instrumentation - specifically synthetic aperture radar and scatterometers and output from the Weather Research and Forecast (WRF) model. Spatial wind fields and vertical profiles of wind speed from WRF and from the full in situ observational suite exhibit excellent agreement in a proof-of-principle experiment conducted in north Indiana particularly during convective conditions, but showed some discrepancies during the breakdown of the nocturnal stable layer. Our second experiment in May 2013 focused on triangulating a volume above an area of coastal water extending from the port in Cleveland out to an offshore water intake crib (about 5 km) and back to the coast, and includes extremely high resolution WRF simulations designed to characterize the coastal zone. Vertically pointing continuous-wave lidars were operated at each apex of the triangle, while the scanning Doppler lidar scanned out across the water over 90 degrees azimuth angle. Preliminary results pertaining to

  10. Examining In-Cloud Convective Turbulence in Relation to Total Lightning and the 3D Wind Field of Severe Thunderstorms

    NASA Astrophysics Data System (ADS)

    Al-Momar, S. A.; Deierling, W.; Williams, J. K.; Hoffman, E. G.

    2014-12-01

    Convectively induced turbulence (CIT) is commonly listed as a cause or factor in weather-related commercial aviation accidents. In-cloud CIT is generated in part by shears between convective updrafts and downdrafts. Total lightning is also dependent on a robust updraft and the resulting storm electrification. The relationship between total lightning and turbulence could prove useful in operational aviation settings with the use of future measurements from the geostationary lightning mapper (GLM) onboard the GOES-R satellite. Providing nearly hemispheric coverage of total lightning, the GLM could help identify CIT in otherwise data-sparse locations. For a severe thunderstorm case on 7 June 2012 in northeast Colorado, in-cloud eddy dissipation rate estimates from the NCAR/NEXRAD Turbulence Detection Algorithm were compared with cloud electrification data from the Colorado Lightning Mapping Array and radar products from the Denver, Colorado WSR-88D. These comparisons showed that high concentrations of very high frequency (VHF) source densities emitted by lightning occurred near and downstream of the storm's convective core. Severe turbulence was also shown to occur near this area, extending near the melting level of the storm and spreading upward and outward. Additionally, increases/decreases in VHF sources and turbulence volumes occurred within a few minutes of each other; although, light turbulence was shown to increase near one storm's dissipation. This may be due to increased shear from the now downdraft dominate storm. The 3D wind field from this case, obtained by either a dual-Doppler or a Variational Doppler Radar Assimilation System (VDRAS) analysis, will also be examined to further study the relationships between total lightning and thunderstorm kinematics. If these results prove to be robust, lightning may serve as a strong indicator of the location of moderate or greater turbulence.

  11. A non-CFD modeling system for computing 3D wind and concentration fields in urban environments

    SciTech Connect

    Nelson, Matthew A; Brown, Michael J; Williams, Michael D; Gowardhan, Akshay; Pardyjak, Eric R

    2010-01-01

    The Quick Urban & Industrial Complex (QUIC) Dispersion Modeling System has been developed to rapidly compute the transport and dispersion of toxic agent releases in the vicinity of buildings. It is composed of an empirical-diagnostic wind solver, an 'urbanized' Lagrangian random-walk model, and a graphical user interface. The code has been used for homeland security and environmental air pollution applications. In this paper, we discuss the wind solver methodology and improvements made to the original Roeckle schemes in order to better capture flow fields in dense built-up areas. The mode1-computed wind and concentration fields are then compared to measurements from several field experiments. Improvements to the QUIC Dispersion Modeling System have been made to account for the inhomogeneous and complex building layouts found in large cities. The logic that has been introduced into the code is described and comparisons of model output to full-scale outdoor urban measurements in Oklahoma City and New York City are given. Although far from perfect, the model agreed fairly well with measurements and in many cases performed equally to CFD codes.

  12. Coronal roots of solar wind streams: 3-D MHD modeling

    NASA Technical Reports Server (NTRS)

    Pisanko, Yu. V.

    1995-01-01

    Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic solar wind with structural elements: current sheets, coronal plumes etc. Using the observational information about various coronal emissions one can include these structural elements into the 3-D MHD solar wind model by embedding the discontinuities of given type. Such 3-D MHD structured solar wind is calculated self-consistently: variants are examined via numerical experiments. In particular, the behavior of coronal plumes in the transonic solar wind flow, is modeled. The input information for numerical modeling (for example, the magnetic field map at the very base of the solar corona) can be adjusted so that fast stream arises over the center of the coronal hole, over the coronal hole boundaries and, even, over the region with closed magnetic topology. 3-D MHD equations have the analytical solution which can serve as a model of supersonic trans-alfvenic solar wind in the (5-20) solar radii heliocentric distance interval. The transverse, nonradial total (gas + magnetic field) pressure balance in the flow is the corner-stone of this solution. The solution describes the filamentation (ray-like structure of the solar corona) and streaming (formation of high-speed streams with velocities up to 800 km/sec) as a consequence of the magnetic field spatial inhomogeneous structure and trans-alfvenic character of the flow. The magnetic field works in the model as a 'controller' for the solar wind streaming and filamentation.

  13. World Wind 3D Earth Viewing

    NASA Technical Reports Server (NTRS)

    Hogan, Patrick; Maxwell, Christopher; Kim, Randolph; Gaskins, Tom

    2007-01-01

    World Wind allows users to zoom from satellite altitude down to any place on Earth, leveraging high-resolution LandSat imagery and SRTM (Shuttle Radar Topography Mission) elevation data to experience Earth in visually rich 3D. In addition to Earth, World Wind can also visualize other planets, and there are already comprehensive data sets for Mars and the Earth's moon, which are as easily accessible as those of Earth. There have been more than 20 million downloads to date, and the software is being used heavily by the Department of Defense due to the code s ability to be extended and the evolution of the code courtesy of NASA and the user community. Primary features include the dynamic access to public domain imagery and its ease of use. All one needs to control World Wind is a two-button mouse. Additional guides and features can be accessed through a simplified menu. A JAVA version will be available soon. Navigation is automated with single clicks of a mouse, or by typing in any location to automatically zoom in to see it. The World Wind install package contains the necessary requirements such as the .NET runtime and managed DirectX library. World Wind can display combinations of data from a variety of sources, including Blue Marble, LandSat 7, SRTM, NASA Scientific Visualization Studio, GLOBE, and much more. A thorough list of features, the user manual, a key chart, and screen shots are available at http://worldwind.arc.nasa.gov.

  14. Magnetocentrifugal Winds in 3D: Nonaxisymmetric Steady State

    SciTech Connect

    Anderson, Jeffrey M.; Li, Zhi-Yun; Krasnopolsky, Ruben; Blandford, Roger D.; /SLAC

    2006-11-28

    Outflows can be loaded and accelerated to high speeds along rapidly rotating, open magnetic field lines by centrifugal forces. Whether such magnetocentrifugally driven winds are stable is a longstanding theoretical problem. As a step towards addressing this problem, we perform the first large-scale 3D MHD simulations that extend to a distance {approx} 10{sup 2} times beyond the launching region, starting from steady 2D (axisymmetric) solutions. In an attempt to drive the wind unstable, we increase the mass loading on one half of the launching surface by a factor of {radical}10, and reduce it by the same factor on the other half. The evolution of the perturbed wind is followed numerically. We find no evidence for any rapidly growing instability that could disrupt the wind during the launching and initial phase of propagation, even when the magnetic field of the magnetocentrifugal wind is toroidally dominated all the way to the launching surface. The strongly perturbed wind settles into a new steady state, with a highly asymmetric mass distribution. The distribution of magnetic field strength is, in contrast, much more symmetric. We discuss possible reasons for the apparent stability, including stabilization by an axial poloidal magnetic field, which is required to bend field lines away from the vertical direction and produce a magnetocentrifugal wind in the first place.

  15. C3Winds: A Novel 3D Wind Observing System to Characterize Severe Weather Events

    NASA Astrophysics Data System (ADS)

    Kelly, M. A.; Wu, D. L.; Yee, J. H.; Boldt, J.; Demajistre, R.; Reynolds, E.; Tripoli, G. J.; Oman, L.; Prive, N.; Heidinger, A. K.; Wanzong, S.

    2015-12-01

    The CubeSat Constellation Cloud Winds (C3Winds) is a NASA Earth Venture Instrument (EV-I) concept with the primary objective to resolve high-resolution 3D dynamic structures of severe wind events. Rapid evolution of severe weather events highlights the need for high-resolution mesoscale wind observations. Yet mesoscale observations of severe weather dynamics are quite rare, especially over the ocean where extratropical and tropical cyclones (ETCs and TCs) can undergo explosive development. Measuring wind velocity at the mesoscale from space remains a great challenge, but is critically needed to understand and improve prediction of severe weather and tropical cyclones. Based on compact, visible/IR imagers and a mature stereoscopic technique, C3Winds has the capability to measure high-resolution (~2 km) cloud motion vectors and cloud geometric heights accurately by tracking cloud features from two formation-flying CubeSats, separated by 5-15 minutes. Complementary to lidar wind measurements from space, C3Winds will provide high-resolution wind fields needed for detailed investigations of severe wind events in occluded ETCs, rotational structures inside TC eyewalls, and ozone injections associated with tropopause folding events. Built upon mature imaging technologies and long history of stereoscopic remote sensing, C3Winds provides an innovative, cost-effective solution to global wind observations with the potential for increased diurnal sampling via CubeSat constellation.

  16. Transforming Wind Turbine Blade Mold Manufacturing with 3D Printing

    SciTech Connect

    Zayas, Jose; Johnson, Mark

    2016-06-28

    Innovation in the design and manufacturing of wind power generation components continues to be critical to achieving our national renewable energy goals. As a result of this challenge, the U.S. Department of Energy's Wind Program and Advanced Manufacturing Office are partnering with public and private organizations to apply additive manufacturing, commonly known as 3D printing, to the production of wind turbine blade molds.

  17. Transforming Wind Turbine Blade Mold Manufacturing with 3D Printing

    ScienceCinema

    Zayas, Jose; Johnson, Mark

    2016-08-17

    Innovation in the design and manufacturing of wind power generation components continues to be critical to achieving our national renewable energy goals. As a result of this challenge, the U.S. Department of Energy's Wind Program and Advanced Manufacturing Office are partnering with public and private organizations to apply additive manufacturing, commonly known as 3D printing, to the production of wind turbine blade molds.

  18. Use of 3D Printing for Custom Wind Tunnel Fabrication

    NASA Astrophysics Data System (ADS)

    Gagorik, Paul; Bates, Zachary; Issakhanian, Emin

    2016-11-01

    Small-scale wind tunnels for the most part are fairly simple to produce with standard building equipment. However, the intricate bell housing and inlet shape of an Eiffel type wind tunnel, as well as the transition from diffuser to fan in a rectangular tunnel can present design and construction obstacles. With the help of 3D printing, these shapes can be custom designed in CAD models and printed in the lab at very low cost. The undergraduate team at Loyola Marymount University has built a custom benchtop tunnel for gas turbine film cooling experiments. 3D printing is combined with conventional construction methods to build the tunnel. 3D printing is also used to build the custom tunnel floor and interchangeable experimental pieces for various experimental shapes. This simple and low-cost tunnel is a custom solution for specific engineering experiments for gas turbine technology research.

  19. Visualization of 3-D tensor fields

    NASA Technical Reports Server (NTRS)

    Hesselink, L.

    1996-01-01

    Second-order tensor fields have applications in many different areas of physics, such as general relativity and fluid mechanics. The wealth of multivariate information in tensor fields makes them more complex and abstract than scalar and vector fields. Visualization is a good technique for scientists to gain new insights from them. Visualizing a 3-D continuous tensor field is equivalent to simultaneously visualizing its three eigenvector fields. In the past, research has been conducted in the area of two-dimensional tensor fields. It was shown that degenerate points, defined as points where eigenvalues are equal to each other, are the basic singularities underlying the topology of tensor fields. Moreover, it was shown that eigenvectors never cross each other except at degenerate points. Since we live in a three-dimensional world, it is important for us to understand the underlying physics of this world. In this report, we describe a new method for locating degenerate points along with the conditions for classifying them in three-dimensional space. Finally, we discuss some topological features of three-dimensional tensor fields, and interpret topological patterns in terms of physical properties.

  20. Note: 3D printed spheroid for uniform magnetic field generation

    NASA Astrophysics Data System (ADS)

    Öztürk, Y.; Aktaş, B.

    2016-10-01

    This article is focused on a novel and practical production method for a uniform magnetic field generator. The method involves building of a surface coil template using a desktop 3D printer and winding of a conducting wire onto the structure using surface grooves as a guide. Groove pattern was based on the parametric spheroidal helical coil formula. The coil was driven by a current source and the magnetic field inside was measured using a Hall probe placed into the holes on the printed structure. The measurements are found to be in good agreement with our finite element analysis results and indicate a fairly uniform field inside.

  1. Extracting full-field dynamic strain on a wind turbine rotor subjected to arbitrary excitations using 3D point tracking and a modal expansion technique

    NASA Astrophysics Data System (ADS)

    Baqersad, Javad; Niezrecki, Christopher; Avitabile, Peter

    2015-09-01

    Health monitoring of rotating structures such as wind turbines and helicopter rotors is generally performed using conventional sensors that provide a limited set of data at discrete locations near or on the hub. These sensors usually provide no data on the blades or inside them where failures might occur. Within this paper, an approach was used to extract the full-field dynamic strain on a wind turbine assembly subject to arbitrary loading conditions. A three-bladed wind turbine having 2.3-m long blades was placed in a semi-built-in boundary condition using a hub, a machining chuck, and a steel block. For three different test cases, the turbine was excited using (1) pluck testing, (2) random impacts on blades with three impact hammers, and (3) random excitation by a mechanical shaker. The response of the structure to the excitations was measured using three-dimensional point tracking. A pair of high-speed cameras was used to measure displacement of optical targets on the structure when the blades were vibrating. The measured displacements at discrete locations were expanded and applied to the finite element model of the structure to extract the full-field dynamic strain. The results of the paper show an excellent correlation between the strain predicted using the proposed approach and the strain measured with strain-gages for each of the three loading conditions. The approach used in this paper to predict the strain showed higher accuracy than the digital image correlation technique. The new expansion approach is able to extract dynamic strain all over the entire structure, even inside the structure beyond the line of sight of the measurement system. Because the method is based on a non-contacting measurement approach, it can be readily applied to a variety of structures having different boundary and operating conditions, including rotating blades.

  2. 3D touchable holographic light-field display.

    PubMed

    Yamaguchi, Masahiro; Higashida, Ryo

    2016-01-20

    We propose a new type of 3D user interface: interaction with a light field reproduced by a 3D display. The 3D display used in this work reproduces a 3D light field, and a real image can be reproduced in midair between the display and the user. When using a finger to touch the real image, the light field from the display will scatter. Then, the 3D touch sensing is realized by detecting the scattered light by a color camera. In the experiment, the light-field display is constructed with a holographic screen and a projector; thus, a preliminary implementation of a 3D touch is demonstrated.

  3. Fast and slow radiation-driven wind solutions using ZEUS-3D

    NASA Astrophysics Data System (ADS)

    Araya, I.; Curé, M.; ud-Doula, A.; Santillán, A.

    2014-10-01

    Currently, the theory of radiation-driven winds of massive stars possess three known solutions for the velocity and density profiles of the stellar winds, namely: the fast, Ω -slow and δ -slow solutions. In order to confirm their stability we use a time-dependent numerical hydrodynamic code called ZEUS-3D, and then we compare their results with the stationary solutions from our numerical hydrodynamic code. ZEUS-3D needs an initial trial solution to start to integrate, for this we use the stationary solution (from our code) or a β-law for the velocity field. In both cases we obtain the same results. Fast and both slow stationary solutions are attained in ZEUS-3D and are all stable. Furthermore, there is a very good agreement with the velocity and density fields from ZEUS-3D and our code, having differences between the terminal velocities lower than 3%. In addition, we found that ZEUS-3D is very sensitive to the boundary conditions (base density and velocity profile), in some cases we obtain kinks in the velocity profiles, similar to the ones obtained by Madura et al. (2007) for stars with high rotation. Such kinks are most likely the result of the wind being mass overloaded, but further investigation is needed to understand its nature better. Currently, we are exploring the effects of small perturbation at the base of the wind in order to study possible transitions or oscillations between δ-slow and fast solutions.

  4. Comparative visual analysis of 3D urban wind simulations

    NASA Astrophysics Data System (ADS)

    Röber, Niklas; Salim, Mohamed; Grawe, David; Leitl, Bernd; Böttinger, Michael; Schlünzen, Heinke

    2016-04-01

    Climate simulations are conducted in large quantity for a variety of different applications. Many of these simulations focus on global developments and study the Earth's climate system using a coupled atmosphere ocean model. Other simulations are performed on much smaller regional scales, to study very small fine grained climatic effects. These microscale climate simulations pose similar, yet also different, challenges for the visualization and the analysis of the simulation data. Modern interactive visualization and data analysis techniques are very powerful tools to assist the researcher in answering and communicating complex research questions. This presentation discusses comparative visualization for several different wind simulations, which were created using the microscale climate model MITRAS. The simulations differ in wind direction and speed, but are all centered on the same simulation domain: An area of Hamburg-Wilhelmsburg that hosted the IGA/IBA exhibition in 2013. The experiments contain a scenario case to analyze the effects of single buildings, as well as examine the impact of the Coriolis force within the simulation. The scenario case is additionally compared with real measurements from a wind tunnel experiment to ascertain the accuracy of the simulation and the model itself. We also compare different approaches for tree modeling and evaluate the stability of the model. In this presentation, we describe not only our workflow to efficiently and effectively visualize microscale climate simulation data using common 3D visualization and data analysis techniques, but also discuss how to compare variations of a simulation and how to highlight the subtle differences in between them. For the visualizations we use a range of different 3D tools that feature techniques for statistical data analysis, data selection, as well as linking and brushing.

  5. 3D-PTV around Operational Wind Turbines

    NASA Astrophysics Data System (ADS)

    Brownstein, Ian; Dabiri, John

    2016-11-01

    Laboratory studies and numerical simulations of wind turbines are typically constrained in how they can inform operational turbine behavior. Laboratory experiments are usually unable to match both pertinent parameters of full-scale wind turbines, the Reynolds number (Re) and tip speed ratio, using scaled-down models. Additionally, numerical simulations of the flow around wind turbines are constrained by the large domain size and high Re that need to be simulated. When these simulations are preformed, turbine geometry is typically simplified resulting in flow structures near the rotor not being well resolved. In order to bypass these limitations, a quantitative flow visualization method was developed to take in situ measurements of the flow around wind turbines at the Field Laboratory for Optimized Wind Energy (FLOWE) in Lancaster, CA. The apparatus constructed was able to seed an approximately 9m x 9m x 5m volume in the wake of the turbine using artificial snow. Quantitative measurements were obtained by tracking the evolution of the artificial snow using a four camera setup. The methodology for calibrating and collecting data, as well as preliminary results detailing the flow around a 2kW vertical-axis wind turbine (VAWT), will be presented.

  6. 3D Simulations of Helmet Streamer Dynamics and Implications for the Slow Solar Wind

    NASA Astrophysics Data System (ADS)

    Higginson, Aleida K.; Antiochos, Spiro K.; DeVore, C. R.; Zurbuchen, Thomas H.

    2015-04-01

    The source of the slow solar wind at the Sun is still an issue of intense debate in solar and heliospheric physics. Because the majority of the solar wind observed at Earth is slow wind, understanding its origin is essential for understanding and predicting Earth’s space weather environment. In-situ and remote observations show that, when compared to the fast wind, the slow solar wind corresponds to higher freeze-in temperatures, as indicated by charge-state ratios, and more corona-like elemental abundance ratios. These results indicate that the most likely source for the slow wind is the hot plasma in the closed-field corona, but the release mechanism(s) for the wind from the closed-field regions is far from understood. We perform fully dynamic, 3D MHD simulations in order to the study the opening and closing of the Sun’s magnetic field that leads to the escape of the slow solar wind. In particular, we calculate the dynamics of helmet streamers that are driven by photospheric motions such as supergranular flows. We determine in detail the opening and closing of coronal flux, and discuss the implications of our results for theories of slow wind origin, especially the S-Web model. We also determine observational signatures for the upcoming inner heliosphere missions Solar Orbiter and Solar Probe Plus.This work was supported by the NASA SR&T and TR&T Programs.

  7. Light field display and 3D image reconstruction

    NASA Astrophysics Data System (ADS)

    Iwane, Toru

    2016-06-01

    Light field optics and its applications become rather popular in these days. With light field optics or light field thesis, real 3D space can be described in 2D plane as 4D data, which we call as light field data. This process can be divided in two procedures. First, real3D scene is optically reduced with imaging lens. Second, this optically reduced 3D image is encoded into light field data. In later procedure we can say that 3D information is encoded onto a plane as 2D data by lens array plate. This transformation is reversible and acquired light field data can be decoded again into 3D image with the arrayed lens plate. "Refocusing" (focusing image on your favorite point after taking a picture), light-field camera's most popular function, is some kind of sectioning process from encoded 3D data (light field data) to 2D image. In this paper at first I show our actual light field camera and our 3D display using acquired and computer-simulated light field data, on which real 3D image is reconstructed. In second I explain our data processing method whose arithmetic operation is performed not in Fourier domain but in real domain. Then our 3D display system is characterized by a few features; reconstructed image is of finer resolutions than density of arrayed lenses and it is not necessary to adjust lens array plate to flat display on which light field data is displayed.

  8. A 3-D aerodynamic method for the analysis of isolated horizontal-axis wind turbines

    SciTech Connect

    Ammara, I.; Masson, C.; Paraschivoiu, I.

    1997-12-31

    In most existing performance-analysis methods, wind turbines are considered isolated so that interference effects caused by other rotors or by the site topography are neglected. The main objective of this paper is to propose a practical 3-D method suitable for the study of these effects, in order to optimize the arrangement and the positioning of Horizontal-Axis Wind Turbines (HAWTs) in a wind farm. In the proposed methodology, the flow field around isolated HAWTs is predicted by solving the 3-D, time-averaged, steady-state, incompressible, Navier-Stokes equations in which the turbines are represented by distributions of momentum sources. The resulting governing equations are solved using a Control-Volume Finite Element Method (CVFEM). The fundamental aspects related to the development of a practical 3-D method are discussed in this paper, with an emphasis on some of the challenges that arose during its implementation. The current implementation is limited to the analysis of isolated HAWTs. Preliminary results have indicated that, the proposed 3-D method reaches the same level of accuracy, in terms of performance predictions, that the previously developed 2-D axisymmetric model and the well-known momentum-strip theory, while still using reasonable computers resources. It can be considered as a useful tool for the design of HAWTs. Its main advantages, however, are its intrinsic capacity to predict the details of the flow in the wake, and its capabilities of modelling arbitrary wind-turbine arrangements and including ground effects.

  9. Recent US Activities Toward Development of a Global Tropospheric 3D Wind Profiling System

    NASA Astrophysics Data System (ADS)

    Gentry, B. M.; Atlas, R.; Baker, W.; Emmitt, G. D.; Hardesty, R. M.; Kakar, R. K.; Kavaya, M. J.; Mango, S.; Miller, K.; Riishojgaard, L. P.

    2008-12-01

    The wind field plays a unique dynamical role in forcing the mass field to adjust to it at all scales in the tropics, and at small scales in the extra-tropics. Because of this unique role, knowledge of the wind field is required to accurately specify the global initial conditions for numerical weather forecasting. In addition to improving numerical weather prediction, there is also a need for improved accuracy of wind fields to assess long term sensitivity of the general circulation to climate change and to improve horizontal and vertical transport estimates of important atmospheric constituents. In spite of the significance, the 3-D structure of the wind field remains largely unobserved on a global scale. A new satellite mission to accurately measure the global wind field would fill this important gap in the Global Observing System. Space-based Doppler wind lidar has been identified as the key technology necessary to meet the global wind profiling requirement. The 2007 NRC Decadal Survey for Earth Science lists a Global Tropospheric 3-D Wind mission as one of the 15 priority missions recommended for NASA in the next decade. The NRC survey recommended a two phase approach to achieving an operational global wind measurement capability. The first recommended step is for NASA to develop the technology and fly a pre-operational mission to demonstrate the technology and measurement concept and establish the performance standards for an operational wind mission. Phase two would be to develop and fly an operational wind system in the 2025 timeframe. The technology approach recommended is a hybrid Doppler wind lidar (HDWL). The HDWL takes advantage of the complementary capabilities of two Doppler lidar technologies, a coherent Doppler lidar sensing winds from the aerosol backscattered laser signal at a wavelength of 2 microns and a direct detection Doppler lidar sensing winds from the molecular backscattered laser signal at 355 nm. The direct detection Doppler system

  10. 3D Solar Wind Structure Features Characterizing the Rise of Cycle 24

    NASA Astrophysics Data System (ADS)

    Luhmann, J. G.; Ellenburg, M. A.; Riley, P.; Lee, C. O.; Arge, C. N.; Jian, L.; Russell, C. T.; Simunac, K.; Galvin, A. B.; Petrie, G. J.

    2011-12-01

    Since the launch of the STEREO mission in 2006, there has been renewed interest in the 3D structure of the solar wind, spurred in part by the unusual cycle 23 solar minimum and current solar cycle rise. Of particular significance for this subject has been the ubiquitous occurrence of low latitude coronal holes and coronal pseudo-streamers. These coupled features have been common both because of the relative strength of high order spherical harmonic content of the global coronal field, and the weakness of the field compared to the previous two well-observed cycles. We consider the effects of the low latitude coronal holes and pseudo-streamers on the near-ecliptic solar wind and interplanetary field. In particular, we illustrate how the now common passage of streams with low latitude sources and pseudo-streamer boundaries is changing our traditional perceptions of local solar wind structures.

  11. Natural 3D content on glasses-free light-field 3D cinema

    NASA Astrophysics Data System (ADS)

    Balogh, Tibor; Nagy, Zsolt; Kovács, Péter Tamás.; Adhikarla, Vamsi K.

    2013-03-01

    This paper presents a complete framework for capturing, processing and displaying the free viewpoint video on a large scale immersive light-field display. We present a combined hardware-software solution to visualize free viewpoint 3D video on a cinema-sized screen. The new glasses-free 3D projection technology can support larger audience than the existing autostereoscopic displays. We introduce and describe our new display system including optical and mechanical design considerations, the capturing system and render cluster for producing the 3D content, and the various software modules driving the system. The indigenous display is first of its kind, equipped with front-projection light-field HoloVizio technology, controlling up to 63 MP. It has all the advantages of previous light-field displays and in addition, allows a more flexible arrangement with a larger screen size, matching cinema or meeting room geometries, yet simpler to set-up. The software system makes it possible to show 3D applications in real-time, besides the natural content captured from dense camera arrangements as well as from sparse cameras covering a wider baseline. Our software system on the GPU accelerated render cluster, can also visualize pre-recorded Multi-view Video plus Depth (MVD4) videos on this light-field glasses-free cinema system, interpolating and extrapolating missing views.

  12. 3D radiative transfer in colliding wind binaries: Application of the SimpleX algorithm to 3D SPH simulations

    NASA Astrophysics Data System (ADS)

    Madura, Thomas; Clementel, Nicola; Kruip, Chael; Icke, Vincent; Gull, Theodore

    2014-09-01

    We present the first results of full 3D radiative transfer simulations of the colliding stellar winds in a massive binary system. We accomplish this by applying the SIMPLEX algorithm for 3D radiative transfer on an unstructured Delaunay grid to recent 3D smoothed particle hydrodynamics (SPH) simulations of the colliding winds in the binary system η Carinae. We use SIMPLEX to obtain detailed ionization fractions of hydrogen and helium, in 3D, at the resolution of the original SPH simulations. We show how the SIMPLEX simulations can be used to generate synthetic spectral data cubes for comparison to data obtained with the Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph as part of a multi-cycle program to map changes in η Car's extended interacting wind structures across one binary cycle. Comparison of the HST observations to the SIMPLEX models can help lead to more accurate constraints on the orbital, stellar, and wind parameters of the η Car system, such as the primary's mass-loss rate and the companion's temperature and luminosity. While we initially focus specifically on the η Car binary, the numerical methods employed can be applied to numerous other colliding wind (WR140, WR137, WR19) and dusty 'pinwheel' (WR104, WR98a) binary systems. One of the biggest remaining mysteries is how dust can form and survive in such systems that contain a hot, luminous O star. Coupled with 3D hydrodynamical simulations, SIMPLEX simulations have the potential to help determine the regions where dust can form and survive in these unique objects.

  13. 3-D MHD disk wind simulations of protostellar jets

    NASA Astrophysics Data System (ADS)

    Staff, Jan E.; Koning, Nico; Ouyed, Rachid; Tanaka, Kei; Tan, Jonathan C.

    2016-01-01

    We present the results of large scale, three-dimensional magnetohydrodynamics simulations of disk winds for different initial magnetic field configurations. The jets are followed from the source to distances, which are resolvable by HST and ALMA observations. Our simulations show that jets are heated along their length by many shocks. The mass of the protostar is a free parameter that can be inserted in the post processing of the data, and we apply the simulations to both low mass and high mass protostars. For the latter we also compute the expected diagnostics when the outflow is photoionized by the protostar. We compute the emission lines that are produced, and find excellent agreement with observations. For a one solar mass protostar, we find the jet width to be between 20 and 30 au while the maximum velocities perpendicular to the jet are found to be 100 km s-1. The initially less open magnetic field configuration simulations result in a wider, two-component jet; a cylindrically shaped outer jet surrounding a narrow and much faster, inner jet. For the initially most open magnetic field configuration the kink mode creates a narrow corkscrew-like jet without a clear Keplerian rotation profile and even regions where we observe rotation opposite to the disk (counter-rotating). This is not seen in the less open field configurations.

  14. 3D printing meets computational astrophysics: deciphering the structure of η Carinae's inner colliding winds

    NASA Astrophysics Data System (ADS)

    Madura, T. I.; Clementel, N.; Gull, T. R.; Kruip, C. J. H.; Paardekooper, J.-P.

    2015-06-01

    We present the first 3D prints of output from a supercomputer simulation of a complex astrophysical system, the colliding stellar winds in the massive (≳120 M⊙), highly eccentric (e ˜ 0.9) binary star system η Carinae. We demonstrate the methodology used to incorporate 3D interactive figures into a PDF (Portable Document Format) journal publication and the benefits of using 3D visualization and 3D printing as tools to analyse data from multidimensional numerical simulations. Using a consumer-grade 3D printer (MakerBot Replicator 2X), we successfully printed 3D smoothed particle hydrodynamics simulations of η Carinae's inner (r ˜ 110 au) wind-wind collision interface at multiple orbital phases. The 3D prints and visualizations reveal important, previously unknown `finger-like' structures at orbital phases shortly after periastron (φ ˜ 1.045) that protrude radially outwards from the spiral wind-wind collision region. We speculate that these fingers are related to instabilities (e.g. thin-shell, Rayleigh-Taylor) that arise at the interface between the radiatively cooled layer of dense post-shock primary-star wind and the fast (3000 km s-1), adiabatic post-shock companion-star wind. The success of our work and easy identification of previously unrecognized physical features highlight the important role 3D printing and interactive graphics can play in the visualization and understanding of complex 3D time-dependent numerical simulations of astrophysical phenomena.

  15. Wide Area Wind Field Monitoring Status & Results

    SciTech Connect

    Alan Marchant; Jed Simmons

    2011-09-30

    Volume-scanning elastic has been investigated as a means to derive 3D dynamic wind fields for characterization and monitoring of wind energy sites. An eye-safe volume-scanning lidar system was adapted for volume imaging of aerosol concentrations out to a range of 300m. Reformatting of the lidar data as dynamic volume images was successfully demonstrated. A practical method for deriving 3D wind fields from dynamic volume imagery was identified and demonstrated. However, the natural phenomenology was found to provide insufficient aerosol features for reliable wind sensing. The results of this study may be applicable to wind field measurement using injected aerosol tracers.

  16. A global 3-D MHD model of the solar wind with Alfven waves

    NASA Technical Reports Server (NTRS)

    Usmanov, A. V.

    1995-01-01

    A fully three-dimensional solar wind model that incorporates momentum and heat addition from Alfven waves is developed. The proposed model upgrades the previous one by considering self-consistently the total system consisting of Alfven waves propagating outward from the Sun and the mean polytropic solar wind flow. The simulation region extends from the coronal base (1 R(sub s) out to beyond 1 AU. The fully 3-D MHD equations written in spherical coordinates are solved in the frame of reference corotating with the Sun. At the inner boundary, the photospheric magnetic field observations are taken as boundary condition and wave energy influx is prescribed to be proportional to the magnetic field strength. The results of the model application for several time intervals are presented.

  17. Imaging 3D strain field monitoring during hydraulic fracturing processes

    NASA Astrophysics Data System (ADS)

    Chen, Rongzhang; Zaghloul, Mohamed A. S.; Yan, Aidong; Li, Shuo; Lu, Guanyi; Ames, Brandon C.; Zolfaghari, Navid; Bunger, Andrew P.; Li, Ming-Jun; Chen, Kevin P.

    2016-05-01

    In this paper, we present a distributed fiber optic sensing scheme to study 3D strain fields inside concrete cubes during hydraulic fracturing process. Optical fibers embedded in concrete were used to monitor 3D strain field build-up with external hydraulic pressures. High spatial resolution strain fields were interrogated by the in-fiber Rayleigh backscattering with 1-cm spatial resolution using optical frequency domain reflectometry. The fiber optics sensor scheme presented in this paper provides scientists and engineers a unique laboratory tool to understand the hydraulic fracturing processes in various rock formations and its impacts to environments.

  18. 3D quantum gravity and effective noncommutative quantum field theory.

    PubMed

    Freidel, Laurent; Livine, Etera R

    2006-06-09

    We show that the effective dynamics of matter fields coupled to 3D quantum gravity is described after integration over the gravitational degrees of freedom by a braided noncommutative quantum field theory symmetric under a kappa deformation of the Poincaré group.

  19. Effects of 3D Virtual Simulators in the Introductory Wind Energy Course: A Tool for Teaching Engineering Concepts

    SciTech Connect

    Do, Phuong T.; Moreland, John R.; Delgado, Catherine; Wilson, Kristina; Wang, Xiuling; Zhou, Chenn; Ice, Phil

    2013-01-01

    Our research provides an innovative solution for optimizing learning effectiveness and improving postsecondary education through the development of virtual simulators that can be easily used and integrated into existing wind energy curriculum. Two 3D virtual simulators are developed in our laboratory for use in an immersive 3D virtual reality (VR) system or for 3D display on a 2D screen. Our goal is to apply these prototypical simulators to train postsecondary students and professionals in wind energy education; and to offer experiential learning opportunities in 3D modeling, simulation, and visualization. The issue of transferring learned concepts to practical applications is a widespread problem in postsecondary education. Related to this issue is a critical demand to educate and train a generation of professionals for the wind energy industry. With initiatives such as the U.S. Department of Energy's “20% Wind Energy by 2030” outlining an exponential increase of wind energy capacity over the coming years, revolutionary educational reform is needed to meet the demand for education in the field of wind energy. These developments and implementation of Virtual Simulators and accompanying curriculum will propel national reforms, meeting the needs of the wind energy industrial movement and addressing broader educational issues that affect a number of disciplines.

  20. Effects of 3D Virtual Simulators in the Introductory Wind Energy Course: A Tool for Teaching Engineering Concepts

    DOE PAGES

    Do, Phuong T.; Moreland, John R.; Delgado, Catherine; ...

    2013-01-01

    Our research provides an innovative solution for optimizing learning effectiveness and improving postsecondary education through the development of virtual simulators that can be easily used and integrated into existing wind energy curriculum. Two 3D virtual simulators are developed in our laboratory for use in an immersive 3D virtual reality (VR) system or for 3D display on a 2D screen. Our goal is to apply these prototypical simulators to train postsecondary students and professionals in wind energy education; and to offer experiential learning opportunities in 3D modeling, simulation, and visualization. The issue of transferring learned concepts to practical applications is amore » widespread problem in postsecondary education. Related to this issue is a critical demand to educate and train a generation of professionals for the wind energy industry. With initiatives such as the U.S. Department of Energy's “20% Wind Energy by 2030” outlining an exponential increase of wind energy capacity over the coming years, revolutionary educational reform is needed to meet the demand for education in the field of wind energy. These developments and implementation of Virtual Simulators and accompanying curriculum will propel national reforms, meeting the needs of the wind energy industrial movement and addressing broader educational issues that affect a number of disciplines.« less

  1. Advances toward field application of 3D hydraulic tomography

    NASA Astrophysics Data System (ADS)

    Cardiff, M. A.; Barrash, W.; Kitanidis, P. K.

    2011-12-01

    Hydraulic tomography (HT) is a technique that shows great potential for aquifer characterization and one that holds the promise of producing 3D hydraulic property distributions, given suitable equipment. First suggested over 15 years ago, HT assimilates distributed aquifer pressure (head) response data collected during a series of multiple pumping tests to produce estimates of aquifer property variability. Unlike traditional curve-matching analyses, which assume homogeneity or "effective" parameters within the radius of influence of a hydrologic test, HT analysis relies on numerical models with detailed heterogeneity in order to invert for the highly resolved 3D parameter distribution that jointly fits all data. Several numerical and laboratory investigations of characterization using HT have shown that property distributions can be accurately estimated between observation locations when experiments are correctly designed - a property not always shared by other, simpler 1D characterization approaches such as partially-penetrating slug tests. HT may represent one of the best methods available for obtaining detailed 3D aquifer property descriptions, especially in deep or "hard" aquifer materials, where direct-push methods may not be feasible. However, to date HT has not yet been widely adopted at contaminated field sites. We believe that current perceived impediments to HT adoption center around four key issues: 1) A paucity in the scientific literature of proven, cross-validated 3D field applications 2) A lack of guidelines and best practices for performing field 3D HT experiments; 3) Practical difficulty and time commitment associated with the installation of a large number of high-accuracy sampling locations, and the running of a large number of pumping tests; and 4) Computational difficulty associated with solving large-scale inverse problems for parameter identification. In this talk, we present current results in 3D HT research that addresses these four issues

  2. Wind Turbine Wake Characterization from Temporally Disjunct 3-D Measurements

    SciTech Connect

    Doubrawa, Paula; Barthelmie, Rebecca J.; Wang, Hui; Pryor, S. C.; Churchfield, Matthew

    2016-11-01

    Scanning LiDARs can be used to obtain three-dimensional wind measurements in and beyond the atmospheric surface layer. In this work, metrics characterizing wind turbine wakes are derived from LiDAR observations and from large-eddy simulation (LES) data, which are used to recreate the LiDAR scanning geometry. The metrics are calculated for two-dimensional planes in the vertical and cross-stream directions at discrete distances downstream of a turbine under single-wake conditions. The simulation data are used to estimate the uncertainty when mean wake characteristics are quantified from scanning LiDAR measurements, which are temporally disjunct due to the time that the instrument takes to probe a large volume of air. Based on LES output, we determine that wind speeds sampled with the synthetic LiDAR are within 10% of the actual mean values and that the disjunct nature of the scan does not compromise the spatial variation of wind speeds within the planes. We propose scanning geometry density and coverage indices, which quantify the spatial distribution of the sampled points in the area of interest and are valuable to design LiDAR measurement campaigns for wake characterization. We find that scanning geometry coverage is important for estimates of the wake center, orientation and length scales, while density is more important when seeking to characterize the velocity deficit distribution.

  3. Wind turbine wake characterization from temporally disjunct 3-D measurements

    SciTech Connect

    Doubrawa, Paula; Barthelmie, Rebecca J.; Wang, Hui; Pryor, S. C.; Churchfield, Matthew

    2016-11-10

    Scanning LiDARs can be used to obtain three-dimensional wind measurements in and beyond the atmospheric surface layer. In this work, metrics characterizing wind turbine wakes are derived from LiDAR observations and from large-eddy simulation (LES) data, which are used to recreate the LiDAR scanning geometry. The metrics are calculated for two-dimensional planes in the vertical and cross-stream directions at discrete distances downstream of a turbine under single-wake conditions. The simulation data are used to estimate the uncertainty when mean wake characteristics are quantified from scanning LiDAR measurements, which are temporally disjunct due to the time that the instrument takes to probe a large volume of air. Based on LES output, we determine that wind speeds sampled with the synthetic LiDAR are within 10% of the actual mean values and that the disjunct nature of the scan does not compromise the spatial variation of wind speeds within the planes. We propose scanning geometry density and coverage indices, which quantify the spatial distribution of the sampled points in the area of interest and are valuable to design LiDAR measurement campaigns for wake characterization. Lastly, we find that scanning geometry coverage is important for estimates of the wake center, orientation and length scales, while density is more important when seeking to characterize the velocity deficit distribution.

  4. Wind turbine wake characterization from temporally disjunct 3-D measurements

    DOE PAGES

    Doubrawa, Paula; Barthelmie, Rebecca J.; Wang, Hui; ...

    2016-11-10

    Scanning LiDARs can be used to obtain three-dimensional wind measurements in and beyond the atmospheric surface layer. In this work, metrics characterizing wind turbine wakes are derived from LiDAR observations and from large-eddy simulation (LES) data, which are used to recreate the LiDAR scanning geometry. The metrics are calculated for two-dimensional planes in the vertical and cross-stream directions at discrete distances downstream of a turbine under single-wake conditions. The simulation data are used to estimate the uncertainty when mean wake characteristics are quantified from scanning LiDAR measurements, which are temporally disjunct due to the time that the instrument takes tomore » probe a large volume of air. Based on LES output, we determine that wind speeds sampled with the synthetic LiDAR are within 10% of the actual mean values and that the disjunct nature of the scan does not compromise the spatial variation of wind speeds within the planes. We propose scanning geometry density and coverage indices, which quantify the spatial distribution of the sampled points in the area of interest and are valuable to design LiDAR measurement campaigns for wake characterization. Lastly, we find that scanning geometry coverage is important for estimates of the wake center, orientation and length scales, while density is more important when seeking to characterize the velocity deficit distribution.« less

  5. Wind forcing of upland lake hydrodynamics: implementation and validation of a 3D numerical model

    NASA Astrophysics Data System (ADS)

    Morales, L.; French, J.; Burningham, H.; Evans, C.; Battarbee, R.

    2010-12-01

    Upland lakes act as important archives of environmental change, yet inferences based on the analysis of sediment cores are frequently compromised by an incomplete understanding of the hydrodynamic processes controlling the distribution and completeness of lake sediment sequences and their linkages to wider environmental factors. Many upland lakes are characterized by complex vertical and horizontal circulation patterns induced by the action of wind on the water surface. Wind forcing is important not only for the resuspension of bottom sediments in shallow marginal areas, but may also control the broader distribution of sediment accumulation. The work presented here represents the first stage of a project aimed at elucidating the linkages between wind forcing and the distribution of bottom sediments in upland lakes and the extent to which simple 'sediment focusing' models provide an adequate basis for predicting optimal locations for the acquisition of core samples for palaeolimnological analysis. As a first step, a 3D numerical hydrodynamic model is implemented for Llyn Conwy, a small oligotrophic upland lake in North Wales, UK. This utilises the community ocean model, FVCOM, that solves the Navier-Stokes equations in 3D on an unstructured triangular mesh using the finite volume method. A new graphical user interface has been developed for FVCOM to facilitate pre- and post-processing of lake modelling problems. At Llyn Conwy, the model is forced using local meteorological data and validated against vertical temperature profiles recorded by a long-term buoy deployment and short-term observations of vertical current structure measured using an upward-looking acoustic doppler profiler and surface circulation obtained from GPS drifters. Challenges in the application of FVCOM to a small lake include the design of a mesh that ensures numerical stability whilst resolving a complex bathymetry, and the need for careful treatment of model 'spin-up'. Once calibrated, the

  6. Age Dependence of Wind Properties for Solar-type Stars: A 3D Study

    NASA Astrophysics Data System (ADS)

    Réville, Victor; Folsom, Colin P.; Strugarek, Antoine; Brun, Allan Sacha

    2016-12-01

    Young and rapidly rotating stars are known for intense, dynamo-generated magnetic fields. Spectropolarimetric observations of those stars in precisely aged clusters are key input for gyrochronology and magnetochronology. We use Zeeman Doppler imaging maps of several young K-type stars of similar mass and radius but with various ages and rotational periods to perform three-dimensional (3D) numerical MHD simulations of their coronae and follow the evolution of their magnetic properties with age. Those simulations yield the coronal structure as well as the instant torque exerted by the magnetized, rotating wind on the star. As stars get older, we find that the angular momentum loss decreases with {{{Ω }}}\\star 3, which is the reason for the convergence on the Skumanich law. For the youngest stars of our sample, the angular momentum loss shows signs of saturation around 8{{{Ω }}}⊙ , which is a common value used in spin evolution models for K-type stars. We compare these results to semianalytical models and existing braking laws. We observe a complex wind-speed distribution for the youngest stars with slow, intermediate, and fast wind components, which are the result of interaction with intense and nonaxisymmetric magnetic fields. Consequently, in our simulations, the stellar wind structure in the equatorial plane of young stars varies significantly from a solar configuration, delivering insight about the past of the solar system interplanetary medium.

  7. 3-D numerical simulations of eruption clouds: Effects of the environmental wind on the turbulent mixing

    NASA Astrophysics Data System (ADS)

    Suzuki, Y. J.; Koyaguchi, T.

    2011-12-01

    During an explosive volcanic eruption, a mixture of volcanic gas and solid pyroclasts are ejected from a volcanic vent with a high temperature. As it rises, the mixture entrains ambient air owing to turbulent mixing. The entrained air expands by heating from the hot pyroclasts, and the eruption cloud (i.e., the ejected material plus the entrained air) rises as a buoyant plume. Because the plume height is principally determined by the balance between the thermal energy ejected at the vent and the work done in transporting the ejected material plus entrained air through the atmospheric stratification, it is controlled by the efficiency of turbulent mixing; as the amount of entrained air increases, the plume height decreases. In the 1-D models of eruption column (e.g., Woods, 1988), the plume height is calculated on the assumption that the mean inflow velocity across the edge of turbulent jet and/or plume is proportional to the mean vertical velocity (Morton et al., 1956). Experimental studies suggest that the proportionality constant (i.e., entrainment coefficient, k), which represents the efficiency of turbulent mixing, is about 0.10 for pure plumes when there is no wind. When an environmental wind is present, however, the interaction between a buoyant plume and the wind may enhance the entrainment of air and can significantly decrease the plume height (Bursik, 2001). In order to investigate the effects of wind on the vortical structures and the efficiency of turbulent mixing in an eruption cloud, we have carried out 3-D numerical simulations of eruption column which is ejected in a wind field. The simulation results indicate that a buoyant plume vertically rises as a "strong plume" (e.g., Bonadonna et al., 2003) when the wind velocity is low: the cloud reaches the neutral buoyancy level and overshoots until the upward momentum is exhausted. In this case, the plume height is consistent with prediction by the 1-D model with k~0.10. When the wind velocity is high, on

  8. 3D temperature field reconstruction using ultrasound sensing system

    NASA Astrophysics Data System (ADS)

    Liu, Yuqian; Ma, Tong; Cao, Chengyu; Wang, Xingwei

    2016-04-01

    3D temperature field reconstruction is of practical interest to the power, transportation and aviation industries and it also opens up opportunities for real time control or optimization of high temperature fluid or combustion process. In our paper, a new distributed optical fiber sensing system consisting of a series of elements will be used to generate and receive acoustic signals. This system is the first active temperature field sensing system that features the advantages of the optical fiber sensors (distributed sensing capability) and the acoustic sensors (non-contact measurement). Signals along multiple paths will be measured simultaneously enabled by a code division multiple access (CDMA) technique. Then a proposed Gaussian Radial Basis Functions (GRBF)-based approach can approximate the temperature field as a finite summation of space-dependent basis functions and time-dependent coefficients. The travel time of the acoustic signals depends on the temperature of the media. On this basis, the Gaussian functions are integrated along a number of paths which are determined by the number and distribution of sensors. The inversion problem to estimate the unknown parameters of the Gaussian functions can be solved with the measured times-of-flight (ToF) of acoustic waves and the length of propagation paths using the recursive least square method (RLS). The simulation results show an approximation error less than 2% in 2D and 5% in 3D respectively. It demonstrates the availability and efficiency of our proposed 3D temperature field reconstruction mechanism.

  9. 3D hydrodynamical and radiative transfer modeling of η Carinae's colliding winds

    NASA Astrophysics Data System (ADS)

    Madura, T. I.; Clementel, N.; Gull, T. R.; Kruip, C. J. H.; Paardekooper, J.-P.; Icke, V.

    We present results of full 3D hydrodynamical and radiative transfer simulations of the colliding stellar winds in the massive binary system η Carinae. We accomplish this by applying the SimpleX algorithm for 3D radiative transfer on an unstructured Voronoi-Delaunay grid to recent 3D smoothed particle hydrodynamics (SPH) simulations of the binary colliding winds. We use SimpleX to obtain detailed ionization fractions of hydrogen and helium, in 3D, at the resolution of the original SPH simulations. We investigate several computational domain sizes and Luminous Blue Variable primary star mass-loss rates. We furthermore present new methods of visualizing and interacting with output from complex 3D numerical simulations, including 3D interactive graphics and 3D printing. While we initially focus on η Car, the methods employed can be applied to numerous other colliding wind (WR 140, WR 137, WR 19) and dusty `pinwheel' (WR 104, WR 98a) binary systems. Coupled with 3D hydrodynamical simulations, SimpleX simulations have the potential to help determine the regions where various observed time-variable emission and absorption lines form in these unique objects.

  10. Advancing the field of 3D biomaterial printing.

    PubMed

    Jakus, Adam E; Rutz, Alexandra L; Shah, Ramille N

    2016-01-11

    3D biomaterial printing has emerged as a potentially revolutionary technology, promising to transform both research and medical therapeutics. Although there has been recent progress in the field, on-demand fabrication of functional and transplantable tissues and organs is still a distant reality. To advance to this point, there are two major technical challenges that must be overcome. The first is expanding upon the limited variety of available 3D printable biomaterials (biomaterial inks), which currently do not adequately represent the physical, chemical, and biological complexity and diversity of tissues and organs within the human body. Newly developed biomaterial inks and the resulting 3D printed constructs must meet numerous interdependent requirements, including those that lead to optimal printing, structural, and biological outcomes. The second challenge is developing and implementing comprehensive biomaterial ink and printed structure characterization combined with in vitro and in vivo tissue- and organ-specific evaluation. This perspective outlines considerations for addressing these technical hurdles that, once overcome, will facilitate rapid advancement of 3D biomaterial printing as an indispensable tool for both investigating complex tissue and organ morphogenesis and for developing functional devices for a variety of diagnostic and regenerative medicine applications.

  11. 3-D Hybrid Kinetic Modeling of the Interaction Between the Solar Wind and Lunar-like Exospheric Pickup Ions in Case of Oblique/ Quasi-Parallel/Parallel Upstream Magnetic Field

    NASA Technical Reports Server (NTRS)

    Lipatov, A. S.; Farrell, W. M.; Cooper, J. F.; Sittler, E. C., Jr.; Hartle, R. E.

    2015-01-01

    The interactions between the solar wind and Moon-sized objects are determined by a set of the solar wind parameters and plasma environment of the space objects. The orientation of upstream magnetic field is one of the key factors which determines the formation and structure of bow shock wave/Mach cone or Alfven wing near the obstacle. The study of effects of the direction of the upstream magnetic field on lunar-like plasma environment is the main subject of our investigation in this paper. Photoionization, electron-impact ionization and charge exchange are included in our hybrid model. The computational model includes the self-consistent dynamics of the light (hydrogen (+), helium (+)) and heavy (sodium (+)) pickup ions. The lunar interior is considered as a weakly conducting body. Our previous 2013 lunar work, as reported in this journal, found formation of a triple structure of the Mach cone near the Moon in the case of perpendicular upstream magnetic field. Further advances in modeling now reveal the presence of strong wave activity in the upstream solar wind and plasma wake in the cases of quasiparallel and parallel upstream magnetic fields. However, little wave activity is found for the opposite case with a perpendicular upstream magnetic field. The modeling does not show a formation of the Mach cone in the case of theta(Sub B,U) approximately equal to 0 degrees.

  12. 3-D MHD Simulation of Oscillating Field Current Drive

    NASA Astrophysics Data System (ADS)

    Ebrahimi, F.; Prager, S. C.; Wright, J. C.

    2000-10-01

    Oscillating Field Current Drive (OFCD) is a proposed low frequency steady-state current drive technique for the Reversed Field Pinch (RFP). In OFCD toroidal and poloidal oscillating electric fields are applied with 90^circ phase difference to inject magnetic helicity. In the present work, the 3-D nonlinear, resistive MHD code DEBS is used to simulate OFCD in relaxed RFP plasmas. The present simulations are at high Lundquist number S=10^5 and low spect ratio R/a=1.5. The physics issues investigated are the response of background magnetic fluctuations to the oscillating fields, the relative contributions of the tearing mode dynamo and the oscillating fields to the current profile, and the sustainment and control of the steady-state current profile. Initial results with low amplitude oscillating fields show the expected increase in magnetic helicity and current. Results with higher amplitude will also be presented.

  13. Sensitivity of the Earth Magnetosphere to the Solar Wind Activity: 3D Macroparticle Model

    NASA Astrophysics Data System (ADS)

    Baraka, S. M.; Ben Jaffel, L.

    2006-05-01

    A new approach is proposed to study the sensitivity of the Earth Magnetosphere to the variability of the Solar Wind bulk velocity. A numerical particles in cell (PIC) method initially proposed by Buneman (1993) has been adopted and modified to carry out the study. Space was stretched as cubic boxes of dimension 155x105x105 Re filled with 2 million of Solar Wind particles, with Earth is located at 60x52x53 Re. The magnetic field of Earth was hypothetically set to zero, and then switched on. The formation of the magnetospheric cavity and its elongation around the planet was observed to evolve with time until a steady state topology of the system is attained with the classical structure of a magnetosphere. We also found that the cavity is repopulated by clouds of particles from the Solar Wind, producing the current sheet-- a thin plasma sheet that stands at the equatorial plane. The study was carried out with the very basic elements of the interaction processes as described by Maxwell and Lorentz equations. IMF was then included as a steady southward magnetic field. Drift velocity of the Solar Wind was changed to simulate compression/depression of the system. 3-D analysis of the response of the magnetosphere dayside to that variation was studied, and the corresponding relaxation time of the magnetopause interface was measured. In response to the Solar Wind drift velocity imposed drop-off, a ~ 15 Re gap in the incoming Solar Wind plasma appeared moving toward Earth. As soon as the gap hit the initial shock of the steady magnetosphere, a reconnection between the Earth magnetic field and IMF was noticed at the dayside magnetopause when IMF was included. Injection of nightside of the magnetosphere by energetic particles due to magnetic erosion and reconnection is observed. During the expansion phase of the disturbance, the outer boundary of the dayside magnetopause broke up during the absence of the IMF as it responded to the reduction of the ram pressure, whilst

  14. Solar Wind Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Smith, E. J.

    1995-01-01

    The magnetic fields originate as coronal fields that are converted into space by the supersonic, infinitely conducting, solar wind. On average, the sun's rotation causes the field to wind up and form an Archimedes Spiral. However, the field direction changes almost continuously on a variety of scales and the irregular nature of these changes is often interpreted as evidence that the solar wind flow is turbulent.

  15. 3D Hydrodynamical and Radiative Transfer Modeling of Eta Carinae's Colliding Winds

    NASA Astrophysics Data System (ADS)

    Madura, Thomas Ignatius; Clementel, Nicola; Gull, Theodore R.; Kruip, Chael J. H.; Paardekooper, Jan-Pieter; Icke, Vincent

    2015-08-01

    We present the results of full 3D hydrodynamical and radiative transfer simulations of the colliding stellar winds in the massive binary system Eta Carinae (Clementel, Madura, et al. 2014, MNRAS, 443, 2475 and Clementel, Madura, et al. 2015, MNRAS, 447, 2445). We accomplish this by applying the SimpleX algorithm for 3D radiative transfer on an unstructured Voronoi-Delaunay grid to 3D smoothed particle hydrodynamics simulations of the binary colliding winds. We use SimpleX to obtain detailed ionization fractions of hydrogen and helium in 3D. We investigate several computational domain sizes and Luminous Blue Variable primary-star mass-loss rates. We show how the SimpleX simulations can be used to generate synthetic spectral data cubes for comparison to data obtained with the Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph as part of a multi-cycle program to map changes in Eta Carinae's spatially extended interacting wind structures across one binary cycle. Comparison of the HST observations to the SimpleX models can help lead to more accurate constraints on the orbital, stellar, and wind parameters of the Eta Carinae system, such as the LBV primary's mass-loss rate and the companion star's temperature and luminosity. We furthermore present new methods of visualizing and interacting with output from complex 3D numerical simulations, including 3D interactive graphics and 3D printing (Madura et al. 2015, arXiv:1503.00716). While we initially focus specifically on Eta Carinae, the methods employed can be applied to numerous other colliding wind (WR 140, WR 137, WR 19) and dusty ‘pinwheel’ (WR 112, WR 104, WR 98a) binary systems. Coupled with 3D hydrodynamical simulations, SimpleX simulations have the potential to help determine the regions where dust can form and survive in these unique objects.

  16. 3D deformation field throughout the interior of materials.

    SciTech Connect

    Jin, Huiqing; Lu, Wei-Yang

    2013-09-01

    This report contains the one-year feasibility study for our three-year LDRD proposal that is aimed to develop an experimental technique to measure the 3D deformation fields inside a material body. In this feasibility study, we first apply Digital Volume Correlation (DVC) algorithm to pre-existing in-situ Xray Computed Tomography (XCT) image sets with pure rigid body translation. The calculated displacement field has very large random errors and low precision that are unacceptable. Then we enhance these tomography images by setting threshold of the intensity of each slice. DVC algorithm is able to obtain accurate deformation fields from these enhanced image sets and the deformation fields are consistent with the global mechanical loading that is applied to the specimen. Through this study, we prove that the internal markers inside the pre-existing tomography images of aluminum alloy can be enhanced and are suitable for DVC to calculate the deformation field throughout the material body.

  17. Visualizing 3D velocity fields near contour surfaces

    SciTech Connect

    Max, N.; Crawfis, R.; Grant, C.

    1994-03-01

    Vector field rendering is difficult in 3D because the vector icons overlap and hide each other. We propose four different techniques for visualizing vector fields only near surfaces. The first uses motion blurred particles in a thickened region around the surface. The second uses a voxel grid to contain integral curves of the vector field. The third uses many antialiased lines through the surface, and the fourth uses hairs sprouting from the surface and then bending in the direction of the vector field. All the methods use the graphite pipeline, allowing real time rotation and interaction, and the first two methods can animate the texture to move in the flow determined by the velocity field.

  18. 3D Printing Meets Computational Astrophysics: Deciphering the Structure of Eta Carinae’s Colliding Winds Using 3D Prints of Smoothed Particle Hydrodynamics Simulations

    NASA Astrophysics Data System (ADS)

    Madura, Thomas; Gull, Theodore R.; Clementel, Nicola; Paardekooper, Jan-Pieter; Kruip, Chael; Corcoran, Michael F.; Hamaguchi, Kenji; Teodoro, Mairan

    2015-01-01

    We present the first 3D prints of output from a supercomputer simulation of a complex astrophysical system, the colliding stellar winds in the massive (>120 MSun), highly eccentric (e ~ 0.9) binary Eta Carinae. Using a consumer-grade 3D printer (Makerbot Replicator 2X), we successfully printed 3D smoothed particle hydrodynamics simulations of Eta Carinae's inner (r ~110 AU) wind-wind collision interface at multiple orbital phases. These 3D prints reveal important, previously unknown 'finger-like' structures at orbital phases shortly after periastron (φ ~1.045) that protrude radially outward from the spiral wind-wind collision region. We speculate that these fingers are related to instabilities (e.g. Rayleigh-Taylor) that arise at the interface between the radiatively-cooled layer of dense post-shock primary-star wind and the hot, adiabatic post-shock companion-star wind. The success of our work and easy identification of previously unknown physical features highlight the important role 3D printing can play in the visualization and understanding of complex 3D time-dependent numerical simulations of astrophysical phenomena.

  19. Electric fields and field-aligned currents in polar regions of the solar corona: 3-D MHD consideration

    NASA Technical Reports Server (NTRS)

    Pisanko, Yu. V.

    1995-01-01

    The calculation of the solar rotation electro-dynamical effects in the near-the-Sun solar wind seems more convenient from the non-inertial corotating reference frame. This implies some modification of the 3-D MHD equations generally on the base of the General Theory of Relativity. The paper deals with the search of stationary (in corotating non-inertial reference frame) solutions of the modified 3-D MHD equations for the in near-the-Sun high latitude sub-alfvenic solar wind. The solution is obtained requiring electric fields and field-aligned electric currents in the high latitude near-the-Sun solar wind. Various scenario are explored self-consistently via a number of numerical experiments. The analogy with the high latitude Earth's magnetosphere is used for the interpretation of the results. Possible observational manifestations are discussed.

  20. The 3D Flow Field Around an Embedded Planet

    NASA Astrophysics Data System (ADS)

    Fung, Jeffrey; Artymowicz, Pawel; Wu, Yanqin

    2015-10-01

    3D modifications to the well-studied 2D flow topology around an embedded planet have the potential to resolve long-standing problems in planet formation theory. We present a detailed analysis of the 3D isothermal flow field around a 5 Earth-mass planet on a fixed circular orbit, simulated using our graphics processing unit hydrodynamics code PEnGUIn. We find that, overall, the horseshoe region has a columnar structure extending vertically much beyond the Hill sphere of the planet. This columnar structure is only broken for some of the widest horseshoe streamlines, along which high altitude fluid descends rapidly into the planet’s Bondi sphere, performs one horseshoe turn, and exits the Bondi sphere radially in the midplane. A portion of this flow exits the horseshoe region altogether, which we refer to as the “transient” horseshoe flow. The flow continues as it rolls up into a pair of up-down symmetric horizontal vortex lines shed into the wake of the planet. This flow, unique to 3D, affects both planet accretion and migration. It prevents the planet from sustaining a hydrostatic atmosphere due to its intrusion into the Bondi sphere, and leads to a significant corotation torque on the planet, unanticipated by 2D analysis. In the reported simulation, starting with a {{Σ }}˜ {r}-3/2 radial surface density profile, this torque is positive and partially cancels with the negative differential Lindblad torque, resulting in a factor of three slower planet migration rate. Finally, we report 3D effects can be suppressed by a sufficiently large disk viscosity, leading to results similar to 2D.

  1. The performance & flow visualization studies of three-dimensional (3-D) wind turbine blade models

    NASA Astrophysics Data System (ADS)

    Sutrisno, Prajitno, Purnomo, W., Setyawan B.

    2016-06-01

    Recently, studies on the design of 3-D wind turbine blades have a less attention even though 3-D blade products are widely sold. In contrary, advanced studies in 3-D helicopter blade tip have been studied rigorously. Studies in wind turbine blade modeling are mostly assumed that blade spanwise sections behave as independent two-dimensional airfoils, implying that there is no exchange of momentum in the spanwise direction. Moreover, flow visualization experiments are infrequently conducted. Therefore, a modeling study of wind turbine blade with visualization experiment is needed to be improved to obtain a better understanding. The purpose of this study is to investigate the performance of 3-D wind turbine blade models with backward-forward swept and verify the flow patterns using flow visualization. In this research, the blade models are constructed based on the twist and chord distributions following Schmitz's formula. Forward and backward swept are added to the rotating blades. Based on this, the additional swept would enhance or diminish outward flow disturbance or stall development propagation on the spanwise blade surfaces to give better blade design. Some combinations, i. e., b lades with backward swept, provide a better 3-D favorable rotational force of the rotor system. The performance of the 3-D wind turbine system model is measured by a torque meter, employing Prony's braking system. Furthermore, the 3-D flow patterns around the rotating blade models are investigated by applying "tuft-visualization technique", to study the appearance of laminar, separated, and boundary layer flow patterns surrounding the 3-dimentional blade system.

  2. A full field, 3-D velocimeter for microgravity crystallization experiments

    NASA Technical Reports Server (NTRS)

    Brodkey, Robert S.; Russ, Keith M.

    1991-01-01

    The programming and algorithms needed for implementing a full-field, 3-D velocimeter for laminar flow systems and the appropriate hardware to fully implement this ultimate system are discussed. It appears that imaging using a synched pair of video cameras and digitizer boards with synched rails for camera motion will provide a viable solution to the laminar tracking problem. The algorithms given here are simple, which should speed processing. On a heavily loaded VAXstation 3100 the particle identification can take 15 to 30 seconds, with the tracking taking less than one second. It seeems reasonable to assume that four image pairs can thus be acquired and analyzed in under one minute.

  3. 3-D flame temperature field reconstruction with multiobjective neural network

    NASA Astrophysics Data System (ADS)

    Wan, Xiong; Gao, Yiqing; Wang, Yuanmei

    2003-02-01

    A novel 3-D temperature field reconstruction method is proposed in this paper, which is based on multiwavelength thermometry and Hopfield neural network computed tomography. A mathematical model of multi-wavelength thermometry is founded, and a neural network algorithm based on multiobjective optimization is developed. Through computer simulation and comparison with the algebraic reconstruction technique (ART) and the filter back-projection algorithm (FBP), the reconstruction result of the new method is discussed in detail. The study shows that the new method always gives the best reconstruction results. At last, temperature distribution of a section of four peaks candle flame is reconstructed with this novel method.

  4. 3D print of polymer bonded rare-earth magnets, and 3D magnetic field scanning with an end-user 3D printer

    NASA Astrophysics Data System (ADS)

    Huber, C.; Abert, C.; Bruckner, F.; Groenefeld, M.; Muthsam, O.; Schuschnigg, S.; Sirak, K.; Thanhoffer, R.; Teliban, I.; Vogler, C.; Windl, R.; Suess, D.

    2016-10-01

    3D print is a recently developed technique, for single-unit production, and for structures that have been impossible to build previously. The current work presents a method to 3D print polymer bonded isotropic hard magnets with a low-cost, end-user 3D printer. Commercially available isotropic NdFeB powder inside a PA11 matrix is characterized, and prepared for the printing process. An example of a printed magnet with a complex shape that was designed to generate a specific stray field is presented, and compared with finite element simulation solving the macroscopic Maxwell equations. For magnetic characterization, and comparing 3D printed structures with injection molded parts, hysteresis measurements are performed. To measure the stray field outside the magnet, the printer is upgraded to a 3D magnetic flux density measurement system. To skip an elaborate adjusting of the sensor, a simulation is used to calibrate the angles, sensitivity, and the offset of the sensor. With this setup, a measurement resolution of 0.05 mm along the z-axes is achievable. The effectiveness of our calibration method is shown. With our setup, we are able to print polymer bonded magnetic systems with the freedom of having a specific complex shape with locally tailored magnetic properties. The 3D scanning setup is easy to mount, and with our calibration method we are able to get accurate measuring results of the stray field.

  5. 3-D magnetic field calculations for wiggglers using MAGNUS-3D

    SciTech Connect

    Pissanetzky, S.; Tompkins, P.

