Science.gov

Sample records for 2-km horizontal grid

  1. Magnetic Anomalies of the Fennoscandian Shield on a 2km resolution grid

    NASA Astrophysics Data System (ADS)

    Korhonen, Juha V.; Aaro, Sven; Reidar Skilbrei, Jan; All, Tarmo

    2010-05-01

    Joint magnetic anomaly grid of the Fennoscandian Shield was released 2002, smoothed and used as data for the WDMAM2007. In comparison with MF5 this grid showed superior characteristics to other sets. The data will be released as a 2 km resolution grid for the WDMAM2011 with eventual updates of anomaly levels.

  2. EXAMINATION OF MODEL PREDICTIONS AT DIFFERENT HORIZONTAL GRID RESOLUTIONS

    EPA Science Inventory

    While fluctuations in meteorological and air quality variables occur on a continuum of spatial scales, the horizontal grid spacing of coupled meteorological and photochemical models sets a lower limit on the spatial scales that they can resolve. However, both computational costs ...

  3. Regional Climate Modelling: impact of horizontal grid resolution on precipitation estimates over Ireland

    NASA Astrophysics Data System (ADS)

    McGrath, Ray; Nolan, Paul

    2016-04-01

    Regional Climate Models (RCMs) are widely used to dynamically downscale the outputs from global climate model simulations. There is some evidence that high resolution RCMs with explicit convection can provide more accurate information on extreme precipitation events compared to coarse resolution simulations with parameterized convection. In flooding applications, where the interest may be focused on precipitation over a relatively large river catchment area, compared to the model grid spacing, the value of enhanced resolution needs to be quantified. This is addressed in a study using two RCMs: the COnsortium for Small-scale Modeling-Climate Limited-area Modelling (COSMO-CLM) model (version CCLM_5.00) and the Weather Research and Forecasting (WRF) model (version 3.7.1). Using ERA-Interim global re-analysis data as boundaries, climate simulations were performed for the period 1981-2015, for an area focused on Ireland, using model horizontal grid spacings of 18, 6 and 2 km (WRF) and 18, 6 and 1.5 km (COSMO-CLM). Model hourly precipitation outputs were compared with gridded and point observational datasets for time intervals extending from hours to seasons to assess the performance of the RCMs at the different resolutions.

  4. Research on Atmospheric Motion in Horizontal Discrete Grids

    NASA Astrophysics Data System (ADS)

    Liu, Yudi; Wang, Bin; Ji, Zhongzhen

    2003-01-01

    Starting from the linear shallow-water equations and using Arakawa A-E and Z grids, a study is made of inertia-gravitational and Rossby waves in the six grids from the perspectives of frequency and group velocity. Results indicate that grids C, Z, and E thereof give smaller distortion compared to the others.

  5. Computational dispersion properties of horizontal staggered grids for atmospheric and ocean models

    NASA Technical Reports Server (NTRS)

    Fox-Rabinovitz, Michael S.

    1991-01-01

    The computational dispersion properties of horizontally and time-horizontally staggered grids utilizing corresponding centered-difference techniques for approximation of the adjustment, or gravity wave equations, are examined in terms of their group velocity characteristics. Results are acquired for oceanic and atmospheric models, the former being characterized by a much smaller Rossby radius of deformation. For all grids considered additional filtering is required to control and even eliminate waves with poor computational dispersion characteristics. Computational dispersion properties along with other computational characteristics and requirements give some guidance for an optimal selection of an appropriate grid for an ocean or atmospheric model.

  6. Enhancement of natural-convection heat transfer from a horizontal heated plate using grid fins

    SciTech Connect

    Kitamura, Kenzo; Nagae, Naoyuki; Kimura, Fumiyoshi

    1996-01-01

    An enhancement technique was developed for natural-convection heat transfer from a horizontal heated plate. In order to enhance the heat transfer, grid fins made of copper plates were soldered to the copper base plate. These grid fins function not only as an extended surface but also as a heat-transfer promoter. The apparent heat-transfer coefficient of the above enhanced plate were measured and compared with those of a nontreated, smooth plate and a conventional plate with vertical straight fins. It was found that the highest performance is achieved by the present plate. By adopting grid fins with appropriate size and height, the heat-transfer coefficient at the central portion of the present plate is increased by 35% compared to that of the conventional finned plate with the same fin area of fin height.

  7. Sub-grid drag models for horizontal cylinder arrays immersed in gas-particle multiphase flows

    SciTech Connect

    Sarkar, Avik; Sun, Xin; Sundaresan, Sankaran

    2013-09-08

    Immersed cylindrical tube arrays often are used as heat exchangers in gas-particle fluidized beds. In multiphase computational fluid dynamics (CFD) simulations of large fluidized beds, explicit resolution of small cylinders is computationally infeasible. Instead, the cylinder array may be viewed as an effective porous medium in coarse-grid simulations. The cylinders' influence on the suspension as a whole, manifested as an effective drag force, and on the relative motion between gas and particles, manifested as a correction to the gas-particle drag, must be modeled via suitable sub-grid constitutive relationships. In this work, highly resolved unit-cell simulations of flow around an array of horizontal cylinders, arranged in a staggered configuration, are filtered to construct sub-grid, or `filtered', drag models, which can be implemented in coarse-grid simulations. The force on the suspension exerted by the cylinders is comprised of, as expected, a buoyancy contribution, and a kinetic component analogous to fluid drag on a single cylinder. Furthermore, the introduction of tubes also is found to enhance segregation at the scale of the cylinder size, which, in turn, leads to a reduction in the filtered gas-particle drag.

  8. Toward Energetically Consistent Parameterization of Horizontal and Vertical Sub-Grid Mixing for High-Resolution NWP Models

    NASA Astrophysics Data System (ADS)

    Bao, Jian-Wen; Grell, Eveyn; Michelson, Sara

    2013-04-01

    All numerical weather prediction (NWP) models require parameterizations of sub-grid turbulent mixing in both horizontal and vertical directions. Traditionally, due to the high aspect ratio between the horizontal and vertical dimensions of grids used in NWP models, it is assumed that the parameterizations of horizontal and vertical sub-grid mixing can be parameterized separately and most research efforts in the NWP community to parameterize sub-grid turbulent mixing has been focused on the vertical sub-grid turbulent mixing in the planetary boundary layer (PBL). Consequently, the parameterized vertical sub-grid mixing is formulated according to the vertical mixing theory in the PBL, while the parameterized horizontal sub-grid turbulent mixing in NWP models is formulated to be dependent on the grid-resolved strain rate and used mostly as numerical tuning parameter. Such a framework of parameterizing sub-grid turbulent mixing has a fundamental drawback: the conversion of grid-scale kinetic energy (KE) to sub-grid turbulent kinetic energy (TKE) is not consistently constrained between the vertical and horizontal directions. As the resolution of NWP models increases steadily, such that grid spacing becomes comparable to the typical size of largest energy-containing eddies, a more general and energetically consistent treatment of horizontal and vertical sub-grid turbulent mixing is required to overcome the drawback of the traditional parameterization approach. This presentation highlights major results from a series of sensitivity experiments with the Advanced Research WRF (ARW) model that were carried out for the purpose of comparing and evaluating a more general and energetically consistent parameterization of horizontal and vertical sub-grid turbulent mixing with two traditional schemes for parameterizing vertical sub-grid turbulent mixing in NWP models that share the same strain-rate-dependent parameterization for horizontal sub-grid turbulent mixing: the K

  9. Coupled ocean-atmosphere modeling on horizontally icosahedral and vertically hybrid-isentropic/isopycnic grids.

    NASA Astrophysics Data System (ADS)

    Bleck, Rainer; Sun, Shan; Li, Haiqin; Benjamin, Stan

    2016-04-01

    Current efforts to close the gap between weather prediction and climate models have led to the construction of a coupled ocean-atmosphere system consisting of two high-resolution component models, operating on matching icosahedral grids and utilizing adaptive, near-isentropic/isopycnic vertical coordinates. The two components models, FIM and HYCOM (the latter converted to an icosahedral mesh for this purpose), have been tested extensively in twice-daily global medium-range weather prediction (http://fim.noaa.gov) and in real-time ocean data assimilation (http://hycom.org), respectively. The use of matching horizontal grids, currently at resolutions of 15km, 30km and 60km, avoids coastline ambiguities and interpolation errors at the air-sea interface. The intended purpose of the coupled model being subseasonal-to-seasonal prediction, our focus is on mid-term precipitation biases and the statistical steadiness of the atmospheric circulation (blocking frequency, Rossby wave breaking, meridional heat transport, etc.), as well as on possible causes of ocean model drift. An attempt is made to isolate the weather model's role in modifying water mass properties and ocean circulations (including meridional overturning) by comparing coupled model results to ocean-only experiments forced by observed atmospheric boundary conditions. A multi-decadal run at 60km resolution is used to illustrate ENSO variability in the coupled system.

  10. Effect of horizontal grid resolution on simulations of the subtropical mode water in the North Pacific

    NASA Astrophysics Data System (ADS)

    Lee, Ho Jin; Yeop Kim, Sang; Lee, Kyung Eun

    2016-04-01

    We investigate how the Subtopical Mode Water (STMW) can be simulated differently in the North Pacific using a global Ocean General Circulation Model (OGCM) with non-eddying and eddy permitting resolution. The OGCM used in this study is the MOM version 4.1 and has a total of 50 levels along the vertical direction with enhanced resolution near the surface. The CORE version 2 (normal year forcing) data derived from the air-sea flux climatology averaged over 60 years (1948‑2007) are used to calculate heat, salt and momentum fluxes with a bulk formula at the sea surface. The sea surface salinity is restored to the climatological monthly mean surface salinity of the Polar Science Center Hydrographic Climatology on a 60-day timescale, to make up the fresh water flux at the sea surface. Two models that have horizontal resolutions of 1° and 1/4 °, respectively, are integrated during 50 years. The inter-annual variation of the STMW volume was well reproduced with the eddy-permitting grid resolution although the model was forced by a climatological atmospheric forcing. The annual formation and erosion volume of STMW varies by 7% and 9% of the mean volume, respectively.

  11. Application of MM5 in China: Model evaluation, seasonal variations, and sensitivity to horizontal grid resolutions

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Cheng, Shu-Hui; Chen, Yao-Sheng; Wang, Wen-Xing

    2011-07-01

    The rapid growth of energy consumption in conjunction with economic development during past decades in East Asia, especially China, caused severe air pollution problems at local and regional scales. Understanding of the meteorological conditions for air pollution is essential to the understanding of the formation mechanism of air pollutants and the development of effective emission control strategies to reduce air pollution. In this paper, the Fifth Generation National Center for Atmospheric Research (NCAR)/Pennsylvania State University (PSU) Mesoscale Model (MM5) modeling system is applied to simulate meteorological fields during selected six 1-month periods in 2007/2008 over a triple-nested modeling domain covering East Asia, the eastern China, and Shandong Province at horizontal grid resolutions of 36-, 12-, and 4-km, respectively. MM5 generally reproduces well the observations in the eastern China but performs worse in the western China and northeastern China. Largest biases occur in 2-m temperatures (T2) and wind speed and wind direction at 10-m in haze months (i.e., winter) and daily mean precipitation (Precip) in non-haze months (i.e., summer), due to limitations of the model in simulating snow cover and convective precipitation. Meteorological predictions agree more closely with observations at urban sites than those at the coastal and mountain sites where the model performance deteriorates because of complex terrains, influences of urban heat island effect and land/sea breezes, and higher elevations. Model results at 12-km in Shandong Province show an overall better performance than those at 4- or 36-km while the results at 4-km show worst performance due to inaccurate land use and the model's incapability in simulating meteorological processes at a fine scale.

  12. Photochemical grid model performance with varying horizontal grid resolution and sub-grid plume treatment for the Martins Creek near-field SO2 study

    NASA Astrophysics Data System (ADS)

    Baker, Kirk R.; Hawkins, Andy; Kelly, James T.

    2014-12-01

    Near source modeling is needed to assess primary and secondary pollutant impacts from single sources and single source complexes. Source-receptor relationships need to be resolved from tens of meters to tens of kilometers. Dispersion models are typically applied for near-source primary pollutant impacts but lack complex photochemistry. Photochemical models provide a realistic chemical environment but are typically applied using grid cell sizes that may be larger than the distance between sources and receptors. It is important to understand the impacts of grid resolution and sub-grid plume treatments on photochemical modeling of near-source primary pollution gradients. Here, the CAMx photochemical grid model is applied using multiple grid resolutions and sub-grid plume treatment for SO2 and compared with a receptor mesonet largely impacted by nearby sources approximately 3-17 km away in a complex terrain environment. Measurements are compared with model estimates of SO2 at 4- and 1-km resolution, both with and without sub-grid plume treatment and inclusion of finer two-way grid nests. Annual average estimated SO2 mixing ratios are highest nearest the sources and decrease as distance from the sources increase. In general, CAMx estimates of SO2 do not compare well with the near-source observations when paired in space and time. Given the proximity of these sources and receptors, accuracy in wind vector estimation is critical for applications that pair pollutant predictions and observations in time and space. In typical permit applications, predictions and observations are not paired in time and space and the entire distributions of each are directly compared. Using this approach, model estimates using 1-km grid resolution best match the distribution of observations and are most comparable to similar studies that used dispersion and Lagrangian modeling systems. Model-estimated SO2 increases as grid cell size decreases from 4 km to 250 m. However, it is notable that the

  13. Cartesian grid simulations of bubbling fluidized beds with a horizontal tube bundle

    SciTech Connect

    Li, Tingwen; Dietiker, Jean-Francois; Zhang, Yongmin; Shahnam, Mehrdad

    2011-12-01

    In this paper, the flow hydrodynamics in a bubbling fluidized bed with submerged horizontal tube bundle was numerically investigated with an open-source code: Multiphase Flow with Interphase eXchange (MFIX). A newly implemented cut-cell technique was employed to deal with the curved surface of submerged tubes. A series of 2D simulations were conducted to study the effects of gas velocity and tube arrangement on the flow pattern. Hydrodynamic heterogeneities on voidage, particle velocity, bubble fraction, and frequency near the tube circumferential surface were successfully predicted by this numerical method, which agrees qualitatively with previous experimental findings and contributes to a sounder understanding of the non-uniform heat transfer and erosion around a horizontal tube. A 3D simulation was also conducted. Significant differences between 2D and 3D simulations were observed with respect to bed expansion, bubble distribution, voidage, and solids velocity profiles. Hence, the 3D simulation is needed for quantitative prediction of flow hydrodynamics. On the other hand, the flow characteristics and bubble behavior at the tube surface are similar under both 2D and 3D simulations as far as the bubble frequency and bubble phase fraction are concerned. Comparison with experimental data showed that qualitative agreement was obtained in both 2D and 3D simulations for the bubble characteristics at the tube surface.

  14. Analyzing the Effect of Tropical Cyclones on the Upper Ocean Using an Ocean General Circulation Model with Varying Horizontal Grid Resolution

    NASA Astrophysics Data System (ADS)

    Li, H.; Sriver, R. L.

    2015-12-01

    Tropical cyclones (TCs) have the potential to influence regional and global climate through their interactions with the upper ocean. Here we present results from a suite of ocean-only model experiments featuring the Community Earth System Model (CESM), in which we analyze the effect of tropical cyclone wind forcing on the global ocean using three different horizontal ocean grid resolutions (3˚, 1˚, and 0.1˚). The ocean simulations are forced with identical atmospheric inputs from the Coordinated Ocean-Ice Reference Experiments version 2 (COREv2) normal year forcing conditions, featuring global blended TC winds from a fully-coupled CESM simulation with a 25 km atmosphere [Small et al., 2014]. The simulated TC climatology shows good agreement with observational estimates of annual TC statistics, including annual frequency, intensity distributions, and geographic distributions. Each simulation is 10 years, which includes a 5-year spin up and 5 years of TC-wind forcing. In addition, we conduct corresponding control simulations for each grid resolution configuration without applied TC forcing. We will discuss the TC-induced ocean responses across a variety of spatial and temporal scales. A key highlight of this work is analyzing the effect of ocean horizontal grid resolution on TC-induced ocean responses, particularly at resolutions capable of simulating mesoscale ocean eddies.

  15. Examining the sensitivity of MM5-CMAQ predictions to explicit microphysics schemes and horizontal grid resolutions, Part I—Database, evaluation protocol, and precipitation predictions

    NASA Astrophysics Data System (ADS)

    Queen, Ashley; Zhang, Yang; Gilliam, Robert; Pleim, Jonathan

    2008-05-01

    Wet deposition of chemical species is one of the most difficult processes to simulate in three-dimensional (3-D) air quality models, due to the complex interplay among meteorology, cloud, and atmospheric chemistry. Different cloud microphysical treatments and horizontal grid resolutions in 3-D models can directly affect simulated clouds, precipitation, and wet deposition. In this study, the performance and sensitivity of the simulated precipitation, concentrations, and wet deposition to different explicit microphysics schemes and horizontal grid resolutions are evaluated for August and December 2002 for a domain centered over North Carolina (NC). Four explicit microphysics schemes in MM5 are examined: Reisner 1 (R1), Reisner 2 (R2), Dudhia (SI), and Hsie (WR). The precipitation evaluation indicates that monthly-average precipitation amounts are underpredicted by all schemes in both August and December at all sites except for the R1 August simulation that shows overpredictions at National Acid Deposition Program (NADP) sites. An increased sensitivity to microphysics schemes is found at locations in both the coastal plain and mountain regions in August and the mountain region in December. The differences in simulation results in August and December are mainly attributed to seasonal differences in dominant meteorological forcing (mesoscale vs. synoptic, respectively). Among the schemes tested, R2 and SI give the best overall performance in predicting precipitation for both months. These findings are applicable for NC and neighboring states with similar meteorological and emission characteristics.

  16. The Stagger-grid: A grid of 3D stellar atmosphere models. II. Horizontal and temporal averaging and spectral line formation

    NASA Astrophysics Data System (ADS)

    Magic, Z.; Collet, R.; Hayek, W.; Asplund, M.

    2013-12-01

    Aims: We study the implications of averaging methods with different reference depth scales for 3D hydrodynamical model atmospheres computed with the Stagger-code. The temporally and spatially averaged (hereafter denoted as ⟨3D⟩) models are explored in the light of local thermodynamic equilibrium (LTE) spectral line formation by comparing spectrum calculations using full 3D atmosphere structures with those from ⟨3D⟩ averages. Methods: We explored methods for computing mean ⟨3D⟩ stratifications from the Stagger-grid time-dependent 3D radiative hydrodynamical atmosphere models by considering four different reference depth scales (geometrical depth, column-mass density, and two optical depth scales). Furthermore, we investigated the influence of alternative averages (logarithmic, enforced hydrostatic equilibrium, flux-weighted temperatures). For the line formation we computed curves of growth for Fe i and Fe ii lines in LTE. Results: The resulting ⟨3D⟩ stratifications for the four reference depth scales can be very different. We typically find that in the upper atmosphere and in the superadiabatic region just below the optical surface, where the temperature and density fluctuations are highest, the differences become considerable and increase for higher Teff, lower log g, and lower [Fe / H]. The differential comparison of spectral line formation shows distinctive differences depending on which ⟨3D⟩ model is applied. The averages over layers of constant column-mass density yield the best mean ⟨3D⟩ representation of the full 3D models for LTE line formation, while the averages on layers at constant geometrical height are the least appropriate. Unexpectedly, the usually preferred averages over layers of constant optical depth are prone to increasing interference by reversed granulation towards higher effective temperature, in particular at low metallicity. Appendix A is available in electronic form at http://www.aanda.orgMean ⟨3D⟩ models are

  17. 2.5D modelling of a horizontal electric dipole using Finite Difference method with non-uniform grids and preconditioned sparse matrices

    NASA Astrophysics Data System (ADS)

    Miranda, D. D.; Howard, A. Q.

    2012-12-01

    Computational modelling of geophysical data is an important step in the process of hydrocarbon exploration. It consists in simulating the exploratory procedure and realistic geological environments. It allows a preliminary evaluation of the exploration feasibility of a particular terrain or geological model, indicating the best conditions for geophysical surveys. In this paper, we assess the Finite Difference frequency domain method for modelling the electromagnetic response of a horizontal electric dipole in 1D and 2.5D geometries. The non-uniform grid is refined in regions where the electromagnetic fields vary rapidly, namely the regions where we have variation in conductivity distribution and near the source dipole. We chose the horizontal electromagnetic dipole because it is the source normally used in the marine controlled-source electromagnetic surveys (mCSEM), which is the next step in our research. The mCSEM, also known as Sea Bed Logging, is a method for detection and characterization of thin resistive structures, like hydrocarbon reservoirs, often located in regions of deep water. It consists of a mobile electric dipole or a magnetic loop as a source, positioned near the sea floor where an array of electric and magnetic receivers are deployed. The source transmitter uses a low frequency signal on the order of 1Hz, that diffuses both in the ocean and in the sediments beneath it and is captured by the receivers . Amplitude and phase of this signal depend on the electrical conductivity of the seabed environment. The complexity of the environments and the large dimensions of the geological domains that we want to investigate make the modelling procedure extremely demanding, since the Finite Difference method requires a total discretization of the studied domain, resulting in large systems of linear equations, which can make the procedure long and expensive. Non-uniform grids and exploitation of the sparse property of the Finite Difference matrices are example

  18. A 2-km walking test for assessing the cardiorespiratory fitness of healthy adults.

    PubMed

    Oja, P; Laukkanen, R; Pasanen, M; Tyry, T; Vuori, I

    1991-08-01

    A simple walking test was developed with 159 (females = 80, males = 79) healthy 20-65-year-old subjects. All the subjects first walked the distances of 1.0, 1.5 and 2.0 km on a flat dirt road. Half of the participants were tested in the laboratory for maximal oxygen uptake (VO2max), and the 2-km test was repeated again twice. In a comparison of the three distances, the 2-km test was repeatable, the most preferable subjectively and the most accurate in predicting VO2max. A sex-specific prediction model including walking time, heart rate at the end of the walk, age and body mass index predicted 73-75% of the variance in VO2max (ml.kg-1.min-1) and that with body weight 66-76%, with a standard error of estimate of the order of 9-15% of the mean. The cross-validation of the models yielded reasonable accuracy in obese men and women and in moderately active men, and less accuracy in moderately active women and highly active men. These results suggest that a fast 2-km walk supplemented with simple measurements is a feasible and accurate alternative for determining the cardiorespiratory fitness of healthy adults.

  19. Demonstration of Femtosecond-Phase Stabilization in 2 km OpticalFiber

    SciTech Connect

    Staples, J.W.; Wilcox, R.; Byrd, J.M.

    2007-06-01

    Long-term phase drifts of less than a femtosecond per hour have been demonstrated in a 2 km length of single-mode optical fiber, stabilized interferometrically at 1530 nm. Recent improvements include a wide-band phase detector that reduces the possibility of fringe jumping due to fast external perturbations of the fiber and locking of the master CW laser wavelength to an atomic absorption line. Mode-locked lasers may be synchronized using two wavelengths of the comb, multiplexed over one fiber, each wavelength individually interferometrically stabilized.

  20. Faraday laser using 1.2 km fiber as an extended cavity

    NASA Astrophysics Data System (ADS)

    Tao, Zhiming; Zhang, Xiaogang; Pan, Duo; Chen, Mo; Zhu, Chuanwen; Chen, Jingbiao

    2016-07-01

    We demonstrate a Faraday laser using a 1.2 km fiber as an extended cavity, which provides optical feedback and obtains small free spectrum range (FSR) of 83 kHz, and have succeeded in limiting the laser frequency to a crossover transition {5}2{S}1/2,F=2\\to {5}2{P}3/2,F\\prime =1,3 of the natural 87Rb at 780 nm. The Faraday laser is based on a Faraday anomalous dispersion optical filter (FADOF) with an ultra-narrow bandwidth and the long fiber extended cavity of 1.2 km. The peak transmission assigned to the crossover transition F=2\\to F\\prime =1,3 in the FADOF is 20.5% with an ultra-narrow bandwidth of 29.1 MHz. The Allan deviation of the Faraday laser is around 6.0× {10}-11 in 0.06 to 1 s sampling time. Laser frequency is always kept in the center of the transmitted peak assigned to F=2\\to F\\prime =1,3. The Faraday laser realized here can provide light exactly resonant with an atomic transition used for atom-photon interaction experiments and is insensitive to diode temperature and injection current fluctuations.

  1. Faraday laser using 1.2 km fiber as an extended cavity

    NASA Astrophysics Data System (ADS)

    Tao, Zhiming; Zhang, Xiaogang; Pan, Duo; Chen, Mo; Zhu, Chuanwen; Chen, Jingbiao

    2016-07-01

    We demonstrate a Faraday laser using a 1.2 km fiber as an extended cavity, which provides optical feedback and obtains small free spectrum range (FSR) of 83 kHz, and have succeeded in limiting the laser frequency to a crossover transition {5}2{S}1/2,F=2\\to {5}2{P}3/2,F\\prime =1,3 of the natural 87Rb at 780 nm. The Faraday laser is based on a Faraday anomalous dispersion optical filter (FADOF) with an ultra-narrow bandwidth and the long fiber extended cavity of 1.2 km. The peak transmission assigned to the crossover transition F=2\\to F\\prime =1,3 in the FADOF is 20.5% with an ultra-narrow bandwidth of 29.1 MHz. The Allan deviation of the Faraday laser is around 6.0× {10}-11 in 0.06 to 1 s sampling time. Laser frequency is always kept in the center of the transmitted peak assigned to F=2\\to F\\prime =1,3. The Faraday laser realized here can provide light exactly resonant with an atomic transition used for atom–photon interaction experiments and is insensitive to diode temperature and injection current fluctuations.

  2. Assessment of the effects of horizontal grid resolution on long-term air quality trends using coupled WRF-CMAQ simulations

    EPA Science Inventory

    The objective of this study is to determine the adequacy of using a relatively coarse horizontal resolution (i.e. 36 km) to simulate long-term trends of pollutant concentrations and radiation variables with the coupled WRF-CMAQ model. WRF-CMAQ simulations over the continental Uni...

  3. The cytotoxic mechanism of karlotoxin 2 (KmTx 2) from Karlodinium veneficum (Dinophyceae)

    PubMed Central

    Deeds, Jonathan R.; Hoesch, Robert E.; Place, Allen R.; Kao, Joseph P.Y.

    2015-01-01

    This study demonstrates that the polyketide toxin karlotoxin 2 (KmTx 2) produced by Karlodinium veneficum, a dinoflagellate associated with fish kills in temperate estuaries worldwide, alters vertebrate cell membrane permeability. Microfluorimetric and electrophysiological measurements were used to determine that vertebrate cellular toxicity occurs through non-selective permeabilization of plasma membranes, leading to osmotic cell lysis. Previous studies showed that KmTx 2 is lethal to fish at naturally-occurring concentrations measured during fish kills, while sub-lethal doses severely damage gill epithelia. This study provides a mechanistic explanation for the association between K. veneficum blooms and fish kills that has long been observed in temperate estuaries worldwide. PMID:25546005

  4. Sensitivity of WRF simulations of Hurricane Ivan to horizontal resolution

    NASA Astrophysics Data System (ADS)

    Gentry, Megan Suzanne

    As finer resolutions become possible in numerical modeling, it has become increasingly common to turn off the cumulus parameterization scheme in favor of explicit simulation of convection. To the author's knowledge, the grid spacing at which it is appropriate to do so in a tropical cyclone (TC) case has not been systematically investigated. Therefore, this study examines the sensitivity of explicit model simulations of Hurricane Ivan (2004) to changes in horizontal grid spacing, when grid spacing between 12 and 2 km is used. As grid spacing decreases, the minimum central pressure of Ivan deepens, droping by approximately 20 hPa as grid spacing decreases from 4 to 2 km. However, the 8-, 6-, and 4-km simulations have intensity differences of only around 10 hPa between them. The structure shown by model-simulated radar, as well as model-simulated satellite infra-red (IR) temperatures, shows that the eyewall of the coarser resolution simulations (12- to 6-km) is highly asymmetrical and elliptically-shaped, with two large maxima (minima) in reflectivity (cloud top temperature) rotating about the TC center. The 4- and 2- km runs have more circular eyewalls, with more numerous and larger maxima (minima) in reflectivity (cloud top temperature) embedded within the eyewall, as well as better developed spiral bands. Temporal and spatial averaging, done at a given radius over azimuth, show the system-averaged quanitites in cross-section and reveal differences in the structure of the TC core and eyewall. The finer resolution simulations have larger updrafts and more subsidence within the eye. However, the warming of the eye, relative to the other runs, is confined to the upper levels of the troposphere. The eyewall of the TC in the finer resolution runs slopes radially outward less with height, as the horizontal temperature gradient changes little with height, compared with the coarser simulations. This lack of warming in the lower- and mid-levels of the TC eye indicates a

  5. Cultivation of methanogenic community from 2-km deep subseafloor coalbeds using a continuous-flow bioreactor

    NASA Astrophysics Data System (ADS)

    Imachi, H.; Tasumi, E.; Morono, Y.; Ito, M.; Takai, K.; Inagaki, F.

    2013-12-01

    Deep subseafloor environments associated with hydrocarbon reservoirs have been least explored by previous scientific drilling and hence the nature of deep subseafloor life and its ecological roles in the carbon cycle remain largely unknown. In this study, we performed cultivation of subseafloor methanogenic communities using a continuous-flow bioreactor with polyurethane sponges, called down-flow hanging sponge (DHS) reactor. The sample used for the reactor cultivation was obtained from 2 km-deep coalbeds off the Shimokita Peninsula of Japan, the northwestern Pacific, during the Integrated Ocean Drilling Program (IODP) Expedition 337 using a riser drilling technology of the drilling vessel Chikyu. The coalbed samples were incubated anaerobically in the DHS reactor at the in-situ temperature of 40°C. Synthetic seawater supplemented with a tiny amount of yeast extract, acetate, propionate and butyrate was provided into the DHS reactor. After 34 days of the bioreactor operation, a small production of methane was observed. The methane concentration was gradually increased and the stable carbon isotopic composition of methane was consistency 13C-depleted during the bioreactor operation, indicating the occurrence of microbial methanogenesis. Microscopic observation showed that the enrichment culture contained a variety of microorganisms, including methanogen-like rod-shaped cells with F420 auto-fluorescence. Interestingly, many spore-like particles were observed in the bioreactor enrichment. Phylogenetic analysis of 16S rRNA genes showed the growth of phylogenetically diverse bacteria and archaea in the DHS reactor. Predominant archaeal components were closely related to hydrogenotrophic methanogens within the genus Methanobacterium. Some predominant bacteria were related to the spore-formers within the class Clostridia, which are overall in good agreement with microscopic observations. By analyzing ion images using a nano-scale secondary ion mass spectrometry (Nano

  6. Horizontal Variability of Water and Its Relationship to Cloud Fraction near the Tropical Tropopause: Using Aircraft Observations of Water Vapor to Improve the Representation of Grid-scale Cloud Formation in GEOS-5

    NASA Technical Reports Server (NTRS)

    Selkirk, Henry B.; Molod, Andrea M.

    2014-01-01

    Large-scale models such as GEOS-5 typically calculate grid-scale fractional cloudiness through a PDF parameterization of the sub-gridscale distribution of specific humidity. The GEOS-5 moisture routine uses a simple rectangular PDF varying in height that follows a tanh profile. While below 10 km this profile is informed by moisture information from the AIRS instrument, there is relatively little empirical basis for the profile above that level. ATTREX provides an opportunity to refine the profile using estimates of the horizontal variability of measurements of water vapor, total water and ice particles from the Global Hawk aircraft at or near the tropopause. These measurements will be compared with estimates of large-scale cloud fraction from CALIPSO and lidar retrievals from the CPL on the aircraft. We will use the variability measurements to perform studies of the sensitivity of the GEOS-5 cloud-fraction to various modifications to the PDF shape and to its vertical profile.

  7. Observations of earthquake source parameters at 2 km depth in the Long Valley Caldera, eastern California

    USGS Publications Warehouse

    Prejean, Stephanie G.; Ellsworth, William L.

    2001-01-01

    To investigate seismic source parameter scaling and seismic efficiency in the Long Valley caldera, California, we measured source parameters for 41 earthquakes (M 0.5 to M 5) recorded at 2 km depth in the Long Valley Exploratory Well. Borehole recordings provide a wide frequency bandwidth, typically 1 to 200–300 Hz, and greatly reduce seismic noise and path effects compared to surface recordings. We calculated source parameters in both the time and frequency domains for P and S waves. At frequencies above the corner frequency, spectra decay faster than ω3, indicating that attenuation plays an important role in shaping the spectra (path averaged Qp = 100–400, Qs = 200–800). Source parameters are corrected for attenuation and radiation pattern. Both static stress drops and apparent stresses range from approximately 0.01 to 30 MPa. Although static stress drops do not vary with seismic moment for these data, our analyses are consistent with apparent stress increasing with increasing moment. To estimate tectonic driving stress and seismic efficiencies in the region, we combined source parameter measurements with knowledge of the stress field and a Coulomb failure criterion to infer a driving stress of 40–70 MPa. Subsequent seismic efficiencies are consistent with McGarr's (1999) hypothesis of a maximum seismic efficiency of 6%.

  8. A grid amplifier

    NASA Technical Reports Server (NTRS)

    Kim, Moonil; Weikle, Robert M., II; Hacker, Jonathan B.; Delisio, Michael P.; Rutledge, David B.; Rosenberg, James J.; Smith, R. P.

    1991-01-01

    A 50-MESFET grid amplifier is reported that has a gain of 11 dB at 3.3 GHz. The grid isolates the input from the output by using vertical polarization for the input beam and horizontal polarization for the transmitted output beam. The grid unit cell is a two-MESFET differential amplifier. A simple calibration procedure allows the gain to be calculated from a relative power measurement. This grid is a hybrid circuit, but the structure is suitable for fabrication as a monolithic wafer-scale integrated circuit, particularly at millimeter wavelengths.

  9. Ensemble flood simulation for a small dam catchment in Japan using 10 and 2 km resolution nonhydrostatic model rainfalls

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kenichiro; Otsuka, Shigenori; Apip; Saito, Kazuo

    2016-08-01

    This paper presents a study on short-term ensemble flood forecasting specifically for small dam catchments in Japan. Numerical ensemble simulations of rainfall from the Japan Meteorological Agency nonhydrostatic model (JMA-NHM) are used as the input data to a rainfall-runoff model for predicting river discharge into a dam. The ensemble weather simulations use a conventional 10 km and a high-resolution 2 km spatial resolutions. A distributed rainfall-runoff model is constructed for the Kasahori dam catchment (approx. 70 km2) and applied with the ensemble rainfalls. The results show that the hourly maximum and cumulative catchment-average rainfalls of the 2 km resolution JMA-NHM ensemble simulation are more appropriate than the 10 km resolution rainfalls. All the simulated inflows based on the 2 and 10 km rainfalls become larger than the flood discharge of 140 m3 s-1, a threshold value for flood control. The inflows with the 10 km resolution ensemble rainfall are all considerably smaller than the observations, while at least one simulated discharge out of 11 ensemble members with the 2 km resolution rainfalls reproduces the first peak of the inflow at the Kasahori dam with similar amplitude to observations, although there are spatiotemporal lags between simulation and observation. To take positional lags into account of the ensemble discharge simulation, the rainfall distribution in each ensemble member is shifted so that the catchment-averaged cumulative rainfall of the Kasahori dam maximizes. The runoff simulation with the position-shifted rainfalls shows much better results than the original ensemble discharge simulations.

  10. Horizontal variability of aerosol optical depth observed during the ARCTAS airborne experiment

    NASA Astrophysics Data System (ADS)

    Shinozuka, Y.; Redemann, J.

    2011-08-01

    We present statistics on the horizontal variability of aerosol optical depth (AOD) directly measured from the NASA P-3 aircraft. Our measurements during two contrasting phases (in Alaska and Canada) of the ARCTAS mission arguably constrain the variability in most aerosol environments common over the globe. In the Canada phase, which features local emissions, 499 nm AOD has a median relative standard deviation (stdrel, med) of 19 % and 9 % and an autocorrelation (r) of 0.37 and 0.71 over 20 km and 6 km horizontal segments, respectively. In the Alaska phase, which features long-range transport, the variability is considerably lower (stdrel, med = 3 %, r = 0.92 even over 35.2 km). Compared to the magnitude of AOD, its wavelength dependence varies less in the Canada phase, more in the Alaska phase. We translate these findings from straight-line flight tracks into grid boxes and points, to help interpretation and design of satellite remote sensing, suborbital observations and transport modeling.

  11. Horizontal variability of aerosol optical depth observed during the ARCTAS airborne experiment

    NASA Astrophysics Data System (ADS)

    Shinozuka, Y.; Redemann, J.

    2011-05-01

    We present statistics on the horizontal variability of aerosol optical depth (AOD) directly measured from the NASA P-3 aircraft. Our measurements during two contrasting phases (in Alaska and Canada) of the ARCTAS mission arguably constrain the variability in most aerosol environments common over the globe. In the Canada phase, which features local emissions, 499 nm AOD has a median relative standard deviation (stdrel,med) of 19 % and 9 % and an autocorrelation (r) of 0.37 and 0.71 over 20 km and 6 km horizontal segments, respectively. In the Alaska phase, which features long-range transport, the variability is considerably lower (stdrel,med = 3 %, r = 0.92 even over 35.2 km). Compared to the magnitude of AOD, its wavelength dependence varies less in the Canada phase, more in the Alaska phase. We translate these findings from straight-line flight tracks into grid boxes and points, to help interpretation and design of satellite remote sensing, suborbital observations and transport modeling.

  12. 2 cm spatial-resolution and 2 km range Brillouin optical fiber sensor using a transient differential pulse pair.

    PubMed

    Dong, Yongkang; Zhang, Hongying; Chen, Liang; Bao, Xiaoyi

    2012-03-20

    We report a high-spatial-resolution and long-range distributed temperature sensor through optimizing differential pulse-width pair Brillouin optical time-domain analysis (DPP-BOTDA). In DPP-BOTDA, the differential signal suffers from a signal-to-noise ratio (SNR) reduction with respect to the original signals, and for a fixed pulse-width difference the SNR reduction increases with the pulse width. Through reducing the pulse width to a transient regime (near to or less than the phonon lifetime) to decrease the SNR reduction after the differential process, the optimized 8/8.2 ns pulse pair is applied to realize a 2 cm spatial resolution, where a pulse generator with a 150 ps fall-time is used to ensure the effective resolution of DPP-BOTDA. In the experiment, a 2 cm spatial-resolution hot-spot detection with a 2 °C temperature accuracy is demonstrated over a 2 km sensing fiber. PMID:22441465

  13. Extension of the operating parameters of the two stage light gas gun to velocities below 2 km/sec.

    SciTech Connect

    Thoe, R S

    2007-08-28

    The Joint Actinide Shock Physics Experimental Facility (JASPER) located in area 27 at the Nevada Test Site Has been tasked with providing high accuracy information on the Equation Of State (EOS) and other dynamic properties of weapons grade plutonium and other actinides important to the stockpile stewardship program. In the past 5 years this facility has provided dozens of experimental data points for the accurate determination of pressure density relationship for these materials over a broad pressure range. In order to complete this survey it is necessary to extend the low pressure region to include projectile velocities below 2 km/s. For most gas gun facilities this would present not too great a difficulty, one could simply decrease the amount of propellant along with a decrease in the strength of the petal valve, However JASPER requires that the piston be securely embedded in the Acceleration Reservoir (AR) as part of the containment system. The projectile must remain flat and undistorted. This requirement makes the attainment of slow velocities problematic. This talk will discuss the JASPER Facility, A finite difference code developed to give predictive capability for two stage gas guns, and a set of experiments performed to demonstrate this capability.

  14. Perfluorocarbon Tracer Experiments on a 2 km Scale in Manchester Showing Ingress of Pollutants into a Building

    NASA Astrophysics Data System (ADS)

    Matthews, James; Wright, Matthew; Bacak, Asan; Silva, Hugo; Priestley, Michael; Martin, Damien; Percival, Carl; Shallcross, Dudley

    2016-04-01

    Cyclic perfluorocarbons (PFCs) have been used to measure the passage of air in urban and rural settings as they are chemically inert, non-toxic and have low background concentrations. The use of pre-concentrators and chemical ionisation gas chromatography enables concentrations of a few parts per quadrillion (ppq) to be measured in bag samples. Three PFC tracers were used in Manchester, UK in the summer of 2015 to map airflow in the city and ingress into buildings: perfluomethylcyclohexane (PMCH), perfluoro-2-4-dimethylcyclohexane (mPDMCH) and perfluoro-2-methyl-3-ethylpentene (PMEP). A known quantity of each PFC was released for 15 minutes from steel canisters using pre-prepared PFC mixtures. Release points were chosen to be upwind of the central sampling location (Simon Building, University of Manchester) and varied in distance up to 2.2 km. Six releases using one or three tracers in different configurations and under different conditions were undertaken in the summer. Three further experiments were conducted in the Autumn, to more closely investigate the rate of ingress and decay of tracer indoors. In each experiment, 10 litre samples were made over 30 minutes into Tedlar bags, starting at the same time the as PFC release. Samples were taken in 11 locations chosen from 15 identified areas including three in public parks, three outside within the University of Manchester area, seven inside and five outside of the Simon building and two outside a building nearby. For building measurements, receptors were placed inside the buildings on different floors; outside measurements were achieved through a sample line out of the window. Three of the sample positions inside the Simon building were paired with samplers outside to allow indoor-outdoor comparisons. PFC concentrations varied depending on location and height. The highest measured concentrations occurred when the tracer was released at sunrise; up to 330 ppq above background (11 ppq) of PMCH was measured at the 6

  15. MAGNETIC GRID

    DOEpatents

    Post, R.F.

    1960-08-01

    An electronic grid is designed employing magnetic forces for controlling the passage of charged particles. The grid is particularly applicable to use in gas-filled tubes such as ignitrons. thyratrons, etc., since the magnetic grid action is impartial to the polarity of the charged particles and, accordingly. the sheath effects encountered with electrostatic grids are not present. The grid comprises a conductor having sections spaced apart and extending in substantially opposite directions in the same plane, the ends of the conductor being adapted for connection to a current source.

  16. Horizontal drilling developments

    SciTech Connect

    Gust, D.

    1997-05-01

    The advantages of horizontal drilling are discussed. Use of horizontal drilling has climbed in the past half decade as technology and familiarity offset higher costs with higher production rates and greater recoveries from new and existing wells. In essence, all types of horizontal wells expose a larger section of the reservoir to the wellbore with a resulting increase in flow rates. (A horizontal well may also be drilled to provide coning control or to intersect vertical fractures.) Thus, drilling horizontally, both onshore and offshore, reduces the number of wells necessary to develop a field.

  17. Fibonacci Grids

    NASA Technical Reports Server (NTRS)

    Swinbank, Richard; Purser, James

    2006-01-01

    Recent years have seen a resurgence of interest in a variety of non-standard computational grids for global numerical prediction. The motivation has been to reduce problems associated with the converging meridians and the polar singularities of conventional regular latitude-longitude grids. A further impetus has come from the adoption of massively parallel computers, for which it is necessary to distribute work equitably across the processors; this is more practicable for some non-standard grids. Desirable attributes of a grid for high-order spatial finite differencing are: (i) geometrical regularity; (ii) a homogeneous and approximately isotropic spatial resolution; (iii) a low proportion of the grid points where the numerical procedures require special customization (such as near coordinate singularities or grid edges). One family of grid arrangements which, to our knowledge, has never before been applied to numerical weather prediction, but which appears to offer several technical advantages, are what we shall refer to as "Fibonacci grids". They can be thought of as mathematically ideal generalizations of the patterns occurring naturally in the spiral arrangements of seeds and fruit found in sunflower heads and pineapples (to give two of the many botanical examples). These grids possess virtually uniform and highly isotropic resolution, with an equal area for each grid point. There are only two compact singular regions on a sphere that require customized numerics. We demonstrate the practicality of these grids in shallow water simulations, and discuss the prospects for efficiently using these frameworks in three-dimensional semi-implicit and semi-Lagrangian weather prediction or climate models.

  18. Development of Gridded Fields of Urban Canopy Parameters for Advanced Urban Meteorological and Air Quality Models

    EPA Science Inventory

    Urban dispersion and air quality simulation models applied at various horizontal scales require different levels of fidelity for specifying the characteristics of the underlying surfaces. As the modeling scales approach the neighborhood level (~1 km horizontal grid spacing), the...

  19. Grid Computing

    NASA Astrophysics Data System (ADS)

    Foster, Ian

    2001-08-01

    The term "Grid Computing" refers to the use, for computational purposes, of emerging distributed Grid infrastructures: that is, network and middleware services designed to provide on-demand and high-performance access to all important computational resources within an organization or community. Grid computing promises to enable both evolutionary and revolutionary changes in the practice of computational science and engineering based on new application modalities such as high-speed distributed analysis of large datasets, collaborative engineering and visualization, desktop access to computation via "science portals," rapid parameter studies and Monte Carlo simulations that use all available resources within an organization, and online analysis of data from scientific instruments. In this article, I examine the status of Grid computing circa 2000, briefly reviewing some relevant history, outlining major current Grid research and development activities, and pointing out likely directions for future work. I also present a number of case studies, selected to illustrate the potential of Grid computing in various areas of science.

  20. Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross Bracing Detail, Vertical Cross Bracing-End Detail - Cumberland Covered Bridge, Spanning Mississinewa River, Matthews, Grant County, IN

  1. Grid reliability

    NASA Astrophysics Data System (ADS)

    Saiz, P.; Andreeva, J.; Cirstoiu, C.; Gaidioz, B.; Herrala, J.; Maguire, E. J.; Maier, G.; Rocha, R.

    2008-07-01

    Thanks to the Grid, users have access to computing resources distributed all over the world. The Grid hides the complexity and the differences of its heterogeneous components. In such a distributed system, it is clearly very important that errors are detected as soon as possible, and that the procedure to solve them is well established. We focused on two of its main elements: the workload and the data management systems. We developed an application to investigate the efficiency of the different centres. Furthermore, our system can be used to categorize the most common error messages, and control their time evolution.

  2. Cloud feedback studies with a physics grid

    SciTech Connect

    Dipankar, Anurag; Stevens, Bjorn

    2013-02-07

    During this project the investigators implemented a fully parallel version of dual-grid approach in main frame code ICON, implemented a fully conservative first-order interpolation scheme for horizontal remapping, integrated UCLA-LES micro-scale model into ICON to run parallely in selected columns, and did cloud feedback studies on aqua-planet setup to evaluate the classical parameterization on a small domain. The micro-scale model may be run in parallel with the classical parameterization, or it may be run on a "physics grid" independent of the dynamics grid.

  3. Horizontal carbon nanotube alignment.

    PubMed

    Cole, Matthew T; Cientanni, Vito; Milne, William I

    2016-09-21

    The production of horizontally aligned carbon nanotubes offers a rapid means of realizing a myriad of self-assembled near-atom-scale technologies - from novel photonic crystals to nanoscale transistors. The ability to reproducibly align anisotropic nanostructures has huge technological value. Here we review the present state-of-the-art in horizontal carbon nanotube alignment. For both in and ex situ approaches, we quantitatively assess the reported linear packing densities alongside the degree of alignment possible for each of these core methodologies. PMID:27546174

  4. Horizontal carbon nanotube alignment.

    PubMed

    Cole, Matthew T; Cientanni, Vito; Milne, William I

    2016-09-21

    The production of horizontally aligned carbon nanotubes offers a rapid means of realizing a myriad of self-assembled near-atom-scale technologies - from novel photonic crystals to nanoscale transistors. The ability to reproducibly align anisotropic nanostructures has huge technological value. Here we review the present state-of-the-art in horizontal carbon nanotube alignment. For both in and ex situ approaches, we quantitatively assess the reported linear packing densities alongside the degree of alignment possible for each of these core methodologies.

  5. Horizontal Advanced Tensiometer

    SciTech Connect

    Hubbell, Joel M.; Sisson, James B.

    2004-06-22

    An horizontal advanced tensiometer is described that allows the monitoring of the water pressure of soil positions, particularly beneath objects or materials that inhibit the use of previous monitoring wells. The tensiometer includes a porous cup, a pressure transducer (with an attached gasket device), an adaptive chamber, at least one outer guide tube which allows access to the desired horizontal position, a transducer wire, a data logger and preferably an inner guide tube and a specialized joint which provides pressure on the inner guide tube to maintain the seal between the gasket of the transducer and the adaptive chamber.

  6. The evolution of horizontal-branch stars - Theoretical sequences

    NASA Technical Reports Server (NTRS)

    Lee, Young-Wook; Demarque, Pierre

    1990-01-01

    A new grid of standard (i.e., solar CNO/Fe, no core rotation, and including semiconvection) horizontal-branch evolutionary sequences are presented which extend the grid of Sweigart both by including the final phase of core helium exhaustion and by using a finer grid of compositions. These sequences were constructed specifically for the studies of the Sandage period-shift effect and the second parameter phenomenon among the Galactic globular clusters. The numerical results for the observable characteristics of the sequences are tabulated which can be directly used to synthesize the observed horizontal-branch distributions. The present computations suggest that the observed difference in period change of RR Lyrae stars in the globular clusters M3 and M15 could be attributed, at least in the mean, to stellar evolution.

  7. Estimating worldwide solar radiation resources on a 40km grid

    SciTech Connect

    Maxwell, E.L.; George, R.L.; Brady, E.H.

    1996-11-01

    During 1995, the National Renewable Energy Laboratory (NREL), initiated the Data Grid Task under the auspices of DOE`s Resource Assessment Program. A data grid is a framework of uniformly spaced locations (grid points) for which data are available. Estimates of monthly averages of direct normal, diffuse horizontal, and global horizontal daily-total solar radiation energy (kWh/m{sup 2}) are being made for each point on a grid covering the US, Mexico, the Caribbean, and southern Canada. The grid points are separated by approximately 40 km. Using interpolation methods, the digital data grid can be used to estimate solar resources at any location. The most encouraging result to date has been the location of sources providing worldwide data for most of the input parameters required for modeling daily total solar radiation. This is a multiyear task expected to continue through the rest of this century.

  8. Occurrence of microbial acetate-oxidation in ~2 km-deep coal-bearing sediments off the Shimokita Peninsula, Japan (IODP Expedition 337)

    NASA Astrophysics Data System (ADS)

    Ijiri, A.; Inagaki, F.

    2015-12-01

    During the Integrated Ocean Drilling Program (IODP) Expedition 337 in 2012, the riser-drilling vessel Chikyu extended the previous world depth record of scientific ocean drilling and made one of the deepest scientific borehole down to 2466 m below the seafloor (mbsf) at Site C0020 Hole A off the Shimokita Peninsula, Japan. The sedimentary sequence consists of 17 lignite layers below 1.5 km bellow the seafloor. Microbiological and geochemical data consistently showed evidence for the existence of microbial communities associated with lignite coal beds in the coal-bearing sediments (Inagaki and Hinrichs et al., Science, 2015). Since lignite coals produce substantial dissolved organic compounds during the burial alternation process, volatile fatty acids may play important roles for microbial life and its activity in the deep sedimentary environment. To address this hypothesis, we measured methanogenic and acetate-oxidation activities by radiotracer incubation experiments using 14C-labelled substrate ([2-14C]-acetate) immediately after core recovery. Activity of aceticlastic methanogenesis was observed in the sediment above the coal-baring layers (>1990 mbsf), ranging from 0.2 to 1.2 pmol cm-3 d-1. The highest activity was observed in a coal-bed horizon at 1990 mbsf. However, aceticlastic methanogenesis was below the detection limit in sediment samples below the 2 km-coal layers. Activity of acetate oxidation to CO2 was measured by 14CO2 production rate from [2-14C]-acetate. Interestingly, the acetate-oxidation activity was observed in sediments above the coal beds, which values were generally higher than those of methanogenesis with the maximum value of 33 pmol cm-3 d-1 at 1800 mbsf. The rates gradually decreased with increasing depth from 1800 mbsf and reached below the detection limit (i.e., 0.05 pmol cm-3 d-1) in 2 km-deep coal-bed samples. The occurrence of relatively high acetate oxidation at ~1800 mbsf above the coal formation suggests that microbes respire

  9. Safe Grid

    NASA Technical Reports Server (NTRS)

    Chow, Edward T.; Stewart, Helen; Korsmeyer, David (Technical Monitor)

    2003-01-01

    The biggest users of GRID technologies came from the science and technology communities. These consist of government, industry and academia (national and international). The NASA GRID is moving into a higher technology readiness level (TRL) today; and as a joint effort among these leaders within government, academia, and industry, the NASA GRID plans to extend availability to enable scientists and engineers across these geographical boundaries collaborate to solve important problems facing the world in the 21 st century. In order to enable NASA programs and missions to use IPG resources for program and mission design, the IPG capabilities needs to be accessible from inside the NASA center networks. However, because different NASA centers maintain different security domains, the GRID penetration across different firewalls is a concern for center security people. This is the reason why some IPG resources are been separated from the NASA center network. Also, because of the center network security and ITAR concerns, the NASA IPG resource owner may not have full control over who can access remotely from outside the NASA center. In order to obtain organizational approval for secured remote access, the IPG infrastructure needs to be adapted to work with the NASA business process. Improvements need to be made before the IPG can be used for NASA program and mission development. The Secured Advanced Federated Environment (SAFE) technology is designed to provide federated security across NASA center and NASA partner's security domains. Instead of one giant center firewall which can be difficult to modify for different GRID applications, the SAFE "micro security domain" provide large number of professionally managed "micro firewalls" that can allow NASA centers to accept remote IPG access without the worry of damaging other center resources. The SAFE policy-driven capability-based federated security mechanism can enable joint organizational and resource owner approved remote

  10. Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Horizontal Cross Bracing Detail, Vertical Cross Bracing Detail, Horizontal Cross Bracing Joint, Vertical Cross Bracing End Detail - Ceylon Covered Bridge, Limberlost Park, spanning Wabash River at County Road 900 South, Geneva, Adams County, IN

  11. Horizontally mounted solar collector

    NASA Technical Reports Server (NTRS)

    Black, D. H. (Inventor)

    1979-01-01

    Solar energy is collected by using a vertical deflector assembly, a stationary reflector and a horizontally mounted solar collector. The deflector assembly contains a plurality of vanes which change the direction of the solar energy to the vertical, while constantly keeping the same side of the deflector facing the sun. The vertical rays are then reflected off the stationary reflector and are then absorbed by the collector.

  12. Measurements of CO2, CH4, H2O, and HDO over a 2-km Outdoor Path with Dual-Comb Spectroscopy

    NASA Astrophysics Data System (ADS)

    Rieker, G. B.; Giorgetta, F. R.; Coddington, I.; Swann, W. C.; Sinclair, L. C.; Cromer, C.; Baumann, E.; Newbury, N. R.; Kofler, J.; Petron, G.; Sweeney, C.; Tans, P. P.

    2013-12-01

    We demonstrate simultaneous sensing of CO2, CH4, H2O, and HDO over a 2-km outdoor open air path using dual-frequency-comb absorption spectroscopy (DCS). Our implementation of the DCS technique simultaneously offers broad spectral coverage (>8 THz, 267 cm-1) and fine spectral point spacing (100 MHz, 0.0033 cm-1) with a coherent eye-safe beam. The spectrometer, which is adapted from [Zolot et al., 2012], consists of two mutually coherent Erbium-doped fiber frequency-comb lasers which create a broad spectrum of perfectly spaced narrow linewidth frequency elements (';comb teeth') near 1.6 μm. The comb light is transmitted by a telescope and active steering mirrors from the roof of the NIST Boulder laboratory to a 50-cm flat mirror located 1 km away. The return light is received by a second telescope and carried via multimode fiber to a detector. The greenhouse gas absorption attenuates the teeth from the two combs that are coincident with the relevant molecular resonant frequencies. We purposefully offset the frequencies between the two frequency combs in a Vernier-like fashion so that each pair of comb teeth from the two combs results in a unique rf heterodyne beat frequency on the photodiode. The spectral spacing between subsequent comb teeth pairs is 100 MHz, far lower than the ~4 GHz linewidths of small molecule absorption features in the atmosphere. Because of the narrow comb linewidth, there is an essentially negligible instrument lineshape. The measured absorption spectrum can thus resolve neighboring absorption features of different species, and can be compared directly with HITRAN and recent greenhouse gas absorption models developed for satellite- and ground-based carbon observatories to determine the path-integrated concentrations of the absorbing species. Measurements covering the complete 30013←00001 absorption band of CO2 and absorption features of CH4, H2O and HDO between 1.6-1.67 μm were performed under a variety of atmospheric conditions. During

  13. Grid Data Management and Customer Demands at MeteoSwiss

    NASA Astrophysics Data System (ADS)

    Rigo, G.; Lukasczyk, Ch.

    2010-09-01

    Data grids constitute the required input form for a variety of applications. Therefore, customers increasingly expect climate services to not only provide measured data, but also grids of these with the required configurations on an operational basis. Currently, MeteoSwiss is establishing a production chain for delivering data grids by subscription directly from the data warehouse in order to meet the demand for precipitation data grids by governmental, business and science customers. The MeteoSwiss data warehouse runs on an Oracle database linked with an ArcGIS Standard edition geodatabase. The grids are produced by Unix-based software written in R called GRIDMCH which extracts the station data from the data warehouse and stores the files in the file system. By scripts, the netcdf-v4 files are imported via an FME interface into the database. Currently daily and monthly deliveries of daily precipitation grids are available from MeteoSwiss with a spatial resolution of 2.2km x 2.2km. These daily delivered grids are a preliminary based on 100 measuring sites whilst the grid of the monthly delivery of daily sums is calculated out of about 430 stations. Crucial for the absorption by the customers is the understanding of and the trust into the new grid product. Clearly stating needs which can be covered by grid products, the customers require a certain lead time to develop applications making use of the particular grid. Therefore, early contacts and a continuous attendance as well as flexibility in adjusting the production process to fulfill emerging customer needs are important during the introduction period. Gridding over complex terrain can lead to temporally elevated uncertainties in certain areas depending on the weather situation and coverage of measurements. Therefore, careful instructions on the quality and use and the possibility to communicate the uncertainties of gridded data proofed to be essential especially to the business and science customers who require

  14. GridMan: A grid manipulation system

    NASA Technical Reports Server (NTRS)

    Eiseman, Peter R.; Wang, Zhu

    1992-01-01

    GridMan is an interactive grid manipulation system. It operates on grids to produce new grids which conform to user demands. The input grids are not constrained to come from any particular source. They may be generated by algebraic methods, elliptic methods, hyperbolic methods, parabolic methods, or some combination of methods. The methods are included in the various available structured grid generation codes. These codes perform the basic assembly function for the various elements of the initial grid. For block structured grids, the assembly can be quite complex due to a large number of clock corners, edges, and faces for which various connections and orientations must be properly identified. The grid generation codes are distinguished among themselves by their balance between interactive and automatic actions and by their modest variations in control. The basic form of GridMan provides a much more substantial level of grid control and will take its input from any of the structured grid generation codes. The communication link to the outside codes is a data file which contains the grid or section of grid.

