WorldWideScience

Sample records for high resolution wind

  1. High-Resolution Wind Measurements for Offshore Wind Energy Development

    Science.gov (United States)

    Nghiem, Son V.; Neumann, Gregory

    2011-01-01

    A mathematical transform, called the Rosette Transform, together with a new method, called the Dense Sampling Method, have been developed. The Rosette Transform is invented to apply to both the mean part and the fluctuating part of a targeted radar signature using the Dense Sampling Method to construct the data in a high-resolution grid at 1-km posting for wind measurements over water surfaces such as oceans or lakes.

  2. High resolution wind measurements for offshore wind energy development

    Science.gov (United States)

    Nghiem, Son Van (Inventor); Neumann, Gregory (Inventor)

    2013-01-01

    A method, apparatus, system, article of manufacture, and computer readable storage medium provide the ability to measure wind. Data at a first resolution (i.e., low resolution data) is collected by a satellite scatterometer. Thin slices of the data are determined. A collocation of the data slices are determined at each grid cell center to obtain ensembles of collocated data slices. Each ensemble of collocated data slices is decomposed into a mean part and a fluctuating part. The data is reconstructed at a second resolution from the mean part and a residue of the fluctuating part. A wind measurement is determined from the data at the second resolution using a wind model function. A description of the wind measurement is output.

  3. High Resolution Atmospheric Modeling for Wind Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, M; Bulaevskaya, V; Glascoe, L; Singer, M

    2010-03-18

    The ability of the WRF atmospheric model to forecast wind speed over the Nysted wind park was investigated as a function of time. It was found that in the time period we considered (August 1-19, 2008), the model is able to predict wind speeds reasonably accurately for 48 hours ahead, but that its forecast skill deteriorates rapidly after 48 hours. In addition, a preliminary analysis was carried out to investigate the impact of vertical grid resolution on the forecast skill. Our preliminary finding is that increasing vertical grid resolution does not have a significant impact on the forecast skill of the WRF model over Nysted wind park during the period we considered. Additional simulations during this period, as well as during other time periods, will be run in order to validate the results presented here. Wind speed is a difficult parameter to forecast due the interaction of large and small length scale forcing. To accurately forecast the wind speed at a given location, the model must correctly forecast the movement and strength of synoptic systems, as well as the local influence of topography / land use on the wind speed. For example, small deviations in the forecast track or strength of a large-scale low pressure system can result in significant forecast errors for local wind speeds. The purpose of this study is to provide a preliminary baseline of a high-resolution limited area model forecast performance against observations from the Nysted wind park. Validating the numerical weather prediction model performance for past forecasts will give a reasonable measure of expected forecast skill over the Nysted wind park. Also, since the Nysted Wind Park is over water and some distance from the influence of terrain, the impact of high vertical grid spacing for wind speed forecast skill will also be investigated.

  4. A high resolution global wind atlas - improving estimation of world wind resources

    DEFF Research Database (Denmark)

    Badger, Jake; Ejsing Jørgensen, Hans

    2011-01-01

    to population centres, electrical transmission grids, terrain types, and protected land areas are important parts of the resource assessment downstream of the generation of wind climate statistics. Related to these issues of integration are the temporal characteristics and spatial correlation of the wind...... resources. These aspects will also be addressed by the Global Wind Atlas. The Global Wind Atlas, through a transparent methodology, will provide a unified, high resolution, and public domain dataset of wind energy resources for the whole world. The wind atlas data will be the most appropriate wind resource...

  5. High resolution climatological wind measurements for wind energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, H. [Uppsala Univ. (Sweden). Dept. of Meteorology

    1996-12-01

    Measurements with a combined cup anemometer/wind vane instrument, developed at the Department of Meteorology in Uppsala, is presented. The instrument has a frequency response of about 1 Hz, making it suitable not only for mean wind measurements, but also for studies of atmospheric turbulence. It is robust enough to be used for climatological purposes. Comparisons with data from a hot-film anemometer show good agreement, both as regards standard deviations and the spectral decomposition of the turbulent wind signal. The cup anemometer/wind vane instrument is currently used at three sites within the Swedish wind energy research programme. These measurements are shortly described, and a few examples of the results are given. 1 ref, 10 figs

  6. High resolution wind turbine wake measurements with a scanning lidar

    DEFF Research Database (Denmark)

    Herges, T. G.; Maniaci, D. C.; Naughton, B. T.

    2017-01-01

    High-resolution lidar wake measurements are part of an ongoing field campaign being conducted at the Scaled Wind Farm Technology facility by Sandia National Laboratories and the National Renewable Energy Laboratory using a customized scanning lidar from the Technical University of Denmark. One...

  7. A high resolution WRF model for wind energy forecasting

    Science.gov (United States)

    Vincent, Claire Louise; Liu, Yubao

    2010-05-01

    The increasing penetration of wind energy into national electricity markets has increased the demand for accurate surface layer wind forecasts. There has recently been a focus on forecasting the wind at wind farm sites using both statistical models and numerical weather prediction (NWP) models. Recent advances in computing capacity and non-hydrostatic NWP models means that it is possible to nest mesoscale models down to Large Eddy Simulation (LES) scales over the spatial area of a typical wind farm. For example, the WRF model (Skamarock 2008) has been run at a resolution of 123 m over a wind farm site in complex terrain in Colorado (Liu et al. 2009). Although these modelling attempts indicate a great hope for applying such models for detailed wind forecasts over wind farms, one of the obvious challenges of running the model at this resolution is that while some boundary layer structures are expected to be modelled explicitly, boundary layer eddies into the inertial sub-range can only be partly captured. Therefore, the amount and nature of sub-grid-scale mixing that is required is uncertain. Analysis of Liu et al. (2009) modelling results in comparison to wind farm observations indicates that unrealistic wind speed fluctuations with a period of around 1 hour occasionally occurred during the two day modelling period. The problem was addressed by re-running the same modelling system with a) a modified diffusion constant and b) two-way nesting between the high resolution model and its parent domain. The model, which was run with horizontal grid spacing of 370 m, had dimensions of 505 grid points in the east-west direction and 490 points in the north-south direction. It received boundary conditions from a mesoscale model of resolution 1111 m. Both models had 37 levels in the vertical. The mesoscale model was run with a non-local-mixing planetary boundary layer scheme, while the 370 m model was run with no planetary boundary layer scheme. It was found that increasing the

  8. Estimation of the high-spatial-resolution variability in extreme wind speeds for forestry applications

    Directory of Open Access Journals (Sweden)

    A. Venäläinen

    2017-07-01

    Full Text Available The bioeconomy has an increasing role to play in climate change mitigation and the sustainable development of national economies. In Finland, a forested country, over 50 % of the current bioeconomy relies on the sustainable management and utilization of forest resources. Wind storms are a major risk that forests are exposed to and high-spatial-resolution analysis of the most vulnerable locations can produce risk assessment of forest management planning. In this paper, we examine the feasibility of the wind multiplier approach for downscaling of maximum wind speed, using 20 m spatial resolution CORINE land-use dataset and high-resolution digital elevation data. A coarse spatial resolution estimate of the 10-year return level of maximum wind speed was obtained from the ERA-Interim reanalyzed data. Using a geospatial re-mapping technique the data were downscaled to 26 meteorological station locations to represent very diverse environments. Applying a comparison, we find that the downscaled 10-year return levels represent 66 % of the observed variation among the stations examined. In addition, the spatial variation in wind-multiplier-downscaled 10-year return level wind was compared with the WAsP model-simulated wind. The heterogeneous test area was situated in northern Finland, and it was found that the major features of the spatial variation were similar, but in some locations, there were relatively large differences. The results indicate that the wind multiplier method offers a pragmatic and computationally feasible tool for identifying at a high spatial resolution those locations with the highest forest wind damage risks. It can also be used to provide the necessary wind climate information for wind damage risk model calculations, thus making it possible to estimate the probability of predicted threshold wind speeds for wind damage and consequently the probability (and amount of wind damage for certain forest stand configurations.

  9. A high-resolution assessment of wind and wave energy potentials in the Red Sea

    KAUST Repository

    Langodan, Sabique; Viswanadhapalli, Yesubabu; Dasari, Hari Prasad; Knio, Omar; Hoteit, Ibrahim

    2016-01-01

    This study presents an assessment of the potential for harvesting wind and wave energy from the Red Sea based on an 18-year high-resolution regional atmospheric reanalysis recently generated using the Advanced Weather Research Forecasting model

  10. Observation of high-resolution wind fields and offshore wind turbine wakes using TerraSAR-X imagery

    Science.gov (United States)

    Gies, Tobias; Jacobsen, Sven; Lehner, Susanne; Pleskachevsky, Andrey

    2014-05-01

    1. Introduction Numerous large-scale offshore wind farms have been built in European waters and play an important role in providing renewable energy. Therefore, knowledge of behavior of wakes, induced by large wind turbines and their impact on wind power output is important. The spatial variation of offshore wind turbine wake is very complex, depending on wind speed, wind direction, ambient atmospheric turbulence and atmospheric stability. In this study we demonstrate the application of X-band TerraSAR-X (TS-X) data with high spatial resolution for studies on wind turbine wakes in the near and far field of the offshore wind farm Alpha Ventus, located in the North Sea. Two cases which different weather conditions and different wake pattern as observed in the TS-X image are presented. 2. Methods The space-borne synthetic aperture radar (SAR) is a unique sensor that provides two-dimensional information on the ocean surface. Due to their high resolution, daylight and weather independency and global coverage, SARs are particularly suitable for many ocean and coastal applications. SAR images reveal wind variations on small scales and thus represent a valuable means in detailed wind-field analysis. The general principle of imaging turbine wakes is that the reduced wind speed downstream of offshore wind farms modulates the sea surface roughness, which in turn changes the Normalized Radar Cross Section (NRCS, denoted by σ0) in the SAR image and makes the wake visible. In this study we present two cases at the offshore wind farm Alpha Ventus to investigate turbine-induced wakes and the retrieved sea surface wind field. Using the wind streaks, visible in the TS-X image and the shadow behind the offshore wind farm, induced by turbine wake, the sea surface wind direction is derived and subsequently the sea surface wind speed is calculated using the latest generation of wind field algorithm XMOD2. 3. Case study alpha ventus Alpha Ventus is located approximately 45 km from the

  11. NOAA high resolution sea surface winds data from Synthetic Aperture Radar (SAR) on the RADARSAT-2 satellite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Synthetic Aperture Radar (SAR)-derived high resolution wind products are calculated from high resolution SAR images of normalized radar cross section (NRCS) of the...

  12. A high-resolution assessment of wind and wave energy potentials in the Red Sea

    KAUST Repository

    Langodan, Sabique

    2016-08-24

    This study presents an assessment of the potential for harvesting wind and wave energy from the Red Sea based on an 18-year high-resolution regional atmospheric reanalysis recently generated using the Advanced Weather Research Forecasting model. This model was initialized with ERA-Interim global data and the Red Sea reanalysis was generated using a cyclic three-dimensional variational approach assimilating available data in the region. The wave hindcast was generated using WAVEWATCH III on a 5 km resolution grid, forced by the Red Sea reanalysis surface winds. The wind and wave products were validated against data from buoys, scatterometers and altimeters. Our analysis suggests that the distribution of wind and wave energy in the Red Sea is inhomogeneous and is concentrated in specific areas, characterized by various meteorological conditions including weather fronts, mesoscale vortices, land and sea breezes and mountain jets. A detailed analysis of wind and wave energy variation was performed at three hotspots representing the northern, central and southern parts of the Red Sea. Although there are potential sites for harvesting wind energy from the Red Sea, there are no potential sites for harvesting wave energy because wave energy in the Red Sea is not strong enough for currently available wave energy converters. Wave energy should not be completely ignored, however, at least from the perspective of hybrid wind-wave projects. (C) 2016 Elsevier Ltd. All rights reserved.

  13. Surface drag effects on simulated wind fields in high-resolution atmospheric forecast model

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Kyo Sun; Lim, Jong Myoung; Ji, Young Yong [Environmental Radioactivity Assessment Team,Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Shin, Hye Yum [NOAA/Geophysical Fluid Dynamics Laboratory, Princeton (United States); Hong, Jin Kyu [Yonsei University, Seoul (Korea, Republic of)

    2017-04-15

    It has been reported that the Weather Research and Forecasting (WRF) model generally shows a substantial over prediction bias at low to moderate wind speeds and winds are too geostrophic (Cheng and Steenburgh 2005), which limits the application of WRF model in the area that requires the accurate surface wind estimation such as wind-energy application, air-quality studies, and radioactive-pollutants dispersion studies. The surface drag generated by the subgrid-scale orography is represented by introducing a sink term in the momentum equation in their studies. The purpose of our study is to evaluate the simulated meteorological fields in the high-resolution WRF framework, that includes the parameterization of subgrid-scale orography developed by Mass and Ovens (2010), and enhance the forecast skill of low-level wind fields, which plays an important role in transport and dispersion of air pollutants including radioactive pollutants. The positive bias in 10-m wind speed is significantly alleviated by implementing the subgrid-scale orography parameterization, while other meteorological fields including 10-m wind direction are not changed. Increased variance of subgrid- scale orography enhances the sink of momentum and further reduces the bias in 10-m wind speed.

  14. Wind Resource Assessment in Complex Terrain with a High-Resolution Numerical Weather Prediction Model

    Science.gov (United States)

    Gruber, Karin; Serafin, Stefano; Grubišić, Vanda; Dorninger, Manfred; Zauner, Rudolf; Fink, Martin

    2014-05-01

    A crucial step in planning new wind farms is the estimation of the amount of wind energy that can be harvested in possible target sites. Wind resource assessment traditionally entails deployment of masts equipped for wind speed measurements at several heights for a reasonably long period of time. Simplified linear models of atmospheric flow are then used for a spatial extrapolation of point measurements to a wide area. While linear models have been successfully applied in the wind resource assessment in plains and offshore, their reliability in complex terrain is generally poor. This represents a major limitation to wind resource assessment in Austria, where high-altitude locations are being considered for new plant sites, given the higher frequency of sustained winds at such sites. The limitations of linear models stem from two key assumptions in their formulation, the neutral stratification and attached boundary-layer flow, both of which often break down in complex terrain. Consequently, an accurate modeling of near-surface flow over mountains requires the adoption of a NWP model with high horizontal and vertical resolution. This study explores the wind potential of a site in Styria in the North-Eastern Alps. The WRF model is used for simulations with a maximum horizontal resolution of 800 m. Three nested computational domains are defined, with the innermost one encompassing a stretch of the relatively broad Enns Valley, flanked by the main crest of the Alps in the south and the Nördliche Kalkalpen of similar height in the north. In addition to the simulation results, we use data from fourteen 10-m wind measurement sites (of which 7 are located within valleys and 5 near mountain tops) and from 2 masts with anemometers at several heights (at hillside locations) in an area of 1600 km2 around the target site. The potential for wind energy production is assessed using the mean wind speed and turbulence intensity at hub height. The capacity factor is also evaluated

  15. High Temporal Resolution Tropospheric Wind Profile Observations at NASA Kennedy Space Center During Hurricane Irma

    Science.gov (United States)

    Decker, Ryan K.; Barbre, Robert E., Jr.; Huddleston, Lisa; Brauer, Thomas; Wilfong, Timothy

    2018-01-01

    The NASA Kennedy Space Center (KSC) operates a 48-MHz Tropospheric/Stratospheric Doppler Radar Wind Profiler (TDRWP) on a continual basis generating wind profiles between 2-19 km in the support of space launch vehicle operations. A benefit of the continual operability of the system is the ability to provide unique observations of severe weather events such as hurricanes. Over the past two Atlantic Hurricane seasons the TDRWP has made high temporal resolution wind profile observations of Hurricane Irma in 2017 and Hurricane Matthew in 2016. Hurricane Irma was responsible for power outages to approximately 2/3 of Florida's population during its movement over the state(Stein,2017). An overview of the TDRWP system configuration, brief summary of Hurricanes Irma and Matthew storm track in proximity to KSC, characteristics of the tropospheric wind observations from the TDRWP during both events, and discussion of the dissemination of TDRWP data during the event will be presented.

  16. Assessment of offshore wind power potential in the Aegean and Ionian Seas based on high-resolution hindcast model results

    Directory of Open Access Journals (Sweden)

    Takvor Soukissian

    2017-03-01

    Full Text Available In this study long-term wind data obtained from high-resolution hindcast simulations is used to analytically assess offshore wind power potential in the Aegean and Ionian Seas and provide wind climate and wind power potential characteristics at selected locations, where offshore wind farms are at the concept/planning phase. After ensuring the good model performance through detailed validation against buoy measurements, offshore wind speed and wind direction at 10 m above sea level are statistically analyzed on the annual and seasonal time scale. The spatial distribution of the mean wind speed and wind direction are provided in the appropriate time scales, along with the mean annual and the inter-annual variability; these statistical quantities are useful in the offshore wind energy sector as regards the preliminary identification of favorable sites for exploitation of offshore wind energy. Moreover, the offshore wind power potential and its variability are also estimated at 80 m height above sea level. The obtained results reveal that there are specific areas in the central and the eastern Aegean Sea that combine intense annual winds with low variability; the annual offshore wind power potential in these areas reach values close to 900 W/m2, suggesting that a detailed assessment of offshore wind energy would be worth noticing and could lead in attractive investments. Furthermore, as a rough estimate of the availability factor, the equiprobable contours of the event [4 m/s ≤ wind speed ≤ 25 m/s] are also estimated and presented. The selected lower and upper bounds of wind speed correspond to typical cut-in and cut-out wind speed thresholds, respectively, for commercial offshore wind turbines. Finally, for seven offshore wind farms that are at the concept/planning phase the main wind climate and wind power density characteristics are also provided.

  17. Verification of high resolution simulation of precipitation and wind in Portugal

    Science.gov (United States)

    Menezes, Isilda; Pereira, Mário; Moreira, Demerval; Carvalheiro, Luís; Bugalho, Lourdes; Corte-Real, João

    2017-04-01

    Demand of energy and freshwater continues to grow as the global population and demands increase. Precipitation feed the freshwater ecosystems which provides a wealth of goods and services for society and river flow to sustain native species and natural ecosystem functions. The adoption of the wind and hydro-electric power supplies will sustain energy demands/services without restricting the economic growth and accelerated policies scenarios. However, the international meteorological observation network is not sufficiently dense to directly support high resolution climatic research. In this sense, coupled global and regional atmospheric models constitute the most appropriate physical and numerical tool for weather forecasting and downscaling in high resolution grids with the capacity to solve problems resulting from the lack of observed data and measuring errors. Thus, this study aims to calibrate and validate of the WRF regional model from precipitation and wind fields simulation, in high spatial resolution grid cover in Portugal. The simulations were performed in two-way nesting with three grids of increasing resolution (60 km, 20 km and 5 km) and the model performance assessed for the summer and winter months (January and July), using input variables from two different reanalyses and forecasted databases (ERA-Interim and NCEP-FNL) and different forcing schemes. The verification procedure included: (i) the use of several statistics error estimators, correlation based measures and relative errors descriptors; and, (ii) an observed dataset composed by time series of hourly precipitation, wind speed and direction provided by the Portuguese meteorological institute for a comprehensive set of weather stations. Main results suggested the good ability of the WRF to: (i) reproduce the spatial patterns of the mean and total observed fields; (ii) with relatively small values of bias and other errors; and, (iii) and good temporal correlation. These findings are in good

  18. NOAA high resolution sea surface winds data from Synthetic Aperture Radar (SAR) on the Sentinel-1 satellites

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set consists of high resolution sea surface winds data produced from Synthetic Aperture Radar (SAR) on board Sentinel-1A and Sentinel-1B satellites. This...

  19. High-resolution observations of the near-surface wind field over an isolated mountain and in a steep river canyon

    Science.gov (United States)

    B. W. Butler; N. S. Wagenbrenner; J. M. Forthofer; B. K. Lamb; K. S. Shannon; D. Finn; R. M. Eckman; K. Clawson; L. Bradshaw; P. Sopko; S. Beard; D. Jimenez; C. Wold; M. Vosburgh

    2015-01-01

    A number of numerical wind flow models have been developed for simulating wind flow at relatively fine spatial resolutions (e.g., 100 m); however, there are very limited observational data available for evaluating these high-resolution models. This study presents high-resolution surface wind data sets collected from an isolated mountain and a steep river canyon. The...

  20. Development of a procedure to model high-resolution wind profiles from smoothed or low-frequency data

    Science.gov (United States)

    Camp, D. W.

    1977-01-01

    The derivation of simulated Jimsphere wind profiles from low-frequency rawinsonde data and a generated set of white noise data are presented. A computer program is developed to model high-resolution wind profiles based on the statistical properties of data from the Kennedy Space Center, Florida. Comparison of the measured Jimsphere data, rawinsonde data, and the simulated profiles shows excellent agreement.

  1. 76 FR 56735 - Small Takes of Marine Mammals Incidental to Specified Activities; Cape Wind's High Resolution...

    Science.gov (United States)

    2011-09-14

    ... sound propagation. Cape Wind Associates would use a boomer to obtain deeper resolution of geologic layering that cannot be imaged by the chirp. An Applied Acoustics 200, 300, or similar model would be used...

  2. High resolution modelling of wind fields for optimization of empirical storm flood predictions

    Science.gov (United States)

    Brecht, B.; Frank, H.

    2014-05-01

    High resolution wind fields are necessary to predict the occurrence of storm flood events and their magnitude. Deutscher Wetterdienst (DWD) created a catalogue of detailed wind fields of 39 historical storms at the German North Sea coast from the years 1962 to 2011. The catalogue is used by the Niedersächsisches Landesamt für Wasser-, Küsten- und Naturschutz (NLWKN) coastal research center to improve their flood alert service. The computation of wind fields and other meteorological parameters is based on the model chain of the DWD going from the global model GME via the limited-area model COSMO with 7 km mesh size down to a COSMO model with 2.2 km. To obtain an improved analysis COSMO runs are nudged against observations for the historical storms. The global model GME is initialised from the ERA reanalysis data of the European Centre for Medium-Range Weather Forecasts (ECMWF). As expected, we got better congruency with observations of the model for the nudging runs than the normal forecast runs for most storms. We also found during the verification process that different land use data sets could influence the results considerably.

  3. Wind turbine extraction from high spatial resolution remote sensing images based on saliency detection

    Science.gov (United States)

    Chen, Jingbo; Yue, Anzhi; Wang, Chengyi; Huang, Qingqing; Chen, Jiansheng; Meng, Yu; He, Dongxu

    2018-01-01

    The wind turbine is a device that converts the wind's kinetic energy into electrical power. Accurate and automatic extraction of wind turbine is instructive for government departments to plan wind power plant projects. A hybrid and practical framework based on saliency detection for wind turbine extraction, using Google Earth image at spatial resolution of 1 m, is proposed. It can be viewed as a two-phase procedure: coarsely detection and fine extraction. In the first stage, we introduced a frequency-tuned saliency detection approach for initially detecting the area of interest of the wind turbines. This method exploited features of color and luminance, was simple to implement, and was computationally efficient. Taking into account the complexity of remote sensing images, in the second stage, we proposed a fast method for fine-tuning results in frequency domain and then extracted wind turbines from these salient objects by removing the irrelevant salient areas according to the special properties of the wind turbines. Experiments demonstrated that our approach consistently obtains higher precision and better recall rates. Our method was also compared with other techniques from the literature and proves that it is more applicable and robust.

  4. Surface Wind Regionalization over Complex Terrain: Evaluation and Analysis of a High-Resolution WRF Simulation

    NARCIS (Netherlands)

    Jiménez, P.A.; González-Rouco, J.F.; García-Bustamante, E.; Navarro, J.; Montávez, J.P.; Vilà-Guerau de Arellano, J.; Dudhia, J.; Muñoz-Roldan, A.

    2010-01-01

    This study analyzes the daily-mean surface wind variability over an area characterized by complex topography through comparing observations and a 2-km-spatial-resolution simulation performed with the Weather Research and Forecasting (WRF) model for the period 1992–2005. The evaluation focuses on the

  5. Spatial models for probabilistic prediction of wind power with application to annual-average and high temporal resolution data

    DEFF Research Database (Denmark)

    Lenzi, Amanda; Pinson, Pierre; Clemmensen, Line Katrine Harder

    2017-01-01

    average wind power generation, and for a high temporal resolution (typically wind power averages over 15-min time steps). In both cases, we use a spatial hierarchical statistical model in which spatial correlation is captured by a latent Gaussian field. We explore how such models can be handled...... with stochastic partial differential approximations of Matérn Gaussian fields together with Integrated Nested Laplace Approximations. We demonstrate the proposed methods on wind farm data from Western Denmark, and compare the results to those obtained with standard geostatistical methods. The results show...

  6. HIGH-RESOLUTION X-RAY SPECTROSCOPY REVEALS THE SPECIAL NATURE OF WOLF-RAYET STAR WINDS

    Energy Technology Data Exchange (ETDEWEB)

    Oskinova, L. M.; Hamann, W.-R. [Institute for Physics and Astronomy, University Potsdam, 14476 Potsdam (Germany); Gayley, K. G. [Department of Physics and Astronomy, University of Iowa, Iowa City, IA 52245 (United States); Huenemoerder, D. P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37663 (United States); Pollock, A. M. T., E-mail: lida@astro.physik.uni-potsdam.de [European Space Agency XMM-Newton Science Operations Centre, European Space Astronomy Centre, Apartado 78, Villanueva de la Canada, 28691 Madrid (Spain)

    2012-03-10

    We present the first high-resolution X-ray spectrum of a putatively single Wolf-Rayet (WR) star. 400 ks observations of WR 6 by the XMM-Newton telescope resulted in a superb quality high-resolution X-ray spectrum. Spectral analysis reveals that the X-rays originate far out in the stellar wind, more than 30 stellar radii from the photosphere, and thus outside the wind acceleration zone where the line-driving instability (LDI) could create shocks. The X-ray emitting plasma reaches temperatures up to 50 MK and is embedded within the unshocked, 'cool' stellar wind as revealed by characteristic spectral signatures. We detect a fluorescent Fe line at Almost-Equal-To 6.4 keV. The presence of fluorescence is consistent with a two-component medium, where the cool wind is permeated with the hot X-ray emitting plasma. The wind must have a very porous structure to allow the observed amount of X-rays to escape. We find that neither the LDI nor any alternative binary scenario can explain the data. We suggest a scenario where X-rays are produced when the fast wind rams into slow 'sticky clumps' that resist acceleration. Our new data show that the X-rays in single WR star are generated by some special mechanism different from the one operating in the O-star winds.

  7. Assimilating high-resolution winds from a Doppler lidar using an ensemble Kalman filter with lateral boundary adjustment

    Directory of Open Access Journals (Sweden)

    Masahiro Sawada

    2015-03-01

    Full Text Available Monitoring severe weather, including wind shear and clear air turbulence, is important for aviation safety. To provide accurate information for nowcasts and very short-range forecasts up to an hour, a rapid-update prediction system has been developed, with a particular focus on lateral boundary adjustment (LBA using the local ensemble transform Kalman filter (LETKF. Due to the small forecast domain, limited-area forecasts are dominated by the lateral boundary conditions from coarse-resolution global forecasts. To effectively extend the forecast lead time for the small domain, a new LBA scheme using the LETKF has been developed and assessed with three sea-breeze front cases. Observing system simulation experiments for high-resolution winds from a simulated Doppler lidar were performed with the Japan Meteorological Agency Nonhydrostatic Mesoscale Model at a horizontal resolution of 400 m and 15-minute update cycle. The results indicate that the LBA improved the forecast significantly. In particular, the 1-hour wind-speed forecast with the LBA is as accurate as the 15-minute forecast without the LBA. The assimilation of Doppler lidar high-resolution wind data with the LBA is a promising approach for very short-range forecasts up to an hour with a small domain, such as for aviation weather.

  8. Characterization Of Ocean Wind Vector Retrievals Using ERS-2 High-Resolution Long-Term Dataset And Buoy Measurements

    Science.gov (United States)

    Polverari, F.; Talone, M.; Crapolicchio, R. Levy, G.; Marzano, F.

    2013-12-01

    The European Remote-sensing Satellite (ERS)-2 scatterometer provides wind retrievals over Ocean. To satisfy the needs of high quality and homogeneous set of scatterometer measurements, the European Space Agency (ESA) has developed the project Advanced Scatterometer Processing System (ASPS) with which a long-term dataset of new ERS-2 wind products, with an enhanced resolution of 25km square, has been generated by the reprocessing of the entire ERS mission. This paper presents the main results of the validation work of such new dataset using in situ measurements provided by the Prediction and Research Moored Array in the Tropical Atlantic (PIRATA). The comparison indicates that, on average, the scatterometer data agree well with buoys measurements, however the scatterometer tends to overestimates lower winds and underestimates higher winds.

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

    Science.gov (United States)

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

    2017-12-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a ESPA-Class (50 kg) micro-satellite. Low fabrication and launch costs enable a LEO sun-synchronous sounding constellation that would provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's Atmospheric Infrared Sounder. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. In this third year of a NASA Instrument incubator program, the compact infrared spectrometer has been integrated into an airborne version of the instrument for high-altitude flights on a NASA ER2. The purpose of these airborne tests is to examine the potential for improved capabilities for tracking atmospheric motion-vector wind tracer features, and determining their height using hyper-spectral sounding and

  10. High-resolution humidity profiles retrieved from wind profiler radar measurements

    Science.gov (United States)

    Saïd, Frédérique; Campistron, Bernard; Di Girolamo, Paolo

    2018-03-01

    The retrieval of humidity profiles from wind profiler radars has already been documented in the past 30 years and is known to be neither as straightforward and nor as robust as the retrieval of the wind velocity. The main constraint to retrieve the humidity profile is the necessity to combine measurements from the wind profiler and additional measurements (such as observations from radiosoundings at a coarser time resolution). Furthermore, the method relies on some assumptions and simplifications that restrict the scope of its application. The first objective of this paper is to identify the obstacles and limitations and solve them, or at least define the field of applicability. To improve the method, we propose using the radar capacity to detect transition levels, such as the top level of the boundary layer, marked by a maximum in the radar reflectivity. This forces the humidity profile from the free troposphere and from the boundary layer to coincide at this level, after an optimization of the calibration coefficients, and reduces the error. The resulting mean bias affecting the specific humidity profile never exceeds 0.25 g kg-1. The second objective is to explore the capability of the algorithm to retrieve the humidity vertical profiles for an operational purpose by comparing the results with observations from a Raman lidar.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Science.gov (United States)

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

    2016-10-01

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

  14. Assimilation of low-level wind in a high-resolution mesoscale model using the back and forth nudging algorithm

    Directory of Open Access Journals (Sweden)

    Jean-François Mahfouf

    2012-06-01

    Full Text Available The performance of a new data assimilation algorithm called back and forth nudging (BFN is evaluated using a high-resolution numerical mesoscale model and simulated wind observations in the boundary layer. This new algorithm, of interest for the assimilation of high-frequency observations provided by ground-based active remote-sensing instruments, is straightforward to implement in a realistic atmospheric model. The convergence towards a steady-state profile can be achieved after five iterations of the BFN algorithm, and the algorithm provides an improved solution with respect to direct nudging. It is shown that the contribution of the nudging term does not dominate over other model physical and dynamical tendencies. Moreover, by running backward integrations with an adiabatic version of the model, the nudging coefficients do not need to be increased in order to stabilise the numerical equations. The ability of BFN to produce model changes upstream from the observations, in a similar way to 4-D-Var assimilation systems, is demonstrated. The capacity of the model to adjust to rapid changes in wind direction with the BFN is a first encouraging step, for example, to improve the detection and prediction of low-level wind shear phenomena through high-resolution mesoscale modelling over airports.

  15. HRensembleHR. High resolution ensemble for Horns Rev. Final project report; Offshore wind power

    Energy Technology Data Exchange (ETDEWEB)

    2010-03-15

    The wind farm output of an offshore-farm such as Horns Rev changes between nearly constant output to highly variable power output. A balance responsible will therefore benefit from knowing the variability of a wind farm in advance. Some understanding of the observed variability and the corresponding forecast error on offshore wind farms had been gathered in the past few years, while a large fraction (about 60%) of the error still lacked understanding and required further intense research. This was the outset at the beginning of the HREnsemble project. Results from the wave study, variability study, ocean coupling, findings from the sensitivity experiments, the iEnKF short-term forecast and finally the demonstration phase have given significant synergy. The most basic research result in the project is that the two empirical mode decomposition approaches, Hilbert-Huang and later the Ensemble Empirical Mode Decomposition (EEMD). Both approaches confirmed that significant variability exists in offshore conditions. It was found that the variability of the short time-scales (24 minutes) are either not explicitly visible in the grid-scale of the NWP models or in the best case significantly smoothed out in all of the tested model configurations. If we interpret 2/3 of the variability due to vertical waves not present in the mean flow and 1/3 of the variability due to meso-scale weather, then the model results and EEMD are consistent. We can however not verify this theory. At present we do not know if EEMD counts neither the events correct nor whether the ensemble forecast suppresses variability. The existence of variability above the time-scale related to friction between ocean waves and air can in fact explain some of the inconsistent results published in the literature and set a question mark behind the correctness of the calculation of friction in wave, ocean and weather modelling. (LN)

  16. High-resolution Statistics of Solar Wind Turbulence at Kinetic Scales Using the Magnetospheric Multiscale Mission

    Energy Technology Data Exchange (ETDEWEB)

    Chasapis, Alexandros; Matthaeus, W. H.; Parashar, T. N.; Maruca, B. A. [University of Delaware, Newark, DE (United States); Fuselier, S. A.; Burch, J. L. [Southwest Research Institute, San Antonio, TX (United States); Phan, T. D. [Space Sciences Laboratory, University of California, Berkeley, CA (United States); Moore, T. E.; Pollock, C. J.; Gershman, D. J. [NASA Goddard Space Flight Center, Greenbelt, MD (United States); Torbert, R. B. [University of New Hampshire, Durham, NH (United States); Russell, C. T.; Strangeway, R. J., E-mail: chasapis@udel.edu [University of California, Los Angeles, CA (United States)

    2017-07-20

    Using data from the Magnetospheric Multiscale (MMS) and Cluster missions obtained in the solar wind, we examine second-order and fourth-order structure functions at varying spatial lags normalized to ion inertial scales. The analysis includes direct two-spacecraft results and single-spacecraft results employing the familiar Taylor frozen-in flow approximation. Several familiar statistical results, including the spectral distribution of energy, and the sale-dependent kurtosis, are extended down to unprecedented spatial scales of ∼6 km, approaching electron scales. The Taylor approximation is also confirmed at those small scales, although small deviations are present in the kinetic range. The kurtosis is seen to attain very high values at sub-proton scales, supporting the previously reported suggestion that monofractal behavior may be due to high-frequency plasma waves at kinetic scales.

  17. Climatology of the Iberia coastal low-level wind jet: weather research forecasting model high-resolution results

    Directory of Open Access Journals (Sweden)

    Pedro M. M. Soares

    2013-01-01

    Full Text Available Coastal low-level jets (CLLJ are a low-tropospheric wind feature driven by the pressure gradient produced by a sharp contrast between high temperatures over land and lower temperatures over the sea. This contrast between the cold ocean and the warm land in the summer is intensified by the impact of the coastal parallel winds on the ocean generating upwelling currents, sharpening the temperature gradient close to the coast and giving rise to strong baroclinic structures at the coast. During summertime, the Iberian Peninsula is often under the effect of the Azores High and of a thermal low pressure system inland, leading to a seasonal wind, in the west coast, called the Nortada (northerly wind. This study presents a regional climatology of the CLLJ off the west coast of the Iberian Peninsula, based on a 9 km resolution downscaling dataset, produced using the Weather Research and Forecasting (WRF mesoscale model, forced by 19 years of ERA-Interim reanalysis (1989–2007. The simulation results show that the jet hourly frequency of occurrence in the summer is above 30% and decreases to about 10% during spring and autumn. The monthly frequencies of occurrence can reach higher values, around 40% in summer months, and reveal large inter-annual variability in all three seasons. In the summer, at a daily base, the CLLJ is present in almost 70% of the days. The CLLJ wind direction is mostly from north-northeasterly and occurs more persistently in three areas where the interaction of the jet flow with local capes and headlands is more pronounced. The coastal jets in this area occur at heights between 300 and 400 m, and its speed has a mean around 15 m/s, reaching maximum speeds of 25 m/s.

  18. Large-scale, high-resolution wind resource mapping for wind farm planning and development in South Africa

    DEFF Research Database (Denmark)

    Mortensen, Niels Gylling; Badger, Jake; Hansen, Jens Carsten

    2014-01-01

    estimates are designed for national and provincial planning and strategic environmental impact assessment for wind power in South Africa and the results have therefore been made available in common GIS formats. The database of results is in the public domain and can be downloaded from the WASA web site...

  19. High-Time-Resolution Study of Magnetic Holes in the Solar Wind

    Science.gov (United States)

    Lazarus, Alan; Kasper, Justin; Stevens, Michael

    2003-01-01

    The objectives of this investigation are to determine the internal plasma structure of kinetic-scale and larger scale magnetic holes, and to determine their stability, their source mechanism(s), and their spatial extent. It is also of importance to determine the relationship between kinetic-scale holes and long-duration holes. As smaller and smaller magnetic depressions are investigated in order to make this a complete study, a robust criterion is necessary for distinguishing magnetic holes from random or unresolvable fluctuations in the interplanetary magnetic field. In order to resolve this ambiguity, we obtained from the MFI experiments magnetic field measurements from the WIND spacecraft at a time resolution of 46 to 184 ms over certain periods. We have also devised a measure of certainty for magnetic hole detections. The certainty factor, q, is defined as the difference between the mean magnetic field in the hole and the local magnetic field, in units of the local standard deviation of the field strength. For fullest generality, it is necessary to calculate this q over the range of available scales of interest, from 60 ms up to 300 s. This technique establishes a two dimensional matrix of relative probabilities that a hole of some duration (d) might exist in the data set at a given time (t). In identifying q-peaks in time and duration, we also come upon a natural method for distinguishing holes with internal structure from multiple holes in close proximity or holes nested inside of others. If two q-peaks are more than a half-width apart, they are simply said to be separate events.

  20. Initialization of high resolution surface wind simulations using NWS gridded data

    Science.gov (United States)

    J. Forthofer; K. Shannon; Bret Butler

    2010-01-01

    WindNinja is a standalone computer model designed to provide the user with simulations of surface wind flow. It is deterministic and steady state. It is currently being modified to allow the user to initialize the flow calculation using National Digital Forecast Database. It essentially allows the user to downscale the coarse scale simulations from meso-scale models to...

  1. High Resolution Results and Scalability of Numerical Modeling of Wind Flow at White Sands Missile Range

    National Research Council Canada - National Science Library

    Haines, Patrick A; Grove, David J; Sun, Wen-Yih; Hsu, Wu-Ron

    2004-01-01

    ...) and large scale turbulence scale (20 m to 200 m). It is a fully explicit, compressible three-dimensional code and has compared quite to a wide variety of known analytical solution or observed situations including the Boulder Wind Storm...

  2. High-resolution computational algorithms for simulating offshore wind turbines and farms: Model development and validation

    Energy Technology Data Exchange (ETDEWEB)

    Calderer, Antoni [Univ. of Minnesota, Minneapolis, MN (United States); Yang, Xiaolei [Stony Brook Univ., NY (United States); Angelidis, Dionysios [Univ. of Minnesota, Minneapolis, MN (United States); Feist, Chris [Univ. of Minnesota, Minneapolis, MN (United States); Guala, Michele [Univ. of Minnesota, Minneapolis, MN (United States); Ruehl, Kelley [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Guo, Xin [Univ. of Minnesota, Minneapolis, MN (United States); Boomsma, Aaron [Univ. of Minnesota, Minneapolis, MN (United States); Shen, Lian [Univ. of Minnesota, Minneapolis, MN (United States); Sotiropoulos, Fotis [Stony Brook Univ., NY (United States)

    2015-10-30

    The present project involves the development of modeling and analysis design tools for assessing offshore wind turbine technologies. The computational tools developed herein are able to resolve the effects of the coupled interaction of atmospheric turbulence and ocean waves on aerodynamic performance and structural stability and reliability of offshore wind turbines and farms. Laboratory scale experiments have been carried out to derive data sets for validating the computational models.

  3. Sensitivity of a Navy Regional Ocean Model to High-Resolution Atmospheric and Scatterometer Wind Forcing

    Science.gov (United States)

    2003-09-01

    available until June 1999, synthetic QuikSCAT winds were generated using software provided by the Aerospace Corporation ( Stodden and Galasso, 1996...1994: Methods of Satellite Oceanography. Berkeley: University of California Press, 360 pp. Stodden , D.Y., and G.D. Galasso, 1996

  4. Mapping near-surface air temperature, pressure, relative humidity and wind speed over Mainland China with high spatiotemporal resolution

    Science.gov (United States)

    Li, Tao; Zheng, Xiaogu; Dai, Yongjiu; Yang, Chi; Chen, Zhuoqi; Zhang, Shupeng; Wu, Guocan; Wang, Zhonglei; Huang, Chengcheng; Shen, Yan; Liao, Rongwei

    2014-09-01

    As part of a joint effort to construct an atmospheric forcing dataset for mainland China with high spatiotemporal resolution, a new approach is proposed to construct gridded near-surface temperature, relative humidity, wind speed and surface pressure with a resolution of 1 km×1 km. The approach comprises two steps: (1) fit a partial thin-plate smoothing spline with orography and reanalysis data as explanatory variables to ground-based observations for estimating a trend surface; (2) apply a simple kriging procedure to the residual for trend surface correction. The proposed approach is applied to observations collected at approximately 700 stations over mainland China. The generated forcing fields are compared with the corresponding components of the National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis dataset and the Princeton meteorological forcing dataset. The comparison shows that, both within the station network and within the resolutions of the two gridded datasets, the interpolation errors of the proposed approach are markedly smaller than the two gridded datasets.

  5. Solar Wind Turbulence from MHD to Sub-ion Scales: High-resolution Hybrid Simulations

    Czech Academy of Sciences Publication Activity Database

    Franci, L.; Verdini, A.; Matteini, L.; Landi, S.; Hellinger, Petr

    2015-01-01

    Roč. 804, č. 2 (2015), L39/1-L39/5 ISSN 2041-8205 R&D Projects: GA ČR(CZ) GA15-10057S Grant - others:EU(XE) SHOCK Project No. 284515 Institutional support: RVO:67985815 Keywords : magnetohydrodynamics * plasmas * solar wind Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.487, year: 2015

  6. High Resolution Mapping of Wind Speed Using Active Distributed Temperature Sensing

    Science.gov (United States)

    Sayde, C.; Thomas, C. K.; Wagner, J.; Selker, J. S.

    2013-12-01

    We present a novel approach to continuously measure wind speed simultaneously at thousands of locations using actively heated fiber optics with a distributed temperature sensing system (DTS). Analogous to a hot-wire anemometer, this approach is based on the principal of velocity-dependent heat transfer from a heated surface: The temperature difference between the heated surface and ambient air is a function of the convective cooling of the air flowing past the surface. By knowing the thermal properties of the heated surface, the heating input, and ambient temperature, wind speed can be calculated. In our case, the heated surface consists of a thin stainless steel tube that can exceed several km in length. A fiber optic is enclosed within the stainless steel tube to report the heated tube temperature, which in this case was sampled every 0.125 m. Ambient temperature were measured by an independent fiber optic cable located proximally to the stainless steel tube. We will present the theoretical bases of measuring wind speed using heated fiber optic as well as validation of this method in the field. In the field testing, more than 5000 simultaneous wind speed measurements were obtained every 5.5 second at 3 elevations (2m, 1m, and 0.5 m) every 0.125 m along a 230 m transects located across a shallow gulley in Nunn, CO. This method, which provides both air temperature and wind speed spanning four orders of magnitude in spatial scale (0.1 - 1,000m) opens up many important opportunities for testing basic theories in micro-meteorology regarding spatial scales of turbulent length scales as a function of distance from the earth, development of internal boundary layers, applicability of Taylors hypothesis, etc. The equipment employed, including the heating system, which is available to all US scientists, was provided by CTEMPs.org thanks to the generous grant support from the National Science Foundation under Grant Number 1129003. Any opinions, findings, and conclusions or

  7. High-resolution numerical simulation of summer wind field comparing WRF boundary-layer parametrizations over complex Arctic topography: case study from central Spitsbergen

    Czech Academy of Sciences Publication Activity Database

    Láska, K.; Chládová, Zuzana; Hošek, Jiří

    2017-01-01

    Roč. 26, č. 4 (2017), s. 391-408 ISSN 0941-2948 Institutional support: RVO:68378289 Keywords : surface wind field * model evaluation * topographic effect * circulation pattern * Svalbard Subject RIV: DG - Athmosphere Sciences, Meteorology OBOR OECD: Meteorology and atmospheric sciences Impact factor: 1.989, year: 2016 http://www.schweizerbart.de/papers/metz/detail/prepub/87659/High_resolution_numerical_simulation_of_summer_wind_field_comparing_WRF_boundary_layer_parametrizations_over_complex_Arctic_topography_case_study_from_central_Spitsbergen

  8. High Spatial Resolution X-Ray Spectroscopy of the IC 443 Pulsar Wind Nebula and Environs

    Science.gov (United States)

    Swartz, Douglas A.; Pavlov, George G.; Clarke, Tracy; Castelletti, Gabriela; Zavlin, Vyacheslav E.; Bucciantini, Niccolò; Karovska, Margarita; van der Horst, Alexander J.; Yukita, Mihoko; Weisskopf, Martin C.

    2015-07-01

    Deep Chandra ACIS observations of the region around the putative pulsar, CXOU J061705.3+222127, in the supernova remnant (SNR) IC 443 reveal an ˜5″ radius ring-like structure surrounding the pulsar and a jet-like feature oriented roughly north-south across the ring and through the pulsar's location at 06h17m5.ˢ200 + 22°21‧27.″52 (J2000.0 coordinates). The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar, (2) the non-thermal spectrum and morphology of the surrounding nebula are consistent with a pulsar wind, and (3) the spectrum at greater distances is consistent with thermal emission from the SNR. The cometary shape of the nebula, suggesting motion toward the southwest, appears to be subsonic: There is no evidence either spectrally or morphologically for a bow shock or contact discontinuity; the nearly circular ring is not distorted by motion through the ambient medium; and the shape near the apex of the nebula is narrow. Comparing this observation with previous observations of the same target, we set a 99% confidence upper limit to the proper motion of CXOU J061705.3+222127 to be less than 44 mas yr-1 (310 km s-1 for a distance of 1.5 kpc), with the best-fit (but not statistically significant) projected direction toward the west.

  9. High Spatial Resolution X-Ray Spectroscopy of the IC443 Pulsar Wind Nebula

    Science.gov (United States)

    Swartz, Douglas A.; Weisskopf, Martin C.; Bucciantini, Niccolo; Clarke, Tracy E.; Karovska, Margarita; Pavlov, George G.; van der Horst, Alexander; Yukita, Mihoko; Zavlin, Vyacheslav

    2014-08-01

    Deep Chandra ACIS observations of the region around the putative pulsar CXOU J061705.3+222127, in the supernova remnant IC443, reveal a ~5" radius ring-like morphology surrounding the pulsar and a jet-like structure oriented roughly north-south across the ring and through the pulsar's location. The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar, (2) the non-thermal spectrum and morphology of the surrounding nebula are consistent with a pulsar wind, and (3) the spectrum at greater distances is consistent with thermal emission from the supernova remnant. The cometary shape of the nebula, suggesting motion towards the southwest, appears to be subsonic: There is no evidence for a strong bow shock; and the ring is not distorted by motion through the ambient medium. Comparing this observation with historical observations of the same target we set a 99-% confidence upper limit to the proper motion of CXOU J061705.3+222127 to be less than 310 km/s, with the best-fit (but not statistically significant) direction toward the west.

  10. HIGH SPATIAL RESOLUTION X-RAY SPECTROSCOPY OF THE IC 443 PULSAR WIND NEBULA AND ENVIRONS

    International Nuclear Information System (INIS)

    Swartz, Douglas A.; Zavlin, Vyacheslav E.; Pavlov, George G.; Clarke, Tracy; Castelletti, Gabriela; Bucciantini, Niccolò; Karovska, Margarita; Horst, Alexander J. van der; Yukita, Mihoko; Weisskopf, Martin C.

    2015-01-01

    Deep Chandra ACIS observations of the region around the putative pulsar, CXOU J061705.3+222127, in the supernova remnant (SNR) IC 443 reveal an ∼5″ radius ring-like structure surrounding the pulsar and a jet-like feature oriented roughly north–south across the ring and through the pulsar's location at 06 h 17 m 5. s 200 + 22°21′27.″52 (J2000.0 coordinates). The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar, (2) the non-thermal spectrum and morphology of the surrounding nebula are consistent with a pulsar wind, and (3) the spectrum at greater distances is consistent with thermal emission from the SNR. The cometary shape of the nebula, suggesting motion toward the southwest, appears to be subsonic: There is no evidence either spectrally or morphologically for a bow shock or contact discontinuity; the nearly circular ring is not distorted by motion through the ambient medium; and the shape near the apex of the nebula is narrow. Comparing this observation with previous observations of the same target, we set a 99% confidence upper limit to the proper motion of CXOU J061705.3+222127 to be less than 44 mas yr −1 (310 km s −1 for a distance of 1.5 kpc), with the best-fit (but not statistically significant) projected direction toward the west

  11. HIGH SPATIAL RESOLUTION X-RAY SPECTROSCOPY OF THE IC 443 PULSAR WIND NEBULA AND ENVIRONS

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, Douglas A.; Zavlin, Vyacheslav E. [USRA, Astrophysics Office, NASA Marshall Space Flight Center, ZP12, Huntsville, AL 35812 (United States); Pavlov, George G. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Clarke, Tracy [Remote Sensing Division, Code 7213, Naval Research Laboratory, 4555 Overlook Avenue, SW, Washington, DC (United States); Castelletti, Gabriela [Instituto de Astronomía y Física del Espacio (IAFE, CONICET-UBA), CC67, Suc. 28, 1428, Buenos Aires (Argentina); Bucciantini, Niccolò [INAF—Osservatorio Astrofisico di Arcetri, L. go E. Fermi 5, I-50125 Firenze (Italy); Karovska, Margarita [Smithsonian Astrophysical Observatory, MS 4, 60 Garden Street, Cambridge, MA 02138 (United States); Horst, Alexander J. van der [Department of Physics, The George Washington University, 725 21 Street NW, Washington, DC 20052 (United States); Yukita, Mihoko [The Johns Hopkins University, Homewood Campus, Baltimore, MD 21218 (United States); Weisskopf, Martin C. [Astrophysics Office, NASA Marshall Space Flight Center, ZP12, Huntsville, AL 35812 (United States)

    2015-07-20

    Deep Chandra ACIS observations of the region around the putative pulsar, CXOU J061705.3+222127, in the supernova remnant (SNR) IC 443 reveal an ∼5″ radius ring-like structure surrounding the pulsar and a jet-like feature oriented roughly north–south across the ring and through the pulsar's location at 06{sup h}17{sup m}5.{sup s}200 + 22°21′27.″52 (J2000.0 coordinates). The observations further confirm that (1) the spectrum and flux of the central object are consistent with a rotation-powered pulsar, (2) the non-thermal spectrum and morphology of the surrounding nebula are consistent with a pulsar wind, and (3) the spectrum at greater distances is consistent with thermal emission from the SNR. The cometary shape of the nebula, suggesting motion toward the southwest, appears to be subsonic: There is no evidence either spectrally or morphologically for a bow shock or contact discontinuity; the nearly circular ring is not distorted by motion through the ambient medium; and the shape near the apex of the nebula is narrow. Comparing this observation with previous observations of the same target, we set a 99% confidence upper limit to the proper motion of CXOU J061705.3+222127 to be less than 44 mas yr{sup −1} (310 km s{sup −1} for a distance of 1.5 kpc), with the best-fit (but not statistically significant) projected direction toward the west.

  12. High-resolution multi-model projections of onshore wind resources over Portugal under a changing climate

    Science.gov (United States)

    Nogueira, Miguel; Soares, Pedro M. M.; Tomé, Ricardo; Cardoso, Rita M.

    2018-05-01

    We present a detailed evaluation of wind energy density (WED) over Portugal, based on the EURO-CORDEX database of high-resolution regional climate model (RCM) simulations. Most RCMs showed reasonable accuracy in reproducing the observed near-surface wind speed. The climatological patterns of WED displayed large sub-regional heterogeneity, with higher values over coastal regions and steep orography. Subsequently, we investigated the future changes of WED throughout the twenty-first century, considering mid- and end-century periods, and two emission scenarios (RCP4.5 and RCP8.5). On the yearly average, the multi-model ensemble WED changes were below 10% (15%) under RCP4.5 (RCP8.5). However, the projected WED anomalies displayed strong seasonality, dominated by low positive values in summer (< 10% for both scenarios), negative values in winter and spring (up to - 10% (- 20%) under RCP4.5 (RCP8.5)), and stronger negative anomalies in autumn (up to - 25% (- 35%) under RCP4.5 (RCP8.5)). These projected WED anomalies displayed large sub-regional variability. The largest reductions (and lowest increases) are linked to the northern and central-eastern elevated terrain, and the southwestern coast. In contrast, the largest increases (and lowest reductions) are linked to the central-western orographic features of moderate elevation. The projections also showed changes in inter-annual variability of WED, with small increases for annual averages, but with distinct behavior when considering year-to-year variability over a specific season: small increases in winter, larger increases in summer, slight decrease in autumn, and no relevant change in spring. The changes in inter-annual variability also displayed strong dependence on the underlying terrain. Finally, we found significant model spread in the magnitude of projected WED anomalies and inter-annual variability, affecting even the signal of the changes.

  13. Conflict Resolution for Wind-Optimal Aircraft Trajectories in North Atlantic Oceanic Airspace with Wind Uncertainties

    Science.gov (United States)

    Rodionova, Olga; Sridhar, Banavar; Ng, Hok K.

    2016-01-01

    Air traffic in the North Atlantic oceanic airspace (NAT) experiences very strong winds caused by jet streams. Flying wind-optimal trajectories increases individual flight efficiency, which is advantageous when operating in the NAT. However, as the NAT is highly congested during peak hours, a large number of potential conflicts between flights are detected for the sets of wind-optimal trajectories. Conflict resolution performed at the strategic level of flight planning can significantly reduce the airspace congestion. However, being completed far in advance, strategic planning can only use predicted environmental conditions that may significantly differ from the real conditions experienced further by aircraft. The forecast uncertainties result in uncertainties in conflict prediction, and thus, conflict resolution becomes less efficient. This work considers wind uncertainties in order to improve the robustness of conflict resolution in the NAT. First, the influence of wind uncertainties on conflict prediction is investigated. Then, conflict resolution methods accounting for wind uncertainties are proposed.

  14. Validating the WRF-Chem model for wind energy applications using High Resolution Doppler Lidar data from a Utah 2012 field campaign

    Science.gov (United States)

    Mitchell, M. J.; Pichugina, Y. L.; Banta, R. M.

    2015-12-01

    Models are important tools for assessing potential of wind energy sites, but the accuracy of these projections has not been properly validated. In this study, High Resolution Doppler Lidar (HRDL) data obtained with high temporal and spatial resolution at heights of modern turbine rotors were compared to output from the WRF-chem model in order to help improve the performance of the model in producing accurate wind forecasts for the industry. HRDL data were collected from January 23-March 1, 2012 during the Uintah Basin Winter Ozone Study (UBWOS) field campaign. A model validation method was based on the qualitative comparison of the wind field images, time-series analysis and statistical analysis of the observed and modeled wind speed and direction, both for case studies and for the whole experiment. To compare the WRF-chem model output to the HRDL observations, the model heights and forecast times were interpolated to match the observed times and heights. Then, time-height cross-sections of the HRDL and WRF-Chem wind speed and directions were plotted to select case studies. Cross-sections of the differences between the observed and forecasted wind speed and directions were also plotted to visually analyze the model performance in different wind flow conditions. A statistical analysis includes the calculation of vertical profiles and time series of bias, correlation coefficient, root mean squared error, and coefficient of determination between two datasets. The results from this analysis reveals where and when the model typically struggles in forecasting winds at heights of modern turbine rotors so that in the future the model can be improved for the industry.

  15. Developing high-resolution spatial data of migration corridors for avian species of concern in regions of high potential wind development

    Energy Technology Data Exchange (ETDEWEB)

    Katzner, Todd [West Virginia Univ., Morgantown, WV (United States)

    2014-06-15

    The future of the US economy, our national security, and our environmental quality all depend on decreasing our reliance on foreign oil and on fossil fuels. An essential component of decreasing this reliance is the development of alternative energy sources. Wind power is among the most important alternative energy sources currently available, and the mid-Atlantic region is a primary focus for wind power development. In addition to being important to the development of wind power, the mid-Atlantic region holds a special responsibility for the conservation of the eastern North America's golden eagles (Aquila chrysaetos). This small population breeds in northeastern Canada, winters in the southern Appalachians, and nearly all of these birds pass through the mid-Atlantic region twice each year. Movement of these birds is not random and, particularly during spring and autumn, migrating golden eagles concentrate in a narrow 30-50 mile wide corridor in central Pennsylvania. Thus, because the fate of these rare birds may depend on responsible management of the habitat they use it is critical to use research to identify ways to mitigate prospective impacts on this and similar raptor species. The goal of this project was to develop high-resolution spatial risk maps showing migration corridors of and habitat use by eastern golden eagles in regions of high potential for wind development. To accomplish this, we first expanded existing models of raptor migration for the eastern USA to identify broad-scale migration patterns. We then used data from novel high-resolution tracking devices to discover routes of passage and detailed flight behavior of individual golden eagles throughout the eastern USA. Finally, we integrated these data and models to predict population-level migration patterns and individual eagle flight behavior on migration. We then used this information to build spatially explicit, probabilistic maps showing relative risk to birds from wind development. This

  16. High spectral resolution lidar based on quad mach zehnder interferometer for aerosols and wind measurements on board space missions

    Science.gov (United States)

    Mariscal, Jean-François; Bruneau, Didier; Pelon, Jacques; Van Haecke, Mathilde; Blouzon, Frédéric; Montmessin, Franck; Chepfer, Hélène

    2018-04-01

    We present the measurement principle and the optical design of a Quad Mach Zehnder (QMZ) interferometer as HSRL technique, allowing simultaneous measurements of particle backscattering and wind velocity. Key features of this concept is to operate with a multimodal laser and do not require any frequency stabilization. These features are relevant especially for space applications for which high technical readiness level is required.

  17. High resolution modelling results of the wind flow over Canary Islands during the meteorological situation of the extratropical storm Delta (28–30 November 2005

    Directory of Open Access Journals (Sweden)

    J. M. Baldasano

    2008-05-01

    Full Text Available On 28–29 November 2005 an extratropical storm affected the Canary Islands causing significant damage related to high average wind speeds and intense gusts over some islands of the archipelago. Delta was the twenty-sixth tropical or subtropical storm of the 2005 Atlantic hurricane season. It represents an unusual meteorological phenomenon for that region, and its impacts were underestimated by the different operational meteorological forecasts during the previous days of the arrival of the low near Canary Islands. The aim of this study is to reproduce the local effects of the flow that were observed over the Canary Islands during the travel of the Delta storm near the region using high-resolution mesoscale meteorological simulations. The Advanced Research Weather Research & Forecasting Model (WRF-ARW is applied at 9, 3 and 1 km horizontal resolution using ECMWF forecasts as initial and boundary conditions. The high-resolution simulation will outline the main features that contributed to the high wind speeds observed in the archipelago. Variations in vertical static stability, vertical windshear and the intense synoptic winds of the southwestern part of Delta with a warm core at 850 hPa were the main characteristics that contributed to the development and amplification of intense gravity waves while the large-scale flow interacted with the complex topography of the islands.

  18. High spectral resolution lidar based on quad mach zehnder interferometer for aerosols and wind measurements on board space missions

    Directory of Open Access Journals (Sweden)

    Mariscal Jean-François

    2018-01-01

    Full Text Available We present the measurement principle and the optical design of a Quad Mach Zehnder (QMZ interferometer as HSRL technique, allowing simultaneous measurements of particle backscattering and wind velocity. Key features of this concept is to operate with a multimodal laser and do not require any frequency stabilization. These features are relevant especially for space applications for which high technical readiness level is required.