    1988-01-01

    The recent but steady trend toward increased magnetic and geometric complexity in the design of wigglers and undulators, of which tapered wigglers, hybrid structures, laced electromagnetic wigglers, magnetic cladding, twisters and magic structures are examples, has caused a need for reliable 3-D computer models and a better understanding of the behavior of magnetic systems in three dimensions. The capabilities of the MAGNUS-3D Group of Programs are ideally suited to solve this class of problems and provide insight into 3-D effects. MAGNUS-3D can solve any problem of Magnetostatics involving permanent magnets, linear or nonlinear ferromagnetic materials and electric conductors of any shape in space. The magnetic properties of permanent magnets are described by the complete nonlinear demagnetization curve as provided by the manufacturer, or, at the user's choice, by a simpler approximation involving the coercive force, the residual induction and the direction of magnetization. The ferromagnetic materials are described by a magnetization table and an accurate interpolation relation. An internal library with properties of common industrial steels is available. The conductors are independent of the mesh and are described in terms of conductor elements from an internal library.

  6. Vertical profiles of the 3-D wind velocity retrieved from multiple wind lidars performing triple range-height-indicator scans

    DOE PAGES

    Debnath, Mithu; Iungo, G. Valerio; Ashton, Ryan; ...

    2017-02-06

    Vertical profiles of 3-D wind velocity are retrieved from triple range-height-indicator (RHI) scans performed with multiple simultaneous scanning Doppler wind lidars. This test is part of the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign carried out at the Boulder Atmospheric Observatory. The three wind velocity components are retrieved and then compared with the data acquired through various profiling wind lidars and high-frequency wind data obtained from sonic anemometers installed on a 300 m meteorological tower. The results show that the magnitude of the horizontal wind velocity and the wind direction obtained from the triple RHI scans are generally retrieved with goodmore » accuracy. However, poor accuracy is obtained for the evaluation of the vertical velocity, which is mainly due to its typically smaller magnitude and to the error propagation connected with the data retrieval procedure and accuracy in the experimental setup.« less

  7. Vertical profiles of the 3-D wind velocity retrieved from multiple wind lidars performing triple range-height-indicator scans

    SciTech Connect

    Debnath, Mithu; Iungo, G. Valerio; Ashton, Ryan; Brewer, W. Alan; Choukulkar, Aditya; Delgado, Ruben; Lundquist, Julie K.; Shaw, William J.; Wilczak, James M.; Wolfe, Daniel

    2017-01-01

    Vertical profiles of 3-D wind velocity are retrieved from triple range-height-indicator (RHI) scans performed with multiple simultaneous scanning Doppler wind lidars. This test is part of the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign carried out at the Boulder Atmospheric Observatory. The three wind velocity components are retrieved and then compared with the data acquired through various profiling wind lidars and high-frequency wind data obtained from sonic anemometers installed on a 300 m meteorological tower. The results show that the magnitude of the horizontal wind velocity and the wind direction obtained from the triple RHI scans are generally retrieved with good accuracy. However, poor accuracy is obtained for the evaluation of the vertical velocity, which is mainly due to its typically smaller magnitude and to the error propagation connected with the data retrieval procedure and accuracy in the experimental setup.

  8. Vertical profiles of the 3-D wind velocity retrieved from multiple wind lidars performing triple range-height-indicator scans

    NASA Astrophysics Data System (ADS)

    Debnath, Mithu; Valerio Iungo, G.; Ashton, Ryan; Brewer, W. Alan; Choukulkar, Aditya; Delgado, Ruben; Lundquist, Julie K.; Shaw, William J.; Wilczak, James M.; Wolfe, Daniel

    2017-02-01

    Vertical profiles of 3-D wind velocity are retrieved from triple range-height-indicator (RHI) scans performed with multiple simultaneous scanning Doppler wind lidars. This test is part of the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign carried out at the Boulder Atmospheric Observatory. The three wind velocity components are retrieved and then compared with the data acquired through various profiling wind lidars and high-frequency wind data obtained from sonic anemometers installed on a 300 m meteorological tower. The results show that the magnitude of the horizontal wind velocity and the wind direction obtained from the triple RHI scans are generally retrieved with good accuracy. However, poor accuracy is obtained for the evaluation of the vertical velocity, which is mainly due to its typically smaller magnitude and to the error propagation connected with the data retrieval procedure and accuracy in the experimental setup.

  9. 3D Electromagnetic Particle-in-Cell simulations of the solar wind interaction with lunar magnetic anomalies

    NASA Astrophysics Data System (ADS)

    Deca, J.; Lapenta, G.; Divin, A. V.; Lembege, B.; Markidis, S.

    2013-12-01

    Unlike the Earth and Mercury, our Moon has no global magnetic field and is therefore not shielded from the impinging solar wind by a magnetosphere. However, lunar magnetic field measurements made by the Apollo missions provided direct evidence that the Moon has regions of small-scale crustal magnetic fields, ranging up to a few 100km in scale size with surface magnetic field strengths up to hundreds of nanoTeslas. More recently, the Lunar Prospector spacecraft has provided high-resolution observations allowing to construct magnetic field maps of the entire Moon, confirming the earlier results from Apollo, but also showing that the lunar plasma environment is much richer than earlier believed. Typically the small-scale magnetic fields are non-dipolar and rather tiny compared to the lunar radius and mainly clustered on the far side of the moon. Using iPic3D we present the first 3D fully kinetic and electromagnetic Particle-in-Cell simulations of the solar wind interaction with lunar magnetic anomalies. We study the behaviour of a dipole model with variable surface magnetic field strength under changing solar wind conditions and confirm that lunar crustal magnetic fields may indeed be strong enough to stand off the solar wind and form a mini-magnetosphere, as suggested by MHD and hybrid simulations and spacecraft observations. 3D-PIC simulations reveal to be very helpful to analyze the diversion/braking of the particle flux and the characteristics of the resulting particles accumulation. The particle flux to the surface is significantly reduced at the magnetic anomaly, surrounded by a region of enhanced density due to the magnetic mirror effect. Second, the ability of iPic3D to resolve all plasma components (heavy ions, protons and electrons) allows to discuss in detail the electron physics leading to the highly non-adiabatic interactions expected as well as the implications for solar wind shielding of the lunar surface, depending on the scale size (solar wind protons

  10. Analysis and measurement of the 3D magnetic field in a rotating magnetic field driven FRC

    NASA Astrophysics Data System (ADS)

    Velas, K. M.; Milroy, R. D.

    2012-10-01

    A translatable three-axis probe was installed on TCSU shortly before its shutdown. The probe has 90 windings that simultaneously measure Br, Bθ, and Bz at 30 radial positions. Positioning the probe at multiple axial positions and taking multiple repeatable shots allows for a full r-z map of the magnetic field. Probe measurements are used to calculate the end-shorting torque and the rotating magnetic field (RMF) torque. The torque applied to the plasma is the RMF torque reduced by the shorting torque. An estimate of the plasma resistivity is made based on the steady state balance between the applied torque and the resistive torque. The steady state data from applying a 10 kHz low pass filter used in conjunction with data at the RMF frequency yields a map of the full 3D rotating field structure. Data from even- and odd-parity experiments will be presented. The NIMROD code has been adapted to simulate the TCSU experiment using boundary conditions adjusted to match both even- and odd-parity experimental conditions. A comparison of the n=0 components of the calculated fields to the 3-axis probe measurements shows agreement in the magnetic field structure of the FRC as well as in the jet region.

  11. Exploration 3-D Seismic Field Test/Native Tribes Initiative

    SciTech Connect

    Carroll, Herbert B.; Chen, K.C.; Guo, Genliang; Johnson, W.I.; Reeves,T.K.; Sharma,Bijon

    1999-04-27

    To determine current acquisition procedures and costs and to further the goals of the President's Initiative for Native Tribes, a seismic-survey project is to be conducted on Osage tribal lands. The goals of the program are to demonstrate the capabilities, costs, and effectiveness of 3-D seismic work in a small-operator setting and to determine the economics of such a survey. For these purposes, typical small-scale independent-operator practices are being followed and a shallow target chose in an area with a high concentration of independent operators. The results will be analyzed in detail to determine if there are improvements and/or innovations which can be easily introduced in field-acquisition procedures, in processing, or in data manipulation and interpretation to further reduce operating costs and to make the system still more active to the small-scale operator.

  12. Validation of US3D for Capsule Aerodynamics using 05-CA Wind Tunnel Test Data

    NASA Technical Reports Server (NTRS)

    Schwing, Alan

    2012-01-01

    Several comparisons of computational fluid dynamics to wind tunnel test data are shown for the purpose of code validation. The wind tunnel test, 05-CA, uses a 7.66% model of NASA's Multi-Purpose Crew Vehicle in the 11-foot test section of the Ames Unitary Plan Wind tunnel. A variety of freestream conditions over four Mach numbers and three angles of attack are considered. Test data comparisons include time-averaged integrated forces and moments, time-averaged static pressure ports on the surface, and Strouhal Number. The applicability of the US3D code to subsonic and transonic flow over a bluff body is assessed on a comprehensive data set. With close comparison, this work validates US3D for highly separated flows similar to those examined here.

  13. Advanced prior modeling for 3D bright field electron tomography

    NASA Astrophysics Data System (ADS)

    Sreehari, Suhas; Venkatakrishnan, S. V.; Drummy, Lawrence F.; Simmons, Jeffrey P.; Bouman, Charles A.

    2015-03-01

    Many important imaging problems in material science involve reconstruction of images containing repetitive non-local structures. Model-based iterative reconstruction (MBIR) could in principle exploit such redundancies through the selection of a log prior probability term. However, in practice, determining such a log prior term that accounts for the similarity between distant structures in the image is quite challenging. Much progress has been made in the development of denoising algorithms like non-local means and BM3D, and these are known to successfully capture non-local redundancies in images. But the fact that these denoising operations are not explicitly formulated as cost functions makes it unclear as to how to incorporate them in the MBIR framework. In this paper, we formulate a solution to bright field electron tomography by augmenting the existing bright field MBIR method to incorporate any non-local denoising operator as a prior model. We accomplish this using a framework we call plug-and-play priors that decouples the log likelihood and the log prior probability terms in the MBIR cost function. We specifically use 3D non-local means (NLM) as the prior model in the plug-and-play framework, and showcase high quality tomographic reconstructions of a simulated aluminum spheres dataset, and two real datasets of aluminum spheres and ferritin structures. We observe that streak and smear artifacts are visibly suppressed, and that edges are preserved. Also, we report lower RMSE values compared to the conventional MBIR reconstruction using qGGMRF as the prior model.

  14. New techniques in 3D scalar and vector field visualization

    SciTech Connect

    Max, N.; Crawfis, R.; Becker, B.

    1993-05-05

    At Lawrence Livermore National Laboratory (LLNL) we have recently developed several techniques for volume visualization of scalar and vector fields, all of which use back-to-front compositing. The first renders volume density clouds by compositing polyhedral volume cells or their faces. The second is a ``splatting`` scheme which composites textures used to reconstruct the scalar or vector fields. One version calculates the necessary texture values in software, and another takes advantage of hardware texture mapping. The next technique renders contour surface polygons using semi-transparent textures, which adjust appropriately when the surfaces deform in a flow, or change topology. The final one renders the ``flow volume`` of smoke or dye tracer swept out by a fluid flowing through a small generating polygon. All of these techniques are applied to a climate model data set, to visualize cloud density and wind velocity.

  15. 3D augmented reality for improving social acceptance and public participation in wind farms planning

    NASA Astrophysics Data System (ADS)

    Grassi, S.; Klein, T. M.

    2016-09-01

    Wind energy is one of the most important source of renewable energy characterized by a significant growth in the last decades and giving a more and more relevant contribution to the energy supply. One of the main disadvantages of a faster integration of wind energy into the energy mix is related to the visual impact of wind turbines on the landscape. In addition, the siting of new massive infrastructures has the potential to threaten a community's well-being if new projects are perceived being unfair. The public perception of the impact of wind turbines on the landscape is also crucial for their acceptance. The implementation of wind energy projects is hampered often because of a lack of planning or communication tools enabling a more transparent and efficient interaction between all stakeholders involved in the projects (i.e. developers, local communities and administrations, NGOs, etc.). Concerning the visual assessment of wind farms, a critical gap lies in effective visualization tools to improve the public perception of alternative wind turbines layouts. In this paper, we describe the advantages of a 3D dynamical and interactive visualization platform for an augmented reality to support wind energy planners in order to enhance the social acceptance of new wind energy projects.

  16. 3D Magnetotelluic characterization of the Coso GeothermalField

    SciTech Connect

    Newman, Gregory A.; Hoversten, G. Michael; Wannamaker, Philip E.; Gasperikova, Erika

    2007-04-23

    -dimensional conductivitymodel. Initial analysis of the Coso MT data was carried out using 2D MTimaging. An initial 3D conductivity model was constructed from a seriesof 2D resistivity images obtained using the inline electric fieldmeasurements (Zyx impedance elements) along several measurementtransects. This model was then refined through a 3D inversion process.This model shows the controlling geological structures possiblyinfluencing well production at Coso and correlations with mapped surfacefeatures such as faults and regional geoelectric strike. The 3D modelalso illustrates the refinement in positioning of conductivity contactswhen compared to isolated 2D inversion transects. The conductivity modelhas also been correlated with microearthquake locations, well fluidproduction intervals and most importantly with an acoustic and shearvelocity model derived by Wu and Lees (1999). This later correlationshows the near-vertical high conductivity structure on the eastern flankof the producing field is also a zone of increased acoustic velocity andincreased Vp/Vs ratio bounded by mapped fault traces. South of theDevil's Kitchen is an area of high geothermal well density, where highlyconductive near surface material is interpreted as a clay cap alterationzone manifested from the subsurface geothermal fluids and relatedgeochemistry. Beneath the clay cap, however, the conductivity isnondescript, whereas the Vp/Vs ratio is enhanced over the productionintervals. It is recommended that more MT data sites be acquired to thesouthwest of the Devil's Kitchen area to better refine the conductivitymodel in that area.

  17. Electromagnetic 2D/3D Particle-in-Cell simulations of the solar wind interaction with lunar crustal anomalies.

    NASA Astrophysics Data System (ADS)

    Deca, Jan; Lapenta, Giovanni; Lembège, Bertrand; Divin, Andrey; Markidis, Stefano; Amaya, Jorge

    2013-04-01

    We present the first 2D/3D fully kinetic Particle-in-Cell simulations of the solar wind interaction with lunar crustal magnetic anomalies. The simulations are performed using the implicit electromagnetic Particle-in-Cell code iPIC3D [Markidis, Lapenta & Rizwan-uddin, 2010]. Multiscale physics is resolved for all plasma components (heavy ions, protons and electrons) in the code, recently updated with a set of open boundary conditions designed for solar wind-body interactions. We use a dipole to model the crustal anomaly. The dipole center is located outside the computational domain and the boundary representing the lunar surface is modeled as a particle-absorbing plane. Photo-emission from the lunar surface is at this point not included, but will be in future work. We study the behaviour of the dipole model with variable surface magnetic field strength under changing solar wind conditions and confirm that lunar crustal magnetic fields may indeed be strong enough to stand off the solar wind and form a mini-magnetosphere, as suggested by MHD simulations [Harnett & Winglee, 2000, 2002, 2003] and spacecraft observations [Kurata et al., 2005; Halekas et al., 2008; Wieser et al., 2010]. 3D-PIC simulations reveal to be very helpful to analyze the diversion/braking of the particle flux and the characteristics of the resulting particles accumulation. The particle flux to the surface is significantly reduced at the magnetic anomaly, surrounded by a region of enhanced density due to the magnetic mirror effect. Finally we will present preliminary results on the interaction of the solar wind with weaker magnetic anomalies in which highly non-adiabatic interactions are expected.

  18. 3-D Finite Element Analyses of the Egan Cavern Field

    SciTech Connect

    Klamerus, E.W.; Ehgartner, B.L.

    1999-02-01

    Three-dimensional finite element analyses were performed for the two gas-filled storage caverns at the Egan field, Jennings dome, Louisiana. The effects of cavern enlargement on surface subsidence, storage loss, and cavern stability were investigated. The finite element model simulated the leaching of caverns to 6 and 8 billion cubic feet (BCF) and examined their performance at various operating conditions. Operating pressures varied from 0.15 psi/ft to 0.9 psi/ft at the bottom of the lowest cemented casing. The analysis also examined the stability of the web or pillar of salt between the caverns under differential pressure loadings. The 50-year simulations were performed using JAC3D, a three dimensional finite element analysis code for nonlinear quasistatic solids. A damage criterion based on onset of dilatancy was used to evaluate cavern instability. Dilation results from the development of microfractures in salt and, hence, potential increases in permeability onset occurs well before large scale failure. The analyses predicted stable caverns throughout the 50-year period for the range of pressures investigated. Some localized salt damage was predicted near the bottom walls of the caverns if the caverns are operated at minimum pressure for long periods of time. Volumetric cavern closures over time due to creep were moderate to excessive depending on the salt creep properties and operating pressures. However, subsidence above the cavern field was small and should pose no problem, to surface facilities.

  19. First Lunar Wake Passage of ARTEMIS: Discrimination of Wake Effects and Solar Wind Fluctuations by 3D Hybrid Simulations

    NASA Technical Reports Server (NTRS)

    Wiehle, S.; Plaschke, F.; Motschmann, U.; Glassmeier, K. H.; Auster, H. U.; Angelopoulos, V.; Mueller, J.; Kriegel, H.; Georgescu, E.; Halekas, J.; Sibeck, D. G.; McFadden, J. P.

    2011-01-01

    The spacecraft P1 of the new ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun) mission passed the lunar wake for the first time on February 13, 2010. We present magnetic field and plasma data of this event and results of 3D hybrid simulations. As the solar wind magnetic field was highly dynamic during the passage, a simulation with stationary solar wind input cannot distinguish whether distortions were caused by these solar wind variations or by the lunar wake; therefore, a dynamic real-time simulation of the flyby has been performed. The input values of this simulation are taken from NASA OMNI data and adapted to the P1 data, resulting in a good agreement between simulation and measurements. Combined with the stationary simulation showing non-transient lunar wake structures, a separation of solar wind and wake effects is achieved. An anisotropy in the magnitude of the plasma bulk flow velocity caused by a non-vanishing magnetic field component parallel to the solar wind flow and perturbations created by counterstreaming ions in the lunar wake are observed in data and simulations. The simulations help to interpret the data granting us the opportunity to examine the entire lunar plasma environment and, thus, extending the possibilities of measurements alone: A comparison of a simulation cross section to theoretical predictions of MHD wave propagation shows that all three basic MHD modes are present in the lunar wake and that their expansion governs the lunar wake refilling process.

  20. 3D Modeling of Forbidden Line Emission in the Binary Wind Interaction Region of Eta Carinae

    NASA Technical Reports Server (NTRS)

    Madura, Thomas; Gull, T. R.; Owocki, S.; Okazaki, A. T.; Russell, C. M. P.

    2010-01-01

    We present recent work using three-dimensional (3D) Smoothed Particle Hydrodynamics (SPH) simulations to model the high ([Fe III], [Ar III], [Ne III] and [S III]) and low ([Fe II], [Ni II]) ionization forbidden emission lines observed in Eta Carinae using the HST/STIS. These structures are interpreted as the time-averaged, outer extensions of the primary wind and the wind-wind interaction region directly excited by the FUV of the hot companion star of this massive binary system. We discuss how analyzing the results of the 3D SPH simulations and synthetic slit spectra and comparing them to the spectra obtained with the HST/STIS helps us determine the absolute orientation of the binary orbit and helps remove the degeneracy inherent to models based solely on the observed RXTE X-ray light curve. A key point of this work is that spatially resolved observations like those with HST/STIS and comparison to 3D models are necessary to determine the alignment or misalignment of the orbital angular momentum axis with the Homunculus, or correspondingly, the alignment of the orbital plane with the Homunculus skirt.

  1. 3D Radiative Transfer in Eta Carinae: Application of the SimpleX Algorithm to 3D SPH Simulations of Binary Colliding Winds

    NASA Technical Reports Server (NTRS)

    Clementel, N.; Madura, T. I.; Kruip, C.J.H.; Icke, V.; Gull, T. R.

    2014-01-01

    Eta Carinae is an ideal astrophysical laboratory for studying massive binary interactions and evolution, and stellar wind-wind collisions. Recent three-dimensional (3D) simulations set the stage for understanding the highly complex 3D flows in eta Car. Observations of different broad high- and low-ionization forbidden emission lines provide an excellent tool to constrain the orientation of the system, the primary's mass-loss rate, and the ionizing flux of the hot secondary. In this work we present the first steps towards generating synthetic observations to compare with available and future HST/STIS data. We present initial results from full 3D radiative transfer simulations of the interacting winds in eta Car.We use the SimpleX algorithm to post-process the output from 3D SPH simulations and obtain the ionization fractions of hydrogen and helium assuming three different mass-loss rates for the primary star. The resultant ionization maps of both species constrain the regions where the observed forbidden emission lines can form. Including collisional ionization is necessary to achieve a better description of the ionization states, especially in the areas shielded from the secondary's radiation. We find that reducing the primary's mass-loss rate increases the volume of ionized gas, creating larger areas where the forbidden emission lines can form.We conclude that post processing 3D SPH data with SimpleX is a viable tool to create ionization maps for eta Car.

  2. 3D Radiative Transfer in Eta Carinae: Application of the SimpleX Algorithm to 3D SPH Simulations of Binary Colliding Winds

    NASA Technical Reports Server (NTRS)

    Clementel, N.; Madura, T. I.; Kruip, C. J. H.; Icke, V.; Gull, T. R.

    2014-01-01

    Eta Carinae is an ideal astrophysical laboratory for studying massive binary interactions and evolution, and stellar wind-wind collisions. Recent three-dimensional (3D) simulations set the stage for understanding the highly complex 3D flows in Eta Car. Observations of different broad high- and low-ionization forbidden emission lines provide an excellent tool to constrain the orientation of the system, the primary's mass-loss rate, and the ionizing flux of the hot secondary. In this work we present the first steps towards generating synthetic observations to compare with available and future HST/STIS data. We present initial results from full 3D radiative transfer simulations of the interacting winds in Eta Car. We use the SimpleX algorithm to post-process the output from 3D SPH simulations and obtain the ionization fractions of hydrogen and helium assuming three different mass-loss rates for the primary star. The resultant ionization maps of both species constrain the regions where the observed forbidden emission lines can form. Including collisional ionization is necessary to achieve a better description of the ionization states, especially in the areas shielded from the secondary's radiation. We find that reducing the primary's mass-loss rate increases the volume of ionized gas, creating larger areas where the forbidden emission lines can form. We conclude that post processing 3D SPH data with SimpleX is a viable tool to create ionization maps for Eta Car.

  3. An approach to 3D magnetic field calculation using numerical and differential algebra methods

    SciTech Connect

    Caspi, S.; Helm, M.; Laslett, L.J.; Brady, V.O.

    1992-07-17

    Motivated by the need for new means for specification and determination of 3D fields that are produced by electromagnetic lens elements in the region interior to coil windings and seeking to obtain techniques that will be convenient for accurate conductor placement and dynamical study of particle motion, we have conveniently gene the representation of a 2D magnetic field to 3D. We have shown that the 3 dimensioal magnetic field components of a multipole magnet in the curl-fire divergence-fire region near the axis r=0 can be derived from one dimensional functions A{sub n}(z) and their derivatives (part 1). In the region interior to coil windings of accelerator magnets the three spatial components of magnet fields can be expressed in terms of harmonic components'' proportional to functions sin (n{theta}) or cos (n{theta}) of the azimuthal angle. The r,z dependence of any such component can then be expressed in terms of powers of r times functions A{sub n}(z) and their derivatives. For twodimensional configurations B{sub z} of course is identically zero, the derivatives of A{sub n}(z) vanish, and the harmonic components of the transverse field then acquire a simple proportionality B{sub r,n} {proportional to} r{sup n-1} sin (n{theta}),B{sub {theta},n} {proportional to} r{sup n-1} cos (n{theta}), whereas in a 3-D configuration the more complex nature of the field gives rise to additional so-called psuedomultipole'' components as judged by additional powers of r required in the development of the field. Computation of the 3-D magnetic field arising at a sequence of field points, as a direct result of a specified current configuration or coil geometry, can be calculated explicitly through use of the Biot-Savart law and from such data the coefficients can then be derived for a general development of the type indicated above. We indicate, discuss, and illustrate two means by which this development may be performed.

  4. Kinematics and flow fields in 3D around swimming lamprey using light field PIV

    NASA Astrophysics Data System (ADS)

    Lehn, Andrea M.; Techet, Alexandra H.

    2016-11-01

    The fully time-resolved 3D kinematics and flow field velocities around freely swimming sea lamprey are derived using 3D light field imaging PIV. Lighthill's Elongated Body Theory (EBT) predicts that swimmers with anguilliform kinematics likened to lamprey, and similarly eels, will exhibit relatively poor propulsive efficiency. However, previous experimental studies of eel locomotion utilizing 2D PIV suggest disagreement with EBT estimates of wake properties; although, the thrust force generated by such swimmers has yet to be fully resolved using 3D measurements. A light field imaging array of multiple high-speed cameras is used to perform 3D synthetic aperture PIV around ammocoete sea lamprey (Petromyzon marinus). Fluid mechanics equations are used to determine thrust force generation, leading experimental studies closer to underpinning the physical mechanisms that enable aquatic locomotion of long, slender undulatory swimmers.

  5. Experimental 3D Asynchronous Field Programmable Gate Array (FPGA)

    DTIC Science & Technology

    2015-03-01

    microprocessor . 3.1. Asynchronous FPGA Overview In terms of the major building blocks, the asynchronous FPGA (AFPGA) architecture looks like a traditional...devices—from O(N1/2) to O(N1/3), where N is the number of devices in the system. 3D chip stacking has been proposed as a way to improve microprocessor

  6. Heat Transfer Affected by Transverse Magnetic Field using 3D Modeling of Arc Plasma

    NASA Astrophysics Data System (ADS)

    Maeda, Yoshifumi; Tanaka, Tatsuro; Yamamoto, Shinji; Iwao, Toru

    2016-10-01

    Gas shielded metal arc welding is used to join the various metal because this is the high quality joining technology. Thus, this welding is used for a welding of large buildings such as bridges and LNG tanks. However, the welding defect caused by the heat transfer decrement may occur with increasing the wind velocity. This is because that the convection loss increases because the arc deflects to leeward side with increasing the wind velocity. In order to prevent from the arc deflection, it is used that the transverse magnetic field is applied to the arc. However, the arc deflection occurs with increasing the transverse magnetic field excessively. The energy balance of the arc is changed with increasing the convection loss caused by the arc deflection, and the heat transfer to the anode decreases. Therefore, the analysis including the arc and anode is necessary to elucidate the heat transfer to the anode. In this paper, the heat transfer affected by the transverse magnetic field using 3D modeling of the arc plasma is elucidated. The heat transfer to the anode is calculated by using the EMTF(electromagnetic thermal fluid) simulation with increasing the transverse magnetic field. As a result, the heat transfer decreased with increasing the transverse magnetic field.

  7. A 3-D High Speed Photographic Survey For Bomb Dropping In The Wind Tunnel

    NASA Astrophysics Data System (ADS)

    Junren, Chen; Liangyi, Chen; Yuxian, Nie; Wenxing, Chen

    1989-06-01

    High speed Stereophotography may obtain 3-D information of the motion object. This paper deals with a high speed stereophotographic survey of dropping bomb in wind tunnel and measurement of its displacement, velocity, acceleration, angle of attack and yaw angle. Two high speed cinecameras are used, the two optical axes of the cameras are perpendicular to each other and in a plane being vertical to the plumb line. The optical axis of a camera (front camera) is parallel with the aircraft body, and the another (side camera) is perpendicular. Before taking the object and image distance of the two cameras must be measured by photographic method. The photographic rate is 304 fps.

  8. Study of the internal magnetic field of Mercury through 3D hybrid simulations

    NASA Astrophysics Data System (ADS)

    Leclercq, Ludivine; Marcel Chanteur, Gerard; Modolo, Ronan; Leblanc, Francois; Schmidt, Carl; Langlais, Benoît; Thebault, Erwan

    2016-10-01

    In 1974, Mariner 10 discovered the intrinsic magnetic field of Mercury which interacts with the solar wind, leading to the formation of a magnetosphere. In spite of the recent MESSENGER observations, this magnetosphere remains quite unknown, especially in the Southern hemisphere. In order to improve our understanding of the Hermean magnetosphere, and to prepare the Bepi-Colombo mission (ESA/JAXA), we simulated the magnetized environment of Mercury using the model named LatHyS (LATMOS Hybrid Simulation). LatHyS is a 3D parallel multi-species hybrid code which has been applied to Mars, Titan and Ganymede, which has recently be improved by the implementation of a multi-grid method allowing to refine the spatial resolution near the planetary object (40 km in the case of Mercury). In order to investigate the Hermean environment, several hybrid simulations have been performed considering different internal field models, and results are compared with MESSENGER observations.

  9. A new 3D LDV system for the NASA Ames 6 x 6 ft. wind tunnel

    NASA Technical Reports Server (NTRS)

    Owen, F. K.; Orngard, G. M.; Mcdevitt, T. K.

    1985-01-01

    An obvious extension of wind tunnel laser Doppler velocimetry (LDV), which is currently mainly limited to two-component measurements, would involve the measurement of three simultaneous velocity components. The present paper is concerned with an approach to reduce the degree of optical complexity involved in the design of a three-dimensional (3D) LDV system, taking into account the use of polarization separation. Such a system, utilizing polarization as well as color separation, has been designed and tested in a 6 x 6 foot supersonic wind tunnel. The considered instrument was designed for the on line measurement of three mean velocity components, turbulence levels, and shear stresses on a number of models under a wide variety of test conditions. Attention is given to optical details, data reduction, and sample application.

  10. Assessment of 3D aerodynamic effects on the behaviour of floating wind turbines

    NASA Astrophysics Data System (ADS)

    Manolas, D.; Riziotis, V.; Voutsinas, S.

    2014-12-01

    Current state-of-art models for floating wind turbines are built by merging separate modules addressing the four basic aspects leading to a compound hydro-servo-aero-elastic time domain solver. While current state-of-the-art models differ in many aspects, they all use the blade element momentum (BEM) aerodynamic modelling. Due to its low cost, BEM is the standard choice for design purposes. However the use of BEM entails several semi-empirical corrections and add-ons that need reconsideration and recalibration when new features appear. For floating wind turbines, the effect of the floater motions is such a new feature. In the present paper, this aspect is investigated by comparing BEM based results against 3D free-wake simulations. Deterministic as well as stochastic simulations are presented in pure aerodynamic and full aeroelastic context. It is confirmed that asymmetric inflow originating from yaw misalignment and shear give significant differences reflected on mean values and amplitudes.

  11. Methodology for the Assessment of 3D Conduction Effects in an Aerothermal Wind Tunnel Test

    NASA Technical Reports Server (NTRS)

    Oliver, Anthony Brandon

    2010-01-01

    This slide presentation reviews a method for the assessment of three-dimensional conduction effects during test in a Aerothermal Wind Tunnel. The test objectives were to duplicate and extend tests that were performed during the 1960's on thermal conduction on proturberance on a flat plate. Slides review the 1D versus 3D conduction data reduction error, the analysis process, CFD-based analysis, loose coupling method that simulates a wind tunnel test run, verification of the CFD solution, Grid convergence, Mach number trend, size trends, and a Sumary of the CFD conduction analysis. Other slides show comparisons to pretest CFD at Mach 1.5 and 2.16 and the geometries of the models and grids.

  12. Three-fluid, 3D MHD solar wind modeling with turbulence transport and eddy viscosity

    NASA Astrophysics Data System (ADS)

    Usmanov, A. V.; Goldstein, M. L.; Matthaeus, W. H.

    2014-12-01

    We present results from a three-fluid, fully three-dimensional MHD solar wind model that includes turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a co-moving system of three species: the solar wind protons, electrons, and interstellar pickup protons. Separate energy equations are employed for each species. We obtain numerical solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations in the region from 0.3 to 100 AU. The integrated system of equations includes 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. 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 turbulence parameters, throughout the heliosphere. The model results are compared with observations on WIND, Ulysses and Voyager 2 spacecraft. This work is partially supported by LWS and Heliophysics Grand Challenges programs.

  13. Calibration of 3-D wind measurements on a single engine research aircraft

    NASA Astrophysics Data System (ADS)

    Mallaun, C.; Giez, A.; Baumann, R.

    2015-02-01

    An innovative calibration method for the wind speed measurement using a boom mounted Rosemount model 858 AJ air velocity probe is introduced. The method is demonstrated for a sensor system installed on a medium size research aircraft which is used for measurements in the atmospheric boundary layer. The method encounters a series of coordinated flight manoeuvres to directly estimate the aerodynamic influences on the probe and to calculate the measurement uncertainties. The introduction of a differential Global Positioning System (DGPS) combined with a high accuracy Inertial Reference System (IRS) has brought major advances to airborne measurement techniques. The exact determination of geometrical height allows the use of the pressure signal as an independent parameter. Furthermore, the exact height information and the stepwise calibration process lead to maximum accuracy. The results show a measurement uncertainty for the aerodynamic influence of the dynamic and static pressures of 0.1 hPa. The applied parametrisation does not require any height dependencies or time shifts. After extensive flight tests a correction for the flow angles (attack and sideslip angles) was found, which is necessary for a successful wind calculation. A new method is demonstrated to correct for the aerodynamic influence on the sideslip angle. For the 3-D wind vector (with 100 Hz resolution) a novel error propagation scheme is tested, which determines the measurement uncertainties to be 0.3 m s-1 for the horizontal and 0.2 m s-1 for the vertical wind components.

  14. Calibration of 3-D wind measurements on a single-engine research aircraft

    NASA Astrophysics Data System (ADS)

    Mallaun, C.; Giez, A.; Baumann, R.

    2015-08-01

    An innovative calibration method for the wind speed measurement using a boom-mounted Rosemount model 858 AJ air velocity probe is introduced. The method is demonstrated for a sensor system installed on a medium-size research aircraft which is used for measurements in the atmospheric boundary layer. The method encounters a series of coordinated flight manoeuvres to directly estimate the aerodynamic influences on the probe and to calculate the measurement uncertainties. The introduction of a differential Global Positioning System (DGPS) combined with a high-accuracy inertial reference system (IRS) has brought major advances to airborne measurement techniques. The exact determination of geometrical height allows the use of the pressure signal as an independent parameter. Furthermore, the exact height information and the stepwise calibration process lead to maximum accuracy. The results show a measurement uncertainty for the aerodynamic influence of the dynamic and static pressures of 0.1 hPa. The applied parametrisation does not require any height dependencies or time shifts. After extensive flight tests a correction for the flow angles (attack and sideslip angles) was found, which is necessary for a successful wind calculation. A new method is demonstrated to correct for the aerodynamic influence on the sideslip angle. For the three-dimensional (3-D) wind vector (with 100 Hz resolution) a novel error propagation scheme is tested, which determines the measurement uncertainties to be 0.3 m s-1 for the horizontal and 0.2 m s-1 for the vertical wind components.

  15. 3D simulation of coaxial carbon nanotube field effect transistor

    NASA Astrophysics Data System (ADS)

    Hien, Dinh Sy; Thi Luong, Nguyen; Tuan, Thi Tran Anh; Viet Nga, Dinh

    2009-09-01

    We provide a model of coaxial CNTFET geometry. Coaxial devices are of special interest because their geometry allows for better electrostatics. We explore the possibilities of using non-equilibrium Green's function method to get I-V characteristics for CNTFETs. This simulator also includes a graphic user interface (GUI) of Matlab. We review the capabilities of the simulator, and give examples of typical CNTFET's 3D simulations (current-voltage characteristics are a function of parameters such as the length of CNTFET, gate thickness and temperature). The obtained I-V characteristics of the CNTFET are also presented by analytical equations.

  16. Automated objective characterization of visual field defects in 3D

    NASA Technical Reports Server (NTRS)

    Fink, Wolfgang (Inventor)

    2006-01-01

    A method and apparatus for electronically performing a visual field test for a patient. A visual field test pattern is displayed to the patient on an electronic display device and the patient's responses to the visual field test pattern are recorded. A visual field representation is generated from the patient's responses. The visual field representation is then used as an input into a variety of automated diagnostic processes. In one process, the visual field representation is used to generate a statistical description of the rapidity of change of a patient's visual field at the boundary of a visual field defect. In another process, the area of a visual field defect is calculated using the visual field representation. In another process, the visual field representation is used to generate a statistical description of the volume of a patient's visual field defect.

  17. A 3-D Look at Wind-Sculpted Ridges in Aeolis

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Layers of bedrock etched by wind to form sharp, elongated ridges known to geomorphologists as yardangs are commonplace in the southern Elysium Planitia/southern Amazonis region of Mars. The ridges shown in this 3-D composite of two overlapping Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images occur in the eastern Aeolis region of southern Elysium Planitia near 2.3oS, 206.8oW. To view the picture in stereo, you need red-blue 3-D glasses (red filter over the left eye, blue over the right). For wind to erode bedrock into the patterns seen here, the rock usually must consist of something that is fine-grained and of nearly uniform grain size, such as sand. It must also be relatively easy to erode. For decades, most Mars researchers have interpreted these materials to be eroded deposits of volcanic ash. Nothing in the new picture shown here can support nor refute this earlier speculation. The entire area is mantled by light-toned dust. Small landslides within this thin dust layer form dark streaks on some of the steeper slopes in this picture (for more examples and explanations for these streaks, see previous web pages listed below).

    The stereo (3-D) picture was compiled using an off-nadir view taken by the MOC during the Aerobrake-1 subphase of the mission in January 1998 with a nadir (straight-down-looking) view acquired in October 2000. The total area shown is about 6.7 kilometers (4.2 miles) wide by 2.5 kilometers (1.5 miles) high and is illuminated by sunlight from the upper right. The relief in the stereo image is quite exaggerated: the ridges are between about 50 and 100 meters (about 165-330 feet) high. North is toward the lower right.

  18. 3D stress field simulation for Greater Munich, Germany

    NASA Astrophysics Data System (ADS)

    Ziegler, Moritz; Heidbach, Oliver; Reinecker, John; Przybycin, Anna Maria; Scheck-Wenderoth, Magdalena

    2016-04-01

    Geotechnical applications such as tunneling, storage of waste, wellbore planning, or reservoir engineering requires detailed 3D information on the rock properties and behavior of the continuum. One of the key parameters is the contemporary crustal in-situ stress state. However, generally the availability of stress data on reservoir scale is scarce or no data exists at all. Furthermore, stress data is often limited to the orientation of the maximum horizontal stress. Hence, geomechanical-numerical modelling provides an approximation of a continuous description of the 3D in-situ stress state. We present a model workflow that shows (1) how to calibrate a regional scale model of Greater Munich with stress orientations and magnitudes mainly from borehole data and (2) how to derive from the regional model boundary conditions for a local high-resolution model of a geothermal reservoir site. This approach using two models is an alternative to the required trade-off between resolution, computational cost and a sufficient number of calibration data which is otherwise inevitable for a single model. The incorporated 3D geological models contain the topography from a digital elevation model and 6 stratigraphic units with different elasto-plastic rock properties. The local model mimics the area of a planned reservoir and its resolution is significantly higher than in the regional model and down to 10 m near the planned borehole trajectories using 21×106 tetrahedron finite elements with linear approximation functions. The uncertainties of the calibrated regional model are large since no information on the magnitude of the maximum horizontal stress is available. Even in the entire Greater Munich area only two reliable leak-off tests that deliver the magnitude of the minimum horizontal stress could be used. These uncertainties are transferred also to the local model. Hence we also show how to quantify for the workflow in general the systematic uncertainties and discuss

  19. Integration of real-time 3D capture, reconstruction, and light-field display

    NASA Astrophysics Data System (ADS)

    Zhang, Zhaoxing; Geng, Zheng; Li, Tuotuo; Pei, Renjing; Liu, Yongchun; Zhang, Xiao

    2015-03-01

    Effective integration of 3D acquisition, reconstruction (modeling) and display technologies into a seamless systems provides augmented experience of visualizing and analyzing real objects and scenes with realistic 3D sensation. Applications can be found in medical imaging, gaming, virtual or augmented reality and hybrid simulations. Although 3D acquisition, reconstruction, and display technologies have gained significant momentum in recent years, there seems a lack of attention on synergistically combining these components into a "end-to-end" 3D visualization system. We designed, built and tested an integrated 3D visualization system that is able to capture in real-time 3D light-field images, perform 3D reconstruction to build 3D model of the objects, and display the 3D model on a large autostereoscopic screen. In this article, we will present our system architecture and component designs, hardware/software implementations, and experimental results. We will elaborate on our recent progress on sparse camera array light-field 3D acquisition, real-time dense 3D reconstruction, and autostereoscopic multi-view 3D display. A prototype is finally presented with test results to illustrate the effectiveness of our proposed integrated 3D visualization system.

  20. Invariant superoscillatory electromagnetic fields in 3D-space

    NASA Astrophysics Data System (ADS)

    Makris, K. G.; Papazoglou, D. G.; Tzortzakis, S.

    2017-01-01

    We derive exact solutions of Maxwell’s equations based on superoscillatory superpositions of vectorial Bessel beams. These novel beams are diffraction-free and can support subwavelength features in their transverse electromagnetic fields, without the presence of any evanescent waves. These features can be propagated into the far field. Approximate solutions in closed form are also derived based on asymptotic expansions of Bessel functions for simple prescribed subwavelength patterns. The superoscillatory characteristics of both electric, magnetic field components (transverse and longitudinal), and the Poynting vector, as well as, the effect of nonparaxiality are systematically investigated.

  1. 3D fingerprint imaging system based on full-field fringe projection profilometry

    NASA Astrophysics Data System (ADS)

    Huang, Shujun; Zhang, Zonghua; Zhao, Yan; Dai, Jie; Chen, Chao; Xu, Yongjia; Zhang, E.; Xie, Lili

    2014-01-01

    As an unique, unchangeable and easily acquired biometrics, fingerprint has been widely studied in academics and applied in many fields over the years. The traditional fingerprint recognition methods are based on the obtained 2D feature of fingerprint. However, fingerprint is a 3D biological characteristic. The mapping from 3D to 2D loses 1D information and causes nonlinear distortion of the captured fingerprint. Therefore, it is becoming more and more important to obtain 3D fingerprint information for recognition. In this paper, a novel 3D fingerprint imaging system is presented based on fringe projection technique to obtain 3D features and the corresponding color texture information. A series of color sinusoidal fringe patterns with optimum three-fringe numbers are projected onto a finger surface. From another viewpoint, the fringe patterns are deformed by the finger surface and captured by a CCD camera. 3D shape data of the finger can be obtained from the captured fringe pattern images. This paper studies the prototype of the 3D fingerprint imaging system, including principle of 3D fingerprint acquisition, hardware design of the 3D imaging system, 3D calibration of the system, and software development. Some experiments are carried out by acquiring several 3D fingerprint data. The experimental results demonstrate the feasibility of the proposed 3D fingerprint imaging system.

  2. Statistical Flux Tube Properties of 3D Magnetic Carpet Fields

    NASA Astrophysics Data System (ADS)

    Close, R. M.; Parnell, C. E.; Mackay, D. H.; Priest, E. R.

    2003-02-01

    The quiet-Sun photosphere consists of numerous magnetic flux fragments of both polarities that evolve with granular and supergranular flow fields. These concentrations give rise to a web of intermingled magnetic flux tubes which characterise the coronal magnetic field. Here, the nature of these flux tubes is studied. The photosphere is taken to be the source plane and each photospheric fragment is represented by a series of point sources. By analysing the potential field produced by these sources, it is found that the distribution of flux tube lengths obtained by (i) integrating forward from positive sources and (ii) tracing back from negative sources is highly dependent on the total flux imbalance within the region of interest. It is established that the relation between the footpoint separation of a flux tube and its height cannot be assumed to be linear. Where there is a significant imbalance of flux within a region, it is found that fragments of the dominant polarity will have noticeably more connections, on average, than the minority polarity fragments. Despite this difference, the flux from a single fragment of either polarity is typically divided such that (i) 60-70% connects to one opposite-polarity fragment, (ii) 25-30% goes to a further 1 to 2 opposite-polarity fragments, and (iii) any remaining flux may connect to as many as another 50 or more other opposite-polarity fragments. This is true regardless of any flux imbalance within the region. It is found that fragments connect preferentially to their nearest neighbours, with, on average, around 60-70% of flux closing down within 10 Mm of a typical fragment. Only 50% of the flux in a quiet region extends higher than 2.5 Mm above the solar surface and 5-10% extends higher than 25 Mm. The fragments that contribute to the field above this height cover a range of sizes, with even the smallest of fragments contributing to the field at heights of over 50 Mm.

  3. Increasing the depth of field in Multiview 3D images

    NASA Astrophysics Data System (ADS)

    Lee, Beom-Ryeol; Son, Jung-Young; Yano, Sumio; Jung, Ilkwon

    2016-06-01

    A super-multiview condition simulator which can project up to four different view images to each eye is introduced. This simulator with the image having both disparity and perspective informs that the depth of field (DOF) will be extended to more than the default DOF values as the number of simultaneously but separately projected different view images to each eye increase. The DOF range can be extended to near 2 diopters with the four simultaneous view images. However, the DOF value increments are not prominent as the image with both disparity and perspective with the image with disparity only.

  4. Compact, High Energy 2-micron Coherent Doppler Wind Lidar Development for NASA's Future 3-D Winds Measurement from Space

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Koch, Grady; Yu, Jirong; Petros, Mulugeta; Beyon, Jeffrey; Kavaya, Michael J.; Trieu, Bo; Chen, Songsheng; Bai, Yingxin; Petzar, paul; Modlin, Edward A.; Barnes, Bruce W.; Demoz, Belay B.

    2010-01-01

    This paper presents an overview of 2-micron laser transmitter development at NASA Langley Research Center for coherent-detection lidar profiling of winds. The novel high-energy, 2-micron, Ho:Tm:LuLiF laser technology developed at NASA Langley was employed to study laser technology currently envisioned by NASA for future global coherent Doppler lidar winds measurement. The 250 mJ, 10 Hz laser was designed as an integral part of a compact lidar transceiver developed for future aircraft flight. Ground-based wind profiles made with this transceiver will be presented. NASA Langley is currently funded to build complete Doppler lidar systems using this transceiver for the DC-8 aircraft in autonomous operation. Recently, LaRC 2-micron coherent Doppler wind lidar system was selected to contribute to the NASA Science Mission Directorate (SMD) Earth Science Division (ESD) hurricane field experiment in 2010 titled Genesis and Rapid Intensification Processes (GRIP). The Doppler lidar system will measure vertical profiles of horizontal vector winds from the DC-8 aircraft using NASA Langley s existing 2-micron, pulsed, coherent detection, Doppler wind lidar system that is ready for DC-8 integration. The measurements will typically extend from the DC-8 to the earth s surface. They will be highly accurate in both wind magnitude and direction. Displays of the data will be provided in real time on the DC-8. The pulsed Doppler wind lidar of NASA Langley Research Center is much more powerful than past Doppler lidars. The operating range, accuracy, range resolution, and time resolution will be unprecedented. We expect the data to play a key role, combined with the other sensors, in improving understanding and predictive algorithms for hurricane strength and track. 1

  5. 3-D explosions: a meditation on rotation (and magnetic fields)

    NASA Astrophysics Data System (ADS)

    Wheeler, J. C.

    This is the text of an introduction to a workshop on asymmetric explosions held in Austin in June, 2003. The great progress in supernova research over thirty-odd years is briefly reviewed. The context in which the meeting was called is then summarized. The theoretical success of the intrinsically multidimensional delayed detonation paradigm in explaining the nature of Type Ia supernovae coupled with new techniques of observations in the near IR and with spectropolarimetry promise great advances in understanding binary progenitors, the explosion physics, and the ever more accurate application to cosmology. Spectropolarimetry has also revealed the strongly asymmetric nature of core collapse and given valuable perspectives on the supernova - gamma-ray burst connection. The capability of the magneto-rotational instability to rapidly create strong toroidal magnetic fields in the core collapse ambiance is outlined. This physics may be the precursor to driving MHD jets that play a role in asymmetric supernovae. Welcome to the brave new world of three-dimensional explosions!

  6. Solar Wind Heating as Revealed from the Variation of 3D Ion Velocity Distributions across the Magnetic Reconnection Exhaust Region

    NASA Astrophysics Data System (ADS)

    He, J.

    2015-12-01

    Magnetic reconnection within current sheet has been regarded as one of the crucial dissipation and heating processes of coherent structures in the solar wind turbulence. Counter-streaming of ions is an important phenomenon in the reconnection exhaust region ranged from the ion diffusion region to the extended outflow region. It has been suggested by theoretical and numerical models that the ions are going to be picked up by the ejecting magnetic field and show larger T_perpendicular than T_parallel, if the guide field is strong enough (in other word, the shear angle is relatively low). The pick-up behavior seems to favor the heating of heavy ions with high mass-to-charge ratio, since the high M/Q ions have larger gyro-period/transit-time and tend to be non-adiabatic more easily. The above statements from theoretical models have not been thoroughly testified in the solar wind observations, though the changes in total temperature and 1D reduced velocity distribution function had been studied. Until now, it remains unclear about the difference of full 3D velocity distribution for the proton and helium ions between the upstream and the exhaust regions. Here, we will analyze the plasma measurement data from WIND/3DP to explore and compare the parallel and perpendicular heating effect of different species of ions. As a preliminary result, the proton is found to show bi-directional streams in its velocity distribution in some reconnection exhaust regions. The thermalization of the counter-streaming protons will be presented. The relation between proton T_parallel/T_perpendicular and guide field strength (or shear angle) will be studied. The velocity distributions of helium ions will be illustrated, which shows the difference of heating effect between different M/Q ratios.

  7. An industrial light-field camera applied for 3D velocity measurements in a slot jet

    NASA Astrophysics Data System (ADS)

    Seredkin, A. V.; Shestakov, M. V.; Tokarev, M. P.

    2016-10-01

    Modern light-field cameras have found their application in different areas like photography, surveillance and quality control in industry. A number of studies have been reported relatively low spatial resolution of 3D profiles of registered objects along the optical axis of the camera. This article describes a method for 3D velocity measurements in fluid flows using an industrial light-field camera and an alternative reconstruction algorithm based on a statistical approach. This method is more accurate than triangulation when applied for tracking small registered objects like tracer particles in images. The technique was used to measure 3D velocity fields in a turbulent slot jet.

  8. 3D radiative transfer simulations of Eta Carinae's inner colliding winds - II. Ionization structure of helium at periastron

    NASA Astrophysics Data System (ADS)

    Clementel, N.; Madura, T. I.; Kruip, C. J. H.; Paardekooper, J.-P.

    2015-06-01

    Spectral observations of the massive colliding wind binary Eta Carinae show phase-dependent variations, in intensity and velocity, of numerous helium emission and absorption lines throughout the entire 5.54-yr orbit. Approaching periastron, the 3D structure of the wind-wind interaction region (WWIR) gets highly distorted due to the eccentric (e ˜ 0.9) binary orbit. The secondary star (ηB) at these phases is located deep within the primary's dense wind photosphere. The combination of these effects is thought to be the cause of the particularly interesting features observed in the helium lines at periastron. We perform 3D radiative transfer simulations of η Car's interacting winds at periastron. Using the SIMPLEX radiative transfer algorithm, we post-process output from 3D smoothed particle hydrodynamic simulations of the inner 150 au of the η Car system for two different primary star mass-loss rates (dot{M}_{η A}). Using previous results from simulations at apastron as a guide for the initial conditions, we compute 3D helium ionization maps. We find that, for higher dot{M}_{η A}, ηB He0+-ionizing photons are not able to penetrate into the pre-shock primary wind. He+ due to ηB is only present in a thin layer along the leading arm of the WWIR and in a small region close to the stars. Lowering dot{M}_{η A} allows ηB's ionizing photons to reach the expanding unshocked secondary wind on the apastron side of the system, and create a low fraction of He+ in the pre-shock primary wind. With apastron on our side of the system, our results are qualitatively consistent with the observed variations in strength and radial velocity of η Car's helium emission and absorption lines, which helps better constrain the regions where these lines arise.

  9. 3D Mesh Segmentation Based on Markov Random Fields and Graph Cuts

    NASA Astrophysics Data System (ADS)

    Shi, Zhenfeng; Le, Dan; Yu, Liyang; Niu, Xiamu

    3D Mesh segmentation has become an important research field in computer graphics during the past few decades. Many geometry based and semantic oriented approaches for 3D mesh segmentation has been presented. However, only a few algorithms based on Markov Random Field (MRF) has been presented for 3D object segmentation. In this letter, we present a definition of mesh segmentation according to the labeling problem. Inspired by the capability of MRF combining the geometric information and the topology information of a 3D mesh, we propose a novel 3D mesh segmentation model based on MRF and Graph Cuts. Experimental results show that our MRF-based schema achieves an effective segmentation.

  10. LC-lens array with light field algorithm for 3D biomedical applications

    NASA Astrophysics Data System (ADS)

    Huang, Yi-Pai; Hsieh, Po-Yuan; Hassanfiroozi, Amir; Martinez, Manuel; Javidi, Bahram; Chu, Chao-Yu; Hsuan, Yun; Chu, Wen-Chun

    2016-03-01

    In this paper, liquid crystal lens (LC-lens) array was utilized in 3D bio-medical applications including 3D endoscope and light field microscope. Comparing with conventional plastic lens array, which was usually placed in 3D endoscope or light field microscope system to record image disparity, our LC-lens array has higher flexibility of electrically changing its focal length. By using LC-lens array, the working distance and image quality of 3D endoscope and microscope could be enhanced. Furthermore, the 2D/3D switching ability could be achieved if we turn off/on the electrical power on LClens array. In 3D endoscope case, a hexagonal micro LC-lens array with 350um diameter was placed at the front end of a 1mm diameter endoscope. With applying electric field on LC-lens array, the 3D specimen would be recorded as from seven micro-cameras with different disparity. We could calculate 3D construction of specimen with those micro images. In the other hand, if we turn off the electric field on LC-lens array, the conventional high resolution 2D endoscope image would be recorded. In light field microscope case, the LC-lens array was placed in front of the CMOS sensor. The main purpose of LC-lens array is to extend the refocusing distance of light field microscope, which is usually very narrow in focused light field microscope system, by montaging many light field images sequentially focusing on different depth. With adjusting focal length of LC-lens array from 2.4mm to 2.9mm, the refocusing distance was extended from 1mm to 11.3mm. Moreover, we could use a LC wedge to electrically shift the optics axis and increase the resolution of light field.

  11. Semiautomatic approaches to account for 3-D distortion of the electric field from local, near-surface structures in 3-D resistivity inversions of 3-D regional magnetotelluric data

    USGS Publications Warehouse

    Rodriguez, Brian D.

    2017-03-31

    This report summarizes the results of three-dimensional (3-D) resistivity inversion simulations that were performed to account for local 3-D distortion of the electric field in the presence of 3-D regional structure, without any a priori information on the actual 3-D distribution of the known subsurface geology. The methodology used a 3-D geologic model to create a 3-D resistivity forward (“known”) model that depicted the subsurface resistivity structure expected for the input geologic configuration. The calculated magnetotelluric response of the modeled resistivity structure was assumed to represent observed magnetotelluric data and was subsequently used as input into a 3-D resistivity inverse model that used an iterative 3-D algorithm to estimate 3-D distortions without any a priori geologic information. A publicly available inversion code, WSINV3DMT, was used for all of the simulated inversions, initially using the default parameters, and subsequently using adjusted inversion parameters. A semiautomatic approach of accounting for the static shift using various selections of the highest frequencies and initial models was also tested. The resulting 3-D resistivity inversion simulation was compared to the “known” model and the results evaluated. The inversion approach that produced the lowest misfit to the various local 3-D distortions was an inversion that employed an initial model volume resistivity that was nearest to the maximum resistivities in the near-surface layer.

  12. A cross-platform solution for light field based 3D telemedicine.

    PubMed

    Wang, Gengkun; Xiang, Wei; Pickering, Mark

    2016-03-01

    Current telehealth services are dominated by conventional 2D video conferencing systems, which are limited in their capabilities in providing a satisfactory communication experience due to the lack of realism. The "immersiveness" provided by 3D technologies has the potential to promote telehealth services to a wider range of applications. However, conventional stereoscopic 3D technologies are deficient in many aspects, including low resolution and the requirement for complicated multi-camera setup and calibration, and special glasses. The advent of light field (LF) photography enables us to record light rays in a single shot and provide glasses-free 3D display with continuous motion parallax in a wide viewing zone, which is ideally suited for 3D telehealth applications. As far as our literature review suggests, there have been no reports of 3D telemedicine systems using LF technology. In this paper, we propose a cross-platform solution for a LF-based 3D telemedicine system. Firstly, a novel system architecture based on LF technology is established, which is able to capture the LF of a patient, and provide an immersive 3D display at the doctor site. For 3D modeling, we further propose an algorithm which is able to convert the captured LF to a 3D model with a high level of detail. For the software implementation on different platforms (i.e., desktop, web-based and mobile phone platforms), a cross-platform solution is proposed. Demo applications have been developed for 2D/3D video conferencing, 3D model display and edit, blood pressure and heart rate monitoring, and patient data viewing functions. The demo software can be extended to multi-discipline telehealth applications, such as tele-dentistry, tele-wound and tele-psychiatry. The proposed 3D telemedicine solution has the potential to revolutionize next-generation telemedicine technologies by providing a high quality immersive tele-consultation experience.

  13. A 360-degree floating 3D display based on light field regeneration.

    PubMed

    Xia, Xinxing; Liu, Xu; Li, Haifeng; Zheng, Zhenrong; Wang, Han; Peng, Yifan; Shen, Weidong

    2013-05-06

    Using light field reconstruction technique, we can display a floating 3D scene in the air, which is 360-degree surrounding viewable with correct occlusion effect. A high-frame-rate color projector and flat light field scanning screen are used in the system to create the light field of real 3D scene in the air above the spinning screen. The principle and display performance of this approach are investigated in this paper. The image synthesis method for all the surrounding viewpoints is analyzed, and the 3D spatial resolution and angular resolution of the common display zone are employed to evaluate display performance. The prototype is achieved and the real 3D color animation image has been presented vividly. The experimental results verified the representability of this method.

  14. FGG-NUFFT-Based Method for Near-Field 3-D Imaging Using Millimeter Waves

    PubMed Central

    Kan, Yingzhi; Zhu, Yongfeng; Tang, Liang; Fu, Qiang; Pei, Hucheng

    2016-01-01

    In this paper, to deal with the concealed target detection problem, an accurate and efficient algorithm for near-field millimeter wave three-dimensional (3-D) imaging is proposed that uses a two-dimensional (2-D) plane antenna array. First, a two-dimensional fast Fourier transform (FFT) is performed on the scattered data along the antenna array plane. Then, a phase shift is performed to compensate for the spherical wave effect. Finally, fast Gaussian gridding based nonuniform FFT (FGG-NUFFT) combined with 2-D inverse FFT (IFFT) is performed on the nonuniform 3-D spatial spectrum in the frequency wavenumber domain to achieve 3-D imaging. The conventional method for near-field 3-D imaging uses Stolt interpolation to obtain uniform spatial spectrum samples and performs 3-D IFFT to reconstruct a 3-D image. Compared with the conventional method, our FGG-NUFFT based method is comparable in both efficiency and accuracy in the full sampled case and can obtain more accurate images with less clutter and fewer noisy artifacts in the down-sampled case, which are good properties for practical applications. Both simulation and experimental results demonstrate that the FGG-NUFFT-based near-field 3-D imaging algorithm can have better imaging performance than the conventional method for down-sampled measurements. PMID:27657066

  15. FGG-NUFFT-Based Method for Near-Field 3-D Imaging Using Millimeter Waves.

    PubMed

    Kan, Yingzhi; Zhu, Yongfeng; Tang, Liang; Fu, Qiang; Pei, Hucheng

    2016-09-19

    In this paper, to deal with the concealed target detection problem, an accurate and efficient algorithm for near-field millimeter wave three-dimensional (3-D) imaging is proposed that uses a two-dimensional (2-D) plane antenna array. First, a two-dimensional fast Fourier transform (FFT) is performed on the scattered data along the antenna array plane. Then, a phase shift is performed to compensate for the spherical wave effect. Finally, fast Gaussian gridding based nonuniform FFT (FGG-NUFFT) combined with 2-D inverse FFT (IFFT) is performed on the nonuniform 3-D spatial spectrum in the frequency wavenumber domain to achieve 3-D imaging. The conventional method for near-field 3-D imaging uses Stolt interpolation to obtain uniform spatial spectrum samples and performs 3-D IFFT to reconstruct a 3-D image. Compared with the conventional method, our FGG-NUFFT based method is comparable in both efficiency and accuracy in the full sampled case and can obtain more accurate images with less clutter and fewer noisy artifacts in the down-sampled case, which are good properties for practical applications. Both simulation and experimental results demonstrate that the FGG-NUFFT-based near-field 3-D imaging algorithm can have better imaging performance than the conventional method for down-sampled measurements.

  16. Volumetric LiDAR scanning of a wind turbine wake and comparison with a 3D analytical wake model

    NASA Astrophysics Data System (ADS)

    Carbajo Fuertes, Fernando; Porté-Agel, Fernando

    2016-04-01

    A correct estimation of the future power production is of capital importance whenever the feasibility of a future wind farm is being studied. This power estimation relies mostly on three aspects: (1) a reliable measurement of the wind resource in the area, (2) a well-established power curve of the future wind turbines and, (3) an accurate characterization of the wake effects; the latter being arguably the most challenging one due to the complexity of the phenomenon and the lack of extensive full-scale data sets that could be used to validate analytical or numerical models. The current project addresses the problem of obtaining a volumetric description of a full-scale wake of a 2MW wind turbine in terms of velocity deficit and turbulence intensity using three scanning wind LiDARs and two sonic anemometers. The characterization of the upstream flow conditions is done by one scanning LiDAR and two sonic anemometers, which have been used to calculate incoming vertical profiles of horizontal wind speed, wind direction and an approximation to turbulence intensity, as well as the thermal stability of the atmospheric boundary layer. The characterization of the wake is done by two scanning LiDARs working simultaneously and pointing downstream from the base of the wind turbine. The direct LiDAR measurements in terms of radial wind speed can be corrected using the upstream conditions in order to provide good estimations of the horizontal wind speed at any point downstream of the wind turbine. All this data combined allow for the volumetric reconstruction of the wake in terms of velocity deficit as well as turbulence intensity. Finally, the predictions of a 3D analytical model [1] are compared to the 3D LiDAR measurements of the wind turbine. The model is derived by applying the laws of conservation of mass and momentum and assuming a Gaussian distribution for the velocity deficit in the wake. This model has already been validated using high resolution wind-tunnel measurements

  17. 3-D Full-kinetic Simulations of the Solar Wind Interaction with Lunar Magnetic Anomalies: Particle Behaviour

    NASA Astrophysics Data System (ADS)

    Deca, J.; Divin, A. V.; Wang, X.; Lembege, B.; Markidis, S.; Lapenta, G.; Horanyi, M.

    2015-12-01

    We present three-dimensional full-kinetic electromagnetic simulations of the solar wind interaction with lunar crustal magnetic anomalies (LMAs). Using the implicit particle-in-cell code iPic3D, we confirm that LMAs may indeed be strong enough to stand off the solar wind from directly impacting the lunar surface forming a mini-magnetosphere, as suggested by spacecraft observations and theory. In contrast to earlier MHD and hybrid simulations, the full-kinetic nature of iPic3D allows to self-consistently investigate space charge effects, and in particular the electron dynamics dominating the near-surface lunar plasma environment. We describe the general mechanism of the interaction of both a horizontal and vertical dipole model embedded just below the lunar surface focussing on the ion and electron kinetic behaviour of the system. It is shown that the configurations are largely dominated by electron motion, because the LMA scale size is small with respect to the gyro-radius of the solar wind ions. The formation of mini-magnetospheres is an electrostatic effect. Additionally, we discuss typical particle trajectories as well as complete particle distribution functions covering thermal and suprathermal energies, within the interaction region and on viable spacecraft altitudes. Our work opens new frontiers of research toward a deeper understanding of LMAs and is ideally suited to be compared with field or particle observations from spacecraft such as Kaguya (SELENE), Lunar Prospector or ARTEMIS. The ability to evaluate the implications for future lunar exploration as well as lunar science in general hinges on a better understanding of LMAs.This research has received funding from the European Commission's FP7 Program with the grant agreement EHEROES (project 284461, www.eheroes.eu). The simulations were conducted on the computational resources provided by the PRACE Tier-0 project 2013091928 (SuperMUC). This research was supported by the Swedish National Space Board

  18. Fully Kinetic 3D Simulations of the Interaction of the Solar Wind with Mercury

    NASA Astrophysics Data System (ADS)

    Amaya, J.; Deca, J.; Lembege, B.; Lapenta, G.

    2015-12-01

    The planet Mercury has been studied by the space mission Mariner 10, in the 1970's, and by the MESSENGER mission launched in 2004. Interest in the first planet of the Solar System has now been renewed by the launch in 2017 of the BepiColombo mission. MESSENGER and BepiColombo give access to information about the local conditions of the magnetosphere of Mercury. This data must be evaluated in the context of the global interaction between the solar wind and the planet's magnetosphere. Global scale simulations of the planet's environment are necessary to fully understand the data gathered from in-situ measurements. We use three-dimensional simulations to support the scientific goals of the two missions. In contrast with the results based on MHD (Kabin et al., 2000) and hybrid codes (Kallio et Janhumen, 2003; Travnicek et al., 2007, 2010; Richer et al., 2012), the present work is based on the implicit moment Particle-in-Cell (PiC) method, which allows to use large time and space steps, while granting access to the dynamics of the smaller electron scales in the plasma. The purpose of these preliminary PIC simulations is to retrieve the top-level features of Mercury's magnetosphere and its frontiers. We compare the results obtained with the implicit moment PiC method against 3D hybrid simulations. We perform simulations of the global plasma environment of Mercury using the solar wind conditions measured by MESSENGER. We show that complex flows form around the planet, including the development of Kelvin-Helmoltz instabilities at the flanks. We evaluate the dynamics of the shock, magnetosheath, magnetopause, the reconnection areas, the formation of plasma sheet and magnetotail, and the variation of ion/electron plasma flows when crossing these frontiers. The simulations also give access to detailed information about the particle dynamics and their velocity distribution at locations that can be used for comparison with data from MESSENGER and later on with the forthcoming

  19. 3-D residual eddy current field characterisation: applied to diffusion weighted magnetic resonance imaging.

    PubMed

    O'Brien, Kieran; Daducci, Alessandro; Kickler, Nils; Lazeyras, Francois; Gruetter, Rolf; Feiweier, Thorsten; Krueger, Gunnar

    2013-08-01

    Clinical use of the Stejskal-Tanner diffusion weighted images is hampered by the geometric distortions that result from the large residual 3-D eddy current field induced. In this work, we aimed to predict, using linear response theory, the residual 3-D eddy current field required for geometric distortion correction based on phantom eddy current field measurements. The predicted 3-D eddy current field induced by the diffusion-weighting gradients was able to reduce the root mean square error of the residual eddy current field to ~1 Hz. The model's performance was tested on diffusion weighted images of four normal volunteers, following distortion correction, the quality of the Stejskal-Tanner diffusion-weighted images was found to have comparable quality to image registration based corrections (FSL) at low b-values. Unlike registration techniques the correction was not hindered by low SNR at high b-values, and results in improved image quality relative to FSL. Characterization of the 3-D eddy current field with linear response theory enables the prediction of the 3-D eddy current field required to correct eddy current induced geometric distortions for a wide range of clinical and high b-value protocols.