  15. MESH2D GRID GENERATOR DESIGN AND USE

    SciTech Connect

    Flach, G.; Smith, F.

    2012-01-20

    Mesh2d is a Fortran90 program designed to generate two-dimensional structured grids of the form [x(i),y(i,j)] where [x,y] are grid coordinates identified by indices (i,j). The x(i) coordinates alone can be used to specify a one-dimensional grid. Because the x-coordinates vary only with the i index, a two-dimensional grid is composed in part of straight vertical lines. However, the nominally horizontal y(i,j{sub 0}) coordinates along index i are permitted to undulate or otherwise vary. Mesh2d also assigns an integer material type to each grid cell, mtyp(i,j), in a user-specified manner. The complete grid is specified through three separate input files defining the x(i), y(i,j), and mtyp(i,j) variations. The overall mesh is constructed from grid zones that are typically then subdivided into a collection of smaller grid cells. The grid zones usually correspond to distinct materials or larger-scale geometric shapes. The structured grid zones are identified through uppercase indices (I,J). Subdivision of zonal regions into grid cells can be done uniformly, or nonuniformly using either a polynomial or geometric skewing algorithm. Grid cells may be concentrated backward, forward, or toward both ends. Figure 1 illustrates the above concepts in the context of a simple four zone grid.

  16. Horizontal branch evolution

    NASA Astrophysics Data System (ADS)

    Rood, R. T.; Crocker, D. A.

    In 1973 the outstanding problems confronting the theory of horizontal-branch (HB) evolution were the second-parameter problem and the Oosterhoff effect. Despite significant progress, particularly in the observations and in the observation/theory interface, they remain as the outstanding problems of 1988. The Oosterhoff effect is now discussed primarily in the guise of the Sandage period-shift effect. The morphology of the HB seems more complicated than ever. Many clusters show bimodal distributions along the HB. Here these are tentatively considered to be manifestations of the second parameter problem.

  17. Horizontal Temperature Variability in the Stratosphere: Global Variations Inferred from CRISTA Data

    NASA Technical Reports Server (NTRS)

    Eidmann, G.; Offermann, D.; Jarisch, M.; Preusse, P.; Eckermann, S. D.; Schmidlin, F. J.

    2001-01-01

    In two separate orbital campaigns (November, 1994 and August, 1997), the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) instrument acquired global stratospheric data of high accuracy and high spatial resolution. The standard limb-scanned CRISTA measurements resolved atmospheric spatial structures with vertical dimensions greater than or equal to 1.5 - 2 km and horizontal dimensions is greater than or equal to 100 - 200 km. A fluctuation analysis of horizontal temperature distributions derived from these data is presented. This method is somewhat complementary to conventional power-spectral analysis techniques.

  18. Horizontal baffle for nuclear reactors

    DOEpatents

    Rylatt, John A.

    1978-01-01

    A horizontal baffle disposed in the annulus defined between the core barrel and the thermal liner of a nuclear reactor thereby physically separating the outlet region of the core from the annular area below the horizontal baffle. The horizontal baffle prevents hot coolant that has passed through the reactor core from thermally damaging apparatus located in the annulus below the horizontal baffle by utilizing the thermally induced bowing of the horizontal baffle to enhance sealing while accommodating lateral motion of the baffle base plate.

  19. Horizontal SPINning of transposons.

    PubMed

    Gilbert, Clément; Pace, John K; Feschotte, Cédric

    2009-01-01

    The term 'horizontal transfer (HT)' refers to the transfer of genetic material between two reproductively isolated organisms. HT is thought to occur rarely in eukaryotes compared to vertical inheritance, the transmission of DNA from parent to offspring. In a recent study we have provided evidence that a family of DNA transposons, called SPACE INVADERS or SPIN, independently invaded horizontally the genome of seven distantly related tetrapod species and subsequently amplified to high copy number in each of them. This discovery calls for further investigations to better characterize the extent to which genomes have been shaped through HT events. In this addendum, we briefly discuss some general issues regarding the study of HT and further speculate on the sequence of events that could explain the current taxonomic distribution of SPIN. We propose that the presence of SPIN in the opossum (Monodelphis domestica), a taxon endemic to South America, reflects a transoceanic HT event that occurred from Old to New World, between 46 and 15 million years ago.

  20. Data Grid Management Systems

    NASA Technical Reports Server (NTRS)

    Moore, Reagan W.; Jagatheesan, Arun; Rajasekar, Arcot; Wan, Michael; Schroeder, Wayne

    2004-01-01

    The "Grid" is an emerging infrastructure for coordinating access across autonomous organizations to distributed, heterogeneous computation and data resources. Data grids are being built around the world as the next generation data handling systems for sharing, publishing, and preserving data residing on storage systems located in multiple administrative domains. A data grid provides logical namespaces for users, digital entities and storage resources to create persistent identifiers for controlling access, enabling discovery, and managing wide area latencies. This paper introduces data grids and describes data grid use cases. The relevance of data grids to digital libraries and persistent archives is demonstrated, and research issues in data grids and grid dataflow management systems are discussed.

  1. Horizontal axis windmill

    SciTech Connect

    Mundhenke, I.W.

    1984-05-22

    A base frame supports a horizontal shaft having one or more wind driven members secured thereon. Each of the wind driven members includes a shaft of light-weight framing and plurality of elongated longitudinally extending light-weight vanes having wind engaging surfaces. The vanes have a wind driving position on one side of the shaft and a return position of the other, and light-weight wind deflectors disposed at the front of the frame protecting the return position of the vanes from the wind. The wind deflectors are angularly adjustable whereby the deflected wind flowing off the longitudinal edges thereof is selectively directed against the vane surfaces in their driving position. The shaft has an output for operating a selected driven apparatus such as a generator. The base frame is rotatably supported on a pivot for selected adjustment relative to the wind.

  2. HORIZONTAL BOILING REACTOR SYSTEM

    DOEpatents

    Treshow, M.

    1958-11-18

    Reactors of the boiling water type are described wherein water serves both as the moderator and coolant. The reactor system consists essentially of a horizontal pressure vessel divided into two compartments by a weir, a thermal neutronic reactor core having vertical coolant passages and designed to use water as a moderator-coolant posltioned in one compartment, means for removing live steam from the other compartment and means for conveying feed-water and water from the steam compartment to the reactor compartment. The system further includes auxiliary apparatus to utilize the steam for driving a turbine and returning the condensate to the feed-water inlet of the reactor. The entire system is designed so that the reactor is self-regulating and has self-limiting power and self-limiting pressure features.

  3. Horizontally shaken impact pendulums

    NASA Astrophysics Data System (ADS)

    Alexander, T. J.; Xu, Y.; Sidhu, H.

    2016-03-01

    We consider two pendulum masses attached to the same pivot point and which interact with each other through Hertzian impacts. We show that this splitting of the mass leads to an instability in the conservative case, in which initially synchronized large amplitude motion may evolve into out-of-phase (impacting) motion. We then study in detail the response of the impacting masses in the presence of damping and driving through horizontal shaking of the pivot point. We find that synchronized modes are usually accompanied by small amplitude quasi-periodic, or even chaotic, impacts and a number of multi-period solutions may appear in the bifurcation diagram. We reveal the existence and stability of a number of impact modes and scan the frequency response of the system to a series of initial conditions to identify which modes may be more easily generated in experiment.

  4. A new method for gridding DNA microarrays.

    PubMed

    Charalambous, Christoforos C; Matsopoulos, George K

    2013-10-01

    In this paper, a new methodological scheme for the gridding of DNA microarrays is proposed. The scheme composes of a series of processes applied sequentially. Each DNA microarray image is pre-processed to remove any noise and the center of each spot is detected using a template matching algorithm. Then, an initial gridding is automatically placed on the DNA microarray image by 'building' rectangular pyramids around the detected spots' centers. The gridlines "move" between the pyramids, horizontally and vertically, forming this initial grid. Furthermore, a refinement process is applied composing of a five-step approach in order to correct gridding imperfections caused by its initial placement, both in non-spot cases and in more than one spot enclosure cases. The proposed gridding scheme is applied on DNA microarray images under known transformations and on real-world DNA data. Its performance is compared against the projection pursuit method, which is often used due to its speed and simplicity, as well as against a state-of-the-art method, the Optimal Multi-level Thresholding Gridding (OMTG). According to the obtained results, the proposed gridding scheme outperforms both methods, qualitatively and quantitatively.

  5. High cesium concentrations in groundwater in the upper 1.2 km of fractured crystalline rock - Influence of groundwater origin and secondary minerals

    NASA Astrophysics Data System (ADS)

    Mathurin, Frédéric A.; Drake, Henrik; Tullborg, Eva-Lena; Berger, Tobias; Peltola, Pasi; Kalinowski, Birgitta E.; Åström, Mats E.

    2014-05-01

    Dissolved and solid phase cesium (Cs) was studied in the upper 1.2 km of a coastal granitoid fracture network on the Baltic Shield (Äspö Hard Rock Laboratory and Laxemar area, SE Sweden). There unusually high Cs concentrations (up to 5-6 μg L-1) occur in the low-temperature (<20 °C) groundwater. The material includes water collected in earlier hydrochemical monitoring programs and secondary precipitates (fracture coatings) collected on the fracture walls, as follows: (a) hydraulically pristine fracture groundwater sampled through 23 surface boreholes equipped for the retrieval of representative groundwater at controlled depths (Laxemar area), (b) fracture groundwater affected by artificial drainage collected through 80 boreholes drilled mostly along the Äspö Hard Rock Laboratory (underground research facility), (c) surface water collected in local streams, a lake and sea bay, and shallow groundwater collected in 8 regolith boreholes, and (d) 84 new specimens of fracture coatings sampled in cores from the Äspö HRL and Laxemar areas. The groundwater in each area is different, which affects Cs concentrations. The highest Cs concentrations occurred in deep-seated saline groundwater (median Äspö HRL: 4.1 μg L-1; median Laxemar: 3.7 μg L-1) and groundwater with marine origin (Äspö HRL: 4.2 μg L-1). Overall lower, but variable, Cs concentrations were found in other types of groundwater. The similar concentrations of Cs in the saline groundwater, which had a residence time in the order of millions of years, and in the marine groundwater, which had residence times in the order of years, shows that duration of water-rock interactions is not the single and primary control of dissolved Cs in these systems. The high Cs concentrations in the saline groundwater is ascribed to long-term weathering of minerals, primarily Cs-enriched fracture coatings dominated by illite and mixed-layer clays and possibly wall rock micaceous minerals. The high Cs concentrations in the

  6. Spatial services grid

    NASA Astrophysics Data System (ADS)

    Cao, Jian; Li, Qi; Cheng, Jicheng

    2005-10-01

    This paper discusses the concept, key technologies and main application of Spatial Services Grid. The technologies of Grid computing and Webservice is playing a revolutionary role in studying the spatial information services. The concept of the SSG (Spatial Services Grid) is put forward based on the SIG (Spatial Information Grid) and OGSA (open grid service architecture). Firstly, the grid computing is reviewed and the key technologies of SIG and their main applications are reviewed. Secondly, the grid computing and three kinds of SIG (in broad sense)--SDG (spatial data grid), SIG (spatial information grid) and SSG (spatial services grid) and their relationships are proposed. Thirdly, the key technologies of the SSG (spatial services grid) is put forward. Finally, three representative applications of SSG (spatial services grid) are discussed. The first application is urban location based services gird, which is a typical spatial services grid and can be constructed on OGSA (Open Grid Services Architecture) and digital city platform. The second application is region sustainable development grid which is the key to the urban development. The third application is Region disaster and emergency management services grid.

  7. Inferring horizontal gene transfer.

    PubMed

    Ravenhall, Matt; Škunca, Nives; Lassalle, Florent; Dessimoz, Christophe

    2015-05-01

    Horizontal or Lateral Gene Transfer (HGT or LGT) is the transmission of portions of genomic DNA between organisms through a process decoupled from vertical inheritance. In the presence of HGT events, different fragments of the genome are the result of different evolutionary histories. This can therefore complicate the investigations of evolutionary relatedness of lineages and species. Also, as HGT can bring into genomes radically different genotypes from distant lineages, or even new genes bearing new functions, it is a major source of phenotypic innovation and a mechanism of niche adaptation. For example, of particular relevance to human health is the lateral transfer of antibiotic resistance and pathogenicity determinants, leading to the emergence of pathogenic lineages. Computational identification of HGT events relies upon the investigation of sequence composition or evolutionary history of genes. Sequence composition-based ("parametric") methods search for deviations from the genomic average, whereas evolutionary history-based ("phylogenetic") approaches identify genes whose evolutionary history significantly differs from that of the host species. The evaluation and benchmarking of HGT inference methods typically rely upon simulated genomes, for which the true history is known. On real data, different methods tend to infer different HGT events, and as a result it can be difficult to ascertain all but simple and clear-cut HGT events. PMID:26020646

  8. Inferring Horizontal Gene Transfer

    PubMed Central

    Lassalle, Florent; Dessimoz, Christophe

    2015-01-01

    Horizontal or Lateral Gene Transfer (HGT or LGT) is the transmission of portions of genomic DNA between organisms through a process decoupled from vertical inheritance. In the presence of HGT events, different fragments of the genome are the result of different evolutionary histories. This can therefore complicate the investigations of evolutionary relatedness of lineages and species. Also, as HGT can bring into genomes radically different genotypes from distant lineages, or even new genes bearing new functions, it is a major source of phenotypic innovation and a mechanism of niche adaptation. For example, of particular relevance to human health is the lateral transfer of antibiotic resistance and pathogenicity determinants, leading to the emergence of pathogenic lineages [1]. Computational identification of HGT events relies upon the investigation of sequence composition or evolutionary history of genes. Sequence composition-based ("parametric") methods search for deviations from the genomic average, whereas evolutionary history-based ("phylogenetic") approaches identify genes whose evolutionary history significantly differs from that of the host species. The evaluation and benchmarking of HGT inference methods typically rely upon simulated genomes, for which the true history is known. On real data, different methods tend to infer different HGT events, and as a result it can be difficult to ascertain all but simple and clear-cut HGT events. PMID:26020646

  9. Productivity and injectivity of horizontal wells. Quarterly report, October 1--December 31, 1996

    SciTech Connect

    Aziz, K.; Hewett, T.A.

    1997-01-30

    This report describes progress on Tasks 1 and 4, Correlations for cresting behavior in horizontal wells. Research work on developing coarse grid methods to study cresting in horizontal wells was continued. The previous correlations for optimum grid size, breakthrough time, and post breakthrough behavior (i.e., water-oil ratio) were further tested and optimized. Procedures to derive pseudo-functions either using numerical correlations or coarse grid simulations have been proposed and successfully tested. The results reported here and other calculations show that the correlations developed in this work can be applied to a wide range of conditions for predicting the water break-through time (BT) and the water-oil-ratio (PBB) for horizontal wells. All of the correlations are based on the assumption of two-phase, two-dimensional flow in homogeneous reservoirs.

  10. Understanding Horizontal Governance. Research Brief

    ERIC Educational Resources Information Center

    Ferguson, Daniel

    2009-01-01

    Horizontal governance is an umbrella term that covers a range of approaches to policy development, service delivery issues, and management practices. A horizontal initiative may take place across levels of government, across boundaries between units of a single department or agency or among multiple departments or agencies, or across public,…

  11. Parallel grid population

    SciTech Connect

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  12. Scientific Grid computing.

    PubMed

    Coveney, Peter V

    2005-08-15

    We introduce a definition of Grid computing which is adhered to throughout this Theme Issue. We compare the evolution of the World Wide Web with current aspirations for Grid computing and indicate areas that need further research and development before a generally usable Grid infrastructure becomes available. We discuss work that has been done in order to make scientific Grid computing a viable proposition, including the building of Grids, middleware developments, computational steering and visualization. We review science that has been enabled by contemporary computational Grids, and associated progress made through the widening availability of high performance computing.

  13. Effects of vertical shear in modelling horizontal oceanic dispersion

    NASA Astrophysics Data System (ADS)

    Lanotte, A. S.; Corrado, R.; Palatella, L.; Pizzigalli, C.; Schipa, I.; Santoleri, R.

    2016-02-01

    The effect of vertical shear on the horizontal dispersion properties of passive tracer particles on the continental shelf of the South Mediterranean is investigated by means of observation and model data. In situ current measurements reveal that vertical gradients of horizontal velocities in the upper mixing layer decorrelate quite fast ( ˜ 1 day), whereas an eddy-permitting ocean model, such as the Mediterranean Forecasting System, tends to overestimate such decorrelation time because of finite resolution effects. Horizontal dispersion, simulated by the Mediterranean sea Forecasting System, is mostly affected by: (1) unresolved scale motions, and mesoscale motions that are largely smoothed out at scales close to the grid spacing; (2) poorly resolved time variability in the profiles of the horizontal velocities in the upper layer. For the case study we have analysed, we show that a suitable use of deterministic kinematic parametrizations is helpful to implement realistic statistical features of tracer dispersion in two and three dimensions. The approach here suggested provides a functional tool to control the horizontal spreading of small organisms or substance concentrations, and is thus relevant for marine biology, pollutant dispersion as well as oil spill applications.

  14. Horizontal and Vertical Line Designs.

    ERIC Educational Resources Information Center

    Johns, Pat

    2003-01-01

    Presents an art lesson in which students learn about the artist Piet Mondrian and create their own abstract artworks. Focuses on geometric shapes using horizontal and vertical lines. Includes background information about the artist. (CMK)

  15. Method of grid generation

    DOEpatents

    Barnette, Daniel W.

    2002-01-01

    The present invention provides a method of grid generation that uses the geometry of the problem space and the governing relations to generate a grid. The method can generate a grid with minimized discretization errors, and with minimal user interaction. The method of the present invention comprises assigning grid cell locations so that, when the governing relations are discretized using the grid, at least some of the discretization errors are substantially zero. Conventional grid generation is driven by the problem space geometry; grid generation according to the present invention is driven by problem space geometry and by governing relations. The present invention accordingly can provide two significant benefits: more efficient and accurate modeling since discretization errors are minimized, and reduced cost grid generation since less human interaction is required.

  16. Dynamic Power Grid Simulation

    2015-09-14

    GridDyn is a part of power grid simulation toolkit. The code is designed using modern object oriented C++ methods utilizing C++11 and recent Boost libraries to ensure compatibility with multiple operating systems and environments.

  17. IPG Power Grid Overview

    NASA Technical Reports Server (NTRS)

    Hinke, Thomas

    2003-01-01

    This presentation will describe what is meant by grids and then cover the current state of the IPG. This will include an overview of the middleware that is key to the operation of the grid. The presentation will then describe some of the future directions that are planned for the IPG. Finally the presentation will conclude with a brief overview of the Global Grid Forum, which is a key activity that will contribute to the successful availability of grid components.

  18. Chimera Grid Tools

    NASA Technical Reports Server (NTRS)

    Chan, William M.; Rogers, Stuart E.; Nash, Steven M.; Buning, Pieter G.; Meakin, Robert

    2005-01-01

    Chimera Grid Tools (CGT) is a software package for performing computational fluid dynamics (CFD) analysis utilizing the Chimera-overset-grid method. For modeling flows with viscosity about geometrically complex bodies in relative motion, the Chimera-overset-grid method is among the most computationally cost-effective methods for obtaining accurate aerodynamic results. CGT contains a large collection of tools for generating overset grids, preparing inputs for computer programs that solve equations of flow on the grids, and post-processing of flow-solution data. The tools in CGT include grid editing tools, surface-grid-generation tools, volume-grid-generation tools, utility scripts, configuration scripts, and tools for post-processing (including generation of animated images of flows and calculating forces and moments exerted on affected bodies). One of the tools, denoted OVERGRID, is a graphical user interface (GUI) that serves to visualize the grids and flow solutions and provides central access to many other tools. The GUI facilitates the generation of grids for a new flow-field configuration. Scripts that follow the grid generation process can then be constructed to mostly automate grid generation for similar configurations. CGT is designed for use in conjunction with a computer-aided-design program that provides the geometry description of the bodies, and a flow-solver program.

  19. A new monitoring technique for the grounding grids

    NASA Astrophysics Data System (ADS)

    Chikarov, Y.; Lie, T. T.; Nair, N.-K. C.

    2014-09-01

    The performance and reliability of grounding grids depend on its structural integrity. If grounding conductors are damaged, it may cause misoperation of protective relay which leads to trip feeders unnecessarily. It can also cause not only failures on the surroundings such as the grounding grid, secondary circuits' cables, and structural elements but also voltage hazard for human. The circuits may attain unacceptable voltages when short-circuit fault currents occur in these grids. This paper presents the development of a new technique to monitor the operating conditions of the grounding grids of high voltage apparatus and systems without any diggings and forced outages. New concept, principals, a technique and a device shown in the paper have never been described before by the other authors. The technique is based on the evaluation of the electromagnetic field distribution pattern over the damaged horizontal elements of the grid.

  20. FermiGrid

    SciTech Connect

    Yocum, D.R.; Berman, E.; Canal, P.; Chadwick, K.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Sharma, N.; Timm, S.; /Fermilab

    2007-05-01

    As one of the founding members of the Open Science Grid Consortium (OSG), Fermilab enables coherent access to its production resources through the Grid infrastructure system called FermiGrid. This system successfully provides for centrally managed grid services, opportunistic resource access, development of OSG Interfaces for Fermilab, and an interface to the Fermilab dCache system. FermiGrid supports virtual organizations (VOs) including high energy physics experiments (USCMS, MINOS, D0, CDF, ILC), astrophysics experiments (SDSS, Auger, DES), biology experiments (GADU, Nanohub) and educational activities.

  1. Grid Architecture 2

    SciTech Connect

    Taft, Jeffrey D.

    2016-01-01

    The report describes work done on Grid Architecture under the auspices of the Department of Electricity Office of Electricity Delivery and Reliability in 2015. As described in the first Grid Architecture report, the primary purpose of this work is to provide stakeholder insight about grid issues so as to enable superior decision making on their part. Doing this requires the creation of various work products, including oft-times complex diagrams, analyses, and explanations. This report provides architectural insights into several important grid topics and also describes work done to advance the science of Grid Architecture as well.

  2. Productivity and injectivity of horizontal wells. Annual report for the period, March 10, 1994--March 9, 1995

    SciTech Connect

    Fayers, F.J.

    1995-07-01

    Contents of this annual report include the following: (1) detailed well model for reservoir simulation--task 1; (2) comparative aspects of coning behavior in vertical and horizontal wells--task 1; (3) skin factor calculations for vertical, deviated, and horizontal wells--task 2; (4) a dissipation-based coarse grid system and its application to the scaleup of two phase problems--tasks 2 and 4; (5) analyses of experiments at Marathon Oil Company--task 3; (6) development of mechanistic model for multiphase flow in horizontal wells--task 3; and (7) sensitivity studies of wellbore friction and inflow for a horizontal well--task 8.

  3. Understanding The Smart Grid

    SciTech Connect

    2007-11-15

    The report provides an overview of what the Smart Grid is and what is being done to define and implement it. The electric industry is preparing to undergo a transition from a centralized, producer-controlled network to a decentralized, user-interactive one. Not only will the technology involved in the electric grid change, but the entire business model of the industry will change too. A major objective of the report is to identify the changes that the Smart Grid will bring about so that industry participants can be prepared to face them. A concise overview of the development of the Smart Grid is provided. It presents an understanding of what the Smart Grid is, what new business opportunities or risks might come about due to its introduction, and what activities are already taking place regarding defining or implementing the Smart Grid. This report will be of interest to the utility industry, energy service providers, aggregators, and regulators. It will also be of interest to home/building automation vendors, information technology vendors, academics, consultants, and analysts. The scope of the report includes an overview of the Smart Grid which identifies the main components of the Smart Grid, describes its characteristics, and describes how the Smart Grid differs from the current electric grid. The overview also identifies the key concepts involved in the transition to the Smart Grid and explains why a Smart Grid is needed by identifying the deficiencies of the current grid and the need for new investment. The report also looks at the impact of the Smart Grid, identifying other industries which have gone through a similar transition, identifying the overall benefits of the Smart Grid, and discussing the impact of the Smart Grid on industry participants. Furthermore, the report looks at current activities to implement the Smart Grid including utility projects, industry collaborations, and government initiatives. Finally, the report takes a look at key technology

  4. Navigation in Grid Space with the NAS Grid Benchmarks

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Hood, Robert; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    We present a navigational tool for computational grids. The navigational process is based on measuring the grid characteristics with the NAS Grid Benchmarks (NGB) and using the measurements to assign tasks of a grid application to the grid machines. The tool allows the user to explore the grid space and to navigate the execution at a grid application to minimize its turnaround time. We introduce the notion of gridscape as a user view of the grid and show how it can be me assured by NGB, Then we demonstrate how the gridscape can be used with two different schedulers to navigate a grid application through a rudimentary grid.

  5. Grid enabled Service Support Environment - SSE Grid

    NASA Astrophysics Data System (ADS)

    Goor, Erwin; Paepen, Martine

    2010-05-01

    The SSEGrid project is an ESA/ESRIN project which started in 2009 and is executed by two Belgian companies, Spacebel and VITO, and one Dutch company, Dutch Space. The main project objectives are the introduction of a Grid-based processing on demand infrastructure at the Image Processing Centre for earth observation products at VITO and the inclusion of Grid processing services in the Service Support Environment (SSE) at ESRIN. The Grid-based processing on demand infrastructure is meant to support a Grid processing on demand model for Principal Investigators (PI) and allow the design and execution of multi-sensor applications with geographically spread data while minimising the transfer of huge volumes of data. In the first scenario, 'support a Grid processing on demand model for Principal Investigators', we aim to provide processing power close to the EO-data at the processing and archiving centres. We will allow a PI (non-Grid expert user) to upload his own algorithm, as a process, and his own auxiliary data from the SSE Portal and use them in an earth observation workflow on the SSEGrid Infrastructure. The PI can design and submit workflows using his own processes, processes made available by VITO/ESRIN and possibly processes from other users that are available on the Grid. These activities must be user-friendly and not requiring detailed knowledge about the underlying Grid middleware. In the second scenario we aim to design, implement and demonstrate a methodology to set up an earth observation processing facility, which uses large volumes of data from various geographically spread sensors. The aim is to provide solutions for problems that we face today, like wasting bandwidth by copying large volumes of data to one location. We will avoid this by processing the data where they are. The multi-mission Grid-based processing on demand infrastructure will allow developing and executing complex and massive multi-sensor data (re-)processing applications more

  6. Nuclear component horizontal seismic restraint

    DOEpatents

    Snyder, Glenn J.

    1988-01-01

    A nuclear component horizontal seismic restraint. Small gaps limit horizontal displacement of components during a seismic occurrence and therefore reduce dynamic loadings on the free lower end. The reactor vessel and reactor guard vessel use thicker section roll-forged rings welded between the vessel straight shell sections and the bottom hemispherical head sections. The inside of the reactor guard vessel ring forging contains local vertical dovetail slots and upper ledge pockets to mount and retain field fitted and installed blocks. As an option, the horizontal displacement of the reactor vessel core support cone can be limited by including shop fitted/installed local blocks in opposing alignment with the reactor vessel forged ring. Beams embedded in the wall of the reactor building protrude into apertures in the thermal insulation shell adjacent the reactor guard vessel ring and have motion limit blocks attached thereto to provide to a predetermined clearance between the blocks and reactor guard vessel ring.

  7. Securing smart grid technology

    NASA Astrophysics Data System (ADS)

    Chaitanya Krishna, E.; Kosaleswara Reddy, T.; Reddy, M. YogaTeja; Reddy G. M., Sreerama; Madhusudhan, E.; AlMuhteb, Sulaiman

    2013-03-01

    In the developing countries electrical energy is very important for its all-round improvement by saving thousands of dollars and investing them in other sector for development. For Growing needs of power existing hierarchical, centrally controlled grid of the 20th Century is not sufficient. To produce and utilize effective power supply for industries or people we should have Smarter Electrical grids that address the challenges of the existing power grid. The Smart grid can be considered as a modern electric power grid infrastructure for enhanced efficiency and reliability through automated control, high-power converters, modern communications infrastructure along with modern IT services, sensing and metering technologies, and modern energy management techniques based on the optimization of demand, energy and network availability and so on. The main objective of this paper is to provide a contemporary look at the current state of the art in smart grid communications as well as critical issues on smart grid technologies primarily in terms of information and communication technology (ICT) issues like security, efficiency to communications layer field. In this paper we propose new model for security in Smart Grid Technology that contains Security Module(SM) along with DEM which will enhance security in Grid. It is expected that this paper will provide a better understanding of the technologies, potential advantages and research challenges of the smart grid and provoke interest among the research community to further explore this promising research area.

  8. Speckle Imaging Over Horizontal Paths

    SciTech Connect

    Carrano, C J

    2002-05-21

    Atmospheric aberrations reduce the resolution and contrast in surveillance images recorded over horizontal or slant paths. This paper describes our recent horizontal and slant path imaging experiments of extended scenes as well as the results obtained using speckle imaging. The experiments were performed with an 8-inch diameter telescope placed on either a rooftop or hillside and cover ranges of interest from 0.5 km up to 10 km. The scenery includes resolution targets, people, vehicles, and other structures. The improvement in image quality using speckle imaging is dramatic in many cases, and depends significantly upon the atmospheric conditions. We quantify resolution improvement through modulation transfer function measurement comparisons.

  9. Success in horizontal barrier developments

    SciTech Connect

    Pettit, P.J.; Ridenour, D.E.; Jalovec, J.

    1996-06-01

    A successful proof of concept demonstration has been conducted of operational methods and tooling for the in situ construction of underground horizontal barriers for the control and containment of groundwater and contamination. The method involves jet grouting with specially adapted tools guided between twin, parallel wells for the placement of a grout beneath a waste site. The objective of the work is to develop reliable methods of constructing extensive, competent horizontal barriers underneath waste sites without excavating or penetrating the waste during the process.

  10. Solar cell grid patterns

    NASA Technical Reports Server (NTRS)

    Yasui, R. K.; Berman, P. A. (Inventor)

    1976-01-01

    A grid pattern is described for a solar cell of the type which includes a semiconductive layer doped to a first polarity and a top counter-doped layer. The grid pattern comprises a plurality of concentric conductive grids of selected geometric shapes which are centered about the center of the exposed active surface of the counter-doped layer. Connected to the grids is one or more conductors which extend to the cell's periphery. For the pattern area, the grids and conductors are arranged in the pattern to minimize the maximum distance which any injected majority carriers have to travel to reach any of the grids or conductors. The pattern has a multiaxes symmetry with respect to the cell center to minimize the maximum temperature differentials between points on the cell surface and to provide a more uniform temperature distribution across the cell face.

  11. Horizontal electric fields from lightning return strokes

    NASA Technical Reports Server (NTRS)

    Thomson, E. M.; Medelius, P. J.; Rubinstein, M.; Uman, M. A.; Johnson, J.

    1988-01-01

    An experiment to measure simultaneously the wideband horizontal and vertical electric fields from lightning return strokes is described. Typical wave shapes of the measured horizontal and vertical fields are presented, and the horizontal fields are characterized. The measured horizontal fields are compared with calculated horizontal fields obtained by applying the wavetilt formula to the vertical fields. The limitations and sources of error in the measurement technique are discussed.

  12. Theoretical horizontal-branch evolution

    NASA Technical Reports Server (NTRS)

    Sweigart, Allen V.

    1987-01-01

    The general features of the theoretical evolution of canonical horizontal-branch (HB) stars are briefly reviewed with specific emphasis on the track morphology in the HR diagram and the determination of the globular cluster helium abundance. The observational evidence for the occurrence of semiconvection is discussed together with some remaining theoretical uncertainty.

  13. Horizontal drilling installs dutch waterline

    SciTech Connect

    Not Available

    1986-08-01

    A 32-in. potable water line system, installed by Van Eijk Leidingen B.V. in Holland, was laid through an intensively cultivated vegetable gardening area, and designed to furnish additional irrigation water. Using a horizontally drilled 42-in. hole under the Maasdijk, though a difficult job, reduced the length by more than 3 miles.

  14. Dragging a floating horizontal cylinder

    NASA Astrophysics Data System (ADS)

    Lee, Duck-Gyu; Kim, Ho-Young

    2010-11-01

    A cylinder immersed in a fluid stream experiences a drag, and it is well known that the drag coefficient is a function of the Reynolds number only. Here we study the force exerted on a long horizontal cylinder that is dragged perpendicular to its axis while floating on an air-water interface with a high Reynolds number. In addition to the flow-induced drag, the floating body is subjected to capillary forces along the contact line where the three phases of liquid/solid/gas meet. We first theoretically predict the meniscus profile around the horizontally moving cylinder assuming the potential flow, and show that the profile is in good agreement with that obtained experimentally. Then we compare our theoretical predictions and experimental measurement results for the drag coefficient of a floating horizontal cylinder that is given by a function of the Weber number and the Bond number. This study can help us to understand the horizontal motion of partially submerged objects at air-liquid interface, such as semi-aquatic insects and marine plants.

  15. Challenges facing production grids

    SciTech Connect

    Pordes, Ruth; /Fermilab

    2007-06-01

    Today's global communities of users expect quality of service from distributed Grid systems equivalent to that their local data centers. This must be coupled to ubiquitous access to the ensemble of processing and storage resources across multiple Grid infrastructures. We are still facing significant challenges in meeting these expectations, especially in the underlying security, a sustainable and successful economic model, and smoothing the boundaries between administrative and technical domains. Using the Open Science Grid as an example, I examine the status and challenges of Grids operating in production today.

  16. Enhanced Elliptic Grid Generation

    NASA Technical Reports Server (NTRS)

    Kaul, Upender K.

    2007-01-01

    An enhanced method of elliptic grid generation has been invented. Whereas prior methods require user input of certain grid parameters, this method provides for these parameters to be determined automatically. "Elliptic grid generation" signifies generation of generalized curvilinear coordinate grids through solution of elliptic partial differential equations (PDEs). Usually, such grids are fitted to bounding bodies and used in numerical solution of other PDEs like those of fluid flow, heat flow, and electromagnetics. Such a grid is smooth and has continuous first and second derivatives (and possibly also continuous higher-order derivatives), grid lines are appropriately stretched or clustered, and grid lines are orthogonal or nearly so over most of the grid domain. The source terms in the grid-generating PDEs (hereafter called "defining" PDEs) make it possible for the grid to satisfy requirements for clustering and orthogonality properties in the vicinity of specific surfaces in three dimensions or in the vicinity of specific lines in two dimensions. The grid parameters in question are decay parameters that appear in the source terms of the inhomogeneous defining PDEs. The decay parameters are characteristic lengths in exponential- decay factors that express how the influences of the boundaries decrease with distance from the boundaries. These terms govern the rates at which distance between adjacent grid lines change with distance from nearby boundaries. Heretofore, users have arbitrarily specified decay parameters. However, the characteristic lengths are coupled with the strengths of the source terms, such that arbitrary specification could lead to conflicts among parameter values. Moreover, the manual insertion of decay parameters is cumbersome for static grids and infeasible for dynamically changing grids. In the present method, manual insertion and user specification of decay parameters are neither required nor allowed. Instead, the decay parameters are

  17. A New Dynamical Core Based on the Prediction of the Curl of the Horizontal Vorticity

    NASA Astrophysics Data System (ADS)

    Konor, C. S.; Randall, D. A.; Heikes, R. P.

    2015-12-01

    The Vector-Vorticity Dynamical core (VVM) developed by Jung and Arakawa (2008) has important advantages for the use with the anelastic and unified systems of equations. The VVM predicts the horizontal vorticity vector (HVV) at each interface and the vertical vorticity at the top layer of the model. To guarantee that the three-dimensional vorticity is nondivergent, the vertical vorticity at the interior layers is diagnosed from the horizontal divergence of the HVV through a vertical integral from the top to down. To our knowledge, this is the only dynamical core that guarantees the nondivergence of the three-dimensional vorticity. The VVM uses a C-type horizontal grid, which allows a computational mode. While the computational mode does not seem to be serious in the Cartesian grid applications, it may be serious in the icosahedral grid applications because of the extra degree of freedom in such grids. Although there are special filters to minimize the effects of this computational mode, we prefer to eliminate it altogether. We have developed a new dynamical core, which uses a Z-grid to avoid the computational mode mentioned above. The dynamical core predicts the curl of the HVV and diagnoses the horizontal divergence of the HVV from the predicted vertical vorticity. The three-dimensional vorticity is guaranteed to be nondivergent as in the VVM. In this presentation, we will introduce the new dynamical core and show results obtained by using Cartesian and hexagonal grids. We will also compare the solutions to that obtained by the VVM.

  18. Some Considerations on Horizontal Displacement and Horizontal Displacement Coefficient B

    NASA Astrophysics Data System (ADS)

    Tajduś, Krzysztof; Tajduś, Antoni

    2015-12-01

    Mining-induced deformations of the ground surface and within the rock mass may pose danger not only for surface constructions but also for underground objects (e.g., tunnels, underground storages, garages), diverse types of pipelines, electric cables, etc. For a proper evaluation of hazard for surface and underground objects, such parameters as horizontal displacement and horizontal deformations, especially their maximum values, are of crucial importance. The paper is an attempt at a critical review of hitherto accomplished studies and state of the art of predicting horizontal displacement u, in particular the coefficient B, whose value allows determination of the value of maximum displacement if the value of maximum slope is known, or the value of maximum deformation if the value of maximum trough slope is recognized. Since the geodesic observations of fully developed subsidence troughs suggest that the value of the coefficient depends on the depth H, radius of main influences range r and properties of overburden rock, in particular the occurrence of sub-eras Paleogene and Neogene layers (old name: Quaternary and Tertiary) with low strength parameters, therefore a formula is provided in the present paper allowing for the estimation of the influence of those factors on the value of coefficient B.

  19. Geometric grid generation

    NASA Technical Reports Server (NTRS)

    Ives, David

    1995-01-01

    This paper presents a highly automated hexahedral grid generator based on extensive geometrical and solid modeling operations developed in response to a vision of a designer-driven one day turnaround CFD process which implies a designer-driven one hour grid generation process.

  20. Internet 2 Access Grid.

    ERIC Educational Resources Information Center

    Simco, Greg

    2002-01-01

    Discussion of the Internet 2 Initiative, which is based on collaboration among universities, businesses, and government, focuses on the Access Grid, a Computational Grid that includes interactive multimedia within high-speed networks to provide resources to enable remote collaboration among the research community. (Author/LRW)

  1. Security for grids

    SciTech Connect

    Humphrey, Marty; Thompson, Mary R.; Jackson, Keith R.

    2005-08-14

    Securing a Grid environment presents a distinctive set of challenges. This paper groups the activities that need to be secured into four categories: naming and authentication; secure communication; trust, policy, and authorization; and enforcement of access control. It examines the current state of the art in securing these processes and introduces new technologies that promise to meet the security requirements of Grids more completely.

  2. A grid generation system for multi-disciplinary design optimization

    NASA Technical Reports Server (NTRS)

    Jones, William T.; Samareh-Abolhassani, Jamshid

    1995-01-01

    A general multi-block three-dimensional volume grid generator is presented which is suitable for Multi-Disciplinary Design Optimization. The code is timely, robust, highly automated, and written in ANSI 'C' for platform independence. Algebraic techniques are used to generate and/or modify block face and volume grids to reflect geometric changes resulting from design optimization. Volume grids are generated/modified in a batch environment and controlled via an ASCII user input deck. This allows the code to be incorporated directly into the design loop. Generated volume grids are presented for a High Speed Civil Transport (HSCT) Wing/Body geometry as well a complex HSCT configuration including horizontal and vertical tails, engine nacelles and pylons, and canard surfaces.

  3. Data Grid Implementations

    SciTech Connect

    Moore, Reagan W.; Studham, Ronald S.; Rajasekar, Arcot; Watson, Chip; Stockinger, Heinz; Kunszt, Peter; Charlie Catlett and Ian Foster

    2002-02-27

    Data grids link distributed, heterogeneous storage resources into a coherent data management system. From a user perspective, the data grid provides a uniform name space across the underlying storage systems, while supporting retrieval and storage of files. In the high energy physics community, at least six data grids have been implemented for the storage and distribution of experimental data. Data grids are also being used to support projects as diverse as digital libraries (National Library of Medicine Visible Embryo project), federation of multiple astronomy sky surveys (NSF National Virtual Observatory project), and integration of distributed data sets (Long Term Ecological Reserve). Data grids also form the core interoperability mechanisms for creating persistent archives, in which data collections are migrated to new technologies over time. The ability to provide a uniform name space across multiple administration domains is becoming a critical component of national-scale, collaborative projects.

  4. Transforming Power Grid Operations

    SciTech Connect

    Huang, Zhenyu; Guttromson, Ross T.; Nieplocha, Jarek; Pratt, Robert G.

    2007-04-15

    While computation is used to plan, monitor, and control power grids, some of the computational technologies now used are more than a hundred years old, and the complex interactions of power grid components impede real-time operations. Thus it is hard to speed up “state estimation,” the procedure used to estimate the status of the power grid from measured input. State estimation is the core of grid operations, including contingency analysis, automatic generation control, and optimal power flow. How fast state estimation and contingency analysis are conducted (currently about every 5 minutes) needs to be increased radically so the analysis of contingencies is comprehensive and is conducted in real time. Further, traditional state estimation is based on a power flow model and only provides a static snapshot—a tiny piece of the state of a large-scale dynamic machine. Bringing dynamic aspects into real-time grid operations poses an even bigger challenge. Working with the latest, most advanced computing techniques and hardware, researchers at Pacific Northwest National Laboratory (PNNL) intend to transform grid operations by increasing computational speed and improving accuracy. Traditional power grid computation is conducted on single PC hardware platforms. This article shows how traditional power grid computation can be reformulated to take advantage of advanced computing techniques and be converted to high-performance computing platforms (e.g., PC clusters, reconfigurable hardware, scalable multicore shared memory computers, or multithreaded architectures). The improved performance is expected to have a huge impact on how power grids are operated and managed and ultimately will lead to more reliability and better asset utilization to the power industry. New computational capabilities will be tested and demonstrated on the comprehensive grid operations platform in the Electricity Infrastructure Operations Center, which is a newly commissioned PNNL facility for

  5. Horizontal drilling opportunities in Ohio

    SciTech Connect

    Noel, J.A. )

    1991-08-01

    Horizontal drilling has become commonplace in certain parts of Texas. The Austin Chalk is the favorite target, especially where fracture systems are present. The activity has become so intense that leases are now costly or nearly impossible to find. This type of activity was prevalent during the late oil boom, but with vertical wells. So, the same areas that were drilled then are being redone with horizontal drilling. In the past few months, carbonates with little or no evidence of fracture systems are being drilled with some success. Because of the difficulty in lease acquisition, operators are turning their attention elsewhere. Even though horizontal drilling has been conducted limitedly in the Devonian black shales, the Appalachian basin is an area that calls for attention. In Ohio, there have been instances of discoveries of one-well fields in both the Trenton and Trempealeau formations. The initial production from these wells ranges from a few to hundreds of barrels of oil per day. The lack of success in offset wells has been attributed to the interpretation that the producing wells were serendipitously drilled into a limited fractured reservoir. In most cases, the producer is surrounded by clusters of dry holes. These Ohio wells and wells in one other area are studied using well data, spectral and sonic logs, aerial photographs, side-looking radar surveys, and other data. The results are presented on structure contour and lineament maps, and quantitative log interpretations. The maps show the interpretations of those areas of fracture systems that might be viable targets for horizontal drilling.

  6. Horizontal-branch stellar evolution

    NASA Technical Reports Server (NTRS)

    Sweigart, Allen V.

    1990-01-01

    The results of canonical theory for the evolution of horizontal-branch (HB) stars are examined. Particular attention is given to how an HB star maintains the appropriate composition distribution within the semiconvective zone and how this composition is affected by the finite time-dependence with which convective boundaries actually move. Newly developed models based on time-dependent overshooting are presented for both the core-helium-exhaustion and main HB phases.

  7. Remediation using nested, horizontal wells

    SciTech Connect

    Desantis, P.J.; Andrilenas, J.S.; Cheng, S.; Esler, C.; Miller, R.S.; Lew, K.V.

    1995-11-01

    A pair of nested, horizontal wells (one for vapor extraction, one for groundwater extraction) were utilized to remediate a mixed aromatic volatile organic compound (AVOC) and halogenated volatile organic compound (HVOC) soil and groundwater plume. The project site is an operating gasoline service station located in Portland, Oregon. The site has low permeability soils, a thin unconfined aquifer, with a relatively steep groundwater gradient. Each of the nested horizontal wells was drilled using the continuous borehole directional drilling method. The wells are each 110 meters long employing 73 meters of pre-packed well screen. The groundwater extraction well was pumped via vacuum-enhanced methods utilizing a two-pump configuration to eliminate the need for installation of a pump within the horizontal well and to increase both flow and radius of influence in fine-grained soils. Two groundwater models, a 2D analytical model and a finite element model, were utilized to analyze the potential and actual performance of the well. Of the two models used, the finite element model has produced results closely matching the actual performance of the well. After one year of operation, both AVOCs and HVOCs concentrations have been reduced by between 70 to 100%. All but two downgradient site wells have met cleanup standards for AVOCs; all have met substantial compliance for HVOCs.

  8. Anomalous rectification in horizontal cells.

    PubMed Central

    Werblin, F S

    1975-01-01

    1. The electrical properties of horizontal cells in the mudpuppy in light and dark were measured with a pair of micropipettes separated by about 1 mum with low coupling resistance so that no bridge circuitry was required. 2. All horizontal cells studied showed significant anomalous rectification: the current-voltage characteristic for about 60 per cent of the cells studied had a slope resistance of about 20-30 M omega at the dark potential level; the slope resistance increased by about 15% for each 10 mV depolarization and decreased by about 15% for each 10 mV hyperpolarization. The remaining 40% of the horizontal cells showed a higher input resistance at corresponding potential levels but had similar rectifying properties. 3. The increase in resistance with depolrization developed with a time course of about 1/2 sec when steady steps of outward current were passed across the membrane, but the time course for resistance decrease with hyperpolarization was much shorter for steady inward current steps. In about half the horizontal cells there was a transient decrease in resistance lasting about 100 msec immediately following the outward current steps superimposed upon the slower sustained resistance increase. 4. The normal 20-30 mV hyperpolarizing light response was associated with little or no change in input resistance. However, if the membrane potential was held at the dark potential level with extrinsic current, thereby eliminating the potential-dependent resistance change, a light-elicited resistance increase of about 10 M omega was measured. 5. The time-dependent change in membrane resistance elicited by polarizing steps of current obscured the reversal potential for the response. However, when the reversal potential was measured at short times following polarization of the membrane, before the time-dependent resistance change developed, it was estimated at between +15 and +50 m V. 6. The results suggest that the horizontal cell response is mediated by a light

  9. Coorelations for cresting behavior in horizontal wells. Quarterly report, October 1, 1996--December 31, 1996

    SciTech Connect

    Aziz, K.; Hewett, T.A.

    1996-12-31

    The following activities have been carried out in the last three months. (1) The fourth review meeting of the Horizontal Well Industrial Affiliates Program was held on October 10-11 at Stanford. The meeting was well attended and well received. In addition to the project presentations, a number of member presentations were also made at the meeting. (2) Draft plans for the continuation of the two-phase flow experiments were drawn up and sent to Marathon and other members for their review and comments. Series of new experiments with and without the wire wrapped screens used in 1996 are being considered for 1997. (3) Work on the application of horizontal wells for producing gas condensate reservoirs was continued. After verification of the black oil formulation, emphasis is being put on the compositional case where simulation runs have been set up to check the results against a semi-analytical solution. (4) The previous work on the effects of heterogeneities on horizontal well performance was continued and a paper on the subject was completed. Future work in this area will deal with a careful analysis of the interaction of heterogeneity and production performance. (5) Research work on developing coarse grid methods to study cresting in horizontal wells was continued. The previous correlations for optimum grid size, breakthrough time, and post breakthrough behavior (i.e., water-oil ratio) were further tested and optimized. Procedures to derive pseudo-functions either using numerical correlations or coarse grid simulations have been proposed and successfully tested.

  10. Hurricanes in an Aquaplanet World: Implications of the Impacts of External Forcing and Model Horizontal Resolution

    SciTech Connect

    Li, Fuyu; Collins, William D.; Wehner, Michael F.; Leung, Lai-Yung R.

    2013-06-02

    High-resolution climate models have been shown to improve the statistics of tropical storms and hurricanes compared to low-resolution models. The impact of increasing horizontal resolution in the tropical storm simulation is investigated exclusively using a series of Atmospheric Global Climate Model (AGCM) runs with idealized aquaplanet steady-state boundary conditions and a fixed operational storm-tracking algorithm. The results show that increasing horizontal resolution helps to detect more hurricanes, simulate stronger extreme rainfall, and emulate better storm structures in the models. However, increasing model resolution does not necessarily produce stronger hurricanes in terms of maximum wind speed, minimum sea level pressure, and mean precipitation, as the increased number of storms simulated by high-resolution models is mainly associated with weaker storms. The spatial scale at which the analyses are conducted appears to have more important control on these meteorological statistics compared to horizontal resolution of the model grid. When the simulations are analyzed on common low-resolution grids, the statistics of the hurricanes, particularly the hurricane counts, show reduced sensitivity to the horizontal grid resolution and signs of scale invariant.

  11. Computational studies of horizontal axis wind turbines

    NASA Astrophysics Data System (ADS)

    Xu, Guanpeng

    A numerical technique has been developed for efficiently simulating fully three-dimensional viscous fluid flow around horizontal axis wind turbines (HAWT) using a zonal approach. The flow field is viewed as a combination of viscous regions, inviscid regions and vortices. The method solves the costly unsteady Reynolds averaged Navier-Stokes (RANS) equations only in the viscous region around the turbine blades. It solves the full potential equation in the inviscid region where flow is irrotational and isentropic. The tip vortices are simulated using a Lagrangean approach, thus removing the need to accurately resolve them on a fine grid. The hybrid method is shown to provide good results with modest CPU resources. A full Navier-Stokes based methodology has also been developed for modeling wind turbines at high wind conditions where extensive stall may occur. An overset grid based version that can model rotor-tower interactions has been developed. Finally, a blade element theory based methodology has been developed for the purpose of developing improved tip loss models and stall delay models. The effects of turbulence are simulated using a zero equation eddy viscosity model, or a one equation Spalart-Allmaras model. Two transition models, one based on the Eppler's criterion, and the other based on Michel's criterion, have been developed and tested. The hybrid method has been extensively validated for axial wind conditions for three rotors---NREL Phase II, Phase III, and Phase VI configurations. A limited set of calculations has been done for rotors operating under yaw conditions. Preliminary simulations have also been carried out to assess the effects of the tower wake on the rotor. In most of these cases, satisfactory agreement has been obtained with measurements. Using the numerical results from present methodologies as a guide, Prandtl's tip loss model and Corrigan's stall delay model were correlated with present calculations. An improved tip loss model has been

  12. Industry survey for horizontal wells. Final report

    SciTech Connect

    Wilson, D.D.; Kaback, D.S.; Denhan, M.E.; Watkins, D.

    1993-07-01

    An international survey of horizontal environmental wells was performed during May and June of 1993. The purpose of the survey was to provide the environmental industry with an inventory of horizontal environmental wells and information pertaining to the extent of the use of horizontal environmental wells, the variety of horizontal environmental well applications, the types of geologic and hydrogeologic conditions within which horizontal environmental wells have been installed, and the companies that perform horizontal environmental well installations. Other information, such as the cost of horizontal environmental well installations and the results of tests performed on the wells, is not complete but is provided as general information with the caveat that the information should not be used to compare drilling companies. The result of the survey is a catalogue of horizontal environmental wells that are categorized by the objective or use of the wells, the vertical depth of the wells, and the drilling company contracted to install the wells.

  13. Decentral Smart Grid Control

    NASA Astrophysics Data System (ADS)

    Schäfer, Benjamin; Matthiae, Moritz; Timme, Marc; Witthaut, Dirk

    2015-01-01

    Stable operation of complex flow and transportation networks requires balanced supply and demand. For the operation of electric power grids—due to their increasing fraction of renewable energy sources—a pressing challenge is to fit the fluctuations in decentralized supply to the distributed and temporally varying demands. To achieve this goal, common smart grid concepts suggest to collect consumer demand data, centrally evaluate them given current supply and send price information back to customers for them to decide about usage. Besides restrictions regarding cyber security, privacy protection and large required investments, it remains unclear how such central smart grid options guarantee overall stability. Here we propose a Decentral Smart Grid Control, where the price is directly linked to the local grid frequency at each customer. The grid frequency provides all necessary information about the current power balance such that it is sufficient to match supply and demand without the need for a centralized IT infrastructure. We analyze the performance and the dynamical stability of the power grid with such a control system. Our results suggest that the proposed Decentral Smart Grid Control is feasible independent of effective measurement delays, if frequencies are averaged over sufficiently large time intervals.

  14. The open science grid

    SciTech Connect

    Pordes, R.; /Fermilab

    2004-12-01

    The U.S. LHC Tier-1 and Tier-2 laboratories and universities are developing production Grids to support LHC applications running across a worldwide Grid computing system. Together with partners in computer science, physics grid projects and active experiments, we will build a common national production grid infrastructure which is open in its architecture, implementation and use. The Open Science Grid (OSG) model builds upon the successful approach of last year's joint Grid2003 project. The Grid3 shared infrastructure has for over eight months provided significant computational resources and throughput to a range of applications, including ATLAS and CMS data challenges, SDSS, LIGO, and biology analyses, and computer science demonstrators and experiments. To move towards LHC-scale data management, access and analysis capabilities, we must increase the scale, services, and sustainability of the current infrastructure by an order of magnitude or more. Thus, we must achieve a significant upgrade in its functionalities and technologies. The initial OSG partners will build upon a fully usable, sustainable and robust grid. Initial partners include the US LHC collaborations, DOE & NSF Laboratories and Universities & Trillium Grid projects. The approach is to federate with other application communities in the U.S. to build a shared infrastructure open to other sciences and capable of being modified and improved to respond to needs of other applications, including CDF, D0, BaBar, and RHIC experiments. We describe the application-driven, engineered services of the OSG, short term plans and status, and the roadmap for a consortium, its partnerships and national focus.

  15. Trends in life science grid: from computing grid to knowledge grid

    PubMed Central

    Konagaya, Akihiko

    2006-01-01

    Background Grid computing has great potential to become a standard cyberinfrastructure for life sciences which often require high-performance computing and large data handling which exceeds the computing capacity of a single institution. Results This survey reviews the latest grid technologies from the viewpoints of computing grid, data grid and knowledge grid. Computing grid technologies have been matured enough to solve high-throughput real-world life scientific problems. Data grid technologies are strong candidates for realizing "resourceome" for bioinformatics. Knowledge grids should be designed not only from sharing explicit knowledge on computers but also from community formulation for sharing tacit knowledge among a community. Conclusion Extending the concept of grid from computing grid to knowledge grid, it is possible to make use of a grid as not only sharable computing resources, but also as time and place in which people work together, create knowledge, and share knowledge and experiences in a community. PMID:17254294

  16. A Scalable proxy cache for Grid Data Access

    NASA Astrophysics Data System (ADS)

    Cristian Cirstea, Traian; Just Keijser, Jan; Koeroo, Oscar Arthur; Starink, Ronald; Templon, Jeffrey Alan

    2012-12-01

    We describe a prototype grid proxy cache system developed at Nikhef, motivated by a desire to construct the first building block of a future https-based Content Delivery Network for grid infrastructures. Two goals drove the project: firstly to provide a “native view” of the grid for desktop-type users, and secondly to improve performance for physics-analysis type use cases, where multiple passes are made over the same set of data (residing on the grid). We further constrained the design by requiring that the system should be made of standard components wherever possible. The prototype that emerged from this exercise is a horizontally-scalable, cooperating system of web server / cache nodes, fronted by a customized webDAV server. The webDAV server is custom only in the sense that it supports http redirects (providing horizontal scaling) and that the authentication module has, as back end, a proxy delegation chain that can be used by the cache nodes to retrieve files from the grid. The prototype was deployed at Nikhef and tested at a scale of several terabytes of data and approximately one hundred fast cores of computing. Both small and large files were tested, in a number of scenarios, and with various numbers of cache nodes, in order to understand the scaling properties of the system. For properly-dimensioned cache-node hardware, the system showed speedup of several integer factors for the analysis-type use cases. These results and others are presented and discussed.

  17. Grid Connected Functionality

    DOE Data Explorer

    Baker, Kyri; Jin, Xin; Vaidynathan, Deepthi; Jones, Wesley; Christensen, Dane; Sparn, Bethany; Woods, Jason; Sorensen, Harry; Lunacek, Monte

    2016-08-04

    Dataset demonstrating the potential benefits that residential buildings can provide for frequency regulation services in the electric power grid. In a hardware-in-the-loop (HIL) implementation, simulated homes along with a physical laboratory home are coordinated via a grid aggregator, and it is shown that their aggregate response has the potential to follow the regulation signal on a timescale of seconds. Connected (communication-enabled), devices in the National Renewable Energy Laboratory's (NREL's) Energy Systems Integration Facility (ESIF) received demand response (DR) requests from a grid aggregator, and the devices responded accordingly to meet the signal while satisfying user comfort bounds and physical hardware limitations.

  18. Portable Horizontal-Drilling And Positioning Device

    NASA Technical Reports Server (NTRS)

    Smigocki, Edmund; Johnson, Clarence

    1988-01-01

    Portable horizontal-drilling and positioning device, constructed mainly of off-the-shelf components, accurately drills horizontal small holes in irregularly shaped objects. Holes precisely placed and drilled in objects that cannot be moved to shop area. New device provides three axes of movement while maintaining horizontal drilling.

  19. Grid generation and inviscid flow computation about aircraft geometries

    NASA Technical Reports Server (NTRS)

    Smith, Robert E.

    1989-01-01

    Grid generation and Euler flow about fighter aircraft are described. A fighter aircraft geometry is specified by an area ruled fuselage with an internal duct, cranked delta wing or strake/wing combinations, canard and/or horizontal tail surfaces, and vertical tail surfaces. The initial step before grid generation and flow computation is the determination of a suitable grid topology. The external grid topology that has been applied is called a dual-block topology which is a patched C (exp 1) continuous multiple-block system where inner blocks cover the highly-swept part of a cranked wing or strake, rearward inner-part of the wing, and tail components. Outer-blocks cover the remainder of the fuselage, outer-part of the wing, canards and extend to the far field boundaries. The grid generation is based on transfinite interpolation with Lagrangian blending functions. This procedure has been applied to the Langley experimental fighter configuration and a modified F-18 configuration. Supersonic flow between Mach 1.3 and 2.5 and angles of attack between 0 degrees and 10 degrees have been computed with associated Euler solvers based on the finite-volume approach. When coupling geometric details such as boundary layer diverter regions, duct regions with inlets and outlets, or slots with the general external grid, imposing C (exp 1) continuity can be extremely tedious. The approach taken here is to patch blocks together at common interfaces where there is no grid continuity, but enforce conservation in the finite-volume solution. The key to this technique is how to obtain the information required for a conservative interface. The Ramshaw technique which automates the computation of proportional areas of two overlapping grids on a planar surface and is suitable for coding was used. Researchers generated internal duct grids for the Langley experimental fighter configuration independent of the external grid topology, with a conservative interface at the inlet and outlet.