  19. Combining the VAS 3D interpolation method and Wind Atlas methodology to produce a high-resolution wind resource map for the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Hanslian, David; Hošek, Jiří

    2015-01-01

    Roč. 77, May (2015), s. 291-299 ISSN 0960-1481 Institutional support: RVO:68378289 Keywords : wind resource map * wind field modelling * wind measurements * wind climatology * Czech Republic * WAsP Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 3.404, year: 2015 http://www.sciencedirect.com/science/article/pii/S0960148114008398#

  20. On the Binary Nature of Massive Blue Hypergiants: High-resolution X-Ray Spectroscopy Suggests That Cyg OB2 12 is a Colliding Wind Binary

    Energy Technology Data Exchange (ETDEWEB)

    Oskinova, L. M.; Hamann, W.-R.; Shenar, T.; Sander, A. A. C.; Todt, H.; Hainich, R. [Institute for Physics and Astronomy, University Potsdam, D-14476 Potsdam (Germany); Huenemoerder, D. P. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Ignace, R., E-mail: lida@astro.physik.uni-potsdam.de [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37663 (United States)

    2017-08-10

    The blue hypergiant Cyg OB2 12 (B3Ia{sup +}) is a representative member of the class of very massive stars in a poorly understood evolutionary stage. We obtained its high-resolution X-ray spectrum using the Chandra observatory. PoWR model atmospheres were calculated to provide realistic wind opacities and to establish the wind density structure. We find that collisional de-excitation is the dominant mechanism depopulating the metastable upper levels of the forbidden lines of the He-like ions Si xiv and Mg xii. Comparison between the model and observations reveals that X-ray emission is produced in a dense plasma, which could reside only at the photosphere or in a colliding wind zone between binary components. The observed X-ray spectra are well-fitted by thermal plasma models, with average temperatures in excess of 10 MK. The wind speed in Cyg OB2 12 is not high enough to power such high temperatures, but the collision of two winds in a binary system can be sufficient. We used archival data to investigate the X-ray properties of other blue hypergiants. In general, stars of this class are not detected as X-ray sources. We suggest that our new Chandra observations of Cyg OB2 12 can be best explained if Cyg OB2 12 is a colliding wind binary possessing a late O-type companion. This makes Cyg OB2 12 only the second binary system among the 16 known Galactic hypergiants. This low binary fraction indicates that the blue hypergiants are likely products of massive binary evolution during which they either accreted a significant amount of mass or already merged with their companions.

  1. A new method for estimating maximum wind gust speed with a given return period and a high areal resolution

    Czech Academy of Sciences Publication Activity Database

    Pop, Lukáš; Sokol, Zbyněk; Hanslian, David

    2016-01-01

    Roč. 158, November (2016), s. 51-60 ISSN 0167-6105 R&D Projects: GA ČR GAP504/10/0843 Institutional support: RVO:68378289 Keywords : wind gusts * extreme wind map * return period * gumbel distribution * extreme value analysis Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.049, year: 2016 http://www.sciencedirect.com/science/article/pii/S0167610515301677

  2. X-RAY HIGH-RESOLUTION SPECTROSCOPY REVEALS FEEDBACK IN A SEYFERT GALAXY FROM AN ULTRA-FAST WIND WITH COMPLEX IONIZATION AND VELOCITY STRUCTURE

    International Nuclear Information System (INIS)

    Longinotti, A. L.; Krongold, Y.; Guainazzi, M.; Santos-Lleo, M.; Rodriguez-Pascual, P.; Giroletti, M.; Panessa, F.; Costantini, E.

    2015-01-01

    Winds outflowing from active galactic nuclei (AGNs) may carry significant amounts of mass and energy out to their host galaxies. In this paper we report the detection of a sub-relativistic outflow observed in the narrow line Seyfert 1 galaxy IRAS 17020+4544 as a series of absorption lines corresponding to at least five absorption components with an unprecedented wide range of associated column densities and ionization levels and velocities in the range of 23,000–33,000 km s −1 , detected at X-ray high spectral resolution (E/ΔE ∼ 1000) with the ESA's observatory XMM-Newton. The charge states of the material constituting the wind clearly indicate a range of low to moderate ionization states in the outflowing gas and column densities that are significantly lower than observed in highly ionized ultra-fast outflows. We estimate that at least one of the outflow components may carry sufficient energy to substantially suppress star formation and heat the gas in the host galaxy. IRAS 17020+4544 therefore provides an interesting example of feedback by a moderately luminous AGN that is hosted in a spiral galaxy, a case barely envisaged in most evolution models, which often predict that feedback processes take place in massive elliptical galaxies hosting luminous quasars in a post-merger phase

  3. X-RAY HIGH-RESOLUTION SPECTROSCOPY REVEALS FEEDBACK IN A SEYFERT GALAXY FROM AN ULTRA-FAST WIND WITH COMPLEX IONIZATION AND VELOCITY STRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Longinotti, A. L. [Catedrática CONACYT—Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis E. Erro 1, Tonantzintla, Puebla, C.P. 72840, México (Mexico); Krongold, Y. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70264, 04510 Mexico D.F. (Mexico); Guainazzi, M.; Santos-Lleo, M.; Rodriguez-Pascual, P. [ESAC, P.O. Box, 78 E-28691 Villanueva de la Cañada, Madrid (Spain); Giroletti, M. [INAF Osservatorio di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy); Panessa, F. [INAF—Istituto di Astrofisica e Planetologia Spaziali di Roma (IAPS), Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Costantini, E. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

    2015-11-10

    Winds outflowing from active galactic nuclei (AGNs) may carry significant amounts of mass and energy out to their host galaxies. In this paper we report the detection of a sub-relativistic outflow observed in the narrow line Seyfert 1 galaxy IRAS 17020+4544 as a series of absorption lines corresponding to at least five absorption components with an unprecedented wide range of associated column densities and ionization levels and velocities in the range of 23,000–33,000 km s{sup −1}, detected at X-ray high spectral resolution (E/ΔE ∼ 1000) with the ESA's observatory XMM-Newton. The charge states of the material constituting the wind clearly indicate a range of low to moderate ionization states in the outflowing gas and column densities that are significantly lower than observed in highly ionized ultra-fast outflows. We estimate that at least one of the outflow components may carry sufficient energy to substantially suppress star formation and heat the gas in the host galaxy. IRAS 17020+4544 therefore provides an interesting example of feedback by a moderately luminous AGN that is hosted in a spiral galaxy, a case barely envisaged in most evolution models, which often predict that feedback processes take place in massive elliptical galaxies hosting luminous quasars in a post-merger phase.

  4. HRensembleHR. High resolution ensemble for Horns Rev. Final project report. Executive summary; Offshore wind power

    Energy Technology Data Exchange (ETDEWEB)

    2010-03-15

    The development of offshore wind power results in more energy production per area unit and new requirements to the generation forecasts. Measurements from Horns Rev and ensemble forecasts were used to upgrade forecasting tools for the relevant periods and time scales. The most significant development is a new algorithm for short-term forecasts that combines any relevant online measurements by means of ensemble forecasts. (ln)

  5. ANL high resolution injector

    International Nuclear Information System (INIS)

    Minehara, E.; Kutschera, W.; Hartog, P.D.; Billquist, P.

    1985-01-01

    The ANL (Argonne National Laboratory) high-resolution injector has been installed to obtain higher mass resolution and higher preacceleration, and to utilize effectively the full mass range of ATLAS (Argonne Tandem Linac Accelerator System). Preliminary results of the first beam test are reported briefly. The design and performance, in particular a high-mass-resolution magnet with aberration compensation, are discussed. 7 refs., 5 figs., 2 tabs

  6. High Resolution Elevation Contours

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

  7. Ultra high resolution tomography

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, W.S.

    1994-11-15

    Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

  8. High resolution solar observations

    International Nuclear Information System (INIS)

    Title, A.

    1985-01-01

    Currently there is a world-wide effort to develop optical technology required for large diffraction limited telescopes that must operate with high optical fluxes. These developments can be used to significantly improve high resolution solar telescopes both on the ground and in space. When looking at the problem of high resolution observations it is essential to keep in mind that a diffraction limited telescope is an interferometer. Even a 30 cm aperture telescope, which is small for high resolution observations, is a big interferometer. Meter class and above diffraction limited telescopes can be expected to be very unforgiving of inattention to details. Unfortunately, even when an earth based telescope has perfect optics there are still problems with the quality of its optical path. The optical path includes not only the interior of the telescope, but also the immediate interface between the telescope and the atmosphere, and finally the atmosphere itself

  9. High resolution drift chambers

    International Nuclear Information System (INIS)

    Va'vra, J.

    1985-07-01

    High precision drift chambers capable of achieving less than or equal to 50 μm resolutions are discussed. In particular, we compare so called cool and hot gases, various charge collection geometries, several timing techniques and we also discuss some systematic problems. We also present what we would consider an ''ultimate'' design of the vertex chamber. 50 refs., 36 figs., 6 tabs

  10. High resolution data acquisition

    Science.gov (United States)

    Thornton, Glenn W.; Fuller, Kenneth R.

    1993-01-01

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock (38) pulse train (37) and analog circuitry (44) for generating a triangular wave (46) synchronously with the pulse train (37). The triangular wave (46) has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter (18, 32) forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter (26) counts the clock pulse train (37) during the interval to form a gross event interval time. A computer (52) then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  11. Assessing high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.

    1995-01-01

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers...... expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project...... with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h....

  12. High resolution photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Arko, A.J.

    1988-01-01

    Photoelectron Spectroscopy (PES) covers a very broad range of measurements, disciplines, and interests. As the next generation light source, the FEL will result in improvements over the undulator that are larger than the undulater improvements over bending magnets. The combination of high flux and high inherent resolution will result in several orders of magnitude gain in signal to noise over measurements using synchrotron-based undulators. The latter still require monochromators. Their resolution is invariably strongly energy-dependent so that in the regions of interest for many experiments (h upsilon > 100 eV) they will not have a resolving power much over 1000. In order to study some of the interesting phenomena in actinides (heavy fermions e.g.) one would need resolving powers of 10 4 to 10 5 . These values are only reachable with the FEL

  13. High resolution (transformers.

    Science.gov (United States)

    Garcia-Souto, Jose A; Lamela-Rivera, Horacio

    2006-10-16

    A novel fiber-optic interferometric sensor is presented for vibrations measurements and analysis. In this approach, it is shown applied to the vibrations of electrical structures within power transformers. A main feature of the sensor is that an unambiguous optical phase measurement is performed using the direct detection of the interferometer output, without external modulation, for a more compact and stable implementation. High resolution of the interferometric measurement is obtained with this technique (transformers are also highlighted.

  14. High resolution backscattering instruments

    International Nuclear Information System (INIS)

    Coldea, R.

    2001-01-01

    The principle of operation of indirect-geometry time-of-flight spectrometers are presented, including the IRIS at the ISIS spallation neutron source. The key features that make those types of spectrometers ideally suited for low-energy spectroscopy are: high energy resolution over a wide dynamic range, and simultaneous measurement over a large momentum transfer range provided by the wide angular detector coverage. To exemplify these features are discussed of single-crystal experiments of the spin dynamics in the two-dimensional frustrated quantum magnet Cs 2 CuCl 4 . (R.P.)

  15. 天津近海风能资源的高分辨率数值模拟与评估%High-Resolution Numerical Simulation and Assessment of the Offshore Wind Energy Resource in Tianjin

    Institute of Scientific and Technical Information of China (English)

    杨艳娟; 李明财; 任雨; 熊明明

    2011-01-01

    Wind energy is a rapidly growing alternative energy source and has been widely developed around the world over the last 10 years. Offshore wind power generation is now becoming a new trend in the development of future wind power generation because wind tends to blow faster and be more uniform over offshore areas than on the land. Accurate assessment of wind energy resource is fundamental and valuable for wind energy developers and potential wind energy users because it allows them to choose a general area of the estimated high wind resource for more detailed examination. However, it is difficult to make direct observations from meteorological variables over offshore areas, which calls for numerical simulation with high resolution so as to derive the availability and potential of wind energy. The distribution of wind energy resources with 1 km horizontal resolution and 10 m vertical resolution in Tianjin coastal areas was simulated using the numerical model MM5 and Calmet to derive wind energy potential over the offshore areas. In addition, the simulation efficiency was determined by comparing observation data with three wind-measurement towers over the same period. Results show that the annual mean wind speed and trend of daily mean wind speed were simulated well, and the relative deviations between observations and simulated values at three wind measurement towers were 7.11%, 12.99%, and 6.14%, respectively. This suggests that the models are effective in assessing the offshore wind energy resource in Tianjin. The long time wind energy resource was obtained by comparing simulated year’s and recent 20 years’ mean wind speed. It was found that annual mean wind speed is (6.6~7.0)m/s, and annual mean wind power density is above 340w/m2, which indicate that the offshore wind energy resource in Tianjin is exploitable and could be used for grid-connected power generation. The assessment shows that the MM5/Calmet model is capable of providing reasonable wind status

  16. Ensemble Data Assimilation of Wind and Photovoltaic Power Information in the Convection-permitting High-Resolution Model COSMO-DE

    Science.gov (United States)

    Declair, Stefan; Saint-Drenan, Yves-Marie; Potthast, Roland

    2016-04-01

    Determining the amount of weather dependent renewable energy is a demanding task for transmission system operators (TSOs) and wind and photovoltaic (PV) prediction errors require the use of reserve power, which generate costs and can - in extreme cases - endanger the security of supply. In the project EWeLiNE funded by the German government, the German Weather Service and the Fraunhofer Institute on Wind Energy and Energy System Technology develop innovative weather- and power forecasting models and tools for grid integration of weather dependent renewable energy. The key part in energy prediction process chains is the numerical weather prediction (NWP) system. Wind speed and irradiation forecast from NWP system are however subject to several sources of error. The quality of the wind power prediction is mainly penalized by forecast error of the NWP model in the planetary boundary layer (PBL), which is characterized by high spatial and temporal fluctuations of the wind speed. For PV power prediction, weaknesses of the NWP model to correctly forecast i.e. low stratus, the absorption of condensed water or aerosol optical depth are the main sources of errors. Inaccurate radiation schemes (i.e. the two-stream parametrization) are also known as a deficit of NWP systems with regard to irradiation forecast. To mitigate errors like these, NWP model data can be corrected by post-processing techniques such as model output statistics and calibration using historical observational data. Additionally, latest observations can be used in a pre-processing technique called data assimilation (DA). In DA, not only the initial fields are provided, but the model is also synchronized with reality - the observations - and hence the model error is reduced in the forecast. Besides conventional observation networks like radiosondes, synoptic observations or air reports of wind, pressure and humidity, the number of observations measuring meteorological information indirectly such as satellite

  17. Assessing high wind energy penetration

    International Nuclear Information System (INIS)

    Tande, J.O.

    1995-01-01

    In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project settings are close to ideal, including a very capable national utility company, Electra, a conventional power supply system based on imported heavy fuel and gas oil, and favourable wind conditions with an estimated annual average of 9.3 m/s at the hub height of the wind turbines. With the applied case study assumptions, simulations with WINSYS over the lifetime of the assessed wind power investment show that investments up to 4.2 MW are economically viable. The economic optimum is found at 2.4 MW reaching an internal rate of return of almost 8% p.a. This 2.4 MW of wind power would, together with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h. (Author)

  18. High Time Resolution Astrophysics

    CERN Document Server

    Phelan, Don; Shearer, Andrew

    2008-01-01

    High Time Resolution Astrophysics (HTRA) is an important new window to the universe and a vital tool in understanding a range of phenomena from diverse objects and radiative processes. This importance is demonstrated in this volume with the description of a number of topics in astrophysics, including quantum optics, cataclysmic variables, pulsars, X-ray binaries and stellar pulsations to name a few. Underlining this science foundation, technological developments in both instrumentation and detectors are described. These instruments and detectors combined cover a wide range of timescales and can measure fluxes, spectra and polarisation. These advances make it possible for HTRA to make a big contribution to our understanding of the Universe in the next decade.

  19. High resolution ultrasonic densitometer

    International Nuclear Information System (INIS)

    Dress, W.B.

    1983-01-01

    The velocity of torsional stress pulses in an ultrasonic waveguide of non-circular cross section is affected by the temperature and density of the surrounding medium. Measurement of the transit times of acoustic echoes from the ends of a sensor section are interpreted as level, density, and temperature of the fluid environment surrounding that section. This paper examines methods of making these measurements to obtain high resolution, temperature-corrected absolute and relative density and level determinations of the fluid. Possible applications include on-line process monitoring, a hand-held density probe for battery charge state indication, and precise inventory control for such diverse fluids as uranium salt solutions in accountability storage and gasoline in service station storage tanks

  20. High resolution positron tomography

    International Nuclear Information System (INIS)

    Brownell, G.L.; Burnham, C.A.

    1982-01-01

    The limits of spatial resolution in practical positron tomography are examined. The four factors that limit spatial resolution are: positron range; small angle deviation; detector dimensions and properties; statistics. Of these factors, positron range may be considered the fundamental physical limitation since it is independent of instrument properties. The other factors are to a greater or lesser extent dependent on the design of the tomograph

  1. Coupled urban wind flow and indoor natural ventilation modelling on a high-resolution grid: A case study for the Amsterdam ArenA stadium

    NARCIS (Netherlands)

    Hooff, van T.A.J.; Blocken, B.J.E.

    2010-01-01

    Wind flow in urban environments is an important factor governing the dispersion of heat and pollutants from streets, squares and buildings. This paper presents a coupled CFD modelling approach for urban wind flow and indoor natural ventilation. A specific procedure is used to efficiently and

  2. High resolution hadron calorimetry

    International Nuclear Information System (INIS)

    Wigmans, R.

    1987-01-01

    The components that contribute to the signal of a hadron calorimeter and the factors that affect its performance are discussed, concentrating on two aspects; energy resolution and signal linearity. Both are decisively dependent on the relative response to the electromagnetic and the non-electromagnetic shower components, the e/h signal ratio, which should be equal to 1.0 for optimal performance. The factors that determine the value of this ratio are examined. The calorimeter performance is crucially determined by its response to the abundantly present soft neutrons in the shower. The presence of a considerable fraction of hydrogen atoms in the active medium is essential for achieving the best possible results. Firstly, this allows one to tune e/h to the desired value by choosing the appropriate sampling fraction. And secondly, the efficient neutron detection via recoil protons in the readout medium itself reduces considerably the effect of fluctuations in binding energy losses at the nuclear level, which dominate the intrinsic energy resolution. Signal equalization, or compensation (e/h = 1.0) does not seem to be a property unique to 238 U, but can also be achieved with lead and probably even iron absorbers. 21 refs.; 19 figs

  3. High-efficiency wind turbine

    Science.gov (United States)

    Hein, L. A.; Myers, W. N.

    1980-01-01

    Vertical axis wind turbine incorporates several unique features to extract more energy from wind increasing efficiency 20% over conventional propeller driven units. System also features devices that utilize solar energy or chimney effluents during periods of no wind.

  4. High resolution vertical profiles of wind, temperature and humidity obtained by computer processing and digital filtering of radiosonde and radar tracking data from the ITCZ experiment of 1977

    Science.gov (United States)

    Danielson, E. F.; Hipskind, R. S.; Gaines, S. E.

    1980-01-01

    Results are presented from computer processing and digital filtering of radiosonde and radar tracking data obtained during the ITCZ experiment when coordinated measurements were taken daily over a 16 day period across the Panama Canal Zone. The temperature relative humidity and wind velocity profiles are discussed.

  5. Plasma Beta Dependence of the Ion-scale Spectral Break of Solar Wind Turbulence: High-resolution 2D Hybrid Simulations

    Czech Academy of Sciences Publication Activity Database

    Franci, L.; Landi, S.; Matteini, L.; Verdini, A.; Hellinger, Petr

    2016-01-01

    Roč. 833, č. 1 (2016), 91/1-91/7 ISSN 0004-637X R&D Projects: GA ČR GA15-10057S Institutional support: RVO:67985815 Keywords : plasmas * solar wind * turbulence Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.533, year: 2016

  6. Wake flow characteristics at high wind speed

    DEFF Research Database (Denmark)

    Aagaard Madsen, Helge; Larsen, Torben J.; Larsen, Gunner Chr.

    2016-01-01

    Wake flow characteristic at high wind speeds is the main subject of this paper. Although the wake losses decrease at high wind speeds it has been found in a recent study that for multiple wake inflow the increase in loading due to wake effects are substantial even at wind speeds well above rated ...

  7. High wind warning system for Bordeaux, Wyoming.

    Science.gov (United States)

    2010-07-01

    "The state of Wyoming has frequent severe wind conditions, particularly in the southeast corner of the state along Interstate : 80 and Interstate 25. The high winds are problematic in many ways including, interfering with the performance of the : tra...

  8. High resolution metric imaging payload

    Science.gov (United States)

    Delclaud, Y.

    2017-11-01

    Alcatel Space Industries has become Europe's leader in the field of high and very high resolution optical payloads, in the frame work of earth observation system able to provide military government with metric images from space. This leadership allowed ALCATEL to propose for the export market, within a French collaboration frame, a complete space based system for metric observation.

  9. Berkeley High-Resolution Ball

    International Nuclear Information System (INIS)

    Diamond, R.M.

    1984-10-01

    Criteria for a high-resolution γ-ray system are discussed. Desirable properties are high resolution, good response function, and moderate solid angle so as to achieve not only double- but triple-coincidences with good statistics. The Berkeley High-Resolution Ball involved the first use of bismuth germanate (BGO) for anti-Compton shield for Ge detectors. The resulting compact shield permitted rather close packing of 21 detectors around a target. In addition, a small central BGO ball gives the total γ-ray energy and multiplicity, as well as the angular pattern of the γ rays. The 21-detector array is nearly complete, and the central ball has been designed, but not yet constructed. First results taken with 9 detector modules are shown for the nucleus 156 Er. The complex decay scheme indicates a transition from collective rotation (prolate shape) to single- particle states (possibly oblate) near spin 30 h, and has other interesting features

  10. Opportunities for high wind energy penetration

    DEFF Research Database (Denmark)

    Tande, J.O.; Hansen, J.C.

    1997-01-01

    Wind power is today a mature technology, which at windy locations, is economically competitive to conventional power generation technologies. This and growing global environmental concerns have led governments to encourage and plan for wind energy development, a typical aim being 10% of electricity...... consumption. The successful operation of the three major power systems of Cape Verde, with a total wind energy penetration of about 15% since December 1994, demonstrates that power systems can be operated with high penetration of wind energy by adding simple control and monitoring systems only. Thorough...... analyses conclude that expanding to even above 15% wind energy penetration in the Cape Verde power systems is economical. Worldwide, numerous locations with favorable wind conditions and power systems similar to the Capeverdean provide good opportunities for installing wind farms and achieving high wind...

  11. Late Pleistocene and Holocene paleoclimate and alpine glacier fluctuations recorded by high-resolution grain-size data from an alpine lake sediment core, Wind River Range, Wyoming, USA

    Science.gov (United States)

    Thompson Davis, P.; Machalett, Björn; Gosse, John

    2013-04-01

    Varved lake sediments, which provide ideal high-resolution climate proxies, are not commonly available in many geographic areas over long time scales. This paper utilizes high-resolution grain-size analyses (n = 1040) from a 520-cm long sediment core from Lower Titcomb Lake (LTL), which lies just outside the type Titcomb Basin (TTB) moraines in the Wind River Range, Wyoming. The TTB moraines lie between Lower Titcomb Lake and Upper Titcomb Lake (UTL), about 3 km beyond, and 200 m lower than the modern glacier margin and Gannett Peak (Little Ice Age) moraines in the basin. Based on cosmogenic exposure dating, the TTB moraines are believed to be Younger Dryas (YD) age (Gosse et al., 1995) and lie in a geomorphic position similar to several other outer cirque moraines throughout the western American Cordillera. Until recently, many of these outer cirque moraines were believed to be Neoglacial age. The sediment core discussed here is one of five obtained from the two Titcomb Lakes, but is by the far the longest with the oldest sediment depositional record. Two AMS radiocarbon ages from the 445- and 455-cm core depths (about 2% loss on ignition, LOI) suggest that the lake basin may have been ice-free as early as 16.1 or even 16.8 cal 14C kyr, consistent with 10Be and 26Al exposure ages from boulders and bedrock surfaces outside the TTB moraines. The 257-cm depth in the core marks an abrupt transition from inorganic, sticky gray silt below (rock flour production between the 257 and 466 cm core depths appear to be roughly correlative with the YD-Alleröd-Bölling-Meiendorf-Heinrich 1 climate events recognized in other terrestrial records and Northern Atlantic Ocean marine cores, but provide much higher resolution than most of those records from a climate-sensitive alpine region in North America.

  12. Requirements on high resolution detectors

    Energy Technology Data Exchange (ETDEWEB)

    Koch, A. [European Synchrotron Radiation Facility, Grenoble (France)

    1997-02-01

    For a number of microtomography applications X-ray detectors with a spatial resolution of 1 {mu}m are required. This high spatial resolution will influence and degrade other parameters of secondary importance like detective quantum efficiency (DQE), dynamic range, linearity and frame rate. This note summarizes the most important arguments, for and against those detector systems which could be considered. This article discusses the mutual dependencies between the various figures which characterize a detector, and tries to give some ideas on how to proceed in order to improve present technology.

  13. High resolution optical DNA mapping

    Science.gov (United States)

    Baday, Murat

    Many types of diseases including cancer and autism are associated with copy-number variations in the genome. Most of these variations could not be identified with existing sequencing and optical DNA mapping methods. We have developed Multi-color Super-resolution technique, with potential for high throughput and low cost, which can allow us to recognize more of these variations. Our technique has made 10--fold improvement in the resolution of optical DNA mapping. Using a 180 kb BAC clone as a model system, we resolved dense patterns from 108 fluorescent labels of two different colors representing two different sequence-motifs. Overall, a detailed DNA map with 100 bp resolution was achieved, which has the potential to reveal detailed information about genetic variance and to facilitate medical diagnosis of genetic disease.

  14. High angular resolution at LBT

    Science.gov (United States)

    Conrad, A.; Arcidiacono, C.; Bertero, M.; Boccacci, P.; Davies, A. G.; Defrere, D.; de Kleer, K.; De Pater, I.; Hinz, P.; Hofmann, K. H.; La Camera, A.; Leisenring, J.; Kürster, M.; Rathbun, J. A.; Schertl, D.; Skemer, A.; Skrutskie, M.; Spencer, J. R.; Veillet, C.; Weigelt, G.; Woodward, C. E.

    2015-12-01

    High angular resolution from ground-based observatories stands as a key technology for advancing planetary science. In the window between the angular resolution achievable with 8-10 meter class telescopes, and the 23-to-40 meter giants of the future, LBT provides a glimpse of what the next generation of instruments providing higher angular resolution will provide. We present first ever resolved images of an Io eruption site taken from the ground, images of Io's Loki Patera taken with Fizeau imaging at the 22.8 meter LBT [Conrad, et al., AJ, 2015]. We will also present preliminary analysis of two data sets acquired during the 2015 opposition: L-band fringes at Kurdalagon and an occultation of Loki and Pele by Europa (see figure). The light curves from this occultation will yield an order of magnitude improvement in spatial resolution along the path of ingress and egress. We will conclude by providing an overview of the overall benefit of recent and future advances in angular resolution for planetary science.

  15. High resolution tomographic instrument development

    International Nuclear Information System (INIS)

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational

  16. High resolution tomographic instrument development

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  17. High resolution tomographic instrument development

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  18. Impact of Spatial Resolution on Wind Field Derived Estimates of Air Pressure Depression in the Hurricane Eye

    Directory of Open Access Journals (Sweden)

    Linwood Jones

    2010-03-01

    Full Text Available Measurements of the near surface horizontal wind field in a hurricane with spatial resolution of order 1–10 km are possible using airborne microwave radiometer imagers. An assessment is made of the information content of the measured winds as a function of the spatial resolution of the imager. An existing algorithm is used which estimates the maximum surface air pressure depression in the hurricane eye from the maximum wind speed. High resolution numerical model wind fields from Hurricane Frances 2004 are convolved with various HIRAD antenna spatial filters to observe the impact of the antenna design on the central pressure depression in the eye that can be deduced from it.

  19. Wind power bidding in electricity markets with high wind penetration

    International Nuclear Information System (INIS)

    Vilim, Michael; Botterud, Audun

    2014-01-01

    Highlights: • We analyze the pricing systems and wind power trading in electricity markets. • We propose a model that captures the relation between market prices and wind power. • A probabilistic bidding model can increase profits for wind power producers. • Profit maximizing bidding strategies carry risks for power system operators. • We conclude that modifications of current market designs may be needed. - Abstract: Objective: The optimal day-ahead bidding strategy is studied for a wind power producer operating in an electricity market with high wind penetration. Methods: A generalized electricity market is studied with minimal assumptions about the structure of the production, bidding, or consumption of electricity. Two electricity imbalance pricing schemes are investigated, the one price and the two price scheme. A stochastic market model is created to capture the price effects of wind power production and consumption. A bidding algorithm called SCOPES (Supply Curve One Price Estimation Strategy) is developed for the one price system. A bidding algorithm called MIMICS (Multivariate Interdependence Minimizing Imbalance Cost Strategy) is developed for the two price system. Results: Both bidding strategies are shown to have advantages over the assumed “default” bidding strategy, the point forecast. Conclusion: The success of these strategies even in the case of high deviation penalties in a one price system and the implicit deviation penalties of the two price system has substantial implications for power producers and system operators in electricity markets with a high level of wind penetration. Practice implications: From an electricity market design perspective, the results indicate that further penalties or regulations may be needed to reduce system imbalance

  20. Section on High Resolution Optical Imaging (HROI)

    Data.gov (United States)

    Federal Laboratory Consortium — The Section on High Resolution Optical Imaging (HROI) develops novel technologies for studying biological processes at unprecedented speed and resolution. Research...

  1. High Resolution Thermometry for EXACT

    Science.gov (United States)

    Panek, J. S.; Nash, A. E.; Larson, M.; Mulders, N.

    2000-01-01

    High Resolution Thermometers (HRTs) based on SQUID detection of the magnetization of a paramagnetic salt or a metal alloy has been commonly used for sub-nano Kelvin temperature resolution in low temperature physics experiments. The main applications to date have been for temperature ranges near the lambda point of He-4 (2.177 K). These thermometers made use of materials such as Cu(NH4)2Br4 *2H2O, GdCl3, or PdFe. None of these materials are suitable for EXACT, which will explore the region of the He-3/He-4 tricritical point at 0.87 K. The experiment requirements and properties of several candidate paramagnetic materials will be presented, as well as preliminary test results.

  2. High Voltage Power Transmission for Wind Energy

    Science.gov (United States)

    Kim, Young il

    The high wind speeds and wide available area at sea have recently increased the interests on offshore wind farms in the U.S.A. As offshore wind farms become larger and are placed further from the shore, the power transmission to the onshore grid becomes a key feature. Power transmission of the offshore wind farm, in which good wind conditions and a larger installation area than an onshore site are available, requires the use of submarine cable systems. Therefore, an underground power cable system requires unique design and installation challenges not found in the overhead power cable environment. This paper presents analysis about the benefit and drawbacks of three different transmission solutions: HVAC, LCC/VSC HVDC in the grid connecting offshore wind farms and also analyzed the electrical characteristics of underground cables. In particular, loss of HV (High Voltage) subsea power of the transmission cables was evaluated by the Brakelmann's theory, taking into account the distributions of current and temperature.

  3. High speed, High resolution terahertz spectrometers

    International Nuclear Information System (INIS)

    Kim, Youngchan; Yee, Dae Su; Yi, Miwoo; Ahn, Jaewook

    2008-01-01

    A variety of sources and methods have been developed for terahertz spectroscopy during almost two decades. Terahertz time domain spectroscopy (THz TDS)has attracted particular attention as a basic measurement method in the fields of THz science and technology. Recently, asynchronous optical sampling (AOS)THz TDS has been demonstrated, featuring rapid data acquisition and a high spectral resolution. Also, terahertz frequency comb spectroscopy (TFCS)possesses attractive features for high precision terahertz spectroscopy. In this presentation, we report on these two types of terahertz spectrometer. Our high speed, high resolution terahertz spectrometer is demonstrated using two mode locked femtosecond lasers with slightly different repetition frequencies without a mechanical delay stage. The repetition frequencies of the two femtosecond lasers are stabilized by use of two phase locked loops sharing the same reference oscillator. The time resolution of our terahertz spectrometer is measured using the cross correlation method to be 270 fs. AOS THz TDS is presented in Fig. 1, which shows a time domain waveform rapidly acquired on a 10ns time window. The inset shows a zoom into the signal with 100ps time window. The spectrum obtained by the fast Fourier Transformation (FFT)of the time domain waveform has a frequency resolution of 100MHz. The dependence of the signal to noise ratio (SNR)on the measurement time is also investigated

  4. High-resolution observations of IRAS 08544-4431. Detection of a disk orbiting a post-AGB star and of a slow disk wind

    Science.gov (United States)

    Bujarrabal, V.; Castro-Carrizo, A.; Winckel, H. Van; Alcolea, J.; Contreras, C. Sánchez; Santander-García, M.; Hillen, M.

    2018-06-01

    Context. Aims: In order to study the effects of rotating disks in the post-asymptotic giant branch (post-AGB) evolution, we observe a class of binary post-AGB stars that seem to be systematically surrounded by equatorial disks and slow outflows. Although the rotating dynamics had only been well identified in three cases, the study of such structures is thought to be fundamental to the understanding of the formation of disks in various phases of the late evolution of binary stars and the ejection of planetary nebulae from evolved stars. Methods: We present ALMA maps of 12CO and 13CO J = 3-2 lines in the source IRAS 08544-4431, which belongs to the above mentioned class of objects. We analyzed the data by means of nebula models, which account for the expectedly composite source and can reproduce the data. From our modeling, we estimated the main nebula parameters, including the structure and dynamics and the density and temperature distributions. We discuss the uncertainties of the derived values and, in particular, their dependence on the distance. Results: Our observations reveal the presence of an equatorial disk in rotation; a low-velocity outflow is also found, probably formed of gas expelled from the disk. The main characteristics of our observations and modeling of IRAS 08544-4431 are similar to those of better studied objects, confirming our interpretation. The disk rotation indicates a total central mass of about 1.8 M⊙, for a distance of 1100 pc. The disk is found to be relatively extended and has a typical diameter of 4 × 1016 cm. The total nebular mass is 2 × 10-2 M⊙, of which 90% corresponds to the disk. Assuming that the outflow is due to mass loss from the disk, we derive a disk lifetime of 10 000 yr. The disk angular momentum is found to be comparable to that of the binary system at present. Assuming that the disk angular momentum was transferred from the binary system, as expected, the high values of the disk angular momentum in this and other

  5. High-resolution intravital microscopy.

    Directory of Open Access Journals (Sweden)

    Volker Andresen

    Full Text Available Cellular communication constitutes a fundamental mechanism of life, for instance by permitting transfer of information through synapses in the nervous system and by leading to activation of cells during the course of immune responses. Monitoring cell-cell interactions within living adult organisms is crucial in order to draw conclusions on their behavior with respect to the fate of cells, tissues and organs. Until now, there is no technology available that enables dynamic imaging deep within the tissue of living adult organisms at sub-cellular resolution, i.e. detection at the level of few protein molecules. Here we present a novel approach called multi-beam striped-illumination which applies for the first time the principle and advantages of structured-illumination, spatial modulation of the excitation pattern, to laser-scanning-microscopy. We use this approach in two-photon-microscopy--the most adequate optical deep-tissue imaging-technique. As compared to standard two-photon-microscopy, it achieves significant contrast enhancement and up to 3-fold improved axial resolution (optical sectioning while photobleaching, photodamage and acquisition speed are similar. Its imaging depth is comparable to multifocal two-photon-microscopy and only slightly less than in standard single-beam two-photon-microscopy. Precisely, our studies within mouse lymph nodes demonstrated 216% improved axial and 23% improved lateral resolutions at a depth of 80 µm below the surface. Thus, we are for the first time able to visualize the dynamic interactions between B cells and immune complex deposits on follicular dendritic cells within germinal centers (GCs of live mice. These interactions play a decisive role in the process of clonal selection, leading to affinity maturation of the humoral immune response. This novel high-resolution intravital microscopy method has a huge potential for numerous applications in neurosciences, immunology, cancer research and

  6. High-Resolution Intravital Microscopy

    Science.gov (United States)

    Andresen, Volker; Pollok, Karolin; Rinnenthal, Jan-Leo; Oehme, Laura; Günther, Robert; Spiecker, Heinrich; Radbruch, Helena; Gerhard, Jenny; Sporbert, Anje; Cseresnyes, Zoltan; Hauser, Anja E.; Niesner, Raluca

    2012-01-01

    Cellular communication constitutes a fundamental mechanism of life, for instance by permitting transfer of information through synapses in the nervous system and by leading to activation of cells during the course of immune responses. Monitoring cell-cell interactions within living adult organisms is crucial in order to draw conclusions on their behavior with respect to the fate of cells, tissues and organs. Until now, there is no technology available that enables dynamic imaging deep within the tissue of living adult organisms at sub-cellular resolution, i.e. detection at the level of few protein molecules. Here we present a novel approach called multi-beam striped-illumination which applies for the first time the principle and advantages of structured-illumination, spatial modulation of the excitation pattern, to laser-scanning-microscopy. We use this approach in two-photon-microscopy - the most adequate optical deep-tissue imaging-technique. As compared to standard two-photon-microscopy, it achieves significant contrast enhancement and up to 3-fold improved axial resolution (optical sectioning) while photobleaching, photodamage and acquisition speed are similar. Its imaging depth is comparable to multifocal two-photon-microscopy and only slightly less than in standard single-beam two-photon-microscopy. Precisely, our studies within mouse lymph nodes demonstrated 216% improved axial and 23% improved lateral resolutions at a depth of 80 µm below the surface. Thus, we are for the first time able to visualize the dynamic interactions between B cells and immune complex deposits on follicular dendritic cells within germinal centers (GCs) of live mice. These interactions play a decisive role in the process of clonal selection, leading to affinity maturation of the humoral immune response. This novel high-resolution intravital microscopy method has a huge potential for numerous applications in neurosciences, immunology, cancer research and developmental biology

  7. High-Resolution Mass Spectrometers

    Science.gov (United States)

    Marshall, Alan G.; Hendrickson, Christopher L.

    2008-07-01

    Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

  8. Ultra-high resolution AMOLED

    Science.gov (United States)

    Wacyk, Ihor; Prache, Olivier; Ghosh, Amal

    2011-06-01

    AMOLED microdisplays continue to show improvement in resolution and optical performance, enhancing their appeal for a broad range of near-eye applications such as night vision, simulation and training, situational awareness, augmented reality, medical imaging, and mobile video entertainment and gaming. eMagin's latest development of an HDTV+ resolution technology integrates an OLED pixel of 3.2 × 9.6 microns in size on a 0.18 micron CMOS backplane to deliver significant new functionality as well as the capability to implement a 1920×1200 microdisplay in a 0.86" diagonal area. In addition to the conventional matrix addressing circuitry, the HDTV+ display includes a very lowpower, low-voltage-differential-signaling (LVDS) serialized interface to minimize cable and connector size as well as electromagnetic emissions (EMI), an on-chip set of look-up-tables for digital gamma correction, and a novel pulsewidth- modulation (PWM) scheme that together with the standard analog control provides a total dimming range of 0.05cd/m2 to 2000cd/m2 in the monochrome version. The PWM function also enables an impulse drive mode of operation that significantly reduces motion artifacts in high speed scene changes. An internal 10-bit DAC ensures that a full 256 gamma-corrected gray levels are available across the entire dimming range, resulting in a measured dynamic range exceeding 20-bits. This device has been successfully tested for operation at frame rates ranging from 30Hz up to 85Hz. This paper describes the operational features and detailed optical and electrical test results for the new AMOLED WUXGA resolution microdisplay.

  9. High resolution, high speed ultrahigh vacuum microscopy

    International Nuclear Information System (INIS)

    Poppa, Helmut

    2004-01-01

    The history and future of transmission electron microscopy (TEM) is discussed as it refers to the eventual development of instruments and techniques applicable to the real time in situ investigation of surface processes with high resolution. To reach this objective, it was necessary to transform conventional high resolution instruments so that an ultrahigh vacuum (UHV) environment at the sample site was created, that access to the sample by various in situ sample modification procedures was provided, and that in situ sample exchanges with other integrated surface analytical systems became possible. Furthermore, high resolution image acquisition systems had to be developed to take advantage of the high speed imaging capabilities of projection imaging microscopes. These changes to conventional electron microscopy and its uses were slowly realized in a few international laboratories over a period of almost 40 years by a relatively small number of researchers crucially interested in advancing the state of the art of electron microscopy and its applications to diverse areas of interest; often concentrating on the nucleation, growth, and properties of thin films on well defined material surfaces. A part of this review is dedicated to the recognition of the major contributions to surface and thin film science by these pioneers. Finally, some of the important current developments in aberration corrected electron optics and eventual adaptations to in situ UHV microscopy are discussed. As a result of all the path breaking developments that have led to today's highly sophisticated UHV-TEM systems, integrated fundamental studies are now possible that combine many traditional surface science approaches. Combined investigations to date have involved in situ and ex situ surface microscopies such as scanning tunneling microscopy/atomic force microscopy, scanning Auger microscopy, and photoemission electron microscopy, and area-integrating techniques such as x-ray photoelectron

  10. High-resolution ultrasonic spectroscopy

    Directory of Open Access Journals (Sweden)

    V. Buckin

    2018-03-01

    Full Text Available High-resolution ultrasonic spectroscopy (HR-US is an analytical technique for direct and non-destructive monitoring of molecular and micro-structural transformations in liquids and semi-solid materials. It is based on precision measurements of ultrasonic velocity and attenuation in analysed samples. The application areas of HR-US in research, product development, and quality and process control include analysis of conformational transitions of polymers, ligand binding, molecular self-assembly and aggregation, crystallisation, gelation, characterisation of phase transitions and phase diagrams, and monitoring of chemical and biochemical reactions. The technique does not require optical markers or optical transparency. The HR-US measurements can be performed in small sample volumes (down to droplet size, over broad temperature range, at ambient and elevated pressures, and in various measuring regimes such as automatic temperature ramps, titrations and measurements in flow.

  11. High resolution eddy current microscopy

    Science.gov (United States)

    Lantz, M. A.; Jarvis, S. P.; Tokumoto, H.

    2001-01-01

    We describe a sensitive scanning force microscope based technique for measuring local variations in resistivity by monitoring changes in the eddy current induced damping of a cantilever with a magnetic tip oscillating above a conducting sample. To achieve a high sensitivity, we used a cantilever with an FeNdBLa particle mounted on the tip. Resistivity measurements are demonstrated on a silicon test structure with a staircase doping profile. Regions with resistivities of 0.0013, 0.0041, and 0.022 Ω cm are clearly resolved with a lateral resolution of approximately 180 nm. For this range of resistivities, the eddy current induced damping is found to depend linearly on the sample resistivity.

  12. Development of AMS high resolution injector system

    International Nuclear Information System (INIS)

    Bao Yiwen; Guan Xialing; Hu Yueming

    2008-01-01

    The Beijing HI-13 tandem accelerator AMS high resolution injector system was developed. The high resolution energy achromatic system consists of an electrostatic analyzer and a magnetic analyzer, which mass resolution can reach 600 and transmission is better than 80%. (authors)

  13. High temperature co-axial winding transformers

    Science.gov (United States)

    Divan, Deepakraj M.; Novotny, Donald W.

    1993-01-01

    The analysis and design of co-axial winding transformers is presented. The design equations are derived and the different design approaches are discussed. One of the most important features of co-axial winding transformers is the fact that the leakage inductance is well controlled and can be made low. This is not the case in conventional winding transformers. In addition, the power density of co-axial winding transformers is higher than conventional ones. Hence, using co-axial winding transformers in a certain converter topology improves the power density of the converter. The design methodology used in meeting the proposed specifications of the co-axial winding transformer specifications are presented and discussed. The final transformer design was constructed in the lab. Co-axial winding transformers proved to be a good choice for high power density and high frequency applications. They have a more predictable performance compared with conventional transformers. In addition, the leakage inductance of the transformer can be controlled easily to suit a specific application. For space applications, one major concern is the extraction of heat from power apparatus to prevent excessive heating and hence damaging of these units. Because of the vacuum environment, the only way to extract heat is by using a cold plate. One advantage of co-axial winding transformers is that the surface area available to extract heat from is very large compared to conventional transformers. This stems from the unique structure of the co-axial transformer where the whole core surface area is exposed and can be utilized for cooling effectively. This is a crucial issue here since most of the losses are core losses.

  14. Lake topography and wind waves determining seasonal-spatial dynamics of total suspended matter in turbid Lake Taihu, China: assessment using long-term high-resolution MERIS data.

    Science.gov (United States)

    Zhang, Yunlin; Shi, Kun; Liu, Xiaohan; Zhou, Yongqiang; Qin, Boqiang

    2014-01-01

    Multiple comprehensive in situ bio-optical investigations were conducted from 2005 to 2010 and covered a large variability of total suspended matter (TSM) in Lake Taihu to calibrate and validate a TSM concentration estimation model based on Medium Resolution Imaging Spectrometer (MERIS) data. The estimation model of the TSM concentration in Lake Taihu was developed using top-of-atmosphere (TOA) radiance of MERIS image data at band 9 in combination with a regional empirical atmospheric correction model, which was strongly correlated with the in situ TSM concentration (r(2) = 0.720, pwind speed and TSM concentration (r(2)= 0.685, pwind speed in the TSM variations in Lake Taihu. In addition, a low TSM concentration was linked to the appearance of submerged aquatic vegetation (SAV). Therefore, TSM dynamics were controlled by the lake topography, wind-driven sediment resuspension and SAV distribution.

  15. 75 FR 47301 - Cedro Hill Wind LLC; Butler Ridge Wind Energy Center, LLC; High Majestic Wind Energy Center, LLC...

    Science.gov (United States)

    2010-08-05

    ...- 000; EG10-34-000; EG10-34-000; EG10-35-000; EG10-36-000; EG10-37-000; EG10-38-000] Cedro Hill Wind LLC; Butler Ridge Wind Energy Center, LLC; High Majestic Wind Energy Center, LLC; Wessington Wind Energy Center, LLC; Juniper Canyon Wind Power LLC; Loraine Windpark Project, LLC; White Oak Energy LLC; Meadow...

  16. Modeling of the dynamics of wind to power conversion including high wind speed behavior

    DEFF Research Database (Denmark)

    Litong-Palima, Marisciel; Bjerge, Martin Huus; Cutululis, Nicolaos Antonio

    2016-01-01

    This paper proposes and validates an efficient, generic and computationally simple dynamic model for the conversion of the wind speed at hub height into the electrical power by a wind turbine. This proposed wind turbine model was developed as a first step to simulate wind power time series...... for power system studies. This paper focuses on describing and validating the single wind turbine model, and is therefore neither describing wind speed modeling nor aggregation of contributions from a whole wind farm or a power system area. The state-of-the-art is to use static power curves for the purpose...... of power system studies, but the idea of the proposed wind turbine model is to include the main dynamic effects in order to have a better representation of the fluctuations in the output power and of the fast power ramping especially because of high wind speed shutdowns of the wind turbine. The high wind...

  17. High-resolution electron microscopy

    CERN Document Server

    Spence, John C H

    2013-01-01

    This new fourth edition of the standard text on atomic-resolution transmission electron microscopy (TEM) retains previous material on the fundamentals of electron optics and aberration correction, linear imaging theory (including wave aberrations to fifth order) with partial coherence, and multiple-scattering theory. Also preserved are updated earlier sections on practical methods, with detailed step-by-step accounts of the procedures needed to obtain the highest quality images of atoms and molecules using a modern TEM or STEM electron microscope. Applications sections have been updated - these include the semiconductor industry, superconductor research, solid state chemistry and nanoscience, and metallurgy, mineralogy, condensed matter physics, materials science and material on cryo-electron microscopy for structural biology. New or expanded sections have been added on electron holography, aberration correction, field-emission guns, imaging filters, super-resolution methods, Ptychography, Ronchigrams, tomogr...

  18. On Space-Time Resolution of Inflow Representations for Wind Turbine Loads Analysis

    Directory of Open Access Journals (Sweden)

    Lance Manuel

    2012-06-01

    Full Text Available Efficient spatial and temporal resolution of simulated inflow wind fields is important in order to represent wind turbine dynamics and derive load statistics for design. Using Fourier-based stochastic simulation of inflow turbulence, we first investigate loads for a utility-scale turbine in the neutral atmospheric boundary layer. Load statistics, spectra, and wavelet analysis representations for different space and time resolutions are compared. Next, large-eddy simulation (LES is employed with space-time resolutions, justified on the basis of the earlier stochastic simulations, to again derive turbine loads. Extreme and fatigue loads from the two approaches used in inflow field generation are compared. On the basis of simulation studies carried out for three different wind speeds in the turbine’s operating range, it is shown that inflow turbulence described using 10-meter spatial resolution and 1 Hz temporal resolution is adequate for assessing turbine loads. Such studies on the investigation of adequate filtering or resolution of inflow wind fields help to establish efficient strategies for LES and other physical or stochastic simulation needed in turbine loads studies.

  19. Planning for shallow high resolution seismic surveys

    CSIR Research Space (South Africa)

    Fourie, CJS

    2008-11-01

    Full Text Available of the input wave. This information can be used in conjunction with this spreadsheet to aid the geophysicist in designing shallow high resolution seismic surveys to achieve maximum resolution and penetration. This Excel spreadsheet is available free from...

  20. High resolution NMR in zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Anix [INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela). Dept. de Analisis y Evalucion

    1992-12-31

    In this work {sup 29} Si and {sup 27} Al NMR spectroscopy was used to study various types of zeolites. The corresponding spectra were used to measure the Si/Al ratios, to follow chemical modifications induced by acid and hydrothermal treatments, to determine non-equivalent crystallographic sites in highly dealuminated mordenites, and to detect modifications of faujasites due to the insertion of titanium atoms in the lattice. (author) 7 refs., 7 figs., 2 tabs.

  1. High resolution NMR in zeolites

    International Nuclear Information System (INIS)

    Diaz, Anix

    1991-01-01

    In this work 29 Si and 27 Al NMR spectroscopy was used to study various types of zeolites. The corresponding spectra were used to measure the Si/Al ratios, to follow chemical modifications induced by acid and hydrothermal treatments, to determine non-equivalent crystallographic sites in highly dealuminated mordenites, and to detect modifications of faujasites due to the insertion of titanium atoms in the lattice. (author)

  2. VLTI-AMBER Velocity-Resolved Aperture-Synthesis Imaging of Eta Carinae with a Spectral Resolution of 12 000: Studies of the Primary Star Wind and Innermost Wind-Wind Collision Zone

    Science.gov (United States)

    Weigelt, G.; Hofmann, K.-H.; Schertl, D.; Clementel, N.; Corcoran, M. F.; Damineli, A.; de Wit, W.-J.; Grellmann, R.; Groh, J.; Guieu, S.; hide

    2016-01-01

    The mass loss from massive stars is not understood well. Eta Carinae is a unique object for studying the massive stellar wind during the luminous blue variable phase. It is also an eccentric binary with a period of 5.54 yr. The nature of both stars is uncertain, although we know from X-ray studies that there is a wind-wind collision whose properties change with orbital phase. Aims. We want to investigate the structure and kinematics of Car's primary star wind and wind-wind collision zone with a high spatial resolution of approx.6 mas (approx.14 au) and high spectral resolution of R = 12 000. Methods. Observations of Car were carried out with the ESO Very Large Telescope Interferometer (VLTI) and the AMBER instrument between approximately five and seven months before the August 2014 periastron passage. Velocity-resolved aperture-synthesis images were reconstructed from the spectrally dispersed interferograms. Interferometric studies can provide information on the binary orbit, the primary wind, and the wind collision. Results. We present velocity-resolved aperture-synthesis images reconstructed in more than 100 di erent spectral channels distributed across the Br(gamma) 2.166 micron emission line. The intensity distribution of the images strongly depends on wavelength. At wavelengths corresponding to radial velocities of approximately -140 to -376 km/s measured relative to line center, the intensity distribution has a fan-shaped structure. At the velocity of -277 km/s, the position angle of the symmetry axis of the fan is 126. The fan-shaped structure extends approximately 8.0 mas (approx.18:8 au) to the southeast and 5.8 mas (approx.13:6 au) to the northwest, measured along the symmetry axis at the 16% intensity contour. The shape of the intensity distributions suggests that the obtained images are the first direct images of the innermost wind-wind collision zone. Therefore, the observations provide velocity-dependent image structures that can be used to test three

  3. High resolution sequence stratigraphy in China

    International Nuclear Information System (INIS)

    Zhang Shangfeng; Zhang Changmin; Yin Yanshi; Yin Taiju

    2008-01-01

    Since high resolution sequence stratigraphy was introduced into China by DENG Hong-wen in 1995, it has been experienced two development stages in China which are the beginning stage of theory research and development of theory research and application, and the stage of theoretical maturity and widely application that is going into. It is proved by practices that high resolution sequence stratigraphy plays more and more important roles in the exploration and development of oil and gas in Chinese continental oil-bearing basin and the research field spreads to the exploration of coal mine, uranium mine and other strata deposits. However, the theory of high resolution sequence stratigraphy still has some shortages, it should be improved in many aspects. The authors point out that high resolution sequence stratigraphy should be characterized quantitatively and modelized by computer techniques. (authors)

  4. High resolution CT of the chest

    Energy Technology Data Exchange (ETDEWEB)

    Barneveld Binkhuysen, F H [Eemland Hospital (Netherlands), Dept. of Radiology

    1996-12-31

    Compared to conventional CT high resolution CT (HRCT) shows several extra anatomical structures which might effect both diagnosis and therapy. The extra anatomical structures were discussed briefly in this article. (18 refs.).

  5. High-resolution spectrometer at PEP

    International Nuclear Information System (INIS)

    Weiss, J.M.; HRS Collaboration.

    1982-01-01

    A description is presented of the High Resolution Spectrometer experiment (PEP-12) now running at PEP. The advanced capabilities of the detector are demonstrated with first physics results expected in the coming months

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

    Science.gov (United States)

    Singh, Upendra N.; Koch, Grady; Yu, Jirong; Petros, Mulugeta; Beyon, Jeffrey; Kavaya, Michael J.; Trieu, Bo; Chen, Songsheng; Bai, Yingxin; Petzar, paul; hide

    2010-01-01

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

  7. Ultra-high resolution coded wavefront sensor

    KAUST Repository

    Wang, Congli

    2017-06-08

    Wavefront sensors and more general phase retrieval methods have recently attracted a lot of attention in a host of application domains, ranging from astronomy to scientific imaging and microscopy. In this paper, we introduce a new class of sensor, the Coded Wavefront Sensor, which provides high spatio-temporal resolution using a simple masked sensor under white light illumination. Specifically, we demonstrate megapixel spatial resolution and phase accuracy better than 0.1 wavelengths at reconstruction rates of 50 Hz or more, thus opening up many new applications from high-resolution adaptive optics to real-time phase retrieval in microscopy.

  8. Structure of high-resolution NMR spectra

    CERN Document Server

    Corio, PL

    2012-01-01

    Structure of High-Resolution NMR Spectra provides the principles, theories, and mathematical and physical concepts of high-resolution nuclear magnetic resonance spectra.The book presents the elementary theory of magnetic resonance; the quantum mechanical theory of angular momentum; the general theory of steady state spectra; and multiple quantum transitions, double resonance and spin echo experiments.Physicists, chemists, and researchers will find the book a valuable reference text.

  9. High resolution fire risk mapping in Italy

    Science.gov (United States)

    Fiorucci, Paolo; Biondi, Guido; Campo, Lorenzo; D'Andrea, Mirko

    2014-05-01

    The high topographic and vegetation heterogeneity makes Italy vulnerable to forest fires both in the summer and in winter. In particular, northern regions are predominantly characterized by a winter fire regime, mainly due to frequent extremely dry winds from the north, while southern and central regions and the large islands are characterized by a severe summer fire regime, because of the higher temperatures and prolonged lack of precipitation. The threat of wildfires in Italy is not confined to wooded areas as they extend to agricultural areas and urban-forest interface areas. The agricultural and rural areas, in the last century, have been gradually abandoned, especially in areas with complex topography. Many of these areas were subject to reforestation, leading to the spread of pioneer species mainly represented by Mediterranean conifer, which are highly vulnerable to fire. Because of the frequent spread of fire, these areas are limited to the early successional stages, consisting mainly of shrub vegetation; its survival in the competition with the climax species being ensured by the spread of fire itself. Due to the frequency of fire ignition — almost entirely man caused — the time between fires on the same area is at least an order of magnitude less than the time that would allow the establishment of forest climax species far less vulnerable to fire. In view of the limited availability of fire risk management resources, most of which are used in the management of national and regional air services, it is necessary to precisely identify the areas most vulnerable to fire risk. The few resources available can thus be used on a yearly basis to mitigate problems in the areas at highest risk by defining a program of forest management interventions, which is expected to make a significant contribution to the problem in a few years' time. The goal of such detailed planning is to dramatically reduce the costs associated with water bombers fleet management and fire

  10. Recipes for correcting the impact of effective mesoscale resolution on the estimation of extreme winds

    DEFF Research Database (Denmark)

    Larsén, Xiaoli Guo; Ott, Søren; Badger, Jake

    2012-01-01

    Extreme winds derived from simulations using mesoscale models are underestimated due to the effective spatial and temporal resolutions. This is reflected in the spectral domain as an energy deficit in the mesoscale range. The energy deficit implies smaller spectral moments and thus underestimatio...

  11. High tracking resolution detectors. Final Technical Report

    International Nuclear Information System (INIS)

    Vasile, Stefan; Li, Zheng

    2010-01-01

    High-resolution tracking detectors based on Active Pixel Sensor (APS) have been valuable tools in Nuclear Physics and High-Energy Physics research, and have contributed to major discoveries. Their integration time, radiation length and readout rate is a limiting factor for the planed luminosity upgrades in nuclear and high-energy physics collider-based experiments. The goal of this program was to demonstrate and develop high-gain, high-resolution tracking detector arrays with faster readout, and shorter radiation length than APS arrays. These arrays may operate as direct charged particle detectors or as readouts of high resolution scintillating fiber arrays. During this program, we developed in CMOS large, high-resolution pixel sensor arrays with integrated readout, and reset at pixel level. Their intrinsic gain, high immunity to surface and moisture damage, will allow operating these detectors with minimal packaging/passivation requirements and will result in radiation length superior to APS. In Phase I, we designed and fabricated arrays with calorimetric output capable of sub-pixel resolution and sub-microsecond readout rate. The technical effort was dedicated to detector and readout structure development, performance verification, as well as to radiation damage and damage annealing.

  12. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.

    2016-01-01

    and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed solar wind speed (root-mean-square error, RMSE ≈100 km/s) but tend to either overestimate (ESWF) or underestimate (WSA) the number of high-speed solar wind streams (threat......High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...

  13. Ultra-high resolution protein crystallography

    International Nuclear Information System (INIS)

    Takeda, Kazuki; Hirano, Yu; Miki, Kunio

    2010-01-01

    Many protein structures have been determined by X-ray crystallography and deposited with the Protein Data Bank. However, these structures at usual resolution (1.5< d<3.0 A) are insufficient in their precision and quantity for elucidating the molecular mechanism of protein functions directly from structural information. Several studies at ultra-high resolution (d<0.8 A) have been performed with synchrotron radiation in the last decade. The highest resolution of the protein crystals was achieved at 0.54 A resolution for a small protein, crambin. In such high resolution crystals, almost all of hydrogen atoms of proteins and some hydrogen atoms of bound water molecules are experimentally observed. In addition, outer-shell electrons of proteins can be analyzed by the multipole refinement procedure. However, the influence of X-rays should be precisely estimated in order to derive meaningful information from the crystallographic results. In this review, we summarize refinement procedures, current status and perspectives for ultra high resolution protein crystallography. (author)

  14. Design of High Performance Permanent-Magnet Synchronous Wind Generators

    Directory of Open Access Journals (Sweden)

    Chun-Yu Hsiao

    2014-11-01

    Full Text Available This paper is devoted to the analysis and design of high performance permanent-magnet synchronous wind generators (PSWGs. A systematic and sequential methodology for the design of PMSGs is proposed with a high performance wind generator as a design model. Aiming at high induced voltage, low harmonic distortion as well as high generator efficiency, optimal generator parameters such as pole-arc to pole-pitch ratio and stator-slot-shoes dimension, etc. are determined with the proposed technique using Maxwell 2-D, Matlab software and the Taguchi method. The proposed double three-phase and six-phase winding configurations, which consist of six windings in the stator, can provide evenly distributed current for versatile applications regarding the voltage and current demands for practical consideration. Specifically, windings are connected in series to increase the output voltage at low wind speed, and in parallel during high wind speed to generate electricity even when either one winding fails, thereby enhancing the reliability as well. A PMSG is designed and implemented based on the proposed method. When the simulation is performed with a 6 Ω load, the output power for the double three-phase winding and six-phase winding are correspondingly 10.64 and 11.13 kW. In addition, 24 Ω load experiments show that the efficiencies of double three-phase winding and six-phase winding are 96.56% and 98.54%, respectively, verifying the proposed high performance operation.