  20. 3D airflow dynamics over transverse ridges Mpekweni, South Africa: implications for dune field migration behaviour

    NASA Astrophysics Data System (ADS)

    Jackson, Derek; Cooper, Andrew; Green, Andrew; Beyers, Meiring; Wiles, Errol; Benallack, Keegan

    2016-04-01

    Un-vegetated dune fields provide excellent opportunities to examine airflow dynamics over various types and scales of dune landforms. The three dimensional surface over which lower boundary layers travel, help adjust surface airflow and consequently the aeolian response of the dunes themselves. The use of computational fluid dynamic (CFD) modelling in recent studies now enables investigation of the 3D behaviour of airflow over complex terrain, providing new insights into heterogeneous surface flow and aeolian response of dune surfaces on a large (dunefield) scale. Using a largely un-vegetated coastal dune field site at Mpekweni, Eastern Cape, South Africa, a detailed (0.1m gridded) terrestrial laser scanning survey was conducted to create a high resolution topographical surface. Using local wind flow measurements and local met station records as input, CFD modelling was performed for a number of scenarios involving variable direction and magnitude to examine surface flow patterns across multiple dune forms. Near surface acceleration, expansion and separation of airflow inducing convergence and divergence (steering) of flow velocity streamlines are investigated. Flow acceleration over dune crests/brink lines is a key parameter in driving dune migration and slip face dynamics. Dune aspect ratio (height to length) is also important in determining the degree of crestal flow acceleration, with an increase in flow associated with increasing aspect ratios. Variations in dune height appear to be the most important parameter in driving general flow acceleration. The results from the study provide new insights into dune migration behaviour at this site as well as surface flow behaviour across multiple dune configurations and length scales within un-vegetated dune fields.

  1. Quantitative 3D electromagnetic field determination of 1D nanostructures from single projection

    SciTech Connect

    Phatak, Charudatta; Knoop, Ludvig de; Houdellier, Florent; Gatel, Christophe; Hytch, Martin J.; Masseboeuf, Aurelien

    2016-03-10

    One-dimensional (1D) nanostructures have been regarded as the most promising building blocks for nanoelectronics and nanocomposite material systems as well as for alternative energy applications. Although they result in confinement of a material, their properties and interactions with other nanostructures are still very much three-dimensional (3D) in nature. In this work, we present a novel method for quantitative determination of the 3D electromagnetic fields in and around 1D nanostructures using a single electron wave phase image, thereby eliminating the cumbersome acquisition of tomographic data. Using symmetry arguments, we have reconstructed the 3D magnetic field of a nickel nanowire as well as the 3D electric field around a carbon nanotube field emitter, from one single projection. The accuracy of quantitative values determined here is shown to be a better fit to the physics at play than the value obtained by conventional analysis. Furthermore the 3D reconstructions can then directly be visualized and used in the design of functional 3D architectures built using 1D nanostructures.

  2. Quantitative 3D electromagnetic field determination of 1D nanostructures from single projection

    DOE PAGES

    Phatak, Charudatta; Knoop, Ludvig de; Houdellier, Florent; ...

    2016-03-10

    One-dimensional (1D) nanostructures have been regarded as the most promising building blocks for nanoelectronics and nanocomposite material systems as well as for alternative energy applications. Although they result in confinement of a material, their properties and interactions with other nanostructures are still very much three-dimensional (3D) in nature. In this work, we present a novel method for quantitative determination of the 3D electromagnetic fields in and around 1D nanostructures using a single electron wave phase image, thereby eliminating the cumbersome acquisition of tomographic data. Using symmetry arguments, we have reconstructed the 3D magnetic field of a nickel nanowire as wellmore » as the 3D electric field around a carbon nanotube field emitter, from one single projection. The accuracy of quantitative values determined here is shown to be a better fit to the physics at play than the value obtained by conventional analysis. Furthermore the 3D reconstructions can then directly be visualized and used in the design of functional 3D architectures built using 1D nanostructures.« less

  3. Quantitative 3D electromagnetic field determination of 1D nanostructures from single projection

    SciTech Connect

    Phatak, C.; Knoop, L. de; Houdellier, F.; Gatel, C.; Hÿtch, M. J.; Masseboeuf, A.

    2016-05-01

    One-dimensional (1D) nanostructures have been regarded as the most promising building blocks for nanoelectronics and nanocomposite material systems as well as for alternative energy applications. Although they result in confinement of a material, their properties and interactions with other nanostructures are still very much three-dimensional (3D) in nature. In this work, we present a novel method for quantitative determination of the 3D electromagnetic fields in and around 1D nanostructures using a single electron wave phase image, thereby eliminating the cumbersome acquisition of tomographic data. Using symmetry arguments, we have reconstructed the 3D magnetic field of a nickel nanowire as well as the 3D electric field around a carbon nanotube field emitter, from one single projection. The accuracy of quantitative values determined here is shown to be a better fit to the physics at play than the value obtained by conventional analysis. Moreover the 3D reconstructions can then directly be visualized and used in the design of functional 3D architectures built using 1D nanostructures.

  4. 3-D MHD disk wind simulations of jets and outflows from high-mass protostars

    NASA Astrophysics Data System (ADS)

    Staff, Jan E.; Tanaka, Kei; Tan, Jonathan C.; Zhang, Yichen; Liu, Mengyao

    2017-01-01

    We present the results of a series of nested, large scale, three-dimensional magnetohydrodynamics simulations of disk winds with a Blandford-Payne like magnetic field configuration, resolving scales from the stellar surface to beyond the core. The goal is to understand the structure of massive protostellar cores at various stages of their formation as the protostellar mass grows from a massive core. At each stage of a given protostellar mass, first, we study how jets and winds develop from the inner accretion disk to ~100 AU scales. We use the results from these simulations to dictate the inner boundary condition of a set of simulation extending to the core boundary at ~10,000 AU of an initially 60 solar mass core. We run separate simulations where the protostellar mass is 1, 2, 4, 8, 12, 16, and 24 Msun, and we are working on making a small grid of models in the context of the Turbulent Core Model with three different core masses and three different core surface densities. The wind is blown into the simulation box with properties derived from the previous jet simulations. We examine the opening angle of the outflow cavity and thus the star formation efficiency from the core due to outflow feedback. We find that the opening angle increases as the protostellar mass grows, but it is always less than 10 degrees, which is surprisingly small compared with previous analytic models. This is caused by the core which confines the outflow. Finally, we use our simulation results as input to a radiative transfer calculation, to compare with observations made by the SOMA survey.

  5. How 3D seismic-CAEX combination affected development of N. Frisco City field in Alabama

    SciTech Connect

    Stephenson, M.; Cox, J.; Jones-Fuentes, P. )

    1992-10-26

    This paper reports that by applying the latest in 3D seismic and computer aided exploration and production (CAEX) technology, small and mid-size independents are changing the methods by which fields are discovered and profitably developed. The combination of 3D and CAEX has, in many cases, altered oilfield economics. Nuevo Energy Co.'s North Frisco City development---located in the updip Jurassic Haynesville trend of Southwest Alabama---offers a case in point. The 3D technology employed at North Frisco City produced and accurate, detailed picture of the subsurface. Ultimately it more than doubled the drilling success rate over that of a nearby, closely related field in which 3D was not used.

  6. ACCRETION OF SUPERSONIC WINDS ONTO BLACK HOLES IN 3D: STABILITY OF THE SHOCK CONE

    SciTech Connect

    Gracia-Linares, M.; Guzmán, F. S.

    2015-10-10

    Using numerical simulations we present the accretion of supersonic winds onto a rotating black hole in three dimensions. We study five representative directions of the wind with respect to the axis of rotation of the black hole and focus on the evolution and stability of the high-density shock cone that is formed during the process. We explore both the regime in which the shock cone is expected to be stable in order to confirm previous results obtained with two-dimensional simulations, and the regime in which the shock cone is expected to show a flip–flop (FF) type of instability. The methods used to attempt a triggering of the instability were (i) the accumulation of numerical errors and (ii) the explicit application of a perturbation on the velocity field after the shock cone was formed. The result is negative, that is, we did not find the FF instability within the parameter space we explored, including cases that are expected to be unstable.

  7. 3D-xy critical properties of YBa2Cu4O8 and magnetic-field-induced 3D to 1D crossover

    NASA Astrophysics Data System (ADS)

    Weyeneth, S.; Schneider, T.; Bukowski, Z.; Karpinski, J.; Keller, H.

    2008-08-01

    We present reversible magnetization data of a YBa2Cu4O8 single crystal and analyze the evidence for 3D-xy critical behavior and a magnetic-field-induced 3D to 1D crossover. Remarkable consistency with these phenomena is observed in agreement with a magnetic-field-induced finite size effect, whereupon the correlation length transverse to the applied magnetic field cannot grow beyond the limiting magnetic length scale LH = (Φ0/(aH))1/2. By applying the appropriate scaling form we obtain the zero-field critical temperature, the 3D to 1D crossover, the vortex melting line and the universal ratios of the related scaling variables. Accordingly there is no continuous phase transition in the (H,T) plane along the Hc2 lines as predicted by the mean-field treatment.

  8. On the magnetotransport of 3D systems in quantizing magnetic field

    NASA Astrophysics Data System (ADS)

    Cheremisin, M. V.

    2014-12-01

    The resistivity components of 3D electron gas placed in quantizing magnetic field are calculated taking into account the correction caused by combined action of the Peltier and Seebeck thermoelectric effects. The longitudinal, transverse and the Hall magnetoresistivities exhibit familiar 1/B-period oscillations being universal functions of magnetic field and temperature.

  9. Time dependent wind fields

    NASA Technical Reports Server (NTRS)

    Chelton, D. B.

    1986-01-01

    Two tasks were performed: (1) determination of the accuracy of Seasat scatterometer, altimeter, and scanning multichannel microwave radiometer measurements of wind speed; and (2) application of Seasat altimeter measurements of sea level to study the spatial and temporal variability of geostrophic flow in the Antarctic Circumpolar Current. The results of the first task have identified systematic errors in wind speeds estimated by all three satellite sensors. However, in all cases the errors are correctable and corrected wind speeds agree between the three sensors to better than 1 ms sup -1 in 96-day 2 deg. latitude by 6 deg. longitude averages. The second task has resulted in development of a new technique for using altimeter sea level measurements to study the temporal variability of large scale sea level variations. Application of the technique to the Antarctic Circumpolar Current yielded new information about the ocean circulation in this region of the ocean that is poorly sampled by conventional ship-based measurements.

  10. Electrochemical fields within 3D reconstructed microstructures of mixed ionic and electronic conducting devices

    NASA Astrophysics Data System (ADS)

    Zhang, Yanxiang; Chen, Yu; Lin, Ye; Yan, Mufu; Harris, William M.; Chiu, Wilson K. S.; Ni, Meng; Chen, Fanglin

    2016-11-01

    The performance and stability of the mixed ionic and electronic conducting (MIEC) membrane devices, such as solid oxide cells (SOCs) and oxygen separation membranes (OSMs) interplay tightly with the transport properties and the three-dimensional (3D) microstructure of the membrane. However, development of the MIEC devices is hindered by the limited knowledge about the distribution of electrochemical fields within the 3D local microstructures, especially at surface and interface. In this work, a generic model conforming to local thermodynamic equilibrium is developed to calculate the electrochemical fields, such as electric potential and oxygen chemical potential, within the 3D microstructure of the MIEC membrane. Stability of the MIEC membrane is evaluated by the distribution of oxygen partial pressure. The cell-level performance such as polarization resistance and voltage vs. current curve can be further calculated. Case studies are performed to demonstrate the capability of the framework by using X-ray computed tomography reconstructed 3D microstructures of a SOC and an OSM. The calculation method demonstrates high computational efficiency for large size 3D tomographic microstructures, and permits parallel calculation. The framework can serve as a powerful tool for correlating the transport properties and the 3D microstructure to the performance and the stability of MIEC devices.

  11. Solar Wind Halo Formation by the Scattering of the Strahl via Direct Cluster/PEACE Observations of the 3D Velocity Distribution Function

    NASA Technical Reports Server (NTRS)

    Figueroa-Vinas, Adolfo; Gurgiolo, Chris A.; Nieves-Chinchilla, Teresa; Goldstein, Melvyn L.

    2010-01-01

    It has been suggested by a number of authors that the solar wind electron halo can be formed by the scattering of the strahl. On frequent occasions we have observed in electron angular skymaps (Phi/Theta-plots) of the electron 3D velocity distribution functions) a bursty-filament of particles connecting the strahl to the solar wind core-halo. These are seen over a very limited energy range. When the magnetic field is well off the nominal solar wind flow direction such filaments are inconsistent with any local forces and are probably the result of strong scattering. Furthermore, observations indicates that the strahl component is frequently and significantly anisotropic (Tper/Tpal approx.2). This provides a possible free energy source for the excitation of whistler waves as a possible scattering mechanism. The empirical observational evidence between the halo and the strahl suggests that the strahl population may be, at least in part, the source of the halo component.

  12. Realistic 3D coherent transfer function inverse filtering of complex fields

    PubMed Central

    Cotte, Yann; Toy, Fatih M.; Arfire, Cristian; Kou, Shan Shan; Boss, Daniel; Bergoënd, Isabelle; Depeursinge, Christian

    2011-01-01

    We present a novel technique for three-dimensional (3D) image processing of complex fields. It consists in inverting the coherent image formation by filtering the complex spectrum with a realistic 3D coherent transfer function (CTF) of a high-NA digital holographic microscope. By combining scattering theory and signal processing, the method is demonstrated to yield the reconstruction of a scattering object field. Experimental reconstructions in phase and amplitude are presented under non-design imaging conditions. The suggested technique is best suited for an implementation in high-resolution diffraction tomography based on sample or illumination rotation. PMID:21833359

  13. Realistic 3D coherent transfer function inverse filtering of complex fields.

    PubMed

    Cotte, Yann; Toy, Fatih M; Arfire, Cristian; Kou, Shan Shan; Boss, Daniel; Bergoënd, Isabelle; Depeursinge, Christian

    2011-08-01

    We present a novel technique for three-dimensional (3D) image processing of complex fields. It consists in inverting the coherent image formation by filtering the complex spectrum with a realistic 3D coherent transfer function (CTF) of a high-NA digital holographic microscope. By combining scattering theory and signal processing, the method is demonstrated to yield the reconstruction of a scattering object field. Experimental reconstructions in phase and amplitude are presented under non-design imaging conditions. The suggested technique is best suited for an implementation in high-resolution diffraction tomography based on sample or illumination rotation.

  14. DIRECT DETECTION OF THE HELICAL MAGNETIC FIELD GEOMETRY FROM 3D RECONSTRUCTION OF PROMINENCE KNOT TRAJECTORIES

    SciTech Connect

    Zapiór, Maciej; Martinez-Gómez, David

    2016-02-01

    Based on the data collected by the Vacuum Tower Telescope located in the Teide Observatory in the Canary Islands, we analyzed the three-dimensional (3D) motion of so-called knots in a solar prominence of 2014 June 9. Trajectories of seven knots were reconstructed, giving information of the 3D geometry of the magnetic field. Helical motion was detected. From the equipartition principle, we estimated the lower limit of the magnetic field in the prominence to ≈1–3 G and from the Ampère’s law the lower limit of the electric current to ≈1.2 × 10{sup 9} A.

  15. Evidence of Toroidally Localized Turbulence with Applied 3D Fields in the DIII-D Tokamak.

    PubMed

    Wilcox, R S; Shafer, M W; Ferraro, N M; McKee, G R; Zeng, L; Rhodes, T L; Canik, J M; Paz-Soldan, C; Nazikian, R; Unterberg, E A

    2016-09-23

    New evidence indicates that there is significant 3D variation in density fluctuations near the boundary of weakly 3D tokamak plasmas when resonant magnetic perturbations are applied to suppress transient edge instabilities. The increase in fluctuations is concomitant with an increase in the measured density gradient, suggesting that this toroidally localized gradient increase could be a mechanism for turbulence destabilization in localized flux tubes. Two-fluid magnetohydrodynamic simulations find that, although changes to the magnetic field topology are small, there is a significant 3D variation of the density gradient within the flux surfaces that is extended along field lines. This modeling agrees qualitatively with the measurements. The observed gradient and fluctuation asymmetries are proposed as a mechanism by which global profile gradients in the pedestal could be relaxed due to a local change in the 3D equilibrium. These processes may play an important role in pedestal and scrape-off layer transport in ITER and other future tokamak devices with small applied 3D fields.

  16. Evidence of toroidally localized turbulence with applied 3D fields in the DIII-D tokamak

    DOE PAGES

    Wilcox, R. S.; Shafer, M. W.; Ferraro, N. M.; ...

    2016-09-21

    New evidence indicates that there is significant 3D variation in density fluctuations near the boundary of weakly 3D tokamak plasmas when resonant magnetic perturbations are applied to suppress transient edge instabilities. The increase in fluctuations is concomitant with an increase in the measured density gradient, suggesting that this toroidally localized gradient increase could be a mechanism for turbulence destabilization in localized flux tubes. Two-fluid magnetohydrodynamic simulations find that, although changes to the magnetic field topology are small, there is a significant 3D variation of the density gradient within the flux surfaces that is extended along field lines. This modeling agreesmore » qualitatively with the measurements. The observed gradient and fluctuation asymmetries are proposed as a mechanism by which global profile gradients in the pedestal could be relaxed due to a local change in the 3D equilibrium. In conclusion, these processes may play an important role in pedestal and scrape-off layer transport in ITER and other future tokamak devices with small applied 3D fields.« less

  17. Evidence of toroidally localized turbulence with applied 3D fields in the DIII-D tokamak

    SciTech Connect

    Wilcox, R. S.; Shafer, M. W.; Ferraro, N. M.; McKee, G. R.; Zeng, L.; Rhodes, T. L.; Canik, J. M.; Paz-Soldan, C.; Nazikian, R.; Unterberg, E. A.

    2016-09-21

    New evidence indicates that there is significant 3D variation in density fluctuations near the boundary of weakly 3D tokamak plasmas when resonant magnetic perturbations are applied to suppress transient edge instabilities. The increase in fluctuations is concomitant with an increase in the measured density gradient, suggesting that this toroidally localized gradient increase could be a mechanism for turbulence destabilization in localized flux tubes. Two-fluid magnetohydrodynamic simulations find that, although changes to the magnetic field topology are small, there is a significant 3D variation of the density gradient within the flux surfaces that is extended along field lines. This modeling agrees qualitatively with the measurements. The observed gradient and fluctuation asymmetries are proposed as a mechanism by which global profile gradients in the pedestal could be relaxed due to a local change in the 3D equilibrium. In conclusion, these processes may play an important role in pedestal and scrape-off layer transport in ITER and other future tokamak devices with small applied 3D fields.

  18. 3D Concrete Printing Concept Could Solve Tall-Wind Dilemma

    ScienceCinema

    Cotrell, Jason; Jenne, Scott; Butterfield, Sandy

    2017-01-06

    When building a wind turbine, you want to make it as tall as possible to capture stronger, faster winds aloft. But taller tower bases become too large to be transported over the road—a constraint that has kept average U.S. wind turbine heights at 80 meters for the last 10 years. A Lab-Corps project undertaken by the National Renewable Energy Laboratory has found a potential solution: automated concrete manufacturing.

  19. 3D Concrete Printing Concept Could Solve Tall-Wind Dilemma

    SciTech Connect

    Cotrell, Jason; Jenne, Scott; Butterfield, Sandy

    2016-12-29

    When building a wind turbine, you want to make it as tall as possible to capture stronger, faster winds aloft. But taller tower bases become too large to be transported over the road—a constraint that has kept average U.S. wind turbine heights at 80 meters for the last 10 years. A Lab-Corps project undertaken by the National Renewable Energy Laboratory has found a potential solution: automated concrete manufacturing.

  20. 3-D seismic velocity and attenuation structures in the geothermal field

    SciTech Connect

    Nugraha, Andri Dian; Syahputra, Ahmad; Fatkhan,; Sule, Rachmat

    2013-09-09

    We conducted delay time tomography to determine 3-D seismic velocity structures (Vp, Vs, and Vp/Vs ratio) using micro-seismic events in the geothermal field. The P-and S-wave arrival times of these micro-seismic events have been used as input for the tomographic inversion. Our preliminary seismic velocity results show that the subsurface condition of geothermal field can be fairly delineated the characteristic of reservoir. We then extended our understanding of the subsurface physical properties through determining of attenuation structures (Qp, Qs, and Qs/Qp ratio) using micro-seismic waveform. We combined seismic velocities and attenuation structures to get much better interpretation of the reservoir characteristic. Our preliminary attanuation structures results show reservoir characterization can be more clearly by using the 3-D attenuation model of Qp, Qs, and Qs/Qp ratio combined with 3-D seismic velocity model of Vp, Vs, and Vp/Vs ratio.

  1. Synthesis of 3D Model of a Magnetic Field-Influenced Body from a Single Image

    NASA Technical Reports Server (NTRS)

    Wang, Cuilan; Newman, Timothy; Gallagher, Dennis

    2006-01-01

    A method for recovery of a 3D model of a cloud-like structure that is in motion and deforming but approximately governed by magnetic field properties is described. The method allows recovery of the model from a single intensity image in which the structure's silhouette can be observed. The method exploits envelope theory and a magnetic field model. Given one intensity image and the segmented silhouette in the image, the method proceeds without human intervention to produce the 3D model. In addition to allowing 3D model synthesis, the method's capability to yield a very compact description offers further utility. Application of the method to several real-world images is demonstrated.

  2. 3-D Flow Field Diagnostics and Validation Studies using Stereoscopic Tracking Velocimetry

    NASA Technical Reports Server (NTRS)

    Cha, Soyoung Stephen; Ramachandran, Narayanan; Whitaker, Ann F. (Technical Monitor)

    2002-01-01

    The measurement of 3-D three-component velocity fields is of great importance in both ground and space experiments for understanding materials processing and fluid physics. Here, we present the investigation results of stereoscopic tracking velocimetry (STV) for measuring 3-D velocity fields. The effort includes diagnostic technology development, experimental velocity measurement, and comparison with analytical and numerical computation. The advantages of STV stems from the system simplicity for building compact hardware and in software efficiency for continual near-real-time process monitoring. It also has illumination flexibility for observing volumetric flow fields from arbitrary directions. STV is based on stereoscopic CCD observations of particles seeded in a flow. Neural networks are used for data analysis. The developed diagnostic tool is tested with a simple directional solidification apparatus using Succinonitrile. The 3-D velocity field in the liquid phase is measured and compared with results from detailed numerical computations. Our theoretical, numerical, and experimental effort has shown STV to be a viable candidate for reliably quantifying the 3-D flow field in materials processing and fluids experiments.

  3. Motion field estimation for a dynamic scene using a 3D LiDAR.

    PubMed

    Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington

    2014-09-09

    This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively.

  4. Motion Field Estimation for a Dynamic Scene Using a 3D LiDAR

    PubMed Central

    Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington

    2014-01-01

    This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (LiDAR) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D LiDAR-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D LiDAR measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively. PMID:25207868

  5. Numerical Optimization Strategy for Determining 3D Flow Fields in Microfluidics

    NASA Astrophysics Data System (ADS)

    Eden, Alex; Sigurdson, Marin; Mezic, Igor; Meinhart, Carl

    2015-11-01

    We present a hybrid experimental-numerical method for generating 3D flow fields from 2D PIV experimental data. An optimization algorithm is applied to a theory-based simulation of an alternating current electrothermal (ACET) micromixer in conjunction with 2D PIV data to generate an improved representation of 3D steady state flow conditions. These results can be used to investigate mixing phenomena. Experimental conditions were simulated using COMSOL Multiphysics to solve the temperature and velocity fields, as well as the quasi-static electric fields. The governing equations were based on a theoretical model for ac electrothermal flows. A Nelder-Mead optimization algorithm was used to achieve a better fit by minimizing the error between 2D PIV experimental velocity data and numerical simulation results at the measurement plane. By applying this hybrid method, the normalized RMS velocity error between the simulation and experimental results was reduced by more than an order of magnitude. The optimization algorithm altered 3D fluid circulation patterns considerably, providing a more accurate representation of the 3D experimental flow field. This method can be generalized to a wide variety of flow problems. This research was supported by the Institute for Collaborative Biotechnologies through grant W911NF-09-0001 from the U.S. Army Research Office.

  6. Color Flat Panel Displays: 3D Autostereoscopic Brassboard and Field Sequential Illumination Technology.

    DTIC Science & Technology

    1997-06-01

    DTI has advanced autostereoscopic and field sequential color (FSC) illumination technologies for flat panel displays. Using a patented backlight...technology, DTI has developed prototype 3D flat panel color display that provides stereoscopic viewing without the need for special glasses or other... autostereoscopic viewing. Discussions of system architecture, critical component specifications and resultant display characteristics are provided. Also

  7. 3-D field computation: The near-triumph of commerical codes

    SciTech Connect

    Turner, L.R.

    1995-07-01

    In recent years, more and more of those who design and analyze magnets and other devices are using commercial codes rather than developing their own. This paper considers the commercial codes and the features available with them. Other recent trends with 3-D field computation include parallel computation and visualization methods such as virtual reality systems.

  8. Modeling solar wind mass-loading in the vicinity of the Sun using 3-D MHD simulations

    NASA Astrophysics Data System (ADS)

    Rasca, A. P.; Horányi, M.; Oran, R.; Holst, B.

    2014-01-01

    Collisionless shocks due to mass-loading were first discussed to describe the solar wind flow around a cometary atmosphere, showing its choking effects on the flow. Recent observations have led to an increased interest in mass-loading occurring in the solar corona due to both sungrazing comets and collisional debris production by sunward migrating interplanetary dust particles. The 1-D simulations with a hydrodynamic model have illustrated the impact on the solar wind from abrupt mass-loading in the coronal region. Full 3-D magnetohydrodynamic (MHD) simulations using a solar corona model based on the Block-Adaptive-Tree-Solarwind-Roe-Upwind-Scheme code provide a more realistic coronal environment for modeling specific events applicable to modeling the mass-loaded coronal wind. A specific application is introduced modeling the mass-loading effects from a sungrazing comet.

  9. Field lens multiplexing in holographic 3D displays by using Bragg diffraction based volume gratings

    NASA Astrophysics Data System (ADS)

    Fütterer, G.

    2016-11-01

    Applications, which can profit from holographic 3D displays, are the visualization of 3D data, computer-integrated manufacturing, 3D teleconferencing and mobile infotainment. However, one problem of holographic 3D displays, which are e.g. based on space bandwidth limited reconstruction of wave segments, is to realize a small form factor. Another problem is to provide a reasonable large volume for the user placement, which means to provide an acceptable freedom of movement. Both problems should be solved without decreasing the image quality of virtual and real object points, which are generated within the 3D display volume. A diffractive optical design using thick hologram gratings, which can be referred to as Bragg diffraction based volume gratings, can provide a small form factor and high definition natural viewing experience of 3D objects. A large collimated wave can be provided by an anamorphic backlight unit. The complex valued spatial light modulator add local curvatures to the wave field he is illuminated with. The modulated wave field is focused onto to the user plane by using a volume grating based field lens. Active type liquid crystal gratings provide 1D fine tracking of approximately +/- 8° deg. Diffractive multiplex has to be implemented for each color and for a set of focus functions providing coarse tracking. Boundary conditions of the diffractive multiplexing are explained. This is done in regards to the display layout and by using the coupled wave theory (CWT). Aspects of diffractive cross talk and its suppression will be discussed including longitudinal apodized volume gratings.

  10. Investigation of the 3-D actinic flux field in mountainous terrain

    PubMed Central

    Wagner, J.E.; Angelini, F.; Blumthaler, M.; Fitzka, M.; Gobbi, G.P.; Kift, R.; Kreuter, A.; Rieder, H.E.; Simic, S.; Webb, A.; Weihs, P.

    2011-01-01

    During three field campaigns spectral actinic flux was measured from 290–500 nm under clear sky conditions in Alpine terrain and the associated O3- and NO2-photolysis frequencies were calculated and the measurement products were then compared with 1-D- and 3-D-model calculations. To do this 3-D-radiative transfer model was adapted for actinic flux calculations in mountainous terrain and the maps of the actinic flux field at the surface, calculated with the 3-D-radiative transfer model, are given. The differences between the 3-D- and 1-D-model results for selected days during the campaigns are shown, together with the ratios of the modeled actinic flux values to the measurements. In many cases the 1-D-model overestimates actinic flux by more than the measurement uncertainty of 10%. The results of using a 3-D-model generally show significantly lower values, and can underestimate the actinic flux by up to 30%. This case study attempts to quantify the impact of snow cover in combination with topography on spectral actinic flux. The impact of snow cover on the actinic flux was ~ 25% in narrow snow covered valleys, but for snow free areas there were no significant changes due snow cover in the surrounding area and it is found that the effect snow-cover at distances over 5 km from the point of interest was below 5%. Overall the 3-D-model can calculate actinic flux to the same accuracy as the 1-D-model for single points, but gives a much more realistic view of the surface actinic flux field in mountains as topography and obstruction of the horizon are taken into account. PMID:26412915

  11. HyperCube: a hyperspectral CubeSat constellation for measurements of 3D winds

    NASA Astrophysics Data System (ADS)

    Glumb, Ronald; Lapsley, Michael; Luce, Scott; Déry, Jean-Philippe; Scott, Deron; Nielsen, Tim

    2016-09-01

    Global measurements of vertically resolved atmospheric wind profiles offer the potential for improved weather forecasts and superior predictions of atmospheric wind patterns. Harris' HyperCube constellation of twelve 6U hyperspectral CubeSats can provide measurements of global tropospheric wind profiles from space at very low cost. It is a commercially funded enterprise in which the data from the satellites is provided to users on a subscription basis. This requires that the design of each satellite be optimized for minimum cost, yet with a reasonably long service life. This paper will focus on the design, operations, and projected performance of the HyperCube system.

  12. 3D radiative transfer simulations of Eta Carinae's inner colliding winds - I. Ionization structure of helium at apastron

    NASA Astrophysics Data System (ADS)

    Clementel, N.; Madura, T. I.; Kruip, C. J. H.; Paardekooper, J.-P.; Gull, T. R.

    2015-03-01

    The highly eccentric binary system Eta Carinae (η Car) shows numerous time-variable emission and absorption features. These observational signatures are the result of interactions between the complex three-dimensional (3D) wind-wind collision regions and photoionization by the luminous stars. Specifically, helium presents several interesting spectral features that provide important clues on the geometry and physical proprieties of the system and the individual stars. We use the SIMPLEX algorithm to post-process 3D smoothed particle hydrodynamics simulation output of the interacting winds in η Car in order to obtain the fractions of ionized helium assuming three different primary star (ηA) mass-loss rates. The resultant ionization maps constrain the regions where helium is singly- and doubly-ionized. We find that reducing ηA's mass-loss rate (dot{M}_{η A}) increases the volume of He+. Lowering dot{M}_{η A} produces large variations in the volume of He+ in the pre-shock ηA wind on the periastron side of the system. Our results show that binary orientations in which apastron is on our side of the system are more consistent with available observations. We suggest that small variations in dot{M}_{η A} might explain the observed increase in He I absorption in recent decades, although numerous questions regarding this scenario remain open. We also propose that the absence of broad He I lines in the spectra of η Car between its 1890's eruption and ˜1944 might be explained by ηB's He0+-ionizing photons not being able to penetrate the wind-wind interaction region, due to a higher dot{M}_{η A} at that time (by a factor ≳2, compared to the present value).

  13. IMPROVED WIND AND TURBULENCE MEASUREMENTS USING A LOW-COST 3-D SONIC ANEMOMETER AT A LOW-WIND SITE

    SciTech Connect

    Bowen, B

    2007-05-11

    A year of data from sonic anemometer and mechanical wind sensors was analyzed and compared at a low-wind site. Results indicate that 15-minute average and peak 1-second wind speeds (u) from the sonic agree well with data derived from a co-located cup anemometer over a wide range of speeds. Wind direction data derived from the sonic also agree closely with those from a wind vane except for very low wind speeds. Values of standard deviation of longitudinal wind speed ({sigma}{sub u}) and wind direction fluctuations ({delta}{sub {theta}}) from the sonic and mechanical sensors agree well for times with u > 2 ms{sup -1} but show significant differences with lower u values. The most significant differences are associated with the standard deviation of vertical wind fluctuations ({sigma}{sub w}): the co-located vertical propeller anemometer yields values increasingly less than those measured by the sonic anemometer as u decreases from 2.5 approaching 0 ms{sup -1}. The combination of u over-estimation and under-estimation of {sigma}{sub w} from the mechanical sensors at low wind speeds causes considerable under-estimation of the standard deviation of vertical wind angle fluctuations ({sigma}{sub {phi}}), an indicator of vertical dispersion. Calculations of {sigma}{sub {phi}} from sonic anemometer measurements are typically 5{sup o} to 10{sup o} higher when the mechanical instruments indicate that {sigma}{sub {phi}} < 5{sup o} or so. The errors in both the propeller anemometer and cup anemometer, caused by their inability to respond to higher frequency (smaller scale) turbulent fluctuations, can therefore lead to large (factors of 2 to 10 or more) errors in the vertical dispersion during stable conditions with light winds.

  14. 3D Kinetic Simulation of Plasma Jet Penetration in Magnetic Field

    NASA Astrophysics Data System (ADS)

    Galkin, Sergei A.; Bogatu, I. N.; Kim, J. S.

    2009-11-01

    A high velocity plasmoid penetration through a magnetic barrier is a problem of a great experimental and theoretical interest. Our LSP PIC code 3D fully kinetic numerical simulations of high density (10^16 cm-3) high velocity (30-140 km/sec) plasma jet/bullet, penetrating through the transversal magnetic field, demonstrate three different regimes: reflection by field, penetration by magnetic field expulsion and penetration by magnetic self-polarization. The behavior depends on plasma jet parameters and its composition: hydrogen, carbon (A=12) and C60-fullerene (A=720) plasmas were investigated. The 3D simulation of two plasmoid head-on injections along uniform magnetic field lines is analyzed. Mini rail plasma gun (accelerator) modeling is also presented and discussed.

  15. Moving from Batch to Field Using the RT3D Reactive Transport Modeling System

    NASA Astrophysics Data System (ADS)

    Clement, T. P.; Gautam, T. R.

    2002-12-01

    The public domain reactive transport code RT3D (Clement, 1997) is a general-purpose numerical code for solving coupled, multi-species reactive transport in saturated groundwater systems. The code uses MODFLOW to simulate flow and several modules of MT3DMS to simulate the advection and dispersion processes. RT3D employs the operator-split strategy which allows the code solve the coupled reactive transport problem in a modular fashion. The coupling between reaction and transport is defined through a separate module where the reaction equations are specified. The code supports a versatile user-defined reaction option that allows users to define their own reaction system through a Fortran-90 subroutine, known as the RT3D-reaction package. Further a utility code, known as BATCHRXN, allows the users to independently test and debug their reaction package. To analyze a new reaction system at a batch scale, users should first run BATCHRXN to test the ability of their reaction package to model the batch data. After testing, the reaction package can simply be ported to the RT3D environment to study the model response under 1-, 2-, or 3-dimensional transport conditions. This paper presents example problems that demonstrate the methods for moving from batch to field-scale simulations using BATCHRXN and RT3D codes. The first example describes a simple first-order reaction system for simulating the sequential degradation of Tetrachloroethene (PCE) and its daughter products. The second example uses a relatively complex reaction system for describing the multiple degradation pathways of Tetrachloroethane (PCA) and its daughter products. References 1) Clement, T.P, RT3D - A modular computer code for simulating reactive multi-species transport in 3-Dimensional groundwater aquifers, Battelle Pacific Northwest National Laboratory Research Report, PNNL-SA-28967, September, 1997. Available at: http://bioprocess.pnl.gov/rt3d.htm.

  16. Feasibility of using PRESAGE® for relative 3D dosimetry of small proton fields

    PubMed Central

    Zhao, Li; Newton, Joseph; Oldham, Mark; Das, Indra J; Cheng, Chee-Wai; Adamovics, John

    2013-01-01

    Small field dosimetry is challenging due to the finite size of the conventional detectors that underestimate the dose distribution. With the fast development of the dynamic proton beam delivery system, it is essential to find a dosimeter which can be used for 3D dosimetry of small proton fields. We investigated the feasibility of using a proton formula PRESAGE® for 3D dosimetry of small fields in a uniform scanning proton beam delivery system with dose layer stacking technology. The relationship between optical density and the absorbed dose was found to be linear through small volume cuvette studies for both photon and proton irradiation. Two circular fields and three patient-specific fields were used for proton treatment planning calculation and beam delivery. The measured results were compared with the calculated results in the form of lateral dose profiles, depth dose, isodose plots and gamma index analysis. For the circular field study, lateral dose profile comparison showed that the relative PRESAGE® profile falls within ± 5% from the calculated profile for most of the spatial range. For unmodulated depth dose comparison, the agreement between the measured and calculated results was within 3% in the beam entrance region before the Bragg peak. However, at the Bragg peak, there was about 20% underestimation of the absorbed dose from PRESAGE®. For patient-specific field 3D dosimetry, most of the data points within the target volume passed gamma analysis for 3% relative dose difference and 3 mm distance to agreement criteria. Our results suggest that this proton formula PRESAGE® dosimeter has the potential for 3D dosimetry of small fields in proton therapy, but further investigation is needed to improve the dose under-response of the PRESAGE® in the Bragg peak region. PMID:23103526

  17. 3D Visualization of near real-time remote-sensing observation for hurricanes field campaign using Google Earth API

    NASA Astrophysics Data System (ADS)

    Li, P.; Turk, J.; Vu, Q.; Knosp, B.; Hristova-Veleva, S. M.; Lambrigtsen, B.; Poulsen, W. L.; Licata, S.

    2009-12-01

    NASA is planning a new field experiment, the Genesis and Rapid Intensification Processes (GRIP), in the summer of 2010 to better understand how tropical storms form and develop into major hurricanes. The DC-8 aircraft and the Global Hawk Unmanned Airborne System (UAS) will be deployed loaded with instruments for measurements including lightning, temperature, 3D wind, precipitation, liquid and ice water contents, aerosol and cloud profiles. During the field campaign, both the spaceborne and the airborne observations will be collected in real-time and integrated with the hurricane forecast models. This observation-model integration will help the campaign achieve its science goals by allowing team members to effectively plan the mission with current forecasts. To support the GRIP experiment, JPL developed a website for interactive visualization of all related remote-sensing observations in the GRIP’s geographical domain using the new Google Earth API. All the observations are collected in near real-time (NRT) with 2 to 5 hour latency. The observations include a 1KM blended Sea Surface Temperature (SST) map from GHRSST L2P products; 6-hour composite images of GOES IR; stability indices, temperature and vapor profiles from AIRS and AMSU-B; microwave brightness temperature and rain index maps from AMSR-E, SSMI and TRMM-TMI; ocean surface wind vectors, vorticity and divergence of the wind from QuikSCAT; the 3D precipitation structure from TRMM-PR and vertical profiles of cloud and precipitation from CloudSAT. All the NRT observations are collected from the data centers and science facilities at NASA and NOAA, subsetted, re-projected, and composited into hourly or daily data products depending on the frequency of the observation. The data products are then displayed on the 3D Google Earth plug-in at the JPL Tropical Cyclone Information System (TCIS) website. The data products offered by the TCIS in the Google Earth display include image overlays, wind vectors, clickable

  18. Wave optics theory and 3-D deconvolution for the light field microscope.

    PubMed

    Broxton, Michael; Grosenick, Logan; Yang, Samuel; Cohen, Noy; Andalman, Aaron; Deisseroth, Karl; Levoy, Marc

    2013-10-21

    Light field microscopy is a new technique for high-speed volumetric imaging of weakly scattering or fluorescent specimens. It employs an array of microlenses to trade off spatial resolution against angular resolution, thereby allowing a 4-D light field to be captured using a single photographic exposure without the need for scanning. The recorded light field can then be used to computationally reconstruct a full volume. In this paper, we present an optical model for light field microscopy based on wave optics, instead of previously reported ray optics models. We also present a 3-D deconvolution method for light field microscopy that is able to reconstruct volumes at higher spatial resolution, and with better optical sectioning, than previously reported. To accomplish this, we take advantage of the dense spatio-angular sampling provided by a microlens array at axial positions away from the native object plane. This dense sampling permits us to decode aliasing present in the light field to reconstruct high-frequency information. We formulate our method as an inverse problem for reconstructing the 3-D volume, which we solve using a GPU-accelerated iterative algorithm. Theoretical limits on the depth-dependent lateral resolution of the reconstructed volumes are derived. We show that these limits are in good agreement with experimental results on a standard USAF 1951 resolution target. Finally, we present 3-D reconstructions of pollen grains that demonstrate the improvements in fidelity made possible by our method.

  19. Wave optics theory and 3-D deconvolution for the light field microscope

    PubMed Central

    Broxton, Michael; Grosenick, Logan; Yang, Samuel; Cohen, Noy; Andalman, Aaron; Deisseroth, Karl; Levoy, Marc

    2013-01-01

    Light field microscopy is a new technique for high-speed volumetric imaging of weakly scattering or fluorescent specimens. It employs an array of microlenses to trade off spatial resolution against angular resolution, thereby allowing a 4-D light field to be captured using a single photographic exposure without the need for scanning. The recorded light field can then be used to computationally reconstruct a full volume. In this paper, we present an optical model for light field microscopy based on wave optics, instead of previously reported ray optics models. We also present a 3-D deconvolution method for light field microscopy that is able to reconstruct volumes at higher spatial resolution, and with better optical sectioning, than previously reported. To accomplish this, we take advantage of the dense spatio-angular sampling provided by a microlens array at axial positions away from the native object plane. This dense sampling permits us to decode aliasing present in the light field to reconstruct high-frequency information. We formulate our method as an inverse problem for reconstructing the 3-D volume, which we solve using a GPU-accelerated iterative algorithm. Theoretical limits on the depth-dependent lateral resolution of the reconstructed volumes are derived. We show that these limits are in good agreement with experimental results on a standard USAF 1951 resolution target. Finally, we present 3-D reconstructions of pollen grains that demonstrate the improvements in fidelity made possible by our method. PMID:24150383

  20. 3D Extended Logging for Geothermal Resources: Field Trials with the Geo-Bilt System

    SciTech Connect

    Mallan, R; Wilt, M; Kirkendall, B; Kasameyer, P

    2002-05-29

    Geo-BILT (Geothermal Borehole Induction Logging Tool) is an extended induction logging tool designed for 3D resistivity imaging around a single borehole. The tool was developed for deployment in high temperature geothermal wells under a joint program funded by the California Energy Commission, Electromagnetic Instruments (EMI) and the U.S. Department of Energy. EM1 was responsible for tool design and manufacture, and numerical modeling efforts were being addressed at Lawrence Livermore Laboratory (LLNL) and other contractors. The field deployment was done by EM1 and LLNL. The tool operates at frequencies from 2 to 42 kHz, and its design features a series of three-component magnetic sensors offset at 2 and 5 meters from a three-component magnetic source. The combined package makes it possible to do 3D resistivity imaging, deep into the formation, from a single well. The manufacture and testing of the tool was completed in spring of 2001, and the initial deployment of Geo-BILT occurred in May 2001 at the Lost Hills oil field in southern California at leases operated by Chevron USA. This site was chosen for the initial field test because of the favorable geological conditions and the availability of a number of wells suitable for tool deployment. The second deployment occurred in April 2002 at the Dixie Valley geothermal field, operated by Caithness Power LLC, in central Nevada. This constituted the first test in a high temperature environment. The Chevron site features a fiberglass-cased observation well in the vicinity of a water injector. The injected water, which is used for pressure maintenance and for secondary sweep of the heavy oil formation, has a much lower resistivity than the oil bearing formation. This, in addition to the non-uniform flow of this water, creates a 3D resistivity structure, which is analogous to conditions produced from flowing fractures adjacent to geothermal boreholes. Therefore, it is an excellent site for testing the 3D capability of

  1. Coherent Doppler Wind Lidar Development at NASA Langley Research Center for NASA Space-Based 3-D Winds Mission

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Kavaya, Michael J.; Yu, Jirong; Koch, Grady J.

    2012-01-01

    We review the 20-plus years of pulsed transmit laser development at NASA Langley Research Center (LaRC) to enable a coherent Doppler wind lidar to measure global winds from earth orbit. We briefly also discuss the many other ingredients needed to prepare for this space mission.

  2. Radial electric field 3D modeling for wire arrays driving dynamic hohlraums on Z.

    SciTech Connect

    Mock, Raymond Cecil

    2007-06-01

    The anode-cathode structure of the Z-machine wire array results in a higher negative radial electric field (Er) on the wires near the cathode relative to the anode. The magnitude of this field has been shown to anti-correlate with the axial radiation top/bottom symmetry in the DH (Dynamic Hohlraum). Using 3D modeling, the structure of this field is revealed for different wire-array configurations and for progressive mechanical alterations, providing insight for minimizing the negative Er on the wire array in the anode-to-cathode region of the DH. Also, the 3D model is compared to Sasorov's approximation, which describes Er at the surface of the wire in terms of wire-array parameters.

  3. Using the CAVE virtual-reality environment as an aid to 3-D electromagnetic field computation

    SciTech Connect

    Turner, L.R.; Levine, D.; Huang, M.; Papka, M; Kettunen, L.

    1995-08-01

    One of the major problems in three-dimensional (3-D) field computation is visualizing the resulting 3-D field distributions. A virtual-reality environment, such as the CAVE, (CAVE Automatic Virtual Environment) is helping to overcome this problem, thus making the results of computation more usable for designers and users of magnets and other electromagnetic devices. As a demonstration of the capabilities of the CAVE, the elliptical multipole wiggler (EMW), an insertion device being designed for the Advanced Photon Source (APS) now being commissioned at Argonne National Laboratory (ANL), wa made visible, along with its fields and beam orbits. Other uses of the CAVE in preprocessing and postprocessing computation for electromagnetic applications are also discussed.

  4. Exploring Direct 3D Interaction for Full Horizontal Parallax Light Field Displays Using Leap Motion Controller

    PubMed Central

    Adhikarla, Vamsi Kiran; Sodnik, Jaka; Szolgay, Peter; Jakus, Grega

    2015-01-01

    This paper reports on the design and evaluation of direct 3D gesture interaction with a full horizontal parallax light field display. A light field display defines a visual scene using directional light beams emitted from multiple light sources as if they are emitted from scene points. Each scene point is rendered individually resulting in more realistic and accurate 3D visualization compared to other 3D displaying technologies. We propose an interaction setup combining the visualization of objects within the Field Of View (FOV) of a light field display and their selection through freehand gesture tracked by the Leap Motion Controller. The accuracy and usefulness of the proposed interaction setup was also evaluated in a user study with test subjects. The results of the study revealed high user preference for free hand interaction with light field display as well as relatively low cognitive demand of this technique. Further, our results also revealed some limitations and adjustments of the proposed setup to be addressed in future work. PMID:25875189

  5. Analysis of 3d Magnetotelluric Measurements Over the Coso Geothermal Field

    NASA Astrophysics Data System (ADS)

    Newman, G. A.; Gasperikova, E.; Hoversten, M.

    2007-12-01

    We have carried out an investigation of the Coso Geothermal field utilizing a dense grid of magnetotelluric (MT) stations plus a single line of contiguous bipole array profiling over the east flank of the field. Motivation for this study is that electrical resistivity/conductivity mapping can contribute to better understanding of enhanced geothermal systems (EGS) by imaging the geometry, bounds and controlling structures in existing production, and by monitoring changes in the underground resistivity properties in the vicinity of injection due to fracture porosity enhancement. Initial analysis of the Coso MT data was carried out using 2D MT imaging technology to construct a starting 3D resistivity model from a series of 2D resistivity images obtained using the inline electric field measurements (Zxy impedance elements) along different measurement transects. This model was then refined through a 3D inversion process. The 3D resisitivity model clearly showed the controlling geological structures influencing well production at Coso and shows correlations with mapped surface features such as faults and regional geoelectric strike. We have also correlated the model with an acoustic and shear velocity model of the field to show that the near-vertical high conductivity (low resistivity) structure on the eastern flank of the producing field is also a zone of increase acoustic velocity and increased Vp/Vs ratio.

  6. Critical Point Cancellation in 3D Vector Fields: Robustness and Discussion.

    PubMed

    Skraba, Primoz; Rosen, Paul; Wang, Bei; Chen, Guoning; Bhatia, Harsh; Pascucci, Valerio

    2016-02-29

    Vector field topology has been successfully applied to represent the structure of steady vector fields. Critical points, one of the essential components of vector field topology, play an important role in describing the complexity of the extracted structure. Simplifying vector fields via critical point cancellation has practical merit for interpreting the behaviors of complex vector fields such as turbulence. However, there is no effective technique that allows direct cancellation of critical points in 3D. This work fills this gap and introduces the first framework to directly cancel pairs or groups of 3D critical points in a hierarchical manner with a guaranteed minimum amount of perturbation based on their robustness, a quantitative measure of their stability. In addition, our framework does not require the extraction of the entire 3D topology, which contains non-trivial separation structures, and thus is computationally effective. Furthermore, our algorithm can remove critical points in any subregion of the domain whose degree is zero and handle complex boundary configurations, making it capable of addressing challenging scenarios that may not be resolved otherwise. We apply our method to synthetic and simulation datasets to demonstrate its effectiveness.

  7. 3D Wind Reconstruction and Turbulence Estimation in the Boundary Layer from Doppler Lidar Measurements using Particle Method

    NASA Astrophysics Data System (ADS)

    Rottner, L.; Baehr, C.

    2014-12-01

    Turbulent phenomena in the atmospheric boundary layer (ABL) are characterized by small spatial and temporal scales which make them difficult to observe and to model.New remote sensing instruments, like Doppler Lidar, give access to fine and high-frequency observations of wind in the ABL. This study suggests to use a method of nonlinear estimation based on these observations to reconstruct 3D wind in a hemispheric volume, and to estimate atmospheric turbulent parameters. The wind observations are associated to particle systems which are driven by a local turbulence model. The particles have both fluid and stochastic properties. Therefore, spatial averages and covariances may be deduced from the particles. Among the innovative aspects, we point out the absence of the common hypothesis of stationary-ergodic turbulence and the non-use of particle model closure hypothesis. Every time observations are available, 3D wind is reconstructed and turbulent parameters such as turbulent kinectic energy, dissipation rate, and Turbulent Intensity (TI) are provided. This study presents some results obtained using real wind measurements provided by a five lines of sight Lidar. Compared with classical methods (e.g. eddy covariance) our technic renders equivalent long time results. Moreover it provides finer and real time turbulence estimations. To assess this new method, we suggest computing independently TI using different observation types. First anemometer data are used to have TI reference.Then raw and filtered Lidar observations have also been compared. The TI obtained from raw data is significantly higher than the reference one, whereas the TI estimated with the new algorithm has the same order.In this study we have presented a new class of algorithm to reconstruct local random media. It offers a new way to understand turbulence in the ABL, in both stable or convective conditions. Later, it could be used to refine turbulence parametrization in meteorological meso-scale models.

  8. A 3D radiative transfer framework . VII. Arbitrary velocity fields in the Eulerian frame

    NASA Astrophysics Data System (ADS)

    Seelmann, A. M.; Hauschildt, P. H.; Baron, E.

    2010-11-01

    Aims: A solution of the radiative-transfer problem in 3D with arbitrary velocity fields in the Eulerian frame is presented. The method is implemented in our 3D radiative transfer framework and used in the PHOENIX/3D code. It is tested by comparison to our well-tested 1D co-moving frame radiative transfer code, where the treatment of a monotonic velocity field is implemented in the Lagrangian frame. The Eulerian formulation does not need much additional memory and is useable on state-of-the-art computers, even large-scale applications with 1000's of wavelength points are feasible. Methods: In the Eulerian formulation of the problem, the photon is seen by the atom at a Doppler-shifted wavelength depending on its propagation direction, which leads to a Doppler-shifted absorption and emission. This leads to a different source function and a different Λ^* operator in the radiative transfer equations compared to the static case. Results: The results of the Eulerian 3D spherical calculations are compared to our well-tested 1D Lagrangian spherical calculations, the agreement is, up to vmax = 1 × 103 km s-1 very good. Test calculation in other geometries are also shown.

  9. Eta Carinae: An Observational Testbed for 3-D Interacting Wind Modeling

    NASA Technical Reports Server (NTRS)

    Gull, Theodore; Madura, Tom; Groh, Jose; Corcoran, Mike; Owocki, Stan

    2011-01-01

    Eta Car, with its very massive interacting winds, provides shocked arc-like structures dense enough to trace in forbidden emission lines out to 0.7" (1700 AU). As the massive binary is in a very elliptical orbit (e approx. 0.9), the spatial and velocity structures of these winds change over the 5.54 year period. We can tract ionization structures by several forbidden emission lines. With the addition of radiative transfer on a time-step frame-by-frame basis, we are learning much new information on the ballistic structures, and may gain insight on how molecules and dust might form in these very massive systems.

  10. Effects of the LBV Primary's Mass-loss Rate on the 3D Hydrodynamics of eta Carinae's Colliding Winds

    NASA Technical Reports Server (NTRS)

    Madura, Thomas I.; Gull, Theodore R.; Cocoran, M.; Okazaki, A.; Owocki, S.; Russell, C.; Hamaguchi, K.; Clementel, N; Groh, J.; Hillier, D. J.

    2013-01-01

    At the heart of eta Carinae's spectacular "Homunculus" nebula lies an extremely luminous (L(sub Total) greater than approximately 5 × 10(exp 6) solar luminosity) colliding wind binary with a highly eccentric (e approximately 0.9), 5.54-year orbit (Figure 1). The primary of the system, a Luminous Blue Variable (LBV), is our closest (D approximately 2.3 kpc) and best example of a pre-hypernova or pre-gamma ray burst environment. The remarkably consistent and periodic RXTE X-ray light curve surprisingly showed a major change during the system's last periastron in 2009, with the X-ray minimum being approximately 50% shorter than the minima of the previous two cycles1. Between 1998 and 2011, the strengths of various broad stellar wind emission lines (e.g. Halpha, Fe II) in line-of-sight (l.o.s.) also decreased by factors of 1.5 - 3 relative to the continuum2. The current interpretation for these changes is that they are due to a gradual factor of 2 - 4 drop in the primary's mass-loss rate over the last approximately 15 years1, 2. However, while a secular change is seen for a direct view of the central source, little to no change is seen in profiles at high stellar latitudes or reflected off of the dense, circumbinary material known as the "Weigelt blobs"2, 3. Moreover, model spectra generated with CMFGEN predict that a factor of 2 - 4 drop in the primary's mass-loss rate should lead to huge changes in the observed spectrum, which thus far have not been seen. Here we present results from large- (plus or minus 1620 AU) and small- (plus or minus 162 AU) domain, full 3D smoothed particle hydrodynamics (SPH) simulations of eta Car's massive binary colliding winds for three different primary-star mass-loss rates (2.4, 4.8, and 8.5 × 10(exp -4) solar mass/yr). The goal is to investigate how the mass-loss rate affects the 3D geometry and dynamics of eta Car's optically-thick wind and spatially-extended wind-wind collision (WWC) regions, both of which are known sources of

  11. Capabilities of wind tunnels with two-adaptive walls to minimize boundary interference in 3-D model testing

    NASA Technical Reports Server (NTRS)

    Rebstock, Rainer; Lee, Edwin E., Jr.

    1989-01-01

    An initial wind tunnel test was made to validate a new wall adaptation method for 3-D models in test sections with two adaptive walls. First part of the adaptation strategy is an on-line assessment of wall interference at the model position. The wall induced blockage was very small at all test conditions. Lift interference occurred at higher angles of attack with the walls set aerodynamically straight. The adaptation of the top and bottom tunnel walls is aimed at achieving a correctable flow condition. The blockage was virtually zero throughout the wing planform after the wall adjustment. The lift curve measured with the walls adapted agreed very well with interference free data for Mach 0.7, regardless of the vertical position of the wing in the test section. The 2-D wall adaptation can significantly improve the correctability of 3-D model data. Nevertheless, residual spanwise variations of wall interference are inevitable.

  12. Surface strain-field determination of tympanic membrane using 3D-digital holographic interferometry

    NASA Astrophysics Data System (ADS)

    Hernandez-Montes, María del S.; Mendoza Santoyo, Fernando; Muñoz, Silvino; Perez, Carlos; de la Torre, Manuel; Flores, Mauricio; Alvarez, Luis

    2015-08-01

    In order to increase the understanding of soft tissues mechanical properties, 3D Digital Holographic Interferometry (3D-DHI) was used to quantify the strain-field on a cat tympanic membrane (TM) surface. The experiments were carried out applying a constant sound-stimuli pressure of 90 dB SPL (0.632 Pa) on the TM at 1.2 kHz. The technique allows the accurate acquisition of the micro-displacement data along the x, y and z directions, which is a must for a full characterization of the tissue mechanical behavior under load, and for the calculation of the strain-field in situ. The displacements repeatability in z direction shows a standard deviation of 0.062 μm at 95% confidence level. In order to realize the full 3D characterization correctly the contour of the TM surface was measured employing the optically non-contact two-illumination positions contouring method. The x, y and z displacements combined with the TM contour data allow the evaluation its strain-field by spatially differentiating the u(m,n), v(m,n), and w(m,n) deformation components. The accurate and correct determination of the TM strain-field leads to describing its elasticity, which is an important parameter needed to improve ear biomechanics studies, audition processes and TM mobility in both experimental measurements and theoretical analysis of ear functionality and its modeling.

  13. 3D turbulence measurements in inhomogeneous boundary layers with three wind LiDARs

    NASA Astrophysics Data System (ADS)

    Carbajo Fuertes, Fernando; Valerio Iungo, Giacomo; Porté-Agel, Fernando

    2014-05-01

    One of the most challenging tasks in atmospheric anemometry is obtaining reliable turbulence measurements of inhomogeneous boundary layers at heights or in locations where is not possible or convenient to install tower-based measurement systems, e.g. mountainous terrain, cities, wind farms, etc. Wind LiDARs are being extensively used for the measurement of averaged vertical wind profiles, but they can only successfully accomplish this task under the limiting conditions of flat terrain and horizontally homogeneous flow. Moreover, it has been shown that common scanning strategies introduce large systematic errors in turbulence measurements, regardless of the characteristics of the flow addressed. From the point of view of research, there exist a variety of techniques and scanning strategies to estimate different turbulence quantities but most of them rely in the combination of raw measurements with atmospheric models. Most of those models are only valid under the assumption of horizontal homogeneity. The limitations stated above can be overcome by a new triple LiDAR technique which uses simultaneous measurements from three intersecting Doppler wind LiDARs. It allows for the reconstruction of the three-dimensional velocity vector in time as well as local velocity gradients without the need of any turbulence model and with minimal assumptions [EGU2013-9670]. The triple LiDAR technique has been applied to the study of the flow over the campus of EPFL in Lausanne (Switzerland). The results show the potential of the technique for the measurement of turbulence in highly complex boundary layer flows. The technique is particularly useful for micrometeorology and wind engineering studies.

  14. The impact of 3D fields on tearing mode stability of H-modes

    NASA Astrophysics Data System (ADS)

    Buttery, R. J.; Gerhardt, S.; La Haye, R. J.; Liu, Y. Q.; Reimerdes, H.; Sabbagh, S.; Chu, M. S.; Osborne, T. H.; Park, J.-K.; Pinsker, R. I.; Strait, E. J.; Yu, J. H.; DIII-D, the; NSTX Teams

    2011-07-01

    New processes have been discovered in the interaction of 3D fields with tearing mode stability at low torque and modest β on DIII-D and NSTX. These are thought to arise from the plasma response at the tearing resonant surface, which theoretically is expected to depend strongly on plasma rotation and underlying intrinsic tearing stability. This leads to sensitivities additional to those previously identified at low density where the plasma rotation is more readily stopped, or at high βN where ideal MHD responses amplify the fields (where βN is the plasma β divided by the ratio of plasma current to minor radius multiplied by toroidal field). It is found that the threshold size for 3D fields to induce modes tends to zero as the natural tearing βN limit is approached. 3D field sensitivity is further enhanced at low rotation, with magnetic probing detecting an increased response to applied fields in such regimes. Modelling with the MARS-F code confirms the interpretation with the usual plasma screening response breaking down in low rotation plasmas and a tearing response developing, opening the door to additional sensitivities to β and the current profile. Typical field thresholds to induce modes in torque-free βN ~ 1.5 H-modes are well below those in ohmic plasmas or plasmas near the ideal βN limit. The strong interaction with the tearing mode βN limit is identified through rotation shear, which is decreased by the 3D field, leading to decreased tearing stability. Thus both locked and rotating mode field thresholds can be considered in terms of a torque balance, with sufficient braking leading to destabilization of a mode. On this basis new measurements of the principal parameter scalings for error field threshold have been obtained in torque-free H-modes leading to new predictions for error field sensitivity in ITER. The scalings have similar exponents to ohmic plasmas, but with seven times lower threshold at the ITER baseline βN value of 1.8, and a linear

  15. Total-Field Technique for 3-D Modeling of Short Period Teleseismic Waves

    NASA Astrophysics Data System (ADS)

    Monteiller, V.; Beller, S.; Operto, S.; Nissen-Meyer, T.; Tago Pacheco, J.; Virieux, J.

    2014-12-01

    The massive development of dense seismic arrays and the rapid increase in computing capacity allow today to consider application of full waveform inversion of teleseismic data for high-resolution lithospheric imaging. We present an hybrid numerical method that allows for the modellingof short period teleseismic waves in 3D lithospheric target with both the discontinuous Galerkin finite elements method and finite difference method, opening the possibility to perform waveform inversion of seismograms recorded by dense regional broadband arrays. However, despite the supercomputer ability, the forward-problem remains expensive at global scale for teleseismic configuration especially when 3D numerical methods are considered. In order to perform the forward problem in a reasonable amount of time, we reduce the computational domain in which full waveform modelling is performed. We define a 3D regional domain located below the seismological network that is embedded in a homogeneous background or axisymmetric model, in which the seismic wavefield can be computed efficiently. The background wavefield is used to compute the full wavefield in the 3D regional domain using the so-called total-field/scattered-field technique. This method relies on the decomposition of the wavefield into a background and a scattered wavefields. The computational domain is subdivided into three sub-domains: an outer domain formed by the perfectly-matched absorbing layers, an intermediate domain in which only the outgoing wavefield scattered by the lithospheric heterogeneities is computed, and the inner domain formed by the lithospheric target in which the full wavefield is computed. In this study, we shall present simulations in realistic lithospheric target when the axisymetric background wavefield is computed with the AxiSEM softwave and the 3D simulation in lithospheric target model is performed with the discontinuous Galerkin or finite difference method.

  16. Hybrid wide-field and scanning microscopy for high-speed 3D imaging.

    PubMed

    Duan, Yubo; Chen, Nanguang

    2015-11-15

    Wide-field optical microscopy is efficient and robust in biological imaging, but it lacks depth sectioning. In contrast, scanning microscopic techniques, such as confocal microscopy and multiphoton microscopy, have been successfully used for three-dimensional (3D) imaging with optical sectioning capability. However, these microscopic techniques are not very suitable for dynamic real-time imaging because they usually take a long time for temporal and spatial scanning. Here, a hybrid imaging technique combining wide-field microscopy and scanning microscopy is proposed to accelerate the image acquisition process while maintaining the 3D optical sectioning capability. The performance was demonstrated by proof-of-concept imaging experiments with fluorescent beads and zebrafish liver.

  17. 3-D Modeling of Magnetic Fields for the Lithium Tokamak eXperiment

    NASA Astrophysics Data System (ADS)

    Logan, N.; Berzak, L.; Kaita, R.; Majeski, R.; Menard, J.; Zakharov, L.

    2010-11-01

    The Lithium Tokamak eXperiment (LTX) is designed to investigate low-recycling operating regimes by surrounding 85% of the last closed flux surface with liquid lithium evaporated onto a copper and stainless steel shell conformal to the plasma. Fields generated by currents in this conducting shell have significant effects on magnetic configurations. To understand these effects, the commercially available code Aether [http://www.fieldp.com] is used to simulate time varying magnetic fields in a 3-D model of LTX. The model is built using LTX CAD files and divided into a regular mesh for computing the evolution of coupled electromagnetic vector quantities through time and space. Applicable boundary conditions and symmetries are analyzed. Comparisons with measured data, results from a 2-D code, and results from a 3-D code designed specifically for LTX demonstrate the possible benefits and limitations of using this commercial code.

  18. Reproducing Electric Field Observations during Magnetic Storms by means of Rigorous 3-D Modelling and Distortion Matrix Co-estimation

    NASA Astrophysics Data System (ADS)

    Püthe, Christoph; Manoj, Chandrasekharan; Kuvshinov, Alexey

    2015-04-01

    Electric fields induced in the conducting Earth during magnetic storms drive currents in power transmission grids, telecommunication lines or buried pipelines. These geomagnetically induced currents (GIC) can cause severe service disruptions. The prediction of GIC is thus of great importance for public and industry. A key step in the prediction of the hazard to technological systems during magnetic storms is the calculation of the geoelectric field. To address this issue for mid-latitude regions, we developed a method that involves 3-D modelling of induction processes in a heterogeneous Earth and the construction of a model of the magnetospheric source. The latter is described by low-degree spherical harmonics; its temporal evolution is derived from observatory magnetic data. Time series of the electric field can be computed for every location on Earth's surface. The actual electric field however is known to be perturbed by galvanic effects, arising from very local near-surface heterogeneities or topography, which cannot be included in the conductivity model. Galvanic effects are commonly accounted for with a real-valued time-independent distortion matrix, which linearly relates measured and computed electric fields. Using data of various magnetic storms that occurred between 2000 and 2003, we estimated distortion matrices for observatory sites onshore and on the ocean bottom. Strong correlations between modellings and measurements validate our method. The distortion matrix estimates prove to be reliable, as they are accurately reproduced for different magnetic storms. We further show that 3-D modelling is crucial for a correct separation of galvanic and inductive effects and a precise prediction of electric field time series during magnetic storms. Since the required computational resources are negligible, our approach is suitable for a real-time prediction of GIC. For this purpose, a reliable forecast of the source field, e.g. based on data from satellites

  19. Validation of US3D for Capsule Aerodynamics using 05-CA Wind Tunnel Test Data

    NASA Technical Reports Server (NTRS)

    Schwing, Alan

    2012-01-01

    RANS is ill-suited for analysis of these problems. For transonic and supersonic cases, US3D shows fairly good agreement using DES across all cases. Separation prediction and resulting backshell pressure are problems across all portions of this analysis. This becomes more of an issue at lower Mach numbers: .Stagnation pressures not as large - wake and backshell are more significant .Errors on shoulder act on a large area - small discrepancies manifest as large changes Subsonic comparisons are mixed with regard to integrated loads and merit more attention. Dominant unsteady behavior (wake shedding) resolved well, though.

