Science.gov

Sample records for advanced along-track scanning

  1. Directional Effects on Land Surface Temperatures Observed from Dual-View Data of the Advanced Along-Track Scanning Radiometer

    NASA Astrophysics Data System (ADS)

    Galve, Joan M.; Coll, Cesar; Niclos, Raquel; Valor, Enric; Sanchez, Juan Manuel

    2016-08-01

    The thermal radiance emitted by heterogeneous, non- isothermal land surfaces depends on the observation and illumination angles and their individual temperatures and emissivities. Therefore, the analysis of the angular variations in equivalent brightness temperature can be used to infer the thermal state of the sample components. The dual-view capability of the Advanced Along-Track Scanning Radiometer (AATSR) can be used to estimate the difference in brightness surface temperature (BST) between the near-simultaneous nadir and forward views in the 11 and 12μm bands. We developed a methodology to obtain the BSTs for the 11 and 12μm bands at nadir and forward views using an accurate single-channel atmospheric correction method on a pixel-by-pixel basis. The methodology was applied to two AATSR scenes over central-east Spain, on August 6, 2005 (daytime and night- time). The average value of the angular BST difference was 3.2K for daytime and 0.8K for night-time in the 11μmband, being similar for the 12μm band.

  2. Next generation along track scanning radiometer - SLSTR

    NASA Astrophysics Data System (ADS)

    Frerick, J.; Nieke, J.; Mavrocordatos, C.; Berruti, B.; Donlon, C.; Cosi, M.; Engel, W.; Bianchi, S.; Smith, Dave

    2012-10-01

    Since 1991, along track scanning radiometers (A)ATSR have been flown on a series of satellite platforms. These instruments use an along-track scanning design that provides two views of the same earth target through different atmospheric paths. Dual-view multispectral measurements can be used to derive an accurate atmospheric correction when retrieving geophysical parameters such as Sea Surface Temperature (SST). In addition, the (A)ATSR family of instruments use actively cooled detector systems and two precision calibration blackbody targets to maintain and manage on-board calibration. Visible channel calibration is implemented using a solar diffuser viewed once per orbit. As a consequence of these design features, resulting data derived from (A)ATSR instruments is both accurate and well characterized. After 10 years of Service the ENVISAT platform was lost in early 2012 asnd AATSR operations stopped. The Global Monitoring for Environment and Security (GMES) Sentinel-3 "Sea Land Surface Temperature Radiometer" (SLSTR) instrument is the successor to the AATSR family of instruments and is expected to launch in April 2014. The challenge for SLSTR is to develop and deliver a new instrument with identical or improved performance to that of the (A)ATSR family. The SLSTR design builds on the heritage features of the (A)ATSR with important extensions to address GMES requirements. SLSTR maintains the main instrument principles (along-track scanning, a two point infrared on-board radiometric calibration, actively cooled detectors, solar diffuser). The design also includes more spectral channels including additional bands at 1.3 and 2.2 μm providing enhanced cloud detection, dedicated fire channels, an increase of dual view swath from 500 to 740 km, an increase in the nadir swath of 1400 km. The increase in swath has led to, a new optical front-end design incorporating two rotating scan mirrors (with encoders to provide pointing knowledge) and an innovative flip mechanism to

  3. Post-processing to remove residual clouds from aerosol optical depth retrieved using the Advanced Along Track Scanning Radiometer

    NASA Astrophysics Data System (ADS)

    Sogacheva, Larisa; Kolmonen, Pekka; Virtanen, Timo H.; Rodriguez, Edith; Saponaro, Giulia; de Leeuw, Gerrit

    2017-02-01

    Cloud misclassification is a serious problem in the retrieval of aerosol optical depth (AOD), which might considerably bias the AOD results. On the one hand, residual cloud contamination leads to AOD overestimation, whereas the removal of high-AOD pixels (due to their misclassification as clouds) leads to underestimation. To remove cloud-contaminated areas in AOD retrieved from reflectances measured with the (Advanced) Along Track Scanning Radiometers (ATSR-2 and AATSR), using the ATSR dual-view algorithm (ADV) over land or the ATSR single-view algorithm (ASV) over ocean, a cloud post-processing (CPP) scheme has been developed at the Finnish Meteorological Institute (FMI) as described in Kolmonen et al. (2016). The application of this scheme results in the removal of cloud-contaminated areas, providing spatially smoother AOD maps and favourable comparison with AOD obtained from the ground-based reference measurements from the AERONET sun photometer network. However, closer inspection shows that the CPP also removes areas with elevated AOD not due to cloud contamination, as shown in this paper. We present an improved CPP scheme which better discriminates between cloud-free and cloud-contaminated areas. The CPP thresholds have been further evaluated and adjusted according to the findings. The thresholds for the detection of high-AOD regions (> 60 % of the retrieved pixels should be high-AOD (> 0.6) pixels), and cloud contamination criteria for low-AOD regions have been accepted as the default for AOD global post-processing in the improved CPP. Retaining elevated AOD while effectively removing cloud-contaminated pixels affects the resulting global and regional mean AOD values as well as coverage. Effects of the CPP scheme on both spatial and temporal variation for the period 2002-2012 are discussed. With the improved CPP, the AOD coverage increases by 10-15 % with respect to the existing scheme. The validation versus AERONET shows an improvement of the correlation

  4. Limb-darkening models from along-track operation of the ERBE scanning radiometer

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis; Manalo-Smith, Natividad; Avis, Lee M.

    1994-01-01

    During January and August 1985, the scanning radiometers of the Earth Radiation Budget Experiment(ERBE) aboard the Earth Radiation Budget Satellite (ERBS) and the NOAA-9 satellite were operated in along-track scanning modes. Along-track scanning permits the study of many measurement problems. It provides the data for developing a limb-darkening model for a single site over a short period of time and also permits the indentification of the scene from data taken at smaller nadir angles. The earth-emitted radiation measured by the scanners has been analyzed to produce limb-darkening models for a variety of scene types. Limb-darkening models relate the radiance in any given direction to the radiant flux. The scene types were computed using measurements within 10 deg of zenith. The models have values near zenith of 1.02-1.09. The typical zenith values of the model are 1.06 for both day and night for ERBS, and for NOAA-9, 1.06 for day and 1.05 for night. Mean models are formed for the ERBS and NOAA-9 results and are found to differ less than 1%, the ERBS results being the higher. The models vary about 1% with latitude near zenith and agree with earlier models that were used to analyze ERBE data typically to 2%.

  5. Limb-darkening functions as derived from along-track operation of the ERBE scanning radiometer for January 1985

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis; Manalo, Natividad; Suttles, John T.; Walker, Ira

    1989-01-01

    During January 1985, the scanning radiometer aboard the Earth Radiation Budget Satellite was operated to scan along-track. These data have been analyzed to produce limb-darkening functions for Earth emitted radiation, which relate the radiance in any given direction to the radiant exitance. Limb-darkening functions are presented in tabular form and shown as figures for 10 day cases and 12 night cases, corresponding to various scene types and latitude zones. The scene types were computed using measurements within 10 deg of zenith. The limb-darkening functions have values of 1.03 to 1.09 at zenith, with 1.06 being typical. It is found that latitude causes a variation on the order of 1 percent, except for zenith angles greater than 70 deg. These limb-darkening models are about 2 percent higher at zenith than the models derived from Nimbus 7 data.

  6. Limb-darkening functions as derived from along-track operation of the ERBE scanning radiometers for August 1985

    NASA Technical Reports Server (NTRS)

    Smith, G. Louis; Manalo, Natividad D.; Avis, Lee M.

    1990-01-01

    During August 1985, the scanning radiometers of the Earth Radiation Budget Experiment aboard the Earth Radiation Budget Satellite (ERBS) and the NOAA-9 satellite were operated in along-track scanning modes. These data were analyzed to produce limb darkening functions for Earth-emitted radiation, which relates the radiance in any given direction to the radiant exitence. Limb darkening functions are presented and shown as figures for day and night for each spacecraft. The scene types were computed using measurements within 10 deg of zenith. The models have values near zenith of 1.02 to 1.09, with values near 1.06 being typical. The typical value of the model is 1.06 for both day and night for ERBS, and for NOAA-9, the typical value at zenith is 1.06 for day and 1.05 for night. Mean models are formed for the ERBS and for the NOAA-9 results and are found to differ less than 1 percent, the ERBS results being the higher. The models vary about 1 percent with latitude near zenith.

  7. Global comparisons between the modified Pathfinder derived sea surface temperature and skin temperatures from the along-track scanning radiometer on board ERS-2: how close are we getting?

    NASA Technical Reports Server (NTRS)

    Vazquez, J.

    2001-01-01

    Sea Surface Temperatures (SST) as derived from the Pathfinder Sea Surface Temperature Data Set and the Along-Track Scanning Radiometer on-board the European Remote Sensing Satellite provide a unique opportunity for comparing two independent SST data sets.

  8. Towards a long-term Science Exploitation Plan for the Sea and Land Surface Temperature Radiometer on Sentinel-3 and the Along-Track Scanning Radiometers

    NASA Astrophysics Data System (ADS)

    Remedios, John J.; Llewellyn-Jones, David

    2014-05-01

    The Sea and Land Surface Temperature Radiometer (SLSTR) on Sentinel-3 is the latest satellite instrument in a series of dual-angle optical and thermal sensors, the Along-Track Scanning Radiometers (ATSRs). Operating on Sentinel-3, the SLSTR has a number of significant improvements compared to the original ATSRs including wider swaths for nadir and dual angles, emphasis on all surface temperature domains, dedicated fire channels and additional cloud channels. The SLSTR therefore provides some excellent opportunities to extend science undertaken with the ATSRs whilst also providing long-term data sets to investigate climate change. The European Space Agency, together with the Department of Energy and Climate Change, sponsored the production of an Exploitation Plan for the ATSRs. In the last year, this been extended to cover the SLSTR also. The plan enables UK and European member states to plan activities related to SLSTR in a long-term context. Covering climate change, oceanography, land surface, atmosphere and cryosphere science, particular attention is paid to the exploitation of long-term data sets. In the case of SLSTR, relevant products include sea, land, lake and ice surface temperatures; aerosols and clouds; fires and gas flares; land surface reflectances. In this presentation, the SLSTR and ATSR science Exploitation Plan will be outlined with emphasis on SLSTR science opportunities, on appropriate co-ordinating mechanisms and on example implementation plans. Particular attention will be paid to the challenges of linking ATSR records with SLSTR to provide consistent long-term data sets, and on the international context of such data sets. The exploitation plan approach to science may prove relevant and useful for other Sentinel instruments.

  9. Along-Track Reef Imaging System (ATRIS)

    USGS Publications Warehouse

    Brock, John; Zawada, Dave

    2006-01-01

    "Along-Track Reef Imaging System (ATRIS)" describes the U.S. Geological Survey's Along-Track Reef Imaging System, a boat-based sensor package for rapidly mapping shallow water benthic environments. ATRIS acquires high resolution, color digital images that are accurately geo-located in real-time.

  10. Sentinel-1 TOPS interferometry for along-track displacement measurement

    NASA Astrophysics Data System (ADS)

    Jiang, H. J.; Pei, Y. Y.; Li, J.

    2017-02-01

    The European Space Agency’s Sentinel-1 mission, a constellation of two C-band synthetic aperture radar (SAR) satellites, utilizes terrain observation by progressive scan (TOPS) antenna beam steering as its default operation mode to achieve wide-swath coverage and short revisit time. The beam steering during the TOPS acquisition provides a means to measure azimuth motion by using the phase difference between forward and backward looking interferograms within regions of burst overlap. Hence, there are two spectral diversity techniques for along-track displacement measurement, including multi-aperture interferometry (MAI) and “burst overlap interferometry”. This paper analyses the measurement accuracies of MAI and burst overlap interferometry. Due to large spectral separation in the overlap region, burst overlap interferometry is a more sensitive measurement. We present a TOPS interferometry approach for along-track displacement measurement. The phase bias caused by azimuth miscoregistration is first estimated by burst overlap interferometry over stationary regions. After correcting the coregistration error, the MAI phase and the interferometric phase difference between burst overlaps are recalculated to obtain along-track displacements. We test the approach with Sentinel-1 TOPS interferometric data over the 2015 Mw 7.8 Nepal earthquake fault. The results prove the feasibility of our approach and show the potential of joint estimation of along-track displacement with burst overlap interferometry and MAI.

  11. Dual frequency along-track interferometry

    NASA Technical Reports Server (NTRS)

    Carande, R. E.; Goldstein, R. M.; Lou, Y.; Miller, T.; Wheeler, K.

    1991-01-01

    In recent months, the JPL Airborne Synthetic Aperture Radar (AIRSAR) System has had a C-band Along-Track Interferometer installed. This, in addition to the L-band interferometer already operating in the system, makes it possible to simultaneously acquire two frequency interferometer data. Also, another upgrade involving the radar digital system allows each interferometer to be operated in such a way as to obtain two along-track interferometric baselines differing by a factor of 2 in length. An engineering checkout flight has demonstrated the ability to acquire and process both frequencies to high-resolution velocity maps of the ocean surface. The status of these interferometers and some initial data are presented.

  12. Advanced oxidation scanning probe lithography

    NASA Astrophysics Data System (ADS)

    Ryu, Yu K.; Garcia, Ricardo

    2017-04-01

    Force microscopy enables a variety of approaches to manipulate and/or modify surfaces. Few of those methods have evolved into advanced probe-based lithographies. Oxidation scanning probe lithography (o-SPL) is the only lithography that enables the direct and resist-less nanoscale patterning of a large variety of materials, from metals to semiconductors; from self-assembled monolayers to biomolecules. Oxidation SPL has also been applied to develop sophisticated electronic and nanomechanical devices such as quantum dots, quantum point contacts, nanowire transistors or mechanical resonators. Here, we review the principles, instrumentation aspects and some device applications of o-SPL. Our focus is to provide a balanced view of the method that introduces the key steps in its evolution, provides some detailed explanations on its fundamentals and presents current trends and applications. To illustrate the capabilities and potential of o-SPL as an alternative lithography we have favored the most recent and updated contributions in nanopatterning and device fabrication.

  13. Advanced oxidation scanning probe lithography.

    PubMed

    Ryu, Yu K; Garcia, Ricardo

    2017-04-07

    Force microscopy enables a variety of approaches to manipulate and/or modify surfaces. Few of those methods have evolved into advanced probe-based lithographies. Oxidation scanning probe lithography (o-SPL) is the only lithography that enables the direct and resist-less nanoscale patterning of a large variety of materials, from metals to semiconductors; from self-assembled monolayers to biomolecules. Oxidation SPL has also been applied to develop sophisticated electronic and nanomechanical devices such as quantum dots, quantum point contacts, nanowire transistors or mechanical resonators. Here, we review the principles, instrumentation aspects and some device applications of o-SPL. Our focus is to provide a balanced view of the method that introduces the key steps in its evolution, provides some detailed explanations on its fundamentals and presents current trends and applications. To illustrate the capabilities and potential of o-SPL as an alternative lithography we have favored the most recent and updated contributions in nanopatterning and device fabrication.

  14. The optical system of the Along Track Scanning Radiometer (ATSR)

    NASA Astrophysics Data System (ADS)

    Gray, Peter F.

    1986-01-01

    The optical arrangement of ATSR (for sea-surface temperature measurement) is described. Radiometric constraints upon the sizes, positions and temperatures of stops in the system are discussed and their impact on the design summarized. Data on the predicted image resolution are given, allowing for residual geometrical aberrations, diffraction, signal integration time and a manufacturing/assembly error budget.

  15. Multi-static MIMO along track interferometry (ATI)

    NASA Astrophysics Data System (ADS)

    Knight, Chad; Deming, Ross; Gunther, Jake

    2016-05-01

    Along-track interferometry (ATI) has the ability to generate high-quality synthetic aperture radar (SAR) images and concurrently detect and estimate the positions of ground moving target indicators (GMTI) with moderate processing requirements. This paper focuses on several different ATI system configurations, with an emphasis on low-cost configurations employing no active electronic scanned array (AESA). The objective system has two transmit phase centers and four receive phase centers and supports agile adaptive radar behavior. The advantages of multistatic, multiple input multiple output (MIMO) ATI system configurations are explored. The two transmit phase centers can employ a ping-pong configuration to provide the multistatic behavior. For example, they can toggle between an up and down linear frequency modulated (LFM) waveform every other pulse. The four receive apertures are considered in simple linear spatial configurations. Simulated examples are examined to understand the trade space and verify the expected results. Finally, actual results are collected with the Space Dynamics Laboratorys (SDL) FlexSAR system in diverse configurations. The theory, as well as the simulated and actual SAR results, are presented and discussed.

  16. Current Measurements in Rivers by Spaceborne Along-Track Interferometric Synthetic Aperture Radar

    NASA Astrophysics Data System (ADS)

    Romeiser, R.; Gruenler, S.; Stammer, D.

    2007-12-01

    The along-track interferometric synthetic aperture radar (along-track InSAR) technique permits a high-resolution imaging of ocean surface current fields all over the world from satellites. Results of the Shuttle Radar Topography Mission (SRTM) in early 2000 and theoretical findings indicate that spaceborne along-track InSARs are also suitable for current retrievals in rivers if the water surface is at least 200-300 m wide and sufficiently rough for microwave backscattering at slanting incidence. Accordingly, the technique is quite attractive for global river runoff monitoring, where it can complement water level and surface slope measurements by advanced radar altimeters and other efforts. The German satellite TerraSAR-X, which was launched in June 2007, will permit along-track interferometry in an experimental mode of operation. This will be the first opportunity for repeated current measurements from space at selected test sites during a period of several years. In this presentation we give an overview of basic principles and theoretical limits of current measurements by along-track InSAR, example results from SRTM, and predicted along-track InSAR capabilities of TerraSAR-X. An SRTM-derived surface current field in the lower Elbe river (Germany) agrees well with numerical hydrodynamic model results; characteristic lateral current variations around a pronounced main flow channel in the 1500 m wide river are resolved. Despite clearly suboptimal instrument parameters, TerraSAR-X simulations indicate an even better data quality. Depending on width, surface roughness, and relative flow direction of a river, current estimates with an accuracy better than 0.1 m/s will be possible with an effective spatial resolution of a few hundred meters to kilometers.

  17. A Time Domain Along-Track SAR Interferometry Method

    NASA Astrophysics Data System (ADS)

    Cao, N.; Lee, H.; Jung, H. C.

    2015-12-01

    Differential interferometric synthetic aperture radar (DInSAR) has already been proven to be a useful technique for measuring ground displacement at millimeter level. One major drawback of traditional DInSAR technique is that only 1-D deformation in slant range direction can be detected. In order to obtain along-track displacement using a single InSAR pair, two major attempts have been made. The first one is based on cross-correlation between two SAR amplitude images. The second attempt is based on split-beam processing to generate two SAR images from forward- and backward-looking beams. Comparing with the former method, this multiple-aperture SAR interferometry (MAI) can achieve much better measurement accuracy. The major drawback of the MAI method is degraded signal to noise ratio (SNR) and along-track resolution since total along-track integration time decreases in the split-beam procedure. In order to improve the SNR and along-track resolution as well as to extract the terrain displacement in the along-track direction, a time domain along-track SAR interferometry method is proposed in this study. Using traditional time domain backprojection method, the phase component corresponding to slant range direction offset can be estimated and removed from the range compressed SAR signal. Then a phase estimation procedure is implemented to obtain the phase component in the along-track direction. Using ALOS PALSAR data over Kilauea Volcano area in Hawai'i, our experimental results demonstrate the improved performance of the proposed method in extracting 2-D terrain deformation map from one pair of SAR images.

  18. Tight formation flying for an along-track SAR interferometer

    NASA Astrophysics Data System (ADS)

    Gill, Eberhard; Runge, Hartmut

    2004-08-01

    While space-borne synthetic aperture radar (SAR) has evolved into a mature technology over the past two decades, there is a growing interest in interferometric SAR applications. Especially along-track interferometry with its capability to resolve the velocity of on-ground objects and ocean currents is of high interest for scientific applications. The accuracy of the resolved velocity on ground scales directly with the along-track separation between adjacent SAR antennas. Since space vehicles are quite limited in size, a formation flying approach with two SAR instruments distributed onto two spacecraft thus appears to be an innovative approach to along-track SAR interferometry. In the framework of an ESA study, this paper discusses the potential benefits, drawbacks and problems associated with a close formation flight for an along-track interferometry SAR mission. To this end, the absolute and relative orbit reconstruction requirements for the SAR processing chain are derived from basic interferometric principles as well as appropriate baselines of the satellite formation in L-Band and X-Band. A discussion of potential space-borne navigation sensors is presented along with the accuracy of state-of-the-art relative orbit reconstruction. Finally, appropriate thrusters for formation acquisition and control are discussed together with approaches to formation flying guidance and control as well as fuel consumption.

  19. Vector Along-Track Interferometry for Ocean Current mapping

    NASA Technical Reports Server (NTRS)

    Rodriguez, Ernesto; Imel, David; Madsen, Soren

    1996-01-01

    We examine the feasibility of measuring Along-Track Interferometric (ATI) vector ocean velocities using the azimuth beamwidth of the SAR antenna to obtain angular diversity, at the expense of spatial resolution. A simple model of the measurement is introduced for point targets and moving ocean surfaces to help interpret the velocity measurements.

  20. Phase-wrapping ambiguity in along-track interferometry

    NASA Astrophysics Data System (ADS)

    Deming, Ross; Ilin, Roman; Best, Matthew

    2013-05-01

    In a previous SPIE paper we described several variations of along-track interferometry (ATI), which can be used for moving target detection and geo-location in clutter. ATI produces a phase map in range/Doppler coordinates by combining radar data from several receive channels separated fore-and-aft (along-track) on the sensor platform. In principle, the radial velocity of a moving target can be estimated from the ATI phase of the pixels in the target signature footprint. Once the radial velocity is known, the target azimuth follows directly. Unfortunately, the ATI phase is wrapped, i.e., it repeats in the interval [-π, π], and therefore the mapping from ATI phase to target azimuth is non-unique. In fact, depending on the radar system parameters, each detected target can map to several equally-likely azimuth values. In the present paper we discuss a signal processing method for resolving the phase wrapping ambiguity, in which the radar bandwidth is split into a high and low sub-band in software, and an ATI phase map is generated for each. By subtracting these two phase maps we can generate a coarse, but unambiguous, radial velocity estimate. This coarse estimate is then combined with the fine, but ambiguous estimate to pinpoint the target radial velocity, and therefore its azimuth. Since the coarse estimate is quite sensitive to noise, a rudimentary tracker is used to help smooth out the phase errors. The method is demonstrated on Gotcha 2006 Challenge data.

  1. Mitigation of along-track artifacts in unconstrained mass transport models based on GRACE satellite data

    NASA Astrophysics Data System (ADS)

    Ditmar, Pavel; Hashemi Farahani, Hassan; Encarnação, João.

    2010-05-01

    The satellite gravity mission GRACE (Gravity Recovery And Climate Experiment), which was launched in 2002, offers a unique opportunity to monitor tiny variations of the Earth's gravity and associated mass transport from space. In particular, the redistribution of water in the Earth's system can be traced in this way, which is critical for monitoring key climate indicators such as ice-sheet mass balance, terrestrial water-storage change, sea-level rise, and ocean circulation. Unfortunately, mass transport models based on GRACE data suffer from along-track artifacts. In order to suppress these artifacts, various filtering algorithms are applied to unconstrained GRACE-based models at the post-processing stage. However, any filtering not only suppresses noise but also distorts signals. Therefore, it is important to study the precise origin of the along-track artifacts in an attempt to mitigate them already at the level of unconstrained solutions. We identify two major causes of along-track artifacts: (1) the presence of low-frequency noise in GRACE data and (2) the observation principle of the GRACE satellite mission, which results in a poor sensitivity of the collected inter-satellite ranging data to the East-West gradient of the gravity field. According to our studies, an increased level of noise at low frequencies can be mostly explained by inaccuracies in the estimated orbits of GRACE satellites. To suppress this type of noise, we propose: (i) to use more advanced orbit determination procedures that allow deficiencies of available force models to be mitigated; (ii) to apply proper data weighting in the frequency domain, so that that the influence of frequencies with a large noise level is downweighted. As far as East-West gradients are concerned, we find it important to use the statistically optimal combination of GRACE inter-satellite ranging data with other observations (particularly, absolute positions of GRACE and CHAMP satellites). The added value of each of

  2. Testing of Advanced Generic Scan Mechanisms (AGSM)

    NASA Astrophysics Data System (ADS)

    Anderson, M. J.; Forshaw, T.; Parzianello, G.

    2013-09-01

    AGSM was envisaged as a generic scan drive mechanism for large across track scanners (e.g. EGPM mission). The two Breadboard Models (BBM's) tested in this programme were foreseen as technology demonstrators and incorporated some novel features, i.e:• Electrical power transfer through the ball bearings• Lead-lubricated bearings with lightweight, ball riding cages for long lifetime (120 million revs) with lead-bronze inserts to replenish lubricant.• A small (< 1 microlitre) drop of Z25 oil added to one bearing to help reduce wear of the lead lubricant film during ground operation.This paper details the results and findings from testing BBM2 and compares them to those from testing carried out on a previous BBM (BBM1) [1].

  3. Advanced scanning methods with tracking optical coherence tomography

    PubMed Central

    Ferguson, R. Daniel; Iftimia, Nicusor V.; Ustun, Teoman; Wollstein, Gadi; Ishikawa, Hiroshi; Gabriele, Michelle L.; Dilworth, William D.; Kagemann, Larry; Schuman, Joel S.

    2013-01-01

    An upgraded optical coherence tomography system with integrated retinal tracker (TOCT) was developed. The upgraded system uses improved components to extend the tracking bandwidth, fully integrates the tracking hardware into the optical head of the clinical OCT system, and operates from a single software platform. The system was able to achieve transverse scan registration with sub-pixel accuracy (~10 μm). We demonstrate several advanced scan sequences with the TOCT, including composite scans averaged (co-added) from multiple B-scans taken consecutively and several hours apart, en face images collected by summing the A-scans of circular, line, and raster scans, and three-dimensional (3D) retinal maps of the fovea and optic disc. The new system achieves highly accurate OCT scan registration yielding composite images with significantly improved spatial resolution, increased signal-to-noise ratio, and reduced speckle while maintaining well-defined boundaries and sharp fine structure compared to single scans. Precise re-registration of multiple scans over separate imaging sessions demonstrates TOCT utility for longitudinal studies. En face images and 3D data cubes generated from these data reveal high fidelity image registration with tracking, despite scan durations of more than one minute. PMID:19498823

  4. Blind phase calibration for along-track interferometry: application to Gotcha data set

    NASA Astrophysics Data System (ADS)

    Uysal, Faruk; Murthy, Vinay; Scarborough, Steven M.

    2014-06-01

    Along-Track Interferometry (ATI) has been widely used for ground moving target indication (GMTI) in airborne synthetic aperture radar (SAR) systems. In ideal cases, the ATI phase obtained using two phase centers that are aligned in the along-track dimension yield clutter-only pixels with zero phase. However, the platform's motion may create a cross-track displacement between the two phase centers and in turn offset the phase centers' baseline from the along track dimension. This cross-track offset leads to non-zero phase for clutter-only pixels, necessitating calibration for accurate GMTI. This paper proposes a blind calibration method to correct the along-track baseline error in ATI-SAR systems. The success of the proposed method is shown on a set of measured data from the Gotcha sensor.

  5. Application of scanning acoustic microscopy to advanced structural ceramics

    NASA Technical Reports Server (NTRS)

    Vary, Alex; Klima, Stanley J.

    1987-01-01

    A review is presentod of research investigations of several acoustic microscopy techniques for application to structural ceramics for advanced heat engines. Results obtained with scanning acoustic microscopy (SAM), scanning laser acoustic microscopy (SLAM), scanning electron acoustic microscopy (SEAM), and photoacoustic microscopy (PAM) are compared. The techniques were evaluated on research samples of green and sintered monolithic silicon nitrides and silicon carbides in the form of modulus-of-rupture bars containing deliberately introduced flaws. Strengths and limitations of the techniques are described with emphasis on statistics of detectability of flaws that constitute potential fracture origins.

  6. Along-Track Products from NASA's Operation IceBridge Flight Line Data

    NASA Astrophysics Data System (ADS)

    Rogers, S. R.; Scambos, T. A.; Raup, B. H.; Haran, T. M.; Kaminski, M. L.

    2011-12-01

    A set of value-added data products (VAPs)is being developed at the National Snow and Ice Data Center (NSIDC) from the along-flight multi-sensor data sets gathered during the IceBridge flights of the DC-8 and P-3 NASA aircraft. These new products co-locate data from the IceBridge sensor suite and derive useful analysis parameters using one or more of the data streams. There are two along-track data sets being developed at NSIDC, one intended to facilitate ice sheet dynamics investigations, and one to characterize ice sheet surface and near-surface processes. Ice dynamics along-track products currently incorporate data from the Airborne Topographic Mapper (ATM), Sanders Gravimeter, Multi-Channel Coherent Depth Sounder (MCORDS) ice-penetrating radar system, and Digital Mapping System (DMS) camera. Derived products currently include regional slope (four hundred meter horizontal scale) and driving stress. Ice-dynamics along-track products currently under development focus on comparisons of the gravity and ice thickness data, as well as more detailed ice flow analysis. The along-track IceBridge data will be integrated with existing ice-sheet-wide data sets (for Greenland and Antarctica) such as DEMs, bed elevation and ice thickness, free-air anomaly from satellite data, and balance velocity. Ice sheet surface properties along-track products combine co-located data from the ATM, snow radar or accumulation radar, and DMS instrument, extracting roughness data, layer depth for radar reflections and images along with basic instrument measurement values. In addition to scientific parameters, various data vetting parameters determine how well aligned the sensors are for a given flight line point. A related product for sea ice properties, sea ice freeboard, and estimated sea ice thickness is being developed by NASA-GSFC personnel. The along-track VAPs are formatted into comma-separated values files for easy access by the science community. They are being integrated into the

  7. Along Track Interferometry Synthetic Aperture Radar (ATI-SAR) Techniques for Ground Moving Target Detection

    DTIC Science & Technology

    2006-01-01

    DISTRIBUTION CODE 13. ABSTRACT (Maximum 200 Words) Conventional along track interferometric synthetic aperature radar , ATI-SAR, approaches can detect...House, Inc., Norwood, MA, 1995. [14] R. Bamler and P. Hartl, " Synthetic aperture radar interferometry," Inverse Problems, vol. 14, R1-R54, 1998. [15... SYNTHETIC APERTURE RADAR (ATI-SAR) TECHNIQUES FOR GROUND MOVING TARGET DETECTION Stiefvater Consultants

  8. H Scan/AHP advanced technology proposal evaluation process

    SciTech Connect

    Mack, S.; Valladares, M.R.S. de

    1996-10-01

    It is anticipated that a family of high value/impact projects will be funded by the Hydrogen Program to field test hydrogen technologies that are at advanced stages of development. These projects will add substantial value to the Program in several ways, by: demonstrating successful integration of multiple advanced technologies, providing critical insight on issues of larger scale equipment design, construction and operations management, yielding cost and performance data for competitive analysis, refining and deploying enhanced safety measures. These projects will be selected through a competitive proposal evaluation process. Because of the significant scope and funding levels of projects at these development phases, Program management has indicated the need for an augmented proposal evaluation strategy to ensure that supported projects are implemented by capable investigative teams and that their successful completion will optimally advance programmatic objectives. These objectives comprise a complex set of both quantitative and qualitative factors, many of which can only be estimated using expert judgment and opinion. To meet the above need, the National Renewable Energy Laboratory (NREL) and Energetics Inc. have jointly developed a proposal evaluation methodology called H Scan/AHP. The H Scan component of the process was developed by NREL. It is a two-part survey instrument that substantially augments the type and scope of information collected in a traditional proposal package. The AHP (Analytic Hierarchy Process) component was developed by Energetics. The AHP is an established decision support methodology that allows the Program decision makers to evaluate proposals relatively based on a unique set of weighted criteria that they have determined.

  9. PTM Along Track Algorithm to Maintain Spacing During Same Direction Pair-Wise Trajectory Management Operations

    NASA Technical Reports Server (NTRS)

    Carreno, Victor A.

    2015-01-01

    Pair-wise Trajectory Management (PTM) is a cockpit based delegated responsibility separation standard. When an air traffic service provider gives a PTM clearance to an aircraft and the flight crew accepts the clearance, the flight crew will maintain spacing and separation from a designated aircraft. A PTM along track algorithm will receive state information from the designated aircraft and from the own ship to produce speed guidance for the flight crew to maintain spacing and separation

  10. Moving Target Detection with Along-Track SAR Interferometry. A Theoretical Analysis

    DTIC Science & Technology

    2002-08-01

    1994). Intensity and Phase Statistics of Multilook Polarimetric and Interfer- ometric SAR Imagery. IEEE Trans. Geoscience and Remote Sensing, GRS-32(5... Multilook Polarimetric Signatures. IEEE Trans. Geoscience and Remote Sensing, GRS-32(3), 562-574. 4. Gierull, C.H. (July 2001). Statistics of SAR ...Along-Track SAR Interferometry A Theoretical Analysis Christoph H. Gierull DISTRIBUTION STATEMENTA Approved for Public Release Distribution Unlimited

  11. What Limits an Altimeter's Resolution of Along-Track Geoid Slope? Insights from Saral and Cryosat

    NASA Astrophysics Data System (ADS)

    Smith, W. H. F.

    2014-12-01

    Satellite altimeter data collected along densely spaced ground tracks can map the marine gravity field, revealing the tectonic fabric of the sea floor. This application requires high accuracy of the along-track derivative of sea surface height over distances shorter than 80 km, and so is very sensitive to the instrument's range precision and any factors that produce short-scale along-track correlation of range measurement errors. To date the altimeters that have collected data over a dense network of ground tracks all acquired their largest data sets in Ku band and employing conventional (incoherent) processing. Two new altimeters go beyond conventional Ku instruments. SARAL AltiKa operates as an incoherent altimeter at Ka-band, and CryoSat collects some Ku-band data in a SAR mode to permit coherent processing for aperture synthesis and delay-Doppler calculations. The along-track range noise correlation characteristics of each of these new measurements are different from what has been seen in previous altimeters. SARAL AltiKa has a lower noise floor than pre-Cryosat Ku-band instruments and its noise spectrum shows decorrelation at different wavelengths, in partial agreement with theoretical work on speckle noise decorrelation over homogeneous surfaces. This improved noise performance results in demonstrable improvement in the resolution of geoid anomalies over small seamounts. Retracking of Cryosat's SAR mode multi-looked waveform yields a decorrelation of range errors unlike that found in conventional instruments, such that it doesn't require two-pass retracking to get the best geoid slope resolution. This is due mainly to the waveform's shape, which yields partial derivatives with respect to geophysical parameter estimates that are more nearly orthogonal than in conventional Ku-band Brown model waveforms. Further understanding of the limits on range precision in these instruments will require understanding of the heterogeneities in reflecting surfaces that are

  12. Arc Welders' pneumoconiosis: application of advanced scanning electron microscopy.

    PubMed

    Guidotti, T L; Abraham, J L; DeNee, P B; Smith, J R

    1978-01-01

    Study of lung tissue from necropsy of a 58-year-old arc welder with arc welders' pneumoconiosis, confirmed by history, chest radiography, and pathology, demonstrates the versatility and usefulness of new techniques in scanning electron microscopy (SEM). Secondary electron imaging, the most familiar SEM mode, showed heavy cellular infiltrates in alveoli, the interstitium, and within the interstices of loose whorled fibrotic nodules. Backscattered electron imaging, in which contrast is proportional to elemental atomic number, revealed intracellular metal particles not otherwise visible. Microprobe analysis, energy-dispersive x-ray spectrometry, mapped elemeental iron over the particle image and identified traces of silicon in the whorled nodules. Arc welders' pneumoconiosis appears to be more than a benign siderosis resulting from particulate iron deposition. Simultaneous exposure to other components of welding fumes may alter the pathologic picture, inducing a more complicated fibrotic reaction. The more recently developed advanced techniques of SEM are well suited to the study of pneumoconioses and other problems of heterogenous tissue and mixed chemical systems.

  13. Along-track interferometry for simultaneous SAR and GMTI: application to Gotcha challenge data

    NASA Astrophysics Data System (ADS)

    Deming, Ross W.

    2011-06-01

    This paper describes several alternative techniques for detecting and localizing slowly-moving targets in cultural clutter using synthetic aperture radar (SAR) data. Here, single-pass data is jointly processed from two or more receive channels which are spatially offset in the along-track direction. We concentrate on two clutter cancelation methods known as the displaced phase center antenna (DPCA) technique and along-track SAR interferometry (AT-InSAR). Unlike the commonly-used space-time adaptive processing (STAP) techniques, both DPCA and AT-InSAR tend to perform well in the presence of non-homogeneous urban or mountainous clutter. We show, mathematically, the striking similarities between DPCA and AT-InSAR. Furthermore, we demonstrate using experimental SAR data that these two techniques yield complementary information, which can be combined into a "hybrid" technique that incorporates the advantages of each for significantly better performance. Results are generated using the Gotcha challenge data, acquired using a three-channel X-band spotlight SAR system.

  14. Summary of along-track data from the Earth radiation budget satellite for several major desert regions

    NASA Technical Reports Server (NTRS)

    Brooks, David R.; Fenn, Marta A.

    1988-01-01

    For several days in January and August 1985, the Earth Radiation Budget Satellite, a component of the Earth Radiation Budget Experiment (ERBE), was operated in an along-track scanning mode. A survey of radiance measurements is given for four desert areas in Africa, the Arabian Peninsula, Australia, and the Sahel region of Africa. Each overflight provides radiance information for four scene categories: clear, partly cloudy, mostly cloudy, and overcast. The data presented include the variation of radiance in each scene classification as a function of viewing zenith angle during each overflight of the five target areas. Several features of interest in the development of anisotropic models are evident, including day-night differences in longwave limb darkening and the azimuthal dependence of short wave radiance. There is some evidence that surface features may introduce thermal or visible shadowing that is not incorporated in the usual descriptions of the anisotropic behavior of radiance as viewed from space. The data also demonstrate that the ERBE scene classification algorithms give results that, at least for desert surfaces, are a function of viewing geometry.

  15. Innovative advanced occlusion planning with superimposed CT and optical scans.

    PubMed

    Tremblay, Gilbert

    2011-04-01

    In order to increase the likelihood of a successful treatment plan outcome, it is critical to be able to effectively view the patient's underlying bony skeletal relationship of his or her TMJ. An innovative approach suggested to achieve this is to use the CT scan, optical scan, and Kois deprogrammer. Once the vertical dimension has been increased, the novelty of this approach is the ability to superimpose both scans along with the Kois deprogrammer and, using computer software, evaluate the TMJ position in three dimensions. This case presentation describes how TMJ CT scan evaluation is used in planning a complex rehabilitation case, given that the occlusion structures can be visualized independently and interactively.

  16. Moving target detection in foliage using along track monopulse synthetic aperture radar imaging.

    PubMed

    Soumekh, M

    1997-01-01

    This paper presents a method for detecting moving targets embedded in foliage from the monostatic and bistatic synthetic aperture radar (SAR) data obtained via two airborne radars. The two radars, which are mounted on the same aircraft, have different coordinates in the along track (cross-range) domain. However, unlike the interferometric SAR systems used for topographic mapping, the two radars possess a common range and altitude (i.e., slant range). The resultant monopulse SAR images are used to construct difference and interferometric images for moving target detection. It is shown that the signatures of the stationary targets are weakened in these images. Methods for estimating a moving target's motion parameters are discussed. Results for an ultrawideband UHF SAR system are presented.

  17. Advanced gamma ray technology for scanning cargo containers.

    PubMed

    Orphan, Victor J; Muenchau, Ernie; Gormley, Jerry; Richardson, Rex

    2005-01-01

    The shipping industry is striving to increase security for cargo containers without significantly impeding traffic. Three Science Applications International Corporation (SAIC) development programs are supporting this effort. SAIC's ICIS system combines SAIC's VACIS gamma ray imaging, radiation scanning, OCR, elemental analysis and other technologies to scan containers for nuclear materials and other hazards in normal terminal traffic. SAIC's enhanced gamma ray detector improves VACIS image resolution by a factor of three. And SAIC's EmptyView software analyzes VACIS images to automatically verify empty containers.