  15. Assessment of prediction skill in equatorial Pacific Ocean in high resolution model of CFS

    Science.gov (United States)

    Arora, Anika; Rao, Suryachandra A.; Pillai, Prasanth; Dhakate, Ashish; Salunke, Kiran; Srivastava, Ankur

    2018-01-01

    The effect of increasing atmospheric resolution on prediction skill of El Niño southern oscillation phenomenon in climate forecast system model is explored in this paper. Improvement in prediction skill for sea surface temperature (SST) and winds at all leads compared to low resolution model in the tropical Indo-Pacific basin is observed. High resolution model is able to capture extreme events reasonably well. As a result, the signal to noise ratio is improved in the high resolution model. However, spring predictability barrier (SPB) for summer months in Nino 3 and Nino 3.4 region is stronger in high resolution model, in spite of improvement in overall prediction skill and dynamics everywhere else. Anomaly correlation coefficient of SST in high resolution model with observations in Nino 3.4 region targeting boreal summer months when predicted at lead times of 3-8 months in advance decreased compared its lower resolution counterpart. It is noted that higher variance of winds predicted in spring season over central equatorial Pacific compared to observed variance of winds results in stronger than normal response on subsurface ocean, hence increases SPB for boreal summer months in high resolution model.

  16. High-Resolution PET Detector. Final report

    International Nuclear Information System (INIS)

    Karp, Joel

    2014-01-01

    The objective of this project was to develop an understanding of the limits of performance for a high resolution PET detector using an approach based on continuous scintillation crystals rather than pixelated crystals. The overall goal was to design a high-resolution detector, which requires both high spatial resolution and high sensitivity for 511 keV gammas. Continuous scintillation detectors (Anger cameras) have been used extensively for both single-photon and PET scanners, however, these instruments were based on NaI(Tl) scintillators using relatively large, individual photo-multipliers. In this project we investigated the potential of this type of detector technology to achieve higher spatial resolution through the use of improved scintillator materials and photo-sensors, and modification of the detector surface to optimize the light response function.We achieved an average spatial resolution of 3-mm for a 25-mm thick, LYSO continuous detector using a maximum likelihood position algorithm and shallow slots cut into the entrance surface

  17. Global High Resolution Sea Surface Flux Parameters From Multiple Satellites

    Science.gov (United States)

    Zhang, H.; Reynolds, R. W.; Shi, L.; Bates, J. J.

    2007-05-01

    Advances in understanding the coupled air-sea system and modeling of the ocean and atmosphere demand increasingly higher resolution data, such as air-sea fluxes of up to 3 hourly and every 50 km. These observational requirements can only be met by utilizing multiple satellite observations. Generation of such high resolution products from multiple-satellite and in-situ observations on an operational basis has been started at the U.S. National Oceanic and Atmospheric Administration (NOAA) National Climatic Data Center. Here we describe a few products that are directly related to the computation of turbulent air-sea fluxes. Sea surface wind speed has been observed from in-situ instruments and multiple satellites, with long-term observations ranging from one satellite in the mid 1987 to six or more satellites since mid 2002. A blended product with a global 0.25° grid and four snapshots per day has been produced for July 1987 to present, using a near Gaussian 3-D (x, y, t) interpolation to minimize aliases. Wind direction has been observed from fewer satellites, thus for the blended high resolution vector winds and wind stresses, the directions are taken from the NCEP Re-analysis 2 (operationally run near real time) for climate consistency. The widely used Reynolds Optimum Interpolation SST analysis has been improved with higher resolutions (daily and 0.25°). The improvements use both infrared and microwave satellite data that are bias-corrected by in- situ observations for the period 1985 to present. The new versions provide very significant improvements in terms of resolving ocean features such as the meandering of the Gulf Stream, the Aghulas Current, the equatorial jets and other fronts. The Ta and Qa retrievals are based on measurements from the AMSU sounder onboard the NOAA satellites. Ta retrieval uses AMSU-A data, while Qa retrieval uses both AMSU-A and AMSU-B observations. The retrieval algorithms are developed using the neural network approach. Training

  18. A high resolution portable spectroscopy system

    International Nuclear Information System (INIS)

    Kulkarni, C.P.; Vaidya, P.P.; Paulson, M.; Bhatnagar, P.V.; Pande, S.S.; Padmini, S.

    2003-01-01

    Full text: This paper describes the system details of a High Resolution Portable Spectroscopy System (HRPSS) developed at Electronics Division, BARC. The system can be used for laboratory class, high-resolution nuclear spectroscopy applications. The HRPSS consists of a specially designed compact NIM bin, with built-in power supplies, accommodating a low power, high resolution MCA, and on-board embedded computer for spectrum building and communication. A NIM based spectroscopy amplifier and a HV module for detector bias are integrated (plug-in) in the bin. The system communicates with a host PC via a serial link. Along-with a laptop PC, and a portable HP-Ge detector, the HRPSS offers a laboratory class performance for portable applications

  19. High-resolution multi-slice PET

    International Nuclear Information System (INIS)

    Yasillo, N.J.; Chintu Chen; Ordonez, C.E.; Kapp, O.H.; Sosnowski, J.; Beck, R.N.

    1992-01-01

    This report evaluates the progress to test the feasibility and to initiate the design of a high resolution multi-slice PET system. The following specific areas were evaluated: detector development and testing; electronics configuration and design; mechanical design; and system simulation. The design and construction of a multiple-slice, high-resolution positron tomograph will provide substantial improvements in the accuracy and reproducibility of measurements of the distribution of activity concentrations in the brain. The range of functional brain research and our understanding of local brain function will be greatly extended when the development of this instrumentation is completed

  20. High resolution neutron spectroscopy for helium isotopes

    International Nuclear Information System (INIS)

    Abdel-Wahab, M.S.; Klages, H.O.; Schmalz, G.; Haesner, B.H.; Kecskemeti, J.; Schwarz, P.; Wilczynski, J.

    1992-01-01

    A high resolution fast neutron time-of-flight spectrometer is described, neutron time-of-flight spectra are taken using a specially designed TDC in connection to an on-line computer. The high time-of-flight resolution of 5 ps/m enabled the study of the total cross section of 4 He for neutrons near the 3/2 + resonance in the 5 He nucleus. The resonance parameters were determined by a single level Breit-Winger fit to the data. (orig.)

  1. Smartphone microendoscopy for high resolution fluorescence imaging

    Directory of Open Access Journals (Sweden)

    Xiangqian Hong

    2016-09-01

    Full Text Available High resolution optical endoscopes are increasingly used in diagnosis of various medical conditions of internal organs, such as the cervix and gastrointestinal (GI tracts, but they are too expensive for use in resource-poor settings. On the other hand, smartphones with high resolution cameras and Internet access have become more affordable, enabling them to diffuse into most rural areas and developing countries in the past decade. In this paper, we describe a smartphone microendoscope that can take fluorescence images with a spatial resolution of 3.1 μm. Images collected from ex vivo, in vitro and in vivo samples using the device are also presented. The compact and cost-effective smartphone microendoscope may be envisaged as a powerful tool for detecting pre-cancerous lesions of internal organs in low and middle-income countries (LMICs.

  2. High resolution Neutron and Synchrotron Powder Diffraction

    International Nuclear Information System (INIS)

    Hewat, A.W.

    1986-01-01

    The use of high-resolution powder diffraction has grown rapidly in the past years, with the development of Rietveld (1967) methods of data analysis and new high-resolution diffractometers and multidetectors. The number of publications in this area has increased from a handful per year until 1973 to 150 per year in 1984, with a ten-year total of over 1000. These papers cover a wide area of solid state-chemistry, physics and materials science, and have been grouped under 20 subject headings, ranging from catalysts to zeolites, and from battery electrode materials to pre-stressed superconducting wires. In 1985 two new high-resolution diffractometers are being commissioned, one at the SNS laboratory near Oxford, and one at the ILL in Grenoble. In different ways these machines represent perhaps the ultimate that can be achieved with neutrons and will permit refinement of complex structures with about 250 parameters and unit cell volumes of about 2500 Angstrom/sp3/. The new European Synchotron Facility will complement the Grenoble neutron diffractometers, and extend the role of high-resolution powder diffraction to the direct solution of crystal structures, pioneered in Sweden

  3. High resolution CT in diffuse lung disease

    International Nuclear Information System (INIS)

    Webb, W.R.

    1995-01-01

    High resolution CT (computerized tomography) was discussed in detail. The conclusions were HRCT is able to define lung anatomy at the secondary lobular level and define a variety of abnormalities in patients with diffuse lung diseases. Evidence from numerous studies indicates that HRCT can play a major role in the assessment of diffuse infiltrative lung disease and is indicate clinically (95 refs.)

  4. Classification of high resolution satellite images

    OpenAIRE

    Karlsson, Anders

    2003-01-01

    In this thesis the Support Vector Machine (SVM)is applied on classification of high resolution satellite images. Sveral different measures for classification, including texture mesasures, 1st order statistics, and simple contextual information were evaluated. Additionnally, the image was segmented, using an enhanced watershed method, in order to improve the classification accuracy.

  5. High resolution CT in diffuse lung disease

    Energy Technology Data Exchange (ETDEWEB)

    Webb, W R [California Univ., San Francisco, CA (United States). Dept. of Radiology

    1996-12-31

    High resolution CT (computerized tomography) was discussed in detail. The conclusions were HRCT is able to define lung anatomy at the secondary lobular level and define a variety of abnormalities in patients with diffuse lung diseases. Evidence from numerous studies indicates that HRCT can play a major role in the assessment of diffuse infiltrative lung disease and is indicate clinically (95 refs.).

  6. High-resolution clean-sc

    NARCIS (Netherlands)

    Sijtsma, P.; Snellen, M.

    2016-01-01

    In this paper a high-resolution extension of CLEAN-SC is proposed: HR-CLEAN-SC. Where CLEAN-SC uses peak sources in “dirty maps” to define so-called source components, HR-CLEAN-SC takes advantage of the fact that source components can likewise be derived from points at some distance from the peak,

  7. A High-Resolution Stopwatch for Cents

    Science.gov (United States)

    Gingl, Z.; Kopasz, K.

    2011-01-01

    A very low-cost, easy-to-make stopwatch is presented to support various experiments in mechanics. The high-resolution stopwatch is based on two photodetectors connected directly to the microphone input of a sound card. Dedicated free open-source software has been developed and made available to download. The efficiency is demonstrated by a free…

  8. Detectors for high resolution dynamic pet

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.

    1983-05-01

    This report reviews the motivation for high spatial resolution in dynamic positron emission tomography of the head and the technical problems in realizing this objective. We present recent progress in using small silicon photodiodes to measure the energy deposited by 511 keV photons in small BGO crystals with an energy resolution of 9.4% full-width at half-maximum. In conjunction with a suitable phototube coupled to a group of crystals, the photodiode signal to noise ratio is sufficient for the identification of individual crystals both for conventional and time-of-flight positron tomography

  9. A high-resolution ocean circulation model of the Gulf of Naples and adjacent areas

    International Nuclear Information System (INIS)

    De Ruggero, P.

    2013-01-01

    The implementation of a high-resolution circulation model of a southern Tyrrhenian coastal area is discussed. The sigma-coordinate Princeton Ocean Model (POM) is implemented with a 1/144° resolution in a domain that includes highly urbanized coastal areas, such as the Gulf of Naples and the nearby gulfs of Gaeta and Salerno, that are particularly relevant from oceanographic, ecological and social viewpoints. The model takes initial and boundary conditions from a 1/48° resolution POM model of the whole Tyrrhenian Sea. The main forcing is provided by ECMWF wind data, but an alternative wind field obtained from the Italian Space Agency COSMO-SkyMed X-band Synthetic Aperture Radar data is also tested. Fundamental aspects of coastal modeling, such as the relative importance of local and remote forcing in semi-enclosed seas, and the sensitivity to different wind products are discussed.

  10. Constructing a WISE High Resolution Galaxy Atlas

    Science.gov (United States)

    Jarrett, T. H.; Masci, F.; Tsai, C. W.; Petty, S.; Cluver, M.; Assef, Roberto J.; Benford, D.; Blain, A.; Bridge, C.; Donoso, E.; hide

    2012-01-01

    After eight months of continuous observations, the Wide-field Infrared Survey Explorer (WISE) mapped the entire sky at 3.4 micron, 4.6 micron, 12 micron, and 22 micron. We have begun a dedicated WISE High Resolution Galaxy Atlas project to fully characterize large, nearby galaxies and produce a legacy image atlas and source catalog. Here we summarize the deconvolution techniques used to significantly improve the spatial resolution of WISE imaging, specifically designed to study the internal anatomy of nearby galaxies. As a case study, we present results for the galaxy NGC 1566, comparing the WISE enhanced-resolution image processing to that of Spitzer, Galaxy Evolution Explorer, and ground-based imaging. This is the first paper in a two-part series; results for a larger sample of nearby galaxies are presented in the second paper.

  11. High resolution imaging of boron carbide microstructures

    International Nuclear Information System (INIS)

    MacKinnon, I.D.R.; Aselage, T.; Van Deusen, S.B.

    1986-01-01

    Two samples of boron carbide have been examined using high resolution transmission electron microscopy (HRTEM). A hot-pressed B 13 C 2 sample shows a high density of variable width twins normal to (10*1). Subtle shifts or offsets of lattice fringes along the twin plane and normal to approx.(10*5) were also observed. A B 4 C powder showed little evidence of stacking disorder in crystalline regions

  12. Sensitivity Analysis of Expected Wind Extremes over the Northwestern Sahara and High Atlas Region.

    Science.gov (United States)

    Garcia-Bustamante, E.; González-Rouco, F. J.; Navarro, J.

    2017-12-01

    A robust statistical framework in the scientific literature allows for the estimation of probabilities of occurrence of severe wind speeds and wind gusts, but does not prevent however from large uncertainties associated with the particular numerical estimates. An analysis of such uncertainties is thus required. A large portion of this uncertainty arises from the fact that historical observations are inherently shorter that the timescales of interest for the analysis of return periods. Additional uncertainties stem from the different choices of probability distributions and other aspects related to methodological issues or physical processes involved. The present study is focused on historical observations over the Ouarzazate Valley (Morocco) and in a high-resolution regional simulation of the wind in the area of interest. The aim is to provide extreme wind speed and wind gust return values and confidence ranges based on a systematic sampling of the uncertainty space for return periods up to 120 years.

  13. World Wind

    Data.gov (United States)

    National Aeronautics and Space Administration — World Wind allows any user to zoom from satellite altitude into any place on Earth, leveraging high resolution LandSat imagery and SRTM elevation data to experience...

  14. High resolution SETI: Experiences and prospects

    Science.gov (United States)

    Horowitz, Paul; Clubok, Ken

    Megachannel spectroscopy with sub-Hertz resolution constitutes an attractive strategy for a microwave search for extraterrestrial intelligence (SETI), assuming the transmission of a narrowband radiofrequency beacon. Such resolution matches the properties of the interstellar medium, and the necessary Doppler corrections provide a high degree of interference rejection. We have constructed a frequency-agile receiver with an FFT-based 8 megachannel digital spectrum analyzer, on-line signal recognition, and multithreshold archiving. We are using it to conduct a meridian transit search of the northern sky at the Harvard-Smithsonian 26-m antenna, with a second identical system scheduled to begin observations in Argentina this month. Successive 400 kHz spectra, at 0.05 Hz resolution, are searched for features characteristic of an intentional narrowband beacon transmission. These spectra are centered on guessable frequencies (such as λ21 cm), referenced successively to the local standard of rest, the galactic barycenter, and the cosmic blackbody rest frame. This search has rejected interference admirably, but is greatly limited both in total frequency coverage and sensitivity to signals other than carriers. We summarize five years of high resolution SETI at Harvard, in the context of answering the questions "How useful is narrowband SETI, how serious are its limitations, what can be done to circumvent them, and in what direction should SETI evolve?" Increasingly powerful signal processing hardware, combined with ever-higher memory densities, are particularly relevant, permitting the construction of compact and affordable gigachannel spectrum analyzers covering hundreds of megahertz of instantaneous bandwidth.

  15. HIGH RESOLUTION OPTICAL AND NIR SPECTRA OF HBC 722

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong-Eun; Park, Sunkyung [School of Space Research, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Green, Joel D.; Cochran, William D. [Department of Astronomy, University of Texas at Austin, TX (United States); Kang, Wonseok; Lee, Sang-Gak [National Youth Space Center, 200 Deokheungyangjjok-gil, Dongil-myeon, Goheung-gun, Jeollanam-do 548-951 (Korea, Republic of); Sung, Hyun-Il, E-mail: jeongeun.lee@khu.ac.kr, E-mail: sunkyung@khu.ac.kr, E-mail: joel@astro.as.utexas.edu, E-mail: wdc@astro.as.utexas.edu, E-mail: wskang@kywa.or.kr, E-mail: sanggak@kywa.or.kr, E-mail: hisung@kasi.re.kr [Korea Astronomy and Space Science Institute, 776 Daedeok-daero, Yuseong-gu, Daejeon 305-348 (Korea, Republic of)

    2015-07-01

    We present the results of high resolution (R ≥ 30,000) optical and near-IR spectroscopic monitoring observations of HBC 722, a recent FU Orionis object that underwent an accretion burst in 2010. We observed HBC 722 in the optical/near-IR with the Bohyunsan Optical Echelle Spectrograph, Hobby–Eberly Telescope-HRS, and Immersion Grating Infrared Spectrograph, at various points in the outburst. We found atomic lines with strongly blueshifted absorption features or P Cygni profiles, both evidence of a wind driven by the accretion. Some lines show a broad double-peaked absorption feature, evidence of disk rotation. However, the wind-driven and disk-driven spectroscopic features are anti-correlated in time; the disk features became strong as the wind features disappeared. This anti-correlation might indicate that the rebuilding of the inner disk was interrupted by the wind pressure during the first 2 years. The half-width at half-depth of the double-peaked profiles decreases with wavelength, indicative of the Keplerian rotation; the optical spectra with the disk feature are fitted by a G5 template stellar spectrum convolved with a rotation velocity of 70 km s{sup −1} while the near-IR disk features are fitted by a K5 template stellar spectrum convolved with a rotation velocity of 50 km s{sup −1}. Therefore, the optical and near-IR spectra seem to trace the disk at 39 and 76 R{sub ⊙}, respectively. We fit a power-law temperature distribution in the disk, finding an index of 0.8, comparable to optically thick accretion disk models.

  16. High resolution NMR theory and chemical applications

    CERN Document Server

    Becker, Edwin D

    2012-01-01

    High Resolution NMR: Theory and Chemical Applications discusses the principles and theory of nuclear magnetic resonance and how this concept is used in the chemical sciences. This book is written at an intermediate level, with mathematics used to augment verbal descriptions of the phenomena. This text pays attention to developing and interrelating four approaches - the steady state energy levels, the rotating vector picture, the density matrix, and the product operator formalism. The style of this book is based on the assumption that the reader has an acquaintance with the general principles of quantum mechanics, but no extensive background in quantum theory or proficiency in mathematics is required. This book begins with a description of the basic physics, together with a brief account of the historical development of the field. It looks at the study of NMR in liquids, including high resolution NMR in the solid state and the principles of NMR imaging and localized spectroscopy. This book is intended to assis...

  17. High resolution NMR theory and chemical applications

    CERN Document Server

    Becker, Edwin D

    1999-01-01

    High Resolution NMR provides a broad treatment of the principles and theory of nuclear magnetic resonance (NMR) as it is used in the chemical sciences. It is written at an "intermediate" level, with mathematics used to augment, rather than replace, clear verbal descriptions of the phenomena. The book is intended to allow a graduate student, advanced undergraduate, or researcher to understand NMR at a fundamental level, and to see illustrations of the applications of NMR to the determination of the structure of small organic molecules and macromolecules, including proteins. Emphasis is on the study of NMR in liquids, but the treatment also includes high resolution NMR in the solid state and the principles of NMR imaging and localized spectroscopy. Careful attention is given to developing and interrelating four approaches - steady state energy levels, the rotating vector picture, the density matrix, and the product operator formalism. The presentation is based on the assumption that the reader has an acquaintan...

  18. High-resolution flurescence spectroscopy in immunoanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Grubor, Nenad M. [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    The work presented in this dissertation combines highly sensitive and selective fluorescence line-narrowing spectroscopy (FLNS) detection with various modes of immunoanalytical techniques. It has been shown that FLNS is capable of directly probing molecules immunocomplexed with antibodies, eliminating analytical ambiguities that may arise from interferences that accompany traditional immunochemical techniques. Moreover, the utilization of highly cross-reactive antibodies for highly specific analyte determination has been demonstrated. Finally, they demonstrate the first example of the spectral resolution of diastereomeric analytes based on their interaction with a cross-reactive antibody.

  19. High-Altitude Wind Power Generation

    NARCIS (Netherlands)

    Fagiano, L.; Milanese, M.; Piga, D.

    2010-01-01

    Abstract—The paper presents the innovative technology of highaltitude wind power generation, indicated as Kitenergy, which exploits the automatic flight of tethered airfoils (e.g., power kites) to extract energy from wind blowing between 200 and 800 m above the ground. The key points of this

  20. High resolution simulations of orographic flow over a complex terrain on the Southeast coast of Brazil

    Science.gov (United States)

    Chou, S. C.; Zolino, M. M.; Gomes, J. L.; Bustamante, J. F.; Lima-e-Silva, P. P.

    2012-04-01

    The Eta Model is used operationally by CPTEC to produce weather forecasts over South America since 1997. The model has gone through upgrades. In order to prepare the model for operational higher resolution forecasts, the model is configured and tested over a region of complex topography located near the coast of Southeast Brazil. The Eta Model was configured, with 2-km horizontal resolution and 50 layers. The Eta-2km is a second nesting, it is driven by Eta-15km, which in its turn is driven by Era-Interim reanalyses. The model domain includes the two Brazilians cities, Rio de Janeiro and Sao Paulo, urban areas, preserved tropical forest, pasture fields, and complex terrain and coastline. Mountains can rise up to about 700m. The region suffers frequent events of floods and landslides. The objective of this work is to evaluate high resolution simulations of wind and temperature in this complex area. Verification of model runs uses observations taken from the nuclear power plant. Accurate near-surface wind direction and magnitude are needed for the plant emergency plan and winds are highly sensitive to model spatial resolution and atmospheric stability. Verification of two cases during summer shows that model has clear diurnal cycle signal for wind in that region. The area is characterized by weak winds which makes the simulation more difficult. The simulated wind magnitude is about 1.5m/s, which is close to observations of about 2m/s; however, the observed change of wind direction of the sea breeze is fast whereas it is slow in the simulations. Nighttime katabatic flow is captured by the simulations. Comparison against Eta-5km runs show that the valley circulation is better described in the 2-km resolution run. Simulated temperatures follow closely the observed diurnal cycle. Experiments improving some surface conditions such as the surface temperature and land cover show simulation error reduction and improved diurnal cycle.

  1. High-Resolution MRI in Rectal Cancer

    International Nuclear Information System (INIS)

    Dieguez, Adriana

    2010-01-01

    High-resolution MRI is the best method of assessing the relation of the rectal tumor with the potential circumferential resection margin (CRM). Therefore it is currently considered the method of choice for local staging of rectal cancer. The primary surgery of rectal cancer is total mesorectal excision (TME), which plane of dissection is formed by the mesorectal fascia surrounding mesorectal fat and rectum. This fascia will determine the circumferential margin of resection. At the same time, high resolution MRI allows adequate pre-operative identification of important prognostic risk factors, improving the selection and indication of therapy for each patient. This information includes, besides the circumferential margin of resection, tumor and lymph node staging, extramural vascular invasion and the description of lower rectal tumors. All these should be described in detail in the report, being part of the discussion in the multidisciplinary team, the place where the decisions involving the patient with rectal cancer will take place. The aim of this study is to provide the information necessary to understand the use of high resolution MRI in the identification of prognostic risk factors in rectal cancer. The technical requirements and standardized report for this study will be describe, as well as the anatomical landmarks of importance for the total mesorectal excision (TME), as we have said is the surgery of choice for rectal cancer. (authors) [es

  2. Resolution 8.069/12. It approve the regulations for the large size structures installation, destined for wind power generation

    International Nuclear Information System (INIS)

    2012-01-01

    This resolution approve the regulations for the large size structures installation, destined to wind power generation. The objective of this rule is to regulate the urban conditions of the facilities and the environmental guarantees, safety and inhabitants wholesomeness

  3. USGS High Resolution Orthoimagery Collection - Historical - National Geospatial Data Asset (NGDA) High Resolution Orthoimagery

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — USGS high resolution orthorectified images from The National Map combine the image characteristics of an aerial photograph with the geometric qualities of a map. An...

  4. Active x-ray optics for high resolution space telescopes

    Science.gov (United States)

    Doel, Peter; Atkins, Carolyn; Brooks, D.; Feldman, Charlotte; Willingale, Richard; Button, Tim; Rodriguez Sanmartin, Daniel; Meggs, Carl; James, Ady; Willis, Graham; Smith, Andy

    2017-11-01

    The Smart X-ray Optics (SXO) Basic Technology project started in April 2006 and will end in October 2010. The aim is to develop new technologies in the field of X-ray focusing, in particular the application of active and adaptive optics. While very major advances have been made in active/adaptive astronomical optics for visible light, little was previously achieved for X-ray optics where the technological challenges differ because of the much shorter wavelengths involved. The field of X-ray astronomy has been characterized by the development and launch of ever larger observatories with the culmination in the European Space Agency's XMM-Newton and NASA's Chandra missions which are currently operational. XMM-Newton uses a multi-nested structure to provide modest angular resolution ( 10 arcsec) but large effective area, while Chandra sacrifices effective area to achieve the optical stability necessary to provide sub-arc second resolution. Currently the European Space Agency (ESA) is engaged in studies of the next generation of X-ray space observatories, with the aim of producing telescopes with increased sensitivity and resolution. To achieve these aims several telescopes have been proposed, for example ESA and NASA's combined International X-ray Observatory (IXO), aimed at spectroscopy, and NASA's Generation-X. In the field of X-ray astronomy sub 0.2 arcsecond resolution with high efficiency would be very exciting. Such resolution is unlikely to be achieved by anything other than an active system. The benefits of a such a high resolution would be important for a range of astrophysics subjects, for example the potential angular resolution offered by active X-ray optics could provide unprecedented structural imaging detail of the Solar Wind bowshock interaction of comets, planets and similar objects and auroral phenomena throughout the Solar system using an observing platform in low Earth orbit. A major aim of the SXO project was to investigate the production of thin

  5. Moderate resolution spectrophotometry of high redshift quasars

    Science.gov (United States)

    Schneider, Donald P.; Schmidt, Maarten; Gunn, James E.

    1991-01-01

    A uniform set of photometry and high signal-to-noise moderate resolution spectroscopy of 33 quasars with redshifts larger than 3.1 is presented. The sample consists of 17 newly discovered quasars (two with redshifts in excess of 4.4) and 16 sources drawn from the literature. The objects in this sample have r magnitudes between 17.4 and 21.4; their luminosities range from -28.8 to -24.9. Three of the 33 objects are broad absorption line quasars. A number of possible high redshift damped Ly-alpha systems were found.

  6. SPIRAL2/DESIR high resolution mass separator

    Energy Technology Data Exchange (ETDEWEB)

    Kurtukian-Nieto, T., E-mail: kurtukia@cenbg.in2p3.fr [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Baartman, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver B.C., V6T 2A3 (Canada); Blank, B.; Chiron, T. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Davids, C. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Delalee, F. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Duval, M. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); El Abbeir, S.; Fournier, A. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Lunney, D. [CSNSM-IN2P3-CNRS, Université de Paris Sud, F-91405 Orsay (France); Méot, F. [BNL, Upton, Long Island, New York (United States); Serani, L. [Centre d’Études Nucléaires de Bordeaux Gradignan, Université Bordeaux 1-CNRS/IN2P3, BP 120, F-33175 Gradignan Cedex (France); Stodel, M.-H.; Varenne, F. [GANIL, CEA/DSM-CNRS/IN2P3, Bd Henri Becquerel, BP 55027, F-14076 Caen Cedex 5 (France); and others

    2013-12-15

    DESIR is the low-energy part of the SPIRAL2 ISOL facility under construction at GANIL. DESIR includes a high-resolution mass separator (HRS) with a designed resolving power m/Δm of 31,000 for a 1 π-mm-mrad beam emittance, obtained using a high-intensity beam cooling device. The proposed design consists of two 90-degree magnetic dipoles, complemented by electrostatic quadrupoles, sextupoles, and a multipole, arranged in a symmetric configuration to minimize aberrations. A detailed description of the design and results of extensive simulations are given.

  7. Pumped storage in systems with very high wind penetration

    International Nuclear Information System (INIS)

    Tuohy, A.; O'Malley, M.

    2011-01-01

    This paper examines the operation of the Irish power system with very high levels of wind energy, with and without pumped storage. A unit commitment model which accounts for the uncertainty in wind power is used. It is shown that as wind penetration increases, the optimal operation of storage depends on wind output as well as load. The main benefit from storage is shown to be a decrease in wind curtailment. The economics of the system are examined to find the level at which storage justifies its capital costs and inefficiencies. It is shown that the uncertainty of wind makes the option of storage more attractive. The size of the energy store has an impact on results. At lower levels of installed wind (up to approximately 50% of energy from wind in Ireland), the reduction in curtailment is insufficient to justify building storage. At greater levels of wind, storage reduces curtailment sufficiently to justify the additional capital costs. It can be seen that if storage replaces OCGTs in the plant mix instead of CCGTs, then the level at which it justifies itself is lower. Storage increases the level of carbon emissions at wind penetration below 60%. - Research highlights: → Examines operation of pumped storage unit in a system with levels of wind from 34%-68% of energy. → High capital cost of storage is not justified until system has high (approx. 45%) wind penetration. → Results are driven by the amount of wind curtailment avoided and plant mix of system. → Other flexible options (e.g. interconnection) offer many of the same benefits as storage.

  8. Processing method for high resolution monochromator

    International Nuclear Information System (INIS)

    Kiriyama, Koji; Mitsui, Takaya

    2006-12-01

    A processing method for high resolution monochromator (HRM) has been developed at Japanese Atomic Energy Agency/Quantum Beam Science Directorate/Synchrotron Radiation Research unit at SPring-8. For manufacturing a HRM, a sophisticated slicing machine and X-ray diffractometer have been installed for shaping a crystal ingot and orienting precisely the surface of a crystal ingot, respectively. The specification of the slicing machine is following; Maximum size of a diamond blade is φ 350mm in diameter, φ 38.1mm in the spindle diameter, and 2mm in thickness. A large crystal such as an ingot with 100mm in diameter, 200mm in length can be cut. Thin crystal samples such as a wafer can be also cut using by another sample holder. Working distance of a main shaft with the direction perpendicular to working table in the machine is 350mm at maximum. Smallest resolution of the main shaft with directions of front-and-back and top-and-bottom are 0.001mm read by a digital encoder. 2mm/min can set for cutting samples in the forward direction. For orienting crystal faces relative to the blade direction adjustment, a one-circle goniometer and 2-circle segment are equipped on the working table in the machine. A rotation and a tilt of the stage can be done by manual operation. Digital encoder in a turn stage is furnished and has angle resolution of less than 0.01 degrees. In addition, a hand drill as a supporting device for detailed processing of crystal is prepared. Then, an ideal crystal face can be cut from crystal samples within an accuracy of about 0.01 degrees. By installation of these devices, a high energy resolution monochromator crystal for inelastic x-ray scattering and a beam collimator are got in hand and are expected to be used for nanotechnology studies. (author)

  9. Investigation of wind behaviour around high-rise buildings

    Science.gov (United States)

    Mat Isa, Norasikin; Fitriah Nasir, Nurul; Sadikin, Azmahani; Ariff Hairul Bahara, Jamil

    2017-09-01

    A study on the investigation of wind behaviour around the high-rise buildings is done through an experiment using a wind tunnel and computational fluid dynamics. High-rise buildings refer to buildings or structures that have more than 12 floors. Wind is invisible to the naked eye; thus, it is hard to see and analyse its flow around and over buildings without the use of proper methods, such as the use of wind tunnel and computational fluid dynamics software.The study was conducted on buildings located in Presint 4, Putrajaya, Malaysia which is the Ministry of Rural and Regional Development, Ministry of Information Communications and Culture, Ministry of Urban Wellbeing, Housing and Local Government and the Ministry of Women, Family, and Community by making scaled models of the buildings. The parameters in which this study is conducted on are, four different wind velocities used based on the seasonal monsoons, and wind direction. ANSYS Fluent workbench software is used to compute the simulations in order to achieve the objectives of this study. The data from the computational fluid dynamics are validated with the experiment done through the wind tunnel. From the results obtained through the use of the computation fluid dynamics, this study can identify the characteristics of wind around buildings, including boundary layer of the buildings, separation flow, wake region and etc. Then analyses is conducted on the occurance resulting from the wind that passes the buildings based on the velocity difference between before and after the wind passes the buildings.

  10. High Penetrated Wind Farm Impacts on the Electricity Price

    DEFF Research Database (Denmark)

    Haji Bashi, Mazaher; Yousefi, G. R.; Bak, Claus Leth

    2016-01-01

    of the high penetrated wind farm integration into electricity markets. Then, stochastic programming approach is employed to compare the volume of trades for a typical wind farm in a high and low wind penetrated market. Although increasing price spikes and volatility was reported in the literature......Energy trading policies, intermittency of wind farm output power, low marginal cost of the production, are the key factors that cause the wind farms to be effective on the electricity price. In this paper, the Danish electricity market is studied as a part of Nord Pool. Considering the completely...... fossil fuel free overview in Danish energy policies, and the currently great share of wind power (more than 100% for some hours) in supplying the load, it is an interesting benchmark for the future electricity markets. Negative prices, price spikes, and price volatility are considered as the main effects...

  11. The EUV dayglow at high spectral resolution

    International Nuclear Information System (INIS)

    Morrison, M.D.; Bowers, C.W.; Feldman, P.D.; Meier, R.R.

    1990-01-01

    Rocket observations of the dayglow spectrum of the terrestrial atmosphere between 840 angstrom and 1860 angstrom at 2 angstrom resolution were obtained with a sounding rocket payload flown on January 17, 1985. Additionally, spectra were also obtained using a 0.125-m focal length scanning Ebert-Fastie monochromator covering the wavelength interval of 1150-1550 angstrom at 7 angstrom resolution on this flight and on a sounding rocket flight on August 29, 1983, under similar viewing geometries and solar zenith angles. Three bands of the N 2 c' 4 system are seen clearly resolved in the dayglow. Analysis of high-resolution N 2 Lyman-Birge-Hopfield data shows no anomalous vibrational distribution as has been reported from other observations. The altitude profiles of the observed O and N 2 emissions demonstrate that the MSIS-83 model O and N 2 densities are appropriate for the conditions of both the 1983 and 1985 rocket flights. A reduction of a factor of 2 in the model O 2 density is required for both flights to reproduce the low-altitude atomic oxygen emission profiles. The volume excitation rates calculated using the Hinteregger et al. (1981) SC number-sign 21REFW solar reference spectrum and the photoelectron flux model of Strickland and Meier (1982) need to be scaled upward by a factor of 1.4 for both fights to match the observations

  12. Dynamic high resolution imaging of rats

    International Nuclear Information System (INIS)

    Miyaoka, R.S.; Lewellen, T.K.; Bice, A.N.

    1990-01-01

    A positron emission tomography with the sensitivity and resolution to do dynamic imaging of rats would be an invaluable tool for biological researchers. In this paper, the authors determine the biological criteria for dynamic positron emission imaging of rats. To be useful, 3 mm isotropic resolution and 2-3 second time binning were necessary characteristics for such a dedicated tomograph. A single plane in which two objects of interest could be imaged simultaneously was considered acceptable. Multi-layered detector designs were evaluated as a possible solution to the dynamic imaging and high resolution imaging requirements. The University of Washington photon history generator was used to generate data to investigate a tomograph's sensitivity to true, scattered and random coincidences for varying detector ring diameters. Intrinsic spatial uniformity advantages of multi-layered detector designs over conventional detector designs were investigated using a Monte Carlo program. As a result, a modular three layered detector prototype is being developed. A module will consist of a layer of five 3.5 mm wide crystals and two layers of six 2.5 mm wide crystals. The authors believe adequate sampling can be achieved with a stationary detector system using these modules. Economical crystal decoding strategies have been investigated and simulations have been run to investigate optimum light channeling methods for block decoding strategies. An analog block decoding method has been proposed and will be experimentally evaluated to determine whether it can provide the desired performance

  13. Quasar Winds as Dust Factories at High Redshift

    OpenAIRE

    Elvis, Martin; Marengo, Massimo; Karovska, Margarita

    2003-01-01

    Winds from AGN and quasars will form large amounts of dust, as the cool gas in these winds passes through the (pressure, temperature) region where dust is formed in AGB stars. Conditions in the gas are benign to dust at these radii. As a result quasar winds may be a major source of dust at high redshifts, obviating a difficulty with current observations, and requiring far less dust to exist at early epochs.

  14. Integrated High Resolution Monitoring of Mediterranean vegetation

    Science.gov (United States)

    Cesaraccio, Carla; Piga, Alessandra; Ventura, Andrea; Arca, Angelo; Duce, Pierpaolo; Mereu, Simone

    2017-04-01

    The study of the vegetation features in a complex and highly vulnerable ecosystems, such as Mediterranean maquis, leads to the need of using continuous monitoring systems at high spatial and temporal resolution, for a better interpretation of the mechanisms of phenological and eco-physiological processes. Near-surface remote sensing techniques are used to quantify, at high temporal resolution, and with a certain degree of spatial integration, the seasonal variations of the surface optical and radiometric properties. In recent decades, the design and implementation of global monitoring networks involved the use of non-destructive and/or cheaper approaches such as (i) continuous surface fluxes measurement stations, (ii) phenological observation networks, and (iii) measurement of temporal and spatial variations of the vegetation spectral properties. In this work preliminary results from the ECO-SCALE (Integrated High Resolution Monitoring of Mediterranean vegetation) project are reported. The project was manly aimed to develop an integrated system for environmental monitoring based on digital photography, hyperspectral radiometry , and micrometeorological techniques during three years of experimentation (2013-2016) in a Mediterranean site of Italy (Capo Caccia, Alghero). The main results concerned the analysis of chromatic coordinates indices from digital images, to characterized the phenological patterns for typical shrubland species, determining start and duration of the growing season, and the physiological status in relation to different environmental drought conditions; then the seasonal patterns of canopy phenology, was compared to NEE (Net Ecosystem Exchange) patterns, showing similarities. However, maximum values of NEE and ER (Ecosystem respiration), and short term variation, seemed mainly tuned by inter annual pattern of meteorological variables, in particular of temperature recorded in the months preceding the vegetation green-up. Finally, green signals

  15. High-resolution X-ray television and high-resolution video recorders

    International Nuclear Information System (INIS)

    Haendle, J.; Horbaschek, H.; Alexandrescu, M.

    1977-01-01

    The improved transmission properties of the high-resolution X-ray television chain described here make it possible to transmit more information per television image. The resolution in the fluoroscopic image, which is visually determined, depends on the dose rate and the inertia of the television pick-up tube. This connection is discussed. In the last few years, video recorders have been increasingly used in X-ray diagnostics. The video recorder is a further quality-limiting element in X-ray television. The development of function patterns of high-resolution magnetic video recorders shows that this quality drop may be largely overcome. The influence of electrical band width and number of lines on the resolution in the X-ray television image stored is explained in more detail. (orig.) [de

  16. High-resolution phylogenetic microbial community profiling

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Esther; Coleman-Derr, Devin; Bowman, Brett; Schwientek, Patrick; Clum, Alicia; Copeland, Alex; Ciobanu, Doina; Cheng, Jan-Fang; Gies, Esther; Hallam, Steve; Tringe, Susannah; Woyke, Tanja

    2014-03-17

    The representation of bacterial and archaeal genome sequences is strongly biased towards cultivated organisms, which belong to merely four phylogenetic groups. Functional information and inter-phylum level relationships are still largely underexplored for candidate phyla, which are often referred to as microbial dark matter. Furthermore, a large portion of the 16S rRNA gene records in the GenBank database are labeled as environmental samples and unclassified, which is in part due to low read accuracy, potential chimeric sequences produced during PCR amplifications and the low resolution of short amplicons. In order to improve the phylogenetic classification of novel species and advance our knowledge of the ecosystem function of uncultivated microorganisms, high-throughput full length 16S rRNA gene sequencing methodologies with reduced biases are needed. We evaluated the performance of PacBio single-molecule real-time (SMRT) sequencing in high-resolution phylogenetic microbial community profiling. For this purpose, we compared PacBio and Illumina metagenomic shotgun and 16S rRNA gene sequencing of a mock community as well as of an environmental sample from Sakinaw Lake, British Columbia. Sakinaw Lake is known to contain a large age of microbial species from candidate phyla. Sequencing results show that community structure based on PacBio shotgun and 16S rRNA gene sequences is highly similar in both the mock and the environmental communities. Resolution power and community representation accuracy from SMRT sequencing data appeared to be independent of GC content of microbial genomes and was higher when compared to Illumina-based metagenome shotgun and 16S rRNA gene (iTag) sequences, e.g. full-length sequencing resolved all 23 OTUs in the mock community, while iTags did not resolve closely related species. SMRT sequencing hence offers various potential benefits when characterizing uncharted microbial communities.

  17. High resolution transmission spectroscopy as a diagnostic for Jovian exoplanet atmospheres: constraints from theoretical models

    Energy Technology Data Exchange (ETDEWEB)

    Kempton, Eliza M.-R. [Department of Physics, Grinnell College, Grinnell, IA 50112 (United States); Perna, Rosalba [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Heng, Kevin, E-mail: kemptone@grinnell.edu [University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern (Switzerland)

    2014-11-01

    We present high resolution transmission spectra of giant planet atmospheres from a coupled three-dimensional (3D) atmospheric dynamics and transmission spectrum model that includes Doppler shifts which arise from winds and planetary motion. We model Jovian planets covering more than two orders of magnitude in incident flux, corresponding to planets with 0.9-55 day orbital periods around solar-type stars. The results of our 3D dynamical models reveal certain aspects of high resolution transmission spectra that are not present in simple one-dimensional (1D) models. We find that the hottest planets experience strong substellar to anti-stellar (SSAS) winds, resulting in transmission spectra with net blueshifts of up to 3 km s{sup –1}, whereas less irradiated planets show almost no net Doppler shifts. We find only minor differences between transmission spectra for atmospheres with temperature inversions and those without. Compared to 1D models, peak line strengths are significantly reduced for the hottest atmospheres owing to Doppler broadening from a combination of rotation (which is faster for close-in planets under the assumption of tidal locking) and atmospheric winds. Finally, high resolution transmission spectra may be useful in studying the atmospheres of exoplanets with optically thick clouds since line cores for very strong transitions should remain optically thick to very high altitude. High resolution transmission spectra are an excellent observational test for the validity of 3D atmospheric dynamics models, because they provide a direct probe of wind structures and heat circulation. Ground-based exoplanet spectroscopy is currently on the verge of being able to verify some of our modeling predictions, most notably the dependence of SSAS winds on insolation. We caution that interpretation of high resolution transmission spectra based on 1D atmospheric models may be inadequate, as 3D atmospheric motions can produce a noticeable effect on the absorption

  18. High resolution extremity CT for biomechanics modeling

    International Nuclear Information System (INIS)

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-01-01

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling

  19. High resolution extremity CT for biomechanics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-09-23

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling.

  20. High-resolution computer-aided moire

    Science.gov (United States)

    Sciammarella, Cesar A.; Bhat, Gopalakrishna K.

    1991-12-01

    This paper presents a high resolution computer assisted moire technique for the measurement of displacements and strains at the microscopic level. The detection of micro-displacements using a moire grid and the problem associated with the recovery of displacement field from the sampled values of the grid intensity are discussed. A two dimensional Fourier transform method for the extraction of displacements from the image of the moire grid is outlined. An example of application of the technique to the measurement of strains and stresses in the vicinity of the crack tip in a compact tension specimen is given.

  1. High-resolution stratigraphy with strontium isotopes.

    Science.gov (United States)

    Depaolo, D J; Ingram, B L

    1985-02-22

    The isotopic ratio of strontium-87 to strontium-86 shows no detectable variation in present-day ocean water but changes slowly over millions of years. The strontium contained in carbonate shells of marine organisms records the ratio of strontium-87 to strontium-86 of the oceans at the time that the shells form. Sedimentary rocks composed of accumulated fossil carbonate shells can be dated and correlated with the use of high precision measurements of the ratio of strontium-87 to strontium-86 with a resolution that is similar to that of other techniques used in age correlation. This method may prove valuable for many geological, paleontological, paleooceanographic, and geochemical problems.

  2. Laboratory of High resolution gamma spectrometry

    International Nuclear Information System (INIS)

    Mendez G, A.; Giber F, J.; Rivas C, I.; Reyes A, B.

    1992-01-01

    The Department of Nuclear Experimentation of the Nuclear Systems Management requests the collaboration of the Engineering unit for the supervision of the execution of the work of the High resolution Gamma spectrometry and low bottom laboratory, using the hut of the sub critic reactor of the Nuclear Center of Mexico. This laboratory has the purpose of determining the activity of special materials irradiated in nuclear power plants. In this report the architecture development, concepts, materials and diagrams for the realization of this type of work are presented. (Author)

  3. Novel high resolution tactile robotic fingertips

    DEFF Research Database (Denmark)

    Drimus, Alin; Jankovics, Vince; Gorsic, Matija

    2014-01-01

    This paper describes a novel robotic fingertip based on piezoresistive rubber that can sense pressure tactile stimuli with a high spatial resolution over curved surfaces. The working principle is based on a three-layer sandwich structure (conductive electrodes on top and bottom and piezoresistive...... with specialized data acquisition electronics that acquire 500 frames per second provides rich information regarding contact force, shape and angle for bio- inspired robotic fingertips. Furthermore, a model of estimating the force of contact based on values of the cells is proposed....

  4. High Power Density Power Electronic Converters for Large Wind Turbines

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk

    . For these VSCs, high power density is required due to limited turbine nacelle space. Also, high reliability is required since maintenance cost of these remotely located wind turbines is quite high and these turbines operate under harsh operating conditions. In order to select a high power density and reliability......In large wind turbines (in MW and multi-MW ranges), which are extensively utilized in wind power plants, full-scale medium voltage (MV) multi-level (ML) voltage source converters (VSCs) are being more preferably employed nowadays for interfacing these wind turbines with electricity grids...... VSC solution for wind turbines, first, the VSC topology and the switch technology to be employed should be specified such that the highest possible power density and reliability are to be attained. Then, this qualitative approach should be complemented with the power density and reliability...

  5. High-resolution vertical velocities and their power spectrum observed with the MAARSY radar - Part 1: frequency spectrum

    Science.gov (United States)

    Li, Qiang; Rapp, Markus; Stober, Gunter; Latteck, Ralph

    2018-04-01

    The Middle Atmosphere Alomar Radar System (MAARSY) installed at the island of Andøya has been run for continuous probing of atmospheric winds in the upper troposphere and lower stratosphere (UTLS) region. In the current study, we present high-resolution wind measurements during the period between 2010 and 2013 with MAARSY. The spectral analysis applying the Lomb-Scargle periodogram method has been carried out to determine the frequency spectra of vertical wind velocity. From a total of 522 days of observations, the statistics of the spectral slope have been derived and show a dependence on the background wind conditions. It is a general feature that the observed spectra of vertical velocity during active periods (with wind velocity > 10 m s-1) are much steeper than during quiet periods (with wind velocity wind conditions considered together the general spectra are obtained and their slopes are compared with the background horizontal winds. The comparisons show that the observed spectra become steeper with increasing wind velocities under quiet conditions, approach a spectral slope of -5/3 at a wind velocity of 10 m s-1 and then roughly maintain this slope (-5/3) for even stronger winds. Our findings show an overall agreement with previous studies; furthermore, they provide a more complete climatology of frequency spectra of vertical wind velocities under different wind conditions.

  6. Reducing AC-Winding Losses in High-Current High-Power Inductors

    DEFF Research Database (Denmark)

    Nymand, Morten; Madawala, Udaya K.; Andersen, Michael Andreas E.

    2009-01-01

    Foil windings are preferable in high-current high-power inductors to realize compact designs and to reduce dc-current losses. At high frequency, however, proximity effect will cause very significant increase in ac resistance in multi-layer windings, and lead to high ac winding losses. This paper ...

  7. High resolution and high speed positron emission tomography data acquisition

    International Nuclear Information System (INIS)

    Burgiss, S.G.; Byars, L.G.; Jones, W.F.; Casey, M.E.

    1986-01-01

    High resolution positron emission tomography (PET) requires many detectors. Thus, data collection systems for PET must have high data rates, wide data paths, and large memories to histogram the events. This design uses the VMEbus to cost effectively provide these features. It provides for several modes of operation including real time sorting, list mode data storage, and replay of stored list mode data

  8. Vertical-axial component wind turbine with a high coefficient using for wind energy

    International Nuclear Information System (INIS)

    Yersin, Ch. Sh.; Manatbev, R.K.; Yersina, A. K.; Tulepbergenov, A. K.

    2012-01-01

    The report presents the results of research and development on of promising wind units carousel type with a high ratio utilization of wind energy. This devices use a well-known invention – the wind turbine Darrieus. The rotation of the turbine is due to the action of ascensional power to aerodynamic well-streamlined symmetrical about the chord wing profiles of NASA, which are working wind turbine blades. The shaft rotation can be connected with the working blades of one of two ways: using the “swings” or the way “troposkino”. Darrieus turbine has a ratio utilization of wind energy xmax=045. Despite the fact that this is a good indicator of the efficiency of the turbine working, the proposed option allows us to significantly increase the value of this coefficient. The bases methodology of this research is a method of technical and technological research and development design of prospective wind energy construction (WES). Key words: wind turbine, the blade, coefficient utilization of wind energy

  9. High Resolution Powder Diffraction and Structure Determination

    International Nuclear Information System (INIS)

    Cox, D. E.

    1999-01-01

    It is clear that high-resolution synchrotrons X-ray powder diffraction is a very powerful and convenient tool for material characterization and structure determination. Most investigations to date have been carried out under ambient conditions and have focused on structure solution and refinement. The application of high-resolution techniques to increasingly complex structures will certainly represent an important part of future studies, and it has been seen how ab initio solution of structures with perhaps 100 atoms in the asymmetric unit is within the realms of possibility. However, the ease with which temperature-dependence measurements can be made combined with improvements in the technology of position-sensitive detectors will undoubtedly stimulate precise in situ structural studies of phase transitions and related phenomena. One challenge in this area will be to develop high-resolution techniques for ultra-high pressure investigations in diamond anvil cells. This will require highly focused beams and very precise collimation in front of the cell down to dimensions of 50 (micro)m or less. Anomalous scattering offers many interesting possibilities as well. As a means of enhancing scattering contrast it has applications not only to the determination of cation distribution in mixed systems such as the superconducting oxides discussed in Section 9.5.3, but also to the location of specific cations in partially occupied sites, such as the extra-framework positions in zeolites, for example. Another possible application is to provide phasing information for ab initio structure solution. Finally, the precise determination of f as a function of energy through an absorption edge can provide useful information about cation oxidation states, particularly in conjunction with XANES data. In contrast to many experiments at a synchrotron facility, powder diffraction is a relatively simple and user-friendly technique, and most of the procedures and software for data analysis

  10. Limiting liability via high resolution image processing

    Energy Technology Data Exchange (ETDEWEB)

    Greenwade, L.E.; Overlin, T.K.

    1996-12-31

    The utilization of high resolution image processing allows forensic analysts and visualization scientists to assist detectives by enhancing field photographs, and by providing the tools and training to increase the quality and usability of field photos. Through the use of digitized photographs and computerized enhancement software, field evidence can be obtained and processed as `evidence ready`, even in poor lighting and shadowed conditions or darkened rooms. These images, which are most often unusable when taken with standard camera equipment, can be shot in the worst of photographic condition and be processed as usable evidence. Visualization scientists have taken the use of digital photographic image processing and moved the process of crime scene photos into the technology age. The use of high resolution technology will assist law enforcement in making better use of crime scene photography and positive identification of prints. Valuable court room and investigation time can be saved and better served by this accurate, performance based process. Inconclusive evidence does not lead to convictions. Enhancement of the photographic capability helps solve one major problem with crime scene photos, that if taken with standard equipment and without the benefit of enhancement software would be inconclusive, thus allowing guilty parties to be set free due to lack of evidence.

  11. High-Resolution Scintimammography: A Pilot Study

    Energy Technology Data Exchange (ETDEWEB)

    Rachel F. Brem; Joelle M. Schoonjans; Douglas A. Kieper; Stan Majewski; Steven Goodman; Cahid Civelek

    2002-07-01

    This study evaluated a novel high-resolution breast-specific gamma camera (HRBGC) for the detection of suggestive breast lesions. Methods: Fifty patients (with 58 breast lesions) for whom a scintimammogram was clinically indicated were prospectively evaluated with a general-purpose gamma camera and a novel HRBGC prototype. The results of conventional and high-resolution nuclear studies were prospectively classified as negative (normal or benign) or positive (suggestive or malignant) by 2 radiologists who were unaware of the mammographic and histologic results. All of the included lesions were confirmed by pathology. Results: There were 30 benign and 28 malignant lesions. The sensitivity for detection of breast cancer was 64.3% (18/28) with the conventional camera and 78.6% (22/28) with the HRBGC. The specificity with both systems was 93.3% (28/30). For the 18 nonpalpable lesions, sensitivity was 55.5% (10/18) and 72.2% (13/18) with the general-purpose camera and the HRBGC, respectively. For lesions 1 cm, 7 of 15 were detected with the general-purpose camera and 10 of 15 with the HRBGC. Four lesions (median size, 8.5 mm) were detected only with the HRBGC and were missed by the conventional camera. Conclusion: Evaluation of indeterminate breast lesions with an HRBGC results in improved sensitivity for the detection of cancer, with greater improvement shown for nonpalpable and 1-cm lesions.

  12. High resolution studies of barium Rydberg states

    International Nuclear Information System (INIS)

    Eliel, E.R.

    1982-01-01

    The subtle structure of Rydberg states of barium with orbital angular momentum 0, 1, 2 and 3 is investigated. Some aspects of atomic theory for a configuration with two valence electrons are reviewed. The Multi Channel Quantum Defect Theory (MQDT) is concisely introduced as a convenient way to describe interactions between Rydberg series. Three high-resolution UV studies are presented. The first two, presenting results on a transition in indium and europium serve as an illustration of the frequency doubling technique. The third study is of hyperfine structure and isotope shifts in low-lying p states in Sr and Ba. An extensive study of the 6snp and 6snf Rydberg states of barium is presented with particular emphasis on the 6snf states. It is shown that the level structure cannot be fully explained with the model introduced earlier. Rather an effective two-body spin-orbit interaction has to be introduced to account for the observed splittings, illustrating that high resolution studies on Rydberg states offer an unique opportunity to determine the importance of such effects. Finally, the 6sns and 6snd series are considered. The hyperfine induced isotope shift in the simple excitation spectra to 6sns 1 S 0 is discussed and attention is paid to series perturbers. It is shown that level mixing parameters can easily be extracted from the experimental data. (Auth.)

  13. Principles of high resolution NMR in solids

    CERN Document Server

    Mehring, Michael

    1983-01-01

    The field of Nuclear Magnetic Resonance (NMR) has developed at a fascinating pace during the last decade. It always has been an extremely valuable tool to the organic chemist by supplying molecular "finger print" spectra at the atomic level. Unfortunately the high resolution achievable in liquid solutions could not be obtained in solids and physicists and physical chemists had to live with unresolved lines open to a wealth of curve fitting procedures and a vast amount of speculations. High resolution NMR in solids seemed to be a paradoxon. Broad structure­ less lines are usually encountered when dealing with NMR in solids. Only with the recent advent of mUltiple pulse, magic angle, cross-polarization, two-dimen­ sional and multiple-quantum spectroscopy and other techniques during the last decade it became possible to resolve finer details of nuclear spin interactions in solids. I have felt that graduate students, researchers and others beginning to get involved with these techniques needed a book which trea...

  14. High-altitude wind resources in the Middle East

    KAUST Repository

    Yip, Chak Man Andrew; Gunturu, Udaya; Stenchikov, Georgiy L.

    2017-01-01

    In the Middle East, near-surface wind resources are intermittent. However, high-altitude wind resources are abundant, persistent, and readily available and may provide alternative energy resources in this fossil-fuel-dependent region. Using wind field data from the Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2), this study identifies areas favorable to the deployment of airborne wind energy (AWE) systems in the Middle East and computes the optimal heights at which such systems would best operate. AWE potential is estimated using realistic AWE system specifications and assumptions about deployment scenarios and is compared with the near-surface wind generation potential with respect to diurnal and seasonal variability. The results show the potential utility of AWE in areas in the Middle East where the energy demand is high. In particular, Oman and Saudi Arabia have a high level of the potential power generation with low annual variability.

  15. High-altitude wind resources in the Middle East

    KAUST Repository

    Yip, Chak Man Andrew

    2017-08-23

    In the Middle East, near-surface wind resources are intermittent. However, high-altitude wind resources are abundant, persistent, and readily available and may provide alternative energy resources in this fossil-fuel-dependent region. Using wind field data from the Modern-Era Retrospective Analysis for Research and Applications Version 2 (MERRA-2), this study identifies areas favorable to the deployment of airborne wind energy (AWE) systems in the Middle East and computes the optimal heights at which such systems would best operate. AWE potential is estimated using realistic AWE system specifications and assumptions about deployment scenarios and is compared with the near-surface wind generation potential with respect to diurnal and seasonal variability. The results show the potential utility of AWE in areas in the Middle East where the energy demand is high. In particular, Oman and Saudi Arabia have a high level of the potential power generation with low annual variability.

  16. Scottish Sea Lochs: High Resolution Archives of North Atlantic Climate

    Science.gov (United States)

    Norgaard-Pedersen, N.; Austin, W. E.; Cage, A. G.; Shimmield, T. M.; Gillibrand, P. A.

    2002-12-01

    The sea lochs (fjords) of NW Scotland bridge the land-ocean interface in a region of Europe which is particularly well situated to monitor changes in westerly air flow. Inter-annual atmospheric circulation changes at this latitude are largely governed by the North Atlantic Oscillation (NAO), in turn influencing both westerlies and precipitation. Comparing two extreme recent NAO years, circulation modelling results from Loch Sunart, NW Scotland, reveal a clear response to freshwater runoff and wind forcing in both magnitude and rate of deep-water renewal events. Scottish fjords, because of the relatively small impact which salinity has on d18Owater (0.18 % per salinity unit), potentially provide NW Europe's most useful study sites in coastal palaeoclimate research, particularly where palaeotemperature is the primary record of interest. New data from a high-resolution record (7 yr sample resolution), spanning the last two millennia, from the deepest part of the main basin of Loch Sunart illustrate significant multi-decadal to centennial scale variability in the sedimentary and stable isotope record of epibenthic foraminifera Cibicides lobatulus. The long-term pattern in benthic d18O appears to reflect bottom water temperature differences of 1-2§C, resolving climatic periods such as the Medieval Warm Period and the Little Ice Age. Since the core site is connected with shelf waters (i.e. no shallow sill) it seems likely that this paleotemperature reflects changing shelf water, not the exchange process as a function of long-term runoff/wind forcing. Grain size data and XRF data point to catchment-wide responses (weathering and erosion) which appear to show the largest variability during the last millennium, driven either by rainfall and temperature and/or land-use. Pb-isotope data, constraining the modern and industrial period, suggest accelerated sedimentation rates over this interval. On-going work attempts to calibrate proxy data with instrumental historical data.