  20. Simultaneous 3D Strain and Flow Fields Measurement of a Model Artery under Unsteady Flows

    NASA Astrophysics Data System (ADS)

    Toloui, Mostafa; Sheng, Jian

    2011-11-01

    Fluid-Structure Interaction imposes challenges in both aero-elasticity and biomedical studies. A simultaneous solid deformation and fluid flow measurement technique based on digital in-line holographic particle tracking velocimetry (PTV) has been developed. It allows us to measure concurrently 3D strain field of a deforming structure and the unsteady flow near it. To facilitate the measurement, both wall and flow are seeded with tracer particles distinguished by size. The motion of these tracers provides the 3D deformation of the wall and the 3D velocity distribution of the flow separately. A fully index matched facility including transparent artery and NaI solution is constructed to enable observations near the wall or through the complex geometry. An arterial model with the inner diameter of 9.5 mm and the thickness of 0.9 mm is manufactured from the cross-linked transparent PDMS at the mixing ratio of 1:10 and doped with mono-dispersed 19 μm polystyrene particles. A cinematic holographic PTV system is used to trace the 3D particle motion in the model and flow simultaneously. Preliminary study is performed within a sample volume of 15 × 15 × 75 mm with the spatial resolution of 7.4 μm in lateral and 10 μm in depth. Uncertainty and accuracy analysis will be reported. NSF Grant No: CBET-0844647.

  1. Full-field strain measurements on turbomachinery components using 3D SLDV technology

    NASA Astrophysics Data System (ADS)

    Maguire, Martyn; Sever, Ibrahim

    2016-06-01

    This paper focuses on measurements of 3D Operating Deflection Shapes (ODSs), and subsequently, construction of full-field surface strain maps of a number of turbomachinery components. For this purpose a 3D Scanning Laser Doppler Vibrometer (SLDV) is used. The ODS measurements are performed for a large number of modes and results obtained are compared with the 1-D shapes that are most commonly measured. It is demonstrated that the 3D measurements are a significant improvement over the 1-D case in terms of independent amount of extra information they provide. This is confirmed through comparisons with FE results. Special tests are carried out to recover the full-field strain on scanned faces of the components used. Visual comparison of these measurements with FE counterparts reveal that strain maps can be successfully measured, not only for low frequency modes but also for highly complex high frequency ones. These maps are measured with different levels of input force to assess the linearity of strain results to varying response amplitudes. Lessons learnt and observations made are summarised in concluding remarks and the scope of future work to take this study into the production environment is discussed. This study constitutes a unique comprehensive investigation into full-field strain measurements using real application hardware and a large frequency range.

  2. Wind field model-based estimation of Seasat scatterometer winds

    NASA Technical Reports Server (NTRS)

    Long, David G.

    1993-01-01

    A model-based approach to estimating near-surface wind fields over the ocean from Seasat scatterometer (SASS) measurements is presented. The approach is a direct assimilation technique in which wind field model parameters are estimated directly from the scatterometer measurements of the radar backscatter of the ocean's surface using maximum likelihood principles. The wind field estimate is then computed from the estimated model parameters. The wind field model used in this approach is based on geostrophic approximation and on simplistic assumptions about the wind field vorticity and divergence but includes ageostrophic winds. Nine days of SASS data were processed to obtain unique wind estimates. Comparisons in performance to the traditional two-step (point-wise wind retrieval followed by ambiguity removal) wind estimate method and the model-based method are provided using both simulated radar backscatter measurements and actual SASS measurements. In the latter case the results are compared to wind fields determined using subjective ambiguity removal. While the traditional approach results in missing measurements and reduced effective swath width due to fore/aft beam cell coregistration problems, the model-based approach uses all available measurements to increase the effective swath width and to reduce data gaps. The results reveal that the model-based wind estimates have accuracy comparable to traditionally estimated winds with less 'noise' in the directional estimates, particularly at low wind speeds.

  3. Commissioning a small-field biological irradiator using point, 2D, and 3D dosimetry techniques

    SciTech Connect

    Newton, Joseph; Oldham, Mark; Thomas, Andrew; Li Yifan; Adamovics, John; Kirsch, David G.; Das, Shiva

    2011-12-15

    Purpose: To commission a small-field biological irradiator, the XRad225Cx from Precision x-Ray, Inc., for research use. The system produces a 225 kVp x-ray beam and is equipped with collimating cones that produce both square and circular radiation fields ranging in size from 1 to 40 mm. This work incorporates point, 2D, and 3D measurements to determine output factors (OF), percent-depth-dose (PDD) and dose profiles at multiple depths. Methods: Three independent dosimetry systems were used: ion-chambers (a farmer chamber and a micro-ionisation chamber), 2D EBT2 radiochromic film, and a novel 3D dosimetry system (DLOS/PRESAGE registered ). Reference point dose rates and output factors were determined from in-air ionization chamber measurements for fields down to {approx}13 mm using the formalism of TG61. PDD, profiles, and output factors at three separate depths (0, 0.5, and 2 cm), were determined for all field sizes from EBT2 film measurements in solid water. Several film PDD curves required a scaling correction, reflecting the challenge of accurate film alignment in very small fields. PDDs, profiles, and output factors were also determined with the 3D DLOS/PRESAGE registered system which generated isotropic 0.2 mm data, in scan times of 20 min. Results: Surface output factors determined by ion-chamber were observed to gradually drop by {approx}9% when the field size was reduced from 40 to 13 mm. More dramatic drops were observed for the smallest fields as determined by EBT{approx}18% and {approx}42% for the 2.5 mm and 1 mm fields, respectively. PRESAGE registered and film output factors agreed well for fields <20 mm (where 3D data were available) with mean deviation of 2.2% (range 1%-4%). PDD values at 2 cm depth varied from {approx}72% for the 40 mm field, down to {approx}55% for the 1 mm field. EBT and PRESAGE registered PDDs agreed within {approx}3% in the typical therapy region (1-4 cm). At deeper depths the EBT curves were slightly steeper (2.5% at 5 cm

  4. FUN3D Airload Predictions for the Full-Scale UH-60A Airloads Rotor in a Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Lee-Rausch, Elizabeth M.; Biedron, Robert T.

    2013-01-01

    An unsteady Reynolds-Averaged Navier-Stokes solver for unstructured grids, FUN3D, is used to compute the rotor performance and airloads of the UH-60A Airloads Rotor in the National Full-Scale Aerodynamic Complex (NFAC) 40- by 80-foot Wind Tunnel. The flow solver is loosely coupled to a rotorcraft comprehensive code, CAMRAD-II, to account for trim and aeroelastic deflections. Computations are made for the 1-g level flight speed-sweep test conditions with the airloads rotor installed on the NFAC Large Rotor Test Apparatus (LRTA) and in the 40- by 80-ft wind tunnel to determine the influence of the test stand and wind-tunnel walls on the rotor performance and airloads. Detailed comparisons are made between the results of the CFD/CSD simulations and the wind tunnel measurements. The computed trends in solidity-weighted propulsive force and power coefficient match the experimental trends over the range of advance ratios and are comparable to previously published results. Rotor performance and sectional airloads show little sensitivity to the modeling of the wind-tunnel walls, which indicates that the rotor shaft-angle correction adequately compensates for the wall influence up to an advance ratio of 0.37. Sensitivity of the rotor performance and sectional airloads to the modeling of the rotor with the LRTA body/hub increases with advance ratio. The inclusion of the LRTA in the simulation slightly improves the comparison of rotor propulsive force between the computation and wind tunnel data but does not resolve the difference in the rotor power predictions at mu = 0.37. Despite a more precise knowledge of the rotor trim loads and flight condition, the level of comparison between the computed and measured sectional airloads/pressures at an advance ratio of 0.37 is comparable to the results previously published for the high-speed flight test condition.

  5. 3D-HST WFC3-SELECTED PHOTOMETRIC CATALOGS IN THE FIVE CANDELS/3D-HST FIELDS: PHOTOMETRY, PHOTOMETRIC REDSHIFTS, AND STELLAR MASSES

    SciTech Connect

    Skelton, Rosalind E.; Whitaker, Katherine E.; Momcheva, Ivelina G.; Van Dokkum, Pieter G.; Bezanson, Rachel; Leja, Joel; Nelson, Erica J.; Oesch, Pascal; Brammer, Gabriel B.; Labbé, Ivo; Franx, Marijn; Fumagalli, Mattia; Van der Wel, Arjen; Da Cunha, Elisabete; Maseda, Michael V.; Förster Schreiber, Natascha; Kriek, Mariska; Lundgren, Britt F.; Magee, Daniel; Marchesini, Danilo; and others

    2014-10-01

    The 3D-HST and CANDELS programs have provided WFC3 and ACS spectroscopy and photometry over ≈900 arcmin{sup 2} in five fields: AEGIS, COSMOS, GOODS-North, GOODS-South, and the UKIDSS UDS field. All these fields have a wealth of publicly available imaging data sets in addition to the Hubble Space Telescope (HST) data, which makes it possible to construct the spectral energy distributions (SEDs) of objects over a wide wavelength range. In this paper we describe a photometric analysis of the CANDELS and 3D-HST HST imaging and the ancillary imaging data at wavelengths 0.3-8 μm. Objects were selected in the WFC3 near-IR bands, and their SEDs were determined by carefully taking the effects of the point-spread function in each observation into account. A total of 147 distinct imaging data sets were used in the analysis. The photometry is made available in the form of six catalogs: one for each field, as well as a master catalog containing all objects in the entire survey. We also provide derived data products: photometric redshifts, determined with the EAZY code, and stellar population parameters determined with the FAST code. We make all the imaging data that were used in the analysis available, including our reductions of the WFC3 imaging in all five fields. 3D-HST is a spectroscopic survey with the WFC3 and ACS grisms, and the photometric catalogs presented here constitute a necessary first step in the analysis of these grism data. All the data presented in this paper are available through the 3D-HST Web site (http://3dhst.research.yale.edu)

  6. The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation. Report 2: The Study for the Distance 9.5Rs

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Sittler, Edward C.; Hartle, Richard E.; Cooper, John F.

    2010-01-01

    Our paper is a 2.5D and 3D numerical plasma models of the interaction of the solar wind (SW) with the Solar Probe Plus spacecraft (SPPSC). These results should be interpreted as a basic plasma model for which the derived SW interaction with spacecraft (SC) could have consequences for both plasma wave and electron plasma measurements on board SC in the inner heliosphere. We observe an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of the electromagnetic field oscillation about of (0.015-0.06) V/m. The compression waves and the jumps in an electric field with an amplitude of about 1.5 V/m and (12-18) V/m were also observed. The observed strong electromagnetic perturbations may be a crucial point in the electromagnetic measurements, which were planned in future Solar Probe Plus mission.

  7. Constraints on Decreases in Eta Carinae's Mass-loss from 3D Hydrodynamic Simulations of Its Binary Colliding Winds

    NASA Technical Reports Server (NTRS)

    Madura, T. I.; Gull, T. R.; Okazaki, A. T.; Russell, C. M. P.; Owocki, S. P.; Groh, J. H.; Corcoran, M. F.; Hamaguchi, K.; Teodoro, M.

    2013-01-01

    Recent work suggests that the mass-loss rate of the primary star Eta-A in the massive colliding wind binary Eta Carinae dropped by a factor of 2-3 between 1999 and 2010. We present result from large- (+/- 1545 au) and small- (+/- 155 au) domain, 3D smoothed particle hydrodynamics (SPH) simulations of Eta Car's colliding winds for three Eta-A mass-loss rates ( (dot-M(sub Eta-A) = 2.4, 4.8 and 8.5 × 10(exp -4) M(solar)/ yr), investigating the effects on the dynamics of the binary wind-wind collision (WWC). These simulations include orbital motion, optically thin radiative cooling and radiative forces. We find that dot-M Eta-A greatly affects the time-dependent hydrodynamics at all spatial scales investigated. The simulations also show that the post-shock wind of the companion star Eta-B switches from the adiabatic to the radiative-cooling regime during periastron passage (Phi approx.= 0.985-1.02). This switchover starts later and ends earlier the lower the value of dot-M Eta-A and is caused by the encroachment of the wind of Eta-A into the acceleration zone of Eta-B's wind, plus radiative inhibition of Eta-B's wind by Eta-A. The SPH simulations together with 1D radiative transfer models of Eta-A's spectra reveal that a factor of 2 or more drop in dot-M EtaA should lead to substantial changes in numerous multiwavelength observables. Recent observations are not fully consistent with the model predictions, indicating that any drop in dot- M Eta-A was likely by a factor of approx. < 2 and occurred after 2004. We speculate that most of the recent observed changes in Eta Car are due to a small increase in the WWC opening angle that produces significant effects because our line of sight to the system lies close to the dense walls of the WWC zone. A modest decrease in dot-M Eta-A may be responsible, but changes in the wind/stellar parameter of Eta-B, while less likely, cannot yet be fully ruled out. We suggest observations during Eta-Car's next periastron in 2014 to further

  8. Observations of the 3-D distribution of interplanetary electrons and ions from solar wind plasma to low energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Lin, R. P.; Anderson, K. A.; Ashford, S.; Carlson, C.; Curtis, D.; Ergun, R.; Larson, D.; McFadden, J.; McCarthy, M.; Parks, G. K.

    1995-01-01

    The 3-D Plasma and Energetic Particle instrument on the GGS Wind spacecraft (launched November 1, 1994) is designed to make measurements of the full three-dimensional distribution of suprathermal electrons and ions from solar wind plasma to low energy cosmic rays, with high sensitivity, wide dynamic range, good energy and angular resolution, and high time resolution. Three pairs of double-ended telescopes, each with two or three closely sandwiched passivated ion implanted silicon detectors measure electrons and ions from approximately 20 keV to greater than or equal to 300 keV. Four top-hat symmetrical spherical section electrostatic analyzers with microchannel plate detectors, a large and a small geometric factor analyzer for electrons and a similar pair for ions, cover from approximately 3 eV to 30 keV. We present preliminary observations of the electron and ion distributions in the absence of obvious solar impulsive events and upstream particles. The quiet time electron energy spectrum shows a smooth approximately power law fall-off extending from the halo population at a few hundred eV to well above approximately 100 keV The quiet time ion energy spectrum also shows significant fluxes over this energy range. Detailed 3-D distributions and their temporal variations will be presented.

  9. Wind Field Measurements With Airborne Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Menzies, Robert T.

    1999-01-01

    In collaboration with lidar atmospheric remote sensing groups at NASA Marshall Space Flight Center and National Oceanic and Atmospheric Administration (NOAA) Environmental Technology Laboratory, we have developed and flown the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) lidar on the NASA DC-8 research aircraft. The scientific motivations for this effort are: to obtain measurements of subgrid scale (i.e. 2-200 km) processes and features which may be used to improve parameterizations in global/regional-scale models; to improve understanding and predictive capabilities on the mesoscale; and to assess the performance of Earth-orbiting Doppler lidar for global tropospheric wind measurements. MACAWS is a scanning Doppler lidar using a pulsed transmitter and coherent detection; the use of the scanner allows 3-D wind fields to be produced from the data. The instrument can also be radiometrically calibrated and used to study aerosol, cloud, and surface scattering characteristics at the lidar wavelength in the thermal infrared. MACAWS was used to study surface winds off the California coast near Point Arena, with an example depicted in the figure below. The northerly flow here is due to the Pacific subtropical high. The coastal topography interacts with the northerly flow in the marine inversion layer, and when the flow passes a cape or point that juts into the winds, structures called "hydraulic expansion fans" are observed. These are marked by strong variation along the vertical and cross-shore directions. The plots below show three horizontal slices at different heights above sea level (ASL). Bottom plots are enlargements of the area marked by dotted boxes above. The terrain contours are in 200-m increments, with the white spots being above 600-m elevation. Additional information is contained in the original.

  10. Bias Field Inconsistency Correction of Motion-Scattered Multislice MRI for Improved 3D Image Reconstruction

    PubMed Central

    Kim, Kio; Habas, Piotr A.; Rajagopalan, Vidya; Scott, Julia A.; Corbett-Detig, James M.; Rousseau, Francois; Barkovich, A. James; Glenn, Orit A.; Studholme, Colin

    2012-01-01

    A common solution to clinical MR imaging in the presence of large anatomical motion is to use fast multi-slice 2D studies to reduce slice acquisition time and provide clinically usable slice data. Recently, techniques have been developed which retrospectively correct large scale 3D motion between individual slices allowing the formation of a geometrically correct 3D volume from the multiple slice stacks. One challenge, however, in the final reconstruction process is the possibility of varying intensity bias in the slice data, typically due to the motion of the anatomy relative to imaging coils. As a result, slices which cover the same region of anatomy at different times may exhibit different sensitivity. This bias field inconsistency can induce artifacts in the final 3D reconstruction that can impact both clinical interpretation of key tissue boundaries and the automated analysis of the data. Here we describe a framework to estimate and correct the bias field inconsistency in each slice collectively across all motion corrupted image slices. Experiments using synthetic and clinical data show that the proposed method reduces intensity variability in tissues and improves the distinction between key tissue types. PMID:21511561

  11. Bias field inconsistency correction of motion-scattered multislice MRI for improved 3D image reconstruction.

    PubMed

    Kim, Kio; Habas, Piotr A; Rajagopalan, Vidya; Scott, Julia A; Corbett-Detig, James M; Rousseau, Francois; Barkovich, A James; Glenn, Orit A; Studholme, Colin

    2011-09-01

    A common solution to clinical MR imaging in the presence of large anatomical motion is to use fast multislice 2D studies to reduce slice acquisition time and provide clinically usable slice data. Recently, techniques have been developed which retrospectively correct large scale 3D motion between individual slices allowing the formation of a geometrically correct 3D volume from the multiple slice stacks. One challenge, however, in the final reconstruction process is the possibility of varying intensity bias in the slice data, typically due to the motion of the anatomy relative to imaging coils. As a result, slices which cover the same region of anatomy at different times may exhibit different sensitivity. This bias field inconsistency can induce artifacts in the final 3D reconstruction that can impact both clinical interpretation of key tissue boundaries and the automated analysis of the data. Here we describe a framework to estimate and correct the bias field inconsistency in each slice collectively across all motion corrupted image slices. Experiments using synthetic and clinical data show that the proposed method reduces intensity variability in tissues and improves the distinction between key tissue types.

  12. Anisotropic heat transport in integrable and chaotic 3-D magnetic fields

    SciTech Connect

    Del-Castillo-Negrete, Diego B; Blazevski, D.; Chacon, Luis

    2012-01-01

    A study of anisotropic heat transport in 3-D chaotic magnetic fields is presented. The approach is based on the recently proposed Lagrangian-Green s function (LG) method in Ref. [1] that allows an efficient and accurate integration of the parallel transport equation applicable to general magnetic fields with local or non-local parallel flux closures. We focus on reversed shear magnetic field configurations known to exhibit separatrix reconnection and shearless transport barriers. The role of reconnection and magnetic field line chaos on temperature transport is studied. Numerical results are presented on the anomalous relaxation of radial temperature gradients in the presence of shearless Cantori partial barri- ers. Also, numerical evidence of non-local effective radial temperature transport in chaotic fields is presented. Going beyond purely parallel transport, the LG method is generalized to include finite perpendicular diffusivity, and the problem of temperature flattening inside a magnetic island is studied.

  13. 3D structure and conductive thermal field of the Upper Rhine Graben

    NASA Astrophysics Data System (ADS)

    Freymark, Jessica; Sippel, Judith; Scheck-Wenderoth, Magdalena; Bär, Kristian; Stiller, Manfred; Fritsche, Johann-Gerhard; Kracht, Matthias

    2016-04-01

    The Upper Rhine Graben (URG) was formed as part of the European Cenozoic Rift System in a complex extensional setting. At present-day, it has a large socioeconomic relevance as it provides a great potential for geothermal energy production in Germany and France. For the utilisation of this energy resource it is crucial to understand the structure and the observed temperature anomalies in the rift basin. In the framework of the EU-funded "IMAGE" project (Integrated Methods for Advanced Geothermal Exploration), we apply a data-driven numerical modelling approach to quantify the processes and properties controlling the spatial distribution of subsurface temperatures. Typically, reservoir-scale numerical models are developed for predictions on the subsurface hydrothermal conditions and for reducing the risk of drilling non-productive geothermal wells. One major problem related to such models is setting appropriate boundary conditions that define, for instance, how much heat enters the reservoir from greater depths. Therefore, we first build a regional lithospheric-scale 3D structural model, which covers not only the entire URG but also adjacent geological features like the Black Forest and the Vosges Mountains. In particular, we use a multidisciplinary dataset (e.g. well data, seismic reflection data, existing structural models, gravity) to construct the geometries of the sediments, the crust and the lithospheric mantle that control the spatial distribution of thermal conductivity and radiogenic heat production and hence temperatures. By applying a data-based and lithology-dependent parameterisation of this lithospheric-scale 3D structural model and a 3D finite element method, we calculate the steady-state conductive thermal field for the entire region. Available measured temperatures (down to depths of up to 5 km) are considered to validate the 3D thermal model. We present major characteristics of the lithospheric-scale 3D structural model and results of the 3D

  14. Exact spectra of strong coulomb correlations of 3-D 2-e harmonic dots in magnetic field

    NASA Astrophysics Data System (ADS)

    Aggarwal, Priyanka; Sharma, Shivalika; Kaur, Harsimran; Singh, Sunny; Hazra, Ram Kuntal

    2017-01-01

    Applications of 3-D 2-e systems have proliferated very fast due to technological advancements in wide range of phenomena from atomic landscape to mesoscopic scale. The unusual properties of atomic/mesoscopic systems are the results of interplaying charge interactions among different bound states. The non-trivial e-e correlations in electrically and/or magnetically confined systems improvise wealth of intriguing challenges at fundamental level due to lack of exact solution of Schrödinger equations. For the first time, a novel methodology of exactly finite summed coulomb correlations invented by us is so handy that even usual programmable calculator can be used to examine the electronic structures of 3-D 2-e harmonic dots in perpendicular magnetic field (symmetric gauge). Statistics of electronic levels, heat capacity measurements and magnetization (T∼1 K) are also investigated in brief to probe the degree of disorderedness.

  15. 3D position estimation using a single coil and two magnetic field sensors.

    PubMed

    Tadayon, P; Staude, G; Felderhoff, T

    2015-01-01

    This paper presents an algorithm which enables the estimation of relative 3D position of a sensor module with two magnetic sensors with respect to a magnetic field source using a single transmitting coil. Starting with the description of the ambiguity problem caused by using a single coil, a system concept comprising two sensors having a fixed spatial relation to each other is introduced which enables the unique determination of the sensors' position in 3D space. For this purpose, an iterative two-step algorithm is presented: In a first step, the data of one sensor is used to limit the number of possible position solutions. In a second step, the spatial relation between the sensors is used to determine the correct sensor position.

  16. Effects of 3D Toroidally Asymmetric Magnetic Field on Tokamak Magnetic Surfaces

    NASA Astrophysics Data System (ADS)

    Lao, L. L.

    2005-10-01

    The effects of 3D error magnetic field on magnetic surfaces are investigated using the DIII-D internal coils (I-Coils). Slowly rotating n=1 traveling waves at 5 Hz and various amplitudes were applied to systematically perturb the edge surfaces by programming the I-Coil currents. The vertical separatrix location difference between EFIT magnetic reconstructions that assumes toroidal symmetry and Thomson scattering Te measurements responds in phase to the applied perturbed field. The oscillation amplitudes increase with the strength of the applied field but are much smaller than those expected from the applied field alone. The results indicate that plasma response is important. Various plasma response models based on results from the MHD codes MARS and GATO are being developed and compared to the experimental observations. To more accurately evaluate the effects of magnetic measurement errors, a new form of the magnetic uncertainty matrix is also being implemented into EFIT. Details will be presented.

  17. The distribution of 3D superconductivity near the second critical field

    NASA Astrophysics Data System (ADS)

    Kachmar, Ayman; Nasrallah, Marwa

    2016-09-01

    We study the minimizers of the Ginzburg-Landau energy functional with a uniform magnetic field in a three dimensional bounded domain. The functional depends on two positive parameters, the Ginzburg-Landau parameter and the intensity of the applied magnetic field, and acts on complex-valued functions and vector fields. We establish a formula for the distribution of the L 2-norm of the minimizing complex-valued function (order parameter). The formula is valid in the regime where the Ginzburg-Landau parameter is large and the applied magnetic field is close to and strictly below the second critical field—the threshold value corresponding to the transition from the superconducting to the normal phase in the bulk of the sample. Earlier results are valid in 2D domains and for the L 4-norm in 3D domains.

  18. [A 3D FEM model for calculation of electromagnetic fields in transmagnetic stimulation].

    PubMed

    Seilwinder, J; Kammer, T; Andrä, W; Bellemann, M E

    2002-01-01

    We developed a realistic finite elements method (FEM) model of the brain for the calculation of electromagnetic fields in transcranial magnetic stimulation (TMS). A focal butterfly stimulation coil was X-rayed, parameterized, and modeled. The magnetic field components of the TMS coil were calculated and compared for validation to pointwise measurements of the magnetic fields with a Hall sensor. We found a mean deviation of 7.4% at an axial distance of 20 mm to the coil. A 3D brain model with the biological tissues of white and gray matter, bone, and cerebrospinal fluid was developed. At a current sweep of 1000 A in 120 microseconds, the maximum induced current density in gray matter was 177 mA/m2 and the strongest electric field gradient covered an area of 40 mm x 53 mm.

  19. Neoclassical Tearing Mode Locking Avoidance by 3D Fields and Recovery of High Confinement

    NASA Astrophysics Data System (ADS)

    Okabayashi, M.; Budny, B.; Brennan, D.; Ferraro, N.; Grierson, B.; Jardin, S.; Logan, N.; Nazikian, R.; Tobias, B.; Wang, Z.; Strait, E.; de Grassie, J.; La Haye, R.; Paz-Soldan, C.; Taylor, Z.; Shiraki, D.; Hanson, J.; Holcomb, C.; Liu, Y.

    2016-10-01

    A slowly rotating n=1 helical magnetic field has been applied for Neoclassical Tearing Mode (NTM) locking avoidance in the DIII-D tokamak. This 3D field applied through feedback recovered a high performance configuration by rebuilding a H-mode edge and high ion temperature internal transport barrier in the plasma core, although, at present, the βn was reduced by 30%. The m/n=2/1 component of 3D field served to avoid NTM locking, while the m/n=1 and the m/n=(4-5)/1 components recover core confinement and H-mode edge. Preliminary analysis shows a quasi-steady helical plasma flow was built up around the core, mostly parallel to the equilibrium magnetic field. The optimization of m-components with n=1 is a promising approach for integrating optimizations of MHD stability from core to edge. Supported in part by the US DOE under DE-AC02-09CH11466, DE-FG02-99ER54531, DE-SC0003913 and DE-FC02-04ER54698.

  20. Application of rank-ordered multifractal analysis (ROMA) to intermittent fluctuations in 3D turbulent flows, 2D MHD simulation and solar wind data

    NASA Astrophysics Data System (ADS)

    Wu, C.; Chang, T.

    2010-12-01

    A new method in describing the multifractal characteristics of intermittent events was introduced by Cheng and Wu [Chang T. and Wu C.C., Physical Rev, E77, 045401(R), 2008]. The procedure provides a natural connection between the rank-ordered spectrum and the idea of one-parameter scaling for monofractals. This technique has been demonstrated using results obtained from a 2D MHD simulation. It has also been successfully applied to in-situ solar wind observations [Chang T., Wu, C.C. and Podesta, J., AIP Conf Proc. 1039, 75, 2008], and the broadband electric field oscillations from the auroral zone [Tam, S.W.Y. et al., Physical Rev, E81, 036414, 2010]. We take the next step in this procedure. By using the ROMA spectra and the scaled probability distribution functions (PDFs), raw PDFs can be calculated, which can be compared directly with PDFs from observations or simulation results. In addition to 2D MHD simulation results and in-situ solar wind observation, we show clearly using the ROMA analysis the multifractal character of the 3D fluid simulation data obtained from the JHU turbulence database cluster at http://turbulence.pha.jhu.edu. In particular, we show the scaling of the non-symmetrical PDF for the parallel-velocity fluctuations of this 3D fluid data.

  1. Effects of electromagnetic field frequencies on chondrocytes in 3D cell-printed composite constructs.

    PubMed

    Yi, Hee-Gyeong; Kang, Kyung Shin; Hong, Jung Min; Jang, Jinah; Park, Moon Nyeo; Jeong, Young Hun; Cho, Dong-Woo

    2016-07-01

    In cartilage tissue engineering, electromagnetic field (EMF) therapy has been reported to have a modest effect on promoting cartilage regeneration. However, these studies were conducted using different frequencies of EMF to stimulate chondrocytes. Thus, it is necessary to investigate the effect of EMF frequency on cartilage formation. In addition to the stimulation, a scaffold is required to satisfy the characteristics of cartilage such as its hydrated and dense extracellular matrix, and a mechanical resilience to applied loads. Therefore, we 3D-printed a composite construct composed of a polymeric framework and a chondrocyte-laden hydrogel. Here, we observed frequency-dependent positive and negative effects on chondrogenesis using a 3D cell-printed cartilage tissue. We found that a frequency of 45 Hz promoted gene expression and secretion of extracellular matrix molecules of chondrocytes. In contrast, a frequency of 7.5 Hz suppressed chondrogenic differentiation in vitro. Additionally, the EMF-treated composite constructs prior to implantation showed consistent results with those of in vitro, suggesting that in vitro pre-treatment with different EMF frequencies provides different capabilities for the enhancement of cartilage formation in vivo. This correlation between EMF frequency and 3D-printed chondrocytes suggests the necessity for optimization of EMF parameters when this physical stimulus is applied to engineered cartilage. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1797-1804, 2016.

  2. Offshore wind resource estimation from satellite SAR wind field maps

    NASA Astrophysics Data System (ADS)

    Hasager, C. B.; Nielsen, M.; Astrup, P.; Barthelmie, R.; Dellwik, E.; Jensen, N. O.; Jørgensen, B. H.; Pryor, S. C.; Rathmann, O.; Furevik, B. R.

    2005-10-01

    A wind resource estimation study based on a series of 62 satellite wind field maps is presented. The maps were retrieved from imaging synthetic aperture radar (SAR) data. The wind field maps were used as input to the software RWT, which calculates the offshore wind resource based on spatial averaging (footprint modelling) of the wind statistic in each satellite image. The calculated statistics can then be input to the program WAsP and used in lieu of in-situ observations by meteorological instruments. A regional wind climate map based on satellite SAR images delineates significant spatial wind speed variations. The site of investigation was Horns Rev in the North Sea, where a meteorological time series is used for comparison. The advantages and limitations of these new techniques, which seem particularly useful for mapping of the regional wind climate, are discussed. Copyright

  3. AdS/CFT for 3D higher-spin gravity coupled to matter fields

    NASA Astrophysics Data System (ADS)

    Fujisawa, Ippei; Nakagawa, Kenta; Nakayama, Ryuichi

    2014-03-01

    New holographic prescription for the model of 3d higher-spin gravity coupled to real matter fields Bμν and C, which was introduced in Fujisawa and Nakayama (2014 Class. Quantum Grav. 31 015003), is formulated. By using a local symmetry, two of the components of Bμν are eliminated, and gauge-fixing conditions are imposed such that the non-vanishing component, Bϕρ, satisfies a covariantly-constancy condition in the background of Chern-Simons gauge fields Aμ, \\bar{A}_{\\mu }. In this model, solutions to the classical equations of motion for Aμ and \\bar{A}_{\\mu } are non-flat due to the interactions with matter fields. The solutions for the gauge fields can, however, be split into two parts, flat gauge fields A_{\\mu }, \\bar{A}_{\\mu }, and those terms that depend on the matter fields. The equations for the matter fields then coincide with covariantly-constancy equations in the flat backgrounds A_{\\mu } and \\bar{A}_{\\mu }, which are exactly the same as those in linearized 3d Vasiliev gravity. The two- and three-point correlation functions of the single-trace operators and the higher-spin currents in the boundary CFT are computed by using an on-shell action tr (Bϕρ C). This term does not depend on coordinates due to the matter equations of motion, and it is not necessary to take the near-boundary limit ρ → ∞. Analysis is presented for SL(3,R) × SL(3,R) as well as HS[\\frac{1}{2}] \\times HS[\\frac{1}{2}] higher-spin gravity. In the latter model, scalar operators with scaling dimensions Δ+ = 3/2 and Δ- = 1/2 appear in a single quantization.

  4. 3D Design, Contruction, and Field Analysis of CIS Main Dipole Magnets

    NASA Astrophysics Data System (ADS)

    Berg, G. P. A.; Fox, W.; Friesel, D. L.; Rinckel, T.

    1997-05-01

    The lattice for CIS ( Cooler Injection Synchroton ) requires four laminated 90^circ main dipole magnets with bending radius ρ = 1.273 m, EFL = 2 m, and an edge angle of 12^circ. Optimum Cooler injection and injection in the planned 15 GeV LISS ring requires operation up to about 1.75 T. Initial operation of 1 Hz, with later upgrade to 5 Hz is planned. We will present 2D and 3D field calculations used to optimize the shape of laminations and endpacks of the magnet. Endpacks are designed to determine edge angle and to compensate hexapole components, in particular above 1.4 T where saturation becomes significant. The large dipole curvature required a new type of dipole construction. Each magnet consists of wedge shaped blocks fabricated from stamped lamination of cold rolled low carbon iron. B-stage (dry) epopy was used for bonding and insulation. The end blocks are machined to include the calculated 3D shape of the endpacks. All four magnets were mapped in the field range from 0.3 T - 1.8 T. Comparison of calculations and data in terms of B(I) curves, EFL, edge angle, and hexapole component as function of field excitation will be presented. The constructed magnets are well within expected specifications.

  5. 3D geometry of the strain-field at transform plate boundaries: Implications for seismic rupture

    SciTech Connect

    Bodin, P.; Bilham, R. |

    1994-11-01

    We examine the amplitude and distribution of slip on vertical frictionless faults in the zone of concentrated shear strain that is characteristic of transform plate boundaries. We study both a 2D and a 3D approximation to this strain field. Mean displacements on ruptures within the zone of concentrated shear strain are proportional to the shear strain at failure when they are short, and are limited by plate displacements since the last major earthquake when they are long. The transition between these two behaviors occurs when the length of the dislocation approaches twice the thickness of the seismogenic crust, approximately the breadth of the zone of concentrated shear strain observed geodetically at transform plate boundaries. This result explains the observed non-linear scaling relation between seismic moment and rupture length. A geometrical consequence of the 3D model, in which the strain-field tapers downward, is that moderate earthquakes with rupture lengths similar to the thickness of the crust tend to slip more at depth than near the surface. Seismic moments estimated from surface slip in moderate earthquakes (M less than or equal to 7) will thus be underestimated. Shallow creep, if its along-strike dimension is extensive, can reduce a surface slip deficit that would otherwise develop on faults on which M less than 7 events are typical. In the absence of surface creep or other forms of off-fault deformation great earthquakes may be necessary features of transform boundaries with downward-tapering strain-fields.

  6. Automated Atom-By-Atom Three-Dimensional (3D) Reconstruction of Field Ion Microscopy Data.

    PubMed

    Dagan, Michal; Gault, Baptiste; Smith, George D W; Bagot, Paul A J; Moody, Michael P

    2017-03-20

    An automated procedure has been developed for the reconstruction of field ion microscopy (FIM) data that maintains its atomistic nature. FIM characterizes individual atoms on the specimen's surface, evolving subject to field evaporation, in a series of two-dimensional (2D) images. Its unique spatial resolution enables direct imaging of crystal defects as small as single vacancies. To fully exploit FIM's potential, automated analysis tools are required. The reconstruction algorithm developed here relies on minimal assumptions and is sensitive to atomic coordinates of all imaged atoms. It tracks the atoms across a sequence of images, allocating each to its respective crystallographic plane. The result is a highly accurate 3D lattice-resolved reconstruction. The procedure is applied to over 2000 tungsten atoms, including ion-implanted planes. The approach is further adapted to analyze carbides in a steel matrix, demonstrating its applicability to a range of materials. A vast amount of information is collected during the experiment that can underpin advanced analyses such as automated detection of "out of sequence" events, subangstrom surface displacements and defects effects on neighboring atoms. These analyses have the potential to reveal new insights into the field evaporation process and contribute to improving accuracy and scope of 3D FIM and atom probe characterization.

  7. Locating earthquakes in west Texas oil fields using 3-D anisotropic velocity models

    SciTech Connect

    Hua, Fa; Doser, D.; Baker, M. . Dept. of Geological Sciences)

    1993-02-01

    Earthquakes within the War-Wink gas field, Ward County, Texas, that have been located with a 1-D velocity model occur near the edges and top of a naturally occurring overpressured zone. Because the War-Wink field is a structurally controlled anticline with significant velocity anisotropy associated with the overpressured zone and finely layered evaporites, the authors have attempted to re-locate earthquakes using a 3-D anisotropic velocity model. Preliminary results with this model give the unsatisfactory result that many earthquakes previously located at the top of the overpressured zone (3-3.5 km) moved into the evaporites (1-1.5 km) above the field. They believe that this result could be caused by: (1) aliasing the velocity model; or (2) problems in determining the correct location minima when several minima exist. They are currently attempting to determine which of these causes is more likely for the unsatisfactory result observed.

  8. Noise analysis for near field 3-D FM-CW radar imaging systems

    SciTech Connect

    Sheen, David M.

    2015-06-19

    Near field radar imaging systems are used for several applications including concealed weapon detection in airports and other high-security venues. Despite the near-field operation, phase noise and thermal noise can limit the performance in several ways including reduction in system sensitivity and reduction of image dynamic range. In this paper, the effects of thermal noise, phase noise, and processing gain are analyzed in the context of a near field 3-D FM-CW imaging radar as might be used for concealed weapon detection. In addition to traditional frequency domain analysis, a time-domain simulation is employed to graphically demonstrate the effect of these noise sources on a fast-chirping FM-CW system.

  9. 3-D RESERVOIR AND STOCHASTIC FRACTURE NETWORK MODELING FOR ENHANCED OIL RECOVERY, CIRCLE RIDGE PHOSPHORIA/TENSLEEP RESERVOIR, WIND RIVER RESERVATION, ARAPAHO AND SHOSHONE TRIBES, WYOMING

    SciTech Connect

    Paul La Pointe; Jan Hermanson; Robert Parney; Thorsten Eiben; Mike Dunleavy; Ken Steele; John Whitney; Darrell Eubanks; Roger Straub

    2002-11-18

    This report describes the results made in fulfillment of contract DE-FG26-00BC15190, ''3-D Reservoir and Stochastic Fracture Network Modeling for Enhanced Oil Recovery, Circle Ridge Phosphoria/Tensleep Reservoir, Wind River Reservation, Arapaho and Shoshone Tribes, Wyoming''. The goal of this project is to improve the recovery of oil from the Tensleep and Phosphoria Formations in Circle Ridge Oilfield, located on the Wind River Reservation in Wyoming, through an innovative integration of matrix characterization, structural reconstruction, and the characterization of the fracturing in the reservoir through the use of discrete fracture network models. Fields in which natural fractures dominate reservoir permeability, such as the Circle Ridge Field, often experience sub-optimal recovery when recovery processes are designed and implemented that do not take advantage of the fracture systems. For example, a conventional waterflood in a main structural block of the Field was implemented and later suspended due to unattractive results. It is estimated that somewhere less than 20% of the OOIP in the Circle Ridge Field have been recovered after more than 50 years' production. Marathon Oil Company identified the Circle Ridge Field as an attractive candidate for several advanced IOR processes that explicitly take advantage of the natural fracture system. These processes require knowledge of the distribution of matrix porosity, permeability and oil saturations; and understanding of where fracturing is likely to be well-developed or poorly developed; how the fracturing may compartmentalize the reservoir; and how smaller, relatively untested subthrust fault blocks may be connected to the main overthrust block. For this reason, the project focused on improving knowledge of the matrix properties, the fault block architecture and to develop a model that could be used to predict fracture intensity, orientation and fluid flow/connectivity properties. Knowledge of matrix properties was

  10. Wind Turbines Adaptation to the Variability of the Wind Field

    NASA Astrophysics Data System (ADS)

    Ulianov, Yuriy; Martynenko, Gennadii; Misaylov, Vitaliy; Soliannikova, Iuliia

    2010-05-01

    WIND TURBINES ADAPTATION TO THE VARIABILITY OF THE WIND FIELD The subject of our scientific research is wind power turbines (WPT) with the horizontal axis which were now common in the world. Efficient wind turbines work is largely determined by non-stationarity of the wind field, expressed in its gustiness, the presence of vertical and horizontal shifts of wind speed and direction. At critical values of the wind parameters WPT has aerodynamic and mechanical overload, leading to breakdowns, premature wear and reduce the life of the wind turbine. To prevent accidents at the peak values of wind speed it is used the regulatory system of windwheels. WPT control systems provide a process orientation of the wind turbine rotor axis in the line of the mean wind. Wind turbines are also equipped with braking device used to protect against breakdowns when a significant increase in the wind. In general, all these methods of regulation are not always effective. Thus, in practice there may be situations when the wind speed is many times greater than the stated limit. For example, if there are microbursts in the atmospheric boundary layer, low-level wind shears caused by its gust front, storms, etc. It is required for a wind power turbine adaptation to intensive short-term wind impulses and considerable vertical wind shifts that the data about them shall be obtained ahead of time. To do this it is necessary to have the information on the real structure of the wind field in the area of the blade sweep for the minimum range against the wind that is determined by the mean speed and the system action time. The implementation of acoustic and laser traditional wind sounding systems is limited by ambient acoustic noise, by heavy rain, snowfall and by fog. There are free of these disadvantages the inclined radioacoustic sounding (IRASS) technique which works for a system of remote detection and control of wind gusts. IRASS technique is realized as low-potential Doppler pulse radar

  11. Towards Automated Large-Scale 3D Phenotyping of Vineyards under Field Conditions.

    PubMed

    Rose, Johann Christian; Kicherer, Anna; Wieland, Markus; Klingbeil, Lasse; Töpfer, Reinhard; Kuhlmann, Heiner

    2016-12-15

    In viticulture, phenotypic data are traditionally collected directly in the field via visual and manual means by an experienced person. This approach is time consuming, subjective and prone to human errors. In recent years, research therefore has focused strongly on developing automated and non-invasive sensor-based methods to increase data acquisition speed, enhance measurement accuracy and objectivity and to reduce labor costs. While many 2D methods based on image processing have been proposed for field phenotyping, only a few 3D solutions are found in the literature. A track-driven vehicle consisting of a camera system, a real-time-kinematic GPS system for positioning, as well as hardware for vehicle control, image storage and acquisition is used to visually capture a whole vine row canopy with georeferenced RGB images. In the first post-processing step, these images were used within a multi-view-stereo software to reconstruct a textured 3D point cloud of the whole grapevine row. A classification algorithm is then used in the second step to automatically classify the raw point cloud data into the semantic plant components, grape bunches and canopy. In the third step, phenotypic data for the semantic objects is gathered using the classification results obtaining the quantity of grape bunches, berries and the berry diameter.

  12. Effects of 2D and 3D Error Fields on the SAS Divertor Magnetic Topology

    NASA Astrophysics Data System (ADS)

    Trevisan, G. L.; Lao, L. L.; Strait, E. J.; Guo, H. Y.; Wu, W.; Evans, T. E.

    2016-10-01

    The successful design of plasma-facing components in fusion experiments is of paramount importance in both the operation of future reactors and in the modification of operating machines. Indeed, the Small Angle Slot (SAS) divertor concept, proposed for application on the DIII-D experiment, combines a small incident angle at the plasma strike point with a progressively opening slot, so as to better control heat flux and erosion in high-performance tokamak plasmas. Uncertainty quantification of the error fields expected around the striking point provides additional useful information in both the design and the modeling phases of the new divertor, in part due to the particular geometric requirement of the striking flux surfaces. The presented work involves both 2D and 3D magnetic error field analysis on the SAS strike point carried out using the EFIT code for 2D equilibrium reconstruction, V3POST for vacuum 3D computations and the OMFIT integrated modeling framework for data analysis. An uncertainty in the magnetic probes' signals is found to propagate non-linearly as an uncertainty in the striking point and angle, which can be quantified through statistical analysis to yield robust estimates. Work supported by contracts DE-FG02-95ER54309 and DE-FC02-04ER54698.

  13. Towards Automated Large-Scale 3D Phenotyping of Vineyards under Field Conditions

    PubMed Central

    Rose, Johann Christian; Kicherer, Anna; Wieland, Markus; Klingbeil, Lasse; Töpfer, Reinhard; Kuhlmann, Heiner

    2016-01-01

    In viticulture, phenotypic data are traditionally collected directly in the field via visual and manual means by an experienced person. This approach is time consuming, subjective and prone to human errors. In recent years, research therefore has focused strongly on developing automated and non-invasive sensor-based methods to increase data acquisition speed, enhance measurement accuracy and objectivity and to reduce labor costs. While many 2D methods based on image processing have been proposed for field phenotyping, only a few 3D solutions are found in the literature. A track-driven vehicle consisting of a camera system, a real-time-kinematic GPS system for positioning, as well as hardware for vehicle control, image storage and acquisition is used to visually capture a whole vine row canopy with georeferenced RGB images. In the first post-processing step, these images were used within a multi-view-stereo software to reconstruct a textured 3D point cloud of the whole grapevine row. A classification algorithm is then used in the second step to automatically classify the raw point cloud data into the semantic plant components, grape bunches and canopy. In the third step, phenotypic data for the semantic objects is gathered using the classification results obtaining the quantity of grape bunches, berries and the berry diameter. PMID:27983669

  14. Surface rippling during solidification of binary polycrystalline alloy: Insights from 3-D phase-field simulations

    NASA Astrophysics Data System (ADS)

    Ankit, Kumar; Xing, Hui; Selzer, Michael; Nestler, Britta; Glicksman, Martin E.

    2017-01-01

    The mechanisms by which crystalline imperfections initiate breakdown of a planar front during directional solidification remain a topic of longstanding interest. Previous experimental findings show that the solid-liquid interface adjacent to a grain boundary provides a potential site where morphological instabilities initiate. However, interpretation of experimental data is difficult for complex 3-D diffusion fields that develop around grain multi-junctions and boundary ridges. We apply a phase-field approach to investigate factors that induce interfacial instabilities during directional solidification of a binary polycrystalline alloy. Using 2-D simulations, we establish the influence of solid-liquid interfacial energies on the spatial localization of initial interfacial perturbations. Based on parametric studies, we predict that grain misorientation and supersaturation in the melt provide major crystal growth factors determining solute segregation responsible for surface rippling. Subsequent breakdown of boundary ridges into periodic rows of hills, as simulated in 3-D, conform well with experiments. Finally, the significance of crystal misorientation relationships is elucidated in inducing spatial alignment of surface ripples.

  15. 3D and 4D GPR for Stratigraphic and Hydrologic Characterization of Field Sites

    NASA Astrophysics Data System (ADS)

    Grasmueck, M.; Viggiano, D. A.

    2008-05-01

    In a time of almost unlimited mobility, information, and connectivity it is surprising how our knowledge of natural systems becomes fragmented as soon as we enter the ground. Excavation, drilling, and 2D geophysics are unable to capture the spatio-temporal variability inside soil and rock volumes at the 1-10m scale. The problem is the lack of efficient and high-resolution imaging for the near surface domain. We have developed a high- resolution 3D Ground Penetrating Radar (GPR) system suitable for data acquisition at field sites. To achieve sharp and repeatable subsurface imaging we have integrated GPR with a rotary laser/IR strobe system. With 40 xyz coordinate updates per second, continuously moving GPR antennae can be tracked centimeter precise. A real-time LED guidance system shows the GPR antenna operator how to follow pre-computed survey tracks. Without having to stake out hundreds of survey tracks anymore one person now can scan an area of up to 600m2 per hour with a dual GPR antenna at 1m/s with 0.1m line spacing. The coordinate and GPR data are fused in real-time providing a first look of the subsurface in horizontal map view for quality control and in-field site assessment during data acquisition. The precision of the laser positioning system enables centimeter accurate repeat surveys to image and quantify water content changes in the vadose zone. To verify quantitative results of such 4D GPR we performed a controlled pond infiltration injecting 3200L of water from a 4x4m temporary pond with a thin soil layer and 5m of unsaturated porous limestone below. A total of sixteen repeated 3D GPR surveys were acquired just before the infiltration and in the following 2 weeks. All data were recorded with 250MHz antennae on a 5x10cm grid covering an area of 18x20m. Data processing included 3D migration and extraction of time shifts between pairs of time- lapse 3D GPR surveys. From the time shifts water content changes were computed using the Topp equation. The

  16. 3D-NTT: a versatile integral field spectro-imager for the NTT

    NASA Astrophysics Data System (ADS)

    Marcelin, M.; Amram, P.; Balard, P.; Balkowski, C.; Boissin, O.; Boulesteix, J.; Carignan, C.; Daigle, O.; de Denus Baillargeon, M.-M.; Epinat, B.; Gach, J.-L.; Hernandez, O.; Rigaud, F.; Vallée, P.

    2008-07-01

    The 3D-NTT is a visible integral field spectro-imager offering two modes. A low resolution mode (R ~ 300 to 6 000) with a large field of view Tunable Filter (17'x17') and a high resolution mode (R ~ 10 000 to 40 000) with a scanning Fabry-Perot (7'x7'). It will be operated as a visitor instrument on the NTT from 2009. Two large programmes will be led: "Characterizing the interstellar medium of nearby galaxies with 2D maps of extinction and abundances" (PI M. Marcelin) and "Gas accretion and radiative feedback in the early universe" (PI J. Bland Hawthorn). Both will be mainly based on the Tunable Filter mode. This instrument is being built as a collaborative effort between LAM (Marseille), GEPI (Paris) and LAE (Montreal). The website adress of the instrument is : http://www.astro.umontreal.ca/3DNTT

  17. 3-D reservoir characterization of the House Creek oil field, Powder River Basin, Wyoming

    USGS Publications Warehouse

    Higley, Debra K.; Pantea, Michael P.; Slatt, Roger M.

    1997-01-01

    This CD-ROM is intended to serve a broad audience. An important purpose is to explain geologic and geochemical factors that control petroleum production from the House Creek Field. This information may serve as an analog for other marine-ridge sandstone reservoirs. The 3-D slide and movie images are tied to explanations and 2-D geologic and geochemical images to visualize geologic structures in three dimensions, explain the geologic significance of porosity/permeability distribution across the sandstone bodies, and tie this to petroleum production characteristics in the oil field. Movies, text, images including scanning electron photomicrographs (SEM), thin-section photomicrographs, and data files can be copied from the CD-ROM for use in external mapping, statistical, and other applications.

  18. 3D numerical study of the propagation characteristics of a consequence of coronal mass ejections in a structured ambient solar wind

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Feng, X. S.

    2015-12-01

    CMEs have been identified as a prime causal link between solar activity and large, nonrecurrent geomagnetic storm. In order to improve geomagnetic storm predictions, a careful study of CME's propagation characteristics is important. Here, we analyze and quantitatively study the evolution and propagation characteristics of coronal mass ejections (CMEs) launched at several positions into a structured real ambient solar wind by using a three-dimensional (3D) numerical magnetohydrodynamics (MHD) simulation. The ambient solar wind structure during Carrington rotation 2095 is selected, which is an appropriate around activity minimum and declining phase. The CME is initiated by a simple spherical plasmoid model: a spheromak magnetic structure with high speed, high pressure and high plasma density plasmoid. We present a detailed analysis of the plasma, magnetic field, geoeffectiveness, and composition signatures of these CMEs. Results show that the motion and local appearance of a CME in interplanetary space is strongly affected by its interaction with the background solar wind structure, including its velocity, density, and magnetic structures. The simulations show that the initial launched position substantially affects the IP evolution of the CMEs influencing the propagation velocity, the shape, the trajectory and even the geo-effectiveness

  19. LIDAR Wind Speed Measurements of Evolving Wind Fields

    SciTech Connect

    Simley, E.; Pao, L. Y.

    2012-07-01

    Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed Taylor's frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations to create a more realistic measurement model. A simple model of wind evolution is applied to a frozen wind field used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements are also evaluated with a large eddy simulation of a stable boundary layer provided by the National Center for Atmospheric Research. Simulation results show the combined effects of LIDAR errors and wind evolution for realistic turbine-mounted LIDAR measurement scenarios.

  20. Holographic display system for dynamic synthesis of 3D light fields with increased space bandwidth product.

    PubMed

    Agour, Mostafa; Falldorf, Claas; Bergmann, Ralf B

    2016-06-27

    We present a new method for the generation of a dynamic wave field with high space bandwidth product (SBP). The dynamic wave field is generated from several wave fields diffracted by a display which comprises multiple spatial light modulators (SLMs) each having a comparably low SBP. In contrast to similar approaches in stereoscopy, we describe how the independently generated wave fields can be coherently superposed. A major benefit of the scheme is that the display system may be extended to provide an even larger display. A compact experimental configuration which is composed of four phase-only SLMs to realize the coherent combination of independent wave fields is presented. Effects of important technical parameters of the display system on the wave field generated across the observation plane are investigated. These effects include, e.g., the tilt of the individual SLM and the gap between the active areas of multiple SLMs. As an example of application, holographic reconstruction of a 3D object with parallax effects is demonstrated.

  1. Analysis of the repeatability of time-lapse 3d vsp multicomponent surveys, delhi field

    NASA Astrophysics Data System (ADS)

    Carvalho, Mariana Fernandes de

    Delhi Field is a producing oil field located in northeastern Louisiana. In order to monitor the CO2 sweep efficiency, time-lapse 3D seismic data have been acquired in this area. Time-lapse studies are increasingly used to evaluate changes in the seismic response induced by the production of hydrocarbons or the injection of water, CO2 or steam into a reservoir. A 4D seismic signal is generated by a combination of production and injection effects within the reservoir as well as non-repeatability effects. In order to get reliable results from time-lapse seismic methods, it is important to distinguish the production and injection effects from the non-repeatability effects in the 4D seismic signal. Repeatability of 4D land seismic data is affected by several factors. The most significant of them are: source and receiver geometry inaccuracies, differences in seismic sources signatures, variations in the immediate near surface and ambient non-repeatable noise. In this project, two 3D multicomponent VSP surveys acquired in Delhi Field were used to quantify the relative contribution of each factor that can affect the repeatability in land seismic data. The factors analyzed in this study were: source and receiver geometry inaccura- cies, variations in the immediate near surface and ambient non-repeatable noise. This study showed that all these factors had a significant impact on the repeatability of the successive multicomponent VSP surveys in Delhi Field. This project also shows the advantages and disadvantages in the use of different repeata- bility metrics, normalized-root-mean-square (NRMS) difference and signal-to-distortion ratio (SDR) attribute, to evaluate the level of seismic repeatability between successive time-lapse seismic surveys. It is observed that NRMS difference is greatly influenced by time-shifts and that SDR attribute combined with the time-shift may give more distinct and representative repeatability information than the NRMS difference.

  2. Engineering a 3D microfluidic culture platform for tumor-treating field application

    PubMed Central

    Pavesi, Andrea; Adriani, Giulia; Tay, Andy; Warkiani, Majid Ebrahimi; Yeap, Wei Hseun; Wong, Siew Cheng; Kamm, Roger D.

    2016-01-01

    The limitations of current cancer therapies highlight the urgent need for a more effective therapeutic strategy. One promising approach uses an alternating electric field; however, the mechanisms involved in the disruption of the cancer cell cycle as well as the potential adverse effects on non-cancerous cells must be clarified. In this study, we present a novel microfluidic device with embedded electrodes that enables the application of an alternating electric field therapy to cancer cells in a 3D extracellular matrix. To demonstrate the potential of our system to aid in designing and testing new therapeutic approaches, cancer cells and cancer cell aggregates were cultured individually or co-cultured with endothelial cells. The metastatic potential of the cancer cells was reduced after electric field treatment. Moreover, the proliferation rate of the treated cancer cells was lower compared with that of the untreated cells, whereas the morphologies and proliferative capacities of the endothelial cells were not significantly affected. These results demonstrate that our novel system can be used to rapidly screen the effect of an alternating electric field on cancer and normal cells within an in vivo-like microenvironment with the potential to optimize treatment protocols and evaluate synergies between tumor-treating field treatment and chemotherapy. PMID:27215466

  3. Engineering a 3D microfluidic culture platform for tumor-treating field application

    NASA Astrophysics Data System (ADS)

    Pavesi, Andrea; Adriani, Giulia; Tay, Andy; Warkiani, Majid Ebrahimi; Yeap, Wei Hseun; Wong, Siew Cheng; Kamm, Roger D.

    2016-05-01

    The limitations of current cancer therapies highlight the urgent need for a more effective therapeutic strategy. One promising approach uses an alternating electric field; however, the mechanisms involved in the disruption of the cancer cell cycle as well as the potential adverse effects on non-cancerous cells must be clarified. In this study, we present a novel microfluidic device with embedded electrodes that enables the application of an alternating electric field therapy to cancer cells in a 3D extracellular matrix. To demonstrate the potential of our system to aid in designing and testing new therapeutic approaches, cancer cells and cancer cell aggregates were cultured individually or co-cultured with endothelial cells. The metastatic potential of the cancer cells was reduced after electric field treatment. Moreover, the proliferation rate of the treated cancer cells was lower compared with that of the untreated cells, whereas the morphologies and proliferative capacities of the endothelial cells were not significantly affected. These results demonstrate that our novel system can be used to rapidly screen the effect of an alternating electric field on cancer and normal cells within an in vivo-like microenvironment with the potential to optimize treatment protocols and evaluate synergies between tumor-treating field treatment and chemotherapy.

  4. AC electric field induced dipole-based on-chip 3D cell rotation.

    PubMed

    Benhal, Prateek; Chase, J Geoffrey; Gaynor, Paul; Oback, Björn; Wang, Wenhui

    2014-08-07

    The precise rotation of suspended cells is one of the many fundamental manipulations used in a wide range of biotechnological applications such as cell injection and enucleation in nuclear transfer (NT) cloning. Noticeably scarce among the existing rotation techniques is the three-dimensional (3D) rotation of cells on a single chip. Here we present an alternating current (ac) induced electric field-based biochip platform, which has an open-top sub-mm square chamber enclosed by four sidewall electrodes and two bottom electrodes, to achieve rotation about the two axes, thus 3D cell rotation. By applying an ac potential to the four sidewall electrodes, an in-plane (yaw) rotating electric field is generated and in-plane rotation is achieved. Similarly, by applying an ac potential to two opposite sidewall electrodes and the two bottom electrodes, an out-of-plane (pitch) rotating electric field is generated and rolling rotation is achieved. As a prompt proof-of-concept, bottom electrodes were constructed with transparent indium tin oxide (ITO) using the standard lift-off process and the sidewall electrodes were constructed using a low-cost micro-milling process and then assembled to form the chip. Through experiments, we demonstrate rotation of bovine oocytes of ~120 μm diameter about two axes, with the capability of controlling the rotation direction and the rate for each axis through control of the ac potential amplitude, frequency, and phase shift, and cell medium conductivity. The maximum observed rotation rate reached nearly 140° s⁻¹, while a consistent rotation rate reached up to 40° s⁻¹. Rotation rate spectra for zona pellucida-intact and zona pellucida-free oocytes were further compared and found to have no effective difference. This simple, transparent, cheap-to-manufacture, and open-top platform allows additional functional modules to be integrated to become a more powerful cell manipulation system.

  5. Fine resolution 3D temperature fields off Kerguelen from instrumented penguins

    NASA Astrophysics Data System (ADS)

    Charrassin, Jean-Benoît; Park, Young-Hyang; Le Maho, Yvon; Bost, Charles-André

    2004-12-01

    The use of diving animals as autonomous vectors of oceanographic instruments is rapidly increasing, because this approach yields cost-efficient new information and can be used in previously poorly sampled areas. However, methods for analyzing the collected data are still under development. In particular, difficulties may arise from the heterogeneous data distribution linked to animals' behavior. Here we show how raw temperature data collected by penguin-borne loggers were transformed to a regular gridded dataset that provided new information on the local circulation off Kerguelen. A total of 16 king penguins ( Aptenodytes patagonicus) were equipped with satellite-positioning transmitters and with temperature-time-depth recorders (TTDRs) to record dive depth and sea temperature. The penguins' foraging trips recorded during five summers ranged from 140 to 600 km from the colony and 11,000 dives >100 m were recorded. Temperature measurements recorded during diving were used to produce detailed 3D temperature fields of the area (0-200 m). The data treatment included dive location, determination of the vertical profile for each dive, averaging and gridding of those profiles onto 0.1°×0.1° cells, and optimal interpolation in both the horizontal and vertical using an objective analysis. Horizontal fields of temperature at the surface and 100 m are presented, as well as a vertical section along the main foraging direction of the penguins. Compared to conventional temperature databases (Levitus World Ocean Atlas and historical stations available in the area), the 3D temperature fields collected from penguins are extremely finely resolved, by one order finer. Although TTDRs were less accurate than conventional instruments, such a high spatial resolution of penguin-derived data provided unprecedented detailed information on the upper level circulation pattern east of Kerguelen, as well as the iron-enrichment mechanism leading to a high primary production over the Kerguelen

  6. Conceptual design of the 3D magnetic field configuration relevant to the magnetopause reconnection in the SPERF

    NASA Astrophysics Data System (ADS)

    Mao, Aohua; Ji, Hantao; Ren, Yang; E, Peng; Wang, Zhibin; Xiao, Qingmei; Xiao, Chijie

    2016-10-01

    A new terrella device, the Space Plasma Environment Research Facility (SPERF), is designed and under construction in China, with Asymmetric Reconnection EXperiment (AREX) as one component to study the interaction between the magnetosheath and magnetosphere plasmas. AREX will provide a unique platform for studying asymmetric magnetic reconnection relevant to the magnetopause, via a set of coils for simulating ``solar-wind-side'' magnetosheath field and a dipole field on the ``magnetosphere-side''. Thus it could be able to investigate a range of important issues in the magnetosphere geometry, such as the electron and ion-scale dynamics in the current sheet, particle and energy transfer from magnetosheath to magnetosphere, particle energization/heating during magnetic reconnection, 3D and asymmetric effects in fast reconnection, and so on. The plasma is generated by two flux cores at the ``magnetosheath-side'' and one electron cyclotron resonance source at the ``magnetosphere-side''. Different kinds of coils with specific current driven functions, as well as advanced diagnostics are designed. Motivation, overview of the AREX design and reconnection scenarios will be discussed.

  7. Understanding the effects of dielectric medium, substrate, and depth on electric fields and SERS of quasi-3D plasmonic nanostructures.

    PubMed

    Xu, Jiajie; Kvasnička, Pavel; Idso, Matthew; Jordan, Roger W; Gong, Heng; Homola, Jiří; Yu, Qiuming

    2011-10-10

    The local electric field distribution and the effect of surface-enhanced Raman spectroscopy (SERS) were investigated on the quasi-3D (Q3D) plasmonic nanostructures formed by gold nanohole and nanodisc array layers physically separated by a dielectric medium. The local electric fields at the top gold nanoholes and bottom gold nanodiscs as a function of the dielectric medium, substrate, and depth of Q3D plasmonic nanostructures upon the irradiation of a 785 nm laser were calculated using the three-dimensional finite-difference time-domain (3D-FDTD) method. The intensity of the maximum local electric fields was shown to oscillate with the depth and the stronger local electric fields occurring at the top or bottom gold layer strongly depend on the dielectric medium, substrate, and depth of the nanostructure. This phenomenon was determined to be related to the Fabry-Pérot interference effect and the interaction of localized surface plasmons (LSPs). The enhancement factors (EFs) of SERS obtained from the 3D-FDTD simulations were compared to those calculated from the SERS experiments conducted on the Q3D plasmonic nanostructures fabricated on silicon and ITO coated glass substrates with different depths. The same trend was obtained from both methods. The capabilities of tuning not only the intensity but also the location of the maximum local electric fields by varying the depth, dielectric medium, and substrate make Q3D plasmonic nanostructures well suited for highly sensitive and reproducible SERS detection and analysis.

  8. The 3-D solar radioastronomy and the structure of the corona and the solar wind. [solar probes of solar activity

    NASA Technical Reports Server (NTRS)

    Steinberg, J. L.; Caroubalos, C.

    1976-01-01

    The mechanism causing solar radio bursts (1 and 111) is examined. It is proposed that a nonthermal energy source is responsible for the bursts; nonthermal energy is converted into electromagnetic energy. The advantages are examined for an out-of-the-ecliptic solar probe mission, which is proposed as a means of stereoscopically viewing solar radio bursts, solar magnetic fields, coronal structure, and the solar wind.

  9. Terahertz 3D printed diffractive lens matrices for field-effect transistor detector focal plane arrays.

    PubMed

    Szkudlarek, Krzesimir; Sypek, Maciej; Cywiński, Grzegorz; Suszek, Jarosław; Zagrajek, Przemysław; Feduniewicz-Żmuda, Anna; Yahniuk, Ivan; Yatsunenko, Sergey; Nowakowska-Siwińska, Anna; Coquillat, Dominique; But, Dmytro B; Rachoń, Martyna; Węgrzyńska, Karolina; Skierbiszewski, Czesław; Knap, Wojciech

    2016-09-05

    We present the concept, the fabrication processes and the experimental results for materials and optics that can be used for terahertz field-effect transistor detector focal plane arrays. More specifically, we propose 3D printed arrays of a new type - diffractive multi-zone lenses of which the performance is superior to that of previously used mono-zone diffractive or refractive elements and evaluate them with GaN/AlGaN field-effect transistor terahertz detectors. Experiments performed in the 300-GHz atmospheric window show that the lens arrays offer both a good efficiency and good uniformity, and may improve the signal-to-noise ratio of the terahertz field-effect transistor detectors by more than one order of magnitude. In practice, we tested 3 × 12 lens linear arrays with printed circuit board THz detector arrays used in postal security scanners and observed significant signal-to-noise improvements. Our results clearly show that the proposed technology provides a way to produce cost-effective, reproducible, flat optics for large-size field-effect transistor THz-detector focal plane arrays.

  10. Simultaneous measurement of 3D zooplankton trajectories and surrounding fluid velocity field in complex flows.

    PubMed

    Adhikari, Deepak; Gemmell, Brad J; Hallberg, Michael P; Longmire, Ellen K; Buskey, Edward J

    2015-11-01

    We describe an automated, volumetric particle image velocimetry (PIV) and tracking method that measures time-resolved, 3D zooplankton trajectories and surrounding volumetric fluid velocity fields simultaneously and non-intrusively. The method is demonstrated for groups of copepods flowing past a wall-mounted cylinder. We show that copepods execute escape responses when subjected to a strain rate threshold upstream of a cylinder, but the same threshold range elicits no escape responses in the turbulent wake downstream. The method was also used to document the instantaneous slip velocity of zooplankton and the resulting differences in trajectory between zooplankton and non-inertial fluid particles in the unsteady wake flow, showing the method's capability to quantify drift for both passive and motile organisms in turbulent environments. Applications of the method extend to any group of organisms interacting with the surrounding fluid environment, where organism location, larger-scale eddies and smaller-scale fluid deformation rates can all be tracked and analyzed.