  20. Panspermia and horizontal gene transfer

    NASA Astrophysics Data System (ADS)

    Klyce, Brig

    2009-08-01

    Evidence that extremophiles are hardy and ubiquitous is helping to make panspermia a respectable theory. But even if life on Earth originally came from space, biologists assume that the subsequent evolution of life is still governed by the darwinian paradigm. In this review we show how panspermia could amend darwinism and point to a cosmic source for, not only extremophiles but, all of life. This version of panspermia can be called "strong panspermia." To support this theory we will discuss recent evidence pertaining to horizontal gene transfer, viruses, genes apparently older than the Earthly evolution of the features they encode, and primate-specific genes without identifiable precursors.

  1. Grid Computing Education Support

    SciTech Connect

    Steven Crumb

    2008-01-15

    The GGF Student Scholar program enabled GGF the opportunity to bring over sixty qualified graduate and under-graduate students with interests in grid technologies to its three annual events over the three-year program.

  2. Space Development Grid Portal

    NASA Technical Reports Server (NTRS)

    Vaziri, Arsi

    2004-01-01

    This viewgraph presentation provides information on the development of a portal to provide secure and distributed grid computing for Payload Operations Integrated Center and Mission Control Center ground services.

  3. Implementing Production Grids

    NASA Technical Reports Server (NTRS)

    Johnston, William E.; Ziobarth, John (Technical Monitor)

    2002-01-01

    We have presented the essence of experience gained in building two production Grids, and provided some of the global context for this work. As the reader might imagine, there were a lot of false starts, refinements to the approaches and to the software, and several substantial integration projects (SRB and Condor integrated with Globus) to get where we are today. However, the point of this paper is to try and make it substantially easier for others to get to the point where Information Power Grids (IPG) and the DOE Science Grids are today. This is what is needed in order to move us toward the vision of a common cyber infrastructure for science. The author would also like to remind the readers that this paper primarily represents the actual experiences that resulted from specific architectural and software choices during the design and implementation of these two Grids. The choices made were dictated by the criteria laid out in section 1. There is a lot more Grid software available today that there was four years ago, and various of these packages are being integrated into IPG and the DOE Grids. However, the foundation choices of Globus, SRB, and Condor would not be significantly different today than they were four years ago. Nonetheless, if the GGF is successful in its work - and we have every reason to believe that it will be - then in a few years we will see that the 28 functions provided by these packages will be defined in terms of protocols and MIS, and there will be several robust implementations available for each of the basic components, especially the Grid Common Services. The impact of the emerging Web Grid Services work is not yet clear. It will likely have a substantial impact on building higher level services, however it is the opinion of the author that this will in no way obviate the need for the Grid Common Services. These are the foundation of Grids, and the focus of almost all of the operational and persistent infrastructure aspects of Grids.

  4. Grid in Geosciences

    NASA Astrophysics Data System (ADS)

    Petitdidier, Monique; Schwichtenberg, Horst

    2010-05-01

    The worldwide Earth science community covers a mosaic of disciplines and players such as academia, industry, national surveys, international organizations, and so forth. It provides a scientific basis for addressing societal issues, which require that the Earth science community utilize massive amounts of data, both in real and remote time. This data is usually distributed among many different organizations and data centers. These facts, the utilization of massive, distributed data amounts, explain the interest of the Earth science community for Grid technology, also noticeable by the variety of applications ported and tools developed. In parallel to the participation in EGEE, other projects involving ES disciplines were or have been carried out as related projects to EGEE (Enabling Grids for E-sciencE) such as CYCLOPS, SEEGrid, EELA2, EUASIA or outside e.g., in the framework of WGISS/CEOS. Numerous applications in atmospheric chemistry, meteorology, seismology, hydrology, pollution, climate and biodiversity were deployed successfully on Grid. In order to fulfill requirements of risk management, several prototype applications have been deployed using OGC (Open geospatial Consortium) components with Grid middleware. Examples are in hydrology for flood or Black Sea Catchment monitoring, and in fire monitoring. Meteorological, pollution and climate applications are based on meteorological models ported on Grid such as MM5 (Mesoscale Model), WRF (Weather Research and Forecasting), RAMS (Regional Atmospheric Modeling System) or CAM (Community Atmosphere Model). Seismological applications on Grid are numerous in locations where their occurrence is important and computer resources too small; then interfaces and gateways have been developed to facilitate the access to data and specific software and avoid work duplication. A portal has been deployed for commercial seismological software, Geocluster, for academic users. In this presentation examples of such applications will

  5. Exploring Hypersonic, Unstructured-Grid Issues through Structured Grids

    NASA Technical Reports Server (NTRS)

    Mazaheri, Ali R.; Kleb, Bill

    2007-01-01

    Pure-tetrahedral unstructured grids have been shown to produce asymmetric heat transfer rates for symmetric problems. Meanwhile, two-dimensional structured grids produce symmetric solutions and as documented here, introducing a spanwise degree of freedom to these structured grids also yields symmetric solutions. The effects of grid skewness and other perturbations of structured-grids are investigated to uncover possible mechanisms behind the unstructured-grid solution asymmetries. By using controlled experiments around a known, good solution, the effects of particular grid pathologies are uncovered. These structured-grid experiments reveal that similar solution degradation occurs as for unstructured grids, especially for heat transfer rates. Non-smooth grids within the boundary layer is also shown to produce large local errors in heat flux but do not affect surface pressures.

  6. Near-Body Grid Adaption for Overset Grids

    NASA Technical Reports Server (NTRS)

    Buning, Pieter G.; Pulliam, Thomas H.

    2016-01-01

    A solution adaption capability for curvilinear near-body grids has been implemented in the OVERFLOW overset grid computational fluid dynamics code. The approach follows closely that used for the Cartesian off-body grids, but inserts refined grids in the computational space of original near-body grids. Refined curvilinear grids are generated using parametric cubic interpolation, with one-sided biasing based on curvature and stretching ratio of the original grid. Sensor functions, grid marking, and solution interpolation tasks are implemented in the same fashion as for off-body grids. A goal-oriented procedure, based on largest error first, is included for controlling growth rate and maximum size of the adapted grid system. The adaption process is almost entirely parallelized using MPI, resulting in a capability suitable for viscous, moving body simulations. Two- and three-dimensional examples are presented.

  7. Using Grid Benchmarks for Dynamic Scheduling of Grid Applications

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; Hood, Robert

    2003-01-01

    Navigation or dynamic scheduling of applications on computational grids can be improved through the use of an application-specific characterization of grid resources. Current grid information systems provide a description of the resources, but do not contain any application-specific information. We define a GridScape as dynamic state of the grid resources. We measure the dynamic performance of these resources using the grid benchmarks. Then we use the GridScape for automatic assignment of the tasks of a grid application to grid resources. The scalability of the system is achieved by limiting the navigation overhead to a few percent of the application resource requirements. Our task submission and assignment protocol guarantees that the navigation system does not cause grid congestion. On a synthetic data mining application we demonstrate that Gridscape-based task assignment reduces the application tunaround time.

  8. Beyond grid security

    NASA Astrophysics Data System (ADS)

    Hoeft, B.; Epting, U.; Koenig, T.

    2008-07-01

    While many fields relevant to Grid security are already covered by existing working groups, their remit rarely goes beyond the scope of the Grid infrastructure itself. However, security issues pertaining to the internal set-up of compute centres have at least as much impact on Grid security. Thus, this talk will present briefly the EU ISSeG project (Integrated Site Security for Grids). In contrast to groups such as OSCT (Operational Security Coordination Team) and JSPG (Joint Security Policy Group), the purpose of ISSeG is to provide a holistic approach to security for Grid computer centres, from strategic considerations to an implementation plan and its deployment. The generalised methodology of Integrated Site Security (ISS) is based on the knowledge gained during its implementation at several sites as well as through security audits, and this will be briefly discussed. Several examples of ISS implementation tasks at the Forschungszentrum Karlsruhe will be presented, including segregation of the network for administration and maintenance and the implementation of Application Gateways. Furthermore, the web-based ISSeG training material will be introduced. This aims to offer ISS implementation guidance to other Grid installations in order to help avoid common pitfalls.

  9. GRIDS: Grid-Scale Rampable Intermittent Dispatchable Storage

    SciTech Connect

    2010-09-01

    GRIDS Project: The 12 projects that comprise ARPA-E’s GRIDS Project, short for “Grid-Scale Rampable Intermittent Dispatchable Storage,” are developing storage technologies that can store renewable energy for use at any location on the grid at an investment cost less than $100 per kilowatt hour. Flexible, large-scale storage would create a stronger and more robust electric grid by enabling renewables to contribute to reliable power generation.

  10. Running with horizontal pulling forces: the benefits of towing.

    PubMed

    Grabowski, Alena M; Kram, Rodger

    2008-10-01

    Towing, or running with a horizontal pulling force, is a common technique used by adventure racing teams. During an adventure race, the slowest person on a team determines the team's overall performance. To improve overall performance, a faster runner tows a slower runner with an elastic cord attached to their waists. Our purpose was to create and validate a model that predicts the optimal towing force needed by two runners to achieve their best overall performance. We modeled the effects of towing forces between two runners that differ in solo 10-km performance time and/or body mass. We calculated the overall time that could be saved with towing for running distances of 10, 20, and 42.2-km based on equations from previous research. Then, we empirically tested our 10-km model on 15 runners. Towing improved overall running performance considerably and our model accurately predicted this performance improvement. For example, if two runners (a 70 kg runner with a 35 min solo 10-km time and a 70-kg runner with a 50-min solo 10-km time) maintain an optimal towing force throughout a 10-km race, they can improve overall performance by 15%, saving almost 8 min. Ultimately, the race performance time and body mass of each runner determine the optimal towing force.

  11. Orphan penumbrae: Submerging horizontal fields

    NASA Astrophysics Data System (ADS)

    Jurčák, J.; Bellot Rubio, L. R.; Sobotka, M.

    2014-04-01

    Aims: We investigate the properties of orphan penumbrae, which are photospheric filamentary structures observed in active regions near polarity inversion lines that resemble the penumbra of regular sunspots but are not connected to any umbra. Methods: We use Hinode data from the Solar Optical Telescope to determine the properties of orphan penumbrae. Spectropolarimetric data are employed to obtain the vector magnetic field and line-of-sight velocities in the photosphere. Magnetograms are used to study the overall evolution of these structures, and G-band and Ca ii H filtergrams are to investigate their brightness and apparent horizontal motions. Results: Orphan penumbrae form between regions of opposite polarity in places with horizontal magnetic fields. Their magnetic configuration is that of Ω-shaped flux ropes. In the two cases studied here, the opposite-polarity regions approach each other with time and the whole structure submerges as the penumbral filaments disappear. Orphan penumbrae are very similar to regular penumbrae, including the existence of strong gas flows. Therefore, they could have a similar origin. The main difference between them is the absence of a "background" magnetic field in orphan penumbrae. This could explain most of the observed differences. Conclusions: The fast flows we detect in orphan penumbrae may be caused by the siphon flow mechanism. Based on the similarities between orphan and regular penumbrae, we propose that the Evershed flow is also a manifestation of siphon flows. A movie attached to Fig. 11 is available in electronic form at http://www.aanda.org

  12. The Benefits of Grid Networks

    ERIC Educational Resources Information Center

    Tennant, Roy

    2005-01-01

    In the article, the author talks about the benefits of grid networks. In speaking of grid networks the author is referring to both networks of computers and networks of humans connected together in a grid topology. Examples are provided of how grid networks are beneficial today and the ways in which they have been used.

  13. Computer Code Generates Homotopic Grids

    NASA Technical Reports Server (NTRS)

    Moitra, Anutosh

    1992-01-01

    HOMAR is computer code using homotopic procedure to produce two-dimensional grids in cross-sectional planes, which grids then stacked to produce quasi-three-dimensional grid systems for aerospace configurations. Program produces grids for use in both Euler and Navier-Stokes computation of flows. Written in FORTRAN 77.

  14. Smart Grid Integration Laboratory

    SciTech Connect

    Troxell, Wade

    2011-12-22

    The initial federal funding for the Colorado State University Smart Grid Integration Laboratory is through a Congressionally Directed Project (CDP), DE-OE0000070 Smart Grid Integration Laboratory. The original program requested in three one-year increments for staff acquisition, curriculum development, and instrumentation all which will benefit the Laboratory. This report focuses on the initial phase of staff acquisition which was directed and administered by DOE NETL/ West Virginia under Project Officer Tom George. Using this CDP funding, we have developed the leadership and intellectual capacity for the SGIC. This was accomplished by investing (hiring) a core team of Smart Grid Systems engineering faculty focused on education, research, and innovation of a secure and smart grid infrastructure. The Smart Grid Integration Laboratory will be housed with the separately funded Integrid Laboratory as part of CSU's overall Smart Grid Integration Center (SGIC). The period of performance of this grant was 10/1/2009 to 9/30/2011 which included one no cost extension due to time delays in faculty hiring. The Smart Grid Integration Laboratory's focus is to build foundations to help graduate and undergraduates acquire systems engineering knowledge; conduct innovative research; and team externally with grid smart organizations. Using the results of the separately funded Smart Grid Workforce Education Workshop (May 2009) sponsored by the City of Fort Collins, Northern Colorado Clean Energy Cluster, Colorado State University Continuing Education, Spirae, and Siemens has been used to guide the hiring of faculty, program curriculum and education plan. This project develops faculty leaders with the intellectual capacity to inspire its students to become leaders that substantially contribute to the development and maintenance of Smart Grid infrastructure through topics such as: (1) Distributed energy systems modeling and control; (2) Energy and power conversion; (3) Simulation of

  15. GridLAB-D/SG

    SciTech Connect

    2011-08-30

    GridLAB-D is a new power system simulation tool that provides valuable information to users who design and operate electric power transmission and distribution systems, and to utilities that wish to take advantage of the latest smart grid technology. This special release of GridLAB-D was developed to study the proposed Smart Grid technology that is used by Battelle Memorial Institute in the AEP gridSMART demonstration project in Northeast Columbus, Ohio.

  16. Productivity and Injectivity of Horizontal Wells

    SciTech Connect

    Aziz, Khalid; Hewett, Thomas A.; Arbabi, Sepehr; Smith, Marilyn

    1999-11-16

    The generation of suitable simulation grids for heterogeneous media and specific discretization issues that arise. Streamlines and equipotentials are used to define our base grids. Since streamlines are concentrated in high velocity regions they provide a natural means of clustering fine grid cells in crucial flow regions. For complex configurations and particularly for strongly heterogeneous regions the resulting grid cells can become very distorted due to extremely high curvatures. Two types of cell centered formulation are examined together with a cell vertex-point distributed scheme. Important distinctions are found for highly distorted cells. The new grids are tested for accuracy in terms of critical breakthrough parameters and it is shown that a much higher level of grid resolution is required by conventional simulators in order to achieve results that are comparable with those computed on relatively coarse streamline-potential grids.

  17. Complex Volume Grid Generation Through the Use of Grid Reusability

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.

    1997-01-01

    This paper presents a set of surface and volume grid generation techniques which reuse existing surface and volume grids. These methods use combinations of data manipulations to reduce grid generation time, improve grid characteristics, and increase the capabilities of existing domain discretization software. The manipulation techniques utilize physical and computational domains to produce basis function on which to operate and modify grid character and smooth grids using Trans-Finite Interpolation, a vector interpolation method and parametric re-mapping technique. With these new techniques, inviscid grids can be converted to viscous grids, multiple zone grid adaption can be performed to improve CFD solver efficiency, and topological changes to improve modeling of flow fields can be done simply and quickly. Examples of these capabilities are illustrated as applied to various configurations.

  18. Explorando nuevos horizontes en NASA

    NASA Astrophysics Data System (ADS)

    Villanueva, G. L.

    A pesar de la incesante expansión del Universo iniciada con el Big Bang 14 mil millones de años atrás, nuestro Universo se siente cada día más cercano. La inquebrantable vocación de la humanidad por descubrir nuevos horizontes ha permitido el acercamiento de civilizaciones en nuestro planeta y nos ha permitido conocer nuestro lugar en el Universo como nunca antes. En este artículo presento una breve sinopsis de nuestro trabajo que se relaciona con diversas investigaciones con implicaciones astrobiológicas, desde el origen de los ingredientes de la "sopa de la vida", hasta la evolución y composición de la atmósfera de Marte.

  19. Horizontal gene transfer in choanoflagellates.

    PubMed

    Tucker, Richard P

    2013-01-01

    Horizontal gene transfer (HGT), also known as lateral gene transfer, results in the rapid acquisition of genes from another organism. HGT has long been known to be a driving force in speciation in prokaryotes, and there is evidence for HGT from symbiotic and infectious bacteria to metazoans, as well as from protists to bacteria. Recently, it has become clear that as many as a 1,000 genes in the genome of the choanoflagellate Monosiga brevicollis may have been acquired by HGT. Interestingly, these genes reportedly come from algae, bacteria, and other choanoflagellate prey. Some of these genes appear to have allowed an ancestral choanoflagellate to exploit nutrient-poor environments and were not passed on to metazoan descendents. However, some of these genes are also found in animal genomes, suggesting that HGT into a common ancestor of choanozoans and animals may have contributed to metazoan evolution.

  20. An Adaptive Unstructured Grid Method by Grid Subdivision, Local Remeshing, and Grid Movement

    NASA Technical Reports Server (NTRS)

    Pirzadeh, Shahyar Z.

    1999-01-01

    An unstructured grid adaptation technique has been developed and successfully applied to several three dimensional inviscid flow test cases. The approach is based on a combination of grid subdivision, local remeshing, and grid movement. For solution adaptive grids, the surface triangulation is locally refined by grid subdivision, and the tetrahedral grid in the field is partially remeshed at locations of dominant flow features. A grid redistribution strategy is employed for geometric adaptation of volume grids to moving or deforming surfaces. The method is automatic and fast and is designed for modular coupling with different solvers. Several steady state test cases with different inviscid flow features were tested for grid/solution adaptation. In all cases, the dominant flow features, such as shocks and vortices, were accurately and efficiently predicted with the present approach. A new and robust method of moving tetrahedral "viscous" grids is also presented and demonstrated on a three-dimensional example.

  1. NREL Smart Grid Projects

    SciTech Connect

    Hambrick, J.

    2012-01-01

    Although implementing Smart Grid projects at the distribution level provides many advantages and opportunities for advanced operation and control, a number of significant challenges must be overcome to maintain the high level of safety and reliability that the modern grid must provide. For example, while distributed generation (DG) promises to provide opportunities to increase reliability and efficiency and may provide grid support services such as volt/var control, the presence of DG can impact distribution operation and protection schemes. Additionally, the intermittent nature of many DG energy sources such as photovoltaics (PV) can present a number of challenges to voltage regulation, etc. This presentation provides an overview a number of Smart Grid projects being performed by the National Renewable Energy Laboratory (NREL) along with utility, industry, and academic partners. These projects include modeling and analysis of high penetration PV scenarios (with and without energy storage), development and testing of interconnection and microgrid equipment, as well as the development and implementation of advanced instrumentation and data acquisition used to analyze the impacts of intermittent renewable resources. Additionally, standards development associated with DG interconnection and analysis as well as Smart Grid interoperability will be discussed.

  2. Sensitivity of precipitation forecast skill to horizontal resolution

    NASA Astrophysics Data System (ADS)

    McDonald, Brett Eugene

    Quantitative precipitation forecasts from operational and research numerical weather prediction models available from the National Centers for Environmental Prediction (NCEP) are evaluated over the western United States. Forecasts from three versions of the Eta model developed at the NCEP are analyzed during the period January-May 1997. While each version of the model underwent modification during the verification period, the primary differences between the versions are horizontal and vertical resolution. Precipitation forecasts from the Nested Grid Model and climatology are used as references. Station 24-h precipitation reports from several data sources are combined to verify the model forecasts. Various objective techniques to measure model accuracy and skill are examined. Among other measures, skill defined from the mean-squared error of the model forecasts relative to that of climatological forecasts is found to discriminate between forecasts that are subjectively judged to be good from those that are not. Sensitivity to verification measure and observational uncertainty, trade-offs between verification at stations as opposed to grid points, and the utility of categorizing errors by model forecast amount are studied. A method is developed to downscale model quantitative precipitation forecasts from coarse resolution grids to high resolution grids based on monthly climatological distributions of precipitation. During winter, the downscaled forecasts are slightly better than the unmodified forecasts. However, the version of the Eta model run at 10-km horizontal resolution over the western United States had greater accuracy for large precipitation amounts compared to the downscaled forecasts. For precipitation amounts greater than 25.4 mm (1.0 in), the versions of the Eta model at higher resolution are more accurate during winter. However, the false alarm rate tends to be large for those models as well. Experimental modifications to the convective parameterization

  3. A Variable Resolution Stretched Grid General Circulation Model: Regional Climate Simulation

    NASA Technical Reports Server (NTRS)

    Fox-Rabinovitz, Michael S.; Takacs, Lawrence L.; Govindaraju, Ravi C.; Suarez, Max J.

    2000-01-01

    The development of and results obtained with a variable resolution stretched-grid GCM for the regional climate simulation mode, are presented. A global variable resolution stretched- grid used in the study has enhanced horizontal resolution over the U.S. as the area of interest The stretched-grid approach is an ideal tool for representing regional to global scale interaction& It is an alternative to the widely used nested grid approach introduced over a decade ago as a pioneering step in regional climate modeling. The major results of the study are presented for the successful stretched-grid GCM simulation of the anomalous climate event of the 1988 U.S. summer drought- The straightforward (with no updates) two month simulation is performed with 60 km regional resolution- The major drought fields, patterns and characteristics such as the time averaged 500 hPa heights precipitation and the low level jet over the drought area. appear to be close to the verifying analyses for the stretched-grid simulation- In other words, the stretched-grid GCM provides an efficient down-scaling over the area of interest with enhanced horizontal resolution. It is also shown that the GCM skill is sustained throughout the simulation extended to one year. The developed and tested in a simulation mode stretched-grid GCM is a viable tool for regional and subregional climate studies and applications.

  4. Fusion Data Grid Service

    NASA Astrophysics Data System (ADS)

    Shasharina, Svetlana; Wang, Nanbor

    2004-11-01

    Simulations and experiments in the fusion and plasma physics community generate large datasets at remote sites. Visualization and analysis of these datasets are difficult because of the incompatibility among the various data formats adopted by simulation, experiments, and analysis tools, and the large sizes of analyzed data. Grids and Web Services technologies are capable of providing solutions for such heterogeneous settings, but need to be customized to the field-specific needs and merged with distributed technologies currently used by the community. This paper describes how we are addressing these issues in the Fusion Grid Service under development. We also present performance results of relevant data transfer mechanisms including binary SOAP, DIME, GridFTP and MDSplus and CORBA. We will describe the status of data converters (between HDF5 and MDSplus data types), developed in collaboration with MIT (J. Stillerman). Finally, we will analyze bottlenecks of MDSplus data transfer mechanism (work performed in collaboration with General Atomics (D. Schissel and M. Qian).

  5. Information Power Grid Posters

    NASA Technical Reports Server (NTRS)

    Vaziri, Arsi

    2003-01-01

    This document is a summary of the accomplishments of the Information Power Grid (IPG). Grids are an emerging technology that provide seamless and uniform access to the geographically dispersed, computational, data storage, networking, instruments, and software resources needed for solving large-scale scientific and engineering problems. The goal of the NASA IPG is to use NASA's remotely located computing and data system resources to build distributed systems that can address problems that are too large or complex for a single site. The accomplishments outlined in this poster presentation are: access to distributed data, IPG heterogeneous computing, integration of large-scale computing node into distributed environment, remote access to high data rate instruments,and exploratory grid environment.

  6. Collection Efficiency and Ice Accretion Characteristics of Two Full Scale and One 1/4 Scale Business Jet Horizontal Tails

    NASA Technical Reports Server (NTRS)

    Bidwell, Colin S.; Papadakis, Michael

    2005-01-01

    Collection efficiency and ice accretion calculations have been made for a series of business jet horizontal tail configurations using a three-dimensional panel code, an adaptive grid code, and the NASA Glenn LEWICE3D grid based ice accretion code. The horizontal tail models included two full scale wing tips and a 25 percent scale model. Flow solutions for the horizontal tails were generated using the PMARC panel code. Grids used in the ice accretion calculations were generated using the adaptive grid code ICEGRID. The LEWICE3D grid based ice accretion program was used to calculate impingement efficiency and ice shapes. Ice shapes typifying rime and mixed icing conditions were generated for a 30 minute hold condition. All calculations were performed on an SGI Octane computer. The results have been compared to experimental flow and impingement data. In general, the calculated flow and collection efficiencies compared well with experiment, and the ice shapes appeared representative of the rime and mixed icing conditions for which they were calculated.

  7. Reduction of a grid moire pattern by integrating a carbon-interspaced high precision x-ray grid with a digital radiographic detector

    SciTech Connect

    Yoon, Jai-Woong; Park, Young-Guk; Park, Chun-Joo; Kim, Do-Il; Lee, Jin-Ho; Chung, Nag-Kun; Choe, Bo-Young; Suh, Tae-Suk; Lee, Hyoung-Koo

    2007-11-15

    The stationary grid commonly used with a digital x-ray detector causes a moire interference pattern due to the inadequate sampling of the grid shadows by the detector pixels. There are limitations with the previous methods used to remove the moire such as imperfect electromagnetic interference shielding and the loss of image information. A new method is proposed for removing the moire pattern by integrating a carbon-interspaced high precision x-ray grid with high grid line uniformity with the detector for frequency matching. The grid was aligned to the detector by translating and rotating the x-ray grid with respect to the detector using microcontrolled alignment mechanism. The gap between the grid and the detector surface was adjusted with micrometer precision to precisely match the projected grid line pitch to the detector pixel pitch. Considering the magnification of the grid shadows on the detector plane, the grids were manufactured such that the grid line frequency was slightly higher than the detector sampling frequency. This study examined the factors that affect the moire pattern, particularly the line frequency and displacement. The frequency of the moire pattern was found to be sensitive to the angular displacement of the grid with respect to the detector while the horizontal translation alters the phase but not the moire frequency. The frequency of the moire pattern also decreased with decreasing difference in frequency between the grid and the detector, and a moire-free image was produced after complete matching for a given source to detector distance. The image quality factors including the contrast, signal-to-noise ratio and uniformity in the images with and without the moire pattern were investigated.

  8. SPRITE MRI of bubbly flow in a horizontal pipe.

    PubMed

    Sankey, Mark; Yang, Zhi; Gladden, Lynn; Johns, Michael L; Lister, Derek; Newling, Benedict

    2009-08-01

    Bubble flow is characterised by numerous phase interfaces and turbulence, leading to fast magnetic resonance signal decay and artefacts in spin-warp imaging. In this paper, the SPRITE MRI pulse sequence, with its potential for very short encoding times, is demonstrated as an ideal technique for studying such dynamic systems. It has been used to acquire liquid velocity and relative intensity maps of two-phase gas-liquid dispersed bubble flow in a horizontal pipe at a liquid Reynolds number of 14,500. The fluids were air and water and a turbulence grid was used to generate a dispersed bubble flow pattern. The SPRITE technique shows promise for future research in gas-liquid flow. PMID:19481190

  9. GridPV Toolbox

    2014-07-15

    Matlab Toolbox for simulating the impact of solar energy on the distribution grid. The majority of the functions are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving GridPV Toolbox information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in the OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feedermore » on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions.« less

  10. GridPV Toolbox

    SciTech Connect

    Broderick, Robert; Quiroz, Jimmy; Grijalva, Santiago; Reno, Matthew; Coogan, Kyle

    2014-07-15

    Matlab Toolbox for simulating the impact of solar energy on the distribution grid. The majority of the functions are useful for interfacing OpenDSS and MATLAB, and they are of generic use for commanding OpenDSS from MATLAB and retrieving GridPV Toolbox information from simulations. A set of functions is also included for modeling PV plant output and setting up the PV plant in the OpenDSS simulation. The toolbox contains functions for modeling the OpenDSS distribution feeder on satellite images with GPS coordinates. Finally, example simulations functions are included to show potential uses of the toolbox functions.

  11. System for Estimating Horizontal Velocity During Descent

    NASA Technical Reports Server (NTRS)

    Johnson, Andrew; Cheng, Yang; Wilson, Reg; Goguen, Jay; Martin, Alejandro San; Leger, Chris; Matthies, Larry

    2007-01-01

    The descent image motion estimation system (DIMES) is a system of hardware and software, designed for original use in estimating the horizontal velocity of a spacecraft descending toward a landing on Mars. The estimated horizontal velocity is used in generating rocket-firing commands to reduce the horizontal velocity as part of an overall control scheme to minimize the landing impact. DIMES can also be used for estimating the horizontal velocity of a remotely controlled or autonomous aircraft for purposes of navigation and control.

  12. Essential Grid Workflow Monitoring Elements

    SciTech Connect

    Gunter, Daniel K.; Jackson, Keith R.; Konerding, David E.; Lee,Jason R.; Tierney, Brian L.

    2005-07-01

    Troubleshooting Grid workflows is difficult. A typicalworkflow involves a large number of components networks, middleware,hosts, etc. that can fail. Even when monitoring data from all thesecomponents is accessible, it is hard to tell whether failures andanomalies in these components are related toa given workflow. For theGrid to be truly usable, much of this uncertainty must be elim- inated.We propose two new Grid monitoring elements, Grid workflow identifiersand consistent component lifecycle events, that will make Gridtroubleshooting easier, and thus make Grids more usable, by simplifyingthe correlation of Grid monitoring data with a particular Gridworkflow.

  13. Distributed Accounting on the Grid

    NASA Technical Reports Server (NTRS)

    Thigpen, William; Hacker, Thomas J.; McGinnis, Laura F.; Athey, Brian D.

    2001-01-01

    By the late 1990s, the Internet was adequately equipped to move vast amounts of data between HPC (High Performance Computing) systems, and efforts were initiated to link together the national infrastructure of high performance computational and data storage resources together into a general computational utility 'grid', analogous to the national electrical power grid infrastructure. The purpose of the Computational grid is to provide dependable, consistent, pervasive, and inexpensive access to computational resources for the computing community in the form of a computing utility. This paper presents a fully distributed view of Grid usage accounting and a methodology for allocating Grid computational resources for use on a Grid computing system.

  14. Enabling Campus Grids with Open Science Grid Technology

    NASA Astrophysics Data System (ADS)

    Weitzel, Derek; Bockelman, Brian; Fraser, Dan; Pordes, Ruth; Swanson, David

    2011-12-01

    The Open Science Grid is a recognized key component of the US national cyber-infrastructure enabling scientific discovery through advanced high throughput computing. The principles and techniques that underlie the Open Science Grid can also be applied to Campus Grids since many of the requirements are the same, even if the implementation technologies differ. We find five requirements for a campus grid: trust relationships, job submission, resource independence, accounting, and data management. The Holland Computing Center's campus grid at the University of Nebraska-Lincoln was designed to fulfill the requirements of a campus grid. A bridging daemon was designed to bring non-Condor clusters into a grid managed by Condor. Condor features which make it possible to bridge Condor sites into a multi-campus grid have been exploited at the Holland Computing Center as well.

  15. Assessment of the horizontal resolution of retrieval products derived from MIPAS observations.

    PubMed

    Carlotti, M; Dinelli, B M; Papandrea, E; Ridolfi, M

    2007-08-01

    We report the results of a study aimed at the assessment of the trade-off between precision and horizontal resolution of the retrieval products of MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) operating onboard the ENVIronmental SATellite. By exploiting different observation setups we could perform the study by acting on both the retrieval and the sampling grids. Our results are compared with those previously obtained on simulated observations [Appl. Opt. 43, 1-11 (2004)]. We show that the horizontal sampling of the atmosphere operated by the spectrometer cannot be pushed beyond some limits without inducing unacceptable correlations among the retrieved profiles. These correlations show-up only when using a two-dimensional retrieval algorithm and can be evaluated through the instabilities that they trigger in the horizontal distribution of the retrieval products. In order to reduce these instabilities we compare the strategy of degrading the retrieval grid with the strategy of applying horizontal regularization. We discuss the different trade-off between precision and spatial resolution connected with the two strategies. The method adopted in this study, is applicable to any orbiting limb sounder measuring along the orbit track.

  16. Grid-size dependence of Cauchy boundary conditions used to simulate stream-aquifer interactions

    USGS Publications Warehouse

    Mehl, S.; Hill, M.C.

    2010-01-01

    This work examines the simulation of stream–aquifer interactions as grids are refined vertically and horizontally and suggests that traditional methods for calculating conductance can produce inappropriate values when the grid size is changed. Instead, different grid resolutions require different estimated values. Grid refinement strategies considered include global refinement of the entire model and local refinement of part of the stream. Three methods of calculating the conductance of the Cauchy boundary conditions are investigated. Single- and multi-layer models with narrow and wide streams produced stream leakages that differ by as much as 122% as the grid is refined. Similar results occur for globally and locally refined grids, but the latter required as little as one-quarter the computer execution time and memory and thus are useful for addressing some scale issues of stream–aquifer interactions. Results suggest that existing grid-size criteria for simulating stream–aquifer interactions are useful for one-layer models, but inadequate for three-dimensional models. The grid dependence of the conductance terms suggests that values for refined models using, for example, finite difference or finite-element methods, cannot be determined from previous coarse-grid models or field measurements. Our examples demonstrate the need for a method of obtaining conductances that can be translated to different grid resolutions and provide definitive test cases for investigating alternative conductance formulations.

  17. Unlocking the smart grid

    SciTech Connect

    Rokach, Joshua Z.

    2010-10-15

    The country has progressed in a relatively short time from rotary dial phones to computers, cell phones, and iPads. With proper planning and orderly policy implementation, the same will happen with the Smart Grid. Here are some suggestions on how to proceed. (author)

  18. APEC Smart Grid Initiative

    SciTech Connect

    Bloyd, Cary N.

    2012-03-01

    This brief paper describes the activities of the Asia Pacific Economic Cooperation (APEC) Smart Grid Initiative (ASGI) which is being led by the U.S. and developed by the APEC Energy Working Group. In the paper, I describe the origin of the initiative and briefly mention the four major elements of the initiative along with existing APEC projects which support it.

  19. NSTAR Smart Grid Pilot

    SciTech Connect

    Rabari, Anil; Fadipe, Oloruntomi

    2014-03-31

    NSTAR Electric & Gas Corporation (“the Company”, or “NSTAR”) developed and implemented a Smart Grid pilot program beginning in 2010 to demonstrate the viability of leveraging existing automated meter reading (“AMR”) deployments to provide much of the Smart Grid functionality of advanced metering infrastructure (“AMI”), but without the large capital investment that AMI rollouts typically entail. In particular, a central objective of the Smart Energy Pilot was to enable residential dynamic pricing (time-of-use “TOU” and critical peak rates and rebates) and two-way direct load control (“DLC”) by continually capturing AMR meter data transmissions and communicating through customer-sited broadband connections in conjunction with a standardsbased home area network (“HAN”). The pilot was supported by the U.S. Department of Energy’s (“DOE”) through the Smart Grid Demonstration program. NSTAR was very pleased to not only receive the funding support from DOE, but the guidance and support of the DOE throughout the pilot. NSTAR is also pleased to report to the DOE that it was able to execute and deliver a successful pilot on time and on budget. NSTAR looks for future opportunities to work with the DOE and others in future smart grid projects.

  20. Widespread horizontal transfer of retrotransposons

    PubMed Central

    Walsh, Ali Morton; Kortschak, R. Daniel; Gardner, Michael G.; Bertozzi, Terry; Adelson, David L.

    2013-01-01

    In higher organisms such as vertebrates, it is generally believed that lateral transfer of genetic information does not readily occur, with the exception of retroviral infection. However, horizontal transfer (HT) of protein coding repetitive elements is the simplest way to explain the patchy distribution of BovB, a long interspersed element (LINE) about 3.2 kb long, that has been found in ruminants, marsupials, squamates, monotremes, and African mammals. BovB sequences are a major component of some of these genomes. Here we show that HT of BovB is significantly more widespread than believed, and we demonstrate the existence of two plausible arthropod vectors, specifically reptile ticks. A phylogenetic tree built from BovB sequences from species in all of these groups does not conform to expected evolutionary relationships of the species, and our analysis indicates that at least nine HT events are required to explain the observed topology. Our results provide compelling evidence for HT of genetic material that has transformed vertebrate genomes. PMID:23277587

  1. Widespread horizontal transfer of retrotransposons.

    PubMed

    Walsh, Ali Morton; Kortschak, R Daniel; Gardner, Michael G; Bertozzi, Terry; Adelson, David L

    2013-01-15

    In higher organisms such as vertebrates, it is generally believed that lateral transfer of genetic information does not readily occur, with the exception of retroviral infection. However, horizontal transfer (HT) of protein coding repetitive elements is the simplest way to explain the patchy distribution of BovB, a long interspersed element (LINE) about 3.2 kb long, that has been found in ruminants, marsupials, squamates, monotremes, and African mammals. BovB sequences are a major component of some of these genomes. Here we show that HT of BovB is significantly more widespread than believed, and we demonstrate the existence of two plausible arthropod vectors, specifically reptile ticks. A phylogenetic tree built from BovB sequences from species in all of these groups does not conform to expected evolutionary relationships of the species, and our analysis indicates that at least nine HT events are required to explain the observed topology. Our results provide compelling evidence for HT of genetic material that has transformed vertebrate genomes. PMID:23277587

  2. Widespread horizontal transfer of retrotransposons.

    PubMed

    Walsh, Ali Morton; Kortschak, R Daniel; Gardner, Michael G; Bertozzi, Terry; Adelson, David L

    2013-01-15

    In higher organisms such as vertebrates, it is generally believed that lateral transfer of genetic information does not readily occur, with the exception of retroviral infection. However, horizontal transfer (HT) of protein coding repetitive elements is the simplest way to explain the patchy distribution of BovB, a long interspersed element (LINE) about 3.2 kb long, that has been found in ruminants, marsupials, squamates, monotremes, and African mammals. BovB sequences are a major component of some of these genomes. Here we show that HT of BovB is significantly more widespread than believed, and we demonstrate the existence of two plausible arthropod vectors, specifically reptile ticks. A phylogenetic tree built from BovB sequences from species in all of these groups does not conform to expected evolutionary relationships of the species, and our analysis indicates that at least nine HT events are required to explain the observed topology. Our results provide compelling evidence for HT of genetic material that has transformed vertebrate genomes.

  3. Horizontally opposed internal combustion engine

    SciTech Connect

    Honkanen, E.G.

    1992-07-28

    This patent describes a internal combustion engine. It comprises a base plate coincident with a horizontal plane and generally symmetrical with respect to a central longitudinal axis coincident with a vertical plane extending between fore and aft ends of the base plate, a main power crankshaft suspended below the base plate and extending parallel with the central longitudinal axis, a plurality of open-ended piston cylinders disposed below the base plate arranged in axially aligned pairs, a pair of auxiliary crankshafts detachably journaled below the base plate on opposite sides of the vertical plane; a connecting rod assembly pivotally interconnecting the pair of auxiliary crankshafts with the main power crankshaft; a piston assembly in each of the cylinders operatively connected with the associated auxiliary crankshaft and including a piston having a head, a wrist-pin and a connecting rod connecting the wrist-pin of each piston with the associated auxiliary crankshaft; a fuel induction assembly for admitting a combustible fuel mixture into the cylinders between the opposed heads of the pistons in a controlled sequence correlated to the receding movement of the pistons in the cylinders in a fuel intake stroke; means for igniting the fuel mixture compressed between the juxtaposed heads of the pistons; means for exhausting from the cylinders the products of combustion of the fuel mixture in correlation to the movement of the pistons in an exhaust stroke; and means including an oil pan enclosing the auxiliary crankshafts.

  4. The surveillance error grid.

    PubMed

    Klonoff, David C; Lias, Courtney; Vigersky, Robert; Clarke, William; Parkes, Joan Lee; Sacks, David B; Kirkman, M Sue; Kovatchev, Boris

    2014-07-01

    Currently used error grids for assessing clinical accuracy of blood glucose monitors are based on out-of-date medical practices. Error grids have not been widely embraced by regulatory agencies for clearance of monitors, but this type of tool could be useful for surveillance of the performance of cleared products. Diabetes Technology Society together with representatives from the Food and Drug Administration, the American Diabetes Association, the Endocrine Society, and the Association for the Advancement of Medical Instrumentation, and representatives of academia, industry, and government, have developed a new error grid, called the surveillance error grid (SEG) as a tool to assess the degree of clinical risk from inaccurate blood glucose (BG) monitors. A total of 206 diabetes clinicians were surveyed about the clinical risk of errors of measured BG levels by a monitor. The impact of such errors on 4 patient scenarios was surveyed. Each monitor/reference data pair was scored and color-coded on a graph per its average risk rating. Using modeled data representative of the accuracy of contemporary meters, the relationships between clinical risk and monitor error were calculated for the Clarke error grid (CEG), Parkes error grid (PEG), and SEG. SEG action boundaries were consistent across scenarios, regardless of whether the patient was type 1 or type 2 or using insulin or not. No significant differences were noted between responses of adult/pediatric or 4 types of clinicians. Although small specific differences in risk boundaries between US and non-US clinicians were noted, the panel felt they did not justify separate grids for these 2 types of clinicians. The data points of the SEG were classified in 15 zones according to their assigned level of risk, which allowed for comparisons with the classic CEG and PEG. Modeled glucose monitor data with realistic self-monitoring of blood glucose errors derived from meter testing experiments plotted on the SEG when compared to

  5. 850-nm Zn-diffusion vertical-cavity surface-emitting lasers with with oxide-relief structure for high-speed and energy-efficient optical interconnects from very-short to medium (2km) reaches

    NASA Astrophysics Data System (ADS)

    Shi, Jin-Wei; Wei, Chia-Chien; Chen, Jason (Jyehong); Yang, Ying-Jay

    2015-03-01

    High-speed and "green" ~850 nm vertical-cavity surface-emitting lasers (VCSELs) have lately attracted lots of attention due to their suitability for applications in optical interconnects (OIs). To further enhance the speed and its maximum allowable linking distance of VCSELs are two major trends to meet the requirement of OI in next generation data centers. Recently, by use of the advanced 850 nm VCSEL technique, data rate as high as 64 Gbit/sec over 57m and 20 Gbit/sec over 2km MMF transmission have been demonstrated, respectively. Here, we will review our recent work about 850 nm Zn-diffusion VCSELs with oxide-relief apertures to further enhance the above-mentioned performances. By using Zn-diffusion, we can not only reduce the device resistance but also manipulate the number of optical modes to benefit transmission. Combing such device, which has excellent single-mode (SMSR >30 dB) and high-power (~7mW) performance, with advanced modulation format (OFDM), record-high bit-rate-distance-product through MMF (2.3 km×28 Gbit/sec) has been demonstrated. Furthermore, by selective etching away the oxide aperture inside Zn-diffusion VCSEL, significant enhancement of device speed, D-factor, and reliability can be observed. With such unique VCSEL structure, >40 Gbit/sec energy-efficient transmission over 100m MMF under extremely low-driving current density (<10kA/cm2) has been successfully demonstrated.

  6. Worldwide experience shows horizontal well success

    SciTech Connect

    Karlsson, H.; Bitto, R.

    1989-03-01

    The convergence of technology and experience has made horizontal drilling an important tool in increasing production and solving a variety of completion problems. Since the early 1980s, horizontal drilling has been used to improve production on more than 700 oil and gas wells throughout the world. Approximately 200 horizontal wells were drilled in 1988 alone. Interest in horizontal drilling has been accelerating rapidly as service companies have developed and offered new technology for drilling and producing horizontal wells. Simultaneously, oil companies have developed better methods for evaluating reservoirs for potential horizontal applications, while their production departments have gained experience at completing and producing them. To date, most horizontal wells have been drilled in the United States. A major application is to complete naturally fractured formations, such as the Austin chalk in Texas, the Bakken shale in the Williston basin, the Spraberry in West Texas and the Devonian shale in the Eastern states. In addition, many horizontal wells have been drilled to produce the Niagaran reefs and the irregular Antrim shale reservoirs in Michigan.

  7. 33 CFR 84.17 - Horizontal sectors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Horizontal sectors. 84.17 Section 84.17 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INLAND NAVIGATION RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.17 Horizontal sectors....

  8. Current Grid operation and future role of the Grid

    NASA Astrophysics Data System (ADS)

    Smirnova, O.

    2012-12-01

    Grid-like technologies and approaches became an integral part of HEP experiments. Some other scientific communities also use similar technologies for data-intensive computations. The distinct feature of Grid computing is the ability to federate heterogeneous resources of different ownership into a seamless infrastructure, accessible via a single log-on. Like other infrastructures of similar nature, Grid functioning requires not only technologically sound basis, but also reliable operation procedures, monitoring and accounting. The two aspects, technological and operational, are closely related: weaker is the technology, more burden is on operations, and other way around. As of today, Grid technologies are still evolving: at CERN alone, every LHC experiment uses an own Grid-like system. This inevitably creates a heavy load on operations. Infrastructure maintenance, monitoring and incident response are done on several levels, from local system administrators to large international organisations, involving massive human effort worldwide. The necessity to commit substantial resources is one of the obstacles faced by smaller research communities when moving computing to the Grid. Moreover, most current Grid solutions were developed under significant influence of HEP use cases, and thus need additional effort to adapt them to other applications. Reluctance of many non-HEP researchers to use Grid negatively affects the outlook for national Grid organisations, which strive to provide multi-science services. We started from the situation where Grid organisations were fused with HEP laboratories and national HEP research programmes; we hope to move towards the world where Grid will ultimately reach the status of generic public computing and storage service provider and permanent national and international Grid infrastructures will be established. How far will we be able to advance along this path, depends on us. If no standardisation and convergence efforts will take place

  9. Spectral methods on arbitrary grids

    NASA Technical Reports Server (NTRS)

    Carpenter, Mark H.; Gottlieb, David

    1995-01-01

    Stable and spectrally accurate numerical methods are constructed on arbitrary grids for partial differential equations. These new methods are equivalent to conventional spectral methods but do not rely on specific grid distributions. Specifically, we show how to implement Legendre Galerkin, Legendre collocation, and Laguerre Galerkin methodology on arbitrary grids.

  10. Grid Interaction Technical Team Roadmap

    SciTech Connect

    2013-06-01

    The mission of the Grid Interaction Technical Team (GITT) is to support a transition scenario to large scale grid-connected vehicle charging with transformational technology, proof of concept and information dissemination. The GITT facilitates technical coordination and collaboration between vehicle-grid connectivity and communication activities among U.S. DRIVE government and industry partners.

  11. Ion Engine Grid Gap Measurements

    NASA Technical Reports Server (NTRS)

    Soulas, Gerge C.; Frandina, Michael M.

    2004-01-01

    A simple technique for measuring the grid gap of an ion engine s ion optics during startup and steady-state operation was demonstrated with beam extraction. The grid gap at the center of the ion optics assembly was measured with a long distance microscope that was focused onto an alumina pin that protruded through the center accelerator grid aperture and was mechanically attached to the screen grid. This measurement technique was successfully applied to a 30 cm titanium ion optics assembly mounted onto an NSTAR engineering model ion engine. The grid gap and each grid s movement during startup from room temperature to both full and low power were measured. The grid gaps with and without beam extraction were found to be significantly different. The grid gaps at the ion optics center were both significantly smaller than the cold grid gap and different at the two power levels examined. To avoid issues associated with a small grid gap during thruster startup with titanium ion optics, a simple method was to operate the thruster initially without beam extraction to heat the ion optics. Another possible method is to apply high voltage to the grids prior to igniting the discharge because power deposition to the grids from the plasma is lower with beam extraction than without. Further testing would be required to confirm this approach.

  12. Characteristics of grid zone heat transfer in a gas-solid fluidized bed

    SciTech Connect

    Ho, T.C.; Wang, R.C.; Hopper, J.R.

    1987-05-01

    The grid zone in a gas-solid fluidized bed reactor has been observed to play a critical role in governing the reactor performance, particularly in shallow and large beds with fast reactions. However, despite its importance the grid zone behavior is far from completely understood, due mainly to its complexity and the few efforts to study it. One of the important aspects on the grid zone behavior is the heat transfer between the bed and immersed horizontal tubes. Although this subject has been under intensive study in the bubbling zone and freeboard area, no systematic work has been performed in the grid zone. Others examined the phenomenon and concluded that the existing heat transfer correlations for the bubbling zone give erroneous results when applied to the grid zone, especially at high velocities. The finding is expected since the two zones are significantly different in their hydrodynamic characteristics. An example of a process involving grid zone heat transfer is the shallow fluidized bed heat exchanger. The exchanger is operated at an extremely low bed height (6-10 cm) with horizontal fin tubes in the grid region. The authors reported a higher than expected heat transfer rate (compared to the bubbling bed heat transfer rate).

  13. Cloud Computing for the Grid: GridControl: A Software Platform to Support the Smart Grid

    SciTech Connect

    2012-02-08

    GENI Project: Cornell University is creating a new software platform for grid operators called GridControl that will utilize cloud computing to more efficiently control the grid. In a cloud computing system, there are minimal hardware and software demands on users. The user can tap into a network of computers that is housed elsewhere (the cloud) and the network runs computer applications for the user. The user only needs interface software to access all of the cloud’s data resources, which can be as simple as a web browser. Cloud computing can reduce costs, facilitate innovation through sharing, empower users, and improve the overall reliability of a dispersed system. Cornell’s GridControl will focus on 4 elements: delivering the state of the grid to users quickly and reliably; building networked, scalable grid-control software; tailoring services to emerging smart grid uses; and simulating smart grid behavior under various conditions.

  14. Gridded electron reversal ionizer

    NASA Technical Reports Server (NTRS)

    Chutjian, Ara (Inventor)

    1993-01-01

    A gridded electron reversal ionizer forms a three dimensional cloud of zero or near-zero energy electrons in a cavity within a filament structure surrounding a central electrode having holes through which the sample gas, at reduced pressure, enters an elongated reversal volume. The resultant negative ion stream is applied to a mass analyzer. The reduced electron and ion space-charge limitations of this configuration enhances detection sensitivity for material to be detected by electron attachment, such as narcotic and explosive vapors. Positive ions may be generated by generating electrons having a higher energy, sufficient to ionize the target gas and pulsing the grid negative to stop the electron flow and pulsing the extraction aperture positive to draw out the positive ions.

  15. Smart Grid Demonstration Project

    SciTech Connect

    Miller, Craig; Carroll, Paul; Bell, Abigail

    2015-03-11

    The National Rural Electric Cooperative Association (NRECA) organized the NRECA-U.S. Department of Energy (DOE) Smart Grid Demonstration Project (DE-OE0000222) to install and study a broad range of advanced smart grid technologies in a demonstration that spanned 23 electric cooperatives in 12 states. More than 205,444 pieces of electronic equipment and more than 100,000 minor items (bracket, labels, mounting hardware, fiber optic cable, etc.) were installed to upgrade and enhance the efficiency, reliability, and resiliency of the power networks at the participating co-ops. The objective of this project was to build a path for other electric utilities, and particularly electrical cooperatives, to adopt emerging smart grid technology when it can improve utility operations, thus advancing the co-ops’ familiarity and comfort with such technology. Specifically, the project executed multiple subprojects employing a range of emerging smart grid technologies to test their cost-effectiveness and, where the technology demonstrated value, provided case studies that will enable other electric utilities—particularly electric cooperatives— to use these technologies. NRECA structured the project according to the following three areas: Demonstration of smart grid technology; Advancement of standards to enable the interoperability of components; and Improvement of grid cyber security. We termed these three areas Technology Deployment Study, Interoperability, and Cyber Security. Although the deployment of technology and studying the demonstration projects at coops accounted for the largest portion of the project budget by far, we see our accomplishments in each of the areas as critical to advancing the smart grid. All project deliverables have been published. Technology Deployment Study: The deliverable was a set of 11 single-topic technical reports in areas related to the listed technologies. Each of these reports has already been submitted to DOE, distributed to co-ops, and

  16. Wireless Communications in Smart Grid

    NASA Astrophysics Data System (ADS)

    Bojkovic, Zoran; Bakmaz, Bojan

    Communication networks play a crucial role in smart grid, as the intelligence of this complex system is built based on information exchange across the power grid. Wireless communications and networking are among the most economical ways to build the essential part of the scalable communication infrastructure for smart grid. In particular, wireless networks will be deployed widely in the smart grid for automatic meter reading, remote system and customer site monitoring, as well as equipment fault diagnosing. With an increasing interest from both the academic and industrial communities, this chapter systematically investigates recent advances in wireless communication technology for the smart grid.

  17. TRMM Gridded Text Products

    NASA Technical Reports Server (NTRS)

    Stocker, Erich Franz

    2007-01-01

    NASA's Tropical Rainfall Measuring Mission (TRMM) has many products that contain instantaneous or gridded rain rates often among many other parameters. However, these products because of their completeness can often seem intimidating to users just desiring surface rain rates. For example one of the gridded monthly products contains well over 200 parameters. It is clear that if only rain rates are desired, this many parameters might prove intimidating. In addition, for many good reasons these products are archived and currently distributed in HDF format. This also can be an inhibiting factor in using TRMM rain rates. To provide a simple format and isolate just the rain rates from the many other parameters, the TRMM product created a series of gridded products in ASCII text format. This paper describes the various text rain rate products produced. It provides detailed information about parameters and how they are calculated. It also gives detailed format information. These products are used in a number of applications with the TRMM processing system. The products are produced from the swath instantaneous rain rates and contain information from the three major TRMM instruments: radar, radiometer, and combined. They are simple to use, human readable, and small for downloading.

  18. Open-System Magma Reservoir Affects Gas Segregation, Vesiculation, Fragmentation and Lava/Pyroclast Dispersal During the 1.2 km-deep 2007-2010 Submarine Eruption at West Mata Volcano

    NASA Astrophysics Data System (ADS)

    Rubin, K. H.; Clague, D. A.; Embley, R. W.; Hellebrand, E.; Soule, S. A.; Resing, J.

    2014-12-01

    West Mata, a small, active rear-arc volcano in the NE Lau Basin, erupts crystal and gas rich boninite magma. Eruptions were observed at the summit (1.2 km water depth) during 5 ROV Jason dives in 2009 (the deepest erupting submarine volcano observed to date). Subsequent ROV and ship-based bathymetric mapping revealed that a pit crater formed and the summit eruption ceased in 2010, with roughly simultaneous eruptions along the SW rift zone. During the summit eruption, a combination of water depth, H2O-CO2-rich and high crystallinity magma, a split in the conduit to feed two vent sites, and waxing/waning magma supply led to a range of effusive/explosive eruption styles and volcanic deposit types. The 2-3 vent Hades cluster and the lone Prometheus vent had different eruption characteristics. Petrographic, petrologic and geochemical studies of erupted products indicate a change in magma composition in time and space over a period of 3.5 yrs, suggesting a small, open-system magma reservoir within the volcano. Prometheus (1174m depth) produced mostly pyroclastic material during our observations (e.g., highly vesicular glowing fluidal ejecta that cooled in the water column and rounded recycled dense clasts), but sampling and 210Po radiometric dating show that several months prior pillowed lava flows, subsequently covered with cm-sized pyroclasts, had flowed >50m from the vent. In contrast, vents at Hades (1200m depth) cycled between lava production and vigorous degassing, 10-20m high fire fountains and bursts of glowing lava-skinned bubbles, the products of which froze/broke in the water column, forming unstable cones of spatter and scoria near the vents. We hypothesize that bubbles collapse rather than form lava balloons because of skin brittleness (from high crystal content) and hydrostatic pressure. Clast settling times and patterns suggest >100m water column rise height for 10+ cm-sized fragments. Pillow flows were also observed to be issuing from the base of the

  19. Constructing the ASCI computational grid

    SciTech Connect

    BEIRIGER,JUDY I.; BIVENS,HUGH P.; HUMPHREYS,STEVEN L.; JOHNSON,WILBUR R.; RHEA,RONALD E.

    2000-06-01

    The Accelerated Strategic Computing Initiative (ASCI) computational grid is being constructed to interconnect the high performance computing resources of the nuclear weapons complex. The grid will simplify access to the diverse computing, storage, network, and visualization resources, and will enable the coordinated use of shared resources regardless of location. To match existing hardware platforms, required security services, and current simulation practices, the Globus MetaComputing Toolkit was selected to provide core grid services. The ASCI grid extends Globus functionality by operating as an independent grid, incorporating Kerberos-based security, interfacing to Sandia's Cplant{trademark},and extending job monitoring services. To fully meet ASCI's needs, the architecture layers distributed work management and criteria-driven resource selection services on top of Globus. These services simplify the grid interface by allowing users to simply request ''run code X anywhere''. This paper describes the initial design and prototype of the ASCI grid.

  20. 3D Structured Grid Adaptation

    NASA Technical Reports Server (NTRS)

    Banks, D. W.; Hafez, M. M.

    1996-01-01

    Grid adaptation for structured meshes is the art of using information from an existing, but poorly resolved, solution to automatically redistribute the grid points in such a way as to improve the resolution in regions of high error, and thus the quality of the solution. This involves: (1) generate a grid vis some standard algorithm, (2) calculate a solution on this grid, (3) adapt the grid to this solution, (4) recalculate the solution on this adapted grid, and (5) repeat steps 3 and 4 to satisfaction. Steps 3 and 4 can be repeated until some 'optimal' grid is converged to but typically this is not worth the effort and just two or three repeat calculations are necessary. They also may be repeated every 5-10 time steps for unsteady calculations.

  1. The Open Science Grid status and architecture

    SciTech Connect

    Pordes, Ruth; Petravick, Don; Kramer, Bill; Olsen, James D.; Livny, Miron; Roy, Gordon A.; Avery, Paul Ralph; Blackburn, Kent; Wenaus, Torre J.; Wuerthwein, Frank K.; Foster, Ian; /Chicago U. /Indiana U.

    2007-09-01

    The Open Science Grid (OSG) provides a distributed facility where the Consortium members provide guaranteed and opportunistic access to shared computing and storage resources. The OSG project[1] is funded by the National Science Foundation and the Department of Energy Scientific Discovery through Advanced Computing program. The OSG project provides specific activities for the operation and evolution of the common infrastructure. The US ATLAS and US CMS collaborations contribute to and depend on OSG as the US infrastructure contributing to the World Wide LHC Computing Grid on which the LHC experiments distribute and analyze their data. Other stakeholders include the STAR RHIC experiment, the Laser Interferometer Gravitational-Wave Observatory (LIGO), the Dark Energy Survey (DES) and several Fermilab Tevatron experiments- CDF, D0, MiniBoone etc. The OSG implementation architecture brings a pragmatic approach to enabling vertically integrated community specific distributed systems over a common horizontal set of shared resources and services. More information can be found at the OSG web site: www.opensciencegrid.org.