  17. TerraClimate, a high-resolution global dataset of monthly climate and climatic water balance from 1958–2015

    OpenAIRE

    Abatzoglou, John T.; Dobrowski, Solomon Z.; Parks, Sean A.; Hegewisch, Katherine C.

    2018-01-01

    We present TerraClimate, a dataset of high-spatial resolution (1/24°, ~4-km) monthly climate and climatic water balance for global terrestrial surfaces from 1958–2015. TerraClimate uses climatically aided interpolation, combining high-spatial resolution climatological normals from the WorldClim dataset, with coarser resolution time varying (i.e., monthly) data from other sources to produce a monthly dataset of precipitation, maximum and minimum temperature, wind speed, vapor pressure, and sol...

  18. High Resolution Displays Using NCAP Liquid Crystals

    Science.gov (United States)

    Macknick, A. Brian; Jones, Phil; White, Larry

    1989-07-01

    Nematic curvilinear aligned phase (NCAP) liquid crystals have been found useful for high information content video displays. NCAP materials are liquid crystals which have been encapsulated in a polymer matrix and which have a light transmission which is variable with applied electric fields. Because NCAP materials do not require polarizers, their on-state transmission is substantially better than twisted nematic cells. All dimensional tolerances are locked in during the encapsulation process and hence there are no critical sealing or spacing issues. By controlling the polymer/liquid crystal morphology, switching speeds of NCAP materials have been significantly improved over twisted nematic systems. Recent work has combined active matrix addressing with NCAP materials. Active matrices, such as thin film transistors, have given displays of high resolution. The paper will discuss the advantages of NCAP materials specifically designed for operation at video rates on transistor arrays; applications for both backlit and projection displays will be discussed.

  19. High resolution crystal calorimetry at LHC

    International Nuclear Information System (INIS)

    Schneegans, M.; Ferrere, D.; Lebeau, M.; Vivargent, M.

    1991-01-01

    The search for Higgs bosons above Lep200 reach could be one of the main tasks of the future pp and ee colliders. In the intermediate mass region, and in particular in the range 80-140 GeV/c 2 , only the 2-photon decay mode of a Higgs produced inclusively or in association with a W, gives a good chance of observation. A 'dedicated' very high resolution calorimeter with photon angle reconstruction and pion identification capability should detect a Higgs signal with high probability. A crystal calorimeter can be considered as a conservative approach to such a detector, since a large design and operation experience already exists. The extensive R and D needed for finding a dense, fast and radiation hard crystal, is under way. Guide-lines for designing an optimum calorimeter for LHC are discussed and preliminary configurations are given. (author) 7 refs., 3 figs., 2 tabs

  20. A High Efficiency Wind Energy System

    DEFF Research Database (Denmark)

    Khan, M. Z.; Hussain, M. M.; Naveed, M. M.

    2012-01-01

    In this paper, a wind generator system that employs a Fourphase Interleaved Bi-directional DC / DC Converter, a Selective Harmonic Elimination Sinusoidal Pulse Width Modulation (SHE SPWM) based Inverter and a PermanentMagnet Synchronous Generator (PMSG) is studied. The merits of using the topolog...

  1. Concept for a new high resolution high intensity diffractometer

    Energy Technology Data Exchange (ETDEWEB)

    Stuhr, U [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    A concept of a new time-of-flight powder-diffractometer for a thermal neutral beam tube at SINQ is presented. The design of the instrument optimises the contradictory conditions of high intensity and high resolution. The high intensity is achieved by using many neutron pulses simultaneously. By analysing the time-angle-pattern of the detected neutrons an assignment of the neutrons to a single pulse is possible. (author) 3 figs., tab., refs.

  2. High resolution computed tomography of positron emitters

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Budinger, T.F.; Cahoon, J.L.; Huesman, R.H.; Jackson, H.G.

    1976-10-01

    High resolution computed transaxial radionuclide tomography has been performed on phantoms containing positron-emitting isotopes. The imaging system consisted of two opposing groups of eight NaI(Tl) crystals 8 mm x 30 mm x 50 mm deep and the phantoms were rotated to measure coincident events along 8960 projection integrals as they would be measured by a 280-crystal ring system now under construction. The spatial resolution in the reconstructed images is 7.5 mm FWHM at the center of the ring and approximately 11 mm FWHM at a radius of 10 cm. We present measurements of imaging and background rates under various operating conditions. Based on these measurements, the full 280-crystal system will image 10,000 events per sec with 400 μCi in a section 1 cm thick and 20 cm in diameter. We show that 1.5 million events are sufficient to reliably image 3.5-mm hot spots with 14-mm center-to-center spacing and isolated 9-mm diameter cold spots in phantoms 15 to 20 cm in diameter

  3. High resolution CT of temporal bone trauma

    International Nuclear Information System (INIS)

    Youn, Eun Kyung

    1986-01-01

    Radiographic studies of the temporal bone following head trauma are indicated when there is cerebrospinal fluid otorrhea or rhinorrhoea, hearing loss, or facial nerve paralysis. Plain radiography displays only 17-30% of temporal bone fractures and pluridirectional tomography is both difficult to perform, particularly in the acutely ill patient, and less satisfactory for the demonstration of fine fractures. Consequently, high resolution CT is the imaging method of choice for the investigation of suspected temporal bone trauma and allows special resolution of fine bony detail comparable to that attainable by conventional tomography. Eight cases of temporal bone trauma examined at Korea General Hospital April 1985 through May 1986. The results were as follows: Seven patients (87%) suffered longitudinal fractures. In 6 patients who had purely conductive hearing loss, CT revealed various ossicular chain abnormality. In one patient who had neuro sensory hearing loss, CT demonstrated intract ossicular with a fracture nearing lateral wall of the lateral semicircular canal. In one patient who had mixed hearing loss, CT showed complex fracture.

  4. Analysis of chaos in high-dimensional wind power system.

    Science.gov (United States)

    Wang, Cong; Zhang, Hongli; Fan, Wenhui; Ma, Ping

    2018-01-01

    A comprehensive analysis on the chaos of a high-dimensional wind power system is performed in this study. A high-dimensional wind power system is more complex than most power systems. An 11-dimensional wind power system proposed by Huang, which has not been analyzed in previous studies, is investigated. When the systems are affected by external disturbances including single parameter and periodic disturbance, or its parameters changed, chaotic dynamics of the wind power system is analyzed and chaotic parameters ranges are obtained. Chaos existence is confirmed by calculation and analysis of all state variables' Lyapunov exponents and the state variable sequence diagram. Theoretical analysis and numerical simulations show that the wind power system chaos will occur when parameter variations and external disturbances change to a certain degree.

  5. Validation of High Wind Retrievals from the Cyclone Global Navigation Satellite System (CYGNSS) Mission

    Science.gov (United States)

    McKague, D. S.; Ruf, C. S.; Balasubramaniam, R.; Clarizia, M. P.

    2017-12-01

    The Cyclone Global Navigation Satellite System (CYGNSS) mission, launched in December of 2016, provides all-weather observations of sea surface winds. Using GPS-based bistatic reflectometry, the CYGNSS satellites can estimate sea surface winds even through a hurricane eye wall. This, combined with the high temporal resolution of the CYGNSS constellation (median revisit time of 2.8 hours), yields unprecedented ability to estimate hurricane strength winds. While there are a number of other sources of sea surface wind estimates, such as buoys, dropsondes, passive and active microwave from aircraft and satellite, and models, the combination of all-weather, high accuracy, short revisit time, high spatial coverage, and continuous operation of the CYGNSS mission enables significant advances in the understanding, monitoring, and prediction of cyclones. Validating CYGNSS wind retrievals over the bulk of the global wind speed distribution, which peaks at around 7 meters per second, is relatively straight-forward, requiring spatial-temporal matching of observations with independent sources (such as those mentioned above). Validating CYGNSS wind retrievals for "high" winds (> 20 meters per second), though, is problematic. Such winds occur only in intense storms. While infrequent, making validation opportunities also infrequent and problematic due to their intense nature, such storms are important to study because of the high potential for damage and loss of life. This presentation will describe the efforts of the CYGNSS Calibration/Validation team to gather measurements of high sea surface winds for development and validation of the CYGNSS geophysical model function (GMF), which forms the basis of retrieving winds from CYGNSS observations. The bulk of these observations come from buoy measurements as well as aircraft ("hurricane hunter") measurements from passive microwave and dropsondes. These data are matched in space and time to CYGNSS observations for training of the

  6. High resolution CT of the lung

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Harumi (Kyoto Univ. (Japan). Faculty of Medicine)

    1991-02-01

    The emergence of computed tomography (CT) in the early 1970s has greatly contributed to diagnostic radiology. The brain was the first organ examined with CT, followed by the abdomen. For the chest, CT has also come into use shortly after the introduction in the examination of the thoracic cavity and mediastinum. CT techniques were, however, of limited significance in the evaluation of pulmonary diseases, especially diffuse pulmonary diseases. High-resolution CT (HRCT) has been introduced in clinical investigations of the lung field. This article is designed to present chest radiographic and conventional tomographic interpretations and to introduce findings of HRCT corresponding to the same shadows, with a summation of the significance of HRCT and issues of diagnostic imaging. Materials outlined are tuberculosis, pneumoconiosis, bronchopneumonia, mycoplasma pneumonia, lymphangitic carcinomatosis, sarcoidosis, diffuse panbronchiolitis, interstitial pneumonia, and pulmonary emphysema. Finally, an overview of basic investigations evolved from HRCT is given. (N.K.) 140 refs.

  7. Classification of High Spatial Resolution, Hyperspectral ...

    Science.gov (United States)

    EPA announced the availability of the final report,Classification of High Spatial Resolution, Hyperspectral Remote Sensing Imagery of the Little Miami River Watershed in Southwest Ohio, USA . This report and associated land use/land cover (LULC) coverage is the result of a collaborative effort among an interdisciplinary team of scientists with the U.S. Environmental Protection Agency's (U.S. EPA's) Office of Research and Development in Cincinnati, Ohio. A primary goal of this project is to enhance the use of geography and spatial analytic tools in risk assessment, and to improve the scientific basis for risk management decisions affecting drinking water and water quality. The land use/land cover classification is derived from 82 flight lines of Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery acquired from July 24 through August 9, 2002 via fixed-wing aircraft.

  8. A high resolution jet analysis for LEP

    International Nuclear Information System (INIS)

    Hariri, S.

    1992-11-01

    A high resolution multijet analysis of hadronic events produced in e + e - annihilation at a C.M.S. energy of 91.2 GeV is described. Hadronic events produced in e + e - annihilations are generated using the Monte Carlo program JETSET7.3 with its two options: Matrix Element (M.E.) and Parton Showers (P.S.). The shower option is used with its default parameter values while the M.E. option is used with an invariant mass cut Y CUT =0.01 instead of 0.02. This choice ensures a better continuity in the evolution of the event shape variables. (K.A.) 3 refs.; 26 figs.; 1 tab

  9. High resolution VUV facility at INDUS-1

    International Nuclear Information System (INIS)

    Krishnamurty, G.; Saraswathy, P.; Rao, P.M.R.; Mishra, A.P.; Kartha, V.B.

    1993-01-01

    Synchrotron radiation (SR) generated in the electron storage rings is an unique source for the study of atomic and molecular spectroscopy especially in the vacuum ultra violet region. Realizing the potential of this light source, efforts are in progress to develop a beamline facility at INDUS-1 to carry out high resolution atomic and molecular spectroscopy. This beam line consists of a fore-optic which is a combination of three cylindrical mirrors. The mirrors are so chosen that SR beam having a 60 mrad (horizontal) x 6 mrad (vertical) divergence is focussed onto a slit of a 6.65 metre off-plane spectrometer in Eagle Mount equipped with horizontal slit and vertical dispersion. The design of the various components of the beam line is completed. It is decided to build the spectrometer as per the requirements of the user community. Details of the various aspects of the beam line will be presented. (author). 3 figs

  10. High-resolution CT of airway reactivity

    International Nuclear Information System (INIS)

    Herold, C.J.; Brown, R.H.; Hirshman, C.A.; Mitzner, W.; Zerhouni, E.A.

    1990-01-01

    Assessment of airway reactivity has generally been limited to experimental nonimaging models. This authors of this paper used high-resolution CT (HRCT) to evaluate airway reactivity and to calculate airway resistance (Raw) compared with lung resistance (RL). Ten anesthetized and ventilated dogs were investigated with HRCT (10 contiguous 2-mm sections through the lower lung lobes) during control state, following aerosol histamine challenge, and following posthistamine hyperinflation. The HRCT scans were digitized, and areas of 10 airways per dog (diameter, 1-10 mm) were measured with a computer edging process. Changes in airway area and Raw (calculated by 1/[area] 2 ) were measured. RL was assessed separately, following the same protocol. Data were analyzed by use of a paired t-test with significance at p < .05

  11. High resolution tomography using analog coding

    International Nuclear Information System (INIS)

    Brownell, G.L.; Burnham, C.A.; Chesler, D.A.

    1985-01-01

    As part of a 30-year program in the development of positron instrumentation, the authors have developed a high resolution bismuth germanate (BGO) ring tomography (PCR) employing 360 detectors and 90 photomultiplier tubes for one plane. The detectors are shaped as trapezoid and are 4 mm wide at the front end. When assembled, they form an essentially continuous cylindrical detector. Light from a scintillation in the detector is viewed through a cylindrical light pipe by the photomultiplier tubes. By use of an analog coding scheme, the detector emitting light is identified from the phototube signals. In effect, each phototube can identify four crystals. PCR is designed as a static device and does not use interpolative motion. This results in considerable advantage when performing dynamic studies. PCR is the positron tomography analog of the γ-camera widely used in nuclear medicine

  12. High-resolution CT of otosclerosis

    International Nuclear Information System (INIS)

    Dewen, Yang; Kodama, Takao; Tono, Tetsuya; Ochiai, Reiji; Kiyomizu, Kensuke; Suzuki, Yukiko; Yano, Takanori; Watanabe, Katsushi

    1997-01-01

    High-resolution CT (HRCT) scans of thirty-two patients (60 ears) with the clinical diagnosis of fenestral otosclerosis were evaluated retrospectively. HRCT was performed with 1-mm-thick targeted sections and 1-mm (36 ears) or 0.5-mm (10 ears) intervals in the semiaxial projection. Seven patients (14 ears) underwent helical scanning with a 1-mm slice thickness and 1-mm/sec table speed. Forty-five ears (75%) were found to have one or more otospongiotic or otosclerotic foci on HRCT. In most instances (30 ears), the otospongiotic foci were found in the region of the fissula ante fenestram. No significant correlations between CT findings and air conduction threshold were observed. We found a significant relationship between lesions of the labyrinthine capsule and sensorineural hearing loss. We conclude that HRCT is a valuable modality for diagnosing otosclerosis, especially when otospongiotic focus is detected. (author)

  13. High resolution CT in pulmonary sarcoidosis

    International Nuclear Information System (INIS)

    Spina, Juan C.; Curros, Marisela L.; Gomez, M.; Gonzalez, A.; Chacon, Carolina; Guerendiain, G.

    2000-01-01

    Objectives: To establish the particular advantages of High Resolution CT (HRCT) for the diagnosis of pulmonary sarcoidosis. Material and Methods: A series of fourteen patients, (4 men and 10 women; mean age 44,5 years) with thoracic sarcoidosis. All patients were studied using HRCT and diagnosis was confirmed for each case. Confidence intervals were obtained for different disease manifestations. Results: The most common findings were: lymph node enlargement (n=14 patients), pulmonary nodules (n=13), thickening of septa (n=6), peribronquial vascular thickening (n=5) pulmonary pseudo mass (n=5) and signs of fibrosis (n=4). The stage most commonly observed was stage II. It is worth noting that no cases of pleural effusion or cavitations of pulmonary lesions were observed. Conclusions: In this series, confidence interval overlapping for lymph node enlargement, single pulmonary nodules and septum thickening, allows to infer that their presence in a young adult, with few clinical symptoms, forces to rule out first the possibility of sarcoidosis. (author)

  14. Improved methods for high resolution electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, J.R.

    1987-04-01

    Existing methods of making support films for high resolution transmission electron microscopy are investigated and novel methods are developed. Existing methods of fabricating fenestrated, metal reinforced specimen supports (microgrids) are evaluated for their potential to reduce beam induced movement of monolamellar crystals of C/sub 44/H/sub 90/ paraffin supported on thin carbon films. Improved methods of producing hydrophobic carbon films by vacuum evaporation, and improved methods of depositing well ordered monolamellar paraffin crystals on carbon films are developed. A novel technique for vacuum evaporation of metals is described which is used to reinforce microgrids. A technique is also developed to bond thin carbon films to microgrids with a polymer bonding agent. Unique biochemical methods are described to accomplish site specific covalent modification of membrane proteins. Protocols are given which covalently convert the carboxy terminus of papain cleaved bacteriorhodopsin to a free thiol. 53 refs., 19 figs., 1 tab.

  15. High resolution infrared spectroscopy of symbiotic stars

    International Nuclear Information System (INIS)

    Bensammar, S.

    1989-01-01

    We report here very early results of high resolution (5x10 3 - 4x10 4 ) infrared spectroscopy (1 - 2.5 μm) of different symbiotic stars (T CrB, RW Hya, CI Cyg, PU Vul) observed with the Fourier Transform Spectrometer of the 3.60m Canada France Hawaii Telescope. These stars are usually considered as interacting binaries and only little details are known about the nature of their cool component. CO absorption lines are detected for the four stars. Very different profiles of hydrogen Brackett γ and helium 10830 A lines are shown for CI Cyg observed at different phases, while Pu Vul shows very intense emission lines

  16. Capillary detectors for high resolution tracking

    International Nuclear Information System (INIS)

    Annis, P.; Bay, A.; Bonekaemper, D.; Buontempo, S.; Ereditato, A.; Fabre, J.P.; Fiorillo, G.; Frekers, D.; Frenkel, A.; Galeazzi, F.; Garufi, F.; Goldberg, J.; Golovkin, S.; Hoepfner, K.; Konijn, J.; Kozarenko, E.; Kreslo, I.; Liberti, B.; Martellotti, G.; Medvedkov, A.; Mommaert, C.; Panman, J.; Penso, G.; Petukhov, Yu.; Rondeshagen, D.; Tyukov, V.; Vasilchenko, V.; Vilain, P.; Vischers, J.L.; Wilquet, G.; Winter, K.; Wolff, T.; Wong, H.

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 x 10 5 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on electron bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented. (orig.)

  17. Capillary detectors for high resolution tracking

    CERN Document Server

    Annis, P

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 × 105 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on Electron Bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented.

  18. GRANULOMETRIC MAPS FROM HIGH RESOLUTION SATELLITE IMAGES

    Directory of Open Access Journals (Sweden)

    Catherine Mering

    2011-05-01

    Full Text Available A new method of land cover mapping from satellite images using granulometric analysis is presented here. Discontinuous landscapes such as steppian bushes of semi arid regions and recently growing urban settlements are especially concerned by this study. Spatial organisations of the land cover are quantified by means of the size distribution analysis of the land cover units extracted from high resolution remotely sensed images. A granulometric map is built by automatic classification of every pixel of the image according to the granulometric density inside a sliding neighbourhood. Granulometric mapping brings some advantages over traditional thematic mapping by remote sensing by focusing on fine spatial events and small changes in one peculiar category of the landscape.

  19. High resolution imaging detectors and applications

    CERN Document Server

    Saha, Swapan K

    2015-01-01

    Interferometric observations need snapshots of very high time resolution of the order of (i) frame integration of about 100 Hz or (ii) photon-recording rates of several megahertz (MHz). Detectors play a key role in astronomical observations, and since the explanation of the photoelectric effect by Albert Einstein, the technology has evolved rather fast. The present-day technology has made it possible to develop large-format complementary metal oxide–semiconductor (CMOS) and charge-coupled device (CCD) array mosaics, orthogonal transfer CCDs, electron-multiplication CCDs, electron-avalanche photodiode arrays, and quantum-well infrared (IR) photon detectors. The requirements to develop artifact-free photon shot noise-limited images are higher sensitivity and quantum efficiency, reduced noise that includes dark current, read-out and amplifier noise, smaller point-spread functions, and higher spectral bandwidth. This book aims to address such systems, technologies and design, evaluation and calibration, control...

  20. High resolution mid-infrared spectroscopy based on frequency upconversion

    DEFF Research Database (Denmark)

    Dam, Jeppe Seidelin; Hu, Qi; Tidemand-Lichtenberg, Peter

    2013-01-01

    signals can be analyzed. The obtainable frequency resolution is usually in the nm range where sub nm resolution is preferred in many applications, like gas spectroscopy. In this work we demonstrate how to obtain sub nm resolution when using upconversion. In the presented realization one object point...... high resolution spectral performance by observing emission from hot water vapor in a butane gas burner....

  1. A high resolution solar atlas for fluorescence calculations

    Science.gov (United States)

    Hearn, M. F.; Ohlmacher, J. T.; Schleicher, D. G.

    1983-01-01

    The characteristics required of a solar atlas to be used for studying the fluorescence process in comets are examined. Several sources of low resolution data were combined to provide an absolutely calibrated spectrum from 2250 A to 7000A. Three different sources of high resolution data were also used to cover this same spectral range. The low resolution data were then used to put each high resolution spectrum on an absolute scale. The three high resolution spectra were then combined in their overlap regions to produce a single, absolutely calibrated high resolution spectrum over the entire spectral range.

  2. CONDITIONED ANALYSIS OF HIGH-LATITUDE SOLAR WIND INTERMITTENCY

    International Nuclear Information System (INIS)

    D'Amicis, R.; Consolini, G.; Bavassano, B.; Bruno, R.

    2012-01-01

    The solar wind is a turbulent medium displaying intermittency. Its intermittent features have been widely documented and studied, showing how the intermittent character is different in fast and slow wind. In this paper, a statistical conditioned analysis of the solar wind intermittency for a period of high-latitude fast solar wind is presented. In particular, the intermittent features are investigated as a function of the Alfvénic degree of fluctuations at a given scale. The results show that the main contribution to solar wind intermittency is due to non-Alfvénic structures, while Alfvénic increments are found to be characterized by a smaller level of intermittency than the previous ones. Furthermore, the lifetime statistics of Alfvénic periods are discussed in terms of a multiscale texture of randomly oriented flux tubes.

  3. Dynamic wind interference effects between high chimneys

    International Nuclear Information System (INIS)

    Ruscheweyh, H.; Traetner, A.

    2000-01-01

    In an extensive wind tunnel study vortex-induced cross-wind vibrations of chimneys in a row and in grouped arrangements have been investigated. Most of the model tests have been executed in the subcritical Reynolds number range. In order to indicate the influence of the Reynolds number, some tests have been executed at simulated transcritical Reynolds number range in the large wind tunnel NKl in Dresden. It could be shown, that the exciting forces at stacks in a row and in grouped arrangements are multiple larger in the subcritical range than in the transcritical range and cannot be transferred to full-scale concrete stacks. On the contrary the variation of the Strouhal number versus distance ratio is less influenced by the Reynolds number. It could be verified, that the diameter ratio d 2 /d 1 of the luff-side stack to the lee-side stack is of major importance. A recommendation for the estimation of vortex-induced vibrations of concrete stacks in a row and in grouped arrangements could be developed from the results with simulated transcritical Reynolds number. Strouhal number factors, ψ s , and exciting force factors, ψ lat , could be evaluated in dependency of the distance ratio a/d 1 of the stacks. A proposal for practical application is given in Fig. 10 and 11. It is compared with the proposal for stacks in a row which is given in the German Standard DIN 4133 for steel stacks. (orig.) [de

  4. High-Resolution Integrated Optical System

    Science.gov (United States)

    Prakapenka, V. B.; Goncharov, A. F.; Holtgrewe, N.; Greenberg, E.

    2017-12-01

    Raman and optical spectroscopy in-situ at extreme high pressure and temperature conditions relevant to the planets' deep interior is a versatile tool for characterization of wide range of properties of minerals essential for understanding the structure, composition, and evolution of terrestrial and giant planets. Optical methods, greatly complementing X-ray diffraction and spectroscopy techniques, become crucial when dealing with light elements. Study of vibrational and optical properties of minerals and volatiles, was a topic of many research efforts in past decades. A great deal of information on the materials properties under extreme pressure and temperature has been acquired including that related to structural phase changes, electronic transitions, and chemical transformations. These provide an important insight into physical and chemical states of planetary interiors (e.g. nature of deep reservoirs) and their dynamics including heat and mass transport (e.g. deep carbon cycle). Optical and vibrational spectroscopy can be also very instrumental for elucidating the nature of the materials molten states such as those related to the Earth's volatiles (CO2, CH4, H2O), aqueous fluids and silicate melts, planetary ices (H2O, CH4, NH3), noble gases, and H2. The optical spectroscopy study performed concomitantly with X-ray diffraction and spectroscopy measurements at the GSECARS beamlines on the same sample and at the same P-T conditions would greatly enhance the quality of this research and, moreover, will provide unique new information on chemical state of matter. The advanced high-resolution user-friendly integrated optical system is currently under construction and expected to be completed by 2018. In our conceptual design we have implemented Raman spectroscopy with five excitation wavelengths (266, 473, 532, 660, 946 nm), confocal imaging, double sided IR laser heating combined with high temperature Raman (including coherent anti-Stokes Raman scattering) and

  5. High Resolution Modeling of Hurricanes in a Climate Context

    Science.gov (United States)

    Knutson, T. R.

    2007-12-01

    Modeling of tropical cyclone activity in a climate context initially focused on simulation of relatively weak tropical storm-like disturbances as resolved by coarse grid (200 km) global models. As computing power has increased, multi-year simulations with global models of grid spacing 20-30 km have become feasible. Increased resolution also allowed for simulation storms of increasing intensity, and some global models generate storms of hurricane strength, depending on their resolution and other factors, although detailed hurricane structure is not simulated realistically. Results from some recent high resolution global model studies are reviewed. An alternative for hurricane simulation is regional downscaling. An early approach was to embed an operational (GFDL) hurricane prediction model within a global model solution, either for 5-day case studies of particular model storm cases, or for "idealized experiments" where an initial vortex is inserted into an idealized environments derived from global model statistics. Using this approach, hurricanes up to category five intensity can be simulated, owing to the model's relatively high resolution (9 km grid) and refined physics. Variants on this approach have been used to provide modeling support for theoretical predictions that greenhouse warming will increase the maximum intensities of hurricanes. These modeling studies also simulate increased hurricane rainfall rates in a warmer climate. The studies do not address hurricane frequency issues, and vertical shear is neglected in the idealized studies. A recent development is the use of regional model dynamical downscaling for extended (e.g., season-length) integrations of hurricane activity. In a study for the Atlantic basin, a non-hydrostatic model with grid spacing of 18km is run without convective parameterization, but with internal spectral nudging toward observed large-scale (basin wavenumbers 0-2) atmospheric conditions from reanalyses. Using this approach, our

  6. Wind load effects on high rise buildings in Peninsular Malaysia

    Science.gov (United States)

    Nizamani, Z.; Thang, K. C.; Haider, B.; Shariff, M.

    2018-04-01

    Wind is a randomly varying dynamic phenomenon composed of a multitude of eddies of varying sizes and rotational characteristics along a general stream of air moving relative to the ground. These eddies give wind its gustiness, creating fluctuation and results in a complex flow characteristics. The wind vector at any point can be regarded as the sum of mean wind vector and the fluctuation components. These components not only vary with height but also dependant on the approach terrain and topography. Prevailing wind exerts pressure onto the structural surfaces. The effects of wind pressure in the form of shear and bending moments are found to be a major problem in structural failure. This study aims to study the effects of wind load on a fifteen-storey high rise building using EN 1991-1-4 code and MS1553:2002. The simulation results showed that by increasing the wind speed, the storey resultant forces, namely storey shear and storey moment increases significantly. Furthermore, simulation results according to EN 1991-1-4 yield higher values compared to the simulation results according to MS1553:2002.

  7. High-resolution downscaling for hydrological management

    Science.gov (United States)

    Ulbrich, Uwe; Rust, Henning; Meredith, Edmund; Kpogo-Nuwoklo, Komlan; Vagenas, Christos

    2017-04-01

    Hydrological modellers and water managers require high-resolution climate data to model regional hydrologies and how these may respond to future changes in the large-scale climate. The ability to successfully model such changes and, by extension, critical infrastructure planning is often impeded by a lack of suitable climate data. This typically takes the form of too-coarse data from climate models, which are not sufficiently detailed in either space or time to be able to support water management decisions and hydrological research. BINGO (Bringing INnovation in onGOing water management; ) aims to bridge the gap between the needs of hydrological modellers and planners, and the currently available range of climate data, with the overarching aim of providing adaptation strategies for climate change-related challenges. Producing the kilometre- and sub-daily-scale climate data needed by hydrologists through continuous simulations is generally computationally infeasible. To circumvent this hurdle, we adopt a two-pronged approach involving (1) selective dynamical downscaling and (2) conditional stochastic weather generators, with the former presented here. We take an event-based approach to downscaling in order to achieve the kilometre-scale input needed by hydrological modellers. Computational expenses are minimized by identifying extremal weather patterns for each BINGO research site in lower-resolution simulations and then only downscaling to the kilometre-scale (convection permitting) those events during which such patterns occur. Here we (1) outline the methodology behind the selection of the events, and (2) compare the modelled precipitation distribution and variability (preconditioned on the extremal weather patterns) with that found in observations.

  8. Toward high-resolution optoelectronic retinal prosthesis

    Science.gov (United States)

    Palanker, Daniel; Huie, Philip; Vankov, Alexander; Asher, Alon; Baccus, Steven

    2005-04-01

    It has been already demonstrated that electrical stimulation of retina can produce visual percepts in blind patients suffering from macular degeneration and retinitis pigmentosa. Current retinal implants provide very low resolution (just a few electrodes), while several thousand pixels are required for functional restoration of sight. We present a design of the optoelectronic retinal prosthetic system that can activate a retinal stimulating array with pixel density up to 2,500 pix/mm2 (geometrically corresponding to a visual acuity of 20/80), and allows for natural eye scanning rather than scanning with a head-mounted camera. The system operates similarly to "virtual reality" imaging devices used in military and medical applications. An image from a video camera is projected by a goggle-mounted infrared LED-LCD display onto the retina, activating an array of powered photodiodes in the retinal implant. Such a system provides a broad field of vision by allowing for natural eye scanning. The goggles are transparent to visible light, thus allowing for simultaneous utilization of remaining natural vision along with prosthetic stimulation. Optical control of the implant allows for simple adjustment of image processing algorithms and for learning. A major prerequisite for high resolution stimulation is the proximity of neural cells to the stimulation sites. This can be achieved with sub-retinal implants constructed in a manner that directs migration of retinal cells to target areas. Two basic implant geometries are described: perforated membranes and protruding electrode arrays. Possibility of the tactile neural stimulation is also examined.

  9. HIGH RESOLUTION AIRBORNE SHALLOW WATER MAPPING

    Directory of Open Access Journals (Sweden)

    F. Steinbacher

    2012-07-01

    Full Text Available In order to meet the requirements of the European Water Framework Directive (EU-WFD, authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river

  10. High Resolution Airborne Shallow Water Mapping

    Science.gov (United States)

    Steinbacher, F.; Pfennigbauer, M.; Aufleger, M.; Ullrich, A.

    2012-07-01

    In order to meet the requirements of the European Water Framework Directive (EU-WFD), authorities face the problem of repeatedly performing area-wide surveying of all kinds of inland waters. Especially for mid-sized or small rivers this is a considerable challenge imposing insurmountable logistical efforts and costs. It is therefore investigated if large-scale surveying of a river system on an operational basis is feasible by employing airborne hydrographic laser scanning. In cooperation with the Bavarian Water Authority (WWA Weilheim) a pilot project was initiated by the Unit of Hydraulic Engineering at the University of Innsbruck and RIEGL Laser Measurement Systems exploiting the possibilities of a new LIDAR measurement system with high spatial resolution and high measurement rate to capture about 70 km of riverbed and foreland for the river Loisach in Bavaria/Germany and the estuary and parts of the shoreline (about 40km in length) of lake Ammersee. The entire area surveyed was referenced to classic terrestrial cross-section surveys with the aim to derive products for the monitoring and managing needs of the inland water bodies forced by the EU-WFD. The survey was performed in July 2011 by helicopter and airplane and took 3 days in total. In addition, high resolution areal images were taken to provide an optical reference, offering a wide range of possibilities on further research, monitoring, and managing responsibilities. The operating altitude was about 500 m to maintain eye-safety, even for the aided eye, the airspeed was about 55 kts for the helicopter and 75 kts for the aircraft. The helicopter was used in the alpine regions while the fixed wing aircraft was used in the plains and the urban area, using appropriate scan rates to receive evenly distributed point clouds. The resulting point density ranged from 10 to 25 points per square meter. By carefully selecting days with optimum water quality, satisfactory penetration down to the river bed was achieved

  11. High-resolution CCD imaging alternatives

    Science.gov (United States)

    Brown, D. L.; Acker, D. E.

    1992-08-01

    High resolution CCD color cameras have recently stimulated the interest of a large number of potential end-users for a wide range of practical applications. Real-time High Definition Television (HDTV) systems are now being used or considered for use in applications ranging from entertainment program origination through digital image storage to medical and scientific research. HDTV generation of electronic images offers significant cost and time-saving advantages over the use of film in such applications. Further in still image systems electronic image capture is faster and more efficient than conventional image scanners. The CCD still camera can capture 3-dimensional objects into the computing environment directly without having to shoot a picture on film develop it and then scan the image into a computer. 2. EXTENDING CCD TECHNOLOGY BEYOND BROADCAST Most standard production CCD sensor chips are made for broadcast-compatible systems. One popular CCD and the basis for this discussion offers arrays of roughly 750 x 580 picture elements (pixels) or a total array of approximately 435 pixels (see Fig. 1). FOR. A has developed a technique to increase the number of available pixels for a given image compared to that produced by the standard CCD itself. Using an inter-lined CCD with an overall spatial structure several times larger than the photo-sensitive sensor areas each of the CCD sensors is shifted in two dimensions in order to fill in spatial gaps between adjacent sensors.

  12. Review of Power System Stability with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Rui; Hu, Weihao; Chen, Zhe

    2015-01-01

    analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical......This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing...

  13. High resolution modelling of the North Icelandic Irminger Current (NIIC

    Directory of Open Access Journals (Sweden)

    K. Logemann

    2006-01-01

    Full Text Available The northward inflow of Atlantic Water through Denmark Strait – the North Icelandic Irminger Current (NIIC – is simulated with a numerical model of the North Atlantic and Arctic Ocean. The model uses the technique of adaptive grid refinement which allows a high spatial resolution (1 km horizontal, 10 m vertical around Iceland. The model is used to assess time and space variability of volume and heat fluxes for the years 1997–2003. Passive tracers are applied to study origin and composition of NIIC water masses. The NIIC originates from two sources: the Irminger Current, flowing as part of the sub-polar gyre in 100–500 m depth along the Reykjanes Ridge and the shallow Icelandic coastal current, flowing north-westward on the south-west Icelandic shelf. The ratio of volume flux between the deep and shallow branch is around 2:1. The NIIC continues as a warm and saline branch northward through Denmark Strait where it entrains large amounts of polar water due to the collision with the southward flowing East Greenland Current. After passing Denmark Strait, the NIIC follows the coast line eastward being an important heat source for north Icelandic waters. At least 60% of the temporal temperature variability of north Icelandic waters is caused by the NIIC. The NIIC volume and heat transport is highly variable and depends strongly on the wind field north-east of Denmark Strait. Daily means can change from 1 Sv eastward to 2 Sv westward within a few days. Highest monthly mean transport rates occur in summer when winds from north are weak, whereas the volume flux is reduced by around 50% in winter. Summer heat flux rates can be even three times higher than in winter. The simulation also shows variability on the interannual scale. In particular weak winds from north during winter 2002/2003 combined with mild weather conditions south of Iceland led to anomalous high NIIC volume (+40% and heat flux (+60% rates. In this period, simulated north Icelandic

  14. Resolution enhancement of low quality videos using a high-resolution frame

    NARCIS (Netherlands)

    Pham, T.Q.; Van Vliet, L.J.; Schutte, K.

    2006-01-01

    This paper proposes an example-based Super-Resolution (SR) algorithm of compressed videos in the Discrete Cosine Transform (DCT) domain. Input to the system is a Low-Resolution (LR) compressed video together with a High-Resolution (HR) still image of similar content. Using a training set of

  15. An Experimental High-Resolution Forecast System During the Vancouver 2010 Winter Olympic and Paralympic Games

    Science.gov (United States)

    Mailhot, J.; Milbrandt, J. A.; Giguère, A.; McTaggart-Cowan, R.; Erfani, A.; Denis, B.; Glazer, A.; Vallée, M.

    2014-01-01

    Environment Canada ran an experimental numerical weather prediction (NWP) system during the Vancouver 2010 Winter Olympic and Paralympic Games, consisting of nested high-resolution (down to 1-km horizontal grid-spacing) configurations of the GEM-LAM model, with improved geophysical fields, cloud microphysics and radiative transfer schemes, and several new diagnostic products such as density of falling snow, visibility, and peak wind gust strength. The performance of this experimental NWP system has been evaluated in these winter conditions over complex terrain using the enhanced mesoscale observing network in place during the Olympics. As compared to the forecasts from the operational regional 15-km GEM model, objective verification generally indicated significant added value of the higher-resolution models for near-surface meteorological variables (wind speed, air temperature, and dewpoint temperature) with the 1-km model providing the best forecast accuracy. Appreciable errors were noted in all models for the forecasts of wind direction and humidity near the surface. Subjective assessment of several cases also indicated that the experimental Olympic system was skillful at forecasting meteorological phenomena at high-resolution, both spatially and temporally, and provided enhanced guidance to the Olympic forecasters in terms of better timing of precipitation phase change, squall line passage, wind flow channeling, and visibility reduction due to fog and snow.

  16. A method for generating high resolution satellite image time series

    Science.gov (United States)

    Guo, Tao

    2014-10-01

    There is an increasing demand for satellite remote sensing data with both high spatial and temporal resolution in many applications. But it still is a challenge to simultaneously improve spatial resolution and temporal frequency due to the technical limits of current satellite observation systems. To this end, much R&D efforts have been ongoing for years and lead to some successes roughly in two aspects, one includes super resolution, pan-sharpen etc. methods which can effectively enhance the spatial resolution and generate good visual effects, but hardly preserve spectral signatures and result in inadequate analytical value, on the other hand, time interpolation is a straight forward method to increase temporal frequency, however it increase little informative contents in fact. In this paper we presented a novel method to simulate high resolution time series data by combing low resolution time series data and a very small number of high resolution data only. Our method starts with a pair of high and low resolution data set, and then a spatial registration is done by introducing LDA model to map high and low resolution pixels correspondingly. Afterwards, temporal change information is captured through a comparison of low resolution time series data, and then projected onto the high resolution data plane and assigned to each high resolution pixel according to the predefined temporal change patterns of each type of ground objects. Finally the simulated high resolution data is generated. A preliminary experiment shows that our method can simulate a high resolution data with a reasonable accuracy. The contribution of our method is to enable timely monitoring of temporal changes through analysis of time sequence of low resolution images only, and usage of costly high resolution data can be reduces as much as possible, and it presents a highly effective way to build up an economically operational monitoring solution for agriculture, forest, land use investigation

  17. Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Monolithic Interferometer Design and Test

    Science.gov (United States)

    Harlander, John M.; Englert, Christoph R.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Zastera, Vaz; Bach, Bernhard W.; Mende, Stephen B.

    2017-10-01

    The design and laboratory tests of the interferometers for the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument which measures thermospheric wind and temperature for the NASA-sponsored Ionospheric Connection (ICON) Explorer mission are described. The monolithic interferometers use the Doppler Asymmetric Spatial Heterodyne (DASH) Spectroscopy technique for wind measurements and a multi-element photometer approach to measure thermospheric temperatures. The DASH technique and overall optical design of the MIGHTI instrument are described in an overview followed by details on the design, element fabrication, assembly, laboratory tests and thermal control of the interferometers that are the heart of MIGHTI.

  18. High resolution gas volume change sensor

    International Nuclear Information System (INIS)

    Dirckx, Joris J. J.; Aernouts, Jef E. F.; Aerts, Johan R. M.

    2007-01-01

    Changes of gas quantity in a system can be measured either by measuring pressure changes or by measuring volume changes. As sensitive pressure sensors are readily available, pressure change is the commonly used technique. In many physiologic systems, however, buildup of pressure influences the gas exchange mechanisms, thus changing the gas quantity change rate. If one wants to study the gas flow in or out of a biological gas pocket, measurements need to be done at constant pressure. In this article we present a highly sensitive sensor for quantitative measurements of gas volume change at constant pressure. The sensor is based on optical detection of the movement of a droplet of fluid enclosed in a capillary. The device is easy to use and delivers gas volume data at a rate of more than 15 measurements/s and a resolution better than 0.06 μl. At the onset of a gas quantity change the sensor shows a small pressure artifact of less than 15 Pa, and at constant change rates the pressure artifact is smaller than 10 Pa or 0.01% of ambient pressure

  19. Photoionization of Ar2 at high resolution

    International Nuclear Information System (INIS)

    Dehmer, P.M.

    1982-01-01

    The relative photoionization cross section of Ar 2 was determined at a resolution of 0.07 A in the wavelength region from 800 to 850 A using a new photoionization mass spectrometer that combines a high intensity helium continuum lamp with a free supersonic molecular beam source. In the region studied, the photoionization cross section is dominated by autoionization of molecular Rydberg states, and the structure is diffuse owing to the combined effects of autoionization and predissociation. The molecular photoionization spectrum is extremely complex and shows little resemblence either to the corresponding atomic spectrum (indicating that the spectrum of the dimer is not simply a perturbed atomic spectrum) or to the molecular absorption spectrum at longer wavelengths. The regular vibrational progressions seen at longer wavelengths are absent above the first ionization potential. Detailed spectroscopic analysis is possible for only a small fraction of the observed features; however, vibrational intervals of 50--100 cm -1 suggest that some of the Rydberg states have B 2 Pi/sub 3/2g/ ionic cores. A comparison of the absorption and photoionization spectra shows that, at wavelengths shorter than approx.835 A, many of the excited states decay via mechanisms other than autoionization

  20. DUACS: Toward High Resolution Sea Level Products

    Science.gov (United States)

    Faugere, Y.; Gerald, D.; Ubelmann, C.; Claire, D.; Pujol, M. I.; Antoine, D.; Desjonqueres, J. D.; Picot, N.

    2016-12-01

    The DUACS system produces, as part of the CNES/SALP project, and the Copernicus Marine Environment and Monitoring Service, high quality multimission altimetry Sea Level products for oceanographic applications, climate forecasting centers, geophysic and biology communities... These products consist in directly usable and easy to manipulate Level 3 (along-track cross-calibrated SLA) and Level 4 products (multiple sensors merged as maps or time series) and are available in global and regional version (Mediterranean Sea, Arctic, European Shelves …).The quality of the products is today limited by the altimeter technology "Low Resolution Mode" (LRM), and the lack of available observations. The launch of 2 new satellites in 2016, Jason-3 and Sentinel-3A, opens new perspectives. Using the global Synthetic Aperture Radar mode (SARM) coverage of S3A and optimizing the LRM altimeter processing (retracking, editing, ...) will allow us to fully exploit the fine-scale content of the altimetric missions. Thanks to this increase of real time altimetry observations we will also be able to improve Level-4 products by combining these new Level-3 products and new mapping methodology, such as dynamic interpolation. Finally these improvements will benefit to downstream products : geostrophic currents, Lagrangian products, eddy atlas… Overcoming all these challenges will provide major upgrades of Sea Level products to better fulfill user needs.

  1. High resolution simultaneous measurements of airborne radionuclides

    International Nuclear Information System (INIS)

    Abe, T.; Yamaguchi, Y.; Tanaka, K.; Komura, K.

    2006-01-01

    High resolution (2-3 hrs) simultaneous measurements of airborne radionuclides, 212 Pb, 210 Pb and 7 Be, have been performed by using extremely low background Ge detectors at Ogoya Underground Laboratory. We have measured above radionuclides at three monitoring points viz, 1) Low Level Radioactivity Laboratory (LLRL) Kanazawa University, 2) Shishiku Plateau (640 m MSL) located about 8 km from LLRL to investigate vertical difference of activity levels, and 3) Hegura Island (10 m MSL) located about 50 km from Noto Peninsula in the Sea of Japan to evaluate the influences of Asian continent or mainland of Japan on the variation to the activity levels. Variations of short-lived 212 Pb concentration showed noticeable time lags between at LLRL and at Shishiku Plateau. These time lags might be caused by change of height of a planetary boundary layer. On the contrary, variations of long-lived 210 Pb and 7 Be showed simultaneity at three locations because of homogeneity of these concentrations all over the area. (author)

  2. LCA of electricity systems with high wind power penetration

    DEFF Research Database (Denmark)

    Turconi, Roberto; O' Dwyer, C. O.; Flynn, D.

    Electricity systems are shifting from being based on fossil fuels towards renewable sources to enhance energy security and mitigate climate change. However, by introducing high shares of variable renewables - such as wind and solar - dispatchable power plants are required to vary their output...... to fulfill the remaining electrical demand, potentially increasing their environmental impacts [1,2]. In this study the environmental impacts of potential short-term future electricity systems in Ireland with high shares of wind power (35-50% of total installed capacity) were evaluated using life cycle...... considered: while not outweighing the benefits from increasing wind energy, cycling emissions are not negligible and should thus be systematically included (i.e. by using emission factors per unit of fuel input rather than per unit of power generated). Cycling emissions increased with the installed wind...

  3. Seychelles Dome variability in a high resolution ocean model

    Science.gov (United States)

    Nyadjro, E. S.; Jensen, T.; Richman, J. G.; Shriver, J. F.

    2016-02-01

    The Seychelles-Chagos Thermocline Ridge (SCTR; 5ºS-10ºS, 50ºE-80ºE) in the tropical Southwest Indian Ocean (SWIO) has been recognized as a region of prominence with regards to climate variability in the Indian Ocean. Convective activities in this region have regional consequences as it affect socio-economic livelihood of the people especially in the countries along the Indian Ocean rim. The SCTR is characterized by a quasi-permanent upwelling that is often associated with thermocline shoaling. This upwelling affects sea surface temperature (SST) variability. We present results on the variability and dynamics of the SCTR as simulated by the 1/12º high resolution HYbrid Coordinate Ocean Model (HYCOM). It is observed that locally, wind stress affects SST via Ekman pumping of cooler subsurface waters, mixing and anomalous zonal advection. Remotely, wind stress curl in the eastern equatorial Indian Ocean generates westward-propagating Rossby waves that impacts the depth of the thermocline which in turn impacts SST variability in the SCTR region. The variability of the contributions of these processes, especially with regard to the Indian Ocean Dipole (IOD) are further examined. In a typical positive IOD (PIOD) year, the net vertical velocity in the SCTR is negative year-round as easterlies along the region are intensified leading to a strong positive curl. This vertical velocity is caused mainly by anomalous local Ekman downwelling (with peak during September-November), a direct opposite to the climatology scenario when local Ekman pumping is positive (upwelling favorable) year-round. The anomalous remote contribution to the vertical velocity changes is minimal especially during the developing and peak stages of PIOD events. In a typical negative IOD (NIOD) year, anomalous vertical velocity is positive almost year-round with peaks in May and October. The remote contribution is positive, in contrast to the climatology and most of the PIOD years.

  4. Microgrid optimal scheduling considering impact of high penetration wind generation

    Science.gov (United States)

    Alanazi, Abdulaziz

    The objective of this thesis is to study the impact of high penetration wind energy in economic and reliable operation of microgrids. Wind power is variable, i.e., constantly changing, and nondispatchable, i.e., cannot be controlled by the microgrid controller. Thus an accurate forecasting of wind power is an essential task in order to study its impacts in microgrid operation. Two commonly used forecasting methods including Autoregressive Integrated Moving Average (ARIMA) and Artificial Neural Network (ANN) have been used in this thesis to improve the wind power forecasting. The forecasting error is calculated using a Mean Absolute Percentage Error (MAPE) and is improved using the ANN. The wind forecast is further used in the microgrid optimal scheduling problem. The microgrid optimal scheduling is performed by developing a viable model for security-constrained unit commitment (SCUC) based on mixed-integer linear programing (MILP) method. The proposed SCUC is solved for various wind penetration levels and the relationship between the total cost and the wind power penetration is found. In order to reduce microgrid power transfer fluctuations, an additional constraint is proposed and added to the SCUC formulation. The new constraint would control the time-based fluctuations. The impact of the constraint on microgrid SCUC results is tested and validated with numerical analysis. Finally, the applicability of proposed models is demonstrated through numerical simulations.

  5. The High-Resolution IRAS Galaxy Atlas

    Science.gov (United States)

    Cao, Yu; Terebey, Susan; Prince, Thomas A.; Beichman, Charles A.; Oliversen, R. (Technical Monitor)

    1997-01-01

    An atlas of the Galactic plane (-4.7 deg is less than b is less than 4.7 deg), along with the molecular clouds in Orion, rho Oph, and Taurus-Auriga, has been produced at 60 and 100 microns from IRAS data. The atlas consists of resolution-enhanced co-added images with 1 min - 2 min resolution and co-added images at the native IRAS resolution. The IRAS Galaxy Atlas, together with the Dominion Radio Astrophysical Observatory H(sub I) line/21 cm continuum and FCRAO CO (1-0) Galactic plane surveys, which both have similar (approx. 1 min) resolution to the IRAS atlas, provides a powerful tool for studying the interstellar medium, star formation, and large-scale structure in our Galaxy. This paper documents the production and characteristics of the atlas.

  6. Kinetic Energy from Supernova Feedback in High-resolution Galaxy Simulations

    Science.gov (United States)

    Simpson, Christine M.; Bryan, Greg L.; Hummels, Cameron; Ostriker, Jeremiah P.

    2015-08-01

    We describe a new method for adding a prescribed amount of kinetic energy to simulated gas modeled on a cartesian grid by directly altering grid cells’ mass and velocity in a distributed fashion. The method is explored in the context of supernova (SN) feedback in high-resolution (˜10 pc) hydrodynamic simulations of galaxy formation. Resolution dependence is a primary consideration in our application of the method, and simulations of isolated explosions (performed at different resolutions) motivate a resolution-dependent scaling for the injected fraction of kinetic energy that we apply in cosmological simulations of a 109 M⊙ dwarf halo. We find that in high-density media (≳50 cm-3) with coarse resolution (≳4 pc per cell), results are sensitive to the initial kinetic energy fraction due to early and rapid cooling. In our galaxy simulations, the deposition of small amounts of SN energy in kinetic form (as little as 1%) has a dramatic impact on the evolution of the system, resulting in an order-of-magnitude suppression of stellar mass. The overall behavior of the galaxy in the two highest resolution simulations we perform appears to converge. We discuss the resulting distribution of stellar metallicities, an observable sensitive to galactic wind properties, and find that while the new method demonstrates increased agreement with observed systems, significant discrepancies remain, likely due to simplistic assumptions that neglect contributions from SNe Ia and stellar winds.

  7. A high resolution β-detector

    International Nuclear Information System (INIS)

    Charon, Y.; Cuzon, J.C.; Tricoire, H.; Valentin, L.

    1987-01-01

    We present a detector which associates a charge coupled device to a light amplifier. This image sensor must detect weak β-activity, with a 10 μm resolution and should replace the autoradiographic films used for molecular hybridization. The best results are obtained with the 35 S emittor, for which the resolution and the efficiency are respectively 20 μm and 100% (relative to the measured standard source)

  8. High resolution spectrometry for relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Gabor, G; Schimmerling, W; Greiner, D; Bieser, F; Lindstrom, P [California Univ., Berkeley (USA). Lawrence Berkeley Lab.

    1975-12-01

    Several techniques are discussed for velocity and energy spectrometry of relativistic heavy ions with good resolution. A foil telescope with chevron channel plate detectors is described. A test of this telescope was performed using 2.1 GeV/A C/sup 6 +/ ions, and a time-of-flight resolution of 160 ps was measured. Qualitative information on the effect of foil thickness was also obtained.

  9. Toward reduced transport errors in a high resolution urban CO2 inversion system

    Directory of Open Access Journals (Sweden)

    Aijun Deng

    2017-05-01

    Full Text Available We present a high-resolution atmospheric inversion system combining a Lagrangian Particle Dispersion Model (LPDM and the Weather Research and Forecasting model (WRF, and test the impact of assimilating meteorological observation on transport accuracy. A Four Dimensional Data Assimilation (FDDA technique continuously assimilates meteorological observations from various observing systems into the transport modeling system, and is coupled to the high resolution CO2 emission product Hestia to simulate the atmospheric mole fractions of CO2. For the Indianapolis Flux Experiment (INFLUX project, we evaluated the impact of assimilating different meteorological observation systems on the linearized adjoint solutions and the CO2 inverse fluxes estimated using observed CO2 mole fractions from 11 out of 12 communications towers over Indianapolis for the Sep.-Nov. 2013 period. While assimilating WMO surface measurements improved the simulated wind speed and direction, their impact on the planetary boundary layer (PBL was limited. Simulated PBL wind statistics improved significantly when assimilating upper-air observations from the commercial airline program Aircraft Communications Addressing and Reporting System (ACARS and continuous ground-based Doppler lidar wind observations. Wind direction mean absolute error (MAE decreased from 26 to 14 degrees and the wind speed MAE decreased from 2.0 to 1.2 m s–1, while the bias remains small in all configurations (< 6 degrees and 0.2 m s–1. Wind speed MAE and ME are larger in daytime than in nighttime. PBL depth MAE is reduced by ~10%, with little bias reduction. The inverse results indicate that the spatial distribution of CO2 inverse fluxes were affected by the model performance while the overall flux estimates changed little across WRF simulations when aggregated over the entire domain. Our results show that PBL wind observations are a potent tool for increasing the precision of urban meteorological reanalyses

  10. Zeolites - a high resolution electron microscopy study

    International Nuclear Information System (INIS)

    Alfredsson, V.

    1994-10-01

    High resolution transmission electron microscopy (HRTEM) has been used to investigate a number of zeolites (EMT, FAU, LTL, MFI and MOR) and a member of the mesoporous M41S family. The electron optical artefact, manifested as a dark spot in the projected centre of the large zeolite channels, caused by insufficient transfer of certain reflections in the objective lens has been explained. The artefact severely hinders observation of materials confined in the zeolite channels and cavities. It is shown how to circumvent the artefact problem and how to image confined materials in spite of disturbance caused by the artefact. Image processing by means of a Wiener filter has been applied for removal of the artefact. The detailed surface structure of FAU has been investigated. Comparison of experimental micrographs with images simulated using different surface models indicates that the surface can be terminated in different ways depending on synthesis methods. The dealuminated form of FAU (USY) is covered by an amorphous region. Platinum incorporated in FAU has a preponderance to aggregate in the (111) twin planes, probably due to a local difference in cage structure with more spacious cages. It is shown that platinum is intra-zeolitic as opposed to being located on the external surface of the zeolite crystal. This could be deduced from tomography of ultra-thin sections among observations. HRTEM studies of the mesoporous MCM-41 show that the pores have a hexagonal shape and also supports the mechanistic model proposed which involves a cooperative formation of a mesophase including the silicate species as well as the surfactant. 66 refs, 24 figs

  11. Risk assessment of electric generation systems with high wind penetration

    International Nuclear Information System (INIS)

    Salgado Duarte, Yorlandys; Castillo Serpa, Alfredo M. del

    2017-01-01

    The research evaluates the risk function of an Electric Generation System (SGE) with high wind power penetration using the Sequential Monte Carlo Simulation (SMCS) method, which allows calculating indicators that characterize the performance of the SGE with expected average values. The research uses a Markov model of two states or four states according to the characteristics of the generator to simulate the instantaneous capacity. The primary sources of each conventional generator are assumed to be always available; however, wind power depends on the wind behavior in each analyzed region. In this research, the Chronological Series and Weibull models are used to model the wind behavior, and the analyzes are performed in the IEEE-RTS system. The work shows that the behavior of the probabilistic indicators used to analyze the static capacity of the SGE is determined by the model used to simulate the stochastic of the generators and by the primary energy source. (author)

  12. Developing a high-resolution regional atmospheric reanalysis for Australia

    Science.gov (United States)

    White, Christopher; Fox-Hughes, Paul; Su, Chun-Hsu; Jakob, Dörte; Kociuba, Greg; Eisenberg, Nathan; Steinle, Peter; Harris, Rebecca; Corney, Stuart; Love, Peter; Remenyi, Tomas; Chladil, Mark; Bally, John; Bindoff, Nathan

    2017-04-01

    A dynamically consistent, long-term atmospheric reanalysis can be used to support high-quality assessments of environmental risk and likelihood of extreme events. Most reanalyses are presently based on coarse-scale global systems that are not suitable for regional assessments in fire risk, water and natural resources, amongst others. The Australian Bureau of Meteorology is currently working to close this gap by producing a high-resolution reanalysis over the Australian and New Zealand region to construct a sequence of atmospheric conditions at sub-hourly intervals over the past 25 years from 1990. The Australia reanalysis consists of a convective-scale analysis nested within a 12 km regional-scale reanalysis, which is bounded by a coarse-scale ERA-Interim reanalysis that provides the required boundary and initial conditions. We use an unchanging atmospheric modelling suite based on the UERRA system used at the UK Met Office and the more recent version of the Bureau of Meteorology's operational numerical prediction model used in ACCESS-R (Australian Community Climate and Earth-System Simulator-Regional system). An advanced (4-dimensional variational) data assimilation scheme is used to optimally combine model physics with multiple observations from aircrafts, sondes, surface observations and satellites to create a best estimate of state of the atmosphere over a 6-hour moving window. This analysis is in turn used to drive a higher-resolution (1.5 km) downscaling model over selected subdomains within Australia, currently eastern New South Wales and Tasmania, with the capability to support this anywhere in the Australia-New Zealand domain. The temporal resolution of the gridded analysis fields for both the regional and higher-resolution subdomains are generally one hour, with many fields such as 10 m winds and 2 m temperatures available every 10 minutes. The reanalysis also produces many other variables that include wind, temperature, moisture, pressure, cloud cover

  13. High Resolution Hurricane Storm Surge and Inundation Modeling (Invited)

    Science.gov (United States)

    Luettich, R.; Westerink, J. J.