  11. Layout consistent segmentation of 3-D meshes via conditional random fields and spatial ordering constraints.

    PubMed

    Zouhar, Alexander; Baloch, Sajjad; Tsin, Yanghai; Fang, Tong; Fuchs, Siegfried

    2010-01-01

    We address the problem of 3-D Mesh segmentation for categories of objects with known part structure. Part labels are derived from a semantic interpretation of non-overlapping subsurfaces. Our approach models the label distribution using a Conditional Random Field (CRF) that imposes constraints on the relative spatial arrangement of neighboring labels, thereby ensuring semantic consistency. To this end, each label variable is associated with a rich shape descriptor that is intrinsic to the surface. Randomized decision trees and cross validation are employed for learning the model, which is eventually applied using graph cuts. The method is flexible enough for segmenting even geometrically less structured regions and is robust to local and global shape variations.

  12. Brain tumor segmentation in 3D MRIs using an improved Markov random field model

    NASA Astrophysics Data System (ADS)

    Yousefi, Sahar; Azmi, Reza; Zahedi, Morteza

    2011-10-01

    Markov Random Field (MRF) models have been recently suggested for MRI brain segmentation by a large number of researchers. By employing Markovianity, which represents the local property, MRF models are able to solve a global optimization problem locally. But they still have a heavy computation burden, especially when they use stochastic relaxation schemes such as Simulated Annealing (SA). In this paper, a new 3D-MRF model is put forward to raise the speed of the convergence. Although, search procedure of SA is fairly localized and prevents from exploring the same diversity of solutions, it suffers from several limitations. In comparison, Genetic Algorithm (GA) has a good capability of global researching but it is weak in hill climbing. Our proposed algorithm combines SA and an improved GA (IGA) to optimize the solution which speeds up the computation time. What is more, this proposed algorithm outperforms the traditional 2D-MRF in quality of the solution.

  13. 2D-3D registration for brain radiation therapy using a 3D CBCT and a single limited field-of-view 2D kV radiograph

    NASA Astrophysics Data System (ADS)

    Munbodh, R.; Moseley, D. J.

    2014-03-01

    We report results of an intensity-based 2D-3D rigid registration framework for patient positioning and monitoring during brain radiotherapy. We evaluated two intensity-based similarity measures, the Pearson Correlation Coefficient (ICC) and Maximum Likelihood with Gaussian noise (MLG) derived from the statistics of transmission images. A useful image frequency band was identified from the bone-to-no-bone ratio. Validation was performed on gold-standard data consisting of 3D kV CBCT scans and 2D kV radiographs of an anthropomorphic head phantom acquired at 23 different poses with parameter variations along six degrees of freedom. At each pose, a single limited field of view kV radiograph was registered to the reference CBCT. The ground truth was determined from markers affixed to the phantom and visible in the CBCT images. The mean (and standard deviation) of the absolute errors in recovering each of the six transformation parameters along the x, y and z axes for ICC were varphix: 0.08(0.04)°, varphiy: 0.10(0.09)°, varphiz: 0.03(0.03)°, tx: 0.13(0.11) mm, ty: 0.08(0.06) mm and tz: 0.44(0.23) mm. For MLG, the corresponding results were varphix: 0.10(0.04)°, varphiy: 0.10(0.09)°, varphiz: 0.05(0.07)°, tx: 0.11(0.13) mm, ty: 0.05(0.05) mm and tz: 0.44(0.31) mm. It is feasible to accurately estimate all six transformation parameters from a 3D CBCT of the head and a single 2D kV radiograph within an intensity-based registration framework that incorporates the physics of transmission images.

  14. 3-D analysis and interpretation of magnetotelluric data from the Aluto-Langano geothermal field, Ethiopia

    NASA Astrophysics Data System (ADS)

    Samrock, F.; Kuvshinov, A.; Bakker, J.; Jackson, A.; Fisseha, S.

    2015-09-01

    The Main Ethiopian Rift Valley encompasses a number of volcanoes, which are known to be actively deforming with reoccurring periods of uplift and setting. One of the regions where temporal changes take place is the Aluto volcanic complex. It hosts a productive geothermal field and the only currently operating geothermal power plant of Ethiopia. We carried out magnetotelluric (MT) measurements in early 2012 in order to identify the source of unrest. Broad-band MT data (0.001-1000 s) have been acquired at 46 sites covering the expanse of the Aluto volcanic complex with an average site spacing of 1 km. Based on this MT data it is possible to map the bulk electrical resistivity of the subsurface down to depths of several kilometres. Resistivity is a crucial geophysical parameter in geothermal exploration as hydrothermal and magmatic reservoirs are typically related to low resistive zones, which can be easily sensed by MT. Thus by mapping the electrical conductivity one can identify and analyse geothermal systems with respect to their temperature, extent and potential for production of energy. 3-D inversions of the observed MT data from Aluto reveal the typical electrical conductivity distribution of a high-enthalpy geothermal system, which is mainly governed by the hydrothermal alteration mineralogy. The recovered 3-D conductivity models provide no evidence for an active deep magmatic system under Aluto. Forward modelling of the tippers rather suggest that occurrence of melt is predominantly at lower crustal depths along an off-axis fault zone a few tens of kilometres west of the central rift axis. The absence of an active magmatic system implies that the deforming source is most likely situated within the shallow hydrothermal system of the Aluto-Langano geothermal field.

  15. 3-D seismic data for field development: Landslide field case study

    SciTech Connect

    Raeuchle, S.K.; Carr, T.R.; Tucker, R.D. )

    1990-05-01

    The Landslide field is located on the extreme southern flank of the San Joaquin basin, approximately 25 mi south of Bakersfield, California. The field, discovered in 1985, has produced in excess 9 million bbl of oil with an estimated ultimate recovery of more than 13 MMBO. The Miocene Stevens sands, which form the reservoir units at Landslide field, are interpreted as a series of constructional submarine fan deposits. Deposition of the fans was controlled by paleotopography with an abrupt updip pinch-out of the sands to the southwest. The three-dimensional seismic data over the field was used to locate the bottom hole of the landslide 22X-30 development well as close to this abrupt updip pinchout as possible in order to maximize oil recovery. A location was selected two traces (330 ft) from the updip pinch-out as mapped on the seismic data. The well was successfully drilled during 1989, encountering 150 ft of net sand with initial production in excess of 1,500 bbl of oil/day. A pressure buildup test indicates the presence of a boundary approximately 200 ft from the well bore. This boundary is interpreted as the updip pinchout of the Stevens sands against the paleohigh. Based on examination of changes in amplitude, the absence or presence of reservoir-quality sand can be mapped across the paleohighs. Application of three-dimensional seismic data, integration with well data, and in particular reconstruction cuts tied closely to existing wells can be used to map the ultimate extent of the field and contribute to efficient development.

  16. 3D Gravity Field Modelling of the Lithosphere along the Dead Sea Transform (DESERT 2002)

    NASA Astrophysics Data System (ADS)

    Götze, H.-J.; Ebbing, J.; Schmidt, S.; Rykakov, M.; Hassouneh, M.; Hrahsha, M.; El-Kelani, R.; Desert Group

    2003-04-01

    From March to May 2002 a gravity field campaign has to be conducted in the area of Dead Sea Rift/Dead Sea Transform with regard to the isostatic state, the crustal density structure of the transform and the lithospheric rigidity in the Central Arava Valley (Jordan). Our multi-national and interdisciplinary gravity group with participants from the Geophysical Institute of Israel, the Natural Resources Authority (Jordan), and the An-Najah National University (Palestine), takes part in the interdisciplinary and international DESERT program which is coordinated by the GeoForschungsZentrum (GFZ, Potsdam, Germany). The study area is located about 100 km away from both the basin of the Dead Sea and the Gulf of Elat/Aqaba basin, respectively. Between March and May 2002 some 800 new gravity observations were recorded at a local scale in the Arava valley and at regional scale along the DESERT seismic line. Station spacing in the area of the Arava valley was 100 - 300 m and in the nearest neighbourhood of the fault 50 m only. The survey of detailed observations covered an area of 10 by 10 km and was completed by a likewise dense survey at the western side of the valley in Israel. All gravity data were tied to the IGSN -71 gravity datum and are terrain-corrected as well. The station complete Bouguer gravity field, Free air anomaly and residual isostatic anomalies (based on both Airy and Vening-Meinesz models) were merged with the existing regional gravity data bases of the region. Constraining information for the 3D density models came from recent geophysical field data acquisition and consist of seismic, seismological, electromagnetic studies, and geological mapping which represent the integrated part of the interdisciplinary research program. Novel methods e.g. curvature techniques, and Euler deconvolution of the gravity fields shed new insight into the structure of upper and lower crust and the causing density domains. In particular the "dip-curvature" reveal a clear course

  17. Gravity Field Analysis and 3D Density Modeling of the Lithosphere Along the Dead Sea Transform

    NASA Astrophysics Data System (ADS)

    Goetze, H.; Ebbing, J.; Hese, F.; Kollersberger, T.; Schmidt, S.; Rybakov, M.; Hassouneh, M.; Hrahsha, M.; El Kelani, R.

    2002-12-01

    The gravity field of Dead Sea Rift / Dead Sea Transform was investigated with regard to the isostatic state, the crustal density structure of the orogeny and the rigidity of the lithosphere in the Central Arava Valley. Our multi-national and interdisciplinary gravity group with participants from the Geophysical Institute of Israel, the Natural Resources Authority (Jordan), and the An-Najah National University (Palestine), is aiming to study the crustal density structure, the isostatic state of the lithosphere and mechanical properties of the Dead Sea Rift system under the framework of the international DESERT program which is coordinated by the GeoForschungsZentrum (GFZ, Potsdam, Germany). The study area is located about 100 km away from both the basin of the Dead Sea and the Gulf of Elat/Aqaba basin, respectively. Between March and May 2002 some 800 new gravity observations were recorded at a local (Arava valley) and regional scale (along the DESERT seismic line). Station spacing in the Arava valley was 100 - 300 m and in the nearest neighborhood of the fault 50 m only. The survey of detailed observations covered an area of 10 by 10 km and was completed by a likewise dense survey at the western side of the valley in Israel. All gravity data were tied to the IGSN -71 gravity datum and are terrain-corrected as well. The station complete Bouguer gravity field, Free air anomaly and residual isostatic anomalies (based on both Airy and Vening-Meinesz models) were merged with the existing regional gravity data bases of the region. Constraining information for the 3D density models at regional and local came from recent geophysical field data acquisition and consist of seismic, seismological, electromagnetic, and geologic studies which represent the integrated part of the interdisciplinary research program. Novel methods e.g. curvature techniques, and Euler deconvolution of the gravity fields shed new insight into the structure of upper and lower crust and the causing

  18. Analysis of the 3D magnetic field and its errors for undulators with iron poles

    SciTech Connect

    Ingold, G.; Bahrdt, J.; Gaupp, A.

    1995-12-31

    The attainable field strength and field quality, such as the optical phase error, the electron beam displacement within the undulator and higher order multipoles of the magnetic field, are discussed. These issues are critical to the design and construction of short period undulators for use in short wavelength FEL or for operation in third generation light sources. We discuss two approaches: (i) For superferric undulators the construction of a full length device would rely on the optimum sorting of precision machined undulator segments. Magnetic data on segments with 20 periods (period length 8.80mm) will be presented. (ii) For hybrid undulators the sorting has to be done on individual poles and magnets. For this approach typical error sources such as machining tolerances, magnetization errors of the permanent magnet material and assembly errors are modeled in 3D and compared to induced errors on an existing hybrid undulator segment. In case of undulators having a full length of hundred periods at least five times as many individual parts have to be characterized. This should be done automatically where both the mechanical and magnetic data before and after the assembly of the magnetic structure are recorded in one step. A CNC programmable measuring device suitable for this task will shortly be presented.

  19. Formulation, stability and application of a semi-coupled 3-D four-field algorithm

    SciTech Connect

    Kunz, R.F.; Siebert, B.W.; Cope, W.K.; Foster, N.F.; Antal, S.P.; Ettorre, S.M.

    1996-06-01

    A new 3-D four-field algorithm has been developed to predict general two-phase flows. Ensemble averaged transport equations of mass, momentum, energy and turbulence transport are solved for each field (continuous liquid, continuous vapor, disperse liquid, disperse vapor). This four-field structure allows for analysis of adiabatic and boiling systems which contain flow regimes from bubbly through annular. Interfacial mass, momentum, turbulence and heat transfer models provide coupling between phases. A new semi-coupled implicit method is utilized to solve the set of 25 equations which arise in the formulation. In this paper, three important component numerical strategies employed in the method are summarized. These include: (1) incorporation of interfacial momentum force terms in the control volume face flux reconstruction, (2) phase coupling at the linear solver level, and in the pressure-velocity coupling itself and (3) a multi-step Jacobi block correction scheme for efficient solution of the pressure-Poisson equation. The necessity/effectiveness of these strategies is demonstrated in applications to realistic engineering flows. Though some heated flow test cases are considered, the particular numerics discussed here are germane to adiabatic flows with and without mass transfer.

  20. Flow Web: a graph based user interface for 3D flow field exploration

    NASA Astrophysics Data System (ADS)

    Xu, Lijie; Shen, Han-Wei

    2010-01-01

    While there have been intensive efforts in developing better 3D flow visualization techniques, little attention has been paid to the design of better user interfaces and more effective data exploration work flow. In this paper, we propose a novel graph-based user interface called Flow Web to enable more systematic explorations of 3D flow data. The Flow Web is a node-link graph that is constructed to highlight the essential flow structures where a node represents a region in the field and a link connects two nodes if there exist particles traveling between the regions. The direction of an edge implies the flow path, and the weight of an edge indicates the number of particles traveling through the connected nodes. Hierarchical flow webs are created by splitting or merging nodes and edges to allow for easy understanding of the underlying flow structures. To draw the Flow Web, we adopt force based graph drawing algorithms to minimize edge crossings, and use a hierarchical layout to facilitate the study of flow patterns step by step. The Flow Web also supports user queries to the properties of nodes and links. Examples of the queries for node properties include the degrees, complexity, and some associated physical attributes such as velocity magnitude. Queries for edges include weights, flow path lengths, existence of circles and so on. It is also possible to combine multiple queries using operators such as and , or, not. The FlowWeb supports several types of user interactions. For instance, the user can select nodes from the subgraph returned by a query and inspect the nodes with more details at different levels of detail. There are multiple advantages of using the graph-based user interface. One is that the user can identify regions of interest much more easily since, unlike inspecting 3D regions, there is very little occlusion. It is also much more convenient for the user to query statistical information about the nodes and links at different levels of detail. With

  1. A multi-stage 3-D stress field modelling approach exemplified in the Bavarian Molasse Basin

    NASA Astrophysics Data System (ADS)

    Ziegler, Moritz O.; Heidbach, Oliver; Reinecker, John; Przybycin, Anna M.; Scheck-Wenderoth, Magdalena

    2016-09-01

    The knowledge of the contemporary in situ stress state is a key issue for safe and sustainable subsurface engineering. However, information on the orientation and magnitudes of the stress state is limited and often not available for the areas of interest. Therefore 3-D geomechanical-numerical modelling is used to estimate the in situ stress state and the distance of faults from failure for application in subsurface engineering. The main challenge in this approach is to bridge the gap in scale between the widely scattered data used for calibration of the model and the high resolution in the target area required for the application. We present a multi-stage 3-D geomechanical-numerical approach which provides a state-of-the-art model of the stress field for a reservoir-scale area from widely scattered data records. Therefore, we first use a large-scale regional model which is calibrated by available stress data and provides the full 3-D stress tensor at discrete points in the entire model volume. The modelled stress state is used subsequently for the calibration of a smaller-scale model located within the large-scale model in an area without any observed stress data records. We exemplify this approach with two-stages for the area around Munich in the German Molasse Basin. As an example of application, we estimate the scalar values for slip tendency and fracture potential from the model results as measures for the criticality of fault reactivation in the reservoir-scale model. The modelling results show that variations due to uncertainties in the input data are mainly introduced by the uncertain material properties and missing SHmax magnitude estimates needed for a more reliable model calibration. This leads to the conclusion that at this stage the model's reliability depends only on the amount and quality of available stress information rather than on the modelling technique itself or on local details of the model geometry. Any improvements in modelling and increases

  2. Adaptive multi-GPU Exchange Monte Carlo for the 3D Random Field Ising Model

    NASA Astrophysics Data System (ADS)

    Navarro, Cristóbal A.; Huang, Wei; Deng, Youjin

    2016-08-01

    This work presents an adaptive multi-GPU Exchange Monte Carlo approach for the simulation of the 3D Random Field Ising Model (RFIM). The design is based on a two-level parallelization. The first level, spin-level parallelism, maps the parallel computation as optimal 3D thread-blocks that simulate blocks of spins in shared memory with minimal halo surface, assuming a constant block volume. The second level, replica-level parallelism, uses multi-GPU computation to handle the simulation of an ensemble of replicas. CUDA's concurrent kernel execution feature is used in order to fill the occupancy of each GPU with many replicas, providing a performance boost that is more notorious at the smallest values of L. In addition to the two-level parallel design, the work proposes an adaptive multi-GPU approach that dynamically builds a proper temperature set free of exchange bottlenecks. The strategy is based on mid-point insertions at the temperature gaps where the exchange rate is most compromised. The extra work generated by the insertions is balanced across the GPUs independently of where the mid-point insertions were performed. Performance results show that spin-level performance is approximately two orders of magnitude faster than a single-core CPU version and one order of magnitude faster than a parallel multi-core CPU version running on 16-cores. Multi-GPU performance is highly convenient under a weak scaling setting, reaching up to 99 % efficiency as long as the number of GPUs and L increase together. The combination of the adaptive approach with the parallel multi-GPU design has extended our possibilities of simulation to sizes of L = 32 , 64 for a workstation with two GPUs. Sizes beyond L = 64 can eventually be studied using larger multi-GPU systems.

  3. A package for 3-D unstructured grid generation, finite-element flow solution and flow field visualization

    NASA Technical Reports Server (NTRS)

    Parikh, Paresh; Pirzadeh, Shahyar; Loehner, Rainald

    1990-01-01

    A set of computer programs for 3-D unstructured grid generation, fluid flow calculations, and flow field visualization was developed. The grid generation program, called VGRID3D, generates grids over complex configurations using the advancing front method. In this method, the point and element generation is accomplished simultaneously, VPLOT3D is an interactive, menudriven pre- and post-processor graphics program for interpolation and display of unstructured grid data. The flow solver, VFLOW3D, is an Euler equation solver based on an explicit, two-step, Taylor-Galerkin algorithm which uses the Flux Corrected Transport (FCT) concept for a wriggle-free solution. Using these programs, increasingly complex 3-D configurations of interest to aerospace community were gridded including a complete Space Transportation System comprised of the space-shuttle orbitor, the solid-rocket boosters, and the external tank. Flow solutions were obtained on various configurations in subsonic, transonic, and supersonic flow regimes.

  4. Construction of Extended 3D Field of Views of the Internal Bladder Wall Surface: A Proof of Concept

    NASA Astrophysics Data System (ADS)

    Ben-Hamadou, Achraf; Daul, Christian; Soussen, Charles

    2016-09-01

    3D extended field of views (FOVs) of the internal bladder wall facilitate lesion diagnosis, patient follow-up and treatment traceability. In this paper, we propose a 3D image mosaicing algorithm guided by 2D cystoscopic video-image registration for obtaining textured FOV mosaics. In this feasibility study, the registration makes use of data from a 3D cystoscope prototype providing, in addition to each small FOV image, some 3D points located on the surface. This proof of concept shows that textured surfaces can be constructed with minimally modified cystoscopes. The potential of the method is demonstrated on numerical and real phantoms reproducing various surface shapes. Pig and human bladder textures are superimposed on phantoms with known shape and dimensions. These data allow for quantitative assessment of the 3D mosaicing algorithm based on the registration of images simulating bladder textures.

  5. Design and testing of indigenous cost effective three dimensional radiation field analyser (3D RFA).

    PubMed

    Ganesh, K M; Pichandi, A; Nehru, R M; Ravikumar, M

    2014-06-01

    The aim of the study is to design and validate an indigenous three dimensional Radiation Field Analyser (3D RFA). The feed system made for X, Y and Z axis movements is of lead screw with deep ball bearing mechanism made up of stain less steel driven by stepper motors with accuracy less than 0.5 mm. The telescopic column lifting unit was designed using linear actuation technology for lifting the water phantom. The acrylic phantom with dimensions of 800 x 750 x 570 mm was made with thickness of 15 mm. The software was developed in visual basic programming language, classified into two types, viz. beam analyzer software and beam acquisition software. The premeasurement checks were performed as per TG 106 recommendations. The physical parameters of photon PDDs such as Dmax, D10, D20 and Quality Index (QI), and the electron PDDs such as R50, Rp, E0, Epo and X-ray contamination values can be obtained instantaneously by using the developed RFA system. Also the results for profile data such as field size, central axis deviation, penumbra, flatness and symmetry calculated according to various protocols can be obtained for both photon and electron beams. The result of PDDs for photon beams were compared with BJR25 supplement values and the profile data were compared with TG 40 recommendation. The results were in agreement with standard protocols.

  6. pynoddy 1.0: an experimental platform for automated 3-D kinematic and potential field modelling

    NASA Astrophysics Data System (ADS)

    Florian Wellmann, J.; Thiele, Sam T.; Lindsay, Mark D.; Jessell, Mark W.

    2016-03-01

    We present a novel methodology for performing experiments with subsurface structural models using a set of flexible and extensible Python modules. We utilize the ability of kinematic modelling techniques to describe major deformational, tectonic, and magmatic events at low computational cost to develop experiments testing the interactions between multiple kinematic events, effect of uncertainty regarding event timing, and kinematic properties. These tests are simple to implement and perform, as they are automated within the Python scripting language, allowing the encapsulation of entire kinematic experiments within high-level class definitions and fully reproducible results. In addition, we provide a link to geophysical potential-field simulations to evaluate the effect of parameter uncertainties on maps of gravity and magnetics. We provide relevant fundamental information on kinematic modelling and our implementation, and showcase the application of our novel methods to investigate the interaction of multiple tectonic events on a pre-defined stratigraphy, the effect of changing kinematic parameters on simulated geophysical potential fields, and the distribution of uncertain areas in a full 3-D kinematic model, based on estimated uncertainties in kinematic input parameters. Additional possibilities for linking kinematic modelling to subsequent process simulations are discussed, as well as additional aspects of future research. Our modules are freely available on github, including documentation and tutorial examples, and we encourage the contribution to this project.

  7. pynoddy 1.0: an experimental platform for automated 3-D kinematic and potential field modelling

    NASA Astrophysics Data System (ADS)

    Wellmann, J. F.; Thiele, S. T.; Lindsay, M. D.; Jessell, M. W.

    2015-11-01

    We present a novel methodology for performing experiments with subsurface structural models using a set of flexible and extensible Python modules. We utilise the ability of kinematic modelling techniques to describe major deformational, tectonic, and magmatic events at low computational cost to develop experiments testing the interactions between multiple kinematic events, effect of uncertainty regarding event timing, and kinematic properties. These tests are simple to implement and perform, as they are automated within the Python scripting language, allowing the encapsulation of entire kinematic experiments within high-level class definitions and fully reproducible results. In addition, we provide a~link to geophysical potential-field simulations to evaluate the effect of parameter uncertainties on maps of gravity and magnetics. We provide relevant fundamental information on kinematic modelling and our implementation, and showcase the application of our novel methods to investigate the interaction of multiple tectonic events on a pre-defined stratigraphy, the effect of changing kinematic parameters on simulated geophysical potential-fields, and the distribution of uncertain areas in a full 3-D kinematic model, based on estimated uncertainties in kinematic input parameters. Additional possibilities for linking kinematic modelling to subsequent process simulations are discussed, as well as additional aspects of future research. Our modules are freely available on github, including documentation and tutorial examples, and we encourage the contribution to this project.

  8. Experimental pencil beam kernels derivation for 3D dose calculation in flattening filter free modulated fields.

    PubMed

    Azcona, Juan Diego; Barbés, Benigno; Wang, Lilie; Burguete, Javier

    2016-01-07

    This paper presents a method to obtain the pencil-beam kernels that characterize a megavoltage photon beam generated in a flattening filter free (FFF) linear accelerator (linac) by deconvolution from experimental measurements at different depths. The formalism is applied to perform independent dose calculations in modulated fields. In our previous work a formalism was developed for ideal flat fluences exiting the linac's head. That framework could not deal with spatially varying energy fluences, so any deviation from the ideal flat fluence was treated as a perturbation. The present work addresses the necessity of implementing an exact analysis where any spatially varying fluence can be used such as those encountered in FFF beams. A major improvement introduced here is to handle the actual fluence in the deconvolution procedure. We studied the uncertainties associated to the kernel derivation with this method. Several Kodak EDR2 radiographic films were irradiated with a 10 MV FFF photon beam from two linacs from different vendors, at the depths of 5, 10, 15, and 20cm in polystyrene (RW3 water-equivalent phantom, PTW Freiburg, Germany). The irradiation field was a 50mm diameter circular field, collimated with a lead block. The 3D kernel for a FFF beam was obtained by deconvolution using the Hankel transform. A correction on the low dose part of the kernel was performed to reproduce accurately the experimental output factors. Error uncertainty in the kernel derivation procedure was estimated to be within 0.2%. Eighteen modulated fields used clinically in different treatment localizations were irradiated at four measurement depths (total of fifty-four film measurements). Comparison through the gamma-index to their corresponding calculated absolute dose distributions showed a number of passing points (3%, 3mm) mostly above 99%. This new procedure is more reliable and robust than the previous one. Its ability to perform accurate independent dose calculations was

  9. Experimental pencil beam kernels derivation for 3D dose calculation in flattening filter free modulated fields

    NASA Astrophysics Data System (ADS)

    Diego Azcona, Juan; Barbés, Benigno; Wang, Lilie; Burguete, Javier

    2016-01-01

    This paper presents a method to obtain the pencil-beam kernels that characterize a megavoltage photon beam generated in a flattening filter free (FFF) linear accelerator (linac) by deconvolution from experimental measurements at different depths. The formalism is applied to perform independent dose calculations in modulated fields. In our previous work a formalism was developed for ideal flat fluences exiting the linac’s head. That framework could not deal with spatially varying energy fluences, so any deviation from the ideal flat fluence was treated as a perturbation. The present work addresses the necessity of implementing an exact analysis where any spatially varying fluence can be used such as those encountered in FFF beams. A major improvement introduced here is to handle the actual fluence in the deconvolution procedure. We studied the uncertainties associated to the kernel derivation with this method. Several Kodak EDR2 radiographic films were irradiated with a 10 MV FFF photon beam from two linacs from different vendors, at the depths of 5, 10, 15, and 20cm in polystyrene (RW3 water-equivalent phantom, PTW Freiburg, Germany). The irradiation field was a 50mm diameter circular field, collimated with a lead block. The 3D kernel for a FFF beam was obtained by deconvolution using the Hankel transform. A correction on the low dose part of the kernel was performed to reproduce accurately the experimental output factors. Error uncertainty in the kernel derivation procedure was estimated to be within 0.2%. Eighteen modulated fields used clinically in different treatment localizations were irradiated at four measurement depths (total of fifty-four film measurements). Comparison through the gamma-index to their corresponding calculated absolute dose distributions showed a number of passing points (3%, 3mm) mostly above 99%. This new procedure is more reliable and robust than the previous one. Its ability to perform accurate independent dose calculations was

  10. 3-D water vapor field in the atmospheric boundary layer observed with scanning differential absorption lidar

    NASA Astrophysics Data System (ADS)

    Späth, Florian; Behrendt, Andreas; Muppa, Shravan Kumar; Metzendorf, Simon; Riede, Andrea; Wulfmeyer, Volker

    2016-04-01

    High-resolution three-dimensional (3-D) water vapor data of the atmospheric boundary layer (ABL) are required to improve our understanding of land-atmosphere exchange processes. For this purpose, the scanning differential absorption lidar (DIAL) of the University of Hohenheim (UHOH) was developed as well as new analysis tools and visualization methods. The instrument determines 3-D fields of the atmospheric water vapor number density with a temporal resolution of a few seconds and a spatial resolution of up to a few tens of meters. We present three case studies from two field campaigns. In spring 2013, the UHOH DIAL was operated within the scope of the HD(CP)2 Observational Prototype Experiment (HOPE) in western Germany. HD(CP)2 stands for High Definition of Clouds and Precipitation for advancing Climate Prediction and is a German research initiative. Range-height indicator (RHI) scans of the UHOH DIAL show the water vapor heterogeneity within a range of a few kilometers up to an altitude of 2 km and its impact on the formation of clouds at the top of the ABL. The uncertainty of the measured data was assessed for the first time by extending a technique to scanning data, which was formerly applied to vertical time series. Typically, the accuracy of the DIAL measurements is between 0.5 and 0.8 g m-3 (or < 6 %) within the ABL even during daytime. This allows for performing a RHI scan from the surface to an elevation angle of 90° within 10 min. In summer 2014, the UHOH DIAL participated in the Surface Atmosphere Boundary Layer Exchange (SABLE) campaign in southwestern Germany. Conical volume scans were made which reveal multiple water vapor layers in three dimensions. Differences in their heights in different directions can be attributed to different surface elevation. With low-elevation scans in the surface layer, the humidity profiles and gradients can be related to different land cover such as maize, grassland, and forest as well as different surface layer

  11. ORBXYZ: a 3D single-particle orbit code for following charged-particle trajectories in equilibrium magnetic fields

    SciTech Connect

    Anderson, D.V.; Cohen, R.H.; Ferguson, J.R.; Johnston, B.M.; Sharp, C.B.; Willmann, P.A.

    1981-06-30

    The single particle orbit code, TIBRO, has been modified extensively to improve the interpolation methods used and to allow use of vector potential fields in the simulation of charged particle orbits on a 3D domain. A 3D cubic B-spline algorithm is used to generate spline coefficients used in the interpolation. Smooth and accurate field representations are obtained. When vector potential fields are used, the 3D cubic spline interpolation formula analytically generates the magnetic field used to push the particles. This field has del.BETA = 0 to computer roundoff. When magnetic induction is used the interpolation allows del.BETA does not equal 0, which can lead to significant nonphysical results. Presently the code assumes quadrupole symmetry, but this is not an essential feature of the code and could be easily removed for other applications. Many details pertaining to this code are given on microfiche accompanying this report.

  12. ORBXYZ: A 3D single-particle orbit code for following charged particle trajectories in equilibrium magnetic fields

    NASA Astrophysics Data System (ADS)

    Anderson, D. V.; Cohen, R. H.; Ferguson, J. R.; Johnston, B. M.; Sharp, C. B.; Willmann, P. A.

    1981-06-01

    The single particle orbit code, TIBRO, was modified extensively to improve the interpolation methods used and to allow use of vector potential fields in the simulation of charged particle orbits on a 3D domain. A 3D cubic B-spline algorithm is used to generate spline coefficients used in the interpolation. Smooth and accurate field representations are obtained. When vector potential fields are used, the 3D cubic spline interpolation formula analytically generates the magnetic field used to push the particles. This field has del.BETA = 0 to computer roundoff. When magnetic induction is used the interpolation allows del.BETA does not equal 0, which can lead to significant nonphysical results. Presently the code assumes quadrupole symmetry, but this is not an essential feature of the code and could be easily removed for other applications.

  13. Coherence holography by achromatic 3-D field correlation of generic thermal light with an imaging Sagnac shearing interferometer.

    PubMed

    Naik, Dinesh N; Ezawa, Takahiro; Singh, Rakesh Kumar; Miyamoto, Yoko; Takeda, Mitsuo

    2012-08-27

    We propose a new technique for achromatic 3-D field correlation that makes use of the characteristics of both axial and lateral magnifications of imaging through a common-path Sagnac shearing interferometer. With this technique, we experimentally demonstrate, for the first time to our knowledge, 3-D image reconstruction of coherence holography with generic thermal light. By virtue of the achromatic axial shearing implemented by the difference in axial magnifications in imaging, the technique enables coherence holography to reconstruct a 3-D object with an axial depth beyond the short coherence length of the thermal light.

  14. Non-Ideal ELM Stability and Non-Axisymmetric Field Penetration Calculations with M3D-C1

    NASA Astrophysics Data System (ADS)

    Ferraro, N. M.; Chu, M. S.; Snyder, P. B.; Jardin, S. C.; Luo, X.

    2009-11-01

    Numerical studies of ELM stability and non-axisymmetric field penetration in diverted DIII-D and NSTX equilibria are presented, with resistive and finite Larmor radius effects included. These results are obtained with the nonlinear two-fluid code M3D-C1, which has recently been extended to allow linear non-axisymmetric calculations. Benchmarks of M3D-C1 with ideal codes ELITE and GATO show good agreement for the linear stability of peeling-ballooning modes in the ideal limit. New calculations of the resistive stability of ideally stable DIII-D equilibria are presented. M3D-C1 has also been used to calculate the linear response to non-axisymmetric external fields; these calculations are benchmarked with Surfmn and MARS-F. New numerical methods implemented in M3D-C1 are presented, including the treatment of boundary conditions with C^1 elements in a non-rectangular mesh.

  15. LIDAR Wind Speed Measurements of Evolving Wind Fields

    SciTech Connect

    Simley, E.; Pao, L. Y.; Kelley, N.; Jonkman, B.; Frehlich, R.

    2012-01-01

    Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feedforward control systems that are designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. Past studies have assumed the validity of physicist G.I. Taylor's 1938 frozen turbulence hypothesis, which implies that turbulence remains unchanged as it advects downwind at the mean wind speed. With Taylor's hypothesis applied, the only source of wind speed measurement error is distortion caused by the LIDAR. This study introduces wind evolution, characterized by the longitudinal coherence of the wind, to LIDAR measurement simulations using the National Renewable Energy Laboratory's (NREL's) 5-megawatt turbine model to create a more realistic measurement model. A simple model of wind evolution was applied to a frozen wind field that was used in previous studies to investigate the effects of varying the intensity of wind evolution. LIDAR measurements were also evaluated using a large eddy simulation (LES) of a stable boundary layer that was provided by the National Center for Atmospheric Research. The LIDAR measurement scenario investigated consists of a hub-mounted LIDAR that scans a circle of points upwind of the turbine in order to estimate the wind speed component in the mean wind direction. Different combinations of the preview distance that is located upwind of the rotor and the radius of the scan circle were analyzed. It was found that the dominant source of measurement error for short preview distances is the detection of transverse and vertical wind speeds from the line-of-sight LIDAR measurement. It was discovered in previous studies that, in the absence of wind evolution, the dominant source of error for large preview distances

  16. Field verification of the wind tunnel coefficients

    NASA Technical Reports Server (NTRS)

    Gawronski, W. K.; Mellstrom, J. A.

    1994-01-01

    Accurate information about wind action on antennas is required for reliable prediction of antenna pointing errors in windy weather and for the design of an antenna controller with wind disturbance rejection properties. The wind tunnel data obtained 3 years ago using a scaled antenna model serves as an antenna industry standard, frequently used for the first purpose. The accuracy of the wind tunnel data has often been challenged, since they have not yet been tested in a field environment (full-aized antenna, real wind, actual terrain, etc.). The purpose of this investigation was to obtain selected field measurements and compare them with the available wind tunnel data. For this purpose, wind steady-state torques of the DSS-13 antenna were measured, and dimensionless wind torque coefficients were obtained for a variety of yaw and elevation angles. The results showed that the differences between the wind tunnel torque coefficients and the field torque coefficients were less than 10 percent of their values. The wind-gusting action on the antenna was characterized by the power spectra of the antenna encoder and the antenna torques. The spectra showed that wind gusting primarily affects the antenna principal modes.

  17. 3D phase-field modelling of dislocation loop sink strengths

    NASA Astrophysics Data System (ADS)

    Thuinet, L.; Rouchette, H.; Legris, A.

    2017-01-01

    This work presents a 3D phase-field model to correctly evaluate dislocation loop sink strength. This method is applied to a wide range of microstructures (dislocation loops of various types with isotropic or anisotropic elasticity, like in Zr, cohabitation of different types of loop in the same calculation domain), which allows to exhibit several original results. Among them, in the case of isotropic elasticity, our model shows that the sink strength of vacancy loops is higher than that of interstitial ones for low loop radii. In the case of Zr, the effect on sink biases of the shape anisotropy of self-interstitial atoms, already exhibited in the case of straight dislocations, is enhanced for loops and stabilizes basal vacancy and prism-plane interstitial ones. Moreover, isotropic elastic interactions promote the coexistence of parallel vacancy and interstitial loops. This result is still valid in the case of prism-plane loops in Zr, which could provide explanations to several experimental facts.

  18. Quantifying the 3D Odorant Concentration Field Used by Actively Tracking Blue Crabs

    NASA Astrophysics Data System (ADS)

    Webster, D. R.; Dickman, B. D.; Jackson, J. L.; Weissburg, M. J.

    2007-11-01

    Blue crabs and other aquatic organisms locate food and mates by tracking turbulent odorant plumes. The odorant concentration fluctuates unpredictably due to turbulent transport, and many characteristics of the fluctuation pattern have been hypothesized as useful cues for orienting to the odorant source. To make a direct linkage between tracking behavior and the odorant concentration signal, we developed a measurement system based the laser induced fluorescence technique to quantify the instantaneous 3D concentration field surrounding actively tracking blue crabs. The data suggest a correlation between upstream walking speed and the concentration of the odorant signal arriving at the antennule chemosensors, which are located near the mouth region. More specifically, we note an increase in upstream walking speed when high concentration bursts arrive at the antennules location. We also test hypotheses regarding the ability of blue crabs to steer relative to the plume centerline based on the signal contrast between the chemosensors located on their leg appendages. These chemosensors are located much closer to the substrate compared to the antennules and are separated by the width of the blue crab. In this case, it appears that blue crabs use the bilateral signal comparison to track along the edge of the plume.

  19. Free energy force field (FEFF) 3D-QSAR analysis of a set of Plasmodium falciparum dihydrofolate reductase inhibitors

    NASA Astrophysics Data System (ADS)

    Santos-Filho, Osvaldo A.; Mishra, Rama K.; Hopfinger, A. J.

    2001-09-01

    Free energy force field (FEFF) 3D-QSAR analysis was used to construct ligand-receptor binding models for a set of 18 structurally diverse antifolates including pyrimethamine, cycloguanil, methotrexate, aminopterin and trimethoprim, and 13 pyrrolo[2,3-d]pyrimidines. The molecular target (`receptor') used was a 3D-homology model of a specific mutant type of Plasmodium falciparum (Pf) dihydrofolate reductase (DHFR). The dependent variable of the 3D-QSAR models is the IC50 inhibition constant for the specific mutant type of PfDHFR. The independent variables of the 3D-QSAR models (the descriptors) are scaled energy terms of a modified first-generation AMBER force field combined with a hydration shell aqueous solvation model and a collection of 2D-QSAR descriptors often used in QSAR studies. Multiple temperature molecular dynamics simulation (MDS) and the genetic function approximation (GFA) were employed using partial least square (PLS) and multidimensional linear regressions as the fitting functions to develop FEFF 3D-QSAR models for the binding process. The significant FEFF energy terms in the best 3D-QSAR models include energy contributions of the direct ligand-receptor interaction. Some changes in conformational energy terms of the ligand due to binding to the enzyme are also found to be important descriptors. The FEFF 3D-QSAR models indicate some structural features perhaps relevant to the mechanism of resistance of the PfDHFR to current antimalarials. The FEFF 3D-QSAR models are also compared to receptor-independent (RI) 4D-QSAR models developed in an earlier study and subsequently refined using recently developed generalized alignment rules.

  20. SHANK DESIGNS AND SOIL SURFACE TREATMENTS ON 1,3-D EMISSIONS IN A NURSERY FIELD TRIAL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In California, tree and grapevine field nurseries must meet the CDFA requirements for nematode-free planting stock. Telone II (1,3-D) is the only methyl bromide alternative accepted by CDFA’s Nursery Stock Nematode Certification program, but its use is subject to environmental regulations. A field t...

  1. Reconstructing the 3D coronal magnetic field using a Potential Field Source Surface model comparing different magnetograph input data

    NASA Astrophysics Data System (ADS)

    Kruse, M. A., II; Peleikis, T.; Berger, L.; Wimmer-Schweingruber, R. F.

    2014-12-01

    We utilize a Potential Field Source Sourface (PFSS) model developed by Altschuler & Newkirk (1969) to model and analyze the coronal magnetic field up to the source surface at 2.5 solar radii. As the photospheric boundary to that model we employ data from several instruments, namely the Wilcox Solar Observatory, NSO's Kitt Peak Vacuum Telescope, the Michelson Doppler Imager onboard the SOHO spacecraft and its successor, the Helioseismic and Magnetic Imager onboard SDO. Instead of the harmonic function approach commonly used, we employ a three dimensional computational grid and methods of computational fluid dynamics to solve the governing equations in order to easily incorporate more complex phenomena if the need for doing so arises during the course of our work. Another advantage of the grid approach is the possibility to outsource the computational work to a parallel computing architecture like NVIDIA's CUDA, which we employ to speed up processing time and increase data throughput significantly. The obtained magnetic field data is utilized in several ways. First it is compared with in-situ data from several spacecraft like Ulysses to validate the employed PFSS model. We further use the expansion geometry of the magnetic field as an input to a 1D-solar-wind model developed by Cranmer et al. (2007) to determine characteristics of the solar wind in several magnetic flux tubes. We can then infer the theoretical charge-state composition inside these flux tubes, which in turn can be employed to test our hypotheses on the origin of the slow solar wind.

  2. Erosion by Wind: Field Measurement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wind erosion and deposition results when wind moves soil from a bare susceptible surface to another location downwind. Although placement of permanent vertical references such as pins or rods has been used to measure soil redistribution, it is more commonly measured by capturing sediment moving dur...

  3. Corrigendum to "Measuring the 3-D wind vector with a weight-shiftmicrolight aircraft" published in Atmos. Meas. Tech., 4, 1421-1444, 2011

    NASA Astrophysics Data System (ADS)

    Metzger, S.; Junkermann, W.; Butterbach-Bahl, K.; Schmid, H. P.; Foken, T.

    2011-07-01

    This study investigates whether the 3-D wind vector can be measured reliably from a highly transportable and low-cost weight-shift microlight aircraft. We draw up a transferable procedure to accommodate flow distortion originating from the aircraft body and -wing. This procedure consists of the analysis of aircraft dynamics and seven successive calibration steps. For our aircraft the horizontal wind components receive their greatest single amendment (14 %, relative to the initial uncertainty) from the correction of flow distortion magnitude in the dynamic pressure computation. Conversely the vertical wind component is most of all improved (31 %) by subsequent steps considering the 3-D flow distortion distribution in the flow angle computations. Therein the influences of the aircraft's trim (53 %), as well as changes in the aircraft lift (16 %) are considered by using the measured lift coefficient as explanatory variable. Three independent lines of analysis are used to evaluate the quality of the wind measurement: (a) A wind tunnel study in combination with the propagation of sensor uncertainties defines the systems input uncertainty to ≈0.6 m s-1 at the extremes of a 95 % confidence interval. (b) During severe vertical flight manoeuvres the deviation range of the vertical wind component does not exceed 0.3 m s-1. (c) The comparison with ground based wind measurements yields an overall operational uncertainty (root mean square error) of ≈0.4 m s-1 for the horizontal and ≈0.3 m s-1 for the vertical wind components. No conclusive dependence of the uncertainty on the wind magnitude (<8 m s-1) or true airspeed (ranging from 23-30 m s-1) is found. Hence our analysis provides the necessary basis to study the wind measurement precision and spectral quality, which is prerequisite for reliable Eddy-Covariance flux measurements.

  4. The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation. Report 1; The Study for the Distance 4.5Rs

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Sittler, Edward C.; Hartle, Richard E.; Cooper, John F.

    2010-01-01

    Our report devotes a 3D numerical hybrid model of the interaction of the solar wind with the Solar Probe spacecraft. The SPP model includes 3 main parts, namely, a non-conducting heat shield, a support system, and cylindrical section or spacecraft bus that contains the particle analysis devices and antenna. One observes an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of about (0.06-0.6) V/m. The compression waves and the jumps in an electric field with an amplitude of about (0.15-0.7) V/m were also observed. The wave amplitudes are comparable to or greater than previously estimated max wave amplitudes that SPP is expected to measure. The results of our hybrid simulation will be useful for understanding the plasma environment near the SPP spacecraft at the distance 4.5 Rs. Future simulation will take into account the charging of the spacecraft, the charge separation effects, an outgassing from heat shield, a photoionization and an electron impact ionization effects near the spacecraft.

  5. The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation. Report 1; The Study for the Distance 4.5Rs

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Sittler, Edward C.; Hartle, Richard E.; Cooper, John F.

    2010-01-01

    Our report devotes a 3D numerical hybrid model of the interaction of the solar wind with the Solar Probe spacecraft. The Solar Probe Plus (SPP) model includes 3 main parts, namely, a non-conducting heat shield, a support system, and cylindrical section or spacecraft bus that contains the particle analysis devices and antenna. One observes an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of about (0.06-0.6) V/m. The compression waves and the jumps in an electric field with an amplitude of about (0.15-0.7) V/m were also observed. The wave amplitudes are comparable to or greater than previously estimated max wave amplitudes that SPP is expected to measure. The results of our hybrid simulation will be useful for understanding the plasma environment near the SPP spacecraft at the distance 4.5 Rs. Future simulation will take into account the charging of the spacecraft, the charge separation effects, an outgassing from heat shield, a photoionization and an electron impact ionization effects near the spacecraft.

  6. Cardiac tissue structure. Electric field interactions in polarizing the heart: 3D computer models and applications

    NASA Astrophysics Data System (ADS)

    Entcheva, Emilia

    1998-11-01

    The goal of this research is to investigate the interactions between the cardiac tissue structure and applied electric fields in producing complex polarization patterns. It is hypothesized that the response of the heart in the conditions of strong electric shocks, as those applied in defibrillation, is dominated by mechanisms involving the cardiac muscle structure perceived as a continuum. Analysis is carried out in three-dimensional models of the heart with detailed fiber architecture. Shock-induced transmembrane potentials are calculated using the bidomain model in its finite element implementation. The major new findings of this study can be summarized as follows: (1) The mechanisms of polarization due to cardiac fiber curvature and fiber rotation are elucidated in three-dimensional ellipsoidal hearts of variable geometry; (2) Results are presented showing that the axis of stimulation and the polarization axis on a whole heart level might differ significantly due to geometric and anisotropic factors; (3) Virtual electrode patterns are demonstrated numerically inside the ventricular wall in internal defibrillation conditions. The role of the tissue-bath interface in shaping the shock-induced polarization is revealed; (4) The generation of 3D phase singularity scrolls by shock-induced intramural virtual electrode patterns is proposed as evidence for a possible new mechanism for the failure to defibrillate. The results of this study emphasize the role of unequal anisotropy in the intra- and extracellular domains, as well as the salient fiber architecture characteristics, such as curvature and transmural rotation, in polarizing the myocardium. Experimental support of the above findings was actively sought and found in recent optical mapping studies using voltage-sensitive dyes. If validated in vivo, these findings would significantly enrich the prevailing concepts about the mechanisms of stimulation and defibrillation of the heart.

  7. Comparison of Phase-Based 3D Near-Field Source Localization Techniques for UHF RFID

    PubMed Central

    Parr, Andreas; Miesen, Robert; Vossiek, Martin

    2016-01-01

    In this paper, we present multiple techniques for phase-based narrowband backscatter tag localization in three-dimensional space with planar antenna arrays or synthetic apertures. Beamformer and MUSIC localization algorithms, known from near-field source localization and direction-of-arrival estimation, are applied to the 3D backscatter scenario and their performance in terms of localization accuracy is evaluated. We discuss the impact of different transceiver modes known from the literature, which evaluate different send and receive antenna path combinations for a single localization, as in multiple input multiple output (MIMO) systems. Furthermore, we propose a new Singledimensional-MIMO (S-MIMO) transceiver mode, which is especially suited for use with mobile robot systems. Monte-Carlo simulations based on a realistic multipath error model ensure spatial correlation of the simulated signals, and serve to critically appraise the accuracies of the different localization approaches. A synthetic uniform rectangular array created by a robotic arm is used to evaluate selected localization techniques. We use an Ultra High Frequency (UHF) Radiofrequency Identification (RFID) setup to compare measurements with the theory and simulation. The results show how a mean localization accuracy of less than 30 cm can be reached in an indoor environment. Further simulations demonstrate how the distance between aperture and tag affects the localization accuracy and how the size and grid spacing of the rectangular array need to be adapted to improve the localization accuracy down to orders of magnitude in the centimeter range, and to maximize array efficiency in terms of localization accuracy per number of elements. PMID:27347976

  8. Ocean Wave Simulation Based on Wind Field.

    PubMed

    Li, Zhongyi; Wang, Hao

    2016-01-01

    Ocean wave simulation has a wide range of applications in movies, video games and training systems. Wind force is the main energy resource for generating ocean waves, which are the result of the interaction between wind and the ocean surface. While numerous methods to handle simulating oceans and other fluid phenomena have undergone rapid development during the past years in the field of computer graphic, few of them consider to construct ocean surface height field from the perspective of wind force driving ocean waves. We introduce wind force to the construction of the ocean surface height field through applying wind field data and wind-driven wave particles. Continual and realistic ocean waves result from the overlap of wind-driven wave particles, and a strategy was proposed to control these discrete wave particles and simulate an endless ocean surface. The results showed that the new method is capable of obtaining a realistic ocean scene under the influence of wind fields at real time rates.

  9. Simulation of bootstrap current in 2D and 3D ideal magnetic fields in tokamaks

    NASA Astrophysics Data System (ADS)

    Raghunathan, M.; Graves, J. P.; Cooper, W. A.; Pedro, M.; Sauter, O.

    2016-09-01

    We aim to simulate the bootstrap current for a MAST-like spherical tokamak using two approaches for magnetic equilibria including externally caused 3D effects such as resonant magnetic perturbations (RMPs), the effect of toroidal ripple, and intrinsic 3D effects such as non-resonant internal kink modes. The first approach relies on known neoclassical coefficients in ideal MHD equilibria, using the Sauter (Sauter et al 1999 Phys. Plasmas 6 2834) expression valid for all collisionalities in axisymmetry, and the second approach being the quasi-analytic Shaing-Callen (Shaing and Callen 1983 Phys. Fluids 26 3315) model in the collisionless regime for 3D. Using the ideal free-boundary magnetohydrodynamic code VMEC, we compute the flux-surface averaged bootstrap current density, with the Sauter and Shaing-Callen expressions for 2D and 3D ideal MHD equilibria including an edge pressure barrier with the application of resonant magnetic perturbations, and equilibria possessing a saturated non-resonant 1/1 internal kink mode with a weak internal pressure barrier. We compare the applicability of the self-consistent iterative model on the 3D applications and discuss the limitations and advantages of each bootstrap current model for each type of equilibrium.

  10. Time-lapse 3D VSP monitoring of a carbon dioxide injection project at Delhi Field, Louisiana

    NASA Astrophysics Data System (ADS)

    Lubis, Muhammad Husni Mubarak

    Delhi Field is a producing oil field located in northeastern Louisiana. The estimated original oil in place (OOIP) is 357 mmbo and approximately 54% of OOIP has been produced through the primary production and water-flooding. A CO2-EOR program has been implemented since November 2009 to recover an additional 17% of OOIP. Reservoir surveillance using time-lapse 3D seismic data has been conducted to monitor the CO2 sweep efficiency. The goal of this study is to monitor the CO2 flow-path in the area around the injector using time-lapse 3D VSP data. For this purpose, two 3D VSPs acquired in June 2010 and again in August 2011 were processed together. Fluid substitution and VSP modeling were performed to understand the influence of pore-fluid saturation change on VSP records. A cross-equalization was performed to improve the similarity of the datasets. This step is important to reduce the ambiguity in time-lapse observation. The splice of a 3D VSP image into the surface seismic data becomes the key point in determining the reflector of the reservoir. By integrating the observation from the modeling and the splice of 3D VSP image to surface seismic, the CO2 flow-path from injector 164-3 can be identified from 3D time-lapse VSP data. The CO2 was not radially distributed around the injector, but moved toward southwest direction. This finding is also consistent with the flow-path interpreted from surface seismic. This consistency implies that time-lapse 3D VSP surveys at Delhi Field confirm and augment the time-lapse interpretation from surface seismic data.

  11. Non-linear dynamics of viscous bilayers subjected to an electric field: 3D phase field simulations

    NASA Astrophysics Data System (ADS)

    Dritselis, Christos; Karapetsas, George; Bontozoglou, Vasilis

    2014-11-01

    The scope of this work is to investigate the non-linear dynamics of the electro-hydrodynamic instability of a bilayer of immiscible liquids. We consider the case of two viscous films which is separated from the top electrode by air. We assume that the liquids are perfect dielectrics and consider the case of both flat and patterned electrodes. We develop a computational model using the diffuse interface method and carry out 3D numerical simulations fully accounting for the flow and electric field in all phases. We perform a parametric study and investigate the influence of the electric properties of fluids, applied voltage and various geometrical characteristics of the mask. The authors acknowledge the support by the General Secretariat of Research and Technology of Greece under the action ``Supporting Postdoctoral Researchers'' (Grant Number PE8/906), co-funded by the European Social Fund and National Resources.

  12. 3D ELECTRON DENSITY DISTRIBUTIONS IN THE SOLAR CORONA DURING SOLAR MINIMA: ASSESSMENT FOR MORE REALISTIC SOLAR WIND MODELING

    SciTech Connect

    Patoul, Judith de; Foullon, Claire; Riley, Pete E-mail: c.foullon@exeter.ac.uk

    2015-11-20

    Knowledge of the electron density distribution in the solar corona put constraints on the magnetic field configurations for coronal modeling and on initial conditions for solar wind modeling. We work with polarized SOHO/LASCO-C2 images from the last two recent minima of solar activity (1996–1997 and 2008–2010), devoid of coronal mass ejections. The goals are to derive the 4D electron density distributions in the corona by applying a newly developed time-dependent tomographic reconstruction method and to compare the results between the two solar minima and with two magnetohydrodynamic models. First, we confirm that the values of the density distribution in thermodynamic models are more realistic than in polytropic ones. The tomography provides more accurate distributions in the polar regions, and we find that the density in tomographic and thermodynamic solutions varies with the solar cycle in both polar and equatorial regions. Second, we find that the highest-density structures do not always correspond to the predicted large-scale heliospheric current sheet or its helmet streamer but can follow the locations of pseudo-streamers. We deduce that tomography offers reliable density distributions in the corona, reproducing the slow time evolution of coronal structures, without prior knowledge of the coronal magnetic field over a full rotation. Finally, we suggest that the highest-density structures show a differential rotation well above the surface depending on how they are magnetically connected to the surface. Such valuable information on the rotation of large-scale structures could help to connect the sources of the solar wind to their in situ counterparts in future missions such as Solar Orbiter and Solar Probe Plus.

  13. Extension of the Optimized Virtual Fields Method to estimate viscoelastic material parameters from 3D dynamic displacement fields

    PubMed Central

    Connesson, N.; Clayton, E.H.; Bayly, P.V.; Pierron, F.

    2015-01-01

    In-vivo measurement of the mechanical properties of soft tissues is essential to provide necessary data in biomechanics and medicine (early cancer diagnosis, study of traumatic brain injuries, etc.). Imaging techniques such as Magnetic Resonance Elastography (MRE) can provide 3D displacement maps in the bulk and in vivo, from which, using inverse methods, it is then possible to identify some mechanical parameters of the tissues (stiffness, damping etc.). The main difficulties in these inverse identification procedures consist in dealing with the pressure waves contained in the data and with the experimental noise perturbing the spatial derivatives required during the processing. The Optimized Virtual Fields Method (OVFM) [1], designed to be robust to noise, present natural and rigorous solution to deal with these problems. The OVFM has been adapted to identify material parameter maps from Magnetic Resonance Elastography (MRE) data consisting of 3-dimensional displacement fields in harmonically loaded soft materials. In this work, the method has been developed to identify elastic and viscoelastic models. The OVFM sensitivity to spatial resolution and to noise has been studied by analyzing 3D analytically simulated displacement data. This study evaluates and describes the OVFM identification performances: different biases on the identified parameters are induced by the spatial resolution and experimental noise. The well-known identification problems in the case of quasi-incompressible materials also find a natural solution in the OVFM. Moreover, an a posteriori criterion to estimate the local identification quality is proposed. The identification results obtained on actual experiments are briefly presented. PMID:26146416

  14. Segmentation of Image Data from Complex Organotypic 3D Models of Cancer Tissues with Markov Random Fields

    PubMed Central

    Robinson, Sean; Guyon, Laurent; Nevalainen, Jaakko; Toriseva, Mervi

    2015-01-01

    Organotypic, three dimensional (3D) cell culture models of epithelial tumour types such as prostate cancer recapitulate key aspects of the architecture and histology of solid cancers. Morphometric analysis of multicellular 3D organoids is particularly important when additional components such as the extracellular matrix and tumour microenvironment are included in the model. The complexity of such models has so far limited their successful implementation. There is a great need for automatic, accurate and robust image segmentation tools to facilitate the analysis of such biologically relevant 3D cell culture models. We present a segmentation method based on Markov random fields (MRFs) and illustrate our method using 3D stack image data from an organotypic 3D model of prostate cancer cells co-cultured with cancer-associated fibroblasts (CAFs). The 3D segmentation output suggests that these cell types are in physical contact with each other within the model, which has important implications for tumour biology. Segmentation performance is quantified using ground truth labels and we show how each step of our method increases segmentation accuracy. We provide the ground truth labels along with the image data and code. Using independent image data we show that our segmentation method is also more generally applicable to other types of cellular microscopy and not only limited to fluorescence microscopy. PMID:26630674

  15. Rare meshes FEM scheme for quasi-stationary electromagnetic fields determination 3D problems

    NASA Astrophysics Data System (ADS)

    Chekmarev, D. T.; Kalinin, A. V.; Sadovsky, V. V.; Tiukhtina, A. A.

    2016-11-01

    The initial-boundary value problem for the quasi-stationary magnetic approximation of the Maxwell equations in inhomogeneous media is studied. The considered problem is reduced to the variational problem of determining the vector magnetic potential. The special gauge for vector magnetic and scalar electrical potentials is used. The well-posedness of the problems is established under general conditions on the coefficients and the applicability of the projection methods for these problems is validated. For the numerical solution of this problem provides to use the effective rare mesh FEM scheme for 3D problems. This scheme is well- proven in 3D elasticity and plasticity problems solving.

  16. Accurate, full chip 3D electromagnetic field model for non-Manhattan mask corners

    NASA Astrophysics Data System (ADS)

    Lam, Michael; Clifford, Chris; Oliver, Michael; Fryer, David; Tejnil, Edita; Adam, Kostas

    2015-03-01

    The physical process of mask manufacturing produces absorber geometry with significantly less than 90 degree fidelity at corners. The non-Manhattan mask geometry is an essential contributor to the aerial image and resulting patterning performance through focus. Current state of the art models for corner rounding employ "chopping" a 90 degree mask corner, replacing the corner with a small 45 degree edge. In this paper, a methodology is presented to approximate the impact of 3D EMF effects introduced by corners with rounded edges. The approach is integrated into a full chip 3D mask simulation methodology based on the Domain Decomposition Method (DDM) with edge to edge crosstalk correction.

  17. Extended field-of-view and increased-signal 3D holographic illumination with time-division multiplexing.

    PubMed

    Yang, Samuel J; Allen, William E; Kauvar, Isaac; Andalman, Aaron S; Young, Noah P; Kim, Christina K; Marshel, James H; Wetzstein, Gordon; Deisseroth, Karl

    2015-12-14

    Phase spatial light modulators (SLMs) are widely used for generating multifocal three-dimensional (3D) illumination patterns, but these are limited to a field of view constrained by the pixel count or size of the SLM. Further, with two-photon SLM-based excitation, increasing the number of focal spots penalizes the total signal linearly--requiring more laser power than is available or can be tolerated by the sample. Here we analyze and demonstrate a method of using galvanometer mirrors to time-sequentially reposition multiple 3D holograms, both extending the field of view and increasing the total time-averaged two-photon signal. We apply our approach to 3D two-photon in vivo neuronal calcium imaging.

  18. Extended field-of-view and increased-signal 3D holographic illumination with time-division multiplexing

    PubMed Central

    Yang, Samuel J.; Allen, William E.; Kauvar, Isaac; Andalman, Aaron S.; Young, Noah P.; Kim, Christina K.; Marshel, James H.; Wetzstein, Gordon; Deisseroth, Karl

    2016-01-01

    Phase spatial light modulators (SLMs) are widely used for generating multifocal three-dimensional (3D) illumination patterns, but these are limited to a field of view constrained by the pixel count or size of the SLM. Further, with two-photon SLM-based excitation, increasing the number of focal spots penalizes the total signal linearly—requiring more laser power than is available or can be tolerated by the sample. Here we analyze and demonstrate a method of using galvanometer mirrors to time-sequentially reposition multiple 3D holograms, both extending the field of view and increasing the total time-averaged two-photon signal. We apply our approach to 3D two-photon in vivo neuronal calcium imaging. PMID:26699047

  19. A hybrid experimental-numerical technique for determining 3D velocity fields from planar 2D PIV data

    NASA Astrophysics Data System (ADS)

    Eden, A.; Sigurdson, M.; Mezić, I.; Meinhart, C. D.

    2016-09-01

    Knowledge of 3D, three component velocity fields is central to the understanding and development of effective microfluidic devices for lab-on-chip mixing applications. In this paper we present a hybrid experimental-numerical method for the generation of 3D flow information from 2D particle image velocimetry (PIV) experimental data and finite element simulations of an alternating current electrothermal (ACET) micromixer. A numerical least-squares optimization algorithm is applied to a theory-based 3D multiphysics simulation in conjunction with 2D PIV data to generate an improved estimation of the steady state velocity field. This 3D velocity field can be used to assess mixing phenomena more accurately than would be possible through simulation alone. Our technique can also be used to estimate uncertain quantities in experimental situations by fitting the gathered field data to a simulated physical model. The optimization algorithm reduced the root-mean-squared difference between the experimental and simulated velocity fields in the target region by more than a factor of 4, resulting in an average error less than 12% of the average velocity magnitude.

  20. 3D Numerical Simulation of the Wave and Current Loads on a Truss Foundation of the Offshore Wind Turbine During the Extreme Typhoon Event

    NASA Astrophysics Data System (ADS)

    Lin, C. W.; Wu, T. R.; Chuang, M. H.; Tsai, Y. L.

    2015-12-01

    The wind in Taiwan Strait is strong and stable which offers an opportunity to build offshore wind farms. However, frequently visited typhoons and strong ocean current require more attentions on the wave force and local scour around the foundation of the turbine piles. In this paper, we introduce an in-house, multi-phase CFD model, Splash3D, for solving the flow field with breaking wave, strong turbulent, and scour phenomena. Splash3D solves Navier-Stokes Equation with Large-Eddy Simulation (LES) for the fluid domain, and uses volume of fluid (VOF) with piecewise linear interface reconstruction (PLIC) method to describe the break free-surface. The waves were generated inside the computational domain by internal wave maker with a mass-source function. This function is designed to adequately simulate the wave condition under observed extreme events based on JONSWAP spectrum and dispersion relationship. Dirichlet velocity boundary condition is assigned at the upper stream boundary to induce the ocean current. At the downstream face, the sponge-layer method combined with pressure Dirichlet boundary condition is specified for dissipating waves and conducting current out of the domain. Numerical pressure gauges are uniformly set on the structure surface to obtain the force distribution on the structure. As for the local scour around the foundation, we developed Discontinuous Bi-viscous Model (DBM) for the development of the scour hole. Model validations were presented as well. The force distribution under observed irregular wave condition was extracted by the irregular-surface force extraction (ISFE) method, which provides a fast and elegant way to integrate the force acting on the surface of irregular structure. From the Simulation results, we found that the total force is mainly induced by the impinging waves, and the force from the ocean current is about 2 order of magnitude smaller than the wave force. We also found the dynamic pressure, wave height, and the

  1. Online Stereo 3D Simulation in Studying the Spherical Pendulum in Conservative Force Field

    ERIC Educational Resources Information Center

    Zabunov, Svetoslav S.

    2013-01-01

    The current paper aims at presenting a modern e-learning method and tool that is utilized in teaching physics in the universities. An online stereo 3D simulation is used for e-learning mechanics and specifically the teaching of spherical pendulum as part of the General Physics course for students in the universities. This approach was realized on…

  2. Wavelet Analysis for Wind Fields Estimation

    PubMed Central

    Leite, Gladeston C.; Ushizima, Daniela M.; Medeiros, Fátima N. S.; de Lima, Gilson G.

    2010-01-01

    Wind field analysis from synthetic aperture radar images allows the estimation of wind direction and speed based on image descriptors. In this paper, we propose a framework to automate wind direction retrieval based on wavelet decomposition associated with spectral processing. We extend existing undecimated wavelet transform approaches, by including à trous with B3 spline scaling function, in addition to other wavelet bases as Gabor and Mexican-hat. The purpose is to extract more reliable directional information, when wind speed values range from 5 to 10 ms−1. Using C-band empirical models, associated with the estimated directional information, we calculate local wind speed values and compare our results with QuikSCAT scatterometer data. The proposed approach has potential application in the evaluation of oil spills and wind farms. PMID:22219699

  3. Wavelet analysis for wind fields estimation.

    PubMed

    Leite, Gladeston C; Ushizima, Daniela M; Medeiros, Fátima N S; de Lima, Gilson G

    2010-01-01

    Wind field analysis from synthetic aperture radar images allows the estimation of wind direction and speed based on image descriptors. In this paper, we propose a framework to automate wind direction retrieval based on wavelet decomposition associated with spectral processing. We extend existing undecimated wavelet transform approaches, by including à trous with B(3) spline scaling function, in addition to other wavelet bases as Gabor and Mexican-hat. The purpose is to extract more reliable directional information, when wind speed values range from 5 to 10 ms(-1). Using C-band empirical models, associated with the estimated directional information, we calculate local wind speed values and compare our results with QuikSCAT scatterometer data. The proposed approach has potential application in the evaluation of oil spills and wind farms.

  4. Properties of the prominence magnetic field and plasma distributions as obtained from 3D whole-prominence fine structure modeling

    NASA Astrophysics Data System (ADS)

    Gunár, S.; Mackay, D. H.

    2016-07-01

    Aims: We analyze distributions of the magnetic field strength and prominence plasma (temperature, pressure, plasma β, and mass) using the 3D whole-prominence fine structure model. Methods: The model combines a 3D magnetic field configuration of an entire prominence, obtained from non-linear force-free field simulations, with a detailed semi-empirically derived description of the prominence plasma. The plasma is located in magnetic dips in hydrostatic equilibrium and is distributed along multiple fine structures within the 3D magnetic model. Results: We show that in the modeled prominence, the variations of the magnetic field strength and its orientation are insignificant on scales comparable to the smallest dimensions of the observed prominence fine structures. We also show the ability of the 3D whole-prominence fine structure model to reveal the distribution of the prominence plasma with respect to its temperature within the prominence volume. This provides new insights into the composition of the prominence-corona transition region. We further demonstrate that the values of the plasma β are small throughout the majority of the modeled prominences when realistic photospheric magnetic flux distributions and prominence plasma parameters are assumed. While this is generally true, we also find that in the region with the deepest magnetic dips, the plasma β may increase towards unity. Finally, we show that the mass of the modeled prominence plasma is in good agreement with the mass of observed non-eruptive prominences.