  18. Exploring Multi-Sensor Satellite Synergies to Provide Direction to High Resolution Along-Track Altimtery Currents

    NASA Astrophysics Data System (ADS)

    Nencioli, Francesco; Quartly, Graham; Miller, Peter

    2015-12-01

    A new approach to compute along-track velocity components by combining altimetry-based across-track components and front directions from remote sensing maps of surface chlorophyll concentration is proposed. The analysis focuses on the South Madagascar region characterized by the strong East Madagascar Current and sharp gradients of surface tracers. The results are compared against in-situ observations from three moorings along the Jason-1 track 196. Accurate information on the total velocity direction is the key factor for obtaining accurate estimates of along-track velocities. Although with some limitations, surface tracer fronts can be successfully used to retrieve such information.

  19. Raman mapping using advanced line-scanning systems: geological applications.

    PubMed

    Bernard, Sylvain; Beyssac, Olivier; Benzerara, Karim

    2008-11-01

    By allowing nondestructive chemical and structural imaging of heterogeneous samples with a micrometer spatial resolution, Raman mapping offers unique capabilities for assessing the spatial distribution of both mineral and organic phases within geological samples. Recently developed line-scanning Raman mapping techniques have made it possible to acquire Raman maps over large, millimeter-sized, zones of interest owing to a drastic decrease of the data acquisition time without losing spatial or spectral resolution. The synchronization of charge-coupled device (CCD) measurements with x,y motorized stage displacement has allowed dynamic line-scanning Raman mapping to be even more efficient: total acquisition time may be reduced by a factor higher than 100 compared to point-by-point mapping. Using two chemically and texturally complex geological samples, a fossil megaspore in a metamorphic rock and aragonite-garnet intergrowths in an Eclogitic marble, we compare here two recent versions of line-scanning Raman mapping systems and discuss their respective advantages and disadvantages in terms of acquisition time, image quality, spatial and imaging resolutions, and signal-to-noise ratio. We show that line-scanning Raman mapping techniques are particularly suitable for the characterization of such samples, which are representative of the general complexity of geological samples.

  20. Time-Domain Simulation of Along-Track Interferometric SAR for Moving Ocean Surfaces.

    PubMed

    Yoshida, Takero; Rheem, Chang-Kyu

    2015-06-10

    A time-domain simulation of along-track interferometric synthetic aperture radar (AT-InSAR) has been developed to support ocean observations. The simulation is in the time domain and based on Bragg scattering to be applicable for moving ocean surfaces. The time-domain simulation is suitable for examining velocities of moving objects. The simulation obtains the time series of microwave backscattering as raw signals for movements of ocean surfaces. In terms of realizing Bragg scattering, the computational grid elements for generating the numerical ocean surface are set to be smaller than the wavelength of the Bragg resonant wave. In this paper, the simulation was conducted for a Bragg resonant wave and irregular waves with currents. As a result, the phases of the received signals from two antennas differ due to the movement of the numerical ocean surfaces. The phase differences shifted by currents were in good agreement with the theoretical values. Therefore, the adaptability of the simulation to observe velocities of ocean surfaces with AT-InSAR was confirmed.

  1. Theoretical Accuracy of Along-Track Displacement Measurements from Multiple-Aperture Interferometry (MAI)

    PubMed Central

    Jung, Hyung-Sup; Lee, Won-Jin; Zhang, Lei

    2014-01-01

    The measurement of precise along-track displacements has been made with the multiple-aperture interferometry (MAI). The empirical accuracies of the MAI measurements are about 6.3 and 3.57 cm for ERS and ALOS data, respectively. However, the estimated empirical accuracies cannot be generalized to any interferometric pair because they largely depend on the processing parameters and coherence of the used SAR data. A theoretical formula is given to calculate an expected MAI measurement accuracy according to the system and processing parameters and interferometric coherence. In this paper, we have investigated the expected MAI measurement accuracy on the basis of the theoretical formula for the existing X-, C- and L-band satellite SAR systems. The similarity between the expected and empirical MAI measurement accuracies has been tested as well. The expected accuracies of about 2–3 cm and 3–4 cm (γ = 0.8) are calculated for the X- and L-band SAR systems, respectively. For the C-band systems, the expected accuracy of Radarsat-2 ultra-fine is about 3–4 cm and that of Sentinel-1 IW is about 27 cm (γ = 0.8). The results indicate that the expected MAI measurement accuracy of a given interferometric pair can be easily calculated by using the theoretical formula. PMID:25251408

  2. SCAN+

    SciTech Connect

    Kenneth Krebs, John Svoboda

    2009-11-01

    SCAN+ is a software application specifically designed to control the positioning of a gamma spectrometer by a two dimensional translation system above spent fuel bundles located in a sealed spent fuel cask. The gamma spectrometer collects gamma spectrum information for the purpose of spent fuel cask fuel loading verification. SCAN+ performs manual and automatic gamma spectrometer positioning functions as-well-as exercising control of the gamma spectrometer data acquisitioning functions. Cask configuration files are used to determine the positions of spent fuel bundles. Cask scanning files are used to determine the desired scan paths for scanning a spent fuel cask allowing for automatic unattended cask scanning that may take several hours.

  3. Recent advances in submolecular resolution with scanning probe microscopy.

    PubMed

    Gross, Leo

    2011-04-01

    Recently scanning probe microscopy has made tremendous progress in imaging organic molecules with high lateral resolution. Atoms and bonds within individual molecules have been clearly resolved, indicating the exciting potential of this technique for studying molecular structures, bonding within and between molecules, molecular conformational changes and chemical reactions at the single-molecule level. It turns out that the key step enabling such studies is an atomically controlled functionalization of the microscope tip. In this Perspective, the different techniques used for high-resolution molecular imaging, their implementations, advantages and limitations are described, and possible scientific areas of applications are discussed.

  4. Regularization of Mars Reconnaissance Orbiter CRISM along-track oversampled hyperspectral imaging observations of Mars

    NASA Astrophysics Data System (ADS)

    Kreisch, C. D.; O'Sullivan, J. A.; Arvidson, R. E.; Politte, D. V.; He, L.; Stein, N. T.; Finkel, J.; Guinness, E. A.; Wolff, M. J.; Lapôtre, M. G. A.

    2017-01-01

    Mars Reconnaissance Orbiter Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) hyperspectral image data have been acquired in an along-track oversampled (ATO) mode with the intent of processing the data to better than the nominal ∼18 m/pixel ground resolution. We have implemented an iterative maximum log-likelihood method (MLM) that utilizes the instrument spectral and spatial transfer functions and includes a penalty function to regularize the data. Products are produced both in sensor space and as projected hyperspectral image cubes at 12 m/pixel. Preprocessing steps include retrieval of surface single scattering albedos (SSA) using the Hapke Function and DISORT-based radiative modeling of atmospheric gases and aerosols. Resultant SSA cubes are despiked to remove extrema and tested to ensure that the remaining data are Poisson-distributed, an underlying assumption for the MLM algorithm implementation. Two examples of processed ATO data sets are presented. ATO0002EC79 covers the route taken by the Curiosity rover during its initial ascent of Mount Sharp in Gale Crater. SSA data are used to model mineral abundances and grain sizes predicted to be present in the Namib barchan sand dune sampled and analyzed by Curiosity. CRISM based results compare favorably to in situ results derived from Curiosity's measurement campaign. ATO0002DDF9 covers Marathon Valley on the Cape Tribulation rim segment of Endeavour Crater. SSA spectra indicate the presence of a minor component of Fe3+ and Mg2+ smectites on the valley floor and walls. Localization to 12 m/pixel provided the detailed spatial information needed for the Opportunity rover to traverse to and characterize those outcrops that have the deepest absorptions. The combination of orbital and rover-based data show that the smectite-bearing outcrops in Marathon Valley are impact breccias that are basaltic in composition and that have been isochemically altered in a low water to rock environment.

  5. Towards a Combined Surface Temperature Dataset for the Arctic from the Along-Track Scanning Radiometers (ATSRs)

    NASA Astrophysics Data System (ADS)

    Dodd, Emma; Veal, Karen; Corlett, Gary; Ghent, Darren; Remedios, John

    2016-04-01

    Surface Temperature (ST) changes in the Polar Regions are predicted to be more rapid than either global averages or responses in lower latitudes. Observations increasingly confirm these findings in the Arctic. It is, therefore, particularly important to monitor Arctic climate change. Satellites are particularly relevant to observations of Polar latitudes as they are well-served by low-Earth orbiting satellites. Whilst clouds often cause problems for satellite observations of the surface, in situ observations are much sparser. The ATSRs are accurate infra-red satellite radiometers, designed explicitly for climate standard observations and particularly suited to ST observations. ATSR radiance observations have been used to retrieve sea and land ST for a series of three instruments over a period greater than twenty years. This series will be extended with the launch of SLSTR on Sentinel 3, which has the same key design features necessary for providing climate quality ST datasets. We have combined land, ocean and sea-ice ST retrievals from ATSR-2 and AATSR to produce a new ST dataset for the Arctic; the ATSR Arctic combined Surface Temperature (AAST) dataset. The method of cloud-clearing, use of auxiliary data for ice classification and the ST retrievals used for each surface-type will be described. We will establish the accuracy of sea-ice and land-ice retrievals with recent results from validation against in situ data. We will also discuss the results from the calculation and propagation of uncertainties in the AAST dataset. Time series of ST anomalies for each surface type will be presented. The time series for open ocean in the Arctic Polar Region shows a significant warming trend during the AATSR mission. Time series for land, land-ice and sea-ice show high variability as expected but also interesting patterns. Overall, our purpose is to present the state-of-the-art for ATSR observations of ST change in the Arctic and hence indicate confidence we can have in temperature change across all three domains, and in combination.

  6. Effects of curved approach paths and advanced displays on pilot scan patterns

    NASA Technical Reports Server (NTRS)

    Harris, R. L., Sr.; Mixon, R. W.

    1981-01-01

    The effect on pilot scan behavior of both advanced cockpit and advanced manuevers was assessed. A series of straight-in and curved landing approaches were performed in the Terminal Configured Vehicle (TCV) simulator. Two comparisons of pilot scan behavior were made: (1) pilot scan behavior for straight-in approaches compared with scan behavior previously obtained in a conventionally equipped simulator, and (2) pilot scan behavior for straight-in approaches compared with scan behavior for curved approaches. The results indicate very similar scanning patterns during the straight-in approaches in the conventional and advanced cockpits. However, for the curved approaches pilot attention shifted to the electronic horizontal situation display (moving map), and a new eye scan path appeared between the map and the airspeed indicator. The very high dwell percentage and dwell times on the electronic displays in the TCV simulator during the final portions of the approaches suggest that the electronic attitude direction indicator was well designed for these landing approaches.

  7. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Levin, Barnaby D. A.; Padgett, Elliot; Chen, Chien-Chun; Scott, M. C.; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D.; Robinson, Richard D.; Ercius, Peter; Kourkoutis, Lena F.; Miao, Jianwei; Muller, David A.; Hovden, Robert

    2016-06-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data.

  8. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy

    PubMed Central

    Levin, Barnaby D.A.; Padgett, Elliot; Chen, Chien-Chun; Scott, M.C.; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D.; Robinson, Richard D.; Ercius, Peter; Kourkoutis, Lena F.; Miao, Jianwei; Muller, David A.; Hovden, Robert

    2016-01-01

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data. PMID:27272459

  9. Nanomaterial datasets to advance tomography in scanning transmission electron microscopy.

    PubMed

    Levin, Barnaby D A; Padgett, Elliot; Chen, Chien-Chun; Scott, M C; Xu, Rui; Theis, Wolfgang; Jiang, Yi; Yang, Yongsoo; Ophus, Colin; Zhang, Haitao; Ha, Don-Hyung; Wang, Deli; Yu, Yingchao; Abruña, Hector D; Robinson, Richard D; Ercius, Peter; Kourkoutis, Lena F; Miao, Jianwei; Muller, David A; Hovden, Robert

    2016-06-07

    Electron tomography in materials science has flourished with the demand to characterize nanoscale materials in three dimensions (3D). Access to experimental data is vital for developing and validating reconstruction methods that improve resolution and reduce radiation dose requirements. This work presents five high-quality scanning transmission electron microscope (STEM) tomography datasets in order to address the critical need for open access data in this field. The datasets represent the current limits of experimental technique, are of high quality, and contain materials with structural complexity. Included are tomographic series of a hyperbranched Co2P nanocrystal, platinum nanoparticles on a carbon nanofibre imaged over the complete 180° tilt range, a platinum nanoparticle and a tungsten needle both imaged at atomic resolution by equal slope tomography, and a through-focal tilt series of PtCu nanoparticles. A volumetric reconstruction from every dataset is provided for comparison and development of post-processing and visualization techniques. Researchers interested in creating novel data processing and reconstruction algorithms will now have access to state of the art experimental test data.

  10. The Method for Calculating Atmospheric Drag Coefficient Based on the Characteristics of Along-track Error in LEO Orbit Prediction

    NASA Astrophysics Data System (ADS)

    Wang, H. B.; Zhao, C. Y.; Liu, Z. G.; Zhang, W.

    2016-07-01

    The errors of atmosphere density model and drag coefficient are the major factors to restrain the accuracy of orbit prediction for the LEO (Low Earth Orbit) objects, which would affect unfavorably the space missions that need a high-precision orbit. This paper brings out a new method for calculating the drag coefficient based on the divergence laws of prediction error's along-track component. Firstly, we deduce the expression of along-track error in LEO's orbit prediction, revealing the comprehensive effect of the initial orbit and model's errors in the along-track direction. According to this expression, we work out a suitable drag coefficient adopted in prediction step on the basis of some certain information from orbit determination step, which will limit the increasing rate of along-track error and reduce the largest error in this direction, then achieving the goal of improving the accuracy of orbit prediction. In order to verify the method's accuracy and successful rate in the practice of orbit prediction, we use the full-arcs high precision position data from the GPS receiver on GRACE-A. The result shows that this new method can significantly improve the accuracy of prediction by about 45%, achieving a successful rate of about 71% and an effective rate of about 86%, with respect to classical method which uses the fitted drag coefficient directly from orbit determination step. Furthermore, the new method shows a preferable application value, because it is effective for low, moderate, and high solar radiation levels, as well as some quiet and moderate geomagnetic activity condition.

  11. Inspection results of advanced (sub-50nm design rule) reticles using the TeraScanHR

    NASA Astrophysics Data System (ADS)

    Sier, Jean-Paul; Broadbent, William; Yu, Paul

    2008-04-01

    Results from the recently available TeraScanHR reticle inspection system were published in early 2007. These results showed excellent inspection capability for 45nm logic and 5xnm half-pitch memory advanced production reticles, thus meeting the industry need for the mid-2007 start of production. The system has been in production use since that time. In early 2007, some evidence was shown of capability to inspect reticles for 32nm logic and sub-50nm half-pitch memory, but the results were incomplete due to the limited availability of such reticles. However, more of these advanced reticles have become available since that time. In this paper, inspection results of these advanced reticles from various leading-edge reticle manufacturers using the TeraScanHR are shown. These results indicate that the system has the capability to provide the needed inspection sensitivity for continued development work to support the industry roadmap.

  12. Parameterized desert/clear atmosphere limb-darkening model derived from earth radiation budget satellite along-track measurements

    NASA Technical Reports Server (NTRS)

    Brooks, David R.; Fenn, Marta A.

    1989-01-01

    A parameterized desert/clear atmosphere limb-darkening model was derived using longwave measurements from the Earth Radiation Budget Satellite operating in a unique along-track mode that allows all points along the ground track to be viewed over an entire range of viewing zenith angles at essentially constant solar zenith angle. Application of the model to radiances for scenes defined as clear desert by the Earth Radiation Budget Experiment data analysis algorithms shows that this parameterized model reflects the geographical and diurnal behavior expected for the limb-darkening phenomenon.

  13. The Scanning Electron Microscope As An Accelerator For The Undergraduate Advanced Physics Laboratory

    SciTech Connect

    Peterson, Randolph S.; Berggren, Karl K.; Mondol, Mark

    2011-06-01

    Few universities or colleges have an accelerator for use with advanced physics laboratories, but many of these institutions have a scanning electron microscope (SEM) on site, often in the biology department. As an accelerator for the undergraduate, advanced physics laboratory, the SEM is an excellent substitute for an ion accelerator. Although there are no nuclear physics experiments that can be performed with a typical 30 kV SEM, there is an opportunity for experimental work on accelerator physics, atomic physics, electron-solid interactions, and the basics of modern e-beam lithography.

  14. Preliminary analysis results of the Sea Surface Observation by a High Resolution Along-Track Interferometric SAR

    NASA Astrophysics Data System (ADS)

    Kojima, S.

    2013-12-01

    There are many requirements to detect the moving targets such as cars and ships in SAR images as well as to measure their speed. In particular, there are strongly requirements to detect ships and measure the ocean waves and the sea surface currents regardless of the time or the weather in the case of the ship accidents or the oil spill accidents because the rescue operation should be operated at the anytime. To satisfy these requirements, NICT developed the airborne along-track interferometric SAR (AT-InSAR) system in 2011. Kojima[1][2] carried out the preliminary experiments using a truck and ship to check its function and clarify its capability for the detection of the moving targets, and confirmed that its performance was satisfied with its specifications. The purpose of this study is to make clear the relationship between the phenomena on the sea surface such as the ocean waves and the velocity estimated from the AT-InSAR data, and the capability of the sea surface measurement by the AT-InSAR. In addition, the method to estimate wave directional spectra from AT-InSAR data is developed. The sea surface observation was carried out 3 km off the coast of Ooarai, the northeast of Tokyo, JAPAN on the 23th of August 2011. I observed the sea surface in the fine special resolution (0.3 m) and took a special average (1 m) to reduce noise. First of all, I estimated the wave velocity from the AT-InSAR images and calculated the 2D wave number spectra from it. And then, I estimated the directional wave spectra using the dispersion relation. As a result, it was clarified that the ocean waves could be measured by the AT-InSAR. In addition, it made clear that the bow waves and stern waves generated by a running ship could be detected by AT-InSAR. References [1] S. Kojima, T. Umehara, J. Uemoto, T. Kobayashi, M. Satake and S. Uratsuka, 'Development of Pi-SAR2 Along-Track Interferometric SAR System', IGARSS 2013, pp. 3159-3162, Aug. 2013. [2] S. Kojima, 'Evaluation of the Ship

  15. Modelling an advanced ManPAD with dual band detectors and a rosette scanning seeker head

    NASA Astrophysics Data System (ADS)

    Birchenall, Richard P.; Richardson, Mark A.; Butters, Brian; Walmsley, Roy

    2012-01-01

    Man Portable Air Defence Systems (ManPADs) have been a favoured anti aircraft weapon since their appearance on the military proliferation scene in the mid 1960s. Since this introduction there has been a 'cat and mouse' game of Missile Countermeasures (CMs) and the aircraft protection counter counter measures (CCMs) as missile designers attempt to defeat the aircraft platform protection equipment. Magnesium Teflon Viton (MTV) flares protected the target aircraft until the missile engineers discovered the art of flare rejection using techniques including track memory and track angle bias. These early CCMs relied upon CCM triggering techniques such as the rise rate method which would just sense a sudden increase in target energy and assume that a flare CM had been released by the target aircraft. This was not as reliable as was first thought as aspect changes (bringing another engine into the field of view) or glint from the sun could inadvertently trigger a CCM when not needed. The introduction of dual band detectors in the 1980s saw a major advance in CCM capability allowing comparisons between two distinct IR bands to be made thus allowing the recognition of an MTV flare to occur with minimal false alarms. The development of the rosette scan seeker in the 1980s complemented this advancement allowing the scene in the missile field of view (FOV) to be scanned by a much smaller (1/25) instantaneous FOV (IFOV) with the spectral comparisons being made at each scan point. This took the ManPAD from a basic IR energy detector to a pseudo imaging system capable of analysing individual elements of its overall FOV allowing more complex and robust CCM to be developed. This paper continues the work published in [1,2] and describes the method used to model an advanced ManPAD with a rosette scanning seeker head and robust CCMs similar to the Raytheon Stinger RMP.

  16. Cyclonic activity in the eastern Gulf of Mexico: Characterization from along-track altimetry and in situ drifter trajectories

    NASA Astrophysics Data System (ADS)

    Le Hénaff, Matthieu; Kourafalou, Vassiliki H.; Dussurget, Renaud; Lumpkin, Rick

    2014-01-01

    The shedding sequence of the Loop Current (LC) inside the Gulf of Mexico (GoM) is strongly influenced by cyclonic frontal eddies around its edge. Along-track altimetry data, analyzed based on a wavelet decomposition to provide estimates of individual cyclones' diameter, amplitude and relative vorticity, and in situ surface drifter data from the Global Drifter Program, are used to investigate the cyclonic activity in the eastern Gulf of Mexico, where the LC extends and retracts. By analyzing this ∼20 year long (1992-2011) combined set of observation data records, we were able to complement previous findings, to confirm results from modeling studies and to provide new insights on the LC frontal dynamics. Drifter data indicate, for the first time, that Loop Current Frontal Eddies (LCFEs) are in solid-body rotation close to their core. This property makes relative vorticity the most robust diagnostic from along-track altimetry for characterizing LCFEs in the eastern GoM, based on consistent comparisons with drifter data. Both data sets are complementary for describing the LCFEs' regional variability. LCFEs observed in the deep southeastern GoM show intense relative vorticity, but they are not frequently observed. The study of an unprecedented, long drifter trajectory suggests that they are not intensified locally. This implies that, among LCFEs coming from the northern GoM, only intense ones reach the deep southeastern GoM. The observation datasets provide, for the first time, quantitative evidences of processes so far only identified with models: LCFEs are intensified when they are advected over the Mississippi Fan in the northern GoM; a small area north of Campeche Bank shows intense LCFE activity. The altimetry and drifter data confirm and complement results from more limited datasets: LCFEs forming the Tortugas Eddies, at the entrance of the Straits of Florida, are the most intensely observed LCFEs in altimetry. Coming from the GoM interior, they can be modified

  17. Advanced three-dimensional scan methods in the nanopositioning and nanomeasuring machine

    NASA Astrophysics Data System (ADS)

    Hausotte, T.; Percle, B.; Jäger, G.

    2009-08-01

    The nanopositioning and nanomeasuring machine developed at the Ilmenau University of Technology was originally designed for surface measurements within a measuring volume of 25 mm × 25 mm × 5 mm. The interferometric length measuring and drive systems make it possible to move the stage with a resolution of 0.1 nm and a positioning uncertainty of less than 10 nm in all three axes. Various measuring tasks are possible depending on the installed probe system. Most of the sensors utilized are one-dimensional surface probes; however, some tasks require measuring sidewalls and other three-dimensional features. A new control system, based on the I++ DME specification, was implemented in the device. The I++ DME scan functions were improved and special scan functions added to allow advanced three-dimensional scan methods, further fulfilling the demands of scanning force microscopy and micro-coordinate measurements. This work gives an overview of these new functions and the application of them for several different measurements.

  18. Measurement of slow-moving along-track displacement from an efficient multiple-aperture SAR interferometry (MAI) stacking

    USGS Publications Warehouse

    Jo, Min-Jeong; Jung, Hyung-Sup; Won, Joong-Sun; Poland, Michael; Miklius, Asta; Lu, Zhong

    2015-01-01

    Multiple-aperture SAR interferometry (MAI) has demonstrated outstanding measurement accuracy of along-track displacement when compared to pixel-offset-tracking methods; however, measuring slow-moving (cm/year) surface displacement remains a challenge. Stacking of multi-temporal observations is a potential approach to reducing noise and increasing measurement accuracy, but it is difficult to achieve a significant improvement by applying traditional stacking methods to multi-temporal MAI interferograms. This paper proposes an efficient MAI stacking method, where multi-temporal forward- and backward-looking residual interferograms are individually stacked before the MAI interferogram is generated. We tested the performance of this method using ENVISAT data from Kīlauea Volcano, Hawai‘i, where displacement on the order of several centimeters per year is common. By comparing results from the proposed stacking methods with displacements from GPS data, we documented measurement accuracies of about 1.03 and 1.07 cm/year for the descending and ascending tracks, respectively—an improvement of about a factor of two when compared with that from the conventional stacking approach. Three-dimensional surface-displacement maps can be constructed by combining stacked InSAR and MAI observations, which will contribute to a better understanding of a variety of geological phenomena.

  19. Adapted Treatment Guided by Interim PET-CT Scan in Advanced Hodgkin’s Lymphoma

    PubMed Central

    Johnson, Peter; Federico, Massimo; Kirkwood, Amy; Fosså, Alexander; Berkahn, Leanne; Carella, Angelo; d’Amore, Francesco; Enblad, Gunilla; Franceschetto, Antonella; Fulham, Michael; Luminari, Stefano; O’Doherty, Michael; Patrick, Pip; Roberts, Thomas; Sidra, Gamal; Stevens, Lindsey; Smith, Paul; Trotman, Judith; Viney, Zaid; Radford, John; Barrington, Sally

    2016-01-01

    Background We tested interim positron-emission tomography–computed tomography (PET-CT) as a measure of early response to chemotherapy in order to guide treatment for patients with advanced Hodgkin’s lymphoma. Methods Patients with newly diagnosed advanced classic Hodgkin’s lymphoma underwent a baseline PET-CT scan, received two cycles of ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) chemotherapy, and then underwent an interim PET-CT scan. Images were centrally reviewed with the use of a 5-point scale for PET findings. Patients with negative PET findings after two cycles were randomly assigned to continue ABVD (ABVD group) or omit bleomycin (AVD group) in cycles 3 through 6. Those with positive PET findings after two cycles received BEACOPP (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone). Radiotherapy was not recommended for patients with negative findings on interim scans. The primary outcome was the difference in the 3-year progression-free survival rate between randomized groups, a noninferiority comparison to exclude a difference of 5 or more percentage points. Results A total of 1214 patients were registered; 937 of the 1119 patients (83.7%) who underwent an interim PET-CT scan according to protocol had negative findings. With a median follow-up of 41 months, the 3-year progression-free survival rate and overall survival rate in the ABVD group were 85.7% (95% confidence interval [CI], 82.1 to 88.6) and 97.2% (95% CI, 95.1 to 98.4), respectively; the corresponding rates in the AVD group were 84.4% (95% CI, 80.7 to 87.5) and 97.6% (95% CI, 95.6 to 98.7). The absolute difference in the 3-year progression-free survival rate (ABVD minus AVD) was 1.6 percentage points (95% CI, −3.2 to 5.3). Respiratory adverse events were more severe in the ABVD group than in the AVD group. BEACOPP was given to the 172 patients with positive findings on the interim scan, and 74.4% had negative findings on a third

  20. A carrier phase delay technique for along-track sea surface slope determination at high spatial resolution

    NASA Astrophysics Data System (ADS)

    Cardellach, Estel; Soulat, François

    2016-04-01

    This study presents a new processing technique for radar altimeter systems to retrieve the slope of the instantaneous sea surface along the specular point trajectory at high resolution (kilometer level or below). Initially, the technique has been designed as a way to improve and complement bi-static passive altimetry observation done with signals of the Global Navigation Satellite Systems (GNSS reflectometry or GNSS-R). However, its applicability is not limited to bi-static systems, and it could be extended to mono-static ones such as Doppler altimeters. The technique uses synthetic focusing techniques to obtain a simultaneous stack of reflected EM signals from a broad set of 'scatterers' along the specular point trajectory. The phase information derived from an interferometric processing should be symmetrical with respect to the central (actual) specular point when the surface does not present any along track gradient. Therefore, any surface slopes along this direction will be depicted through the phase asymmetries with respect to the central specular point. We propose an interferometric inversion scheme to retrieve the slope along the track at high spatial resolution, with estimates that are in principle free of media corrections (e.g., tropospheric delay) given the differential measurements applied within baselines of few hundreds of meters. This technique can contribute improving the resolution of fine topographic structures with low-precision group-delay altimetric systems, such as GNSS-R, and it also has potential to improve mono-static Doppler altimeter measurements over open ocean and coastal areas. We will present the technique, the theoretical frame as well as results obtained with synthetic data and preliminary results based on actual data.

  1. Advances in 4D Treatment Planning for Scanned Particle Beam Therapy — Report of Dedicated Workshops

    PubMed Central

    Bert, Christoph; Graeff, Christian; Riboldi, Marco; Nill, Simeon; Baroni, Guido; Knopf, Antje-Christin

    2014-01-01

    We report on recent progress in the field of mobile tumor treatment with scanned particle beams, as discussed in the latest editions of the 4D treatment planning workshop. The workshop series started in 2009, with about 20 people from 4 research institutes involved, all actively working on particle therapy delivery and development. The first workshop resulted in a summary of recommendations for the treatment of mobile targets, along with a list of requirements to apply these guidelines clinically. The increased interest in the treatment of mobile tumors led to a continuously growing number of attendees: the 2012 edition counted more than 60 participants from 20 institutions and commercial vendors. The focus of research discussions among workshop participants progressively moved from 4D treatment planning to complete 4D treatments, aiming at effective and safe treatment delivery. Current research perspectives on 4D treatments include all critical aspects of time resolved delivery, such as in-room imaging, motion detection, beam application, and quality assurance techniques. This was motivated by the start of first clinical treatments of hepato cellular tumors with a scanned particle beam, relying on gating or abdominal compression for motion mitigation. Up to date research activities emphasize significant efforts in investigating advanced motion mitigation techniques, with a specific interest in the development of dedicated tools for experimental validation. Potential improvements will be made possible in the near future through 4D optimized treatment plans that require upgrades of the currently established therapy control systems for time resolved delivery. But since also these novel optimization techniques rely on the validity of the 4DCT, research focusing on alternative 4D imaging technique, such as MRI based 4DCT generation will continue. PMID:24354749

  2. Global Climate Monitoring with the EOS PM-Platform's Advanced Microwave Scanning Radiometer (AMSR-E)

    NASA Technical Reports Server (NTRS)

    Spencer, Roy W.

    2002-01-01

    The Advanced Microwave Scanning 2 Radiometer (AMSR-E) is being built by NASDA to fly on NASA's PM Platform (now called Aqua) in December 2000. This is in addition to a copy of AMSR that will be launched on Japan's ADEOS-II satellite in 2001. The AMSRs improve upon the window frequency radiometer heritage of the SSM/I and SMMR instruments. Major improvements over those instruments include channels spanning the 6.9 GHz to 89 GHz frequency range, and higher spatial resolution from a 1.6 m reflector (AMSR-E) and 2.0 m reflector (ADEOS-II AMSR). The ADEOS-II AMSR also will have 50.3 and 52.8 GHz channels, providing sensitivity to lower tropospheric temperature. NASA funds an AMSR-E Science Team to provide algorithms for the routine production of a number of standard geophysical products. These products will be generated by the AMSR-E Science Investigator-led Processing System (SIPS) at the Global Hydrology Resource Center (GHRC) in Huntsville, Alabama. While there is a separate NASDA-sponsored activity to develop algorithms and produce products from AMSR, as well as a Joint (NASDA-NASA) AMSR Science Team 3 activity, here I will review only the AMSR-E Team's algorithms and how they benefit from the new capabilities that AMSR-E will provide. The US Team's products will be archived at the National Snow and Ice Data Center (NSIDC).

  3. Science Data Processing for the Advanced Microwave Scanning Radiometer: Earth Observing System

    NASA Technical Reports Server (NTRS)

    Goodman, H. Michael; Regner, Kathryn; Conover, Helen; Ashcroft, Peter; Wentz, Frank; Conway, Dawn; Lobl, Elena; Beaumont, Bruce; Hawkins, Lamar; Jones, Steve

    2004-01-01

    The National Aeronautics and Space Administration established the framework for the Science Investigator-led Processing Systems (SIPS) to enable the Earth science data products to be produced by personnel directly associated with the instrument science team and knowledgeable of the science algorithms. One of the first instantiations implemented for NASA was the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) SIPS. The AMSR-E SIPS is a decentralized, geographically distributed ground data processing system composed of two primary components located in California and Alabama. Initial science data processing is conducted at Remote Sensing Systems (RSS) in Santa Rosa, California. RSS ingests antenna temperature orbit data sets from JAXA and converts them to calibrated, resampled, geolocated brightness temperatures. The brightness temperatures are sent to the Global Hydrology and Climate Center in Huntsville, Alabama, which generates the geophysical science data products (e.g., water vapor, sea surface temperature, sea ice extent, etc.) suitable for climate research and applications usage. These science products are subsequently sent to the National Snow and Ice Data Center Distributed Active Archive Center in Boulder, Colorado for archival and dissemination to the at-large science community. This paper describes the organization, coordination, and production techniques employed by the AMSR-E SIPS in implementing, automating and operating the distributed data processing system.

  4. Three-dimensional displacement field of the 2015 Mw8.3 Illapel earthquake (Chile) from across- and along-track Sentinel-1 TOPS interferometry

    NASA Astrophysics Data System (ADS)

    Grandin, R.; Klein, E.; Métois, M.; Vigny, C.

    2016-03-01

    Wide-swath imaging has become a standard acquisition mode for radar missions aiming at applying synthetic aperture radar interferometry (InSAR) at global scale with enhanced revisit frequency. Increased swath width, compared to classical Stripmap imaging mode, is achieved at the expense of azimuthal resolution. This makes along-track displacements, and subsequently north-south displacements, difficult to measure using conventional split-beam (multiple-aperture) InSAR or cross-correlation techniques. Alternatively, we show here that the along-track component of ground motion can be deduced from the double difference between backward and forward looking interferograms within regions of burst overlap. "Burst overlap interferometry" takes advantage of the large squint angle diversity of Sentinel-1 (˜1°) to achieve subdecimetric accuracy on the along-track component of ground motion. We demonstrate the efficiency of this method using Sentinel-1 data covering the 2015 Mw8.3 Illapel earthquake (Chile) for which we retrieve the full 3-D displacement field and validate it against observations from a dense network of GPS sensors.

  5. Global Climate Monitoring with the Eos Pm-Platform's Advanced Microwave Scanning Radiometer (AMSR-E)

    NASA Technical Reports Server (NTRS)

    Spencer, Roy W.

    2000-01-01

    The Advanced Microwave Scanning Radiometer (AMSR-E) is being built by NASDA to fly on NASA's PM Platform (now called "Aqua") in December 2000. This is in addition to a copy of AMSR that will be launched on Japan's ADEOS-11 satellite in 2001. The AMSRs improve upon the window frequency radiometer heritage of the SSM[l and SMMR instruments. Major improvements over those instruments include channels spanning the 6.9 GHz to 89 GHz frequency range, and higher spatial resolution from a 1.6 m reflector (AMSR-E) and 2.0 m reflector (ADEOS-11 AMSR). The ADEOS-11 AMSR also will have 50.3 and 52.8 GHz channels, providing sensitivity to lower tropospheric temperature. NASA funds an AMSR-E Science Team to provide algorithms for the routine production of a number of standard geophysical products. These products will be generated by the AMSR-E Science Investigator-led Processing System (SIPS) at the Global Hydrology Resource Center (GHRC) in Huntsville, Alabama. While there is a separate NASDA-sponsored activity to develop algorithms and produce products from AMSR, as well as a Joint (NASDA-NASA) AMSR Science Team activity, here I will review only the AMSR-E Team's algorithms and how they benefit from the new capabilities that AMSR-E will provide. The U.S. Team's products will be archived at the National Snow and Ice Data Center (NSIDC). Further information about AMSR-E can be obtained at http://www.jzhcc.msfc.nasa.Vov/AMSR.

  6. Biases in Total Precipitable Water Vapor Climatologies from Atmospheric Infrared Sounder and Advanced Microwave Scanning Radiometer

    NASA Technical Reports Server (NTRS)

    Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Eldering, Annmarie; Aumann, Hartmut H.; Chahine, Moustafa T.

    2006-01-01

    We examine differences in total precipitable water vapor (PWV) from the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Scanning Radiometer (AMSR-E) experiments sharing the Aqua spacecraft platform. Both systems provide estimates of PWV over water surfaces. We compare AIRS and AMSR-E PWV to constrain AIRS retrieval uncertainties as functions of AIRS retrieved infrared cloud fraction. PWV differences between the two instruments vary only weakly with infrared cloud fraction up to about 70%. Maps of AIRS-AMSR-E PWV differences vary with location and season. Observational biases, when both instruments observe identical scenes, are generally less than 5%. Exceptions are in cold air outbreaks where AIRS is biased moist by 10-20% or 10-60% (depending on retrieval processing) and at high latitudes in winter where AIRS is dry by 5-10%. Sampling biases, from different sampling characteristics of AIRS and AMSR-E, vary in sign and magnitude. AIRS sampling is dry by up to 30% in most high-latitude regions but moist by 5-15% in subtropical stratus cloud belts. Over the northwest Pacific, AIRS samples conditions more moist than AMSR-E by a much as 60%. We hypothesize that both wet and dry sampling biases are due to the effects of clouds on the AIRS retrieval methodology. The sign and magnitude of these biases depend upon the types of cloud present and on the relationship between clouds and PWV. These results for PWV imply that climatologies of height-resolved water vapor from AIRS must take into consideration local meteorological processes affecting AIRS sampling.

  7. Advances in Scanning Reflectarray Antennas Based on Ferroelectric Thin Film Phase Shifters for Deep Space Communications

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R.

    2007-01-01

    Though there are a few examples of scanning phased array antennas that have flown successfully in space, the quest for low-cost, high-efficiency, large aperture microwave phased arrays continues. Fixed and mobile applications that may be part of a heterogeneous exploration communication architecture will benefit from the agile (rapid) beam steering and graceful degradation afforded by phased array antennas. The reflectarray promises greater efficiency and economy compared to directly-radiating varieties. Implementing a practical scanning version has proven elusive. The ferroelectric reflectarray, under development and described herein, involves phase shifters based on coupled microstrip patterned on Ba(x)Sr(1-x)TiO3 films, that were laser ablated onto LaAlO3 substrates. These devices outperform their semiconductor counterparts from X- through and K-band frequencies. There are special issues associated with the implementation of a scanning reflectarray antenna, especially one realized with thin film ferroelectric phase shifters. This paper will discuss these issues which include: relevance of phase shifter loss; modulo 2(pi) effects and phase shifter transient effects on bit error rate; scattering from the ground plane; presentation of a novel hybrid ferroelectric-semiconductor phase shifter; and the effect of mild radiation exposure on phase shifter performance.

  8. Further development of soft X-ray scanning microscopy with anelliptical undulator at the Advanced Light Source

    SciTech Connect

    Warwick, Tony; Ade, Harald; Fakra, Sirine; Gilles, Mary; Hitchcock, Adam; Kilcoyne, David; Shuh, David; Tyliszczak, Tolek

    2003-04-02

    Soft x-ray scanning microscopy (1) is under continuing development at the Advanced Light Source. Significant progress has been made implementing new scan control systems in both operational microscopes (2) and they now operate at beam lines 5.3.2 and 11.0.2 with interferometer servo scanning and stabilization. The interferometer servo loop registers the images on a universal x/y coordinate system and locks the x-ray spot on selected features for spectro-microscopic studies. At the present time zone plates are in use with 35nm outer zone width and the imaging spatial resolution is at the diffraction limit of these lenses. Current research programs are underway in areas of polymer chemistry, environmental chemistry and materials science. A dedicated polymer STXM is in operation on a bend magnet beam line (4) and is the subject of a separate article (3) in this issue. Here we focus on the capabilities of STXM at a new beam line that employs an elliptical undulator (5) to give control of the polarization of the x-ray beam. This facility is in the process of commissioning and some results are available, other capabilities will be developed during the first half of 2003.