    2010-12-01

    Coastal counties are home to nearly 60% of the U.S. population and industry that accounts for over 16 million jobs and 10% of the U.S. annual gross domestic product. However, these areas are susceptible to some of the most destructive forces in nature, including tsunamis, floods, and severe storm-related hazards. Since 1900, tropical cyclones making landfall on the US Gulf of Mexico Coast have caused more than 9,000 deaths; nearly 2,000 deaths have occurred during the past half century. Tropical cyclone-related adjusted, annualized losses in the US have risen from 1.3 billion from 1949-1989, to 10.1 billion from 1990-1995, and $35.8 billion per year for the period 2001-2005. The risk associated with living and doing business in the coastal areas that are most susceptible to tropical cyclones is exacerbated by rising sea level and changes in the characteristics of severe storms associated with global climate change. In the five years since hurricane Katrina devastated the northern Gulf of Mexico Coast, considerable progress has been made in the development and utilization of high resolution coupled storm surge and wave models. Recent progress will be presented with the ADCIRC + SWAN storm surge and wave models. These tightly coupled models use a common unstructured grid in the horizontal that is capable of covering large areas while also providing high resolution (i.e., base resolution down to 20m plus smaller subgrid scale features such as sea walls and levees) in areas that are subject to surge and inundation. Hydrodynamic friction and overland winds are adjusted to account for local land cover. The models scale extremely well on modern high performance computers allowing rapid turnaround on large numbers of compute cores. The models have been adopted for FEMA National Flood Insurance Program studies, hurricane protection system design and risk analysis, and quasi-operational forecast systems for several regions of the country. They are also being evaluated as

  14. High Resolution Sensor for Nuclear Waste Characterization

    International Nuclear Information System (INIS)

    Kanai Shah; William Higgins; Edgar V. Van Loef

    2006-01-01

    Gamma ray spectrometers are an important tool in the characterization of radioactive waste. Important requirements for gamma ray spectrometers used in this application include good energy resolution, high detection efficiency, compact size, light weight, portability, and low power requirements. None of the available spectrometers satisfy all of these requirements. The goal of the Phase I research was to investigate lanthanum halide and related scintillators for nuclear waste clean-up. LaBr 3 :Ce remains a very promising scintillator with high light yield and fast response. CeBr 3 is attractive because it is very similar to LaBr 3 :Ce in terms of scintillation properties and also has the advantage of much lower self-radioactivity, which may be important in some applications. CeBr 3 also shows slightly higher light yield at higher temperatures than LaBr 3 and may be easier to produce with high uniformity in large volume since it does not require any dopants. Among the mixed lanthanum halides, the light yield of LaBr x I 3-x :Ce is lower and the difference in crystal structure of the binaries (LaBr 3 and LaI 3 ) makes it difficult to grow high quality crystals of the ternary as the iodine concentration is increased. On the other hand, LaBr x I 3-x :Ce provides excellent performance. Its light output is high and it provides fast response. The crystal structures of the two binaries (LaBr 3 and LaCl 3 ) are very similar. Overall, its scintillation properties are very similar to those for LaBr 3 :Ce. While the gamma-ray stopping efficiency of LaBr x I 3-x :Ce is lower than that for LaBr 3 :Ce (primarily because the density of LaCl 3 is lower than that of LaBr 3 ), it may be easier to grow large crystals of LaBr x I 3-x :Ce than LaBr 3 :Ce since in some instances (for example, Cd x Zn 1-x Te), the ternary compounds provide increased flexibility in the crystal lattice. Among the new dopants, Eu 2+ and Pr 3+ , tried in LaBr 3 host crystals, the Eu 2+ doped samples exhibited

  15. High resolution time integration for SN radiation transport

    International Nuclear Information System (INIS)

    Thoreson, Greg; McClarren, Ryan G.; Chang, Jae H.

    2009-01-01

    First-order, second-order, and high resolution time discretization schemes are implemented and studied for the discrete ordinates (S N ) equations. The high resolution method employs a rate of convergence better than first-order, but also suppresses artificial oscillations introduced by second-order schemes in hyperbolic partial differential equations. The high resolution method achieves these properties by nonlinearly adapting the time stencil to use a first-order method in regions where oscillations could be created. We employ a quasi-linear solution scheme to solve the nonlinear equations that arise from the high resolution method. All three methods were compared for accuracy and convergence rates. For non-absorbing problems, both second-order and high resolution converged to the same solution as the first-order with better convergence rates. High resolution is more accurate than first-order and matches or exceeds the second-order method

  16. Wind Energy Resource Atlas of Armenia

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.; Schwartz, M.; Scott, G.; Haymes, S.; Heimiller, D.; George, R.

    2003-07-01

    This wind energy resource atlas identifies the wind characteristics and distribution of the wind resource in the country of Armenia. The detailed wind resource maps and other information contained in the atlas facilitate the identification of prospective areas for use of wind energy technologies for utility-scale power generation and off-grid wind energy applications. The maps portray the wind resource with high-resolution (1-km2) grids of wind power density at 50-m above ground. The wind maps were created at the National Renewable Energy Laboratory (NREL) using a computerized wind mapping system that uses Geographic Information System (GIS) software.

  17. Impact of model resolution on simulated wind, drifting snow and surface mass balance in Terre Adélie, East Antarctica

    NARCIS (Netherlands)

    Lenaerts, J.T.M.|info:eu-repo/dai/nl/314850163; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; Scarchilli, C.; Agosta, C.

    2012-01-01

    This paper presents the impact of model resolution on the simulated wind speed, drifting snow climate and surface mass balance (SMB) of Terre Ad´elie and its surroundings, East Antarctica. We compare regional climate model simulations at 27 and 5.5 km resolution for the year 2009. The wind speed

  18. Coronal holes and high-speed wind streams

    International Nuclear Information System (INIS)

    Zirker, J.B.

    1977-01-01

    Coronal holes low have been identified as Bartel's M regions, i.e., sources of high-speed wind streams that produce recurrent geomagnetic variations. Throughout the Skylab period the polar caps of the Sun were coronal holes, and at lower latitudes the most persistent and recurrent holes were equatorial extensions of the polar caps. The holes rotated 'rigidly' at the equatorial synodic rate. They formed in regions of unipolar photospheric magnetic field, and their internal magnetic fields diverged rapidly with increasing distance from the sun. The geometry of the magnetic field in the inner corona seems to control both the physical properties of the holes and the global distribution of high-speed wind streams in the heliosphere. The latitude variation of the divergence of the coronal magnetic field lines produces corresponding variations in wind speed.During the years of declining solar activity the global field of the corona approximates a perturbed dipole. The divergence of field lines in each hemisphere produces a high-speed wind near the poles and low-speed wind in a narrow belt that coincides with the magnetic neutral sheet. The analysis of electron density measurements within a polar hole indicates that solar wind is accelerated principally in the region between 2 and 5 R/sub s/ and that mechanical wave pressure (possibly Alfven wave) may be responsible for the accleration of the wind. Phenomenological models for the birth and decay of coronal holes have been proposed. Attempts to explain the birth and rigid rotation of holes through dynamo action have been only partially successful. The 11-year variation of cosmic ray intensities at the earth may result from cyclic variation of open field regions associated with coronal holes

  19. High resolution time integration for Sn radiation transport

    International Nuclear Information System (INIS)

    Thoreson, Greg; McClarren, Ryan G.; Chang, Jae H.

    2008-01-01

    First order, second order and high resolution time discretization schemes are implemented and studied for the S n equations. The high resolution method employs a rate of convergence better than first order, but also suppresses artificial oscillations introduced by second order schemes in hyperbolic differential equations. All three methods were compared for accuracy and convergence rates. For non-absorbing problems, both second order and high resolution converged to the same solution as the first order with better convergence rates. High resolution is more accurate than first order and matches or exceeds the second order method. (authors)

  20. An investigation of tropical Atlantic bias in a high-resolution coupled regional climate model

    Energy Technology Data Exchange (ETDEWEB)

    Patricola, Christina M.; Saravanan, R.; Hsieh, Jen-Shan [Texas A and M University, Department of Atmospheric Sciences, College Station, TX (United States); Li, Mingkui; Xu, Zhao [Texas A and M University, Department of Oceanography, College Station, TX (United States); Ocean University of China, Key Laboratory of Physical Oceanography of Ministry of Education, Qingdao (China); Chang, Ping [Texas A and M University, Department of Oceanography, College Station, TX (United States); Ocean University of China, Key Laboratory of Physical Oceanography of Ministry of Education, Qingdao (China); Second Institute of Oceanography, State Key Laboratory of Satellite Ocean Environment Dynamics, Hangzhou, Zhejiang (China)

    2012-11-15

    Coupled atmosphere-ocean general circulation models (AOGCMs) commonly fail to simulate the eastern equatorial Atlantic boreal summer cold tongue and produce a westerly equatorial trade wind bias. This tropical Atlantic bias problem is investigated with a high-resolution (27-km atmosphere represented by the Weather Research and Forecasting Model, 9-km ocean represented by the Regional Ocean Modeling System) coupled regional climate model. Uncoupled atmospheric simulations test climate sensitivity to cumulus, land-surface, planetary boundary layer, microphysics, and radiation parameterizations and reveal that the radiation scheme has a pronounced impact in the tropical Atlantic. The CAM radiation simulates a dry precipitation (up to -90%) and cold land-surface temperature (up to -8 K) bias over the Amazon related to an over-representation of low-level clouds and almost basin-wide westerly trade wind bias. The Rapid Radiative Transfer Model and Goddard radiation simulates doubled Amazon and Congo Basin precipitation rates and a weak eastern Atlantic trade wind bias. Season-long high-resolution coupled regional model experiments indicate that the initiation of the warm eastern equatorial Atlantic sea surface temperature (SST) bias is more sensitive to the local rather than basin-wide trade wind bias and to a wet Congo Basin instead of dry Amazon - which differs from AOGCM simulations. Comparisons between coupled and uncoupled simulations suggest a regional Bjerknes feedback confined to the eastern equatorial Atlantic amplifies the initial SST, wind, and deepened thermocline bias, while barrier layer feedbacks are relatively unimportant. The SST bias in some CRCM simulations resembles the typical AOGCM bias indicating that increasing resolution is unlikely a simple solution to this problem. (orig.)

  1. EMODnet High Resolution Seabed Mapping - further developing a high resolution digital bathymetry for European seas

    Science.gov (United States)

    Schaap, D.; Schmitt, T.

    2017-12-01

    Access to marine data is a key issue for the EU Marine Strategy Framework Directive and the EU Marine Knowledge 2020 agenda and includes the European Marine Observation and Data Network (EMODnet) initiative. EMODnet aims at assembling European marine data, data products and metadata from diverse sources in a uniform way. The EMODnet Bathymetry project has developed Digital Terrain Models (DTM) for the European seas. These have been produced from survey and aggregated data sets that are indexed with metadata by adopting the SeaDataNet Catalogue services. SeaDataNet is a network of major oceanographic data centres around the European seas that manage, operate and further develop a pan-European infrastructure for marine and ocean data management. The latest EMODnet Bathymetry DTM release has a grid resolution of 1/8 arcminute and covers all European sea regions. Use has been made of circa 7800 gathered survey datasets and composite DTMs. Catalogues and the EMODnet DTM are published at the dedicated EMODnet Bathymetry portal including a versatile DTM viewing and downloading service. End December 2016 the Bathymetry project has been succeeded by EMODnet High Resolution Seabed Mapping (HRSM). This continues gathering of bathymetric in-situ data sets with extra efforts for near coastal waters and coastal zones. In addition Satellite Derived Bathymetry data are included to fill gaps in coverage of the coastal zones. The extra data and composite DTMs will increase the coverage of the European seas and its coastlines, and provide input for producing an EMODnet DTM with a common resolution of 1/16 arc minutes. The Bathymetry Viewing and Download service will be upgraded to provide a multi-resolution map and including 3D viewing. The higher resolution DTMs will also be used to determine best-estimates of the European coastline for a range of tidal levels (HAT, MHW, MSL, Chart Datum, LAT), thereby making use of a tidal model for Europe. Extra challenges will be `moving to the

  2. The high resolution spaghetti hadron calorimeter

    International Nuclear Information System (INIS)

    Jenni, P.; Sonderegger, P.; Paar, H.P.; Wigmans, R.

    1987-01-01

    It is proposed to build a prototype for a hadron calorimeter with scintillating plastic fibres as active material. The absorber material is lead. Provided that these components are used in the appropriate volume ratio, excellent performance may be expected, e.g. an energy resolution of 30%/√E for jet detection. The proposed design offers additional advantages compared to the classical sandwich calorimeter structures in terms of granularity, hermiticity, uniformity, compactness, readout, radiation resistivity, stability and calibration. 22 refs.; 7 figs

  3. Objective high Resolution Analysis over Complex Terrain with VERA

    Science.gov (United States)

    Mayer, D.; Steinacker, R.; Steiner, A.

    2012-04-01

    VERA (Vienna Enhanced Resolution Analysis) is a model independent, high resolution objective analysis of meteorological fields over complex terrain. This system consists of a special developed quality control procedure and a combination of an interpolation and a downscaling technique. Whereas the so called VERA-QC is presented at this conference in the contribution titled "VERA-QC, an approved Data Quality Control based on Self-Consistency" by Andrea Steiner, this presentation will focus on the method and the characteristics of the VERA interpolation scheme which enables one to compute grid point values of a meteorological field based on irregularly distributed observations and topography related aprior knowledge. Over a complex topography meteorological fields are not smooth in general. The roughness which is induced by the topography can be explained physically. The knowledge about this behavior is used to define the so called Fingerprints (e.g. a thermal Fingerprint reproducing heating or cooling over mountainous terrain or a dynamical Fingerprint reproducing positive pressure perturbation on the windward side of a ridge) under idealized conditions. If the VERA algorithm recognizes patterns of one or more Fingerprints at a few observation points, the corresponding patterns are used to downscale the meteorological information in a greater surrounding. This technique allows to achieve an analysis with a resolution much higher than the one of the observational network. The interpolation of irregularly distributed stations to a regular grid (in space and time) is based on a variational principle applied to first and second order spatial and temporal derivatives. Mathematically, this can be formulated as a cost function that is equivalent to the penalty function of a thin plate smoothing spline. After the analysis field has been divided into the Fingerprint components and the unexplained part respectively, the requirement of a smooth distribution is applied to the

  4. Ulysses solar wind plasma observations at high southerly latitudes.

    Science.gov (United States)

    Phillips, J L; Bame, S J; Feldman, W C; Gosling, J T; Hammond, C M; McComas, D J; Goldstein, B E; Neugebauer, M; Scime, E E; Suess, S T

    1995-05-19

    Solar wind plasma observations made by the Ulysses spacecraft through -80.2 degrees solar latitude and continuing equatorward to -40.1 degrees are summarized. Recurrent high-speed streams and corotating interaction regions dominated at middle latitudes. The speed of the solar wind was typically 700 to 800 kilometers per second poleward of -35 degrees . Corotating reverse shocks persisted farther south than did forward shocks because of the tilt of the heliomagnetic streamer belt. Sporadic coronal mass ejections were seen as far south as -60.5 degrees . Proton temperature was higher and the electron strahl was broader at higher latitudes. The high-latitude wind contained compressional, pressure-balanced, and Alfvénic structures.

  5. High Power Wind Generator Designs with Less or No PMs

    DEFF Research Database (Denmark)

    Boldea, Ion; Tutelea, Lucian; Blaabjerg, Frede

    2014-01-01

    synchronous generators, by doubly-fed (wound rotor) induction and cage induction generators and by introducing new topologies with pertinent costs for high power (MW range) wind energy conversion units. The present overview attempts, based on recent grid specifications, an evaluation of commercial and novel...... considering the interaction with the PWM converter in terms of power/speed range, losses, kVA, and costs) rather than on the control issues which abound in literature, will be of use for future R&D efforts in wind energy conversion, storage and use.......The recent steep increase in high energy permanent magnet (PM) price (above 130$/kg and more) triggered already strong R&D efforts to develop wind generators with less PMs (less weight in NdFeB magnets/kW or the use of ferrite PMs) or fully without PMs. All these by optimizing existing dc excited...

  6. Highly sensitive high resolution Raman spectroscopy using resonant ionization methods

    International Nuclear Information System (INIS)

    Owyoung, A.; Esherick, P.

    1984-05-01

    In recent years, the introduction of stimulated Raman methods has offered orders of magnitude improvement in spectral resolving power for gas phase Raman studies. Nevertheless, the inherent weakness of the Raman process suggests the need for significantly more sensitive techniques in Raman spectroscopy. In this we describe a new approach to this problem. Our new technique, which we call ionization-detected stimulated Raman spectroscopy (IDSRS), combines high-resolution SRS with highly-sensitive resonant laser ionization to achieve an increase in sensitivity of over three orders of magnitude. The excitation/detection process involves three sequential steps: (1) population of a vibrationally excited state via stimulated Raman pumping; (2) selective ionization of the vibrationally excited molecule with a tunable uv source; and (3) collection of the ionized species at biased electrodes where they are detected as current in an external circuit

  7. Evaluation of Dynamical Downscaling Resolution Effect on Wind Energy Forecast Value for a Wind Farm in Central Sweden

    DEFF Research Database (Denmark)

    Rosgaard, Martin Haubjerg; Hahmann, Andrea N.; Nielsen, Torben Skov

    accuracy metric evaluated for wind speed data consistently translates to an improvement for wind power. For two time series describing the temporal development of the same variable, though by different means, it is assumed that phase errors account for most of the departure from perfect correlation between...... the two time series. Results on limited-area NWP model performance, with focus on the 12th to 48th forecast hour horizon relevant for Elspot auction bidding on the Nord Pool Spot market [2], are presented....

  8. High resolution IVEM tomography of biological specimens

    Energy Technology Data Exchange (ETDEWEB)

    Sedat, J.W.; Agard, D.A. [Univ. of California, San Francisco, CA (United States)

    1997-02-01

    Electron tomography is a powerful tool for elucidating the three-dimensional architecture of large biological complexes and subcellular organelles. The introduction of intermediate voltage electron microscopes further extended the technique by providing the means to examine very large and non-symmetrical subcellular organelles, at resolutions beyond what would be possible using light microscopy. Recent studies using electron tomography on a variety of cellular organelles and assemblies such as centrosomes, kinetochores, and chromatin have clearly demonstrated the power of this technique for obtaining 3D structural information on non-symmetric cell components. When combined with biochemical and molecular observations, these 3D reconstructions have provided significant new insights into biological function.

  9. High resolution synchrotron light analysis at ELSA

    Energy Technology Data Exchange (ETDEWEB)

    Switka, Michael; Zander, Sven; Hillert, Wolfgang [Bonn Univ. (Germany). Elektronen-Stretcher Anlage ELSA-Facility (ELSA)

    2013-07-01

    The pulse stretcher ring ELSA provides polarized electrons with energies up to 3.5 GeV for external hadron experiments. In order to suffice the need of stored beam intensities towards 200 mA, advanced beam instability studies need to be carried out. An external diagnostic beamline for synchrotron light analysis has been set up and provides the space for multiple diagnostic tools including a streak camera with time resolution of <1 ps. Beam profile measurements are expected to identify instabilities and reveal their thresholds. The effect of adequate countermeasures is subject to analysis. The current status of the beamline development is presented.

  10. High resolution NMR spectroscopy of synthetic polymers in bulk

    International Nuclear Information System (INIS)

    Komorski, R.A.

    1986-01-01

    The contents of this book are: Overview of high-resolution NMR of solid polymers; High-resolution NMR of glassy amorphous polymers; Carbon-13 solid-state NMR of semicrystalline polymers; Conformational analysis of polymers of solid-state NMR; High-resolution NMR studies of oriented polymers; High-resolution solid-state NMR of protons in polymers; and Deuterium NMR of solid polymers. This work brings together the various approaches for high-resolution NMR studies of bulk polymers into one volume. Heavy emphasis is, of course, given to 13C NMR studies both above and below Tg. Standard high-power pulse and wide-line techniques are not covered

  11. Operation of Power Grids with High Penetration of Wind Power

    Science.gov (United States)

    Al-Awami, Ali Taleb

    The integration of wind power into the power grid poses many challenges due to its highly uncertain nature. This dissertation involves two main components related to the operation of power grids with high penetration of wind energy: wind-thermal stochastic dispatch and wind-thermal coordinated bidding in short-term electricity markets. In the first part, a stochastic dispatch (SD) algorithm is proposed that takes into account the stochastic nature of the wind power output. The uncertainty associated with wind power output given the forecast is characterized using conditional probability density functions (CPDF). Several functions are examined to characterize wind uncertainty including Beta, Weibull, Extreme Value, Generalized Extreme Value, and Mixed Gaussian distributions. The unique characteristics of the Mixed Gaussian distribution are then utilized to facilitate the speed of convergence of the SD algorithm. A case study is carried out to evaluate the effectiveness of the proposed algorithm. Then, the SD algorithm is extended to simultaneously optimize the system operating costs and emissions. A modified multi-objective particle swarm optimization algorithm is suggested to identify the Pareto-optimal solutions defined by the two conflicting objectives. A sensitivity analysis is carried out to study the effect of changing load level and imbalance cost factors on the Pareto front. In the second part of this dissertation, coordinated trading of wind and thermal energy is proposed to mitigate risks due to those uncertainties. The problem of wind-thermal coordinated trading is formulated as a mixed-integer stochastic linear program. The objective is to obtain the optimal tradeoff bidding strategy that maximizes the total expected profits while controlling trading risks. For risk control, a weighted term of the conditional value at risk (CVaR) is included in the objective function. The CVaR aims to maximize the expected profits of the least profitable scenarios, thus

  12. Evaluation of Dynamical Downscaling Resolution Effect on Wind Energy Forecast Value for a Wind Farm in Central Sweden

    DEFF Research Database (Denmark)

    Rosgaard, Martin Haubjerg; Hahmann, Andrea N.; Nielsen, Torben Skov

    2014-01-01

    energy. The present study aims to quantify value added to wind energy forecasts in the 12-48 hour leadtime by downscaling global numerical weather prediction (NWP) data from the National Centers for Environmental Prediction Global Forecast System (GFS) using the limited-area NWP model described...

  13. High resolution transmission imaging without lenses

    International Nuclear Information System (INIS)

    Rodenburg, J M; Hurst, A C; Maiden, A

    2010-01-01

    The whole history of transmission imaging has been dominated by the lens, whether used in visible-light optics, electron optics or X-ray optics. Lenses can be thought of as a very efficient method of processing a wave front scattered from an object into an image of that object. An alternative approach is to undertake this image-formation process using a computational technique. The crudest scattering experiment is to simply record the intensity of a diffraction pattern. Recent progress in so-called diffractive imaging has shown that it is possible to recover the phase of a scattered wavefield from its diffraction pattern alone, as long as the object (or the illumination on the object) is of finite extent. In this paper we present results from a very efficient phase retrieval method which can image infinitely large fields of view. It may have important applications in improving resolution in electron microscopy, or at least allowing low specification microscopes to achieve resolution comparable to state-of-the-art machines.

  14. Scalable Algorithms for Large High-Resolution Terrain Data

    DEFF Research Database (Denmark)

    Mølhave, Thomas; Agarwal, Pankaj K.; Arge, Lars Allan

    2010-01-01

    In this paper we demonstrate that the technology required to perform typical GIS computations on very large high-resolution terrain models has matured enough to be ready for use by practitioners. We also demonstrate the impact that high-resolution data has on common problems. To our knowledge, so...

  15. High-resolution X-ray diffraction studies of multilayers

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; Schnopper, H. W.

    1988-01-01

    High-resolution X-ray diffraction studies of the perfection of state-of-the-art multilayers are presented. Data were obtained using a triple-axis perfect-crystal X-ray diffractometer. Measurements reveal large-scale figure errors in the substrate. A high-resolution triple-axis set up is required...

  16. Achieving sensitive, high-resolution laser spectroscopy at CRIS

    Energy Technology Data Exchange (ETDEWEB)

    Groote, R. P. de [Instituut voor Kern- en Stralingsfysica, KU Leuven (Belgium); Lynch, K. M., E-mail: kara.marie.lynch@cern.ch [EP Department, CERN, ISOLDE (Switzerland); Wilkins, S. G. [The University of Manchester, School of Physics and Astronomy (United Kingdom); Collaboration: the CRIS collaboration

    2017-11-15

    The Collinear Resonance Ionization Spectroscopy (CRIS) experiment, located at the ISOLDE facility, has recently performed high-resolution laser spectroscopy, with linewidths down to 20 MHz. In this article, we present the modifications to the beam line and the newly-installed laser systems that have made sensitive, high-resolution measurements possible. Highlights of recent experimental campaigns are presented.

  17. High resolution UV spectroscopy and laser-focused nanofabrication

    NARCIS (Netherlands)

    Myszkiewicz, G.

    2005-01-01

    This thesis combines two at first glance different techniques: High Resolution Laser Induced Fluorescence Spectroscopy (LIF) of small aromatic molecules and Laser Focusing of atoms for Nanofabrication. The thesis starts with the introduction to the high resolution LIF technique of small aromatic

  18. High-Resolution Sonars: What Resolution Do We Need for Target Recognition?

    Directory of Open Access Journals (Sweden)

    Pailhas Yan

    2010-01-01

    Full Text Available Target recognition in sonar imagery has long been an active research area in the maritime domain, especially in the mine-counter measure context. Recently it has received even more attention as new sensors with increased resolution have been developed; new threats to critical maritime assets and a new paradigm for target recognition based on autonomous platforms have emerged. With the recent introduction of Synthetic Aperture Sonar systems and high-frequency sonars, sonar resolution has dramatically increased and noise levels decreased. Sonar images are distance images but at high resolution they tend to appear visually as optical images. Traditionally algorithms have been developed specifically for imaging sonars because of their limited resolution and high noise levels. With high-resolution sonars, algorithms developed in the image processing field for natural images become applicable. However, the lack of large datasets has hampered the development of such algorithms. Here we present a fast and realistic sonar simulator enabling development and evaluation of such algorithms.We develop a classifier and then analyse its performances using our simulated synthetic sonar images. Finally, we discuss sensor resolution requirements to achieve effective classification of various targets and demonstrate that with high resolution sonars target highlight analysis is the key for target recognition.

  19. High-resolution global irradiance monitoring from photovoltaic systems

    Science.gov (United States)

    Buchmann, Tina; Pfeilsticker, Klaus; Siegmund, Alexander; Meilinger, Stefanie; Mayer, Bernhard; Pinitz, Sven; Steinbrecht, Wolfgang

    2016-04-01

    Reliable and regional differentiated power forecasts are required to guarantee an efficient and economic energy transition towards renewable energies. Amongst other renewable energy technologies, e.g. wind mills, photovoltaic systems are an essential component of this transition being cost-efficient and simply to install. Reliable power forecasts are however required for a grid integration of photovoltaic systems, which among other data requires high-resolution spatio-temporal global irradiance data. Hence the generation of robust reviewed global irradiance data is an essential contribution for the energy transition. To achieve this goal our studies introduce a novel method which makes use of photovoltaic power generation in order to infer global irradiance. The method allows to determine high-resolution temporal global irradiance data (one data point every 15 minutes at each location) from power data of operated photovoltaic systems. Due to the multitude of installed photovoltaic systems (in Germany) the detailed spatial coverage is much better than for example only using global irradiance data from conventional pyranometer networks (e.g. from the German Weather Service). Our designated method is composed of two components: a forward component, i.e. to conclude from predicted global irradiance to photovoltaic (PV) power, and a backward component, i.e. from PV power with suitable calibration to global irradiance. The forward process is modelled by using the radiation transport model libRadtran (B. Mayer and A. Kylling (1)) for clear skies to obtain the characteristics (orientation, size, temperature dependence, …) of individual PV systems. For PV systems in the vicinity of a meteorological station, these data are validated against calibrated pyranometer readings. The forward-modelled global irradiance is used to determine the power efficiency for each photovoltaic system using non-linear optimisation techniques. The backward component uses the power efficiency

  20. Ultra high resolution X-ray detectors

    International Nuclear Information System (INIS)

    Hess, U.; Buehler, M.; Hentig, R. von; Hertrich, T.; Phelan, K.; Wernicke, D.; Hoehne, J.

    2001-01-01

    CSP Cryogenic Spectrometers GmbH is developing cryogenic energy dispersive X-ray spectrometers based on superconducting detector technology. Superconducting sensors exhibit at least a 10-fold improvement in energy resolution due to their low energy gap compared to conventional Si(Li) or Ge detectors. These capabilities are extremely valuable for the analysis of light elements and in general for the analysis of the low energy range of the X-ray spectrum. The spectrometer is based on a mechanical cooler needing no liquid coolants and an adiabatic demagnetization refrigerator (ADR) stage which supplies the operating temperature of below 100 mK for the superconducting sensor. Applications include surface analysis in semiconductor industry as well material analysis for material composition e.g. in ceramics or automobile industry

  1. Effect of high wind conditions on AHX performance for PFBR

    International Nuclear Information System (INIS)

    Goyal, P.; Datta, Anu; Verma, Vishnu; Singh, R.K.

    2013-05-01

    In case of normal shut down or station blackout condition the core decay heat is removed by Safety Grade Decay Heat Removal System (SGDHRS) in PFBR. The Prototype Fast Breeder Reactor (PFBR) is under construction at Kalpakkam. SGDHRS remove decay heat from the core and dissipate it into the environment with the help of Air Heat Exchanger (AHX). SGDHRS consists of four redundant numbers of totally independent circuits capable of removing decay heat from the hot pool through natural convection in the primary and intermediate sodium sides as well as in the air side. Each circuit consists of a sodium to sodium heat exchanger (DHX) and a sodium to AHX connected to intermediate sodium circuit, AHX is located at a higher elevation compared to DHX. AHX is serpentine type finned tube compact heat exchanger with sodium in the tube side and air flowing over finned tubes. A tall stack provides the driving force for the natural convection of air flow through the AHX, when the dampers are opened. The AHX is placed outside of Reactor Control Building (RCB), on the roof of Steam Generator Building. Due to the presence of nearby buildings around the stack, the AHX performance under high wind condition may be affected. A CFD simulation using CFD-ACE+ code has been carried in which effect of high wind condition and nearby building on AHX performance have been studied. For high wind condition various orientation of wind movement was considered for parametric studies. AHX performance for all the cases were compared with the results that obtained for the absence of nearby buildings. A comparative table was prepared to understand how the AHX performance is effected with the high wind condition for various direction and with the presence of nearby building. It was observed that AHX performance is influenced by high wind conditions in most of the cases for with and without presence of nearby building. Hence to ensure the optimal performance of the AHX under high wind conditions its

  2. The wind and the magnetospheric accretion onto the T Tauri star S Coronae Australis at sub-au resolution

    Science.gov (United States)

    Gravity Collaboration; Garcia Lopez, R.; Perraut, K.; Caratti O Garatti, A.; Lazareff, B.; Sanchez-Bermudez, J.; Benisty, M.; Dougados, C.; Labadie, L.; Brandner, W.; Garcia, P. J. V.; Henning, Th.; Ray, T. P.; Abuter, R.; Amorim, A.; Anugu, N.; Berger, J. P.; Bonnet, H.; Buron, A.; Caselli, P.; Clénet, Y.; Coudé Du Foresto, V.; de Wit, W.; Deen, C.; Delplancke-Ströbele, F.; Dexter, J.; Eckart, A.; Eisenhauer, F.; Garcia Dabo, C. E.; Gendron, E.; Genzel, R.; Gillessen, S.; Haubois, X.; Haug, M.; Haussmann, F.; Hippler, S.; Hubert, Z.; Hummel, C. A.; Horrobin, M.; Jocou, L.; Kellner, S.; Kervella, P.; Kulas, M.; Kolb, J.; Lacour, S.; Le Bouquin, J.-B.; Léna, P.; Lippa, M.; Mérand, A.; Müller, E.; Ott, T.; Panduro, J.; Paumard, T.; Perrin, G.; Pfuhl, O.; Ramirez, A.; Rau, C.; Rohloff, R.-R.; Rousset, G.; Scheithauer, S.; Schöller, M.; Straubmeier, C.; Sturm, E.; Thi, W. F.; van Dishoeck, E.; Vincent, F.; Waisberg, I.; Wank, I.; Wieprecht, E.; Wiest, M.; Wiezorrek, E.; Woillez, J.; Yazici, S.; Zins, G.

    2017-12-01

    Aims: To investigate the inner regions of protoplanetary discs, we performed near-infrared interferometric observations of the classical T Tauri binary system S CrA. Methods: We present the first VLTI-GRAVITY high spectral resolution (R 4000) observations of a classical T Tauri binary, S CrA (composed of S CrA N and S CrA S and separated by 1.̋4), combining the four 8m telescopes in dual-field mode. Results: Our observations in the near-infrared K-band continuum reveal a disc around each binary component, with similar half-flux radii of about 0.1 au at d 130 pc, inclinations (i = 28 ± 3° and i = 22 ± 6°), and position angles (PA = 0°± 6° and PA = –2°± 12°), suggesting that they formed from the fragmentation of a common disc. The S CrA N spectrum shows bright He I and Brγ line emission exhibiting inverse P Cygni profiles, typically associated with infalling gas. The continuum-compensated Brγ line visibilities of S CrA N show the presence of a compact Brγ emitting region whose radius is about 0.06 au, which is twice as big as the truncation radius. This component is mostly tracing a wind. Moreover, a slight radius change between the blue- and red-shifted Brγ line components is marginally detected. Conclusions: The presence of an inverse P Cygni profile in the He I and Brγ lines, along with the tentative detection of a slightly larger size of the blue-shifted Brγ line component, hint at the simultaneous presence of a wind and magnetospheric accretion in S CrA N.

  3. Textural Segmentation of High-Resolution Sidescan Sonar Images

    National Research Council Canada - National Science Library

    Kalcic, Maria; Bibee, Dale

    1995-01-01

    .... The high resolution of the 455 kHz sonar imagery also provides much information about the surficial bottom sediments, however their acoustic scattering properties are not well understood at high frequencies...

  4. Texton-based super-resolution for achieving high spatiotemporal resolution in hybrid camera system

    Science.gov (United States)

    Kamimura, Kenji; Tsumura, Norimichi; Nakaguchi, Toshiya; Miyake, Yoichi

    2010-05-01

    Many super-resolution methods have been proposed to enhance the spatial resolution of images by using iteration and multiple input images. In a previous paper, we proposed the example-based super-resolution method to enhance an image through pixel-based texton substitution to reduce the computational cost. In this method, however, we only considered the enhancement of a texture image. In this study, we modified this texton substitution method for a hybrid camera to reduce the required bandwidth of a high-resolution video camera. We applied our algorithm to pairs of high- and low-spatiotemporal-resolution videos, which were synthesized to simulate a hybrid camera. The result showed that the fine detail of the low-resolution video can be reproduced compared with bicubic interpolation and the required bandwidth could be reduced to about 1/5 in a video camera. It was also shown that the peak signal-to-noise ratios (PSNRs) of the images improved by about 6 dB in a trained frame and by 1.0-1.5 dB in a test frame, as determined by comparison with the processed image using bicubic interpolation, and the average PSNRs were higher than those obtained by the well-known Freeman’s patch-based super-resolution method. Compared with that of the Freeman’s patch-based super-resolution method, the computational time of our method was reduced to almost 1/10.

  5. High resolution integral holography using Fourier ptychographic approach.

    Science.gov (United States)

    Li, Zhaohui; Zhang, Jianqi; Wang, Xiaorui; Liu, Delian

    2014-12-29

    An innovative approach is proposed for calculating high resolution computer generated integral holograms by using the Fourier Ptychographic (FP) algorithm. The approach initializes a high resolution complex hologram with a random guess, and then stitches together low resolution multi-view images, synthesized from the elemental images captured by integral imaging (II), to recover the high resolution hologram through an iterative retrieval with FP constrains. This paper begins with an analysis of the principle of hologram synthesis from multi-projections, followed by an accurate determination of the constrains required in the Fourier ptychographic integral-holography (FPIH). Next, the procedure of the approach is described in detail. Finally, optical reconstructions are performed and the results are demonstrated. Theoretical analysis and experiments show that our proposed approach can reconstruct 3D scenes with high resolution.

  6. A high resolution global scale groundwater model

    Science.gov (United States)

    de Graaf, Inge; Sutanudjaja, Edwin; van Beek, Rens; Bierkens, Marc

    2014-05-01

    As the world's largest accessible source of freshwater, groundwater plays a vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and supplies water for agricultural and industrial activities. During times of drought, groundwater storage provides a large natural buffer against water shortage and sustains flows to rivers and wetlands, supporting ecosystem habitats and biodiversity. Yet, the current generation of global scale hydrological models (GHMs) do not include a groundwater flow component, although it is a crucial part of the hydrological cycle. Thus, a realistic physical representation of the groundwater system that allows for the simulation of groundwater head dynamics and lateral flows is essential for GHMs that increasingly run at finer resolution. In this study we present a global groundwater model with a resolution of 5 arc-minutes (approximately 10 km at the equator) using MODFLOW (McDonald and Harbaugh, 1988). With this global groundwater model we eventually intend to simulate the changes in the groundwater system over time that result from variations in recharge and abstraction. Aquifer schematization and properties of this groundwater model were developed from available global lithological maps and datasets (Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013), combined with our estimate of aquifer thickness for sedimentary basins. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. Based on our sensitivity analysis, in which we run the model with various hydrogeological parameter settings, we observed that most variance in groundwater

  7. High resolution microdiffraction studies using synchrotron radiation

    Science.gov (United States)

    Spolenak, R.; Tamura, N.; Valek, B. C.; MacDowell, A. A.; Celestre, R. S.; Padmore, H. A.; Brown, W. L.; Marieb, T.; Batterman, B. W.; Patel, J. R.

    2002-04-01

    The advent of third generation synchrotron light sources in combination with x-ray focusing devices such as Kirkpatrick-Baez mirrors make Laue diffraction on a submicron length scale possible. Analysis of Laue images enables us to determine the deviatoric part of the 3D strain tensor to an accuracy of 2×10-4 in strain with a spatial resolution comparable to the grain size in our thin films. In this paper the application of x-ray microdiffraction to the temperature dependence of the mechanical behavior of a sputtered blanket Cu film and of electroplated damascene Cu lines will be presented. Microdiffraction reveals very large variations in the strain of a film or line from grain to grain. When the strain is averaged over a macroscopic region the results are in good agreement with direct macroscopic stress measurements. However, the strain variations are so large that in some cases in which the average stress is tensile there are some grains actually under compression. The full implications of these observations are still being considered, but it is clear that the mechanical properties of thin film materials are now accessible with new visibility.

  8. Cheetah: A high frame rate, high resolution SWIR image camera

    Science.gov (United States)

    Neys, Joel; Bentell, Jonas; O'Grady, Matt; Vermeiren, Jan; Colin, Thierry; Hooylaerts, Peter; Grietens, Bob

    2008-10-01

    A high resolution, high frame rate InGaAs based image sensor and associated camera has been developed. The sensor and the camera are capable of recording and delivering more than 1700 full 640x512pixel frames per second. The FPA utilizes a low lag CTIA current integrator in each pixel, enabling integration times shorter than one microsecond. On-chip logics allows for four different sub windows to be read out simultaneously at even higher rates. The spectral sensitivity of the FPA is situated in the SWIR range [0.9-1.7 μm] and can be further extended into the Visible and NIR range. The Cheetah camera has max 16 GB of on-board memory to store the acquired images and transfer the data over a Gigabit Ethernet connection to the PC. The camera is also equipped with a full CameralinkTM interface to directly stream the data to a frame grabber or dedicated image processing unit. The Cheetah camera is completely under software control.

  9. Achieving High Resolution Timer Events in Virtualized Environment.

    Science.gov (United States)

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events.

  10. Reproducible high-resolution multispectral image acquisition in dermatology

    Science.gov (United States)

    Duliu, Alexandru; Gardiazabal, José; Lasser, Tobias; Navab, Nassir

    2015-07-01

    Multispectral image acquisitions are increasingly popular in dermatology, due to their improved spectral resolution which enables better tissue discrimination. Most applications however focus on restricted regions of interest, imaging only small lesions. In this work we present and discuss an imaging framework for high-resolution multispectral imaging on large regions of interest.

  11. High-resolution MRI in detecting subareolar breast abscess.

    Science.gov (United States)

    Fu, Peifen; Kurihara, Yasuyuki; Kanemaki, Yoshihide; Okamoto, Kyoko; Nakajima, Yasuo; Fukuda, Mamoru; Maeda, Ichiro

    2007-06-01

    Because subareolar breast abscess has a high recurrence rate, a more effective imaging technique is needed to comprehensively visualize the lesions and guide surgery. We performed a high-resolution MRI technique using a microscopy coil to reveal the characteristics and extent of subareolar breast abscess. High-resolution MRI has potential diagnostic value in subareolar breast abscess. This technique can be used to guide surgery with the aim of reducing the recurrence rate.

  12. High-speed solar wind flow parameters at 1 AU

    International Nuclear Information System (INIS)

    Feldman, W.C.; Asbridge, J.R.; Bame, S.J.; Gosling, J.T.

    1976-01-01

    To develop a set of constraints for theories of solar wind high-speed streams, a detailed study was made of the fastest streams observed at 1 AU during the time period spanning March 1971 through July 1974. Streams were accepted for study only if (1) the maximum speed exceeded 650 km s -1 ; (2) effects of stream-stream dynamical interaction on the flow parameters could be safely separated from the intrinsic characteristics of the high-speed regions; (3) the full width at half maximum (FWHM) of the stream when mapped back to 20 solar radii by using a constant speed approximation was greater than 45degree in Carrington longitude; and (4) there were no obvious solar-activity-induced contaminating effects. Nineteen streams during this time interval satisfied these criteria. Average parameters at 1 AU for those portions of these streams above V=650 km s -1 are given.Not only is it not presently known why electrons are significantly cooler than the protons within high-speed regions, but also observed particle fluxes and convected energy fluxes for speed greater than 650 km s -1 are substantially larger than those values predicted by any of the existing theories of solar wind high-speed streams. More work is therefore needed in refining present solar wind models to see whether suitable modifications and/or combinations of existing theories based on reasonable coronal conditions can accommodate the above high-speed flow parameters

  13. Depth of interaction resolution measurements for a high resolution PET detector using position sensitive avalanche photodiodes

    International Nuclear Information System (INIS)

    Yang Yongfeng; Dokhale, Purushottam A; Silverman, Robert W; Shah, Kanai S; McClish, Mickel A; Farrell, Richard; Entine, Gerald; Cherry, Simon R

    2006-01-01

    We explore dual-ended read out of LSO arrays with two position sensitive avalanche photodiodes (PSAPDs) as a high resolution, high efficiency depth-encoding detector for PET applications. Flood histograms, energy resolution and depth of interaction (DOI) resolution were measured for unpolished LSO arrays with individual crystal sizes of 1.0, 1.3 and 1.5 mm, and for a polished LSO array with 1.3 mm pixels. The thickness of the crystal arrays was 20 mm. Good flood histograms were obtained for all four arrays, and crystals in all four arrays can be clearly resolved. Although the amplitude of each PSAPD signal decreases as the interaction depth moves further from the PSAPD, the sum of the two PSAPD signals is essentially constant with irradiation depth for all four arrays. The energy resolutions were similar for all four arrays, ranging from 14.7% to 15.4%. A DOI resolution of 3-4 mm (including the width of the irradiation band which is ∼2 mm) was obtained for all the unpolished arrays. The best DOI resolution was achieved with the unpolished 1 mm array (average 3.5 mm). The DOI resolution for the 1.3 mm and 1.5 mm unpolished arrays was 3.7 and 4.0 mm respectively. For the polished array, the DOI resolution was only 16.5 mm. Summing the DOI profiles across all crystals for the 1 mm array only degraded the DOI resolution from 3.5 mm to 3.9 mm, indicating that it may not be necessary to calibrate the DOI response separately for each crystal within an array. The DOI response of individual crystals in the array confirms this finding. These results provide a detailed characterization of the DOI response of these PSAPD-based PET detectors which will be important in the design and calibration of a PET scanner making use of this detector approach

  14. A high-resolution European dataset for hydrologic modeling

    Science.gov (United States)

    Ntegeka, Victor; Salamon, Peter; Gomes, Goncalo; Sint, Hadewij; Lorini, Valerio; Thielen, Jutta

    2013-04-01

    There is an increasing demand for large scale hydrological models not only in the field of modeling the impact of climate change on water resources but also for disaster risk assessments and flood or drought early warning systems. These large scale models need to be calibrated and verified against large amounts of observations in order to judge their capabilities to predict the future. However, the creation of large scale datasets is challenging for it requires collection, harmonization, and quality checking of large amounts of observations. For this reason, only a limited number of such datasets exist. In this work, we present a pan European, high-resolution gridded dataset of meteorological observations (EFAS-Meteo) which was designed with the aim to drive a large scale hydrological model. Similar European and global gridded datasets already exist, such as the HadGHCND (Caesar et al., 2006), the JRC MARS-STAT database (van der Goot and Orlandi, 2003) and the E-OBS gridded dataset (Haylock et al., 2008). However, none of those provide similarly high spatial resolution and/or a complete set of variables to force a hydrologic model. EFAS-Meteo contains daily maps of precipitation, surface temperature (mean, minimum and maximum), wind speed and vapour pressure at a spatial grid resolution of 5 x 5 km for the time period 1 January 1990 - 31 December 2011. It furthermore contains calculated radiation, which is calculated by using a staggered approach depending on the availability of sunshine duration, cloud cover and minimum and maximum temperature, and evapotranspiration (potential evapotranspiration, bare soil and open water evapotranspiration). The potential evapotranspiration was calculated using the Penman-Monteith equation with the above-mentioned meteorological variables. The dataset was created as part of the development of the European Flood Awareness System (EFAS) and has been continuously updated throughout the last years. The dataset variables are used as

  15. High-resolution grids of hourly meteorological variables for Germany

    Science.gov (United States)

    Krähenmann, S.; Walter, A.; Brienen, S.; Imbery, F.; Matzarakis, A.

    2018-02-01

    We present a 1-km2 gridded German dataset of hourly surface climate variables covering the period 1995 to 2012. The dataset comprises 12 variables including temperature, dew point, cloud cover, wind speed and direction, global and direct shortwave radiation, down- and up-welling longwave radiation, sea level pressure, relative humidity and vapour pressure. This dataset was constructed statistically from station data, satellite observations and model data. It is outstanding in terms of spatial and temporal resolution and in the number of climate variables. For each variable, we employed the most suitable gridding method and combined the best of several information sources, including station records, satellite-derived data and data from a regional climate model. A module to estimate urban heat island intensity was integrated for air and dew point temperature. Owing to the low density of available synop stations, the gridded dataset does not capture all variations that may occur at a resolution of 1 km2. This applies to areas of complex terrain (all the variables), and in particular to wind speed and the radiation parameters. To achieve maximum precision, we used all observational information when it was available. This, however, leads to inhomogeneities in station network density and affects the long-term consistency of the dataset. A first climate analysis for Germany was conducted. The Rhine River Valley, for example, exhibited more than 100 summer days in 2003, whereas in 1996, the number was low everywhere in Germany. The dataset is useful for applications in various climate-related studies, hazard management and for solar or wind energy applications and it is available via doi: 10.5676/DWD_CDC/TRY_Basis_v001.

  16. Multi element high resolution scintillator structure

    International Nuclear Information System (INIS)

    Cusano, D.A.

    1980-01-01

    A gamma camera scintillator structure, suitable for detecting high energy gamma photons which, in a single scintillator camera, would require a comparatively thick scintillator crystal, so resulting in unacceptable dispersion of light photons, comprises a collimator array of a high Z material with elongated, parallel wall channels with the scintillator material being disposed in one end of the channels so as to form an integrated collimator/scintillator structure. The collimator channel walls are preferably coated with light reflective material and further light reflective surfaces being translucent to gamma photons, may be provided in each channel. The scintillators may be single crystals or preferably comprise a phosphor dispersed in a thermosetting translucent matrix as disclosed in GB2012800A. The light detectors of the assembled camera may be photomultiplier tubes charge coupled devices or charge injection devices. (author)

  17. Dynamics of High-Resolution Networks

    DEFF Research Database (Denmark)

    Sekara, Vedran

    the unprecedented amounts of information collected by mobile phones to gain detailed insight into the dynamics of social systems. This dissertation presents an unparalleled data collection campaign, collecting highly detailed traces for approximately 1000 people over the course of multiple years. The availability...... are we all affected by an ever changing network structure? Answering these questions will enrich our understanding of ourselves, our organizations, and our societies. Yet, mapping the dynamics of social networks has traditionally been an arduous undertaking. Today, however, it is possible to use...... of such dynamic maps allows us to probe the underlying social network and understand how individuals interact and form lasting friendships. More importantly, these highly detailed dynamic maps provide us new perspectives at traditional problems and allow us to quantify and predict human life....

  18. Evaluating the Value of High Spatial Resolution in National Capacity Expansion Models using ReEDS: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Venkat; Cole, Wesley

    2016-07-01

    Power sector capacity expansion models (CEMs) have a broad range of spatial resolutions. This paper uses the Regional Energy Deployment System (ReEDS) model, a long-term national scale electric sector CEM, to evaluate the value of high spatial resolution for CEMs. ReEDS models the United States with 134 load balancing areas (BAs) and captures the variability in existing generation parameters, future technology costs, performance, and resource availability using very high spatial resolution data, especially for wind and solar modeled at 356 resource regions. In this paper we perform planning studies at three different spatial resolutions--native resolution (134 BAs), state-level, and NERC region level--and evaluate how results change under different levels of spatial aggregation in terms of renewable capacity deployment and location, associated transmission builds, and system costs. The results are used to ascertain the value of high geographically resolved models in terms of their impact on relative competitiveness among renewable energy resources.

  19. A Forward-Looking High-Resolution GPR System

    National Research Council Canada - National Science Library

    Kositsky, Joel; Milanfar, Peyman

    1999-01-01

    A high-resolution ground penetrating radar (GPR) system was designed to help define the optimal radar parameters needed for the efficient standoff detection of buried and surface-laid antitank mines...

  20. High-resolution seismic wave propagation using local time stepping

    KAUST Repository

    Peter, Daniel; Rietmann, Max; Galvez, Percy; Ampuero, Jean Paul

    2017-01-01

    High-resolution seismic wave simulations often require local refinements in numerical meshes to accurately capture e.g. steep topography or complex fault geometry. Together with explicit time schemes, this dramatically reduces the global time step

  1. Impact of high resolution land surface initialization in Indian summer ...

    Indian Academy of Sciences (India)

    The direct impact of high resolution land surface initialization on the forecast bias in a regional climate model in recent years ... surface initialization using a regional climate model. ...... ization of the snow field in a cloud model; J. Clim. Appl.

  2. High spectral resolution X-ray observations of AGN

    NARCIS (Netherlands)

    Kaastra, J.S.

    2008-01-01

    brief overview of some highlights of high spectral resolution X-ray observations of AGN is given, mainly obtained with the RGS of XMM-Newton. Future prospects for such observations with XMM-Newton are given.

  3. NOAA High-Resolution Sea Surface Temperature (SST) Analysis Products

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This archive covers two high resolution sea surface temperature (SST) analysis products developed using an optimum interpolation (OI) technique. The analyses have a...

  4. High-resolution SPECT for small-animal imaging

    International Nuclear Information System (INIS)

    Qi Yujin

    2006-01-01

    This article presents a brief overview of the development of high-resolution SPECT for small-animal imaging. A pinhole collimator has been used for high-resolution animal SPECT to provide better spatial resolution and detection efficiency in comparison with a parallel-hole collimator. The theory of imaging characteristics of the pinhole collimator is presented and the designs of the pinhole aperture are discussed. The detector technologies used for the development of small-animal SPECT and the recent advances are presented. The evolving trend of small-animal SPECT is toward a multi-pinhole and a multi-detector system to obtain a high resolution and also a high detection efficiency. (authors)

  5. Towards high-resolution positron emission tomography for small volumes

    International Nuclear Information System (INIS)

    McKee, B.T.A.

    1982-01-01

    Some arguments are made regarding the medical usefulness of high spatial resolution in positron imaging, even if limited to small imaged volumes. Then the intrinsic limitations to spatial resolution in positron imaging are discussed. The project to build a small-volume, high resolution animal research prototype (SHARP) positron imaging system is described. The components of the system, particularly the detectors, are presented and brief mention is made of data acquisition and image reconstruction methods. Finally, some preliminary imaging results are presented; a pair of isolated point sources and 18 F in the bones of a rabbit. Although the detector system is not fully completed, these first results indicate that the goals of high sensitivity and high resolution (4 mm) have been realized. (Auth.)

  6. A temperature-compensated high spatial resolution distributed strain sensor

    International Nuclear Information System (INIS)

    Belal, Mohammad; Cho, Yuh Tat; Ibsen, Morten; Newson, Trevor P

    2010-01-01

    We propose and demonstrate a scheme which utilizes the temperature dependence of spontaneous Raman scattering to provide temperature compensation for a high spatial resolution Brillouin frequency-based strain sensor

  7. Hurricane Satellite (HURSAT) from Advanced Very High Resolution Radiometer (AVHRR)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Huricane Satellite (HURSAT)-Advanced Very High Resolution Radiometer (AVHRR) is used to extend the HURSAT data set such that appling the Objective Dvorak technique...

  8. NanoComposite Polymers for High Resolution Near Infrared Detectors

    Data.gov (United States)

    National Aeronautics and Space Administration — Develop nanocomposite materials with tuned refractive index in the near infra red spectral range as an index-matched immersion lens for high resolution infra-red...

  9. Scene Classification Using High Spatial Resolution Multispectral Data

    National Research Council Canada - National Science Library

    Garner, Jamada

    2002-01-01

    ...), High-spatial resolution (8-meter), 4-color MSI data from IKONOS provide a new tool for scene classification, The utility of these data are studied for the purpose of classifying the Elkhorn Slough and surrounding wetlands in central...

  10. Methodology of high-resolution photography for mural condition database

    Science.gov (United States)

    Higuchi, R.; Suzuki, T.; Shibata, M.; Taniguchi, Y.

    2015-08-01

    Digital documentation is one of the most useful techniques to record the condition of cultural heritage. Recently, high-resolution images become increasingly useful because it is possible to show general views of mural paintings and also detailed mural conditions in a single image. As mural paintings are damaged by environmental stresses, it is necessary to record the details of painting condition on high-resolution base maps. Unfortunately, the cost of high-resolution photography and the difficulty of operating its instruments and software have commonly been an impediment for researchers and conservators. However, the recent development of graphic software makes its operation simpler and less expensive. In this paper, we suggest a new approach to make digital heritage inventories without special instruments, based on our recent our research project in Üzümlü church in Cappadocia, Turkey. This method enables us to achieve a high-resolution image database with low costs, short time, and limited human resources.

  11. High-resolution esophageal pressure topography for esophageal motility disorders

    OpenAIRE

    Hashem Fakhre Yaseri; Gholamreza Hamsi; Tayeb Ramim

    2016-01-01

    Background: High-resolution manometer (HRM) of the esophagus has become the main diagnostic test in the evaluation of esophageal motility disorders. The development of high-resolution manometry catheters and software displays of manometry recordings in color-coded pressure plots have changed the diagnostic assessment of esophageal disease. The first step of the Chicago classification described abnormal esophagogastric junction deglutitive relaxation. The latest classification system, proposed...

  12. Volumetric expiratory high-resolution CT of the lung

    International Nuclear Information System (INIS)

    Nishino, Mizuki; Hatabu, Hiroto

    2004-01-01

    We developed a volumetric expiratory high-resolution CT (HRCT) protocol that provides combined inspiratory and expiratory volumetric imaging of the lung without increasing radiation exposure, and conducted a preliminary feasibility assessment of this protocol to evaluate diffuse lung disease with small airway abnormalities. The volumetric expiratory high-resolution CT increased the detectability of the conducting airway to the areas of air trapping (P<0.0001), and added significant information about extent and distribution of air trapping (P<0.0001)

  13. Developing Visual Editors for High-Resolution Haptic Patterns

    DEFF Research Database (Denmark)

    Cuartielles, David; Göransson, Andreas; Olsson, Tony

    2012-01-01

    In this article we give an overview of our iterative work in developing visual editors for creating high resolution haptic patterns to be used in wearable, haptic feedback devices. During the past four years we have found the need to address the question of how to represent, construct and edit high...... resolution haptic patterns so that they translate naturally to the user’s haptic experience. To solve this question we have developed and tested several visual editors...

  14. High resolution RGB color line scan camera

    Science.gov (United States)

    Lynch, Theodore E.; Huettig, Fred

    1998-04-01

    A color line scan camera family which is available with either 6000, 8000 or 10000 pixels/color channel, utilizes off-the-shelf lenses, interfaces with currently available frame grabbers, includes on-board pixel by pixel offset correction, and is configurable and controllable via RS232 serial port for computer controlled or stand alone operation is described in this paper. This line scan camera is based on an available 8000 element monochrome line scan camera designed by AOA for OEM use. The new color version includes improvements such as better packaging and additional user features which make the camera easier to use. The heart of the camera is a tri-linear CCD sensor with on-chip color balancing for maximum accuracy and pinned photodiodes for low lag response. Each color channel is digitized to 12 bits and all three channels are multiplexed together so that the resulting camera output video is either a 12 or 8 bit data stream at a rate of up to 24Megpixels/sec. Conversion from 12 to 8 bit, or user-defined gamma, is accomplished by on board user-defined video look up tables. The camera has two user-selectable operating modes; lows speed, high sensitivity mode or high speed, reduced sensitivity mode. The intended uses of the camera include industrial inspection, digital archiving, document scanning, and graphic arts applications.

  15. Evaluating the Value of High Spatial Resolution in National Capacity Expansion Models using ReEDS

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Venkat; Cole, Wesley

    2016-07-18

    This poster is based on the paper of the same name, presented at the IEEE Power & Energy Society General Meeting, July18, 2016. Power sector capacity expansion models (CEMs) have a broad range of spatial resolutions. This paper uses the Regional Energy Deployment System (ReEDS) model, a long-term national scale electric sector CEM, to evaluate the value of high spatial resolution for CEMs. ReEDS models the United States with 134 load balancing areas (BAs) and captures the variability in existing generation parameters, future technology costs, performance, and resource availability using very high spatial resolution data, especially for wind and solar modeled at 356 resource regions. In this paper we perform planning studies at three different spatial resolutions - native resolution (134 BAs), state-level, and NERC region level - and evaluate how results change under different levels of spatial aggregation in terms of renewable capacity deployment and location, associated transmission builds, and system costs. The results are used to ascertain the value of high geographically resolved models in terms of their impact on relative competitiveness among renewable energy resources.

  16. High-resolution gravity model of Venus

    Science.gov (United States)

    Reasenberg, R. D.; Goldberg, Z. M.

    1992-01-01

    The anomalous gravity field of Venus shows high correlation with surface features revealed by radar. We extract gravity models from the Doppler tracking data from the Pioneer Venus Orbiter by means of a two-step process. In the first step, we solve the nonlinear spacecraft state estimation problem using a Kalman filter-smoother. The Kalman filter has been evaluated through simulations. This evaluation and some unusual features of the filter are discussed. In the second step, we perform a geophysical inversion using a linear Bayesian estimator. To allow an unbiased comparison between gravity and topography, we use a simulation technique to smooth and distort the radar topographic data so as to yield maps having the same characteristics as our gravity maps. The maps presented cover 2/3 of the surface of Venus and display the strong topography-gravity correlation previously reported. The topography-gravity scatter plots show two distinct trends.

  17. High resolution computed tomography of auditory ossicles

    International Nuclear Information System (INIS)

    Isono, M.; Murata, K.; Ohta, F.; Yoshida, A.; Ishida, O.; Kinki Univ., Osaka

    1990-01-01

    Auditory ossicular sections were scanned at section thicknesses (mm)/section interspaces (mm) of 1.5/1.5 (61 patients), 1.0/1.0 (13 patients) or 1.5/1.0 (33 patients). At any type of section thickness/interspace, the malleal and incudal structures were observed with almost equal frequency. The region of the incudostapedial joint and each component part of the stapes were shown more frequently at a section interspace of 1.0 mm than at 1.5 mm. The visualization frequency of each auditory ossicular component on two or more serial sections was investigated. At a section thickness/section interspace of 1.5/1.5, the visualization rates were low except for large components such as the head of the malleus and the body of the incus, but at a slice interspace of 1.0 mm, they were high for most components of the auditory ossicles. (orig.)

  18. HIGH RESOLUTION ANALOG / DIGITAL POWER SUPPLY CONTROLLER

    International Nuclear Information System (INIS)

    Medvedko, Evgeny A

    2003-01-01

    Corrector magnets for the SPEAR-3 synchrotron radiation source require precision, high-speed control for use with beam-based orbit feedback. A new Controller Analog/Digital Interface card (CANDI) has been developed for these purposes. The CANDI has a 24-bit DAC for current control and three 24-bit Δ-Σ ADCs to monitor current and voltages. The ADCs can be read and the DAC updated at the 4 kHz rate needed for feedback control. A precision 16-bit DAC provides on-board calibration. Programmable multiplexers control internal signal routing for calibration, testing, and measurement. Feedback can be closed internally on current setpoint, externally on supply current, or beam position. Prototype and production tests are reported in this paper. Noise is better than 17 effective bits in a 10 mHz to 2 kHz bandwidth. Linearity and temperature stability are excellent

  19. A Very High Spatial Resolution Detector for Small Animal PET

    International Nuclear Information System (INIS)

    Kanai Shah, M.S.