  5. Toward real-time endoscopically-guided robotic navigation based on a 3D virtual surgical field model

    NASA Astrophysics Data System (ADS)

    Gong, Yuanzheng; Hu, Danying; Hannaford, Blake; Seibel, Eric J.

    2015-03-01

    The challenge is to accurately guide the surgical tool within the three-dimensional (3D) surgical field for roboticallyassisted operations such as tumor margin removal from a debulked brain tumor cavity. The proposed technique is 3D image-guided surgical navigation based on matching intraoperative video frames to a 3D virtual model of the surgical field. A small laser-scanning endoscopic camera was attached to a mock minimally-invasive surgical tool that was manipulated toward a region of interest (residual tumor) within a phantom of a debulked brain tumor. Video frames from the endoscope provided features that were matched to the 3D virtual model, which were reconstructed earlier by raster scanning over the surgical field. Camera pose (position and orientation) is recovered by implementing a constrained bundle adjustment algorithm. Navigational error during the approach to fluorescence target (residual tumor) is determined by comparing the calculated camera pose to the measured camera pose using a micro-positioning stage. From these preliminary results, computation efficiency of the algorithm in MATLAB code is near real-time (2.5 sec for each estimation of pose), which can be improved by implementation in C++. Error analysis produced 3-mm distance error and 2.5 degree of orientation error on average. The sources of these errors come from 1) inaccuracy of the 3D virtual model, generated on a calibrated RAVEN robotic platform with stereo tracking; 2) inaccuracy of endoscope intrinsic parameters, such as focal length; and 3) any endoscopic image distortion from scanning irregularities. This work demonstrates feasibility of micro-camera 3D guidance of a robotic surgical tool.

  6. Multiview and light-field reconstruction algorithms for 360° multiple-projector-type 3D display.

    PubMed

    Zhong, Qing; Peng, Yifan; Li, Haifeng; Su, Chen; Shen, Weidong; Liu, Xu

    2013-07-01

    Both multiview and light-field reconstructions are proposed for a multiple-projector 3D display system. To compare the performance of the reconstruction algorithms in the same system, an optimized multiview reconstruction algorithm with sub-view-zones (SVZs) is proposed. The algorithm divided the conventional view zones in multiview display into several SVZs and allocates more view images. The optimized reconstruction algorithm unifies the conventional multiview reconstruction and light-field reconstruction algorithms, which can indicate the difference in performance when multiview reconstruction is changed to light-field reconstruction. A prototype consisting of 60 projectors with an arc diffuser as its screen is constructed to verify the algorithms. Comparison of different configurations of SVZs shows that light-field reconstruction provides large-scale 3D images with the smoothest motion parallax; thus it may provide better overall performance for large-scale 360° display than multiview reconstruction.

  7. Modeling of 3d Space-time Surface of Potential Fields and Hydrogeologic Modeling of Nuclear Waste Disposal Sites

    NASA Astrophysics Data System (ADS)

    Shestopalov, V.; Bondarenko, Y.; Zayonts, I.; Rudenko, Y.

    Introduction After the Chernobyl Nuclear Power Plant (CNPP) disaster (04.26.1986) a huge amount (over 2000 sq. km) of nuclear wastes appeared within so-called "Cher- nobyl Exclusion Zone" (CEZ). At present there are not enough storage facilities in the Ukraine for safe disposal of nuclear wastes and hazardous chemical wastes. The urgent problem now is safe isolation of these dangerous wastes. According to the developed state program of radioactive waste management, the construction of a na- tional storage facility of nuclear wastes is planned. It is also possible to create regional storage facilities for hazardous chemical wastes. The region of our exploration cov- ers the eastern part of the Korosten Plutone and its slope, reaching the CNPP. 3D Space-Time Surface Imaging of Geophysical Fields. There are only three direct meth- ods of stress field reconstruction in present practice, namely the field investigations based on the large-scale fracturing tests, petrotectonic and optical polarization meth- ods. Unfortunately, all these methods are extremely laborious and need the regular field tests, which is difficult to conduct in the areas of anisotropic rock outcrops. A compilation of magnetic and gravity data covering the CNPP area was carried out as a prelude to an interpretation study. More than thirty map products were generated from magnetic, gravity and geodesy data to prepare the 3D Space-Time Surface Images (3D STSI). Multi-layer topography and geophysic surfaces included: total magnetic intensity, isostatically-corrected Bouguer gravity, aspect and slope, first and second derivatives, vertical and horizontal curvature, histogram characteristics and space cor- relation coefficients between the gradient fields. Many maps shows the first and sec- ond derivatives of the potential fields, with the results of lineament (edge) structure detection superimposed. The lineament or edges of the potential fields are located from maximal gradient in many directions

  8. The history and principles of chemical dosimetry for 3-D radiation fields: gels, polymers and plastics.

    PubMed

    Doran, Simon J

    2009-03-01

    Over recent decades, modern protocols of external beam radiotherapy have been developed that involve very steep dose gradients and are thus extremely sensitive to errors in treatment delivery. A recent credentialling study by the Radiological Physics Center at the MD Anderson Cancer Center (Texas, USA) has noted potentially significant inaccuracies in test treatments at a variety of institutions. 3-D radiation dosimetry (often referred to as "gel dosimetry") may have an important role in commissioning new treatment protocols, to help prevent this type of error. This article discusses the various techniques of 3-D radiation dosimetry, with a focus on the types of radiosensitive samples used and on the optical computed tomography readout technique.

  9. Full-field 3D shape measurement of specular surfaces by direct phase to depth relationship

    NASA Astrophysics Data System (ADS)

    Zhang, Zonghua; Liu, Yue; Huang, Shujun; Niu, Zhenqi; Guo, Jiao; Gao, Nan; Gao, Feng; Jiang, Xiangqian

    2016-11-01

    This paper presents a new Phase Measuring Deflectometry (PMD) method to measure specular object having discontinuous surfaces. A mathematical model is established to directly relate absolute phase and depth, instead of phase and gradient. Based on the model, a hardware measuring system has been set up, which consists of a beam splitter to change the optical path, and two LCD screens to display the same sinusoidal fringe patterns. By using model-based and machine vision method, system calibration is accomplished to provide the required parameters and conditions. The verification tests are given to evaluate the effectiveness of the developed system. The 3D shape of an artificial step having multiple specular surfaces and a concave mirror has been measured. Initial experimental results show that the proposed measurement method can obtain 3D shape of specular objects with discontinuous surface effectively.

  10. SMEI 3D RECONSTRUCTION OF A CORONAL MASS EJECTION INTERACTING WITH A COROTATING SOLAR WIND DENSITY ENHANCEMENT: THE 2008 APRIL 26 CME

    SciTech Connect

    Jackson, B. V.; Buffington, A.; Hick, P. P.; Clover, J. M.; Bisi, M. M.; Webb, D. F.

    2010-12-01

    The Solar Mass Ejection Imager (SMEI) has recorded the brightness responses of hundreds of interplanetary coronal mass ejections (CMEs) in the interplanetary medium. Using a three-dimensional (3D) reconstruction technique that derives its perspective views from outward-flowing solar wind, analysis of SMEI data has revealed the shapes, extents, and masses of CMEs. Here, for the first time, and using SMEI data, we report on the 3D reconstruction of a CME that intersects a corotating region marked by a curved density enhancement in the ecliptic. Both the CME and the corotating region are reconstructed and demonstrate that the CME disrupts the otherwise regular density pattern of the corotating material. Most of the dense CME material passes north of the ecliptic and east of the Sun-Earth line: thus, in situ measurements in the ecliptic near Earth and at the Solar-TErrestrial RElations Observatory Behind spacecraft show the CME as a minor density increase in the solar wind. The mass of the dense portion of the CME is consistent with that measured by the Large Angle Spectrometric Coronagraph on board the Solar and Heliospheric Observatory spacecraft, and is comparable to the masses of many other three-dimensionally reconstructed solar wind features at 1 AU observed in SMEI 3D reconstructions.

  11. Studies of the Vector Field in Shallow Water and in the Presence of 3-D Variability

    DTIC Science & Technology

    2015-09-30

    developed to represent data that would be measured on an acoustic vector sensor . Basic processing schemes were then evaluated to determine if such...data could yield information on the directional nature of the ambient noise. In addition, data collection events were conducted in FY15 with...acoustic vector sensors to provide some test data sets. This allowed some processing strings to be developed. RESULTS 3-D MMPE Modeling: In FY15

  12. Magnetic field induced controllable self-assembly of maghemite nanocrystals: From 3D arrays to 1D nanochains

    NASA Astrophysics Data System (ADS)

    Tang, Yan; Chen, Qianwang; Chen, Rongsheng

    2015-08-01

    A hydrothermal process has been used to synthesize walnut-like maghemite superstructures which can be further self-assembled in a controllable manner into ordered three-dimensional (3D) architectures and one-dimensional (1D) nanochains in the presence of different external magnetic field. The assembly behavior of the maghemite nanoparticles isclosely related to the van der Waals interactions and external-field-induced magnetic dipole interactions. The magnetic properties of these nanostructures are also investigated.

  13. Optical low-cost and portable arrangement for full field 3D displacement measurement using a single camera

    NASA Astrophysics Data System (ADS)

    López-Alba, E.; Felipe-Sesé, L.; Schmeer, S.; Díaz, F. A.

    2016-11-01

    In the current paper, an optical low-cost system for 3D displacement measurement based on a single camera and 3D digital image correlation is presented. The conventional 3D-DIC set-up based on a two-synchronized-cameras system is compared with a proposed pseudo-stereo portable system that employs a mirror system integrated in a device for a straightforward application achieving a novel handle and flexible device for its use in many scenarios. The proposed optical system splits the image by the camera into two stereo images of the object. In order to validate this new approach and quantify its uncertainty compared to traditional 3D-DIC systems, solid rigid in and out-of-plane displacements experiments have been performed and analyzed. The differences between both systems have been studied employing an image decomposition technique which performs a full image comparison. Therefore, results of all field of view are compared with those using a stereoscopy system and 3D-DIC, discussing the accurate results obtained with the proposed device not having influence any distortion or aberration produced by the mirrors. Finally, the adaptability of the proposed system and its accuracy has been tested performing quasi-static and dynamic experiments using a silicon specimen under high deformation. Results have been compared and validated with those obtained from a conventional stereoscopy system showing an excellent level of agreement.

  14. Compartmentalization of the Coso East Flank geothermal field imaged by 3-D full-tensor MT inversion

    NASA Astrophysics Data System (ADS)

    Lindsey, Nathaniel J.; Kaven, Joern Ole; Davatzes, Nicholas; Newman, Gregory A.

    2017-02-01

    Previous magnetotelluric (MT) studies of the high-temperature Coso geothermal system in California identified a subvertical feature of low resistivity (2-5 Ohm m) and appreciable lateral extent (>1 km) in the producing zone of the East Flank field. However, these models could not reproduce gross 3-D effects in the recorded data. We perform 3-D full-tensor inversion and retrieve a resistivity model that out-performs previous 2-D and 3-D off-diagonal models in terms of its fit to the complete 3-D MT data set as well as the degree of modelling bias. Inclusion of secondary Zxx and Zyy data components leads to a robust east-dip (60†) to the previously identified conductive East Flank reservoir feature, which correlates strongly with recently mapped surface faults, downhole well temperatures, 3-D seismic reflection data, and local microseismicity. We perform synthetic forward modelling to test the best-fit dip of this conductor using the response at a nearby MT station. We interpret the dipping conductor as a fractured and fluidized compartment, which is structurally controlled by an unmapped blind East Flank fault zone.

  15. Compartmentalization of the Coso East Flank Geothermal Field Imaged by 3-D Full-tensor MT Inversion

    NASA Astrophysics Data System (ADS)

    Lindsey, Nathaniel J.; Kaven, Joern Ole; Davatzes, Nicholas; Newman, Gregory A.

    2016-11-01

    Previous magnetotelluric (MT) studies of the high-temperature Coso geothermal system in California identified a subvertical feature of low resistivity (2 - 5 Ohm-m) and appreciable lateral extent (>1 km) in the producing zone of the East Flank field. However, these models could not reproduce gross 3-D effects in the recorded data. We perform 3-D full-tensor inversion and retrieve a resistivity model that out-performs previous 2-D and 3-D off-diagonal models in terms of its fit to the complete 3-D MT dataset as well as the degree of modeling bias. Inclusion of secondary Zxx and Zyy data components leads to a robust east-dip (60o) to the previously identified conductive East Flank reservoir feature, which correlates strongly with recently mapped surface faults, downhole well temperatures, 3-D seismic reflection data, and local microseismicity. We perform synthetic forward modeling to test the best fit dip of this conductor using the response at a nearby MT station. We interpret the dipping conductor as a fractured and fluidized compartment, which is structurally-controlled by an unmapped blind East Flank fault zone.

  16. TIME3D-IGGCAS: A New Three-Dimension Theoretical Ionospheric Model in realistic geomagnetic fields

    NASA Astrophysics Data System (ADS)

    Ren, Zhipeng; Liu, Libo; Huijun Le, lake709.; Wan, Weixing

    Based on the previous work, a new global three-dimension theoretical ionospheric model in realistic geomagnetic fields is developed, named Three-Dimension Theoretical Ionospheric Model of the Earth in the Institute of Geology and Geophysics, Chinese Academy of Sciences (TIME3D-IGGCAS). This new model covers the whole ionosphere and plasmasphere. It self-consistently solves the equations of mass continuity, motion and energy of electron and ions to give out the time-dependent three-dimensional structures of the main ionospheric and plasmaspheric parameters in realistic geomagnetic fields, including ion number densities of O+, H+, He+, NO+, O2+ , N2+ and electron; electron and ion temperature; and ion velocity vectors. TIME3D-IGGCAS can also self-consistently run as the module of ionosphere-plasmasphere of GCITEM-IGGCAS (Global Coupled Ionosphere-Thermosphere-Electrodynamics Model developed at Institute of Geology and Geophysics, Chinese Academy of Sciences). We carry out simulations in March Equinox and in June Solstice, and compare the simulated results with that from IRI empirical model. TIME3D-IGGCAS can well reproduce the main ionospheric features in all simulations. We also simulate the ionospheric differences between different kinds of geomagnetic fields. The results suggest that the geomagnetic field configuration obviously affect the ionospheric plasma density, and the differences between NmF2 in realistic geomagnetic fields and that in tilted dipole fields can be larger than 60%.

  17. 3D real-time visualization of blood flow in cerebral aneurysms by light field particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Carlsohn, Matthias F.; Kemmling, André; Petersen, Arne; Wietzke, Lennart

    2016-04-01

    Cerebral aneurysms require endovascular treatment to eliminate potentially lethal hemorrhagic rupture by hemostasis of blood flow within the aneurysm. Devices (e.g. coils and flow diverters) promote homeostasis, however, measurement of blood flow within an aneurysm or cerebral vessel before and after device placement on a microscopic level has not been possible so far. This would allow better individualized treatment planning and improve manufacture design of devices. For experimental analysis, direct measurement of real-time microscopic cerebrovascular flow in micro-structures may be an alternative to computed flow simulations. An application of microscopic aneurysm flow measurement on a regular basis to empirically assess a high number of different anatomic shapes and the corresponding effect of different devices would require a fast and reliable method at low cost with high throughout assessment. Transparent three dimensional 3D models of brain vessels and aneurysms may be used for microscopic flow measurements by particle image velocimetry (PIV), however, up to now the size of structures has set the limits for conventional 3D-imaging camera set-ups. On line flow assessment requires additional computational power to cope with the processing large amounts of data generated by sequences of multi-view stereo images, e.g. generated by a light field camera capturing the 3D information by plenoptic imaging of complex flow processes. Recently, a fast and low cost workflow for producing patient specific three dimensional models of cerebral arteries has been established by stereo-lithographic (SLA) 3D printing. These 3D arterial models are transparent an exhibit a replication precision within a submillimeter range required for accurate flow measurements under physiological conditions. We therefore test the feasibility of microscopic flow measurements by PIV analysis using a plenoptic camera system capturing light field image sequences. Averaging across a sequence of

  18. Transient Hydraulic Tomography in the Field: 3-D K Estimation and Validation in a Highly Heterogeneous Unconfined Aquifer

    NASA Astrophysics Data System (ADS)

    Hochstetler, D. L.; Barrash, W.; Kitanidis, P. K.

    2014-12-01

    Characterizing subsurface hydraulic properties is essential for predicting flow and transport, and thus, for making informed decisions, such as selection and execution of a groundwater remediation strategy; however, obtaining accurate estimates at the necessary resolution with quantified uncertainty is an ongoing challenge. For over a decade, the development of hydraulic tomography (HT) - i.e., conducting a series of discrete interval hydraulic tests, observing distributed pressure signals, and analyzing the data through inversion of all tests together - has shown promise as a subsurface imaging method. Numerical and laboratory 3-D HT studies have enhanced and validated such methodologies, but there have been far fewer 3-D field characterization studies. We use 3-D transient hydraulic tomography (3-D THT) to characterize a highly heterogeneous unconfined alluvial aquifer at an active industrial site near Assemini, Italy. With 26 pumping tests conducted from 13 isolated vertical locations, and pressure responses measured at 63 spatial locations through five clusters of continuous multichannel tubing, we recorded over 800 drawdown curves during the field testing. Selected measurements from each curve were inverted in order to obtain an estimate of the distributed hydraulic conductivity field K(x) as well as uniform ("effective") values of specific storage Ss and specific yield Sy. The estimated K values varied across seven orders of magnitude, suggesting that this is one of the most heterogeneous sites at which HT has ever been conducted. Furthermore, these results are validated using drawdown observations from seven independent tests with pumping performed at multiple locations other than the main pumping well. The validation results are encouraging, especially given the uncertain nature of the problem. Overall, this research demonstrates the ability of 3-D THT to provide high-resolution of structure and local K at a non-research site at the scale of a contaminant

  19. (1 + 3)-D topological superconductors: Screening and confinement in the presence of external fields

    NASA Astrophysics Data System (ADS)

    Gaete, Patricio; Helayël-Neto, José A.

    2016-12-01

    Adopting the gauge-invariant and path-dependent variables formalism, we compute the interaction energy for a topological field theory describing (1 + 3)-D topological superconductors in the presence of external fields. As a result, in the case of a constant electric-field strength expectation value, we show that the interaction energy describes a purely screening phase, encoded in a Yukawa potential. On the other hand, in the case of a constant magnetic-field strength and for a very small Josephson coupling constant, the particle-antiparticle binding potential displays a linear term leading to the confinement of static charge probes along with a screening contribution.

  20. First steps toward 3D high resolution imaging using adaptive optics and full-field optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Blanco, Leonardo; Blavier, Marie; Glanc, Marie; Pouplard, Florence; Tick, Sarah; Maksimovic, Ivan; Chenegros, Guillaume; Mugnier, Laurent; Lacombe, Francois; Rousset, Gérard; Paques, Michel; Le Gargasson, Jean-François; Sahel, Jose-Alain

    2008-09-01

    We describe here two parts of our future 3D fundus camera coupling Adaptive Optics and full-field Optical Coherence Tomography. The first part is an Adaptive Optics flood imager installed at the Quinze-Vingts Hospital, regularly used on healthy and pathological eyes. A posteriori image reconstruction is performed, increasing the final image quality and field of view. The instrument lateral resolution is better than 2 microns. The second part is a full-field Optical Coherence Tomograph, which has demonstrated capability of performing a simple kind of "4 phases" image reconstruction of non biological samples and ex situ retinas. Final aim is to couple both parts in order to achieve 3D high resolution mapping of in vivo retinas.

  1. First MMS Observations of High Time Resolution 3D Electric and Magnetic fields at the Dayside Magnetopause.

    NASA Astrophysics Data System (ADS)

    Torbert, R. B.; Burch, J. L.; Russell, C. T.; Magnes, W.; Ergun, R. E.; Lindqvist, P. A.; Le Contel, O.; Vaith, H.; Macri, J.; Myers, S.; Rau, D.; Needell, J.; King, B.; Granoff, M.; Chutter, M.; Dors, I.; Argall, M. R.; Shuster, J. R.; Olsson, G.; Marklund, G. T.; Khotyaintsev, Y. V.; Eriksson, A. I.; Kletzing, C.; Bounds, S. R.; Anderson, B. J.; Baumjohann, W.; Steller, M.; Bromund, K. R.; Le, G.; Nakamura, R.; Strangeway, R. J.; Leinweber, H. K.; Tucker, S.; Westfall, J.; Fischer, D.; Plaschke, F.; Pollock, C. J.; Giles, B. L.; Moore, T. E.; Mauk, B.; Fuselier, S. A.

    2015-12-01

    The electrodynamics at the magnetopause is key to our understanding of ion and electron acceleration within reconnection regions. The Magnetospheric Multiscale (MMS) fleet of four spacecraft was launched into its Phase-1 equatorial orbit of 12 Re apogee specifically to investigate these regions at the Earth's magnetopause. In addition to a comprehensive suite of particle measurements, MMS makes very high time resolution 3D electric and magnetic field measurements of high accuracy using flux-gate, search coil, 3-axis double probe, and electron drift sensors. In September 2015, the MMS fleet will begin to encounter the dusk-side magnetopause in its initial configuration of approximately 160 km separation, allowing investigation of the spatial and temporal characteristics of important electrodynamics during reconnection. Using these field and particle measurements, we present first observations of 3D magnetic and electric fields (including their parallel component), and inferred current sheets, during active magnetopause crossings using the highest time resolution data available on MMS.

  2. Testing the Validity of the Neoclassical Toroidal Viscosity Model of Torque due to 3D Non-Resonant Magnetic Fields

    NASA Astrophysics Data System (ADS)

    McCubbin, A. J.; Smith, S. P.; Ferraro, N. M.; Callen, J. D.; Meneghini, O.

    2012-10-01

    Understanding the torque applied by resonant and non-resonant magnetic perturbations and its effect on rotation is essential to predict confinement and stability in burning plasmas. Non-axisymmetric 3D fields produced in the DIII-D tokamak apply a torque to the plasma, which can be evaluated through its effect on the plasma rotation. One explanation for this torque is Neoclassical Toroidal Viscosity (NTV) acting through non-resonant field components [1]. We have developed a software framework in which magnetic perturbations calculated by the state of the art two fluid MHD code M3D-C1 can be used in NTV calculations. For discharges with applied external magnetic fields in DIII-D, the experimentally determined torques will be analyzed and compared with NTV models.[4pt] [1] J.D. Callen, Nucl. Fusion 51, 094026 (2011).

  3. Fully automated measurement of field-dependent AMS using MFK1-FA Kappabridge equipped with 3D rotator

    NASA Astrophysics Data System (ADS)

    Chadima, Martin; Studynka, Jan

    2013-04-01

    Low-field magnetic susceptibility of paramagnetic and diamagnetic minerals is field-independent by definition being also field-independent in pure magnetite. On the other hand, in pyrrhotite, hematite and high-Ti titanomagnetite it may be clearly field-dependent. Consequently, the field-dependent AMS enables the magnetic fabric of the latter group of minerals to be separated from the whole-rock AMS. The methods for the determination of the field-dependent AMS consist of separate measurements of each specimen in several fields within the Rayleigh Law range and subsequent processing in which the field-independent and field-dependent AMS components are calculated. The disadvantage of this technique is that each specimen must be measured several times, which is relatively laborious and time consuming. Recently, a new 3D rotator was developed for the MFK1-FA Kappabridge, which rotates the specimen simultaneously about two axes with different velocities. The measurement is fully automated in such a way that, once the specimen is inserted into the rotator, it requires no additional manipulation to measure the full AMS tensor. Consequently, the 3D rotator enables to measure the AMS tensors in the pre-set field intensities without any operator interference. Whole procedure is controlled by newly developed Safyr5 software; once the measurements are finished, the acquired data are immediately processed and can be visualized in a standard way.

  4. Mistic winds, a microsatellite constellation approach to high-resolution observations of the atmosphere using infrared sounding and 3d winds measurements

    NASA Astrophysics Data System (ADS)

    Maschhoff, K. R.; Polizotti, J. J.; Aumann, H. H.; Susskind, J.

    2016-10-01

    MISTiC Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sunsynchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's AIRS that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key remaining technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  5. MISTiC Winds: A micro-satellite constellation approach to high resolution observations of the atmosphere using infrared sounding and 3D winds measurements

    NASA Astrophysics Data System (ADS)

    Maschhoff, K. R.; Polizotti, J. J.; Aumann, H. H.; Susskind, J.

    2016-09-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sunsynchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's AIRS that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key remaining technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  6. MISTiC Winds, a Micro-Satellite Constellation Approach to High Resolution Observations of the Atmosphere using Infrared Sounding and 3D Winds Measurements

    NASA Astrophysics Data System (ADS)

    Maschhoff, K. R.; Polizotti, J. J.; Susskind, J.; Aumann, H. H.

    2015-12-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sun-synchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's Atmospheric Infrared Sounder that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  7. 3D-HST: A WIDE-FIELD GRISM SPECTROSCOPIC SURVEY WITH THE HUBBLE SPACE TELESCOPE

    SciTech Connect

    Brammer, Gabriel B.; Van Dokkum, Pieter G.; Skelton, Rosalind E.; Nelson, Erica; Bezanson, Rachel; Leja, Joel; Lundgren, Britt; Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Labbe, Ivo; Rix, Hans-Walter; Schmidt, Kasper B.; Da Cunha, Elisabete; Kriek, Mariska; Erb, Dawn K.; Fan, Xiaohui; Foerster Schreiber, Natascha; Illingworth, Garth D.; Magee, Dan; and others

    2012-06-01

    We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for a sample of {approx}7000 galaxies at 1 < z < 3.5, the epoch when {approx}60% of all star formation took place, the number density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in galaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin{sup 2}) of the CANDELS Treasury survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of {approx}5 per resolution element at H{sub 140} {approx} 23.1 and a 5{sigma} emission-line sensitivity of {approx}5 Multiplication-Sign 10{sup -17} erg s{sup -1} cm{sup -2} for typical objects, improving by a factor of {approx}2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1 to 1.6 {mu}m at a spatial resolution of {approx}0.''13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary reduction and analysis of the grism observations, including emission-line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of {sigma}(z) = 0.0034(1 + z), or {sigma}(v) Almost-Equal-To 1000 km s{sup -1}. We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z = 4.7, quiescent galaxies at z {approx} 2, and the most distant T-type brown dwarf star known. The combination of the CANDELS and 3D-HST surveys will

  8. Mechanisms of clay smear formation in 3D - a field study

    NASA Astrophysics Data System (ADS)

    Kettermann, Michael; Tronberens, Sebastian; Urai, Janos; Asmus, Sven

    2016-04-01

    Clay smears in sedimentary basins are important factors defining the sealing properties of faults. However, as clay smears are highly complex 3D structures, processes involved in the formation and deformation of clay smears are not well identified and understood. To enhance the prediction of sealing properties of clay smears extensive studies of these structures are necessary including the 3D information. We present extraordinary outcrop data from an open cast lignite mine (Hambach) in the Lower Rhine Embayment, Germany. The faults formed at a depth of 150 m, and have Shale Gouge Ratios between 0.1 and 0.3. Material in the fault zones is layered, with sheared sand, sheared clay and tectonically mixed sand-clay gouge. We studied the 3D thickness distribution of clay smear from a series of thin-spaced incremental cross-sections and several cross-sections in larger distances along the fault. Additionally, we excavated two large clay smear surfaces. Our observations show that clay smears are strongly affected by R- and R'-shears, mostly at the footwall side of our outcrops. These shears can locally cross and offset clay smears, forming holes. Thinnest parts of the clay smears are often located close to source layer cutoffs. Investigating the 3D thickness of the clay smears shows a heterogeneous distribution, rather than a continuous thinning of the smear with increasing distance to the source layers. We found two types of layered clay smears: one with continuous sheared sand between two clay smears providing vertical pathways for fluid flow, and one which consists of overlapping clay patches separated by sheared sand that provide a tortuous pathway across the clay smear. On smaller scale we identified grain-scale mixing as an important process for the formation of clay smears. Sand can be entrained into the clay smear by mixing from the surrounding host rock as well as due to intense shearing of sand lenses that were incorporated into the smear. This causes clay smears

  9. Near-ground tornado wind fields

    SciTech Connect

    McDonald, J.R.

    1984-07-01

    A study of near-ground tornado wind fields has been conducted by inspecting damage and debris patterns found in tornado damage paths. Because there were no significant tornado events (F4 or greater) during the contract performance period, data from the literature and the files of the Institute for Disaster Research were used to perform the analyses. The results indicate: (1) maximum tornado wind speed ever experienced or expected is in the range of 250 to 300 mph; (2) appearance of damage, taken by itself, is a misleading parameter of tornado intensity. Type of construction, age of construction, materials and other construction features significantly affect structural performance of a building subjected to wind loads and should be taken into account in assigning Fujita-Scale ratings; (3) damage to forests gives a good indication of tornado wind field flow patterns, but do not give verifiable values of wind speed; (4) factors such as translational speed, wind direction and path width affect appearance of damage or a tornado; and (5) even the most awesome appearing missiles do not require incredible wind speeds to explain them. Some progress in computer simulation of tornado missiles have been made. 31 references, 8 figures, 2 tables.

  10. GEMINI 3D spectroscopy of BAL + IR + FeII QSOs - I. Decoupling the BAL, QSO, starburst, NLR, supergiant bubbles and galactic wind in Mrk 231

    NASA Astrophysics Data System (ADS)

    Lipari, S.; Sanchez, S. F.; Bergmann, M.; Terlevich, R.; Garcia-Lorenzo, B.; Punsly, B.; Mediavilla, E.; Taniguchi, Y.; Ajiki, M.; Zheng, W.; Acosta, J.; Jahnke, K.

    2009-02-01

    In this paper we present the first results of a study of BAL QSOs (at low and high redshift), based on very deep Gemini GMOS integral field spectroscopy. In particular, the results obtained for the nearest BAL IR-QSO Mrk 231 are presented. For the nuclear region of Mrk 231, the QSO and host galaxy components were modelled, using a new technique of decoupling 3D spectra. From this study, the following main results were found: (i) in the pure host galaxy spectrum an extreme nuclear starburst component was clearly observed, as a very strong increase in the flux, at the blue wavelengths; (ii) the BAL system I is observed in the spectrum of the host galaxy; (iii) in the clean/pure QSO emission spectrum, only broad lines were detected. 3D GMOS individual spectra (specially in the near-infrared CaII triplet) and maps confirm the presence of an extreme and young nuclear starburst (8 < age < 15 Myr), which was detected in a ring or toroid with a radius r = 0.3arcsec ~ 200 pc, around the core of the nucleus. The extreme continuum blue component was detected only to the south of the core of the nucleus. This area is coincident with the region where we previously suggested that the galactic wind is cleaning the nuclear dust. Very deep 3D spectra and maps clearly show that the BAL systems I and II - in the strong `absorption lines' NaIDλ5889-95 and CaII Kλ3933 - are extended (reaching ~1.4-1.6 arcsec ~ 1.2-1.3 kpc, from the nucleus) and clearly elongated at the position angle (PA) close to the radio jet PA, which suggest that the BAL systems I and II are `both' associated with the radio jet. The physical properties of the four expanding nuclear bubbles were analysed, using the GMOS 3D spectra and maps. In particular, we found strong multiple LINER/OF emission-line systems and Wolf-Rayet features in the main knots of the more external super bubble S1 (r = 3.0 kpc). The kinematics of these knots - and the internal bubbles - suggest that they are associated with an area of

  11. Measurements of stress fields near a grain boundary: Exploring blocked arrays of dislocations in 3D

    DOE PAGES

    Guo, Y.; Collins, D. M.; Tarleton, E.; ...

    2015-06-24

    The interaction between dislocation pile-ups and grain boundaries gives rise to heterogeneous stress distributions when a structural metal is subjected to mechanical loading. Such stress heterogeneity leads to preferential sites for damage nucleation and therefore is intrinsically linked to the strength and ductility of polycrystalline metals. To date the majority of conclusions have been drawn from 2D experimental investigations at the sample surface, allowing only incomplete observations. Our purpose here is to significantly advance the understanding of such problems by providing quantitative measurements of the effects of dislocation pile up and grain boundary interactions in 3D. This is accomplished throughmore » the application of differential aperture X-ray Laue micro-diffraction (DAXM) and high angular resolution electron backscatter diffraction (HR-EBSD) techniques. Our analysis demonstrates a similar strain characterization capability between DAXM and HR-EBSD and the variation of stress intensity in 3D reveals that different parts of the same grain boundary may have different strengths in resisting slip transfer, likely due to the local grain boundary curvature.« less

  12. HBT-EP Program: MHD Dynamics and Active Control through 3D Fields and Currents

    NASA Astrophysics Data System (ADS)

    Navratil, G. A.; Abler, M. C.; Bialek, J.; Brooks, J. W.; Byrne, P. J.; Desanto, S.; Hughes, P. E.; Levesque, J. P.; Mauel, M. E.; Rhodes, D. J.; Hansen, C. J.

    2016-10-01

    The HBT-EP active mode control research program aims to: (i) advance understanding of the effects of 3D shaping on advanced tokamak fusion performance, (ii) resolve important MHD issues associated with disruptions, and (iii) measure and mitigate the effects of 3D scrape-off layer (SOL) currents through active and passive control of the plasma edge and conducting boundary structures. A GPU-based low latency control system uses 96 inputs and 64 outputs to control the plasma boundary. An in-vessel adjustable ferritic wall is used to study ferritic RWMs with increased growth rates, RMP response, and disruptivity. A quasi-linear sharp-boundary model is developed to study effects of toroidal curvature and plasma shaping on beta limits with resistive plasmas and walls. Measurement of currents between vessel sections reveals currents running from the plasma to the wall during wall-touching kink modes and disruptions. Asymmetries in plasma current are observed using segmented Rogowski coils. Biased electrodes in the plasma are used to control rotation of external kinks and drive currents in the SOL. An extensive array of SOL current monitors and edge drive electrodes will be installed for pioneering studies of helical edge current control. Supported by U.S. DOE Grant DE-FG02-86ER53222.

  13. Enhanced Electron Heating and Mixing in a 3D Kinetic Simulation for MMS Magnetopause Crossings with Weak Guide Fields

    NASA Astrophysics Data System (ADS)

    Le, Ari; Daughton, William; Chen, Li-Jen; Egedal, Jan

    2016-10-01

    We present a 3D kinetic simulation of asymmetric reconnection with plasma parameters matching the MMS magetopause diffusion region crossing reported by Burch et al. (Science 2016). The simulation was performed with the code VPIC on LANL's Trinity machine, which enabled relatively high grid resolution and numerical particle numbers to resolve the electron diffusion region dynamics. The simulation not only reproduces the reported crescent distributions but also appears to account for new features observed by MMS in other diffusion region events with weak guide fields. Compared to a 2D simulation with the same plasma parameters, drift turbulence in the 3D simulation substantially enhances the mixing and parallel heating of electrons on the magnetosphere side. This modifies the reconnection rate inferred from a recently introduced electron mixing diagnostic. To the magnetosphere side of the in-plane magnetic null, the parallel electric field exhibits a bipolar structure with polarities opposite to the large-scale parallel electric field. The 3D structure of the X line and the particle signature of the inverted bipolar parallel electric field have been observed by MMS.

  14. 3D flash lidar performance in flight testing on the Morpheus autonomous, rocket-propelled lander to a lunar-like hazard field

    NASA Astrophysics Data System (ADS)

    Roback, Vincent E.; Amzajerdian, Farzin; Bulyshev, Alexander E.; Brewster, Paul F.; Barnes, Bruce W.

    2016-05-01

    For the first time, a 3-D imaging Flash Lidar instrument has been used in flight to scan a lunar-like hazard field, build a 3-D Digital Elevation Map (DEM), identify a safe landing site, and, in concert with an experimental Guidance, Navigation, and Control system, help to guide the Morpheus autonomous, rocket-propelled, free-flying lander to that safe site on the hazard field. The flight tests served as the TRL 6 demo of the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) system and included launch from NASA-Kennedy, a lunar-like descent trajectory from an altitude of 250m, and landing on a lunar-like hazard field of rocks, craters, hazardous slopes, and safe sites 400m down-range. The ALHAT project developed a system capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar is a second generation, compact, real-time, air-cooled instrument. Based upon extensive on-ground characterization at flight ranges, the Flash Lidar was shown to be capable of imaging hazards from a slant range of 1 km with an 8 cm range precision and a range accuracy better than 35 cm, both at 1-σ. The Flash Lidar identified landing hazards as small as 30 cm from the maximum slant range which Morpheus could achieve (450 m); however, under certain wind conditions it was susceptible to scintillation arising from air heated by the rocket engine and to pre-triggering on a dust cloud created during launch and transported down-range by wind.

  15. 3-D Flash Lidar Performance in Flight Testing on the Morpheus Autonomous, Rocket-Propelled Lander to a Lunar-Like Hazard Field

    NASA Technical Reports Server (NTRS)

    Roback, Vincent E.; Amzajerdian, Farzin; Bulyshev, Alexander E.; Brewster, Paul F.; Barnes, Bruce W.

    2016-01-01

    For the first time, a 3-D imaging Flash Lidar instrument has been used in flight to scan a lunar-like hazard field, build a 3-D Digital Elevation Map (DEM), identify a safe landing site, and, in concert with an experimental Guidance, Navigation, and Control (GN&C) system, help to guide the Morpheus autonomous, rocket-propelled, free-flying lander to that safe site on the hazard field. The flight tests served as the TRL 6 demo of the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) system and included launch from NASA-Kennedy, a lunar-like descent trajectory from an altitude of 250m, and landing on a lunar-like hazard field of rocks, craters, hazardous slopes, and safe sites 400m down-range. The ALHAT project developed a system capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar is a second generation, compact, real-time, air-cooled instrument. Based upon extensive on-ground characterization at flight ranges, the Flash Lidar was shown to be capable of imaging hazards from a slant range of 1 km with an 8 cm range precision and a range accuracy better than 35 cm, both at 1-delta. The Flash Lidar identified landing hazards as small as 30 cm from the maximum slant range which Morpheus could achieve (450 m); however, under certain wind conditions it was susceptible to scintillation arising from air heated by the rocket engine and to pre-triggering on a dust cloud created during launch and transported down-range by wind.

  16. 3D galaxy clustering with future wide-field surveys: Advantages of a spherical Fourier-Bessel analysis

    NASA Astrophysics Data System (ADS)

    Lanusse, F.; Rassat, A.; Starck, J.-L.

    2015-06-01

    Context. Upcoming spectroscopic galaxy surveys are extremely promising to help in addressing the major challenges of cosmology, in particular in understanding the nature of the dark universe. The strength of these surveys, naturally described in spherical geometry, comes from their unprecedented depth and width, but an optimal extraction of their three-dimensional information is of utmost importance to best constrain the properties of the dark universe. Aims: Although there is theoretical motivation and novel tools to explore these surveys using the 3D spherical Fourier-Bessel (SFB) power spectrum of galaxy number counts Cℓ(k,k'), most survey optimisations and forecasts are based on the tomographic spherical harmonics power spectrum C(ij)_ℓ. The goal of this paper is to perform a new investigation of the information that can be extracted from these two analyses in the context of planned stage IV wide-field galaxy surveys. Methods: We compared tomographic and 3D SFB techniques by comparing the forecast cosmological parameter constraints obtained from a Fisher analysis. The comparison was made possible by careful and coherent treatment of non-linear scales in the two analyses, which makes this study the first to compare 3D SFB and tomographic constraints on an equal footing. Nuisance parameters related to a scale- and redshift-dependent galaxy bias were also included in the computation of the 3D SFB and tomographic power spectra for the first time. Results: Tomographic and 3D SFB methods can recover similar constraints in the absence of systematics. This requires choosing an optimal number of redshift bins for the tomographic analysis, which we computed to be N = 26 for zmed ≃ 0.4, N = 30 for zmed ≃ 1.0, and N = 42 for zmed ≃ 1.7. When marginalising over nuisance parameters related to the galaxy bias, the forecast 3D SFB constraints are less affected by this source of systematics than the tomographic constraints. In addition, the rate of increase of the

  17. Tangible 3D printouts of scientific data volumes with FOSS - an emerging field for research

    NASA Astrophysics Data System (ADS)

    Löwe, Peter; Klump, Jens; Wickert, Jens; Ludwig, Marcel; Frigeri, Alessandro

    2013-04-01

    Humans are very good in using both hands and eyes for tactile pattern recognition: The german verb for understanding, "begreifen" literally means "getting a (tactile) grip on a matter". This proven and time honoured concept has been in use since prehistoric times. While the amount of scientific data continues to grow, researchers still need all the support to help them visualize the data content before their inner eye. Immersive data-visualisations are helpful, yet fail to provide tactile feedback as provided from tangible objects. The need for tangible representations of geospatial information to solve real world problems eventually led to the advent of 3d-globes by M. Behaim in the 15th century and has continued since. The production of a tangible representation of a scientific data set with some fidelity is just the final step of an arc, leading from the physical world into scientific reasoning and back: The process starts with a physical observation, or a model, by a sensor which produces a data stream which is turned into a geo-referenced data set. This data is turned into a volume representation which is converted into command sequences for the printing device, leading to the creation of a 3d-printout. Finally, the new specimen has to be linked to its metadata to ensure its scientific meaning and context. On the technical side, the production of a tangible data-print has been realized as a pilot workflow based on the Free and Open Source Geoinformatics tools GRASS GIS and Paraview to convert scientific data volume into stereolithography datasets (stl) for printing on a RepRap printer. The initial motivation to use tangible representations of complex data was the task of quality assessments on tsunami simulation data sets in the FP7 TRIDEC project (www.tridec-online.eu). For this, 3d-prints of space time cubes of tsunami wave spreading patterns were produced. This was followed by print-outs of volume data derived from radar sounders (MARSIS, SHARAD) imaging

  18. Observation of toroidal variation of density gradients and turbulence in DIII-D with 3D fields during ELM suppression

    NASA Astrophysics Data System (ADS)

    Wilcox, R. S.; Schafer, M. W.; Canik, J. M.; Unterberg, E. A.; Wingen, A.; Ferraro, N. M.; McKee, G. R.; Zeng, L.; Rhodes, T. L.

    2016-10-01

    Significant 3D variation in broadband density fluctuations is observed using beam emission spectroscopy and Doppler backscattering near the boundary of weakly 3D plasmas in DIII-D when non-axisymmetric fields are applied to suppress ELMs. The increase in fluctuations is concomitant with an increase in the density gradient measured using profile reflectometry, suggesting that this toroidally localized density gradient could be a mechanism for turbulence destabilization in localized flux tubes. Although changes to magnetic surface topology are shown to be too small to affect turbulence stability directly, two-fluid M3D-C1 simulations find that there is a significant 3D variation of density within flux surfaces in the pedestal. These modeled local density changes modify the local pressure- and density- gradient scale lengths, and measured turbulence is shown to increase on flux tubes with larger gradients. Work supported by the US DOE under contracts DE-AC05-00OR22725, DE-AC02-09CH11466, DE-FG02-08ER54999 and DE-FG02-08ER54984.

  19. Label-free subcellular 3D live imaging of preimplantation mouse embryos with full-field optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Zheng, Jing-gao; Lu, Danyu; Chen, Tianyuan; Wang, Chengming; Tian, Ning; Zhao, Fengying; Huo, Tiancheng; Zhang, Ning; Chen, Dieyan; Ma, Wanyun; Sun, Jia-lin; Xue, Ping

    2012-07-01

    Early patterning and polarity is of fundamental interest in preimplantation embryonic development. Label-free subcellular 3D live imaging is very helpful to its related studies. We have developed a novel system of full-field optical coherence tomography (FF-OCT) for noninvasive 3D subcellular live imaging of preimplantation mouse embryos with no need of dye labeling. 3D digitized embryos can be obtained by image processing. Label-free 3D live imaging is demonstrated for the mouse embryos at various typical preimplantation stages with a spatial resolution of 0.7 μm and imaging rate of 24 fps. Factors that relate to early patterning and polarity, such as pronuclei in zygote, shapes of zona pellucida, location of second polar body, cleavage planes, and the blastocyst axis, can be quantitatively measured. The angle between the two second cleavage planes is accurately measured to be 87 deg. It is shown that FF-OCT provides a potential breakthrough for early patterning, polarity formation, and many other preimplantation-related studies in mammalian developmental biology.

  20. Super-resolved 3-D imaging of live cells' organelles from bright-field photon transmission micrographs.

    PubMed

    Rychtáriková, Renata; Náhlík, Tomáš; Shi, Kevin; Malakhova, Daria; Macháček, Petr; Smaha, Rebecca; Urban, Jan; Štys, Dalibor

    2017-03-18

    Current biological and medical research is aimed at obtaining a detailed spatiotemporal map of a live cell's interior to describe and predict cell's physiological state. We present here an algorithm for complete 3-D modelling of cellular structures from a z-stack of images obtained using label-free wide-field bright-field light-transmitted microscopy. The method visualizes 3-D objects with a volume equivalent to the area of a camera pixel multiplied by the z-height. The computation is based on finding pixels of unchanged intensities between two consecutive images of an object spread function. These pixels represent strongly light-diffracting, light-absorbing, or light-emitting objects. To accomplish this, variables derived from Rényi entropy are used to suppress camera noise. Using this algorithm, the detection limit of objects is only limited by the technical specifications of the microscope setup-we achieve the detection of objects of the size of one camera pixel. This method allows us to obtain 3-D reconstructions of cells from bright-field microscopy images that are comparable in quality to those from electron microscopy images.

  1. Langley Field wind tunnel apparatus

    NASA Technical Reports Server (NTRS)

    Bacon, D L

    1921-01-01

    The difficulties experienced in properly holding thin tipped or tapered airfoils while testing on an N.P.L. type aerodynamic balance even at low air speeds, and the impossibility of holding even solid metal models at the high speeds attainable at the National Advisory Committee's wind tunnel, necessitated the design of a balance which would hold model airfoils of any thickness and at speeds up to 150 m.p.h. In addition to mechanical strength and rigidity, it was highly desirable that the balance readings should require a minimum amount of correction and mathematical manipulation in order to obtain the lift and drag coefficients and the center of pressure. The balance described herein is similar to one in use at the University of Gottingen, the main difference lying in the addition of a device for reading the center of pressure directly, without the necessity of any correction whatsoever. Details of the design and operation of the device are given.

  2. 3D model of small-scale density cavities in the auroral magnetosphere with field-aligned current

    NASA Astrophysics Data System (ADS)

    Bespalov, P. A.; Misonova, V. G.; Savina, O. N.

    2016-09-01

    We propose a 3D model of small-scale density cavities stimulated by an auroral field-aligned current and an oscillating field-aligned current of kinetic Alfvén waves. It is shown that when the field-aligned current increases so that the electron drift velocity exceeds a value of the order of the electron thermal velocity, the plasma becomes unstable to the formation of cavities with low density and strong electric field. The condition of instability is associated with the value of the background magnetic field. In the case of a relatively weak magnetic field (where the electron gyro-radius is greater than the ion acoustic wavelength), the current instability can lead to the formation of one-dimensional cavities along the magnetic field. In the case of a stronger magnetic field (where the ion acoustic wavelength is greater than the electron gyro-radius, but still is less than the ion gyro-radius), the instability can lead to the formation of 3D density cavities. In this case, the spatial scales of the cavity, both along and across the background magnetic field, can be comparable, and at the earlier stage of the cavity formation they are of the order of the ion acoustic wavelength. Rarefactions of the cavity density are accompanied by an increase in the electric field and are limited by the pressure of bipolar electric fields that occur within them. The estimates of typical density cavity characteristics and the results of numerical solutions agree with known experimental data: small-scale structures with a sufficiently strong electric field are observed in the auroral regions with strong field-aligned current.

  3. Lessons in modern digital field geology: Open source software, 3D techniques, and the new world of digital mapping

    NASA Astrophysics Data System (ADS)

    Pavlis, Terry; Hurtado, Jose; Langford, Richard; Serpa, Laura

    2014-05-01

    Although many geologists refuse to admit it, it is time to put paper-based geologic mapping into the historical archives and move to the full potential of digital mapping techniques. For our group, flat map digital geologic mapping is now a routine operation in both research and instruction. Several software options are available, and basic proficiency with the software can be learned in a few hours of instruction and practice. The first practical field GIS software, ArcPad, remains a viable, stable option on Windows-based systems. However, the vendor seems to be moving away from ArcPad in favor of mobile software solutions that are difficult to implement without GIS specialists. Thus, we have pursued a second software option based on the open source program QGIS. Our QGIS system uses the same shapefile-centric data structure as our ArcPad system, including similar pop-up data entry forms and generic graphics for easy data management in the field. The advantage of QGIS is that the same software runs on virtually all common platforms except iOS, although the Android version remains unstable as of this writing. A third software option we are experimenting with for flat map-based field work is Fieldmove, a derivative of the 3D-capable program Move developed by Midland Valley. Our initial experiments with Fieldmove are positive, particularly with the new, inexpensive (<300Euros) Windows tablets. However, the lack of flexibility in data structure makes for cumbersome workflows when trying to interface our existing shapefile-centric data structures to Move. Nonetheless, in spring 2014 we will experiment with full-3D immersion in the field using the full Move software package in combination with ground based LiDAR and photogrammetry. One new workflow suggested by our initial experiments is that field geologists should consider using photogrammetry software to capture 3D visualizations of key outcrops. This process is now straightforward in several software packages, and

  4. A genetic algorithm particle pairing technique for 3D velocity field extraction in holographic particle image velocimetry

    NASA Astrophysics Data System (ADS)

    Sheng, J.; Meng, H.

    This research explores a novel technique, using Genetic Algorithm Particle Pairing (GAPP) to extract three-dimensional (3D) velocity fields of complex flows. It is motivated by Holographic Particle Image Velocimetry (HPIV), in which intrinsic speckle noise hinders the achievement of high particle density required for conventional correlation methods in extracting 3D velocity fields, especially in regions with large velocity gradients. The GA particle pairing method maps particles recorded at the first exposure to those at the second exposure in a 3D space, providing one velocity vector for each particle pair instead of seeking statistical averaging. Hence, particle pairing can work with sparse seeding and complex 3D velocity fields. When dealing with a large number of particles from two instants, however, the accuracy of pairing results and processing speed become major concerns. Using GA's capability to search a large solution space parallelly, our algorithm can efficiently find the best mapping scenarios among a large number of possible particle pairing schemes. During GA iterations, different pairing schemes or solutions are evaluated based on fluid dynamics. Two types of evaluation functions are proposed, tested, and embedded into the GA procedures. Hence, our Genetic Algorithm Particle Pairing (GAPP) technique is characterized by robustness in velocity calculation, high spatial resolution, good parallelism in handling large data sets, and high processing speed on parallel architectures. It has been successfully tested on a simple HPIV measurement of a real trapped vortex flow as well as a series of numerical experiments. In this paper, we introduce the principle of GAPP, analyze its performance under different parameters, and evaluate its processing speed on different computer architectures.

  5. Automated bone segmentation from large field of view 3D MR images of the hip joint

    NASA Astrophysics Data System (ADS)

    Xia, Ying; Fripp, Jurgen; Chandra, Shekhar S.; Schwarz, Raphael; Engstrom, Craig; Crozier, Stuart

    2013-10-01

    Accurate bone segmentation in the hip joint region from magnetic resonance (MR) images can provide quantitative data for examining pathoanatomical conditions such as femoroacetabular impingement through to varying stages of osteoarthritis to monitor bone and associated cartilage morphometry. We evaluate two state-of-the-art methods (multi-atlas and active shape model (ASM) approaches) on bilateral MR images for automatic 3D bone segmentation in the hip region (proximal femur and innominate bone). Bilateral MR images of the hip joints were acquired at 3T from 30 volunteers. Image sequences included water-excitation dual echo stead state (FOV 38.6 × 24.1 cm, matrix 576 × 360, thickness 0.61 mm) in all subjects and multi-echo data image combination (FOV 37.6 × 23.5 cm, matrix 576 × 360, thickness 0.70 mm) for a subset of eight subjects. Following manual segmentation of femoral (head-neck, proximal-shaft) and innominate (ilium+ischium+pubis) bone, automated bone segmentation proceeded via two approaches: (1) multi-atlas segmentation incorporating non-rigid registration and (2) an advanced ASM-based scheme. Mean inter- and intra-rater reliability Dice's similarity coefficients (DSC) for manual segmentation of femoral and innominate bone were (0.970, 0.963) and (0.971, 0.965). Compared with manual data, mean DSC values for femoral and innominate bone volumes using automated multi-atlas and ASM-based methods were (0.950, 0.922) and (0.946, 0.917), respectively. Both approaches delivered accurate (high DSC values) segmentation results; notably, ASM data were generated in substantially less computational time (12 min versus 10 h). Both automated algorithms provided accurate 3D bone volumetric descriptions for MR-based measures in the hip region. The highly computational efficient ASM-based approach is more likely suitable for future clinical applications such as extracting bone-cartilage interfaces for potential cartilage segmentation.

  6. Quantification of gully volume using very high resolution DSM generated through 3D reconstruction from airborne and field digital imagery

    NASA Astrophysics Data System (ADS)

    Castillo, Carlos; Zarco-Tejada, Pablo; Laredo, Mario; Gómez, Jose Alfonso

    2013-04-01

    Major advances have been made recently in automatic 3D photo-reconstruction techniques using uncalibrated and non-metric cameras (James and Robson, 2012). However, its application on soil conservation studies and landscape feature identification is currently at the outset. The aim of this work is to compare the performance of a remote sensing technique using a digital camera mounted on an airborne platform, with 3D photo-reconstruction, a method already validated for gully erosion assessment purposes (Castillo et al., 2012). A field survey was conducted in November 2012 in a 250 m-long gully located in field crops on a Vertisol in Cordoba (Spain). The airborne campaign was conducted with a 4000x3000 digital camera installed onboard an aircraft flying at 300 m above ground level to acquire 6 cm resolution imagery. A total of 990 images were acquired over the area ensuring a large overlap in the across- and along-track direction of the aircraft. An ortho-mosaic and the digital surface model (DSM) were obtained through automatic aerial triangulation and camera calibration methods. For the field-level photo-reconstruction technique, the gully was divided in several reaches to allow appropriate reconstruction (about 150 pictures taken per reach) and, finally, the resulting point clouds were merged into a unique mesh. A centimetric-accuracy GPS provided a benchmark dataset for gully perimeter and distinguishable reference points in order to allow the assessment of measurement errors of the airborne technique and the georeferenciation of the photo-reconstruction 3D model. The uncertainty on the gully limits definition was explicitly addressed by comparison of several criteria obtained by 3D models (slope and second derivative) with the outer perimeter obtained by the GPS operator identifying visually the change in slope at the top of the gully walls. In this study we discussed the magnitude of planimetric and altimetric errors and the differences observed between the

  7. Reproducing electric field observations during magnetic storms by means of rigorous 3-D modelling and distortion matrix co-estimation

    NASA Astrophysics Data System (ADS)

    Püthe, Christoph; Manoj, Chandrasekharan; Kuvshinov, Alexey

    2014-12-01

    Electric fields induced in the conducting Earth by geomagnetic disturbances drive currents in power transmission grids, telecommunication lines or buried pipelines, which can cause service disruptions. A key step in the prediction of the hazard to technological systems during magnetic storms is the calculation of the geoelectric field. To address this issue for mid-latitude regions, we revisit a method that involves 3-D modelling of induction processes in a heterogeneous Earth and the construction of a magnetospheric source model described by low-degree spherical harmonics from observatory magnetic data. The actual electric field, however, is known to be perturbed by galvanic effects, arising from very local near-surface heterogeneities or topography, which cannot be included in the model. Galvanic effects are commonly accounted for with a real-valued time-independent distortion matrix, which linearly relates measured and modelled electric fields. Using data of six magnetic storms that occurred between 2000 and 2003, we estimate distortion matrices for observatory sites onshore and on the ocean bottom. Reliable estimates are obtained, and the modellings are found to explain up to 90% of the measurements. We further find that 3-D modelling is crucial for a correct separation of galvanic and inductive effects and a precise prediction of the shape of electric field time series during magnetic storms. Since the method relies on precomputed responses of a 3-D Earth to geomagnetic disturbances, which can be recycled for each storm, the required computational resources are negligible. Our approach is thus suitable for real-time prediction of geomagnetically induced currents by combining it with reliable forecasts of the source field.

  8. Tomographic reconstruction of circularly polarized high-harmonic fields: 3D attosecond metrology.

    PubMed

    Chen, Cong; Tao, Zhensheng; Hernández-García, Carlos; Matyba, Piotr; Carr, Adra; Knut, Ronny; Kfir, Ofer; Zusin, Dimitry; Gentry, Christian; Grychtol, Patrik; Cohen, Oren; Plaja, Luis; Becker, Andreas; Jaron-Becker, Agnieszka; Kapteyn, Henry; Murnane, Margaret

    2016-02-01

    Bright, circularly polarized, extreme ultraviolet (EUV) and soft x-ray high-harmonic beams can now be produced using counter-rotating circularly polarized driving laser fields. Although the resulting circularly polarized harmonics consist of relatively simple pairs of peaks in the spectral domain, in the time domain, the field is predicted to emerge as a complex series of rotating linearly polarized bursts, varying rapidly in amplitude, frequency, and polarization. We extend attosecond metrology techniques to circularly polarized light by simultaneously irradiating a copper surface with circularly polarized high-harmonic and linearly polarized infrared laser fields. The resulting temporal modulation of the photoelectron spectra carries essential phase information about the EUV field. Utilizing the polarization selectivity of the solid surface and by rotating the circularly polarized EUV field in space, we fully retrieve the amplitude and phase of the circularly polarized harmonics, allowing us to reconstruct one of the most complex coherent light fields produced to date.

  9. Tomographic reconstruction of circularly polarized high-harmonic fields: 3D attosecond metrology

    PubMed Central

    Chen, Cong; Tao, Zhensheng; Hernández-García, Carlos; Matyba, Piotr; Carr, Adra; Knut, Ronny; Kfir, Ofer; Zusin, Dimitry; Gentry, Christian; Grychtol, Patrik; Cohen, Oren; Plaja, Luis; Becker, Andreas; Jaron-Becker, Agnieszka; Kapteyn, Henry; Murnane, Margaret

    2016-01-01

    Bright, circularly polarized, extreme ultraviolet (EUV) and soft x-ray high-harmonic beams can now be produced using counter-rotating circularly polarized driving laser fields. Although the resulting circularly polarized harmonics consist of relatively simple pairs of peaks in the spectral domain, in the time domain, the field is predicted to emerge as a complex series of rotating linearly polarized bursts, varying rapidly in amplitude, frequency, and polarization. We extend attosecond metrology techniques to circularly polarized light by simultaneously irradiating a copper surface with circularly polarized high-harmonic and linearly polarized infrared laser fields. The resulting temporal modulation of the photoelectron spectra carries essential phase information about the EUV field. Utilizing the polarization selectivity of the solid surface and by rotating the circularly polarized EUV field in space, we fully retrieve the amplitude and phase of the circularly polarized harmonics, allowing us to reconstruct one of the most complex coherent light fields produced to date. PMID:26989782

  10. Can symmetry transitions of complex fields enable 3-d control of fluid vorticity?

    SciTech Connect

    Martin, James E.; Solis, Kyle Jameson

    2015-08-01

    Methods of inducing vigorous noncontact fluid flow are important to technologies involving heat and mass transfer and fluid mixing, since they eliminate the need for moving parts, pipes and seals, all of which compromise system reliability. Unfortunately, traditional noncontact flow methods are few, and have limitations of their own. We have discovered two classes of fields that can induce fluid vorticity without requiring either gravity or a thermal gradient. The first class we call Symmetry-Breaking Rational Fields. These are triaxial fields comprised of three orthogonal components, two ac and one dc. The second class is Rational Triad Fields, which differ in that all three components are alternating. In this report we quantify the induced vorticity for a wide variety of fields and consider symmetry transitions between these field types. These transitions give rise to orbiting vorticity vectors, a technology for non-contact, non-stationary fluid mixing.

  11. Finite Element Treatment of Vortex States in 3D Cubic Superconductors in a Tilted Magnetic Field

    NASA Astrophysics Data System (ADS)

    Peng, Lin; Cai, Chuanbing

    2017-03-01

    The time-dependent Ginzburg-Landau equations have been solved numerically by a finite element analysis for superconducting samples with a cubic shape in a tilted magnetic field. We obtain different vortex patterns as a function of the external magnetic field. With a magnetic field not parallel to the x- or y-axis, the vortices attempt to change their orientation accordingly. Our analysis of the corresponding changes in the magnetic response in different directions can provide information not only about vorticity but also about the three-dimensional vortex arrangement, even about the very subtle changes for the superconducting samples with a cubic shape in a tilted magnetic field.

  12. Correlations of Surface Deformation and 3D Flow Field in a Compliant Wall Turbulent Channel Flow.

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Zhang, Cao; Katz, Joseph

    2015-11-01

    This study focuses on the correlations between surface deformation and flow features, including velocity, vorticity and pressure, in a turbulent channel flow over a flat, compliant Polydimethylsiloxane (PDMS) wall. The channel centerline velocity is 2.5 m/s, and the friction Reynolds number is 2.3x103. Analysis is based on simultaneous measurements of the time resolved 3D velocity and surface deformation using tomographic PIV and Mach-Zehnder Interferometry. The volumetric pressure distribution is calculated plane by plane by spatially integrating the material acceleration using virtual boundary, omni-directional method. Conditional sampling based on local high/low pressure and deformation events reveals the primary flow structures causing the deformation. High pressure peaks appear at the interface between sweep and ejection, whereas the negative deformations peaks (dent) appear upstream, under the sweeps. The persistent phase lag between flow and deformations are presumably caused by internal damping within the PDMS. Some of the low pressure peaks and strong ejections are located under the head of hairpin vortices, and accordingly, are associated with positive deformation (bump). Others bumps and dents are correlated with some spanwise offset large inclined quasi-streamwise vortices that are not necessarily associated with hairpins. Sponsored by ONR.

  13. Assessing soil water storage distribution under sprinkler irrigation by coupling 3D simulations and field observations

    NASA Astrophysics Data System (ADS)

    Taha, Uday; Shabeeb, Ahmed; dragonetti, giovanna; Lamaddalena, Nicola; Coppola, Antonio

    2016-04-01

    This work analyzed the variability of sprinkler irrigation application over a bare soil, both in terms of water application efficiency and uniformity, by integrating and comparing the information on the irrigation depth data (ID), as measured by catch cans, soil water storage in the upper root zone, as measured by TDR probes, and a 3D simulations of water flow in soils. Three irrigation tests were performed at three different pressures (2, 3 and 4 bar). A lateral water redistribution was observed and simulated after each irrigation event by comparing spatial distributions of site-specific water application efficiency (AEs), as well as ratios of site-specific actual water storage increase (SWEs) and irrigation depth (IDs) to the water content before irrigation. Because of soil water redistribution processes, distribution uniformity based on soil storages was systematically higher than the catch can uniformity. The obvious consequence of lateral water redistribution processes was that the soil smoothing action on non-uniformity observed at the surface increased both with depth and over time. At a given depth the uniformity of soil water storages always attained the same value, whatever the pressure considered and the catch can-based uniformity coefficient. It was concluded that, for the case of random distribution of ID, the uniformity of water storages is driven by the soil behavior rather than by the irrigation system.

  14. Parallelized 3D CSEM modeling using edge-based finite element with total field formulation and unstructured mesh

    NASA Astrophysics Data System (ADS)

    Cai, Hongzhu; Hu, Xiangyun; Li, Jianhui; Endo, Masashi; Xiong, Bin

    2017-02-01

    We solve the 3D controlled-source electromagnetic (CSEM) problem using the edge-based finite element method. The modeling domain is discretized using unstructured tetrahedral mesh. We adopt the total field formulation for the quasi-static variant of Maxwell's equation and the computation cost to calculate the primary field can be saved. We adopt a new boundary condition which approximate the total field on the boundary by the primary field corresponding to the layered earth approximation of the complicated conductivity model. The primary field on the modeling boundary is calculated using fast Hankel transform. By using this new type of boundary condition, the computation cost can be reduced significantly and the modeling accuracy can be improved. We consider that the conductivity can be anisotropic. We solve the finite element system of equations using a parallelized multifrontal solver which works efficiently for multiple source and large scale electromagnetic modeling.

  15. Extending field life in offshore Gulf of Mexico using 3-D seismic survey

    SciTech Connect

    Bulling, T.P.; Olsen, R.S. )

    1990-05-01

    Discovered by ARCO in 1967, the High Island 24L field (lower Miocene) is located in the Texas state waters of the Gulf of Mexico. By 1986, the field had produced 320 billion ft{sup 3} of gas and 3.0 million bbl of oil. An engineering field study completed in 1986 showed the field was declining and would be unprofitable within 3 yr. Study of reservoir maps revealed three basin problems: volumetric reserve calculations were less than reserves produced, hydrocarbon-water contacts were inconsistent between wells thought to be in communication, and ultimate recoveries could not be accurately calculated. Attempts to remap the field with the existing two-dimensional seismic data base and well data proved unsuccessful. In 1986, a three-dimensional seismic survey was acquired in an effort to evaluate the true present worth and potential of the field. Remapping of 30 reservoir horizons began in 1987. The integration of detailed well log correlations tied to the dense grid of quality three dimensional seismic data improved the reservoir maps. These maps helped resolve engineering problems by defining the configuration of the reservoirs more accurately. Reservoir maps now closely match volumetrics, fluid contacts within reservoir units are consistent, and a better definition of extension well opportunities exists. The authors study resulted in six additional wells. These wells along with engineering modifications and operations cost containment resulted in the extension of the economic life of the High Island 24-L field by at least 8 yr.

  16. 3-D heterogeneous field data versus 2-D simulations. How can it be accomplished in a sedimentary porous formation?

    NASA Astrophysics Data System (ADS)

    Darvini, G.; Salandin, P.