  9. Electrical characterization of dislocations in gallium nitride using advanced scanning probe techniques

    NASA Astrophysics Data System (ADS)

    Simpkins, Blake Shelley Ginsberg

    GaN-based materials are promising for high speed and power applications such as amplifier and communications circuits. Ga, In, and AIN-based alloys span a wide optical range (2--6.1 eV) and exhibit strong polarizations making them useful in many devices; however, films are highly defective (˜10 8 dislocations cm-2) due to lack of suitable substrates. Thus, nanoscale electronic characterization of these dislocations is critical for device and growth optimization. Scanning probe techniques enable characterization at length-scales unattainable by conventional techniques. First, scanning Kelvin probe microscopy (SKPM) was used to image surface potential variations due to charged dislocations in HVPE-grown GaN. The film's structural evolution "with thickness was monitored showing a decrease in dislocation density, likely through dislocation reaction. Numerical simulations were used to investigate tip-size effects when imaging highly localized (tens of nm) potential variations indicating that measured dislocation induced potential features in GaN can be much smaller (˜80%) than true variations. Next, capacitance variations in MBE-grown HFETs, due to dislocations-induced carrier depletion, were imaged with scanning capacitance microscopy (SCM). The distribution of these charged centers was correlated with buffer schemes showing that an AIN buffer leads to pseudomorphic (2D) nucleation and randomly distributed misfit dislocations while deposition directly on SiC results in island (3D) nucleation and a domain structure with dislocations grouped at domain boundaries. Hall measurements and numerical simulations were also carried out to further study the implications of these microstructures. Numerical results indicated that randomly distributed dislocations deplete a larger fraction of free carriers than the same density of grouped dislocations and correlated favorably with Hall results. Correlated SKPM and conductive AFM (C-AFM) measurements were then used to study

  10. Soft tissue response to mandibular advancement using 3D CBCT scanning.

    PubMed

    Almeida, R C; Cevidanes, L H S; Carvalho, F A R; Motta, A T; Almeida, M A O; Styner, M; Turvey, T; Proffit, W R; Phillips, C

    2011-04-01

    This prospective longitudinal study assessed the 3D soft tissue changes following mandibular advancement surgery. Cranial base registration was performed for superimposition of virtual models built from cone beam computed tomography (CBCT) volumes. Displacements at the soft and hard tissue chin (n = 20), lower incisors and lower lip (n = 21) were computed for presurgery to splint removal (4-6-week surgical outcome), presurgery to 1 year postsurgery (1-year surgical outcome), and splint removal to 1 year postsurgery (postsurgical adaptation). Qualitative evaluations of color maps illustrated the surgical changes and postsurgical adaptations, but only the lower lip showed statistically significant postsurgical adaptations. Soft and hard tissue chin changes were significantly correlated for each of the intervals evaluated: presurgery to splint removal (r = 0.92), presurgery to 1 year postsurgery (r = 0.86), and splint removal to 1 year postsurgery (r = 0.77). A statistically significant correlation between lower incisor and lower lip was found only between presurgery and 1 year postsurgery (r = 0.55). At 1 year after surgery, 31% of the lower lip changes were explained by changes in the lower incisor position while 73% of the soft tissue chin changes were explained by the hard chin. This study suggests that 3D soft tissue response to mandibular advancement surgery is markedly variable.

  11. Recent advances and potential applications of modulated differential scanning calorimetry (mDSC) in drug development.

    PubMed

    Knopp, Matthias Manne; Löbmann, Korbinian; Elder, David P; Rades, Thomas; Holm, René

    2016-05-25

    Differential scanning calorimetry (DSC) is frequently the thermal analysis technique of choice within preformulation and formulation sciences because of its ability to provide detailed information about both the physical and energetic properties of a substance and/or formulation. However, conventional DSC has shortcomings with respect to weak transitions and overlapping events, which could be solved by the use of the more sophisticated modulated DSC (mDSC). mDSC has multiple potential applications within the pharmaceutical field and the present review provides an up-to-date overview of these applications. It is aimed to serve as a broad introduction to newcomers, and also as a valuable reference for those already practising in the field. Complex mDSC was introduced more than two decades ago and has been an important tool for the quantification of amorphous materials and development of freeze-dried formulations. However, as discussed in the present review, a number of other potential applications could also be relevant for the pharmaceutical scientist.

  12. The Value of Restaging With Chest and Abdominal CT/MRI Scan After Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer.

    PubMed

    Liu, Guo-Chen; Zhang, Xu; Xie, E; An, Xin; Cai, Pei-Qiang; Zhu, Ying; Tang, Jing-Hua; Kong, Ling-Heng; Lin, Jun-Zhong; Pan, Zhi-Zhong; Ding, Pei-Rong

    2015-11-01

    Little was known with regard to the value of preoperative systemic restaging for patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT). This study was designed to evaluate the role of chest and abdominal computed tomography (CT) scan or magnetic resonance imaging (MRI) on preoperative restaging in LARC after neoadjuvant CRT and to assess the impact on treatment strategy.Between January 2007 and April 2013, 386 newly diagnosed consecutive patients with LARC who underwent neoadjuvant CRT and received restaging with chest and abdominal CT/MRI scan were included. Imaging results before and after CRT were analyzed.Twelve patients (3.1%) (6 liver lesions, 2 peritoneal lesions, 2 distant lymph node lesions, 1 lung lesions, 1 liver and lung lesions) were diagnosed as suspicious metastases on the restaging scan after radiotherapy. Seven patients (1.8%) were confirmed as metastases by pathology or long-term follow-up. The treatment strategy was changed in 5 of the 12 patients as a result of restaging CT/MRI findings. Another 10 patients (2.6%) who present with normal restaging imaging findings were diagnosed as metastases intra-operatively. The sensitivity, specificity accuracy, negative predictive value, and positive predictive values of restaging CT/MRI was 41.4%, 98.6%, 58.3%, and 97.3%, respectively.The low incidence of metastases and minimal consequences for the treatment plan question the clinical value of routine restaging of chest and abdomen after neoadjuvant CRT. Based on this study, a routine restaging CT/MRI of chest and abdomen in patients with rectal cancer after neoadjuvant CRT is not advocated, carcino-embryonic antigen (CEA) -guided CT/MRI restaging might be an alternative.

  13. The evaluation of retinal circulation in advanced diabetic retinopathy before and after panretinal laser photocoagulation by scanning laser opthalmoscope

    NASA Astrophysics Data System (ADS)

    Okano, Tadashi

    2005-07-01

    I investigated the effects of panretinal laser photocoagulation (PRP) on the velocity of retinal circulation in diabetic retinopathy. The retinal circulation was evaluated by means of rapid serial fluorescein angiography (FAG), employing scanning laser ophthalmoscope. FAG was conducted at the rate of 30 frames per seconds in video-tape. Disc-to-macula transit time (DMTT) was defined as the parameter to evaluate the retinal circulation. Diabetic 28 eyes with advanced diabetic retinopathy were examined to measure the DMTT before and after PRP. Normal 30 eyes used as control. Mean DMTT decreased from 9.8+/-1.5 seconds before PRP to 8.2+/-1.5 seconds after PRP in 28 diabetic eyes. The value with improvement after PRP was significantly shorter than the value before PRP ( p < 0.05 ). These values before and after PRP were significantly longer than that (3.7+/-0.7 seconds ) in normal 30 eyes ( p < 0.01 ). Retinal circulation is retarded in diabetic retinopathy. The retardation of retinal circulation in diabetic retinopathy improves after PRP, but the value after PRP can not recover until the control level. This study was performed to reveal therapeutic effect to panretinal laser photocoagulation (PRP) for the retardation of retinal circulation in diabetic retinopathy. I investigated the effects of PRP on the velocity of retinal circulation in patients with advanced diabetic retinopathy.

  14. Control and acquisition systems for new scanning transmission x-ray microscopes at Advanced Light Source (abstract)

    NASA Astrophysics Data System (ADS)

    Tyliszczak, T.; Hitchcock, P.; Kilcoyne, A. L. D.; Ade, H.; Hitchcock, A. P.; Fakra, S.; Steele, W. F.; Warwick, T.

    2002-03-01

    Two new scanning x-ray transmission microscopes are being built at beamline 5.3.2 and beamline 7.0 of the Advanced Light Source that have novel aspects in their control and acquisition systems. Both microscopes use multiaxis laser interferometry to improve the precision of pixel location during imaging and energy scans as well as to remove image distortions. Beam line 5.3.2 is a new beam line where the new microscope will be dedicated to studies of polymers in the 250-600 eV energy range. Since this is a bending magnet beam line with lower x-ray brightness than undulator beam lines, special attention is given to the design not only to minimize distortions and vibrations but also to optimize the controls and acquisition to improve data collection efficiency. 5.3.2 microscope control and acquisition is based on a PC computer running WINDOWS 2000. All mechanical stages are moved by stepper motors with rack mounted controllers. A dedicated counter board is used for counting and timing and a multi-input/output board is used for analog acquisition and control of the focusing mirror. A three axis differential laser interferometer is being used to improve stability and precision by careful tracking of the relative positions of the sample and zone plate. Each axis measures the relative distance between a mirror placed on the sample stage and a mirror attached to the zone plate holder. Agilent Technologies HP 10889A servo-axis interferometer boards are used. While they were designed to control servo motors, our tests show that they can be used to directly control the piezo stage. The use of the interferometer servo-axis boards provides excellent point stability for spectral measurements. The interferometric feedback also provides active vibration isolation which reduces deleterious impact of mechanical vibrations up to 20-30 Hz. It also can improve the speed and precision of image scans. Custom C++ software has been written to provide user friendly control of the microscope

  15. Benthic habitat classification in Lignumvitae Key Basin, Florida Bay, using the U.S. Geological Survey Along-Track Reef Imaging System (ATRIS)

    USGS Publications Warehouse

    Reich, C.D.; Zawada, D.G.; Thompson, P.R.; Reynolds, C.E.; Spear, A.H.; Umberger, D.K.; Poore, R.Z.

    2011-01-01

    The Comprehensive Everglades Restoration Plan (CERP) funded in partnership between the U.S. Army Corps of Engineers, South Florida Water Management District, and other Federal, local and Tribal members has in its mandate a guideline to protect and restore freshwater flows to coastal environments to pre-1940s conditions (CERP, 1999). Historic salinity data are sparse for Florida Bay, so it is difficult for water managers to decide what the correct quantity, quality, timing, and distribution of freshwater are to maintain a healthy and productive estuarine ecosystem. Proxy records of seasurface temperature (SST) and salinity have proven useful in south Florida. Trace-element chemistry on foraminifera and molluscan shells preserved in shallow-water sediments has provided some information on historical salinity and temperature variability in coastal settings, but little information is available for areas within the main part of Florida Bay (Brewster-Wingard and others, 1996). Geochemistry of coral skeletons can be used to develop subannually resolved proxy records for SST and salinity. Previous studies suggest corals, specifically Solenastrea bournoni, present in the lower section of Florida Bay near Lignumvitae Key, may be suitable for developing records of SST and salinity for the past century, but the distribution and species composition of the bay coral community have not been well documented (Hudson and others, 1989; Swart and others, 1999). Oddly, S. bournoni thrives in the study area because it can grow on a sandy substratum and can tolerate highly turbid water. Solenastrea bournoni coral heads in this area should be ideally located to provide a record (~100-150 years) of past temperature and salinity variations in Florida Bay. The goal of this study was to utilize the U.S. Geological Survey's (USGS) Along-Track Reef Imaging System (ATRIS) capability to further our understanding of the abundance, distribution, and size of corals in the Lignumvitae Key Basin. The

  16. A High-altitude, Advanced-technology Scanning Laser Altimeter for the Elevation for the Nation Program

    NASA Astrophysics Data System (ADS)

    Harding, D. J.

    2007-12-01

    In January of this year the National Research Council's Committee on Floodplain Mapping Technologies recommended to Congress that an Elevation for the Nation program be initiated to enable modernization of the nation's floodplain maps and to support the many other nationwide programs reliant on high-accuracy elevation data. Their recommendation is to acquire a national, high-resolution, seamless, consistent, public-domain, elevation data set created using airborne laser swath mapping (ALSM). Although existing commercial ALSM assets can acquire elevation data of sufficient accuracy, achieving nationwide consistency in a cost-effective manner will be a challenge employing multiple low-flying commercial systems conducting local to regional mapping. This will be particularly true in vegetated terrain where reproducible measurements of ground topography and vegetation structure are required for change-detection purposes. An alternative approach using an advanced technology, wide-swath, high-altitude laser altimeter is described here, based on the Swath Imaging Multi-polarization Photon-counting Lidar (SIMPL) under development via funding from NASA's Instrument Incubator Program. The approach envisions a commercial, federal agency and state partnership, with the USGS providing program coordination, NASA implementing the advanced technology instrumentation, the commercial sector conducting data collection and processing and states defining map product requirements meeting their specific needs. An Instrument Synthesis and Analysis (ISAL) study conducted at Goddard Space Flight Center evaluated an instrument compliment deployed on a long-range Gulfstream G550 platform operating at 12 km altitude. The English Electric Canberra is an alternative platform also under consideration. Instrumentation includes a scanning, multi-beam laser altimeter that maps a 10 km wide swath, IMU and Star Trackers for attitude determination, JPL's Global Differential GPS implementation for

  17. Advanced human carotid plaque progression correlates positively with flow shear stress using follow-up scan data: an in vivo MRI multi-patient 3D FSI study.

    PubMed

    Yang, Chun; Canton, Gador; Yuan, Chun; Ferguson, Marina; Hatsukami, Thomas S; Tang, Dalin

    2010-09-17

    Although it has been well-accepted that atherosclerosis initiation and early progression correlate negatively with flow wall shear stresses (FSS), increasing evidence suggests mechanisms governing advanced plaque progression are not well understood. Fourteen patients were scanned 2-4 times at 18 month intervals using a histologically validated multi-contrast magnetic resonance imaging (MRI) protocol to acquire carotid plaque progression data. Thirty-two scan pairs (baseline and follow-up scans) were formed with slices matched for model construction and analysis. 3D fluid-structure interaction (FSI) models were constructed and plaque wall stress (PWS) and flow shear stress (FSS) were obtained from all matching lumen data points (400-1000 per plaque; 100 points per matched slice) to quantify correlations with plaque progression measured by vessel wall thickness increase (WTI). Using FSS and PWS data from follow-up scan, 21 out of 32 scan pairs showed a significant positive correlation between WTI and FSS (positive/negative/no significance ratio=21/8/3), and 26 out of 32 scan pairs showed a significant negative correlation between WTI and PWS (positive/negative/no significance ratio=2/26/4). The mean FSS value of lipid core nodes (n=5294) from all 47 plaque models was 63.5dyn/cm(2), which was 45% higher than that from all normal vessel nodes (n=27553, p<0.00001). The results from this intensive FSI study indicate that flow shear stress from follow-up scan correlates positively with advanced plaque progression which is different from what has been observed in plaque initiation and early-stage progression. It should be noted that the correlation results do not automatically lead to any causality conclusions.

  18. AVIRIS scan drive design and performance

    NASA Technical Reports Server (NTRS)

    Miller, D. C.

    1987-01-01

    The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) images the ground with an instantaneous field of view (IFOV) of 1 mrad. The IFOV is scanned 30 deg from left to right to provide the cross-track dimension of the image, while the aircraft's motion provides the along-track dimension. The scanning frequency is 12 Hz, with a scan efficiency of 70 percent. The scan mirror has an effective diameter of 5.7 in, and its positional accuracy is a small fraction of a milliradian of the nominal position-time profile. Described are the design and performance of the scan drive mechanism. Tradeoffs among various approaches are discussed, and the reasons given for the selection of the cam drive.

  19. Advances in Multi-Sensor Scanning and Visualization of Complex Plants: the Utmost Case of a Reactor Building

    NASA Astrophysics Data System (ADS)

    Hullo, J.-F.; Thibault, G.; Boucheny, C.

    2015-02-01

    In a context of increased maintenance operations and workers generational renewal, a nuclear owner and operator like Electricité de France (EDF) is interested in the scaling up of tools and methods of "as-built virtual reality" for larger buildings and wider audiences. However, acquisition and sharing of as-built data on a large scale (large and complex multi-floored buildings) challenge current scientific and technical capacities. In this paper, we first present a state of the art of scanning tools and methods for industrial plants with very complex architecture. Then, we introduce the inner characteristics of the multi-sensor scanning and visualization of the interior of the most complex building of a power plant: a nuclear reactor building. We introduce several developments that made possible a first complete survey of such a large building, from acquisition, processing and fusion of multiple data sources (3D laser scans, total-station survey, RGB panoramic, 2D floor plans, 3D CAD as-built models). In addition, we present the concepts of a smart application developed for the painless exploration of the whole dataset. The goal of this application is to help professionals, unfamiliar with the manipulation of such datasets, to take into account spatial constraints induced by the building complexity while preparing maintenance operations. Finally, we discuss the main feedbacks of this large experiment, the remaining issues for the generalization of such large scale surveys and the future technical and scientific challenges in the field of industrial "virtual reality".

  20. Bisphosphonate-related osteonecrosis of jaws in advanced stage breast cancer was detected from bone scan: a case report

    PubMed Central

    Chirappapha, Prakasit; Thongjood, Thanaporn; Aroonroch, Rangsima

    2017-01-01

    Bisphosphonates (BPs) are indicated to treat skeletal-related events (SREs) for cancer patients with bone metastasis. We report a 79-year-old woman with advanced stage breast cancer with bone metastasis who was prescribed BPs (zoledronate), then developed osteonecrosis of jaw. We provide a brief review of the pathogenesis, diagnosis and treatment of this complication. PMID:28210558

  1. Current status of the global change observation mission - water SHIZUKU (GCOM-W) and the advanced microwave scanning radiometer 2 (AMSR2) (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Maeda, Takashi; Kachi, Misako; Kasahara, Marehito

    2016-10-01

    Japan Aerospace Exploration Agency (JAXA) launched the Global Change Observation Mission - Water (GCOM-W) or "SHIZUKU" in 18 May 2012 (JST) from JAXA's Tanegashima Space Center. The GCOM-W satellite joins to NASA's A-train orbit since June 2012, and its observation is ongoing. The GCOM-W satellite carries the Advanced Microwave Scanning Radiometer 2 (AMSR2). The AMSR2 is a multi-frequency, total-power microwave radiometer system with dual polarization channels for all frequency bands, and successor microwave radiometer to the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) loaded on the NASA's Aqua satellite. The AMSR-E kept observation in the slower rotation speed (2 rotations per minute) for cross-calibration with AMSR2 since December 2012, its operation ended in December 2015. The AMSR2 is designed almost similarly as the AMSR-E. The AMSR2 has a conical scanning system with large-size offset parabolic antenna, a feed horn cluster to realize multi-frequency observation, and an external calibration system with two temperature standards. However, some important improvements are made. For example, the main reflector size of the AMSR2 is expanded to 2.0 m to observe the Earth's surface in higher spatial resolution, and 7.3-GHz channel is newly added to detect radio frequency interferences at 6.9 GHz. In this paper, we present a recent topic for the AMSR2 (i.e., RFI detection performances) and the current operation status of the AMSR2.

  2. Advances in imaging and quantification of electrical properties at the nanoscale using Scanning Microwave Impedance Microscopy (sMIM)

    NASA Astrophysics Data System (ADS)

    Friedman, Stuart; Yang, Yongliang; Amster, Oskar

    2015-03-01

    Scanning Microwave Impedance Microscopy (sMIM) is a mode for Atomic Force Microscopy (AFM) enabling imaging of unique contrast mechanisms and measurement of local permittivity and conductivity at the 10's of nm length scale. Recent results will be presented illustrating high-resolution electrical features such as sub 15 nm Moire' patterns in Graphene, carbon nanotubes of various electrical states and ferro-electrics. In addition to imaging, the technique is suited to a variety of metrology applications where specific physical properties are determined quantitatively. We will present research activities on quantitative measurements using multiple techniques to determine dielectric constant (permittivity) and conductivity (e.g. dopant concentration) for a range of materials. Examples include bulk dielectrics, low-k dielectric thin films, capacitance standards and doped semiconductors. Funded in part by DOE SBIR DE-SC0009586.

  3. Global digital topography mapping using a scanning radar altimeter

    NASA Technical Reports Server (NTRS)

    Elachi, C.; Im, K. E.; Li, F.; Rodriguez, E.

    1987-01-01

    The conceptual design of a Scanning Radar Altimeter system capable of collecting less than 300-m spatial and less than 3-m height resolution digital topography data for the entire globe, from an orbital platform, is presented. A 37-GHz frequency SRA system is used to achieve the requisite resolution while reducing antenna length in the along-track dimension. Near-global coverage in a short time period is obtained by scanning the antenna beam cross-track, in a swath of about 100 km. Attention is given to the algorithm that will be used to retrieve pixel height from the return waveform.

  4. A hard x-ray scanning microprobe for fluorescence imaging and microdiffraction at the Advanced Photon Source

    SciTech Connect

    Cai, L.; Lai, B.; Yun, W.; Ilinski, P.; Legnini, D.; Maser, J.; Rodrigues, W.

    1999-11-02

    A hard x-ray scanning microprobe based on zone plate optics and undulator radiation, in the energy region from 6 to 20 keV, has reached a focal spot size (FWHM) of 0.15 {micro}m (v) x 0.6 {micro}m (h), and a photon flux of 4 x 10{sup 9} photons/sec/0.01%BW. Using a slit 44 meters upstream to create a virtual source, a circular beam spot of 0.15 {micro}m in diameter can be obtained with a photon flux of one order of magnitude less. During fluorescence mapping of trace elements in a single human ovarian cell, the microprobe exhibited an imaging sensitivity for Pt (L{sub a} line) of 80 attograms/{micro}m{sup 2} for a count rate of 10 counts per second. The x-ray microprobe has been used to map crystallographic strain and multiquantum well thickness in micro-optoelectronic devices produced with the selective area growth technique.

  5. Scanned-beam x-ray source technology for photon backscatter imaging technique of mine detection: advanced technology research

    NASA Astrophysics Data System (ADS)

    Burchanowski, Charlotte M.; Moler, Robert B.; Shope, Steve L.

    1995-06-01

    A very high power, state-of-the-art, scanning x-ray source has been developed for use with an x-ray backscatter system that detects and images buried land mines. This paper describes the distinctive qualities of the x-ray source technology necessary to prove the feasibility of the mine detection technique in the field. The imaging system requires that an x-ray beam, having a nominal illumination area on the ground of two centimeters by two centimeters, sweeps across a width of three meters in a time of 15 milliseconds or less. The source must produce an integrated flux of 106 x-rays (min) at 120 kVp (min) for each pixel. The source technology is based on a plasma-focused electrom beam operating up to 140 kilovolts with a current of 0.7 ampere. The electrom beam is magnetically shaped to form a thin ellipse with dimensions of approximately one millimeter by ten millimeters. The scanner is designed to run continuously with target temperature of 160 degrees F (max). The overall design allows the scanner to run with operational and auxilary power generators in the field. A unique 400 hertz, 440 volt, 3-phase, SCR-controlled, low energy storage DC source, with low ripple and 1% voltage regulation, supplies the scanner with 100 kilowatts of power at up to 160 kilovolts. The uniqueness of the mine detection technique and scanner design limits radiation hazards: 1) focusing and tight collimation minimizes stray x-rays; 2) the x-rays travel directly into the ground and are mostly absorbed; 3) radiation leakage from the source is not permitted; and 4) backscatter radiation is strongly localized around the irradiation area, is directed upward, and has a small angular distribution.

  6. Visualising reacting single atoms under controlled conditions: Advances in atomic resolution in situ Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM)

    NASA Astrophysics Data System (ADS)

    Boyes, Edward D.; Gai, Pratibha L.

    2014-02-01

    Advances in atomic resolution Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM) for probing gas-solid catalyst reactions in situ at the atomic level under controlled reaction conditions of gas environment and temperature are described. The recent development of the ESTEM extends the capability of the ETEM by providing the direct visualisation of single atoms and the atomic structure of selected solid state heterogeneous catalysts in their working states in real-time. Atomic resolution E(S)TEM provides a deeper understanding of the dynamic atomic processes at the surface of solids and their mechanisms of operation. The benefits of atomic resolution-E(S)TEM to science and technology include new knowledge leading to improved technological processes with substantial economic benefits, improved healthcare, reductions in energy needs and the management of environmental waste generation. xml:lang="fr"

  7. Radionucleotide scanning in osteomyelitis

    SciTech Connect

    Sachs, W.; Kanat, I.O.

    1986-07-01

    Radionucleotide bone scanning can be an excellent adjunct to the standard radiograph and clinical findings in the diagnosis of osteomyelitis. Bone scans have the ability to detect osteomyelitis far in advance of the standard radiograph. The sequential use of technetium and gallium has been useful in differentiating cellulitis and osteomyelitis. Serial scanning with technetium and gallium may be used to monitor the response of osteomyelitis to antibiotic therapy.

  8. Nuclear Scans

    MedlinePlus

    Nuclear scans use radioactive substances to see structures and functions inside your body. They use a special ... images. Most scans take 20 to 45 minutes. Nuclear scans can help doctors diagnose many conditions, including ...

  9. WBC scan

    MedlinePlus

    ... in the body. It is a type of nuclear scan . How the Test is Performed Blood will ... radiation. Due to the slight radiation exposure, most nuclear scans (including WBC scan) are not recommended for ...

  10. Liver scan

    MedlinePlus

    ... Nuclear scan - technetium; Nuclear scan - liver or spleen Images Liver scan References Lidofsky S. Jaundice. In: Feldman M, ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  11. PET scan

    MedlinePlus

    ... may have an allergic reaction to the tracer material. Some people have pain, redness, or swelling at ... with diabetes. Most PET scans are now performed along with a CT scan. This combination scan ...

  12. Nanoscale mapping of lithium-ion diffusion in a cathode within an all-solid-state lithium-ion battery by advanced scanning probe microscopy techniques.

    PubMed

    Zhu, Jing; Lu, Li; Zeng, Kaiyang

    2013-02-26

    High-resolution real-space mapping of Li-ion diffusion in the LiNi(1/3)Co(1/3)Mn(1/3)O₂ cathode within an all-solid-state thin film Li-ion battery has been conducted using advanced scanning probe microscopy techniques, namely, band excitation electrochemical strain microscopy (BE-ESM) and conductive atomic force microscopy. In addition, local variations of the electrochemical response in the LiNi(1/3)Co(1/3)Mn(1/3)O₂ thin film cathode at different cycling stages have been investigated. This work demonstrates the unique feature and applications of the BE-ESM technique on battery research. The results allow us to establish a direct relationship of the changes in ionic mobility as well as the electrochemical activity at the nanoscale with the numbers of charge/discharge cycles. Furthermore, various factors influencing the BE-ESM measurements, including sample mechanical properties (e.g., elastic and dissipative properties) as well as surface electrical properties, have also been studied to investigate the coupling effects on the electrochemical strain. The study on the relationships between the Li-ion redistribution and microstructure of the electrode materials within thin film Li-ion battery will provide further understanding of the electrochemical degradation mechanisms of Li-ion rechargeable batteries at the nanoscale.

  13. Assimilation of Along-track Altimetry Data Into An Eddy-permitting Primitive-equation Model of The North and Tropical Atlantic Ocean Using Isopycnal-eof Order-reduction

    NASA Astrophysics Data System (ADS)

    Faucher, P.; de Mey, P.; Gavart, M.

    We present and discuss altimetric assimilation experiments into a primitive-equation model of the North Atlantic using isopycnal EOFs to propagate the altimeter sig- nal downwards and to the other model variables. Faucher, Gavart and De Mey (JGR, 2002) showed from a set of historical hydrographic data that the dominant isopycnal EOF accounts for most of the surface dynamic height variability in the North Atlantic ocean. In addition the reduced-order observability problem for altimetry is more nat- urally studied in isopycnal coordinates because the displacement of isopycnals is the largest contribution of deep ocean dynamics to the sea-level changes. The 1/3 degree ocean model from the CLIPPER and MERCATOR projects (based on OPA 8.1 code developped at LODYC, Paris) was used to solve the primitive equations from 20S to 70N. The assimilation experiments were performed with the combined along-track TOPEX-POSEIDON and ERS-1 data sets between 1 january 1993 and 31 decem- ber 1993. We implemented a multivariate reduced-order optimal interpolation method (SOFA: De Mey and Benkiran, 2002) with a vertical projection of altimetry data using data-based isopycnal EOFs. This paper will show and discuss compared results from several approaches in different regions of the North Atlantic.

  14. Remote Sensing Observatory Validation of Surface Soil Moisture Using Advanced Microwave Scanning Radiometer E, Common Land Model, and Ground Based Data: Case Study in SMEX03 Little River Region, Georgia, U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Optimal soil moisture estimation may be characterized by inter-comparisons among remotely sensed measurements, ground-based measurements, and land surface models. In this study, we compared soil moisture from Advanced Microwave Scanning Radiometer E (AMSR-E), ground-based measurements, and Soil-Vege...

  15. Bone Scan

    MedlinePlus

    ... Mayo Clinic Staff A bone scan is a nuclear imaging test that helps diagnose and track several ... you're nursing. A bone scan is a nuclear imaging procedure. In nuclear imaging, tiny amounts of ...

  16. CT Scans

    MedlinePlus

    ... cross-sectional pictures of your body. Doctors use CT scans to look for Broken bones Cancers Blood clots Signs of heart disease Internal bleeding During a CT scan, you lie still on a table. The table ...

  17. Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) Validation Data Management at the National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC)

    NASA Astrophysics Data System (ADS)

    Marquis, M. C.; Paserba, A. M.

    2003-12-01

    The National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC) is supporting the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) validation activity. NSIDC has designed and developed a web portal to data and information collected during NASA's AMSR-E Validation Program: (http://nsidc.org/data/amsr_validation/.) The AMSR-E validation experiments address three disciplines: soil moisture, rainfall and cryospheric validation campaigns. This poster describes all these experiments (past, present and future). NSIDC provides documentation, e.g., user guides, as well as metadata documents (DIFS) submitted to the Global Change Master Directory (GCMD), for all the AMSR-E validation experiments. NSIDC further supports the validation activities by collaborating with the AMSR-E Science Investigator-led Processing System (SIPS) to provide scientists in the field (e.g., Arctic and Antarctic ship and flight campaigns) with quick, easy access to AMSR-E data for their validation experiments. NSIDC provides subsets of reformatted data in a manner most convenient to the validation scientists while they conduct their experiments. The AMSR-E is a mission instrument launched aboard NASA's Aqua Satellite on 4 May 2002. The Aqua mission provides a multi-disciplinary study of the Earth's atmospheric, oceanic, cryospheric, and land processes and their relationship to global change. With six instruments aboard, the Aqua Satellite will travel in a polar, sun-synchronous orbit. NSIDC will archive and distribute all AMSR-E products, including Levels 1A, 2, and 3 data. Users can order Level-1A AMSR-E data beginning 19 June 2003 and Level-2A data beginning 01 September 2003. Other products will be available in March 2004.

  18. Use of positron emission tomography scan response to guide treatment change for locally advanced gastric cancer: the Memorial Sloan Kettering Cancer Center experience

    PubMed Central

    Won, Elizabeth; Shah, Manish A.; Schöder, Heiko; Strong, Vivian E.; Coit, Daniel G.; Brennan, Murray F.; Kelsen, David P.; Janjigian, Yelena Y.; Tang, Laura H.; Capanu, Marinela; Rizk, Nabil P.; Allen, Peter J.; Bains, Manjit S.

    2016-01-01

    Background Early metabolic response on 18-fluorodeoxyglucose-positron emission tomography (FDG-PET) during neoadjuvant chemotherapy is PET non-responders have poor outcomes whether continuing chemotherapy or proceeding directly to surgery. Use of PET may identify early treatment failure, sparing patients from inactive therapy and allowing for crossover to alternative therapies. We examined the effectiveness of PET directed switching to salvage chemotherapy in the PET non-responders. Methods Patients with locally advanced resectable FDG-avid gastric or gastroesophageal junction (GEJ) adenocarcinoma received bevacizumab 15 mg/kg, epirubicin 50 mg/m2, cisplatin 60 mg/m2 day 1, and capecitabine 625 mg/m2 bid (ECX) every 21 days. PET scan was obtained at baseline and after cycle 1. PET responders, (i.e., ≥35% reduction in FDG uptake at the primary tumor) continued ECX + bev. Non-responders switched to docetaxel 30 mg/m2, irinotecan 50 mg/mg2 day 1 and 8 plus bevacizumab every 21 days for 2 cycles. Patients then underwent surgery. The primary objective was to improve the 2-year disease free survival (DFS) from 30% (historical control) to 53% in the non-responders. Results Twenty evaluable patients enrolled before the study closed for poor accrual. Eleven were PET responders and the 9 non-responders switched to the salvage regimen. With a median follow-up of 38.2 months, the 2-year DFS was 55% [95% confidence interval (CI), 30–85%] in responders compared with 56% in the non-responder group (95% CI, 20–80%, P=0.93). Conclusions The results suggest that changing chemotherapy regimens in PET non-responding patients may improve outcomes. Results from this pilot trial are hypothesis generating and suggest that PET directed neoadjuvant therapy merits evaluation in a larger trial. PMID:27563439

  19. Renal scan

    MedlinePlus

    ... and urinate often to help remove the radioactive material from the body. How to Prepare for the Test Tell your health care provider if you take ... drink additional fluids before the scan. How the Test will ... into the vein. However, you will not feel the radioactive material. The scanning table may be hard and cold. ...

  20. Gallium scan

    MedlinePlus

    ... material called gallium and is a type of nuclear medicine exam. A related test is gallium scan ... Brown ML, Forstrom LA, et al. Society of nuclear medicine procedure guideline for gallium scintigraphy in inflammation. ...

  1. CT Scan

    MedlinePlus

    ... exposing your baby to radiation. Reactions to contrast material In certain cases, your doctor may recommend you ... for a few hours before your scan Contrast material A special dye called a contrast material is ...

  2. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER): Data Products for the High Spatial Resolution Imager on NASA's EOS-AMI Platform

    NASA Technical Reports Server (NTRS)

    Abrams, M.

    1999-01-01

    The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is a high spatial resolution, multispectral imager with along-track stereo capabilities scheduled for launch on the first NASA spacecraft of the Earth Observing System (EOS AM-1) in mid-1999.

  3. Effect of advanced irrigation protocols on self-expanding Smart-Seal obturation system: A scanning electron microscopic push-out bond strength study

    PubMed Central

    Hegde, Vibha; Arora, Shashank

    2015-01-01

    Introduction: The aim of this study was to evaluate the effect of different final irrigation activation techniques affect the bond strength of self-expanding Smart-Seal obturation at the different thirds of root canal space. Materials and Methods: One hundred single-rooted human teeth were prepared using the Pro-Taper system to size F3, and a final irrigation regimen using 3% sodium hypochlorite and 17% EDTA was performed. The specimens were randomly divided into five groups (n = 20) according to the final irrigation activation technique used as follows: No activation (control), manual dynamic activation (MDA), CanalBrush activation, ultrasonic activation (UA) and EndoActivator. Five specimens from each group were subjected to scanning electron microscopic observation for assessment of the smear layer removal after the final irrigation procedures. All remaining roots were then obturated with Smart-Seal obturation system. A push-out test was used to measure the bond strength between the root canal dentin and Smart-Seal paste. The data obtained from the push-out test were analyzed using two-way analysis of variance and Tukey post-hoc tests. Conclusions: It was observed that UA improved the bond strength of Smart-Seal obturation in the coronal and middle third and MDA/EndoActivator in the apical third of the root canal space. PMID:25684907

  4. Design of a scanning probe microscope with advanced sample treatment capabilities: An atomic force microscope combined with a miniaturized inductively coupled plasma source.

    PubMed

    Hund, Markus; Herold, Hans

    2007-06-01

    We describe the design and performance of an atomic force microscope (AFM) combined with a miniaturized inductively coupled plasma source working at a radio frequency of 27.12 MHz. State-of-the-art scanning probe microscopes (SPMs) have limited in situ sample treatment capabilities. Aggressive treatments such as plasma etching or harsh treatments such as etching in aggressive liquids typically require the removal of the sample from the microscope. Consequently, time consuming procedures are required if the same sample spot has to be imaged after successive processing steps. We have developed a first prototype of a SPM which features a quasi in situ sample treatment using a modified commercial atomic force microscope. A sample holder is positioned in a special reactor chamber; the AFM tip can be retracted by several millimeters so that the chamber can be closed for a treatment procedure. Most importantly, after the treatment, the tip is moved back to the sample with a lateral drift per process step in the 20 nm regime. The performance of the prototype is characterized by consecutive plasma etching of a nanostructured polymer film.

  5. Head CT scan

    MedlinePlus

    Brain CT; Cranial CT; CT scan - skull; CT scan - head; CT scan - orbits; CT scan - sinuses; Computed tomography - cranial; CAT scan - brain ... conditions: Birth (congenital) defect of the head or brain Brain infection Brain tumor Buildup of fluid inside ...

  6. Leg CT scan

    MedlinePlus

    CAT scan - leg; Computed axial tomography scan - leg; Computed tomography scan - leg; CT scan - leg ... scanners can perform the exam without stopping.) A computer creates separate images of the body area, called ...

  7. Arm CT scan

    MedlinePlus

    CAT scan - arm; Computed axial tomography scan - arm; Computed tomography scan - arm; CT scan - arm ... scanners can perform the exam without stopping.) A computer creates separate images of the arm area, called ...

  8. Fetal cardiac scanning today.

    PubMed

    Allan, Lindsey

    2010-07-01

    The ability to examine the structure of the fetal heart in real-time started over 30 years ago now. The field has seen very great advances since then, both in terms of technical improvements in ultrasound equipment and in dissemination of operator skills. A great deal has been learnt about normal cardiac function in the human fetus throughout gestation and how it is affected by pathologies of pregnancy. There is increasing recognition of abnormal heart structure during routine obstetric scanning, allowing referral for specialist diagnosis and counselling. It is now possible to make accurate diagnosis of cardiac malformations as early as 12 weeks of gestation. Early diagnosis of a major cardiac malformation in the fetus can provide the parents with a comprehensive prognosis, enabling them to make the most informed choice about the management of the pregnancy.

  9. Knee CT scan

    MedlinePlus

    CAT scan - knee; Computed axial tomography scan - knee; Computed tomography scan - knee ... scanners can perform the exam without stopping.) A computer makes several images of the body area. These ...

  10. HIDA Scan (Cholescintigraphy)

    MedlinePlus

    HIDA scan Overview By Mayo Clinic Staff A hepatobiliary (HIDA) scan is an imaging procedure used to diagnose ... the liver, gallbladder and bile ducts. For a HIDA scan, also known as cholescintigraphy and hepatobiliary scintigraphy, ...

  11. Lumbar spine CT scan

    MedlinePlus

    CAT scan - lumbar spine; Computed axial tomography scan - lumbar spine; Computed tomography scan - lumbar spine; CT - lower back ... stopping.) A computer creates separate images of the spine area, called slices. These images can be stored, ...

  12. Coronary Calcium Scan

    MedlinePlus

    ... Scan Coronary Calcium Scan Related Topics Angina Atherosclerosis Coronary Heart Disease Electrocardiogram Heart Attack Send a link to NHLBI ... calcium, or calcifications, are a sign of atherosclerosis, coronary heart disease, or coronary microvascular disease. A coronary calcium scan ...