  2. Progress in Grid Generation: From Chimera to DRAGON Grids

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Kao, Kai-Hsiung

    1994-01-01

    Hybrid grids, composed of structured and unstructured grids, combines the best features of both. The chimera method is a major stepstone toward a hybrid grid from which the present approach is evolved. The chimera grid composes a set of overlapped structured grids which are independently generated and body-fitted, yielding a high quality grid readily accessible for efficient solution schemes. The chimera method has been shown to be efficient to generate a grid about complex geometries and has been demonstrated to deliver accurate aerodynamic prediction of complex flows. While its geometrical flexibility is attractive, interpolation of data in the overlapped regions - which in today's practice in 3D is done in a nonconservative fashion, is not. In the present paper we propose a hybrid grid scheme that maximizes the advantages of the chimera scheme and adapts the strengths of the unstructured grid while at the same time keeps its weaknesses minimal. Like the chimera method, we first divide up the physical domain by a set of structured body-fitted grids which are separately generated and overlaid throughout a complex configuration. To eliminate any pure data manipulation which does not necessarily follow governing equations, we use non-structured grids only to directly replace the region of the arbitrarily overlapped grids. This new adaptation to the chimera thinking is coined the DRAGON grid. The nonstructured grid region sandwiched between the structured grids is limited in size, resulting in only a small increase in memory and computational effort. The DRAGON method has three important advantages: (1) preserving strengths of the chimera grid; (2) eliminating difficulties sometimes encountered in the chimera scheme, such as the orphan points and bad quality of interpolation stencils; and (3) making grid communication in a fully conservative and consistent manner insofar as the governing equations are concerned. To demonstrate its use, the governing equations are

  3. Horizontal fields generated by return strokes

    NASA Technical Reports Server (NTRS)

    Cooray, Vernon

    1991-01-01

    Horizontal fields generated by return strokes play an important role in the interaction of lightning generated electric fields with power lines. In many of the recent investigations on the interaction of lightning electromagnetic fields with power lines, the horizontal field was calculated by employing the expression for the tilt of the electric field of a plane wave propagating over finitely conducting earth. The method is suitable for calculating horizontal fields generated by return strokes at distances as close as 200m. At these close ranges, the use of the wavetilt expression can cause large errors.

  4. Enhancing control of grid distribution in algebraic grid generation

    NASA Technical Reports Server (NTRS)

    Steinthorsson, E.; Shih, T. I.-P.; Roelke, R. J.

    1992-01-01

    Three techniques are presented to enhance the control of grid-point distribution for a class of algebraic grid generation methods known as the two-, four- and six-boundary methods. First, multidimensional stretching functions are presented, and a technique is devised to construct them based on the desired distribution of grid points along certain boundaries. Second, a normalization procedure is proposed which allows more effective control over orthogonality of grid lines at boundaries and curvature of grid lines near boundaries. And third, interpolating functions based on tension splines are introduced to control curvature of grid lines in the interior of the spatial domain. In addition to these three techniques, consistency conditions are derived which must be satisfied by all user-specified data employed in the grid generation process to control grid-point distribution. The usefulness of the techniques developed in this study was demonstrated by using them in conjunction with the two- and four-boundary methods to generate several grid systems, including a three-dimensional grid system in the coolant passage of a radial turbine blade with serpentine channels and pin fins.

  5. GridTool: A surface modeling and grid generation tool

    NASA Technical Reports Server (NTRS)

    Samareh-Abolhassani, Jamshid

    1995-01-01

    GridTool is designed around the concept that the surface grids are generated on a set of bi-linear patches. This type of grid generation is quite easy to implement, and it avoids the problems associated with complex CAD surface representations and associated surface parameterizations. However, the resulting surface grids are close to but not on the original CAD surfaces. This problem can be alleviated by projecting the resulting surface grids onto the original CAD surfaces. GridTool is designed primary for unstructured grid generation systems. Currently, GridTool supports VGRID and FELISA systems, and it can be easily extended to support other unstructured grid generation systems. The data in GridTool is stored parametrically so that once the problem is set up, one can modify the surfaces and the entire set of points, curves and patches will be updated automatically. This is very useful in a multidisciplinary design and optimization process. GridTool is written entirely in ANSI 'C', the interface is based on the FORMS library, and the graphics is based on the GL library. The code has been tested successfully on IRIS workstations running IRIX4.0 and above. The memory is allocated dynamically, therefore, memory size will depend on the complexity of geometry/grid. GridTool data structure is based on a link-list structure which allows the required memory to expand and contract dynamically according to the user's data size and action. Data structure contains several types of objects such as points, curves, patches, sources and surfaces. At any given time, there is always an active object which is drawn in magenta, or in their highlighted colors as defined by the resource file which will be discussed later.

  6. Smart Grid Risk Management

    NASA Astrophysics Data System (ADS)

    Abad Lopez, Carlos Adrian

    Current electricity infrastructure is being stressed from several directions -- high demand, unreliable supply, extreme weather conditions, accidents, among others. Infrastructure planners have, traditionally, focused on only the cost of the system; today, resilience and sustainability are increasingly becoming more important. In this dissertation, we develop computational tools for efficiently managing electricity resources to help create a more reliable and sustainable electrical grid. The tools we present in this work will help electric utilities coordinate demand to allow the smooth and large scale integration of renewable sources of energy into traditional grids, as well as provide infrastructure planners and operators in developing countries a framework for making informed planning and control decisions in the presence of uncertainty. Demand-side management is considered as the most viable solution for maintaining grid stability as generation from intermittent renewable sources increases. Demand-side management, particularly demand response (DR) programs that attempt to alter the energy consumption of customers either by using price-based incentives or up-front power interruption contracts, is more cost-effective and sustainable in addressing short-term supply-demand imbalances when compared with the alternative that involves increasing fossil fuel-based fast spinning reserves. An essential step in compensating participating customers and benchmarking the effectiveness of DR programs is to be able to independently detect the load reduction from observed meter data. Electric utilities implementing automated DR programs through direct load control switches are also interested in detecting the reduction in demand to efficiently pinpoint non-functioning devices to reduce maintenance costs. We develop sparse optimization methods for detecting a small change in the demand for electricity of a customer in response to a price change or signal from the utility

  7. Grid-based Meteorological and Crisis Applications

    NASA Astrophysics Data System (ADS)

    Hluchy, Ladislav; Bartok, Juraj; Tran, Viet; Lucny, Andrej; Gazak, Martin

    2010-05-01

    We present several applications from domain of meteorology and crisis management we developed and/or plan to develop. Particularly, we present IMS Model Suite - a complex software system designed to address the needs of accurate forecast of weather and hazardous weather phenomena, environmental pollution assessment, prediction of consequences of nuclear accident and radiological emergency. We discuss requirements on computational means and our experiences how to meet them by grid computing. The process of a pollution assessment and prediction of the consequences in case of radiological emergence results in complex data-flows and work-flows among databases, models and simulation tools (geographical databases, meteorological and dispersion models, etc.). A pollution assessment and prediction requires running of 3D meteorological model (4 nests with resolution from 50 km to 1.8 km centered on nuclear power plant site, 38 vertical levels) as well as running of the dispersion model performing the simulation of the release transport and deposition of the pollutant with respect to the numeric weather prediction data, released material description, topography, land use description and user defined simulation scenario. Several post-processing options can be selected according to particular situation (e.g. doses calculation). Another example is a forecasting of fog as one of the meteorological phenomena hazardous to the aviation as well as road traffic. It requires complicated physical model and high resolution meteorological modeling due to its dependence on local conditions (precise topography, shorelines and land use classes). An installed fog modeling system requires a 4 time nested parallelized 3D meteorological model with 1.8 km horizontal resolution and 42 levels vertically (approx. 1 million points in 3D space) to be run four times daily. The 3D model outputs and multitude of local measurements are utilized by SPMD-parallelized 1D fog model run every hour. The fog

  8. Recompletion by horizontal drilling pays off

    SciTech Connect

    Holifield, R.H.; Rehm, B.

    1989-03-01

    More than 20 wells have been recompleted in the Giddings field by drilling a new, horizontal interval from existing 5 1/2-in. cased wells for distances of 300 to 1,250 ft. Recompleting existing wells is much cheaper than drilling a new well. Plus, the new completions, overall, produce better. The horizontal wells are routinely profitable now, and pay out occurs in 3 to 24 months. During this program, the techniques for slim-hole- medium-radius, horizontal drilling in Giddings have been mastered and costs have dropped 75%. It is believed that this program may be the first (or among the first) continuing horizontal project drilled out of cased wells with repeatable profitability as opposed to projected viability.

  9. Grid crusher apparatus and method

    SciTech Connect

    McDaniels, J.D. Jr.

    1994-01-11

    A grid crusher apparatus and method are provided for a nuclear fuel rod consolidation system. Spacer grids are crushed within a basket which is then placed in a storage canister. The grid crusher apparatus has a ram assembly and a basket driving mechanism. The ram assembly has a sleeve ram and a central ram. The sleeve ram surrounds the central ram which is longitudinally movable within the sleeve ram. The central ram protrudes from the sleeve ram at a ram contact end and is retractable upon application of a preselected force to the central ram so that the central ram is flush with the sleeve ram at the ram contact end. The basket driving mechanism is configured to move the basket containing a spacer grid towards the ram contact end so that the spacer grid is crushed within the basket. The spacer grid is crushed by the combination of successive forces from the central ram and the sleeve ram, respectively. Essentially, the central portion of the spacer grid is crushed first, and then the remaining outer portion of the spacer grid is crushed to complete the crushing action of the spacer grid. The foregoing process is repeated for other spacer grids until the basket reaches a predetermined allowable capacity, and then the basket is stored in a storage canister. 11 figs.

  10. Horizontal sidetrack taps reservoir sweet spots''

    SciTech Connect

    Wible, J.R. )

    1994-02-21

    Cutting a window at 85[degree] deviation allowed a sidetrack to pass through the high-resistivity sections in a Gulf of Mexico reservoir. Results from logging-while-drilling (LWD) tools indicated the original horizontal bore dropped too low in the reservoir, possibly leading to a low productivity well. The subsequent sidetrack successfully delivered the desired well bore, and the increased productivity justified the efforts in cutting a window in the horizontal section.

  11. Report of the Horizontal Launch Study

    NASA Technical Reports Server (NTRS)

    Wilhite, Alan W.; Bartolotta, Paul A.

    2011-01-01

    A study of horizontal launch concepts has been conducted. This study, jointly sponsored by the Defense Advanced Research Projects Agency (DARPA) and the National Aeronautics and Space Administration (NASA) was tasked to estimate the economic and technical viability of horizontal launch approaches. The study team identified the key parameters and critical technologies which determine mission viability and reported on the state of the art of critical technologies, along with objectives for technology development.

  12. Evaluating the Information Power Grid using the NAS Grid Benchmarks

    NASA Technical Reports Server (NTRS)

    VanderWijngaartm Rob F.; Frumkin, Michael A.

    2004-01-01

    The NAS Grid Benchmarks (NGB) are a collection of synthetic distributed applications designed to rate the performance and functionality of computational grids. We compare several implementations of the NGB to determine programmability and efficiency of NASA's Information Power Grid (IPG), whose services are mostly based on the Globus Toolkit. We report on the overheads involved in porting existing NGB reference implementations to the IPG. No changes were made to the component tasks of the NGB can still be improved.

  13. Emotion recognition (sometimes) depends on horizontal orientations

    PubMed Central

    Huynh, Carol M; Balas, Benjamin

    2014-01-01

    Face recognition depends critically on horizontal orientations (Goffaux & Dakin, 2010). Face images that lack horizontal features are harder to recognize than those that have that information preserved. Presently, we asked if facial emotional recognition also exhibits this dependency by asking observers to categorize orientation-filtered happy and sad expressions. Furthermore, we aimed to dissociate image-based orientation energy from object-based orientation by rotating images 90-degrees in the picture-plane. In our first experiment, we showed that the perception of emotional expression does depend on horizontal orientations and that object-based orientation constrained performance more than image-based orientation. In Experiment 2 we showed that mouth openness (i.e. open versus closed-mouths) also influenced the emotion-dependent reliance on horizontal information. Lastly, we describe a simple computational analysis that demonstrates that the impact of mouth openness was not predicted by variation in the distribution of orientation energy across horizontal and vertical orientation bands. Overall, our results suggest that emotion recognition does largely depend on horizontal information defined relative to the face, but that this bias is modulated by multiple factors that introduce variation in appearance across and within distinct emotions. PMID:24664854

  14. The Volume Grid Manipulator (VGM): A Grid Reusability Tool

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.

    1997-01-01

    This document is a manual describing how to use the Volume Grid Manipulation (VGM) software. The code is specifically designed to alter or manipulate existing surface and volume structured grids to improve grid quality through the reduction of grid line skewness, removal of negative volumes, and adaption of surface and volume grids to flow field gradients. The software uses a command language to perform all manipulations thereby offering the capability of executing multiple manipulations on a single grid during an execution of the code. The command language can be input to the VGM code by a UNIX style redirected file, or interactively while the code is executing. The manual consists of 14 sections. The first is an introduction to grid manipulation; where it is most applicable and where the strengths of such software can be utilized. The next two sections describe the memory management and the manipulation command language. The following 8 sections describe simple and complex manipulations that can be used in conjunction with one another to smooth, adapt, and reuse existing grids for various computations. These are accompanied by a tutorial section that describes how to use the commands and manipulations to solve actual grid generation problems. The last two sections are a command reference guide and trouble shooting sections to aid in the use of the code as well as describe problems associated with generated scripts for manipulation control.

  15. GridPP: the UK grid for particle physics.

    PubMed

    Britton, D; Cass, A J; Clarke, P E L; Coles, J; Colling, D J; Doyle, A T; Geddes, N I; Gordon, J C; Jones, R W L; Kelsey, D P; Lloyd, S L; Middleton, R P; Patrick, G N; Sansum, R A; Pearce, S E

    2009-06-28

    The start-up of the Large Hadron Collider (LHC) at CERN, Geneva, presents a huge challenge in processing and analysing the vast amounts of scientific data that will be produced. The architecture of the worldwide grid that will handle 15 PB of particle physics data annually from this machine is based on a hierarchical tiered structure. We describe the development of the UK component (GridPP) of this grid from a prototype system to a full exploitation grid for real data analysis. This includes the physical infrastructure, the deployment of middleware, operational experience and the initial exploitation by the major LHC experiments. PMID:19451101

  16. GridPP: the UK grid for particle physics.

    PubMed

    Britton, D; Cass, A J; Clarke, P E L; Coles, J; Colling, D J; Doyle, A T; Geddes, N I; Gordon, J C; Jones, R W L; Kelsey, D P; Lloyd, S L; Middleton, R P; Patrick, G N; Sansum, R A; Pearce, S E

    2009-06-28

    The start-up of the Large Hadron Collider (LHC) at CERN, Geneva, presents a huge challenge in processing and analysing the vast amounts of scientific data that will be produced. The architecture of the worldwide grid that will handle 15 PB of particle physics data annually from this machine is based on a hierarchical tiered structure. We describe the development of the UK component (GridPP) of this grid from a prototype system to a full exploitation grid for real data analysis. This includes the physical infrastructure, the deployment of middleware, operational experience and the initial exploitation by the major LHC experiments.

  17. Adventures in Computational Grids

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela P.; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    Sometimes one supercomputer is not enough. Or your local supercomputers are busy, or not configured for your job. Or you don't have any supercomputers. You might be trying to simulate worldwide weather changes in real time, requiring more compute power than you could get from any one machine. Or you might be collecting microbiological samples on an island, and need to examine them with a special microscope located on the other side of the continent. These are the times when you need a computational grid.

  18. TASMANIAN Sparse Grids Module

    SciTech Connect

    and Drayton Munster, Miroslav Stoyanov

    2013-09-20

    Sparse Grids are the family of methods of choice for multidimensional integration and interpolation in low to moderate number of dimensions. The method is to select extend a one dimensional set of abscissas, weights and basis functions by taking a subset of all possible tensor products. The module provides the ability to create global and local approximations based on polynomials and wavelets. The software has three components, a library, a wrapper for the library that provides a command line interface via text files ad a MATLAB interface via the command line tool.

  19. TASMANIAN Sparse Grids Module

    2013-09-20

    Sparse Grids are the family of methods of choice for multidimensional integration and interpolation in low to moderate number of dimensions. The method is to select extend a one dimensional set of abscissas, weights and basis functions by taking a subset of all possible tensor products. The module provides the ability to create global and local approximations based on polynomials and wavelets. The software has three components, a library, a wrapper for the library thatmore » provides a command line interface via text files ad a MATLAB interface via the command line tool.« less

  20. The EUAsiaGrid Project

    NASA Astrophysics Data System (ADS)

    Paganoni, Marco

    The EUAsiaGrid proposal contributes to the aims of the Research Infrastructures part of the EU Seventh Framework Programme (FP7) by promoting interoperation between the European and the Asian-Pacific Grids. The project, with a total number of 15 partners coordinated by INFN, started on April 1st 2008. It will disseminate the knowledge about the EGEE Grid infrastructure, organize specific training events and support applications both within the scientific communities with an already long experience in the Computing Grids (High Energy Physics, Computational Chemistry, Bioinformatics and Biomedics) and in the most recent ones (Social Sciences, Disaster Mitigation, Cultural Heritage). Ultimately the EUAsiaGrid project will pave the way towards a common e-Infrastructure with the European and the Asian Grids.

  1. Prepares Overset Grids for Processing

    1998-04-22

    Many large and complex computational problems require multiple, structured, generically overlapped (overset) grids to obtain numerical solutions in a timely manner. BREAKUP significantly reduces required compute times by preparing overset grids for processing on massively parallel computers. BREAKUP subdivides the original grids for use on a user-specified number of parallel processors. Grid-to-grid and intragrid communications are maintained in the parallel environment via connectivity tables generated by BREAKUP. The subgrids are formed to be statically loadmore » balanced and to incur a minimum of communication between the subgrids. When the output of BREAKUP is submitted to an appropriately modified flow solver, subgrid solutions will be updated simultaneously. This contrasts to the much less efficient solution method of updating each original grid sequentially as done in the past.« less

  2. Prepares Overset Grids for Processing

    SciTech Connect

    Barnette, Daniel W.

    1998-04-22

    Many large and complex computational problems require multiple, structured, generically overlapped (overset) grids to obtain numerical solutions in a timely manner. BREAKUP significantly reduces required compute times by preparing overset grids for processing on massively parallel computers. BREAKUP subdivides the original grids for use on a user-specified number of parallel processors. Grid-to-grid and intragrid communications are maintained in the parallel environment via connectivity tables generated by BREAKUP. The subgrids are formed to be statically load balanced and to incur a minimum of communication between the subgrids. When the output of BREAKUP is submitted to an appropriately modified flow solver, subgrid solutions will be updated simultaneously. This contrasts to the much less efficient solution method of updating each original grid sequentially as done in the past.

  3. A Vertically Flow-Following, Icosahedral Grid Model for Medium-Range and Seasonal Prediction. Part 1: Model Description

    NASA Technical Reports Server (NTRS)

    Bleck, Rainer; Bao, Jian-Wen; Benjamin, Stanley G.; Brown, John M.; Fiorino, Michael; Henderson, Thomas B.; Lee, Jin-Luen; MacDonald, Alexander E.; Madden, Paul; Middlecoff, Jacques; Rosinski, James; Smirnova, Tanya G.; Sun, Shan; Wang, Ning

    2015-01-01

    A hydrostatic global weather prediction model based on an icosahedral horizontal grid and a hybrid terrain following/ isentropic vertical coordinate is described. The model is an extension to three spatial dimensions of a previously developed, icosahedral, shallow-water model featuring user-selectable horizontal resolution and employing indirect addressing techniques. The vertical grid is adaptive to maximize the portion of the atmosphere mapped into the isentropic coordinate subdomain. The model, best described as a stacked shallow-water model, is being tested extensively on real-time medium-range forecasts to ready it for possible inclusion in operational multimodel ensembles for medium-range to seasonal prediction.

  4. On unstructured grids and solvers

    NASA Technical Reports Server (NTRS)

    Barth, T. J.

    1990-01-01

    The fundamentals and the state-of-the-art technology for unstructured grids and solvers are highlighted. Algorithms and techniques pertinent to mesh generation are discussed. It is shown that grid generation and grid manipulation schemes rely on fast multidimensional searching. Flow solution techniques for the Euler equations, which can be derived from the integral form of the equations are discussed. Sample calculations are also provided.

  5. Smart Grid Enabled EVSE

    SciTech Connect

    None, None

    2014-10-15

    The combined team of GE Global Research, Federal Express, National Renewable Energy Laboratory, and Consolidated Edison has successfully achieved the established goals contained within the Department of Energy’s Smart Grid Capable Electric Vehicle Supply Equipment funding opportunity. The final program product, shown charging two vehicles in Figure 1, reduces by nearly 50% the total installed system cost of the electric vehicle supply equipment (EVSE) as well as enabling a host of new Smart Grid enabled features. These include bi-directional communications, load control, utility message exchange and transaction management information. Using the new charging system, Utilities or energy service providers will now be able to monitor transportation related electrical loads on their distribution networks, send load control commands or preferences to individual systems, and then see measured responses. Installation owners will be able to authorize usage of the stations, monitor operations, and optimally control their electricity consumption. These features and cost reductions have been developed through a total system design solution.

  6. Grid Task Execution

    NASA Technical Reports Server (NTRS)

    Hu, Chaumin

    2007-01-01

    IPG Execution Service is a framework that reliably executes complex jobs on a computational grid, and is part of the IPG service architecture designed to support location-independent computing. The new grid service enables users to describe the platform on which they need a job to run, which allows the service to locate the desired platform, configure it for the required application, and execute the job. After a job is submitted, users can monitor it through periodic notifications, or through queries. Each job consists of a set of tasks that performs actions such as executing applications and managing data. Each task is executed based on a starting condition that is an expression of the states of other tasks. This formulation allows tasks to be executed in parallel, and also allows a user to specify tasks to execute when other tasks succeed, fail, or are canceled. The two core components of the Execution Service are the Task Database, which stores tasks that have been submitted for execution, and the Task Manager, which executes tasks in the proper order, based on the user-specified starting conditions, and avoids overloading local and remote resources while executing tasks.

  7. OGC and Grid Interoperability in enviroGRIDS Project

    NASA Astrophysics Data System (ADS)

    Gorgan, Dorian; Rodila, Denisa; Bacu, Victor; Giuliani, Gregory; Ray, Nicolas

    2010-05-01

    EnviroGRIDS (Black Sea Catchment Observation and Assessment System supporting Sustainable Development) [1] is a 4-years FP7 Project aiming to address the subjects of ecologically unsustainable development and inadequate resource management. The project develops a Spatial Data Infrastructure of the Black Sea Catchment region. The geospatial technologies offer very specialized functionality for Earth Science oriented applications as well as the Grid oriented technology that is able to support distributed and parallel processing. One challenge of the enviroGRIDS project is the interoperability between geospatial and Grid infrastructures by providing the basic and the extended features of the both technologies. The geospatial interoperability technology has been promoted as a way of dealing with large volumes of geospatial data in distributed environments through the development of interoperable Web service specifications proposed by the Open Geospatial Consortium (OGC), with applications spread across multiple fields but especially in Earth observation research. Due to the huge volumes of data available in the geospatial domain and the additional introduced issues (data management, secure data transfer, data distribution and data computation), the need for an infrastructure capable to manage all those problems becomes an important aspect. The Grid promotes and facilitates the secure interoperations of geospatial heterogeneous distributed data within a distributed environment, the creation and management of large distributed computational jobs and assures a security level for communication and transfer of messages based on certificates. This presentation analysis and discusses the most significant use cases for enabling the OGC Web services interoperability with the Grid environment and focuses on the description and implementation of the most promising one. In these use cases we give a special attention to issues such as: the relations between computational grid and

  8. Grid Generation Techniques Utilizing the Volume Grid Manipulator

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.

    1998-01-01

    This paper presents grid generation techniques available in the Volume Grid Manipulation (VGM) code. The VGM code is designed to manipulate existing line, surface and volume grids to improve the quality of the data. It embodies an easy to read rich language of commands that enables such alterations as topology changes, grid adaption and smoothing. Additionally, the VGM code can be used to construct simplified straight lines, splines, and conic sections which are common curves used in the generation and manipulation of points, lines, surfaces and volumes (i.e., grid data). These simple geometric curves are essential in the construction of domain discretizations for computational fluid dynamic simulations. By comparison to previously established methods of generating these curves interactively, the VGM code provides control of slope continuity and grid point-to-point stretchings as well as quick changes in the controlling parameters. The VGM code offers the capability to couple the generation of these geometries with an extensive manipulation methodology in a scripting language. The scripting language allows parametric studies of a vehicle geometry to be efficiently performed to evaluate favorable trends in the design process. As examples of the powerful capabilities of the VGM code, a wake flow field domain will be appended to an existing X33 Venturestar volume grid; negative volumes resulting from grid expansions to enable flow field capture on a simple geometry, will be corrected; and geometrical changes to a vehicle component of the X33 Venturestar will be shown.

  9. From the grid to the smart grid, topologically

    NASA Astrophysics Data System (ADS)

    Pagani, Giuliano Andrea; Aiello, Marco

    2016-05-01

    In its more visionary acceptation, the smart grid is a model of energy management in which the users are engaged in producing energy as well as consuming it, while having information systems fully aware of the energy demand-response of the network and of dynamically varying prices. A natural question is then: to make the smart grid a reality will the distribution grid have to be upgraded? We assume a positive answer to the question and we consider the lower layers of medium and low voltage to be the most affected by the change. In our previous work, we analyzed samples of the Dutch distribution grid (Pagani and Aiello, 2011) and we considered possible evolutions of these using synthetic topologies modeled after studies of complex systems in other technological domains (Pagani and Aiello, 2014). In this paper, we take an extra important step by defining a methodology for evolving any existing physical power grid to a good smart grid model, thus laying the foundations for a decision support system for utilities and governmental organizations. In doing so, we consider several possible evolution strategies and apply them to the Dutch distribution grid. We show how increasing connectivity is beneficial in realizing more efficient and reliable networks. Our proposal is topological in nature, enhanced with economic considerations of the costs of such evolutions in terms of cabling expenses and economic benefits of evolving the grid.

  10. NAS Grid Benchmarks: A Tool for Grid Space Exploration

    NASA Technical Reports Server (NTRS)

    Frumkin, Michael; VanderWijngaart, Rob F.; Biegel, Bryan (Technical Monitor)

    2001-01-01

    We present an approach for benchmarking services provided by computational Grids. It is based on the NAS Parallel Benchmarks (NPB) and is called NAS Grid Benchmark (NGB) in this paper. We present NGB as a data flow graph encapsulating an instance of an NPB code in each graph node, which communicates with other nodes by sending/receiving initialization data. These nodes may be mapped to the same or different Grid machines. Like NPB, NGB will specify several different classes (problem sizes). NGB also specifies the generic Grid services sufficient for running the bench-mark. The implementor has the freedom to choose any specific Grid environment. However, we describe a reference implementation in Java, and present some scenarios for using NGB.

  11. How to drill horizontal sections faster

    SciTech Connect

    Chaffin, M. )

    1991-12-01

    This paper reports that fewer trips, reduced slide time and lower drag during sliding have resulted from the application of downhole-adjustable stabilizers to horizontal drilling. Faster drilling times mean lower measurement while drilling (MWD) cost, and less wear on downhole equipment, motors and bits. These advantages combined with reduced drilling shocks have increased drilling rates and efficiency. Applying existing technology in new situations is an important way of reducing the cost of finding, exploring for and developing reserves. Engineers are responsible for using current technology to its fullest and developing new technology to reduce drilling expenses. Horizontal drilling was used in its early stages to develop the Austin chalk formation in Pearsall oil field more effectively. As procedures were generated to drill horizontal wells, Oryx drilling engineers began to develop new technology and investigate ways for existing technology to be used or altered to fit horizontal drilling programs. The new technology of downhole-adjustable stabilizers has been used successfully to further improve horizontal drilling efficiency.

  12. Grid cells on steeply sloping terrain: evidence for planar rather than volumetric encoding

    PubMed Central

    Hayman, Robin M. A.; Casali, Giulio; Wilson, Jonathan J.; Jeffery, Kate J.

    2015-01-01

    Neural encoding of navigable space involves a network of structures centered on the hippocampus, whose neurons –place cells – encode current location. Input to the place cells includes afferents from the entorhinal cortex, which contains grid cells. These are neurons expressing spatially localized activity patches, or firing fields, that are evenly spaced across the floor in a hexagonal close-packed array called a grid. It is thought that grids function to enable the calculation of distances. The question arises as to whether this odometry process operates in three dimensions, and so we queried whether grids permeate three-dimensional (3D) space – that is, form a lattice – or whether they simply follow the environment surface. If grids form a 3D lattice then this lattice would ordinarily be aligned horizontally (to explain the usual hexagonal pattern observed). A tilted floor would transect several layers of this putative lattice, resulting in interruption of the hexagonal pattern. We model this prediction with simulated grid lattices, and show that the firing of a grid cell on a 40°-tilted surface should cover proportionally less of the surface, with smaller field size, fewer fields, and reduced hexagonal symmetry. However, recording of real grid cells as animals foraged on a 40°-tilted surface found that firing of grid cells was almost indistinguishable, in pattern or rate, from that on the horizontal surface, with if anything increased coverage and field number, and preserved field size. It thus appears unlikely that the sloping surface transected a lattice. However, grid cells on the slope displayed slightly degraded firing patterns, with reduced coherence and slightly reduced symmetry. These findings collectively suggest that the grid cell component of the metric representation of space is not fixed in absolute 3D space but is influenced both by the surface the animal is on and by the relationship of this surface to the horizontal, supporting the

  13. Successful drilling of the first horizontal well in a mature field

    SciTech Connect

    Marruffo, I.; Achong, C.

    1996-08-01

    This paper discusses how the decision to drill the first horizontal well of a reservoir was taken, based on Production acceleration and the incremental economy of cash flow. The reservoir is located in the Guafita-Norto Field in Western Venezuela, contiguous to the La Yuca-Cano Limon Fields in Colombia. Guafita-Norte has 183 million stb of remaining oil reserves with 26 production wells on electrical submergible pumps. The STOIP of this under saturated reservoir (bubble point pressure is 36 psi) is 160 million stb with an initial GOR of 10 stf/stb, having a permeability between 1.5-12 darcies with a strong water drive, water coning and sanding problems due to fines migration. During 1995, it was decided to drill the first horizontal well in the reservoir based on a 3-D numerical simulation with radial flow (for water coning) and local grid refinement (for horizontal wells) coupled to an economic analysis. The simulation predetermines an initial production rate for a horizontal well 2.5 times greater than for a vertical one, and the incremental cash flow for the horizontal well is 4.5 MM$ larger for the vertical one in four (4) years, with a ROR of 200%. The horizontal well was drilled with oil-based mud to avoid hole collapse, and it was completed open hole with a single screen pack. The well is currently producing between 2000 and 3500 stb/d, clean, on natural flow. This study has clearly shown that the ultimate and decisive parameter to be weighed before undertaking this type of project, is the economic analysis, which must be performed as extensively as the technical analysis.

  14. The Open Science Grid

    SciTech Connect

    Pordes, Ruth; Kramer, Bill; Olson, Doug; Livny, Miron; Roy, Alain; Avery, Paul; Blackburn, Kent; Wenaus, Torre; Wurthwein, Frank; Gardner, Rob; Wilde, Mike; /Chicago U. /Indiana U.

    2007-06-01

    The Open Science Grid (OSG) provides a distributed facility where the Consortium members provide guaranteed and opportunistic access to shared computing and storage resources. OSG provides support for and evolution of the infrastructure through activities that cover operations, security, software, troubleshooting, addition of new capabilities, and support for existing and engagement with new communities. The OSG SciDAC-2 project provides specific activities to manage and evolve the distributed infrastructure and support its use. The innovative aspects of the project are the maintenance and performance of a collaborative (shared & common) petascale national facility over tens of autonomous computing sites, for many hundreds of users, transferring terabytes of data a day, executing tens of thousands of jobs a day, and providing robust and usable resources for scientific groups of all types and sizes. More information can be found at the OSG web site: www.opensciencegrid.org.

  15. Oxygen-enhanced models for globular cluster stars. III - Horizontal-branch sequences

    NASA Technical Reports Server (NTRS)

    Dorman, Ben

    1992-01-01

    A large grid of horizontal-branch (HB) evolutionary sequences which have been calculated with core expansion and semiconvection and with enhanced oxygen composition are presented and described. Tracks for 10 different metallicities are computed; they range from (Fe/H) = -0.47 to -2.26 and comprise a total of 115 sequences. The evolution is traced from the zero-age horizontal-branch (ZAHB) to the lower AGB at a point where log L/solar luminosity = 2.25. All of the sequences are illustrated on both the theoretical H-R diagram and on the B, V color-magnitude diagram. A complete set of tables for the ZAHB models and a representative sample of tabulations of the track parameters are provided. The phenomena which control HB evolution morphology, and existing certainties in theoretical HB models are discussed.

  16. Horizontal drilling techniques at Prudhoe Bay, Alaska

    SciTech Connect

    Wilkirson, J.P.; Smith, J.H.; Stagg, T.O.; Walters, D.A.

    1986-01-01

    Three extended departure horizontal wells have been drilled and completed at Prudhoe Bay, Alaska by Standard Alaska Production Company. Horizontal slotted liner completions of 1575 feet (480 m), 1637 feet (499 m), and 1163 feet (354 m) were accomplished at an average vertical depth of 9000 feet (2743 m). Improvements in technology and operating procedures have resulted in a cost per foot reduction of 40% over the three well program. When compared to conventional completions, initial production data indicates rate benefits of 300% and a major increase in ultimate recovery. This paper discusses the development of the techniques used to drill horizontal wells at Prudhoe Bay and reviews the drilling operations for each well.

  17. ESP's placed in horizontal lateral increase production

    SciTech Connect

    Gallup, A.; Wilson, B.L. ); Marshall, R. )

    1990-06-18

    By design, the electric submersible pump (ESP) is an effective method of lifting fluids from horizontal wells. But this ESP application does have unique installation and operating parameters that need to be considered. ESP's have been used for many years in directional wells. This application provides an experience base for understanding deflection limits on the unit. To avoid damaging the ESP, special equipment may be required in some horizontal installations. This paper discusses how several ESP's have been designed specifically for medium-radius wells. In these applications, the deeper pump setting provides for a significant increase in production rate. In general, to realize the full benefit of a horizontal installation, the ESP should be considered when planning, drilling, and completing the well.

  18. Successful horizontal completions require an integrated approach

    SciTech Connect

    Richard, B.; Smejkal, K.; Penberthy, W. Jr.

    1997-01-01

    While a perfect well completion may not exist, depleting a hydrocarbon resource at a sustained high rate--without a workover--is the ultimate goal. Unfortunately, many horizontal well completions fail to achieve this due to wellbore damage or loss of reservoir pressure. These conditions manifest themselves in reduced production rates, extended well life and reduced profitability. Standard completion techniques are not always compatible with each other for site specific well applications. The combination of two incompatible technologies or slight changes in a completion procedure may negatively impact productivity. Hence, the most successful horizontal completion results are obtained using a compatible integrated system approach--an approach that carefully combines the best completion tools and processes to deliver an undamaged well completed at the lowest possible cost. After studying the compatibilities of various drill-in fluids, screens, filter cakes and gravel packs, recommended procedures are presented for successfully completing horizontal wells.

  19. TIGER: Turbomachinery interactive grid generation

    NASA Technical Reports Server (NTRS)

    Soni, Bharat K.; Shih, Ming-Hsin; Janus, J. Mark

    1992-01-01

    A three dimensional, interactive grid generation code, TIGER, is being developed for analysis of flows around ducted or unducted propellers. TIGER is a customized grid generator that combines new technology with methods from general grid generation codes. The code generates multiple block, structured grids around multiple blade rows with a hub and shroud for either C grid or H grid topologies. The code is intended for use with a Euler/Navier-Stokes solver also being developed, but is general enough for use with other flow solvers. TIGER features a silicon graphics interactive graphics environment that displays a pop-up window, graphics window, and text window. The geometry is read as a discrete set of points with options for several industrial standard formats and NASA standard formats. Various splines are available for defining the surface geometries. Grid generation is done either interactively or through a batch mode operation using history files from a previously generated grid. The batch mode operation can be done either with a graphical display of the interactive session or with no graphics so that the code can be run on another computer system. Run time can be significantly reduced by running on a Cray-YMP.

  20. LAPS Grid generation and adaptation

    NASA Astrophysics Data System (ADS)

    Pagliantini, Cecilia; Delzanno, Gia Luca; Guo, Zehua; Srinivasan, Bhuvana; Tang, Xianzhu; Chacon, Luis

    2011-10-01

    LAPS uses a common-data framework in which a general purpose grid generation and adaptation package in toroidal and simply connected domains is implemented. The initial focus is on implementing the Winslow/Laplace-Beltrami method for generating non-overlapping block structured grids. This is to be followed by a grid adaptation scheme based on Monge-Kantorovich optimal transport method [Delzanno et al., J. Comput. Phys,227 (2008), 9841-9864], that equidistributes application-specified error. As an initial set of applications, we will lay out grids for an axisymmetric mirror, a field reversed configuration, and an entire poloidal cross section of a tokamak plasma reconstructed from a CMOD experimental shot. These grids will then be used for computing the plasma equilibrium and transport in accompanying presentations. A key issue for Monge-Kantorovich grid optimization is the choice of error or monitor function for equi-distribution. We will compare the Operator Recovery Error Source Detector (ORESD) [Lapenta, Int. J. Num. Meth. Eng,59 (2004) 2065-2087], the Tau method and a strategy based on the grid coarsening [Zhang et al., AIAA J,39 (2001) 1706-1715] to find an ``optimal'' grid. Work supported by DOE OFES.

  1. Structured and unstructured grid generation.

    PubMed

    Thompson, J F; Weatherill, N P

    1992-01-01

    Current techniques in composite-block-structured grid generation and unstructured grid generation for general 3D geometries are summarized, including both algebraic and elliptic generation procedures for the former and Delaunay tessellations for the latter. Citations of relevant theory are given. Examples of applications for several geometries are included. PMID:1424687

  2. Intelligent automated surface grid generation

    NASA Technical Reports Server (NTRS)

    Yao, Ke-Thia; Gelsey, Andrew

    1995-01-01

    The goal of our research is to produce a flexible, general grid generator for automated use by other programs, such as numerical optimizers. The current trend in the gridding field is toward interactive gridding. Interactive gridding more readily taps into the spatial reasoning abilities of the human user through the use of a graphical interface with a mouse. However, a sometimes fruitful approach to generating new designs is to apply an optimizer with shape modification operators to improve an initial design. In order for this approach to be useful, the optimizer must be able to automatically grid and evaluate the candidate designs. This paper describes and intelligent gridder that is capable of analyzing the topology of the spatial domain and predicting approximate physical behaviors based on the geometry of the spatial domain to automatically generate grids for computational fluid dynamics simulators. Typically gridding programs are given a partitioning of the spatial domain to assist the gridder. Our gridder is capable of performing this partitioning. This enables the gridder to automatically grid spatial domains of wide range of configurations.

  3. Grid generation using classical techniques

    NASA Technical Reports Server (NTRS)

    Moretti, G.

    1980-01-01

    A brief historical review of conformal mapping and its applications to problems in fluid mechanics and electromagnetism is presented. The use of conformal mapping as a grid generator is described. The philosophy of the 'closed form' approach and its application to a Neumann problem is discussed. Karman-Trefftz mappings and grids for ablated, three dimensional bodies are also discussed.

  4. MIPAS-ENVISAT limb-sounding measurements: trade-off study for improvement of horizontal resolution.

    PubMed

    Ridolfi, Marco; Magnani, Luca; Carlotti, Massimo; Dinelli, Bianca Maria

    2004-11-01

    The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is a limb-scanning spectrometer that has operated onboard the Environmental Satellite since the end of March 2002. Common features of limb-scanning experiments are both high vertical resolution and poor horizontal resolution. We exploit the two-dimensional geo-fit retrieval approach [Appl. Opt. 40, 1872-1875 (2001)] to investigate the possibility of improving the horizontal resolution of MIPAS measurements. Two different strategies are considered for this purpose, one exploiting the possibility (offered by the geo-fit analysis method) for an arbitrary definition of the retrieval grid, the other based on the possibility of saving measurement time by degrading the spectral resolution of the interferometer. The performances of the two strategies are compared in terms of the trade-off between the attained horizontal resolution and the retrieval precision. We find that for ozone it is possible to improve by a factor of 2 the horizontal resolution, which in the nominal measurement plan is approximately 530 km. This improvement corresponds to a degradation of the retrieval precision, which on average varies from a factor of 1.4 to 2.5, depending on the adopted spectral resolution.

  5. Regional Data Assimilation Using a Stretched-Grid Approach and Ensemble Calculations

    NASA Technical Reports Server (NTRS)

    Fox-Rabinovitz, M. S.; Takacs, L. L.; Govindaraju, R. C.; Atlas, Robert (Technical Monitor)

    2002-01-01

    The global variable resolution stretched grid (SG) version of the Goddard Earth Observing System (GEOS) Data Assimilation System (DAS) incorporating the GEOS SG-GCM (Fox-Rabinovitz 2000, Fox-Rabinovitz et al. 2001a,b), has been developed and tested as an efficient tool for producing regional analyses and diagnostics with enhanced mesoscale resolution. The major area of interest with enhanced regional resolution used in different SG-DAS experiments includes a rectangle over the U.S. with 50 or 60 km horizontal resolution. The analyses and diagnostics are produced for all mandatory levels from the surface to 0.2 hPa. The assimilated regional mesoscale products are consistent with global scale circulation characteristics due to using the SG-approach. Both the stretched grid and basic uniform grid DASs use the same amount of global grid-points and are compared in terms of regional product quality.

  6. On Multigrid for Overlapping Grids

    SciTech Connect

    Henshaw, W

    2004-01-13

    The solution of elliptic partial differential equations on composite overlapping grids using multigrid is discussed. An approach is described that provides a fast and memory efficient scheme for the solution of boundary value problems in complex geometries. The key aspects of the new scheme are an automatic coarse grid generation algorithm, an adaptive smoothing technique for adjusting residuals on different component grids, and the use of local smoothing near interpolation boundaries. Other important features include optimizations for Cartesian component grids, the use of over-relaxed Red-Black smoothers and the generation of coarse grid operators through Galerkin averaging. Numerical results in two and three dimensions show that very good multigrid convergence rates can be obtained for both Dirichlet and Neumann/mixed boundary conditions. A comparison to Krylov based solvers shows that the multigrid solver can be much faster and require significantly less memory.

  7. Space shuttle horizontal flight test plan

    NASA Technical Reports Server (NTRS)

    Mosley, R. L.

    1972-01-01

    A horizontal takeoff flight test concept for testing space shuttle vehicles is presented. The guidelines used in planning and support requirements for the flight tests are developed. Details of the test program are provided. The instrumentation requirements are defined. The limitations imposed by the short flight endurance and restricted maneuvering capability of the shuttle booster/orbiter in the horizontal mode are described. The test program covers the following investigations. (1) stall and lift boundary tests, (2)takeoff and landing tests, (3) level flight speed power tests, (4) longitudinal and laterial directional dynamic stability, and (5) static directional stability.

  8. MODFLOW-2000, the U.S. Geological Survey modular ground-water model -- Documentation of the Model-Layer Variable-Direction Horizontal Anisotropy (LVDA) capability of the Hydrogeologic-Unit Flow (HUF) package

    USGS Publications Warehouse

    Anderman, Evan R.; Kipp, K.L.; Hill, Mary C.; Valstar, Johan; Neupauer, R.M.

    2002-01-01

    This report documents the model-layer variable-direction horizontal anisotropy (LVDA) capability of the Hydrogeologic-Unit Flow (HUF) Package of MODFLOW-2000. The LVDA capability allows the principal directions of horizontal anisotropy to be different than the model-grid row and column directions, and for the directions to vary on a cell-by-cell basis within model layers. The HUF Package calculates effective hydraulic properties for model grid cells based on hydraulic properties of hydrogeologic units with thicknesses defined independently of the model layers. These hydraulic properties include, among other characteristics, hydraulic conductivity and a horizontal anisotropy ratio. Using the LVDA capability, horizontal anisotropy direction is defined for model grid cells within which one or more hydrogeologic units may occur. For each grid cell, the HUF Package calculates the effective horizontal hydraulic conductivity along the primary direction of anisotropy using the hydrogeologic-unit hydraulic conductivities, and calculates the effective horizontal hydraulic conductivity along the orthogonal anisotropy direction using the effective primary direction hydraulic conductivities and horizontal anisotropy ratios. The direction assigned to the model layer effective primary hydraulic conductivity is specified using a new data set defined by the LVDA capability, when active, to calculate coefficients needed to solve the ground-water flow equation. Use of the LVDA capability is illustrated in four simulation examples, which also serve to verify hydraulic heads, advective-travel paths, and sensitivities calculated using the LVDA capability. This version of the LVDA capability defines variable-direction horizontal anisotropy using model layers, not the hydrogeologic units defined by the HUF Package. This difference needs to be taken into account when designing model layers and hydrogeologic units to produce simulations that accurately represent a given field problem. This

  9. Optimizing solar-cell grid geometry

    NASA Technical Reports Server (NTRS)

    Crossley, A. P.

    1969-01-01

    Trade-off analysis and mathematical expressions calculate optimum grid geometry in terms of various cell parameters. Determination of the grid geometry provides proper balance between grid resistance and cell output to optimize the energy conversion process.

  10. Single grid accelerator for an ion thrustor

    NASA Technical Reports Server (NTRS)

    Margosian, P. M.; Nakanishi, S. (Inventor)

    1973-01-01

    A single grid accelerator system for an ion thrustor is discussed. A layer of dielectric material is interposed between this metal grid and the chamber containing an ionized propellant for protecting the grid against sputtering erosion.

  11. Grid Integration Studies: Data Requirements, Greening the Grid

    SciTech Connect

    Katz, Jessica

    2015-06-01

    A grid integration study is an analytical framework used to evaluate a power system with high penetration levels of variable renewable energy (VRE). A grid integration study simulates the operation of the power system under different VRE scenarios, identifying reliability constraints and evaluating the cost of actions to alleviate those constraints. These VRE scenarios establish where, how much, and over what timeframe to build generation and transmission capacity, ideally capturing the spatial diversity benefits of wind and solar resources. The results help build confidence among policymakers, system operators, and investors to move forward with plans to increase the amount of VRE on the grid.

  12. Horizontally scaling dCache SRM with the Terracotta platform

    NASA Astrophysics Data System (ADS)

    Perelmutov, T.; Crawford, M.; Moibenko, A.; Oleynik, G.

    2011-12-01

    The dCache disk caching file system has been chosen by a majority of LHC experiments' Tier 1 centers for their data storage needs. It is also deployed at many Tier 2 centers. The Storage Resource Manager (SRM) is a standardized grid storage interface and a single point of remote entry into dCache, and hence is a critical component. SRM must scale to increasing transaction rates and remain resilient against changing usage patterns. The initial implementation of the SRM service in dCache suffered from an inability to support clustered deployment, and its performance was limited by the hardware of a single node. Using the Terracotta platform[l], we added the ability to horizontally scale the dCache SRM service to run on multiple nodes in a cluster configuration, coupled with network load balancing. This gives site administrators the ability to increase the performance and reliability of SRM service to face the ever-increasing requirements of LHC data handling. In this paper we will describe the previous limitations of the architecture SRM server and how the Terracotta platform allowed us to readily convert single node service into a highly scalable clustered application.

  13. Sensitivity of Radiative Convective Equilibrium Simulations to Horizontal Resolution.

    NASA Astrophysics Data System (ADS)

    Pauluis, Olivier; Garner, Stephen

    2006-07-01

    This paper investigates the impacts of horizontal resolution on the statistical behavior of convection. An idealized radiative convective equilibrium is simulated for model resolutions ranging between 2 and 50 km. The simulations are compared based upon the analysis of the mean state, the energy and water vapor transport, and the probability distribution functions for various quantities. It is shown that, at a coarse resolution, the model is unable to capture the mixing associated with shallow clouds. This results in a dry bias in the lower troposphere, and in an excessive amount of water clouds. Despite this deficiency, the coarse resolution simulations are able to reproduce reasonably well the statistical properties of deep convective towers. This is particularly apparent in the cloud ice and vertical velocity distributions that exhibit a very robust behavior.A theoretical scaling for the vertical velocity as function of the grid resolution is derived based upon the behavior of an idealized air bubble. It is shown that the vertical velocity of an ascending air parcel is determined by its aspect ratio, with a wide, flat parcel rising at a much slower pace than a narrow one. This theoretical scaling law exhibits a similar sensitivity to that of the numerical simulations. It is used to renormalize the probability distribution functions for vertical velocity, which show a very good agreement for resolutions up to 16 km. This new scaling law offers a way to improve direct simulations of deep convection in coarse resolution models.


  14. Horizontally scaling dChache SRM with the Terracotta platform

    SciTech Connect

    Perelmutov, T.; Crawford, M.; Moibenko, A.; Oleynik, G.; /Fermilab

    2011-01-01

    The dCache disk caching file system has been chosen by a majority of LHC experiments Tier 1 centers for their data storage needs. It is also deployed at many Tier 2 centers. The Storage Resource Manager (SRM) is a standardized grid storage interface and a single point of remote entry into dCache, and hence is a critical component. SRM must scale to increasing transaction rates and remain resilient against changing usage patterns. The initial implementation of the SRM service in dCache suffered from an inability to support clustered deployment, and its performance was limited by the hardware of a single node. Using the Terracotta platform, we added the ability to horizontally scale the dCache SRM service to run on multiple nodes in a cluster configuration, coupled with network load balancing. This gives site administrators the ability to increase the performance and reliability of SRM service to face the ever-increasing requirements of LHC data handling. In this paper we will describe the previous limitations of the architecture SRM server and how the Terracotta platform allowed us to readily convert single node service into a highly scalable clustered application.

  15. Atmospheric Climate Model Experiments Performed at Multiple Horizontal Resolutions

    SciTech Connect

    Phillips, T; Bala, G; Gleckler, P; Lobell, D; Mirin, A; Maxwell, R; Rotman, D

    2007-12-21

    This report documents salient features of version 3.3 of the Community Atmosphere Model (CAM3.3) and of three climate simulations in which the resolution of its latitude-longitude grid was systematically increased. For all these simulations of global atmospheric climate during the period 1980-1999, observed monthly ocean surface temperatures and sea ice extents were prescribed according to standard Atmospheric Model Intercomparison Project (AMIP) values. These CAM3.3 resolution experiments served as control runs for subsequent simulations of the climatic effects of agricultural irrigation, the focus of a Laboratory Directed Research and Development (LDRD) project. The CAM3.3 model was able to replicate basic features of the historical climate, although biases in a number of atmospheric variables were evident. Increasing horizontal resolution also generally failed to ameliorate the large-scale errors in most of the climate variables that could be compared with observations. A notable exception was the simulation of precipitation, which incrementally improved with increasing resolution, especially in regions where orography plays a central role in determining the local hydroclimate.

  16. Optimising the vertical grid for numerical simulations of the Black Sea dynamics

    NASA Astrophysics Data System (ADS)

    Shapiro, G. I.; Pickering, J.; Luneva, M. V.

    2012-04-01

    In contrast to analytical methods which deal with continuous functions, solutions obtained using numerical methods depend on the type of discretisation used in the model. It is known that not only different classes of discretisation (such as finite difference, finite element, finite volume etc.) result in different numerical outputs but also variations within the same class may have significant effect on the quality of simulation. When it comes to discretization in the vertical, examples include z- or terrain-following coordinate systems all of which have their advantages and disadvantages. The aim of this study is to identify how sensitive modelling results are to changes in the vertical grid structure, under condition that all other parameters, both physical (e.g. initial temperature and salinity field and meteo forcing) and numerical ( e.g. time step, horizontal resolution, number of vertical layers) are kept the same. The simulations were carried out using the NEMO ocean model at 6 km resolution for the Black Sea which has both deep (more than 2 km) areas and an extensive (hundreds of kilometres) continental shelf. The shelf break, where the slope changes abruptly, is traditionally a difficult location for many types of models. The terrain-following coordinate systems (such as s- and sigma-) are prone the pressure gradient (PG) errors, while z-coordinate systems create a serrated edge near the bottom. Some improvements are provided by z-coordinates with partial steps; however this approach has its own limitations. In this study we compare 4 vertical coordinate system: z-, s-, hybrid (s- on top of z-), and advanced hybrid (modified s- on top of z-). The latter two are the new systems, not yet implemented in the standard NEMO code and developed specifically for this study. The hybrid system uses s-coordinates in the upper layer of the ocean, from the sea surface to the depth of the shelf break and z-coordinate below this level. Such configuration minimizes the PG

  17. 33 CFR 84.17 - Horizontal sectors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... practical cut-off at not more than 5 degrees outside the prescribed sectors. (b) All-round lights shall be... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.17 Horizontal sectors. (a)(1... intensities. The intensities shall decrease to reach practical cut-off between 1 and 3 degrees outside...

  18. 33 CFR 84.17 - Horizontal sectors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... practical cut-off at not more than 5 degrees outside the prescribed sectors. (b) All-round lights shall be... RULES ANNEX I: POSITIONING AND TECHNICAL DETAILS OF LIGHTS AND SHAPES § 84.17 Horizontal sectors. (a)(1... intensities. The intensities shall decrease to reach practical cut-off between 1 and 3 degrees outside...

  19. Horizontally separated 1-in-1 crossing insertions

    SciTech Connect

    Syphers, M.J.

    1985-10-01

    Previous to this workshop, realistic lattices have been developed for vertically separated l-in-l (e.g., D.E. Johnson, A.A. Garren) and 2-in-1 (e.g., S. Heifets) magnets as well as for horizontally separated 2-in-l magnets (e.g., SSC RDS). Bringing together the widely separated ({approximately}60-70 cm) beams in a reasonable length of tunnel and keeping the dispersion zero at the interaction point has been difficult in the vertical l-in-l case. Most designs have required spacial 2-in-1 quadrupoles near the interaction point where the beams are separated by 15 cm or less. It is not clear that such magnets, as dictated by some of these lattice designs, can easily be built. The purpose of this exercise is to provide a crossing insertion for a realistic lattice which involves horizontally separated l-in-l magnets. The following horizontal crossing insertions, which incorporate the dispersion suppressors and phase trombones into the major arcs, need no special 2-in-1 magnets near the interaction point. The dispersion at the IP created by the horizontal crossing can be cancelled by the dispersion suppressor and one set of triplets.

  20. A laboratory investigation of cementing horizontal wells

    SciTech Connect

    Wilson, M.A.; Sabins, F.L. )

    1988-09-01

    Obtaining a successful cement job will remain one of the most important factors to the productive life of any well and will be especially critical for horizontal-well completions. Achieving a high mud-displacement efficiency under highly deviated or horizontal-well conditions requires that special attention be given to the many aspects of drilling/completion practices - e.g., drill-fluid systems and properties and casing and hole sizes - to obtain optimum mud displacement and cementing results. A study of factors affecting mud-displacement efficiency focused on cementing an ultralow-permeability formation that is being evaluated as a subject for horizontal completion. Realistic laboratory testing was conducted on a large-scale test model that has been used for many years to evaluate factors influencing drilling-fluid displacement efficiency. Factors evaluated for this study included influence of hold and pipe sizes, pipe centralization, displacement rates, and spacer systems. Findings from this study provided specific recommendations for low-permeability reservoirs that also can be applied to horizontally drilled wells. Various techniques for cementing horizonal wells will be discussed and general recommendations will be given.

  1. Teaching Activities on Horizontal Nuclear Proliferation.

    ERIC Educational Resources Information Center

    Zola, John

    1990-01-01

    Provides learning activities concerning the horizontal proliferation of nuclear weapons. Includes step-by-step directions for four activities: (1) the life cycle of nuclear weapons; (2) nuclear nonproliferation: pros and cons; (3) the nuclear power/nuclear weapons connection; and (4) managing nuclear proliferation. (NL)

  2. Cutting Down the Tall Poppies: Horizontal Violence.

    ERIC Educational Resources Information Center

    Funk, Carole

    Many women in educational leadership positions experience negative treatment from female teachers and female superintendents. This phenomenon is known as horizontal violence, "the curious behavior of members of oppressed groups who often lash out at their peers in response to oppression instead of attacking their oppressors." This paper explores…

  3. Orthodontic extrusion of horizontally impacted mandibular molars

    PubMed Central

    Ma, Zhigui; Yang, Chi; Zhang, Shanyong; Xie, Qianyang; Shen, Yuqing; Shen, Pei

    2014-01-01

    Objective: To introduce and evaluate a novel approach in treating horizontally impacted mandibular second and third molars. Materials and methods: An orthodontic technique was applied for treatment of horizontally impacted mandibular second and third molars, which included a push-type spring for rotation first, and then a cantilever for extrusion. There were 8 mandibular third molars (M3s) and 2 second molars (M2s) in this study. Tooth mobility, extraction time, the inclination and parallelism of the impacted tooth, alveolar bone height of the adjacent tooth, and the relationship of impacted M3 and the inferior alveolar nerve (IAN) were evaluated. Results: Two horizontally impacted M2s could be upright in the arch and good occlusal relationships were obtained after treatment. All impacted M3s were successfully separated from the IAN, without any neurologic consequences. The average extraction time was 5 minutes. There was a significant change in the inclination and parallelism of the impacted tooth after treatment. A new bone apposition with the average height of 3.2 mm was noted distal to the adjacent tooth. Conclusions: This two-step orthodontic technique as presented here may be a safe and feasible alternative in management of severely horizontally impacted mandibular molars, which achieves a successful separation of M3s from the IAN and an excellent position for M2s. PMID:25419364

  4. [From vertical to horizontal. Writing in adolescence].

    PubMed

    Catheline-Antipoff, N

    1995-04-01

    Writing at adolescence has a non negligible part in identity's construction. Vertical writing as tags, graphs and graffiti refer to a narcissism deficiency and express a pulsional necessity, whereas, horizontal writing as private diaries, letters and novels express object's search and are made in dreaming attitude.

  5. Electroluminescence from completely horizontally oriented dye molecules

    NASA Astrophysics Data System (ADS)

    Komino, Takeshi; Sagara, Yuta; Tanaka, Hiroyuki; Oki, Yuji; Nakamura, Nozomi; Fujimoto, Hiroshi; Adachi, Chihaya

    2016-06-01

    A complete horizontal molecular orientation of a linear-shaped thermally activated delayed fluorescent guest emitter 2,6-bis(4-(10Hphenoxazin-10-yl)phenyl)benzo[1,2-d:5,4-d'] bis(oxazole) (cis-BOX2) was obtained in a glassy host matrix by vapor deposition. The orientational order of cis-BOX2 depended on the combination of deposition temperature and the type of host matrix. Complete horizontal orientation was obtained when a thin film with cis-BOX2 doped in a 4,4'-bis(N-carbazolyl)-1,1'-biphenyl (CBP) host matrix was fabricated at 200 K. The ultimate orientation of guest molecules originates from not only the kinetic relaxation but also the kinetic stability of the deposited guest molecules on the film surface during film growth. Utilizing the ultimate orientation, a highly efficient organic light-emitting diode with the external quantum efficiency of 33.4 ± 2.0% was realized. The thermal stability of the horizontal orientation of cis-BOX2 was governed by the glass transition temperature (Tg) of the CBP host matrix; the horizontal orientation was stable unless the film was annealed above Tg.