    2009-12-01

    To analyze the impact of the hydraulic conductivity K spatial variability in a real field case (as an example to delimitate a well catchment), numerical simulations can be reasonably developed in a two-dimensional vertical average context. Nevertheless the plume evolution is a consequence of a more complex three-dimensional heterogeneous structure whose vertical variability dominates the dispersion phenomena at local scale. In larger domains, the effect of the vertical heterogeneity combines itself with that one due to the horizontal variability of K, and only when the plume has travelled a large number of (horizontal) integral scales, its evolution can be analyzed in a regional context, under the hypothesis that the transmissivity spatial distribution prevails. Until this limit is reached, the vertical and horizontal variability of K are combined to give a fully 3-D dispersion process. In all these situations, to successfully accomplish the 3-D heterogeneous structure of the aquifer in 2-D simulations, more than the planimetric depth-averaged variability of K must be accounted for. To define the uncertainty related to the use of different planimetric schematizations of the real hydraulic conductivity spatial distribution, we present here the results of some numerical experiments that compare the 3-D plume evolution with 2-D simulations developed by tacking into account different hydraulic conductivity distribution schematization, by considering a hierarchical architecture of media also. This description of a sedimentary formation combined with the finite size of the plume requires theoretical and numerical tools able to take into account the flow field inhomogeneity and the ergodicity lack that characterize the transport phenomena. Following this way it will be possible to quantify / reduce the uncertainty related to a 2-D schematization in a large number of real cases where the domain spans between the local and the regional scale and whose dimension may lead to

  17. Electric field-controlled directed migration of neural progenitor cells in 2D and 3D environments.

    PubMed

    Meng, Xiaoting; Li, Wenfei; Young, Fraser; Gao, Runchi; Chalmers, Laura; Zhao, Min; Song, Bing

    2012-02-16

    Endogenous electric fields (EFs) occur naturally in vivo and play a critical role during tissue/organ development and regeneration, including that of the central nervous system(1,2). These endogenous EFs are generated by cellular regulation of ionic transport combined with the electrical resistance of cells and tissues. It has been reported that applied EF treatment can promote functional repair of spinal cord injuries in animals and humans(3,4). In particular, EF-directed cell migration has been demonstrated in a wide variety of cell types(5,6), including neural progenitor cells (NPCs)(7,8). Application of direct current (DC) EFs is not a commonly available technique in most laboratories. We have described detailed protocols for the application of DC EFs to cell and tissue cultures previously(5,11). Here we present a video demonstration of standard methods based on a calculated field strength to set up 2D and 3D environments for NPCs, and to investigate cellular responses to EF stimulation in both single cell growth conditions in 2D, and the organotypic spinal cord slice in 3D. The spinal cordslice is an ideal recipient tissue for studying NPC ex vivo behaviours, post-transplantation, because the cytoarchitectonic tissue organization is well preserved within these cultures(9,10). Additionally, this ex vivo model also allows procedures that are not technically feasible to track cells in vivo using time-lapse recording at the single cell level. It is critically essential to evaluate cell behaviours in not only a 2D environment, but also in a 3D organotypic condition which mimicks the in vivo environment. This system will allow high-resolution imaging using cover glass-based dishes in tissue or organ culture with 3D tracking of single cell migration in vitro and ex vivo and can be an intermediate step before moving onto in vivo paradigms.

  18. The 3-D effects in the long-term solar wind speed rise observed by Voyager 2 in early 1994

    NASA Technical Reports Server (NTRS)

    Pizzo, V. J.; Paularena, K. I.; Richardson, J. D.; Lazarus, A. J.; Belcher, J. W.

    1995-01-01

    In early 1994, Voyager 2 at 42-43 AU near heliolatitude 10 deg S observed over a period of approximately 100 days a remarkable sequence of quasi-recurrent stream fronts, wherein the background (ambient) speed rose steadily from approximately 450 to approximately 550 km/s while the mean period of the streams decreased from the usual 25 days down to approximately 20 days. A qualitative explanation for this effect can be derived from IMP observations, which show that the amplitude of the stream structure at 1 AU increased monotonically in late 1993, concurrent with major secular evolution in the corona. The reduction in period, then, amounts to a doppler shift due to the progressive overtaking of successively faster streams in the sequence. Attempts to model this process quantitatively with 1-D dynamic simulations falter on three accounts: (1) the reduction in period is overestimated, (2) the simulation predicts many more fronts surviving to 43 AU than are observed by Voyager; (3) the density variations are much too large. It is argued that inclusion of the 3-D geometry in the simulation would resolve most all these shortcomings. Using a series of calculations executed with 1-D, 2-D, and 3-D MHD models of hypothetical tilted-dipole flows, we show that: (1) the radial propagation velocities of 3-D fronts are less than those of 1-D or 2-D fronts, owing to the tilt of (and increased shearing across) the interaction surfaces hence the overtaking rate of successive streams is reduced; (2) in a tilted-dipole geometry, the reverse fronts should largely disappear from the equatorial plane by 43 AU, effectively halving the number of fronts to be observed (see companion paper on predominance of forward fronts at Voyager); and (3) the density enhancements would be much smaller than predicted by a 1-D model.

  19. Wave Phase-Sensitive Transformation of 3d-Straining of Mechanical Fields

    NASA Astrophysics Data System (ADS)

    Smirnov, I. N.; Speranskiy, A. A.

    2015-11-01

    It is the area of research of oscillatory processes in elastic mechanical systems. Technical result of innovation is creation of spectral set of multidimensional images which reflect time-correlated three-dimensional vector parameters of metrological, and\\or estimated, and\\or design parameters of oscillations in mechanical systems. Reconstructed images of different dimensionality integrated in various combinations depending on their objective function can be used as homeostatic profile or cybernetic image of oscillatory processes in mechanical systems for an objective estimation of current operational conditions in real time. The innovation can be widely used to enhance the efficiency of monitoring and research of oscillation processes in mechanical systems (objects) in construction, mechanical engineering, acoustics, etc. Concept method of vector vibrometry based on application of vector 3D phase- sensitive vibro-transducers permits unique evaluation of real stressed-strained states of power aggregates and loaded constructions and opens fundamental innovation opportunities: conduct of continuous (on-line regime) reliable monitoring of turboagregates of electrical machines, compressor installations, bases, supports, pipe-lines and other objects subjected to damaging effect of vibrations; control of operational safety of technical systems at all the stages of life cycle including design, test production, tuning, testing, operational use, repairs and resource enlargement; creation of vibro-diagnostic systems of authentic non-destructive control of anisotropic characteristics of materials resistance of power aggregates and loaded constructions under outer effects and operational flaws. The described technology is revolutionary, universal and common for all branches of engineering industry and construction building objects.

  20. 3-D RPIC Simulations of Relativistic Jets: Particle Acceleration, Magnetic Field Generation, and Emission

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.; Mizuno, Y.; Hardee, P.; Hededal, C. B.; Fishman, G. J.

    2006-01-01

    Recent PIC simulations using injected relativistic electron-ion (electro-positron) jets into ambient plasmas show that acceleration occurs in relativistic shocks. The Weibel instability created in shocks is responsible for particle acceleration, and generation and amplification of highly inhomogeneous, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection in relativistic jets. The "jitter" radiation from deflected electrons has different properties than the synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understand the complex time evolution and spectral structure in relativistic jets and gamma-ray bursts. We will present recent PIC simulations which show particle acceleration and magnetic field generation. We will also calculate associated self-consistent emission from relativistic shocks.

  1. FLASHFLOOD: A 3D Field-based similarity search and alignment method for flexible molecules

    NASA Astrophysics Data System (ADS)

    Pitman, Michael C.; Huber, Wolfgang K.; Horn, Hans; Krämer, Andreas; Rice, Julia E.; Swope, William C.

    2001-07-01

    A three-dimensional field-based similarity search and alignment method for flexible molecules is introduced. The conformational space of a flexible molecule is represented in terms of fragments and torsional angles of allowed conformations. A user-definable property field is used to compute features of fragment pairs. Features are generalizations of CoMMA descriptors (Silverman, B.D. and Platt, D.E., J. Med. Chem., 39 (1996) 2129.) that characterize local regions of the property field by its local moments. The features are invariant under coordinate system transformations. Features taken from a query molecule are used to form alignments with fragment pairs in the database. An assembly algorithm is then used to merge the fragment pairs into full structures, aligned to the query. Key to the method is the use of a context adaptive descriptor scaling procedure as the basis for similarity. This allows the user to tune the weights of the various feature components based on examples relevant to the particular context under investigation. The property fields may range from simple, phenomenological fields, to fields derived from quantum mechanical calculations. We apply the method to the dihydrofolate/methotrexate benchmark system, and show that when one injects relevant contextual information into the descriptor scaling procedure, better results are obtained more efficiently. We also show how the method works and include computer times for a query from a database that represents approximately 23 million conformers of seventeen flexible molecules.

  2. The development of a 3-D laser velocimeter for the NASA Langley low turbulence pressure wind tunnel

    NASA Technical Reports Server (NTRS)

    Jones, Gregory S.; Adams, Wendell G.; Crespi, Pierre H.; Houser, Michael J.; Inenaga, Andrew S.

    1990-01-01

    The design of an orthogonal, three-dimensional laser velocimeter with in situ sizing (LVIS) system for a high-Reynolds-number facility, the NASA Langley low turbulence pressure wind tunnel (LTPT), is discussed. Special attention is paid to the laser velocimeter seeding subsystems, while all other subsystems are approached from the users standpoint. The evaluation of the LVIS system leads to the conclusion that seeding of large scale pressure wind tunnels remains a problem, while using the polydispersed seeding requires further investigation. A Cassegrain mirror receiver optics may be successfully implemented in lieu of similar lens systems. General agreement is observed between the mean velocity LVIS measurements as compared to conventional pitot and hot-wire data.

  3. Dynamical system of scalar field from 2-dimension to 3-D and its cosmological implications

    NASA Astrophysics Data System (ADS)

    Fang, Wei; Tu, Hong; Huang, Jiasheng; Shu, Chenggang

    2016-09-01

    We give the three-dimensional dynamical autonomous systems for most of the popular scalar field dark energy models including (phantom) quintessence, (phantom) tachyon, K-essence, and general non-canonical scalar field models, change the dynamical variables from variables (x, y, λ ) to observable related variables (w_{φ }, Ω _{φ }, λ ), and show the intimate relationships between those scalar fields that the three-dimensional system of K-essence can reduce to (phantom) tachyon, general non-canonical scalar field can reduce to (phantom) quintessence and K-essence can also reduce to (phantom) quintessence for some special cases. For the applications of the three-dimensional dynamical systems, we investigate several special cases and give the exactly dynamical solutions in detail. In the end of this paper, we argue that it is more convenient and also has more physical meaning to express the differential equations of dynamical systems in (w_{φ }, Ω _{φ }, λ ) instead of variables (x, y, λ ) and to investigate the dynamical system in three dimensions instead of two dimensions. We also raise a question about the possibility of the chaotic behavior in the spatially flat single scalar field FRW cosmological models in the presence of ordinary matter.

  4. Small-Field Measurements of 3D Polymer Gel Dosimeters through Optical Computed Tomography

    PubMed Central

    Shih, Cheng-Ting; Lee, Yao-Ting; Wu, Shin-Hua; Yao, Chun-Hsu; Hsieh, Bor-Tsung

    2016-01-01

    With advances in therapeutic instruments and techniques, three-dimensional dose delivery has been widely used in radiotherapy. The verification of dose distribution in a small field becomes critical because of the obvious dose gradient within the field. The study investigates the dose distributions of various field sizes by using NIPAM polymer gel dosimeter. The dosimeter consists of 5% gelatin, 5% monomers, 3% cross linkers, and 5 mM THPC. After irradiation, a 24 to 96 hour delay was applied, and the gel dosimeters were read by a cone beam optical computed tomography (optical CT) scanner. The dose distributions measured by the NIPAM gel dosimeter were compared to the outputs of the treatment planning system using gamma evaluation. For the criteria of 3%/3 mm, the pass rates for 5 × 5, 3 × 3, 2 × 2, 1 × 1, and 0.5 × 0.5 cm2 were as high as 91.7%, 90.7%, 88.2%, 74.8%, and 37.3%, respectively. For the criteria of 5%/5 mm, the gamma pass rates of the 5 × 5, 3 × 3, and 2 × 2 cm2 fields were over 99%. The NIPAM gel dosimeter provides high chemical stability. With cone-beam optical CT readouts, the NIPAM polymer gel dosimeter has potential for clinical dose verification of small-field irradiation. PMID:26974434

  5. 3D hybrid simulations of the plasma penetration across a magnetic field

    NASA Astrophysics Data System (ADS)

    Omelchenko, Yuri

    2016-10-01

    The expansion of hot dense plasmas across ambient magnetic fields in physical systems with spatial scales comparable to the ion gyro and inertial lengths is of great interest to space physics and fusion. This work presents results from recent three-dimensional hybrid simulations (kinetic ions, fluid electrons) of experiments at the LAPD and Nevada Terawatt Facility where short-pulse lasers are used to ablate solid targets to produce plasmas that expand across external magnetic fields. The first simulation recreates flutelike density striations observed at the leading edge of the carbon plasma and predicts an early destruction of the magnetic cavity in agreement with experimental evidence. In the second simulation the plasma contains protons and carbon ions produced during the ablation of a polyethylene target. A mechanism is demonstrated that allows protons to penetrate the magnetic field in the form of a collimated flow while the carbon ion component forms a supporting magnetic structure. The role of ion kinetic and Hall effects in creating an electric field responsible for plasma transport is discussed and results are compared to experimental data. The hybrid simulations are performed with a massively parallel hybrid code, HYPERS that advances fields and particles asynchronously on time scales determined by local physical and geometric properties. Supported by US DOE Award DE-SC0012345.

  6. The measurement of 3-D asymmetric temperature field by using real time laser interferometric tomography

    NASA Astrophysics Data System (ADS)

    Wang, Dezhong; Zhuang, Tiange

    2001-09-01

    A real time nondestructive temperature measurement technique based on laser holographic interference tomography technique is presented. An He-Ne laser is used as light source, and a CCD video camera is used to grab the interferogram. This laser holographic tomography technique is applied to the measurement of the temperature fields generated by two heated rods. Since data error is inevitable in engineering measurement, it is necessary to study the reconstruction techniques for reconstructing the temperature field. Three techniques including convolution back projection (CBP), algebra reconstruction technique (ART) and simultaneous iterative reconstruction technique (SIRT) are studied. Based on the reconstruction techniques and experimental situation, ART is used to reconstruct the asymmetric temperature fields. The thermocouples are used to measure the temperatures of the two heated rods. Comparing the reconstructed result with the measured temperature value, a satisfactory result is obtained.

  7. Light field otoscope design for 3D in vivo imaging of the middle ear

    PubMed Central

    Bedard, Noah; Shope, Timothy; Hoberman, Alejandro; Haralam, Mary Ann; Shaikh, Nader; Kovačević, Jelena; Balram, Nikhil; Tošić, Ivana

    2016-01-01

    We present a light field digital otoscope designed to measure three-dimensional shape of the tympanic membrane. This paper describes the optical and anatomical considerations we used to develop the prototype, along with the simulation and experimental measurements of vignetting, field curvature, and lateral resolution. Using an experimental evaluation procedure, we have determined depth accuracy and depth precision of our system to be 0.05–0.07 mm and 0.21–0.44 mm, respectively. To demonstrate the application of our light field otoscope, we present the first three-dimensional reconstructions of tympanic membranes in normal and otitis media conditions, acquired from children who participated in a feasibility study at the Children’s Hospital of Pittsburgh of the University of Pittsburgh Medical Center. PMID:28101416

  8. LDA measurement of the passage flow field in a 3-D airfoil cascade

    NASA Technical Reports Server (NTRS)

    Stauter, R. C.; Fleeter, S.

    1986-01-01

    Three-dimensional internal flow computational models are currently being developed to predict the flow through turbomachinery blade rows. For these codes to be of quantitative value, they must be verified with data obtained in experiments which model the fundamental flow phenomena. In this paper, the complete three-dimensional flow field through a subsonic annular cascade of cambered airfoils is experimentally quantified. In particular, detailed three-dimensional data are obtained to quantify the inlet velocity profile, the cascade passage velocity field, and the exit region flow field. The primary instrumentation for acquiring these data is a single-channel Laser Doppler Anemometer operating in the backscatter mode, with chordwise distributions of airfoil surface static pressure taps also utilized. Appropriate data are correlated with predictions from the MERIDL/TSONIC codes.

  9. Fabrication 3D buried channel optical waveguide modulators on field-driven ion exchange process

    NASA Astrophysics Data System (ADS)

    Zhou, Zigang; Chen, Wenqiang; Zhu, Li; Li, Jing; Luo, Xiaoying

    2010-10-01

    A high electric field technique was developed to fabricate buried optical waveguide modulator on K9 optical glass. The 80V voltage was applied on the glass to accelerate the field-driven ion exchange process by expeditiously replacing host sodium ions in the glass with silver ions. As a result, the optical loss for optical waveguide modulator was measured using the edge coupling technique with a 0.6328μm He-Ne laser. Loss of 0.20 dB/cm was obtained for channel waveguides of 25μm in depth, relatively low for waveguides of such depth at red wavelength.

  10. 3D modeling of the total electric field induced by transcranial magnetic stimulation using the boundary element method

    NASA Astrophysics Data System (ADS)

    Salinas, F. S.; Lancaster, J. L.; Fox, P. T.

    2009-06-01

    Transcranial magnetic stimulation (TMS) delivers highly localized brain stimulations via non-invasive externally applied magnetic fields. This non-invasive, painless technique provides researchers and clinicians with a unique tool capable of stimulating both the central and peripheral nervous systems. However, a complete analysis of the macroscopic electric fields produced by TMS has not yet been performed. In this paper, we addressed the importance of the secondary E-field created by surface charge accumulation during TMS using the boundary element method (BEM). 3D models were developed using simple head geometries in order to test the model and compare it with measured values. The effects of tissue geometry, size and conductivity were also investigated. Finally, a realistically shaped head model was used to assess the effect of multiple surfaces on the total E-field. Secondary E-fields have the greatest impact at areas in close proximity to each tissue layer. Throughout the head, the secondary E-field magnitudes typically range from 20% to 35% of the primary E-field's magnitude. The direction of the secondary E-field was generally in opposition to the primary E-field; however, for some locations, this was not the case (i.e. going from high to low conductivity tissues). These findings show that realistically shaped head geometries are important for accurate modeling of the total E-field.

  11. Optical measurement of the dynamic strain field of a fan blade using a 3D scanning vibrometer

    NASA Astrophysics Data System (ADS)

    Vuye, C.; Vanlanduit, S.; Presezniak, F.; Steenackers, G.; Guillaume, P.

    2011-07-01

    Understanding the origin of the stress and strain distribution is crucial to increase the durability of components under dynamic loading. Numerical simulations based on finite element (FE) models help with this understanding but must be validated by real measured data. Updating the FE model using the measured data is often the next step in the design process. In this paper the recently developed 3D-scanning laser doppler vibrometer (3D-SLDV) is used to measure the 3D-displacement of a fan blade, which is then used to calculate the dynamic strain distributions. The measurement principle and experimental setup are discussed thoroughly. The experimental results are validated by using a FE model on the one hand and strain gage measurements on the other. It is shown that this technique is capable of measuring normal strain far below 1 microstrain. This technique has the potential to fill in the gap of accurately measuring small (full-field) normal and shear strains at both low and high frequencies, where other optical techniques (and strain gages) would certainly fail.

  12. Resolving the 3D velocity field inside a Roughness Sublayer in a turbulent channel flow using HPIV

    NASA Astrophysics Data System (ADS)

    Talapatra, Siddharth; Katz, Joseph

    2010-11-01

    Microscopic holographic PIV is used to measure the 3D velocity field within the roughness sublayer of a turbulent channel flow at Reτ of 3400. Recording holograms through a rough surface is facilitated by matching the optical refractive index of the rough wall with that of the working fluid, a concentrated solution of NaI in water. The pyramidal roughness height is k=0.45mm, the sample volume size is 3.2x1.8x1.8mm^3, the long dimension being in the streamwise direction, and the wall-normal range is -0.333D grid to obtain vectors with a spacing of 60μm or 8.5 wall units. The data show that at y/k<0.5, there is a preferred channeling of the flow along paths that circumvent the pyramid crest lines. Planar vorticity distribution from different perspectives as well as 3D isosurfaces show that the near wall region is flooded by quasi-streamwise vortices that are aligned at shallow angles and have a typical streamwise extent of 1-2k.

  13. New Method for the Characterization of 3D Preferential Flow Paths at the Field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preferential flow paths development in the field is the result of the complex interaction of multiple processes relating to the soil's structure, moisture condition, stress level, and biological activities. Visualizing and characterizing the cracking behavior and preferential paths evolution with so...

  14. Web-based Visualization and Query of semantically segmented multiresolution 3D Models in the Field of Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Auer, M.; Agugiaro, G.; Billen, N.; Loos, L.; Zipf, A.

    2014-05-01

    Many important Cultural Heritage sites have been studied over long periods of time by different means of technical equipment, methods and intentions by different researchers. This has led to huge amounts of heterogeneous "traditional" datasets and formats. The rising popularity of 3D models in the field of Cultural Heritage in recent years has brought additional data formats and makes it even more necessary to find solutions to manage, publish and study these data in an integrated way. The MayaArch3D project aims to realize such an integrative approach by establishing a web-based research platform bringing spatial and non-spatial databases together and providing visualization and analysis tools. Especially the 3D components of the platform use hierarchical segmentation concepts to structure the data and to perform queries on semantic entities. This paper presents a database schema to organize not only segmented models but also different Levels-of-Details and other representations of the same entity. It is further implemented in a spatial database which allows the storing of georeferenced 3D data. This enables organization and queries by semantic, geometric and spatial properties. As service for the delivery of the segmented models a standardization candidate of the OpenGeospatialConsortium (OGC), the Web3DService (W3DS) has been extended to cope with the new database schema and deliver a web friendly format for WebGL rendering. Finally a generic user interface is presented which uses the segments as navigation metaphor to browse and query the semantic segmentation levels and retrieve information from an external database of the German Archaeological Institute (DAI).

  15. A 3D model of crustal magnetization at the Pinacate Volcanic Field, NW Sonora, Mexico

    NASA Astrophysics Data System (ADS)

    García-Abdeslem, Juan; Calmus, Thierry

    2015-08-01

    The Pinacate Volcanic Field (PVF) is located near the western border of the southern Basin and Range province, in the State of Sonora NW Mexico, and within the Gulf of California Extensional Province. This volcanic field contains the shield volcano Santa Clara, which mainly consists of basaltic to trachytic volcanic rocks, and reaches an altitude of 1200 m. The PVF disrupts a series of discontinuous ranges of low topographic relief aligned in a NW direction, which consist mainly of Proterozoic metamorphic rocks and Proterozoic through Paleogene granitoids. The PVF covers an area of approximately 60 by 55 km, and includes more than 400 well-preserved cinder cones and vents and eight maar craters. It was active from about 1.7 Ma until about 13 ka. We have used the ages and magnetic polarities of the volcanic rocks, along with mapped magnetic anomalies and their inverse modeling to determine that the Pinacate Volcanic Field was formed during two volcanic episodes. The oldest one built the Santa Clara shield volcano of basaltic and trachytic composition, and occurred during the geomagnetic Matuyama Chron of reverse polarity, which also includes the normal polarity Jaramillo and Olduvai Subchrons, thus imprinting both normal and reverse magnetization in the volcanic products. The younger Pinacate series of basaltic composition represents monogenetic volcanic activity that extends all around the PVF and occurred during the subsequent geomagnetic Brunhes Chron of normal polarity. Magnetic anomalies toward the north of the Santa Clara volcano are the most intense in the PVF, and their inverse modeling indicates the presence of a large subsurface body magnetized in the present direction of the geomagnetic field. This suggests that the magma chambers at depth cooled below the Curie temperature during the Brunhes Chron.

  16. A Full Field, 3-D Velocimeter for NASA's Microgravity Science Program

    NASA Technical Reports Server (NTRS)

    Meyer, Maryjo B.; Bethea, Mark D.

    1992-01-01

    One of NASA's new Advanced Technology Development projects is stereo imaging velocimetry. Using multiple CCD cameras, the velocimeter will digitize and store images of microscopic seed particles suspended in flowing transparent fluid systems. The data will be processed to obtain full-field, three-dimensional, quantitative velocity data. With successful evolution of the technology, the velocimeter will become part of NASA's flight hardware arsenal, available to both established experiments and new proposals.

  17. 3D Electron Spin Relaxation Control by Electric Field in Quantum Wells

    NASA Astrophysics Data System (ADS)

    Marie, Xavier

    2012-02-01

    We have measured the electron spin relaxation time in (111)-oriented GaAs quantum wells by time-resolved photoluminescence. By embedding the QWs in a PIN or NIP structure we demonstrate the tuning of the conduction band spin splitting and hence the spin relaxation time with an applied external electric field applied along the growth z direction . The application of an external electric field of 50 kV/cm yields a two-order of magnitude increase of the spin relaxation time which can reach values larger than 30 ns; this is a consequence of the electric field tuning of the spin-orbit conduction band splitting which can almost vanish when the Rashba term compensates exactly the Dresselhaus one [1]. The spin quantum beats measurements under transverse magnetic field prove that the D'Yakonov-Perel (DP) spin relaxation time is not only increased for the Sz electron spin component but also for both Sx and Sy. These results contrast drastically with the (001) and (110) quantum wells.The role of the cubic Dresselhaus terms on the spin relaxation anisotropy will finally be discussed. The tuning or suppression of the DP electron spin relaxation demonstrated here for GaAs/AlGaAs quantum wells grown on (111) substrates is also possible in many other III-V and II-VI zinc-blende nanostructures since the principle relies only on symmetry considerations. [4pt] [1] A. Balocchi, Q. H. Duong, P. Renucci, B. L. Liu, C. Fontaine, T. Amand, D. Lagarde, and X. Marie, Phys. Rev. Lett 107, 136604(2011)

  18. 3D magnetic field configuration of small-scale reconnection events in the solar plasma atmosphere

    NASA Astrophysics Data System (ADS)

    Shimizu, T.

    2015-10-01

    The outer solar atmosphere, i.e., the corona and the chromosphere, is replete with small energy-release events, which are accompanied by transient brightening and jet-like ejections. These events are considered to be magnetic reconnection events in the solar plasma, and their dynamics have been studied using recent advanced observations from the Hinode spacecraft and other observatories in space and on the ground. These events occur at different locations in the solar atmosphere and vary in their morphology and amount of the released energy. The magnetic field configurations of these reconnection events are inferred based on observations of magnetic fields at the photospheric level. Observations suggest that these magnetic configurations can be classified into two groups. In the first group, two anti-parallel magnetic fields reconnect to each other, yielding a 2D emerging flux configuration. In the second group, helical or twisted magnetic flux tubes are parallel or at a relative angle to each other. Reconnection can occur only between anti-parallel components of the magnetic flux tubes and may be referred to as component reconnection. The latter configuration type may be more important for the larger class of small-scale reconnection events. The two types of magnetic configurations can be compared to counter-helicity and co-helicity configurations, respectively, in laboratory plasma collision experiments.

  19. 3D magnetic field configuration of small-scale reconnection events in the solar plasma atmosphere

    SciTech Connect

    Shimizu, T.

    2015-10-15

    The outer solar atmosphere, i.e., the corona and the chromosphere, is replete with small energy-release events, which are accompanied by transient brightening and jet-like ejections. These events are considered to be magnetic reconnection events in the solar plasma, and their dynamics have been studied using recent advanced observations from the Hinode spacecraft and other observatories in space and on the ground. These events occur at different locations in the solar atmosphere and vary in their morphology and amount of the released energy. The magnetic field configurations of these reconnection events are inferred based on observations of magnetic fields at the photospheric level. Observations suggest that these magnetic configurations can be classified into two groups. In the first group, two anti-parallel magnetic fields reconnect to each other, yielding a 2D emerging flux configuration. In the second group, helical or twisted magnetic flux tubes are parallel or at a relative angle to each other. Reconnection can occur only between anti-parallel components of the magnetic flux tubes and may be referred to as component reconnection. The latter configuration type may be more important for the larger class of small-scale reconnection events. The two types of magnetic configurations can be compared to counter-helicity and co-helicity configurations, respectively, in laboratory plasma collision experiments.

  20. 3-D RPIC simulations of relativistic jets: Particle acceleration, magnetic field generation, and emission

    NASA Technical Reports Server (NTRS)

    Nishikawa, K.-I.

    2006-01-01

    Nonthermal radiation observed from astrophysical systems containing (relativistic) jets and shocks, e.g., supernova remnants, active galactic nuclei (AGNs), gamma-ray bursts (GRBs), and Galactic microquasar systems usually have power-law emission spectra. Fermi acceleration is the mechanism usually assumed for the acceleration of particles in astrophysical environments. Recent PIC simulations using injected relativistic electron-ion (electro-positron) jets show that acceleration occurs within the downstream jet, rather than by the scattering of particles back and forth across the shock as in Fermi acceleration. Shock acceleration is a ubiquitous phenomenon in astrophysical plasmas. Plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel instability) created in the .shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The "jitter" radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants. We will review recent PIC simulations which show particle acceleration in jets.

  1. Scenario Testing and Sensitivity Analysis for 3-D Kinematic Models and Geophysical Fields

    NASA Astrophysics Data System (ADS)

    Wellmann, Florian; Lindsay, Mark; Jessell, Mark

    2015-04-01

    Geological models are widely used to represent the structural setting of the subsurface. Commonly, a single model is generated for a region, representing the best interpretation of the structural setting in the light of all available information. It is, however, widely accepted that a such created model still contains uncertainties. We hypothesise here that it is possible to transform a single kinematic model into a powerful predictive tool for scenario analysis and uncertainty quantification. We extend the functionality of a kinematic structural and geophysical modelling approach, implemented in the software Noddy, with a set newly developed Python modules to expose, generalise and automate essential parts of the modelling workflow. We show how these methods enable us to quickly generate and analyse different geological scenarios. In addition to the geological model, Noddy also enables the direct calculation of geophysical fields of gravity and magnetics. We can use this functionality to compare the model to measured potential fields. With an example for a fold and thrust belt model, we show how to quickly estimate how changes in the model (due to parameter uncertainties, for example) affect the calculated gravity field in the model range. Finally, we present the possibility to efficiently generate an ensemble of model realisations for predictive geomodel analysis with an application to a case study in the Gippsland Basin, Victoria. The results show that our approach can successfully extend the functionality of traditional modelling methods with an additional layer of predictive power towards an efficient evaluation of uncertainties in structural geological models.

  2. Theoretical analysis of volume moiré tomography based on double orthogonal gratings for real 3D flow fields diagnosis

    NASA Astrophysics Data System (ADS)

    Sun, Nan; Song, Yang; Wang, Jia; Li, Zhen-hua; He, An-zhi

    2012-11-01

    Moiré tomography is an important technique to diagnose the flow field. However, the traditional moiré deflectometry cannot meet the requirements of Volume Moiré Tomography (VMT). In this Letter, an improved moiré deflected system based on double orthogonal gratings is introduced for real 3-D reconstruction. The proposed method could obtain the first-order partial derivatives in two vertical directions of the projection in one time. Comparing with the traditional moiré deflectometry, the proposed system is more effective and easier to realize the multi-direction data acquisition.

  3. Solwnd: A 3D Compressible MHD Code for Solar Wind Studies. Version 1.0: Cartesian Coordinates

    NASA Technical Reports Server (NTRS)

    Deane, Anil E.

    1996-01-01

    Solwnd 1.0 is a three-dimensional compressible MHD code written in Fortran for studying the solar wind. Time-dependent boundary conditions are available. The computational algorithm is based on Flux Corrected Transport and the code is based on the existing code of Zalesak and Spicer. The flow considered is that of shear flow with incoming flow that perturbs this base flow. Several test cases corresponding to pressure balanced magnetic structures with velocity shear flow and various inflows including Alfven waves are presented. Version 1.0 of solwnd considers a rectangular Cartesian geometry. Future versions of solwnd will consider a spherical geometry. Some discussions of this issue is presented.

  4. Developments in digital in-line holography enable validated measurement of 3D particle field dynamics.

    SciTech Connect

    Guildenbecher, Daniel Robert

    2013-12-01

    Digital in-line holography is an optical technique which can be applied to measure the size, three-dimensional position, and three-component velocity of disperse particle fields. This work summarizes recent developments at Sandia National Laboratories focused on improvement in measurement accuracy, experimental validation, and applications to multiphase flows. New routines are presented which reduce the uncertainty in measured position along the optical axis to a fraction of the particle diameter. Furthermore, application to liquid atomization highlights the ability to measure complex, three-dimensional structures. Finally, investigation of particles traveling at near sonic conditions prove accuracy despite significant experimental noise due to shock-waves.

  5. 3-D Modelling of Stretched Solitary Waves along Magnetic Field Lines

    NASA Astrophysics Data System (ADS)

    Muschietti, L.; Roth, I.; Carlson, C. W.; Berthomier, M.

    2001-12-01

    A model is presented for a new type of fast solitary waves which is observed by FAST in downward current regions of the auroral zone. The three-dimensional, coherent structures are electrostatic, have a positive potential, and move along the ambient magnetic field lines with speeds on the order of the electron drift. Their potential profile in the parallel direction, which can be directly measured, is flat-top whereby it cannot fit to the Gaussian shape used in previous work. Their potential profile in the perpendicular direction can only be inferred from a measured unipolar electric signal. We develop an extended BGK model which includes a flattened potential and an assumed cylindrical symmetry around a centric magnetic field line. The model envisions concentric shells of trapped electrons slowly drifting azimuthally while bouncing back and forth in the parallel direction. The electron dynamics is analysed in terms of three basic motions that occur on different time scales. These are defined by the cyclotron frequency Ω e, the bounce frequency ω b, and the azimuthal drift frequency ω γ , for which explicit analytical expressions are obtained. Subject to the ordering ω γ <<ωb<< Ωe, we calculate self-consistent distribution functions in terms of approximate constants of motion. Constraints on the parameters characterizing the amplitude and shape of the stretched solitary wave are discussed.

  6. Modelling of plasma response to 3D external magnetic field perturbations in EAST

    NASA Astrophysics Data System (ADS)

    Yang, Xu; Sun, Youwen; Liu, Yueqiang; Gu, Shuai; Liu, Yue; Wang, Huihui; Zhou, Lina; Guo, Wenfeng

    2016-11-01

    Sustained mitigation and/or suppression of type-I edge localized modes (ELMs) has been achieved in EAST high-confinement plasmas, utilizing the resonant magnetic perturbation (RMP) fields produced by two rows of magnetic coils located just inside the vacuum vessel. Systematic toroidal modelling of the plasma response to these RMP fields with various coil configurations (with dominant toroidal mode number n  = 1, 2, 3, 4) in EAST is, for the first time, carried out by using the MARS-F code (Liu et al 2000 Phys. Plasmas 7 3681), with results reported here. In particular, the plasma response is computed with varying coil phasing (the toroidal phase difference of the coil currents) between the upper and lower rows of coils, from 0 to 360°. Four figures of merit, constructed based on the MARS-F computations, are used to determine the optimal coil phasing. The modelled results, taking into account the plasma response, agree well with the experimental observations in terms of the coil phasing for both the mitigated and the suppressed ELM cases in EAST experiments. This study provides a crucial confirmation of the role of the plasma edge peeling response in ELM control, complementing similar studies carried out for other tokamak devices.

  7. Optimization of computations for adjoint field and Jacobian needed in 3D CSEM inversion

    NASA Astrophysics Data System (ADS)

    Dehiya, Rahul; Singh, Arun; Gupta, Pravin K.; Israil, M.

    2017-01-01

    We present the features and results of a newly developed code, based on Gauss-Newton optimization technique, for solving three-dimensional Controlled-Source Electromagnetic inverse problem. In this code a special emphasis has been put on representing the operations by block matrices for conjugate gradient iteration. We show how in the computation of Jacobian, the matrix formed by differentiation of system matrix can be made independent of frequency to optimize the operations at conjugate gradient step. The coarse level parallel computing, using OpenMP framework, is used primarily due to its simplicity in implementation and accessibility of shared memory multi-core computing machine to almost anyone. We demonstrate how the coarseness of modeling grid in comparison to source (comp`utational receivers) spacing can be exploited for efficient computing, without compromising the quality of the inverted model, by reducing the number of adjoint calls. It is also demonstrated that the adjoint field can even be computed on a grid coarser than the modeling grid without affecting the inversion outcome. These observations were reconfirmed using an experiment design where the deviation of source from straight tow line is considered. Finally, a real field data inversion experiment is presented to demonstrate robustness of the code.

  8. On the spatial distribution of seismicity and the 3D tectonic stress field in western Greece

    NASA Astrophysics Data System (ADS)

    Kassaras, Ioannis; Kapetanidis, Vasilis; Karakonstantis, Andreas

    2016-10-01

    We analyzed a large number of focal mechanisms and relocated earthquake hypocenters to investigate the geodynamics of western Greece, the most seismically active part of the Aegean plate-boundary zone. This region was seismically activated multiple times during the last decade, providing a large amount of enhanced quality new information that was obtained by the Hellenic Unified Seismological Network (HUSN). Relocated seismicity using a double-difference method appears to be concentrated above ∼35 km depth, exhibiting spatial continuity along the convergence boundary and being clustered elsewhere. Earthquakes are confined within the accreted sediments escarpment of the down-going African plate against the un-deformed Eurasian hinterland. The data arrangement shows that Pindos constitutes a seismic boundary along which large stress heterogeneities occur. In Cephalonia no seismicity is found to be related with the offshore Cephalonia Transform Fault (CTF). Onshore, Nsbnd S crustal extension dominates, while in central and south Peloponnesus the stress field appears rotated by 90°. Shearing-stress obliquity by 30° is indicated along the major strike-slip faults, consistent with clockwise crustal rotation. Within the lower crust, the stress field appears affected by plate kinematics and distributed deformation of the lower crust and upper mantle, which guide the regional geodynamics.

  9. Source fields reconstruction with 3D mapping by means of the virtual acoustic volume concept

    NASA Astrophysics Data System (ADS)

    Forget, S.; Totaro, N.; Guyader, J. L.; Schaeffer, M.

    2016-10-01

    This paper presents the theoretical framework of the virtual acoustic volume concept and two related inverse Patch Transfer Functions (iPTF) identification methods (called u-iPTF and m-iPTF depending on the chosen boundary conditions for the virtual volume). They are based on the application of Green's identity on an arbitrary closed virtual volume defined around the source. The reconstruction of sound source fields combines discrete acoustic measurements performed at accessible positions around the source with the modal behavior of the chosen virtual acoustic volume. The mode shapes of the virtual volume can be computed by a Finite Element solver to handle the geometrical complexity of the source. As a result, it is possible to identify all the acoustic source fields at the real surface of an irregularly shaped structure and irrespective of its acoustic environment. The m-iPTF method is introduced for the first time in this paper. Conversely to the already published u-iPTF method, the m-iPTF method needs only acoustic pressure and avoids particle velocity measurements. This paper is focused on its validation, both with numerical computations and by experiments on a baffled oil pan.

  10. Cooperative field test program for wind systems

    SciTech Connect

    Bollmeier, W.S. II; Dodge, D.M.

    1992-03-01

    The objectives of the Federal Wind Energy Program, managed by the US Department of Energy (DOE), are (1) to assist industry and utilities in achieving a multi-regional US market penetration of wind systems, and (2) to establish the United States as the world leader in the development of advanced wind turbine technology. In 1984, the program conducted a series of planning workshops with representatives from the wind energy industry to obtain input on the Five-Year Research Plan then being prepared by DOE. One specific suggestion that came out of these meetings was that the federal program should conduct cooperative research tests with industry to enhance the technology transfer process. It was also felt that the active involvement of industry in DOE-funded research would improve the state of the art of wind turbine technology. DOE established the Cooperative Field Test Program (CFTP) in response to that suggestion. This program was one of the first in DOE to feature joint industry-government research test teams working toward common objectives.

  11. Innovative simultaneous confocal full-field 3D surface profilometry for in situ automatic optical inspection (AOI)

    NASA Astrophysics Data System (ADS)

    Chen, Liang-Chia; Chang, Yi-Wei

    2010-06-01

    Rapid acquisition of surface 3D contour information using optical detection has attracted tremendous interest in the field of automatic optical inspection (AOI) and how to avoid or minimize environmental vibration or disturbance has become a critical issue in in situ inspection. Owing to its high longitudinal measurability and excellent vertical resolution, optical confocal microscopy has become extremely important for surface profilometry. This study presents a novel simultaneous confocal full-field 3D surface profilometer using structured fringe projection. The developed confocal optical system is capable of acquiring multiple images at various object depths to perform surface 3D reconstruction by a single image shot without the need for time-consuming vertical scanning. In this method, four conjugate image-sensing modules are configured at four different designated focusing positions, which are controlled by a specially designed beam-splitting optical module. A focal-depth response (FDR) curve can be established by fitting the four focus measurements obtained from these designated positions to achieve simultaneous confocal vertical scanning. In addition, using the principle of optical grating projection, a structured fringe pattern is generated for lateral scanning to enhance the spatial measurement resolution. To examine the performance of the developed system, an accurate step-height target and some industrial micro semiconductor components were measured. The results show that the depth measurement resolution can reach up to 0.1 µm and the maximum measurement error is within 1.5% of the overall range, indicating both accuracy and repeatability of the proposed confocal measurement approach.

  12. Multi-modal digital holographic microscopy for wide-field fluorescence and 3D phase imaging

    NASA Astrophysics Data System (ADS)

    Quan, Xiangyu; Xia, Peng; Matoba, Osamu; Nitta, Koichi; Awatsuji, Yasuhiro

    2016-03-01

    Multi-modal digital holographic microscopy is a combination of epifluorescence microscopy and digital holographic microscopy, the main function of which is to obtain images from fluorescence intensity and quantified phase contrasts, simultaneously. The proposed system is mostly beneficial to biological studies, with the reason that often the studies are depending on fluorescent labeling techniques to detect certain intracellular molecules, while phase information reflecting properties of unstained transparent elements. This paper is presenting our latest researches on applications such as randomly moving micro-fluorescent beads and living cells of Physcomitrella patens. The experiments are succeeded on obtaining a succession of wide-field fluorescent images and holograms from micro-beads, and different depths focusing is realized via numerical reconstruction. Living cells of Physcomitrella patens are recorded in the static manner, the reconstruction distance indicates thickness of cellular structure. These results are implementing practical applications toward many biomedical science researches.

  13. Influence of shallow flow on the deep geothermal field of Berlin - Results from 3D models

    NASA Astrophysics Data System (ADS)

    Frick, Maximilian; Sippel, Judith; Scheck-Wenderoth, Magdalena; Cacace, Mauro; Hassanzadegan, Alireza

    2015-04-01

    The goal of this study is to quantify the influence of fluid-driven heat transport on the subsurface temperature distribution of the city of Berlin, Germany. Berlin is located in the Northeast German Basin filled with several kilometers of sediments. Two of the clastic sedimentary units, namely the Middle Buntsandstein and the Sedimentary Rotliegend are of particular interest for geothermal exploration. Previous studies in the Northeast German Basin have already shown that subsurface temperature distributions are highly dependent on the geometries and properties of the geological units. Our work benefits strongly from these studies that involve numerical modeling of coupled conductive and convective heat transport. We follow a two-step approach where we first improve an existing structural model by integrating newly available 57 geological cross-sections, well data and deep seismics (down to ~4 km). Secondly, we perform a sensitivity analysis in which we investigate the effects of varying physical fluid and rock properties as well as hydraulic and thermal boundary conditions on the resulting temperature configuration. Computed temperatures are validated via comparison with existing well temperature measurements in the area. Of special interest for this study is the influence of the shallow aquifer systems on the subsurface temperature field. The major constituents of this system are the Quaternary silts and sands, the Tertiary Rupelian clay and the Tertiary sands beneath the Rupelian. These units have different hydraulic properties. The Rupelian clay represents a major aquitard in this respect hydraulically disconnecting the pre- and post-Rupelian succession. This aquitard shows a heterogeneous thickness distribution locally characterized by different hydrogeological windows (i.e. domains of no thickness) enabling intra-aquifer groundwater circulation at depth thus having a first-order effect on the shallow thermal field. As result of the simulations, we present

  14. 3D transient electromagnetic simulation using a modified correspondence principle for wave and diffusion fields

    NASA Astrophysics Data System (ADS)

    Hu, Y.; Ji, Y.; Egbert, G. D.

    2015-12-01

    The fictitious time domain method (FTD), based on the correspondence principle for wave and diffusion fields, has been developed and used over the past few years primarily for marine electromagnetic (EM) modeling. Here we present results of our efforts to apply the FTD approach to land and airborne TEM problems which can reduce the computer time several orders of magnitude and preserve high accuracy. In contrast to the marine case, where sources are in the conductive sea water, we must model the EM fields in the air; to allow for topography air layers must be explicitly included in the computational domain. Furthermore, because sources for most TEM applications generally must be modeled as finite loops, it is useful to solve directly for the impulse response appropriate to the problem geometry, instead of the point-source Green functions typically used for marine problems. Our approach can be summarized as follows: (1) The EM diffusion equation is transformed to a fictitious wave equation. (2) The FTD wave equation is solved with an explicit finite difference time-stepping scheme, with CPML (Convolutional PML) boundary conditions for the whole computational domain including the air and earth , with FTD domain source corresponding to the actual transmitter geometry. Resistivity of the air layers is kept as low as possible, to compromise between efficiency (longer fictitious time step) and accuracy. We have generally found a host/air resistivity contrast of 10-3 is sufficient. (3)A "Modified" Fourier Transform (MFT) allow us recover system's impulse response from the fictitious time domain to the diffusion (frequency) domain. (4) The result is multiplied by the Fourier transformation (FT) of the real source current avoiding time consuming convolutions in the time domain. (5) The inverse FT is employed to get the final full waveform and full time response of the system in the time domain. In general, this method can be used to efficiently solve most time-domain EM

  15. 3D effects of edge magnetic field configuration on divertor/scrape-off layer transport and optimization possibilities for a future reactor

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Xu, Y.; Ida, K.; Corre, Y.; Feng, Y.; Schmitz, O.; Frerichs, H.; Tabares, F. L.; Evans, T. E.; Coenen, J. W.; Liang, Y.; Bader, A.; Itoh, K.; Yamada, H.; Ghendrih, Ph.; Ciraolo, G.; Tafalla, D.; Lopez-Fraguas, A.; Guo, H. Y.; Cui, Z. Y.; Reiter, D.; Asakura, N.; Wenzel, U.; Morita, S.; Ohno, N.; Peterson, B. J.; Masuzaki, S.

    2015-10-01

    This paper assesses the three-dimensional (3D) effects of the edge magnetic field structure on divertor/scrape-off layer transport, based on an inter-machine comparison of experimental data and on the recent progress of 3D edge transport simulation. The 3D effects are elucidated as a consequence of competition between transports parallel (\\parallel ) and perpendicular (\\bot ) to the magnetic field, in open field lines cut by divertor plates, or in magnetic islands. The competition has strong impacts on divertor functions, such as determination of the divertor density regime, impurity screening and detachment control. The effects of magnetic perturbation on the edge electric field and turbulent transport are also discussed. Parameterization to measure the 3D effects on the edge transport is attempted for the individual divertor functions. Based on the suggested key parameters, an operation domain of the 3D divertor configuration is discussed for future devices.

  16. Solar wind interaction with Mars' upper atmosphere: Results from 3-D studies using one-way coupling between the Multi-fluid MHD, the M-GITM and the AMPS models

    NASA Astrophysics Data System (ADS)

    Dong, C.; Bougher, S. W.; Ma, Y.; Toth, G.; Lee, Y.; Nagy, A. F.; Tenishev, V.; Pawlowski, D. J.; Meng, X.; Combi, M. R.

    2013-12-01

    The study of the solar wind interaction with Mars upper atmosphere/ionosphere has triggered a great of interest in recent years. Among the large number of topics in this research area, the investigation of ion escape fluxes has become increasingly important due to its potential impact on the long-term evolution of Mars atmosphere (e.g., loss of water) over its history. In the present work, we adopt the 3-D Mars cold neutral atmosphere profiles (0~300 km) from the newly developed and validated Mars Global Ionosphere Thermosphere Model (M-GITM) and the 3-D hot oxygen profiles (100km~5RM) from the exosphere Monte Carlo model Adaptive Mesh Particle Simulator (AMPS). We apply these 3-D model outputs fields into the 3-D BATS-R-US Mars multi-fluid MHD model (100km~20RM) that can better simulate the interplay between Mars upper atmosphere and solar wind by considering the dynamics of individual ion species. The multi-fluid model solves separate continuity, momentum and energy equations for each ion species (H+, O+, O2+, CO2+). The M-GITM model together with the AMPS exosphere model take into account the effects of solar cycle and seasonal variations on both cold and hot neutral atmospheres, allowing us to investigate the corresponding effects on the Mars upper atmosphere ion escape by using a one-way coupling approach, i.e., both the M-GITM and AMPS model outputs are used as the inputs for the multi-fluid model and M-GITM is used as input into the AMPS exosphere model. The calculations are carried out for selected cases with different nominal solar wind, solar cycle and crustal field orientation conditions. This work has the potential to provide predictions of ion escape rates for comparison to future data to be returned by the MAVEN primary mission (2014-2016) and thereby improve our understanding of present day escape processes. Acknowledgments: The work presented here was supported by NASA grants NNH10CC04C, NNX09AL26G, NSF grant ATM-0535811.

  17. Full-physics 3D heterogeneous simulations of electromagnetic induction fields on level and deformed sea ice

    SciTech Connect

    Samluk, Jesse P.; Geiger, Cathleen A.; Weiss, Chester J.; Kolodzey, James

    2015-10-01

    In this article we explore simulated responses of electromagnetic (EM) signals relative to in situ field surveys and quantify the effects that different values of conductivity in sea ice have on the EM fields. We compute EM responses of ice types with a three-dimensional (3-D) finite-volume discretization of Maxwell's equations and present 2-D sliced visualizations of their associated EM fields at discrete frequencies. Several interesting observations result: First, since the simulator computes the fields everywhere, each gridcell acts as a receiver within the model volume, and captures the complete, coupled interactions between air, snow, sea ice and sea water as a function of their conductivity; second, visualizations demonstrate how 1-D approximations near deformed ice features are violated. But the most important new finding is that changes in conductivity affect EM field response by modifying the magnitude and spatial patterns (i.e. footprint size and shape) of current density and magnetic fields. These effects are demonstrated through a visual feature we define as 'null lines'. Null line shape is affected by changes in conductivity near material boundaries as well as transmitter location. Our results encourage the use of null lines as a planning tool for better ground-truth field measurements near deformed ice types.

  18. Modelling of 3D fields due to ferritic inserts and test blanket modules in toroidal geometry at ITER

    NASA Astrophysics Data System (ADS)

    Liu, Yueqiang; Äkäslompolo, Simppa; Cavinato, Mario; Koechl, Florian; Kurki-Suonio, Taina; Li, Li; Parail, Vassili; Saibene, Gabriella; Särkimäki, Konsta; Sipilä, Seppo; Varje, Jari

    2016-06-01

    Computations in toroidal geometry are systematically performed for the plasma response to 3D magnetic perturbations produced by ferritic inserts (FIs) and test blanket modules (TBMs) for four ITER plasma scenarios: the 15 MA baseline, the 12.5 MA hybrid, the 9 MA steady state, and the 7.5 MA half-field helium plasma. Due to the broad toroidal spectrum of the FI and TBM fields, the plasma response for all the n  =  1-6 field components are computed and compared. The plasma response is found to be weak for the high-n (n  >  4) components. The response is not globally sensitive to the toroidal plasma flow speed, as long as the latter is not reduced by an order of magnitude. This is essentially due to the strong screening effect occurring at a finite flow, as predicted for ITER plasmas. The ITER error field correction coils (EFCC) are used to compensate the n  =  1 field errors produced by FIs and TBMs for the baseline scenario for the purpose of avoiding mode locking. It is found that the middle row of the EFCC, with a suitable toroidal phase for the coil current, can provide the best correction of these field errors, according to various optimisation criteria. On the other hand, even without correction, it is predicted that these n  =  1 field errors will not cause substantial flow damping for the 15 MA baseline scenario.

  19. Full-physics 3D heterogeneous simulations of electromagnetic induction fields on level and deformed sea ice

    DOE PAGES

    Samluk, Jesse P.; Geiger, Cathleen A.; Weiss, Chester J.; ...

    2015-10-01

    In this article we explore simulated responses of electromagnetic (EM) signals relative to in situ field surveys and quantify the effects that different values of conductivity in sea ice have on the EM fields. We compute EM responses of ice types with a three-dimensional (3-D) finite-volume discretization of Maxwell's equations and present 2-D sliced visualizations of their associated EM fields at discrete frequencies. Several interesting observations result: First, since the simulator computes the fields everywhere, each gridcell acts as a receiver within the model volume, and captures the complete, coupled interactions between air, snow, sea ice and sea water asmore » a function of their conductivity; second, visualizations demonstrate how 1-D approximations near deformed ice features are violated. But the most important new finding is that changes in conductivity affect EM field response by modifying the magnitude and spatial patterns (i.e. footprint size and shape) of current density and magnetic fields. These effects are demonstrated through a visual feature we define as 'null lines'. Null line shape is affected by changes in conductivity near material boundaries as well as transmitter location. Our results encourage the use of null lines as a planning tool for better ground-truth field measurements near deformed ice types.« less

  20. 3D Online Submicron Scale Observation of Mixed Metal Powder's Microstructure Evolution in High Temperature and Microwave Compound Fields

    PubMed Central

    Xu, Feng; Hu, Xiao-fang; Xiao, Yu; Xiao, Ti-qiao

    2014-01-01

    In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT) technique; the spatial resolution was enhanced to 0.37 μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth. PMID:24737986

  1. Full-field dynamic displacement and strain measurement using pulsed and high-speed 3D image correlation photogrammetry

    NASA Astrophysics Data System (ADS)

    Schmidt, Timothy; Tyson, John; Galanulis, Konstantin

    2004-02-01

    3D image correlation is a robust method for measuring full-field displacements and strains using a calibrated pair of video cameras. Underlying principles and benefits are reviewed, and the method is compared to both 3D ESPI and 2D image correlation. Several applications combining image correlation photogrammetry with stroboscopic illumination and/or high-speed video cameras are presented. Operational strains in ionic polymeric muscle samples and electro-restrictive actuators are determined. The use of short-duration white light pulses to study automobile tires on road wheels at speeds up to 150 miles per hour is demonstrated. Initial work measuring strains on an 18" flywheel in a spin pit at up to 35,000 rpm is described. A notched rubber dogbone sample is pulled to failure at 125% strain in 38 milliseconds, and hundreds of full-field strain maps are captured. This paper includes discussion of sample preparation methods and special lighting systems, including pulsed arc lamps and pulsed lasers. A matrix of capability using available high speed cameras is included.

  2. A direct approach for instantaneous 3D density field reconstruction from background-oriented schlieren (BOS) measurements

    NASA Astrophysics Data System (ADS)

    Nicolas, F.; Todoroff, V.; Plyer, A.; Le Besnerais, G.; Donjat, D.; Micheli, F.; Champagnat, F.; Cornic, P.; Le Sant, Y.

    2016-01-01

    We present a new numerical method for reconstruction of instantaneous density volume from 3D background-oriented schlieren (3DBOS) measurements, with a validation on a dedicated flexible experimental BOS bench. In contrast to previous works, we use a direct formulation where density is estimated from measured deviation fields without the intermediate step of density gradient reconstruction. Regularization techniques are implemented to deal with the ill-posed problem encountered. The resulting high-dimensional optimization is conducted by conjugate gradient techniques. A parallel algorithm, implemented on graphics processing unit, helps to speed up the calculation. The resulting software is validated on synthetic BOS images of a 3D density field issued from a numerical simulation. Then, we describe a dedicated 3DBOS experimental facility which has been built to study various BOS settings and to assess the performance of the proposed numerical reconstruction process. Results on various datasets illustrate the potential of the method for flow characterization and measurement in real-world conditions.

  3. 3D online submicron scale observation of mixed metal powder's microstructure evolution in high temperature and microwave compound fields.

    PubMed

    Kang, Dan; Xu, Feng; Hu, Xiao-fang; Dong, Bo; Xiao, Yu; Xiao, Ti-qiao

    2014-01-01

    In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT) technique; the spatial resolution was enhanced to 0.37  μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth.

  4. A cubic interpolation pipeline for fast computation of 3D deformation fields modeled using B-splines

    NASA Astrophysics Data System (ADS)

    Castro-Pareja, Carlos R.; Shekhar, Raj

    2006-02-01

    Fast computation of 3D deformation fields is critical to bringing the application of automated elastic image registration algorithms to routine clinical practice. However, it lies beyond the computational power of current microprocessors; therefore requiring implementations using either massively parallel computers or application-specific hardware accelerators. The use of massively parallel computers in a clinical setting is not practical or cost-effective, therefore making the use of hardware accelerators necessary. We present a hardware pipeline that allows accelerating the computation of 3D deformation fields to speeds up to two orders of magnitude faster than software implementations on current workstations and about 64 times faster than other previously reported architectures. The pipeline implements a version of the free-form deformation calculation algorithm, which is optimized to minimize the number of arithmetic operations required to calculate the transformation of a given set of neighboring voxels, thereby achieving an efficient and compact implementation in hardware which allows its use as part of a larger system.

  5. Automated torso organ segmentation from 3D CT images using conditional random field

    NASA Astrophysics Data System (ADS)

    Nimura, Yukitaka; Hayashi, Yuichiro; Kitasaka, Takayuki; Misawa, Kazunari; Mori, Kensaku

    2016-03-01

    This paper presents a segmentation method for torso organs using conditional random field (CRF) from medical images. A lot of methods have been proposed to enable automated extraction of organ regions from volumetric medical images. However, it is necessary to adjust empirical parameters of them to obtain precise organ regions. In this paper, we propose an organ segmentation method using structured output learning which is based on probabilistic graphical model. The proposed method utilizes CRF on three-dimensional grids as probabilistic graphical model and binary features which represent the relationship between voxel intensities and organ labels. Also we optimize the weight parameters of the CRF using stochastic gradient descent algorithm and estimate organ labels for a given image by maximum a posteriori (MAP) estimation. The experimental result revealed that the proposed method can extract organ regions automatically using structured output learning. The error of organ label estimation was 6.6%. The DICE coefficients of right lung, left lung, heart, liver, spleen, right kidney, and left kidney are 0.94, 0.92, 0.65, 0.67, 0.36, 0.38, and 0.37, respectively.

  6. Effects of field-of-view restriction on manoeuvring in a 3-D environment.

    PubMed

    Toet, A; Jansen, S E M; Delleman, N J

    2008-03-01

    Field-of-view (FOV) restrictions are known to affect human behaviour and to degrade performance for a range of different tasks. However, the relationship between human locomotion performance in complex environments and FOV size is currently not fully known. This paper examined the effects of FOV restrictions on the performance of participants manoeuvring through an obstacle course with horizontal and vertical barriers. All FOV restrictions tested (the horizontal FOV was either 30 degrees , 75 degrees or 120 degrees , while the vertical FOV was always 48 degrees ) significantly reduced performance compared to the unrestricted condition. Both the time and the number of footsteps needed to traverse the entire obstacle course increased with a decreasing FOV size. The relationship between FOV restriction and manoeuvring performance that was determined can be used to formulate requirements for FOV restricting devices that are deployed to perform time-limited human locomotion tasks in complex structured environments, such as night-vision goggles and head-mounted displays used in training and entertainment systems.

  7. Quality assessment of reverse engineering process based on full-field true-3D optical measurements

    NASA Astrophysics Data System (ADS)

    Kujawinska, Malgorzata; Sitnik, Robert

    2000-08-01

    In the paper the sequential steps of reverse engineering based on the data gathered by full-field optical system are discussed. Each step is concerned from the point of view of its influence on the final quality of the shape of manufactured object. At first the modern shape measurement system based on the combination of fringe projection, Grey code and experimental calibration is presented. The system enables the determination of absolute coordinates of the object measured from many directions. The dependence of the quality of the cloud of points on the type of object and the measurement procedure is discussed. Then the methods of transferring the experimental data into CAD/CAM/CAE system are presented. The quality of the virtual object in the form of closed triangular mesh is analyzed. Basing on this virtual object the copy of initial body is produced and measured. The accuracy of the object manufactured is determined and the main sources of errors are discussed. The modifications of the system and algorithms that minimize the errors are proposed. The reverse engineering sequence is presented is illustrated by several examples.

  8. AE3D

    SciTech Connect

    Spong, Donald A

    2016-06-20

    AE3D solves for the shear Alfven eigenmodes and eigenfrequencies in a torodal magnetic fusion confinement device. The configuration can be either 2D (e.g. tokamak, reversed field pinch) or 3D (e.g. stellarator, helical reversed field pinch, tokamak with ripple). The equations solved are based on a reduced MHD model and sound wave coupling effects are not currently included.

  9. Construction of surface pressure field from scatterometer wind field

    NASA Technical Reports Server (NTRS)

    Wurtele, Morton G.; Hsu, Carol H.; Cunningham, Glen F.; Woiceshyn, Peter M.

    1989-01-01

    An account of the construction of surface pressure fields from Seasat-A satellite scatterometer (SASS) winds as carried out by different methods, and the comparison of these pressure fields with those derived from in situ ship observations is presented. On the assumption that the pressure adjusts itself instantaneously to the motion field, it may be computed by various methods. One of these makes use of planetary boundary theory, and of the possible techniques in this category a two-layer iterative scheme admitting of the parametrization of diabatic and baroclinic effects and of secondary flow was chosen. A second method involves the assumption of zero two-dimensional divergence, leading to a Laplace's equation (the balance equation) in pressure, with the wind field serving as a forcing function. This method does not accommodate adiabatic or baroclinic effects, and requires a knowledge of the pressure at all boundary points. Two comparison fields are used for validation: the conventional operational analyses of the US National Meteorological Center (NMC), and the special analyses of the Gulf of Alaska Experiment (GOASEX), which were done by hand. The results of the computations were as follows: (1) The pressure fields, as computed from the SASS winds alone, closely approximated the NMC fields in regions where reasonable in situ coverage was available (typically, one or two mb differences over most of the chart, three to four mb in extreme cases); (2) In some cases the SASS-derived pressure fields displayed high-resolution phenomena not detected by the NMC fields, but evident in the GOASEX data; and, (3) As expected, the pressure fields derived from the balance equation were much smoother and less well resolved than the SASS-derived or NMC fields. The divergence as measured from the SASS winds is smaller than, but of the same order of magnitude as, the vorticity.

  10. Present-Day 3D Velocity Field of Eastern North America Based on Continuous GPS Observations

    NASA Astrophysics Data System (ADS)

    Goudarzi, Mohammad Ali; Cocard, Marc; Santerre, Rock

    2016-07-01

    The Saint Lawrence River valley in eastern Canada was studied using observations of continuously operating GPS (CGPS) stations. The area is one of the most seismically active regions in eastern North America characterized by many earthquakes, which is also subject to an ongoing glacial isostatic adjustment. We present the current three-dimensional velocity field of eastern North America obtained from more than 14 years (9 years on average) of data at 112 CGPS stations. Bernese GNSS and GITSA software were used for CGPS data processing and position time series analysis, respectively. The results show the counterclockwise rotation of the North American plate in the No-Net-Rotation model with the average of 16.8 ± 0.7 mm/year constrained to ITRF 2008. We also present an ongoing uplift model for the study region based on the present-day CGPS observations. The model shows uplift all over eastern Canada with the maximum rate of 13.7 ± 1.2 mm/year and subsidence to the south mainly over northern USA with a typical rate of -1 to -2 mm/year and the minimum value of -2.7 ± 1.4 mm/year. We compared our model with the rate of radial displacements from the ICE-5G model. Both models agree within 0.02 mm/year at the best stations; however, our model shows a systematic spatial tilt compared to ICE-5G. The misfits between two models amount to the maximum relative subsidence of -6.1 ± 1.1 mm/year to the east and maximum relative uplift of 5.9 ± 2.7 mm/year to the west. The intraplate horizontal velocities are radially outward from the centers of maximum uplift and are inward to the centers of maximum subsidence with the typical velocity of 1-1.6 ± 0.4 mm/year that is in agreement with the ICE-5G model to the first order.

  11. Optimization and Use of 3D sintered porous material in medical field for mixing fibrin glue.

    NASA Astrophysics Data System (ADS)

    Delmotte, Y.; Laroumanie, H.; Brossard, G.

    2012-04-01

    In medical field, Mixing of two or more chemical components (liquids and/or gases) is extremely important as improper mixing can affect the physico-chemical properties of the final product. At Baxter Healthcare Corporation, we are using a sintered porous material (PM) as a micro-mixer in medical device for mixing Fibrinogen and Thrombin in order to obtain a homogeneous polymerized Fibrin glue clot used in surgery. First trials were carried out with an interconnected PM from Porvair® (made of PE - porosity: 40% - permeability: 18Darcy). The injection rate is very low, usually about 10mL/min (Re number about 50) which keeps fluids in a laminar flow. Such a low flow rate does not favour mixing of fluids having gradient of viscosity if a mixer is not used. Promising results that were obtained lead the team to understand this ability to mix fluids which will be presented in the poster. Topology of porous media (PM) which associates a solid phase with interconnected (or not) porous structure is known and used in many commodity products. Researches on PM usually focus on flows inside this structure. By opposition to transport and filtration capacity, as well as mechanic and thermic properties, mixing is rarely associated with PM. However over the past few years, we shown that some type of PM have a real capacity to mix certain fluids. Poster will also describe the problematic of mixing complex biological fluids as fibrinogen and Thrombin. They indeed present a large viscosity difference (ratio about 120) limiting the diffusion and the interaction between the two solutions. As those products are expensive, we used Water (1cPo) and Glycerol 87% (120cPo) which are matching the viscosities of Thrombin and Fibrinogen. A parametric investigation of the "porous micro-mixer" as well as a scale up investigation was carried out to examine the influence of both diffusion and advection to successful mix fluids of different viscosity. Experiments were implemented with Planar Laser

  12. 3D mechanical modeling of the GPS velocity field along the North Anatolian fault

    NASA Astrophysics Data System (ADS)

    Provost, Ann-Sophie; Chéry, Jean; Hassani, Riad

    2003-04-01

    The North Anatolian fault (NAF) extends over 1500 km in a complex tectonic setting. In this region of the eastern Mediterranean, collision of the Arabian, African and Eurasian plates resulted in creation of mountain ranges (i.e. Zagros, Caucasus) and the westward extrusion of the Anatolian block. In this study we investigate the effects of crustal rheology on the long-term displacement rate along the NAF. Heat flow and geodetic data are used to constrain our mechanical model, built with the three-dimensional finite element code ADELI. The fault motion occurs on a material discontinuity of the model which is controlled by a Coulomb-type friction. The rheology of the lithosphere is composed of a frictional upper crust and a viscoelastic lower crust. The lithosphere is supported by a hydrostatic pressure at its base (representing the asthenospheric mantle). We model the long-term deformation of the surroundings of the NAF by adjusting the effective fault friction and also the geometry of the surface fault trace. To do so, we used a frictional range of 0.0-0.2 for the fault, and a viscosity varying between 10 19 and 10 21 Pa s. One of the most striking results of our rheological tests is that the upper part of the fault is locked if the friction exceeds 0.2. By comparing our results with geodetic measurements [McClusky et al., J. Geophys. Res. B 105 (2000) 5695-5719] and tectonic observations, we have defined a realistic model in which the displacement rate on the NAF reaches ˜17 mm/yr for a viscosity of 10 19 Pa s and a fault friction of 0.05. This strongly suggests that the NAF is a weak fault like the San Andreas fault in California. Adding topography with its corresponding crustal root does not induce gravity flow of Anatolia. Rather, it has the counter-intuitive effect of decreasing the westward Anatolian escape. We find a poor agreement between our calculated velocity field and what is observed with GPS in the Marmara and the Aegean regions. We suspect that the

  13. Computer-aided detection of lung nodules: false positive reduction using a 3D gradient field method

    NASA Astrophysics Data System (ADS)

    Ge, Zhanyu; Sahiner, Berkman; Chan, Heang-Ping; Hadjiiski, Lubomir M.; Wei, Jun; Bogot, Naama; Cascade, Philip N.; Kazerooni, Ella A.; Zhou, Chuan

    2004-05-01

    We are developing a computer-aided detection system to aid radiologists in diagnosing lung cancer in thoracic computed tomographic (CT) images. The purpose of this study was to improve the false-positive (FP) reduction stage of our algorithm by developing and incorporating a gradient field technique. This technique extracts 3D shape information from the gray-scale values within a volume of interest. The gradient field feature values are higher for spherical objects, and lower for elongated and irregularly-shaped objects. A data set of 55 thin CT scans from 40 patients was used to evaluate the usefulness of the gradient field technique. After initial nodule candidate detection and rule-based first stage FP reduction, there were 3487 FP and 65 true positive (TP) objects in our data set. Linear discriminant classifiers with and without the gradient field feature were designed for the second stage FP reduction. The accuracy of these classifiers was evaluated using the area Az under the receiver operating characteristic (ROC) curve. The Az values were 0.93 and 0.91 with and without the gradient field feature, respectively. The improvement with the gradient field feature was statistically significant (p=0.01).