  13. High-resolution imaging of rain systems with the advanced microwave precipitation radiometer

    NASA Technical Reports Server (NTRS)

    Spencer, Roy W.; Hood, Robbie E.; Lafontaine, Frank J.; Smith, Eric A.; Platt, Robert; Galliano, Joe; Griffin, Vanessa L.; Lobl, Elena

    1994-01-01

    An advanced Microwave Precipitation Radiometer (AMPR) has been developed and flown in the NASA ER-2-high-altitude aircraft for imaging various atmospheric and surface processes, primarily the internal structure of rain clouds. The AMPR is a scanning four-frequency total power microwave radiometer that is externally calibrated with high-emissivity warm and cold loads. Separate antenna systems allow the sampling of the 10.7- and 19.35-GHz channels at the same spatial resolution, while the 37.1- and 85.5-GHz channels utilize the same multifrequency feedhorn as the 19.35-GHz channel. Spatial resolutions from an aircraft altitude of 20-km range from 0.6 km at 85.5 GHz to 2.8 km at 19.35 and 10.7 GHz. All channels are sampled every 0.6 km in both along-track and cross-track directions, leading to a contiguous sampling pattern of the 85.5-GHz 3-dB beamwidth footprints, 2.3X oversampling of the 37.1-GHz data, and 4.4X oversampling of the 19.35- and 10.7-GHz data. Radiometer temperature sensitivities range from 0.2 to 0.5 C. Details of the system are described, including two different calibration systems and their effect on the data collected. Examples of oceanic rain systems are presented from Florida and the tropical west Pacific that illustrate the wide variety of cloud water, rainwater, and precipitation-size ice combinations that are observable from aircraft altitudes.

  14. Validation of Earth Radiation Budget Experiment scanning radiometer data inversion procedures

    NASA Technical Reports Server (NTRS)

    Manalo, Natividad D.; Smith, G. L.; Green, Richard N.; Avis, Lee M.; Suttles, John T.

    1990-01-01

    Validation techniques were implemented in the inversion of scanner radiometer data to assess the accuracy of the top of atmosphere radiant fluxes. An evaluation of SW radiant flux standard deviations for the same scene type shows that they contribute about 6.0 W/sq m for viewing zenith angles less than 55 deg and can reach values of up to 17.6 W/sq m for larger zenith angles in the backward scanning position. Three-channel intercomparison results, presented as color graphic displays and histograms, effectively validate the radiance measurements and the spectral factors. Along-track data were used to validate limb-darkening models and showed good agreement with current ERBE models. These validation techniques were found to be very effective in assessing the quality of the radiant fluxes generated by the ERBE inversion algorithm.

  15. RBC nuclear scan

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003835.htm RBC nuclear scan To use the sharing features on this page, please enable JavaScript. An RBC nuclear scan uses small amounts of radioactive material to ...

  16. Heart PET scan

    MedlinePlus

    Heart nuclear medicine scan; Heart positron emission tomography; Myocardial PET scan ... Udelson JE, Dilsizian V, Bonow RO. Nuclear cardiology. In: Mann DL, ... A Textbook of Cardiovascular Medicine . 10th ed. Philadelphia, ...

  17. Abdominal CT scan

    MedlinePlus

    Computed tomography scan - abdomen; CT scan - abdomen; CT abdomen and pelvis ... 2016:chap 133. Radiologyinfo.org. Computed tomography (CT) - abdomen and pelvis. Updated June 16, 2016. www.radiologyinfo. ...

  18. Bone density scan (image)

    MedlinePlus

    ... bone the higher the risk of fractures. A bone scan, along with a patient's medical history, is a ... and whether any preventative treatment is needed. A bone density scan has the advantage of being painless and exposing ...

  19. Cardiac CT Scan

    MedlinePlus

    ... CT Scan Related Topics Aneurysm Coronary Calcium Scan Coronary Heart Disease Heart Attack Pulmonary Embolism Send a link to ... imaging test can help doctors detect or evaluate coronary heart disease, calcium buildup in the coronary arteries, problems with ...

  20. Multipurpose binocular scanning apparatus

    NASA Technical Reports Server (NTRS)

    Chamberlain, F. R.; Parker, G. L.

    1969-01-01

    Optical gimballing apparatus directs narrow fields of view throughout solid angle approaching 4 pi steradians. Image rotation produced by scanning can be eliminated or altered by gear trains directly linked to the scanning drive assembly. It provides the basis for a binocular scanning capability.

  1. Differential Multiphoton Laser Scanning Microscopy

    SciTech Connect

    Field, Jeffrey J.; Sheetz, Kraig E.; Chandler, Eric V.; Hoover, Erich E.; Young, Michael D.; Ding, Shi-you; Sylvester, Anne W.; Kleinfeld, David; Squier, Jeff A.

    2012-01-01

    Multifocal multiphoton laser scanning microscopy (mfMPLSM) in the biological and medical sciences has the potential to become a ubiquitous tool for obtaining high-resolution images at video rates. While current implementations of mfMPLSM achieve very high frame rates, they are limited in their applicability to essentially those biological samples that exhibit little or no scattering. In this paper, we report on a method for mfMPLSM in which whole-field detection with a single detector, rather than detection with a matrix of detectors, such as a charge-coupled device (CCD) camera, is implemented. This advance makes mfMPLSM fully compatible for use in imaging through scattering media. Further, we demonstrate that this method makes it possible to simultaneously obtain multiple images and view differences in excitation parameters in a single scan of the specimen.

  2. Rapid frequency scan EPR.

    PubMed

    Tseitlin, Mark; Rinard, George A; Quine, Richard W; Eaton, Sandra S; Eaton, Gareth R

    2011-08-01

    In rapid frequency scan EPR with triangular scans, sufficient time must be allowed to insure that the magnetization in the x, y plane decays to baseline at the end of the scan, which typically is about 5T(2) after the spins are excited. To permit relaxation of signals excited toward the extremes of the scan the total scan time required may be much longer than 5T(2). However, with periodic, saw-tooth excitation, the slow-scan EPR spectrum can be recovered by Fourier deconvolution of data recorded with a total scan period of 5T(2), even if some spins are excited later in the scan. This scan time is similar to polyphase excitation methods. The peak power required for either polyphase excitation or rapid frequency scans is substantially smaller than for pulsed EPR. The use of an arbitrary waveform generator (AWG) and cross loop resonator facilitated implementation of the rapid frequency scan experiments reported here. The use of constant continuous low B(1), periodic excitation waveform, and constant external magnetic field is similar to polyphase excitation, but could be implemented without the AWG that is required for polyphase excitation.

  3. Rapid Frequency Scan EPR

    PubMed Central

    Tseitlin, Mark; Rinard, George A.; Quine, Richard W.; Eaton, Sandra S.; Eaton, Gareth R.

    2011-01-01

    In rapid frequency scan EPR with triangular scans, sufficient time must be allowed to insure that the magnetization in the x,y plane decays to baseline at the end of the scan, which typically is about 5 T2 after the spins are excited. To permit relaxation of signals excited toward the extremes of the scan the total scan time required may be much longer than 5 T2. However, with periodic, saw-tooth excitation, the slow-scan EPR spectrum can be recovered by Fourier deconvolution of data recorded with a total scan period of 5 T2, even if some spins are excited later in the scan. This scan time is similar to polyphase excitation methods. The peak power required for either polyphase excitation or rapid frequency scans is substantially smaller than for pulsed EPR. The use of an arbitrary waveform generator (AWG) and cross loop resonator facilitated implementation of the rapid frequency scan experiments reported here. The use of constant continuous low B1, periodic excitation waveform, and constant external magnetic field is similar to polyphase excitation, but could be implemented without the AWG that is required for polyphase excitation. PMID:21664848

  4. Line-scanning, stage scanning confocal microscope

    NASA Astrophysics Data System (ADS)

    Carucci, John A.; Stevenson, Mary; Gareau, Daniel

    2016-03-01

    We created a line-scanning, stage scanning confocal microscope as part of a new procedure: video assisted micrographic surgery (VAMS). The need for rapid pathological assessment of the tissue on the surface of skin excisions very large since there are 3.5 million new skin cancers diagnosed annually in the United States. The new design presented here is a confocal microscope without any scanning optics. Instead, a line is focused in space and the sample, which is flattened, is physically translated such that the line scans across its face in a direction perpendicular to the line its self. The line is 6mm long and the stage is capable of scanning 50 mm, hence the field of view is quite large. The theoretical diffraction-limited resolution is 0.7um lateral and 3.7um axial. However, in this preliminary report, we present initial results that are a factor of 5-7 poorer in resolution. The results are encouraging because they demonstrate that the linear array detector measures sufficient signal from fluorescently labeled tissue and also demonstrate the large field of view achievable with VAMS.

  5. Bone scanning in otolaryngology.

    PubMed

    Noyek, A M

    1979-09-01

    Modern radionuclide bone scanning has introduced a new concept in physiologic and anatomic diagnostic imaging to general medicine. As otolaryngologists must diagnose and treat disease in relation to the bony and/or cartilaginous supporting structures of the neurocranium and upper airway, this modality should be included in the otolaryngologist's diagnostic armamentarium. It is the purpose of this manuscript to study the specific applications of bone scanning to our specialty at this time, based on clinical experience over the past three years. This thesis describes the development of bone scanning in general (history of nuclear medicine and nuclear physics; history of bone scanning in particular). General concepts in nuclear medicine are then presented; these include a discussion of nuclear semantics, principles of radioactive emmissions, the properties 99mTc as a radionuclide, and the tracer principle. On the basis of these general concepts, specific concepts in bone scanning are then brought forth. The physiology of bone and the action of the bone scan agents is presented. Further discussion considers the availability and production of the bone scan agent, patient factors, the gamma camera, the triphasic bone scan and the ultimate diagnostic principle of the bone scan. Clinical applications of bone scanning in otolaryngology are then presented in three sections. Proven areas of application include the evaluation of malignant tumors of the head and neck, the diagnosis of temporomandibular joint disorders, the diagnosis of facial fractures, the evaluation of osteomyelitis, nuclear medicine imaging of the larynx, and the assessment of systemic disease. Areas of adjunctive or supplementary value are also noted, such as diagnostic imaging of meningioma. Finally, areas of marginal value in the application of bone scanning are described.

  6. Electron Beam Scanning in Industrial Applications

    NASA Astrophysics Data System (ADS)

    Jongen, Yves; Herer, Arnold

    1996-05-01

    Scanned electron beams are used within many industries for applications such as sterilization of medical disposables, crosslinking of wire and cables insulating jackets, polymerization and degradation of resins and biomaterials, modification of semiconductors, coloration of gemstones and glasses, removal of oxides from coal plant flue gasses, and the curing of advanced composites and other molded forms. X-rays generated from scanned electron beams make yet other applications, such as food irradiation, viable. Typical accelerators for these applications range in beam energy from 0.5MeV to 10 MeV, with beam powers between 5 to 500kW and scanning widths between 20 and 300 cm. Since precise control of dose delivery is required in many of these applications, the integration of beam characteristics, product conveyance, and beam scanning mechanisms must be well understood and optimized. Fundamental issues and some case examples are presented.

  7. Resonant scanning mechanism

    NASA Astrophysics Data System (ADS)

    Wallace, John; Newman, Mike; Gutierrez, Homero; Hoffman, Charlie; Quakenbush, Tim; Waldeck, Dan; Leone, Christopher; Ostaszewski, Miro

    2014-10-01

    Ball Aerospace & Technologies Corp. developed a Resonant Scanning Mechanism (RSM) capable of combining a 250- Hz resonant scan about one axis with a two-hertz triangular scan about the orthogonal axis. The RSM enables a rapid, high-density scan over a significant field of regard (FOR) while minimizing size, weight, and power requirements. The azimuth scan axis is bearing mounted allowing for 30° of mechanical travel, while the resonant elevation axis is flexure and spring mounted with five degrees of mechanical travel. Pointing-knowledge error during quiescent static pointing at room temperature across the full range is better than 100 μrad RMS per axis. The compact design of the RSM, roughly the size of a soda can, makes it an ideal mechanism for use on low-altitude aircraft and unmanned aerial vehicles. Unique aspects of the opto-mechanical design include i) resonant springs which allow for a high-frequency scan axis with low power consumption; and ii) an independent lower-frequency scan axis allowing for a wide FOR. The pointing control system operates each axis independently and employs i) a position loop for the azimuth axis; and ii) a unique combination of parallel frequency and amplitude control loops for the elevation axis. All control and pointing algorithms are hosted on a 200-MHz microcontroller with 516 KB of RAM on a compact 3"×4" digital controller, also of Ball design.

  8. Nuclear Heart Scan

    MedlinePlus

    ... into your blood and travels to your heart. Nuclear heart scans use single photon emission computed tomography (SPECT) or cardiac positron emission tomography (PET) to detect the energy from the tracer to make pictures of your ...

  9. Slow Scan Telemedicine

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Originally developed under contract for NASA by Ball Bros. Research Corporation for acquiring visual information from lunar and planetary spacecraft, system uses standard closed circuit camera connected to a device called a scan converter, which slows the stream of images to match an audio circuit, such as a telephone line. Transmitted to its destination, the image is reconverted by another scan converter and displayed on a monitor. In addition to assist scans, technique allows transmission of x-rays, nuclear scans, ultrasonic imagery, thermograms, electrocardiograms or live views of patient. Also allows conferencing and consultation among medical centers, general practitioners, specialists and disease control centers. Commercialized by Colorado Video, Inc., major employment is in business and industry for teleconferencing, cable TV news, transmission of scientific/engineering data, security, information retrieval, insurance claim adjustment, instructional programs, and remote viewing of advertising layouts, real estate, construction sites or products.

  10. Photothermal imaging scanning microscopy

    DOEpatents

    Chinn, Diane; Stolz, Christopher J.; Wu, Zhouling; Huber, Robert; Weinzapfel, Carolyn

    2006-07-11

    Photothermal Imaging Scanning Microscopy produces a rapid, thermal-based, non-destructive characterization apparatus. Also, a photothermal characterization method of surface and subsurface features includes micron and nanoscale spatial resolution of meter-sized optical materials.

  11. Thoracic spine CT scan

    MedlinePlus

    ... Narrowing of the spine ( spinal stenosis ) Scoliosis Tumor Risks Risks of CT scans include: Exposure to radiation ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  12. Brain PET scan

    MedlinePlus

    ... Tell the difference between Parkinson disease and other movement disorders Several PET scans may be taken to determine ... identify where the seizures start in your brain Movement disorders (such as Parkinson disease )

  13. Cervical MRI scan

    MedlinePlus

    ... magnetic resonance imaging) scan uses energy from strong magnets to create pictures of the part of the ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  14. Leg MRI scan

    MedlinePlus

    ... resonance imaging) scan of the leg uses strong magnets to create pictures of the leg. This may ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  15. Arm MRI scan

    MedlinePlus

    ... arm MRI (magnetic resonance imaging) scan uses strong magnets to create pictures of the upper and lower ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  16. Thyroid Scan and Uptake

    MedlinePlus Videos and Cool Tools

    ... A thyroid scan is a type of nuclear medicine imaging. The radioactive iodine uptake test (RAIU) is ... thyroid function, but does not involve imaging. Nuclear medicine is a branch of medical imaging that uses ...

  17. Pediatric CT Scans

    Cancer.gov

    The Radiation Epidemiology Branch and collaborators have initiated a retrospective cohort study to evaluate the relationship between radiation exposure from CT scans conducted during childhood and adolescence and the subsequent development of cancer.

  18. Fiber-Scanned Microdisplays

    NASA Technical Reports Server (NTRS)

    Crossman-Bosworth, Janet; Seibel, Eric

    2010-01-01

    Helmet- and head-mounted display systems, denoted fiber-scanned microdisplays, have been proposed to provide information in an "augmented reality" format (meaning that the information would be optically overlaid on the user's field of view).

  19. Multiple Reflector Scanning Antennas

    NASA Astrophysics Data System (ADS)

    Shen, Bing

    Narrow beamwidth antenna systems are important to remote sensing applications and point-to-point communication systems. In many applications the main beam of the antenna radiation pattern must be scannable over a region of space. Scanning by mechanically skewing the entire antenna assembly is difficult and in many situations is unacceptable. Performance during scan is, of course, also very important. Traditional reflector systems employing the well-focused paraboloidal -shaped main reflector accomplish scan by motion of a few feeds, or by phase steering a focal plane feed array. Such scanning systems can experience significant gain loss. Traditional reflecting systems with a spherical main reflector have low aperture efficiency and poor side lobe and cross polarization performance. This dissertation introduces a new approach to the design of scanning spherical reflector systems, in which the performance weaknesses of high cross polarization and high side lobe levels are avoided. Moreover, the low aperture utilization common in spherical reflectors is overcome. As an improvement to this new spherical main reflector configuration, a flat mirror reflector is introduced to minimize the mechanical difficulties to scan the main beam. In addition to the reflector system design, reflector antenna performance evaluation is also important. The temperature resolution issue important for earth observation radiometer antennas is studied, and a new method to evaluate and optimize such temperature resolution is introduced.

  20. Wide scanning spherical antenna

    NASA Technical Reports Server (NTRS)

    Shen, Bing (Inventor); Stutzman, Warren L. (Inventor)

    1995-01-01

    A novel method for calculating the surface shapes for subreflectors in a suboptic assembly of a tri-reflector spherical antenna system is introduced, modeled from a generalization of Galindo-Israel's method of solving partial differential equations to correct for spherical aberration and provide uniform feed to aperture mapping. In a first embodiment, the suboptic assembly moves as a single unit to achieve scan while the main reflector remains stationary. A feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan thereby eliminating the need to oversize the main spherical reflector. In an alternate embodiment, both the main spherical reflector and the suboptic assembly are fixed. A flat mirror is used to create a virtual image of the suboptic assembly. Scan is achieved by rotating the mirror about the spherical center of the main reflector. The feed horn is tilted during scan to maintain the illuminated area on the main spherical reflector fixed throughout the scan.

  1. Dexter: Data Extractor for scanned graphs

    NASA Astrophysics Data System (ADS)

    Demleitner, Markus

    2011-12-01

    The NASA Astrophysics Data System (ADS) now holds 1.3 million scanned pages, containing numerous plots and figures for which the original data sets are lost or inaccessible. The availability of scans of the figures can significantly ease the regeneration of the data sets. For this purpose, the ADS has developed Dexter, a Java applet that supports the user in this process. Dexter's basic functionality is to let the user manually digitize a plot by marking points and defining the coordinate transformation from the logical to the physical coordinate system. Advanced features include automatic identification of axes, tracing lines and finding points matching a template.

  2. Femtosecond scanning tunneling microscope

    SciTech Connect

    Taylor, A.J.; Donati, G.P.; Rodriguez, G.; Gosnell, T.R.; Trugman, S.A.; Some, D.I.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). By combining scanning tunneling microscopy with ultrafast optical techniques we have developed a novel tool to probe phenomena on atomic time and length scales. We have built and characterized an ultrafast scanning tunneling microscope in terms of temporal resolution, sensitivity and dynamic range. Using a novel photoconductive low-temperature-grown GaAs tip, we have achieved a temporal resolution of 1.5 picoseconds and a spatial resolution of 10 nanometers. This scanning tunneling microscope has both cryogenic and ultra-high vacuum capabilities, enabling the study of a wide range of important scientific problems.

  3. Vector generator scan converter

    DOEpatents

    Moore, J.M.; Leighton, J.F.

    1988-02-05

    High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardware for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold. 7 figs.

  4. Vector generator scan converter

    DOEpatents

    Moore, James M.; Leighton, James F.

    1990-01-01

    High printing speeds for graphics data are achieved with a laser printer by transmitting compressed graphics data from a main processor over an I/O (input/output) channel to a vector generator scan converter which reconstructs a full graphics image for input to the laser printer through a raster data input port. The vector generator scan converter includes a microprocessor with associated microcode memory containing a microcode instruction set, a working memory for storing compressed data, vector generator hardward for drawing a full graphic image from vector parameters calculated by the microprocessor, image buffer memory for storing the reconstructed graphics image and an output scanner for reading the graphics image data and inputting the data to the printer. The vector generator scan converter eliminates the bottleneck created by the I/O channel for transmitting graphics data from the main processor to the laser printer, and increases printer speed up to thirty fold.

  5. Adaptive Optical Scanning Holography

    PubMed Central

    Tsang, P. W. M.; Poon, Ting-Chung; Liu, J.-P.

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  6. Adaptive Optical Scanning Holography

    NASA Astrophysics Data System (ADS)

    Tsang, P. W. M.; Poon, Ting-Chung; Liu, J.-P.

    2016-02-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably.

  7. Scanning computed confocal imager

    DOEpatents

    George, John S.

    2000-03-14

    There is provided a confocal imager comprising a light source emitting a light, with a light modulator in optical communication with the light source for varying the spatial and temporal pattern of the light. A beam splitter receives the scanned light and direct the scanned light onto a target and pass light reflected from the target to a video capturing device for receiving the reflected light and transferring a digital image of the reflected light to a computer for creating a virtual aperture and outputting the digital image. In a transmissive mode of operation the invention omits the beam splitter means and captures light passed through the target.

  8. Design of an Airborne L-Band Cross-Track Scanning Scatterometer

    NASA Technical Reports Server (NTRS)

    Hilliard, Lawrence M. (Technical Monitor)

    2002-01-01

    In this report, we describe the design of an airborne L-band cross-track scanning scatterometer suitable for airborne operation aboard the NASA P-3 aircraft. The scatterometer is being designed for joint operation with existing L-band radiometers developed by NASA for soil moisture and ocean salinity remote sensing. In addition, design tradeoffs for a space-based radar system have been considered, with particular attention given to antenna architectures suitable for sharing the antenna between the radar and radiometer. During this study, we investigated a number of imaging techniques, including the use of real and synthetic aperture processing in both the along track and cross-track dimensions. The architecture selected will permit a variety of beamforming algorithms to be implemented, although real aperture processing, with hardware beamforming, provides better sidelobe suppression than synthetic array processing and superior signal-to-noise performance. In our discussions with the staff of NASA GSFC, we arrived at an architecture that employs complete transmit/receive modules for each subarray. Amplitude and phase control at each of the transmit modules will allow a low-sidelobe transmit pattern to be generated over scan angles of +/- 50 degrees. Each receiver module will include all electronics necessary to downconvert the received signal to an IF offset of 30 MHz where it will be digitized for further processing.

  9. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, Shimon; Chemla, Daniel S.; Ogletree, D. Frank; Botkin, David

    1995-01-01

    An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

  10. Teaching the SCANS Competencies.

    ERIC Educational Resources Information Center

    Department of Labor, Washington, DC. Secretary's Commission on Achieving Necessary Skills.

    SCANS (the Secretary's Commission on Achieving Necessary Skills) provides definitions of the knowledge students and workers need for workplace success and methods for applying these principles in communities throughout the United States. This document contains six articles that give education and training practitioners practical suggestions for…

  11. SCANS: The Missing Link.

    ERIC Educational Resources Information Center

    Price-Machado, Donna

    Three specific classroom techniques for teaching vocational English as a Second Language to adults are discussed. They are three items on the SCANS (Secretary's Commission on Achieving Necessary Skills) list of "easy things" to do to integrate workplace basics into the classroom, designed to encourage a student-focused classroom. They…

  12. The Organizational Scan.

    ERIC Educational Resources Information Center

    Tosti, Donald; Jackson, Stephanie D.

    1997-01-01

    Performance technologists like quick, cheap analysis that is rigorous and comprehensive. This article presents the organization scan model which makes successful compromises between the technologist's obligation to be rigorous and comprehensive and the sponsor's obligation to save money and time. Includes "Societal Bottom Line: Measurable…

  13. Gallbladder radionuclide scan

    MedlinePlus

    ... please enable JavaScript. Gallbladder radionuclide scan is a test that uses radioactive material to check gallbladder function. It is also used ... for bile duct blockage or leak. How the Test is Performed ... called a gamma emitting tracer into a vein. This material collects mostly in the liver. It will then ...

  14. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

    1995-05-16

    An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

  15. Bone scanning in clinical practice

    SciTech Connect

    Fogelman, I. )

    1987-01-01

    The topics covered in this book include the history of bone scanning, mechanisms of uptake of diphosphonate in bone, the normal bone scan, and the role of bone scanning in clinical practice. The aim of this book is to provide a source of reference relating to bone scan imaging for all those who are interested in the skeleton.

  16. Validation of burst overlapping for ALOS-2 PALSAR-2 ScanSAR-ScanSAR interferometry

    NASA Astrophysics Data System (ADS)

    Natsuaki, Ryo; Motohka, Takeshi; Ohki, Masato; Watanabe, Manabu; Suzuki, Shinichi

    2016-10-01

    The Phased Array type L-band Synthetic Aperture Radar-2 (PALSAR-2) aboard the Advanced Land Observing Satellite- 2 (ALOS-2, "DAICHI-2") is the latest L-band spaceborne synthetic aperture radar (SAR). PALSAR-2 observes the world mainly with 10 m resolution / 70 km swath Stripmap mode and 25 m resolution / 350 km swath ScanSAR mode. The 3-m resolution Stripmap mode is mainly used upon Japan. 350 km ScanSAR observation could detect large scale deformation e.g., the Mw 7.8 Gorkha, Nepal earthquake and its aftershocks in 2015. ALOS-2 ScanSAR is the first one that supports ScanSAR-ScanSAR interferometry in L-band spaceborne SAR. However, because of the parameter setting error for the orbit estimation, ALOS-2 PALSAR-2 ScanSAR could achieve little number of interferometric pair until the software modification on February 8, 2015. That is, the burst overlap timing required for the interferometric analysis was insufficient and it depends on the observation date. In this paper, we report the investigation results of this case and discuss the current status of the ALOS-2 ScanSAR InSAR. Some archives achieved before February 8, 2015 can be used for interferometric analysis with after Feb. 8. However, most of them have no interferometric pair. We also report that the archives acquired after February 8, have enough burst overlapping.

  17. Optical scanning holographic microscopy

    NASA Astrophysics Data System (ADS)

    Poon, Ting-Chung; Doh, Kyu B.; Schilling, Bradley W.; Wu, Ming H.; Shinoda, Kazunori K.; Suzuki, Yoshiji

    1995-03-01

    We first review a newly developed 3D imaging technique called optical scanning holography (OSH), and discuss recording and reconstruction of a point object using the principle of OSH. We then derive 3D holographic magnification, using three points configured as a 3D object. Finally, we demonstrated 3D imaging capability of OSH by holographically recording two planar objects at different depths and reconstructing the hologram digitally.

  18. Fly-scan ptychography

    DOE PAGES

    Huang, Xiaojing; Lauer, Kenneth; Clark, Jesse N.; ...

    2015-03-13

    We report an experimental ptychography measurement performed in fly-scan mode. With a visible-light laser source, we demonstrate a 5-fold reduction of data acquisition time. By including multiple mutually incoherent modes into the incident illumination, high quality images were successfully reconstructed from blurry diffraction patterns. This approach significantly increases the throughput of ptychography, especially for three-dimensional applications and the visualization of dynamic systems.

  19. Scanning micro-sclerometer

    DOEpatents

    Oliver, Warren C.; Blau, Peter J.

    1994-01-01

    A scanning micro-sclerometer measures changes in contact stiffness and correlates these changes to characteristics of a scratch. A known force is applied to a contact junction between two bodies and a technique employing an oscillating force is used to generate the contact stiffness between the two bodies. As the two bodies slide relative to each other, the contact stiffness changes. The change is measured to characterize the scratch.

  20. Scanning micro-sclerometer

    DOEpatents

    Oliver, W.C.; Blau, P.J.

    1994-11-01

    A scanning micro-sclerometer measures changes in contact stiffness and correlates these changes to characteristics of a scratch. A known force is applied to a contact junction between two bodies and a technique employing an oscillating force is used to generate the contact stiffness between the two bodies. As the two bodies slide relative to each other, the contact stiffness changes. The change is measured to characterize the scratch. 2 figs.

  1. Forensic Scanning Electron Microscope

    NASA Astrophysics Data System (ADS)

    Keeley, R. H.

    1983-03-01

    The scanning electron microscope equipped with an x-ray spectrometer is a versatile instrument which has many uses in the investigation of crime and preparation of scientific evidence for the courts. Major applications include microscopy and analysis of very small fragments of paint, glass and other materials which may link an individual with a scene of crime, identification of firearms residues and examination of questioned documents. Although simultaneous observation and chemical analysis of the sample is the most important feature of the instrument, other modes of operation such as cathodoluminescence spectrometry, backscattered electron imaging and direct x-ray excitation are also exploited. Marks on two bullets or cartridge cases can be compared directly by sequential scanning with a single beam or electronic linkage of two instruments. Particles of primer residue deposited on the skin and clothing when a gun is fired can be collected on adhesive tape and identified by their morphology and elemental composition. It is also possible to differentiate between the primer residues of different types of ammunition. Bullets may be identified from the small fragments left behind as they pass through the body tissues. In the examination of questioned documents the scanning electron microscope is used to establish the order in which two intersecting ink lines were written and to detect traces of chemical markers added to the security inks on official documents.

  2. Scanning ultrafast electron microscopy.

    PubMed

    Yang, Ding-Shyue; Mohammed, Omar F; Zewail, Ahmed H

    2010-08-24

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for which the pulse contains at most one or a few electrons, thus achieving imaging without the space-charge effect between electrons, and still in ten(s) of seconds. For imaging, the secondary electrons from surface structures are detected, as demonstrated here for material surfaces and biological specimens. By recording backscattered electrons, diffraction patterns from single crystals were also obtained. Scanning pulsed-electron microscopy with the acquired spatiotemporal resolutions, and its efficient heat-dissipation feature, is now poised to provide in situ 4D imaging and with environmental capability.

  3. Scanning radiographic apparatus

    SciTech Connect

    Albert, R.D.

    1980-04-01

    Visual display of dental, medical or other radiographic images is realized with an x-ray tube in which an electron beam is scanned through an x-y raster pattern on a broad anode plate, the scanning being synchronized with the x-y sweep signals of a cathode ray tube display and the intensity signal for the display being derived from a small x-ray detector which receives x-rays that have passed through the subject to be imaged. Positioning and support of the detector are provided for by disposing the detector in a probe which may be attached to the x-ray tube at any of a plurality of different locations and by providing a plurality of such probes of different configuration in order to change focal length, to accommodate to different detector placements relative to the subject, to enhance patient comfort and to enable production of both periapical images and wider angle pantomographic images. High image definition with reduced radiation dosage is provided for by a lead glass collimator situated between the x-ray tube and subject and having a large number of spaced-apart minute radiation transmissive passages convergent on the position of the detector. Releasable mounting means enable changes of collimator in conjunction with changes of the probe to change focal length. A control circuit modifies the x-y sweep signals applied to the x-ray tube and modulates electron beam energy and current in order to correct for image distortions and other undesirable effects which can otherwise be present in a scanning x-ray system.

  4. Controlled Scanning Probe Lithography

    NASA Astrophysics Data System (ADS)

    Ruskell, Todd G.; Sarid, Dror; Workman, Richard K.; Pyle, Jason L.

    1997-03-01

    A method for real-time monitoring of the quality and quantity of silicon oxide grown on silicon using conducting-tip scanning probe lithography has been developed. The sub-picoampere tip-sample currents measured during lithography in ambient conditions are shown to be proportional to the amount of silicon oxide being grown. In addition, we have demonstrated the ability to control the composition of the grown material by altering the lithographic environment. Silicon nitride growth is shown to result from lithography on silicon samples in an environment of annhydrous ammonia.

  5. Battery scanning system

    SciTech Connect

    Dieu, L.F.

    1984-11-20

    A battery scanning system which is capable of monitoring and displaying the voltage of each cell in a battery or upon command provides the cell voltage distribution by displaying the cell number and voltage value of highest and lowest cell. The system has a digital logic system, display, input switches for operator generated variables, an alarm, relays, relay selection gates, an optically coupled isolation amplifier, power source and an analog-digital converter. The optically coupled analog amplifier electrically isolates the system from the battery so that large voltage offsets will not adversely affect the automatic measuring of the cells.

  6. Scanning Quantum Dot Microscopy

    NASA Astrophysics Data System (ADS)

    Wagner, Christian; Green, Matthew F. B.; Leinen, Philipp; Deilmann, Thorsten; Krüger, Peter; Rohlfing, Michael; Temirov, Ruslan; Tautz, F. Stefan

    2015-07-01

    We introduce a scanning probe technique that enables three-dimensional imaging of local electrostatic potential fields with subnanometer resolution. Registering single electron charging events of a molecular quantum dot attached to the tip of an atomic force microscope operated at 5 K, equipped with a qPlus tuning fork, we image the quadrupole field of a single molecule. To demonstrate quantitative measurements, we investigate the dipole field of a single metal adatom adsorbed on a metal surface. We show that because of its high sensitivity the technique can probe electrostatic potentials at large distances from their sources, which should allow for the imaging of samples with increased surface roughness.

  7. Real Scan Evolution.

    DTIC Science & Technology

    1982-02-01

    Computer Image Generation Visual Simulation Computer Graphics Al gortthm Geometric Model tng 1%ABSTRACT (C.tla. -mm. .00n ad N ue-e""V ONd Ofmi* OF 61"knsee...envtronments. modeled as a single valued el evatYo fnction of horizontal location. The objecttve of the development was to analyze the feasibility of a real...generator capable of creating complex Imagery .in real time? Is the solution amenable to efficient off-lne modeling of complex environments? The Real Scan

  8. Scans Solo: A One-Person Environmental Scanning Process.

    ERIC Educational Resources Information Center

    Clagett, Craig A.

    An effective environmental scan will improve the quality of community college planning and decision making by alerting institutional leaders to the challenges and opportunities in the environment. Scanning can be done in three ways: (1) establishing a scanning committee to gather and synthesize information to guide planning; (2) sponsoring a…

  9. Free motion scanning system

    DOEpatents

    Sword, Charles K.

    2000-01-01

    The present invention relates to an ultrasonic scanner system and method for the imaging of a part system, the scanner comprising: a probe assembly spaced apart from the surface of the part including at least two tracking signals for emitting radiation and a transmitter for emitting ultrasonic waves onto a surface in order to induce at least a portion of the waves to be reflected from the part, at least one detector for receiving the radiation wherein the detector is positioned to receive the radiation from the tracking signals, an analyzer for recognizing a three-dimensional location of the tracking signals based on the emitted radiation, a differential converter for generating an output signal representative of the waveform of the reflected waves, and a device such as a computer for relating said tracking signal location with the output signal and projecting an image of the resulting data. The scanner and method are particularly useful to acquire ultrasonic inspection data by scanning the probe over a complex part surface in an arbitrary scanning pattern.

  10. Ultrafast scanning tunneling microscopy

    SciTech Connect

    Botkin, D.A. |

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  11. Pulmonary ventilation/perfusion scan

    MedlinePlus

    ... JavaScript. A pulmonary ventilation/perfusion scan involves two nuclear scan tests to measure breathing (ventilation) and circulation ( ... In: Mettler FA, Guiberteau MJ, eds. Essentials of Nuclear Medicine Imaging . 6th ed. Philadelphia, PA: Elsevier Saunders; ...

  12. Surface Studies by Scanning Probe Microscopy

    NASA Astrophysics Data System (ADS)

    Kim, Ho-Seob

    The scanning probe microscopy reported here includes scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and atomic force microscopy (AFM). The scanning tunneling microscope is a novel tool which can reveal the atomic structure and electronic properties of surfaces using a probe with a sharp tip. An additional technique, atomic force microscopy has the potential to record geometric structures for both conducting and non -conducting materials. The first AFM designs utilized short range forces between a small stylus and a sample surface to produce high resolution images of defects and structural features of the surface. The current-voltage characteristics were also investigated during dynamic changes of the tunnel current and barrier height with an additional technology, tunneling spectroscopy. An advanced design for an AFM has been developed which utilizes a dielectric tunnel junction to retain the high sensitivity of tunnel current control over force ranges between 10^{-6} and 10 ^{-11}N. This AFM has been successfully applied to physical and biological samples. Scanning probe techniques have been developed and applied to a range of sample types including conductors, semi-conductors and non-conductors. Each technique utilizes the same electronics, computers, and imaging facilities. A fundamental problem of the atomic structure of graphite has existed since the inception of STM images. The experimental and theoretical hypotheses have been considered and a resolution of the problem has been developed as reported in this dissertation. Unprecedented resolving power, greater than 1A, has confirmed our hypothesis and has been correctly correlated with the structure of graphite surface. This dissertation also presents the results from studies of the surface structure of: MoS_2 , Cu, Au, Ag, Si, CdTe, HgTe, Fe_2 O_3, mica, gypsum, purple membranes with protein chains, and an organic photoconducting material, by scanning probe microscopes.

  13. Rotational scanning atomic force microscopy.

    PubMed

    Ulčinas, A; Vaitekonis, Š

    2017-03-10

    A non-raster scanning technique for atomic force microscopy (AFM) imaging which combines rotational and translational motion is presented. The use of rotational motion for the fast scan axis allows us to significantly increase the scanning speed while imaging a large area (diameter > 30 μm). An image reconstruction algorithm and the factors influencing the resolution of the technique are discussed. The experimental results show the potential of the rotational scanning technique for high-throughput large area AFM investigation.

  14. Rotational scanning atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Ulčinas, A.; Vaitekonis, Š.

    2017-03-01

    A non-raster scanning technique for atomic force microscopy (AFM) imaging which combines rotational and translational motion is presented. The use of rotational motion for the fast scan axis allows us to significantly increase the scanning speed while imaging a large area (diameter > 30 μm). An image reconstruction algorithm and the factors influencing the resolution of the technique are discussed. The experimental results show the potential of the rotational scanning technique for high-throughput large area AFM investigation.

  15. The Scanning Process: Getting Started.

    ERIC Educational Resources Information Center

    Renfro, William L.; Morrison, James L.

    1983-01-01

    Scanning the external environment will become more essential to colleges in the coming decade. Developing an environmental scanning system can identify important emerging issues that may constitute either threats or opportunities. The organizational features of a mature scanning process are described. (MLW)

  16. Software for visualization, analysis, and manipulation of laser scan images

    NASA Astrophysics Data System (ADS)

    Burnsides, Dennis B.

    1997-03-01

    The recent introduction of laser surface scanning to scientific applications presents a challenge to computer scientists and engineers. Full utilization of this two- dimensional (2-D) and three-dimensional (3-D) data requires advances in techniques and methods for data processing and visualization. This paper explores the development of software to support the visualization, analysis and manipulation of laser scan images. Specific examples presented are from on-going efforts at the Air Force Computerized Anthropometric Research and Design (CARD) Laboratory.

  17. A scanning cavity microscope

    PubMed Central

    Mader, Matthias; Reichel, Jakob; Hänsch, Theodor W.; Hunger, David

    2015-01-01

    Imaging the optical properties of individual nanosystems beyond fluorescence can provide a wealth of information. However, the minute signals for absorption and dispersion are challenging to observe, and only specialized techniques requiring sophisticated noise rejection are available. Here we use signal enhancement in a high-finesse scanning optical microcavity to demonstrate ultra-sensitive imaging. Harnessing multiple interactions of probe light with a sample within an optical resonator, we achieve a 1,700-fold signal enhancement compared with diffraction-limited microscopy. We demonstrate quantitative imaging of the extinction cross-section of gold nanoparticles with a sensitivity less than 1 nm2; we show a method to improve the spatial resolution potentially below the diffraction limit by using higher order cavity modes, and we present measurements of the birefringence and extinction contrast of gold nanorods. The demonstrated simultaneous enhancement of absorptive and dispersive signals promises intriguing potential for optical studies of nanomaterials, molecules and biological nanosystems. PMID:26105690

  18. Telescopic horizon scanning.

    PubMed

    Koenderink, Jan

    2014-12-20

    The problem of "distortionless" viewing with terrestrial telescopic systems (mainly "binoculars") remains problematic. The so called "globe effect" is only partially counteracted in modern designs. Theories addressing the phenomenon have never reached definitive closure. In this paper, we show that exact distortionless viewing with terrestrial telescopic systems is not possible in general, but that it is in principle possible in-very frequent in battle field and marine applications-the case of horizon scanning. However, this involves cylindrical optical elements. For opto-electronic systems, a full solution is more readily feasible. The solution involves a novel interpretation of the relevant constraints and objectives. For final design decisions, it is not necessary to rely on a corpus of psychophysical (or ergonomic) data, although one has to decide whether the instrument is intended as an extension of the eye or as a "pictorial" device.