  6. Horizontal Axis Levitron--A Physics Demonstration

    ERIC Educational Resources Information Center

    Michaelis, Max M.

    2014-01-01

    After a brief history of the Levitron, the first horizontal axis Levitron is reported. Because it is easy to operate, it lends itself to educational physics experiments and analogies. Precession and nutation are visualized by reflecting the beam from a laser pointer off the "spignet". Precession is fundamental to nuclear magnetic…

  7. National Smart Water Grid

    SciTech Connect

    Beaulieu, R A

    2009-07-13

    The United States repeatedly experiences floods along the Midwest's large rivers and droughts in the arid Western States that cause traumatic environmental conditions with huge economic impact. With an integrated approach and solution these problems can be alleviated. Tapping into the Mississippi River and its tributaries, the world's third largest fresh water river system, during flood events will mitigate the damage of flooding and provide a new source of fresh water to the Western States. The trend of increased flooding on the Midwest's large rivers is supported by a growing body of scientific literature. The Colorado River Basin and the western states are experiencing a protracted multi-year drought. Fresh water can be pumped via pipelines from areas of overabundance/flood to areas of drought or high demand. Calculations document 10 to 60 million acre-feet (maf) of fresh water per flood event can be captured from the Midwest's Rivers and pumped via pipelines to the Colorado River and introduced upstream of Lake Powell, Utah, to destinations near Denver, Colorado, and used in areas along the pipelines. Water users of the Colorado River include the cities in southern Nevada, southern California, northern Arizona, Colorado, Utah, Indian Tribes, and Mexico. The proposed start and end points, and routes of the pipelines are documented, including information on right-of-ways necessary for state and federal permits. A National Smart Water Grid{trademark} (NSWG) Project will create thousands of new jobs for construction, operation, and maintenance and save billions in drought and flood damage reparations tax dollars. The socio-economic benefits of NWSG include decreased flooding in the Midwest; increased agriculture, and recreation and tourism; improved national security, transportation, and fishery and wildlife habitats; mitigated regional climate change and global warming such as increased carbon capture; decreased salinity in Colorado River water crossing the US

  8. An electrostatic analog for generating cascade grids

    NASA Technical Reports Server (NTRS)

    Adamczyk, J. J.

    1980-01-01

    Accurate and efficient numerical simulation of flows through turbomachinery blade rows depends on the topology of the computational grids. These grids must reflect the periodic nature of turbomachinery blade row geometries and conform to the blade shapes. Three types of grids can be generated that meet these minimal requirements: through-flow grids, O-type grids, and C-type grids. A procedure which can be used to generate all three types of grids is presented. The resulting grids are orthogonal and can be stretched to capture the essential physics of the flow. A discussion is also presented detailing the extension of the generation procedure to three dimensional geometries.

  9. GridOPTICS Software System

    2014-02-24

    GridOPTICS Software System (GOSS) is a middleware that facilitates creation of new, modular and flexible operational and planning platforms that can meet the challenges of the next generation power grid. GOSS enables Department of Energy, power system utilities, and vendors to build better tools faster. GOSS makes it possible to integrate Future Power Grid Initiative software products/prototypes into existing power grid software systems, including the PNNL PowerNet and EIOC environments. GOSS is designed to allowmore » power grid applications developed for different underlying software platforms installed in different utilities to communicate with ease. This can be done in compliance with existing security and data sharing policies between the utilities. GOSS not only supports one-to-one data transfer between applications, but also publisher/subscriber scheme. To support interoperability requirements of future EMS, GOSS is designed for CIM compliance. In addition to this, it supports authentication and authorization capabilities to protect the system from cyber threats. In summary, the contributions of the GOSS middleware are as follows: • A platform to support future EMS development. • A middleware that promotes interoperability between power grid applications. • A distributed architecture that separates data sources from power grid applications. • Support for data exchange with either one-to-one or publisher/subscriber interfaces. • An authentication and authorization scheme for limiting the access to data between utilities.« less

  10. GridOPTICS Software System

    SciTech Connect

    Akyol, Bora A; Ciraci, PNNL Selim; Gibson, PNNL Tara; Rice, PNNL Mark; Sharma, PNNL Poorva; Yin, PNNL Jian; Allwardt, PNNL Craig; PNNL,

    2014-02-24

    GridOPTICS Software System (GOSS) is a middleware that facilitates creation of new, modular and flexible operational and planning platforms that can meet the challenges of the next generation power grid. GOSS enables Department of Energy, power system utilities, and vendors to build better tools faster. GOSS makes it possible to integrate Future Power Grid Initiative software products/prototypes into existing power grid software systems, including the PNNL PowerNet and EIOC environments. GOSS is designed to allow power grid applications developed for different underlying software platforms installed in different utilities to communicate with ease. This can be done in compliance with existing security and data sharing policies between the utilities. GOSS not only supports one-to-one data transfer between applications, but also publisher/subscriber scheme. To support interoperability requirements of future EMS, GOSS is designed for CIM compliance. In addition to this, it supports authentication and authorization capabilities to protect the system from cyber threats. In summary, the contributions of the GOSS middleware are as follows: • A platform to support future EMS development. • A middleware that promotes interoperability between power grid applications. • A distributed architecture that separates data sources from power grid applications. • Support for data exchange with either one-to-one or publisher/subscriber interfaces. • An authentication and authorization scheme for limiting the access to data between utilities.

  11. A Java commodity grid kit.

    SciTech Connect

    von Laszewski, G.; Foster, I.; Gawor, J.; Lane, P.; Mathematics and Computer Science

    2001-07-01

    In this paper we report on the features of the Java Commodity Grid Kit. The Java CoG Kit provides middleware for accessing Grid functionality from the Java framework. Java CoG Kit middleware is general enough to design a variety of advanced Grid applications with quite different user requirements. Access to the Grid is established via Globus protocols, allowing the Java CoG Kit to communicate also with the C Globus reference implementation. Thus, the Java CoG Kit provides Grid developers with the ability to utilize the Grid, as well as numerous additional libraries and frameworks developed by the Java community to enable network, Internet, enterprise, and peer-to peer computing. A variety of projects have successfully used the client libraries of the Java CoG Kit to access Grids driven by the C Globus software. In this paper we also report on the efforts to develop server side Java CoG Kit components. As part of this research we have implemented a prototype pure Java resource management system that enables one to run Globus jobs on platforms on which a Java virtual machine is supported, including Windows NT machines.

  12. Insights into horizontal acquisition patterns of dormancy and reactivation regulon genes in mycobacterial species using a partitioning-based framework.

    PubMed

    Mehra, Varun; Ghosh, Tarini Shankar; Mande, Sharmila S

    2016-09-01

    Horizontal Gene Transfer (HGT) events, initially thought to be rare in Mycobacterium tuberculosis, have recently been shown to be involved in the acquisition of virulence operons in M. tuberculosis. We have developed a new partitioning framework based HGT prediction algorithm, called Grid3M, and applied the same for the prediction of HGTs in Mycobacteria. Validation and testing using simulated and real microbial genomes indicated better performance of Grid3M as compared with other widely used HGT prediction methods. Specific analysis of the genes belonging to dormancy/reactivation regulons across 14 mycobacterial genomes indicated that horizontal acquisition is specifically restricted to important accessory proteins. The results also revealed Burkholderia species to be a probable source of HGT genes belonging to these regulons. The current study provides a basis for similar analyses investigating the functional/evolutionary aspects of HGT genes in other pathogens. A database of Grid3M predicted HGTs in completely sequenced genomes is available at https://metagenomics.atc.tcs.com/Grid3M/. PMID:27581938

  13. Buildings-to-Grid Technical Opportunities: From the Grid Perspective

    SciTech Connect

    Kropski, Ben; Pratt, Rob

    2014-03-28

    This paper outlines the nature of the power grid, lists challenges and barriers to the implementation of a transactive energy ecosystem, and provides concept solutions to current technological impediments.

  14. Running medical image analysis on GridFactory desktop grid.

    PubMed

    Orellana, Frederik; Niinimaki, Marko; Zhou, Xin; Rosendahl, Peter; Müller, Henning; Waananen, Anders

    2009-01-01

    At the Geneva University Hospitals work is in progress to establish a computing facility for medical image analysis, potentially using several hundreds of desktop computers. Typically, hospitals do not have a computer infrastructure dedicated to research, nor can the data leave the hospital network for the reasons of privacy. For this purpose, a novel batch system called GridFactory has been tested along-side with the well-known batch system Condor. GridFactory's main benefits, compared to other batch systems, lie in its virtualization support and firewall friendliness. The tests involved running visual feature extraction from 50,000 anonymized medical images on a small local grid of 20 desktop computers. A comparisons with a Condor based batch system in the same computers is then presented. The performance of GridFactory is found satisfactory. PMID:19593040

  15. Development and Verification of a Computational Fluid Dynamics Model of a Horizontal-Axis Tidal Current Turbine

    SciTech Connect

    Lawson, M. J.; Li, Y.; Sale, D. C.

    2011-10-01

    This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines. Qualitative measures of the CFD solutions were independent of the grid resolution. Conversely, quantitative comparisons of the results indicated that the use of coarse computational grids results in an under prediction of the hydrodynamic forces on the turbine blade in comparison to the forces predicted using more resolved grids. For the turbine operating conditions considered in this study, the effect of the computational timestep on the CFD solution was found to be minimal, and the results from steady and transient simulations were in good agreement. Additionally, the CFD results were compared to corresponding blade element momentum method calculations and reasonable agreement was shown. Nevertheless, we expect that for other turbine operating conditions, where the flow over the blade is separated, transient simulations will be required.

  16. Overset grids in compressible flow

    NASA Technical Reports Server (NTRS)

    Eberhardt, S.; Baganoff, D.

    1985-01-01

    Numerical experiments have been performed to investigate the importance of boundary data handling with overset grids in computational fluid dynamics. Experience in using embedded grid techniques in compressible flow has shown that shock waves which cross grid boundaries become ill defined and convergence is generally degraded. Numerical boundary schemes were studied to investigate the cause of these problems and a viable solution was generated using the method of characteristics to define a boundary scheme. The model test problem investigated consisted of a detached shock wave on a 2-dimensional Mach 2 blunt, cylindrical body.

  17. Grid Visualization Tool

    NASA Technical Reports Server (NTRS)

    Chouinard, Caroline; Fisher, Forest; Estlin, Tara; Gaines, Daniel; Schaffer, Steven

    2005-01-01

    The Grid Visualization Tool (GVT) is a computer program for displaying the path of a mobile robotic explorer (rover) on a terrain map. The GVT reads a map-data file in either portable graymap (PGM) or portable pixmap (PPM) format, representing a gray-scale or color map image, respectively. The GVT also accepts input from path-planning and activity-planning software. From these inputs, the GVT generates a map overlaid with one or more rover path(s), waypoints, locations of targets to be explored, and/or target-status information (indicating success or failure in exploring each target). The display can also indicate different types of paths or path segments, such as the path actually traveled versus a planned path or the path traveled to the present position versus planned future movement along a path. The program provides for updating of the display in real time to facilitate visualization of progress. The size of the display and the map scale can be changed as desired by the user. The GVT was written in the C++ language using the Open Graphics Library (OpenGL) software. It has been compiled for both Sun Solaris and Linux operating systems.

  18. National transmission grid study

    SciTech Connect

    Abraham, Spencer

    2003-05-31

    The National Energy Policy Plan directed the U.S. Department of Energy (DOE) to conduct a study to examine the benefits of establishing a national electricity transmission grid and to identify transmission bottlenecks and measures to address them. DOE began by conducting an independent analysis of U.S. electricity markets and identifying transmission system bottlenecks using DOE’s Policy Office Electricity Modeling System (POEMS). DOE’s analysis, presented in Section 2, confirms the central role of the nation’s transmission system in lowering costs to consumers through increased trade. More importantly, DOE’s analysis also confirms the results of previous studies, which show that transmission bottlenecks and related transmission system market practices are adding hundreds of millions of dollars to consumers’ electricity bills each year. A more detailed technical overview of the use of POEMS is provided in Appendix A. DOE led an extensive, open, public input process and heard a wide range of comments and recommendations that have all been considered.1 More than 150 participants registered for three public workshops held in Detroit, MI (September 24, 2001); Atlanta, GA (September 26, 2001); and Phoenix, AZ (September 28, 2001).

  19. Symbolic Constraint Maintenance Grid

    NASA Technical Reports Server (NTRS)

    James, Mark

    2006-01-01

    Version 3.1 of Symbolic Constraint Maintenance Grid (SCMG) is a software system that provides a general conceptual framework for utilizing pre-existing programming techniques to perform symbolic transformations of data. SCMG also provides a language (and an associated communication method and protocol) for representing constraints on the original non-symbolic data. SCMG provides a facility for exchanging information between numeric and symbolic components without knowing the details of the components themselves. In essence, it integrates symbolic software tools (for diagnosis, prognosis, and planning) with non-artificial-intelligence software. SCMG executes a process of symbolic summarization and monitoring of continuous time series data that are being abstractly represented as symbolic templates of information exchange. This summarization process enables such symbolic- reasoning computing systems as artificial- intelligence planning systems to evaluate the significance and effects of channels of data more efficiently than would otherwise be possible. As a result of the increased efficiency in representation, reasoning software can monitor more channels and is thus able to perform monitoring and control functions more effectively.

  20. Towards a new high resolution gridded daily precipitation dataset over Europe

    NASA Astrophysics Data System (ADS)

    Toreti, Andrea; Naveau, Philippe

    2016-04-01

    The availability of high resolution daily gridded observational datasets is essential in many applications and to properly evaluate regional climate models. As the horizontal resolution of such models has significantly increased in recent modelling exercises (e.g., Euro-Cordex), while the one of the available observational datasets has remained constant (approx. 25km), new approaches are needed to develop gridded dataset of daily precipitation. Here, we discuss a statistical conceptual framework to combine data from neighbouring stations and model outputs. Our approach is based on recent statistical models for precipitation distributions, meshed with a data assimilation scheme. Our study focuses on the European region.

  1. Oscillating-grid experiments in water and superfluid helium

    NASA Astrophysics Data System (ADS)

    Honey, Rose E.; Hershberger, Robert; Donnelly, Russell J.; Bolster, Diogo

    2014-05-01

    Passing a fluid through a grid is a well-known mechanism used to study the properties of turbulence. Oscillating a horizontal grid vertically in a tank has also been used extensively and is considered to be a source of almost homogenous isotropic turbulence. When the oscillating grid is turned on a turbulent flow is induced. A front translates into the experimental tank, behind which the flow is highly turbulent. Long predicted that the growth of such a front would grow diffusively as the square root of time (i.e., d ˜√t ) and Dickinson and Long presented experimental evidence for the diffusive result at a low mesh Reynolds number of 555. This paper revisits these experiments and attempts a set of two models for the advancing front in both square and round tanks. We do not observe significant differences between runs in square and round tanks. The experiments in water reach mesh Reynolds numbers of order 30000. Using some data from superfluid helium experiments we are able to explore mesh Reynolds numbers to about 43000. We find the power law for the advancing front decreases weakly with the mesh Reynolds number. Using a very long tank we find that the turbulent front stops completely at a certain depth and attempt a simple explanation for that behavior. We study the propagation of the turbulent front into tubes of different diameters inserted into the main tank. We show that these tubes exclude wavelengths much larger than the tube diameter. We explore the variation of the position of the steady-state boundary H on tube diameter D and find that H =cD with c ˜2. We suggest this may be explained by saturation of the energy-containing length scale ℓe. We also report on the effect of plugging up just one hole of the grid. Finally, we recall some earlier oscillating grid experiments in superfluid 4He in the light of the present results.

  2. Oscillating-grid experiments in water and superfluid helium.

    PubMed

    Honey, Rose E; Hershberger, Robert; Donnelly, Russell J; Bolster, Diogo

    2014-05-01

    Passing a fluid through a grid is a well-known mechanism used to study the properties of turbulence. Oscillating a horizontal grid vertically in a tank has also been used extensively and is considered to be a source of almost homogenous isotropic turbulence. When the oscillating grid is turned on a turbulent flow is induced. A front translates into the experimental tank, behind which the flow is highly turbulent. Long predicted that the growth of such a front would grow diffusively as the square root of time (i.e., d ∼ sqrt[t]) and Dickinson and Long presented experimental evidence for the diffusive result at a low mesh Reynolds number of 555. This paper revisits these experiments and attempts a set of two models for the advancing front in both square and round tanks. We do not observe significant differences between runs in square and round tanks. The experiments in water reach mesh Reynolds numbers of order 30000. Using some data from superfluid helium experiments we are able to explore mesh Reynolds numbers to about 43000. We find the power law for the advancing front decreases weakly with the mesh Reynolds number. Using a very long tank we find that the turbulent front stops completely at a certain depth and attempt a simple explanation for that behavior. We study the propagation of the turbulent front into tubes of different diameters inserted into the main tank. We show that these tubes exclude wavelengths much larger than the tube diameter. We explore the variation of the position of the steady-state boundary H on tube diameter D and find that H = cD with c ∼ 2. We suggest this may be explained by saturation of the energy-containing length scale ℓ(e). We also report on the effect of plugging up just one hole of the grid. Finally, we recall some earlier oscillating grid experiments in superfluid (4)He in the light of the present results. PMID:25353889

  3. isochrones: Stellar model grid package

    NASA Astrophysics Data System (ADS)

    Morton, Timothy D.

    2015-03-01

    Isochrones, written in Python, simplifies common tasks often done with stellar model grids, such as simulating synthetic stellar populations, plotting evolution tracks or isochrones, or estimating the physical properties of a star given photometric and/or spectroscopic observations.

  4. Modal Analysis for Grid Operation

    SciTech Connect

    2011-03-03

    MANGO software is to provide a solution for improving small signal stability of power systems through adjusting operator-controllable variables using PMU measurement. System oscillation problems are one of the major threats to the grid stability and reliability in California and the Western Interconnection. These problems result in power fluctuations, lower grid operation efficiency, and may even lead to large-scale grid breakup and outages. This MANGO software aims to solve this problem by automatically generating recommended operation procedures termed Modal Analysis for Grid Operation (MANGO) to improve damping of inter-area oscillation modes. The MANGO procedure includes three steps: recognizing small signal stability problems, implementing operating point adjustment using modal sensitivity, and evaluating the effectiveness of the adjustment. The MANGO software package is designed to help implement the MANGO procedure.

  5. Assistive Awareness in Smart Grids

    NASA Astrophysics Data System (ADS)

    Bourazeri, Aikaterini; Almajano, Pablo; Rodriguez, Inmaculada; Lopez-Sanchez, Maite

    The following sections are included: * Introduction * Background * The User-Infrastructure Interface * User Engagement through Assistive Awareness * Research Impact * Serious Games for Smart Grids * Serious Game Technology * Game scenario * Game mechanics * Related Work * Summary and Conclusions

  6. Articulating Support for Horizontal Resistive Exercise

    NASA Technical Reports Server (NTRS)

    Gundo, Daniel; Schaffner, Grant; Bentley, Jason; Loehr, James A.

    2005-01-01

    A versatile mechanical device provides support for a user engaged in any of a variety of resistive exercises in a substantially horizontal orientation. The unique features and versatility of the device promise to be useful in bedrest studies, rehabilitation, and specialized strength training. The device affords a capability for selectively loading and unloading of portions of the user s body through its support mechanisms, so that specific parts of the body can be trained with little or no effect on other parts that may be disabled or in the process of recovery from injury. Thus, the device is ideal for rehabilitation exercise programs prescribed by physicians and physical therapists. The capability for selective loading and support also offers potential benefits to strength and conditioning trainers and athletes who wish to selectively strengthen selected parts. The principal innovative aspect of the device is that it supports the subject s weight while enabling the subject, lying substantially horizontally, to perform an exercise that closely approximates a full standing squat. The device includes mechanisms that support the subject in such a way that the hips are free to translate both horizontally and vertically and are free to rotate about the line connecting the hips. At the same time, the shoulders are free to translate horizontally while the upper back is free to rotate about the line connecting the shoulders. Among the mechanisms for hip motion and support is a counterbalance that offsets the weight of the subject as the subject s pelvis translates horizontally and vertically and rotates the pelvis about the line connecting the hips. The counterbalance is connected to a pelvic support system that allows these pelvic movements. The subject is also supported at the shoulder by a mechanism that can tilt to provide continuous support of the upper back while allowing the rotation required for arching the back as the pelvis is displaced. The shoulder support

  7. Smart Wire Grid: Resisting Expectations

    ScienceCinema

    Ramsay, Stewart; Lowe, DeJim

    2016-07-12

    Smart Wire Grid's DSR technology (Discrete Series Reactor) can be quickly deployed on electrical transmission lines to create intelligent mesh networks capable of quickly rerouting electricity to get power where and when it's needed the most. With their recent ARPA-E funding, Smart Wire Grid has been able to move from prototype and field testing to building out a US manufacturing operation in just under a year.

  8. Parallel Power Grid Simulation Toolkit

    SciTech Connect

    Smith, Steve; Kelley, Brian; Banks, Lawrence; Top, Philip; Woodward, Carol

    2015-09-14

    ParGrid is a 'wrapper' that integrates a coupled Power Grid Simulation toolkit consisting of a library to manage the synchronization and communication of independent simulations. The included library code in ParGid, named FSKIT, is intended to support the coupling multiple continuous and discrete even parallel simulations. The code is designed using modern object oriented C++ methods utilizing C++11 and current Boost libraries to ensure compatibility with multiple operating systems and environments.

  9. Reinventing Batteries for Grid Storage

    ScienceCinema

    Banerjee, Sanjoy

    2016-07-12

    The City University of New York's Energy Institute, with the help of ARPA-E funding, is creating safe, low cost, rechargeable, long lifecycle batteries that could be used as modular distributed storage for the electrical grid. The batteries could be used at the building level or the utility level to offer benefits such as capture of renewable energy, peak shaving and microgridding, for a safer, cheaper, and more secure electrical grid.

  10. Smart Wire Grid: Resisting Expectations

    SciTech Connect

    Ramsay, Stewart; Lowe, DeJim

    2014-03-03

    Smart Wire Grid's DSR technology (Discrete Series Reactor) can be quickly deployed on electrical transmission lines to create intelligent mesh networks capable of quickly rerouting electricity to get power where and when it's needed the most. With their recent ARPA-E funding, Smart Wire Grid has been able to move from prototype and field testing to building out a US manufacturing operation in just under a year.

  11. Towards Smart Grid Dynamic Ratings

    NASA Astrophysics Data System (ADS)

    Cheema, Jamal; Clark, Adrian; Kilimnik, Justin; Pavlovski, Chris; Redman, David; Vu, Maria

    2011-08-01

    The energy distribution industry is giving greater attention to smart grid solutions as a means for increasing the capabilities, efficiency and reliability of the electrical power network. The smart grid makes use of intelligent monitoring and control devices throughout the distribution network to report on electrical properties such as voltage, current and power, as well as raising network alarms and events. A further aspect of the smart grid embodies the dynamic rating of electrical assets of the network. This fundamentally involves a rating of the load current capacity of electrical assets including feeders, transformers and switches. The mainstream approach to rate assets is to apply the vendor plate rating, which often under utilizes assets, or in some cases over utilizes when environmental conditions reduce the effective rated capacity, potentially reducing lifetime. Using active intelligence we have developed a rating system that rates assets in real time based upon several events. This allows for a far more efficient and reliable electrical grid that is able to extend further the life and reliability of the electrical network. In this paper we describe our architecture, the observations made during development and live deployment of the solution into operation. We also illustrate how this solution blends with the smart grid by proposing a dynamic rating system for the smart grid.

  12. AstroGrid-D: Grid technology for astronomical science

    NASA Astrophysics Data System (ADS)

    Enke, Harry; Steinmetz, Matthias; Adorf, Hans-Martin; Beck-Ratzka, Alexander; Breitling, Frank; Brüsemeister, Thomas; Carlson, Arthur; Ensslin, Torsten; Högqvist, Mikael; Nickelt, Iliya; Radke, Thomas; Reinefeld, Alexander; Reiser, Angelika; Scholl, Tobias; Spurzem, Rainer; Steinacker, Jürgen; Voges, Wolfgang; Wambsganß, Joachim; White, Steve

    2011-02-01

    We present status and results of AstroGrid-D, a joint effort of astrophysicists and computer scientists to employ grid technology for scientific applications. AstroGrid-D provides access to a network of distributed machines with a set of commands as well as software interfaces. It allows simple use of computer and storage facilities and to schedule or monitor compute tasks and data management. It is based on the Globus Toolkit middleware (GT4). Chapter 1 describes the context which led to the demand for advanced software solutions in Astrophysics, and we state the goals of the project. We then present characteristic astrophysical applications that have been implemented on AstroGrid-D in chapter 2. We describe simulations of different complexity, compute-intensive calculations running on multiple sites (Section 2.1), and advanced applications for specific scientific purposes (Section 2.2), such as a connection to robotic telescopes (Section 2.2.3). We can show from these examples how grid execution improves e.g. the scientific workflow. Chapter 3 explains the software tools and services that we adapted or newly developed. Section 3.1 is focused on the administrative aspects of the infrastructure, to manage users and monitor activity. Section 3.2 characterises the central components of our architecture: The AstroGrid-D information service to collect and store metadata, a file management system, the data management system, and a job manager for automatic submission of compute tasks. We summarise the successfully established infrastructure in chapter 4, concluding with our future plans to establish AstroGrid-D as a platform of modern e-Astronomy.

  13. Horizontal modular dry irradiated fuel storage system

    DOEpatents

    Fischer, Larry E.; McInnes, Ian D.; Massey, John V.

    1988-01-01

    A horizontal, modular, dry, irradiated fuel storage system (10) includes a thin-walled canister (12) for containing irradiated fuel assemblies (20), which canister (12) can be positioned in a transfer cask (14) and transported in a horizontal manner from a fuel storage pool (18), to an intermediate-term storage facility. The storage system (10) includes a plurality of dry storage modules (26) which accept the canister (12) from the transfer cask (14) and provide for appropriate shielding about the canister (12). Each module (26) also provides for air cooling of the canister (12) to remove the decay heat of the irradiated fuel assemblies (20). The modules (26) can be interlocked so that each module (26) gains additional shielding from the next adjacent module (26). Hydraulic rams (30) are provided for inserting and removing the canisters (12) from the modules (26).

  14. Elf cites 5 advantages of horizontal drilling

    SciTech Connect

    Not Available

    1984-06-01

    ELF Aquitaine used horizontal drilling during a pilot test program to bring commercial production from its Rospo Mare oil discovery in the Adriatic, which would have been a costly disappointment if drilled by a conventional vertical well bore. Rospo Mare is a large reservoir containing a top column of highly viscous crude underlain by a water column. The company felt that a well bore that penetrated the reservoir vertically would bring early flooding of the oil column and yield only water. By penetrating the reservoir with a horizontal well drilled high in the oil column, the well successfully produced on numerous tests from Oct. 1982 until the end of the test program in 1983. Production was termed excellent, with productivity during tests reportedly reaching ca 15 times the rate produced from nearby vertical wells. However, ELF said the results usually average ca 5 times the usual rate of vertical wells.

  15. Film condensation in a horizontal rectangular duct

    NASA Technical Reports Server (NTRS)

    Lu, Qing; Suryanarayana, N. V.

    1993-01-01

    Condensation heat transfer in a horizontal rectangular duct was experimentally and analytically investigated. To prevent the dripping of condensate on the film, the experiment was conducted inside a horizontal rectangular duct with vapor condensing only on the bottom cooled plate of the duct. R-113 and FC-72 (Fluorinert Electronic Fluid developed by the 3M Company) were used as the condensing fluids. The experimental program included measurements of film thickness, local and average heat transfer coefficients, wave length, wave speed, and a study of wave initiation. The measured film thickness was used to obtain the local heat transfer coefficient. The wave initiation was studied both with condensation and with an adiabatic air-liquid flow. The test sections used in both experiments were identical.

  16. Horizontal slug flow modeling and metering

    SciTech Connect

    Kouba, G.E.

    1986-01-01

    An experimental and theoretical investigation of horizontal two-phase slug flow was performed with the purpose of developing a method to measure the in-situ flow rates of the liquid and the gas phases using non-intrusive devices. A microcomputer based data acquisition system was used to acquire slug flow data on a 3 in.(76.2 mm) diameter, 1370 ft (418 m) long, horizontal pipeline. These data include the following slug characteristics: liquid holdups in the slug and film, slug and gas pocket lengths, and slug translational velocity. The data were gathered over a wide range of flow conditions in groups of constant superficial liquid and mixture velocities. The volumetric phase flow rate equation, for either liquid or gas, was developed for slug flow conditions. Within the flow rate equation, a key flow distribution parameter was defined that related the phase velocity in the slug to the translational velocity of the slug.

  17. Grid-Optimization Program for Photovoltaic Cells

    NASA Technical Reports Server (NTRS)

    Daniel, R. E.; Lee, T. S.

    1986-01-01

    CELLOPT program developed to assist in designing grid pattern of current-conducting material on photovoltaic cell. Analyzes parasitic resistance losses and shadow loss associated with metallized grid pattern on both round and rectangular solar cells. Though performs sensitivity studies, used primarily to optimize grid design in terms of bus bar and grid lines by minimizing power loss. CELLOPT written in APL.

  18. Horizontal drilling in shallow, geologically complex reservoirs

    SciTech Connect

    Venable, S.D.

    1992-01-01

    The objective of this project is to test the concept that multiple hydraulic fracturing from a directionally-drilled horizontal well, using the medium radius build rate method, can increase gas production sufficiently to justify economic viability over conventional stimulated vertical wells. The test well is located in Yuma County, Colorado, in a favorable area of established production to avoid exploration risks. This report presents: background information; project description which covers location selection/geologic considerations; and preliminary work plan. (AT)

  19. Horizontal drilling in shallow, geologically complex reservoirs

    SciTech Connect

    Venable, S.D.

    1992-10-01

    The objective of this project is to test the concept that multiple hydraulic fracturing from a directionally-drilled horizontal well, using the medium radius build rate method, can increase gas production sufficiently to justify economic viability over conventional stimulated vertical wells. The test well is located in Yuma County, Colorado, in a favorable area of established production to avoid exploration risks. This report presents: background information; project description which covers location selection/geologic considerations; and preliminary work plan. (AT)

  20. Management of horizontally impacted dilacerated lateral incisor

    PubMed Central

    Katta, Anil Kumar; Peddu, Revathi; Vannala, Venkataramana; Dasari, Vaishnavi

    2015-01-01

    Impaction of maxillary lateral incisor with odontome and retained deciduous tooth is not often seen in regular dental practice. Impaction of anterior teeth cause generalized spacing which affects the esthetics of the face. Here we report a case of an 18-year-old patient with horizontally impacted dilacerated lateral incisor, which was bought into occlusion with the help of orthodontic tooth movement within a span of 18 months. PMID:26538954

  1. Spin stabilized magnetic levitation of horizontal rotors.

    SciTech Connect

    Romero, Louis Anthony

    2004-10-01

    In this paper we present an analysis of a new configuration for achieving spin stabilized magnetic levitation. In the classical configuration, the rotor spins about a vertical axis; and the spin stabilizes the lateral instability of the top in the magnetic field. In this new configuration the rotor spins about a horizontal axis; and the spin stabilizes the axial instability of the top in the magnetic field.

  2. A paradigm for parallel unstructured grid generation

    SciTech Connect

    Gaither, A.; Marcum, D.; Reese, D.

    1996-12-31

    In this paper, a sequential 2D unstructured grid generator based on iterative point insertion and local reconnection is coupled with a Delauney tessellation domain decomposition scheme to create a scalable parallel unstructured grid generator. The Message Passing Interface (MPI) is used for distributed communication in the parallel grid generator. This work attempts to provide a generic framework to enable the parallelization of fast sequential unstructured grid generators in order to compute grand-challenge scale grids for Computational Field Simulation (CFS). Motivation for moving from sequential to scalable parallel grid generation is presented. Delaunay tessellation and iterative point insertion and local reconnection (advancing front method only) unstructured grid generation techniques are discussed with emphasis on how these techniques can be utilized for parallel unstructured grid generation. Domain decomposition techniques are discussed for both Delauney and advancing front unstructured grid generation with emphasis placed on the differences needed for both grid quality and algorithmic efficiency.

  3. Striped ratio grids for scatter estimation

    NASA Astrophysics Data System (ADS)

    Hsieh, Scott S.; Wang, Adam S.; Star-Lack, Josh

    2016-03-01

    Striped ratio grids are a new concept for scatter management in cone-beam CT. These grids are a modification of conventional anti-scatter grids and consist of stripes which alternate between high grid ratio and low grid ratio. Such a grid is related to existing hardware concepts for scatter estimation such as blocker-based methods or primary modulation, but rather than modulating the primary, the striped ratio grid modulates the scatter. The transitions between adjacent stripes can be used to estimate and subtract the remaining scatter. However, these transitions could be contaminated by variation in the primary radiation. We describe a simple nonlinear image processing algorithm to estimate scatter, and proceed to validate the striped ratio grid on experimental data of a pelvic phantom. The striped ratio grid is emulated by combining data from two scans with different grids. Preliminary results are encouraging and show a significant reduction of scatter artifact.

  4. Ion beamlet vectoring by grid translation

    NASA Technical Reports Server (NTRS)

    Homa, J. M.; Wilbur, P. J.

    1982-01-01

    Ion beamlet vectoring is investigated by collecting deflection and divergence angle data for two-grid systems as a function of the relative displacement of these grids. Results show that at large displacements, accelerator grid impingement becomes a limiting factor and this determines the useful range of beamlet deflection. Beamlet deflection was shown to vary linearly with grid offset angle over this range. Values of deflection-to-offset angle ratio and useful range of deflection are presented as functions of grid-hole geometries, perveance levels, and accelerating voltages. It is found that the divergence of the beamlets is unaffected by deflection over the useful range of beamlet deflection. The grids of a typical dished-grid ion thruster are examined to determine where over the grid surface the grid offsets exceed the useful range, which indicates the regions on the surface where high accelerator grid impingment is probably occurring.

  5. Sensitivity of snow cover to horizontal resolution in a land surface model

    NASA Astrophysics Data System (ADS)

    Dutra, E.; Kotlarski, S.; Viterbo, P.; Balsamo, G.; Miranda, P. M. A.; Schär, C.

    2010-09-01

    Snow cover is a highly variable land surface condition that exerts a strong control on the heat and moisture budget of the overlying atmosphere. Modeling studies based on long integrations of global circulation models (GCM) are normally carried out at very low resolution (typically coarser than 100 km) due to their high computational demand. On local scales, snow cover plays an important socioeconomic role, ranging from water management applications to outdoor recreation. These latter applications vary in horizontal resolution from a few hundred meters to a few kilometers, where small scale topography, land cover and local circulation effects play a significant role. In this study our focus will be on horizontal scales ranging from typical GCM global climate modeling to high resolution global weather forecasts. In the land surface component of a GCM (land surface model - LSM), snow cover temporal and spatial variability is mainly determined by the overlying atmospheric conditions. However, once snowfall settles on the ground, the sub-grid scale variability associated with complex terrain and land cover variability (not resolved at the model resolution) is parameterized following simple physical and/or empirical relations. The present study intends to access the impact of horizontal resolution in the European Centre for Medium-Range Weather Forecasts (ECMWF) land surface model (HTESSEL). HTESSEL is forced by the ECMWF operational weather forecasts since March 2006 to December 2009 (runs in offline/stand-alone mode). The control run is carried out at the horizontal resolution of the forecasts at TL799 (gaussian reduced grid N400 -about 25 km). Two lower horizontal resolutions are then tested: TL255 (gaussian reduced grid - about 80 km, same as the ERA-Interim reanalysis), and TL95 (gaussian reduced grid N48 - about 200 km). The length of the simulations is rather small (only 46 months), however global meteorological forcing at 25 km can only be accessed through the

  6. Scaling Up Renewable Energy Generation: Aligning Targets and Incentives with Grid Integration Considerations, Greening The Grid

    SciTech Connect

    Katz, Jessica; Cochran, Jaquelin

    2015-05-27

    Greening the Grid provides technical assistance to energy system planners, regulators, and grid operators to overcome challenges associated with integrating variable renewable energy into the grid. This document, part of a Greening the Grid toolkit, provides power system planners with tips to help secure and sustain investment in new renewable energy generation by aligning renewable energy policy targets and incentives with grid integration considerations.

  7. Simulation of the Summer Monsoon Rainfall over East Asia using the NCEP GFS Cumulus Parameterization at Different Horizontal Resolutions

    SciTech Connect

    Lim, Kyo-Sun; Hong, Song You; Yoon, Jin-Ho; Han, Jongil

    2014-10-01

    The most recent version of Simplified Arakawa-Schubert (SAS) cumulus scheme in National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) (GFS SAS) has been implemented into the Weather and Research Forecasting (WRF) model with a modification of triggering condition and convective mass flux to become depending on model’s horizontal grid spacing. East Asian Summer Monsoon of 2006 from June to August is selected to evaluate the performance of the modified GFS SAS scheme. Simulated monsoon rainfall with the modified GFS SAS scheme shows better agreement with observation compared to the original GFS SAS scheme. The original GFS SAS scheme simulates the similar ratio of subgrid-scale precipitation, which is calculated from a cumulus scheme, against total precipitation regardless of model’s horizontal grid spacing. This is counter-intuitive because the portion of resolved clouds in a grid box should be increased as the model grid spacing decreases. This counter-intuitive behavior of the original GFS SAS scheme is alleviated by the modified GFS SAS scheme. Further, three different cumulus schemes (Grell and Freitas, Kain and Fritsch, and Betts-Miller-Janjic) are chosen to investigate the role of a horizontal resolution on simulated monsoon rainfall. The performance of high-resolution modeling is not always enhanced as the spatial resolution becomes higher. Even though improvement of probability density function of rain rate and long wave fluxes by the higher-resolution simulation is robust regardless of a choice of cumulus parameterization scheme, the overall skill score of surface rainfall is not monotonically increasing with spatial resolution.

  8. Multiblock grid generation for jet engine configurations

    NASA Technical Reports Server (NTRS)

    Stewart, Mark E. M.

    1992-01-01

    The goal was to create methods for generating grids with minimal human intervention that are applicable to a wide range of problems and compatible with existing numerical methods and with existing and proposed computers. The following topics that are related to multiblock grid generation are briefly covered in viewgraph form: finding a domain decomposition, dimensioning grids, grid smoothing, manipulating grids and decompositions, and some specializations for jet engine configurations.

  9. 12. VIEW LOOKING SOUTHWEST, CHESTNUT ST. (lower horizontal line) TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. VIEW LOOKING SOUTHWEST, CHESTNUT ST. (lower horizontal line) TO WALNUT ST. (upper horizontal line), SHOWING SECOND BANK OF U.S. - Independence National Historical Park, Walnut, Sixth, Chestnut & Second Streets, Philadelphia, Philadelphia County, PA

  10. Idealised simulations of open cellular convection and horizontal wind fluctuations over the North Sea

    NASA Astrophysics Data System (ADS)

    Vincent, Claire Louise; Hahmann, Andrea; Pinson, Pierre; Giebel, Gregor

    2010-05-01

    The Weather Research and Forecasting (WRF) model was used to study the skill, sensitivity and limitations of a mesoscale model in predicting wind speed fluctuations on time scales of tens of minutes to hours. The work was motivated by the severely variable wind conditions that are often observed at the Horns Rev wind farm in the Danish North Sea. From a wind energy perspective, such fluctuations present challenges for both electricity transmission system operators, who must ensure reliability of the electricity grid, and wind farm operators, who must avoid financial losses associated with sudden and unexpected dips in wind power. Good forecasts of the onset of severely variable wind conditions are one way of increasing preparedness for such events. WRF was first used to model an episode of intense wind fluctuations that was observed at an offshore meteorological mast near the Horns Rev wind farm on 23-24th October 2002. WRF was able to reproduce large fluctuations in horizontal wind speed with a similar frequency to that of the observed wind fluctuations. Building on this result, WRF was then set up in an idealised framework as a simple simulation of wind blowing over water. The initialisation of the model was based on the actual conditions during a severely variable wind event over the North Sea. The benefit of running the model in an idealised mode was that individual aspects of model performance could be clearly isolated. During the first few hours of simulation, WRF produced unrealistic fluctuations in wind speed that were dominated by the horizontal grid spacing of the model. After 4 to 5 hours, realistic open cellular convection developed, with large fluctuations in horizontal wind speed similar to those observed in the real case. The structure of the convective cells had a spatial scale of about 30 km, which corresponded closely to cloud patterns seen in a visual satellite picture from the same event. The scale of the cells was largely invariant to changes

  11. Productivity and injectivity of horizontal wells. Quarterly report, October 1--December 31, 1993

    SciTech Connect

    Fayers, F.J.; Aziz, K.; Hewett, T.A.

    1993-03-10

    A number of activities have been carried out in the last three months. A list outlining these efforts is presented below followed by brief description of each activity in the subsequent sections of this report: Progress is being made on the development of a black oil three-phase simulator which will allow the use of a generalized Voronoi grid in the plane perpendicular to a horizontal well. The available analytical solutions in the literature for calculating productivity indices (Inflow Performance) of horizontal wells have been reviewed. The pseudo-steady state analytic model of Goode and Kuchuk has been applied to an example problem. A general mechanistic two-phase flow model is under development. The model is capable of predicting flow transition boundaries for a horizontal pipe at any inclination angle. It also has the capability of determining pressure drops and holdups for all the flow regimes. A large code incorporating all the features of the model has been programmed and is currently being tested.

  12. Grid-based Visualization Framework

    NASA Astrophysics Data System (ADS)

    Thiebaux, M.; Tangmunarunkit, H.; Kesselman, C.

    2003-12-01

    Advances in science and engineering have put high demands on tools for high-performance large-scale visual data exploration and analysis. For example, earthquake scientists can now study earthquake phenomena from first principle physics-based simulations. These simulations can generate large amounts of data, possibly high spatial resolution, and long time series. Single-system visualization software running on commodity machines cannot scale up to the large amounts of data generated by these simulations. To address this problem, we propose a flexible and extensible Grid-based visualization framework for time-critical, interactively controlled visual browsing of spatially and temporally large datasets in a Grid environment. Our framework leverages Grid resources for scalable computation and data storage to maintain performance and interactivity with large visualization jobs. Our framework utilizes Globus Toolkit 2.4 components for security (i.e., GSI), resource allocation and management (i.e., DUROC, GRAM) and communication (i.e., Globus-IO) to couple commodity desktops with remote, scalable storage and computational resources in a Grid for interactive data exploration. There are two major components in this framework---Grid Data Transport (GDT) and the Grid Visualization Utility (GVU). GDT provides libraries for performing parallel data filtering and parallel data exchange among Grid resources. GDT allows arbitrary data filtering to be integrated into the system. It also facilitates multi-tiered pipeline topology construction of compute resources and displays. In addition to scientific visualization applications, GDT can be used to support other applications that require parallel processing and parallel transfer of partial ordered independent files, such as file-set transfer. On top of GDT, we have developed the Grid Visualization Utility (GVU), which is designed to assist visualization dataset management, including file formatting, data transport and automatic

  13. Smart Grid Information Clearinghouse (SGIC)

    SciTech Connect

    Rahman, Saifur

    2014-08-31

    Since the Energy Independence and Security Act of 2007 was enacted, there has been a large number of websites that discusses smart grid and relevant information, including those from government, academia, industry, private sector and regulatory. These websites collect information independently. Therefore, smart grid information was quite scattered and dispersed. The objective of this work was to develop, populate, manage and maintain the public Smart Grid Information Clearinghouse (SGIC) web portal. The information in the SGIC website is comprehensive that includes smart grid information, research & development, demonstration projects, technical standards, costs & benefit analyses, business cases, legislation, policy & regulation, and other information on lesson learned and best practices. The content in the SGIC website is logically grouped to allow easily browse, search and sort. In addition to providing the browse and search feature, the SGIC web portal also allow users to share their smart grid information with others though our online content submission platform. The Clearinghouse web portal, therefore, serves as the first stop shop for smart grid information that collects smart grid information in a non-bias, non-promotional manner and can provide a missing link from information sources to end users and better serve users’ needs. The web portal is available at www.sgiclearinghouse.org. This report summarizes the work performed during the course of the project (September 2009 – August 2014). Section 2.0 lists SGIC Advisory Committee and User Group members. Section 3.0 discusses SGIC information architecture and web-based database application functionalities. Section 4.0 summarizes SGIC features and functionalities, including its search, browse and sort capabilities, web portal social networking, online content submission platform and security measures implemented. Section 5.0 discusses SGIC web portal contents, including smart grid 101, smart grid projects

  14. Development and Verification of a Computational Fluid Dynamics Model of a Horizontal-Axis Tidal Current Turbine

    SciTech Connect

    Lawson, Mi. J.; Li, Y.; Sale, D. C.

    2011-01-01

    This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines (HATTs). First, an HATT blade was designed using the blade element momentum method in conjunction with a genetic optimization algorithm. Several unstructured computational grids were generated using this blade geometry and steady CFD simulations were used to perform a grid resolution study. Transient simulations were then performed to determine the effect of time-dependent flow phenomena and the size of the computational timestep on the numerical solution. Qualitative measures of the CFD solutions were independent of the grid resolution. Conversely, quantitative comparisons of the results indicated that the use of coarse computational grids results in an under prediction of the hydrodynamic forces on the turbine blade in comparison to the forces predicted using more resolved grids. For the turbine operating conditions considered in this study, the effect of the computational timestep on the CFD solution was found to be minimal, and the results from steady and transient simulations were in good agreement. Additionally, the CFD results were compared to corresponding blade element momentum method calculations and reasonable agreement was shown. Nevertheless, we expect that for other turbine operating conditions, where the flow over the blade is separated, transient simulations will be required.

  15. POWER GRID RELIABILITY AND SECURITY

    SciTech Connect

    Bose, Anjan; Venkatasubramanian, Vaithianathan; Hauser, Carl; Bakken, David; Anderson, David; Zhao, Chuanlin; Liu, Dong; Yang, Tao; Meng, Ming; Zhang, Lin; Ning, Jiawei; Tashman, Zaid

    2014-09-30

    This project has led to the development of a real-time simulation platform for electric power grids called Grid Simulator or GridSim for simulating the dynamic and information network interactions of large- scale power systems. The platform consists of physical models of power system components including synchronous generators, loads and control, which are simulated using a modified commercial power simulator namely Transient Stability Analysis Tool (TSAT) [1] together with data cleanup components, as well as an emulated substation level and wide-area power analysis components. The platform also includes realistic representations of communication network middleware that can emulate the real-time information flow back and forth between substations and control centers in wide-area power systems. The platform has been validated on a realistic 6000-bus model of the western American power system. The simulator GridSim developed in this project is the first of its kind in its ability to simulate real-time response of large-scale power grids, and serves as a cost effective real-time stability and control simulation platform for power industry.

  16. The CrossGrid project

    NASA Astrophysics Data System (ADS)

    Kunze, M.; CrossGrid Collaboration

    2003-04-01

    There are many large-scale problems that require new approaches to computing, such as earth observation, environmental management, biomedicine, industrial and scientific modeling. The CrossGrid project addresses realistic problems in medicine, environmental protection, flood prediction, and physics analysis and is oriented towards specific end-users: Medical doctors, who could obtain new tools to help them to obtain correct diagnoses and to guide them during operations; industries, that could be advised on the best timing for some critical operations involving risk of pollution; flood crisis teams, that could predict the risk of a flood on the basis of historical records and actual hydrological and meteorological data; physicists, who could optimize the analysis of massive volumes of data distributed across countries and continents. Corresponding applications will be based on Grid technology and could be complex and difficult to use: the CrossGrid project aims at developing several tools that will make the Grid more friendly for average users. Portals for specific applications will be designed, that should allow for easy connection to the Grid, create a customized work environment, and provide users with all necessary information to get their job done.

  17. ASCI Grid Services summary report.

    SciTech Connect

    Hiebert-Dodd, Kathie L.

    2004-03-01

    The ASCI Grid Services (initially called Distributed Resource Management) project was started under DisCom{sup 2} when distant and distributed computing was identified as a technology critical to the success of the ASCI Program. The goals of the Grid Services project has and continues to be to provide easy, consistent access to all the ASCI hardware and software resources across the nuclear weapons complex using computational grid technologies, increase the usability of ASCI hardware and software resources by providing interfaces for resource monitoring, job submission, job monitoring, and job control, and enable the effective use of high-end computing capability through complex-wide resource scheduling and brokering. In order to increase acceptance of the new technology, the goal included providing these services in both the unclassified as well as the classified user's environment. This paper summarizes the many accomplishments and lessons learned over approximately five years of the ASCI Grid Services Project. It also provides suggestions on how to renew/restart the effort for grid services capability when the situation is right for that need.

  18. Grid Stiffened Structure Analysis Tool

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The Grid Stiffened Analysis Tool contract is contract performed by Boeing under NASA purchase order H30249D. The contract calls for a "best effort" study comprised of two tasks: (1) Create documentation for a composite grid-stiffened structure analysis tool, in the form of a Microsoft EXCEL spread sheet, that was developed by originally at Stanford University and later further developed by the Air Force, and (2) Write a program that functions as a NASTRAN pre-processor to generate an FEM code for grid-stiffened structure. In performing this contract, Task 1 was given higher priority because it enables NASA to make efficient use of a unique tool they already have; Task 2 was proposed by Boeing because it also would be beneficial to the analysis of composite grid-stiffened structures, specifically in generating models for preliminary design studies. The contract is now complete, this package includes copies of the user's documentation for Task 1 and a CD ROM & diskette with an electronic copy of the user's documentation and an updated version of the "GRID 99" spreadsheet.

  19. Study of the Local Horizon. (Spanish Title: Estudio del Horizonte Local.) Estudo do Horizonte Local

    NASA Astrophysics Data System (ADS)

    Ros, Rosa M.

    2009-12-01

    The study of the horizon is fundamental to easy the first observations of the students at any education center. A simple model, to be developed in each center, allows to easy the study and comprehension of the rudiments of astronomy. The constructed model is presented in turn as a simple equatorial clock, other models (horizontal and vertical) may be constructed starting from it. El estudio del horizonte es fundamental para poder facilitar las primeras observaciones de los alumnos en un centro educativo. Un simple modelo, que debe realizarse para cada centro, nos permite facilitar el estudio y la comprensión de los primeros rudimentos astronómicos. El modelo construido se presenta a su vez como un sencillo modelo de reloj ecuatorial y a partir de él se pueden construir otros modelos (horizontal y vertical). O estudo do horizonte é fundamental para facilitar as primeiras observações dos alunos num centro educativo. Um modelo simples, que deve ser feito para cada centro, permite facilitar o estudo e a compreensão dos primeiros rudimentos astronômicos. O modelo construído apresenta-se, por sua vez, como um modelo simples de relógio equatorial e a partir dele pode-se construir outros modelos (horizontal e vertical)

  20. Stable discontinuous grid implementation for collocated-grid finite-difference seismic wave modelling

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenguo; Zhang, Wei; Li, Hong; Chen, Xiaofei

    2013-03-01

    Simulating seismic waves with uniform grid in heterogeneous high-velocity contrast media requires small-grid spacing determined by the global minimal velocity, which leads to huge number of grid points and small time step. To reduce the computational cost, discontinuous grids that use a finer grid at the shallow low-velocity region and a coarser grid at high-velocity regions are needed. In this paper, we present a discontinuous grid implementation for the collocated-grid finite-difference (FD) methods to increase the efficiency of seismic wave modelling. The grid spacing ratio n could be an arbitrary integer n ≥ 2. To downsample the wavefield from the finer grid to the coarser grid, our implementation can simply take the values on the finer grid without employing a downsampling filter for grid spacing ratio n = 2 to achieve stable results for long-time simulation. For grid spacing ratio n ≥ 3, the Gaussian filter should be used as the downsampling filter to get a stable simulation. To interpolate the wavefield from the coarse grid to the finer grid, the trilinear interpolation is used. Combining the efficiency of discontinuous grid with the flexibility of collocated-grid FD method on curvilinear grids, our method can simulate large-scale high-frequency strong ground motion of real earthquake with consideration of surface topography.

  1. YPF uses horizontal reentry to aid thin bed production

    SciTech Connect

    Acosta, M.R.; Leiro, F.A.; Sesano, G.S.; Hill, D.

    1997-01-01

    Reentry and horizontal drilling/completion techniques have proven themselves useful in exploiting thin beds. A pilot horizontal reentry contracted by Yacimiento Petroliferos Fiscales (YPF) for a marginal well in its Lomita Sur field resulted in decreased water coning and production rates four times greater than expected. Further horizontal reentries in this thin-bed field are planned.

  2. Sidewall containment of liquid metal with horizontal alternating magnetic fields

    DOEpatents

    Praeg, Walter F.

    1995-01-01

    An apparatus for confining molten metal with a horizontal alternating magnetic field. In particular, this invention employs a magnet that can produce a horizontal alternating magnetic field to confine a molten metal at the edges of parallel horizontal rollers as a solid metal sheet is cast by counter-rotation of the rollers.

  3. Sidewall containment of liquid metal with horizontal alternating magnetic fields

    DOEpatents

    Pareg, Walter F.

    1990-01-01

    An apparatus for confining molten metal with a horizontal alternating magnetic field. In particular, this invention employs a magnet that can produce a horizontal alternating magnetic field to confine a molten metal at the edges of parallel horizontal rollers as a solid metal sheet is cast by counter-rotation of the rollers.

  4. Horizontal core acquisition and orientation for formation evaluation

    SciTech Connect

    Skopec, R.A. ); Mann, M.M. ); Grier, S.P. )

    1992-03-01

    The increase in horizontal drilling activity has produced a need for improved coring technology. The development of a reliable horizontal (medium-radius) coring and orientation system has greatly improved the acquisition of information necessary for formation evaluation and reservoir engineering. This paper describes newly developed hardware and methods for obtaining horizontal core sections.

  5. Incorporating horizontal membrane stresses into calculations of balance velocities

    NASA Astrophysics Data System (ADS)

    Williams, R.; Hindmarsh, R. C.; Arthern, R.

    2010-12-01

    The prediction of ice-sheet behaviour is becoming increasingly important as observed changes in continental ice masses may be indicators of the operation of instability mechanisms which have the potential to have a significant impact on global sea levels. Predictive forward models require initialisation with existing data in order to best describe the current state of the ice-sheet. In particular, such models need to be calibrated with the viscosity and sliding conditions at the base of the ice-sheet, which in practice are largely unobservable. The balance velocity approach, in which depth-averaged velocities that conserve mass are calculated based on surface elevation and accumulation data, is a suitable method in many cases. Hitherto, balance velocities have been calculated using the Shallow Ice Approximation (SIA), where flow is always parallel to the direction of the slope. The SIA approximation is usually applied to coarse resolutions and assumes that longitudinal stresses are averaged out over distances 10-20 times the ice thickness. However, this method does not capture any fine detail at which longitudinal stresses may be important and the assumption of downhill flow is not always appropriate. Moreover, it is ill-posed as results are severely dependent on grid size. Thus in this study horizontal longitudinal (or membrane) stresses are introduced into calculations for balance velocities. The numerical method is presented and the code is tested by comparing numerical results with various simplified analytical solutions for Newtonian rheology and linear sliding. These analytical and numerical solutions are then used to investigate the conditions under which membrane stresses become important and to explore differences between Newtonian and non-linear rheological cases.

  6. ON JOINT DETERMINISTIC GRID MODELING AND SUB-GRID VARIABILITY CONCEPTUAL FRAMEWORK FOR MODEL EVALUATION

    EPA Science Inventory

    The general situation, (but exemplified in urban areas), where a significant degree of sub-grid variability (SGV) exists in grid models poses problems when comparing gridbased air quality modeling results with observations. Typically, grid models ignore or parameterize processes ...

  7. Grid generation and inviscid flow computation about cranked-winged airplane geometries

    NASA Technical Reports Server (NTRS)

    Eriksson, L.-E.; Smith, R. E.; Wiese, M. R.; Farr, N.

    1987-01-01

    An algebraic grid generation procedure that defines a patched multiple-block grid system suitable for fighter-type aircraft geometries with fuselage and engine inlet, canard or horizontal tail, cranked delta wing and vertical fin has been developed. The grid generation is based on transfinite interpolation and requires little computational power. A finite-volume Euler solver using explicit Runge-Kutta time-stepping has been adapted to this grid system and implemented on the VPS-32 vector processor with a high degree of vectorization. Grids are presented for an experimental aircraft with fuselage, canard, 70-20-cranked wing, and vertical fin. Computed inviscid compressible flow solutions are presented for Mach 2 at 3.79, 7 and 10 deg angles of attack. Conmparisons of the 3.79 deg computed solutions are made with available full-potential flow and Euler flow solutions on the same configuration but with another grid system. The occurrence of an unsteady solution in the 10 deg angle of attack case is discussed.

  8. Wavelet-Based Grid Generation

    NASA Technical Reports Server (NTRS)

    Jameson, Leland

    1996-01-01

    Wavelets can provide a basis set in which the basis functions are constructed by dilating and translating a fixed function known as the mother wavelet. The mother wavelet can be seen as a high pass filter in the frequency domain. The process of dilating and expanding this high-pass filter can be seen as altering the frequency range that is 'passed' or detected. The process of translation moves this high-pass filter throughout the domain, thereby providing a mechanism to detect the frequencies or scales of information at every location. This is exactly the type of information that is needed for effective grid generation. This paper provides motivation to use wavelets for grid generation in addition to providing the final product: source code for wavelet-based grid generation.

  9. Grids: The Top Ten Questions

    DOE PAGES

    Schopf, Jennifer M.; Nitzberg, Bill

    2002-01-01

    The design and implementation of a national computing system and data grid has become a reachable goal from both the computer science and computational science point of view. A distributed infrastructure capable of sophisticated computational functions can bring many benefits to scientific work, but poses many challenges, both technical and socio-political. Technical challenges include having basic software tools, higher-level services, functioning and pervasive security, and standards, while socio-political issues include building a user community, adding incentives for sites to be part of a user-centric environment, and educating funding sources about the needs of this community. This paper details the areasmore » relating to Grid research that we feel still need to be addressed to fully leverage the advantages of the Grid.« less

  10. Grid-free compressive beamforming.

    PubMed

    Xenaki, Angeliki; Gerstoft, Peter

    2015-04-01

    The direction-of-arrival (DOA) estimation problem involves the localization of a few sources from a limited number of observations on an array of sensors, thus it can be formulated as a sparse signal reconstruction problem and solved efficiently with compressive sensing (CS) to achieve high-resolution imaging. On a discrete angular grid, the CS reconstruction degrades due to basis mismatch when the DOAs do not coincide with the angular directions on the grid. To overcome this limitation, a continuous formulation of the DOA problem is employed and an optimization procedure is introduced, which promotes sparsity on a continuous optimization variable. The DOA estimation problem with infinitely many unknowns, i.e., source locations and amplitudes, is solved over a few optimization variables with semidefinite programming. The grid-free CS reconstruction provides high-resolution imaging even with non-uniform arrays, single-snapshot data and under noisy conditions as demonstrated on experimental towed array data.