    2007-01-01

    Positron Emission Tomography (PET) is an in vivo analog of autoradiography and has the potential to become a powerful new tool in imaging biological processes in small laboratory animals. PET imaging of small animals can provide unique information that can help in advancement of human disease models as well as drug development. Clinical PET scanners used for human imaging are bulky, expensive and do not have adequate spatial resolution for small animal studies. Hence, dedicated, low cost instruments are required for conducting small animal studies with higher spatial resolution than what is currently achieved with clinical as well as dedicated small animal PET scanners. The goal of the proposed project is to investigate a new all solid-state detector design for small animal PET imaging. Exceptionally high spatial resolution, good timing resolution, and excellent energy resolution are expected from the proposed detector design. The Phase I project was aimed at demonstrating the feasibility of producing high performance solid-state detectors that provide high sensitivity, spatial resolution, and timing characteristics. Energy resolution characteristics of the new detector were also investigated. The goal of the Phase II project is to advance the promising solid-state detector technology for small animal PET and determine its full potential. Detectors modules will be built and characterized and finally, a bench-top small animal PET system will be assembled and evaluated

  20. Liquid Scintillation High Resolution Spectral Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.; Grau Malonda, A.

    2010-08-06

    The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

  1. High resolution charmonium spectroscopy with antiprotons

    International Nuclear Information System (INIS)

    Seth, K.K.

    1989-01-01

    The ultimate goal of all physics is to understand the elementary interactions and their manifestations in nature. Remarkable success has been achieved in the understanding of the electromagnetic and weak interactions. However, similar success has eluded the understanding of the strong interactions. Quantum ChromoDynamics, QCD, is the attempt to construct an elementary theory of strong interactions patterned after the highly successful electroweak theory [1]. In this paper, it is claimed that QCD is the theory of strong interactions, and that: hadrons are color singlets made of quarks and antiquarks, each of three colors and (so far) three generations. (u.d), (s.c) and (b.t) and six flavors; the short range WCD interaction is correctly patterned after QED as that due to one-gluon exchange and therefore proportional to 1/r; the additional unique feature of QCD is confinement. It is well approximated by a linear confining potential proportional r. The fact of the matter is that none of the above assertions can be proved. They have to be checked against experimental observations

  2. High spectral resolution image of Barnacle Bill

    Science.gov (United States)

    1997-01-01

    The rover Sojourner's first target for measurement by the Alpha-Proton-Xray Spectrometer (APXS) was the rock named Barnacle Bill, located close to the ramp down which the rover made its egress from the lander. The full spectral capability of the Imager for Mars Pathfinder (IMP), consisting of 13 wavelength filters, was used to characterize the rock's surface. The measured area is relatively dark, and is shown in blue. Nearby on the rock surface, soil material is trapped in pits (shown in red).Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  3. Liquid Scintillation High Resolution Spectral Analysis

    International Nuclear Information System (INIS)

    Grau Carles, A.; Grau Malonda, A.

    2010-01-01

    The CIEMAT/NIST and the TDCR methods in liquid scintillation counting are based on the determination of the efficiency for total counting. This paper tries to expand these methods analysing the pulse-height spectrum of radionuclides. To reach this objective we have to generalize the equations used in the model and to analyse the influence of ionization and chemical quench in both spectra and counting efficiency. We present equations to study the influence of different photomultipliers response in systems with one, two or three photomultipliers. We study the effect of the electronic noise discriminator level in both spectra and counting efficiency. The described method permits one to study problems that up to now was not possible to approach, such as the high uncertainty in the standardization of pure beta-ray emitter with low energy when we apply the TDCR method, or the discrepancies in the standardization of some electron capture radionuclides, when the CIEMAT/NIST method is applied. (Author) 107 refs.

  4. Compact and high-resolution optical orbital angular momentum sorter

    Directory of Open Access Journals (Sweden)

    Chenhao Wan

    2017-03-01

    Full Text Available A compact and high-resolution optical orbital angular momentum (OAM sorter is proposed and demonstrated. The sorter comprises a quadratic fan-out mapper and a dual-phase corrector positioned in the pupil plane and the Fourier plane, respectively. The optical system is greatly simplified compared to previous demonstrations of OAM sorting, and the performance in resolution and efficiency is maintained. A folded configuration is set up using a single reflective spatial light modulator (SLM to demonstrate the validity of the scheme. The two phase elements are implemented on the left and right halves of the SLM and connected by a right-angle prism. Experimental results demonstrate the high resolution of the compact OAM sorter, and the current limit in efficiency can be overcome by replacing with transmissive SLMs and removing the beam splitters. This novel scheme paves the way for the miniaturization and integration of high-resolution OAM sorters.

  5. Methodology for Clustering High-Resolution Spatiotemporal Solar Resource Data

    Energy Technology Data Exchange (ETDEWEB)

    Getman, Dan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lopez, Anthony [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dyson, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-09-01

    In this report, we introduce a methodology to achieve multiple levels of spatial resolution reduction of solar resource data, with minimal impact on data variability, for use in energy systems modeling. The selection of an appropriate clustering algorithm, parameter selection including cluster size, methods of temporal data segmentation, and methods of cluster evaluation are explored in the context of a repeatable process. In describing this process, we illustrate the steps in creating a reduced resolution, but still viable, dataset to support energy systems modeling, e.g. capacity expansion or production cost modeling. This process is demonstrated through the use of a solar resource dataset; however, the methods are applicable to other resource data represented through spatiotemporal grids, including wind data. In addition to energy modeling, the techniques demonstrated in this paper can be used in a novel top-down approach to assess renewable resources within many other contexts that leverage variability in resource data but require reduction in spatial resolution to accommodate modeling or computing constraints.

  6. Extension of least squares spectral resolution algorithm to high-resolution lipidomics data

    International Nuclear Information System (INIS)

    Zeng, Ying-Xu; Mjøs, Svein Are; David, Fabrice P.A.; Schmid, Adrien W.

    2016-01-01

    Lipidomics, which focuses on the global study of molecular lipids in biological systems, has been driven tremendously by technical advances in mass spectrometry (MS) instrumentation, particularly high-resolution MS. This requires powerful computational tools that handle the high-throughput lipidomics data analysis. To address this issue, a novel computational tool has been developed for the analysis of high-resolution MS data, including the data pretreatment, visualization, automated identification, deconvolution and quantification of lipid species. The algorithm features the customized generation of a lipid compound library and mass spectral library, which covers the major lipid classes such as glycerolipids, glycerophospholipids and sphingolipids. Next, the algorithm performs least squares resolution of spectra and chromatograms based on the theoretical isotope distribution of molecular ions, which enables automated identification and quantification of molecular lipid species. Currently, this methodology supports analysis of both high and low resolution MS as well as liquid chromatography-MS (LC-MS) lipidomics data. The flexibility of the methodology allows it to be expanded to support more lipid classes and more data interpretation functions, making it a promising tool in lipidomic data analysis. - Highlights: • A flexible strategy for analyzing MS and LC-MS data of lipid molecules is proposed. • Isotope distribution spectra of theoretically possible compounds were generated. • High resolution MS and LC-MS data were resolved by least squares spectral resolution. • The method proposed compounds that are likely to occur in the analyzed samples. • The proposed compounds matched results from manual interpretation of fragment spectra.

  7. Extension of least squares spectral resolution algorithm to high-resolution lipidomics data

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Ying-Xu [Department of Chemistry, University of Bergen, PO Box 7803, N-5020 Bergen (Norway); Mjøs, Svein Are, E-mail: svein.mjos@kj.uib.no [Department of Chemistry, University of Bergen, PO Box 7803, N-5020 Bergen (Norway); David, Fabrice P.A. [Bioinformatics and Biostatistics Core Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL) and Swiss Institute of Bioinformatics (SIB), Lausanne (Switzerland); Schmid, Adrien W. [Proteomics Core Facility, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne (Switzerland)

    2016-03-31

    Lipidomics, which focuses on the global study of molecular lipids in biological systems, has been driven tremendously by technical advances in mass spectrometry (MS) instrumentation, particularly high-resolution MS. This requires powerful computational tools that handle the high-throughput lipidomics data analysis. To address this issue, a novel computational tool has been developed for the analysis of high-resolution MS data, including the data pretreatment, visualization, automated identification, deconvolution and quantification of lipid species. The algorithm features the customized generation of a lipid compound library and mass spectral library, which covers the major lipid classes such as glycerolipids, glycerophospholipids and sphingolipids. Next, the algorithm performs least squares resolution of spectra and chromatograms based on the theoretical isotope distribution of molecular ions, which enables automated identification and quantification of molecular lipid species. Currently, this methodology supports analysis of both high and low resolution MS as well as liquid chromatography-MS (LC-MS) lipidomics data. The flexibility of the methodology allows it to be expanded to support more lipid classes and more data interpretation functions, making it a promising tool in lipidomic data analysis. - Highlights: • A flexible strategy for analyzing MS and LC-MS data of lipid molecules is proposed. • Isotope distribution spectra of theoretically possible compounds were generated. • High resolution MS and LC-MS data were resolved by least squares spectral resolution. • The method proposed compounds that are likely to occur in the analyzed samples. • The proposed compounds matched results from manual interpretation of fragment spectra.

  8. A multi-channel high-resolution time recorder system

    International Nuclear Information System (INIS)

    Zhang Lingyun; Yang Xiaojun; Song Kezhu; Wang Yanfang

    2004-01-01

    This paper introduces a multi-channel and high-speed time recorder system, which was originally designed to work in the experiments of quantum cryptography research. The novelty of the system is that all the hardware logic is performed by only one FPGA. The system can achieve several desirable features, such as simplicity, high resolution and high processing speed. (authors)

  9. Developing Local Scale, High Resolution, Data to Interface with Numerical Storm Models

    Science.gov (United States)

    Witkop, R.; Becker, A.; Stempel, P.

    2017-12-01

    High resolution, physical storm models that can rapidly predict storm surge, inundation, rainfall, wind velocity and wave height at the intra-facility scale for any storm affecting Rhode Island have been developed by Researchers at the University of Rhode Island's (URI's) Graduate School of Oceanography (GSO) (Ginis et al., 2017). At the same time, URI's Marine Affairs Department has developed methods that inhere individual geographic points into GSO's models and enable the models to accurately incorporate local scale, high resolution data (Stempel et al., 2017). This combination allows URI's storm models to predict any storm's impacts on individual Rhode Island facilities in near real time. The research presented here determines how a coastal Rhode Island town's critical facility managers (FMs) perceive their assets as being vulnerable to quantifiable hurricane-related forces at the individual facility scale and explores methods to elicit this information from FMs in a format usable for incorporation into URI's storm models.

  10. Resolution enhancement of low-quality videos using a high-resolution frame

    Science.gov (United States)

    Pham, Tuan Q.; van Vliet, Lucas J.; Schutte, Klamer

    2006-01-01

    This paper proposes an example-based Super-Resolution (SR) algorithm of compressed videos in the Discrete Cosine Transform (DCT) domain. Input to the system is a Low-Resolution (LR) compressed video together with a High-Resolution (HR) still image of similar content. Using a training set of corresponding LR-HR pairs of image patches from the HR still image, high-frequency details are transferred from the HR source to the LR video. The DCT-domain algorithm is much faster than example-based SR in spatial domain 6 because of a reduction in search dimensionality, which is a direct result of the compact and uncorrelated DCT representation. Fast searching techniques like tree-structure vector quantization 16 and coherence search1 are also key to the improved efficiency. Preliminary results on MJPEG sequence show promising result of the DCT-domain SR synthesis approach.

  11. New detector developments for high resolution positron emission tomography

    International Nuclear Information System (INIS)

    Ziegler, S.I.; Pichler, B.; Lorenz, E.

    1998-01-01

    The strength of quantitative, functional imaging using positron emission tomography, specially in small animals, is limited due to the spatial resolution. Therefore, various tomograph designs employing new scintillators, light sensors, or coincidence electronic are investigated to improve resolution without losses in sensitivity. Luminous scintillators with short light decay time in combination with novel readout schemes using photomultipliers or semiconductor detectors are currently tested by several groups and are implemented in tomographs for small animals. This review summarises the state of development in high resolution positron emission tomography with a detailed description of a system incorporating avalanche photodiode arrays and small scintillation crystals. (orig.) [de

  12. High resolution resistivity measurements at the Down Ampney research site

    International Nuclear Information System (INIS)

    Hallam, J.R.; Jackson, P.D.; Rainsbury, M.; Raines, M.

    1991-01-01

    A new high resolution resistivity surveying method is described for fault detection and characterisation. The resolution is shown to be significantly higher than conventional apparent resistivity profiling when applied to geological discontinuities such as faults. Nominal fault locations have been determined to an accuracy of 0.5 m, as proven by drilling. Two dimensional profiling and image enhancement of the resulting 2-D data set indicated the possibility of subsidiary fractures and/or lateral changes within the clay to clay' fault zone. The increased resolution allows greater confidence to be placed on both the fault detection and lateral perturbations derived from processed resistance and resistivity images. (Author)

  13. Performance of a high resolution cavity beam position monitor system

    Science.gov (United States)

    Walston, Sean; Boogert, Stewart; Chung, Carl; Fitsos, Pete; Frisch, Joe; Gronberg, Jeff; Hayano, Hitoshi; Honda, Yosuke; Kolomensky, Yury; Lyapin, Alexey; Malton, Stephen; May, Justin; McCormick, Douglas; Meller, Robert; Miller, David; Orimoto, Toyoko; Ross, Marc; Slater, Mark; Smith, Steve; Smith, Tonee; Terunuma, Nobuhiro; Thomson, Mark; Urakawa, Junji; Vogel, Vladimir; Ward, David; White, Glen

    2007-07-01

    It has been estimated that an RF cavity Beam Position Monitor (BPM) could provide a position measurement resolution of less than 1 nm. We have developed a high resolution cavity BPM and associated electronics. A triplet comprised of these BPMs was installed in the extraction line of the Accelerator Test Facility (ATF) at the High Energy Accelerator Research Organization (KEK) for testing with its ultra-low emittance beam. The three BPMs were each rigidly mounted inside an alignment frame on six variable-length struts which could be used to move the BPMs in position and angle. We have developed novel methods for extracting the position and tilt information from the BPM signals including a robust calibration algorithm which is immune to beam jitter. To date, we have demonstrated a position resolution of 15.6 nm and a tilt resolution of 2.1 μrad over a dynamic range of approximately ±20 μm.

  14. High-resolution spectroscopy of gases for industrial applications

    DEFF Research Database (Denmark)

    Fateev, Alexander; Clausen, Sønnik

    High-resolution spectroscopy of gases is a powerful technique which has various fundamental and practical applications: in situ simultaneous measurements of gas temperature and gas composition, radiative transfer modeling, validation of existing and developing of new databases and etc. Existing...... databases (e.g. HITRAN, HITEMP or CDSD) can normally be used for absorption spectra calculations at limited temperature/pressure ranges. Therefore experimental measurements of absorption/transmission spectra gases (e.g. CO2, H2O or SO2) at high-resolution and elevated temperatures are essential both...... for analysis of complex experimental data and further development of the databases. High-temperature gas cell facilities available at DTU Chemical Engineering are presented and described. The gas cells and high-resolution spectrometers allow us to perform high-quality reference measurements of gases relevant...

  15. Isotope specific resolution recovery image reconstruction in high resolution PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kotasidis, Fotis A. [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva, Switzerland and Wolfson Molecular Imaging Centre, MAHSC, University of Manchester, M20 3LJ, Manchester (United Kingdom); Angelis, Georgios I. [Faculty of Health Sciences, Brain and Mind Research Institute, University of Sydney, NSW 2006, Sydney (Australia); Anton-Rodriguez, Jose; Matthews, Julian C. [Wolfson Molecular Imaging Centre, MAHSC, University of Manchester, Manchester M20 3LJ (United Kingdom); Reader, Andrew J. [Montreal Neurological Institute, McGill University, Montreal QC H3A 2B4, Canada and Department of Biomedical Engineering, Division of Imaging Sciences and Biomedical Engineering, King' s College London, St. Thomas’ Hospital, London SE1 7EH (United Kingdom); Zaidi, Habib [Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211 Geneva (Switzerland); Geneva Neuroscience Centre, Geneva University, CH-1205 Geneva (Switzerland); Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, PO Box 30 001, Groningen 9700 RB (Netherlands)

    2014-05-15

    Purpose: Measuring and incorporating a scanner-specific point spread function (PSF) within image reconstruction has been shown to improve spatial resolution in PET. However, due to the short half-life of clinically used isotopes, other long-lived isotopes not used in clinical practice are used to perform the PSF measurements. As such, non-optimal PSF models that do not correspond to those needed for the data to be reconstructed are used within resolution modeling (RM) image reconstruction, usually underestimating the true PSF owing to the difference in positron range. In high resolution brain and preclinical imaging, this effect is of particular importance since the PSFs become more positron range limited and isotope-specific PSFs can help maximize the performance benefit from using resolution recovery image reconstruction algorithms. Methods: In this work, the authors used a printing technique to simultaneously measure multiple point sources on the High Resolution Research Tomograph (HRRT), and the authors demonstrated the feasibility of deriving isotope-dependent system matrices from fluorine-18 and carbon-11 point sources. Furthermore, the authors evaluated the impact of incorporating them within RM image reconstruction, using carbon-11 phantom and clinical datasets on the HRRT. Results: The results obtained using these two isotopes illustrate that even small differences in positron range can result in different PSF maps, leading to further improvements in contrast recovery when used in image reconstruction. The difference is more pronounced in the centre of the field-of-view where the full width at half maximum (FWHM) from the positron range has a larger contribution to the overall FWHM compared to the edge where the parallax error dominates the overall FWHM. Conclusions: Based on the proposed methodology, measured isotope-specific and spatially variant PSFs can be reliably derived and used for improved spatial resolution and variance performance in resolution

  16. Isotope specific resolution recovery image reconstruction in high resolution PET imaging

    International Nuclear Information System (INIS)

    Kotasidis, Fotis A.; Angelis, Georgios I.; Anton-Rodriguez, Jose; Matthews, Julian C.; Reader, Andrew J.; Zaidi, Habib

    2014-01-01

    Purpose: Measuring and incorporating a scanner-specific point spread function (PSF) within image reconstruction has been shown to improve spatial resolution in PET. However, due to the short half-life of clinically used isotopes, other long-lived isotopes not used in clinical practice are used to perform the PSF measurements. As such, non-optimal PSF models that do not correspond to those needed for the data to be reconstructed are used within resolution modeling (RM) image reconstruction, usually underestimating the true PSF owing to the difference in positron range. In high resolution brain and preclinical imaging, this effect is of particular importance since the PSFs become more positron range limited and isotope-specific PSFs can help maximize the performance benefit from using resolution recovery image reconstruction algorithms. Methods: In this work, the authors used a printing technique to simultaneously measure multiple point sources on the High Resolution Research Tomograph (HRRT), and the authors demonstrated the feasibility of deriving isotope-dependent system matrices from fluorine-18 and carbon-11 point sources. Furthermore, the authors evaluated the impact of incorporating them within RM image reconstruction, using carbon-11 phantom and clinical datasets on the HRRT. Results: The results obtained using these two isotopes illustrate that even small differences in positron range can result in different PSF maps, leading to further improvements in contrast recovery when used in image reconstruction. The difference is more pronounced in the centre of the field-of-view where the full width at half maximum (FWHM) from the positron range has a larger contribution to the overall FWHM compared to the edge where the parallax error dominates the overall FWHM. Conclusions: Based on the proposed methodology, measured isotope-specific and spatially variant PSFs can be reliably derived and used for improved spatial resolution and variance performance in resolution

  17. Isotope specific resolution recovery image reconstruction in high resolution PET imaging.

    Science.gov (United States)

    Kotasidis, Fotis A; Angelis, Georgios I; Anton-Rodriguez, Jose; Matthews, Julian C; Reader, Andrew J; Zaidi, Habib

    2014-05-01

    Measuring and incorporating a scanner-specific point spread function (PSF) within image reconstruction has been shown to improve spatial resolution in PET. However, due to the short half-life of clinically used isotopes, other long-lived isotopes not used in clinical practice are used to perform the PSF measurements. As such, non-optimal PSF models that do not correspond to those needed for the data to be reconstructed are used within resolution modeling (RM) image reconstruction, usually underestimating the true PSF owing to the difference in positron range. In high resolution brain and preclinical imaging, this effect is of particular importance since the PSFs become more positron range limited and isotope-specific PSFs can help maximize the performance benefit from using resolution recovery image reconstruction algorithms. In this work, the authors used a printing technique to simultaneously measure multiple point sources on the High Resolution Research Tomograph (HRRT), and the authors demonstrated the feasibility of deriving isotope-dependent system matrices from fluorine-18 and carbon-11 point sources. Furthermore, the authors evaluated the impact of incorporating them within RM image reconstruction, using carbon-11 phantom and clinical datasets on the HRRT. The results obtained using these two isotopes illustrate that even small differences in positron range can result in different PSF maps, leading to further improvements in contrast recovery when used in image reconstruction. The difference is more pronounced in the centre of the field-of-view where the full width at half maximum (FWHM) from the positron range has a larger contribution to the overall FWHM compared to the edge where the parallax error dominates the overall FWHM. Based on the proposed methodology, measured isotope-specific and spatially variant PSFs can be reliably derived and used for improved spatial resolution and variance performance in resolution recovery image reconstruction. The

  18. Two high-frequency mutual inductance bridges with high resolution

    NARCIS (Netherlands)

    Flokstra, Jakob; Gerritsma, G.J.; Kreuwel, H.J.M.; van der Marel, L.C.

    1980-01-01

    Two mutual inductance bridges are described for operation up to about 100 kHz. Special attention is paid to the sensitivity and resolution of the bridges. Both bridges can be used to measure variations of about 10 pH in the mutual inductance. The first bridge consists of passive elements only

  19. A high resolution large dynamic range TDC circuit implementation

    International Nuclear Information System (INIS)

    Lei Wuhu; Liu Songqiu; Ye Weiguo; Han Hui; Li Pengyu

    2003-01-01

    Time measurement technology is usually used in nuclear experimentation. There are many methods of time measurement. The implementation method of Time to Digital Conversion (TDC) by means of electronic is a classical technology. The range and resolution of TDC is different according with different usage. A wide range and high resolution TDC circuit, including its theory and implementation way, is introduced in this paper. The test result is also given. (authors)

  20. A high resolution large dynamic range TDC circuit implementation

    International Nuclear Information System (INIS)

    Lei Wuhu; Liu Songqiu; Li Pengyu; Han Hui; Ye Yanlin

    2005-01-01

    Time measurement technology is usually used in nuclear experimentation. There are many methods of time measurement. The implementation method of Time to Digital Conversion (TDC) by means of electronics is a classical technology. The range and resolution of TDC is different according with different usage. A wide range and high resolution TDC circuit, including its theory and implementation way, is introduced in this paper. The test result is also given. (authors)

  1. Infrared emission high spectral resolution atlas of the stratospheric limb

    Science.gov (United States)

    Maguire, William C.; Kunde, Virgil G.; Herath, Lawrence W.

    1989-01-01

    An atlas of high resolution infrared emission spectra identifies a number of gaseous atmospheric features significant to stratospheric chemistry in the 770-900/cm and 1100-1360/cm regions at six zenith angles from 86.7 to 95.1 deg. A balloon-borne Michelson interferometer was flown to obtain about 0.03/cm resolution spectra. Two 10/cm extracts are presented here.

  2. Gamma-Ray Imager With High Spatial And Spectral Resolution

    Science.gov (United States)

    Callas, John L.; Varnell, Larry S.; Wheaton, William A.; Mahoney, William A.

    1996-01-01

    Gamma-ray instrument developed to enable both two-dimensional imaging at relatively high spatial resolution and spectroscopy at fractional-photon-energy resolution of about 10 to the negative 3rd power in photon-energy range from 10 keV to greater than 10 MeV. In its spectroscopic aspect, instrument enables identification of both narrow and weak gamma-ray spectral peaks.

  3. High-resolution regional climate model evaluation using variable-resolution CESM over California

    Science.gov (United States)

    Huang, X.; Rhoades, A.; Ullrich, P. A.; Zarzycki, C. M.

    2015-12-01

    Understanding the effect of climate change at regional scales remains a topic of intensive research. Though computational constraints remain a problem, high horizontal resolution is needed to represent topographic forcing, which is a significant driver of local climate variability. Although regional climate models (RCMs) have traditionally been used at these scales, variable-resolution global climate models (VRGCMs) have recently arisen as an alternative for studying regional weather and climate allowing two-way interaction between these domains without the need for nudging. In this study, the recently developed variable-resolution option within the Community Earth System Model (CESM) is assessed for long-term regional climate modeling over California. Our variable-resolution simulations will focus on relatively high resolutions for climate assessment, namely 28km and 14km regional resolution, which are much more typical for dynamically downscaled studies. For comparison with the more widely used RCM method, the Weather Research and Forecasting (WRF) model will be used for simulations at 27km and 9km. All simulations use the AMIP (Atmospheric Model Intercomparison Project) protocols. The time period is from 1979-01-01 to 2005-12-31 (UTC), and year 1979 was discarded as spin up time. The mean climatology across California's diverse climate zones, including temperature and precipitation, is analyzed and contrasted with the Weather Research and Forcasting (WRF) model (as a traditional RCM), regional reanalysis, gridded observational datasets and uniform high-resolution CESM at 0.25 degree with the finite volume (FV) dynamical core. The results show that variable-resolution CESM is competitive in representing regional climatology on both annual and seasonal time scales. This assessment adds value to the use of VRGCMs for projecting climate change over the coming century and improve our understanding of both past and future regional climate related to fine

  4. Highly reliable wind-rolling triboelectric nanogenerator operating in a wide wind speed range

    Science.gov (United States)

    Yong, Hyungseok; Chung, Jihoon; Choi, Dukhyun; Jung, Daewoong; Cho, Minhaeng; Lee, Sangmin

    2016-01-01

    Triboelectric nanogenerators are aspiring energy harvesting methods that generate electricity from the triboelectric effect and electrostatic induction. This study demonstrates the harvesting of wind energy by a wind-rolling triboelectric nanogenerator (WR-TENG). The WR-TENG generates electricity from wind as a lightweight dielectric sphere rotates along the vortex whistle substrate. Increasing the kinetic energy of a dielectric converted from the wind energy is a key factor in fabricating an efficient WR-TENG. Computation fluid dynamics (CFD) analysis is introduced to estimate the precise movements of wind flow and to create a vortex flow by adjusting the parameters of the vortex whistle shape to optimize the design parameters to increase the kinetic energy conversion rate. WR-TENG can be utilized as both a self-powered wind velocity sensor and a wind energy harvester. A single unit of WR-TENG produces open-circuit voltage of 11.2 V and closed-circuit current of 1.86 μA. Additionally, findings reveal that the electrical power is enhanced through multiple electrode patterns in a single device and by increasing the number of dielectric spheres inside WR-TENG. The wind-rolling TENG is a novel approach for a sustainable wind-driven TENG that is sensitive and reliable to wind flows to harvest wasted wind energy in the near future. PMID:27653976

  5. Validation of High-resolution Climate Simulations over Northern Europe.

    Science.gov (United States)

    Muna, R. A.

    2005-12-01

    Two AMIP2-type (Gates 1992) experiments have been performed with climate versions of ARPEGE/IFS model examine for North Atlantic North Europe, and Norwegian region and analyzed the effect of increasing resolution on the simulated biases. The ECMWF reanalysis or ERA-15 has been used to validate the simulations. Each of the simulations is an integration of the period 1979 to 1996. The global simulations used observed monthly mean sea surface temperatures (SST) as lower boundary condition. All aspects but the horizontal resolutions are similar in the two simulations. The first simulation has a uniform horizontal resolution of T63L. The second one has a variable resolution (T106Lc3) with the highest resolution in the Norwegian Sea. Both simulations have 31 vertical layers in the same locations. For each simulation the results were divided into two seasons: winter (DJF) and summer (JJA). The parameters investigated were mean sea level pressure, geopotential and temperature at 850 hPa and 500 hPa. To find out the causes of temperature bias during summer, latent and sensible heat flux, total cloud cover and total precipitation were analyzed. The high-resolution simulation exhibits more or less realistic climate over Nordic, Artic and European region. The overall performance of the simulations shows improvements of generally all fields investigated with increasing resolution over the target area both in winter (DJF) and summer (JJA).

  6. Automated data processing of high-resolution mass spectra

    DEFF Research Database (Denmark)

    Hansen, Michael Adsetts Edberg; Smedsgaard, Jørn

    of the massive amounts of data. We present an automated data processing method to quantitatively compare large numbers of spectra from the analysis of complex mixtures, exploiting the full quality of high-resolution mass spectra. By projecting all detected ions - within defined intervals on both the time...... infusion of crude extracts into the source taking advantage of the high sensitivity, high mass resolution and accuracy and the limited fragmentation. Unfortunately, there has not been a comparable development in the data processing techniques to fully exploit gain in high resolution and accuracy...... infusion analyses of crude extract to find the relationship between species from several species terverticillate Penicillium, and also that the ions responsible for the segregation can be identified. Furthermore the process can automate the process of detecting unique species and unique metabolites....

  7. High resolution manometry findings in patients with esophageal epiphrenic diverticula.

    Science.gov (United States)

    Vicentine, Fernando P P; Herbella, Fernando A M; Silva, Luciana C; Patti, Marco G

    2011-12-01

    The pathophysiology of esophageal epiphrenic diverticula is still uncertain even though a concomitant motility disorder is found in the majority of patients in different series. High resolution manometry may allow detection of motor abnormalities in a higher number of patients with esophageal epiphrenic diverticula compared with conventional manometry. This study aims to evaluate the high resolution manometry findings in patients with esophageal epiphrenic diverticula. Nine individuals (mean age 63 ± 10 years, 4 females) with esophageal epiphrenic diverticula underwent high resolution manometry. A single diverticulum was observed in eight patients and multiple diverticula in one. Visual analysis of conventional tracings and color pressure plots for identification of segmental abnormalities was performed by two researchers experienced in high resolution manometry. Upper esophageal sphincter was normal in all patients. Esophageal body was abnormal in eight patients; lower esophageal sphincter was abnormal in seven patients. Named esophageal motility disorders were found in seven patients: achalasia in six, diffuse esophageal spasm in one. In one patient, a segmental hypercontractile zone was noticed with pressure of 196 mm Hg. High resolution manometry demonstrated motor abnormalities in all patients with esophageal epiphrenic diverticula.

  8. High-resolution WRF-LES simulations for real episodes: A case study for prealpine terrain

    Science.gov (United States)

    Hald, Cornelius; Mauder, Matthias; Laux, Patrick; Kunstmann, Harald

    2017-04-01

    While in most large or regional scale weather and climate models turbulence is parametrized, LES (Large Eddy Simulation) allows for the explicit modeling of turbulent structures in the atmosphere. With the exponential growth in available computing power the technique has become more and more applicable, yet it has mostly been used to model idealized scenarios. It is investigated how well WRF-LES can represent small scale weather patterns. The results are evaluated against different hydrometeorological measurements. We use WRF-LES to model the diurnal cycle for a 48 hour episode in summer over moderately complex terrain in southern Germany. The model setup uses a high resolution digital elevation model, land use and vegetation map. The atmospheric boundary conditions are set by reanalysis data. Schemes for radiation and microphysics and a land-surface model are employed. The biggest challenge in modeling arises from the high horizontal resolution of dx = 30m, since the subgrid-scale model then requires a vertical resolution dz ≈ 10m for optimal results. We observe model instabilities and present solutions like smoothing of the surface input data, careful positioning of the model domain and shortening of the model time step down to a twentieth of a second. Model results are compared to an array of various instruments including eddy covariance stations, LIDAR, RASS, SODAR, weather stations and unmanned aerial vehicles. All instruments are part of the TERENO pre-Alpine area and were employed in the orchestrated measurement campaign ScaleX in July 2015. Examination of the results show reasonable agreement between model and measurements in temperature- and moisture profiles. Modeled wind profiles are highly dependent on the vertical resolution and are in accordance with measurements only at higher wind speeds. A direct comparison of turbulence is made difficult by the purely statistical character of turbulent motions in the model.

  9. High resolution, position sensitive detector for energetic particle beams

    International Nuclear Information System (INIS)

    Marsh, E.P.; Strathman, M.D.; Reed, D.A.; Odom, R.W.; Morse, D.H.; Pontau, A.E.

    1993-01-01

    The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10 10 ), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 μm for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 μm) with an image resolution of better than 0.5 μm has since been developed and its design is presented. (orig.)

  10. High resolution, position sensitive detector for energetic particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, E P [Charles Evans and Associates, Redwood City, CA (United States); Strathman, M D [Charles Evans and Associates, Redwood City, CA (United States); Reed, D A [Charles Evans and Associates, Redwood City, CA (United States); Odom, R W [Charles Evans and Associates, Redwood City, CA (United States); Morse, D H [Sandia National Labs., Livermore, CA (United States); Pontau, A E [Sandia National Labs., Livermore, CA (United States)

    1993-05-01

    The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates a wide dynamic range (>10[sup 10]), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 [mu]m for a field of view of 1 mm has been reported. A higher resolution detector for imaging small beams (<50 [mu]m) with an image resolution of better than 0.5 [mu]m has since been developed and its design is presented. (orig.)

  11. High penetration wind generation impacts on spot prices in the Australian national electricity market

    International Nuclear Information System (INIS)

    Cutler, Nicholas J.; Boerema, Nicholas D.; MacGill, Iain F.; Outhred, Hugh R.

    2011-01-01

    This paper explores wind power integration issues for the South Australian (SA) region of the Australian National Electricity Market (NEM) by assessing the interaction of regional wind generation, electricity demand and spot prices over 2 recent years of market operation. SA's wind energy penetration has recently surpassed 20% and it has only a limited interconnection with other regions of the NEM. As such, it represents an interesting example of high wind penetration in a gross wholesale pool market electricity industry. Our findings suggest that while electricity demand continues to have the greatest influence on spot prices in SA, wind generation levels have become a significant secondary influence, and there is an inverse relationship between wind generation and price. No clear relationship between wind generation and demand has been identified although some periods of extremely high demand may coincide with lower wind generation. Periods of high wind output are associated with generally lower market prices, and also appear to contribute to extreme negative price events. The results highlight the importance of electricity market and renewable policy design in facilitating economically efficient high wind penetrations. - Highlights: → In South Australia (SA) wind generation is having an influence on market prices. → Little or no correlation is found between wind generation and demand. → Wind farms in SA are receiving a lower average price than in other States. → The results highlight the importance of appropriate electricity market design.

  12. Los Angeles megacity: a high-resolution land–atmosphere modelling system for urban CO2 emissions

    Directory of Open Access Journals (Sweden)

    S. Feng

    2016-07-01

    Full Text Available Megacities are major sources of anthropogenic fossil fuel CO2 (FFCO2 emissions. The spatial extents of these large urban systems cover areas of 10 000 km2 or more with complex topography and changing landscapes. We present a high-resolution land–atmosphere modelling system for urban CO2 emissions over the Los Angeles (LA megacity area. The Weather Research and Forecasting (WRF-Chem model was coupled to a very high-resolution FFCO2 emission product, Hestia-LA, to simulate atmospheric CO2 concentrations across the LA megacity at spatial resolutions as fine as  ∼  1 km. We evaluated multiple WRF configurations, selecting one that minimized errors in wind speed, wind direction, and boundary layer height as evaluated by its performance against meteorological data collected during the CalNex-LA campaign (May–June 2010. Our results show no significant difference between moderate-resolution (4 km and high-resolution (1.3 km simulations when evaluated against surface meteorological data, but the high-resolution configurations better resolved planetary boundary layer heights and vertical gradients in the horizontal mean winds. We coupled our WRF configuration with the Vulcan 2.2 (10 km resolution and Hestia-LA (1.3 km resolution fossil fuel CO2 emission products to evaluate the impact of the spatial resolution of the CO2 emission products and the meteorological transport model on the representation of spatiotemporal variability in simulated atmospheric CO2 concentrations. We find that high spatial resolution in the fossil fuel CO2 emissions is more important than in the atmospheric model to capture CO2 concentration variability across the LA megacity. Finally, we present a novel approach that employs simultaneous correlations of the simulated atmospheric CO2 fields to qualitatively evaluate the greenhouse gas measurement network over the LA megacity. Spatial correlations in the atmospheric CO2 fields reflect the coverage of

  13. High-resolution investigations of edge effects in neutron imaging

    International Nuclear Information System (INIS)

    Strobl, M.; Kardjilov, N.; Hilger, A.; Kuehne, G.; Frei, G.; Manke, I.

    2009-01-01

    Edge enhancement is the main effect measured by the so-called inline or propagation-based neutron phase contrast imaging method. The effect has originally been explained by diffraction, and high spatial coherence has been claimed to be a necessary precondition. However, edge enhancement has also been found in conventional imaging with high resolution. In such cases the effects can produce artefacts and hinder quantification. In this letter the edge effects at cylindrical shaped samples and long straight edges have been studied in detail. The enhancement can be explained by refraction and total reflection. Using high-resolution imaging, where spatial resolutions better than 50 μm could be achieved, refraction and total reflection peaks - similar to diffraction patterns - could be separated and distinguished.

  14. 1024 matrix image reconstruction: usefulness in high resolution chest CT

    International Nuclear Information System (INIS)

    Jeong, Sun Young; Chung, Myung Jin; Chong, Se Min; Sung, Yon Mi; Lee, Kyung Soo

    2006-01-01

    We tried to evaluate whether high resolution chest CT with a 1,024 matrix has a significant advantage in image quality compared to a 512 matrix. Each set of 512 and 1024 matrix high resolution chest CT scans with both 0.625 mm and 1.25 mm slice thickness were obtained from 26 patients. Seventy locations that contained twenty-four low density lesions without sharp boundary such as emphysema, and forty-six sharp linear densities such as linear fibrosis were selected; these were randomly displayed on a five mega pixel LCD monitor. All the images were masked for information concerning the matrix size and slice thickness. Two chest radiologists scored the image quality of each ar rowed lesion as follows: (1) undistinguishable, (2) poorly distinguishable, (3) fairly distinguishable, (4) well visible and (5) excellently visible. The scores were compared from the aspects of matrix size, slice thickness and the different observers by using ANOVA tests. The average and standard deviation of image quality were 3.09 (± .92) for the 0.625 mm x 512 matrix, 3.16 (± .84) for the 0.625 mm x 1024 matrix, 2.49 (± 1.02) for the 1.25 mm x 512 matrix, and 2.35 (± 1.02) for the 1.25 mm x 1024 matrix, respectively. The image quality on both matrices of the high resolution chest CT scans with a 0.625 mm slice thickness was significantly better than that on the 1.25 mm slice thickness (ρ < 0.001). However, the image quality on the 1024 matrix high resolution chest CT scans was not significantly different from that on the 512 matrix high resolution chest CT scans (ρ = 0.678). The interobserver variation between the two observers was not significant (ρ = 0.691). We think that 1024 matrix image reconstruction for high resolution chest CT may not be clinical useful

  15. Coordinated Frequency Control of Wind Turbines in Power Systems with High Wind Power Penetration

    DEFF Research Database (Denmark)

    Tarnowski, Germán Claudio

    The integration of large amounts of wind power in power systems presents huge challenges. In particular, with the increase of wind power generation, more regulation reserves would be necessary, the capability of the power system to offer conventional regulating power would be reduced...... particular views. These models were developed and verified during this work, basedaround a particular manufacturer’s wind turbine and on said isolated power system withwind power. The capability of variable speed wind turbines for providing Inertial Response is analysed. To perform this assessment, a control...... generation were studied considering a large share of wind power in the system. Results show the abilities of the architectures to manage the variability of the generated wind power, reducing the impact on the grid frequency and providing suitable frequency regulation service when required. The coordination...

  16. SPECTRA OF STRONG MAGNETOHYDRODYNAMIC TURBULENCE FROM HIGH-RESOLUTION SIMULATIONS

    International Nuclear Information System (INIS)

    Beresnyak, Andrey

    2014-01-01

    Magnetohydrodynamic (MHD) turbulence is present in a variety of solar and astrophysical environments. Solar wind fluctuations with frequencies lower than 0.1 Hz are believed to be mostly governed by Alfvénic turbulence with particle transport depending on the power spectrum and the anisotropy of such turbulence. Recently, conflicting spectral slopes for the inertial range of MHD turbulence have been reported by different groups. Spectral shapes from earlier simulations showed that MHD turbulence is less scale-local compared with hydrodynamic turbulence. This is why higher-resolution simulations, and careful and rigorous numerical analysis is especially needed for the MHD case. In this Letter, we present two groups of simulations with resolution up to 4096 3 , which are numerically well-resolved and have been analyzed with an exact and well-tested method of scaling study. Our results from both simulation groups indicate that the asymptotic power spectral slope for all energy-related quantities, such as total energy and residual energy, is around –1.7, close to Kolmogorov's –5/3. This suggests that residual energy is a constant fraction of the total energy and that in the asymptotic regime of Alfvénic turbulence magnetic and kinetic spectra have the same scaling. The –1.5 slope for energy and the –2 slope for residual energy, which have been suggested earlier, are incompatible with our numerics

  17. Multi-resolution voxel phantom modeling: a high-resolution eye model for computational dosimetry.

    Science.gov (United States)

    Caracappa, Peter F; Rhodes, Ashley; Fiedler, Derek

    2014-09-21

    Voxel models of the human body are commonly used for simulating radiation dose with a Monte Carlo radiation transport code. Due to memory limitations, the voxel resolution of these computational phantoms is typically too large to accurately represent the dimensions of small features such as the eye. Recently reduced recommended dose limits to the lens of the eye, which is a radiosensitive tissue with a significant concern for cataract formation, has lent increased importance to understanding the dose to this tissue. A high-resolution eye model is constructed using physiological data for the dimensions of radiosensitive tissues, and combined with an existing set of whole-body models to form a multi-resolution voxel phantom, which is used with the MCNPX code to calculate radiation dose from various exposure types. This phantom provides an accurate representation of the radiation transport through the structures of the eye. Two alternate methods of including a high-resolution eye model within an existing whole-body model are developed. The accuracy and performance of each method is compared against existing computational phantoms.

  18. High resolution Moessbauer spectroscopy with 67Zn in metallic systems

    International Nuclear Information System (INIS)

    Potzel, W.

    1985-01-01

    Moessbauer experiments on metallic systems are described where the high resolution 93.3 keV resonance in 67 Zn is used. In the first part, the Cu-Zn alloy system is investigated and the high energy resolution of this Moessbauer transition is employed to determine small changes of the s-electron density at the 67 Zn nucleus when the Zn concentration is changed. In the second part, Zn metal is taken as an example to demonstrate that the 93.3 keV transition is also extremely sensitive to small changes of lattice dynamical effects. 7 refs., 18 figs. (author)

  19. High spatial resolution CT image reconstruction using parallel computing

    International Nuclear Information System (INIS)

    Yin Yin; Liu Li; Sun Gongxing

    2003-01-01

    Using the PC cluster system with 16 dual CPU nodes, we accelerate the FBP and OR-OSEM reconstruction of high spatial resolution image (2048 x 2048). Based on the number of projections, we rewrite the reconstruction algorithms into parallel format and dispatch the tasks to each CPU. By parallel computing, the speedup factor is roughly equal to the number of CPUs, which can be up to about 25 times when 25 CPUs used. This technique is very suitable for real-time high spatial resolution CT image reconstruction. (authors)

  20. Progress in high-resolution x-ray holographic microscopy

    International Nuclear Information System (INIS)

    Jacobsen, C.; Kirz, J.; Howells, M.; McQuaid, K.; Rothman, S.; Feder, R.; Sayre, D.

    1987-07-01

    Among the various types of x-ray microscopes that have been demonstrated, the holographic microscope has had the largest gap between promise and performance. The difficulties of fabricating x-ray optical elements have led some to view holography as the most attractive method for obtaining the ultimate in high resolution x-ray micrographs; however, we know of no investigations prior to 1987 that clearly demonstrated submicron resolution in reconstructed images. Previous efforts suffered from problems such as limited resolution and dynamic range in the recording media, low coherent x-ray flux, and aberrations and diffraction limits in visible light reconstruction. We have addressed the recording limitations through the use of an undulator x-ray source and high-resolution photoresist recording media. For improved results in the readout and reconstruction steps, we have employed metal shadowing and transmission electron microscopy, along with numerical reconstruction techniques. We believe that this approach will allow holography to emerge as a practical method of high-resolution x-ray microscopy. 30 refs., 4 figs

  1. Progress in high-resolution x-ray holographic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, C.; Kirz, J.; Howells, M.; McQuaid, K.; Rothman, S.; Feder, R.; Sayre, D.

    1987-07-01

    Among the various types of x-ray microscopes that have been demonstrated, the holographic microscope has had the largest gap between promise and performance. The difficulties of fabricating x-ray optical elements have led some to view holography as the most attractive method for obtaining the ultimate in high resolution x-ray micrographs; however, we know of no investigations prior to 1987 that clearly demonstrated submicron resolution in reconstructed images. Previous efforts suffered from problems such as limited resolution and dynamic range in the recording media, low coherent x-ray flux, and aberrations and diffraction limits in visible light reconstruction. We have addressed the recording limitations through the use of an undulator x-ray source and high-resolution photoresist recording media. For improved results in the readout and reconstruction steps, we have employed metal shadowing and transmission electron microscopy, along with numerical reconstruction techniques. We believe that this approach will allow holography to emerge as a practical method of high-resolution x-ray microscopy. 30 refs., 4 figs.

  2. Quantifying and containing the curse of high resolution coronal imaging

    Directory of Open Access Journals (Sweden)

    V. Delouille

    2008-10-01

    Full Text Available Future missions such as Solar Orbiter (SO, InterHelioprobe, or Solar Probe aim at approaching the Sun closer than ever before, with on board some high resolution imagers (HRI having a subsecond cadence and a pixel area of about (80 km2 at the Sun during perihelion. In order to guarantee their scientific success, it is necessary to evaluate if the photon counts available at these resolution and cadence will provide a sufficient signal-to-noise ratio (SNR. For example, if the inhomogeneities in the Quiet Sun emission prevail at higher resolution, one may hope to locally have more photon counts than in the case of a uniform source. It is relevant to quantify how inhomogeneous the quiet corona will be for a pixel pitch that is about 20 times smaller than in the case of SoHO/EIT, and 5 times smaller than TRACE. We perform a first step in this direction by analyzing and characterizing the spatial intermittency of Quiet Sun images thanks to a multifractal analysis. We identify the parameters that specify the scale-invariance behavior. This identification allows next to select a family of multifractal processes, namely the Compound Poisson Cascades, that can synthesize artificial images having some of the scale-invariance properties observed on the recorded images. The prevalence of self-similarity in Quiet Sun coronal images makes it relevant to study the ratio between the SNR present at SoHO/EIT images and in coarsened images. SoHO/EIT images thus play the role of "high resolution" images, whereas the "low-resolution" coarsened images are rebinned so as to simulate a smaller angular resolution and/or a larger distance to the Sun. For a fixed difference in angular resolution and in Spacecraft-Sun distance, we determine the proportion of pixels having a SNR preserved at high resolution given a particular increase in effective area. If scale-invariance continues to prevail at smaller scales, the conclusion reached with SoHO/EIT images can be transposed

  3. Parameterizing Subgrid-Scale Orographic Drag in the High-Resolution Rapid Refresh (HRRR) Atmospheric Model

    Science.gov (United States)

    Toy, M. D.; Olson, J.; Kenyon, J.; Smirnova, T. G.; Brown, J. M.

    2017-12-01

    The accuracy of wind forecasts in numerical weather prediction (NWP) models is improved when the drag forces imparted on atmospheric flow by subgrid-scale orography are included. Without such parameterizations, only the terrain resolved by the model grid, along with the small-scale obstacles parameterized by the roughness lengths can have an effect on the flow. This neglects the impacts of subgrid-scale terrain variations, which typically leads to wind speeds that are too strong. Using statistical information about the subgrid-scale orography, such as the mean and variance of the topographic height within a grid cell, the drag forces due to flow blocking, gravity wave drag, and turbulent form drag are estimated and distributed vertically throughout the grid cell column. We recently implemented the small-scale gravity wave drag paramterization of Steeneveld et al. (2008) and Tsiringakis et al. (2017) for stable planetary boundary layers, and the turbulent form drag parameterization of Beljaars et al. (2004) in the High-Resolution Rapid Refresh (HRRR) NWP model developed at the National Oceanic and Atmospheric Administration (NOAA). As a result, a high surface wind speed bias in the model has been reduced and small improvement to the maintenance of stable layers has also been found. We present the results of experiments with the subgrid-scale orographic drag parameterization for the regional HRRR model, as well as for a global model in development at NOAA, showing the direct and indirect impacts.

  4. High Resolution Simulations of Future Climate in West Africa Using a Variable-Resolution Atmospheric Model

    Science.gov (United States)

    Adegoke, J. O.; Engelbrecht, F.; Vezhapparambu, S.

    2013-12-01

    In previous work demonstrated the application of a var¬iable-resolution global atmospheric model, the conformal-cubic atmospheric model (CCAM), across a wide range of spatial and time scales to investigate the ability of the model to provide realistic simulations of present-day climate and plausible projections of future climate change over sub-Saharan Africa. By applying the model in stretched-grid mode the versatility of the model dynamics, numerical formulation and physical parameterizations to function across a range of length scales over the region of interest, was also explored. We primarily used CCAM to illustrate the capability of the model to function as a flexible downscaling tool at the climate-change time scale. Here we report on additional long term climate projection studies performed by downscaling at much higher resolutions (8 Km) over an area that stretches from just south of Sahara desert to the southern coast of the Niger Delta and into the Gulf of Guinea. To perform these simulations, CCAM was provided with synoptic-scale forcing of atmospheric circulation from 2.5 deg resolution NCEP reanalysis at 6-hourly interval and SSTs from NCEP reanalysis data uses as lower boundary forcing. CCAM 60 Km resolution downscaled to 8 Km (Schmidt factor 24.75) then 8 Km resolution simulation downscaled to 1 Km (Schmidt factor 200) over an area approximately 50 Km x 50 Km in the southern Lake Chad Basin (LCB). Our intent in conducting these high resolution model runs was to obtain a deeper understanding of linkages between the projected future climate and the hydrological processes that control the surface water regime in this part of sub-Saharan Africa.

  5. Significance of High Resolution GHRSST on prediction of Indian Summer Monsoon

    KAUST Repository

    Jangid, Buddhi Prakash

    2017-02-24

    In this study, the Weather Research and Forecasting (WRF) model was used to assess the importance of very high resolution sea surface temperature (SST) on seasonal rainfall prediction. Two different SST datasets available from the National Centers for Environmental Prediction (NCEP) global model analysis and merged satellite product from Group for High Resolution SST (GHRSST) are used as a lower boundary condition in the WRF model for the Indian Summer Monsoon (ISM) 2010. Before using NCEP SST and GHRSST for model simulation, an initial verification of NCEP SST and GHRSST are performed with buoy measurements. It is found that approximately 0.4 K root mean square difference (RMSD) in GHRSST and NCEP SST when compared with buoy observations available over the Indian Ocean during 01 May to 30 September 2010. Our analyses suggest that use of GHRSST as lower boundary conditions in the WRF model improve the low level temperature, moisture, wind speed and rainfall prediction over ISM region. Moreover, temporal evolution of surface parameters such as temperature, moisture and wind speed forecasts associated with monsoon is also improved with GHRSST forcing as a lower boundary condition. Interestingly, rainfall prediction is improved with the use of GHRSST over the Western Ghats, which mostly not simulated in the NCEP SST based experiment.

  6. Significance of High Resolution GHRSST on prediction of Indian Summer Monsoon

    KAUST Repository

    Jangid, Buddhi Prakash; Kumar, Prashant; Attada, Raju; Kumar, Raj

    2017-01-01

    In this study, the Weather Research and Forecasting (WRF) model was used to assess the importance of very high resolution sea surface temperature (SST) on seasonal rainfall prediction. Two different SST datasets available from the National Centers for Environmental Prediction (NCEP) global model analysis and merged satellite product from Group for High Resolution SST (GHRSST) are used as a lower boundary condition in the WRF model for the Indian Summer Monsoon (ISM) 2010. Before using NCEP SST and GHRSST for model simulation, an initial verification of NCEP SST and GHRSST are performed with buoy measurements. It is found that approximately 0.4 K root mean square difference (RMSD) in GHRSST and NCEP SST when compared with buoy observations available over the Indian Ocean during 01 May to 30 September 2010. Our analyses suggest that use of GHRSST as lower boundary conditions in the WRF model improve the low level temperature, moisture, wind speed and rainfall prediction over ISM region. Moreover, temporal evolution of surface parameters such as temperature, moisture and wind speed forecasts associated with monsoon is also improved with GHRSST forcing as a lower boundary condition. Interestingly, rainfall prediction is improved with the use of GHRSST over the Western Ghats, which mostly not simulated in the NCEP SST based experiment.

  7. High resolution radar satellite imagery analysis for safeguards applications

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Christian; Eineder, Michael [German Aerospace Center, Remote Sensing Technology Institute, Department of SAR Signal Processing, Wessling, (Germany); Rezniczek, Arnold [UBA GmbH, Herzogenrath, (Germany); Niemeyer, Irmgard [Forschungszentrum Juelich, Institue of Energy and Climate Research, IEK-6: Nuclear Waste Management and Reactor Safety, Juelich, (Germany)

    2011-12-15

    For monitoring nuclear sites, the use of Synthetic Aperture Radar (SAR) imagery shows essential promises. Unlike optical remote sensing instruments, radar sensors operate under almost all weather conditions and independently of the sunlight, i.e. time of the day. Such technical specifications are required both for continuous and for ad-hoc, timed surveillance tasks. With Cosmo-Skymed, TerraSARX and Radarsat-2, high-resolution SAR imagery with a spatial resolution up to 1m has recently become available. Our work therefore aims to investigate the potential of high-resolution TerraSAR data for nuclear monitoring. This paper focuses on exploiting amplitude of a single acquisition, assessing amplitude changes and phase differences between two acquisitions, and PS-InSAR processing of an image stack.

  8. High resolution spectroscopy in the microwave and far infrared

    Science.gov (United States)

    Pickett, Herbert M.

    1990-01-01

    High resolution rotational spectroscopy has long been central to remote sensing techniques in atmospheric sciences and astronomy. As such, laboratory measurements must supply the required data to make direct interpretation of data for instruments which sense atmospheres using rotational spectra. Spectral measurements in the microwave and far infrared regions are also very powerful tools when combined with infrared measurements for characterizing the rotational structure of vibrational spectra. In the past decade new techniques were developed which have pushed high resolution spectroscopy into the wavelength region between 25 micrometers and 2 mm. Techniques to be described include: (1) harmonic generation of microwave sources, (2) infrared laser difference frequency generation, (3) laser sideband generation, and (4) ultrahigh resolution interferometers.

  9. Science with High Spatial Resolution Far-Infrared Data

    Science.gov (United States)

    Terebey, Susan (Editor); Mazzarella, Joseph M. (Editor)

    1994-01-01

    The goal of this workshop was to discuss new science and techniques relevant to high spatial resolution processing of far-infrared data, with particular focus on high resolution processing of IRAS data. Users of the maximum correlation method, maximum entropy, and other resolution enhancement algorithms applicable to far-infrared data gathered at the Infrared Processing and Analysis Center (IPAC) for two days in June 1993 to compare techniques and discuss new results. During a special session on the third day, interested astronomers were introduced to IRAS HIRES processing, which is IPAC's implementation of the maximum correlation method to the IRAS data. Topics discussed during the workshop included: (1) image reconstruction; (2) random noise; (3) imagery; (4) interacting galaxies; (5) spiral galaxies; (6) galactic dust and elliptical galaxies; (7) star formation in Seyfert galaxies; (8) wavelet analysis; and (9) supernova remnants.

  10. A cloud mask methodology for high resolution remote sensing data combining information from high and medium resolution optical sensors

    Science.gov (United States)

    Sedano, Fernando; Kempeneers, Pieter; Strobl, Peter; Kucera, Jan; Vogt, Peter; Seebach, Lucia; San-Miguel-Ayanz, Jesús

    2011-09-01

    This study presents a novel cloud masking approach for high resolution remote sensing images in the context of land cover mapping. As an advantage to traditional methods, the approach does not rely on thermal bands and it is applicable to images from most high resolution earth observation remote sensing sensors. The methodology couples pixel-based seed identification and object-based region growing. The seed identification stage relies on pixel value comparison between high resolution images and cloud free composites at lower spatial resolution from almost simultaneously acquired dates. The methodology was tested taking SPOT4-HRVIR, SPOT5-HRG and IRS-LISS III as high resolution images and cloud free MODIS composites as reference images. The selected scenes included a wide range of cloud types and surface features. The resulting cloud masks were evaluated through visual comparison. They were also compared with ad-hoc independently generated cloud masks and with the automatic cloud cover assessment algorithm (ACCA). In general the results showed an agreement in detected clouds higher than 95% for clouds larger than 50 ha. The approach produced consistent results identifying and mapping clouds of different type and size over various land surfaces including natural vegetation, agriculture land, built-up areas, water bodies and snow.

  11. High resolution satellite imagery : from spies to pipeline management

    Energy Technology Data Exchange (ETDEWEB)

    Adam, S. [Canadian Geomatic Solutions Ltd., Calgary, AB (Canada); Farrell, M. [TransCanada Transmission, Calgary, AB (Canada)

    2000-07-01

    The launch of Space Imaging's IKONOS satellite in September 1999 has opened the door for corridor applications. The technology has been successfully implemented by TransCanada PipeLines in mapping over 1500 km of their mainline. IKONOS is the world's first commercial high resolution satellite which collects data at 1-meter black/white and 4-meter multi-spectral. Its use is regulated by the U.S. government. It is the best source of high resolution satellite image data. Other sources include the Indian Space Agency's IRS-1 C/D satellite and the Russian SPIN-2 which provides less reliable coverage. In addition, two more high resolution satellites may be launched this year to provide imagery every day of the year. IKONOS scenes as narrow as 5 km can be purchased. TransCanada conducted a pilot study to determine if high resolution satellite imagery is as effective as ortho-photos for identifying population structures within a buffer of TransCanada's east line right-of-way. The study examined three unique segments where residential, commercial, industrial and public features were compared. It was determined that IKONOS imagery is as good as digital ortho-photos for updating structures from low to very high density areas. The satellite imagery was also logistically easier than ortho-photos to acquire. This will be even more evident when the IKONOS image archives begins to grow. 4 tabs., 3 figs.

  12. High Power Electronics - Key Technology for Wind Turbines

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Ma, Ke

    2014-01-01

    reliability challenges for the future wind turbines are explained. It is concluded that the wind turbine behavior/performance can be significantly improved by introducing power electronics, and there will be higher requirements for the power electronics performances in wind power application....

  13. Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system.

    Science.gov (United States)

    Zeraatkar, Navid; Sajedi, Salar; Farahani, Mohammad Hossein; Arabi, Hossein; Sarkar, Saeed; Ghafarian, Pardis; Rahmim, Arman; Ay, Mohammad Reza

    2014-11-01

    The small-animal High-Resolution SPECT (HiReSPECT) is a dedicated dual-head gamma camera recently designed and developed in our laboratory for imaging of murine models. Each detector is composed of an array of 1.2 × 1.2 mm(2) (pitch) pixelated CsI(Na) crystals. Two position-sensitive photomultiplier tubes (H8500) are coupled to each head's crystal. In this paper, we report on a resolution-recovery-embedded image reconstruction code applicable to the system and present the experimental results achieved using different phantoms and mouse scans. Collimator-detector response functions (CDRFs) were measured via a pixel-driven method using capillary sources at finite distances from the head within the field of view (FOV). CDRFs were then fitted by independent Gaussian functions. Thereafter, linear interpolations were applied to the standard deviation (σ) values of the fitted Gaussians, yielding a continuous map of CDRF at varying distances from the head. A rotation-based maximum-likelihood expectation maximization (MLEM) method was used for reconstruction. A fast rotation algorithm was developed to rotate the image matrix according to the desired angle by means of pre-generated rotation maps. The experiments demonstrated improved resolution utilizing our resolution-recovery-embedded image reconstruction. While the full-width at half-maximum (FWHM) radial and tangential resolution measurements of the system were over 2 mm in nearly all positions within the FOV without resolution recovery, reaching around 2.5 mm in some locations, they fell below 1.8 mm everywhere within the FOV using the resolution-recovery algorithm. The noise performance of the system was also acceptable; the standard deviation of the average counts per voxel in the reconstructed images was 6.6% and 8.3% without and with resolution recovery, respectively. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  14. Constraining Stochastic Parametrisation Schemes Using High-Resolution Model Simulations

    Science.gov (United States)

    Christensen, H. M.; Dawson, A.; Palmer, T.