  19. Scanning the periphery.

    PubMed

    Day, George S; Schoemaker, Paul J H

    2005-11-01

    Companies often face new rivals, technologies, regulations, and other environmental changes that seem to come out of left field. How can they see these changes sooner and capitalize on them? Such changes often begin as weak signals on what the authors call the periphery, or the blurry zone at the edge of an organization's vision. As with human peripheral vision, these signals are difficult to see and interpret but can be vital to success or survival. Unfortunately, most companies lack a systematic method for determining where on the periphery they should be looking, how to interpret the weak signals they see, and how to allocate limited scanning resources. This article provides such a method-a question-based framework for helping companies scan the periphery more efficiently and effectively. The framework divides questions into three categories: learning from the past (What have been our past blind spots? What instructive analogies do other industries offer? Who in the industry is skilled at picking up weak signals and acting on them?); evaluating the present (What important signals are we rationalizing away? What are our mavericks, outliers, complainers, and defectors telling us? What are our peripheral customers and competitors really thinking?); and envisioning the future (What future surprises could really hurt or help us? What emerging technologies could change the game? Is there an unthinkable scenario that might disrupt our business?). Answering these questions is a good first step toward anticipating problems or opportunities that may appear on the business horizon. The article concludes with a self-test that companies can use to assess their need and capability for peripheral vision.

  20. Theoretical simulation of scanning probe microscopy.

    PubMed

    Tsukada, Masaru

    2011-01-01

    Methods of theoretical simulation of scanning probe microscopy, including scanning tunneling microscopy (STM), atomic force microscopy(AFM) and Kelvin prove force microscopy (KPFM) have been reviewed with recent topics as case studies. For the case of the STM simulation, the importance of the tip electronic states is emphasized and some advanced formalism is presented based on the non-equilibrium Green's function theory beyond Bardeen's perturbation theory. For the simulation of AFM, we show examples of 3D-force map for AFM in water, and theoretical analyses for a nano-mechanical experiment on a protein molecule. An attempt to simulate KPFM images based on the electrostatic multi-pole interaction between a tip and a sample is also introduced.

  1. Graphite Gamma Scan Results

    SciTech Connect

    Mark W. Drigert

    2014-04-01

    This report documents the measurement and data analysis of the radio isotopic content for a series of graphite specimens irradiated in the first Advanced Graphite Creep (AGC) experiment, AGC-1. This is the first of a series of six capsules planned as part of the AGC experiment to fully characterize the neutron irradiation effects and radiation creep behavior of current nuclear graphites. The AGC-1 capsule was irradiated in the Advanced Test Reactor (ATR) at INL at approximately 700 degrees C and to a peak dose of 7 dpa (displacements per atom). Details of the irradiation conditions and other characterization measurements performed on specimens in the AGC-1 capsule can be found in “AGC-1 Specimen Post Irradiation Data Report” ORNL/TM 2013/242. Two specimens from six different graphite types are analyzed here. Each specimen is 12.7 mm in diameter by 25.4 mm long. The isotope with the highest activity was 60Co. Graphite type NBG-18 had the highest content of 60Co with an activity of 142.89 µCi at a measurement distance of 47 cm.

  2. Treatment of Alzheimer Disease With CT Scans

    PubMed Central

    Moore, Eugene R.; Hosfeld, Victor D.; Nadolski, David L.

    2016-01-01

    Alzheimer disease (AD) primarily affects older adults. This neurodegenerative disorder is the most common cause of dementia and is a leading source of their morbidity and mortality. Patient care costs in the United States are about 200 billion dollars and will more than double by 2040. This case report describes the remarkable improvement in a patient with advanced AD in hospice who received 5 computed tomography scans of the brain, about 40 mGy each, over a period of 3 months. The mechanism appears to be radiation-induced upregulation of the patient’s adaptive protection systems against AD, which partially restored cognition, memory, speech, movement, and appetite. PMID:27103883

  3. Earth observing scanning polarimeter

    NASA Technical Reports Server (NTRS)

    Travis, Larry

    1993-01-01

    Climate forcing by tropospheric aerosols is receiving increased attention because of the realization that the climate effects may be large, while our knowledge of global aerosol characteristics and temporal changes is very poor. Tropospheric aerosols cause a direct radiative forcing due simply to their scattering and absorption of solar radiation, as well as an indirect effect as cloud condensation nuclei which can modify the shortwave reflectivity of clouds. Sulfate aerosols tend to increase planetary albedo through both the direct and indirect effects; a cooling due to anthropogenic sulfate aerosols has been estimated of order 1 W/sq m, noting that this is similar in magnitude to the present anthropogenic greenhouse gas warming. Other aerosols, including those from biomass burning and wind-blown desert dust are also of potential climatic importance. At present, the only global monitoring of tropospheric aerosols is a NOAA operational product, aerosol optical thickness, obtained using channel-1 (0.58-0.68 mu m) radiances from the AVHRR. With this single channel radiance data, one must use an approach which is based on the inferred excess of reflected radiance owing to scattering by the aerosols over that expected from theoretical calculations. This approach is suited only for situations where the surface has a low albedo that is well known a priori. Thus, the NOAA operational product is restricted to coverage over the ocean at AVHRR scan angles well away from sun glint, and aerosol changes are subject to confusion with changes caused by either optically thin or subpixel clouds. Because optically thin aerosols have only a small effect on the radiance, accurate measurements for optical thickness less than 0.1 (which is a typical background level) are precluded. Moreover, some of the largest and most important aerosol changes are expected over land. The Earth Observing Scanning Polarimeter (EOSP) instrument, based upon design heritage and analysis techniques

  4. Recording and Scanning Advances in Cartographic EBR Systems.

    DTIC Science & Technology

    1981-06-01

    34Cartographic Electron Beam Recording," 2nd Annual William T. Pecora Memorial Symposium on Mapping and Remote Sensing Data, Sponsored ASP, USGS, NASA...using the experimental Cartographic EBR System. These were: (a) GAF Electrostatic Film - toner processed (b) GAF Direct Recording Materials - no...processing required (c) Kodak Direct Recording ESR-l - no processing required (d) GAF Electrostatic Films - color toner processed (e) Kodak S0214

  5. LANL Robotic Vessel Scanning

    SciTech Connect

    Webber, Nels W.

    2015-11-25

    Los Alamos National Laboratory in J-1 DARHT Operations Group uses 6ft spherical vessels to contain hazardous materials produced in a hydrodynamic experiment. These contaminated vessels must be analyzed by means of a worker entering the vessel to locate, measure, and document every penetration mark on the vessel. If the worker can be replaced by a highly automated robotic system with a high precision scanner, it will eliminate the risks to the worker and provide management with an accurate 3D model of the vessel presenting the existing damage with the flexibility to manipulate the model for better and more in-depth assessment.The project was successful in meeting the primary goal of installing an automated system which scanned a 6ft vessel with an elapsed time of 45 minutes. This robotic system reduces the total time for the original scope of work by 75 minutes and results in excellent data accumulation and transmission to the 3D model imaging program.

  6. Differential scanning calorimetry.

    PubMed

    Spink, Charles H

    2008-01-01

    Differential scanning calorimetry (DSC) has emerged as a powerful experimental technique for determining thermodynamic properties of biomacromolecules. The ability to monitor unfolding or phase transitions in proteins, polynucleotides, and lipid assemblies has not only provided data on thermodynamic stability for these important molecules, but also made it possible to examine the details of unfolding processes and to analyze the characteristics of intermediate states involved in the melting of biopolymers. The recent improvements in DSC instrumentation and software have generated new opportunities for the study of the effects of structure and changes in environment on the behavior of proteins, nucleic acids, and lipids. This review presents some of the details of application of DSC to the examination of the unfolding of biomolecules. After a brief introduction to DSC instrumentation used for the study of thermal transitions, the methods for obtaining basic thermodynamic information from the DSC curve are presented. Then, using DNA unfolding as an example, methods for the analysis of the melting transition are presented that allow deconvolution of the DSC curves to determine more subtle characteristics of the intermediate states involved in unfolding. Two types of transitions are presented for analysis, the first example being the unfolding of two large synthetic polynucleotides, which display high cooperativity in the melting process. The second example shows the application of DSC for the study of the unfolding of a simple hairpin oligonucleotide. Details of the data analysis are presented in a simple spreadsheet format.

  7. GPR scan assessment

    NASA Astrophysics Data System (ADS)

    Abbas, Abbas M.; Salah, Hany; Massoud, Usama; Fouad, Mona; Abdel-Hafez, Mahmoud

    2015-06-01

    Mekaad Radwan monument is situated in the neighborhood of Bab Zuweila in the historical Cairo, Egypt. It was constructed at the middle XVII century (1635 AD). The building has a rectangle shape plan (13 × 6 m) with the longitudinal sides approximately WNW-ESE. It comprises three storages namely; the ground floor; the opened floor (RADWAN Bench) and the living floor with a total elevation of 15 m above the street level. The building suffers from severe deterioration phenomena with patterns of damage which have occurred over time. These deterioration and damages could be attributed to foundation problems, subsoil water and also to the earthquake that affected the entire Greater Cairo area in October 1992. Ground Penetrating Radar (GPR) scan was accomplished against the walls of the opened floor (RADWAN Bench) to evaluate the hazard impact on the walls textures and integrity. The results showed an anomalous feature through the southern wall of RADWAN Bench. A mathematical model has been simulated to confirm the obtained anomaly and the model response exhibited a good matching with the outlined anomaly.

  8. Continuous scanning mode for ptychography

    SciTech Connect

    Clark, Jesse N.; Huang, Xiaojing; Harder, Ross; Robinson, Ian K.

    2014-10-15

    We outline how ptychographic imaging can be performed without the need for discrete scan positions. Through an idealized experiment, we demonstrate how a discrete-position scan regime can be replaced with a continuously scanned one with suitable modification of the reconstruction scheme based on coherent modes. The impact of this is that acquisition times can be reduced, significantly aiding ptychographic imaging with x rays, electrons, or visible light.

  9. Continuous scanning mode for ptychography

    SciTech Connect

    Clark, Jesse N.; Huang, Xiaojing; Harder, Ross J.; Robinson, Ian K.

    2014-01-01

    Here, we outline how ptychographic imaging can be performed without the need for discrete scan positions. Through an idealized experiment, we demonstrate how a discrete-position scan regime can be replaced with a continuously scanned one with suitable modification of the reconstruction scheme based on coherent modes. Furthermore, the impact of this is that acquisition times can be reduced, significantly aiding ptychographic imaging with x rays, electrons, or visible light.

  10. Exploring Scanning Probe Microscopy with Mathematica

    NASA Astrophysics Data System (ADS)

    Sarid, Dror

    1997-10-01

    This book/software edition provides a complete set of computational models that describe the physical phenomena associated with scanning tunneling microscopy, atomic force microscopy, and related technologies. Its self-contained presentation spares researchers the valuable time spent hunting through the technical literature in search of prior theoretical results required to understand the models presented. Mathematica code for all examples is included both in the book and at the accompanying ftp site, affording the freedom to change, at will, the values and parameters of specific problems or even modify the programs themselves to suit various modeling needs. Exploring Scanning Probe Microscopy with Mathematica is both a solid professional reference and an advanced-level text, beginning with scanning probe microscopy basics and moving on to cutting-edge techniques, experiments, and theory. In the section devoted to atomic force microscopy, Dr. Sarid describes the mechanical properties of cantilevers, atomic force microscope tip-sample interactions, and cantilever vibration characteristics. This is followed by an in-depth treatment of theoretical and practical aspects of tunneling phenomena, including metal-insulator-metal tunneling and Fowler-Nordheim field emission. The final section features chapters covering density of states in arbitrary dimensions, quantum wells and dots, and electrostatics.

  11. Large energy-spread beam diagnostics through quadrupole scans

    SciTech Connect

    Frederico, Joel; Adli, Erik; Hogan, Mark; Raubenheimer, Tor

    2012-12-21

    The Facility for Advanced Accelerator and Experimental Tests (FACET) is a new user facility at the SLAC National Accelerator Laboratory, servicing next-generation accelerator experiments. The 1.5% RMS energy spread of the FACET beam causes large chromatic aberrations in optics. These aberrations necessitate updated quadrupole scan fits to remain accurate.

  12. Large energy-spread beam diagnostics through quadrupole scans

    SciTech Connect

    Frederico, Joel; Adli, Erik; Hogan, Mark; Raubenheimer, Tor

    2013-01-01

    The Facility for Advanced Accelerator and Experimental Tests (FACET) is a new user facility at the SLAC National Accelerator Laboratory, servicing next-generation accelerator experiments. The 1.5% RMS energy spread of the FACET beam causes large chromatic aberrations in optics. These aberrations necessitate updated quadrupole scan fits to remain accurate.

  13. Document Management: It Prints! It Faxes! It Scans!

    ERIC Educational Resources Information Center

    Briggs, Linda L.

    2006-01-01

    In printing, scanning, copying, and publishing, the new buzzword is combo: combination systems that take the strengths of several pieces of hardware--and sometimes software--and combine them into one. Advances in these technologies can save districts money by cutting the use of staff time, paper, and accessories such as print cartridges. Also,…

  14. Hurricane Wind Field Measurements with Scanning Airborne Doppler Lidar During CAMEX-3

    NASA Technical Reports Server (NTRS)

    Rothermel, Jeffry; Cutten, D. R.; Howell, J. N.; Darby, L. S.; Hardesty, R. M.; Traff, D. M.; Menzies, R. T.

    2000-01-01

    During the 1998 Convection and Moisture Experiment (CAMEX-3), the first hurricane wind field measurements with Doppler lidar were achieved. Wind fields were mapped within the eye, along the eyewall, in the central dense overcast, and in the marine boundary layer encompassing the inflow region. Spatial coverage was determined primarily by cloud distribution and opacity. Within optically-thin cirrus slant range of 20- 25 km was achieved, whereas no propagation was obtained during penetration of dense cloud. Measurements were obtained with the Multi-center Airborne Coherent Atmospheric Wind Sensor (MACAWS) on the NASA DC-8 research aircraft. MACAWS was developed and operated cooperatively by the atmospheric lidar remote sensing groups of NOAA Environmental Technology Laboratory, NASA Marshall Space Flight Center, and Jet Propulsion Laboratory. A pseudo-dual Doppler technique ("co-planar scanning") is used to map the horizontal component of the wind at several vertical levels. Pulses from the laser are directed out the left side of the aircraft in the desired directions using computer-controlled rotating prisms. Upon exiting the aircraft, the beam is completely eyesafe. Aircraft attitude and speed are taken into account during real-time signal processing, resulting in determination of the ground-relative wind to an accuracy of about 1 m/s magnitude and about 10 deg direction. Beam pointing angle errors are about 0.1 deg, equivalent to about 17 m at 10 km. Horizontal resolution is about 1 km (along-track) for typical signal processor and scanner settings; vertical resolution varies with range. Results from CAMEX-3 suggest that scanning Doppler wind lidar can complement airborne Doppler radar by providing wind field measurements in regions that are devoid of hydrometeors. At present MACAWS observations are being assimilated into experimental forecast models and satellite Doppler wind lidar simulations to evaluate the relative impact.

  15. Lung Ventilation/Perfusion Scan

    MedlinePlus

    ... Scan Lung VQ Scan Related Topics Arrhythmia Cough Deep Vein Thrombosis Pulmonary Embolism Send a link to NHLBI to someone by ... this topic. Related reading Chest X Ray Cough Deep Vein Thrombosis Pulmonary Embolism Rate This Content: Updated: December 9, 2016 Twitter ...

  16. An interchangeable scanning Hall probe/scanning SQUID microscope

    SciTech Connect

    Tang, Chiu-Chun; Lin, Hui-Ting; Wu, Sing-Lin; Chen, Tse-Jun; Wang, M. J.; Ling, D. C.; Chi, C. C.; Chen, Jeng-Chung

    2014-08-15

    We have constructed a scanning probe microscope for magnetic imaging, which can function as a scanning Hall probe microscope (SHPM) and as a scanning SQUID microscope (SSM). The scanning scheme, applicable to SHPM and SSM, consists of a mechanical positioning (sub) micron-XY stage and a flexible direct contact to the sample without a feedback control system for the Z-axis. With the interchangeable capability of operating two distinct scanning modes, our microscope can incorporate the advantageous functionalities of the SHPM and SSM with large scan range up to millimeter, high spatial resolution (⩽4 μm), and high field sensitivity in a wide range of temperature (4.2 K-300 K) and magnetic field (10{sup −7} T-1 T). To demonstrate the capabilities of the system, we present magnetic images scanned with SHPM and SSM, including a RbFeB magnet and a nickel grid pattern at room temperature, surface magnetic domain structures of a La{sub 2/3}Ca{sub 1/3}MnO{sub 3} thin film at 77 K, and superconducting vortices in a striped niobium film at 4.2 K.

  17. The value of brain scanning

    PubMed Central

    Riddoch, D.; Drolc, Z.

    1972-01-01

    Over a 3-year period, 667 brain scans were performed, of which the results in 632 have been analysed. Positive scans were found in 68% of 204 cerebral tumours. There was a high rate of detection of meningiomas and malignant gliomas. Scanning was less helpful in visualizing slowly growing gliomas, and those tumours situated in the mid-line or posterior fossa. Metastases occupied an intermediate position. Positive scans occurred in a proportion of patients following acute cerebro-vascular accidents, and in a few other miscellaneous disorders. Virtually all patients with transient cerebral ischaemia, migraine, epilepsy and presenile dementia had normal brain scans. The value and limitations of this investigation have been discussed. PMID:5076491

  18. Differential scanning calorimetry (DSC) of semicrystalline polymers.

    PubMed

    Schick, C

    2009-11-01

    Differential scanning calorimetry (DSC) is an effective analytical tool to characterize the physical properties of a polymer. DSC enables determination of melting, crystallization, and mesomorphic transition temperatures, and the corresponding enthalpy and entropy changes, and characterization of glass transition and other effects that show either changes in heat capacity or a latent heat. Calorimetry takes a special place among other methods. In addition to its simplicity and universality, the energy characteristics (heat capacity C(P) and its integral over temperature T--enthalpy H), measured via calorimetry, have a clear physical meaning even though sometimes interpretation may be difficult. With introduction of differential scanning calorimeters (DSC) in the early 1960s calorimetry became a standard tool in polymer science. The advantage of DSC compared with other calorimetric techniques lies in the broad dynamic range regarding heating and cooling rates, including isothermal and temperature-modulated operation. Today 12 orders of magnitude in scanning rate can be covered by combining different types of DSCs. Rates as low as 1 microK s(-1) are possible and at the other extreme heating and cooling at 1 MK s(-1) and higher is possible. The broad dynamic range is especially of interest for semicrystalline polymers because they are commonly far from equilibrium and phase transitions are strongly time (rate) dependent. Nevertheless, there are still several unsolved problems regarding calorimetry of polymers. I try to address a few of these, for example determination of baseline heat capacity, which is related to the problem of crystallinity determination by DSC, or the occurrence of multiple melting peaks. Possible solutions by using advanced calorimetric techniques, for example fast scanning and high frequency AC (temperature-modulated) calorimetry are discussed.

  19. Re-scan confocal microscopy: scanning twice for better resolution

    PubMed Central

    De Luca, Giulia M.R.; Breedijk, Ronald M.P.; Brandt, Rick A.J.; Zeelenberg, Christiaan H.C.; de Jong, Babette E.; Timmermans, Wendy; Azar, Leila Nahidi; Hoebe, Ron A.; Stallinga, Sjoerd; Manders, Erik M.M.

    2013-01-01

    We present a new super-resolution technique, Re-scan Confocal Microscopy (RCM), based on standard confocal microscopy extended with an optical (re-scanning) unit that projects the image directly on a CCD-camera. This new microscope has improved lateral resolution and strongly improved sensitivity while maintaining the sectioning capability of a standard confocal microscope. This simple technology is typically useful for biological applications where the combination high-resolution and high-sensitivity is required. PMID:24298422

  20. 3D Scan Systems Integration

    DTIC Science & Technology

    2007-11-02

    AGENCY USE ONLY (Leave Blank) 2. REPORT DATE 5 Feb 98 4. TITLE AND SUBTITLE 3D Scan Systems Integration REPORT TYPE AND DATES COVERED...2-89) Prescribed by ANSI Std. Z39-1 298-102 [ EDO QUALITY W3PECTEDI DLA-ARN Final Report for US Defense Logistics Agency on DDFG-T2/P3: 3D...SCAN SYSTEMS INTEGRATION Contract Number SPO100-95-D-1014 Contractor Ohio University Delivery Order # 0001 Delivery Order Title 3D Scan Systems

  1. Circular Scan Streak Tube Development

    NASA Technical Reports Server (NTRS)

    Nevin, S.

    1980-01-01

    A streak tube having circular scan was designed, built and tested. Continuous circular scan, easily derived from out of phase sine waves applied to the conventional deflection plates, permits the timing of pulses traveling long baselines. At the tube's output a circular array of 720 elements is scanned to provide 30 to 40 picosecond resolution. Initial difficulties with electron bombarded silicon arrays were circumvented by using microchannel plates within the streak tube to provide the needed electronic amplification and digital sensitivity and coupling the 720 element arrays to the electron beam by means of a phosphor on a fiber optics. Two ceramic body tubes with S-20 photocathodes were tested and delivered.

  2. Stereo vision based hand-held laser scanning system design

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Wang, Jinming

    2011-11-01

    Although 3D scanning system is used more and more broadly in many fields, such computer animate, computer aided design, digital museums, and so on, a convenient scanning device is expansive for most people to afford. In another hand, imaging devices are becoming cheaper, a stereo vision system with two video cameras cost little. In this paper, a hand held laser scanning system is design based on stereo vision principle. The two video cameras are fixed tighter, and are all calibrated in advance. The scanned object attached with some coded markers is in front of the stereo system, and can be changed its position and direction freely upon the need of scanning. When scanning, the operator swept a line laser source, and projected it on the object. At the same time, the stereo vision system captured the projected lines, and reconstructed their 3D shapes. The code markers are used to translate the coordinate system between scanned points under different view. Two methods are used to get more accurate results. One is to use NURBS curves to interpolate the sections of the laser lines to obtain accurate central points, and a thin plate spline is used to approximate the central points, and so, an exact laser central line is got, which guards an accurate correspondence between tow cameras. Another way is to incorporate the constraint of laser swept plane on the reconstructed 3D curves by a PCA (Principle Component Analysis) algorithm, and more accurate results are obtained. Some examples are given to verify the system.

  3. Determination of Heats of Fusion: Using Differential Scanning Calorimetry for the AP Chemistry Courses.

    ERIC Educational Resources Information Center

    Temme, Susan M.

    1995-01-01

    Describes an exercise designed to be used in an Advanced Placement (AP) chemistry course to accompany the study of thermodynamics. Uses Differential Scanning Calorimetry in teaching the concepts of thermochemistry and thermodynamics. (JRH)

  4. Transverse section radionuclide scanning system

    DOEpatents

    Kuhl, David E.; Edwards, Roy Q.

    1976-01-01

    This invention provides a transverse section radionuclide scanning system for high-sensitivity quantification of brain radioactivity in cross-section picture format in order to permit accurate assessment of regional brain function localized in three-dimensions. High sensitivity crucially depends on overcoming the heretofore known raster type scanning, which requires back and forth detector movement involving dead-time or partial enclosure of the scan field. Accordingly, this invention provides a detector array having no back and forth movement by interlaced detectors that enclose the scan field and rotate as an integral unit around one axis of rotation in a slip ring that continuously transmits the detector data by means of laser emitting diodes, with the advantages that increased amounts of data can be continuously collected, processed and displayed with increased sensitivity according to a suitable computer program.

  5. Studies in Scanning Probe Microscopy.

    DTIC Science & Technology

    2007-11-02

    refereed journals, as well as two books titled Scanning Force Microscopy, With Applications to Electric, Magnetic, and Atomic Forces published by Oxford University Press in 1991 and a revised edition in 1994.

  6. Retinal locus for scanning text.

    PubMed

    Timberlake, George T; Sharma, Manoj K; Grose, Susan A; Maino, Joseph H

    2006-01-01

    A method of mapping the retinal location of text during reading is described in which text position is plotted cumulatively on scanning laser ophthalmoscope retinal images. Retinal locations that contain text most often are the brightest in the cumulative plot, and locations that contain text least often are the darkest. In this way, the retinal area that most often contains text is determined. Text maps were plotted for eight control subjects without vision loss and eight subjects with central scotomas from macular degeneration. Control subjects' text maps showed that the fovea contained text most often. Text maps of five of the subjects with scotomas showed that they used the same peripheral retinal area to scan text and fixate. Text maps of the other three subjects with scotomas showed that they used separate areas to scan text and fixate. Retinal text maps may help evaluate rehabilitative strategies for training individuals with central scotomas to use a particular retinal area to scan text.

  7. Liver echinococcus - CT scan (image)

    MedlinePlus

    This upper abdominal CT scan shows multiple cysts in the liver, caused by dog tapeworm (echinococcus). Note the large circular cyst (seen on the left side of the screen) and multiple smaller cysts throughout ...

  8. Scanned Laser Illuminator/Receiver

    DTIC Science & Technology

    1976-11-01

    illustrate parallel development of the PIN diode /CCD sensor hybrid and the 100W laser . Al- though a detailed cost analysis for procurement of this large...pmww^^W .m^n.m .,** ■ —ssa^ AFAL-TR-76-184 \\ SCANNED LASER ILLUMINATOR/RECEIVER ^ R. A. Honzik and F. B. Warren ^•Martin Marietta...NUMBER 4. TITLE (and Sublille) SCANNED LASER ILLUMINATOR/RECEIVER 5, TYPE OF REPORT & PERIOD COVERED Final Technical Report Dec 75

  9. Low Voltage Scanning Electron Microscopy

    DTIC Science & Technology

    1988-10-01

    Microscopy List of Keywords ,Scanning electron microscopy SEM X -ray .Micoranalysis EDX/EDS -%Low voltage , High resolution -Ceramic surfaces Supported...energy component normal to the surface). (a) Applications to x -ray microanalysis The essential problem leading to the specification of a LVSEM is...illustrated (Fig.l), for a conventional microprobe operated with 20nA probe current, by the contrast of the alumunium (K) x -ray signal as the probe is scanned

  10. Lidar arc scan uncertainty reduction through scanning geometry optimization

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Barthelmie, Rebecca J.; Pryor, Sara C.; Brown, Gareth.

    2016-04-01

    Doppler lidars are frequently operated in a mode referred to as arc scans, wherein the lidar beam scans across a sector with a fixed elevation angle and the resulting measurements are used to derive an estimate of the n minute horizontal mean wind velocity (speed and direction). Previous studies have shown that the uncertainty in the measured wind speed originates from turbulent wind fluctuations and depends on the scan geometry (the arc span and the arc orientation). This paper is designed to provide guidance on optimal scan geometries for two key applications in the wind energy industry: wind turbine power performance analysis and annual energy production prediction. We present a quantitative analysis of the retrieved wind speed uncertainty derived using a theoretical model with the assumption of isotropic and frozen turbulence, and observations from three sites that are onshore with flat terrain, onshore with complex terrain and offshore, respectively. The results from both the theoretical model and observations show that the uncertainty is scaled with the turbulence intensity such that the relative standard error on the 10 min mean wind speed is about 30 % of the turbulence intensity. The uncertainty in both retrieved wind speeds and derived wind energy production estimates can be reduced by aligning lidar beams with the dominant wind direction, increasing the arc span and lowering the number of beams per arc scan. Large arc spans should be used at sites with high turbulence intensity and/or large wind direction variation.

  11. Update on MEMS-based scanned beam imager

    NASA Astrophysics Data System (ADS)

    James, Richard; Gibson, Greg; Metting, Frank; Davis, Wyatt; Drabe, Christian

    2007-01-01

    In 2004, Microvision presented "Scanned Beam Medical Imager" as an introduction to our MEMS-based, full color scanned beam imaging system. This presentation will provide an update of the technological advancements since this initial work from 2004. This recent work includes the development of functional prototypes that are much smaller than previous prototypes using a design architecture that is easily scalable. Performance has been significantly improved by increasing the optical field of views and video refresh rate. Real-time image processing capabilities have been developed to enhance the image quality and functionality over a wide range of operating conditions. Actual images of various objects will be presented.

  12. Negative radionuclide scan in osteoid osteoma. A case report

    SciTech Connect

    Fehring, T.K.; Green, N.E.

    1984-05-01

    Advances in radionuclide imaging have facilitated the accurate diagnosis and surgical excision of osteoid osteoma. While radionuclide imaging has been inconsistent in the diagnosis of certain problems, its accuracy in the diagnosis of osteoid osteoma has been frequently stressed. To date, no case of a negative bone scan in the presence of a histologically proven osteoid osteoma has been reported. The present case report emphasizes that a negative bone scan does not preclude the diagnosis of osteoid osteoma. Clinical suspicion remains the most sensitive indicator of this lesion.

  13. Deconvolution of sinusoidal rapid EPR scans.

    PubMed

    Tseitlin, Mark; Rinard, George A; Quine, Richard W; Eaton, Sandra S; Eaton, Gareth R

    2011-02-01

    In rapid scan EPR the magnetic field is scanned through the signal in a time that is short relative to electron spin relaxation times. Previously it was shown that the slow-scan lineshape could be recovered from triangular rapid scans by Fourier deconvolution. In this paper a general Fourier deconvolution method is described and demonstrated to recover the slow-scan lineshape from sinusoidal rapid scans. Since an analytical expression for the Fourier transform of the driving function for a sinusoidal scan was not readily apparent, a numerical method was developed to do the deconvolution. The slow scan EPR lineshapes recovered from rapid triangular and sinusoidal scans are in excellent agreement for lithium phthalocyanine, a trityl radical, and the nitroxyl radical, tempone. The availability of a method to deconvolute sinusoidal rapid scans makes it possible to scan faster than is feasible for triangular scans because of hardware limitations on triangular scans.

  14. Immersion ultrasonography: simultaneous A-scan and B-scan.

    PubMed

    Coleman, D J; Dallow, R L; Smith, M E

    1979-01-01

    In eyes with opaque media, ophthalmic ultrasound provides a unique source of information that can dramatically affect the course of patient management. In addition, when an ocular abnormality can be visualized, ultrasonography provides information that supplements and complements other diagnostic testing. It provides documentation and differentiation of abnormal states, such as vitreous hemorrhage and intraocular tumor, as well as differentiation of orbital tumors from inflammatory causes of exophthalmos. Additional capabilities of ultrasound are biometric determinations for calculation of intraocular lens implant powers and drug-effectiveness studies. Maximal information is derived from ultrasonography when A-scan and B-scan techniques are employed simultaneously. Flexibility of electronics, variable-frequency transducers, and the use of several different manual scanning patterns aid in detection and interpretation of results. The immersion system of ultrasonography provides these features optimally.

  15. Engineer pedals STS-37 CETA electrical cart along track in JSC MAIL Bldg 9A

    NASA Technical Reports Server (NTRS)

    1990-01-01

    McDonnell Douglas engineer Gary Peters operates crew and equipment translation aid (CETA) electrical hand pedal cart in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A. Peters, wearing extravehicular mobility unit (EMU) boots and positioned in portable foot restraint (PFR), is suspended above CETA cart and track via harness to simulate weightlessness. The electrical cart is moved by electricity generated from turning hand pedals. CETA will be tested in orbit in the payload bay of Atlantis, Orbiter Vehicle (OV) 104, during STS-37.

  16. Currents in Rivers Observed by Spaceborne Along-Track InSAR -CuRiOSATI-

    DTIC Science & Technology

    2010-09-30

    images of ocean and river scenes were acquired in Aperture Switching (AS) mode in spring and summer 2008, including six images of the Elbe river...Germany), which were made available to us in December 2008. In spring 2009, another set of images of the Elbe river was acquired in Dual Receive...Antenna (DRA) mode. In Fall 2009, the acquisition of AS-mode images was continued. The Elbe river was selected as first test site a long time ago because

  17. Currents in Rivers Observed by Spaceborne Along-Track InSAR -- CuRiOSATI

    DTIC Science & Technology

    2011-09-30

    including six images of the Elbe river (Germany), which were made available to us in December 2008. In spring 2009, another set of images of the Elbe ...river was acquired in Dual Receive Antenna (DRA) mode. In Fall 2009, the acquisition of AS-mode images was continued. The Elbe river was selected as...data from (German) governmental agencies. After the Elbe river, the Lena river in Siberia was selected as a second river for routine data

  18. Advanced Science.

    ERIC Educational Resources Information Center

    Coles, Mike; Nelms, Rick

    1996-01-01

    Describes a study that explores the depth and breadth of scientific facts, principles, and procedures which are required in the Advanced General National Vocational Qualifications (GNVQ) science through comparison with GCE Advanced level. The final report takes account of the updated 1996 version of GNVQ science. (DDR)

  19. Studies in scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Sarid, Dror

    1995-06-01

    The following is a final report on our work in the field of Scanning Probe Microscopy (SPM), which has been funded by the AFOSR under Contract #F49620-92-J-0164. The AFOSR funding was instrumental in the establishment of a multi-lab facility at the Optical Sciences Center, which performs research in SPM using two ultrahigh vacuum (UHV) STM facilities, and several Atomic Force Microscopy (AFM) facilities. The fabrication and characterization work performed in the SPM Laboratory is supplemented by infrared (IR) spectroscopy, high resolution transmission electron microscopy (HRTEM), and scanning electron microscopy (SEM), available in other departments on campus. The report covers the following areas: (1) GaAs and CdSe Structures, (2) Optical Interactions on a nm and nsec Scales, (3) Fullerenes on Gold, (4) Fullerenes on MoS2, (5) Fullerenes on Si, (6) SiC, (7) Nanotubes, (8) Scanning Force Microscopy, and (9) Biology.

  20. Scanning laser polarimetry - a review.

    PubMed

    Da Pozzo, Stefano; Marchesan, Roberta; Ravalico, Giuseppe

    2009-01-01

    Glaucoma is a leading cause of irreversible blindness worldwide. Retinal ganglion cells and their axons represent the selective target of the disease. When visual function is still intact on standard automated perimetry and optic disc appearance is suspicious, an early diagnosis may be supported by the identification of a retinal nerve fibre layer (RNFL) defect in the peripapillary area. At present days, computer-based, real-time imaging of the peripapillary RNFL is available through instruments of easy use and with high levels of accuracy and reproducibility. Scanning laser polarimetry is performed by a confocal scanning laser ophthalmoscope with an integrated polarimeter (GDx-VCC). There is a considerable amount of scientific evidence about the role of this imaging technique for glaucoma diagnosis. The aim of this review is to describe the principles of operation, the examination procedure, the clinical role, the results of main diagnostic studies and the future development of the software for the scanning laser polarimetry.

  1. Scanning Terahertz Heterodyne Imaging Systems

    NASA Technical Reports Server (NTRS)

    Siegel, Peter; Dengler, Robert

    2007-01-01

    Scanning terahertz heterodyne imaging systems are now at an early stage of development. In a basic scanning terahertz heterodyne imaging system, (see Figure 1) two far-infrared lasers generate beams denoted the local-oscillator (LO) and signal that differ in frequency by an amount, denoted the intermediate frequency (IF), chosen to suit the application. The LO beam is sent directly to a mixer as one of two inputs. The signal beam is focused to a spot on or in the specimen. After transmission through or reflection from the specimen, the beams are focused to a spot on a terahertz mixer, which extracts the IF outputs. The specimen is mounted on a translation stage, by means of which the focal spot is scanned across the specimen to build up an image.

  2. Geomorphic features off southern California as seen by GLORIA side-scan sonar system

    SciTech Connect

    Edwards, B.D.; Field, M.E.; Carlson, P.R.; Kenyon, N.H.

    1985-02-01

    Approximately 165,000 km/sup 2/ of the sea floor off southern California was mapped during May 1984, as part of a USGS/IOS cooperative program to study the newly proclaimed Exclusive Economic Zone (EEZ) of the US Pacific margin. The area was insonified using the Geological Long-Range Inclined Asdic (GLORIA), a long-range side-scan sonar system. Images were corrected for water-column velocity anomalies, for along-track distortions caused by acoustic ray travel paths. A photomosaic of the overlapping sonographs has been compiled at a scale of 1:375,000. The basins of the inner California continental borderland are characterized by both sinuous channel and fan complexes and by feathery acoustic patterns indicating active sediment transport. In contrast, outer borderland basins appear to be more sediment starved, exhibit large areas of sediment failure, and show significant structural influence. West of Patton Escarpment, the sonographs are dominated by acoustic patterns showing volcanic ridges and seamounts and by deposits of the Monterey and Arguello fans. Arguello fan, for example, exhibits multiple sinuous channels that have transported sediment 60 km south from the canyon mouth. These channels coalesce into a single 100-km long, westward-meandering channel that terminates in a 600-m deep box canyon. A zone of sediment failure is identifiable on the north levee of an upper fan channel. Tectonic trends associated with oceanic basement are highlighted by the terminus of the west-trending Murray Fracture Zone and by the prevailing northeast trend of volcanic ridge and seamount chains.

  3. Research With Scanning Tip Microscopy

    DTIC Science & Technology

    1991-12-31

    08ro P noiwe bae?041Le Research With Scanning Tip Microscopy AFOSR-89-0498 V AUTHOS)i Professor Dror Sarid 7. PFOUImNG 00ANIZATION NAMEIS) AND...forces and (b) surfaces. UNCLASS UNCLASS UNCLASS UL FINAL REPORT TO THE AFOSR ൱-, to J4ti. r Aat io Research in Scanning Tip Microscopy Dror Sarid Dtst...microscopy have been used to investigate (a) forces and (b) surfaces. a. Forces 1. Dror Sarid , Douglas lams, Volker Weissenberger, and L. Stephen Bell

  4. Scanning color optical tomography (SCOT)

    PubMed Central

    Hosseini, Poorya; Sung, Yongjin; Choi, Youngwoon; Lue, Niyom; Yaqoob, Zahid; So, Peter

    2015-01-01

    We have developed an interferometric optical microscope that provides three-dimensional refractive index map of a specimen by scanning the color of three illumination beams. Our design of the interferometer allows for simultaneous measurement of the scattered fields (both amplitude and phase) of such a complex input beam. By obviating the need for mechanical scanning of the illumination beam or detection objective lens; the proposed method can increase the speed of the optical tomography by orders of magnitude. We demonstrate our method using polystyrene beads of known refractive index value and live cells. PMID:26367632

  5. Digital laser scanning fundus camera.

    PubMed

    Plesch, A; Klingbeil, U; Bille, J

    1987-04-15

    Imaging and documentation of the human retina for clinical diagnostics are conventionally achieved by classical optical methods. We designed a digital laser scanning fundus camera. The optoelectronical instrument is based on scanning laser illumination of the retina and a modified video imaging procedure. It is coupled to a digital image buffer and a microcomputer for image storage and processing. Aside from its high sensitivity the LSF incorporates new ophthalmic imaging methods like polarization differential contrast. We give design considerations as well as a description of the instrument and its performance.

  6. Conically scanned holographic lidar telescope

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary (Inventor)

    1993-01-01

    An optical scanning device utilizing a source of optical energy such as laser light backscattered from the earth's atmosphere or transmitted outward as in a lidar, a rotating holographic optical element having an axis of rotation perpendicular to the plane of its substrate, and having a stationary focus which may or may not be located on its axis of rotation, with the holographic optical element diffracting the source of optical energy at an angle to its rotation axis enabling a conical scanning area and a motor for supporting and rotating the rotating holographic optical element, is described.

  7. High precision prism scanning system

    NASA Astrophysics Data System (ADS)

    García-Torales, G.; Flores, J. L.; Muñoz, Roberto X.

    2007-03-01

    Risley prisms are commonly used in continuous scanning manner. Each prism is capable of rotating separately about a common axis at different speeds. Scanning patterns are determined by the ratios of the wedge angles, the speed and direction of rotation of both prisms. The use of this system is conceptually simple. However, mechanical action in most applications becomes a challenge often solved by the design of complex control algorithms. We propose an electronic servomotor system that controls incremental and continuous rotations of the prisms wedges by means of an auto-tuning PID control using a Adaline Neural Network Algorithm, NNA.

  8. Lidar arc scan uncertainty reduction through scanning geometry optimization

    DOE PAGES

    Wang, Hui; Barthelmie, Rebecca J.; Pryor, Sara C.; ...