  11. Grid-free compressive beamforming.

    PubMed

    Xenaki, Angeliki; Gerstoft, Peter

    2015-04-01

    The direction-of-arrival (DOA) estimation problem involves the localization of a few sources from a limited number of observations on an array of sensors, thus it can be formulated as a sparse signal reconstruction problem and solved efficiently with compressive sensing (CS) to achieve high-resolution imaging. On a discrete angular grid, the CS reconstruction degrades due to basis mismatch when the DOAs do not coincide with the angular directions on the grid. To overcome this limitation, a continuous formulation of the DOA problem is employed and an optimization procedure is introduced, which promotes sparsity on a continuous optimization variable. The DOA estimation problem with infinitely many unknowns, i.e., source locations and amplitudes, is solved over a few optimization variables with semidefinite programming. The grid-free CS reconstruction provides high-resolution imaging even with non-uniform arrays, single-snapshot data and under noisy conditions as demonstrated on experimental towed array data. PMID:25920844

  12. Horizontal tapping furnace and method of operation

    SciTech Connect

    Wunsche, E.R.

    1987-07-14

    A metallurgical furnace is described including: a furnace floor and a furnace wall means extending generally upwardly about the floor, the furnace having a vertical axis and a horizontal axis, means mounting the furnace for pivotal tilting movement about the horizontal axis between a non-tilted, normal upright position, and a tilted discharge position with the furnace tilted less than 15/sup 0/ to the vertical axis; a hearth zone defined between the floor and wall means adapted to house a bath of liquid metal of predetermined volume, the hearth zone having an upper end defining a predetermined upper level for the bath and for a layer of liquid slag floating on the upper level, when the furnace is in a non-tilted, normal upright position; the hearth zone having a lower end adjacent the floor, a tapping passage extending through the wall means from a liquid metal discharge outlet at an outer end into the lower end of the hearth zone, at an inner end, the discharge outlet being defined by an outwardly facing passage wall and the passage at the outer end; the tapping passage disposed generally parallel to the horizontal axis and vertically below the predetermined upper level, when the furnace is in the non-tilted, normal, upright position; a discharge outlet closure having a closure surface and pivotally mounted externally of the passage for pivotal to and for movement towards and away from the furnace wall means between a first position. The closure surface engages the passage wall at the outer end to fully close the discharge outlet, and a second position spaced apart from the passage wall.

  13. The Design of Grids in Web Surveys

    PubMed Central

    Couper, Mick P.; Tourangeau, Roger; Conrad, Frederick G.; Zhang, Chan

    2014-01-01

    Grid or matrix questions are associated with a number of problems in Web surveys. In this paper, we present results from two experiments testing the design of grid questions to reduce breakoffs, missing data, and satisficing. The first examines dynamic elements to help guide respondent through the grid, and on splitting a larger grid into component pieces. The second manipulates the visual complexity of the grid and on simplifying the grid. We find that using dynamic feedback to guide respondents through a multi-question grid helps reduce missing data. Splitting the grids into component questions further reduces missing data and motivated underreporting. The visual complexity of the grid appeared to have little effect on performance. PMID:25258472

  14. The Design of Grids in Web Surveys.

    PubMed

    Couper, Mick P; Tourangeau, Roger; Conrad, Frederick G; Zhang, Chan

    2013-06-01

    Grid or matrix questions are associated with a number of problems in Web surveys. In this paper, we present results from two experiments testing the design of grid questions to reduce breakoffs, missing data, and satisficing. The first examines dynamic elements to help guide respondent through the grid, and on splitting a larger grid into component pieces. The second manipulates the visual complexity of the grid and on simplifying the grid. We find that using dynamic feedback to guide respondents through a multi-question grid helps reduce missing data. Splitting the grids into component questions further reduces missing data and motivated underreporting. The visual complexity of the grid appeared to have little effect on performance.

  15. Interactive solution-adaptive grid generation

    NASA Technical Reports Server (NTRS)

    Choo, Yung K.; Henderson, Todd L.

    1992-01-01

    TURBO-AD is an interactive solution-adaptive grid generation program under development. The program combines an interactive algebraic grid generation technique and a solution-adaptive grid generation technique into a single interactive solution-adaptive grid generation package. The control point form uses a sparse collection of control points to algebraically generate a field grid. This technique provides local grid control capability and is well suited to interactive work due to its speed and efficiency. A mapping from the physical domain to a parametric domain was used to improve difficulties that had been encountered near outwardly concave boundaries in the control point technique. Therefore, all grid modifications are performed on a unit square in the parametric domain, and the new adapted grid in the parametric domain is then mapped back to the physical domain. The grid adaptation is achieved by first adapting the control points to a numerical solution in the parametric domain using control sources obtained from flow properties. Then a new modified grid is generated from the adapted control net. This solution-adaptive grid generation process is efficient because the number of control points is much less than the number of grid points and the generation of a new grid from the adapted control net is an efficient algebraic process. TURBO-AD provides the user with both local and global grid controls.

  16. TBGG- INTERACTIVE ALGEBRAIC GRID GENERATION

    NASA Technical Reports Server (NTRS)

    Smith, R. E.

    1994-01-01

    TBGG, Two-Boundary Grid Generation, applies an interactive algebraic grid generation technique in two dimensions. The program incorporates mathematical equations that relate the computational domain to the physical domain. TBGG has application to a variety of problems using finite difference techniques, such as computational fluid dynamics. Examples include the creation of a C-type grid about an airfoil and a nozzle configuration in which no left or right boundaries are specified. The underlying two-boundary technique of grid generation is based on Hermite cubic interpolation between two fixed, nonintersecting boundaries. The boundaries are defined by two ordered sets of points, referred to as the top and bottom. Left and right side boundaries may also be specified, and call upon linear blending functions to conform interior interpolation to the side boundaries. Spacing between physical grid coordinates is determined as a function of boundary data and uniformly spaced computational coordinates. Control functions relating computational coordinates to parametric intermediate variables that affect the distance between grid points are embedded in the interpolation formulas. A versatile control function technique with smooth cubic spline functions is also presented. The TBGG program is written in FORTRAN 77. It works best in an interactive graphics environment where computational displays and user responses are quickly exchanged. The program has been implemented on a CDC Cyber 170 series computer using NOS 2.4 operating system, with a central memory requirement of 151,700 (octal) 60 bit words. TBGG requires a Tektronix 4015 terminal and the DI-3000 Graphics Library of Precision Visuals, Inc. TBGG was developed in 1986.

  17. Does horizontal transmission invalidate cultural phylogenies?

    PubMed Central

    Greenhill, Simon J.; Currie, Thomas E.; Gray, Russell D.

    2009-01-01

    Phylogenetic methods have recently been applied to studies of cultural evolution. However, it has been claimed that the large amount of horizontal transmission that sometimes occurs between cultural groups invalidates the use of these methods. Here, we use a natural model of linguistic evolution to simulate borrowing between languages. The results show that tree topologies constructed with Bayesian phylogenetic methods are robust to realistic levels of borrowing. Inferences about divergence dates are slightly less robust and show a tendency to underestimate dates. Our results demonstrate that realistic levels of reticulation between cultures do not invalidate a phylogenetic approach to cultural and linguistic evolution. PMID:19324763

  18. In situ bioremediation using horizontal wells

    SciTech Connect

    1995-04-01

    In Situ Bioremediation (ISB), which is the term used in this report for Gaseous Nutrient Injection for In Situ Bioremediation, remediates soils and ground water contaminated with volatile organic compounds (VOCs) both above and below the water table. ISB involves injection of air and nutrients (sparging and biostimulation) into the ground water and vacuum extraction to remove .VOCs from the vadose zone concomitant with biodegradation of VOCs. The innovation is in the combination of 3 emerging technologies, air stripping, horizontal wells, and bioremediation via gaseous nutrient injection with a baseline technology, soil vapor extraction, to produce a more efficient in situ remediation system.

  19. Impulse absorption by horizontal magnetic granular chain

    NASA Astrophysics Data System (ADS)

    Leng, Dingxin; Wang, Xiaojie; Liu, Guijie; Sun, Lingyu

    2016-02-01

    The granular medium is known as a protecting material for shock mitigation. We study the impulse absorption of an alignment of magnetic spheres placed horizontally under a non-uniform magnetic field. The phenomenon of the wave dispersion is presented. This system can absorb 85% ˜ 95% (88% ˜ 98%) of the incident peak force (energy) under the applied magnetic field strength in 0.1 T ˜ 1.0 T. The shock attenuation capacities are enhanced by the increment of field strength. With an intelligent control system, it is conceivable that the magnetic granular chain may offer possibilities in developing adaptive shock protectors.

  20. Does horizontal transmission invalidate cultural phylogenies?

    PubMed

    Greenhill, Simon J; Currie, Thomas E; Gray, Russell D

    2009-06-22

    Phylogenetic methods have recently been applied to studies of cultural evolution. However, it has been claimed that the large amount of horizontal transmission that sometimes occurs between cultural groups invalidates the use of these methods. Here, we use a natural model of linguistic evolution to simulate borrowing between languages. The results show that tree topologies constructed with Bayesian phylogenetic methods are robust to realistic levels of borrowing. Inferences about divergence dates are slightly less robust and show a tendency to underestimate dates. Our results demonstrate that realistic levels of reticulation between cultures do not invalidate a phylogenetic approach to cultural and linguistic evolution.

  1. Horizontal stability of a bouncing ball

    NASA Astrophysics Data System (ADS)

    McBennett, Brendan G.; Harris, Daniel M.

    2016-09-01

    We present an investigation of a partially elastic ball bouncing on a vertically vibrated concave parabolic surface in two dimensions. In particular, we demonstrate that simple vertical motion, wherein the ball bounces periodically at the parabola's vertex, is unstable to horizontal perturbations when the parabolic coefficient defining the surface shape exceeds a critical value. The result is a new periodic solution where the ball bounces laterally over the vertex. As the parabola is further steepened, this new solution also becomes unstable which gives rise to other complex periodic and chaotic bouncing states, all characterized by persistent lateral motion.

  2. Convectively cooled electrical grid structure

    DOEpatents

    Paterson, James A.; Koehler, Gary W.

    1982-01-01

    Undesirable distortions of electrical grid conductors (12) from thermal cycling are minimized and related problems such as unwanted thermionic emission and structural failure from overheating are avoided by providing for a flow of fluid coolant within each conductor (12). The conductors (12) are secured at each end to separate flexible support elements (16) which accommodate to individual longitudinal expansion and contraction of each conductor (12) while resisting lateral displacements, the coolant flow preferably being directed into and out of each conductor through passages (48) in the flexible support elements (16). The grid (11) may have a modular or divided construction which facilitates manufacture and repairs.

  3. Convectively cooled electrical grid structure

    DOEpatents

    Paterson, J.A.; Koehler, G.W.

    1980-11-10

    Undesirable distortions of electrical grid conductors from thermal cycling are minimized and related problems such as unwanted thermionic emission and structural failure from overheating are avoided by providing for a flow of fluid coolant within each conductor. The conductors are secured at each end to separate flexible support elements which accommodate to individual longitudinal expansion and contraction of each conductor while resisting lateral displacements, the coolant flow preferably being directed into and out of each conductor through passages in the flexible support elements. The grid may have a modular or divided construction which facilitates manufacture and repairs.

  4. Scientific Computing on the Grid

    SciTech Connect

    Allen, Gabrielle; Seidel, Edward; Shalf, John

    2001-12-12

    Computer simulations are becoming increasingly important as the only means for studying and interpreting the complex processes of nature. Yet the scope and accuracy of these simulations are severely limited by available computational power, even using today's most powerful supercomputers. As we endeavor to simulate the true complexity of nature, we will require much larger scale calculations than are possible at present. Such dynamic and large scale applications will require computational grids and grids require development of new latency tolerant algorithms, and sophisticated code frameworks like Cactus to carry out more complex and high fidelity simulations with a massive degree of parallelism.

  5. GENI: Grid Hardware and Software

    SciTech Connect

    2012-01-09

    GENI Project: The 15 projects in ARPA-E’s GENI program, short for “Green Electricity Network Integration,” aim to modernize the way electricity is transmitted in the U.S. through advances in hardware and software for the electric grid. These advances will improve the efficiency and reliability of electricity transmission, increase the amount of renewable energy the grid can utilize, and provide energy suppliers and consumers with greater control over their power flows in order to better manage peak power demand and cost.

  6. DARHT Radiographic Grid Scale Correction

    SciTech Connect

    Warthen, Barry J.

    2015-02-13

    Recently it became apparent that the radiographic grid which has been used to calibrate the dimensional scale of DARHT radiographs was not centered at the location where the objects have been centered. This offset produced an error of 0.188% in the dimensional scaling of the radiographic images processed using the assumption that the grid and objects had the same center. This paper will show the derivation of the scaling correction, explain how new radiographs are being processed to account for the difference in location, and provide the details of how to correct radiographic image processed with the erroneous scale factor.

  7. Grid for Earth Science Applications

    NASA Astrophysics Data System (ADS)

    Petitdidier, Monique; Schwichtenberg, Horst

    2013-04-01

    The civil society at large has addressed to the Earth Science community many strong requirements related in particular to natural and industrial risks, climate changes, new energies. The main critical point is that on one hand the civil society and all public ask for certainties i.e. precise values with small error range as it concerns prediction at short, medium and long term in all domains; on the other hand Science can mainly answer only in terms of probability of occurrence. To improve the answer or/and decrease the uncertainties, (1) new observational networks have been deployed in order to have a better geographical coverage and more accurate measurements have been carried out in key locations and aboard satellites. Following the OECD recommendations on the openness of research and public sector data, more and more data are available for Academic organisation and SMEs; (2) New algorithms and methodologies have been developed to face the huge data processing and assimilation into simulations using new technologies and compute resources. Finally, our total knowledge about the complex Earth system is contained in models and measurements, how we put them together has to be managed cleverly. The technical challenge is to put together databases and computing resources to answer the ES challenges. However all the applications are very intensive computing. Different compute solutions are available and depend on the characteristics of the applications. One of them is Grid especially efficient for independent or embarrassingly parallel jobs related to statistical and parametric studies. Numerous applications in atmospheric chemistry, meteorology, seismology, hydrology, pollution, climate and biodiversity have been deployed successfully on Grid. In order to fulfill requirements of risk management, several prototype applications have been deployed using OGC (Open geospatial Consortium) components with Grid middleware. The Grid has permitted via a huge number of runs to

  8. Grid Collector: Facilitating Efficient Selective Access from DataGrids

    SciTech Connect

    Wu, Kesheng; Gu, Junmin; Lauret, Jerome; Poskanzer, Arthur M.; Shoshani, Arie; Sim, Alexander; Zhang, Wei-Ming

    2005-05-17

    The Grid Collector is a system that facilitates the effective analysis and spontaneous exploration of scientific data. It combines an efficient indexing technology with a Grid file management technology to speed up common analysis jobs on high-energy physics data and to enable some previously impractical analysis jobs. To analyze a set of high-energy collision events, one typically specifies the files containing the events of interest, reads all the events in the files, and filters out unwanted ones. Since most analysis jobs filter out significant number of events, a considerable amount of time is wasted by reading the unwanted events. The Grid Collector removes this inefficiency by allowing users to specify more precisely what events are of interest and to read only the selected events. This speeds up most analysis jobs. In existing analysis frameworks, the responsibility of bringing files from tertiary storages or remote sites to local disks falls on the users. This forces most of analysis jobs to be performed at centralized computer facilities where commonly used files are kept on large shared file systems. The Grid Collector automates file management tasks and eliminates the labor-intensive manual file transfers. This makes it much easier to perform analyses that require data files on tertiary storages and remote sites. It also makes more computer resources available for analysis jobs since they are no longer bound to the centralized facilities.

  9. Effect of a horizontal plane boundary on a falling horizontal cylinder at low Reynolds number

    NASA Astrophysics Data System (ADS)

    Chen, Y.-J.; Hussey, R. G.

    1980-05-01

    Experimental results are presented for the change in velocity of a slender cylinder with its axis horizontal as it falls through a viscous fluid toward a horizontal plane boundary. When the boundary influence is strong, the deceleration of the cylinder is observed to be constant, and the velocity extrapolates to zero at the boundary. When the relative change in velocity is small (less than 20%), it is observed to depend inversely on the square of the distance from the boundary. The Reynolds number based on cylinder diameter ranges from 2.9 to 0.015 and the Reynolds number based on cylinder length ranges from 122 to 0.16.

  10. Generation of Large-Scale Winds in Horizontally Anisotropic Convection.

    PubMed

    von Hardenberg, J; Goluskin, D; Provenzale, A; Spiegel, E A

    2015-09-25

    We simulate three-dimensional, horizontally periodic Rayleigh-Bénard convection, confined between free-slip horizontal plates and rotating about a distant horizontal axis. When both the temperature difference between the plates and the rotation rate are sufficiently large, a strong horizontal wind is generated that is perpendicular to both the rotation vector and the gravity vector. The wind is turbulent, large-scale, and vertically sheared. Horizontal anisotropy, engendered here by rotation, appears necessary for such wind generation. Most of the kinetic energy of the flow resides in the wind, and the vertical turbulent heat flux is much lower on average than when there is no wind. PMID:26451558

  11. Tuned grid generation with ICEM CFD

    NASA Technical Reports Server (NTRS)

    Wulf, Armin; Akdag, Vedat

    1995-01-01

    ICEM CFD is a CAD based grid generation package that supports multiblock structured, unstructured tetrahedral and unstructured hexahedral grids. Major development efforts have been spent to extend ICEM CFD's multiblock structured and hexahedral unstructured grid generation capabilities. The modules added are: a parametric grid generation module and a semi-automatic hexahedral grid generation module. A fully automatic version of the hexahedral grid generation module for around a set of predefined objects in rectilinear enclosures has been developed. These modules will be presented and the procedures used will be described, and examples will be discussed.

  12. Horizontal flows concurrent with an X2.2 flare in the active region NOAA 11158

    NASA Astrophysics Data System (ADS)

    Beauregard, L.; Verma, M.; Denker, C.

    2012-02-01

    Horizontal proper motions were measured with local correlation tracking (LCT) techniques in active region NOAA 11158 on 2011 February 15 at a time when a major (X2.2) solar flare occurred. The measurements are based on continuum images and magnetograms of the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. The observed shear flows along the polarity inversion line were rather weak (a few 100 m s-1). The counter-streaming region shifted toward the north after the flare. A small circular area with flow speeds of up to 1.2 km s-1 appeared after the flare near a region of rapid penumbral decay. The LCT signal in this region was provided by small-scale photospheric brigthenings, which were associated with fast traveling moving magnetic features. Umbral strengthening and rapid penumbral decay was observed after the flare. Both phenomena were closely tied to kernels of white-light flare emission. The white-light flare only lasted for about 15 min and peaked 4 min earlier than the X-ray flux. In comparison to other major flares, the X2.2 flare in active region NOAA 11158 only produced diminutive photospheric signatures.

  13. Horizontal coherence in the NPAL experiment

    NASA Astrophysics Data System (ADS)

    Vera, Michael; Dzieciuch, Matthew

    2001-05-01

    Acoustic transmissions from a broadband source near Kauai with a center frequency of 75 Hz were recorded on a two-dimensional receiver array at a range of 3900 km as part of the North Pacific Acoustic Laboratory (NPAL) experiment. The receiver array consisted of five vertical line arrays (VLAs), with separations transverse to the propagation path ranging from a few hundred meters to a few kilometers. The coherences derived from the data have been compared to two different numerical predictions based on sound-speed perturbations due to internal waves. An approximation to the acoustic path integral yields a prediction for the length scale of horizontal coherence. Parabolic-equation simulations of propagation from the source to each VLA through multiple realizations of a random internal-wave field provide another estimate of the coherence at each horizontal separation. [Work supported by ONR.] a)J. A. Colosi, B. D. Cornuelle, B. D. Dushaw, M. A. Dzieciuch, B. M. Howe, J. A. Mercer, R. C. Spindel, and P. F. Worcester.

  14. Reservoir visualization for geosteering of horizontal wells

    SciTech Connect

    Bryant, I.D.; Baygun, B.; Frass, M.; Casco, R.

    1996-08-01

    Horizontal infill wells in the Lower Lagunillas reservoir of Bloque IV, Lake Maracaibo are being drilled in thin, oil-bearing zones that have been bypassed by gas. Steering the horizontal sections of these wells requires high resolution reservoir models that can be updated during drilling. An example from well VLD-1152 serves to illustrate how these models are generated and used. Resistivity images collected by wireline and logging-while-drilling (LWD) tools in the pilot well formed the basis of prejob, high resolution modeling of the formation properties. 3-D seismic data and data from an offset vertical seismic profile collected in the pilot well provided the structural model. During drilling information from cuttings and LWD tools was used to continuously update these models. After the well had been drilled, analysis of LWD resistivity images provided a detailed model of the relationship between the well trajectory and the dip of the formation. This information is used to improve interpretation of the LWD logs to provide a petrophysical evaluation of the well.

  15. Horizontal Air Bearing Experiment Number 1

    SciTech Connect

    Clauson, T.L.

    1999-08-31

    The Horizontal Air Bearing Experiment No.1 is a series of tests intended to further the understanding of rotational dynamics. A simple experimental assembly is rotated using the Horizontal Air Bearing and allowed to spin freely as the internal rotational damping is measured. The low friction of the bearing effectively isolates the test assembly, allowing the internal damping of the test object to be evaluated. The experimental assembly is composed of an aluminum ball within a spherical cavity. A flanged pipe section and an auxiliary adapter plate secure the assembly to the Air Bearing interface plate. Three aluminum balls are interchanged to vary test parameters. The aluminum balls are free to move independently as the entire assembly rotates. The aluminum balls vary in diameter and/or surface finish. While the diameter and surface finish is varied, the space between the ball and socket is dry. To examine the effect of viscosity, the space is filled with a lubricant while the ball diameter and surface finish is held constant.

  16. FermiGrid - experience and future plans

    SciTech Connect

    Chadwick, K.; Berman, E.; Canal, P.; Hesselroth, T.; Garzoglio, G.; Levshina, T.; Sergeev, V.; Sfiligoi, I.; Timm, S.; Yocum, D.; /Fermilab

    2007-09-01

    Fermilab supports a scientific program that includes experiments and scientists located across the globe. In order to better serve this community, Fermilab has placed its production computer resources in a Campus Grid infrastructure called 'FermiGrid'. The FermiGrid infrastructure allows the large experiments at Fermilab to have priority access to their own resources, enables sharing of these resources in an opportunistic fashion, and movement of work (jobs, data) between the Campus Grid and National Grids such as Open Science Grid and the WLCG. FermiGrid resources support multiple Virtual Organizations (VOs), including VOs from the Open Science Grid (OSG), EGEE and the Worldwide LHC Computing Grid Collaboration (WLCG). Fermilab also makes leading contributions to the Open Science Grid in the areas of accounting, batch computing, grid security, job management, resource selection, site infrastructure, storage management, and VO services. Through the FermiGrid interfaces, authenticated and authorized VOs and individuals may access our core grid services, the 10,000+ Fermilab resident CPUs, near-petabyte (including CMS) online disk pools and the multi-petabyte Fermilab Mass Storage System. These core grid services include a site wide Globus gatekeeper, VO management services for several VOs, Fermilab site authorization services, grid user mapping services, as well as job accounting and monitoring, resource selection and data movement services. Access to these services is via standard and well-supported grid interfaces. We will report on the user experience of using the FermiGrid campus infrastructure interfaced to a national cyberinfrastructure--the successes and the problems.

  17. Grid Logging: Best Practices Guide

    SciTech Connect

    Tierney, Brian L; Tierney, Brian L; Gunter, Dan

    2008-04-01

    The purpose of this document is to help developers of Grid middleware and application software generate log files that will be useful to Grid administrators, users, developers and Grid middleware itself. Currently, most of the currently generated log files are only useful to the author of the program. Good logging practices are instrumental to performance analysis, problem diagnosis, and security auditing tasks such as incident tracing and damage assessment. This document does not discuss the issue of a logging API. It is assumed that a standard log API such as syslog (C), log4j (Java), or logger (Python) is being used. Other custom logging API or even printf could be used. The key point is that the logs must contain the required information in the required format. At a high level of abstraction, the best practices for Grid logging are: (1) Consistently structured, typed, log events; (2) A standard high-resolution timestamp; (3) Use of logging levels and categories to separate logs by detail and purpose; (4) Consistent use of global and local identifiers; and (5) Use of some regular, newline-delimited ASCII text format. The rest of this document describes each of these recommendations in detail.

  18. Grid-coordinate generation program

    USGS Publications Warehouse

    Cosner, Oliver J.; Horwich, Esther

    1974-01-01

    This program description of the grid-coordinate generation program is written for computer users who are familiar with digital aquifer models. The program computes the coordinates for a variable grid -used in the 'Pinder Model' (a finite-difference aquifer simulator), for input to the CalComp GPCP (general purpose contouring program). The program adjusts the y-value by a user-supplied constant in order to transpose the origin of the model grid from the upper left-hand corner to the lower left-hand corner of the grid. The user has the options of, (1.) choosing the boundaries of the plot; (2.) adjusting the z-values (altitudes) by a constant; (3.) deleting superfluous z-values and (4.) subtracting the simulated surfaces from each other to obtain the decline. Output of this program includes the fixed format CNTL data cards and the other data cards required for input to GPCP. The output from GPCP then is used to produce a potentiometric map or a decline map by means of the CalComp plotter.

  19. Smart Grid Communications System Blueprint

    NASA Astrophysics Data System (ADS)

    Clark, Adrian; Pavlovski, Chris

    2010-10-01

    Telecommunications operators are well versed in deploying 2G and 3G wireless networks. These networks presently support the mobile business user and/or retail consumer wishing to place conventional voice calls and data connections. The electrical power industry has recently commenced transformation of its distribution networks by deploying smart monitoring and control devices throughout their networks. This evolution of the network into a `smart grid' has also motivated the need to deploy wireless technologies that bridge the communication gap between the smart devices and information technology systems. The requirements of these networks differ from traditional wireless networks that communications operators have deployed, which have thus far forced energy companies to consider deploying their own wireless networks. We present our experience in deploying wireless networks to support the smart grid and highlight the key properties of these networks. These characteristics include application awareness, support for large numbers of simultaneous cell connections, high service coverage and prioritized routing of data. We also outline our target blueprint architecture that may be useful to the industry in building wireless and fixed networks to support the smart grid. By observing our experiences, telecommunications operators and equipment manufacturers will be able to augment their current networks and products in a way that accommodates the needs of the emerging industry of smart grids and intelligent electrical networks.

  20. Ground Boundary Conditions for Thermal Convection Over Horizontal Surfaces at High Rayleigh Numbers

    NASA Astrophysics Data System (ADS)

    Hanjalić, K.; Hrebtov, M.

    2016-07-01

    We present "wall functions" for treating the ground boundary conditions in the computation of thermal convection over horizontal surfaces at high Rayleigh numbers using coarse numerical grids. The functions are formulated for an algebraic-flux model closed by transport equations for the turbulence kinetic energy, its dissipation rate and scalar variance, but could also be applied to other turbulence models. The three-equation algebraic-flux model, solved in a T-RANS mode ("Transient" Reynolds-averaged Navier-Stokes, based on triple decomposition), was shown earlier to reproduce well a number of generic buoyancy-driven flows over heated surfaces, albeit by integrating equations up to the wall. Here we show that by using a set of wall functions satisfactory results are found for the ensemble-averaged properties even on a very coarse computational grid. This is illustrated by the computations of the time evolution of a penetrative mixed layer and Rayleigh-Bénard (open-ended, 4:4:1 domain) convection, using 10 × 10 × 100 and 10 × 10 × 20 grids, compared also with finer grids (e.g. 60 × 60 × 100), as well as with one-dimensional treatment using 1 × 1 × 100 and 1 × 1 × 20 nodes. The approach is deemed functional for simulations of a convective boundary layer and mesoscale atmospheric flows, and pollutant transport over realistic complex hilly terrain with heat islands, urban and natural canopies, for diurnal cycles, or subjected to other time and space variations in ground conditions and stratification.

  1. Improving Horizontal Resolution of High-frequency Surface-wave Methods Using Travel-time Tomography

    NASA Astrophysics Data System (ADS)

    Yin, X.; Xia, J.; Sun, S.; Shen, C.

    2015-12-01

    In surface-wave methods, horizontal resolution can be defined as the ability to distinguish anomalous objects that are laterally displaced from each other. And the horizontal length of a recognizable geological anomalous body is measured by the lateral variation of S-wave velocity. Multichannel analysis of surface waves (MASW) method is an efficient tool to determine near-surface shear-wave velocities. The acquisition of the MASW method involves the same source-receiver configuration moved successively by a fixed distance interval (a few to several stations) along a linear survey line, which is called a roll-along acquisition geometry. A pseudo-2D S-wave velocity section is constructed by aligning 1D models, and each inverted 1D S-wave velocity model reflects the vertical S-wave velocity variation at the midpoint of each geophone spread. Although the MASW method can improve the horizontal resolution of S-wave velocity sections to some degree, the amount of fieldwork is increased by the roll-along acquisition geometry. We propose surface-wave tomography method to investigate horizontal resolution of surface-wave exploration. Phase-velocity dispersion curves are calculated by a pair of traces within a multichannel record through cross-correlation combined with a phase-shift scanning method. Then with the utilization of travel-time tomography, we can obtain high resolution pure-path dispersion curves with diverse sizes of grids at different frequencies. Finally, the pseudo-2D S-wave velocity structure is reconstructed by inverting the pure-path dispersion curves. Travel-time tomography of surface waves can extract accurate dispersion curves from a record with a short receiver spacing, and it can effectively enhance the ability of random noise immunity. Synthetic tests and a real-world example have indicated that travel-time tomography has a great potential for improving the horizontal resolution of surface waves. Keywords: Travel-time tomography of surface waves

  2. Optimizing Grid Patterns on Photovoltaic Cells

    NASA Technical Reports Server (NTRS)

    Burger, D. R.

    1984-01-01

    CELCAL computer program helps in optimizing grid patterns for different photovoltaic cell geometries and metalization processes. Five different powerloss phenomena associated with front-surface metal grid pattern on photovoltaic cells.

  3. Additional Security Considerations for Grid Management

    NASA Technical Reports Server (NTRS)

    Eidson, Thomas M.

    2003-01-01

    The use of Grid computing environments is growing in popularity. A Grid computing environment is primarily a wide area network that encompasses multiple local area networks, where some of the local area networks are managed by different organizations. A Grid computing environment also includes common interfaces for distributed computing software so that the heterogeneous set of machines that make up the Grid can be used more easily. The other key feature of a Grid is that the distributed computing software includes appropriate security technology. The focus of most Grid software is on the security involved with application execution, file transfers, and other remote computing procedures. However, there are other important security issues related to the management of a Grid and the users who use that Grid. This note discusses these additional security issues and makes several suggestions as how they can be managed.

  4. Spaceflight Operations Services Grid (SOSG)

    NASA Technical Reports Server (NTRS)

    Bradford, Robert N.; Thigpen, William W.

    2004-01-01

    In an effort to adapt existing space flight operations services to new emerging Grid technologies we are developing a Grid-based prototype space flight operations Grid. This prototype is based on the operational services being provided to the International Space Station's Payload operations located at the Marshall Space Flight Center, Alabama. The prototype services will be Grid or Web enabled and provided to four user communities through portal technology. Users will have the opportunity to assess the value and feasibility of Grid technologies to their specific areas or disciplines. In this presentation descriptions of the prototype development, User-based services, Grid-based services and status of the project will be presented. Expected benefits, findings and observations (if any) to date will also be discussed. The focus of the presentation will be on the project in general, status to date and future plans. The End-use services to be included in the prototype are voice, video, telemetry, commanding, collaboration tools and visualization among others. Security is addressed throughout the project and is being designed into the Grid technologies and standards development. The project is divided into three phases. Phase One establishes the baseline User-based services required for space flight operations listed above. Phase Two involves applying Gridlweb technologies to the User-based services and development of portals for access by users. Phase Three will allow NASA and end users to evaluate the services and determine the future of the technology as applied to space flight operational services. Although, Phase One, which includes the development of the quasi-operational User-based services of the prototype, development will be completed by March 2004, the application of Grid technologies to these services will have just begun. We will provide status of the Grid technologies to the individual User-based services. This effort will result in an extensible

  5. Spaceflight Operations Services Grid (SOSG)

    NASA Technical Reports Server (NTRS)

    Bradford, Robert N.; Thigpen, William W.

    2004-01-01

    In an effort to adapt existing space flight operations services to new emerging Grid technologies we are developing a Grid-based prototype space flight operations Grid. This prototype is based on the operational services being provided to the International Space Station's Payload operations located at the Marshall Space Flight Center, Alabama. The prototype services will be Grid or Web enabled and provided to four user communities through portal technology. Users will have the opportunity to assess the value and feasibility of Grid technologies to their specific areas or disciplines. In this presentation descriptions of the prototype development, User-based services, Grid-based services and status of the project will be presented. Expected benefits, findings and observations (if any) to date will also be discussed. The focus of the presentation will be on the project in general, status to date and future plans. The End-use services to be included in the prototype are voice, video, telemetry, commanding, collaboration tools and visualization among others. Security is addressed throughout the project and is being designed into the Grid technologies and standards development. The project is divided into three phases. Phase One establishes the baseline User-based services required for space flight operations listed above. Phase Two involves applying Gridlweb technologies to the User-based services and development of portals for access by users. Phase Three will allow NASA and end users to evaluate the services and determine the future of the technology as applied to space flight operational services. Although, Phase One, which includes the development of the quasi-operational User-based services of the prototype, development will be completed by March 2004, the application of Grid technologies to these services will have just begun. We will provide status of the Grid technologies to the individual User-based services. This effort will result in an extensible

  6. Estimating the horizontal and vertical direction-of-arrival of water-borne seismic signals in the northern Philippine Sea.

    PubMed

    Freeman, Simon E; D'Spain, Gerald L; Lynch, Stephen D; Stephen, Ralph A; Heaney, Kevin D; Murray, James J; Baggeroer, Arthur B; Worcester, Peter F; Dzieciuch, Matthew A; Mercer, James A

    2013-10-01

    Conventional and adaptive plane-wave beamforming with simultaneous recordings by large-aperture horizontal and vertical line arrays during the 2009 Philippine Sea Engineering Test (PhilSea09) reveal the rate of occurrence and the two-dimensional arrival structure of seismic phases that couple into the deep ocean. A ship-deployed, controlled acoustic source was used to evaluate performance of the horizontal array for a range of beamformer adaptiveness levels. Ninety T-phases from unique azimuths were recorded between Yeardays 107 to 119. T-phase azimuth and S-minus-P-phase time-of-arrival range estimates were validated using United States Geological Survey seismic monitoring network data. Analysis of phases from a seismic event that occurred on Yearday 112 near the east coast of Taiwan approximately 450 km from the arrays revealed a 22° clockwise evolution of T-phase azimuth over 90 s. Two hypotheses to explain such evolution-body wave excitation of multiple sources or in-water scattering-are presented based on T-phase origin sites at the intersection of azimuthal great circle paths and ridge/coastal bathymetry. Propagation timing between the source, scattering region, and array position suggests the mechanism behind the evolution involved scattering of the T-phase from the Ryukyu Ridge and a T-phase formation/scattering location estimation error of approximately 3.2 km. PMID:24116523

  7. Estimating the horizontal and vertical direction-of-arrival of water-borne seismic signals in the northern Philippine Sea.

    PubMed

    Freeman, Simon E; D'Spain, Gerald L; Lynch, Stephen D; Stephen, Ralph A; Heaney, Kevin D; Murray, James J; Baggeroer, Arthur B; Worcester, Peter F; Dzieciuch, Matthew A; Mercer, James A

    2013-10-01

    Conventional and adaptive plane-wave beamforming with simultaneous recordings by large-aperture horizontal and vertical line arrays during the 2009 Philippine Sea Engineering Test (PhilSea09) reveal the rate of occurrence and the two-dimensional arrival structure of seismic phases that couple into the deep ocean. A ship-deployed, controlled acoustic source was used to evaluate performance of the horizontal array for a range of beamformer adaptiveness levels. Ninety T-phases from unique azimuths were recorded between Yeardays 107 to 119. T-phase azimuth and S-minus-P-phase time-of-arrival range estimates were validated using United States Geological Survey seismic monitoring network data. Analysis of phases from a seismic event that occurred on Yearday 112 near the east coast of Taiwan approximately 450 km from the arrays revealed a 22° clockwise evolution of T-phase azimuth over 90 s. Two hypotheses to explain such evolution-body wave excitation of multiple sources or in-water scattering-are presented based on T-phase origin sites at the intersection of azimuthal great circle paths and ridge/coastal bathymetry. Propagation timing between the source, scattering region, and array position suggests the mechanism behind the evolution involved scattering of the T-phase from the Ryukyu Ridge and a T-phase formation/scattering location estimation error of approximately 3.2 km.

  8. Probabilistic Learning by Rodent Grid Cells

    PubMed Central

    Cheung, Allen

    2016-01-01

    Mounting evidence shows mammalian brains are probabilistic computers, but the specific cells involved remain elusive. Parallel research suggests that grid cells of the mammalian hippocampal formation are fundamental to spatial cognition but their diverse response properties still defy explanation. No plausible model exists which explains stable grids in darkness for twenty minutes or longer, despite being one of the first results ever published on grid cells. Similarly, no current explanation can tie together grid fragmentation and grid rescaling, which show very different forms of flexibility in grid responses when the environment is varied. Other properties such as attractor dynamics and grid anisotropy seem to be at odds with one another unless additional properties are assumed such as a varying velocity gain. Modelling efforts have largely ignored the breadth of response patterns, while also failing to account for the disastrous effects of sensory noise during spatial learning and recall, especially in darkness. Here, published electrophysiological evidence from a range of experiments are reinterpreted using a novel probabilistic learning model, which shows that grid cell responses are accurately predicted by a probabilistic learning process. Diverse response properties of probabilistic grid cells are statistically indistinguishable from rat grid cells across key manipulations. A simple coherent set of probabilistic computations explains stable grid fields in darkness, partial grid rescaling in resized arenas, low-dimensional attractor grid cell dynamics, and grid fragmentation in hairpin mazes. The same computations also reconcile oscillatory dynamics at the single cell level with attractor dynamics at the cell ensemble level. Additionally, a clear functional role for boundary cells is proposed for spatial learning. These findings provide a parsimonious and unified explanation of grid cell function, and implicate grid cells as an accessible neuronal population

  9. Best Practices In Overset Grid Generation

    NASA Technical Reports Server (NTRS)

    Chan, William M.; Gomez, Reynaldo J., III; Rogers, Stuart E.; Buning, Pieter G.; Kwak, Dochan (Technical Monitor)

    2002-01-01

    Grid generation for overset grids on complex geometry can be divided into four main steps: geometry processing, surface grid generation, volume grid generation and domain connectivity. For each of these steps, the procedures currently practiced by experienced users are described. Typical problems encountered are also highlighted and discussed. Most of the guidelines are derived from experience on a variety of problems including space launch and return vehicles, subsonic transports with propulsion and high lift devices, supersonic vehicles, rotorcraft vehicles, and turbomachinery.

  10. Carbon/Carbon Grids For Ion Sources

    NASA Technical Reports Server (NTRS)

    Garner, Charles E.

    1995-01-01

    Ion-extraction grids made of carbon/carbon composites used in spacecraft ion engines and industrial ion sources in place of molybdenum grids. In principle, carbon/carbon grids offer greater extraction efficiency and longer life. Grid fabricated by mechanical drilling, laser drilling, or electrical-discharge machining of array of holes in sheet of carbon/carbon. Advantages; better alignment and slower erosion.

  11. The National Grid Project: A system overview

    NASA Technical Reports Server (NTRS)

    Gaither, Adam; Gaither, Kelly; Jean, Brian; Remotigue, Michael; Whitmire, John; Soni, Bharat; Thompson, Joe; Dannenhoffer,, John; Weatherill, Nigel

    1995-01-01

    The National Grid Project (NGP) is a comprehensive numerical grid generation software system that is being developed at the National Science Foundation (NSF) Engineering Research Center (ERC) for Computational Field Simulation (CFS) at Mississippi State University (MSU). NGP is supported by a coalition of U.S. industries and federal laboratories. The objective of the NGP is to significantly decrease the amount of time it takes to generate a numerical grid for complex geometries and to increase the quality of these grids to enable computational field simulations for applications in industry. A geometric configuration can be discretized into grids (or meshes) that have two fundamental forms: structured and unstructured. Structured grids are formed by intersecting curvilinear coordinate lines and are composed of quadrilateral (2D) and hexahedral (3D) logically rectangular cells. The connectivity of a structured grid provides for trivial identification of neighboring points by incrementing coordinate indices. Unstructured grids are composed of cells of any shape (commonly triangles, quadrilaterals, tetrahedra and hexahedra), but do not have trivial identification of neighbors by incrementing an index. For unstructured grids, a set of points and an associated connectivity table is generated to define unstructured cell shapes and neighboring points. Hybrid grids are a combination of structured grids and unstructured grids. Chimera (overset) grids are intersecting or overlapping structured grids. The NGP system currently provides a user interface that integrates both 2D and 3D structured and unstructured grid generation, a solid modeling topology data management system, an internal Computer Aided Design (CAD) system based on Non-Uniform Rational B-Splines (NURBS), a journaling language, and a grid/solution visualization system.

  12. The State of NASA's Information Power Grid

    NASA Technical Reports Server (NTRS)

    Johnston, William E.; Vaziri, Arsi; Tanner, Leigh Ann; Feiereisen, William J.; Thigpen, William; Biegel, Bryan (Technical Monitor)

    2001-01-01

    This viewgraph presentation transfers the concept of the power grid to information sharing in the NASA community. An information grid of this sort would be characterized as comprising tools, middleware, and services for the facilitation of interoperability, distribution of new technologies, human collaboration, and data management. While a grid would increase the ability of information sharing, it would not necessitate it. The onus of utilizing the grid would rest with the users.

  13. Smart Grid Status and Metrics Report

    SciTech Connect

    Balducci, Patrick J.; Weimar, Mark R.; Kirkham, Harold

    2014-07-01

    To convey progress made in achieving the vision of a smart grid, this report uses a set of six characteristics derived from the National Energy Technology Laboratory Modern Grid Strategy. It measures 21 metrics to provide insight into the grid’s capacity to embody these characteristics. This report looks across a spectrum of smart grid concerns to measure the status of smart grid deployment and impacts.

  14. The fundamentals of adaptive grid movement

    NASA Technical Reports Server (NTRS)

    Eiseman, Peter R.

    1990-01-01

    Basic grid point movement schemes are studied. The schemes are referred to as adaptive grids. Weight functions and equidistribution in one dimension are treated. The specification of coefficients in the linear weight, attraction to a given grid or a curve, and evolutionary forces are considered. Curve by curve and finite volume methods are described. The temporal coupling of partial differential equations solvers and grid generators was discussed.

  15. Horizontal Gene Transfer, Dispersal and Haloarchaeal Speciation

    PubMed Central

    Papke, R. Thane; Corral, Paulina; Ram-Mohan, Nikhil; de la Haba, Rafael R.; Sánchez-Porro, Cristina; Makkay, Andrea; Ventosa, Antonio

    2015-01-01

    The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria. PMID:25997110

  16. Passive magnetic bearing for a horizontal shaft

    DOEpatents

    Post, Richard F.

    2003-12-02

    A passive magnetic bearing is composed of a levitation element and a restorative element. The levitation element is composed of a pair of stationary arcuate ferromagnetic segments located within an annular radial-field magnet array. The magnet array is attached to the inner circumference of a hollow shaft end. An attractive force between the arcuate segments and the magnet array acts vertically to levitate the shaft, and also in a horizontal transverse direction to center the shaft. The restorative element is comprised of an annular Halbach array of magnets and a stationary annular circuit array located within the Halbach array. The Halbach array is attached to the inner circumference of the hollow shaft end. A repulsive force between the Halbach array and the circuit array increases inversely to the radial space between them, and thus acts to restore the shaft to its equilibrium axis of rotation when it is displaced therefrom.

  17. Conjugate natural convection between horizontal eccentric cylinders

    NASA Astrophysics Data System (ADS)

    Nasiri, Davood; Dehghan, Ali Akbar; Hadian, Mohammad Reza

    2016-06-01

    This study involved the numerical investigation of conjugate natural convection between two horizontal eccentric cylinders. Both cylinders were considered to be isothermal with only the inner cylinder having a finite wall thickness. The momentum and energy equations were discretized using finite volume method and solved by employing SIMPLER algorithm. Numerical results were presented for various solid-fluid conductivity ratios (KR) and various values of eccentricities in different thickness of inner cylinder wall and also for different angular positions of inner cylinder. From the results, it was observed that in an eccentric case, and for KR < 10, an increase in thickness of inner cylinder wall resulted in a decrease in the average equivalent conductivity coefficient (overline{{K_{eq} }} ); however, a KR > 10 value caused an increase in overline{{K_{eq} }} . It was also concluded that in any angular position of inner cylinder, the value of overline{{K_{eq} }} increased with increase in the eccentricity.

  18. Horizontal Drop of 21- PWR Waste Package

    SciTech Connect

    A.K. Scheider

    2007-01-31

    The objective of this calculation is to determine the structural response of the waste package (WP) dropped horizontally from a specified height. The WP used for that purpose is the 21-Pressurized Water Reactor (PWR) WP. The scope of this document is limited to reporting the calculation results in-terms of stress intensities. This calculation is associated with the WP design and was performed by the Waste Package Design group in accordance with the ''Technical Work Plan for: Waste Package Design Description for LA'' (Ref. 16). AP-3.12Q, ''Calculations'' (Ref. 1 1) is used to perform the calculation and develop the document. The sketches attached to this calculation provide the potential dimensions and materials for the 21-PWR WP design.

  19. Horizontal Gene Exchange in Environmental Microbiota

    PubMed Central

    Aminov, Rustam I.

    2011-01-01

    Horizontal gene transfer (HGT) plays an important role in the evolution of life on the Earth. This view is supported by numerous occasions of HGT that are recorded in the genomes of all three domains of living organisms. HGT-mediated rapid evolution is especially noticeable among the Bacteria, which demonstrate formidable adaptability in the face of recent environmental changes imposed by human activities, such as the use of antibiotics, industrial contamination, and intensive agriculture. At the heart of the HGT-driven bacterial evolution and adaptation are highly sophisticated natural genetic engineering tools in the form of a variety of mobile genetic elements (MGEs). The main aim of this review is to give a brief account of the occurrence and diversity of MGEs in natural ecosystems and of the environmental factors that may affect MGE-mediated HGT. PMID:21845185

  20. Method for horizontally growing ribbon crystal

    NASA Technical Reports Server (NTRS)

    Kudo, B.

    1980-01-01

    A high speed method for forming ribbon crystal of desired width and thickness is characterized by drawing out the ribbon through a space whose distance is 5.7 times that of the thickness of the grown ribbon. The ribbon is drawn out between the molten body of the lower surface and the tip of the upper surface of the seed crystal and growing crystal. The ribbon growing at the tip of the seed crystal is drawn out horizontally and centrifugally by controlling the amount of cooling and heating. The temperature is maintained about equal to the upper surface of the outlets from which the molten substance is drawn, at least in certain portions of the crucible rim, the rim is elevated to prevent dropping of the molten raw material.

  1. Horizontal gene transfer, dispersal and haloarchaeal speciation.

    PubMed

    Papke, R Thane; Corral, Paulina; Ram-Mohan, Nikhil; Haba, Rafael R de la; Sánchez-Porro, Cristina; Makkay, Andrea; Ventosa, Antonio

    2015-01-01

    The Halobacteria are a well-studied archaeal class and numerous investigations are showing how their diversity is distributed amongst genomes and geographic locations. Evidence indicates that recombination between species continuously facilitates the arrival of new genes, and within species, it is frequent enough to spread acquired genes amongst all individuals in the population. To create permanent independent diversity and generate new species, barriers to recombination are probably required. The data support an interpretation that rates of evolution (e.g., horizontal gene transfer and mutation) are faster at creating geographically localized variation than dispersal and invasion are at homogenizing genetic differences between locations. Therefore, we suggest that recurrent episodes of dispersal followed by variable periods of endemism break the homogenizing forces of intrapopulation recombination and that this process might be the principal stimulus leading to divergence and speciation in Halobacteria. PMID:25997110

  2. Large, horizontal-axis wind turbines

    NASA Technical Reports Server (NTRS)

    Linscott, B. S.; Perkins, P.; Dennett, J. T.

    1984-01-01

    Development of the technology for safe, reliable, environmentally acceptable large wind turbines that have the potential to generate a significant amount of electricity at costs competitive with conventional electric generating systems are presented. In addition, these large wind turbines must be fully compatible with electric utility operations and interface requirements. There are several ongoing large wind system development projects and applied research efforts directed toward meeting the technology requirements for utility applications. Detailed information on these projects is provided. The Mod-O research facility and current applied research effort in aerodynamics, structural dynamics and aeroelasticity, composite and hybrid composite materials, and multiple system interaction are described. A chronology of component research and technology development for large, horizontal axis wind turbines is presented. Wind characteristics, wind turbine economics, and the impact of wind turbines on the environment are reported. The need for continued wind turbine research and technology development is explored. Over 40 references are sited and a bibliography is included.

  3. Horizontal Hostility among Non-Meat Eaters

    PubMed Central

    Rothgerber, Hank

    2014-01-01

    The present study examined intergroup judgments made between four groups of non-meat eaters: health vegetarians; ethical vegetarians; health vegans, and ethical vegans. Consistent with hypotheses based on horizontal hostility and the need to maintain ingroup distinctiveness, ethical vegetarians gave unfavorable evaluations to health vegetarians relative to vegans, especially when the mainstream omnivore group was made salient. Contrary to expectations, vegans gave relatively more favorable evaluations to ethical vegetarians than health vegetarians when mainstream salience was low. This was especially true for vegans who were motivated primarily by ethical concerns. When mainstream salience was high, vegans did not distinguish between the vegetarian subgroups. Results suggest that one’s motives for abstaining from meat often play a larger role in this type of intergroup perceptions than one’s dietary practices. PMID:24809342

  4. Horizontal gene transfer: A critical view

    PubMed Central

    Kurland, C. G.; Canback, B.; Berg, Otto G.

    2003-01-01

    It has been suggested that horizontal gene transfer (HGT) is the “essence of phylogeny.” In contrast, much data suggest that this is an exaggeration resulting in part from a reliance on inadequate methods to identify HGT events. In addition, the assumption that HGT is a ubiquitous influence throughout evolution is questionable. Instead, rampant global HGT is likely to have been relevant only to primitive genomes. In modern organisms we suggest that both the range and frequencies of HGT are constrained most often by selective barriers. As a consequence those HGT events that do occur most often have little influence on genome phylogeny. Although HGT does occur with important evolutionary consequences, classical Darwinian lineages seem to be the dominant mode of evolution for modern organisms. PMID:12902542

  5. Décrypthon grid - grid resources dedicated to neuromuscular disorders.

    PubMed

    Bard, N; Bolze, R; Caron, E; Desprez, F; Heymann, M; Friedrich, A; Moulinier, L; Nguyen, N H; Poch, O; Toursel, T

    2010-01-01

    Thanks to the availability of computational grids and their middleware, a seamless access to computation and storage resources is provided to application developers and scientists. The Décrypthon project is one example of such a high performance platform. In this paper, we present the architecture of the platform, the middleware developed to facilitate access to several servers deployed in France, and the data center for integrating large biological datasets over multiple sites, supported by a new query language and integration of various tools. The SM2PH project represents an example of a biological application that exploits the capacities of the Décrypthon grid. The goal of SM2PH is a better understanding of mutations involved in human monogenic diseases, their impact on the 3D structure of the protein and the subsequent consequences for the pathological phenotypes. PMID:20543432

  6. Multiprocessor computer overset grid method and apparatus

    DOEpatents

    Barnette, Daniel W.; Ober, Curtis C.

    2003-01-01

    A multiprocessor computer overset grid method and apparatus comprises associating points in each overset grid with processors and using mapped interpolation transformations to communicate intermediate values between processors assigned base and target points of the interpolation transformations. The method allows a multiprocessor computer to operate with effective load balance on overset grid applications.

  7. 75 FR 55306 - Smart Grid Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-10

    ... National Institute of Standards and Technology Smart Grid Advisory Committee AGENCY: National Institute of Standards and Technology, Department of Commerce. ACTION: Notice of open meeting. SUMMARY: The Smart Grid... provide an update on NIST's Smart Grid program. The agenda may change to accommodate Committee...

  8. 76 FR 12711 - Smart Grid Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... National Institute of Standards and Technology Smart Grid Advisory Committee AGENCY: National Institute of Standards and Technology, Department of Commerce. ACTION: Notice of open meeting. SUMMARY: The Smart Grid... will be posted on the Smart Grid Web site at http://www.nist.gov/smartgrid . DATES: The SGAC will...

  9. 76 FR 46279 - Smart Grid Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-02

    ... National Institute of Standards and Technology Smart Grid Advisory Committee AGENCY: Department of Commerce, National Institute of Standards and Technology ACTION: Notice of open meeting. SUMMARY: The Smart Grid... should be sent to Office of the National Coordinator for Smart Grid Interoperability, National...

  10. ITIL and Grid services at GridKa

    NASA Astrophysics Data System (ADS)

    Marten, H.; Koenig, T.

    2010-04-01

    The Steinbuch Centre for Computing (SCC) is a new organizational unit of the Karlsruhe Institute of Technology (KIT). Founded in February 2008 as a merger of the previous Institute for Scientific Computing of Forschungszentrum Karlsruhe and the Computing Centre of the Technical University Karlsruhe, SCC provides a broad spectrum of IT services for 8.000 employees and 18.000 students and carries out research and development in key areas of information technology under the same roof. SCC is also known to host the German WLCG [1] Tier-1 centre GridKa. In order to accompany the merging of the two existing computing centres located at a distance of about 10 km and to provide common first class services for science, SCC has selected the IT service management according to the industrial quasi-standard "IT Infrastructure Library (ITIL)" [3] as a strategic element. The paper discusses the implementation of a few ITIL key components from the perspective of a Scientific Computing Centre using examples of Grid services at GridKa.

  11. Sensitivity study of subgrid scale ocean mixing under sea ice using a two-column ocean grid in climate model CESM

    NASA Astrophysics Data System (ADS)

    Jin, Meibing; Hutchings, Jennifer; Kawaguchi, Yusuke

    2015-12-01

    Brine drainage from sea ice formation plays a critical role in ocean mixing and seasonal variations of halocline in polar oceans. The horizontal scale of brine drainage and its induced convection is much smaller than a climate model grid and a model tends to produce false ocean mixing when brine drainage is averaged over a grid cell. A two-column ocean grid (TCOG) scheme was implemented in the Community Earth System Model (CESM) using coupled sea ice-ocean model setting to explicitly solve the different vertical mixing in the two sub-columns of one model grid with and without brine rejection. The fraction of grid with brine rejection was tested to be equal to the lead fraction or a small constant number in a series of sensitivity model runs forced by the same atmospheric data from 1978 to 2009. The model results were compared to observations from 29 ice tethered profilers (ITP) in the Arctic Ocean Basin from 2004 to 2009. Compared with the control run using a regular ocean grid, the TCOG simulations showed consistent reduction of model errors in salinity and mixed layer depth (MLD). The model using a small constant fraction grid for brine rejection was found to produce the best model comparison with observations, indicating that the horizontal scale of the brine drainage is very small compared to the sea ice cover and even smaller than the lead fraction. Comparable to models using brine rejection parameterization schemes, TCOG achieved more improvements in salinity but similar in MLD.

  12. 45 Km Horizontal Path Optical Link Experiment

    NASA Technical Reports Server (NTRS)

    Biswas, A.; Ceniceros, J.; Novak, M.; Jeganathan, M.; Portillo, A.; Erickson, D.; Depew, J.; Sanii, B.; Lesh, J. R.

    2000-01-01

    Mountain-top to mountain-top optical link experiments have been initiated at JPL, in order to perform a systems level evaluation of optical communications. Progress made so far is reported. ne NASA, JPL developed optical communications demonstrator (OCD) is used to transmit a laser signal from Strawberry Peak (SP), located in the San Bernadino mountains of California. This laser beam is received by a 0.6 m aperture telescope at JPL's Table Mountain Facility (TMF), located in Wrightwood, California. The optical link is bi-directional with the TMF telescope transmitting a continuous 4-wave (cw) 780 run beacon and the OCD sending back a 840 nm, 100 - 500 Mbps pseudo noise (PN) modulated, laser beam. The optical link path is at an average altitude of 2 km above sea level, covers a range of 46.8 km and provides an atmospheric channel equivalent to approx. 4 air masses. Average received power measured at either end fall well within the uncertainties predicted by link analysis. The reduction in normalized intensity variance (sigma(sup 2, sub I)) for the 4-beam beacon, compared to each individual beam, at SP, was from approx. 0.68 to 0.22. With some allowance for intra-beam mis-alignment, this is consistent with incoherent averaging. The sigma(sup2, sub I) measured at TMF approx. 0.43 +/- 0.22 exceeded the expected aperture averaged value of less than 0.1, probably because of beam wander. The focused spot sizes of approx. 162 +/- 6 microns at the TMF Coude and approx. 64 +/- 3 microns on the OCD compare to the predicted size range of 52 - 172 microns and 57 - 93 microns, respectively. This is consistent with 4 - 5 arcsec of atmospheric "seeing". The preliminary evaluation of OCD's fine tracking indicates that the uncompensated tracking error is approx. 3.3 micro rad compared to approx. 1.7 micro rad observed in the laboratory. Fine tracking performance was intermittent, primarily due to beacon fades on the OCD tracking sensor. The best bit error rates observed while

  13. An adaptive grid method for computing time accurate solutions on structured grids

    NASA Technical Reports Server (NTRS)

    Bockelie, Michael J.; Smith, Robert E.; Eiseman, Peter R.

    1991-01-01

    The solution method consists of three parts: a grid movement scheme; an unsteady Euler equation solver; and a temporal coupling routine that links the dynamic grid to the Euler solver. The grid movement scheme is an algebraic method containing grid controls that generate a smooth grid that resolves the severe solution gradients and the sharp transitions in the solution gradients. The temporal coupling is performed with a grid prediction correction procedure that is simple to implement and provides a grid that does not lag the solution in time. The adaptive solution method is tested by computing the unsteady inviscid solutions for a one dimensional shock tube and a two dimensional shock vortex iteraction.