    2017-12-01

    Stochastic parametrisations are used in weather and climate models as a physically motivated way to represent model error due to unresolved processes. Designing new stochastic schemes has been the target of much innovative research over the last decade. While a focus has been on developing physically motivated approaches, many successful stochastic parametrisation schemes are very simple, such as the European Centre for Medium-Range Weather Forecasts (ECMWF) multiplicative scheme `Stochastically Perturbed Parametrisation Tendencies' (SPPT). The SPPT scheme improves the skill of probabilistic weather and seasonal forecasts, and so is widely used. However, little work has focused on assessing the physical basis of the SPPT scheme. We address this matter by using high-resolution model simulations to explicitly measure the `error' in the parametrised tendency that SPPT seeks to represent. The high resolution simulations are first coarse-grained to the desired forecast model resolution before they are used to produce initial conditions and forcing data needed to drive the ECMWF Single Column Model (SCM). By comparing SCM forecast tendencies with the evolution of the high resolution model, we can measure the `error' in the forecast tendencies. In this way, we provide justification for the multiplicative nature of SPPT, and for the temporal and spatial scales of the stochastic perturbations. However, we also identify issues with the SPPT scheme. It is therefore hoped these measurements will improve both holistic and process based approaches to stochastic parametrisation. Figure caption: Instantaneous snapshot of the optimal SPPT stochastic perturbation, derived by comparing high-resolution simulations with a low resolution forecast model.

  15. Extended-range high-resolution dynamical downscaling over a continental-scale spatial domain with atmospheric and surface nudging

    Science.gov (United States)

    Husain, S. Z.; Separovic, L.; Yu, W.; Fernig, D.

    2014-12-01

    Extended-range high-resolution mesoscale simulations with limited-area atmospheric models when applied to downscale regional analysis fields over large spatial domains can provide valuable information for many applications including the weather-dependent renewable energy industry. Long-term simulations over a continental-scale spatial domain, however, require mechanisms to control the large-scale deviations in the high-resolution simulated fields from the coarse-resolution driving fields. As enforcement of the lateral boundary conditions is insufficient to restrict such deviations, large scales in the simulated high-resolution meteorological fields are therefore spectrally nudged toward the driving fields. Different spectral nudging approaches, including the appropriate nudging length scales as well as the vertical profiles and temporal relaxations for nudging, have been investigated to propose an optimal nudging strategy. Impacts of time-varying nudging and generation of hourly analysis estimates are explored to circumvent problems arising from the coarse temporal resolution of the regional analysis fields. Although controlling the evolution of the atmospheric large scales generally improves the outputs of high-resolution mesoscale simulations within the surface layer, the prognostically evolving surface fields can nevertheless deviate from their expected values leading to significant inaccuracies in the predicted surface layer meteorology. A forcing strategy based on grid nudging of the different surface fields, including surface temperature, soil moisture, and snow conditions, toward their expected values obtained from a high-resolution offline surface scheme is therefore proposed to limit any considerable deviation. Finally, wind speed and temperature at wind turbine hub height predicted by different spectrally nudged extended-range simulations are compared against observations to demonstrate possible improvements achievable using higher spatiotemporal

  16. Real-time database for high resolution neutron monitor measurements

    Energy Technology Data Exchange (ETDEWEB)

    Steigies, Christian T.; Rother, Oliver M.; Wimmer-Schweingruber, Robert F.; Heber, Bernd [IEAP, Christian-Albrechts-Universitaet zu Kiel (Germany)

    2008-07-01

    The worldwide network of standardised neutron monitors is, after 50 years, still the state-of-the-art instrumentation to measure spectral variations of the primary cosmic ray component. These measurements are an ideal complement to space based cosmic ray measurements. Data from the approximately 50 IGY and NM64 neutron monitors is stored locally but also available through data collections sites like the World Data Center (WDC) or the IZMIRAN ftp server. The data from the WDC is in a standard format, but only hourly values are available. IZMIRAN collects the data in the best available time resolution, but the data arrives on the ftp server only hours, sometimes days, after the measurements. Also, the high time-resolution measurements of the different stations do not have a common format, a conversion routine for each station is needed before they can be used for scientific analysis. Supported by the 7th framework program of the European Commission, we are setting up a real-time database where high resolution cosmic ray measurements will be stored and accessible immediately after the measurement. Stations that do not have 1-minute resolution measurements will be upgraded to 1-minute or better resolution with an affordable standard registration system, that will submit the measurements to the database via the internet in real-time.

  17. High resolution multiplexed functional imaging in live embryos (Conference Presentation)

    Science.gov (United States)

    Xu, Dongli; Zhou, Weibin; Peng, Leilei

    2017-02-01

    Fourier multiplexed fluorescence lifetime imaging (FmFLIM) scanning laser optical tomography (FmFLIM-SLOT) combines FmFLIM and Scanning laser optical tomography (SLOT) to perform multiplexed 3D FLIM imaging of live embryos. The system had demonstrate multiplexed functional imaging of zebrafish embryos genetically express Foster Resonant Energy Transfer (FRET) sensors. However, previous system has a 20 micron resolution because the focused Gaussian beam diverges quickly from the focused plane, makes it difficult to achieve high resolution imaging over a long projection depth. Here, we present a high-resolution FmFLIM-SLOT system with achromatic Bessel beam, which achieves 3 micron resolution in 3D deep tissue imaging. In Bessel-FmFLIM-SLOT, multiple laser excitation lines are firstly intensity modulated by a Michelson interferometer with a spinning polygon mirror optical delay line, which enables Fourier multiplexed multi-channel lifetime measurements. Then, a spatial light modulator and a prism are used to transform the modulated Gaussian laser beam to an achromatic Bessel beam. The achromatic Bessel beam scans across the whole specimen with equal angular intervals as sample rotated. After tomography reconstruction and the frequency domain lifetime analysis method, both the 3D intensity and lifetime image of multiple excitation-emission can be obtained. Using Bessel-FmFLIM-SLOT system, we performed cellular-resolution FLIM tomography imaging of live zebrafish embryo. Genetically expressed FRET sensors in these embryo will allow non-invasive observation of multiple biochemical processes in vivo.

  18. The development of high resolution silicon x-ray microcalorimeters

    Science.gov (United States)

    Porter, F. S.; Kelley, R. L.; Kilbourne, C. A.

    2005-12-01

    Recently we have produced x-ray microcalorimeters with resolving powers approaching 2000 at 5.9 keV using a spare XRS microcalorimeter array. We attached 400 um square, 8 um thick HgTe absorbers using a variety of attachment methods to an XRS array and ran the detector array at temperatures between 40 and 60 mK. The best results were for absorbers attached using the standard XRS absorber-pixel thermal isolation scheme utilizing SU8 polymer tubes. In this scenario we achieved a resolution of 3.2 eV FWHM at 5.9 keV. Substituting a silicon spacer for the SU8 tubes also yielded sub-4eV results. In contrast, absorbers attached directly to the thermistor produced significant position dependence and thus degraded resolution. Finally, we tested standard 640um-square XRS detectors at reduced bias power at 50mK and achieved a resolution of 3.7eV, a 50% improvement over the XRS flight instrument. Implanted silicon microcalorimeters are a mature flight-qualified technology that still has a substantial phase space for future development. We will discuss these new high resolution results, the various absorber attachment schemes, planned future improvements, and, finally, their relevance to future high resolution x-ray spectrometers including Constellation-X.

  19. High resolution muon computed tomography at neutrino beam facilities

    International Nuclear Information System (INIS)

    Suerfu, B.; Tully, C.G.

    2016-01-01

    X-ray computed tomography (CT) has an indispensable role in constructing 3D images of objects made from light materials. However, limited by absorption coefficients, X-rays cannot deeply penetrate materials such as copper and lead. Here we show via simulation that muon beams can provide high resolution tomographic images of dense objects and of structures within the interior of dense objects. The effects of resolution broadening from multiple scattering diminish with increasing muon momentum. As the momentum of the muon increases, the contrast of the image goes down and therefore requires higher resolution in the muon spectrometer to resolve the image. The variance of the measured muon momentum reaches a minimum and then increases with increasing muon momentum. The impact of the increase in variance is to require a higher integrated muon flux to reduce fluctuations. The flux requirements and level of contrast needed for high resolution muon computed tomography are well matched to the muons produced in the pion decay pipe at a neutrino beam facility and what can be achieved for momentum resolution in a muon spectrometer. Such an imaging system can be applied in archaeology, art history, engineering, material identification and whenever there is a need to image inside a transportable object constructed of dense materials

  20. Regional and local meteorology influences high-resolution tropospheric ozone concentration in the Los Angeles Basin

    Science.gov (United States)

    Koutzoukis, S.; Jenerette, D.; Chandler, M.; Wang, J.; Ge, C.; Ripplinger, J.

    2017-12-01

    Urban air quality and climate directly affect resident health. The Los Angeles (LA) Basin is a highly populated metropolitan area, with widespread point sources of ozone (O3) precursors (NOx , Volatile Organic Compounds, CO) from fossil fuel combustion. The LA basin exists on a coast-to-mountain gradient, with increasing temperatures towards the Transverse Ranges, which rise to 1700m. Frequently not compliant with 8-hour O3 standards, the LA and South Coast Air Basins are designated as severe and extreme non-attainment areas. Summer weather in the LA basin is characterized by a persistent high pressure system, creating an inversion that traps air pollutants, including O3 precursors, coupled with physical geography that blocks prevailing upper atmosphere air flow. These interactions make neighborhood-level O3 levels more variable than common regional models. Over the summer of 2017, we investigated the importance of local meteorology, wind patterns and air temperature, in transporting and mixing ozone precursors from point sources along the coast-to-mountain gradient. We deployed a network of six EPA federal equivalent method ozone and meteorological sensors in three campaigns in the LA basin along the coast-to-mountain transect. Each campaign, we collaborated with citizen scientists to deploy three sensor stations in two, 4 km2 quadrats, for a total of six high-resolution 4 km2 pixels. O3 concentrations vary greatly along the transect. At the coastal sites, daily O3 ranges from 0ppm to 60ppm and the range increases at the inland sites, to 100ppm. At all sites, there was a positive relationship between wind speed, air temperature, and O3 concentration, with increasing correlation inland. The Pearson correlation coefficient between wind speed and O3 concentration doubles from the coast to inland, and triples between air temperature and O3. The site-specific relationships between O3 and wind direction and temperature vary, suggesting neighborhood-effects from local

  1. High time resolution measurements of the thermosphere from Fabry-Perot Interferometer measurements of atomic oxygen

    Directory of Open Access Journals (Sweden)

    E. A. K. Ford

    2007-06-01

    Full Text Available Recent advances in the performance of CCD detectors have enabled a high time resolution study of the high latitude upper thermosphere with Fabry-Perot Interferometers (FPIs to be performed. 10-s integration times were used during a campaign in April 2004 on an FPI located in northern Sweden in the auroral oval. The FPI is used to study the thermosphere by measuring the oxygen red line emission at 630.0 nm, which emits at an altitude of approximately 240 km. Previous time resolutions have been 4 min at best, due to the cycle of look directions normally observed. By using 10 s rather than 40 s integration times, and by limiting the number of full cycles in a night, high resolution measurements down to 15 s were achievable. This has allowed the maximum variability of the thermospheric winds and temperatures, and 630.0 nm emission intensities, at approximately 240 km, to be determined as a few minutes. This is a significantly greater variability than the often assumed value of 1 h or more. A Lomb-Scargle analysis of this data has shown evidence of gravity wave activity with waves with short periods. Gravity waves are an important feature of mesosphere-lower thermosphere (MLT dynamics, observed using many techniques and providing an important mechanism for energy transfer between atmospheric regions. At high latitudes gravity waves may be generated in-situ by localised auroral activity. Short period waves were detected in all four clear nights when this experiment was performed, in 630.0 nm intensities and thermospheric winds and temperatures. Waves with many periodicities were observed, from periods of several hours, down to 14 min. These waves were seen in all parameters over several nights, implying that this variability is a typical property of the thermosphere.

  2. Latitudinal distribution of the solar wind properties in the low- and high-pressure regimes: Wind observations

    Directory of Open Access Journals (Sweden)

    C. Lacombe

    Full Text Available The solar wind properties depend on λ, the heliomagnetic latitude with respect to the heliospheric current sheet (HCS, more than on the heliographic latitude. We analyse the wind properties observed by Wind at 1 AU during about 2.5 solar rotations in 1995, a period close to the last minimum of solar activity. To determine λ, we use a model of the HCS which we fit to the magnetic sector boundary crossings observed by Wind. We find that the solar wind properties mainly depend on the modulus |λ|. But they also depend on a local parameter, the total pressure (magnetic pressure plus electron and proton thermal pressure. Furthermore, whatever the total pressure, we observe that the plasma properties also depend on the time: the latitudinal gradients of the wind speed and of the proton temperature are not the same before and after the closest HCS crossing. This is a consequence of the dynamical stream interactions. In the low pressure wind, at low |λ|, we find a clear maximum of the density, a clear minimum of the wind speed and of the proton temperature, a weak minimum of the average magnetic field strength, a weak maximum of the average thermal pressure, and a weak maximum of the average β factor. This overdense sheet is embedded in a density halo. The latitudinal thickness is about 5° for the overdense sheet, and 20° for the density halo. The HCS is thus wrapped in an overdense sheet surrounded by a halo, even in the non-compressed solar wind. In the high-pressure wind, the plasma properties are less well ordered as functions of the latitude than in the low-pressure wind; the minimum of the average speed is seen before the HCS crossing. The latitudinal thickness of the high-pressure region is about 20°. Our observations are qualitatively consistent with the numerical model of Pizzo for the deformation of the heliospheric current sheet and plasma sheet.

    Key words: Interplanetary physics (solar wind

  3. Immersion Gratings for Infrared High-resolution Spectroscopy

    Science.gov (United States)

    Sarugaku, Yuki; Ikeda, Yuji; Kobayashi, Naoto; Kaji, Sayumi; Sukegawa, Takashi; Sugiyama, Shigeru; Nakagawa, Takao; Arasaki, Takayuki; Kondo, Sohei; Nakanishi, Kenshi; Yasui, Chikako; Kawakita, Hideyo

    2016-10-01

    High-resolution spectroscopy in the infrared wavelength range is essential for observations of minor isotopologues, such as HDO for water, and prebiotic organic molecules like hydrocarbons/P-bearing molecules because numerous vibrational molecular bands (including non-polar molecules) are located in this wavelength range. High spectral resolution enables us to detect weak lines without spectral line confusion. This technique has been widely used in planetary sciences, e.g., cometary coma (H2O, CO, and organic molecules), the martian atmosphere (CH4, CO2, H2O and HDO), and the upper atmosphere of gas giants (H3+ and organic molecules such as C2H6). Spectrographs with higher resolution (and higher sensitivity) still have a potential to provide a plenty of findings. However, because the size of spectrographs scales with the spectral resolution, it is difficult to realize it.Immersion grating (IG), which is a diffraction grating wherein the diffraction surface is immersed in a material with a high refractive index (n > 2), provides n times higher spectral resolution compared to a reflective grating of the same size. Because IG reduces the size of spectrograph to 1/n compared to the spectrograph with the same spectral resolution using a conventional reflective grating, it is widely acknowledged as a key optical device to realize compact spectrographs with high spectral resolution.Recently, we succeeded in fabricating a CdZnTe immersion grating with the theoretically predicted diffraction efficiency by machining process using an ultrahigh-precision five-axis processing machine developed by Canon Inc. Using the same technique, we completed a practical germanium (Ge) immersion grating with both a reflection coating on the grating surface and the an AR coating on the entrance surface. It is noteworthy that the wide wavelength range from 2 to 20 um can be covered by the two immersion gratings.In this paper, we present the performances and the applications of the immersion

  4. Forest trees filter chronic wind-signals to acclimate to high winds.

    Science.gov (United States)

    Bonnesoeur, Vivien; Constant, Thiéry; Moulia, Bruno; Fournier, Meriem

    2016-05-01

    Controlled experiments have shown that trees acclimate thigmomorphogenetically to wind-loads by sensing their deformation (strain). However, the strain regime in nature is exposed to a full spectrum of winds. We hypothesized that trees avoid overreacting by responding only to winds which bring information on local climate and/or wind exposure. Additionally, competition for light dependent on tree social status also likely affects thigmomorphogenesis. We monitored and manipulated quantitatively the strain regimes of 15 pairs of beech (Fagus sylvatica) trees of contrasting social status in an acclimated stand, and quantified the effects of these regimes on the radial growth over a vegetative season. Trees exposed to artificial bending, the intensity of which corresponds to the strongest wind-induced strains, enhanced their secondary growth by at least 80%. Surprisingly, this reaction was even greater - relatively - for suppressed trees than for dominant ones. Acclimated trees did not sense the different types of wind events in the same way. Daily wind speed peaks due to thermal winds were filtered out. Thigmomorphogenesis was therefore driven by intense storms. Thigmomorphogenesis is also likely to be involved in determining social status. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  5. High-Resolution Electronics: Spontaneous Patterning of High-Resolution Electronics via Parallel Vacuum Ultraviolet (Adv. Mater. 31/2016).

    Science.gov (United States)

    Liu, Xuying; Kanehara, Masayuki; Liu, Chuan; Sakamoto, Kenji; Yasuda, Takeshi; Takeya, Jun; Minari, Takeo

    2016-08-01

    On page 6568, T. Minari and co-workers describe spontaneous patterning based on the parallel vacuum ultraviolet (PVUV) technique, enabling the homogeneous integration of complex, high-resolution electronic circuits, even on large-scale, flexible, transparent substrates. Irradiation of PVUV to the hydrophobic polymer surface precisely renders the selected surface into highly wettable regions with sharply defined boundaries, which spontaneously guides a metal nanoparticle ink into a series of circuit lines and gaps with the widths down to a resolution of 1 μm. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Dye laser light for high-resolution classical photography

    International Nuclear Information System (INIS)

    Geissler, K.K.

    1982-01-01

    The test run with the bubble chamber HOLEBC in October 1981 offered the opportunity of checking the usefulness of de-speckled dye laser light for illumination purposes in high-resolution classical dark field photography of small bubble chambers. (orig./HSI)

  7. High-resolution seismic imaging of the Sohagpur Gondwana basin ...

    Indian Academy of Sciences (India)

    The quality of the high-resolution seismic data depends mainly on the data ..... metric rift geometry. Based on the .... Biswas S K 2003 Regional tectonic framework of the .... Sheth H C, Ray J S, Ray R, Vanderkluysen L, Mahoney J. J, Kumar A ...

  8. Pulmonary Gaucher's disease: high-resolution computed tomographic features

    International Nuclear Information System (INIS)

    Tunaci, A.; Berkmen, Y.M.; Goekmen, E.

    1995-01-01

    CT findings in pulmonary Gaucher's disease have not been previously reported. Chest radiograph of a patient with pulmonary involvement in type I Gaucher's disease proven by biopsy showed linear and reticulo-nodular opacities. High-resolution CT demonstrated thickening of the interlobular septa and between four and six small nodules within secondary lobules, probably each corresponding to an acinus. (orig.)

  9. High resolution techniques using scanning proton microprobe (SPM)

    International Nuclear Information System (INIS)

    Cholewa, M.; Saint, A.; Prawer, S.; Laird, J.S.; Legge, G.J.F.; Bardos, R.A.; Moorhead, G.F.; Taylor, G.N.; Stuart, S.A.; Howard, J.

    1994-01-01

    The very high resolution (down to 50 nm) achieved with low beam currents (fA) in a scanning ion microprobe have lead to many nondestructive techniques of microanalysis. This paper discusses recent developments and applications in the use of 3-D STIM (scanning transmission ion microscopy) Tomography, channeling STIM and IBIC (ion beam induced charge). (orig.)

  10. Structure Identification in High-Resolution Transmission Electron Microscopic Images

    DEFF Research Database (Denmark)

    Vestergaard, Jacob Schack; Kling, Jens; Dahl, Anders Bjorholm

    2014-01-01

    A connection between microscopic structure and macroscopic properties is expected for almost all material systems. High-resolution transmission electron microscopy is a technique offering insight into the atomic structure, but the analysis of large image series can be time consuming. The present ...

  11. Duchenne muscular dystrophy: High-resolution melting curve ...

    African Journals Online (AJOL)

    Duchenne muscular dystrophy: High-resolution melting curve analysis as an affordable diagnostic mutation scanning tool in a South African cohort. ... Genetic screening for D/BMD in South Africa currently includes multiple ligase-dependent probe amplification (MLPA) for exonic deletions and duplications and linkage ...

  12. Role of land state in a high resolution mesoscale model

    Indian Academy of Sciences (India)

    ... Proceedings – Mathematical Sciences · Resonance – Journal of Science ... Land surface characteristics; high resolution mesoscale model; Uttarakhand ... to predict realistic location, timing, amount,intensity and distribution of rainfall ... region embedded within two low pressure centers over Arabian Seaand Bay of Bengal.

  13. A high resolution powder diffractometer using focusing optics

    Indian Academy of Sciences (India)

    E-mail: siruguri@csr.ernet.in. Abstract. In this paper, we describe the design, construction and performance of a new high resolution neutron powder diffractometer that has been installed at the Dhruva reactor, Trombay, India. The instrument employs novel design concepts like the use of bent, perfect crystal monochromator ...

  14. High energy resolution off-resonant X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wojciech, Blachucki [Univ. of Fribourg (Switzerland). Dept. of Physics

    2015-10-16

    This work treats of the high energy resolution off-resonant X-ray spectroscopy (HEROS) method of determining the density of unoccupied electronic states in the vicinity of the absorption edge. HEROS is an alternative to the existing X-ray absorption spectroscopy (XAS) methods and opens the way for new studies not achievable before.

  15. Application of high resolution SNP arrays in patients with congenital ...

    Indian Academy of Sciences (India)

    clinical experience in implementing whole-genome high-resolution SNP arrays to investigate 33 patients with syndromic and .... Online Mendelian Inheritance in Man database (OMIM, ..... of damaged mitochondria through either autophagy or mito- ..... malformations: associations with maternal and infant character- istics in a ...

  16. Workshop on high-resolution, large-acceptance spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Zeidman, B. (ed.)

    1981-01-01

    The purpose of the Workshop on High-Resolution, Large-Acceptance Spectrometers was to provide a means for exchange of information among those actively engaged in the design and construction of these new spectrometers. Thirty-seven papers were prepared for the data base.

  17. Yeast expression proteomics by high-resolution mass spectrometry

    DEFF Research Database (Denmark)

    Walther, Tobias C; Olsen, Jesper Velgaard; Mann, Matthias

    2010-01-01

    -translational controls contribute majorly to regulation of protein abundance, for example in heat shock stress response. The development of new sample preparation methods, high-resolution mass spectrometry and novel bioinfomatic tools close this gap and allow the global quantitation of the yeast proteome under different...

  18. Resolution of RNA using high-performance liquid chromatography

    NARCIS (Netherlands)

    Mclaughlin, L.W.; Bischoff, Rainer

    1987-01-01

    High-performance liquid chromatographic techniques can be very effective for the resolution and isolation of nucleic acids. The characteristic ionic (phosphodiesters) and hydrophobic (nucleobases) properties of RNAs can be exploited for their separation. In this respect anion-exchange and

  19. Novel techniques in VUV high-resolution spectroscopy

    NARCIS (Netherlands)

    Ubachs, W.M.G.; Salumbides, E.J.; Eikema, K.S.E.; de Oliveira, N.; Nahon, L.

    2014-01-01

    Novel VUV sources and techniques for VUV spectroscopy are reviewed. Laser-based VUV sources have been developed via non-linear upconversion of laser pulses in the nanosecond (ns), the picosecond (ps), and femtosecond (fs) domain, and are applied in high-resolution gas phase spectroscopic studies.

  20. High resolution X-ray diffraction studies on unirradiated

    Indian Academy of Sciences (India)

    High-resolution X-ray diffraction technique, employing a three-crystal monochromator–collimator combination is used to study the irradiation induced defects in flux grown Sr-hexaferrite crystals irradiated with 50 MeV Li3+ ion beams at room temperature with a fluence value of 1 × 1014 ions/cm2. The diffraction curves of the ...

  1. High resolution STEM of quantum dots and quantum wires

    DEFF Research Database (Denmark)

    Kadkhodazadeh, Shima

    2013-01-01

    This article reviews the application of high resolution scanning transmission electron microscopy (STEM) to semiconductor quantum dots (QDs) and quantum wires (QWRs). Different imaging and analytical techniques in STEM are introduced and key examples of their application to QDs and QWRs...

  2. Pattern of interstitial lung disease detected by high resolution ...

    African Journals Online (AJOL)

    Background: Diffuse lung diseases constitute a major cause of morbidity and mortality worldwide. High Resolution Computed Tomography (HRCT) is the recommended imaging technique in the diagnosis, assessment and followup of these diseases. Objectives: To describe the pattern of HRCT findings in patients with ...

  3. Remote parallel rendering for high-resolution tiled display walls

    KAUST Repository

    Nachbaur, Daniel

    2014-11-01

    © 2014 IEEE. We present a complete, robust and simple to use hardware and software stack delivering remote parallel rendering of complex geometrical and volumetric models to high resolution tiled display walls in a production environment. We describe the setup and configuration, present preliminary benchmarks showing interactive framerates, and describe our contributions for a seamless integration of all the software components.

  4. Remote parallel rendering for high-resolution tiled display walls

    KAUST Repository

    Nachbaur, Daniel; Dumusc, Raphael; Bilgili, Ahmet; Hernando, Juan; Eilemann, Stefan

    2014-01-01

    © 2014 IEEE. We present a complete, robust and simple to use hardware and software stack delivering remote parallel rendering of complex geometrical and volumetric models to high resolution tiled display walls in a production environment. We describe the setup and configuration, present preliminary benchmarks showing interactive framerates, and describe our contributions for a seamless integration of all the software components.

  5. Human enamel structure studied by high resolution electron microscopy

    International Nuclear Information System (INIS)

    Wen, S.L.

    1989-01-01

    Human enamel structural features are characterized by high resolution electron microscopy. The human enamel consists of polycrystals with a structure similar to Ca10(PO4)6(OH)2. This article describes the structural features of human enamel crystal at atomic and nanometer level. Besides the structural description, a great number of high resolution images are included. Research into the carious process in human enamel is very important for human beings. This article firstly describes the initiation of caries in enamel crystal at atomic and unit-cell level and secondly describes the further steps of caries with structural and chemical demineralization. The demineralization in fact, is the origin of caries in human enamel. The remineralization of carious areas in human enamel has drawn more and more attention as its potential application is realized. This process has been revealed by high resolution electron microscopy in detail in this article. On the other hand, the radiation effects on the structure of human enamel are also characterized by high resolution electron microscopy. In order to reveal this phenomenon clearly, a great number of electron micrographs have been shown, and a physical mechanism is proposed. 26 references

  6. Systematic high-resolution assessment of global hydropower potential

    NARCIS (Netherlands)

    Hoes, Olivier A C; Meijer, Lourens J J; Van Der Ent, Ruud J.|info:eu-repo/dai/nl/364164794; Van De Giesen, Nick C.

    2017-01-01

    Population growth, increasing energy demand and the depletion of fossil fuel reserves necessitate a search for sustainable alternatives for electricity generation. Hydropower could replace a large part of the contribution of gas and oil to the present energy mix. However, previous high-resolution

  7. High-Resolution Geologic Mapping of Martian Terraced Fan Deposits

    Science.gov (United States)

    Wolak, J. M.; Patterson, A. B.; Smith, S. D.; Robbins, N. N.

    2018-06-01

    This abstract documents our initial progress (year 1) mapping terraced fan features on Mars. Our objective is to investigate the role of fluids during fan formation and produce the first high-resolution geologic map (1:18k) of a terraced fan.

  8. Optimal Operation of Plug-In Electric Vehicles in Power Systems with High Wind Power Penetrations

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe

    2013-01-01

    in the power systems with high wind power penetrations. In this paper, the integration of plug-in electric vehicles in the power systems with high wind power penetrations is proposed and discussed. Optimal operation strategies of PEV in the spot market are proposed in order to decrease the energy cost for PEV......The Danish power system has a large penetration of wind power. The wind fluctuation causes a high variation in the power generation, which must be balanced by other sources. The battery storage based Plug-In Electric Vehicles (PEV) may be a possible solution to balance the wind power variations...... owners. Furthermore, the application of battery storage based aggregated PEV is analyzed as a regulation services provider in the power system with high wind power penetrations. The western Danish power system where the total share of annual wind power production is more than 27% of the electrical energy...

  9. Solutions on high-resolution multiple configuration system sensors

    Science.gov (United States)

    Liu, Hua; Ding, Quanxin; Guo, Chunjie; Zhou, Liwei

    2014-11-01

    For aim to achieve an improved resolution in modern image domain, a method of continuous zoom multiple configuration, with a core optics is attempt to establish model by novel principle on energy transfer and high accuracy localization, by which the system resolution can be improved with a level in nano meters. A comparative study on traditional vs modern methods can demonstrate that the dialectical relationship and their balance is important, among Merit function, Optimization algorithms and Model parameterization. The effect of system evaluated criterion that MTF, REA, RMS etc. can support our arguments qualitatively.

  10. Development of high-energy resolution inverse photoemission technique

    International Nuclear Information System (INIS)

    Asakura, D.; Fujii, Y.; Mizokawa, T.

    2005-01-01

    We developed a new inverse photoemission (IPES) machine based on a new idea to improve the energy resolution: off-plane Eagle mounting of the optical system in combination with dispersion matching between incoming electron and outgoing photon. In order to achieve dispersion matching, we have employed a parallel plate electron source and have investigated whether the electron beam is obtained as expected. In this paper, we present the principle and design of the new IPES method and report the current status of the high-energy resolution IPES machine

  11. High-resolution neutron-diffraction measurements to 8 kbar

    Science.gov (United States)

    Bull, C. L.; Fortes, A. D.; Ridley, C. J.; Wood, I. G.; Dobson, D. P.; Funnell, N. P.; Gibbs, A. S.; Goodway, C. M.; Sadykov, R.; Knight, K. S.

    2017-10-01

    We describe the capability to measure high-resolution neutron powder diffraction data to a pressure of at least 8 kbar. We have used the HRPD instrument at the ISIS neutron source and a piston-cylinder design of pressure cell machined from a null-scattering titanium zirconium alloy. Data were collected under hydrostatic conditions from an elpasolite perovskite La?NiMnO?; by virtue of a thinner cell wall on the incident-beam side of the cell, it was possible to obtain data in the instrument's highest resolution back-scattering detector banks up to a maximum pressure of 8.5 kbar.

  12. The most intense electric currents in turbulent high speed solar wind

    Science.gov (United States)

    Podesta, J. J.

    2017-12-01

    Theory and simulations suggest that dissipation of turbulent energy in collisionless astrophysical plasmas occurs most rapidly in spatial regions where the current density is most intense. To advance understanding of plasma heating by turbulent dissipation in the solar corona and solar wind, it is of interest to characterize the properties of plasma regions where the current density takes exceptionally large values and to identify the operative dissipation processes. In the solar wind, the curl of the magnetic field cannot be measured using data from a single spacecraft, however, a suitable proxy for this quantity can be constructed from the spatial derivative of the magnetic field along the flow direction of the plasma. This new approach is used to study the properties of the most intense current carrying structures in a high speed solar wind stream near 1 AU. In this study, based on 11 Hz magnetometer data from the WIND spacecraft, the spatial resolution of the proxy technique is approximately equal to the proton inertial length. Intense current sheets or current carrying structures were identified as events where the magnitude of the current density exceeds μ+5σ, where μ and σ are the mean and standard deviation of the magnitude of the current density (or its proxy), respectively. Statistical studies show (1) the average size of these 5σ events is close to the smallest resolvable scale in the data set, the proton inertial length; (2) the linear distance between neighboring events follows a power law distribution; and (3) the average peak current density of 5σ events is around 1 pA/cm2. The analysis techniques used in these studies have been validated using simulated spacecraft data from three dimensional hybrid simulations which show that results based on the analysis of the proxy are qualitatively and quantitatively similar to results based on the analysis of the true current density.

  13. High-resolution axial MR imaging of tibial stress injuries

    Directory of Open Access Journals (Sweden)

    Mammoto Takeo

    2012-05-01

    Full Text Available Abstract Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries.

  14. Evaluation of a High-Resolution Regional Reanalysis for Europe

    Science.gov (United States)

    Ohlwein, C.; Wahl, S.; Keller, J. D.; Bollmeyer, C.

    2014-12-01

    Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. The regional reanalysis for Europe matches the domain of the CORDEX EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km) and comprises the assimilation of observational data using the existing nudging scheme of COSMO complemented by a special soil moisture analysis with boundary conditions provided by ERA-Interim data. The reanalysis data set covers 6 years (2007-2012) and is currently extended to 16 years. Extensive evaluation of the reanalysis is performed using independent observations with special emphasis on precipitation and high-impact weather situations indicating a better representation of small scale variability. Further, the evaluation shows an added value of the regional reanalysis with respect to the forcing ERA Interim reanalysis and compared to a pure high-resolution dynamical downscaling approach without data assimilation.

  15. The high-resolution regional reanalysis COSMO-REA6

    Science.gov (United States)

    Ohlwein, C.

    2016-12-01

    Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. The regional reanalysis for Europe matches the domain of the CORDEX EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km) and comprises the assimilation of observational data using the existing nudging scheme of COSMO complemented by a special soil moisture analysis with boundary conditions provided by ERA-Interim data. The reanalysis data set covers the past 20 years. Extensive evaluation of the reanalysis is performed using independent observations with special emphasis on precipitation and high-impact weather situations indicating a better representation of small scale variability. Further, the evaluation shows an added value of the regional reanalysis with respect to the forcing ERA Interim reanalysis and compared to a pure high-resolution dynamical downscaling approach without data assimilation.

  16. A High-resolution Reanalysis for the European CORDEX Region

    Science.gov (United States)

    Bentzien, Sabrina; Bollmeyer, Christoph; Crewell, Susanne; Friederichs, Petra; Hense, Andreas; Keller, Jan; Keune, Jessica; Kneifel, Stefan; Ohlwein, Christian; Pscheidt, Ieda; Redl, Stephanie; Steinke, Sandra

    2014-05-01

    A High-resolution Reanalysis for the European CORDEX Region Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. The work presented here focuses on the regional reanalysis for Europe with a domain matching the CORDEX-EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km). The COSMO reanalysis system comprises the assimilation of observational data using the existing nudging scheme of COSMO and is complemented by a special soil moisture analysis and boundary conditions given by ERA-interim data. The reanalysis data set currently covers 6 years (2007-2012). The evaluation of the reanalyses is done using independent observations with special emphasis on precipitation and high-impact weather situations. The development and evaluation of the COSMO-based reanalysis for the CORDEX-Euro domain can be seen as a preparation for joint European activities on the development of an ensemble system of regional reanalyses for Europe.

  17. A high-resolution regional reanalysis for Europe

    Science.gov (United States)

    Ohlwein, C.

    2015-12-01

    Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. The regional reanalysis for Europe matches the domain of the CORDEX EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km) and comprises the assimilation of observational data using the existing nudging scheme of COSMO complemented by a special soil moisture analysis with boundary conditions provided by ERA-Interim data. The reanalysis data set covers the past 20 years. Extensive evaluation of the reanalysis is performed using independent observations with special emphasis on precipitation and high-impact weather situations indicating a better representation of small scale variability. Further, the evaluation shows an added value of the regional reanalysis with respect to the forcing ERA Interim reanalysis and compared to a pure high-resolution dynamical downscaling approach without data assimilation.

  18. High-resolution axial MR imaging of tibial stress injuries

    Science.gov (United States)

    2012-01-01

    Purpose To evaluate the relative involvement of tibial stress injuries using high-resolution axial MR imaging and the correlation with MR and radiographic images. Methods A total of 33 patients with exercise-induced tibial pain were evaluated. All patients underwent radiograph and high-resolution axial MR imaging. Radiographs were taken at initial presentation and 4 weeks later. High-resolution MR axial images were obtained using a microscopy surface coil with 60 × 60 mm field of view on a 1.5T MR unit. All images were evaluated for abnormal signals of the periosteum, cortex and bone marrow. Results Nineteen patients showed no periosteal reaction at initial and follow-up radiographs. MR imaging showed abnormal signals in the periosteal tissue and partially abnormal signals in the bone marrow. In 7 patients, periosteal reaction was not seen at initial radiograph, but was detected at follow-up radiograph. MR imaging showed abnormal signals in the periosteal tissue and entire bone marrow. Abnormal signals in the cortex were found in 6 patients. The remaining 7 showed periosteal reactions at initial radiograph. MR imaging showed abnormal signals in the periosteal tissue in 6 patients. Abnormal signals were seen in the partial and entire bone marrow in 4 and 3 patients, respectively. Conclusions Bone marrow abnormalities in high-resolution axial MR imaging were related to periosteal reactions at follow-up radiograph. Bone marrow abnormalities might predict later periosteal reactions, suggesting shin splints or stress fractures. High-resolution axial MR imaging is useful in early discrimination of tibial stress injuries. PMID:22574840

  19. High-resolution structure of the native histone octamer

    International Nuclear Information System (INIS)

    Wood, Christopher M.; Nicholson, James M.; Lambert, Stanley J.; Chantalat, Laurent; Reynolds, Colin D.; Baldwin, John P.

    2005-01-01

    The high-resolution (1.90 Å) model of the native histone octamer allows structural comparisons to be made with the nucleosome-core particle, along with an identification of a likely core-histone binding site. Crystals of native histone octamers (H2A–H2B)–(H4–H3)–(H3′–H4′)–(H2B′–H2A′) from chick erythrocytes in 2 M KCl, 1.35 M potassium phosphate pH 6.9 diffract X-rays to 1.90 Å resolution, yielding a structure with an R work value of 18.7% and an R free of 22.2%. The crystal space group is P6 5 , the asymmetric unit of which contains one complete octamer. This high-resolution model of the histone-core octamer allows further insight into intermolecular interactions, including water molecules, that dock the histone dimers to the tetramer in the nucleosome-core particle and have relevance to nucleosome remodelling. The three key areas analysed are the H2A′–H3–H4 molecular cluster (also H2A–H3′–H4′), the H4–H2B′ interaction (also H4′–H2B) and the H2A′–H4 β-sheet interaction (also H2A–H4′). The latter of these three regions is important to nucleosome remodelling by RNA polymerase II, as it is shown to be a likely core-histone binding site, and its disruption creates an instability in the nucleosome-core particle. A majority of the water molecules in the high-resolution octamer have positions that correlate to similar positions in the high-resolution nucleosome-core particle structure, suggesting that the high-resolution octamer model can be used for comparative studies with the high-resolution nucleosome-core particle

  20. Topography improvements in MEMS DMs for high-contrast, high-resolution imaging, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop and demonstrate an innovative microfabrication process to substantially improve the surface quality achievable in high-resolution...

  1. Flexible fault ride through strategy for wind farm clusters in power systems with high wind power penetration

    International Nuclear Information System (INIS)

    Wang, Songyan; Chen, Ning; Yu, Daren; Foley, Aoife; Zhu, Lingzhi; Li, Kang; Yu, Jilai

    2015-01-01

    Highlights: • A flexible fault ride through strategy is proposed. • The strategy comprises of grid code requirements and power restrictions. • Slight faults and moderate faults are the main defending objectives. • Temporary overloading capability of the doubly fed induction generator is considered. - Abstract: This paper investigates a flexible fault ride through strategy for power systems in China with high wind power penetration. The strategy comprises of adaptive fault ride through requirements and maximum power restrictions of the wind farms with weak fault ride through capabilities. The slight faults and moderate faults with high probability are the main defending objective of the strategy. The adaptive fault ride through requirement in the strategy consists of two sub fault ride through requirements, a temporary slight voltage ride through requirement corresponding to a slight fault incident, with a moderate voltage ride through requirement corresponding to a moderate fault. The temporary overloading capability of the wind farm is reflected in both requirements to enhance the capability to defend slight faults and to avoid tripping when the crowbar is disconnected after moderate faults are cleared. For those wind farms that cannot meet the adaptive fault ride through requirement, restrictions are put on the maximum power output. Simulation results show that the flexible fault ride through strategy increases the fault ride through capability of the wind farm clusters and reduces the wind power curtailment during faults

  2. Ultra-High Resolution Spectroscopic Remote Sensing: A Microscope on Planetary Atmospheres

    Science.gov (United States)

    Kostiuk, Theodor

    2010-01-01

    Remote sensing of planetary atmospheres is not complete without studies of all levels of the atmosphere, including the dense cloudy- and haze filled troposphere, relatively clear and important stratosphere and the upper atmosphere, which are the first levels to experience the effects of solar radiation. High-resolution spectroscopy can provide valuable information on these regions of the atmosphere. Ultra-high spectral resolution studies can directly measure atmospheric winds, composition, temperature and non-thermal phenomena, which describe the physics and chemistry of the atmosphere. Spectroscopy in the middle to long infrared wavelengths can also probe levels where dust of haze limit measurements at shorter wavelength or can provide ambiguous results on atmospheric species abundances or winds. A spectroscopic technique in the middle infrared wavelengths analogous to a radio receiver. infrared heterodyne spectroscopy [1], will be describe and used to illustrate the detailed study of atmospheric phenomena not readily possible with other methods. The heterodyne spectral resolution with resolving power greater than 1,000.000 measures the true line shapes of emission and absorption lines in planetary atmospheres. The information on the region of line formation is contained in the line shapes. The absolute frequency of the lines can be measured to I part in 100 ,000,000 and can be used to accurately measure the Doppler frequency shift of the lines, directly measuring the line-of-sight velocity of the gas to --Im/s precision (winds). The technical and analytical methods developed and used to measure and analyze infrared heterodyne measurements will be described. Examples of studies on Titan, Venus, Mars, Earth, and Jupiter will be presented. 'These include atmospheric dynamics on slowly rotating bodies (Titan [2] and Venus [3] and temperature, composition and chemistry on Mars 141, Venus and Earth. The discovery and studies of unique atmospheric phenomena will also be

  3. High time resolution boundary layer description using combined remote sensing instruments

    Directory of Open Access Journals (Sweden)

    C. Gaffard

    2008-09-01

    Full Text Available Ground based remote sensing systems for future observation operations will allow continuous monitoring of the lower troposphere at temporal resolutions much better than every 30 min. Observations which may be considered spurious from an individual instrument can be validated or eliminated when considered in conjunction with measurements from other instruments observing at the same location. Thus, improved quality control of atmospheric profiles from microwave radiometers and wind profilers should be sought by considering the measurements from different systems together rather than individually. In future test bed deployments for future operational observing systems, this should be aided by observations from laser ceilometers and cloud radars. Observations of changes in atmospheric profiles at high temporal resolution in the lower troposphere are presented from a 12 channel microwave radiometer and 1290 MHz UHF wind profiler deployed in southern England during the CSIP field experiment in July/August 2005. The observations chosen were from days when thunderstorms occurred in southern England. Rapid changes near the surface in dry layers are considered, both when rain/hail may be falling from above and where the dry air is associated with cold pools behind organised thunderstorms. Also, short term variations in atmospheric profiles and vertical stability are presented on a day with occasional low cloud, when thunderstorms triggered 50 km down wind of the observing site Improved quality control of the individual remote sensing systems need to be implemented, examining the basic quality of the underlying observations as well as the final outputs, and so for instance eliminating ground clutter as far as possible from the basic Doppler spectra measurements of the wind profiler. In this study, this was performed manually. The potential of incorporating these types of instruments in future upper air observational networks leads to the challenge to

  4. High-resolution nuclear magnetic resonance studies of proteins.

    Science.gov (United States)

    Jonas, Jiri

    2002-03-25

    The combination of advanced high-resolution nuclear magnetic resonance (NMR) techniques with high-pressure capability represents a powerful experimental tool in studies of protein folding. This review is organized as follows: after a general introduction of high-pressure, high-resolution NMR spectroscopy of proteins, the experimental part deals with instrumentation. The main section of the review is devoted to NMR studies of reversible pressure unfolding of proteins with special emphasis on pressure-assisted cold denaturation and the detection of folding intermediates. Recent studies investigating local perturbations in proteins and the experiments following the effects of point mutations on pressure stability of proteins are also discussed. Ribonuclease A, lysozyme, ubiquitin, apomyoglobin, alpha-lactalbumin and troponin C were the model proteins investigated.

  5. SAGA GIS based processing of spatial high resolution temperature data

    International Nuclear Information System (INIS)

    Gerlitz, Lars; Bechtel, Benjamin; Kawohl, Tobias; Boehner, Juergen; Zaksek, Klemen

    2013-01-01

    Many climate change impact studies require surface and near surface temperature data with high spatial and temporal resolution. The resolution of state of the art climate models and remote sensing data is often by far to coarse to represent the meso- and microscale distinctions of temperatures. This is particularly the case for regions with a huge variability of topoclimates, such as mountainous or urban areas. Statistical downscaling techniques are promising methods to refine gridded temperature data with limited spatial resolution, particularly due to their low demand for computer capacity. This paper presents two downscaling approaches - one for climate model output and one for remote sensing data. Both are methodically based on the FOSS-GIS platform SAGA. (orig.)

  6. Construction of a high resolution electron beam profile monitor

    International Nuclear Information System (INIS)

    Norem, J.; Dawson, J.; Haberichter, W.; Novak, W.; Reed, L.; Yang, X.F.

    1993-01-01

    Bremsstrahlung from an electron beam on a heavy target can be used to image the beam profile using collimators and slits. The limiting resolution using this system is determined by Fresnel diffraction, and is ∼ √(λd/2), where λ is the photon wavelength and d is determined by the linear dimensions of the system. For linear colliders this resolution could be a few nm. The highest resolution requires detectors which see only high energy, (small λ), photons, and this is accomplished by converting photons to pairs, and detecting Cherenkov light in a nearly forward angle with a CCD detector or streak camera. Tests are planned at the Argonne APS and SLAC FFTB

  7. A high resolution ion microscope for cold atoms

    International Nuclear Information System (INIS)

    Stecker, Markus; Schefzyk, Hannah; Fortágh, József; Günther, Andreas

    2017-01-01

    We report on an ion-optical system that serves as a microscope for ultracold ground state and Rydberg atoms. The system is designed to achieve a magnification of up to 1000 and a spatial resolution in the 100 nm range, thereby surpassing many standard imaging techniques for cold atoms. The microscope consists of four electrostatic lenses and a microchannel plate in conjunction with a delay line detector in order to achieve single particle sensitivity with high temporal and spatial resolution. We describe the design process of the microscope including ion-optical simulations of the imaging system and characterize aberrations and the resolution limit. Furthermore, we present the experimental realization of the microscope in a cold atom setup and investigate its performance by patterned ionization with a structure size down to 2.7 μ m. The microscope meets the requirements for studying various many-body effects, ranging from correlations in cold quantum gases up to Rydberg molecule formation. (paper)

  8. Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry.

    Science.gov (United States)

    Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

    2010-11-01

    In this paper, we address the issue of peptide ion peak detection for high resolution time-of-flight (TOF) mass spectrometry (MS) data. A novel Bayesian peptide ion peak detection method is proposed for TOF data with resolution of 10 000-15 000 full width at half-maximum (FWHW). MS spectra exhibit distinct characteristics at this resolution, which are captured in a novel parametric model. Based on the proposed parametric model, a Bayesian peak detection algorithm based on Markov chain Monte Carlo (MCMC) sampling is developed. The proposed algorithm is tested on both simulated and real datasets. The results show a significant improvement in detection performance over a commonly employed method. The results also agree with expert's visual inspection. Moreover, better detection consistency is achieved across MS datasets from patients with identical pathological condition.

  9. Analysis of a severe weather event over Mecca, Kingdom of Saudi Arabia, using observations and high-resolution modelling

    KAUST Repository

    Dasari, Hari Prasad; Attada, Raju; Knio, Omar; Hoteit, Ibrahim

    2017-01-01

    The dynamic and thermodynamic characteristics of a severe weather event that caused heavy wind and rainfall over Mecca, Kingdom of Saudi Arabia, on 11 September 2015 were investigated using available observations and the Weather Research and Forecasting model configured at 1 km resolution. Analysis of surface, upper air observations and model outputs reveals that the event was initiated by synoptic scale conditions that intensified by interaction with the local topography, triggering strong winds and high convective rainfall. The model predicted the observed characteristics of both rainfall and winds well, accurately predicting the maximum wind speed of 20–25 m s−1 that was sustained for about 2 h. A time series analysis of various atmospheric variables suggests a sudden fall in pressure, temperature and outgoing long wave radiation before the development of the storm, followed by a significant increase in wind speed, latent and moisture fluxes and change in wind direction during the mature stage of the storm. The model outputs suggest that the heavy rainfall was induced by a low-level moisture supply from the Red Sea combined with orographic lifting. Latent heat release from microphysical processes increased the vertical velocities in the mid-troposphere, further increasing the low-level convergence that strengthened the event.

  10. Analysis of a severe weather event over Mecca, Kingdom of Saudi Arabia, using observations and high-resolution modelling

    KAUST Repository

    Dasari, Hari Prasad

    2017-08-10

    The dynamic and thermodynamic characteristics of a severe weather event that caused heavy wind and rainfall over Mecca, Kingdom of Saudi Arabia, on 11 September 2015 were investigated using available observations and the Weather Research and Forecasting model configured at 1 km resolution. Analysis of surface, upper air observations and model outputs reveals that the event was initiated by synoptic scale conditions that intensified by interaction with the local topography, triggering strong winds and high convective rainfall. The model predicted the observed characteristics of both rainfall and winds well, accurately predicting the maximum wind speed of 20–25 m s−1 that was sustained for about 2 h. A time series analysis of various atmospheric variables suggests a sudden fall in pressure, temperature and outgoing long wave radiation before the development of the storm, followed by a significant increase in wind speed, latent and moisture fluxes and change in wind direction during the mature stage of the storm. The model outputs suggest that the heavy rainfall was induced by a low-level moisture supply from the Red Sea combined with orographic lifting. Latent heat release from microphysical processes increased the vertical velocities in the mid-troposphere, further increasing the low-level convergence that strengthened the event.

  11. New DOI identification approach for high-resolution PET detectors

    International Nuclear Information System (INIS)

    Choghadi, Amin; Takahashi, Hiroyuki; Shimazoe, Kenji

    2016-01-01

    Depth-of-interaction (DOI) Identification in positron emission tomography (PET) detectors is getting importance as it improves spatial resolution in both conventional and time-of-flight (TOF) PET, and coincidence time resolution (CTR) in TOF-PET. In both prototypes, spatial resolution is affected by parallax error caused by length of scintillator crystals. This long length also contributes substantial timing uncertainty to the time resolution of TOF-PET. Through DOI identification, both parallax error and the timing uncertainty caused by the length of crystal can be resolved. In this work, a novel approach to estimate DOI was investigated, enjoying the interference of absorbance spectrum of scintillator crystals with their emission spectrum. Because the absorption length is close to zero for shorter wavelengths of crystal emission spectrum, the counts in this range of spectrum highly depend on DOI; that is, higher counts corresponds to deeper interactions. The ratio of counts in this range to the total counts is a good measure to estimate DOI. In order to extract such ratio, two photodetectors for each crystal are used and an optical filter is mounted only on top of one of them. The ratio of filtered output to non-filtered output can be utilized as DOI estimator. For a 2×2×20 mm 3 GAGG:Ce scintillator, 8-mm DOI resolution achieved in our simulations. (author)

  12. Ultra high resolution soft x-ray tomography

    International Nuclear Information System (INIS)

    Haddad, W.S.; Trebes, J.E.; Goodman, D.M.; Lee, H.R.; McNulty, I.; Zalensky, A.O.

    1995-01-01

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5 microm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼ 1,000 angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼ 6,000 angstrom, however some features were clearly reconstructed with a depth resolution of ∼ 1,000 angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution, bringing it down to ∼ 1,200 angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

  13. Ultra high resolution soft x-ray tomography

    International Nuclear Information System (INIS)

    Haddad, W.S.; Trebes, J.E.; Goodman, D.M.

    1995-01-01

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by ∼5μm. A series of nine 2-D images of the object were recorded at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of ∼1000 Angstrom was observed. Artifacts in the reconstruction limited the overall depth resolution to ∼6000 Angstrom, however some features were clearly reconstructed with a depth resolution of ∼1000 Angstrom. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to ∼1200 Angstrom overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range

  14. High resolution tsunami inversion for 2010 Chile earthquake

    Directory of Open Access Journals (Sweden)

    T.-R. Wu

    2011-12-01

    Full Text Available We investigate the feasibility of inverting high-resolution vertical seafloor displacement from tsunami waveforms. An inversion method named "SUTIM" (small unit tsunami inversion method is developed to meet this goal. In addition to utilizing the conventional least-square inversion, this paper also enhances the inversion resolution by Grid-Shifting method. A smooth constraint is adopted to gain stability. After a series of validation and performance tests, SUTIM is used to study the 2010 Chile earthquake. Based upon data quality and azimuthal distribution, we select tsunami waveforms from 6 GLOSS stations and 1 DART buoy record. In total, 157 sub-faults are utilized for the high-resolution inversion. The resolution reaches 10 sub-faults per wavelength. The result is compared with the distribution of the aftershocks and waveforms at each gauge location with very good agreement. The inversion result shows that the source profile features a non-uniform distribution of the seafloor displacement. The highly elevated vertical seafloor is mainly concentrated in two areas: one is located in the northern part of the epicentre, between 34° S and 36° S; the other is in the southern part, between 37° S and 38° S.

  15. Toward high-resolution NMR spectroscopy of microscopic liquid samples

    Energy Technology Data Exchange (ETDEWEB)

    Butler, Mark C.; Mehta, Hardeep S.; Chen, Ying; Reardon, Patrick N.; Renslow, Ryan S.; Khbeis, Michael; Irish, Duane; Mueller, Karl T.

    2017-01-01

    A longstanding limitation of high-resolution NMR spectroscopy is the requirement for samples to have macroscopic dimensions. Commercial probes, for example, are designed for volumes of at least 5 mL, in spite of decades of work directed toward the goal of miniaturization. Progress in miniaturizing inductive detectors has been limited by a perceived need to meet two technical requirements: (1) minimal separation between the sample and the detector, which is essential for sensitivity, and (2) near-perfect magnetic-field homogeneity at the sample, which is typically needed for spectral resolution. The first of these requirements is real, but the second can be relaxed, as we demonstrate here. By using pulse sequences that yield high-resolution spectra in an inhomogeneous field, we eliminate the need for near-perfect field homogeneity and the accompanying requirement for susceptibility matching of microfabricated detector components. With this requirement removed, typical imperfections in microfabricated components can be tolerated, and detector dimensions can be matched to those of the sample, even for samples of volume << 5 uL. Pulse sequences that are robust to field inhomogeneity thus enable small-volume detection with optimal sensitivity. We illustrate the potential of this approach to miniaturization by presenting spectra acquired with a flat-wire detector that can easily be scaled to subnanoliter volumes. In particular, we report high-resolution NMR spectroscopy of an alanine sample of volume 500 pL.

  16. High resolution tsunami inversion for 2010 Chile earthquake

    Science.gov (United States)

    Wu, T.-R.; Ho, T.-C.

    2011-12-01

    We investigate the feasibility of inverting high-resolution vertical seafloor displacement from tsunami waveforms. An inversion method named "SUTIM" (small unit tsunami inversion method) is developed to meet this goal. In addition to utilizing the conventional least-square inversion, this paper also enhances the inversion resolution by Grid-Shifting method. A smooth constraint is adopted to gain stability. After a series of validation and performance tests, SUTIM is used to study the 2010 Chile earthquake. Based upon data quality and azimuthal distribution, we select tsunami waveforms from 6 GLOSS stations and 1 DART buoy record. In total, 157 sub-faults are utilized for the high-resolution inversion. The resolution reaches 10 sub-faults per wavelength. The result is compared with the distribution of the aftershocks and waveforms at each gauge location with very good agreement. The inversion result shows that the source profile features a non-uniform distribution of the seafloor displacement. The highly elevated vertical seafloor is mainly concentrated in two areas: one is located in the northern part of the epicentre, between 34° S and 36° S; the other is in the southern part, between 37° S and 38° S.

  17. PROFIL-360 high resolution steam generator tube profilometry system

    International Nuclear Information System (INIS)

    Glass, S.W.

    1985-01-01

    A high-resolution profilometry system, PROFIL 360, has been developed to assess the condition of steam generator tubes and rapidly produce the data to evaluate the potential for developing in-service leaks. The probe has an electromechanical sensor in a rotating head. This technique has been demonstrated in the field, saving tubes that would have been plugged with the go-gauge criterion and indicating plugging other high-risk candidates that might otherwise not have been removed from service

  18. Profil-360 high resolution steam generator tube profilometry system

    International Nuclear Information System (INIS)

    Glass, S.W.

    1985-01-01

    A high-resolution profilometry system, PROFIL 360, has been developed to assess the condition of steam generator tubes and rapidly produce the data to evaluate the potential for developing in-service leaks. The probe has an electromechanical sensor in a rotating head. This technique has been demonstrated in the field, saving tubes that would have been plugged with the go-gauge criterion and indicating plugging other high-risk candidates that might otherwise not have been removed from service

  19. Enhancing GIS Capabilities for High Resolution Earth Science Grids

    Science.gov (United States)

    Koziol, B. W.; Oehmke, R.; Li, P.; O'Kuinghttons, R.; Theurich, G.; DeLuca, C.

    2017-12-01

    Applications for high performance GIS will continue to increase as Earth system models pursue more realistic representations of Earth system processes. Finer spatial resolution model input and output, unstructured or irregular modeling grids, data assimilation, and regional coordinate systems present novel challenges for GIS frameworks operating in the Earth system modeling domain. This presentation provides an overview of two GIS-driven applications that combine high performance software with big geospatial datasets to produce value-added tools for the modeling and geoscientific community. First, a large-scale interpolation experiment using National Hydrography Dataset (NHD) catchments, a high resolution rectilinear CONUS grid, and the Earth System Modeling Framework's (ESMF) conservative interpolation capability will be described. ESMF is a parallel, high-performance software toolkit that provides capabilities (e.g. interpolation) for building and coupling Earth science applications. ESMF is developed primarily by the NOAA Environmental Software Infrastructure and Interoperability (NESII) group. The purpose of this experiment was to test and demonstrate the utility of high performance scientific software in traditional GIS domains. Special attention will be paid to the nuanced requirements for dealing with high resolution, unstructured grids in scientific data formats. Second, a chunked interpolation application using ESMF and OpenClimateGIS (OCGIS) will demonstrate how spatial subsetting can virtually remove computing resource ceilings for very high spatial resolution interpolation operations. OCGIS is a NESII-developed Python software package designed for the geospatial manipulation of high-dimensional scientific datasets. An overview of the data processing workflow, why a chunked approach is required, and how the application could be adapted to meet operational requirements will be discussed here. In addition, we'll provide a general overview of OCGIS

  20. High-resolution RCMs as pioneers for future GCMs

    Science.gov (United States)

    Schar, C.; Ban, N.; Arteaga, A.; Charpilloz, C.; Di Girolamo, S.; Fuhrer, O.; Hoefler, T.; Leutwyler, D.; Lüthi, D.; Piaget, N.; Ruedisuehli, S.; Schlemmer, L.; Schulthess, T. C.; Wernli, H.