    2016-04-13

    Doppler lidars are frequently operated in a mode referred to as arc scans, wherein the lidar beam scans across a sector with a fixed elevation angle and the resulting measurements are used to derive an estimate of the n minute horizontal mean wind velocity (speed and direction). Previous studies have shown that the uncertainty in the measured wind speed originates from turbulent wind fluctuations and depends on the scan geometry (the arc span and the arc orientation). This paper is designed to provide guidance on optimal scan geometries for two key applications in the wind energy industry: wind turbine power performance analysis and annualmore » energy production prediction. We present a quantitative analysis of the retrieved wind speed uncertainty derived using a theoretical model with the assumption of isotropic and frozen turbulence, and observations from three sites that are onshore with flat terrain, onshore with complex terrain and offshore, respectively. The results from both the theoretical model and observations show that the uncertainty is scaled with the turbulence intensity such that the relative standard error on the 10 min mean wind speed is about 30 % of the turbulence intensity. The uncertainty in both retrieved wind speeds and derived wind energy production estimates can be reduced by aligning lidar beams with the dominant wind direction, increasing the arc span and lowering the number of beams per arc scan. Large arc spans should be used at sites with high turbulence intensity and/or large wind direction variation.« less

  9. Characterization of geolocation accuracy of Suomi NPP Advanced Technology Microwave Sounder measurements

    NASA Astrophysics Data System (ADS)

    Han, Yang; Weng, Fuzhong; Zou, Xiaolei; Yang, Hu; Scott, Deron

    2016-05-01

    The Advanced Technology Microwave Sounder (ATMS) onboard Suomi National Polar-orbiting Partnership satellite has 22 channels at frequencies ranging from 23 to 183 GHz for probing the atmospheric temperature and moisture under all weather conditions. As part of the ATMS calibration and validation activities, the geolocation accuracy of ATMS data must be well characterized and documented. In this study, the coastline crossing method (CCM) and the land-sea fraction method (LFM) are utilized to characterize and quantify the ATMS geolocation accuracy. The CCM is based on the inflection points of the ATMS window channel measurements across the coastlines, whereas the LFM collocates the ATMS window channel data with high-resolution land-sea mask data sets. Since the ATMS measurements provide five pairs of latitude and longitude data for K, Ka, V, W, and G bands, respectively, the window channels 1, 2, 3, 16, and 17 from each of these five bands are chosen for assessing the overall geolocation accuracy. ATMS geolocation errors estimated from both methods are generally consistent from 40 cases in June 2014. The ATMS along-track (cross-track) errors at nadir are within ±4.2 km (±1.2 km) for K/Ka, ±2.6 km (±2.7 km) for V bands, and ±1.2 km (±0.6 km) at W and G bands, respectively. At the W band, the geolocation errors derived from both algorithms are probably less reliable due to a reduced contrast of brightness temperatures in coastal areas. These estimated ATMS along-track and cross-track geolocation errors are well within the uncertainty requirements for all bands.

  10. Scanning Microscopes Using X Rays and Microchannels

    NASA Technical Reports Server (NTRS)

    Wang, Yu

    2003-01-01

    Scanning microscopes that would be based on microchannel filters and advanced electronic image sensors and that utilize x-ray illumination have been proposed. Because the finest resolution attainable in a microscope is determined by the wavelength of the illumination, the xray illumination in the proposed microscopes would make it possible, in principle, to achieve resolutions of the order of nanometers about a thousand times as fine as the resolution of a visible-light microscope. Heretofore, it has been necessary to use scanning electron microscopes to obtain such fine resolution. In comparison with scanning electron microscopes, the proposed microscopes would likely be smaller, less massive, and less expensive. Moreover, unlike in scanning electron microscopes, it would not be necessary to place specimens under vacuum. The proposed microscopes are closely related to the ones described in several prior NASA Tech Briefs articles; namely, Miniature Microscope Without Lenses (NPO-20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43; and Reflective Variants of Miniature Microscope Without Lenses (NPO-20610), NASA Tech Briefs, Vol. 26, No. 9 (September 2002) page 6a. In all of these microscopes, the basic principle of design and operation is the same: The focusing optics of a conventional visible-light microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. A microchannel plate containing parallel, microscopic-cross-section holes much longer than they are wide is placed between a specimen and an image sensor, which is typically the CCD. The microchannel plate must be made of a material that absorbs the illuminating radiation reflected or scattered from the specimen. The microchannels must be positioned and dimensioned so that each one is registered with a pixel on the image sensor. Because most of the radiation incident on the microchannel walls becomes absorbed, the radiation that reaches the

  11. Phase multiplying electronic scanning array

    NASA Technical Reports Server (NTRS)

    Seaton, A. F.

    1969-01-01

    Scanning array was designed with properties of low RF loss and phase control. The array consists of a series of special waveguides, hybrids made up of two variable reactance branch arms for input signals, an edge slot for the difference port, and a sum arm for the unradiated signal.

  12. Environmental Scanning, Vancouver Community College.

    ERIC Educational Resources Information Center

    Yao, Min

    This 1994 environmental scanning report from Vancouver Community College (VCC) reviews the expected effects of the separation of VCC into a new Vancouver Community College and Langara College (LC). The report examines the projected service area student-intake capacity; student characteristics; population growth trends; other postsecondary…

  13. Scanning tunneling microscope nanoetching method

    DOEpatents

    Li, Yun-Zhong; Reifenberger, Ronald G.; Andres, Ronald P.

    1990-01-01

    A method is described for forming uniform nanometer sized depressions on the surface of a conducting substrate. A tunneling tip is used to apply tunneling current density sufficient to vaporize a localized area of the substrate surface. The resulting depressions or craters in the substrate surface can be formed in information encoding patterns readable with a scanning tunneling microscope.

  14. Line-scanning laser ophthalmoscope

    NASA Astrophysics Data System (ADS)

    Hammer, Daniel X.; Ferguson, R. Daniel; Ustun, Teoman E.; Bigelow, Chad E.; Iftimia, Nicusor V.; Webb, Robert H.

    2006-07-01

    Scanning laser ophthalmoscopy (SLO) is a powerful imaging tool with specialized applications limited to research and ophthalmology clinics due in part to instrument size, cost, and complexity. Conversely, low-cost retinal imaging devices have limited capabilities in screening, detection, and diagnosis of diseases. To fill the niche between these two, a hand-held, nonmydriatic line-scanning laser ophthalmoscope (LSLO) is designed, constructed, and tested on normal human subjects. The LSLO has only one moving part and uses a novel optical approach to produce wide-field confocal fundus images. Imaging modes include multiwavelength illumination and live stereoscopic imaging with a split aperture. Image processing and display functions are controlled with two stacked prototype compact printed circuit boards. With near shot-noise limited performance, the digital LSLO camera requires low illumination power (<500 µW) at near-infrared wavelengths. The line-scanning principle of operation is examined in comparison to SLO and other imaging modes. The line-scanning approach produces high-contrast confocal images with nearly the same performance as a flying-spot SLO. The LSLO may significantly enhance SLO utility for routine use by ophthalmologists, optometrists, general practitioners, and also emergency medical personnel and technicians in the field for retinal disease detection and other diverse applications.

  15. Infrared Scanning For Electrical Maintenance

    NASA Astrophysics Data System (ADS)

    Eisenbath, Steven E.

    1983-03-01

    Given the technological age that we have now entered, the purpose of this paper is to relate how infrared scanning can be used for an electrical preventative maintenance program. An infrared scanner is able to produce an image because objects give off infrared radiation in relationship to their temperature. Most electrical problems will show up as an increase in temperature, thereby making the infrared scanner a useful preventative maintenance tool. Because of the sensitivity of most of the scanners, .1 to .2 of a degree, virtually all electrical problems can be pinpointed long before they become a costly failure. One of the early uses of infrared scanning was to check the power company's electrical distribution system. Most of this was performed via aircraft or truck mounted scanning devices which necessitated its semi-permanent mounting. With the advent of small hand held infrared imagers, along with more portability of the larger systems, infrared scanning has gained more popularity in checking electrical distribution systems. But the distribution systems are now a scaled down model, mainly the in-plant electrical systems. By in-plant, I mean any distribution of electricity; once it leaves the power company's grid. This can be in a hospital, retail outlet, warehouse or manufacturing facility.

  16. A CAT scan for cells

    SciTech Connect

    2009-01-01

    Recently, a team of scientists from Berkeley Lab, Stanford University, and the University of California, San Francisco used Berkeley Lab's National Center for X-ray Tomography to capture the changes that occur when Candida albicans is exposed to a new and promising antifungal therapy. http://newscenter.lbl.gov/feature-stories/2009/12/10/cat-scan-cells/

  17. Improvement of CAT scanned images

    NASA Technical Reports Server (NTRS)

    Roberts, E., Jr.

    1980-01-01

    Digital enhancement procedure improves definition of images. Tomogram is generated from large number of X-ray beams. Beams are collimated and small in diameter. Scanning device passes beams sequentially through human subject at many different angles. Battery of transducers opposite subject senses attenuated signals. Signals are transmitted to computer where they are used in construction of image on transverse plane through body.

  18. Single pilot scanning behavior in simulated instrument flight

    NASA Technical Reports Server (NTRS)

    Pennington, J. E.

    1979-01-01

    A simulation of tasks associated with single pilot general aviation flight under instrument flight rules was conducted as a baseline for future research studies on advanced flight controls and avionics. The tasks, ranging from simple climbs and turns to an instrument landing systems approach, were flown on a fixed base simulator. During the simulation the control inputs, state variables, and the pilots visual scan pattern including point of regard were measured and recorded.

  19. Big, Deep, and Smart Data in Scanning Probe Microscopy

    DOE PAGES

    Kalinin, Sergei V.; Strelcov, Evgheni; Belianinov, Alex; ...

    2016-09-27

    Scanning probe microscopy techniques open the door to nanoscience and nanotechnology by enabling imaging and manipulation of structure and functionality of matter on nanometer and atomic scales. We analyze the discovery process by SPM in terms of information flow from tip-surface junction to the knowledge adoption by scientific community. Furthermore, we discuss the challenges and opportunities offered by merging of SPM and advanced data mining, visual analytics, and knowledge discovery technologies.

  20. Advanced Microsensors

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This video looks at a spinoff application of the technology from advanced microsensors -- those that monitor and determine conditions of spacecraft like the Space Shuttle. The application featured is concerned with the monitoring of the health of premature babies.

  1. Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Overview

    USGS Publications Warehouse

    ,

    2008-01-01

    The National Aeronautics and Space Administration (NASA) launched Terra, the Earth Observing System's (EOS) flagship satellite platform on December 18, 1999. The polar-orbiting Terra contains five remote sensing instruments, which enable the scientific study and analyses of global terrestrial processes and manifestations of global change. One of the five instruments is the multispectral Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), which is built in Japan by a consortium of government, industry, and research groups. It has three spectral bands in the visible near-infrared region (VNIR), six bands in the shortwave infrared region (SWIR), and five bands in the thermal infrared region (TIR), with 15-, 30-, and 90-meter ground resolutions, respectively. This combination of wide spectral coverage and high spatial resolution allows ASTER to discriminate among a wide variety of surface materials. The VNIR subsystem also has a backward-viewing telescope for high-resolution (15-meter) stereoscopic observation in the along-track direction, which facilitates the generation of digital elevation models (DEM).

  2. Investigations in optoelectronic image processing in scanning laser microscopy

    NASA Astrophysics Data System (ADS)

    Chaliha, Hiranya Kumar

    A considerable amount of work has been done on scann-ing laser microscopy since its applications were first pointed out by Roberts and Young[1], Minsky [2] and Davidovits et al [3]. The advent of laser has made it possible to focus an intense beam of laser light in a scanning optical microscope (SOM) [4, 5] and hence explore regions of microscopy[6] uncovered by conven-tional microscopy. In the simple SOM [7, 8, 9], the upper spatial frequency in amplitude transmittance or reflectance of an object for which transfer function is nonzero is same as that in a conventional optical microscope. However, in Type II SOM [7] or confocal SOM that employs a coherent or a point detector, the spatial frequency bandwidth is twice that obtained in a conventional microscope. Besides this confocal set-up is found to be very useful in optical sectioning and consequently in 3-D image processing[10, 11, 12] specially of biological specimens. Such systems are also suitable for studies of semiconductor materials [13], super-resolution [14] and various imaginative ways of image processing[15, 16, 17] including phase imaging[18]. A brief survey of related advances in scanning optical microscopy has been covered in the chapter 1 of the thesis. The performance of SOM may be investigated by concent-rating also on signal derived by one dimensional scan of the object specimen. This simplified mode may also be adapted to give wealth of information for biological and semiconductor specimens. Hence we have investigated the design of a scanning laser system suited specifically for studies of line scan image signals of microscopic specimens when probed through a focused laser spot. An electro-mechanical method of scanning of the object specimen has been designed with this aim in mind. Chapter 2, Part A of the thesis deals with the design consider-ations of such a system. For analysis of scan signals at a later instant of time so as to facilitate further processing, an arrangement of microprocessor

  3. A spectrum scanning Stokes polarimeter

    NASA Astrophysics Data System (ADS)

    Baur, T. G.; House, L. L.; Hull, H. K.

    1980-02-01

    A photoelectric polarimeter for measuring line profiles in all four Stokes parameters has been built and operates on the SPO 40 cm coronagraph in a joint project with Sacramento Peak Observatory. A description of the optical and electronic systems and the calibration scheme is presented. Performance parameters determined from observations are also given. The polarimeter package consisting of a pair of KDP's, a quarter wave plate, and a polarizing beam splitter is located at the prime focus of the coronagraph. Modulation of the KDP's encodes polarization information into intensity signals that are electronically detected. The scanning of the spectrum, accomplished by rotating the grating, permits Stokes line profiles to be recorded on magnetic tape for processing. The instrument can be used to scan any line from 3900 to 7000 A with a spectral resolution of 0.01 A. Polarizations as small as 0.001% are detectable. The polarimeter and observing system are computer controlled.

  4. Vertically scanned laser sheet microscopy.

    PubMed

    Dong, Di; Arranz, Alicia; Zhu, Shouping; Yang, Yujie; Shi, Liangliang; Wang, Jun; Shen, Chen; Tian, Jie; Ripoll, Jorge

    2014-01-01

    Laser sheet microscopy is a widely used imaging technique for imaging the three-dimensional distribution of a fluorescence signal in fixed tissue or small organisms. In laser sheet microscopy, the stripe artifacts caused by high absorption or high scattering structures are very common, greatly affecting image quality. To solve this problem, we report here a two-step procedure which consists of continuously acquiring laser sheet images while vertically displacing the sample, and then using the variational stationary noise remover (VSNR) method to further reduce the remaining stripes. Images from a cleared murine colon acquired with a vertical scan are compared with common stitching procedures demonstrating that vertically scanned light sheet microscopy greatly improves the performance of current light sheet microscopy approaches without the need for complex changes to the imaging setup and allows imaging of elongated samples, extending the field of view in the vertical direction.

  5. Scanning phononic lattices with ultrasound

    SciTech Connect

    Vines, R.E.; Wolfe, J.P.; Every, A.V.

    1999-11-01

    A method for probing the elastic properties of newly developed periodic structures using acoustic waves is introduced. Highly anisotropic transmission of surface acoustic waves is observed by continuously scanning the wave vector angle. Preliminary models of wave propagation through multilayers and two-dimensional lattices explain some of the experimental features, while other features can be attributed to the resonant excitation of interface waves. {copyright} {ital 1999} {ital The American Physical Society}

  6. Differential scanning calorimetry of coal

    NASA Technical Reports Server (NTRS)

    Gold, P. I.

    1978-01-01

    Differential scanning calorimetry studies performed during the first year of this project demonstrated the occurrence of exothermic reactions associated with the production of volatile matter in or near the plastic region. The temperature and magnitude of the exothermic peak were observed to be strongly affected by the heating rate, sample mass and, to a lesser extent, by sample particle size. Thermal properties also were found to be influenced by oxidation of the coal sample due to weathering effects.

  7. Mechanically scanned deployable antenna study

    NASA Technical Reports Server (NTRS)

    1983-01-01

    The conceptual design of a Mechanically Scanned Deployable Antenna which is launched by the STS (Space Shuttle) to provide radiometric brightness temperature maps of the Earth and oceans at selected frequency bands in the frequency range of 1.4 GHz to 11 GHz is presented. Unlike previous scanning radiometric systems, multiple radiometers for each frequency are required in order to fill in the resolution cells across the swath created by the 15 meter diameter spin stabilized system. This multiple beam radiometric system is sometimes designated as a ""whiskbroom'' system in that it combines the techniques of the scanning and ""pushbroom'' type systems. The definition of the feed system including possible feed elements and location, determination of the fundamental reflector feed offset geometry including offset angles and f/D ratio, preliminary estimates of the beam efficiency of the feed reflector system, a summary of reflector mesh losses at the proposed radiometric frequency bands, an overall conceptual configuration design and preliminary structural and thermal analyses are included.

  8. Interactive Tools for Measuring Visual Scanning Performance and Reaction Time

    PubMed Central

    Seeanner, Julia; Hennessy, Sarah; Manganelli, Joseph; Crisler, Matthew; Rosopa, Patrick; Jenkins, Casey; Anderson, Michael; Drouin, Nathalie; Belle, Leah; Truesdail, Constance; Tanner, Stephanie

    2017-01-01

    Occupational therapists are constantly searching for engaging, high-technology interactive tasks that provide immediate feedback to evaluate and train clients with visual scanning deficits. This study examined the relationship between two tools: the VISION COACH™ interactive light board and the Functional Object Detection© (FOD) Advanced driving simulator scenario. Fifty-four healthy drivers, ages 21–66 yr, were divided into three age groups. Participants performed braking response and visual target (E) detection tasks of the FOD Advanced driving scenario, followed by two sets of three trials using the VISION COACH Full Field 60 task. Results showed no significant effect of age on FOD Advanced performance but a significant effect of age on VISION COACH performance. Correlations showed that participants’ performance on both braking and E detection tasks were significantly positively correlated with performance on the VISION COACH (.37 < r < .40, p < .01). These tools provide new options for therapists. PMID:28218598

  9. Results from the KLA-Tencor TeraScanXR reticle inspection tool

    NASA Astrophysics Data System (ADS)

    Dayal, Aditya; Mu, Bo; Iyer, Venkat; Lim, Phillip; Goonesekera, Arosha; Broadbent, Bill

    2008-10-01

    The new TeraScanXR reticle inspection system extends the capability of the previous TeraScanHR platform to advanced 32nm logic and 40nm Half Pitch (HP) memory technology nodes. The TeraScanXR has been designed to provide a significant improvement in image quality, defect sensitivity and throughput relative to the HR platform. Defect sensitivity is increased via a combination of improved Die-to-Die (D:D) and Die-to-Database (D:DB) algorithms, as well as enhancements to the image auto-focus (IAF). Modifications to system optics and the introduction of a more powerful image processing computer have enabled a ~2X faster inspection mode. In this paper, we describe the key features of the TeraScanXR platform and present preliminary data that illustrate the capability of this tool. TeraScanHR tools currently at customer sites are field-upgradeable to the TeraScanXR configuration.

  10. Preoperative nuclear scans in patients with melanoma

    SciTech Connect

    Au, F.C.; Maier, W.P.; Malmud, L.S.; Goldman, L.I.; Clark, W.H. Jr.

    1984-05-15

    One hundred forty-one liver scans, 137 brain scans, and 112 bone scans were performed in 192 patients with clinical Stage 1 melanoma. One liver scan was interpreted as abnormal; liver biopsy of that patient showed no metastasis. There were 11 suggestive liver scans; three of the patients with suggestive liver scans had negative liver biopsies. The remaining eight patients were followed from 4 to 6 years and none of those patients developed clinical evidence of hepatic metastases. All of the brain scans were normal. Five patients had suggestive bone scans and none of those patients had manifested symptoms of osseous metastases with a follow-up of 2 to 4.5 years. This study demonstrates that the use of preoperative liver, brain and bone scan in the evaluation of patients with clinical Stage 1 melanoma is virtually unproductive.

  11. High Resolution Scanning Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R. (Inventor); Miranda, Felix A. (Inventor)

    2000-01-01

    The present invention provides a High Resolution Scanning Reflectarray Antenna (HRSRA) for the purpose of tracking ground terminals and space craft communication applications. The present invention provides an alternative to using gimbaled parabolic dish antennas and direct radiating phased arrays. When compared to a gimbaled parabolic dish, the HRSRA offers the advantages of vibration free steering without incurring appreciable cost or prime power penalties. In addition, it offers full beam steering at a fraction of the cost of direct radiating arrays and is more efficient.

  12. Scanning Miniature Microscopes without Lenses

    NASA Technical Reports Server (NTRS)

    Wang, Yu

    2009-01-01

    The figure schematically depicts some alternative designs of proposed compact, lightweight optoelectronic microscopes that would contain no lenses and would generate magnified video images of specimens. Microscopes of this type were described previously in Miniature Microscope Without Lenses (NPO - 20218), NASA Tech Briefs, Vol. 22, No. 8 (August 1998), page 43 and Reflective Variants of Miniature Microscope Without Lenses (NPO 20610), NASA Tech Briefs, Vol. 26, No. 9 (September 1999), page 6a. To recapitulate: In the design and construction of a microscope of this type, the focusing optics of a conventional microscope are replaced by a combination of a microchannel filter and a charge-coupled-device (CCD) image detector. Elimination of focusing optics reduces the size and weight of the instrument and eliminates the need for the time-consuming focusing operation. The microscopes described in the cited prior articles contained two-dimensional CCDs registered with two-dimensional arrays of microchannels and, as such, were designed to produce full two-dimensional images, without need for scanning. The microscopes of the present proposal would contain one-dimensional (line image) CCDs registered with linear arrays of microchannels. In the operation of such a microscope, one would scan a specimen along a line perpendicular to the array axis (in other words, one would scan in pushbroom fashion). One could then synthesize a full two-dimensional image of the specimen from the line-image data acquired at one-pixel increments of position along the scan. In one of the proposed microscopes, a beam of unpolarized light for illuminating the specimen would enter from the side. This light would be reflected down onto the specimen by a nonpolarizing beam splitter attached to the microchannels at their lower ends. A portion of the light incident on the specimen would be reflected upward, through the beam splitter and along the microchannels, to form an image on the CCD. If the

  13. Scanning probe microscopy in catalysis.

    PubMed

    Yeung, King Lun; Yao, Nan

    2004-09-01

    This review discusses the recent progress in the application of scanning probe microscopy (SPM) in catalysis. SPM proves to be an invaluable technique for imaging catalytic surfaces and interfaces. Most SPM research is related to the structural and morphological transformation associated with catalyst preparation and use. Real-time SPM observation of surface dynamics including adsorption, diffusion and reaction, provides invaluable insights to the mechanism of catalysis. SPM is also used to shape and manipulate surfaces and surface processes. Fabrication of nanostructured catalysts, direct manipulation of adsorbed atoms and molecules and tip-mediated reactions are some examples of new SPM approach in catalyst research.

  14. Aperture scanning Fourier ptychographic microscopy

    PubMed Central

    Ou, Xiaoze; Chung, Jaebum; Horstmeyer, Roarke; Yang, Changhuei

    2016-01-01

    Fourier ptychographic microscopy (FPM) is implemented through aperture scanning by an LCOS spatial light modulator at the back focal plane of the objective lens. This FPM configuration enables the capturing of the complex scattered field for a 3D sample both in the transmissive mode and the reflective mode. We further show that by combining with the compressive sensing theory, the reconstructed 2D complex scattered field can be used to recover the 3D sample scattering density. This implementation expands the scope of application for FPM and can be beneficial for areas such as tissue imaging and wafer inspection. PMID:27570705

  15. Advancing Reflectrometry

    DTIC Science & Technology

    2013-05-21

    transmissions, was first demonstrated using Global Navigation Satellite System ( GNSS ) reflections. Recently, reflectometry has been extended to digital... GNSS +R workshop provided an opportunity for engineers and Earth scientists to assess the state of the art, demonstrate new applications, and discuss...18 Eos, Vol. 94, No. 21, 21 May 2013 MEETING -.~ Advancing Reflectometry Workshop on Renectometry Using GNSS and Other Signals of Opportunity

  16. Technological Advancements

    ERIC Educational Resources Information Center

    Kennedy, Mike

    2010-01-01

    The influx of technology has brought significant improvements to school facilities. Many of those advancements can be found in classrooms, but when students head down the hall to use the washrooms, they are likely to find a host of technological innovations that have improved conditions in that part of the building. This article describes modern…

  17. Research Advances

    ERIC Educational Resources Information Center

    King, Angela G.

    2004-01-01

    Research advances, a new feature in Journal of Chemical Engineering that brings information about innovations in current areas of research to high school and college science faculty with an intent to provide educators with timely descriptions of latest progress in research that can be integrated into existing courses to update course content and…

  18. Improved performance of the optically scanned transducer

    NASA Astrophysics Data System (ADS)

    Turner, C. W.; Bolorforosh, M. S.

    1992-11-01

    The rapid increase in the use of ultrasound in both clinical and industrial applications requires more advanced and reliable imaging systems for calibrating and characterizing high performance ultrasonic transducers. The optically scanned hydrophone (OSH) is an alternative imaging system capable of quasi-real time imaging of broadband acoustic fields. The main application of the OSH is in the imaging and characterization of acoustic fields such as those emitted from clinical and therapeutic transducers. In this paper, the recent development of the OSH and its application to real time imaging of broadband acoustic fields are reported. Using improved fabrication techniques the optical sampling efficiency of the OSH has been considerably improved. This is achieved by adopting new assembly techniques and incorporating a novel differential electrode configuration. The improved optical sampling efficiency has provided a more competitive, versatile, and faster imaging system. The performance of the modified OSH is compared against the other types of hydrophone such as the spot poled and the needle types.

  19. Applications of Adaptive Optics Scanning Laser Ophthalmoscopy

    PubMed Central

    Roorda, Austin

    2010-01-01

    Adaptive optics (AO) describes a set of tools to correct or control aberrations in any optical system. In the eye, AO allows for precise control of the ocular aberrations. If used to correct aberrations over a large pupil, for example, cellular level resolution in retinal images can be achieved. AO systems have been demonstrated for advanced ophthalmoscopy as well as for testing and/or improving vision. In fact, AO can be integrated to any ophthalmic instrument where the optics of the eye is involved, with a scope of applications ranging from phoropters to optical coherence tomography systems. In this paper, I discuss the applications and advantages of using AO in a specific system, the adaptive optics scanning laser ophthalmoscope, or AOSLO. Since the Borish award was, in part, awarded to me because of this effort, I felt it appropriate to select this as the topic for this paper. Furthermore, users of AOSLO continue to appreciate the benefits of the technology, some of which were not anticipated at the time of development, and so it is time to revisit this topic and summarize them in a single paper. PMID:20160657

  20. Functional Scanning Probe Imaging of Nanostructured Solar Energy Materials.

    PubMed

    Giridharagopal, Rajiv; Cox, Phillip A; Ginger, David S

    2016-09-20

    From hybrid perovskites to semiconducting polymer/fullerene blends for organic photovoltaics, many new materials being explored for energy harvesting and storage exhibit performance characteristics that depend sensitively on their nanoscale morphology. At the same time, rapid advances in the capability and accessibility of scanning probe microscopy methods over the past decade have made it possible to study processing/structure/function relationships ranging from photocurrent collection to photocarrier lifetimes with resolutions on the scale of tens of nanometers or better. Importantly, such scanning probe methods offer the potential to combine measurements of local structure with local function, and they can be implemented to study materials in situ or devices in operando to better understand how materials evolve in time in response to an external stimulus or environmental perturbation. This Account highlights recent advances in the development and application of scanning probe microscopy methods that can help address such questions while filling key gaps between the capabilities of conventional electron microscopy and newer super-resolution optical methods. Focusing on semiconductor materials for solar energy applications, we highlight a range of electrical and optoelectronic scanning probe microscopy methods that exploit the local dynamics of an atomic force microscope tip to probe key properties of the solar cell material or device structure. We discuss how it is possible to extract relevant device properties using noncontact scanning probe methods as well as how these properties guide materials development. Specifically, we discuss intensity-modulated scanning Kelvin probe microscopy (IM-SKPM), time-resolved electrostatic force microscopy (trEFM), frequency-modulated electrostatic force microscopy (FM-EFM), and cantilever ringdown imaging. We explain these developments in the context of classic atomic force microscopy (AFM) methods that exploit the physics of

  1. Evolution of MEMS scanning mirrors for laser projection in compact consumer electronics

    NASA Astrophysics Data System (ADS)

    Tauscher, Jason; Davis, Wyatt O.; Brown, Dean; Ellis, Matt; Ma, Yunfei; Sherwood, Michael E.; Bowman, David; Helsel, Mark P.; Lee, Sung; Coy, John Wyatt

    2010-02-01

    The applicability of MOEMS scanning mirrors towards the creation of "flying spot" scanned laser displays is well established. The extension of this concept towards compact embedded pico-projectors has required an evolution of scanners and packaging to accommodate the needs of the consumer electronics space. This paper describes the progression of the biaxial MOEMS scanning mirrors developed by Microvision over recent years. Various aspects of the individual designs are compared. Early devices used a combination of magnetic quasistatic actuation and resonant electrostatic operation in an evacuated atmosphere to create a projection engine for retinal scanned displays. Subsequent designs realized the elimination of both the high voltage electrostatic drive and the vacuum package, and a simplification of the actuation scheme through proprietary technical advances. Additional advances have doubled the scan angle capability and greatly miniaturized the MOEMS component while not incurring significant increase in power consumption, making it an excellent fit for the consumer pico-projector application. The simplicity of the scanned laser-based pico-projector optical design enables high resolution and a large effective image size in a thin projection engine, all of which become critical both to the viability of the technology and adoption by consumers. Microvision's first scanned laser pico-projector is built around a MOEMS scanning mirror capable of projecting 16:9 aspect ratio, WVGA display within a 6.6 mm high package. Further evolution on this path promises continued improvement in resolution, size, and power.

  2. Schistosomiasis collection at NHM (SCAN)

    PubMed Central

    2012-01-01

    Background The Natural History Museum (NHM) is developing a repository for schistosomiasis-related material, the Schistosomiasis Collection at NHM (SCAN) as part of its existing Wolfson Wellcome Biomedical Laboratory (WWBL). This is timely because a major research and evaluation effort to understand control and move towards elimination of schistosomiasis in Africa has been initiated by the Schistosomiasis Consortium for Operational Research and Evaluation (SCORE), resulting in the collection of many important biological samples, including larval schistosomes and snails. SCAN will collaborate with a number of research groups and control teams and the repository will acquire samples relevant to both immediate and future research interest. The samples collected through ongoing research and field activities, WWBL’s existing collections, and other acquisitions will be maintained over the long term and made available to the global research community for approved research purposes. Goals include: · Consolidation of the existing NHM schistosome and snail collections and transfer of specimens into suitable long-term storage systems for DNA retrieval, · Long-term and stable storage of specimens collected as part of on going field programmes initially in Africa especially relating to the SCORE research programmes, · Provision of access to snail and schistosome collections for approved research activities. PMID:22943137

  3. Rapid-scan EPR of immobilized nitroxides.

    PubMed

    Yu, Zhelin; Quine, Richard W; Rinard, George A; Tseitlin, Mark; Elajaili, Hanan; Kathirvelu, Velavan; Clouston, Laura J; Boratyński, Przemysław J; Rajca, Andrzej; Stein, Richard; Mchaourab, Hassane; Eaton, Sandra S; Eaton, Gareth R

    2014-10-01

    X-band electron paramagnetic resonance spectra of immobilized nitroxides were obtained by rapid scan at 293 K. Scan widths were 155 G with 13.4 kHz scan frequency for (14)N-perdeuterated tempone and for T4 lysozyme doubly spin labeled with an iodoacetamide spirocyclohexyl nitroxide and 100 G with 20.9 kHz scan frequency for (15)N-perdeuterated tempone. These wide scans were made possible by modifications to our rapid-scan driver, scan coils made of Litz wire, and the placement of highly conducting aluminum plates on the poles of a Bruker 10″ magnet to reduce resistive losses in the magnet pole faces. For the same data acquisition time, the signal-to-noise for the rapid-scan absorption spectra was about an order of magnitude higher than for continuous wave first-derivative spectra recorded with modulation amplitudes that do not broaden the lineshapes.

  4. Rapid-Scan EPR of Immobilized Nitroxides

    PubMed Central

    Yu, Zhelin; Quine, Richard W.; Rinard, George A.; Tseitlin, Mark; Elajaili, Hanan; Kathirvelu, Velavan; Clouston, Laura J.; Boratyński, Przemysław J.; Rajca, Andrzej; Stein, Richard; Mchaourab, Hassane; Eaton, Sandra S.; Eaton, Gareth R.

    2014-01-01

    X-band electron paramagnetic resonance spectra of immobilized nitroxides were obtained by rapid scan at 293 K. Scan widths were 155 G with 13.4 kHz scan frequency for 14N-perdeuterated tempone and for T4 lysozyme doubly spin labeled with an iodoacetamide spirocyclohexyl nitroxide and 100 G with 20.9 kHz scan frequency for 15N-perdeuterated tempone. These wide scans were made possible by modifications to our rapid-scan driver, scan coils made of Litz wire, and the placement of highly conducting aluminum plates on the poles of a Bruker 10" magnet to reduce resistive losses in the magnet pole faces. For the same data acquisition time, the signal-to-noise for the rapid-scan absorption spectra was about an order of magnitude higher than for continuous wave first-derivative spectra recorded with modulation amplitudes that do not broaden the lineshapes. PMID:25240151

  5. Three-dimensional scanning confocal laser microscope

    DOEpatents

    Anderson, R. Rox; Webb, Robert H.; Rajadhyaksha, Milind

    1999-01-01

    A confocal microscope for generating an image of a sample includes a first scanning element for scanning a light beam along a first axis, and a second scanning element for scanning the light beam at a predetermined amplitude along a second axis perpendicular to the first axis. A third scanning element scans the light beam at a predetermined amplitude along a third axis perpendicular to an imaging plane defined by the first and second axes. The second and third scanning element are synchronized to scan at the same frequency. The second and third predetermined amplitudes are percentages of their maximum amplitudes. A selector determines the second and third predetermined amplitudes such that the sum of the percentages is equal to one-hundred percent.

  6. Optical analysis of scanning microstereolithography systems

    NASA Astrophysics Data System (ADS)

    Deshmukh, Suhas P.; Dubey, Shashikant; Gandhi, P. S.

    2006-01-01

    Microstereolithography (MSL) is rapidly developing technique for micro-fabrication. Vector-by-vector scanning MSL has a potential to create true 3D micro-devices as compared to mostly planar (2D-2 1/2 D) devices fabricated by conventional MEMS techniques. Previous literature shows two different scanning methods:(1) Galvanomirror scanning, (2) Photoreactor tank scanning. Galvanomirror scanning technique has higher fabrication speed but poor resolution because of defocusing of laser spot on the resin surface. Photo-reactor tank scanning has higher resolution but produces a wavy structures and limited speed of fabrication. This paper proposes and develops an offaxis lens scanning technique for MSL and carries out optical analysis to compare its performance with the existing techniques mentioned above. The comparison clearly demonstrates improved performance with the proposed offaxis lens scanning technique.

  7. Recent advances in sarcoidosis.

    PubMed

    Morgenthau, Adam S; Iannuzzi, Michael C

    2011-01-01

    Sarcoidosis, a systemic granulomatous disease of undetermined etiology, is characterized by a variable clinical presentation and course. During the past decade, advances have been made in the study of sarcoidosis. The multicenter ACCESS (A Case Control Etiologic Study of Sarcoidosis) trial recruited > 700 subjects with newly diagnosed sarcoidosis and matched control subjects. Investigators were unable to identify a single cause of sarcoidosis, but ACCESS paved the way for subsequent etiologic studies. The Mycobacterium tuberculosis catalase-peroxidase protein has been identified as a potential sarcoidosis antigen. Genetic aspects of the disease have been elucidated further. Genome-wide scans have identified candidate genes. Gene expression analyses have defined cytokine dysregulation in sarcoidosis more clearly. Although the criteria for diagnosis have not changed, sarcoidosis remains a diagnosis of exclusion best supported by a tissue biopsy specimen that demonstrates noncaseating granulomas in a patient with compatible clinical and radiologic features of the disease. Endobronchial ultrasound-guided transbronchial needle aspiration of mediastinal lymph nodes has facilitated diagnosis, often eliminating the need for more invasive procedures, such as mediastinoscopy. PET scanning has proven valuable in locating occult sites of active disease. Currently, no reliable prognostic biomarkers have been identified. The tumor necrosis factor inhibitors, a relatively new class of agents, have been used in patients with refractory disease. It is unclear whether phosphodiesterase-5 inhibitors, prostaglandin analogs, or endothelin antagonists should be used for the treatment of sarcoidosis-associated pulmonary hypertension.

  8. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R.

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  9. Suspension system for gimbal supported scanning payloads

    NASA Technical Reports Server (NTRS)

    Polites, Michael E. (Inventor)

    1995-01-01

    Gimballed scanning devices or instruments are the subject of this invention. Scanning is an important aspect of space science. To achieve a scan pattern some means must be provided which impart to the payload an oscillatory motion. Various forms of machines have been employed for controllably conferring on scanning instruments predetermined scan patterns. They include control moment gyroscopes, reaction wheels, torque motors, reaction control systems, and the like. But rotating unbalanced mass (RUM) devices are a new and efficient way to generate scans in gimballed payloads. RUM devices are superior to previous scanning apparatus, but they require power consuming and frequently complex auxiliary control systems to position and reposition the particular scan pattern relative to a target or a number of targets. Herein the control system is simplified. The most frequently employed method for achieving the various scan patterns is to gimbal the scanning device. Gimbals are suspended in such a way that they can be activated to generate the scan pattern. The suspension means described is for payloads supported in gimbals wherein the payload rotation is restricted by a flex pivot so that the payload oscillates, thereby moving in a scan pattern.

  10. South Carolina Course Alignment Project: Environmental Scan

    ERIC Educational Resources Information Center

    Educational Policy Improvement Center (NJ1), 2007

    2007-01-01

    An "environmental scan" is designed to identify key issues of policy and practice in an area of interest so that action can be taken. By definition, an environmental scan focuses upon areas of concern. However, the results of an environmental scan are not designed to be either an indictment or endorsement of the current way of doing…

  11. Resonant biaxial 7-mm MEMS mirror for omnidirectional scanning

    NASA Astrophysics Data System (ADS)

    Hofmann, U.; Aikio, M.; Janes, J.; Senger, F.; Stenchly, V.; Weiss, M.; Quenzer, H.-J.; Wagner, B.; Benecke, W.

    2013-03-01

    Low-cost automotive laser scanners for environment perception are needed to enable the integration of advanced driver assistant systems (ADAS) into all automotive vehicle segments, a key to reducing the number of traffic accidents on roads. An omnidirectional 360 degree laser scanning concept has been developed based on combination of an omnidirectional lens and a biaxial large aperture MEMS mirror. This omnidirectional scanning concept is the core of a small sized low-cost time-of-flight based range sensor development. This paper describes concept, design, fabrication and first measurement results of a resonant biaxial 7mm gimbal-less MEMS mirror that is electrostatically actuated by stacked vertical comb drives. Identical frequencies of the two resonant axes are necessary to enable the required circle scanning capability. A tripod suspension was chosen since it allows minimizing the frequency splitting of the two resonant axes. Low mirror curvature is achieved by a thickness of the mirror of more than 500 μm. Hermetic wafer level vacuum packaging of such large mirrors based on multiple wafer bonding has been developed to enable to achieve a large mechanical tilt angle of +/- 6.5 degrees in each axis. The 7mm-MEMS mirror demonstrates large angle circular scanning at 1.5kHz.

  12. UAVSAR Active Electronically Scanned Array

    NASA Technical Reports Server (NTRS)

    Sadowy, Gregory, A.; Chamberlain, Neil F.; Zawadzki, Mark S.; Brown, Kyle M.; Fisher, Charles D.; Figueroa, Harry S.; Hamilton, Gary A.; Jones, Cathleen E.; Vorperian, Vatche; Grando, Maurio B.