  14. Vehicle to Grid Demonstration Project

    SciTech Connect

    Willett Kempton; Meryl Gardner; Michael Hidrue; Fouad Kamilev; Sachin Kamboj; Jon Lilley; Rodney McGee; George Parsons; Nat Pearre; Keith Trnka

    2010-12-31

    This report summarizes the activities and accomplishments of a two-year DOE-funded project on Grid-Integrated Vehicles (GIV) with vehicle to grid power (V2G). The project included several research and development components: an analysis of US driving patterns; an analysis of the market for EVs and V2G-capable EVs; development and testing of GIV components (in-car and in-EVSE); interconnect law and policy; and development and filing of patents. In addition, development activities included GIV manufacturing and licensing of technologies developed under this grant. Also, five vehicles were built and deployed, four for the fleet of the State of Delaware, plus one for the University of Delaware fleet.

  15. Spacer grid assembly and locking mechanism

    DOEpatents

    Snyder, Jr., Harold J.; Veca, Anthony R.; Donck, Harry A.

    1982-01-01

    A spacer grid assembly is disclosed for retaining a plurality of fuel rods in substantially parallel spaced relation, the spacer grids being formed with rhombic openings defining contact means for engaging from one to four fuel rods arranged in each opening, the spacer grids being of symmetric configuration with their rhombic openings being asymmetrically offset to permit inversion and relative rotation of the similar spacer grids for improved support of the fuel rods. An improved locking mechanism includes tie bars having chordal surfaces to facilitate their installation in slotted circular openings of the spacer grids, the tie rods being rotatable into locking engagement with the slotted openings.

  16. A 3-D chimera grid embedding technique

    NASA Technical Reports Server (NTRS)

    Benek, J. A.; Buning, P. G.; Steger, J. L.

    1985-01-01

    A three-dimensional (3-D) chimera grid-embedding technique is described. The technique simplifies the construction of computational grids about complex geometries. The method subdivides the physical domain into regions which can accommodate easily generated grids. Communication among the grids is accomplished by interpolation of the dependent variables at grid boundaries. The procedures for constructing the composite mesh and the associated data structures are described. The method is demonstrated by solution of the Euler equations for the transonic flow about a wing/body, wing/body/tail, and a configuration of three ellipsoidal bodies.

  17. Gratia: New Challenges in Grid Accounting

    NASA Astrophysics Data System (ADS)

    Canal, Philippe

    2011-12-01

    Gratia originated as an accounting system for batch systems and Linux process accounting. In production since 2006 at FNAL, it was adopted by the Open Science Grid as a distributed, grid-wide accounting system in 2007. Since adoption Gratia's next challenge has been to adapt to an explosive increase in data volume and to handle several new categories of accounting data. Gratia now accounts for regular grid jobs, file transfers, glide-in jobs, and the state of grid services. We show that Gratia gives access to a thorough picture of the OSG and discuss the complexity caused by newer grid techniques such as pilot jobs, job forwarding, and backfill.

  18. CFD study of isothermal water flow in rod bundle with split-type spacer grid

    NASA Astrophysics Data System (ADS)

    Batta, A.; Class, A. G.

    2014-06-01

    The design of rod bundles in nuclear application nowadays is assessed by CFD (computational fluid dynamics). The accuracy of CFD models need validation. Within the OECD/NEA benchmark MATiS-H (Measurement and Analysis of Turbulent Mixing in Sub-channels - Horizontal) a single-phase water flow in a 5x5 rod bundle is studied. In the benchmark, two types of spacer grids are tested, the swirl type and the split type, where the current study focuses on the split type spacer grid. Comparison of CFD results obtained at Karlsruhe Institut of Technology (KIT) with experimental results of KAERI (Korea Atomic Energy Research Institute) are presented. In the benchmark velocities components along selected lines downstream of the spacer grid are measured and compared to CFD results. The CFD code STAR CCM+ with the Realized k-ɛ model is used. Comparisons with experimental results show quantitative and qualitative agreement for the averaged values of velocity components. Comparisons of results to other benchmark partners using different modeling show that the selected mesh size and models for the analysis of the current case gives relatively accurate results. However, the used turbulent model (Realized k-ɛ does not capture the turbulent intensity correctly. Computation shows that the flow has very high mixing due to the spacer grid, which does not decay within the measurements domain (z/ DH =0-10 downstream of spacer grid). The same conclusion can be drawn from experimental data.

  19. Effects of grid size and aggregation on regional scale landuse scenario calculations using SVAT schemes

    NASA Astrophysics Data System (ADS)

    Bormann, H.

    2006-09-01

    This paper analyses the effect of spatial input data resolution on the simulated effects of regional scale landuse scenarios using the TOPLATS model. A data set of 25 m resolution of the central German Dill catchment (693 km2) and three different landuse scenarios are used for the investigation. Landuse scenarios in this study are field size scenarios, and depending on a specific target field size (0.5 ha, 1.5 ha and 5.0 ha) landuse is determined by optimising economic outcome of agricultural used areas and forest. After an aggregation of digital elevation model, soil map, current landuse and landuse scenarios to 50 m, 75 m, 100 m, 150 m, 200 m, 300 m, 500 m, 1 km and 2 km, water balances and water flow components for a 20 years time period are calculated for the entire Dill catchment as well as for 3 subcatchments without any recalibration. Additionally water balances based on the three landuse scenarios as well as changes between current conditions and scenarios are calculated. The study reveals that both model performance measures (for current landuse) as well as water balances (for current landuse and landuse scenarios) almost remain constant for most of the aggregation steps for all investigated catchments. Small deviations are detected at the resolution of 50 m to 500 m, while significant differences occur at the resolution of 1 km and 2 km which can be explained by changes in the statistics of the input data. Calculating the scenario effects based on increasing grid sizes yields similar results. However, the change effects react more sensitive to data aggregation than simple water balance calculations. Increasing deviations between simulations based on small grid sizes and simulations using grid sizes of 300 m and more are observed. Summarizing, this study indicates that an aggregation of input data for the calculation of regional water balances using TOPLATS type models does not lead to significant errors up to a resolution of 500 m. Focusing on scenario

  20. Grid artifact reduction for direct digital radiography detectors based on rotated stationary grids with homomorphic filtering

    SciTech Connect

    Kim, Dong Sik; Lee, Sanggyun

    2013-06-15

    Purpose: Grid artifacts are caused when using the antiscatter grid in obtaining digital x-ray images. In this paper, research on grid artifact reduction techniques is conducted especially for the direct detectors, which are based on amorphous selenium. Methods: In order to analyze and reduce the grid artifacts, the authors consider a multiplicative grid image model and propose a homomorphic filtering technique. For minimal damage due to filters, which are used to suppress the grid artifacts, rotated grids with respect to the sampling direction are employed, and min-max optimization problems for searching optimal grid frequencies and angles for given sampling frequencies are established. The authors then propose algorithms for the grid artifact reduction based on the band-stop filters as well as low-pass filters. Results: The proposed algorithms are experimentally tested for digital x-ray images, which are obtained from direct detectors with the rotated grids, and are compared with other algorithms. It is shown that the proposed algorithms can successfully reduce the grid artifacts for direct detectors. Conclusions: By employing the homomorphic filtering technique, the authors can considerably suppress the strong grid artifacts with relatively narrow-bandwidth filters compared to the normal filtering case. Using rotated grids also significantly reduces the ringing artifact. Furthermore, for specific grid frequencies and angles, the authors can use simple homomorphic low-pass filters in the spatial domain, and thus alleviate the grid artifacts with very low implementation complexity.

  1. The CMS integration grid testbed

    SciTech Connect

    Graham, Gregory E.

    2004-08-26

    The CMS Integration Grid Testbed (IGT) comprises USCMS Tier-1 and Tier-2 hardware at the following sites: the California Institute of Technology, Fermi National Accelerator Laboratory, the University of California at San Diego, and the University of Florida at Gainesville. The IGT runs jobs using the Globus Toolkit with a DAGMan and Condor-G front end. The virtual organization (VO) is managed using VO management scripts from the European Data Grid (EDG). Gridwide monitoring is accomplished using local tools such as Ganglia interfaced into the Globus Metadata Directory Service (MDS) and the agent based Mona Lisa. Domain specific software is packaged and installed using the Distribution After Release (DAR) tool of CMS, while middleware under the auspices of the Virtual Data Toolkit (VDT) is distributed using Pacman. During a continuous two month span in Fall of 2002, over 1 million official CMS GEANT based Monte Carlo events were generated and returned to CERN for analysis while being demonstrated at SC2002. In this paper, we describe the process that led to one of the world's first continuously available, functioning grids.

  2. Smart Grid Interoperability Maturity Model

    SciTech Connect

    Widergren, Steven E.; Levinson, Alex; Mater, J.; Drummond, R.

    2010-04-28

    The integration of automation associated with electricity resources (including transmission and distribution automation and demand-side resources operated by end-users) is key to supporting greater efficiencies and incorporating variable renewable resources and electric vehicles into the power system. The integration problems faced by this community are analogous to those faced in the health industry, emergency services, and other complex communities with many stakeholders. To highlight this issue and encourage communication and the development of a smart grid interoperability community, the GridWise Architecture Council (GWAC) created an Interoperability Context-Setting Framework. This "conceptual model" has been helpful to explain the importance of organizational alignment in addition to technical and informational interface specifications for "smart grid" devices and systems. As a next step to building a community sensitive to interoperability, the GWAC is investigating an interoperability maturity model (IMM) based on work done by others to address similar circumstances. The objective is to create a tool or set of tools that encourages a culture of interoperability in this emerging community. The tools would measure status and progress, analyze gaps, and prioritize efforts to improve the situation.

  3. Certainty grids for mobile robots

    NASA Technical Reports Server (NTRS)

    Moravec, H. P.

    1987-01-01

    A numerical representation of uncertain and incomplete sensor knowledge called Certainty Grids has been used successfully in several mobile robot control programs, and has proven itself to be a powerful and efficient unifying solution for sensor fusion, motion planning, landmark identification, and many other central problems. Researchers propose to build a software framework running on processors onboard the new Uranus mobile robot that will maintain a probabilistic, geometric map of the robot's surroundings as it moves. The certainty grid representation will allow this map to be incrementally updated in a uniform way from various sources including sonar, stereo vision, proximity and contact sensors. The approach can correctly model the fuzziness of each reading, while at the same time combining multiple measurements to produce sharper map features, and it can deal correctly with uncertainties in the robot's motion. The map will be used by planning programs to choose clear paths, identify locations (by correlating maps), identify well-known and insufficiently sensed terrain, and perhaps identify objects by shape. The certainty grid representation can be extended in the same dimension and used to detect and track moving objects.

  4. Interactive solution-adaptive grid generation procedure

    NASA Technical Reports Server (NTRS)

    Henderson, Todd L.; Choo, Yung K.; Lee, Ki D.

    1992-01-01

    TURBO-AD is an interactive solution adaptive grid generation program under development. The program combines an interactive algebraic grid generation technique and a solution adaptive grid generation technique into a single interactive package. The control point form uses a sparse collection of control points to algebraically generate a field grid. This technique provides local grid control capability and is well suited to interactive work due to its speed and efficiency. A mapping from the physical domain to a parametric domain was used to improve difficulties encountered near outwardly concave boundaries in the control point technique. Therefore, all grid modifications are performed on the unit square in the parametric domain, and the new adapted grid is then mapped back to the physical domain. The grid adaption is achieved by adapting the control points to a numerical solution in the parametric domain using control sources obtained from the flow properties. Then a new modified grid is generated from the adapted control net. This process is efficient because the number of control points is much less than the number of grid points and the generation of the grid is an efficient algebraic process. TURBO-AD provides the user with both local and global controls.

  5. Curvilinear grids for sinuous river channels

    NASA Technical Reports Server (NTRS)

    Tatom, F. B.; Waldrop, W. R.; Smith, S. R.

    1980-01-01

    In order to effectively analyze the flow in sinuous river channels, a curvilinear grid system was developed for use in the appropriate hydrodynamic code. The CENTERLINE program was designed to generate a two dimensional grid for this purpose. The Cartesian coordinates of a series of points along the boundaries of the sinuous channel represent the primary input to CENTERLINE. The program calculates the location of the river centerline, the distance downstream along the centerline, and both radius of curvature and channel width as a function of such distance downstream. These parameters form the basis for the generation of the curvilinear grid. Based on input values for longitudinal and lateral grid spacing, the corresponding grid system is generated and a file is created containing the appropriate parameters for use in the associated explicit finite difference hydrodynamic programs. Because of the option for a nonuniform grid, grid spacing can be concentrated in areas containing the largest flow gradients.

  6. Solving Partial Differential Equations on Overlapping Grids

    SciTech Connect

    Henshaw, W D

    2008-09-22

    We discuss the solution of partial differential equations (PDEs) on overlapping grids. This is a powerful technique for efficiently solving problems in complex, possibly moving, geometry. An overlapping grid consists of a set of structured grids that overlap and cover the computational domain. By allowing the grids to overlap, grids for complex geometries can be more easily constructed. The overlapping grid approach can also be used to remove coordinate singularities by, for example, covering a sphere with two or more patches. We describe the application of the overlapping grid approach to a variety of different problems. These include the solution of incompressible fluid flows with moving and deforming geometry, the solution of high-speed compressible reactive flow with rigid bodies using adaptive mesh refinement (AMR), and the solution of the time-domain Maxwell's equations of electromagnetism.

  7. Generating Composite Overlapping Grids on CAD Geometries

    SciTech Connect

    Henshaw, W.D.

    2002-02-07

    We describe some algorithms and tools that have been developed to generate composite overlapping grids on geometries that have been defined with computer aided design (CAD) programs. This process consists of five main steps. Starting from a description of the surfaces defining the computational domain we (1) correct errors in the CAD representation, (2) determine topology of the patched-surface, (3) build a global triangulation of the surface, (4) construct structured surface and volume grids using hyperbolic grid generation, and (5) generate the overlapping grid by determining the holes and the interpolation points. The overlapping grid generator which is used for the final step also supports the rapid generation of grids for block-structured adaptive mesh refinement and for moving grids. These algorithms have been implemented as part of the Overture object-oriented framework.

  8. Demonstration of a utility industry horizontal drilling system: Horizontal well AMH-5 installation report

    SciTech Connect

    Not Available

    1992-12-31

    The Department of Energy`s Office of Technology Development initiated an integrated demonstration of innovative technologies and systems for cleanup of VOCs in soils and groundwater at the Savannah River Site (SRS) in 1989. The overall goal of the program is demonstration of multiple technologies and systems in the fields of drilling, characterization, monitoring, and remediation at a single test bed. Innovative technologies are compared to one another and to baseline technologies in terms of technical performance and cost effectiveness. Transfer of successfully demonstrated technologies and systems to DOE environmental restoration organizations, to other government agencies, and to industry is a critical part of the program. Directional drilling has been shown to be a successful technique for enhancing access to the subsurface, thus improving remediation systems, especially remediation systems which perform in situ. Demonstration of an innovative directional drilling system at the Integrated Demonstration Site at the SRS, was initiated in June of 1992. The directional drilling system was designed to install an in situ remediation system. The drilling system is an experimental compaction/dry drilling technique developed by Charles Machine Works (Ditch Witch{reg_sign}) of Perry, Oklahoma. A horizontal well was installed in the M Area of the SRS below and parallel to an abandoned tile process sewer line. The installation of the horizontal well was a two-part process. Part one consisted of drilling the borehole, and part two was the horizontal well completion.

  9. Enhancing the resolution of airborne gamma-ray data using horizontal gradients

    NASA Astrophysics Data System (ADS)

    Beamish, David

    2016-09-01

    The spatial resolution characteristics of airborne gamma-ray data are largely controlled by survey elevation and line separation. In the UK, although low nominal surveys altitudes may be permitted, regulatory zones with elevations in excess of 180 m are required above conurbations. Since the data, typically in the form of grids, are evaluated alongside many other detailed geoscientific spatial datasets their absolute resolution limits, together with their spatial characteristics, become relevant. Here, using published software, we study the theoretical resolution characteristics of this form of survey data obtained with a line separation of 200 m. Of particular interest is the airborne response behaviour when non-uniform distributions of radioactivity are encountered. Although ultimately a function of the radioelement-concentration contrast encountered, the calculations reveal that such zones are most difficult to identify when their scale length decreases below the scale of the line separation. This limited resolution then further decreases with elevation. In order to increase our ability to resolve the edges of non-uniform source regions we calculate the horizontal gradient magnitude (HGM) of the observed data. While the data used can be the estimated radioelement concentrations (potassium, thorium and uranium) or their ratios, we demonstrate that the total count is particularly suited to this type of analysis. The theoretical calculations are supported by an examination of survey data across a series of isolated bodies (offshore islands). This empirical study indicates the practical limits to resolution when using the horizontal gradient and these are governed by the survey line separation. The HGM response provides an enhanced mapping of the edges of zones associated with a contrast in flux behaviour. The edges are detected using the maxima in the response and these can be additionally examined using grid curvature analysis. The technique is assessed using

  10. Improving mobile robot localization: grid-based approach

    NASA Astrophysics Data System (ADS)

    Yan, Junchi

    2012-02-01

    Autonomous mobile robots have been widely studied not only as advanced facilities for industrial and daily life automation, but also as a testbed in robotics competitions for extending the frontier of current artificial intelligence. In many of such contests, the robot is supposed to navigate on the ground with a grid layout. Based on this observation, we present a localization error correction method by exploring the geometric feature of the tile patterns. On top of the classical inertia-based positioning, our approach employs three fiber-optic sensors that are assembled under the bottom of the robot, presenting an equilateral triangle layout. The sensor apparatus, together with the proposed supporting algorithm, are designed to detect a line's direction (vertical or horizontal) by monitoring the grid crossing events. As a result, the line coordinate information can be fused to rectify the cumulative localization deviation from inertia positioning. The proposed method is analyzed theoretically in terms of its error bound and also has been implemented and tested on a customary developed two-wheel autonomous mobile robot.

  11. New solutions for the confined horizontal aquifer

    NASA Astrophysics Data System (ADS)

    Akylas, Evangelos; Gravanis, Elias

    2016-04-01

    The Boussinesq equation is a dynamical equation for the free surface of saturated subsurface flows over an impervious bed. Boussinesq equation is non-linear. The non-linearity comes from the reduction of the dimensionality of the problem: The flow is assumed to be vertically homogeneous, therefore the flow rate through a cross section of the flow is proportional to the free surface height times the hydraulic gradient, which is assumed to be equal to the slope of the free surface. In the present work we consider the case of the subsurface flow with horizontal bed. This is a case with an infinite Henderson and Wooding parameter, that is, it is the limiting case where the non-linear term is present in the Boussinesq equation while the linear spatial derivative term vanishes. Nonetheless, no analogue of the kinematic wave exists in this case as there is no exact solution for the build-up phase. Neither is there an exact recession-phase solution that holds in early times, as the Boussinesq separable solution is actually an asymptotic solution for large times. We construct approximate solutions for the horizontal aquifer which utilize directly the dynamical content of the non-linear Boussinesq equation. The approximate character of the solution lies in the fact that we start with a pre-supposed form for the solution, an educated guess, based on the nature of the initial condition as well as empirical observations from the numerical solution of the problem. The forms we shall use are power series of the location variable x along the bed with time-dependent coefficients. The series are not necessarily analytic. The boundary conditions are incorporated in the structure of the series from the beginning. The time-dependent coefficients are then determined by applying the Boussinesq equation and its spatial derivatives at the end-points of the aquifer. The forms are chosen also on the basis of their solubility; we would like to be able to construct explicitly the approximate

  12. Globally Gridded Satellite (GridSat) Observations for Climate Studies

    NASA Technical Reports Server (NTRS)

    Knapp, Kenneth R.; Ansari, Steve; Bain, Caroline L.; Bourassa, Mark A.; Dickinson, Michael J.; Funk, Chris; Helms, Chip N.; Hennon, Christopher C.; Holmes, Christopher D.; Huffman, George J.; Kossin, James P.; Lee, Hai-Tien; Loew, Alexander; Magnusdottir, Gudrun

    2012-01-01

    Geostationary satellites have provided routine, high temporal resolution Earth observations since the 1970s. Despite the long period of record, use of these data in climate studies has been limited for numerous reasons, among them: there is no central archive of geostationary data for all international satellites, full temporal and spatial resolution data are voluminous, and diverse calibration and navigation formats encumber the uniform processing needed for multi-satellite climate studies. The International Satellite Cloud Climatology Project set the stage for overcoming these issues by archiving a subset of the full resolution geostationary data at approx.10 km resolution at 3 hourly intervals since 1983. Recent efforts at NOAA s National Climatic Data Center to provide convenient access to these data include remapping the data to a standard map projection, recalibrating the data to optimize temporal homogeneity, extending the record of observations back to 1980, and reformatting the data for broad public distribution. The Gridded Satellite (GridSat) dataset includes observations from the visible, infrared window, and infrared water vapor channels. Data are stored in the netCDF format using standards that permit a wide variety of tools and libraries to quickly and easily process the data. A novel data layering approach, together with appropriate satellite and file metadata, allows users to access GridSat data at varying levels of complexity based on their needs. The result is a climate data record already in use by the meteorological community. Examples include reanalysis of tropical cyclones, studies of global precipitation, and detection and tracking of the intertropical convergence zone.

  13. Web-based visualization of gridded dataset usings OceanBrowser

    NASA Astrophysics Data System (ADS)

    Barth, Alexander; Watelet, Sylvain; Troupin, Charles; Beckers, Jean-Marie

    2015-04-01

    OceanBrowser is a web-based visualization tool for gridded oceanographic data sets. Those data sets are typically four-dimensional (longitude, latitude, depth and time). OceanBrowser allows one to visualize horizontal sections at a given depth and time to examine the horizontal distribution of a given variable. It also offers the possibility to display the results on an arbitrary vertical section. To study the evolution of the variable in time, the horizontal and vertical sections can also be animated. Vertical section can be generated by using a fixed distance from coast or fixed ocean depth. The user can customize the plot by changing the color-map, the range of the color-bar, the type of the plot (linearly interpolated color, simple contours, filled contours) and download the current view as a simple image or as Keyhole Markup Language (KML) file for visualization in applications such as Google Earth. The data products can also be accessed as NetCDF files and through OPeNDAP. Third-party layers from a web map service can also be integrated. OceanBrowser is used in the frame of the SeaDataNet project (http://gher-diva.phys.ulg.ac.be/web-vis/) and EMODNET Chemistry (http://oceanbrowser.net/emodnet/) to distribute gridded data sets interpolated from in situ observation using DIVA (Data-Interpolating Variational Analysis).

  14. Shallow water model for horizontal centrifugal casting

    NASA Astrophysics Data System (ADS)

    Boháček, J.; Kharicha, A.; Ludwig, A.; Wu, M.

    2012-07-01

    A numerical model was proposed to simulate the solidification process of an outer shell of work roll made by the horizontal centrifugal casting technique. Shallow water model was adopted to solve the 2D average flow dynamics of melt spreading and the average temperature distribution inside the centrifugal casting mould by considering the centrifugal force, Coriolis force, viscous force due to zero velocity on the mould wall, gravity, and energy transport by the flow. Additionally, a 1D sub-model was implemented to consider the heat transfer in the radial direction from the solidifying shell to the mould. The solidification front was tracked by fulfilling the Stefan condition. Radiative and convective heat losses were included from both, the free liquid surface and the outer wall of the mould. Several cases were simulated with the following assumed initial conditions: constant height of the liquid metal (10, 20, and 30 mm), uniform temperature of the free liquid surface (1755 K). The simulation results have shown that while the solidification front remained rather flat, the free surface was disturbed by waves. The amplitude of waves increased with the liquid height. Free surface waves diminished as the solidification proceeded.

  15. Magneto-convective instabilities in horizontal cavities

    NASA Astrophysics Data System (ADS)

    Mistrangelo, Chiara; Bühler, Leo

    2016-02-01

    A linear stability analysis is performed to investigate the onset of convective motions in a flat cavity filled with liquid metal. A volumetric heat source is uniformly distributed in the fluid and a horizontal magnetic field is imposed. Walls perpendicular to the magnetic field are thermally insulating, and the top wall is isothermal and the bottom adiabatic. When a magnetic field is applied, electromagnetic forces tend to transform 3D convective flow structures into quasi-2D rolls aligned to the magnetic field. By integrating 3D equations along magnetic field lines, a quasi-2D mathematical model has been derived. A dissipation term in the 2D equations accounts for 3D viscous effects in boundary layers at Hartmann walls perpendicular to the magnetic field. The influence of various parameters on flow stability is investigated. The flow is stabilized by increasing the magnetic field intensity or the electric conductance of Hartmann walls and by reducing the aspect ratio of the cavity. Numerical simulations are performed to verify the analytical results and to describe the main convective flow patterns in the non-linear regime.

  16. Yaw dynamics of horizontal axis wind turbines

    SciTech Connect

    Hansen, A.C. )

    1992-05-01

    Designers of a horizontal axis wind turbine yaw mechanism are faced with a difficult decision. They know that if they elect to use a yaw- controlled rotor then the system will suffer increased initial cost and increased inherent maintenance and reliability problems. On the other hand, if they elect to allow the rotor to freely yaw they known they will have to account for unknown and random, though bounded, yaw rates. They will have a higher-risk design to trade-off against the potential for cost savings and reliability improvement. The risk of a yaw-free system could be minimized if methods were available for analyzing and understanding yaw behavior. The complexity of yaw behavior has, until recently, discouraged engineers from developing a complete yaw analysis method. The objectives of this work are to (1) provide a fundamental understanding of free-yaw mechanics and the design concepts most effective at eliminating yaw problems, and (2) provide tested design tools and guidelines for use by free-yaw wind systems manufacturers. The emphasis is on developing practical and sufficiently accurate design methods.

  17. Film condensation in a horizontal rectangular duct

    NASA Technical Reports Server (NTRS)

    Lu, Qing; Suryanarayana, N. V.

    1992-01-01

    Condensation heat transfer in an annular flow regime with and without interfacial waves was experimentally investigated. The study included measurements of heat transfer rate with condensation of vapor flowing inside a horizontal rectangular duct and experiments on the initiation of interfacial waves in condensation, and adiabatic air-liquid flow. An analytical model for the condensation was developed to predict condensate film thickness and heat transfer coefficients. Some conclusions drawn from the study are that the condensate film thickness was very thin (less than 0.6 mm). The average heat transfer coefficient increased with increasing the inlet vapor velocity. The local heat transfer coefficient decreased with the axial distance of the condensing surface, with the largest change at the leading edge of the test section. The interfacial shear stress, which consisted of the momentum shear stress and the adiabatic shear stress, appeared to have a significant effect on the heat transfer coefficients. In the experiment, the condensate flow along the condensing surface experienced a smooth flow, a two-dimensional wavy flow, and a three-dimensional wavy flow. In the condensation experiment, the local wave length decreased with the axial distance of the condensing surface and the average wave length decreased with increasing inlet vapor velocity, while the wave speed increased with increasing vapor velocity. The heat transfer measurements are reliable. And, the ultrasonic technique was effective for measuring the condensate film thickness when the surface was smooth or had waves of small amplitude.

  18. Maximal liquid bridges between horizontal cylinders

    NASA Astrophysics Data System (ADS)

    Cooray, Himantha; Huppert, Herbert E.; Neufeld, Jerome A.

    2016-08-01

    We investigate two-dimensional liquid bridges trapped between pairs of identical horizontal cylinders. The cylinders support forces owing to surface tension and hydrostatic pressure that balance the weight of the liquid. The shape of the liquid bridge is determined by analytically solving the nonlinear Laplace-Young equation. Parameters that maximize the trapping capacity (defined as the cross-sectional area of the liquid bridge) are then determined. The results show that these parameters can be approximated with simple relationships when the radius of the cylinders is small compared with the capillary length. For such small cylinders, liquid bridges with the largest cross-sectional area occur when the centre-to-centre distance between the cylinders is approximately twice the capillary length. The maximum trapping capacity for a pair of cylinders at a given separation is linearly related to the separation when it is small compared with the capillary length. The meniscus slope angle of the largest liquid bridge produced in this regime is also a linear function of the separation. We additionally derive approximate solutions for the profile of a liquid bridge, using the linearized Laplace-Young equation. These solutions analytically verify the above-mentioned relationships obtained for the maximization of the trapping capacity.

  19. Horizontal visibility graphs from integer sequences

    NASA Astrophysics Data System (ADS)

    Lacasa, Lucas

    2016-09-01

    The horizontal visibility graph (HVG) is a graph-theoretical representation of a time series and builds a bridge between dynamical systems and graph theory. In recent years this representation has been used to describe and theoretically compare different types of dynamics and has been applied to characterize empirical signals, by extracting topological features from the associated HVGs which have shown to be informative on the class of dynamics. Among some other measures, it has been shown that the degree distribution of these graphs is a very informative feature that encapsulates nontrivial information of the series's generative dynamics. In particular, the HVG associated to a bi-infinite real-valued series of independent and identically distributed random variables is a universal exponential law P(k)=(1/3){(2/3)}k-2, independent of the series marginal distribution. Most of the current applications have however only addressed real-valued time series, as no exact results are known for the topological properties of HVGs associated to integer-valued series. In this paper we explore this latter situation and address univariate time series where each variable can only take a finite number n of consecutive integer values. We are able to construct an explicit formula for the parametric degree distribution {P}n(k), which we prove to converge to the continuous case for large n and deviates otherwise. A few applications are then considered.

  20. Horizontal Shear Wave Imaging of Large Optics

    SciTech Connect

    Quarry, M J

    2007-09-05

    When complete the National Ignition Facility (NIF) will be the world's largest and most energetic laser and will be capable of achieving for the first time fusion ignition in the laboratory. Detecting optics features within the laser beamlines and sizing them at diameters of 0.1 mm to 10 mm allows timely decisions concerning refurbishment and will help with the routine operation of the system. Horizontally polarized shear waves at 10 MHz were shown to accurately detect, locate, and size features created by laser operations from 0.5 mm to 8 mm by placing sensors at the edge of the optic. The shear wave technique utilizes highly directed beams. The outer edge of an optic can be covered with shear wave transducers on four sides. Each transducer sends a pulse into the optic and any damage reflects the pulse back to the transmitter. The transducers are multiplexed, and the collected time waveforms are enveloped and replicated across the width of the element. Multiplying the data sets from four directions produces a map of reflected amplitude to the fourth power, which images the surface of the optic. Surface area can be measured directly from the image, and maximum depth was shown to be correlated to maximum amplitude of the reflected waveform.

  1. Verification of a non-hydrostatic dynamical core using horizontally spectral element vertically finite difference method

    NASA Astrophysics Data System (ADS)

    Choi, S. J.; Kim, J.; Shin, S.

    2014-12-01

    In this presentation, a new non-hydrostatic (NH) dynamical core using the spectral element method (SEM) in the horizontal discretization and the finite difference method (FDM) in the vertical discretization will be presented. By using horizontal SEM, which decomposes the physical domain into smaller pieces with a small communication stencil, we can achieve a high level of scalability. Also by using vertical FDM, we provide an easy way for coupling the dynamics and existing physics packages. The Euler equations used here are in a flux form based on the hybrid sigma hydrostatic pressure vertical coordinate, which are similar to those used in the Weather Research and Forecasting (WRF) model. Within these Euler equations, we use a time-split third-order Runge-Kutta (RK3) for the time discretization. In order to establish robustness, firstly the NH dynamical core is verified in a simplified two dimensional (2D) slice framework by conducting widely used standard benchmark tests, and then we verify the global three dimensional (3D) dynamical core on the cubed-sphere grid with several test cases introduced by Dynamical Core Model Intercomparison Project (DCMIP).

  2. Seasonal variations and horizontal distribution of precipitation over extratropical continental regions in CMIP5

    NASA Astrophysics Data System (ADS)

    Hamada, A.; Hirota, N.; Takayabu, Y. N.

    2012-12-01

    Seasonal variations and horizontal distribution of precipitation over extratropical continental regions by the CMIP5 climate models in their historical runs are evaluated, in comparison with GPCP, CMAP, daily gridded gauge data APHRODITE, and with various reanalysis data. Eight regions are selected over the Eastern Europe, northwestern Russia, Mongolia, northeastern Russia, Alaska, western US, eastern Canada, and eastern US. It is shown that precipitation reproducibility over extratropical continental regions in climate models widely varies depending on regions and seasons, probably attributed to the matching of the precipitation characteristics and treatments of physical processes in the climate models. In some regions, additional treatments of physical processes such as those implemented in the Earth System Models improve the result, while in other regions, horizontal resolution looks essential for the improvements. The reproducibility also varies depending on seasons in a same region, for example, differs between summer and winter in the Eastern Europe. It is also noted that estimated rain amounts considerably vary among GPCP, CMAP, and APHRODITE. Acknowledgment: This study is supported by the 6th GPM/TRMM RA of JAXA, Green Network of Excellence (GRENE) Program by the Ministry of Education, Culture, Sports, Science and Technology, Japan, and Environment Research and Technology Development Fund (A-1201) of the Ministry of the Environment, Japan.

  3. Numerical study of natural convection in a horizontal cylinder filled with water-based alumina nanofluid.

    PubMed

    Meng, Xiangyin; Li, Yan

    2015-01-01

    Natural heat convection of water-based alumina (Al2O3/water) nanofluids (with volume fraction 1% and 4%) in a horizontal cylinder is numerically investigated. The whole three-dimensional computational fluid dynamics (CFD) procedure is performed in a completely open-source way. Blender, enGrid, OpenFOAM and ParaView are employed for geometry creation, mesh generation, case simulation and post process, respectively. Original solver 'buoyantBoussinesqSimpleFoam' is selected for the present study, and a temperature-dependent solver 'buoyantBoussinesqSimpleTDFoam' is developed to ensure the simulation is more realistic. The two solvers are used for same cases and compared to corresponding experimental results. The flow regime in these cases is laminar (Reynolds number is 150) and the Rayleigh number range is 0.7 × 10(7) ~ 5 × 10(7). By comparison, the average natural Nusselt numbers of water and Al2O3/water nanofluids are found to increase with the Rayleigh number. At the same Rayleigh number, the Nusselt number is found to decrease with nanofluid volume fraction. The temperature-dependent solver is found better for water and 1% Al2O3/water nanofluid cases, while the original solver is better for 4% Al2O3/water nanofluid cases. Furthermore, due to strong three-dimensional flow features in the horizontal cylinder, three-dimensional CFD simulation is recommended instead of two-dimensional simplifications.

  4. Numerical study of natural convection in a horizontal cylinder filled with water-based alumina nanofluid

    NASA Astrophysics Data System (ADS)

    Meng, Xiangyin; Li, Yan

    2015-03-01

    Natural heat convection of water-based alumina (Al2O3/water) nanofluids (with volume fraction 1% and 4%) in a horizontal cylinder is numerically investigated. The whole three-dimensional computational fluid dynamics (CFD) procedure is performed in a completely open-source way. Blender, enGrid, OpenFOAM and ParaView are employed for geometry creation, mesh generation, case simulation and post process, respectively. Original solver `buoyantBoussinesqSimpleFoam' is selected for the present study, and a temperature-dependent solver `buoyantBoussinesqSimpleTDFoam' is developed to ensure the simulation is more realistic. The two solvers are used for same cases and compared to corresponding experimental results. The flow regime in these cases is laminar (Reynolds number is 150) and the Rayleigh number range is 0.7 × 107 ~ 5 × 107. By comparison, the average natural Nusselt numbers of water and Al2O3/water nanofluids are found to increase with the Rayleigh number. At the same Rayleigh number, the Nusselt number is found to decrease with nanofluid volume fraction. The temperature-dependent solver is found better for water and 1% Al2O3/water nanofluid cases, while the original solver is better for 4% Al2O3/water nanofluid cases. Furthermore, due to strong three-dimensional flow features in the horizontal cylinder, three-dimensional CFD simulation is recommended instead of two-dimensional simplifications.

  5. The evolution of horizontal branch stars and the calibration of globular cluster ages

    SciTech Connect

    Lee, Y.

    1989-01-01

    Synthetic models of the horizontal branches in globular clusters were constructed from a new grid of standard horizontal branch (HB) evolutionary tracks. These models were used to investigate the period shifts at constant temperature between the RR Lyrae variables in globular clusters of different metallicities and the variation in HB luminosity with Fe/H . It is shown that two effects--the evolution away from the zero-age horizontal branch (ZAHB) and the non-universal relationship between rise time (or amplitude) and effective temperature--are responsible for the disagreement between the HB luminosity-Fe/H relationship found observationally by Sandage (1982) in his investigation of the Oosterhoff effect and the one given by calculations of ZAHB stars. When these two effects are taken into account, the observed relationship between period shift and Fe/H, matches the theoretical model calculations to within the errors. The resulting relation between the mean luminosity of the RR Lyrae variables and Fe/H has approximately one-half the slope of Sandage's relation, which yields a significant correlation between age and Fe/H among the globular clusters that spans approximately 4 Gyrs (for constant O/Fe) over the metallicity range of the galactic halo. The synthetic HB models are also used to investigate the second parameter phenomenon among the galactic globular clusters system. This investigation confirms the earlier suggestion that there is a systematic variation of the second parameter effect with galactocentric distance. It is shown that full consistency with the pulsation theory and with the standard theory of both turnoff and HB evolution can only be achieved if age is the second parameter that most determines the HB morphology.

  6. Applications of horizontal well completions to gas-productive formations

    SciTech Connect

    Hill, R.E.; Peterson, R.E.; Middlebrook, M.I. ); Aslakson, J.K. )

    1993-08-01

    The Gas Research Institute (GRI) has initiated a project to determine the reservoir characteristics and appropriate horizontal well designs in various gas-productive formations. The goal of the project is to evaluate horizontal completions as a means of reducing unit production costs in comparison to vertical well-completion methods. Three gas-productive formations were evaluated in the initial phase of the project: the Mancos B on the Douglas Creek arch in northwestern Colorado; the Davis Sand in the Fort Worth basin; and the Barnett Shale, also in the Fort Worth basin. Geologic and engineering data from vertical wells were collected for each formation and used to strategically plan offset horizontal wells. Specifically, information was gathered to characterize the natural and induced fractures, model the reservoirs, and establish a production baseline for each reservoir. The next phase involved GRI participation in the drilling of the three offset horizontal wells with three independent producers. A 1500-ft horizontal section was air drilled across the Mancos B; a 2000-ft horizontal well was air drilled in the Davis sandstone; and a 2000-ft horizontal section was fluid drilled across the 300-ft-thick Barnett Shale. Each of the horizontal wells exhibit varying reservoir characteristics and associated gas production.

  7. Horizontal technology helps spark Louisiana`s Austin chalk trend

    SciTech Connect

    Koen, A.D.

    1996-04-29

    A handful of companies paced by some of the most active operators in the US are pressing the limits of horizontal technology to ramp up Cretaceous Austin chalk exploration and development (E and D) across Louisiana. Companies find applications in Louisiana for lessons learned drilling horizontal wells to produce chalk intervals in Texas in Giddings, Pearsall, and Brookeland fields. Continuing advances in horizontal well technology are helping operators deal with deeper, hotter reservoirs in more complex geological settings that typify the chalk in Louisiana. Better horizontal drilling, completion, formation evaluation, and stimulation techniques have enabled operators to produce oil and gas from formations previously thought to be uneconomical. Most of the improved capabilities stem from better horizontal tools. Horizontal drilling breakthroughs include dual powered mud motors and retrievable whipstocks, key links in the ability to drill wells with more than one horizontal lateral. Better geosteering tools have enabled operators to maintain horizontal wellbores in desired intervals by signaling bit positions downhole while drilling. This paper reviews the technology and provides a historical perspective on the various drilling programs which have been completed in this trend. It also makes predictions on future drilling successes.

  8. Chord Panel Post, Vertical X Bracing & Horizontal Tie Joint ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Chord Panel Post, Vertical X Bracing & Horizontal Tie Joint Detail; Chord Joining Block & Spacer Block Detail; Cross Bracing Joint Detail; Chord Panel Post Diagonal & Horizontal Tie Joint Detail - Jackson Covered Bridge, Spanning Sugar Creek, CR 775N (Changed from Spanning Sugar Creek), Bloomingdale, Parke County, IN

  9. District Power Equalization, Horizontal Equity and the Property Mix.

    ERIC Educational Resources Information Center

    Hilley, John

    1980-01-01

    Argues that the traditional district power equalization (DPE) grant formula achieves horizontal equity, that the formula must be modified when the measure of fiscal capacity differs from the legal tax base, and that the inclusion of a tax exporting variable leads to the breakdown of horizontal equity. (Author/IRT)

  10. Horizontal biases in rats' use of three-dimensional space.

    PubMed

    Jovalekic, Aleksandar; Hayman, Robin; Becares, Natalia; Reid, Harry; Thomas, George; Wilson, Jonathan; Jeffery, Kate

    2011-09-23

    Rodent spatial cognition studies allow links to be made between neural and behavioural phenomena, and much is now known about the encoding and use of horizontal space. However, the real world is three dimensional, providing cognitive challenges that have yet to be explored. Motivated by neural findings suggesting weaker encoding of vertical than horizontal space, we examined whether rats show a similar behavioural anisotropy when distributing their time freely between vertical and horizontal movements. We found that in two- or three-dimensional environments with a vertical dimension, rats showed a prioritization of horizontal over vertical movements in both foraging and detour tasks. In the foraging tasks, the animals executed more horizontal than vertical movements and adopted a "layer strategy" in which food was collected from one horizontal level before moving to the next. In the detour tasks, rats preferred the routes that allowed them to execute the horizontal leg first. We suggest three possible reasons for this behavioural bias. First, as suggested by Grobety and Schenk, it allows minimisation of energy expenditure, inasmuch as costly vertical movements are minimised. Second, it may be a manifestation of the temporal discounting of effort, in which animals value delayed effort as less costly than immediate effort. Finally, it may be that at the neural level rats encode the vertical dimension less precisely, and thus prefer to bias their movements in the more accurately encoded horizontal dimension. We suggest that all three factors are related, and all play a part.

  11. Unstructured grid research and use at NASA Lewis Research Center

    NASA Technical Reports Server (NTRS)

    Potapczuk, Mark G.

    1993-01-01

    Computational fluid dynamics applications of grid research at LRC include inlets, nozzles, and ducts; turbomachinery; propellers - ducted and unducted; and aircraft icing. Some issues related to internal flow grid generation are resolution requirements on several boundaries, shock resolution vs. grid periodicity, grid spacing at blade/shroud gap, grid generation in turbine blade passages, and grid generation for inlet/nozzle geometries. Aircraft icing grid generation issues include (1) small structures relative to airfoil chord must be resolved; (2) excessive number of grid points in far-field using structured grid; and (3) grid must be recreated as ice shape grows.

  12. Steerable vertical to horizontal energy transducer for mobile robots

    DOEpatents

    Spletzer, Barry L.; Fischer, Gary J.; Feddema, John T.

    2001-01-01

    The present invention provides a steerable vertical to horizontal energy transducer for mobile robots that less complex and requires less power than two degree of freedom tilt mechanisms. The present invention comprises an end effector that, when mounted with a hopping actuator, translates along axis (typically vertical) actuation into combined vertical and horizontal motion. The end effector, or foot, mounts with an end of the actuator that moves toward the support surface (typically a floor or the earth). The foot is shaped so that the first contact with the support surface is off the axis of the actuator. Off-axis contact with the support surface generates an on-axis force (typically resulting in vertical motion) and a moment orthogonal to the axis. The moment initiates a horizontal tumbling motion, and tilts the actuator so that its axis is oriented with a horizontal component and continued actuation generates both vertical and horizontal force.

  13. Survey of Volumetric Grid Generators

    NASA Technical Reports Server (NTRS)

    Woo, Alex; Volakis, John; Hulbert, Greg; Case, Jeff; Presley, Leroy L. (Technical Monitor)

    1994-01-01

    This document is the result of an Internet Survey of Volumetric grid generators. As such we have included information from only the responses which were sent to us. After the initial publication and posting of this survey, we would encourage authors and users of grid generators to send further information. Here is the initial query posted to SIGGRID@nas and the USENET group sci.physics.computational.fluid-dynamics. Date: Sun, 30 Jan 94 11:37:52 -0800 From: woo (Alex Woo x6010 227-6 rm 315) Subject: Info Sought for Survey of Grid Generators I am collecting information and reviews of both government sponsored and commercial mesh generators for large scientific calculations, both block structured and unstructured. If you send me a review of a mesh generator, please indicate its availability and cost. If you are a commercial concern with information on a product, please also include references for possible reviewers. Please email to woo@ra-next.arc.nasa.gov. I will post a summary and probably write a short note for the IEEE Antennas and Propagation Magazine. Alex Woo, MS 227-6 woo@ames.arc.nasa.gov NASA Ames Research Center NASAMAIL ACWOO Moffett Field, CA 94035-1000 SPANET 24582::W00 (415) 604-6010 (FAX) 604-4357 fhplabs,decwrl,uunet)!ames!woo Disclaimer: These are not official statements of NASA or EMCC. We did not include all the submitted text here. Instead we have created a database entry in the freely available and widely used BIBTeX format which has an Uniform Resource Locator (URL) field pointing to more details. The BIBTeX database is modeled after those available from the BIBNET project at University of Utah.

  14. Bootstrapping to a Semantic Grid

    SciTech Connect

    Schwidder, Jens; Talbott, Tara; Myers, James D.

    2005-02-28

    The Scientific Annotation Middleware (SAM) is a set of components and services that enable researchers, applications, problem solving environments (PSE) and software agents to create metadata and annotations about data objects and document the semantic relationships between them. Developed starting in 2001, SAM allows applications to encode metadata within files or to manage metadata at the level of individual relationships as desired. SAM then provides mechanisms to expose metadata and relation¬ships encoded either way as WebDAV properties. In this paper, we report on work to further map this metadata into RDF and discuss the role of middleware such as SAM in bridging between traditional and semantic grid applications.

  15. Grid computing and biomolecular simulation.

    PubMed

    Woods, Christopher J; Ng, Muan Hong; Johnston, Steven; Murdock, Stuart E; Wu, Bing; Tai, Kaihsu; Fangohr, Hans; Jeffreys, Paul; Cox, Simon; Frey, Jeremy G; Sansom, Mark S P; Essex, Jonathan W

    2005-08-15

    Biomolecular computer simulations are now widely used not only in an academic setting to understand the fundamental role of molecular dynamics on biological function, but also in the industrial context to assist in drug design. In this paper, two applications of Grid computing to this area will be outlined. The first, involving the coupling of distributed computing resources to dedicated Beowulf clusters, is targeted at simulating protein conformational change using the Replica Exchange methodology. In the second, the rationale and design of a database of biomolecular simulation trajectories is described. Both applications illustrate the increasingly important role modern computational methods are playing in the life sciences.

  16. Grid cells and cortical representation.

    PubMed

    Moser, Edvard I; Roudi, Yasser; Witter, Menno P; Kentros, Clifford; Bonhoeffer, Tobias; Moser, May-Britt

    2014-07-01

    One of the grand challenges in neuroscience is to comprehend neural computation in the association cortices, the parts of the cortex that have shown the largest expansion and differentiation during mammalian evolution and that are thought to contribute profoundly to the emergence of advanced cognition in humans. In this Review, we use grid cells in the medial entorhinal cortex as a gateway to understand network computation at a stage of cortical processing in which firing patterns are shaped not primarily by incoming sensory signals but to a large extent by the intrinsic properties of the local circuit.

  17. Insightful Workflow For Grid Computing

    SciTech Connect

    Dr. Charles Earl

    2008-10-09

    We developed a workflow adaptation and scheduling system for Grid workflow. The system currently interfaces with and uses the Karajan workflow system. We developed machine learning agents that provide the planner/scheduler with information needed to make decisions about when and how to replan. The Kubrick restructures workflow at runtime, making it unique among workflow scheduling systems. The existing Kubrick system provides a platform on which to integrate additional quality of service constraints and in which to explore the use of an ensemble of scheduling and planning algorithms. This will be the principle thrust of our Phase II work.

  18. The stimulus integration area for horizontal vergence.

    PubMed

    Allison, Robert S; Howard, Ian P; Fang, Xueping

    2004-06-01

    Over what region of space are horizontal disparities integrated to form the stimulus for vergence? The vergence system might be expected to respond to disparities within a small area of interest to bring them into the range of precise stereoscopic processing. However, the literature suggests that disparities are integrated over a fairly large parafoveal area. We report the results of six experiments designed to explore the spatial characteristics of the stimulus for vergence. Binocular eye movements were recorded using magnetic search coils. Each dichoptic display consisted of a central target stimulus that the subject attempted to fuse, and a competing stimulus with conflicting disparity. In some conditions the target was stationary, providing a fixation stimulus. In other conditions, the disparity of the target changed to provide a vergence-tracking stimulus. The target and competing stimulus were combined in a variety of conditions including those in which (1) a transparent textured-disc target was superimposed on a competing textured background, (2) a textured-disc target filled the centre of a competing annular background, and (3) a small target was presented within the centre of a competing annular background of various inner diameters. In some conditions the target and competing stimulus were separated in stereoscopic depth. The results are consistent with a disparity integration area with a diameter of about 5 degrees. Stimuli beyond this integration area can drive vergence in their own right, but they do not appear to be summed or averaged with a central stimulus to form a combined disparity signal. A competing stimulus had less effect on vergence when separated from the target by a disparity pedestal. As a result, we propose that it may be more useful to think in terms of an integration volume for vergence rather than a two-dimensional retinal integration area. PMID:14985895

  19. ARPA-E: Advancing the Electric Grid

    SciTech Connect

    Lemmon, John; Ruiz, Pablo; Sommerer, Tim; Aziz, Michael

    2014-02-24

    The electric grid was designed with the assumption that all energy generation sources would be relatively controllable, and grid operators would always be able to predict when and where those sources would be located. With the addition of renewable energy sources like wind and solar, which can be installed faster than traditional generation technologies, this is no longer the case. Furthermore, the fact that renewable energy sources are imperfectly predictable means that the grid has to adapt in real-time to changing patterns of power flow. We need a dynamic grid that is far more flexible. This video highlights three ARPA-E-funded approaches to improving the grid's flexibility: topology control software from Boston University that optimizes power flow, gas tube switches from General Electric that provide efficient power conversion, and flow batteries from Harvard University that offer grid-scale energy storage.

  20. BREAKUP. Prepares Overset Grids for Processing

    SciTech Connect

    Barnette, D.W.; Ober, C.C.

    1996-02-01

    Many large and complex computational problems require multiple, structured, generically overlapped (overset) grids to obtain numerical solutions in a timely manner. BREAKUP significantly reduces required compute times by preparing overset grids for processing on massively parallel computers. BREAKUP subdivides the original grids for use on a user-specified number of parallel processors. Grid-to-grid and intragrid communications are maintained in the parallel environment via connectivity tables generated by BREAKUP. The subgrids are formed to be statically load balanced and to incur a minimum of communication between the subgrids. When the output of BREAKUP is submitted to an appropriately modified flow solver, subgrid solutions will be updated simultaneously. This contrasts to the much less efficient solution method of updating each original grid sequentially as done in the past.

  1. ARPA-E: Advancing the Electric Grid

    ScienceCinema

    Lemmon, John; Ruiz, Pablo; Sommerer, Tim; Aziz, Michael

    2016-07-12

    The electric grid was designed with the assumption that all energy generation sources would be relatively controllable, and grid operators would always be able to predict when and where those sources would be located. With the addition of renewable energy sources like wind and solar, which can be installed faster than traditional generation technologies, this is no longer the case. Furthermore, the fact that renewable energy sources are imperfectly predictable means that the grid has to adapt in real-time to changing patterns of power flow. We need a dynamic grid that is far more flexible. This video highlights three ARPA-E-funded approaches to improving the grid's flexibility: topology control software from Boston University that optimizes power flow, gas tube switches from General Electric that provide efficient power conversion, and flow batteries from Harvard University that offer grid-scale energy storage.

  2. Unstructured grid generation using the distance function

    NASA Technical Reports Server (NTRS)

    Bihari, Barna L.; Chakravarthy, Sukumar R.

    1991-01-01

    A new class of methods for obtaining level sets to generate unstructured grids is presented. The consecutive grid levels are computed using the distance functions, which corresponds to solving the Hamilton-Jacobi equations representing the equations of motion of fronts propagating with curvature-dependent speed. The relationship between the distance function and the governing equations will be discussed as well as its application to generating grids. Multi-ply connected domains and complex geometries are handled naturally, with a straightforward generalization to several space dimensions. The grid points for the unstructured grid are obtained simultaneously with the grid levels. The search involved in checking for overlapping triangles is minimized by triangulating the entire domain one level at a time.

  3. Grids for Dummies: Featuring Earth Science Data Mining Application

    NASA Technical Reports Server (NTRS)

    Hinke, Thomas H.

    2002-01-01

    This viewgraph presentation discusses the concept and advantages of linking computers together into data grids, an emerging technology for managing information across institutions, and potential users of data grids. The logistics of access to a grid, including the use of the World Wide Web to access grids, and security concerns are also discussed. The potential usefulness of data grids to the earth science community is also discussed, as well as the Global Grid Forum, and other efforts to establish standards for data grids.

  4. Flow Battery Solution for Smart Grid Applications

    SciTech Connect

    none,

    2014-11-30

    To address future grid requirements, a U.S. Department of Energy ARRA Storage Demonstration program was launched in 2009 to commercialize promising technologies needed for stronger and more renewables-intensive grids. Raytheon Ktech and EnerVault received a cost-share grant award from the U.S. Department of Energy to develop a grid-scale storage system based on EnerVault’s iron-chromium redox flow battery technology.

  5. Systems Engineering Building Advances Power Grid Research

    SciTech Connect

    Virden, Jud; Huang, Henry; Skare, Paul; Dagle, Jeff; Imhoff, Carl; Stoustrup, Jakob; Melton, Ron; Stiles, Dennis; Pratt, Rob

    2015-08-19

    Researchers and industry are now better equipped to tackle the nation’s most pressing energy challenges through PNNL’s new Systems Engineering Building – including challenges in grid modernization, buildings efficiency and renewable energy integration. This lab links real-time grid data, software platforms, specialized laboratories and advanced computing resources for the design and demonstration of new tools to modernize the grid and increase buildings energy efficiency.

  6. Improved Gridded Aerosol Data for India

    SciTech Connect

    Gueymard, C.; Sengupta, M.

    2013-11-01

    Using point data from ground sites in and around India equipped with multiwavelength sunphotometers, as well as gridded data from space measurements or from existing aerosol climatologies, an improved gridded database providing the monthly aerosol optical depth at 550 nm (AOD550) and Angstrom exponent (AE) over India is produced. Data from 83 sunphotometer sites are used here as ground truth tocalibrate, optimally combine, and validate monthly gridded data during the period from 2000 to 2012.

  7. FINAL REPORT - CENTER FOR GRID MODERNIZATION

    SciTech Connect

    Markiewicz, Daniel R

    2008-06-30

    The objective of the CGM was to develop high-priority grid modernization technologies in advanced sensors, communications, controls and smart systems to enable use of real-time or near real-time information for monitoring, analyzing and managing distribution and transmission grid conditions. The key strategic approach to carry out individual CGM research and development (R&D) projects was through partnerships, primarily with the GridApp™ Consortium utility members.

  8. Improved nuclear fuel assembly grid spacer

    DOEpatents

    Marshall, John; Kaplan, Samuel

    1977-01-01

    An improved fuel assembly grid spacer and method of retaining the basic fuel rod support elements in position within the fuel assembly containment channel. The improvement involves attachment of the grids to the hexagonal channel and of forming the basic fuel rod support element into a grid structure, which provides a design which is insensitive to potential channel distortion (ballooning) at high fluence levels. In addition the improved method eliminates problems associated with component fabrication and assembly.

  9. Horizontal oil well applications and oil recovery assessment. Volume 1: Success of horizontal well technology, Final report

    SciTech Connect

    Deskins, W.G.; McDonald, W.J.; Knoll, R.G.; Springer, S.J.

    1995-03-01

    Horizontal technology has been applied in over 110 formations in the USA. Volume I of this study addresses the overall success of horizontal technology, especially in less-publicized formations, i.e., other than the Austin Chalk, Bakken, and Niobrara. Operators in the USA. and Canada were surveyed on a formation-by-formation basis by means of a questionnaire. Response data were received describing horizontal well projects in 58 formations in the USA. and 88 in Canada. Operators responses were analyzed for trends in technical and economic success based on lithology (clastics and carbonates) and resource type (light oil, heavy oil, and gas). The potential impact of horizontal technology on reserves was also estimated. A forecast of horizontal drilling activity over the next decade was developed.

  10. Effects of grids in drift tubes

    SciTech Connect

    Okamura M.; Yamauchi, H.

    2012-05-20

    In 2011, we upgraded a 201 MHz buncher in the proton injector for the alternating gradient synchrotron (AGS) - relativistic heavy ion collider (RHIC) complex. In the buncher we installed four grids made of tungsten to improve the transit time factor. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a computerized numerically controlled (CNC) wire cutting electrical discharge machining (EDM). The 3D electric field of the grid was simulated.

  11. A New Elliptical Grid Clustering Method

    NASA Astrophysics Data System (ADS)

    Guansheng, Zheng

    A new base on grid clustering method is presented in this paper. This new method first does unsupervised learning on the high dimensions data. This paper proposed a grid-based approach to clustering. It maps the data onto a multi-dimensional space and applies a linear transformation to the feature space instead of to the objects themselves and then approach a grid-clustering method. Unlike the conventional methods, it uses a multidimensional hyper-eclipse grid cell. Some case studies and ideas how to use the algorithms are described. The experimental results show that EGC can discover abnormity shapes of clusters.

  12. Ion mobility spectrometer with virtual aperture grid

    DOEpatents

    Pfeifer, Kent B.; Rumpf, Arthur N.

    2010-11-23

    An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.

  13. Workshop on Grid Generation and Related Areas

    NASA Technical Reports Server (NTRS)

    1992-01-01

    A collection of papers given at the Workshop on Grid Generation and Related Areas is presented. The purpose of this workshop was to assemble engineers and scientists who are currently working on grid generation for computational fluid dynamics (CFD), surface modeling, and related areas. The objectives were to provide an informal forum on grid generation and related topics, to assess user experience, to identify needs, and to help promote synergy among engineers and scientists working in this area. The workshop consisted of four sessions representative of grid generation and surface modeling research and application within NASA LeRC. Each session contained presentations and an open discussion period.

  14. Development of a smart DC grid model

    NASA Astrophysics Data System (ADS)

    Dalimunthe, Amty Ma'rufah Ardhiyah; Mindara, Jajat Yuda; Panatarani, Camellia; Joni, I. Made

    2016-03-01

    Smart grid and distributed generation should be the solution of the global climate change and the crisis energy of the main source of electrical power generation which is fossil fuel. In order to meet the rising electrical power demand and increasing service quality demands, as well as reduce pollution, the existing power grid infrastructure should be developed into a smart grid and distributed power generation which provide a great opportunity to address issues related to energy efficiency, energy security, power quality and aging infrastructure systems. The conventional of the existing distributed generation system is an AC grid while for a renewable resources requires a DC grid system. This paper explores the model of smart DC grid by introducing a model of smart DC grid with the stable power generation give a minimal and compressed circuitry that can be implemented very cost-effectively with simple components. The PC based application software for controlling was developed to show the condition of the grid and to control the grid become `smart'. The model is then subjected to a severe system perturbation, such as incremental change in loads to test the performance of the system again stability. It is concluded that the system able to detect and controlled the voltage stability which indicating the ability of power system to maintain steady voltage within permissible rangers in normal condition.