  14. Toward acquiring comprehensive radiosurgery field commissioning data using the PRESAGE®/ optical-CT 3D dosimetry system

    NASA Astrophysics Data System (ADS)

    Clift, Corey; Thomas, Andrew; Adamovics, John; Chang, Zheng; Das, Indra; Oldham, Mark

    2010-03-01

    Achieving accurate small field dosimetry is challenging. This study investigates the utility of a radiochromic plastic PRESAGE® read with optical-CT for the acquisition of radiosurgery field commissioning data from a Novalis Tx system with a high-definition multileaf collimator (HDMLC). Total scatter factors (Sc, p), beam profiles, and penumbrae were measured for five different radiosurgery fields (5, 10, 20, 30 and 40 mm) using a commercially available optical-CT scanner (OCTOPUS, MGS Research). The percent depth dose (PDD), beam profile and penumbra of the 10 mm field were also measured using a higher resolution in-house prototype CCD-based scanner. Gafchromic EBT® film was used for independent verification. Measurements of Sc, p made with PRESAGE® and film agreed with mini-ion chamber commissioning data to within 4% for every field (range 0.2-3.6% for PRESAGE®, and 1.6-3.6% for EBT). PDD, beam profile and penumbra measurements made with the two PRESAGE®/optical-CT systems and film showed good agreement with the high-resolution diode commissioning measurements with a competitive resolution (0.5 mm pixels). The in-house prototype optical-CT scanner allowed much finer resolution compared with previous applications of PRESAGE®. The advantages of the PRESAGE® system for small field dosimetry include 3D measurements, negligible volume averaging, directional insensitivity, an absence of beam perturbations, energy and dose rate independence.

  15. CONTINUUM INTENSITY AND [O i] SPECTRAL LINE PROFILES IN SOLAR 3D PHOTOSPHERIC MODELS: THE EFFECT OF MAGNETIC FIELDS

    SciTech Connect

    Fabbian, D.; Moreno-Insertis, F. E-mail: fmi@iac.es

    2015-04-01

    The importance of magnetic fields in three-dimensional (3D) magnetoconvection models of the Sun’s photosphere is investigated in terms of their influence on the continuum intensity at different viewing inclination angles and on the intensity profile of two [O i] spectral lines. We use the RH numerical radiative transfer code to perform a posteriori spectral synthesis on the same time series of magnetoconvection models used in our publications on the effect of magnetic fields on abundance determination. We obtain a good match of the synthetic disk-center continuum intensity to the absolute continuum values from the Fourier Transform Spectrometer (FTS) observational spectrum; the match of the center-to-limb variation synthetic data to observations is also good, thanks, in part, to the 3D radiation transfer capabilities of the RH code. The different levels of magnetic flux in the numerical time series do not modify the quality of the match. Concerning the targeted [O i] spectral lines, we find, instead, that magnetic fields lead to nonnegligible changes in the synthetic spectrum, with larger average magnetic flux causing both of the lines to become noticeably weaker. The photospheric oxygen abundance that one would derive if instead using nonmagnetic numerical models would thus be lower by a few to several centidex. The inclusion of magnetic fields is confirmed to be important for improving the current modeling of the Sun, here in particular in terms of spectral line formation and of deriving consistent chemical abundances. These results may shed further light on the still controversial issue regarding the precise value of the solar oxygen abundance.

  16. 3D Lagrangian VPM: simulations of the near-wake of an actuator disc and horizontal axis wind turbine

    NASA Astrophysics Data System (ADS)

    Berdowski, T.; Ferreira, C.; Walther, J.

    2016-09-01

    The application of a 3-dimensional Lagrangian vortex particle method has been assessed for modelling the near-wake of an axisymmetrical actuator disc and 3-bladed horizontal axis wind turbine with prescribed circulation from the MEXICO (Model EXperiments In COntrolled conditions) experiment. The method was developed in the framework of the open- source Parallel Particle-Mesh library for handling the efficient data-parallelism on a CPU (Central Processing Unit) cluster, and utilized a O(N log N)-type fast multipole method for computational acceleration. Simulations with the actuator disc resulted in a wake expansion, velocity deficit profile, and induction factor that showed a close agreement with theoretical, numerical, and experimental results from literature. Also the shear layer expansion was present; the Kelvin-Helmholtz instability in the shear layer was triggered due to the round-off limitations of a numerical method, but this instability was delayed to beyond 1 diameter downstream due to the particle smoothing. Simulations with the 3-bladed turbine demonstrated that a purely 3-dimensional flow representation is challenging to model with particles. The manifestation of local complex flow structures of highly stretched vortices made the simulation unstable, but this was successfully counteracted by the application of a particle strength exchange scheme. The axial and radial velocity profile over the near wake have been compared to that of the original MEXICO experiment, which showed close agreement between results.

  17. Mars-solar wind interaction: LatHyS, an improved parallel 3-D multispecies hybrid model

    NASA Astrophysics Data System (ADS)

    Modolo, Ronan; Hess, Sebastien; Mancini, Marco; Leblanc, Francois; Chaufray, Jean-Yves; Brain, David; Leclercq, Ludivine; Esteban-Hernández, Rosa; Chanteur, Gerard; Weill, Philippe; González-Galindo, Francisco; Forget, Francois; Yagi, Manabu; Mazelle, Christian

    2016-07-01

    In order to better represent Mars-solar wind interaction, we present an unprecedented model achieving spatial resolution down to 50 km, a so far unexplored resolution for global kinetic models of the Martian ionized environment. Such resolution approaches the ionospheric plasma scale height. In practice, the model is derived from a first version described in Modolo et al. (2005). An important effort of parallelization has been conducted and is presented here. A better description of the ionosphere was also implemented including ionospheric chemistry, electrical conductivities, and a drag force modeling the ion-neutral collisions in the ionosphere. This new version of the code, named LatHyS (Latmos Hybrid Simulation), is here used to characterize the impact of various spatial resolutions on simulation results. In addition, and following a global model challenge effort, we present the results of simulation run for three cases which allow addressing the effect of the suprathermal corona and of the solar EUV activity on the magnetospheric plasma boundaries and on the global escape. Simulation results showed that global patterns are relatively similar for the different spatial resolution runs, but finest grid runs provide a better representation of the ionosphere and display more details of the planetary plasma dynamic. Simulation results suggest that a significant fraction of escaping O+ ions is originated from below 1200 km altitude.

  18. EDITORIAL: 15th Workshop on MHD Stability Control: 3D Magnetic Field Effects in MHD Control 15th Workshop on MHD Stability Control: 3D Magnetic Field Effects in MHD Control

    NASA Astrophysics Data System (ADS)

    Buttery, Richard

    2011-08-01

    This annual workshop on MHD Stability Control has been held since 1996 with a focus on understanding and developing control of MHD instabilities for future fusion reactors. The workshop generally covers a wide range of stability topics: from disruptions, to tearing modes, error fields, ELMs, resistive wall modes (RWMs) and ideal MHD. It spans many device types, particularly tokamaks, stellarators and reversed field pinches, to pull out commonalities in the physics and improve understanding. In 2010 the workshop was held on 15-17 November at the University of Wisconsin in Madison and was combined with the annual US-Japan MHD Workshop. The theme was `3D Magnetic Field Effects in MHD Control', with a focus on multidisciplinary sessions exploring issues of plasma response to 3D fields, the manifestation of such fields in the plasma, and how they influence stability. This has been a topic of renewed interest, with utilisation of 3D fields for ELM control now planned in ITER, and a focus on the application of such fields for error field correction, disruption avoidance, and RWM control. Key issues included the physics of the interaction, types of coils and harmonic spectra needed to control instabilities, and subsidiary effects such as braking (or rotating) the plasma. More generally, a wider range of issues were discussed including RWM physics, tearing mode physics, disruption mitigation, ballooning stability, the snowflake divertor concept, and the line tied pinch! A novel innovation to the meeting was a panel discussion session, this year on Neoclassical Toroidal Viscosity, which ran well; more will be tried next year. In this special section of Plasma Physics and Controlled Fusion we present several of the invited and contributed papers from the 2010 workshop, which have been subject to the normal refereeing procedures of the journal. These papers give a sense of the exceptional quality of the presentations at this workshop, all of which may be found at http

  19. Development of a Compact & Easy-to-Use 3-D Camera for High Speed Turbulent Flow Fields

    DTIC Science & Technology

    2013-12-05

    the 2-D Radon transform to 3-D space, i.e., the 3-D Radon transform. It is proposed that the 3-D Radon transform also has an inverse as does the 2-D...Nishimura, D.G., Principles of magnetic resonance imaging. 1996: Stanford University. 41. Deans, S.R., The Radon transform and some of its applications...2007: DoverPublications. com. 42. Averbuch, A. and Y. Shkolnisky, 3D Fourier based discrete Radon transform. Applied and Computational Harmonic

  20. Numerical simulations of full-wave fields and analysis of channel wave characteristics in 3-D coal mine roadway models

    NASA Astrophysics Data System (ADS)

    Yang, Si-Tong; Wei, Jiu-Chuan; Cheng, Jiu-Long; Shi, Long-Qing; Wen, Zhi-Jie

    2016-12-01

    Currently, numerical simulations of seismic channel waves for the advance detection of geological structures in coal mine roadways focus mainly on modeling twodimensional wave fields and therefore cannot accurately simulate three-dimensional (3-D) full-wave fields or seismic records in a full-space observation system. In this study, we use the first-order velocity-stress staggered-grid finite difference algorithm to simulate 3-D full-wave fields with P-wave sources in front of coal mine roadways. We determine the three components of velocity V x, V y, and V z for the same node in 3-D staggered-grid finite difference models by calculating the average value of V y, and V z of the nodes around the same node. We ascertain the wave patterns and their propagation characteristics in both symmetrical and asymmetric coal mine roadway models. Our simulation results indicate that the Rayleigh channel wave is stronger than the Love channel wave in front of the roadway face. The reflected Rayleigh waves from the roadway face are concentrated in the coal seam, release less energy to the roof and floor, and propagate for a longer distance. There are surface waves and refraction head waves around the roadway. In the seismic records, the Rayleigh wave energy is stronger than that of the Love channel wave along coal walls of the roadway, and the interference of the head waves and surface waves with the Rayleigh channel wave is weaker than with the Love channel wave. It is thus difficult to identify the Love channel wave in the seismic records. Increasing the depth of the receivers in the coal walls can effectively weaken the interference of surface waves with the Rayleigh channel wave, but cannot weaken the interference of surface waves with the Love channel wave. Our research results also suggest that the Love channel wave, which is often used to detect geological structures in coal mine stopes, is not suitable for detecting geological structures in front of coal mine roadways

  1. Predictions of the cycle-to-cycle aerodynamic loads on a yawed wind turbine blade under stalled conditions using a 3D empirical stochastic model

    NASA Astrophysics Data System (ADS)

    ELGAMMI, MOUTAZ; SANT, TONIO

    2016-09-01

    This paper investigates a new approach to model the stochastic variations in the aerodynamic loads on yawed wind turbines experienced at high angles of attack. The method applies the one-dimensional Langevin equation in conjunction with known mean and standard deviation values for the lift and drag data. The method is validated using the experimental data from the NREL Phase VI rotor in which the mean and standard deviation values for the lift and drag are derived through the combined use of blade pressure measurements and a free-wake vortex model. Given that direct blade pressure measurements are used, 3D flow effects arising from the co-existence of dynamic stall and stall delay are taken into account. The model is an important step towards verification of several assumptions characterized as the estimated standard deviation, Gaussian white noise of the data and the estimated drift and diffusion coefficients of the Langevin equation. The results using the proposed assumptions lead to a good agreement with measurements over a wide range of operating conditions. This provides motivation to implement a general fully independent theoretical stochastic model within a rotor aerodynamics model, such as the free-wake vortex or blade-element momentum code, whereby the mean lift and drag coefficients can be estimated using 2D aerofoil data with correction models for 3D dynamic stall and stall delay phenomena, while the corresponding standard derivations are estimated through CFD.

  2. INCREASING OIL RECOVERY THROUGH ADVANCED REPROCESSING OF 3D SEISMIC, GRANT CANYON AND BACON FLAT FIELDS, NYE COUNTY, NEVADA

    SciTech Connect

    Eric H. Johnson; Don E. French

    2001-06-01

    Makoil, Inc., of Orange, California, with the support of the U.S. Department of Energy has reprocessed and reinterpreted the 3D seismic survey of the Grant Canyon area, Railroad Valley, Nye County, Nevada. The project was supported by Dept. of Energy Grant DE-FG26-00BC15257. The Grant Canyon survey covers an area of 11 square miles, and includes Grant Canyon and Bacon Flat oil fields. These fields have produced over 20 million barrels of oil since 1981, from debris slides of Devonian rocks that are beneath 3,500 to 5,000 ft of Tertiary syntectonic deposits that fill the basin of Railroad Valley. High-angle and low-angle normal faults complicate the trap geometry of the fields, and there is great variability in the acoustic characteristics of the overlying valley fill. These factors combine to create an area that is challenging to interpret from seismic reflection data. A 3D seismic survey acquired in 1992-93 by the operator of the fields has been used to identify development and wildcat locations with mixed success. Makoil believed that improved techniques of processing seismic data and additional well control could enhance the interpretation enough to improve the chances of success in the survey area. The project involved the acquisition of hardware and software for survey interpretation, survey reprocessing, and reinterpretation of the survey. SeisX, published by Paradigm Geophysical Ltd., was chosen as the interpretation software, and it was installed on a Dell Precision 610 computer work station with the Windows NT operating system. The hardware and software were selected based on cost, possible addition of compatible modeling software in the future, and the experience of consulting geophysicists in the Billings area. Installation of the software and integration of the hardware into the local office network was difficult at times but was accomplished with some technical support from Paradigm and Hewlett Packard, manufacturer of some of the network equipment. A

  3. Isoparametric fitting: A method for approximating full-field experimental data distributed on any shaped 3D domain

    NASA Astrophysics Data System (ADS)

    Bruno, Luigi

    2016-12-01

    With the present paper, the author proposes a fitting method for approximating experimental data retrieved from any full-field technique. Unlike most of the fitting procedures, the method works on data distributed on a surface of any shape, and the mathematical model is able to take into account of both the 3D shape of the surface and of the experimental quantity to be fitted. The paper reports all the mathematical steps necessary for applying the method, which was tested on two sets of experimental data obtained by an out-of-plane speckle interferometer working in two different conditions of noise. Experimental results showed the capability of the method to work in presence of high level of noise.

  4. Operational Generation of Urban Wind Fields to Support Transport and Dispersion Modeling

    NASA Astrophysics Data System (ADS)

    Copeland, J. H.; Sheu, R.; Brown, M. J.

    2007-12-01

    A realistic wind field is a key component to any transport and dispersion model simulation. In the urban environment observing the wind field accurately is complicated by the presence of the building structures themselves. In situ measurements are only representative over a limited area near the point of observation due to the influence of nearby buildings. Winds observed remotely, via radar or lidar, have good spatial resolution, but are limited to making measurements above rooftop. The Urban Shield project is an emergency response system for hazardous atmospheric releases in Arlington County Virginia. To provide building aware wind fields over a 100 square kilometer area for transport and dispersion modeling we use a combined approach of remotely sensed wind observations and very high resolution, ~10 meters, diagnostic wind modeling. In brief, the system uses 3-D wind analyses from Doppler radar and lidar as input to Los Alamos National Laboratory's QUIC-Urb empirical wind model. An overview of the system and results will be presented.

  5. Solar Wind Halo Formation by the Scattering of the Strahl: Direct Cluster/PEACE Observations of the 3D Velocity Distribution Function

    NASA Astrophysics Data System (ADS)

    Vinas, A. F.; Gurgiolo, C. A.; Nieves-Chinchilla, T.; Wendel, D. E.; Goldstein, M. L.; Fazakerley, A. N.

    2010-12-01

    The current hypothesis of the formation of the solar wind halo electrons is that they are produced from scattering of the strahl. This hypothesis is strengthened by direct observations of the strahl electrons being scattered into the halo in an isolated event. On frequent occasions we have observed in electron angular skymaps (Phi/Theta-plots) of the electron 3D velocity distribution functions, a bursty-filament of particles connecting the strahl to the solar wind core-halo. These are seen over a limited energy range. The observation implies that the formation of the halo is not a continuous process but occurs in bursts in regions where conditions for wave growth providing the scattering are optimum. Sometimes, observations indicates that the strahl component is anisotropic (Tper/Tpal ~ 2). This provides a possible free energy source for the excitation of whistler waves as a possible scattering mechanism, however this condition is not always observed. The empirical observational evidence between the halo and the strahl suggests that the strahl population may be, at least in part, the source of the halo component.

  6. The Effect of Dissipation Mechanism and Guide Field Strength on X-line Spreading in 3D Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Shepherd, Lucas; Cassak, P.; Drake, J.; Gosling, J.; Phan, T.; Shay, M. A.

    2013-07-01

    In two-ribbon flares, the fact that the ribbons separate in time is considered evidence of magnetic reconnection. However, in addition to the ribbons separating, they can also elongate (as seen in animations of, for example, the Bastille Day flare). The elongation is undoubtedly related to the reconnection spreading in the out-of-plane direction. Indeed, naturally occurring magnetic reconnection generally begins in a spatially localized region and spreads in the direction perpendicular to the reconnection plane as time progresses. For example, it was suggested that X-line spreading is necessary to explain the observation of X-lines extending more than 390 Earth radii (Phan et al., Nature, 404, 848, 2006), and has been seen in reconnection experiments. A sizeable out-of-plane (guide) magnetic field is present at flare sites and in the solar wind. Here, we study the effect of dissipation mechanism and the strength of the guide field has on X-line spreading. We present results from three-dimensional numerical simulations of magnetic reconnection, comparing spreading with the Hall term to spreading with anomalous resistivity. Applications to solar flares and magnetic reconnection in the solar wind will be discussed.

  7. Calibrating MMS Electron Drift Instrument (EDI) Ambient Electron Flux Measurements and Characterizing 3D Electric Field Signatures of Magnetic Reconnection

    NASA Astrophysics Data System (ADS)

    Shuster, J. R.; Torbert, R. B.; Vaith, H.; Argall, M. R.; Li, G.; Chen, L. J.; Ergun, R. E.; Lindqvist, P. A.; Marklund, G. T.; Khotyaintsev, Y. V.; Russell, C. T.; Magnes, W.; Le Contel, O.; Pollock, C. J.; Giles, B. L.

    2015-12-01

    The electron drift instruments (EDIs) onboard each MMS spacecraft are designed with large geometric factors (~0.01cm2 str) to facilitate detection of weak (~100 nA) electron beams fired and received by the two gun-detector units (GDUs) when EDI is in its "electric field mode" to determine the local electric and magnetic fields. A consequence of the large geometric factor is that "ambient mode" electron flux measurements (500 eV electrons having 0°, 90°, or 180° pitch angle) can vary depending on the orientation of the EDI instrument with respect to the magnetic field, a nonphysical effect that requires a correction. Here, we present determinations of the θ- and ø-dependent correction factors for the eight EDI GDUs, where θ (ø) is the polar (azimuthal) angle between the GDU symmetry axis and the local magnetic field direction, and compare the corrected fluxes with those measured by the fast plasma instrument (FPI). Using these corrected, high time resolution (~1,000 samples per second) ambient electron fluxes, combined with the unprecedentedly high resolution 3D electric field measurements taken by the spin-plane and axial double probes (SDP and ADP), we are equipped to accurately detect electron-scale current layers and electric field waves associated with the non-Maxwellian (anisotropic and agyrotropic) particle distribution functions predicted to exist in the reconnection diffusion region. We compare initial observations of the diffusion region with distributions and wave analysis from PIC simulations of asymmetric reconnection applicable for modeling reconnection at the Earth's magnetopause, where MMS will begin Science Phase 1 as of September 1, 2015.

  8. The 3-D strain patterns in Turkey using geodetic velocity fields from the RTK-CORS (TR) network

    NASA Astrophysics Data System (ADS)

    Kutoglu, Hakan Senol; Toker, Mustafa; Mekik, Cetin

    2016-03-01

    This study presents our use of GPS data to obtain and quantify the full continuous strain tensor using a 3-D velocity field in Turkey. In this study, GPS velocities improve the estimation of short-term strain tensor fields for determining the seismic hazard of Turkey. The tensorial analysis presents different aspects of deformation, such as the normal and shear strains, including their directions, the compressional and extensional strains. This analysis is appropriate for the characterizing the state of the current seismic deformation. GPS velocity data from continuous measurements (2009-2012) to estimate deformations were processed using the GAMIT/GLOBK software. Using high-rate GPS data from permanent 146 GNSS stations (RTK-CORS-TR network), the strain distribution was determined and interpolated using a biharmonic spline technique. We show the strain field patterns within axial and plane form at several critical locations, and discuss these results within the context of the seismic and tectonic deformation of Turkey. We conclude that the knowledge of the crustal strain patterns provides important information on the location of the main faults and strain accumulation for the hazard assessment. The results show an agreement between the seismic and tectonic strains confirming that there are active crustal deformations in Turkey.

  9. 3D tomographic reconstruction of the internal velocity field of an immiscible drop in a shear flow

    NASA Astrophysics Data System (ADS)

    Kerdraon, Paul; Dalziel, Stuart B.; Goldstein, Raymond E.; Landel, Julien R.; Peaudecerf, Francois J.

    2015-11-01

    We study experimentally the internal flow of a drop attached to a flat substrate and immersed in an immiscible shear flow. Transport inside the drop can play a crucial role in cleaning applications. Internal advection can enhance the mass transfer across the drop surface, thus increasing the cleaning rate. We used microlitre water-glycerol drops on a hydrophobic substrate. The drops were spherical and did not deform significantly under the shear flow. An oil phase of relative viscosity 0.01 to 1 was flowed over the drop. Typical Reynolds numbers inside the drops were of the order of 0.1 to 10. Using confocal microscopy, we performed 3D tomographic reconstruction of the flow field in the drop. The in-plane velocity field was measured using micro-PIV, and the third velocity component was computed from incompressibility. To our knowledge, this study gives the first experimental measurement of the three-dimensional internal velocity field of a drop in a shear flow. Numerical simulations and theoretical models published in the past 30 years predict a toroidal internal recirculation flow, for which the entire surface flows streamwise. However, our measurements reveal a qualitatively different picture with a two-lobed recirculation, featuring two stagnation points at the surface and a reverse surface flow closer to the substrate. This finding appears to be independent of Reynolds number and viscosity ratio in the ranges studied; we conjecture that the observed flow is due to the effect of surfactants at the drop surface.

  10. Comparison Between Field Data and NASA Ames Wind Tunnel Data

    SciTech Connect

    Corbus, D.

    2005-11-01

    The objective of this analysis is to compare the measured data from the NASA Ames wind tunnel experiment to those collected in the field at the National Wind Technology Center (NWTC) with the same turbine configuration. The results of this analysis provide insight into what measurements can be made in the field as opposed to wind tunnel testing.

  11. Wind measurements for non-uniform wind fields from spaceborne scatterometers

    NASA Technical Reports Server (NTRS)

    Chi, Chong-Yung; Li, Fuk K.

    1987-01-01

    Radar backscattering coefficient measurements by spaceborne scatterometers are presently simulated for the case of nonuniform wind fields, by means of a detailed numerical integration of the radar equation. The winds thus estimated are then compared with a nominal field which is defined as the average wind vector over the wind cell. The simulation results obtained for the NASA scatterometer are presented for cases of random wind fields whose spectra are consistent with the Seasat scatterometer sea surface wind spectrum. When the nonuniformity is small, system noise dominates the wind error; wind error degradation is therefore small for both perfect and imperfect coregistration cases. When it is relatively large, however, the wind error degradation persistently increases for both perfect and imperfect coregistrations.

  12. Comparison Study of SEASAT Scatterometer and Conventional Wind Fields

    DTIC Science & Technology

    1988-10-01

    Support was provided by the United States Navy through the Massachusetts Institute of Technology. I Reproduction in whole or in part is permitted for any...remotely sensing surface wind information, developed in response to this requirement for a surface wind field with global coverage and improved spatial...winds provide a unique set of scatterometer wind information for a global comparison with winds from conventional sources. A one-month (12 August to 9

  13. Polymorphism, crystal nucleation and growth in the phase-field crystal model in 2D and 3D

    NASA Astrophysics Data System (ADS)

    Tóth, Gyula I.; Tegze, György; Pusztai, Tamás; Tóth, Gergely; Gránásy, László

    2010-09-01

    We apply a simple dynamical density functional theory, the phase-field crystal (PFC) model of overdamped conservative dynamics, to address polymorphism, crystal nucleation, and crystal growth in the diffusion-controlled limit. We refine the phase diagram for 3D, and determine the line free energy in 2D and the height of the nucleation barrier in 2D and 3D for homogeneous and heterogeneous nucleation by solving the respective Euler-Lagrange (EL) equations. We demonstrate that, in the PFC model, the body-centered cubic (bcc), the face-centered cubic (fcc), and the hexagonal close-packed structures (hcp) compete, while the simple cubic structure is unstable, and that phase preference can be tuned by changing the model parameters: close to the critical point the bcc structure is stable, while far from the critical point the fcc prevails, with an hcp stability domain in between. We note that with increasing distance from the critical point the equilibrium shapes vary from the sphere to specific faceted shapes: rhombic dodecahedron (bcc), truncated octahedron (fcc), and hexagonal prism (hcp). Solving the equation of motion of the PFC model supplied with conserved noise, solidification starts with the nucleation of an amorphous precursor phase, into which the stable crystalline phase nucleates. The growth rate is found to be time dependent and anisotropic; this anisotropy depends on the driving force. We show that due to the diffusion-controlled growth mechanism, which is especially relevant for crystal aggregation in colloidal systems, dendritic growth structures evolve in large-scale isothermal single-component PFC simulations. An oscillatory effective pair potential resembling those for model glass formers has been evaluated from structural data of the amorphous phase obtained by instantaneous quenching. Finally, we present results for eutectic solidification in a binary PFC model.

  14. Wind loads on flat plate photovoltaic array fields (nonsteady winds)

    NASA Technical Reports Server (NTRS)

    Miller, R. D.; Zimmerman, D. K.

    1981-01-01

    Techniques to predict the dynamic response and the structural dynamic loads of flat plate photovoltaic arrays due to wind turbulence were analyzed. Guidelines for use in predicting the turbulent portion of the wind loading on future similar arrays are presented. The dynamic response and the loads dynamic magnification factor of the two array configurations are similar. The magnification factors at a mid chord and outer chord location on the array illustrated and at four points on the chord are shown. The wind tunnel test experimental rms pressure coefficient on which magnification factors are based is shown. It is found that the largest response and dynamic magnification factor occur at a mid chord location on an array and near the trailing edge. A technique employing these magnification factors and the wind tunnel test rms fluctuating pressure coefficients to calculate design pressure loads due to wind turbulence is presented.

  15. Possibilities and limitations of the ART-Sample algorithm for reconstruction of 3D temperature fields and the influence of opaque obstacles.

    PubMed

    Li, Yuanyang; Herman, Cila

    2013-07-01

    The need for the measurement of complex, unsteady, three-dimensional (3D) temperature distributions arises in a variety of engineering applications, and tomographic techniques are applied to accomplish this goal. Holographic interferometry (HI), one of the optical methods used for visualizing temperature fields, combined with tomographic reconstruction techniques requires multi-directional interferometric data to recover the 3D information. However, the presence of opaque obstacles (such as solid objects in the flow field and heaters) in the measurement volume, prevents the probing light beams from traversing the entire measurement volume. As a consequence, information on the average value of the field variable will be lost in regions located in the shade of the obstacle. The capability of the ART-Sample tomographic reconstruction method to recover 3D temperature distributions both in unobstructed temperature fields and in the presence of opaque obstacles is discussed in this paper. A computer code for tomographic reconstruction of 3D temperature fields from 2D projections was developed. In the paper, the reconstruction accuracy is discussed quantitatively both without and with obstacles in the measurement volume for a set of phantom functions mimicking realistic temperature distributions. The reconstruction performance is optimized while minimizing the number of irradiation directions (experimental hardware requirements) and computational effort. For the smooth temperature field both with and without obstacles, the reconstructions produced by this algorithm are good, both visually and using quantitative criteria. The results suggest that the location and the size of the obstacle and the number of viewing directions will affect the reconstruction of the temperature field. When the best performance parameters of the ART-Sample algorithm identified in this paper are used to reconstruct the 3D temperature field, the 3D reconstructions with and without obstacle are

  16. GPU-based, parallel-line, omni-directional integration of measured acceleration field to obtain the 3D pressure distribution

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Zhang, Cao; Katz, Joseph

    2016-11-01

    A PIV based method to reconstruct the volumetric pressure field by direct integration of the 3D material acceleration directions has been developed. Extending the 2D virtual-boundary omni-directional method (Omni2D, Liu & Katz, 2013), the new 3D parallel-line omni-directional method (Omni3D) integrates the material acceleration along parallel lines aligned in multiple directions. Their angles are set by a spherical virtual grid. The integration is parallelized on a Tesla K40c GPU, which reduced the computing time from three hours to one minute for a single realization. To validate its performance, this method is utilized to calculate the 3D pressure fields in isotropic turbulence and channel flow using the JHU DNS Databases (http://turbulence.pha.jhu.edu). Both integration of the DNS acceleration as well as acceleration from synthetic 3D particles are tested. Results are compared to other method, e.g. solution to the Pressure Poisson Equation (e.g. PPE, Ghaemi et al., 2012) with Bernoulli based Dirichlet boundary conditions, and the Omni2D method. The error in Omni3D prediction is uniformly low, and its sensitivity to acceleration errors is local. It agrees with the PPE/Bernoulli prediction away from the Dirichlet boundary. The Omni3D method is also applied to experimental data obtained using tomographic PIV, and results are correlated with deformation of a compliant wall. ONR.

  17. The geothermal field below the city of Berlin, Germany: Results from structurally and parametrically improved 3D Models

    NASA Astrophysics Data System (ADS)

    Frick, Maximilian; Sippel, Judith; Cacace, Mauro; Scheck-Wenderoth, Magdalena

    2016-04-01

    The goal of this study was to quantify the influence of the geological structure and geophysical parametrization of model units on the geothermal field as calculated by 3D numerical simulations of coupled fluid and heat transport for the subsurface of Berlin, Germany. The study area is located in the Northeast German Basin which is filled with several kilometers of sediments. This sedimentary infill includes the clastic sedimentary units Middle Buntsandstein and Sedimentary Rotliegend which are of particular interest for geothermal exploration. Previous studies conducted in the Northeast German Basin have already shown the geometries and properties of the geological units majorly control the distribution of subsurface temperatures. In this study we followed a two-step approach, where we first improved an existing structural model by integrating newly available 57 geological cross-sections, well data and deep seismics (down to ~4 km). Secondly, we performed a sensitivity analysis investigating the effects of varying physical fluid and rock properties on the subsurface temperature field. The results of this study show, that the structural configuration of model units exerts the highest influence on the geothermal field (up to ± 23 K at 1000 m below sea level). Here, the Rupelian clay aquitard, displaying a heterogeneous thickness distribution, locally characterized by hydrogeological windows (i.e. domains of no thickness) enabling intra-aquifer groundwater circulation has been identified as major controlling factor. The new structural configuration of this unit (more continuous, less numerous hydrogeological windows) also leads to a reduction of the influence of different boundary conditions and heat transport mechanisms considered. Additionally, the models results show that calculated temperatures highly depend on geophysical properties of model units whereas the hydraulic conductivity of the Cenozoic succession was identified as most dominant, leading to changes

  18. A 3D MOF constructed from dysprosium(III) oxalate and capping ligands: ferromagnetic coupling and field-induced two-step magnetic relaxation.

    PubMed

    Liu, Cai-Ming; Zhang, De-Qing; Zhu, Dao-Ben

    2016-04-04

    A novel 3D MOF based on dysprosium(iii) oxalate and 1,10-phenanthroline (phen), {[Dy(C2O4)1.5phen]·0.5H2O}n (1), has been hydrothermally synthesized. The Dy(3+) ion acts as a typical Y-shaped node, linking to each other to generate an interesting 3D topology structure. Complex 1 is the first 3D DyMOF displaying both ferromagnetic coupling and field-induced two-step magnetic relaxation.

  19. The Astrobiology Field Guide in World Wind

    NASA Astrophysics Data System (ADS)

    Scalice, D. M.

    2004-12-01

    In collaboration with the Australian Centre for Astrobiology (ACA), and NASA Learning Technologies (NLT), and utilizing the powerful visualization capabilities of their "World Wind" software, the NASA Astrobiology Institute (NAI) is crafting a prototype "Astrobiology Field Guide" to bring the field experiences and stories of astrobiology science to the public and classrooms around the world. The prototype focuses on one region in particular - The Pilbara in Western Australia. This first Field Guide "hotspot" is an internationally recognized area hosting the best known example of the earliest evidence of life on Earth - a stromatolitic chert precipitation in the 3.45 Ga Warrawoona Group. The goal of the Astrobiology Field Guide is to engage students of all ages with the ongoing field expeditions of today's astrobiologists as they explore the ends of the Earth searching for clues to life's origin, evolution, and distribution in the Universe. The NAI hopes to expand this Field Guide to include many more astrobiologically relevant areas across the globe such as Cuatro Cienegas in Mexico, the Rio Tinto in Spain, Yellowstone National Park in the US, and the Lost City hydrothermal vent field on the mid-Atlantic ridge - and possibly sites on Mars. To that end, we will be conducting feasibility studies and evaluations with informal and formal education contacts. The Astrobiology Field Guide is also serving as a cornerstone to educational materials being developed focused on the Pilbara region for use in classrooms in Australia, the UK, and potentially the US. These materials are being developed by the Australian Centre for Astrobiology, and the ICT Innovations Centre at Macquarie University in Sydney, in collaboration with the NAI and the Centre for Astronomy and Science Education at the University of Glamorgan in the UK.

  20. Potential Geophysical Field Transformations and Combined 3D Modelling for Estimation the Seismic Site Effects on Example of Israel

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev; Meirova, Tatiana

    2015-04-01

    It is well-known that the local seismic site effects may have a significant contribution to the intensity of damage and destruction (e.g., Hough et al., 1990; Regnier et al., 2000; Bonnefoy-Claudet et al., 2006; Haase et al., 2010). The thicknesses of sediments, which play a large role in amplification, usually are derived from seismic velocities. At the same time, thickness of sediments may be determined (or defined) on the basis of 3D combined gravity-magnetic modeling joined with available geological materials, seismic data and borehole section examination. Final result of such investigation is a 3D physical-geological model (PGM) reflecting main geological peculiarities of the area under study. Such a combined study needs in application of a reliable 3D mathematical algorithm of computation together with advanced methodology of 3D modeling. For this analysis the developed GSFC software was selected. The GSFC (Geological Space Field Calculation) program was developed for solving a direct 3-D gravity and magnetic prospecting problem under complex geological conditions (Khesin et al., 1996; Eppelbaum and Khesin, 2004). This program has been designed for computing the field of Δg (Bouguer, free-air or observed value anomalies), ΔZ, ΔX, ΔY , ΔT , as well as second derivatives of the gravitational potential under conditions of rugged relief and inclined magnetization. The geological space can be approximated by (1) three-dimensional, (2) semi-infinite bodies and (3) those infinite along the strike closed, L.H. non-closed, R.H. on-closed and open). Geological bodies are approximated by horizontal polygonal prisms. The program has the following main advantages (besides abovementioned ones): (1) Simultaneous computing of gravity and magnetic fields; (2) Description of the terrain relief by irregularly placed characteristic points; (3) Computation of the effect of the earth-air boundary by the method of selection directly in the process of interpretation; (4

  1. Field Trial Results of a 14-channel GPR Integrated with a U.S. Program for 3-D Utility Mapping

    NASA Astrophysics Data System (ADS)

    Anspach, James H.

    2013-04-01

    utilities were mostly undetectable. Through a ground-truthing program of test holes to expose utilities, the depth values derived from the enhanced GPR were fairly consistent and within 15 cm of actual depth. The incomplete underground picture determined by the enhanced GPR reinforces previous studies that show that the mapping of existing underground utilities is a multi-tool effort that takes highly trained and skilled field technicians and data interpreters. The addition of a new GPR tool is valuable in determining continuous depth profiles of imaged utilities. A second and significant benefit is the interpretation of other geotechnical data that benefit project designers. This might include showing geometry, location, intensity, and depths of either areas of anomalies, or of known structures, such as paving thickness, substrate thickness, voids, water table, soil lenses, boulders, bedrock, and so forth. The Florida Department of Transportation has decided to take advantage of this new technology and has entered into an experimental contract with Cardno TBE to incorporate several enhanced GPR arrays with traditional utility detection tools. The goal of this contract will be to provide a 3-D model of existing underground utilities for use in automated construction. The GPR 3-D data model will be melded with conventional subsurface utility engineering and mapping practices and will be required to follow the ASCE 38 standard for utility data reliability.

  2. REGIONAL-SCALE WIND FIELD CLASSIFICATION EMPLOYING CLUSTER ANALYSIS

    SciTech Connect

    Glascoe, L G; Glaser, R E; Chin, H S; Loosmore, G A

    2004-06-17

    The classification of time-varying multivariate regional-scale wind fields at a specific location can assist event planning as well as consequence and risk analysis. Further, wind field classification involves data transformation and inference techniques that effectively characterize stochastic wind field variation. Such a classification scheme is potentially useful for addressing overall atmospheric transport uncertainty and meteorological parameter sensitivity issues. Different methods to classify wind fields over a location include the principal component analysis of wind data (e.g., Hardy and Walton, 1978) and the use of cluster analysis for wind data (e.g., Green et al., 1992; Kaufmann and Weber, 1996). The goal of this study is to use a clustering method to classify the winds of a gridded data set, i.e, from meteorological simulations generated by a forecast model.

  3. Finite element analysis of a 3D moving vacuum arc for transverse magnetic field contacts based on Gundlach's formula

    NASA Astrophysics Data System (ADS)

    Kwak, Chang-Seob; Kim, Hong-Kyu; Kim, Tae-Hoon; Lee, Se-Hee

    2017-01-01

    A systematic numerical method for analyzing a 3D moving vacuum arc was proposed and tested in this research by using a transverse magnetic field (TMF) contact. The analysis was carried out by employing the finite element method and the experimental energy equation defined by Gundlach's formula. In the literature, the vacuum interrupter has been widely applied to medium-voltage switching circuits. TMF-type contacts use the Lorentz force density to move a high-temperature arc so as to prevent the contacts from being melted and damaged. The material erosion caused by the arc on the electrode's surface is an important process that results in the interruptive capabilities of these vacuum interrupters. In a classical arc model, to move the vacuum arc, it is required that the magneto-hydrodynamics be analyzed in the arc region at each step. However, with this approach convergence is difficult, resulting in a very time-consuming. Therefore, we propose a new technique to predict the behaviors of vacuum arc between two electrodes. This new approach adopts the experimental arc voltage equation between two electrodes defined by Gundlach's formula. We verify our proposed model by comparing its results with the arcing behaviors obtained from earlier experiments.

  4. Full 3D correlation tensor computed from double field stereoscopic PIV in a high Reynolds number turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Foucaut, Jean-Marc; Coudert, Sebastien; Stanislas, Michel; Delville, Joel

    2011-04-01

    The turbulence structure near a wall is a very active subject of research and a key to the understanding and modeling of this flow. Many researchers have worked on this subject since the fifties Hama et al. (J Appl Phys 28:388-394, 1957). One way to study this organization consists of computing the spatial two-point correlations. Stanislas et al. (C R Acad Sci Paris 327(2b):55-61, 1999) and Kahler (Exp Fluids 36:114-130, 2004) showed that double spatial correlations can be computed from stereoscopic particle image velocimetry (SPIV) fields and can lead to a better understanding of the turbulent flow organization. The limitation is that the correlation is only computed in the PIV plane. The idea of the present paper is to propose a new method based on a specific stereoscopic PIV experiment that allows the computation of the full 3D spatial correlation tensor. The results obtained are validated by comparison with 2D computation from SPIV. They are in very good agreement with the results of Ganapthisubramani et al. (J Fluid Mech 524:57-80, 2005a).

  5. Full-field wing deformation measurement scheme for in-flight cantilever monoplane based on 3D digital image correlation

    NASA Astrophysics Data System (ADS)

    Li, Lei-Gang; Liang, Jin; Guo, Xiang; Guo, Cheng; Hu, Hao; Tang, Zheng-Zong

    2014-06-01

    In this paper, a new non-contact scheme, based on 3D digital image correlation technology, is presented to measure the full-field wing deformation of in-flight cantilever monoplanes. Because of the special structure of the cantilever wing, two conjugated camera groups, which are rigidly connected and calibrated to an ensemble respectively, are installed onto the vertical fin of the aircraft and record the whole measurement. First, a type of pre-stretched target and speckle pattern are designed to adapt the oblique camera view for accurate detection and correlation. Then, because the measurement cameras are swinging with the aircraft vertical trail all the time, a camera position self-correction method (using control targets sprayed on the back of the aircraft), is designed to orientate all the cameras’ exterior parameters to a unified coordinate system in real time. Besides, for the excessively inclined camera axis and the vertical camera arrangement, a weak correlation between the high position image and low position image occurs. In this paper, a new dual-temporal efficient matching method, combining the principle of seed point spreading, is proposed to achieve the matching of weak correlated images. A novel system is developed and a simulation test in the laboratory was carried out to verify the proposed scheme.

  6. Fully automated prostate segmentation in 3D MR based on normalized gradient fields cross-correlation initialization and LOGISMOS refinement

    NASA Astrophysics Data System (ADS)

    Yin, Yin; Fotin, Sergei V.; Periaswamy, Senthil; Kunz, Justin; Haldankar, Hrishikesh; Muradyan, Naira; Cornud, François; Turkbey, Baris; Choyke, Peter

    2012-02-01

    Manual delineation of the prostate is a challenging task for a clinician due to its complex and irregular shape. Furthermore, the need for precisely targeting the prostate boundary continues to grow. Planning for radiation therapy, MR-ultrasound fusion for image-guided biopsy, multi-parametric MRI tissue characterization, and context-based organ retrieval are examples where accurate prostate delineation can play a critical role in a successful patient outcome. Therefore, a robust automated full prostate segmentation system is desired. In this paper, we present an automated prostate segmentation system for 3D MR images. In this system, the prostate is segmented in two steps: the prostate displacement and size are first detected, and then the boundary is refined by a shape model. The detection approach is based on normalized gradient fields cross-correlation. This approach is fast, robust to intensity variation and provides good accuracy to initialize a prostate mean shape model. The refinement model is based on a graph-search based framework, which contains both shape and topology information during deformation. We generated the graph cost using trained classifiers and used coarse-to-fine search and region-specific classifier training. The proposed algorithm was developed using 261 training images and tested on another 290 cases. The segmentation performance using mean DSC ranging from 0.89 to 0.91 depending on the evaluation subset demonstrates state of the art performance. Running time for the system is about 20 to 40 seconds depending on image size and resolution.

  7. Runaway electrons mitigation by 3D fields: new insights from ASDEX Upgrade and RFX-mod experiments

    NASA Astrophysics Data System (ADS)

    Gobbin, M.; Papp, G.; Marrelli, L.; McCarthy, P. J.; Nocente, M.; Pautasso, G.; Suttrop, W.; Piovesan, P.; Terranova, D.; Valisa, M.

    2016-10-01

    Disruption-generated runaway electron (RE) beams represent a severe threat for tokamak plasma-facing components, thus motivating the search of mitigation techniques. The application of optimized 3D fields might aid this purpose, as was recently investigated in ASDEX Upgrade and RFX-mod. In ASDEX Upgrade discharges, the application of n =1 resonant magnetic perturbations (RMPs) by the B-coils before and during the disruption results in a longer current quench time together with a lower RE current in the post-disruption phase. The strength of the observed effects depends on the upper-to-lower B-coil phasing, i.e. on the poloidal spectrum of the RMPs. These results are analyzed by means of numerical tools, like the guiding center code ORBIT, and the role of plasma response is also investigated. Similar experiments have been performed in RFX-mod low density plasmas where magnetic perturbations of various amplitudes, applied by non-axisymmetric coils, have been found to partially suppress REs. ORBIT simulations indicate, in this case, that RE orbit losses are associated to a raised level of stochasticity in the edge plasma region.

  8. External control of the Drosophila melanogaster egg to imago development period by specific combinations of 3D low-frequency electric and magnetic fields.

    PubMed

    Makarov, Vladimir I; Khmelinskii, Igor

    2016-01-01

    We report that the duration of the egg-to-imago development period of the Drosophila melanogaster, and the imago longevity, are both controllable by combinations of external 3-dimensional (3D) low-frequency electric and magnetic fields (LFEMFs). Both these periods may be reduced or increased by applying an appropriate configuration of external 3D LFEMFs. We report that the longevity of D. melanogaster imagoes correlates with the duration of the egg-to-imago development period of the respective eggs. We infer that metabolic processes in both eggs and imago are either accelerated (resulting in reduced time periods) or slowed down (resulting in increased time periods). We propose that external 3D LFEMFs induce electric currents in live systems as well as mechanical vibrations on sub-cell, whole-cell and cell-group levels. These external fields induce media polarization due to ionic motion and orientation of electric dipoles that could moderate the observed effects. We found that the longevity of D. melanogaster imagoes is affected by action of 3D LFEMFs on the respective eggs in the embryonic development period (EDP). We interpret this effect as resulting from changes in the regulation mechanism of metabolic processes in D. melanogaster eggs, inherited by the resulting imagoes. We also tested separate effects of either 3D electric or 3D magnetic fields, which were significantly weaker.

  9. Mod-2 wind turbine field operations experiment

    NASA Technical Reports Server (NTRS)

    Gordon, L. H.

    1985-01-01

    The three-machine, 7.5 MW Goodnoe Hills located near Goldendale, Washington and is now in a research/experimental operations phase that offers a unique opportunity to study the effects of single and multiple wind turbines interacting with each other, the power grid; and the environment. Following a brief description of the turbine and project history, this paper addresses major problem areas and research and development test results. Field operations, both routine and nonroutine, are discussed. Routine operation to date has produced over 13,379,000 KWh of electrical energy during 11,064 hr of rotation. Nonroutine operation includes suspended activities caused by a crack in the low speed shaft that necessitated a redesign and reinstallation of this assembly on all three turbines. With the world's largest cluster back in full operation, two of the turbines will be operated over the next years to determine their value as energy producer. The third unit will be used primarily for conducting research tests requiring configuration changes to better understand the wind turbine technology. Technical areas summarized pertain to system performance and enhancements. Specific research tests relating to acoustics, TV interference, and wake effects conclude the paper.

  10. Apparatus and method for using radar to evaluate wind flow fields for wind energy applications

    DOEpatents

    Schroeder, John; Hirth, Brian; Guynes, Jerry

    2017-02-21

    The present invention provides an apparatus and method for obtaining data to determine one or more characteristics of a wind flow field using one or more radars. Data is collected from the one or more radars, and analyzed to determine the one or more characteristics of the wind flow field. The one or more radars are positioned to have a portion of the wind flow field within a scanning sector of the one or more radars.

  11. Reactivating of a mature oil field in the Finca-Yopales area, Venezuela, Using 3-D seismic

    SciTech Connect

    Sanchez, M.; Betancourt, H.

    1996-08-01

    The area of Finca-Yopales is located in the Eastern Venezuelan Basin in the Anzoategui State where Corpoven has the Trico and Yopales Norte fields. Based on the interpretation of 134 km{sup 2} of 3-D seismic and the geologic interpretation from 145 wells in the area, we define a better geological and structural model. We were also able to map 6 seismic reflectors corresponding to the units A8, F7, L4U and SI from the Oficina Formation, U2 top of Merecure Formation and the top of the Cretaceous, in order to generate a fault plane for all the area which was converted to depth with a lineal relationship which was obtained from wells available. From this interpretation we obtain the structural levels B4, J2, M1 and U2 which are references for the area, those being regional and trangressive events. The main feature of the structure is a high at the southeast of the area and three fault systems of Cretaceous, Miocene and post-Miocene age. This area has been exploited for a long time, having more than 93% of the inactive drilled wells. The total production up to April, 1995 is 59.14 MMbls; the Trico field is the most prolific, with more than 95% of the production. The sands L`s, U`s, O`s and S`s are the most prospective. This paper present the evaluation of the area and the analysis of the reservoir where we increased the computed reserves.

  12. The differential algebra based multiple level fast multipole algorithm for 3D space charge field calculation and photoemission simulation

    SciTech Connect

    None, None

    2015-09-28

    Coulomb interaction between charged particles inside a bunch is one of the most importance collective effects in beam dynamics, becoming even more significant as the energy of the particle beam is lowered to accommodate analytical and low-Z material imaging purposes such as in the time resolved Ultrafast Electron Microscope (UEM) development currently underway at Michigan State University. In addition, space charge effects are the key limiting factor in the development of ultrafast atomic resolution electron imaging and diffraction technologies and are also correlated with an irreversible growth in rms beam emittance due to fluctuating components of the nonlinear electron dynamics. In the short pulse regime used in the UEM, space charge effects also lead to virtual cathode formation in which the negative charge of the electrons emitted at earlier times, combined with the attractive surface field, hinders further emission of particles and causes a degradation of the pulse properties. Space charge and virtual cathode effects and their remediation are core issues for the development of the next generation of high-brightness UEMs. Since the analytical models are only applicable for special cases, numerical simulations, in addition to experiments, are usually necessary to accurately understand the space charge effect. In this paper we will introduce a grid-free differential algebra based multiple level fast multipole algorithm, which calculates the 3D space charge field for n charged particles in arbitrary distribution with an efficiency of O(n), and the implementation of the algorithm to a simulation code for space charge dominated photoemission processes.

  13. Predicting the natural state of fractured carbonate reservoirs: An Andector Field, West Texas test of a 3-D RTM simulator

    SciTech Connect

    Tuncay, K.; Romer, S.; Ortoleva, P.; Hoak, T.; Sundberg, K.

    1998-12-31

    The power of the reaction, transport, mechanical (RTM) modeling approach is that it directly uses the laws of geochemistry and geophysics to extrapolate fracture and other characteristics from the borehole or surface to the reservoir interior. The objectives of this facet of the project were to refine and test the viability of the basin/reservoir forward modeling approach to address fractured reservoir in E and P problems. The study attempts to resolve the following issues: role of fracturing and timing on present day location and characteristics; clarifying the roles and interplay of flexure dynamics, changing rock rheological properties, fluid pressuring and tectonic/thermal histories on present day reservoir location and characteristics; and test the integrated RTM modeling/geological data approach on a carbonate reservoir. Sedimentary, thermal and tectonic data from Andector Field, West Texas, were used as input to the RTM basin/reservoir simulator to predict its preproduction state. The results were compared with data from producing reservoirs to test the RTM modeling approach. The effects of production on the state of the field are discussed in a companion report. The authors draw the following conclusions: RTM modeling is an important new tool in fractured reservoir E and P analysis; the strong coupling of RTM processes and the geometric and tensorial complexity of fluid flow and stresses require the type of fully coupled, 3-D RTM model for fracture analysis as pioneered in this project; flexure analysis cannot predict key aspects of fractured reservoir location and characteristics; fracture history over the lifetime of a basin is required to understand the timing of petroleum expulsion and migration and the retention properties of putative reservoirs.

  14. The differential algebra based multiple level fast multipole algorithm for 3D space charge field calculation and photoemission simulation

    DOE PAGES

    None, None

    2015-09-28

    Coulomb interaction between charged particles inside a bunch is one of the most importance collective effects in beam dynamics, becoming even more significant as the energy of the particle beam is lowered to accommodate analytical and low-Z material imaging purposes such as in the time resolved Ultrafast Electron Microscope (UEM) development currently underway at Michigan State University. In addition, space charge effects are the key limiting factor in the development of ultrafast atomic resolution electron imaging and diffraction technologies and are also correlated with an irreversible growth in rms beam emittance due to fluctuating components of the nonlinear electron dynamics.more » In the short pulse regime used in the UEM, space charge effects also lead to virtual cathode formation in which the negative charge of the electrons emitted at earlier times, combined with the attractive surface field, hinders further emission of particles and causes a degradation of the pulse properties. Space charge and virtual cathode effects and their remediation are core issues for the development of the next generation of high-brightness UEMs. Since the analytical models are only applicable for special cases, numerical simulations, in addition to experiments, are usually necessary to accurately understand the space charge effect. In this paper we will introduce a grid-free differential algebra based multiple level fast multipole algorithm, which calculates the 3D space charge field for n charged particles in arbitrary distribution with an efficiency of O(n), and the implementation of the algorithm to a simulation code for space charge dominated photoemission processes.« less

  15. MONTE GENEROSO ROCKFALL FIELD TEST (SWITZERLAND): Real size experiment to constraint 2D and 3D rockfall simulations

    NASA Astrophysics Data System (ADS)

    Humair, F.; Matasci, B.; Carrea, D.; Pedrazzini, A.; Loye, A.; Pedrozzi, G.; Nicolet, P.; Jaboyedoff, M.

    2012-04-01

    account the results of the experimental testing are performed and compared with the a-priori simulations. 3D simulations were performed using a software that takes into account the effect of the forest cover in the blocky trajectory (RockyFor 3D) and an other that neglects this aspect (Rotomap; geo&soft international). 2D simulation (RocFall; Rocscience) profiles were located in the blocks paths deduced from 3D simulations. The preliminary results show that: (1) high speed movies are promising and allow us to track the blocks using video software, (2) the a-priori simulations tend to overestimate the runout distance which is certainly due to an underestimation of the obstacles as well as the breaking of the failing rocks which is not taken into account in the models, (3) the trajectories deduced from both a-priori simulation and real size experiment highlights the major influence of the channelized slope morphology on rock paths as it tends to follow the flow direction. This indicates that the 2D simulation have to be performed along the line of flow direction.

  16. Simulation of the surface wind field and wind waves over the Oman Sea

    NASA Astrophysics Data System (ADS)

    Hamzeloo, Sima; Hadi Moeini, Mohammad; Jandaghi Alaee, Majid

    2016-04-01

    Surface wind field is one of the most important factors in the generation of the marine hydrodynamic phenomena such as wind waves that highly affected by the surface winds. Therefore, accessibility to the correct wind field is of great importance for accurate prediction and simulation of the hydrodynamic variables. Nowadays numerical mesoscale weather prediction models are widely applied as powerful tools to simulate wind and other atmospheric variables with predefined temporal and spatial resolution in desired areas. Despite appropriate results of the numerical models in many regions, there are still some complications in the simulation of the surface wind field in areas with complex orography since the surface wind field is highly affected by the local topography, land-sea discontinuity, temperature gradient etc. Nowadays, with the development of high-speed processors the third generation spectral models are generally used for simulation of wind waves. Wind data are the main input parameters of the numerical spectral wave model. Therefore, the quality of the input wind data can be assessed by comparison of the wave model outputs with measured values. The main goal of the current study is to simulate surface wind field over the Oman Sea using WRF modeling system. To verify the model results, the simulated wind speeds were compared with synoptic and buoy measurements and satellite observations. Wind-wave parameters simulated by the spectral model were also compared with wave measurements to verify simulated surface wind field as the input of the wave model. The Comparison simulated wind speed and directions in coastal synoptic stations and QuikSCAT satellite shows sufficient results for both offshore and coastal areas.

  17. SU-E-T-596: Axillary Nodes Radiotherapy Boost Field Dosimetric Impact Study: Oblique Field and Field Optimization in 3D Conventional Breast Cancer Radiation Treatment

    SciTech Connect

    Su, M; Sura, S

    2014-06-01

    Purpose: To evaluate dosimetric impact of two axillary nodes (AX) boost techniques: (1) posterior-oblique optimized field boost (POB), (2) traditional posterior-anterior boost (PAB) with field optimization (O-PAB), for a postmastectomy breast patient with positive axillary lymph nodes. Methods: Five patients, 3 left and 2 right chest walls, were included in this study. All patients were simulated in 5mm CT slice thickness. Supraclavicular (SC) and level I/II/III AX were contoured based on the RTOG atlas guideline. Five treatment plans, (1) tangential chest wall, (2) oblique SC including AX, (3) PAB, O-PAB and POB, were created for each patient. Three plan sums (PS) were generated by sum one of (3) plan with plan (1) and (2). The field optimization was done through PS dose distribution, which included a field adjustment, a fractional dose, a calculation location and a gantry angle selection for POB. A dosimetric impact was evaluated by comparing a SC and AX coverage, a PS maximum dose, an irradiated area percentage volume received dose over 105% prescription dose (V105), an ipsi-laterial mean lung dose (MLD), an ipsi-laterial mean humeral head dose (MHHD), a mean heart dose (MHD) (for left case only) and their DVH amount these three technique. Results: O-PAB, POB and PAB dosimetric results showed that there was no significant different on SC and AX coverage (p>0.43) and MHD (p>0.16). The benefit of sparing lung irradiation from PAB to O-PAB to POB was significant (p<0.004). PAB showed a highest PS maximum dose (p<0.005), V105 (p<0.023) and MLD (compared with OPAB, p=0.055). MHHD showed very sensitive to the patient arm positioning and anatomy. O-PAB convinced a lower MHHD than PAB (p=0.03). Conclusion: 3D CT contouring plays main role in accuracy radiotherapy. Dosimetric advantage of POB and O-PAB was observed for a better normal tissue irradiation sparing.

  18. Calibrating Phase Delay Measurements and Comparison of 3-D Waveform Kernels with and without Near-field Terms

    NASA Astrophysics Data System (ADS)

    Bremner, P. M.; Panning, M. P.

    2012-12-01

    We present the calibration of an automated scheme to properly window the fundamental surface wave mode of an event record. Multi-taper fundamental mode phase delay measurements were made on a synthetic dataset. Measurement errors are reduced when minimal over tone energy is included in the window. The time window is calibrated by simply varying the minimum and maximum surface wave velocities used to determine the beginning and ending window times with source-receiver distance, as opposed to constant velocities. We compare phase delay measurements with and without calibration against measurements made manually. Manual window setting of a small representative subset of event seismograms are used to adjust these minimum and maximum surface wave velocities. The orthogonal 2.5π-prolate spheroidal wave function eigentapers (Slepian tapers) used in multi-taper methods reduce noise biasing, and can provide error estimates in phase delay measurements. Additionally, we examine the effects of excluding near-field terms in the calculation of 3-D finite-frequency waveform kernels for Rayleigh and Love waves on a synthetic dataset. Two methods of kernel calculation based on the single scatterer Born approximation are compared, that of Panning and Nolet (2008) and Zhao and Chevrot (2011). The Panning and Nolet (2008) method calculates the strain Green's tensors for the source-scatterer and scatterer-receiver paths by the summation of asymptotic surface wave modes, which is an inherently far-field approximation. Waveform kernels are then found by convolution (in the time domain) of these strain Green's tensors. The kernels are formulated based on a hexagonal symmetry with an arbitrary orientation. The Zhao and Chevrot (2011) method creates a database of the set of strain Green's tensors for the source-scatterer (two-sided strain Green's tensor) and scatterer-receiver (one-sided strain Green's tensor) paths, and is calculated by normal mode summation. The full-wave waveform

  19. Wind loads on flat plate photovoltaic array fields

    NASA Technical Reports Server (NTRS)

    Miller, R. D.; Zimmerman, D. K.

    1981-01-01

    The results of an experimental analysis (boundary layer wind tunnel test) of the aerodynamic forces resulting from winds acting on flat plate photovoltaic arrays are presented. Local pressure coefficient distributions and normal force coefficients on the arrays are shown and compared to theoretical results. Parameters that were varied when determining the aerodynamic forces included tilt angle, array separation, ground clearance, protective wind barriers, and the effect of the wind velocity profile. Recommended design wind forces and pressures are presented, which envelop the test results for winds perpendicular to the array's longitudinal axis. This wind direction produces the maximum wind loads on the arrays except at the array edge where oblique winds produce larger edge pressure loads. The arrays located at the outer boundary of an array field have a protective influence on the interior arrays of the field. A significant decrease of the array wind loads were recorded in the wind tunnel test on array panels located behind a fence and/or interior to the array field compared to the arrays on the boundary and unprotected from the wind. The magnitude of this decrease was the same whether caused by a fence or upwind arrays.

  20. Computation of load performance and other parameters of extra high speed modified Lundell alternators from 3D-FE magnetic field solutions

    NASA Technical Reports Server (NTRS)

    Wang, R.; Demerdash, N. A.

    1992-01-01

    The combined magnetic vector potential - magnetic scalar potential method of computation of 3D magnetic fields by finite elements, introduced in a companion paper, in combination with state modeling in the abc-frame of reference, are used for global 3D magnetic field analysis and machine performance computation under rated load and overload condition in an example 14.3 kVA modified Lundell alternator. The results vividly demonstrate the 3D nature of the magnetic field in such machines, and show how this model can be used as an excellent tool for computation of flux density distributions, armature current and voltage waveform profiles and harmonic contents, as well as computation of torque profiles and ripples. Use of the model in gaining insight into locations of regions in the magnetic circuit with heavy degrees of saturation is demonstrated. Experimental results which correlate well with the simulations of the load case are given.

  1. Simultaneous full-field 3-D vibrometry of the human eardrum using spatial-bandwidth multiplexed holography

    PubMed Central

    Khaleghi, Morteza; Guignard, Jérémie; Furlong, Cosme; Rosowski, John J.

    2015-01-01

    Abstract. Holographic interferometric methods typically require the use of three sensitivity vectors in order to obtain three-dimensional (3-D) information. Methods based on multiple directions of illumination have limited applications when studying biological tissues that have temporally varying responses such as the tympanic membrane (TM). Therefore, to measure 3-D displacements in such applications, the measurements along all the sensitivity vectors have to be done simultaneously. We propose a multiple-illumination directions approach to measure 3-D displacements from a single-shot hologram that contains displacement information from three sensitivity vectors. The hologram of an object of interest is simultaneously recorded with three incoherently superimposed pairs of reference and object beams. The incident off-axis angles of the reference beams are adjusted such that the frequency components of the multiplexed hologram are completely separate. Because of the differences in the directions and wavelengths of the reference beams, the positions of each reconstructed image corresponding to each sensitivity vector are different. We implemented a registration algorithm to accurately translate individual components of the hologram into a single global coordinate system to calculate 3-D displacements. The results include magnitudes and phases of 3-D sound-induced motions of a human cadaveric TM at several excitation frequencies showing modal and traveling wave motions on its surface. PMID:25984986

  2. Bromoform and Dibromomethane Emission During the SHIVA Western Pacific 2011 Field Campaign: A 3-D Model Case Study

    NASA Astrophysics Data System (ADS)

    Mantle, Hannah; Hossaini, Ryan; Chipperfield, Martyn

    2013-04-01

    Halogenated very short-lived species (VSLS) with atmospheric lifetimes of <6 months can be transported to the stratosphere, particularly in regions experiencing rapid vertical transport due to deep convection. Once in the stratosphere bromine released from VSLS contributes to ozone depletion. While the Montreal Protocol has controlled the emission of longer-lived anthropogenic halogenated species, the quantitative impact of naturally sourced VSLS remains unclear and requires further investigation. We have used the TOMCAT offline global 3-D chemical transport model (CTM) to test different VSLS emission scenarios. In this study, TOMCAT is forced using 6-hourly European Centre for Medium-Range Weather Forecasts analyses, has 60 vertical levels from the surface to ~60 km and a horizontal resolution of 2.8°x2.8°. Previous work using TOMCAT into halogenated VSLS emission and transport has involved the use of fixed surface mixing ratios of 1.2 pptv bromoform and dibromomethane in the bottom two layers of the model surface in the Tropics (Hossaini et al., 2010). Although an accurate representation of surface mixing ratios of these VSLS, the use of spatially varying emission fluxes should allow for improved accuracy in model predictions. The EU-funded SHIVA Malaysia 2011 field campaign provided a comprehensive VSLS dataset obtained in a region where these source gases have the potential to reach the stratosphere and deplete ozone. Observations of VSLS were collected during November and December 2011 on board the DLR Falcon aircraft during sixteen local flights. Fourteen of these flights have been used in this study due to technical difficulties experienced on the remaining two flights. Four emission scenarios, including both top-down and bottom-up approaches derived from airborne measurements and ocean fluxes of VSLS, were used in TOMCAT and each scenario was compared to observations of bromoform and dibromomethane collected during the SHIVA campaign. The mean bias of

  3. Construction of Marine Surface Pressure Fields From Scatterometer Winds Alone

    NASA Technical Reports Server (NTRS)

    Hsu, Carol S.; Wurtele, Morton G.; Cunningham, Glenn F.; Woiceshyn, Peter M.

    1997-01-01

    A series of six-hourly, synoptic, gridded, global surface wind fields with a resolution of 100 km has been generated using the data set of dealiased Seasat satellite scatterometer (SASS) winds produced as described by peteherych et al. (1984). This paper is an account of the construction of surface pressure fields from these SASS synoptic wind fields only, as carried out by differnt methods, and the comparison of these pressure fields with U.S. National Centers for Environmental Prediction (NCEP) analyses, with the pressure fields of the European Center for Medium Range Weather Forecasting (ECMWF) and with the special analyses of the Gulf of Alaska Experiment (GOASEX).

  4. Stress field sensitivity analysis within Mesozoic successions in the Swiss Alpine foreland using 3-D-geomechanical-numerical models

    NASA Astrophysics Data System (ADS)

    Reiter, Karsten; Hergert, Tobias; Heidbach, Oliver

    2016-04-01

    The in situ stress conditions are of key importance for the evaluation of radioactive waste repositories. In stage two of the Swiss site selection program, the three siting areas of high-level radioactive waste are located in the Alpine foreland in northern Switzerland. The sedimentary succession overlays the basement, consisting of variscan crystalline rocks as well as partly preserved Permo-Carboniferous deposits in graben structures. The Mesozoic sequence represents nearly the complete era and is covered by Cenozoic Molasse deposits as well as Quaternary sediments, mainly in the valleys. The target horizon (designated host rock) is an >100 m thick argillaceous Jurassic deposit (Opalinus Clay). To enlighten the impact of site-specific features on the state of stress within the sedimentary succession, 3-D-geomechanical-numerical models with elasto-plastic rock properties are set up for three potential siting areas. The lateral extent of the models ranges between 12 and 20 km, the vertical extent is up to a depth of 2.5 or 5 km below sea level. The sedimentary sequence plus the basement are separated into 10 to 14 rock mechanical units. The Mesozoic succession is inter