    2011-01-01

    The Uninhabited Airborne Vehicle Synthetic Aperture Radar (UAVSAR) is a pod-based, L-band (1.26 GHz), repeatpass, interferometric, synthetic aperture radar (InSAR) used for Earth science applications. Repeat-pass interferometric radar measurements from an airborne platform require an antenna that can be steered to maintain the same angle with respect to the flight track over a wide range of aircraft yaw angles. In order to be able to collect repeat-pass InSAR data over a wide range of wind conditions, UAVSAR employs an active electronically scanned array (AESA). During data collection, the UAVSAR flight software continuously reads the aircraft attitude state measured by the Embedded GPS/INS system (EGI) and electronically steers the beam so that it remains perpendicular to the flight track throughout the data collection

  13. Scanning ARM Cloud Radar Handbook

    SciTech Connect

    Widener, K; Bharadwaj, N; Johnson, K

    2012-06-18

    The scanning ARM cloud radar (SACR) is a polarimetric Doppler radar consisting of three different radar designs based on operating frequency. These are designated as follows: (1) X-band SACR (X-SACR); (2) Ka-band SACR (Ka-SACR); and (3) W-band SACR (W-SACR). There are two SACRs on a single pedestal at each site where SACRs are deployed. The selection of the operating frequencies at each deployed site is predominantly determined by atmospheric attenuation at the site. Because RF attenuation increases with atmospheric water vapor content, ARM's Tropical Western Pacific (TWP) sites use the X-/Ka-band frequency pair. The Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites field the Ka-/W-band frequency pair. One ARM Mobile Facility (AMF1) has a Ka/W-SACR and the other (AMF2) has a X/Ka-SACR.

  14. Scanning Electrochemical Microscopy in Neuroscience

    NASA Astrophysics Data System (ADS)

    Schulte, Albert; Nebel, Michaela; Schuhmann, Wolfgang

    2010-07-01

    This article reviews recent work involving the application of scanning electrochemical microscopy (SECM) to the study of individual cultured living cells, with an emphasis on topographical and functional imaging of neuronal and secretory cells of the nervous and endocrine system. The basic principles of biological SECM and associated negative amperometric-feedback and generator/collector-mode SECM imaging are discussed, and successful use of the methodology for screening soft and fragile membranous objects is outlined. The drawbacks of the constant-height mode of probe movement and the benefits of the constant-distance mode of SECM operation are described. Finally, representative examples of constant-height and constant-distance mode SECM on a variety of live cells are highlighted to demonstrate the current status of single-cell SECM in general and of SECM in neuroscience in particular.

  15. Scanning laser polarimetry in glaucoma.

    PubMed

    Dada, Tanuj; Sharma, Reetika; Angmo, Dewang; Sinha, Gautam; Bhartiya, Shibal; Mishra, Sanjay K; Panda, Anita; Sihota, Ramanjit

    2014-11-01

    Glaucoma is an acquired progressive optic neuropathy which is characterized by changes in the optic nerve head and retinal nerve fiber layer (RNFL). White-on-white perimetry is the gold standard for the diagnosis of glaucoma. However, it can detect defects in the visual field only after the loss of as many as 40% of the ganglion cells. Hence, the measurement of RNFL thickness has come up. Optical coherence tomography and scanning laser polarimetry (SLP) are the techniques that utilize the evaluation of RNFL for the evaluation of glaucoma. SLP provides RNFL thickness measurements based upon the birefringence of the retinal ganglion cell axons. We have reviewed the published literature on the use of SLP in glaucoma. This review elucidates the technological principles, recent developments and the role of SLP in the diagnosis and monitoring of glaucomatous optic neuropathy, in the light of scientific evidence so far.

  16. Multiple-probe scanning probe microscopes for nanoarchitectonic materials science

    NASA Astrophysics Data System (ADS)

    Nakayama, Tomonobu; Shingaya, Yoshitaka; Aono, Masakazu

    2016-11-01

    Nanoarchitectonic systems are of interest for utilizing a vast range of nanoscale materials for future applications requiring a huge number of elemental nanocomponents. To explore the science and technology of nanoarchitectonics, advanced characterization tools that can deal with both nanoscale objects and macroscopically extended nanosystems are demanded. Multiple-probe scanning probe microscopes (MP-SPMs) are powerful tools that meet this demand because they take the advantages of conventional scanning probe microscopes and realize atomically precise electrical measurements, which cannot be done with conventional microprobing systems widely used in characterizing materials and devices. Furthermore, an MP-SPM can be used to operate some nanoarchitectonic systems. In this review, we overview the indispensable features of MP-SPMs together with the past, present and future of MP-SPM technology.

  17. Multimode-Guided-Wave Ultrasonic Scanning of Materials

    NASA Technical Reports Server (NTRS)

    Roth, Don

    2006-01-01

    Two documents discuss a method of characterizing advanced composite materials by use of multimode-guided ultrasonic waves. A transmitting transducer excites modulated (e.g., pulsed) ultrasonic waves at one location on a surface of a plate specimen. The waves interact with microstructure and flaws as they propagate through the specimen to a receiving transducer at a different location. The received signal is analyzed to determine the total (multimode) ultrasonic response of the specimen and utilize this response to evaluate microstructure and flaws. The analysis is performed by software that extracts parameters of signals in the time and frequency domains. Scanning is effected by using computer-controlled motorized translation stages to position the transducers at specified pairs of locations and repeating the measurement, data-acquisition, and data-analysis processes at the successive locations. One document presents results of a scan of a specimen containing a delamination.

  18. Fast scanning mode and its realization in a scanning acoustic microscope

    SciTech Connect

    Ju Bingfeng; Bai Xiaolong; Chen Jian

    2012-03-15

    The scanning speed of the two-dimensional stage dominates the efficiency of mechanical scanning measurement systems. This paper focused on a detailed scanning time analysis of conventional raster and spiral scan modes and then proposed two fast alternative scanning modes. Performed on a self-developed scanning acoustic microscope (SAM), the measured images obtained by using the conventional scan mode and fast scan modes are compared. The total scanning time is reduced by 29% of the two proposed fast scan modes. It will offer a better solution for high speed scanning without sacrificing the system stability, and will not introduce additional difficulties to the configuration of scanning measurement systems. They can be easily applied to the mechanical scanning measuring systems with different driving actuators such as piezoelectric, linear motor, dc motor, and so on. The proposed fast raster and square spiral scan modes are realized in SAM, but not specially designed for it. Therefore, they have universal adaptability and can be applied to other scanning measurement systems with two-dimensional mechanical scanning stages, such as atomic force microscope or scanning tunneling microscope.

  19. Fast scanning mode and its realization in a scanning acoustic microscope.

    PubMed

    Ju, Bing-Feng; Bai, Xiaolong; Chen, Jian

    2012-03-01

    The scanning speed of the two-dimensional stage dominates the efficiency of mechanical scanning measurement systems. This paper focused on a detailed scanning time analysis of conventional raster and spiral scan modes and then proposed two fast alternative scanning modes. Performed on a self-developed scanning acoustic microscope (SAM), the measured images obtained by using the conventional scan mode and fast scan modes are compared. The total scanning time is reduced by 29% of the two proposed fast scan modes. It will offer a better solution for high speed scanning without sacrificing the system stability, and will not introduce additional difficulties to the configuration of scanning measurement systems. They can be easily applied to the mechanical scanning measuring systems with different driving actuators such as piezoelectric, linear motor, dc motor, and so on. The proposed fast raster and square spiral scan modes are realized in SAM, but not specially designed for it. Therefore, they have universal adaptability and can be applied to other scanning measurement systems with two-dimensional mechanical scanning stages, such as atomic force microscope or scanning tunneling microscope.

  20. Advanced Virgo phase cameras

    NASA Astrophysics Data System (ADS)

    van der Schaaf, L.; Agatsuma, K.; van Beuzekom, M.; Gebyehu, M.; van den Brand, J.

    2016-05-01

    A century after the prediction of gravitational waves, detectors have reached the sensitivity needed to proof their existence. One of them, the Virgo interferometer in Pisa, is presently being upgraded to Advanced Virgo (AdV) and will come into operation in 2016. The power stored in the interferometer arms raises from 20 to 700 kW. This increase is expected to introduce higher order modes in the beam, which could reduce the circulating power in the interferometer, limiting the sensitivity of the instrument. To suppress these higher-order modes, the core optics of Advanced Virgo is equipped with a thermal compensation system. Phase cameras, monitoring the real-time status of the beam constitute a critical component of this compensation system. These cameras measure the phases and amplitudes of the laser-light fields at the frequencies selected to control the interferometer. The measurement combines heterodyne detection with a scan of the wave front over a photodetector with pin-hole aperture. Three cameras observe the phase front of these laser sidebands. Two of them monitor the in-and output of the interferometer arms and the third one is used in the control of the aberrations introduced by the power recycling cavity. In this paper the working principle of the phase cameras is explained and some characteristic parameters are described.

  1. The Beatles, the Nobel Prize, and CT scanning of the chest.

    PubMed

    Goodman, Lawrence R

    2010-01-01

    From its first test scan on a mouse, in 1967, to current medical practice, the CT scanner has become a core imaging tool in thoracic diagnosis. Initially financed by money from Beatles' record sales, the first patient scan was performed in 1971. Only 8 years later, a Nobel Prize in Physics and Medicine was awarded to Hounsfield and Cormack for their discovery. This article traces the history of CT scanner development and how each technical advance expanded chest diagnostic frontiers. Chest imaging now accounts for 30% of all CT scanning.

  2. A cryogenic Quadraprobe scanning tunneling microscope system with fabrication capability for nanotransport research.

    PubMed

    Kim, Tae-Hwan; Wang, Zhouhang; Wendelken, John F; Weitering, Hanno H; Li, Wenzhi; Li, An-Ping

    2007-12-01

    We describe the development and the capabilities of an advanced system for nanoscale electrical transport studies. This system consists of a low temperature four-probe scanning tunneling microscope (STM) and a high-resolution scanning electron microscope coupled to a molecular-beam epitaxy sample preparation chamber. The four STM probes can be manipulated independently with subnanometer precision, enabling atomic resolution STM imaging and four-point electrical transport study of surface electronic systems and nanostructured materials at temperatures down to 10 K. Additionally, an integrated energy analyzer allows for scanning Auger microscopy to probe chemical species of nanostructures. Some testing results are presented.

  3. Scanning Tunneling Optical Resonance Microscopy

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Wilt, Dave; Raffaelle, Ryne; Gennett, Tom; Tin, Padetha; Lau, Janice; Castro, Stephanie; Jenkins, Philip; Scheiman, Dave

    2003-01-01

    Scanning tunneling optical resonance microscopy (STORM) is a method, now undergoing development, for measuring optoelectronic properties of materials and devices on the nanoscale by means of a combination of (1) traditional scanning tunneling microscopy (STM) with (2) tunable laser spectroscopy. In STORM, an STM tip probing a semiconductor is illuminated with modulated light at a wavelength in the visible-to-near-infrared range and the resulting photoenhancement of the tunneling current is measured as a function of the illuminating wavelength. The photoenhancement of tunneling current occurs when the laser photon energy is sufficient to excite charge carriers into the conduction band of the semiconductor. Figure 1 schematically depicts a proposed STORM apparatus. The light for illuminating the semiconductor specimen at the STM would be generated by a ring laser that would be tunable across the wavelength range of interest. The laser beam would be chopped by an achromatic liquid-crystal modulator. A polarization-maintaining optical fiber would couple the light to the tip/sample junction of a commercial STM. An STM can be operated in one of two modes: constant height or constant current. A STORM apparatus would be operated in the constant-current mode, in which the height of the tip relative to the specimen would be varied in order to keep the tunneling current constant. In this mode, a feedback control circuit adjusts the voltage applied to a piezoelectric actuator in the STM that adjusts the height of the STM tip to keep the tunneling current constant. The exponential relationship between the tunneling current and tip-to-sample distance makes it relatively easy to implement this mode of operation. The choice of method by which the photoenhanced portion of the tunneling current would be measured depends on choice of the frequency at which the input illumination would be modulated (chopped). If the frequency of modulation were low enough (typically < 10 Hz) that the

  4. Advanced LIGO

    NASA Astrophysics Data System (ADS)

    LIGO Scientific Collaboration; Aasi, J.; Abbott, B. P.; Abbott, R.; Abbott, T.; Abernathy, M. R.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V.; Affeldt, C.; Aggarwal, N.; Aguiar, O. D.; Ain, A.; Ajith, P.; Alemic, A.; Allen, B.; Amariutei, D.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C.; Areeda, J. S.; Ashton, G.; Ast, S.; Aston, S. M.; Aufmuth, P.; Aulbert, C.; Aylott, B. E.; Babak, S.; Baker, P. T.; Ballmer, S. W.; Barayoga, J. C.; Barbet, M.; Barclay, S.; Barish, B. C.; Barker, D.; Barr, B.; Barsotti, L.; Bartlett, J.; Barton, M. A.; Bartos, I.; Bassiri, R.; Batch, J. C.; Baune, C.; Behnke, B.; Bell, A. S.; Bell, C.; Benacquista, M.; Bergman, J.; Bergmann, G.; Berry, C. P. L.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Biscans, S.; Biwer, C.; Blackburn, J. K.; Blackburn, L.; Blair, C. D.; Blair, D.; Bock, O.; Bodiya, T. P.; Bojtos, P.; Bond, C.; Bork, R.; Born, M.; Bose, Sukanta; Brady, P. R.; Braginsky, V. B.; Brau, J. E.; Bridges, D. O.; Brinkmann, M.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Buchman, S.; Buikema, A.; Buonanno, A.; Cadonati, L.; Calderón Bustillo, J.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Caride, S.; Caudill, S.; Cavaglià, M.; Cepeda, C.; Chakraborty, R.; Chalermsongsak, T.; Chamberlin, S. J.; Chao, S.; Charlton, P.; Chen, Y.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Collette, C.; Cominsky, L.; Constancio, M., Jr.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Costa, C. A.; Coughlin, M. W.; Countryman, S.; Couvares, P.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cutler, C.; Dahl, K.; Dal Canton, T.; Damjanic, M.; Danilishin, S. L.; Danzmann, K.; Dartez, L.; Dave, I.; Daveloza, H.; Davies, G. S.; Daw, E. J.; DeBra, D.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; DeRosa, R. T.; DeSalvo, R.; Dhurandhar, S.; D´ıaz, M.; Di Palma, I.; Dojcinoski, G.; Dominguez, E.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Driggers, J. C.; Du, Z.; Dwyer, S.; Eberle, T.; Edo, T.; Edwards, M.; Edwards, M.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Essick, R.; Etzel, T.; Evans, M.; Evans, T.; Factourovich, M.; Fairhurst, S.; Fan, X.; Fang, Q.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Feldbaum, D.; Ferreira, E. C.; Fisher, R. P.; Frei, Z.; Freise, A.; Frey, R.; Fricke, T. T.; Fritschel, P.; Frolov, V. V.; Fuentes-Tapia, S.; Fulda, P.; Fyffe, M.; Gair, J. R.; Gaonkar, S.; Gehrels, N.; Gergely, L. Á.; Giaime, J. A.; Giardina, K. D.; Gleason, J.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gordon, N.; Gorodetsky, M. L.; Gossan, S.; Goßler, S.; Gräf, C.; Graff, P. B.; Grant, A.; Gras, S.; Gray, C.; Greenhalgh, R. J. S.; Gretarsson, A. M.; Grote, H.; Grunewald, S.; Guido, C. J.; Guo, X.; Gushwa, K.; Gustafson, E. K.; Gustafson, R.; Hacker, J.; Hall, E. D.; Hammond, G.; Hanke, M.; Hanks, J.; Hanna, C.; Hannam, M. D.; Hanson, J.; Hardwick, T.; Harry, G. M.; Harry, I. W.; Hart, M.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Hee, S.; Heintze, M.; Heinzel, G.; Hendry, M.; Heng, I. S.; Heptonstall, A. W.; Heurs, M.; Hewitson, M.; Hild, S.; Hoak, D.; Hodge, K. A.; Hollitt, S. E.; Holt, K.; Hopkins, P.; Hosken, D. J.; Hough, J.; Houston, E.; Howell, E. J.; Hu, Y. M.; Huerta, E.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh, M.; Huynh-Dinh, T.; Idrisy, A.; Indik, N.; Ingram, D. R.; Inta, R.; Islas, G.; Isler, J. C.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacobson, M.; Jang, H.; Jawahar, S.; Ji, Y.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Ju, L.; Haris, K.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Katsavounidis, E.; Katzman, W.; Kaufer, H.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kawazoe, F.; Keiser, G. M.; Keitel, D.; Kelley, D. B.; Kells, W.; Keppel, D. G.; Key, J. S.; Khalaidovski, A.; Khalili, F. Y.; Khazanov, E. A.; Kim, C.; Kim, K.; Kim, N. G.; Kim, N.; Kim, Y.-M.; King, E. J.; King, P. J.; Kinzel, D. L.; Kissel, J. S.; Klimenko, S.; Kline, J.; Koehlenbeck, S.; Kokeyama, K.; Kondrashov, V.; Korobko, M.; Korth, W. Z.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Krueger, C.; Kuehn, G.; Kumar, A.; Kumar, P.; Kuo, L.; Landry, M.; Lantz, B.; Larson, S.; Lasky, P. D.; Lazzarini, A.; Lazzaro, C.; Le, J.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Leong, J. R.; Levin, Y.; Levine, B.; Lewis, J.; Li, T. G. F.; Libbrecht, K.; Libson, A.; Lin, A. C.; Littenberg, T. B.; Lockerbie, N. A.; Lockett, V.; Logue, J.; Lombardi, A. L.; Lormand, M.; Lough, J.; Lubinski, M. J.; Lück, H.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Macarthur, J.; MacDonald, T.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magee, R.; Mageswaran, M.; Maglione, C.; Mailand, K.; Mandel, I.; Mandic, V.; Mangano, V.; Mansell, G. L.; Márka, S.; Márka, Z.; Markosyan, A.; Maros, E.; Martin, I. W.; Martin, R. M.; Martynov, D.; Marx, J. N.; Mason, K.; Massinger, T. J.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; Mazzolo, G.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McLin, K.; McWilliams, S.; Meadors, G. D.; Meinders, M.; Melatos, A.; Mendell, G.; Mercer, R. A.; Meshkov, S.; Messenger, C.; Meyers, P. M.; Miao, H.; Middleton, H.; Mikhailov, E. E.; Miller, A.; Miller, J.; Millhouse, M.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moe, B.; Mohanty, S. D.; Mohapatra, S. R. P.; Moore, B.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mow-Lowry, C. M.; Mueller, C. L.; Mueller, G.; Mukherjee, S.; Mullavey, A.; Munch, J.; Murphy, D.; Murray, P. G.; Mytidis, A.; Nash, T.; Nayak, R. K.; Necula, V.; Nedkova, K.; Newton, G.; Nguyen, T.; Nielsen, A. B.; Nissanke, S.; Nitz, A. H.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oppermann, P.; Oram, R.; O'Reilly, B.; Ortega, W.; O'Shaughnessy, R.; Osthelder, C.; Ott, C. D.; Ottaway, D. J.; Ottens, R. S.; Overmier, H.; Owen, B. J.; Padilla, C.; Pai, A.; Pai, S.; Palashov, O.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Papa, M. A.; Paris, H.; Patrick, Z.; Pedraza, M.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Phelps, M.; Pierro, V.; Pinto, I. M.; Pitkin, M.; Poeld, J.; Post, A.; Poteomkin, A.; Powell, J.; Prasad, J.; Predoi, V.; Premachandra, S.; Prestegard, T.; Price, L. R.; Principe, M.; Privitera, S.; Prix, R.; Prokhorov, L.; Puncken, O.; Pürrer, M.; Qin, J.; Quetschke, V.; Quintero, E.; Quiroga, G.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajalakshmi, G.; Rakhmanov, M.; Ramirez, K.; Raymond, V.; Reed, C. M.; Reid, S.; Reitze, D. H.; Reula, O.; Riles, K.; Robertson, N. A.; Robie, R.; Rollins, J. G.; Roma, V.; Romano, J. D.; Romanov, G.; Romie, J. H.; Rowan, S.; Rüdiger, A.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Saleem, M.; Salemi, F.; Sammut, L.; Sandberg, V.; Sanders, J. R.; Sannibale, V.; Santiago-Prieto, I.; Sathyaprakash, B. S.; Saulson, P. R.; Savage, R.; Sawadsky, A.; Scheuer, J.; Schilling, R.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sergeev, A.; Serna, G.; Sevigny, A.; Shaddock, D. A.; Shahriar, M. S.; Shaltev, M.; Shao, Z.; Shapiro, B.; Shawhan, P.; Shoemaker, D. H.; Sidery, T. L.; Siemens, X.; Sigg, D.; Silva, A. D.; Simakov, D.; Singer, A.; Singer, L.; Singh, R.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, M. R.; Smith, R. J. E.; Smith-Lefebvre, N. D.; Son, E. J.; Sorazu, B.; Souradeep, T.; Staley, A.; Stebbins, J.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Steplewski, S.; Stevenson, S.; Stone, R.; Strain, K. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sutton, P. J.; Szczepanczyk, M.; Szeifert, G.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Tellez, G.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thorne, K. S.; Thrane, E.; Tiwari, V.; Tomlinson, C.; Torres, C. V.; Torrie, C. I.; Traylor, G.; Tse, M.; Tshilumba, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; Vallisneri, M.; van Veggel, A. A.; Vass, S.; Vaulin, R.; Vecchio, A.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Vincent-Finley, R.; Vitale, S.; Vo, T.; Vorvick, C.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, H.; Wang, M.; Wang, X.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Welborn, T.; Wen, L.; Wessels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whitcomb, S. E.; White, D. J.; Whiting, B. F.; Wilkinson, C.; Williams, L.; Williams, R.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Worden, J.; Xie, S.; Yablon, J.; Yakushin, I.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yang, Q.; Zanolin, M.; Zhang, Fan; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhu, X. J.; Zucker, M. E.; Zuraw, S.; Zweizig, J.

    2015-04-01

    The Advanced LIGO gravitational wave detectors are second-generation instruments designed and built for the two LIGO observatories in Hanford, WA and Livingston, LA, USA. The two instruments are identical in design, and are specialized versions of a Michelson interferometer with 4 km long arms. As in Initial LIGO, Fabry-Perot cavities are used in the arms to increase the interaction time with a gravitational wave, and power recycling is used to increase the effective laser power. Signal recycling has been added in Advanced LIGO to improve the frequency response. In the most sensitive frequency region around 100 Hz, the design strain sensitivity is a factor of 10 better than Initial LIGO. In addition, the low frequency end of the sensitivity band is moved from 40 Hz down to 10 Hz. All interferometer components have been replaced with improved technologies to achieve this sensitivity gain. Much better seismic isolation and test mass suspensions are responsible for the gains at lower frequencies. Higher laser power, larger test masses and improved mirror coatings lead to the improved sensitivity at mid and high frequencies. Data collecting runs with these new instruments are planned to begin in mid-2015.

  5. A New First-Scan Method for Two-Scan Labeling Algorithms

    NASA Astrophysics Data System (ADS)

    He, Lifeng; Chao, Yuyan; Suzuki, Kenji

    This paper proposes a new first-scan method for two-scan labeling algorithms. In the first scan, our proposed method first scans every fourth image line, and processes the scan line and its two neighbor lines. Then, it processes the remaining lines from top to bottom one by one. Our method decreases the average number of times that must be checked to process a foreground pixel will; thus, the efficiency of labeling can be improved.

  6. Excitation-scanning hyperspectral imaging microscope

    PubMed Central

    Favreau, Peter F.; Hernandez, Clarissa; Heaster, Tiffany; Alvarez, Diego F.; Rich, Thomas C.; Prabhat, Prashant; Leavesley, Silas J.

    2014-01-01

    Abstract. Hyperspectral imaging is a versatile tool that has recently been applied to a variety of biomedical applications, notably live-cell and whole-tissue signaling. Traditional hyperspectral imaging approaches filter the fluorescence emission over a broad wavelength range while exciting at a single band. However, these emission-scanning approaches have shown reduced sensitivity due to light attenuation from spectral filtering. Consequently, emission scanning has limited applicability for time-sensitive studies and photosensitive applications. In this work, we have developed an excitation-scanning hyperspectral imaging microscope that overcomes these limitations by providing high transmission with short acquisition times. This is achieved by filtering the fluorescence excitation rather than the emission. We tested the efficacy of the excitation-scanning microscope in a side-by-side comparison with emission scanning for detection of green fluorescent protein (GFP)-expressing endothelial cells in highly autofluorescent lung tissue. Excitation scanning provided higher signal-to-noise characteristics, as well as shorter acquisition times (300  ms/wavelength band with excitation scanning versus 3  s/wavelength band with emission scanning). Excitation scanning also provided higher delineation of nuclear and cell borders, and increased identification of GFP regions in highly autofluorescent tissue. These results demonstrate excitation scanning has utility in a wide range of time-dependent and photosensitive applications. PMID:24727909

  7. Excitation-scanning hyperspectral imaging microscope.

    PubMed

    Favreau, Peter F; Hernandez, Clarissa; Heaster, Tiffany; Alvarez, Diego F; Rich, Thomas C; Prabhat, Prashant; Leavesley, Silas J

    2014-04-01

    Hyperspectral imaging is a versatile tool that has recently been applied to a variety of biomedical applications, notably live-cell and whole-tissue signaling. Traditional hyperspectral imaging approaches filter the fluorescence emission over a broad wavelength range while exciting at a single band. However, these emission-scanning approaches have shown reduced sensitivity due to light attenuation from spectral filtering. Consequently, emission scanning has limited applicability for time-sensitive studies and photosensitive applications. In this work, we have developed an excitation-scanning hyperspectral imaging microscope that overcomes these limitations by providing high transmission with short acquisition times. This is achieved by filtering the fluorescence excitation rather than the emission. We tested the efficacy of the excitation-scanning microscope in a side-by-side comparison with emission scanning for detection of green fluorescent protein (GFP)-expressing endothelial cells in highly autofluorescent lung tissue. Excitation scanning provided higher signal-to-noise characteristics, as well as shorter acquisition times (300  ms/wavelength band with excitation scanning versus 3  s/wavelength band with emission scanning). Excitation scanning also provided higher delineation of nuclear and cell borders, and increased identification of GFP regions in highly autofluorescent tissue. These results demonstrate excitation scanning has utility in a wide range of time-dependent and photosensitive applications.

  8. Correlation-steered scanning for scanning probe microscopes to overcome thermal drift for ultra-long time scanning.

    PubMed

    Zhang, Liansheng; Long, Qian; Liu, Yongbin; Zhang, Jie; Feng, Zhihua

    2016-07-01

    The thermal effect is one of the most important factors that influence the accuracy of nanoscale measurement and the surface topography of samples in scanning probe microscopes (SPMs). We propose a method called correlation-steered scanning, which is capable of overcoming three-dimensional thermal drifts in real time for ultra-long time scanned images. The image is scanned band by band with overlapping parts between adjacent bands. The vertical drift can be considered as linear and can thus be eliminated together with the tilt of the sample by applying the flattening method. Each band is artificially divided into several blocks for conveniently calculating lateral drifts on the basis of the overlapping area of adjacent bands through digital image correlation. The calculated lateral drifts are compensated to steer the scanning of the subsequent blocks, thus ensuring that all bands are parallel to one another. Experimental results proved that images scanned by the proposed method exhibited less distortions than those obtained from the traditional raster scanning method. The nanoscale measurement results based on the image obtained by the proposed method also showed high accuracy, with an error of less than 1.5%. By scanning as many bands as needed, the correlation-steered scanning method can obtain a highly precise SPM image of an ultra-large area.

  9. Basis for optronic ScanSAR processing

    NASA Astrophysics Data System (ADS)

    Marchese, Linda; Bourqui, Pascal; Turgeon, Sandra; Harnish, Bernd; Suess, Martin; Châteauneuf, François; Bergeron, Alain

    2011-11-01

    ScanSAR is an important imaging mode of operation for SAR systems. It allows extended range coverage albeit at the expense of azimuth resolution. Compared to stripmap, ScanSAR is used more for large swath coverage for mapping and monitoring over a wide area. Applications are numerous and include boreal forest mapping, wetland mapping and soil moisture monitoring. The goal of the present work was thus to explore the possibility of processing ScanSAR data optronicaly. Tests were performed with artificially bursted ASAR stripmap data demonstrating that reconstruction of ScanSAR data using the optronic SAR processor is feasible. This paper describes specifically how the data control and handling of ScanSAR data is performed to make it compatible with the optronic processor that was otherwise specifically designed for stripmap processing. As well, the ScanSAR images generated optronicaly are presented.

  10. Image scanning microscopy with radially polarized light

    NASA Astrophysics Data System (ADS)

    Xiao, Yun; Zhang, Yunhai; Wei, Tongda; Huang, Wei; Shi, Yaqin

    2017-03-01

    In order to improve the resolution of image scanning microscopy, we present a method based on image scanning microscopy and radially polarized light. According to the theory of image scanning microscopy, we get the effective point spread function of image scanning microscopy with the longitudinal component of radially polarized light and a 1 AU detection area, and obtain imaging results of the analyzed samples using this method. Results show that the resolution can be enhanced by 7% compared with that in image scanning microscopy with circularly polarized light, and is 1.54-fold higher than that in confocal microscopy with a pinhole of 1 AU. Additionally, the peak intensity of ISM is 1.54-fold higher than that of a confocal microscopy with a pinhole of 1 AU. In conclusion, the combination of the image scanning microscopy and the radially polarized light could improve the resolution, and it could realize high-resolution and high SNR imaging at the same time.

  11. Advanced Pacemaker

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Synchrony, developed by St. Jude Medical's Cardiac Rhythm Management Division (formerly known as Pacesetter Systems, Inc.) is an advanced state-of-the-art implantable pacemaker that closely matches the natural rhythm of the heart. The companion element of the Synchrony Pacemaker System is the Programmer Analyzer APS-II which allows a doctor to reprogram and fine tune the pacemaker to each user's special requirements without surgery. The two-way communications capability that allows the physician to instruct and query the pacemaker is accomplished by bidirectional telemetry. APS-II features 28 pacing functions and thousands of programming combinations to accommodate diverse lifestyles. Microprocessor unit also records and stores pertinent patient data up to a year.

  12. Scanning Tip Microscopy With Applications To Biology

    NASA Astrophysics Data System (ADS)

    Sarid, Dror; Thall, Edmond H.; Iams, Douglas A.; Ingle, Jeffery T.; Henson, Tammy D.; Lee, Y. C.; Bell, L. Stephen

    1989-06-01

    Scanning tunneling microscopy and atomic force microscopy, denoted here scanning tip microscopy, are two powerful novel techniques for imaging surfaces with atomic resolution. We describe the underlying principles of these two techniques with special emphasis on an instrument developed in our laboratory that uses a laser diode to detect minute deflections of a tip as it raster scans the surface of a sample. Applications of these techniques to research in biology are assessed and their relative merits discussed.

  13. Background removal procedure for rapid scan EPR.

    PubMed

    Tseitlin, Mark; Czechowski, Tomasz; Quine, Richard W; Eaton, Sandra S; Eaton, Gareth R

    2009-01-01

    In rapid scan EPR the changing magnetic field creates a background signal with components at the scan frequency and its harmonics. The amplitude of the background signal increases with scan width and is more significant for weak EPR signals such as are obtained in the presence of magnetic field gradients. A procedure for distinguishing this background from the EPR signal is proposed, mathematically described, and tested for various experimental conditions.

  14. Radiogallium scan in P. carinii pneumonia

    SciTech Connect

    Parthasarathy, K.L.; Bakshi, S.P.; Bender, M.A.

    1982-02-01

    A gallium scan performed on a patient with fever of unknown origin (FUO) revealed an abnormal uptake of radiotracer in the lungs despite negative chest roentgenographic examination and other routine diagnostic studies. Subsequent lung biopsy results confirmed the presence of Pneumocystis (P.) carinii infection. A repeat gallium scan obtained following appropriate antibiotic therapy was essentially normal. The importance of radiogallium scanning in an immunosuppressed patient with FUO is emphasized.

  15. Scanning Tunneling Microscopy Studies of Quasicrystals

    NASA Astrophysics Data System (ADS)

    Becker, Russell S.; Kortan, A. Refik

    The following sections are included: * INTRODUCTION * EXPERIMENTAL * X-RAY DIFFRACTION * SCANNING TUNNELING MICROSCOPY * STRUCTURE MODELLING BASED ON STM * COMPARISON WITH MODELS BASED ON BULK STUDIES * CONCLUSION * REFERENCES

  16. Scanned probe microscope for biological applications

    NASA Astrophysics Data System (ADS)

    Baiburin, Vil B.; Konnov, Nikolai P.; Shcherbakov, Anatolyi A.; Malakhaeva, Alina N.; Zadnova, Svetlana P.; Volkov, Yuri P.

    1997-12-01

    In our biophysical laboratory has been developed a new scanned probe microscope (SPM) for biological application. The SPM allows to investigate a biological samples' surface by means of three different near field microscopes: scanning tunneling microscope (STM), atomic force microscope (AFM) and near field scanning optical microscope (NSOM). The SPM is very rigid and can be operated in ordinary laboratory without any vibration isolation. The scanning area of the microscope is about 10 by 10 micrometers. Some different biological objects were visualized by means of the SPM viz. bacteria (E. Coli, plague, cholera, staphylococcus), macromolecules (DNA, plague proteins) and phage (T2).

  17. An horizon scan of biogeography.

    PubMed

    Dawson, Michael N; Algar, Adam C; Antonelli, Alexandre; Dávalos, Liliana M; Davis, Edward; Early, Regan; Guisan, Antoine; Jansson, Roland; Lessard, Jean-Philippe; Marske, Katharine A; McGuire, Jenny L; Stigall, Alycia L; Swenson, Nathan G; Zimmermann, Niklaus E; Gavin, Daniel G

    2013-01-01

    The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a renaissance for inter-disciplinary research, the importance of recognizing the evolution-ecology continuum across spatial and temporal scales and at different taxonomic, phylogenetic and functional levels, and re-exploration of classical assumptions and hypotheses using new tools. However, advances are taxonomically and geographically biased, and key theoretical frameworks await tools to handle, or strategies to simplify, the biological complexity seen in empirical systems. Current threats to biodiversity require unprecedented integration of knowledge and development of predictive capacity that may enable biogeography to unite its descriptive and hypothetico-deductive branches and establish a greater role within and outside academia.

  18. An horizon scan of biogeography

    PubMed Central

    2014-01-01

    The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a renaissance for inter-disciplinary research, the importance of recognizing the evolution–ecology continuum across spatial and temporal scales and at different taxonomic, phylogenetic and functional levels, and re-exploration of classical assumptions and hypotheses using new tools. However, advances are taxonomically and geographically biased, and key theoretical frameworks await tools to handle, or strategies to simplify, the biological complexity seen in empirical systems. Current threats to biodiversity require unprecedented integration of knowledge and development of predictive capacity that may enable biogeography to unite its descriptive and hypothetico-deductive branches and establish a greater role within and outside academia. PMID:24707348

  19. Advanced Transport Operating Systems Program

    NASA Technical Reports Server (NTRS)

    White, John J.

    1990-01-01

    NASA-Langley's Advanced Transport Operating Systems Program employs a heavily instrumented, B 737-100 as its Transport Systems Research Vehicle (TRSV). The TRSV has been used during the demonstration trials of the Time Reference Scanning Beam Microwave Landing System (TRSB MLS), the '4D flight-management' concept, ATC data links, and airborne windshear sensors. The credibility obtainable from successful flight test experiments is often a critical factor in the granting of substantial commitments for commercial implementation by the FAA and industry. In the case of the TRSB MLS, flight test demonstrations were decisive to its selection as the standard landing system by the ICAO.

  20. Estimation of the noise contributions from blank, transmission and emission scans in PET

    SciTech Connect

    Holm, S.; Jensen, M.; Toft, P.

    1996-08-01

    This work determines the relative importance of noise from blank (B), transmission (T) and emission (E) scans in PET using a GE Advance scanner on a 20 cm cylinder, a brain phantom, and a torso-like ellipse (18/35 cm) with examples of human scans (brain O-15 water and F-18 FDG, heart FDG). Phantom E scans were acquired in both 2D and 3D modes as decay series with C-11 or F-18 over 3--6 decades of Noise Equivalent Counts (NEC). B and T scans were made using two pin sources ({approx} 500 MBq total) over 64-32768 sec. In humans only a limited subset was available. In homogeneous phantoms normalized variance (var) was estimated from pixel distributions in single images. In other objects, including the human studies, calculations were performed on differences of paired images. In all cases a fit was made to a simple noise model. The cylinder data show expected relations of T to B noise proving the adequacy of B scan times {le} 20 min for most purposes. For the brain phantom, a contour plot is provided for var (E,T). In a typical 3D O-15 water study with 0.5 M counts per central slice, a 10 min T-scan adds less than 10% to the total noise level. An example shows how to split a total scan time between E and T scans, in order to minimize the variance.

  1. Efficient terrestrial laser scan segmentation exploiting data structure

    NASA Astrophysics Data System (ADS)

    Mahmoudabadi, Hamid; Olsen, Michael J.; Todorovic, Sinisa

    2016-09-01

    New technologies such as lidar enable the rapid collection of massive datasets to model a 3D scene as a point cloud. However, while hardware technology continues to advance, processing 3D point clouds into informative models remains complex and time consuming. A common approach to increase processing efficiently is to segment the point cloud into smaller sections. This paper proposes a novel approach for point cloud segmentation using computer vision algorithms to analyze panoramic representations of individual laser scans. These panoramas can be quickly created using an inherent neighborhood structure that is established during the scanning process, which scans at fixed angular increments in a cylindrical or spherical coordinate system. In the proposed approach, a selected image segmentation algorithm is applied on several input layers exploiting this angular structure including laser intensity, range, normal vectors, and color information. These segments are then mapped back to the 3D point cloud so that modeling can be completed more efficiently. This approach does not depend on pre-defined mathematical models and consequently setting parameters for them. Unlike common geometrical point cloud segmentation methods, the proposed method employs the colorimetric and intensity data as another source of information. The proposed algorithm is demonstrated on several datasets encompassing variety of scenes and objects. Results show a very high perceptual (visual) level of segmentation and thereby the feasibility of the proposed algorithm. The proposed method is also more efficient compared to Random Sample Consensus (RANSAC), which is a common approach for point cloud segmentation.

  2. Scanning Radar Investigations to Characterize Cloud and Precipitation Processes for ASR

    SciTech Connect

    Venkatachalam, Chandrasekar

    2016-12-17

    The project conducted investigations in the following areas related to scanning radar retrievals: a) Development for Cloud drizzle separation studies for the ENA site based on Doppler Spectra b) Advanced radar retrieval for the SGP site c) Characterizing falling snow using multifrequency dual-polarization measurements d) BAECC field experiment. More details about these investigations can be found within each subtopic within the report.

  3. Micro computed tomography (CT) scanned anatomical gateway to insect pest bioinformatics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An international collaboration to establish an interactive Digital Video Library for a Systems Biology Approach to study the Asian citrus Psyllid and psyllid genomics/proteomics interactions is demonstrated. Advances in micro-CT, digital computed tomography (CT) scan uses X-rays to make detailed pic...