  15. Software for Refining or Coarsening Computational Grids

    NASA Technical Reports Server (NTRS)

    Daines, Russell; Woods, Jody

    2003-01-01

    A computer program performs calculations for refinement or coarsening of computational grids of the type called structured (signifying that they are geometrically regular and/or are specified by relatively simple algebraic expressions). This program is designed to facilitate analysis of the numerical effects of changing structured grids utilized in computational fluid dynamics (CFD) software. Unlike prior grid-refinement and -coarsening programs, this program is not limited to doubling or halving: the user can specify any refinement or coarsening ratio, which can have a noninteger value. In addition to this ratio, the program accepts, as input, a grid file and the associated restart file, which is basically a file containing the most recent iteration of flow-field variables computed on the grid. The program then refines or coarsens the grid as specified, while maintaining the geometry and the stretching characteristics of the original grid. The program can interpolate from the input restart file to create a restart file for the refined or coarsened grid. The program provides a graphical user interface that facilitates the entry of input data for the grid-generation and restart-interpolation routines.

  16. Software for Refining or Coarsening Computational Grids

    NASA Technical Reports Server (NTRS)

    Daines, Russell; Woods, Jody

    2002-01-01

    A computer program performs calculations for refinement or coarsening of computational grids of the type called 'structured' (signifying that they are geometrically regular and/or are specified by relatively simple algebraic expressions). This program is designed to facilitate analysis of the numerical effects of changing structured grids utilized in computational fluid dynamics (CFD) software. Unlike prior grid-refinement and -coarsening programs, this program is not limited to doubling or halving: the user can specify any refinement or coarsening ratio, which can have a noninteger value. In addition to this ratio, the program accepts, as input, a grid file and the associated restart file, which is basically a file containing the most recent iteration of flow-field variables computed on the grid. The program then refines or coarsens the grid as specified, while maintaining the geometry and the stretching characteristics of the original grid. The program can interpolate from the input restart file to create a restart file for the refined or coarsened grid. The program provides a graphical user interface that facilitates the entry of input data for the grid-generation and restart-interpolation routines.

  17. Software for Refining or Coarsening Computational Grids

    NASA Technical Reports Server (NTRS)

    Daines, Russell; Woods, Jody

    2002-01-01

    A computer program performs calculations for refinement or coarsening of computational grids of the type called "structured" (signifying that they are geometrically regular and/or are specified by relatively simple algebraic expressions). This program is designed to facilitate analysis of the numerical effects of changing structured grids utilized in computational fluid dynamics (CFD) software. Unlike prior grid-refinement and -coarsening programs, this program is not limited to doubling or halving: the user can specify any refinement or coarsening ratio, which can have a noninteger value. In addition to this ratio, the program accepts, as input, a grid file and the associated restart file, which is basically a file containing the most recent iteration of flow-field variables computed on the grid. The program then refines or coarsens the grid as specified, while maintaining the geometry and the stretching characteristics of the original grid. The program can interpolate from the input restart file to create a restart file for the refined or coarsened grid. The program provides a graphical user interface that facilitates the entry of input data for the grid-generation and restart-interpolation routines.

  18. Electron Backstreaming Mitigation via a Magnetic Grid

    NASA Technical Reports Server (NTRS)

    Foster, John F.; Roman, Robert F.; Soulas, George C.; Patterson, Michael J.

    2002-01-01

    Electron backstreaming due to accelerator grid hole enlargement has been identified as a failure mechanism that will limit ion thruster service lifetime. Over extended periods of time as accelerator grid apertures enlarge due to erosion, ion thrusters are required to operate at increasingly higher accelerator grid voltages in order to prevent electron backstreaming. These higher voltages give rise to higher grid erosion rates, which in turn accelerates aperture enlargement. Presented here is an approach to mitigate the backflow of electrons into the engine by using a transverse magnetic field.

  19. A Moving Grid Capability for NPARC

    NASA Technical Reports Server (NTRS)

    Slater, John W.

    1998-01-01

    Version 3.1 of the NPARC computational fluid dynamics flow solver introduces a capability to solve unsteady flow on moving multi-block, structured grids with nominally second-order time accuracy. The grid motion is due to segments of the boundary grid that translate and rotate in a rigid-body manner or deform. The grid is regenerated at each time step to accommodate the boundary grid motion. The flow equations and computational models sense the moving grid through the grid velocities, which are computed from a time-difference of the grids at two consecutive time levels. For three-dimensional flow domains, it is assumed that the grid retains a planar character with respect to one coordinate. The application and accuracy of NPARC v3.1 is demonstrated for flow about a flying wedge, rotating flap, a collapsing bump in a duct, and the upstart / restart flow in a variable-geometry inlet. The results compare well with analytic and experimental results.

  20. Application Note: Power Grid Modeling With Xyce.

    SciTech Connect

    Sholander, Peter E.

    2015-06-01

    This application note describes how to model steady-state power flows and transient events in electric power grids with the SPICE-compatible Xyce TM Parallel Electronic Simulator developed at Sandia National Labs. This application notes provides a brief tutorial on the basic devices (branches, bus shunts, transformers and generators) found in power grids. The focus is on the features supported and assumptions made by the Xyce models for power grid elements. It then provides a detailed explanation, including working Xyce netlists, for simulating some simple power grid examples such as the IEEE 14-bus test case.

  1. Best Practices for Unstructured Grid Shock Fitting

    NASA Technical Reports Server (NTRS)

    McCloud, Peter L.

    2017-01-01

    Unstructured grid solvers have well-known issues predicting surface heat fluxes when strong shocks are present. Various efforts have been made to address the underlying numerical issues that cause the erroneous predictions. The present work addresses some of the shortcomings of unstructured grid solvers, not by addressing the numerics, but by applying structured grid best practices to unstructured grids. A methodology for robust shock detection and shock fitting is outlined and applied to production relevant cases. Results achieved by using the Loci-CHEM Computational Fluid Dynamics solver are provided.

  2. Image enhancement with polymer grid triode arrays

    SciTech Connect

    Heeger, A.J.; Heeger, D.J.; Langan, J.

    1995-12-08

    An array of polymer grid triodes connected by a common grid functions as a {open_quotes}plastic retina,{close_quotes} providing local contrast gain control for image enhancement. This simple device, made from layers of conducting polymers, functions as an active resistive network that performs center-surround filtering. The polymer grid triode array with common grid is a continuous analog of the discrete approach of Mead, with a variety of fabrication advantages and significant savings in area within the unit cell of each pixel. 6 refs., 4 figs.

  3. Structured adaptive grid generation using algebraic methods

    NASA Technical Reports Server (NTRS)

    Yang, Jiann-Cherng; Soni, Bharat K.; Roger, R. P.; Chan, Stephen C.

    1993-01-01

    The accuracy of the numerical algorithm depends not only on the formal order of approximation but also on the distribution of grid points in the computational domain. Grid adaptation is a procedure which allows optimal grid redistribution as the solution progresses. It offers the prospect of accurate flow field simulations without the use of an excessively timely, computationally expensive, grid. Grid adaptive schemes are divided into two basic categories: differential and algebraic. The differential method is based on a variational approach where a function which contains a measure of grid smoothness, orthogonality and volume variation is minimized by using a variational principle. This approach provided a solid mathematical basis for the adaptive method, but the Euler-Lagrange equations must be solved in addition to the original governing equations. On the other hand, the algebraic method requires much less computational effort, but the grid may not be smooth. The algebraic techniques are based on devising an algorithm where the grid movement is governed by estimates of the local error in the numerical solution. This is achieved by requiring the points in the large error regions to attract other points and points in the low error region to repel other points. The development of a fast, efficient, and robust algebraic adaptive algorithm for structured flow simulation applications is presented. This development is accomplished in a three step process. The first step is to define an adaptive weighting mesh (distribution mesh) on the basis of the equidistribution law applied to the flow field solution. The second, and probably the most crucial step, is to redistribute grid points in the computational domain according to the aforementioned weighting mesh. The third and the last step is to reevaluate the flow property by an appropriate search/interpolate scheme at the new grid locations. The adaptive weighting mesh provides the information on the desired concentration

  4. An adaptive grid with directional control

    NASA Technical Reports Server (NTRS)

    Brackbill, J. U.

    1993-01-01

    An adaptive grid generator for adaptive node movement is here derived by combining a variational formulation of Winslow's (1981) variable-diffusion method with a directional control functional. By applying harmonic-function theory, it becomes possible to define conditions under which there exist unique solutions of the resulting elliptic equations. The results obtained for the grid generator's application to the complex problem posed by the fluid instability-driven magnetic field reconnection demonstrate one-tenth the computational cost of either a Eulerian grid or an adaptive grid without directional control.

  5. 75 FR 63462 - Smart Grid Interoperability Standards; Notice of Docket Designation for Smart Grid...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Smart Grid Interoperability Standards; Notice of Docket Designation for Smart Grid Interoperability Standards October 7, 2010. 1. The Energy Independence and Security Act...

  6. Maximum horizontal range of volcanic ballistic projectiles ejected during explosive eruptions at Santorini caldera

    NASA Astrophysics Data System (ADS)

    Konstantinou, K. I.

    2015-08-01

    This study investigates the hazard posed by Volcanic Ballistic Projectiles (VBPs) to the Santorini islands considering eruption scenarios that include low (VEI = 2-3) and higher energy (VEI > 3) eruptions. A model that describes rapid decompression of pressurized magma below a caprock along with its fragmentation and acceleration of particles is utilized for estimating initial velocities during vulcanian-style eruptions. These initial velocities are inserted into the ballistic equations assuming that VBPs have a cube-like shape, are subjected to gravity/drag forces and are launched into a zone of reduced drag. Four different diameters of VBPs are considered (0.35 m, 1.0 m, 2.0 m, 3.0 m) and also different values of gas fractions and extent of the reduced drag zone are investigated. The results of these calculations show that an area of 1-2 km width along the western coast of Thera will be within the maximum range of VBPs, provided that the eruptive vent will develop either on Nea Kameni or between Nea Kameni and Thera. Initial velocities for higher energy eruptions are estimated by considering the conversion efficiency of thermal to kinetic energy. For the case of an eruption with VEI = 4 and a number of vents centered between Nea and Palea Kameni, calculations show that the coastal areas of Thera and Therasia are within the maximum horizontal range of VBPs with diameter larger than 0.35 m. As the exact position of the eruptive vent seems to be of crucial importance for determining the areas at risk, continuous seismic and geodetic monitoring of the caldera is needed in order to decipher its likely location.

  7. Characterization of the horizontal optical turbulence (C{/n 2}) data measured at Kongju and Cheonan

    NASA Astrophysics Data System (ADS)

    Yeong Kim, Bo; Lee, Jun Ho; Soo Choi, Young

    2015-06-01

    When light from an object or an astronomical star propagates in the earth's atmosphere, atmospheric turbulence can distort and move the image in various ways. A quantitative measure of the intensity of optical turbulence with a refractive index structure parameter, C {/n 2}, is widely used in the statistical characterization of the random refractive index fluctuations generally referred to as optical turbulence. I this study, we investigated the horizontal optical turbulence in the near infrared region (850nm) at two sites in South Korea (Kongju and Cheonan) by using a scintillometer. The scintillometer measured the refractive index structure parameter C {/n 2} over 2.1- and 0.4-km paths, respectively, in Kongju and Cheonan. The first path was over an urban area characterized by a complicated land-use mix (residential houses, a river, bare ground, etc.) whereas the second path was a building-to-building path at a 15-m height on a university campus. In addition to the scintillometer, an independent weather station recorded meteorological conditions such as wind speed, relative humidity, and temperature. Study results indicate the general patterns of the optical turbulence at both sites agree with previous-reported diurnal patterns; they have two dips in C2n, one at around sunrise and the other at sunset, but the night profiles varied strongly depending on the atmospheric conditions. The average values of C {/n 2} for the measurement period were × 10-15 and 2.90 × 10-14 m-2/3 in Kongju and Cheonan, espectively, thus confirming that the optical field is clearer in the former. In addition, the average values of the Fried parameter, r0, were accordingly estimated to be 8.0 and 2.5 cm over a 2-km optical distance at Kongju and Cheonan, respectively.

  8. Vertical and horizontal NO2 transport in urban area associated with land-sea breeze as observed by ground-based MAX-DOAS

    NASA Astrophysics Data System (ADS)

    Takashima, H.; Kanaya, Y.

    2013-12-01

    Since July 2012, continuous NO2 profile observations have been performed by using ground-based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) at Fukuoka (33.55N, 130.36E), an urban site in Japan. MAX-DOAS is a passive remote sensing technique using scatted visible and ultraviolet solar radiation at several elevation angles, and it can allow us to retrieve vertical information on several trace gasses. In this study, the vertical resolution of the profiles is roughly 1 km below 2 km height. We investigate inhomogeneity of NO2 over Fukuoka by observing at two azimuth angles, Tenjin (downtown area) direction and Itoshima (out of downtown area) direction. Understanding of the spatial inhomogeneity of NO2 in urban area is important for measuring a priori profiles for satellite and for validating chemical transport model. Diurnal variation with maximum in the morning is clearly observed in both directions throughout the year for 0-1 km. Diurnal variation with maximum around noon is sometimes observed in Itoshima direction, which is delayed by 1-2 hours from maxima in Tenjin direction. The NO2 maximum for upper level (1-2 km) is also delayed from the maximum in Tenjin direction. From the analysis of surface wind field, these variations seems to be strongly related to vertical/horizontal transport of high concentration of NO2 from the downtown area (and development of the boundary layer) and horizontal transport of low concentration from ocean associated with land-sea breeze. We also present a comparison of NO2 data measured with the Ozone Monitoring Instrument (OMI) satellite sensor.

  9. Hydrological Scenario Using Tools and Applications Available in enviroGRIDS Portal

    NASA Astrophysics Data System (ADS)

    Bacu, V.; Mihon, D.; Stefanut, T.; Rodila, D.; Cau, P.; Manca, S.; Soru, C.; Gorgan, D.

    2012-04-01

    the other hand, the applications can collaborate at the same architectural levels, which represent the horizontal interoperability. Both the horizontal and vertical interoperability is accomplished by services and by exchanging data. The calibration procedure requires huge computational resources, which are provided by the Grid infrastructure. On the other hand the scenario development through BASHYT requires a flexible way of interaction with the SWAT model in order to easily change the input model. The large user community of SWAT from the enviroGRIDS consortium or outside may greatly benefit from tools and applications related with the calibration process, scenario development and execution from the enviroGRIDS portal. [1]. enviroGRIDS project, http://envirogrids.net/ [2]. Gorgan D., Abbaspour K., Cau P., Bacu V., Mihon D., Giuliani G., Ray N., Lehmann A., Grid Based Data Processing Tools and Applications for Black Sea Catchment Basin. IDAACS 2011 - The 6th IEEE International Conference on Intelligent Data Acquisition and Advanced Computing Systems: Technology and Applications 15-17 September 2011, Prague. IEEE Computer Press, pp. 223 - 228 (2011). [3]. Soil and Water Assessment Tool, http://www.brc.tamus.edu/swat/index.html [4]. Bacu V., Mihon D., Rodila D., Stefanut T., Gorgan D., Grid Based Architectural Components for SWAT Model Calibration. HPCS 2011 - International Conference on High Performance Computing and Simulation, 4-8 July, Istanbul, Turkey, ISBN 978-1-61284-381-0, doi: 10.1109/HPCSim.2011.5999824, pp. 193-198 (2011). [5]. Manca S., Soru C., Cau P., Meloni G., Fiori M., A multi model and multiscale, GIS oriented Web framework based on the SWAT model to face issues of water and soil resource vulnerability. Presentation at the 5th International SWAT Conference, August 3-7, 2009, http://www.brc.tamus.edu/swat/4thswatconf/docs/rooma/session5/Cau-Bashyt.pdf [6]. Bacu V., Mihon D., Stefanut T., Rodila D., Gorgan D., Cau P., Manca S., Grid Based Services and

  10. Formation damage effects on horizontal-well flow efficiency

    SciTech Connect

    Renard, G.; Dupuy, J.M. )

    1991-07-01

    Wellbore damage commonly is accounted for by an apparent skin factor. A better relative index for determining the efficiency with which a well has been drilled and completed is the flow efficiency, the ration of a well's actual PI to ideal PI. The flow efficiency of horizontal wells is derived assuming steady-state flow of an incompressible fluid in a homogeneous, anisotropic medium. A comparison between the flow efficiencies of vertical and horizontal wells indicates that permeability reduction around the wellbore is less detrimental to horizontal wells. This paper shows that the effect of damage around a horizontal wellbore is reduced slightly by increasing the well length. Conversely, if the vertical permeability is less than the horizontal permeability, the anisotropy ratio, {radical} k{sub H}/k{sub V}, magnifies the influence of formation damage near the horizontal wellbore. Examples of flow efficiency calculations assuming a formation damage or a formation collapse around a liner in poorly consolidated formations are provided for horizontal and vertical wells.

  11. Geologic aspects of horizontal drilling in self-sourcing reservoirs

    SciTech Connect

    Illich, H.A. )

    1991-03-01

    Horizontal drilling techniques provide a way to exploit hydrocarbon reserves that are either noneconomic or only marginally economic using vertical drilling techniques. A significant fraction of these reserves is contained in reservoirs that are self-sourcing or in reservoirs that are closely associated with their resources. Most formations drilled as horizontal targets are self-sourcing. The Austin Chalk, Niobrara, Mesaverde, and Bakken are examples of horizontally drilled, self-sourcing reservoir systems. In formations like the Bakken or Austin Chalk, the close relationship between reservoir and source makes risks associated with migration and accumulation less important. Reservoirs of this kind can contain oil or gas and often have little or no associated water. They can be matrix-dominated reservoirs, dual-porosity reservoirs (Mesaverde), or fractured reservoirs (Austin Chalk, Bakken, and Niobrara). Fractured, self-sourcing reservoirs also can possess matrix characteristics that contribute increased recovery efficiency. Most reservoirs drilled horizontally possess matrix characteristics that contribute increased recovery efficiency. Most reservoirs drilled horizontally possess highly heterogeneous reservoir systems. Characterization of the style of reservoir heterogeneity in self-sourcing systems is important if the favorable properties of horizontally oriented bore holes are to be realized. Production data and rock mechanics considerations are important in horizontal drilling ventures. Examples of the use of these data for the purpose of defining reservoir characteristics are discussed. Knowledge of lateral changes in reservoir properties is essential if we are to recover known reserves efficiently.

  12. Chromospheric Circulation Driven by Horizontally Inhomogeneous Heating

    NASA Astrophysics Data System (ADS)

    Vasyliunas, V. M.; Song, P.

    2013-12-01

    The rate of chromospheric heating by damping of Alfvén waves propagating upward from below the photosphere (Song and Vasyliunas, 2011) depends on the strength of the magnetic field. In regions of locally confined very strong magnetic field, particularly at the boundaries of the chromospheric network, the heating rate is greatly enhanced, and the heating per unit mass is concentrated toward higher altitudes. Song and Vasyliunas (2012) proposed that the resulting inhomogeneity of pressure may drive circulating flows in the chromosphere, horizontally away from the strong-field region at one altitude and returning at another. We investigate this circulation further, with particular attention to the flow patterns and to the question to what extent the circulation might be impeded by MHD effects. The heating process acts equally on the plasma and on the neutral gas, but because most of the chromosphere is weakly ionized, the flow is predominantly that of the neutral gas. Below the altitude he at which electron collision frequency equals electron gyrofrequency, all the species (electrons, ions, neutrals) flow together; the magnetic field can change relative to the flow only by diffusion. In the altitude range above he but below the altitude hi at which ion collision frequency equals ion gyrofrequency, ions and neutrals flow together, but electron flow is decoupled from neutral flow; the magnetic field is frozen to the motion of electrons. Above hi neutrals are decoupled from ions, while electrons and ions flow nearly together with the common plasma flow; the magnetic field is frozen to the plasma flow. (This is analogous to the well-studied neutral-wind dynamo process in the terrestrial ionosphere and thermosphere, except that at the Sun there is no counterpart to the non-conducting terrestrial atmosphere.) The circulation, confined to altitudes above he, consists of neutral and ion flow between he and hi; above hi, there is only neutral flow, with ions at rest, while

  13. Photometric identification of blue horizontal branch stars

    NASA Astrophysics Data System (ADS)

    Smith, K. W.; Bailer-Jones, C. A. L.; Klement, R. J.; Xue, X. X.

    2010-11-01

    We investigate the performance of some common machine learning techniques in identifying blue horizontal branch (BHB) stars from photometric data. To train the machine learning algorithms, we use previously published spectroscopic identifications of BHB stars from Sloan digital sky survey (SDSS) data. We investigate the performance of three different techniques, namely k nearest neighbour classification, kernel density estimation for discriminant analysis and a support vector machine (SVM). We discuss the performance of the methods in terms of both completeness (what fraction of input BHB stars are successfully returned as BHB stars) and contamination (what fraction of contaminating sources end up in the output BHB sample). We discuss the prospect of trading off these values, achieving lower contamination at the expense of lower completeness, by adjusting probability thresholds for the classification. We also discuss the role of prior probabilities in the classification performance, and we assess via simulations the reliability of the dataset used for training. Overall it seems that no-prior gives the best completeness, but adopting a prior lowers the contamination. We find that the support vector machine generally delivers the lowest contamination for a given level of completeness, and so is our method of choice. Finally, we classify a large sample of SDSS Data Release 7 (DR7) photometry using the SVM trained on the spectroscopic sample. We identify 27 074 probable BHB stars out of a sample of 294 652 stars. We derive photometric parallaxes and demonstrate that our results are reasonable by comparing to known distances for a selection of globular clusters. We attach our classifications, including probabilities, as an electronic table, so that they can be used either directly as a BHB star catalogue, or as priors to a spectroscopic or other classification method. We also provide our final models so that they can be directly applied to new data. Full Tables 7, A.3

  14. DRAGON Grid: A Three-Dimensional Hybrid Grid Generation Code Developed

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing

    2000-01-01

    Because grid generation can consume 70 percent of the total analysis time for a typical three-dimensional viscous flow simulation for a practical engineering device, payoffs from research and development could reduce costs and increase throughputs considerably. In this study, researchers at the NASA Glenn Research Center at Lewis Field developed a new hybrid grid approach with the advantages of flexibility, high-quality grids suitable for an accurate resolution of viscous regions, and a low memory requirement. These advantages will, in turn, reduce analysis time and increase accuracy. They result from an innovative combination of structured and unstructured grids to represent the geometry and the computation domain. The present approach makes use of the respective strengths of both the structured and unstructured grid methods, while minimizing their weaknesses. First, the Chimera grid generates high-quality, mostly orthogonal meshes around individual components. This process is flexible and can be done easily. Normally, these individual grids are required overlap each other so that the solution on one grid can communicate with another. However, when this communication is carried out via a nonconservative interpolation procedure, a spurious solution can result. Current research is aimed at entirely eliminating this undesired interpolation by directly replacing arbitrary grid overlapping with a nonstructured grid called a DRAGON grid, which uses the same set of conservation laws over the entire region, thus ensuring conservation everywhere. The DRAGON grid is shown for a typical film-cooled turbine vane with 33 holes and 3 plenum compartments. There are structured grids around each geometrical entity and unstructured grids connecting them. In fiscal year 1999, Glenn researchers developed and tested the three-dimensional DRAGON grid-generation tools. A flow solver suitable for the DRAGON grid has been developed, and a series of validation tests are underway.

  15. Irvine Smart Grid Demonstration, a Regional Smart Grid Demonstration Project

    SciTech Connect

    Yinger, Robert; Irwin, Mark

    2015-12-29

    ISGD was a comprehensive demonstration that spanned the electricity delivery system and extended into customer homes. The project used phasor measurement technology to enable substation-level situational awareness, and demonstrated SCE’s next-generation substation automation system. It extended beyond the substation to evaluate the latest generation of distribution automation technologies, including looped 12-kV distribution circuit topology using URCIs. The project team used DVVC capabilities to demonstrate CVR. In customer homes, the project evaluated HAN devices such as smart appliances, programmable communicating thermostats, and home energy management components. The homes were also equipped with energy storage, solar PV systems, and a number of energy efficiency measures (EEMs). The team used one block of homes to evaluate strategies and technologies for achieving ZNE. A home achieves ZNE when it produces at least as much renewable energy as the amount of energy it consumes annually. The project also assessed the impact of device-specific demand response (DR), as well as load management capabilities involving energy storage devices and plug-in electric vehicle charging equipment. In addition, the ISGD project sought to better understand the impact of ZNE homes on the electric grid. ISGD’s SENet enabled end-to-end interoperability between multiple vendors’ systems and devices, while also providing a level of cybersecurity that is essential to smart grid development and adoption across the nation. The ISGD project includes a series of sub-projects grouped into four logical technology domains: Smart Energy Customer Solutions, Next-Generation Distribution System, Interoperability and Cybersecurity, and Workforce of the Future. Section 2.3 provides a more detailed overview of these domains.

  16. Can Clouds replace Grids? Will Clouds replace Grids?

    NASA Astrophysics Data System (ADS)

    Shiers, J. D.

    2010-04-01

    The world's largest scientific machine - comprising dual 27km circular proton accelerators cooled to 1.9oK and located some 100m underground - currently relies on major production Grid infrastructures for the offline computing needs of the 4 main experiments that will take data at this facility. After many years of sometimes difficult preparation the computing service has been declared "open" and ready to meet the challenges that will come shortly when the machine restarts in 2009. But the service is not without its problems: reliability - as seen by the experiments, as opposed to that measured by the official tools - still needs to be significantly improved. Prolonged downtimes or degradations of major services or even complete sites are still too common and the operational and coordination effort to keep the overall service running is probably not sustainable at this level. Recently "Cloud Computing" - in terms of pay-per-use fabric provisioning - has emerged as a potentially viable alternative but with rather different strengths and no doubt weaknesses too. Based on the concrete needs of the LHC experiments - where the total data volume that will be acquired over the full lifetime of the project, including the additional data copies that are required by the Computing Models of the experiments, approaches 1 Exabyte - we analyze the pros and cons of Grids versus Clouds. This analysis covers not only technical issues - such as those related to demanding database and data management needs - but also sociological aspects, which cannot be ignored, neither in terms of funding nor in the wider context of the essential but often overlooked role of science in society, education and economy.

  17. Regional Studies and Applications with a Variable Resolution Stretched Grid Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Fox-Rabinovitz, Michael; Dee, Dick; Takacs, Lawrence

    1999-01-01

    The variable resolution stretched grid (SG) version of the Goddard Earth Observing System (GEOS) Data Assimilation System (DAS) incorporating the GEOS SG-GCM, is used for regional analysis, forecast, and climate applications. The region of interest with enhanced horizontal resolution, mostly used in experiments, is a rectangle over the U.S. The SG-DAS is capable of reproducing regional mesoscale fields, patterns and diagnostics that are not produced by the medium uniform resolution run with the same amount of grid points as for the SG. The SG-DAS regional analyses and diagnostics are used for: validation of regional climate simulation experiments produced with the SG-GCM for the U.S. 1988 summer drought; and are planned to be used for atmospheric chemistry transport experiments. Also, a case study is conducted on a super-typhoon development in December 1997. The SG-DAS appears to be a viable candidate for a variety of regional studies and applications.

  18. An Application of Overset Grids to Payload/Fairing Three-Dimensional Internal Flow CFD Analysis

    NASA Technical Reports Server (NTRS)

    Kandula, Max; Nallasamy, R.; Schallhorn, P.; Duncil, L.

    2007-01-01

    The application of overset grids to the computational fluid dynamics analysis of three-dimensional internal flow in the payload/fairing of an expendable launch vehicle is described. In conjunction with the overset grid system, the flowfield in the payload/fairing configuration is obtained with the aid of OVERFLOW Navier-Stokes code. The solution exhibits a highly three dimensional complex flowfield with swirl, separation, and vortices. Some of the computed flow features are compared with the measured Laser-Doppler Velocimetry (LDV) data on a 1/5th scale model of the payload/fairing configuration. The counter-rotating vortex structures and the location of the saddle point predicted by the CFD analysis are in general agreement with the LDV data. Comparisons of the computed (CFD) velocity profiles on horizontal and vertical lines in the LDV measurement plane in the faring nose region show reasonable agreement with the LDV data.

  19. Temporal and Spatial Comparison of Gridded TMY, TDY, and TGY Data Sets

    SciTech Connect

    Habte, A.; Lopez, A.; Sengupta, M.; Wilcox, S.

    2014-02-01

    Typical Meteorological Year (TMY) data sets provide industry standard resource information for building designers and are commonly used by the solar industry to estimate photovoltaic and concentrating solar power system performance. Historically, TMY data sets were only available for certain station locations, but current TMY data sets are available on the same grid as the National Solar Radiation Database data and are referred to as the gridded TMY. In this report, a comparison of TMY, typical direct (normal irradiance) year (TDY), and typical global (horizontal irradiance) year (TGY) data sets were performed to better understand the impact of ancillary weather variables upon them. These analyses identified geographical areas of high and low temporal and spatial variability, thereby providing insight into the representativeness of a particular TMY data set for use in renewable energy as well as other applications.

  20. Progress in Horizontal and Slant-Path Imaging Speckle Imaging

    SciTech Connect

    Carrano, C J

    2003-01-30

    The difficulty in terrestrial imaging over long horizontal or slant paths is that atmospheric aberrations and distortions reduce the resolution and contrast in images recorded at high resolution. This paper will describe the problem of horizontal-path imaging, briefly cover various methods for imaging over horizontal paths and then describe the speckle imaging method actively being pursued at LLNL. We will review some closer range (1-3 km range) imagery of people we have already published, as well as show new results of vehicles we have obtained over longer slant-range paths greater than 20 km.

  1. Horizontal Transfer and the Evolution of Host-Pathogen Interactions

    PubMed Central

    de la Casa-Esperón, Elena

    2012-01-01

    Horizontal gene transfer has been long known in viruses and prokaryotes, but its importance in eukaryotes has been only acknowledged recently. Close contact between organisms, as it occurs between pathogens and their hosts, facilitates the occurrence of DNA transfer events. Once inserted in a foreign genome, DNA sequences have sometimes been coopted by pathogens to improve their survival or infectivity, or by hosts to protect themselves against the harm of pathogens. Hence, horizontal transfer constitutes a source of novel sequences that can be adopted to change the host-pathogen interactions. Therefore, horizontal transfer can have an important impact on the coevolution of pathogens and their hosts. PMID:23227424

  2. A grid service-based tool for hyperspectral imaging analysis

    NASA Astrophysics Data System (ADS)

    Carvajal, Carmen L.; Lugo, Wilfredo; Rivera, Wilson; Sanabria, John

    2005-06-01

    This paper outlines the design and implementation of Grid-HSI, a Service Oriented Architecture-based Grid application to enable hyperspectral imaging analysis. Grid-HSI provides users with a transparent interface to access computational resources and perform remotely hyperspectral imaging analysis through a set of Grid services. Grid-HSI is composed by a Portal Grid Interface, a Data Broker and a set of specialized Grid services. Grid based applications, contrary to other clientserver approaches, provide the capabilities of persistence and potential transient process on the web. Our experimental results on Grid-HSI show the suitability of the prototype system to perform efficiently hyperspectral imaging analysis.

  3. Parallel Grid Manipulations in Earth Science Calculations

    NASA Technical Reports Server (NTRS)

    Sawyer, W.; Lucchesi, R.; daSilva, A.; Takacs, L. L.

    1999-01-01

    The National Aeronautics and Space Administration (NASA) Data Assimilation Office (DAO) at the Goddard Space Flight Center is moving its data assimilation system to massively parallel computing platforms. This parallel implementation of GEOS DAS will be used in the DAO's normal activities, which include reanalysis of data, and operational support for flight missions. Key components of GEOS DAS, including the gridpoint-based general circulation model and a data analysis system, are currently being parallelized. The parallelization of GEOS DAS is also one of the HPCC Grand Challenge Projects. The GEOS-DAS software employs several distinct grids. Some examples are: an observation grid- an unstructured grid of points at which observed or measured physical quantities from instruments or satellites are associated- a highly-structured latitude-longitude grid of points spanning the earth at given latitude-longitude coordinates at which prognostic quantities are determined, and a computational lat-lon grid in which the pole has been moved to a different location to avoid computational instabilities. Each of these grids has a different structure and number of constituent points. In spite of that, there are numerous interactions between the grids, e.g., values on one grid must be interpolated to another, or, in other cases, grids need to be redistributed on the underlying parallel platform. The DAO has designed a parallel integrated library for grid manipulations (PILGRIM) to support the needed grid interactions with maximum efficiency. It offers a flexible interface to generate new grids, define transformations between grids and apply them. Basic communication is currently MPI, however the interfaces defined here could conceivably be implemented with other message-passing libraries, e.g., Cray SHMEM, or with shared-memory constructs. The library is written in Fortran 90. First performance results indicate that even difficult problems, such as above-mentioned pole rotation- a

  4. Modeling and Grid Generation of Iced Airfoils

    NASA Technical Reports Server (NTRS)

    Vickerman, Mary B.; Baez, Marivell; Braun, Donald C.; Hackenberg, Anthony W.; Pennline, James A.; Schilling, Herbert W.

    2007-01-01

    SmaggIce Version 2.0 is a software toolkit for geometric modeling and grid generation for two-dimensional, singleand multi-element, clean and iced airfoils. A previous version of SmaggIce was described in Preparing and Analyzing Iced Airfoils, NASA Tech Briefs, Vol. 28, No. 8 (August 2004), page 32. To recapitulate: Ice shapes make it difficult to generate quality grids around airfoils, yet these grids are essential for predicting ice-induced complex flow. This software efficiently creates high-quality structured grids with tools that are uniquely tailored for various ice shapes. SmaggIce Version 2.0 significantly enhances the previous version primarily by adding the capability to generate grids for multi-element airfoils. This version of the software is an important step in streamlining the aeronautical analysis of ice airfoils using computational fluid dynamics (CFD) tools. The user may prepare the ice shape, define the flow domain, decompose it into blocks, generate grids, modify/divide/merge blocks, and control grid density and smoothness. All these steps may be performed efficiently even for the difficult glaze and rime ice shapes. Providing the means to generate highly controlled grids near rough ice, the software includes the creation of a wrap-around block (called the "viscous sublayer block"), which is a thin, C-type block around the wake line and iced airfoil. For multi-element airfoils, the software makes use of grids that wrap around and fill in the areas between the viscous sub-layer blocks for all elements that make up the airfoil. A scripting feature records the history of interactive steps, which can be edited and replayed later to produce other grids. Using this version of SmaggIce, ice shape handling and grid generation can become a practical engineering process, rather than a laborious research effort.

  5. Impact of cloud horizontal inhomogeneity and directional sampling on the retrieval of cloud droplet size by the POLDER instrument

    NASA Astrophysics Data System (ADS)

    Shang, H.; Chen, L.; Bréon, F. M.; Letu, H.; Li, S.; Wang, Z.; Su, L.

    2015-11-01

    The principles of cloud droplet size retrieval via Polarization and Directionality of the Earth's Reflectance (POLDER) requires that clouds be horizontally homogeneous. The retrieval is performed by combining all measurements from an area of 150 km × 150 km to compensate for POLDER's insufficient directional sampling. Using POLDER-like data simulated with the RT3 model, we investigate the impact of cloud horizontal inhomogeneity and directional sampling on the retrieval and analyze which spatial resolution is potentially accessible from the measurements. Case studies show that the sub-grid-scale variability in droplet effective radius (CDR) can significantly reduce valid retrievals and introduce small biases to the CDR (~ 1.5 μm) and effective variance (EV) estimates. Nevertheless, the sub-grid-scale variations in EV and cloud optical thickness (COT) only influence the EV retrievals and not the CDR estimate. In the directional sampling cases studied, the retrieval using limited observations is accurate and is largely free of random noise. Several improvements have been made to the original POLDER droplet size retrieval. For example, measurements in the primary rainbow region (137-145°) are used to ensure retrievals of large droplet (> 15 μm) and to reduce the uncertainties caused by cloud heterogeneity. We apply the improved method using the POLDER global L1B data from June 2008, and the new CDR results are compared with the operational CDRs. The comparison shows that the operational CDRs tend to be underestimated for large droplets because the cloudbow oscillations in the scattering angle region of 145-165° are weak for cloud fields with CDR > 15 μm. Finally, a sub-grid-scale retrieval case demonstrates that a higher resolution, e.g., 42 km × 42 km, can be used when inverting cloud droplet size distribution parameters from POLDER measurements.

  6. Impact of surface coupling grids on tropical cyclone extremes in high-resolution atmospheric simulations

    DOE PAGES

    Zarzycki, Colin M.; Reed, Kevin A.; Bacmeister, Julio T.; Craig, Anthony P.; Bates, Susan C.; Rosenbloom, Nan A.

    2016-02-25

    This article discusses the sensitivity of tropical cyclone climatology to surface coupling strategy in high-resolution configurations of the Community Earth System Model. Using two supported model setups, we demonstrate that the choice of grid on which the lowest model level wind stress and surface fluxes are computed may lead to differences in cyclone strength in multi-decadal climate simulations, particularly for the most intense cyclones. Using a deterministic framework, we show that when these surface quantities are calculated on an ocean grid that is coarser than the atmosphere, the computed frictional stress is misaligned with wind vectors in individual atmospheric gridmore » cells. This reduces the effective surface drag, and results in more intense cyclones when compared to a model configuration where the ocean and atmosphere are of equivalent resolution. Our results demonstrate that the choice of computation grid for atmosphere–ocean interactions is non-negligible when considering climate extremes at high horizontal resolution, especially when model components are on highly disparate grids.« less

  7. Spaceflight Operations Services Grid Prototype

    NASA Technical Reports Server (NTRS)

    Bradford, Robert N.; Mehrotra, Piyush; Lisotta, Anthony

    2004-01-01

    NASA over the years has developed many types of technologies and conducted various types of science resulting in numerous variations of operations, data and applications. For example, operations range from deep space projects managed by JPL, Saturn and Shuttle operations managed from JSC and KSC, ISS science operations managed from MSFC and numerous low earth orbit satellites managed from GSFC that are varied and intrinsically different but require many of the same types of services to fulfill their missions. Also, large data sets (databases) of Shuttle flight data, solar system projects and earth observing data exist which because of their varied and sometimes outdated technologies are not and have not been fully examined for additional information and knowledge. Many of the applications/systems supporting operational services e.g. voice, video, telemetry and commanding, are outdated and obsolete. The vast amounts of data are located in various formats, at various locations and range over many years. The ability to conduct unified space operations, access disparate data sets and to develop systems and services that can provide operational services does not currently exist in any useful form. In addition, adding new services to existing operations is generally expensive and with the current budget constraints not feasible on any broad level of implementation. To understand these services a discussion of each one follows. The Spaceflight User-based Services are those services required to conduct space flight operations. Grid Services are those Grid services that will be used to overcome, through middleware software, some or all the problems that currently exists. In addition, Network Services will be discussed briefly. Network Services are crucial to any type of remedy and are evolving adequately to support any technology currently in development.

  8. 77 FR 38768 - Smart Grid Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-29

    ... to Office of the National Coordinator for Smart Grid Interoperability, National Institute of... participate are invited to submit written statements to the Office of the National Coordinator for Smart Grid... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF...

  9. Towards Verification of Unstructured-Grid Solvers

    NASA Technical Reports Server (NTRS)

    Thomas, James L.; Diskin, Boris; Rumsey, Christopher L.

    2008-01-01

    New methodology for verification of finite-volume computational methods using unstructured grids is presented. The discretization order properties are studied in computational windows, easily constructed within a collection of grids or a single grid. Tests are performed within each window and address a combination of problem-, solution-, and discretization/grid-related features affecting discretization error convergence. The windows can be adjusted to isolate particular elements of the computational scheme, such as the interior discretization, the boundary discretization, or singularities. Studies can use traditional grid-refinement computations within a fixed window or downscaling, a recently-introduced technique in which computations are made within windows contracting toward a focal point of interest. Grids within the windows are constrained to be consistently refined, allowing a meaningful assessment of asymptotic error convergence on unstructured grids. Demonstrations of the method are shown, including a comparative accuracy assessment of commonly-used schemes on general mixed grids and the identification of local accuracy deterioration at boundary intersections. Recommendations to enable attainment of design-order discretization errors for large-scale computational simulations are given.

  10. Uncertainty in gridded CO2 emissions estimates

    NASA Astrophysics Data System (ADS)

    Hogue, Susannah; Marland, Eric; Andres, Robert J.; Marland, Gregg; Woodard, Dawn

    2016-05-01

    We are interested in the spatial distribution of fossil-fuel-related emissions of CO2 for both geochemical and geopolitical reasons, but it is important to understand the uncertainty that exists in spatially explicit emissions estimates. Working from one of the widely used gridded data sets of CO2 emissions, we examine the elements of uncertainty, focusing on gridded data for the United States at the scale of 1° latitude by 1° longitude. Uncertainty is introduced in the magnitude of total United States emissions, the magnitude and location of large point sources, the magnitude and distribution of non-point sources, and from the use of proxy data to characterize emissions. For the United States, we develop estimates of the contribution of each component of uncertainty. At 1° resolution, in most grid cells, the largest contribution to uncertainty comes from how well the distribution of the proxy (in this case population density) represents the distribution of emissions. In other grid cells, the magnitude and location of large point sources make the major contribution to uncertainty. Uncertainty in population density can be important where a large gradient in population density occurs near a grid cell boundary. Uncertainty is strongly scale-dependent with uncertainty increasing as grid size decreases. Uncertainty for our data set with 1° grid cells for the United States is typically on the order of ±150%, but this is perhaps not excessive in a data set where emissions per grid cell vary over 8 orders of magnitude.

  11. Simulation of Grid-Fin Control Surfaces

    NASA Technical Reports Server (NTRS)

    Aftosmis, Michael J.

    2011-01-01

    Conference poster using previously disclosed techniques and methods (see ARC 16210 & 16212). We present simulations of grid-fin control surfaces to demonstrate geometric complexity and numerical robustness. These results have relevance to high-performance computing and performance of grid-fin-based control systems.

  12. VGRIDSG: An unstructured surface grid generation program

    NASA Technical Reports Server (NTRS)

    Bockelie, Michael J.

    1993-01-01

    This report contains an overview of the VGRIDSG unstructured surface grid generation program. The VGRIDSG program was created from the VGRID3D unstructured grid generation program developed by Vigyan, Inc. The purpose of this report is to document the changes from the original VGRID3D program and to describe the capabilities of the new program.

  13. The Administrative Grid: A Leader Style Model.

    ERIC Educational Resources Information Center

    Coleman, Donald G.; Heun, Richard E.

    The Administrative Grid was developed to aid in rapid interpretation of orthogonal data on management style. The grid is a simple device for illustrating Z-score values from any instrument with orthogonality determined and scores normalized. The two dimensions, "people" and "task,"are divided into standard deviations and, by plotting perpendicular…

  14. A Debugger for Computational Grid Applications

    NASA Technical Reports Server (NTRS)

    Hood, Robert; Jost, Gabriele; Biegel, Bryan (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of a debugger for computational grid applications. Details are given on NAS parallel tools groups (including parallelization support tools, evaluation of various parallelization strategies, and distributed and aggregated computing), debugger dependencies, scalability, initial implementation, the process grid, and information on Globus.

  15. 76 FR 70412 - Smart Grid Advisory Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-14

    ... National Institute of Standards and Technology Smart Grid Advisory Committee AGENCY: National Institute of Standards and Technology, Department of Commerce. ACTION: Notice of open meeting. SUMMARY: The Smart Grid... agenda may change to accommodate Committee business. The final agenda will be posted on the Smart...

  16. Vertical grid of retrieved atmospheric profiles

    NASA Astrophysics Data System (ADS)

    Ceccherini, Simone; Carli, Bruno; Raspollini, Piera

    2016-05-01

    The choice of the vertical grid of atmospheric profiles retrieved from remote sensing observations is discussed considering the two cases of profiles used to represent the results of individual measurements and of profiles used for subsequent data fusion applications. An ozone measurement of the MIPAS instrument is used to assess, for different vertical grids, the quality of the retrieved profiles in terms of profile values, retrieval errors, vertical resolutions and number of degrees of freedom. In the case of individual retrievals no evident advantage is obtained with the use of a grid finer than the one with a reduced number of grid points, which are optimized according to the information content of the observations. Nevertheless, this instrument dependent vertical grid, which seems to extract all the available information, provides very poor results when used for data fusion applications. A loss of about a quarter of the degrees of freedom is observed when the data fusion is made using the instrument dependent vertical grid relative to the data fusion made using a vertical grid optimized for the data fusion product. This result is explained by the analysis of the eigenvalues of the Fisher information matrix and leads to the conclusion that different vertical grids must be adopted when data fusion is the expected application.

  17. Grids and clouds in the Czech NGI

    NASA Astrophysics Data System (ADS)

    Kundrát, Jan; Adam, Martin; Adamová, Dagmar; Chudoba, Jiří; Kouba, Tomáš; Lokajíček, Miloš; Mikula, Alexandr; Říkal, Václav; Švec, Jan; Vohnout, Rudolf

    2016-09-01

    There are several infrastructure operators within the Czech Republic NGI (National Grid Initiative) which provide users with access to high-performance computing facilities over a grid and cloud interface. This article focuses on those where the primary author has personal first-hand experience. We cover some operational issues as well as the history of these facilities.

  18. Features of the Java commodity grid kit.

    SciTech Connect

    von Laszewski, G.; Gawor, J.; Lane, P.; Rehn, N.; Russell, M.; Mathematics and Computer Science

    2002-11-01

    In this paper we report on the features of the Java Commodity Grid Kit (Java CoG Kit). The Java CoG Kit provides middleware for accessing Grid functionality from the Java framework. Java CoG Kit middleware is general enough to design a variety of advanced Grid applications with quite different user requirements. Access to the Grid is established via Globus Toolkit protocols, allowing the Java CoG Kit to also communicate with the services distributed as part of the C Globus Toolkit reference implementation. Thus, the Java CoG Kit provides Grid developers with the ability to utilize the Grid, as well as numerous additional libraries and frameworks developed by the Java community to enable network, Internet, enterprise and peer-to-peer computing. A variety of projects have successfully used the client libraries of the Java CoG Kit to access Grids driven by the C Globus Toolkit software. In this paper we also report on the efforts to develop serverside Java CoG Kit components. As part of this research we have implemented a prototype pure Java resource management system that enables one to run Grid jobs on platforms on which a Java virtual machine is supported, including Windows NT machines.

  19. Parallel unstructured grid generation for computational aerosciences

    NASA Technical Reports Server (NTRS)

    Shephard, Mark S.

    1993-01-01

    The objective of this research project is to develop efficient parallel automatic grid generation procedures for use in computational aerosciences. This effort is focused on a parallel version of the Finite Octree grid generator. Progress made during the first six months is reported.

  20. Unstructured Grid Generation Techniques and Software

    NASA Technical Reports Server (NTRS)

    Posenau, Mary-Anne K. (Editor)

    1993-01-01

    The Workshop on Unstructured Grid Generation Techniques and Software was conducted for NASA to assess its unstructured grid activities, improve the coordination among NASA centers, and promote technology transfer to industry. The proceedings represent contributions from Ames, Langley, and Lewis Research Centers, and the Johnson and Marshall Space Flight Centers. This report is a compilation of the presentations made at the workshop.

  1. Grid generation: A view from the trenches

    NASA Technical Reports Server (NTRS)

    Ives, David; Miller, Robert; Siddons, William; Vandyke, Kevin

    1995-01-01

    This paper presents 'A view from the trenches' on CFD grid generation from a Pratt & Whitney perspective. We anticipate that other organizations have similar views. We focus on customer expectations and the consequent requirements. We enunciate a vision for grid generation, discuss issues that developers must recognize.

  2. Grid Convergence for Turbulent Flows(Invited)

    NASA Technical Reports Server (NTRS)

    Diskin, Boris; Thomas, James L.; Rumsey, Christopher L.; Schwoppe, Axel

    2015-01-01

    A detailed grid convergence study has been conducted to establish accurate reference solutions corresponding to the one-equation linear eddy-viscosity Spalart-Allmaras turbulence model for two dimensional turbulent flows around the NACA 0012 airfoil and a flat plate. The study involved three widely used codes, CFL3D (NASA), FUN3D (NASA), and TAU (DLR), and families of uniformly refined structured grids that differ in the grid density patterns. Solutions computed by different codes on different grid families appear to converge to the same continuous limit, but exhibit different convergence characteristics. The grid resolution in the vicinity of geometric singularities, such as a sharp trailing edge, is found to be the major factor affecting accuracy and convergence of discrete solutions, more prominent than differences in discretization schemes and/or grid elements. The results reported for these relatively simple turbulent flows demonstrate that CFL3D, FUN3D, and TAU solutions are very accurate on the finest grids used in the study, but even those grids are not sufficient to conclusively establish an asymptotic convergence order.

  3. Electricity grid: When the lights go out

    NASA Astrophysics Data System (ADS)

    Dobson, Ian

    2016-05-01

    The resilience of distribution power grids is put to the test by daily operations as well as by extreme weather events such as hurricanes. An analysis of blackout data in upstate New York now reveals that larger blackouts have a disproportionate effect on grid reliability.

  4. Computing Flows Using Chimera and Unstructured Grids

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Zheng, Yao

    2006-01-01

    DRAGONFLOW is a computer program that solves the Navier-Stokes equations of flows in complexly shaped three-dimensional regions discretized by use of a direct replacement of arbitrary grid overlapping by nonstructured (DRAGON) grid. A DRAGON grid (see figure) is a combination of a chimera grid (a composite of structured subgrids) and a collection of unstructured subgrids. DRAGONFLOW incorporates modified versions of two prior Navier-Stokes-equation-solving programs: OVERFLOW, which is designed to solve on chimera grids; and USM3D, which is used to solve on unstructured grids. A master module controls the invocation of individual modules in the libraries. At each time step of a simulated flow, DRAGONFLOW is invoked on the chimera portion of the DRAGON grid in alternation with USM3D, which is invoked on the unstructured subgrids of the DRAGON grid. The USM3D and OVERFLOW modules then immediately exchange their solutions and other data. As a result, USM3D and OVERFLOW are coupled seamlessly.

  5. Program Generates Two-Dimensional Computational Grids

    NASA Technical Reports Server (NTRS)

    Vu, Bruce T.

    1994-01-01

    TDIGG is fast and versatile computer program for generating two-dimensional computational grids for use in programs solving equations of flow by finite-difference methods. Both algebraic and elliptic grid-generation systems included. Enables user to view results of each iteration. Written in FORTRAN 77.

  6. Applications of GridPix detectors

    NASA Astrophysics Data System (ADS)

    Blanco Carballo, V.; Chefdeville, M.; Decowski, M. P.; Fransen, M.; van der Graaf, H.; Koppert, W. J. C.; Schmitz, J.

    2010-02-01

    GridPix detectors provide an excellent tracking and vertex determination for internal radioactive sources with a 4π angular acceptance. In both WIMP search and neutrinoless double beta decay experiments, we expect that GridPix detectors have the ability to significantly improve the measurements.

  7. Tools and Algorithms to Link Horizontal Hydrologic and Vertical Hydrodynamic Models and Provide a Stochastic Modeling Framework

    NASA Astrophysics Data System (ADS)

    Salah, Ahmad M.; Nelson, E. James; Williams, Gustavious P.

    2010-04-01

    We present algorithms and tools we developed to automatically link an overland flow model to a hydrodynamic water quality model with different spatial and temporal discretizations. These tools run the linked models which provide a stochastic simulation frame. We also briefly present the tools and algorithms we developed to facilitate and analyze stochastic simulations of the linked models. We demonstrate the algorithms by linking the Gridded Surface Subsurface Hydrologic Analysis (GSSHA) model for overland flow with the CE-QUAL-W2 model for water quality and reservoir hydrodynamics. GSSHA uses a two-dimensional horizontal grid while CE-QUAL-W2 uses a two-dimensional vertical grid. We implemented the algorithms and tools in the Watershed Modeling System (WMS) which allows modelers to easily create and use models. The algorithms are general and could be used for other models. Our tools create and analyze stochastic simulations to help understand uncertainty in the model application. While a number of examples of linked models exist, the ability to perform automatic, unassisted linking is a step forward and provides the framework to easily implement stochastic modeling studies.

  8. 27. Credit JTL. Second floor, detail of Eureka horizontal wheat ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    27. Credit JTL. Second floor, detail of Eureka horizontal wheat scourer, by S. Howes Co., (Silver Creek, NY). After leaving scourer, grain passed directly to the Midget Marvel Machine. - Bunker Hill Mill, County Route 26, Bunker Hill, Berkeley County, WV

  9. Nurse Against Nurse: Horizontal Bullying in the Nursing Profession.

    PubMed

    Granstra, Katherine

    2015-01-01

    Healthcare professionals are not immune to bullying; in fact, they experience bullying at an alarming rate. Sometimes the bullying is passed down from superiors, but frequently bullying occurs between coworkers. This is known as "horizontal bullying," and it has become a serious issue within the nursing profession. Horizontal bullying between nurses can cause negative consequences for everyone involved, in particular the nurses, patients, and the entire organization. To fully address and resolve horizontal bullying in the nursing profession, we must consider many factors. The first step is to establish what constitutes bullying and to develop a clear process for dealing with it when it occurs. Before it is possible to eliminate the problem, we need to understand why bullying takes place. To be effective, solutions to the problem of horizontal bullying in the nursing profession must include the entire healthcare industry.

  10. Chord, Horizontal Tie Bar & Crossbracing Joint Details; Crossbracing Center ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Chord, Horizontal Tie Bar & Crossbracing Joint Details; Crossbracing Center Joint Detail; Chord, Panel Posts, Braces & Counterbrace Joint Detail - Brownsville Covered Bridge, Spanning East Fork Whitewater River (moved to Eagle Creek Park, Indianapolis), Brownsville, Union County, IN

  11. Lessons learned from installation of an environmental horizontal well

    SciTech Connect

    Oakley, D.B.; Nickelson, M.D.

    1994-12-31

    At Williams Air Force Base near Phoenix, Arizona, a Pilot Study/Demonstration Study is being performed to evaluate the effectiveness of horizontal vs vertical wells in remediating and containing a jet fuel contaminant plume. An early stage of this project included successful installation of the world`s longest, deepest environmental horizontal wells. The horizontal well was installed using river crossing technology developed for drilling boreholes and installing utility conduits under rivers. Boreholes over 5,000 ft long have been successfully installed using river crossing technology. However, these boreholes are typically shallower than 100 ft below land surface (BLS). Installation of the environmental horizontal well proved to be extremely challenging because of the depth (235 ft BLS), the length (2,500 ft) of the borehole, and the requirements dictated by well installation criteria. Two installation attempts failed before the successful installation.

  12. Naval Air Station Lighter than Air Hangar, wood construction horizontal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Naval Air Station Lighter than Air Hangar, wood construction horizontal rolling door. Drawing no. 2122 820. - Marine Corps Air Station Tustin, Northern Lighter Than Air Ship Hangar, Meffett Avenue & Maxfield Street, Tustin, Orange County, CA

  13. Naval Air Station Lighter than Air Hangar, wood construction horizontal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Naval Air Station Lighter than Air Hangar, wood construction horizontal rolling door. Drawing no. 2122 820. - Marine Corps Air Station Tustin, East of Red Hill Avenue between Edinger Avenue & Barranca Parkway, Tustin, Orange County, CA

  14. Horizontal running mattress suture modified with intermittent simple loops.

    PubMed

    Chacon, Anna H; Shiman, Michael I; Strozier, Narissa; Zaiac, Martin N

    2013-01-01

    Using the combination of a horizontal running mattress suture with intermittent loops achieves both good eversion with the horizontal running mattress plus the ease of removal of the simple loops. This combination technique also avoids the characteristic railroad track marks that result from prolonged non-absorbable suture retention. The unique feature of our technique is the incorporation of one simple running suture after every two runs of the horizontal running mattress suture. To demonstrate its utility, we used the suturing technique on several patients and analyzed the cosmetic outcome with post-operative photographs in comparison to other suturing techniques. In summary, the combination of running horizontal mattress suture with simple intermittent loops demonstrates functional and cosmetic benefits that can be readily taught, comprehended, and employed, leading to desirable aesthetic results and wound edge eversion.

  15. 7. NORTH SIDE CHESTNUT ST. (horizontal line) BETWEEN THIRD (left) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. NORTH SIDE CHESTNUT ST. (horizontal line) BETWEEN THIRD (left) AND BREAD (right) STS., SHOWING OLD BUILDINGS - Independence National Historical Park, Walnut, Sixth, Chestnut & Second Streets, Philadelphia, Philadelphia County, PA

  16. 16. INDEPENDENCE HALL LOOKING SOUTH ON CHESTNUT ST. (horizontal line) ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. INDEPENDENCE HALL LOOKING SOUTH ON CHESTNUT ST. (horizontal line) BETWEEN SIXTH (right) AND FIFTH (left) STS. - Independence National Historical Park, Walnut, Sixth, Chestnut & Second Streets, Philadelphia, Philadelphia County, PA

  17. 2. EAST ELEVATION OF POWER PLANT TEST STAND (HORIZONTAL TEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. EAST ELEVATION OF POWER PLANT TEST STAND (HORIZONTAL TEST STAND REMNANTS OF BUILDING-BLANK WHITE WALL ONLY ORIGINAL REMAINS. - Marshall Space Flight Center, East Test Area, Power Plant Test Stand, Huntsville, Madison County, AL

  18. 10. INTERIOR VIEW OF BUILDING 106, SHOWING HORIZONTAL CATAPULT, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. INTERIOR VIEW OF BUILDING 106, SHOWING HORIZONTAL CATAPULT, LOOKING NORTHEAST - Frankford Arsenal, Building No. 106, South of Tacony Street between Bridge Street & tracks of former Pennsylvania Railroad, Philadelphia, Philadelphia County, PA

  19. 9. INTERIOR VIEW OF BUILDING 106, SHOWING HORIZONTAL CATAPULT, LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. INTERIOR VIEW OF BUILDING 106, SHOWING HORIZONTAL CATAPULT, LOOKING NORTHEAST - Frankford Arsenal, Building No. 106, South of Tacony Street between Bridge Street & tracks of former Pennsylvania Railroad, Philadelphia, Philadelphia County, PA

  20. 7. Underside of Roadbed (Interior beams cast horizontal, imprints of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Underside of Roadbed (Interior beams cast horizontal, imprints of timbers used as formwork visible on abutment walls and beams) - North Bridge, Spanning Quarton Lake branch of River Rouge, Birmingham, Oakland County, MI