    2017-12-01

    Currently large efforts are underway to refine the horizontal resolution of global and regional climate models to O(1 km), with the intent to represent convective clouds explicitly rather than using semi-empirical parameterizations. This refinement will move the governing equations closer to first principles and is expected to reduce the uncertainties of climate models. High resolution is particularly attractive in order to better represent critical cloud feedback processes (e.g. related to global climate sensitivity and extratropical summer convection) and extreme events (such as heavy precipitation events, floods, and hurricanes). The presentation will be illustrated using decade-long simulations at 2 km horizontal grid spacing, some of these covering the European continent on a computational mesh with 1536x1536x60 grid points. To accomplish such simulations, use is made of emerging heterogeneous supercomputing architectures, using a version of the COSMO limited-area weather and climate model that is able to run entirely on GPUs. Results show that kilometer-scale resolution dramatically improves the simulation of precipitation in terms of the diurnal cycle and short-term extremes. The modeling framework is used to address changes of precipitation scaling with climate change. It is argued that already today, modern supercomputers would in principle enable global atmospheric convection-resolving climate simulations, provided appropriately refactored codes were available, and provided solutions were found to cope with the rapidly growing output volume. A discussion will be provided of key challenges affecting the design of future high-resolution climate models. It is suggested that km-scale RCMs should be exploited to pioneer this terrain, at a time when GCMs are not yet available at such resolutions. Areas of interest include the development of new parameterization schemes adequate for km-scale resolution, the exploration of new validation methodologies and data

  1. Enertech 2-kW high-reliability wind system. Phase II. Fabrication and testing

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, J A; Johnson, B A

    1981-06-01

    A high-reliability wind machine rated for 2 kW in a 9 m/s wind has been developed. Activities are summarized that are centered on the fabrication and testing of prototypes of the wind machine. The test results verified that the wind machine met the power output specification and that the variable-pitch rotor effectively controlled the rotor speed for wind speeds up to 50 mph. Three prototypes of the wind machine were shipped to the Rocky Flats test center in September through November of 1979. Work was also performed to reduce the start-up wind speed. The start-up wind speed to the Enertech facility has been reduced to 4.5 m/s.

  2. Radar observations of high-latitude lower-thermospheric and upper-mesospheric winds and their response to geomagnetic activity

    International Nuclear Information System (INIS)

    Johnson, R.M.

    1987-01-01

    Observations made by the Chatanika, Alaska, incoherent scatter radar during the summer months of 1976 to 1081 are analyzed to obtain high resolution lower-thermospheric neutral winds. Average winds and their tidal components are presented and compared to previous observational and model results. Upper-mesospheric neutral-wind observations obtained by the Poke Flat, Alaska Mesosphere-Stratosphere-Troposphere (MST) radar during the summer months of 1980 to 1982 are investigated statistically for evidence of variations due to geomagnetic activity. Observation of upper-mesospheric neutral winds made during two energetic Solar Proton Events (SPEs) by the Poker Flat, MST radar are presented. These results allow the low-altitude limits of magnetospheric coupling to the neutral atmosphere to be determined. Lower-thermospheric neutral winds are coupled to the ion convection driven by typical magnetospheric forcing above about 100 km. Coupling to lower atmospheric levels does not occur except during intervals of extreme disturbance of the magnetosphere-ionosphere-thermosphere system which are also accompanied by dramatically increased ionization in the high-latitude mesosphere, such as SPEs

  3. High resolution study of high mass pairs and high transverse momentum particles

    International Nuclear Information System (INIS)

    Smith, S.R.

    1983-01-01

    Preliminary experiments involving the high resolution spectrometer (experiment 605) at Fermilab are described. The spectrometer is designed for the study of pairs of particles at large invariant masses and single particles at large transverse momenta. A number of applications of the apparatus in the study of Drell-Yan processes, e.g. transverse momentum measurement, are discussed

  4. The role of hydrogen in high wind energy penetration electricity systems: the Irish case

    International Nuclear Information System (INIS)

    Gonzalez, A.; McKeogh, E.; Gallachoir, B.O.

    2004-01-01

    The deployment of wind energy is constrained by wind uncontrollability, which poses operational problems on the electricity supply system at high penetration levels, lessening the value of wind-generated electricity to a significant extent. This paper studies the viability of hydrogen production via electrolysis using wind power that cannot be easily accommodated on the system. The potential benefits of hydrogen and its role in enabling a large penetration of wind energy are assessed, within the context of the enormous wind energy resource in Ireland. The exploitation of this wind resource may in the future give rise to significant amounts of surplus wind electricity, which could be used to produce hydrogen, the zero-emissions fuel that many experts believe will eventually replace fossil fuels in the transport sector. In this paper the operation of a wind powered hydrogen production system is simulated and optimised. The results reveal that, even allowing for significant cost-reductions in electrolyser and associated balance-of-plant equipment, low average surplus wind electricity cost and a high hydrogen market price are also necessary to achieve the economic viability of the technology. These conditions would facilitate the installation of electrolysis units of sufficient capacity to allow an appreciable increase in installed wind power in Ireland. The simulation model was also used to determine the CO 2 abatement potential associated with the wind energy/hydrogen production. (author)

  5. Maximum likelihood positioning algorithm for high-resolution PET scanners

    International Nuclear Information System (INIS)

    Gross-Weege, Nicolas; Schug, David; Hallen, Patrick; Schulz, Volkmar

    2016-01-01

    Purpose: In high-resolution positron emission tomography (PET), lightsharing elements are incorporated into typical detector stacks to read out scintillator arrays in which one scintillator element (crystal) is smaller than the size of the readout channel. In order to identify the hit crystal by means of the measured light distribution, a positioning algorithm is required. One commonly applied positioning algorithm uses the center of gravity (COG) of the measured light distribution. The COG algorithm is limited in spatial resolution by noise and intercrystal Compton scatter. The purpose of this work is to develop a positioning algorithm which overcomes this limitation. Methods: The authors present a maximum likelihood (ML) algorithm which compares a set of expected light distributions given by probability density functions (PDFs) with the measured light distribution. Instead of modeling the PDFs by using an analytical model, the PDFs of the proposed ML algorithm are generated assuming a single-gamma-interaction model from measured data. The algorithm was evaluated with a hot-rod phantom measurement acquired with the preclinical HYPERION II D PET scanner. In order to assess the performance with respect to sensitivity, energy resolution, and image quality, the ML algorithm was compared to a COG algorithm which calculates the COG from a restricted set of channels. The authors studied the energy resolution of the ML and the COG algorithm regarding incomplete light distributions (missing channel information caused by detector dead time). Furthermore, the authors investigated the effects of using a filter based on the likelihood values on sensitivity, energy resolution, and image quality. Results: A sensitivity gain of up to 19% was demonstrated in comparison to the COG algorithm for the selected operation parameters. Energy resolution and image quality were on a similar level for both algorithms. Additionally, the authors demonstrated that the performance of the ML

  6. Gain-scheduled Linear Quadratic Control of Wind Turbines Operating at High Wind Speed

    DEFF Research Database (Denmark)

    Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

    2007-01-01

    This paper addresses state estimation and linear quadratic (LQ) control of variable speed variable pitch wind turbines. On the basis of a nonlinear model of a wind turbine, a set of operating conditions is identified and a LQ controller is designed for each operating point. The controller gains...... are then interpolated linearly to get a control law for the entire operating envelope. A nonlinear state estimator is designed as a combination of two unscented Kalman filters and a linear disturbance estimator. The gain-scheduling variable (wind speed) is then calculated from the output of these state estimators...

  7. Extended-Range High-Resolution Dynamical Downscaling over a Continental-Scale Domain

    Science.gov (United States)

    Husain, S. Z.; Separovic, L.; Yu, W.; Fernig, D.

    2014-12-01

    High-resolution mesoscale simulations, when applied for downscaling meteorological fields over large spatial domains and for extended time periods, can provide valuable information for many practical application scenarios including the weather-dependent renewable energy industry. In the present study, a strategy has been proposed to dynamically downscale coarse-resolution meteorological fields from Environment Canada's regional analyses for a period of multiple years over the entire Canadian territory. The study demonstrates that a continuous mesoscale simulation over the entire domain is the most suitable approach in this regard. Large-scale deviations in the different meteorological fields pose the biggest challenge for extended-range simulations over continental scale domains, and the enforcement of the lateral boundary conditions is not sufficient to restrict such deviations. A scheme has therefore been developed to spectrally nudge the simulated high-resolution meteorological fields at the different model vertical levels towards those embedded in the coarse-resolution driving fields derived from the regional analyses. A series of experiments were carried out to determine the optimal nudging strategy including the appropriate nudging length scales, nudging vertical profile and temporal relaxation. A forcing strategy based on grid nudging of the different surface fields, including surface temperature, soil-moisture, and snow conditions, towards their expected values obtained from a high-resolution offline surface scheme was also devised to limit any considerable deviation in the evolving surface fields due to extended-range temporal integrations. The study shows that ensuring large-scale atmospheric similarities helps to deliver near-surface statistical scores for temperature, dew point temperature and horizontal wind speed that are better or comparable to the operational regional forecasts issued by Environment Canada. Furthermore, the meteorological fields

  8. High-resolution numerical modeling of mesoscale island wakes and sensitivity to static topographic relief data

    Directory of Open Access Journals (Sweden)

    C. G. Nunalee

    2015-08-01

    Full Text Available Recent decades have witnessed a drastic increase in the fidelity of numerical weather prediction (NWP modeling. Currently, both research-grade and operational NWP models regularly perform simulations with horizontal grid spacings as fine as 1 km. This migration towards higher resolution potentially improves NWP model solutions by increasing the resolvability of mesoscale processes and reducing dependency on empirical physics parameterizations. However, at the same time, the accuracy of high-resolution simulations, particularly in the atmospheric boundary layer (ABL, is also sensitive to orographic forcing which can have significant variability on the same spatial scale as, or smaller than, NWP model grids. Despite this sensitivity, many high-resolution atmospheric simulations do not consider uncertainty with respect to selection of static terrain height data set. In this paper, we use the Weather Research and Forecasting (WRF model to simulate realistic cases of lower tropospheric flow over and downstream of mountainous islands using the default global 30 s United States Geographic Survey terrain height data set (GTOPO30, the Shuttle Radar Topography Mission (SRTM, and the Global Multi-resolution Terrain Elevation Data set (GMTED2010 terrain height data sets. While the differences between the SRTM-based and GMTED2010-based simulations are extremely small, the GTOPO30-based simulations differ significantly. Our results demonstrate cases where the differences between the source terrain data sets are significant enough to produce entirely different orographic wake mechanics, such as vortex shedding vs. no vortex shedding. These results are also compared to MODIS visible satellite imagery and ASCAT near-surface wind retrievals. Collectively, these results highlight the importance of utilizing accurate static orographic boundary conditions when running high-resolution mesoscale models.

  9. High resolution color imagery for orthomaps and remote sensing

    Energy Technology Data Exchange (ETDEWEB)

    Fricker, Peter [Leica Geosystems GIS and Mapping, LLC (Switzerland); Gallo, M. Guillermo [Leica Geosystems GIS and Mapping, LLC (United States)

    2005-07-01

    The ADS40 Airborne Digital Pushbroom Sensor is currently the only commercial sensor capable of acquiring color and false color strip images in the low decimeter range at the same high resolution as the black and white stereo images. This high resolution of 12,000 pixels across the entire swath and 100% forward overlap in the image strips result in high quality DSM's, True Ortho's and at the same time allow unbiased remote sensing applications due to color strip images unchanged by pan-sharpening. The paper gives details on how the pushbroom sensor achieves these seemingly difficult technical challenges. It describes how a variety of mapping applications benefit from this sensor, a sensor which acts as a satellite pushbroom sensor within the airborne environment. (author)

  10. High-Resolution Reciprocal Space Mapping for Characterizing Deformation Structures

    DEFF Research Database (Denmark)

    Pantleon, Wolfgang; Wejdemann, Christian; Jakobsen, Bo

    2014-01-01

    With high-angular resolution three-dimensional X-ray diffraction (3DXRD), quantitative information is gained about dislocation structures in individual grains in the bulk of a macroscopic specimen by acquiring reciprocal space maps. In high-resolution 3D reciprocal space maps of tensile......-deformed copper, individual, almost dislocation-free subgrains are identified from high-intensity peaks and distinguished by their unique combination of orientation and elastic strain; dislocation walls manifest themselves as a smooth cloud of lower intensity. The elastic strain shows only minor variations within...... dynamics is followed in situ during varying loading conditions by reciprocal space mapping: during uninterrupted tensile deformation, formation of subgrains is observed concurrently with broadening of Bragg reflections shortly after the onset of plastic deformation. When the traction is terminated, stress...

  11. Development of a metallic magnetic calorimeter for high resolution spectroscopy

    International Nuclear Information System (INIS)

    Linck, M.

    2007-01-01

    In this thesis the development of a metallic magnetic calorimeter for high resolution detection of single x-ray quanta is described. The detector consists of an X-ray absorber and a paramagnetic temperature sensor. The raise in temperature of the paramagnetic sensor due to the absorption of a single X-ray is measured by the change in magnetization of the sensor using a low-noise SQUID magnetometer. The thermodynamic properties of the detector can be described by a theoretical model based on a mean field approximation. This allows for an optimization of the detector design with respect to signal size. The maximal archivable energy resolution is limited by thermodynamic energy fluctuations between absorber, heat bath and thermometer. An interesting field of application for a metallic magnetic calorimeter is X-ray astronomy and the investigation of X-ray emitting objects. Through high-resolution X-ray spectroscopy it is possible to obtain information about physical processes of even far distant objects. The magnetic calorimeter that was developed in this thesis has a metallic absorber with a quantum efficiency of 98% at 6 keV. The energy resolution of the magnetic calorimeter is EFWHM=2.7 eV at 5.9 keV. The deviation of the detector response from a linear behavior of the detector is only 0.8% at 5.9 keV. (orig.)

  12. High-resolution electron microscopy of advanced materials

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, T.E.; Kung, H.H.; Sickafus, K.E.; Gray, G.T. III; Field, R.D.; Smith, J.F. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

    1997-11-01

    This final report chronicles a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The High-Resolution Electron Microscopy Facility has doubled in size and tripled in quality since the beginning of the three-year period. The facility now includes a field-emission scanning electron microscope, a 100 kV field-emission scanning transmission electron microscope (FE-STEM), a 300 kV field-emission high-resolution transmission electron microscope (FE-HRTEM), and a 300 kV analytical transmission electron microscope. A new orientation imaging microscope is being installed. X-ray energy dispersive spectrometers for chemical analysis are available on all four microscopes; parallel electron energy loss spectrometers are operational on the FE-STEM and FE-HRTEM. These systems enable evaluation of local atomic bonding, as well as chemical composition in nanometer-scale regions. The FE-HRTEM has a point-to-point resolution of 1.6 {angstrom}, but the resolution can be pushed to its information limit of 1 {angstrom} by computer reconstruction of a focal series of images. HRTEM has been used to image the atomic structure of defects such as dislocations, grain boundaries, and interfaces in a variety of materials from superconductors and ferroelectrics to structural ceramics and intermetallics.

  13. The demonstration of the auditory ossicles by high resolution CT

    International Nuclear Information System (INIS)

    Lloyd, G.A.S.; Boulay, G.H. du; Phelps, P.D.; Pullicino, P.

    1979-01-01

    The high resolution CT scanning system introduced by EMI in 1978 has added a new dimension to computerised tomography in otology. The apparatus used for this study was an EMI CT 5005 body scanner adapted for head and neck scanning and incorporating a high resolution facility. The latter has proved most advantageous in areas of relatively high differential absorption, so that its application to the demonstration of abnormalities in the petrous temporal bone, and in particular middle ear disease, has been very rewarding. Traumatic ossicular disruptions may now be demonstrated and the high contrast of CT often shows them better than conventional hypocycloidal tomography. The stapes is also better visualised and congenital abnormalities of its superstructure have been recorded. These studies have been achieved with a very acceptable level of radiation to the eye, lens and cornea and the technique is clearly a rival to conventional pluridirectional tomography in the assessment of the petrous temporal bone. With further design improvements high resolution CT could completely replace existing techniques. (orig.) [de

  14. High Resolution Thz and FIR Spectroscopy of SOCl_2

    Science.gov (United States)

    Martin-Drumel, M. A.; Cuisset, A.; Sadovskii, D. A.; Mouret, G.; Hindle, F.; Pirali, O.

    2013-06-01

    Thionyl chloride (SOCl_2) is an extremely powerful oxidant widely used in industrial processes and playing a role in the chemistry of the atmosphere. In addition, it has a molecular configuration similar to that of phosgene (COCl_2), and is therefore of particular interest for security and defense applications. Low resolution vibrational spectra of gas phase SOCl_2 as well as high resolution pure rotational transitions up to 25 GHz have previously been investigated. To date no high resolution data are reported at frequencies higher than 25 GHz. We have investigated the THz absorption spectrum of SOCl_2 in the spectral region 70-650 GHz using a frequency multiplier chain coupled to a 1 m long single path cell containing a pressure of about 15 μbar. At the time of the writing, about 8000 pure rotational transitions of SO^{35}Cl_2 with highest J and K_a values of 110 and 50 respectively have been assigned on the spectrum. We have also recorded the high resolution FIR spectra of SOCl_2 in the spectral range 50-700 wn using synchrotron radiation at the AILES beamline of SOLEIL facility. A White-type cell aligned with an absorption path length of 150 m has been used to record, at a resolution of 0.001 wn, two spectra at pressures of 5 and 56 μbar of SOCl_2. On these spectra all FIR modes of SOCl_2 are observed (ν_2 to ν_6) and present a resolved rotational structure. Their analysis is in progress. T. J. Johnson et al., J. Phys. Chem. A 107, 6183 (2003) D. E. Martz and R. T. Lagemann, J. Chem. Phys. 22,1193 (1954) H. S. P. Müller and M. C. L. Gerry, J. Chem. Soc. Faraday Trans. 90, 3473 (1994)

  15. Advancements in Wind Integration Study Data Modeling: The Wind Integration National Dataset (WIND) Toolkit; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Draxl, C.; Hodge, B. M.; Orwig, K.; Jones, W.; Searight, K.; Getman, D.; Harrold, S.; McCaa, J.; Cline, J.; Clark, C.

    2013-10-01

    Regional wind integration studies in the United States require detailed wind power output data at many locations to perform simulations of how the power system will operate under high-penetration scenarios. The wind data sets that serve as inputs into the study must realistically reflect the ramping characteristics, spatial and temporal correlations, and capacity factors of the simulated wind plants, as well as be time synchronized with available load profiles. The Wind Integration National Dataset (WIND) Toolkit described in this paper fulfills these requirements. A wind resource dataset, wind power production time series, and simulated forecasts from a numerical weather prediction model run on a nationwide 2-km grid at 5-min resolution will be made publicly available for more than 110,000 onshore and offshore wind power production sites.

  16. Imaging collagen type I fibrillogenesis with high spatiotemporal resolution

    International Nuclear Information System (INIS)

    Stamov, Dimitar R; Stock, Erik; Franz, Clemens M; Jähnke, Torsten; Haschke, Heiko

    2015-01-01

    Fibrillar collagens, such as collagen type I, belong to the most abundant extracellular matrix proteins and they have received much attention over the last five decades due to their large interactome, complex hierarchical structure and high mechanical stability. Nevertheless, the collagen self-assembly process is still incompletely understood. Determining the real-time kinetics of collagen type I formation is therefore pivotal for better understanding of collagen type I structure and function, but visualising the dynamic self-assembly process of collagen I on the molecular scale requires imaging techniques offering high spatiotemporal resolution. Fast and high-speed scanning atomic force microscopes (AFM) provide the means to study such processes on the timescale of seconds under near-physiological conditions. In this study we have applied fast AFM tip scanning to study the assembly kinetics of fibrillar collagen type I nanomatrices with a temporal resolution reaching eight seconds for a frame size of 500 nm. By modifying the buffer composition and pH value, the kinetics of collagen fibrillogenesis can be adjusted for optimal analysis by fast AFM scanning. We furthermore show that amplitude-modulation imaging can be successfully applied to extract additional structural information from collagen samples even at high scan rates. Fast AFM scanning with controlled amplitude modulation therefore provides a versatile platform for studying dynamic collagen self-assembly processes at high resolution. - Highlights: • Continuous non-invasive time-lapse investigation of collagen I fibrillogenesis in situ. • Imaging of collagen I self-assembly with high spatiotemporal resolution. • Application of setpoint modulation to study the hierarchical structure of collagen I. • Observing real-time formation of the D-banding pattern in collagen I

  17. Accelerated high-resolution photoacoustic tomography via compressed sensing

    Science.gov (United States)

    Arridge, Simon; Beard, Paul; Betcke, Marta; Cox, Ben; Huynh, Nam; Lucka, Felix; Ogunlade, Olumide; Zhang, Edward

    2016-12-01

    Current 3D photoacoustic tomography (PAT) systems offer either high image quality or high frame rates but are not able to deliver high spatial and temporal resolution simultaneously, which limits their ability to image dynamic processes in living tissue (4D PAT). A particular example is the planar Fabry-Pérot (FP) photoacoustic scanner, which yields high-resolution 3D images but takes several minutes to sequentially map the incident photoacoustic field on the 2D sensor plane, point-by-point. However, as the spatio-temporal complexity of many absorbing tissue structures is rather low, the data recorded in such a conventional, regularly sampled fashion is often highly redundant. We demonstrate that combining model-based, variational image reconstruction methods using spatial sparsity constraints with the development of novel PAT acquisition systems capable of sub-sampling the acoustic wave field can dramatically increase the acquisition speed while maintaining a good spatial resolution: first, we describe and model two general spatial sub-sampling schemes. Then, we discuss how to implement them using the FP interferometer and demonstrate the potential of these novel compressed sensing PAT devices through simulated data from a realistic numerical phantom and through measured data from a dynamic experimental phantom as well as from in vivo experiments. Our results show that images with good spatial resolution and contrast can be obtained from highly sub-sampled PAT data if variational image reconstruction techniques that describe the tissues structures with suitable sparsity-constraints are used. In particular, we examine the use of total variation (TV) regularization enhanced by Bregman iterations. These novel reconstruction strategies offer new opportunities to dramatically increase the acquisition speed of photoacoustic scanners that employ point-by-point sequential scanning as well as reducing the channel count of parallelized schemes that use detector arrays.

  18. Imaging collagen type I fibrillogenesis with high spatiotemporal resolution

    Energy Technology Data Exchange (ETDEWEB)

    Stamov, Dimitar R, E-mail: stamov@jpk.com [JPK Instruments AG, Bouchéstrasse 12, 12435 Berlin (Germany); Stock, Erik [JPK Instruments AG, Bouchéstrasse 12, 12435 Berlin (Germany); Franz, Clemens M [DFG-Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), Wolfgang-Gaede-Strasse 1a, 76131 Karlsruhe (Germany); Jähnke, Torsten; Haschke, Heiko [JPK Instruments AG, Bouchéstrasse 12, 12435 Berlin (Germany)

    2015-02-15

    Fibrillar collagens, such as collagen type I, belong to the most abundant extracellular matrix proteins and they have received much attention over the last five decades due to their large interactome, complex hierarchical structure and high mechanical stability. Nevertheless, the collagen self-assembly process is still incompletely understood. Determining the real-time kinetics of collagen type I formation is therefore pivotal for better understanding of collagen type I structure and function, but visualising the dynamic self-assembly process of collagen I on the molecular scale requires imaging techniques offering high spatiotemporal resolution. Fast and high-speed scanning atomic force microscopes (AFM) provide the means to study such processes on the timescale of seconds under near-physiological conditions. In this study we have applied fast AFM tip scanning to study the assembly kinetics of fibrillar collagen type I nanomatrices with a temporal resolution reaching eight seconds for a frame size of 500 nm. By modifying the buffer composition and pH value, the kinetics of collagen fibrillogenesis can be adjusted for optimal analysis by fast AFM scanning. We furthermore show that amplitude-modulation imaging can be successfully applied to extract additional structural information from collagen samples even at high scan rates. Fast AFM scanning with controlled amplitude modulation therefore provides a versatile platform for studying dynamic collagen self-assembly processes at high resolution. - Highlights: • Continuous non-invasive time-lapse investigation of collagen I fibrillogenesis in situ. • Imaging of collagen I self-assembly with high spatiotemporal resolution. • Application of setpoint modulation to study the hierarchical structure of collagen I. • Observing real-time formation of the D-banding pattern in collagen I.

  19. A Meteorological Distribution System for High Resolution Terrestrial Modeling (MicroMet)

    Science.gov (United States)

    Liston, G. E.; Elder, K.

    2004-12-01

    Spatially distributed terrestrial models generally require atmospheric forcing data on horizontal grids that are of higher resolution than available meteorological data. Furthermore, the meteorological data collected may not necessarily represent the area of interest's meteorological variability. To address these deficiencies, computationally efficient and physically realistic methods must be developed to take available meteorological data sets (e.g., meteorological tower observations) and generate high-resolution atmospheric-forcing distributions. This poster describes MicroMet, a quasi-physically-based, but simple meteorological distribution model designed to produce high-resolution (e.g., 5-m to 1-km horizontal grid increments) meteorological data distributions required to run spatially distributed terrestrial models over a wide variety of landscapes. The model produces distributions of the seven fundamental atmospheric forcing variables required to run most terrestrial models: air temperature, relative humidity, wind speed, wind direction, incoming solar radiation, incoming longwave radiation, and precipitation. MicroMet includes a preprocessor that analyzes meteorological station data and identifies and repairs potential data deficiencies. The model uses known relationships between meteorological variables and the surrounding area (primarily topography) to distribute those variables over any given landscape. MicroMet performs two kinds of adjustments to available meteorological data: 1) when there are data at more than one location, at a given time, the data are spatially interpolated over the domain using a Barnes objective analysis scheme, and 2) physical sub-models are applied to each MicroMet variable to improve its realism at a given point in space and time with respect to the terrain. The three, 25-km by 25-km, Cold Land Processes Experiment (CLPX) mesoscale study areas (MSAs: Fraser, North Park, and Rabbit Ears) will be used as example Micro

  20. High-latitude Conic Current Sheets in the Solar Wind

    Energy Technology Data Exchange (ETDEWEB)

    Khabarova, Olga V.; Obridko, Vladimir N.; Kharshiladze, Alexander F. [Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences (IZMIRAN), Moscow (Russian Federation); Malova, Helmi V. [Scobeltsyn Nuclear Physics Institute of Lomonosov Moscow State University, Moscow (Russian Federation); Kislov, Roman A.; Zelenyi, Lev M. [Space Research Centre of the Polish Academy of Sciences (CBK PAN), Warsaw (Poland); Tokumaru, Munetoshi; Fujiki, Ken’ichi [Institute for Space-Earth Environmental Research, Nagoya University (Japan); Sokół, Justyna M.; Grzedzielski, Stan [Space Research Centre of the Polish Academy of Sciences (CBK), Warsaw (Poland)

    2017-02-10

    We provide observational evidence for the existence of large-scale cylindrical (or conic-like) current sheets (CCSs) at high heliolatitudes. Long-lived CCSs were detected by Ulysses during its passages over the South Solar Pole in 1994 and 2007. The characteristic scale of these tornado-like structures is several times less than a typical width of coronal holes within which the CCSs are observed. CCS crossings are characterized by a dramatic decrease in the solar wind speed and plasma beta typical for predicted profiles of CCSs. Ulysses crossed the same CCS at different heliolatitudes at 2–3 au several times in 1994, as the CCS was declined from the rotation axis and corotated with the Sun. In 2007, a CCS was detected directly over the South Pole, and its structure was strongly highlighted by the interaction with comet McNaught. Restorations of solar coronal magnetic field lines reveal the occurrence of conic-like magnetic separators over the solar poles in both 1994 and 2007. Such separators exist only during solar minima. Interplanetary scintillation data analysis confirms the presence of long-lived low-speed regions surrounded by the typical polar high-speed solar wind in solar minima. Energetic particle flux enhancements up to several MeV/ nuc are observed at edges of the CCSs. We built simple MHD models of a CCS to illustrate its key features. The CCSs may be formed as a result of nonaxiality of the solar rotation axis and magnetic axis, as predicted by the Fisk–Parker hybrid heliospheric magnetic field model in the modification of Burger and coworkers.

  1. Turbulence Simulation of Laboratory Wind-Wave Interaction in High Winds and Upscaling to Ocean Conditions

    Science.gov (United States)

    2016-12-22

    Oceanogr., 46, 1377-1397 Cebeci, T. & P. Bradshaw, 1988: physical and computational aspects of convective heat transfer , Springer-Verlag, p.487...on surface properties and flow separation. Strongly-forced wind seas are characterized by enhanced group modulation , as significant additional...energy flux from the wind augments the hydrodynamic modulations . Using compact steep chirped wave packets, we investigated for the first time the

  2. High throughput screening of ligand binding to macromolecules using high resolution powder diffraction

    Science.gov (United States)

    Von Dreele, Robert B.; D'Amico, Kevin

    2006-10-31

    A process is provided for the high throughput screening of binding of ligands to macromolecules using high resolution powder diffraction data including producing a first sample slurry of a selected polycrystalline macromolecule material and a solvent, producing a second sample slurry of a selected polycrystalline macromolecule material, one or more ligands and the solvent, obtaining a high resolution powder diffraction pattern on each of said first sample slurry and the second sample slurry, and, comparing the high resolution powder diffraction pattern of the first sample slurry and the high resolution powder diffraction pattern of the second sample slurry whereby a difference in the high resolution powder diffraction patterns of the first sample slurry and the second sample slurry provides a positive indication for the formation of a complex between the selected polycrystalline macromolecule material and at least one of the one or more ligands.

  3. High resolution microphotonic needle for endoscopic imaging (Conference Presentation)

    Science.gov (United States)

    Tadayon, Mohammad Amin; Mohanty, Aseema; Roberts, Samantha P.; Barbosa, Felippe; Lipson, Michal

    2017-02-01

    GRIN (Graded index) lens have revolutionized micro endoscopy enabling deep tissue imaging with high resolution. The challenges of traditional GRIN lenses are their large size (when compared with the field of view) and their limited resolution. This is because of the relatively weak NA in standard graded index lenses. Here we introduce a novel micro-needle platform for endoscopy with much higher resolution than traditional GRIN lenses and a FOV that corresponds to the whole cross section of the needle. The platform is based on polymeric (SU-8) waveguide integrated with a microlens micro fabricated on a silicon substrate using a unique molding process. Due to the high index of refraction of the material the NA of the needle is much higher than traditional GRIN lenses. We tested the probe in a fluorescent dye solution (19.6 µM Alexa Flour 647 solution) and measured a numerical aperture of 0.25, focal length of about 175 µm and minimal spot size of about 1.6 µm. We show that the platform can image a sample with the field of view corresponding to the cross sectional area of the waveguide (80x100 µm2). The waveguide size can in principle be modified to vary size of the imaging field of view. This demonstration, combined with our previous work demonstrating our ability to implant the high NA needle in a live animal, shows that the proposed system can be used for deep tissue imaging with very high resolution and high field of view.

  4. Adaptive optics with pupil tracking for high resolution retinal imaging.

    Science.gov (United States)

    Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Harms, Fabrice; Dainty, Chris

    2012-02-01

    Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing ocular aberrations in real time and results in improved high resolution images that reveal the photoreceptor mosaic. Imaging the retina at high resolution has numerous potential medical applications, and yet for the development of commercial products that can be used in the clinic, the complexity and high cost of the present research systems have to be addressed. We present a new method to control the deformable mirror in real time based on pupil tracking measurements which uses the default camera for the alignment of the eye in the retinal imaging system and requires no extra cost or hardware. We also present the first experiments done with a compact adaptive optics flood illumination fundus camera where it was possible to compensate for the higher order aberrations of a moving model eye and in vivo in real time based on pupil tracking measurements, without the real time contribution of a wavefront sensor. As an outcome of this research, we showed that pupil tracking can be effectively used as a low cost and practical adaptive optics tool for high resolution retinal imaging because eye movements constitute an important part of the ocular wavefront dynamics.

  5. Benefits of GMR sensors for high spatial resolution NDT applications

    Science.gov (United States)

    Pelkner, M.; Stegemann, R.; Sonntag, N.; Pohl, R.; Kreutzbruck, M.

    2018-04-01

    Magneto resistance sensors like GMR (giant magneto resistance) or TMR (tunnel magneto resistance) are widely used in industrial applications; examples are position measurement and read heads of hard disk drives. However, in case of non-destructive testing (NDT) applications these sensors, although their properties are outstanding like high spatial resolution, high field sensitivity, low cost and low energy consumption, never reached a technical transfer to an application beyond scientific scope. This paper deals with benefits of GMR/TMR sensors in terms of high spatial resolution testing for different NDT applications. The first example demonstrates the preeminent advantages of MR-elements compared with conventional coils used in eddy current testing (ET). The probe comprises one-wire excitation with an array of MR elements. This led to a better spatial resolution in terms of neighboring defects. The second section concentrates on MFL-testing (magnetic flux leakage) with active field excitation during and before testing. The latter illustrated the capability of highly resolved crack detection of a crossed notch. This example is best suited to show the ability of tiny magnetic field sensors for magnetic material characterization of a sample surface. Another example is based on characterization of samples after tensile test. Here, no external field is applied. The magnetization is only changed due to external load and magnetostriction leading to a field signature which GMR sensors can resolve. This gives access to internal changes of the magnetization state of the sample under test.

  6. High-heat tank safety issue resolution program plan

    International Nuclear Information System (INIS)

    Wang, O.S.

    1993-12-01

    The purpose of this program plan is to provide a guide for selecting corrective actions that will mitigate and/or remediate the high-heat waste tank safety issue for single-shell tank (SST) 241-C-106. This program plan also outlines the logic for selecting approaches and tasks to mitigate and resolve the high-heat safety issue. The identified safety issue for high-heat tank 241-C-106 involves the potential release of nuclear waste to the environment as the result of heat-induced structural damage to the tank's concrete, if forced cooling is interrupted for extended periods. Currently, forced ventilation with added water to promote thermal conductivity and evaporation cooling is used to cool the waste. At this time, the only viable solution identified to resolve this safety issue is the removal of heat generating waste in the tank. This solution is being aggressively pursued as the permanent solution to this safety issue and also to support the present waste retrieval plan. Tank 241-C-106 has been selected as the first SST for retrieval. The program plan has three parts. The first part establishes program objectives and defines safety issues, drivers, and resolution criteria and strategy. The second part evaluates the high-heat safety issue and its mitigation and remediation methods and alternatives according to resolution logic. The third part identifies major tasks and alternatives for mitigation and resolution of the safety issue. Selected tasks and best-estimate schedules are also summarized in the program plan

  7. HIGH-RESOLUTION RADIO OBSERVATIONS OF THE REMNANT OF SN 1987A AT HIGH FREQUENCIES

    International Nuclear Information System (INIS)

    Zanardo, Giovanna; Staveley-Smith, L.; Potter, T. M.; Ng, C.-Y.; Gaensler, B. M.; Manchester, R. N.; Tzioumis, A. K.

    2013-01-01

    We present new imaging observations of the remnant of Supernova (SN) 1987A at 44 GHz, performed in 2011 with the Australia Telescope Compact Array (ATCA). The 0.''35 × 0.''23 resolution of the diffraction-limited image is the highest achieved to date in high-dynamic range. We also present a new ATCA image at 18 GHz derived from 2011 observations, which is super-resolved to 0.''25. The flux density is 40 ± 2 mJy at 44 GHz and 81 ± 6 mJy at 18 GHz. At both frequencies, the remnant exhibits a ring-like emission with two prominent lobes, and an east-west brightness asymmetry that peaks on the eastern lobe. A central feature of fainter emission appears at 44 GHz. A comparison with previous ATCA observations at 18 and 36 GHz highlights higher expansion velocities of the remnant's eastern side. The 18-44 GHz spectral index is α = –0.80 (S ν ∝ν α ). The spectral index map suggests slightly steeper values at the brightest sites on the eastern lobe, whereas flatter values are associated with the inner regions. The remnant morphology at 44 GHz generally matches the structure seen with contemporaneous X-ray and Hα observations. Unlike the Hα emission, both the radio and X-ray emission peaks on the eastern lobe. The regions of flatter spectral index align and partially overlap with the optically visible ejecta. Simple free-free absorption models suggest that emission from a pulsar wind nebula or a compact source inside the remnant may now be detectable at high frequencies or at low frequencies if there are holes in the ionized component of the ejecta.

  8. Ring artifact correction for high-resolution micro CT

    International Nuclear Information System (INIS)

    Kyriakou, Yiannis; Prell, Daniel; Kalender, Willi A

    2009-01-01

    In high-resolution micro CT using flat detectors (FD), imperfect or defect detector elements may cause concentric-ring artifacts due to their continuous over- or underestimation of attenuation values, which often disturb image quality. We here present a dedicated image-based ring artifact correction method for high-resolution micro CT, based on median filtering of the reconstructed image and working on a transformed version of the reconstructed images in polar coordinates. This post-processing method reduced ring artifacts in the reconstructed images and improved image quality for phantom and in in vivo scans. Noise and artifacts were reduced both in transversal and in multi-planar reformations along the longitudinal axis. (note)

  9. Measuring large-scale social networks with high resolution.

    Directory of Open Access Journals (Sweden)

    Arkadiusz Stopczynski

    Full Text Available This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years-the Copenhagen Networks Study. Specifically, we collect data on face-to-face interactions, telecommunication, social networks, location, and background information (personality, demographics, health, politics for a densely connected population of 1000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation and research agenda driving the study. Additionally, the paper details the data-types measured, and the technical infrastructure in terms of both backend and phone software, as well as an outline of the deployment procedures. We document the participant privacy procedures and their underlying principles. The paper is concluded with early results from data analysis, illustrating the importance of multi-channel high-resolution approach to data collection.

  10. High resolution spectroscopy in solids by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Bonagamba, T.J.

    1991-07-01

    The nuclear magnetic resonance (NMR) techniques for High Resolution Spectroscopy in Solids are described. Also the construction project of a partially home made spectrometer and its applications in the characterization of solid samples are shown in detail. The high resolution spectrometer used is implemented with the double resonance multiple pulses sequences and magic angle spinning (MAS) and can be used with solid and liquid samples. The maximum spinning frequency for the MAS experiment is in excess of 5 Khz, the double resonance sequences can be performed with any type of nucleus, in the variable temperature operating range with nitrogen gas: -120 0 C to +160 0 C, and is fully controlled by a Macintosh IIci microcomputer. (author)

  11. High resolution reservoir geological modelling using outcrop information

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Changmin; Lin Kexiang; Liu Huaibo [Jianghan Petroleum Institute, Hubei (China)] [and others

    1997-08-01

    This is China`s first case study of high resolution reservoir geological modelling using outcrop information. The key of the modelling process is to build a prototype model and using the model as a geological knowledge bank. Outcrop information used in geological modelling including seven aspects: (1) Determining the reservoir framework pattern by sedimentary depositional system and facies analysis; (2) Horizontal correlation based on the lower and higher stand duration of the paleo-lake level; (3) Determining the model`s direction based on the paleocurrent statistics; (4) Estimating the sandbody communication by photomosaic and profiles; (6) Estimating reservoir properties distribution within sandbody by lithofacies analysis; and (7) Building the reservoir model in sandbody scale by architectural element analysis and 3-D sampling. A high resolution reservoir geological model of Youshashan oil field has been built by using this method.

  12. High-resolution observation by double-biprism electron holography

    International Nuclear Information System (INIS)

    Harada, Ken; Tonomura, Akira; Matsuda, Tsuyoshi; Akashi, Tetsuya; Togawa, Yoshihiko

    2004-01-01

    High-resolution electron holography has been achieved by using a double-biprism interferometer implemented on a 1 MV field emission electron microscope. The interferometer was installed behind the first magnifying lens to narrow carrier fringes and thus enabled complete separation of sideband Fourier spectrum from center band in reconstruction process. Holograms of Au fine particles and single-crystalline thin films with the finest fringe spacing of 4.2 pm were recorded and reconstructed. The overall holography system including the reconstruction process performed well for holograms in which carrier fringes had a spacing of around 10 pm. High-resolution lattice images of the amplitude and phase were clearly reconstructed without mixing of the center band and sideband information. Additionally, entire holograms were recorded without Fresnel fringes normally generated by the filament electrode of the biprism, and the holograms were thus reconstructed without the artifacts caused by Fresnel fringes

  13. Chromatic Modulator for High Resolution CCD or APS Devices

    Science.gov (United States)

    Hartley, Frank T. (Inventor); Hull, Anthony B. (Inventor)

    2003-01-01

    A system for providing high-resolution color separation in electronic imaging. Comb drives controllably oscillate a red-green-blue (RGB) color strip filter system (or otherwise) over an electronic imaging system such as a charge-coupled device (CCD) or active pixel sensor (APS). The color filter is modulated over the imaging array at a rate three or more times the frame rate of the imaging array. In so doing, the underlying active imaging elements are then able to detect separate color-separated images, which are then combined to provide a color-accurate frame which is then recorded as the representation of the recorded image. High pixel resolution is maintained. Registration is obtained between the color strip filter and the underlying imaging array through the use of electrostatic comb drives in conjunction with a spring suspension system.

  14. HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

    2013-08-01

    Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

  15. Report on the ESO Workshop ''Astronomy at High Angular Resolution''

    Science.gov (United States)

    Boffin, H.; Schmidtobreick, L.; Hussain, G.; Berger, J.-Ph.

    2015-03-01

    A workshop took place in Brussels in 2000 on astrotomography, a generic term for indirect mapping techniques that can be applied to a huge variety of astrophysical systems, ranging from planets, single stars and binaries to active galactic nuclei. It appeared to be timely to revisit the topic given the many past, recent and forthcoming improvements in telescopes and instrumentation. We therefore decided to repeat the astrotomography workshop, but to put it into the much broader context of high angular resolution astronomy. Many techniques, from lucky and speckle imaging, adaptive optics to interferometry, are now widely employed to achieve high angular resolution and they have led to an amazing number of new discoveries. A summary of the workshop themes is presented.

  16. SRS station 16.3: high-resolution applications

    CERN Document Server

    Murphy, B M; Golshan, M; Moore, M; Reid, J; Kowalski, G

    2001-01-01

    Station 16.3 is a high-resolution X-ray diffraction beamline at Daresbury Laboratory Synchrotron Radiation Source. The data presented demonstrate the high-resolution available on the station utilising the recently commissioned four-reflection Si 1 1 1 monochromator and three-reflection Si 1 1 1 analyser. For comparison, a reciprocal space map of the two-bounce Si 1 1 1 monochromator and two-bounce analyser is also shown. Operation of the station is illustrated with examples for silicon, and for diamond. Lattice parameter variations were measured with accuracies in the part per million range and lattice tilts at the arc second level (DuMond, Phys. Rev. 52 (1937) 872).

  17. Turbine component casting core with high resolution region

    Science.gov (United States)

    Kamel, Ahmed; Merrill, Gary B.

    2014-08-26

    A hollow turbine engine component with complex internal features can include a first region and a second, high resolution region. The first region can be defined by a first ceramic core piece formed by any conventional process, such as by injection molding or transfer molding. The second region can be defined by a second ceramic core piece formed separately by a method effective to produce high resolution features, such as tomo lithographic molding. The first core piece and the second core piece can be joined by interlocking engagement that once subjected to an intermediate thermal heat treatment process thermally deform to form a three dimensional interlocking joint between the first and second core pieces by allowing thermal creep to irreversibly interlock the first and second core pieces together such that the joint becomes physically locked together providing joint stability through thermal processing.

  18. Strengthening IAEA safeguards using high-resolution commercial satellite imagery

    International Nuclear Information System (INIS)

    Zhang Hui

    2001-01-01

    Full text: In May 1997, the IAEA Board of Governors adopted the Additional Safeguards Protocol to improve its ability to detect the undeclared production of fissile material. This new strengthened safeguards system has opened the door for the IAEA to use of all types of information, including the potential use of commercial satellite imagery. We have therefore been investigating the feasibility of strengthening IAEA safeguards using commercial satellite imagery. Based on our analysis on a number of one-meter resolution IKONOS satellite images of military nuclear production facilities at nuclear states including Russia, China, India, Pakistan and Israel, we found that the new high-resolution commercial satellite imagery would play a new and valuable role in strengthening IAEA safeguards. Since 1999, images with a resolution of one meter have been available commercially from Space Imaging's IKONOS satellite. One-meter images from other companies are expected to enter the market soon. Although still an order of magnitude less capable than military imaging satellites, the capabilities of these new high-resolution commercial satellites are good enough to detect and identify the major visible characteristics of nuclear production facilities and sites. Unlike the classified spy satellite photos limited to few countries, the commercial satellite imagery is commercially available to anyone who wants to purchase it. Therefore, the new commercial satellite open a new chance that each state, international organizations, and non-governmental groups could use the commercial images to play a more proactive role in monitoring the nuclear activities in related countries and verifying the compliance of non-proliferation agreements. This could help galvanize support for intensified efforts to slow the pace of nuclear proliferation. To produce fissile materials (plutonium and highly enriched uranium) for weapons, a country would operate dedicated plutonium-production reactors and the

  19. High resolution X-ray spectroscopy of laser generated plasmas

    International Nuclear Information System (INIS)

    Faenov, A.Ya.; Skobelev, I.Yu.; Rosmej, F.B.

    1999-01-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.)

  20. High resolution X-ray spectroscopy of laser generated plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Faenov, A.Ya.; Skobelev, I.Yu. [Multicharged Ions Spectra Data Center of VNIIFTRI, Mendeleevo (Russian Federation); Rosmej, F.B. [Technische Hochschule Darmstadt (Germany). Inst. fuer Kernphysik

    1999-11-01

    The application of recently developed spectroscopic instruments in laser produced plasmas with simultaneous high spectral and spatial resolution combined with high luminosity discovered new types of X-ray spectra. These new types are characterised by the disappearance of the resonance lines and the strong emission of dielectronic satellite spectra. Several types of transitions of highly charged ions are discovered which are unknown from usual sources employed in atomic physics. New theoretical models are developed and successfully applied for the interpretation and for plasma diagnostics. (orig.) 28 refs.

  1. High-Resolution Climate Data Visualization through GIS- and Web-based Data Portals

    Science.gov (United States)

    WANG, X.; Huang, G.

    2017-12-01

    Sound decisions on climate change adaptation rely on an in-depth assessment of potential climate change impacts at regional and local scales, which usually requires finer resolution climate projections at both spatial and temporal scales. However, effective downscaling of global climate projections is practically difficult due to the lack of computational resources and/or long-term reference data. Although a large volume of downscaled climate data has been make available to the public, how to understand and interpret the large-volume climate data and how to make use of the data to drive impact assessment and adaptation studies are still challenging for both impact researchers and decision makers. Such difficulties have become major barriers preventing informed climate change adaptation planning at regional scales. Therefore, this research will explore new GIS- and web-based technologies to help visualize the large-volume regional climate data with high spatiotemporal resolutions. A user-friendly public data portal, named Climate Change Data Portal (CCDP, http://ccdp.network), will be established to allow intuitive and open access to high-resolution regional climate projections at local scales. The CCDP offers functions of visual representation through geospatial maps and data downloading for a variety of climate variables (e.g., temperature, precipitation, relative humidity, solar radiation, and wind) at multiple spatial resolutions (i.e., 25 - 50 km) and temporal resolutions (i.e., annual, seasonal, monthly, daily, and hourly). The vast amount of information the CCDP encompasses can provide a crucial basis for assessing impacts of climate change on local communities and ecosystems and for supporting better decision making under a changing climate.

  2. Spatial Ensemble Postprocessing of Precipitation Forecasts Using High Resolution Analyses

    Science.gov (United States)

    Lang, Moritz N.; Schicker, Irene; Kann, Alexander; Wang, Yong

    2017-04-01

    Ensemble prediction systems are designed to account for errors or uncertainties in the initial and boundary conditions, imperfect parameterizations, etc. However, due to sampling errors and underestimation of the model errors, these ensemble forecasts tend to be underdispersive, and to lack both reliability and sharpness. To overcome such limitations, statistical postprocessing methods are commonly applied to these forecasts. In this study, a full-distributional spatial post-processing method is applied to short-range precipitation forecasts over Austria using Standardized Anomaly Model Output Statistics (SAMOS). Following Stauffer et al. (2016), observation and forecast fields are transformed into standardized anomalies by subtracting a site-specific climatological mean and dividing by the climatological standard deviation. Due to the need of fitting only a single regression model for the whole domain, the SAMOS framework provides a computationally inexpensive method to create operationally calibrated probabilistic forecasts for any arbitrary location or for all grid points in the domain simultaneously. Taking advantage of the INCA system (Integrated Nowcasting through Comprehensive Analysis), high resolution analyses are used for the computation of the observed climatology and for model training. The INCA system operationally combines station measurements and remote sensing data into real-time objective analysis fields at 1 km-horizontal resolution and 1 h-temporal resolution. The precipitation forecast used in this study is obtained from a limited area model ensemble prediction system also operated by ZAMG. The so called ALADIN-LAEF provides, by applying a multi-physics approach, a 17-member forecast at a horizontal resolution of 10.9 km and a temporal resolution of 1 hour. The performed SAMOS approach statistically combines the in-house developed high resolution analysis and ensemble prediction system. The station-based validation of 6 hour precipitation sums

  3. Accessing High Spatial Resolution in Astronomy Using Interference Methods

    Science.gov (United States)

    Carbonel, Cyril; Grasset, Sébastien; Maysonnave, Jean

    2018-04-01

    In astronomy, methods such as direct imaging or interferometry-based techniques (Michelson stellar interferometry for example) are used for observations. A particular advantage of interferometry is that it permits greater spatial resolution compared to direct imaging with a single telescope, which is limited by diffraction owing to the aperture of the instrument as shown by Rueckner et al. in a lecture demonstration. The focus of this paper, addressed to teachers and/or students in high schools and universities, is to easily underline both an application of interferometry in astronomy and stress its interest for resolution. To this end very simple optical experiments are presented to explain all the concepts. We show how an interference pattern resulting from the combined signals of two telescopes allows us to measure the distance between two stars with a resolution beyond the diffraction limit. Finally this work emphasizes the breathtaking resolution obtained in state-of-the-art instruments such as the VLTi (Very Large Telescope interferometer).

  4. In situ high-resolution thermal microscopy on integrated circuits.

    Science.gov (United States)

    Zhuo, Guan-Yu; Su, Hai-Ching; Wang, Hsien-Yi; Chan, Ming-Che

    2017-09-04

    The miniaturization of metal tracks in integrated circuits (ICs) can cause abnormal heat dissipation, resulting in electrostatic discharge, overvoltage breakdown, and other unwanted issues. Unfortunately, locating areas of abnormal heat dissipation is limited either by the spatial resolution or imaging acquisition speed of current thermal analytical techniques. A rapid, non-contact approach to the thermal imaging of ICs with sub-μm resolution could help to alleviate this issue. In this work, based on the intensity of the temperature-dependent two-photon fluorescence (TPF) of Rhodamine 6G (R6G) material, we developed a novel fast and non-invasive thermal microscopy with a sub-μm resolution. Its application to the location of hotspots that may evolve into thermally induced defects in ICs was also demonstrated. To the best of our knowledge, this is the first study to present high-resolution 2D thermal microscopic images of ICs, showing the generation, propagation, and distribution of heat during its operation. According to the demonstrated results, this scheme has considerable potential for future in situ hotspot analysis during the optimization stage of IC development.

  5. High Time-Resolved Kinetic Temperatures of Solar Wind Minor Ions Measured with SOHO/CELIAS/CTOF

    Science.gov (United States)

    Janitzek, N. P.; Berger, L.; Drews, C.; Wimmer-Schweingruber, R. F.

    2017-12-01

    Solar wind heavy ions with an atomic number Z > 2 are referred to as minor ions since they represent a fraction of less than one percent of all solar wind ions. They can be therefore regarded as test particles, only reacting to but not driving the dynamics of the solar wind plasma, which makes them a unique diagnostic tool for plasma wave phenomena both in the solar atmosphere and the extended heliosphere. In the past, several studies have investigated the kinetic temperatures of minor ions, but due to low counting statistics these studies are based on ion velocity distribution functions (VDFs) recorded over time periods of several hours. The Charge Time-Of-Flight (CTOF) mass spectrometer as part of the Charge, ELement and Isotope Analysis System (CELIAS) onboard the SOlar and Heliospheric Observatory (SOHO) provides solar wind heavy ion 1D radial VDFs with excellent charge state separation, an unprecedented cadence of 5 minutes and very high counting statistics, exceeding similar state-of-the-art instruments by a factor of ten. In our study, based on CTOF measurements at Langrangian point L1 between DOY 150 and DOY 220 in 1996, we investigate systematically the influence of the VDF time resolution on the derived kinetic temperatures for solar wind silicon and iron ions. The selected ion set spans a wide range of mass-per-charge from 3 amu/e heavy ions with ion-cyclotron waves.

  6. Precision crystal alignment for high-resolution electron microscope imaging

    International Nuclear Information System (INIS)

    Wood, G.J.; Beeching, M.J.

    1990-01-01

    One of the more difficult tasks involved in obtaining quality high-resolution electron micrographs is the precise alignment of a specimen into the required zone. The current accepted procedure, which involves changing to diffraction mode and searching for symmetric point diffraction pattern, is insensitive to small amounts of misalignment and at best qualitative. On-line analysis of the fourier space representation of the image, both for determining and correcting crystal tilt, is investigated. 8 refs., 42 figs

  7. High-Resolution Imaging of Colliding and Merging Galaxies

    Science.gov (United States)

    Whitmore, Brad

    1991-07-01

    We propose to obtain high-resolution images, using the WF/PC, of two colliding and merging galaxies (i.e., NGC 4038/4039 = "The Antennae" and NGC 7252 ="Atoms-for-Peace Galaxy". Our goal is to use HST to make critical observations of each object in order to gain a better understanding of the various phases of the merger process. Our primary objective is to determine whether globular clusters are formed during mergers\\?

  8. Tuberculous otitis media: findings on high-resolution CT

    International Nuclear Information System (INIS)

    Lungenschmid, D.; Buchberger, W.; Schoen, G.; Schoepf, R.; Mihatsch, T.; Birbamer, G.; Wicke, K.

    1993-01-01

    We describe two cases of tuberculous otitis media studied with high-resolution computed tomography (CT). Findings included extensive soft tissue densities with fluid levels in the tympanic cavity, the antrum, the mastoid and petrous air cells. Multifocal bony erosions and reactive bone sclerosis were seen as well. CT proved valuable for planning therapy by accurately displaying the involvement of the various structures of the middle and inner ear. However, the specific nature of the disease could only be presumed. (orig.)

  9. Environmental high resolution electron microscopy and applications to chemical science

    OpenAIRE

    Boyes, Edward; Gai, Pratibha

    2017-01-01

    An environmental cell high resolution electron microscope (EHREM) has been developed for in situ studies of dynamic chemical reactions on the atomic scale. It allows access to metastable intermediate phases of catalysts and to sequences of reversible microstructural and chemical development associated with the activation, deactivation and poisoning of a catalyst. Materials transported through air can be restored or recreated and samples damaged, e.g. by dehydration, by the usual vacuum enviro...

  10. Creating the High-Resolution Settlement Layer - lessons learned

    Science.gov (United States)

    Gros, A.

    2017-12-01

    Facebook publishes the High-resolution Settlement Layer (HRSL: https://ciesin.columbia.edu/data/hrsl/) in collaboration with Columbia University's CIESIN institute and the World Bank. So far, data for 13 countries have been published over the past nine months. HRSL data for Burkina Faso, Ghana, Haiti, Ivory Coast, Madagascar, Malawi, Mexico, The Philippines, Rwanda, South Africa, Sri Lanka, Thailand, and Uganda are available for download. We will present a status update and report on lessons learned.

  11. High-resolution spectroscopy of gases for industrial applications

    OpenAIRE

    Fateev, Alexander; Clausen, Sønnik

    2012-01-01

    High-resolution spectroscopy of gases is a powerful technique which has various fundamental and practical applications: in situ simultaneous measurements of gas temperature and gas composition, radiative transfer modeling, validation of existing and developing of new databases and etc. Existing databases (e.g. HITRAN, HITEMP or CDSD) can normally be used for absorption spectra calculations at limited temperature/pressure ranges. Therefore experimental measurements of absorption/transmission s...

  12. High resolution atomic spectra of rare earths : progress report

    International Nuclear Information System (INIS)

    Saksena, G.D.; Ahmad, S.A.

    1976-01-01

    High resolution studies of atomic spectra of neodymium and gadolinium are being carried out on a recording Fabry-Perot spectrometer. The present progress report concerns work done on new assignments as well as confirmation of recently assigned electronic configurations and evaluation of isotope shifts of energy levels which have been possible from the isotope shift data obtained for several transitions of NdI, NdII and GdI, GdII respectively. (author)

  13. High-resolution CT of lesions of the optic nerve

    International Nuclear Information System (INIS)

    Peyster, R.G.; Hoover, E.D.; Hershey, B.L.; Haskin, M.E.

    1983-01-01

    The optic nerves are well demonstrated by high-resolution computed tomography. Involvement of the optic nerve by optic gliomas and optic nerve sheath meningiomas is well known. However, nonneoplastic processes such as increased intracranial pressure, optic neuritis, Grave ophthalmopathy, and orbital pseudotumor may also alter the appearance of the optic nerve/sheath on computed tomography. Certain clinical and computed tomographic features permit distinction of these nonneoplastic tumefactions from tumors

  14. Detectors for high resolution dynamic positron emission tomography

    International Nuclear Information System (INIS)

    Derenzo, S.E.; Budinger, T.F.; Huesman, R.H.

    1985-01-01

    Tomography is the technique of producing a photographic image of an opaque specimen by transmitting a beam of x-rays or gamma rays through the specimen onto an adjacent photographic film. The image results from variations in thickness, density, and chemical composition, of the specimen. This technique is used to study the metabolism of the human brain. This article examines the design of equipment used for high resolution dynamic positron emission tomography. 27 references, 5 figures, 3 tables

  15. High-Resolution Esophageal Manometry: A Time Motion Study

    Directory of Open Access Journals (Sweden)

    Daniel C Sadowski

    2008-01-01

    Full Text Available INTRODUCTION: High-resolution manometry (HRM of the esophagus is a new technique that provides a more precise assessment of esophageal motility than conventional techniques. Because HRM measures pressure events along the entire length of the esophagus simultaneously, clinical procedure time should be shorter because less catheter manipulation is required. According to manufacturer advertising, the new HRM system is more accurate and up to 50% faster than conventional methods.

  16. High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

    DEFF Research Database (Denmark)

    Dimzon, Ian Ken; Trier, Xenia; Frömel, Tobias

    2016-01-01

    High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid o......-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health. Graphical Abstract ᅟ....

  17. Chronic pneumonitis of infancy: high-resolution CT findings

    International Nuclear Information System (INIS)

    Olsen, Oeystein E.; Owens, Catherine M.; Sebire, Neil J.; Jaffe, Adam

    2004-01-01

    Chronic pneumonitis of infancy (CPI) is a very rare entity. We report the chest radiography and high-resolution CT (HRCT) findings in an infant with histopathologically confirmed CPI. The child was admitted for intensive care 18 h after birth and died at 39 days of age. On HRCT there was diffuse ground-glass change, interlobular septal thickening and discrete centrilobular nodules. An accurate diagnosis is crucial for correct management; however, several entities with the same HRCT findings are recognized. (orig.)

  18. Acute pulmonary injury: high-resolution CT and histopathological spectrum

    Science.gov (United States)

    Obadina, E T; Torrealba, J M

    2013-01-01

    Acute lung injury usually causes hypoxaemic respiratory failure and acute respiratory distress syndrome (ARDS). Although diffuse alveolar damage is the hallmark of ARDS, other histopathological patterns of injury, such as acute and fibrinoid organising pneumonia, can be associated with acute respiratory failure. Acute eosinophilic pneumonia can also cause acute hypoxaemic respiratory failure and mimic ARDS. This pictorial essay reviews the high-resolution CT findings of acute lung injury and the correlative histopathological findings. PMID:23659926

  19. Aspects of pulmonary histiocytosis X on high resolution computed tomography

    International Nuclear Information System (INIS)

    Costa, N.S.S.; Castro Lessa Angela, M.T. de; Angelo Junior, J.R.L.; Silva, F.M.D.; Kavakama, J.; Carvalho, C.R.R. de; Cerri, G.G.

    1995-01-01

    Pulmonary histiocytosis X is a disease that occurs in young adults and presents with nodules and cysts, mainly in upper lobes, with consequent pulmonary fibrosis. These pulmonary changes are virtually pathognomonic findings on high resolution computed tomography, that allows estimate the area of the lung involved and distinguish histiocytosis X from other disorders that also produces nodules and cysts. (author). 10 refs, 2 tabs, 6 figs

  20. COST EFFECTIVE AND HIGH RESOLUTION SUBSURFACE CHARACTERIZATION USING HYDRAULIC TOMOGRAPHY

    Science.gov (United States)

    2017-08-01

    objective of this project is to provide the DoD and its remediation contractors with the HT technology for delineating the spatial distribution of...STATEMENT Approved for public release; distribution is unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Hydraulic Tomography ( HT ) is a high-resolution...performance of subsurface remedial actions at environmental sites. The good technical performance and cost-effectiveness of HT have been demonstrated in