  4. Advanced stellarators

    NASA Astrophysics Data System (ADS)

    Schlüter, Arnulf

    1983-03-01

    Toroidal confinement of a plasma by an external magnetic field is not compatible with axisymmetry, in contrast to confinement by the pinch effect of induced electric currents as in a tokomak or by the reversed field pinch configuration. The existence of magnetic surfaces throughout the region in which grad p ≠ 0 is therefore not guaranteed in such configurations, though it is necessary for MHD-equilibrium when the lines of force possess a finite twist (or "rotational transform"). These twisted equilibria are called stellarators. The other type of external confinement requires all lines of force to be closed upon themselves and p to be function of the well defined quantity Q = φ d l/ B only. The resulting "bumpy" tori are sometimes also referred to as being M + S like. By discussing specific examples it is shown that stellarator configurations exist which retain as much as possible the properties of M + S like configurations, combine these with the magnetic well, and with an approximation to the isodynamic requirement of D. Palumbo. These so-called Advanced Stellarators shown an improvement in predicted particle confinement and beta-limit compared to the classical stellarators. They can also be viewed as forming a system of linked stabilized mirrors of small mirror ratio. These fields can be produced by modular coils. A prototype of such a configuration is being designed by the stellarator division of IPP under the name of Wendelstein VII-AS. Expected physical data and technical details of W VII-AS are given.

  5. Nanoelectrical probing with multiprobe SPM Systems compatible with scanning electron microscopes

    NASA Astrophysics Data System (ADS)

    Lewis, Aaron; Ignatov, Andrey; Taha, Hesham; Zhinoviev, Oleg; Komissar, Anatoly; Krol, Alexander; Lewis, David

    2011-03-01

    A scanning electron microscope compatible platform that permits multiprobe atomic force microscopy based nanoelectrical characterization will be described. To achieve such multiple parameter nanocharacterization with scanning electron microscope compatibility involves a number of innovations both in instrument and probe design. This presentation will focus on how these advances were achieved and the results obtained with such instrumentation on electrical nano-characterization and electrical nano-manipulation. The advances include: 1. Specialized scanners; 2. An ultrasensitive feedback mechanism based on tuning forks with no optical feedback interference that can induce carriers in semiconductor devices; and 3. Unique probes compatible with multiprobe geometries in which the probe tips can be brought into physical contact with one another. Experiments will be described with such systems that will include multiprobe electrical measurements with metal and glass coated coaxial nanowires of platinum. This combination of scanning electron microscopes integrated with multiprobe instrumentation allows for important applications not available today in the field of semiconductor processing technology.

  6. Lung Perfusion Scanning in Hepatic Cirrhosis

    PubMed Central

    Stanley, N. N.; Ackrill, P.; Wood, J.

    1972-01-01

    Abnormal lung perfusion scans using radioactive particles were found in five out of six cases of hepatic cirrhosis with arterial hypoxaemia. None had clinical evidence of cardiopulmonary disease or signs of pulmonary embolism on arteriography. The scan defects are probably caused by a disorder of the pulmonary microvasculature, which may show regional variation in severity. ImagesFIG. 1FIG. 2 PMID:4645896

  7. Implementing SCANS. Highlight Zone: Research @ Work.

    ERIC Educational Resources Information Center

    Packer, Arnold C.; Brainard, Scott

    Foremost among efforts over the last decade to improve the work-related skills required of all young people to meet the demands of American's workplaces was the Secretary's Commission on Achieving Necessary Skills Commission (SCANS). Integral to SCANS were its three-part foundation (basic skills, thinking skills, and personal qualities) and these…

  8. A Student-Built Scanning Tunneling Microscope

    ERIC Educational Resources Information Center

    Ekkens, Tom

    2015-01-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself.…

  9. Camera Systems Rapidly Scan Large Structures

    NASA Technical Reports Server (NTRS)

    2013-01-01

    Needing a method to quickly scan large structures like an aircraft wing, Langley Research Center developed the line scanning thermography (LST) system. LST works in tandem with a moving infrared camera to capture how a material responds to changes in temperature. Princeton Junction, New Jersey-based MISTRAS Group Inc. now licenses the technology and uses it in power stations and industrial plants.

  10. The Scanning Process: Methods and Uses.

    ERIC Educational Resources Information Center

    Renfro, William L.; Morrison, James L.

    1983-01-01

    Developing a rational scanning process that reaches a balance between what is needed and what is possible within the limitations of an institution's resources is discussed. The different kinds of scanning, which kind to use at each stage of the process, and why are described. (MLW)

  11. Torque-while-turnaround scan mirror assembly

    NASA Technical Reports Server (NTRS)

    Starkus, C. J.

    1977-01-01

    A scan mirror assembly which is part of a thematic mapper system is described with emphasis on mechanical aspects of the design. Features of the oscillating scan mirror mechanism include: a low level of structural vibration for the impact energies involved in mirror oscillation and return of energy lost during impact to the mirror by applying torque during the instant of impact.

  12. Optical Scanning for Retrospective Conversion of Information.

    ERIC Educational Resources Information Center

    Hein, Morten

    1986-01-01

    This discussion of the use of optical scanning and computer formatting for retrospective conversion focuses on a series of applications known as Optical Scanning for Creation of Information Databases (OSCID). Prior research in this area and the usefulness of OSCID for creating low-priced machine-readable data representing older materials are…

  13. Live ultrasound volume reconstruction using scout scanning

    NASA Astrophysics Data System (ADS)

    Meyer, Amelie; Lasso, Andras; Ungi, Tamas; Fichtinger, Gabor

    2015-03-01

    Ultrasound-guided interventions often necessitate scanning of deep-seated anatomical structures that may be hard to visualize. Visualization can be improved using reconstructed 3D ultrasound volumes. High-resolution 3D reconstruction of a large area during clinical interventions is challenging if the region of interest is unknown. We propose a two-stage scanning method allowing the user to perform quick low-resolution scouting followed by high-resolution live volume reconstruction. Scout scanning is accomplished by stacking 2D tracked ultrasound images into a low-resolution volume. Then, within a region of interest defined in the scout scan, live volume reconstruction can be performed by continuous scanning until sufficient image density is achieved. We implemented the workflow as a module of the open-source 3D Slicer application, within the SlicerIGT extension and building on the PLUS toolkit. Scout scanning is performed in a few seconds using 3 mm spacing to allow region of interest definition. Live reconstruction parameters are set to provide good image quality (0.5 mm spacing, hole filling enabled) and feedback is given during live scanning by regularly updated display of the reconstructed volume. Use of scout scanning may allow the physician to identify anatomical structures. Subsequent live volume reconstruction in a region of interest may assist in procedures such as targeting needle interventions or estimating brain shift during surgery.

  14. Getting a CAT Scan (For Kids)

    MedlinePlus Videos and Cool Tools

    ... dientes Video: Getting an X-ray Getting a CAT Scan (Video) KidsHealth > For Kids > Getting a CAT Scan (Video) Print A A A en español Obtención de una tomografía computada (video) CAT stands for "computerized axial tomography." Translated, that means ...

  15. Bone scan in metabolic bone diseases. Review.

    PubMed

    Abdelrazek, Saeid; Szumowski, Piotr; Rogowski, Franciszek; Kociura-Sawicka, Agnieszka; Mojsak, Małgorzata; Szorc, Małgorzata

    2012-08-25

    Metabolic bone disease encompasses a number of disorders that tend to present a generalized involvement of the whole skeleton. The disorders are mostly related to increased bone turnover and increased uptake of radiolabelled diphosphonate. Skeletal uptake of 99mTc-labelled diphosphonate depends primarily upon osteoblastic activity, and to a lesser extent, skeletal vascularity. A bone scan image therefore presents a functional display of total skeletal metabolism and has valuable role to play in the assessment of patients with metabolic bone disorders. However, the bone scan appearances in metabolic bone disease are often non-specific, and their recognition depends on increased tracer uptake throughout the whole skeleton. It is the presence of local lesions, as in metastatic disease, that makes a bone scan appearance obviously abnormal. In the early stages, there will be difficulty in evaluating the bone scans from many patients with metabolic bone disease. However, in the more severe cases scan appearances can be quite striking and virtually diagnostic.

  16. Means for Positioning and Repositioning Scanning Instruments

    NASA Technical Reports Server (NTRS)

    Polites, Michael E. (Inventor); Alhorn, Dean C. (Inventor)

    1996-01-01

    A method is presented for positioning a scanning instrument to point toward the center of the desired scan wherein the scan is achieved by rotating unbalanced masses (RUMs) rotating about fixed axes of rotation relative to and associated with the instrument, the RUMs being supported on drive shafts spaced from the center of the mass of the instrument and rotating 180 degrees out-of-phase with each other and in planes parallel to each other to achieve the scan. The elevation and cross-elevation angles of the instrument are sensed to determine any offset and offset time rate-of-change, and the magnitude and direction are converted to a RUM cycle angular velocity component to be superimposed on the nominal velocity of the RUMs. This RUM angular velocity component modulates the RUM angular velocity to cause the speed of the RUMs to increase and decrease during each revolution to drive the instrument toward the desired center of the scan.

  17. An Introduction to PunchScan

    NASA Astrophysics Data System (ADS)

    Popoveniuc, Stefan; Hosp, Ben

    PunchScan is a precinct-read optical-scan balloting system that allows voters to take their ballot with them after scanning. This does not violate the secret ballot principle because the ballots cannot be read without secret information held by the distributed authority in charge of the election. In fact, this election authority will publish the ballots for everyone to see, allowing voters whose ballots were incorrectly omitted to complain. PunchScan vote-counting is performed in private by the election authority - who uses their secret information to decode the ballots - but is verified in public by an auditor.In this paper we describe how and why PunchScan works. We have kept most of the description at an outline level so that it may be used as a straw model of a cryptographic voting system.

  18. Optical scanning holography for stereoscopic display

    NASA Astrophysics Data System (ADS)

    Liu, Jung-Ping; Wen, Hsuan-Hsuan

    2016-10-01

    Optical Scanning Holography (OSH) is a scanning-type digital holographic recording technique. One of OSH's most important properties is that the OSH can record an incoherent hologram, which is free of speckle and thus is suitable for the applications of holographic display. The recording time of a scanning hologram is proportional to the sampling resolution. Hence the viewing angle as well as the resolution of a scanning hologram is limited for avoid too long recording. As a result, the viewing angle is not large enough for optical display. To solve this problem, we recorded two scanning holograms at different viewing angles. The two holograms are synthesized to a single stereoscopic hologram with two main viewing angles. In displaying, two views at the two main viewing angles are reconstructed. Because both views contain full-depth-resolved 3D scenes, the problem of accommodation conflict in conventional stereogram is avoided.

  19. Scanning tunneling microscope assembly, reactor, and system

    SciTech Connect

    Tao, Feng; Salmeron, Miquel; Somorjai, Gabor A

    2014-11-18

    An embodiment of a scanning tunneling microscope (STM) reactor includes a pressure vessel, an STM assembly, and three spring coupling objects. The pressure vessel includes a sealable port, an interior, and an exterior. An embodiment of an STM system includes a vacuum chamber, an STM reactor, and three springs. The three springs couple the STM reactor to the vacuum chamber and are operable to suspend the scanning tunneling microscope reactor within the interior of the vacuum chamber during operation of the STM reactor. An embodiment of an STM assembly includes a coarse displacement arrangement, a piezoelectric fine displacement scanning tube coupled to the coarse displacement arrangement, and a receiver. The piezoelectric fine displacement scanning tube is coupled to the coarse displacement arrangement. The receiver is coupled to the piezoelectric scanning tube and is operable to receive a tip holder, and the tip holder is operable to receive a tip.

  20. 47 CFR 15.121 - Scanning receivers and frequency converters used with scanning receivers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Scanning receivers and frequency converters used with scanning receivers. 15.121 Section 15.121 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Unintentional Radiators § 15.121 Scanning receivers and...

  1. 47 CFR 15.121 - Scanning receivers and frequency converters used with scanning receivers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Scanning receivers and frequency converters used with scanning receivers. 15.121 Section 15.121 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Unintentional Radiators § 15.121 Scanning receivers and...

  2. 47 CFR 15.121 - Scanning receivers and frequency converters used with scanning receivers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Scanning receivers and frequency converters used with scanning receivers. 15.121 Section 15.121 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Unintentional Radiators § 15.121 Scanning receivers and...

  3. 47 CFR 15.121 - Scanning receivers and frequency converters used with scanning receivers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Scanning receivers and frequency converters used with scanning receivers. 15.121 Section 15.121 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Unintentional Radiators § 15.121 Scanning receivers and...

  4. 47 CFR 15.121 - Scanning receivers and frequency converters used with scanning receivers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Scanning receivers and frequency converters used with scanning receivers. 15.121 Section 15.121 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL RADIO FREQUENCY DEVICES Unintentional Radiators § 15.121 Scanning receivers and...

  5. Performances of the scanning system for the CNAO center of oncological hadron therapy

    NASA Astrophysics Data System (ADS)

    Giordanengo, S.; Donetti, M.; Marchetto, F.; Ansarinejad, A.; Attili, A.; Bourhaleb, F.; Burini, F.; Cirio, R.; Fabbricatore, P.; Voelker, F.; Garella, M. A.; Incurvati, M.; Monaco, V.; Pardo, J.; Peroni, C.; Russo, G.; Sacchi, R.; Taddia, G.; Zampieri, A.

    2010-02-01

    In hadron therapy one of the most advanced methods for beam delivery is the active scanning technique which uses fast scanning magnets to drive a narrow particle beam across the target. The Centro Nazionale di Adroterapia Oncologica (CNAO) will treat tumours with this technique. The CNAO scanning system includes two identical dipole magnets for horizontal and vertical beam deflection, each one connected to a fast power supply. The dose delivery system exploits a set of monitor chambers to measure the fluence and position of the beam and drives the beam during the treatment by controlling the sequence of currents set by the power supplies. A test of the dynamic performance of the scanning system has been performed using a Hall probe to measure the field inside the magnet and the results are presented in this paper.

  6. Compact scanning lidar systems using holographic optics

    NASA Astrophysics Data System (ADS)

    Schwemmer, Geary K.; Wilkerson, Thomas D.; Guerra, David

    1998-08-01

    Two scanning lidar systems have been built using holographic optical elements (HOE) that function as a scanning telescope primary optic. One is a ground based lidar using a reflection HOE, and uses a frequency doubled Nd:YAG laser transmitter. The other system is an airborne/ground based system that uses a transmission HOE and operates at the 1064 nm fundamental of the Nd:YAG laser. Each HOE has a focal spot on the center- line, normal to the flat disk holding the hologram, and a field of view (FOV) that points approximately 45 degrees from the normal. Rotating the disk effects a conical scan of the FOV. In both systems, the same HOE is also used to collimate and steer the transmitted laser beam. The utility of using the HOEs to save weight and size in scanning lidars is evidenced by the atmospheric backscatter data collected with these systems. They also will lower the cost of commercial systems due to the low cost of replicating HOEs and the simplified mechanical scanning systems. Development of airborne scanning lidar altimeters and other lidars and passive instruments using holographic optics are underway, including the development of a one meter diameter, space qualified holographic scanning telescope for use in the ultraviolet.

  7. A dynamic scanning method based on signal-statistics for scanning electron microscopy.

    PubMed

    Timischl, F

    2014-01-01

    A novel dynamic scanning method for noise reduction in scanning electron microscopy and related applications is presented. The scanning method dynamically adjusts the scanning speed of the electron beam depending on the statistical behavior of the detector signal and gives SEM images with uniform and predefined standard deviation, independent of the signal value itself. In the case of partially saturated images, the proposed method decreases image acquisition time without sacrificing image quality. The effectiveness of the proposed method is shown and compared to the conventional scanning method and median filtering using numerical simulations.

  8. [Vein Scanning Projection Instrument Based on Two-Dimensional Scanning Mirror].

    PubMed

    Meng, Ya; Wu, Zhichao; Xu, Changping; Qian, Yinbo

    2015-09-01

    With the development of science and technology, new medical equipments is toward the direction of intelligent and portable. In order to assist medical personnel to patients with blood, developing from previous devices, a new kind of vein locating projection instrument based on two-dimensional scanning mirror is put forward. It can scan and project vein image using a scanning mirror. The related algorithm is also be improved, make vein scan projection more practical. The system finally set up can perform well in vein scan projection.

  9. Clinical applications of Genome Polymorphism Scans

    PubMed Central

    Weber, James L

    2006-01-01

    Applications of Genome Polymorphism Scans range from the relatively simple such as gender determination and confirmation of biological relationships, to the relatively complex such as determination of autozygosity and propagation of genetic information throughout pedigrees. Unlike nearly all other clinical DNA tests, the Scan is a universal test – it covers all people and all genes. In balance, I argue that the Genome Polymorphism Scan is the most powerful, affordable clinical DNA test available today. Reviewers: This article was reviewed by Scott Weiss (nominated by Neil Smalheiser), Roberta Pagon (nominated by Jerzy Jurka) and Val Sheffield (nominated by Neil Smalheiser). PMID:16756678

  10. Scanning-Pencil-Beam Radar Scatterometer

    NASA Technical Reports Server (NTRS)

    Long, David G.; Freilich, Michael H.; Leotta, Daniel F.; Noon, Don E.

    1992-01-01

    SCANSCAT conceptual scanning radar scatterometer placed in nearly polar orbit around Earth at altitude of 705 km aboard Spacecraft B of NASA's Earth Observing System. Measures radar backscattering from surface of ocean. Data processed on ground into normalized radar-backscattering cross sections, then processed into velocities of winds near surface of ocean by use of empirical mathematical model of relationship between normalized backscattering cross section, wind vector at scanned spot, and angle of incidence and azimuth angle of radar beam. Accuracy and coverage exceeds those of fan-beam scatterometer. Modified versions of scanning plan useful in laser inspection of surface finishes on machined parts.

  11. Scanning and georeferencing historical USGS quadrangles

    USGS Publications Warehouse

    Davis, Larry R.; Allord, G.J.

    2011-01-01

    The USGS Historical Quadrangle Scanning Project (HQSP) is scanning all scales and all editions of approximately 250,000 topographic maps published by the U.S. Geological Survey (USGS) since the inception of the topographic mapping program in 1884. This scanning will provide a comprehensive digital repository of USGS topographic maps, available to the public at no cost. This project serves the dual purpose of creating a master catalog and digital archive copies of the irreplaceable collection of topographic maps in the USGS Reston Map Library as well as making the maps available for viewing and downloading from the USGS Store and The National Map Viewer.

  12. HEAO-A nominal scanning observation schedule

    NASA Technical Reports Server (NTRS)

    Fishman, G. J.; Stone, R. L.

    1977-01-01

    The HEAO-A observatory, scheduled for launch in late June 1977, will spend most of its orbital lifetime in a scanning mode, spining from 0.03 to 0.1 rpm about an axis aligned with the sun. The dates of availability in the scan band are given for a list of 248 X-ray sources. Celestial maps of source locations and scan planes, and examples of the nighttime elevation of available sources are presented. This document is intended to aid ground-based observers in planning coordinated observations with HEAO-A.

  13. Gigahertz-band electronically scanned antennas

    NASA Astrophysics Data System (ADS)

    Bei, Nikolai A.

    2000-12-01

    Foundation and principles of radio lenses construction of centimeter and millimeter wave ranges with controlled refracting index, combining the quality of phased array antennas with optical devices are stated. Possibilities of the electronically scanning with wide-angle sector and high gain are maintained. Construction principles of scanning antennas with controlled lenses, combining the quality of phased array antennas with optical devices, are stated. Possibilities of electronically scanning with broad angle sector and high gain are maintained. Some examples of construction of antennas millimeter range of waves are listed here.

  14. A microprocessor controlled pressure scanning system

    NASA Technical Reports Server (NTRS)

    Anderson, R. C.

    1976-01-01

    A microprocessor-based controller and data logger for pressure scanning systems is described. The microcomputer positions and manages data from as many as four 48-port electro-mechanical pressure scanners. The maximum scanning rate is 80 pressure measurements per second (20 ports per second on each of four scanners). The system features on-line calibration, position-directed data storage, and once-per-scan display in engineering units of data from a selected port. The system is designed to be interfaced to a facility computer through a shared memory. System hardware and software are described. Factors affecting measurement error in this type of system are also discussed.

  15. Comparison of full-scan and half-scan for cone beam breast CT imaging

    NASA Astrophysics Data System (ADS)

    Chen, Lingyun; Shaw, Chris C.; Lai, Chao-jen; Altunbas, Mustafa C.; Wang, Tianpeng; Tu, Shu-ju; Liu, Xinming

    2006-03-01

    The half-scan cone beam technique, requiring a scan for 180° plus detector width only, can help achieve both shorter scan time as well as higher exposure in each individual projection image. This purpose of this paper is to investigate whether half-scan cone beam CT technique can provide acceptable images for clinical application. The half-scan cone beam reconstruction algorithm uses modified Parker's weighting function and reconstructs from slightly more than half of the projection views for full-scan, giving out promising results. A rotation phantom, stationary gantry bench top system was built to conduct experiments to evaluate half-scan cone beam breast CT technique. A post-mastectomy breast specimen, a stack of lunch meat slices embedded with various sizes of calcifications and a polycarbonate phantom inserted with glandular and adipose tissue equivalents are imaged and reconstructed for comparison study. A subset of full-scan projection images of a mastectomy specimen were extracted and used as the half-scan projection data for reconstruction. The results show half-scan reconstruction algorithm for cone beam breast CT images does not significantly degrade image quality when compared with the images of same or even half the radiation dose level. Our results are encouraging, emphasizing the potential advantages in the use of half-scan technique for cone beam breast imaging.

  16. Pointing and Scanning Control of Optical Instruments using Rotating Unbalanced Masses

    NASA Technical Reports Server (NTRS)

    Bishop, Carlee A.; Hung, John Y.; Polites, Michael E.; Alhorn, Dean C.

    1996-01-01

    Correct pointing direction and scanning motions are essential in the operation of many flight payloads, such as balloon-borne telescopes and space-based X- ray and gamma-ray telescopes. Rotating unbalanced mass (RUM) devices have been recently proposed, implemented and successfully tested to produce a variety of scanning motions. Linear scans, raster scans, and circular scans have been successfully generated on a gimbaled payload using pairs of RUM devices. Theoretical analysis, computer simulations, and experiments have also been used to study the feasibility of using RUM devices to control instrument pointing direction, in addition to generating scanning motion. Dynamic modeling of a gimbaled payload equipped with a pair of RUM devices has been studied, and preliminary testing indicates that the pointing control is indeed feasible. However, there is also great potential for significant performance improvements through more advanced control system analysis, modeling and design. In this paper, modeling and control methods are described to achieve simultaneous scanning and pointing control of a gimbaled payload using rotating unbalance mass (RUM) devices. The model development work builds upon the results of Polites et al. and also some modeling approaches from robotics research. Results of some preliminary experiments are discussed and some nonlinear control methods will be proposed.

  17. SCIENCE BRIEF: ADVANCED CONCEPTS

    EPA Science Inventory

    Research on advanced concepts will evaluate and demonstrate the application of innovative infrastructure designs, management procedures and operational approaches. Advanced concepts go beyond simple asset management. The infusion of these advanced concepts into established wastew...

  18. Intelligent Classification and Visualization of Network Scans

    SciTech Connect

    Chen, L; Muelder, C; Ma, K; Bartoletti, A

    2007-03-01

    Network scans are a common first step in a network intrusion attempt. In order to gain information about a potential network intrusion, it is beneficial to analyze these network scans. Statistical methods such as wavelet scalogram analysis have been used along with visualization techniques in previous methods. However, applying these statistical methods to reduce the data causes a substantial amount of data loss. This paper presents a study of using associative memory learning techniques to directly compare network scans in order to create a classification which can be used by itself or in conjunction with existing visualization techniques to better characterize the sources of these scans. This produces an integrated system of visual and intelligent analysis which is applicable to real world data.

  19. Indium-111 leukocyte scanning and fracture healing

    SciTech Connect

    Mead, L.P.; Scott, A.C.; Bondurant, F.J.; Browner, B.D. )

    1990-01-01

    This study was undertaken to determine the specificity of indium-111 leukocyte scans for osteomyelitis when fractures are present. Midshaft tibial osteotomies were performed in 14 New Zealand white rabbits, seven of which were infected postoperatively with Staphylococcus aureus per Norden's protocol. All 14 rabbits were scanned following injection with 75 microCi of indium 111 at 72 h after osteotomy and at weekly intervals for 4 weeks. Before the rabbits were killed, the fracture sites were cultured to document the presence or absence of infection. The results of all infected osteotomy sites were positive, whereas no positive scans were found in the noninfected osteotomies. We concluded from this study that uncomplicated fracture healing does not result in a positive indium-111 leukocyte scan.

  20. The design of laser scanning galvanometer system

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoling; Zhou, Bin; Xie, Weihao; Zhang, Yuangeng

    2015-02-01

    In this paper, we designed the laser scanning galvanometer system according to our requirements. Based on scanning range of our laser scanning galvanometer system, the design parameters of this system were optimized. During this work, we focused on the design of the f-θ field lens. An optical system of patent lens in the optical manual book, which had three glasses structure, was used in our designs. Combining the aberration theory, the aberration corrections and image quality evaluations were finished using Code V optical design software. An optimum f-θ field lens was designed, which had focal length of 434 mm, pupil diameter of 30 mm, scanning range of 160 mm × 160 mm, and half field angle of 18°×18°. At the last, we studied the influences of temperature changes on our system.

  1. Nanoscale thermometry by scanning thermal microscopy

    NASA Astrophysics Data System (ADS)

    Menges, Fabian; Riel, Heike; Stemmer, Andreas; Gotsmann, Bernd

    2016-07-01

    Measuring temperature is a central challenge in nanoscience and technology. Addressing this challenge, we report the development of a high-vacuum scanning thermal microscope and a method for non-equilibrium scanning probe thermometry. The microscope is built inside an electromagnetically shielded, temperature-stabilized laboratory and features nanoscopic spatial resolution at sub-nanoWatt heat flux sensitivity. The method is a dual signal-sensing technique inferring temperature by probing a total steady-state heat flux simultaneously to a temporally modulated heat flux signal between a self-heated scanning probe sensor and a sample. Contact-related artifacts, which so far limit the reliability of nanoscopic temperature measurements by scanning thermal microscopy, are minimized. We characterize the microscope's performance and demonstrate the benefits of the new thermometry approach by studying hot spots near lithographically defined constrictions in a self-heated metal interconnect.

  2. Getting a CAT Scan (For Kids)

    MedlinePlus

    ... axial tomography." Translated, that means a scanner takes computer pictures of what's going on inside your body. The scan itself is ... Policy Privacy Policy & Terms of Use Visit the Nemours Web ...

  3. Breadboard linear array scan imager program

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The performance was evaluated of large scale integration photodiode arrays in a linear array scan imaging system breadboard for application to multispectral remote sensing of the earth's resources. Objectives, approach, implementation, and test results of the program are presented.

  4. Infrared interferometer with a scanned aperture.

    PubMed

    Edwin, R P

    1975-08-01

    A Twyman-Green interferometer operating at a 3.39-microm wavelength has been built in which the collimator aperture was scanned by a laser beam. The scanning was produced by reflecting the laser beam from a mirror supported by four piezoelectric elements and oscillated about two orthogonal axes. The radiation transmitted by the interferometer was measured by a stationary detector of small area. The complete system offers a cheap and efficient alternative to conventional ir interferometers.

  5. Enhanced effects with scanning force microscopy

    NASA Astrophysics Data System (ADS)

    Howells, S.; Chen, T.; Gallagher, M.; Yi, L.; Sarid, D.

    1991-05-01

    A general theory that describes the operation of scanning force microscopy in the contact force regime is presented. It is shown that force derivatives along the surface of a sample produce images that can be dramatically enhanced relative to those of surface topography. For scanning tunneling microscopy atomic force microscopy configurations, the spring constant of the cantilever and the force derivatives perpendicular to the surface of the sample determine the enhancement, respectively.

  6. Scanning fluorescent microthermal imaging apparatus and method

    DOEpatents

    Barton, Daniel L.; Tangyunyong, Paiboon

    1998-01-01

    A scanning fluorescent microthermal imaging (FMI) apparatus and method is disclosed, useful for integrated circuit (IC) failure analysis, that uses a scanned and focused beam from a laser to excite a thin fluorescent film disposed over the surface of the IC. By collecting fluorescent radiation from the film, and performing point-by-point data collection with a single-point photodetector, a thermal map of the IC is formed to measure any localized heating associated with defects in the IC.

  7. Scanning fluorescent microthermal imaging apparatus and method

    DOEpatents

    Barton, D.L.; Tangyunyong, P.

    1998-01-06

    A scanning fluorescent microthermal imaging (FMI) apparatus and method is disclosed, useful for integrated circuit (IC) failure analysis, that uses a scanned and focused beam from a laser to excite a thin fluorescent film disposed over the surface of the IC. By collecting fluorescent radiation from the film, and performing point-by-point data collection with a single-point photodetector, a thermal map of the IC is formed to measure any localized heating associated with defects in the IC. 1 fig.

  8. Phased-Antenna-Array Conical Scanning

    NASA Technical Reports Server (NTRS)

    Lesh, J. R.

    1984-01-01

    Antenna pointing faster than mechanical scanning. Three antenna phased array connected to receiving signal-processing system through two phase-shifting networks. Two networks simultaneously steer phased array in two slightly-different beam directions; one for scanning, one for tracking. Technique has many uses in military and civilian radar, principally in tracking aircraft, balloonborne weather instruments, and other moving signal sources or reflectors.

  9. CT Scans - Multiple Languages: MedlinePlus

    MedlinePlus

    ... الأشعة المقطعية الحاسوبية - العربية Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) CT (Computerized Tomography) Scan CT ( ... 扫描 - 简体中文 (Chinese - Simplified) Bilingual PDF Health Information Translations Chinese - Traditional (繁體中文) CT (Computerized Tomography) Scan CT ( ...

  10. Study of the Electrical Impedance Scanning

    DTIC Science & Technology

    2007-11-02

    exhibit conductive changes that cause an impedance variation between cancerous ant health tissues. Since there are very few commercial devices...contribute somehow in the evaluation of the parameters involved. Keywords – Electrical Transimpedance Scanning, Breast cancer I. INTRODUCTION The...Electrical Transimpedance Scanning (ETS) is a new technique, non-invasive, non-irradiant, used in the diagnosis of breast cancer . Combined with other

  11. Holographic Optical Elements as Scanning Lidar Telescopes

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.

    2003-01-01

    We have investigated and developed the use of holographic optical elements (HOE) and holographic transmission gratings for scanning lidar telescopes. By rotating a flat HOE in its own plane with the focal spot on the rotation axis, a very simple and compact conical scanning telescope is possible. We developed and tested transmission and reflection HOES for use with the first three harmonics of Nd:YAG lasers, and designed, built, and tested two lidar systems based on this technology.

  12. Feature Adaptive Sampling for Scanning Electron Microscopy

    PubMed Central

    Dahmen, Tim; Engstler, Michael; Pauly, Christoph; Trampert, Patrick; de Jonge, Niels; Mücklich, Frank; Slusallek, Philipp

    2016-01-01

    A new method for the image acquisition in scanning electron microscopy (SEM) was introduced. The method used adaptively increased pixel-dwell times to improve the signal-to-noise ratio (SNR) in areas of high detail. In areas of low detail, the electron dose was reduced on a per pixel basis, and a-posteriori image processing techniques were applied to remove the resulting noise. The technique was realized by scanning the sample twice. The first, quick scan used small pixel-dwell times to generate a first, noisy image using a low electron dose. This image was analyzed automatically, and a software algorithm generated a sparse pattern of regions of the image that require additional sampling. A second scan generated a sparse image of only these regions, but using a highly increased electron dose. By applying a selective low-pass filter and combining both datasets, a single image was generated. The resulting image exhibited a factor of ≈3 better SNR than an image acquired with uniform sampling on a Cartesian grid and the same total acquisition time. This result implies that the required electron dose (or acquisition time) for the adaptive scanning method is a factor of ten lower than for uniform scanning. PMID:27150131

  13. SCAN: A Scalable Model of Attentional Selection.

    PubMed

    Hudson, Patrick T.W.; van den Herik, H Jaap; Postma, Eric O.

    1997-08-01

    This paper describes the SCAN (Signal Channelling Attentional Network) model, a scalable neural network model for attentional scanning. The building block of SCAN is a gating lattice, a sparsely-connected neural network defined as a special case of the Ising lattice from statistical mechanics. The process of spatial selection through covert attention is interpreted as a biological solution to the problem of translation-invariant pattern processing. In SCAN, a sequence of pattern translations combines active selection with translation-invariant processing. Selected patterns are channelled through a gating network, formed by a hierarchical fractal structure of gating lattices, and mapped onto an output window. We show how the incorporation of an expectation-generating classifier network (e.g. Carpenter and Grossberg's ART network) into SCAN allows attentional selection to be driven by expectation. Simulation studies show the SCAN model to be capable of attending and identifying object patterns that are part of a realistically sized natural image. Copyright 1997 Elsevier Science Ltd.

  14. Position-sensitive scanning fluorescence correlation spectroscopy.

    PubMed

    Skinner, Joseph P; Chen, Yan; Müller, Joachim D

    2005-08-01

    Fluorescence correlation spectroscopy (FCS) uses a stationary laser beam to illuminate a small sample volume and analyze the temporal behavior of the fluorescence fluctuations within the stationary observation volume. In contrast, scanning FCS (SFCS) collects the fluorescence signal from a moving observation volume by scanning the laser beam. The fluctuations now contain both temporal and spatial information about the sample. To access the spatial information we synchronize scanning and data acquisition. Synchronization allows us to evaluate correlations for every position along the scanned trajectory. We use a circular scan trajectory in this study. Because the scan radius is constant, the phase angle is sufficient to characterize the position of the beam. We introduce position-sensitive SFCS (PSFCS), where correlations are calculated as a function of lag time and phase. We present the theory of PSFCS and derive expressions for diffusion, diffusion in the presence of flow, and for immobilization. To test PSFCS we compare experimental data with theory. We determine the direction and speed of a flowing dye solution and the position of an immobilized particle. To demonstrate the feasibility of the technique for applications in living cells we present data of enhanced green fluorescent protein measured in the nucleus of COS cells.

  15. Precision controlled atomic resolution scanning transmission electron microscopy using spiral scan pathways

    PubMed Central

    Sang, Xiahan; Lupini, Andrew R.; Ding, Jilai; Kalinin, Sergei V.; Jesse, Stephen; Unocic, Raymond R.

    2017-01-01

    Atomic-resolution imaging in an aberration-corrected scanning transmission electron microscope (STEM) can enable direct correlation between atomic structure and materials functionality. The fast and precise control of the STEM probe is, however, challenging because the true beam location deviates from the assigned location depending on the properties of the deflectors. To reduce these deviations, i.e. image distortions, we use spiral scanning paths, allowing precise control of a sub-Å sized electron probe within an aberration-corrected STEM. Although spiral scanning avoids the sudden changes in the beam location (fly-back distortion) present in conventional raster scans, it is not distortion-free. “Archimedean” spirals, with a constant angular frequency within each scan, are used to determine the characteristic response at different frequencies. We then show that such characteristic functions can be used to correct image distortions present in more complicated constant linear velocity spirals, where the frequency varies within each scan. Through the combined application of constant linear velocity scanning and beam path corrections, spiral scan images are shown to exhibit less scan distortion than conventional raster scan images. The methodology presented here will be useful for in situ STEM imaging at higher temporal resolution and for imaging beam sensitive materials. PMID:28272404

  16. Precision controlled atomic resolution scanning transmission electron microscopy using spiral scan pathways.

    PubMed

    Sang, Xiahan; Lupini, Andrew R; Ding, Jilai; Kalinin, Sergei V; Jesse, Stephen; Unocic, Raymond R

    2017-03-08

    Atomic-resolution imaging in an aberration-corrected scanning transmission electron microscope (STEM) can enable direct correlation between atomic structure and materials functionality. The fast and precise control of the STEM probe is, however, challenging because the true beam location deviates from the assigned location depending on the properties of the deflectors. To reduce these deviations, i.e. image distortions, we use spiral scanning paths, allowing precise control of a sub-Å sized electron probe within an aberration-corrected STEM. Although spiral scanning avoids the sudden changes in the beam location (fly-back distortion) present in conventional raster scans, it is not distortion-free. "Archimedean" spirals, with a constant angular frequency within each scan, are used to determine the characteristic response at different frequencies. We then show that such characteristic functions can be used to correct image distortions present in more complicated constant linear velocity spirals, where the frequency varies within each scan. Through the combined application of constant linear velocity scanning and beam path corrections, spiral scan images are shown to exhibit less scan distortion than conventional raster scan images. The methodology presented here will be useful for in situ STEM imaging at higher temporal resolution and for imaging beam sensitive materials.

  17. Precision controlled atomic resolution scanning transmission electron microscopy using spiral scan pathways

    NASA Astrophysics Data System (ADS)

    Sang, Xiahan; Lupini, Andrew R.; Ding, Jilai; Kalinin, Sergei V.; Jesse, Stephen; Unocic, Raymond R.

    2017-03-01

    Atomic-resolution imaging in an aberration-corrected scanning transmission electron microscope (STEM) can enable direct correlation between atomic structure and materials functionality. The fast and precise control of the STEM probe is, however, challenging because the true beam location deviates from the assigned location depending on the properties of the deflectors. To reduce these deviations, i.e. image distortions, we use spiral scanning paths, allowing precise control of a sub-Å sized electron probe within an aberration-corrected STEM. Although spiral scanning avoids the sudden changes in the beam location (fly-back distortion) present in conventional raster scans, it is not distortion-free. “Archimedean” spirals, with a constant angular frequency within each scan, are used to determine the characteristic response at different frequencies. We then show that such characteristic functions can be used to correct image distortions present in more complicated constant linear velocity spirals, where the frequency varies within each scan. Through the combined application of constant linear velocity scanning and beam path corrections, spiral scan images are shown to exhibit less scan distortion than conventional raster scan images. The methodology presented here will be useful for in situ STEM imaging at higher temporal resolution and for imaging beam sensitive materials.

  18. Genome-wide scans for loci under selection in humans.

    PubMed

    Ronald, James; Akey, Joshua M

    2005-06-01

    Natural selection, which can be defined as the differential contribution of genetic variants to future generations, is the driving force of Darwinian evolution. Identifying regions of the human genome that have been targets of natural selection is an important step in clarifying human evolutionary history and understanding how genetic variation results in phenotypic diversity, it may also facilitate the search for complex disease genes. Technological advances in high-throughput DNA sequencing and single nucleotide polymorphism genotyping have enabled several genome-wide scans of natural selection to be undertaken. Here, some of the observations that are beginning to emerge from these studies will be reviewed, including evidence for geographically restricted selective pressures (ie local adaptation) and a relationship between genes subject to natural selection and human disease. In addition, the paper will highlight several important problems that need to be addressed in future genome-wide studies of natural selection.

  19. Whole-body 3D scanner and scan data report

    NASA Astrophysics Data System (ADS)

    Addleman, Stephen R.

    1997-03-01

    With the first whole-body 3D scanner now available the next adventure confronting the user is what to do with all of the data. While the system was built for anthropologists, it has created interest among users from a wide variety of fields. Users with applications in the fields of anthropology, costume design, garment design, entertainment, VR and gaming have a need for the data in formats unique to their fields. Data from the scanner is being converted to solid models for art and design and NURBS for computer graphics applications. Motion capture has made scan data move and dance. The scanner has created a need for advanced application software just as other scanners have in the past.

  20. Detector non-uniformity in scanning transmission electron microscopy.

    PubMed

    Findlay, S D; LeBeau, J M

    2013-01-01

    A non-uniform response across scanning transmission electron microscope annular detectors has been found experimentally, but is seldom incorporated into simulations. Through case study simulations, we establish the nature and scale of the discrepancies which may arise from failing to account for detector non-uniformity. If standard detectors are used at long camera lengths such that the detector is within or near to the bright field region, we find errors in contrast of the order of 10%, sufficiently small for qualitative work but non-trivial as experiments become more quantitative. In cases where the detector has been characterized in advance, we discuss the detector response normalization and how it may be incorporated in simulations.

  1. Power-efficient nonreciprocal interferometer and linear-scanning fiber-optic catheter for optical coherence tomography.

    PubMed

    Bouma, B E; Tearney, G J

    1999-04-15

    A nonreciprocal fiber-optic interferometer is demonstrated in an optical coherence tomography (OCT) system. The increased power efficiency of this system provides a 4.1-dB advantage over standard Michelson implementations. In addition, a new linear-scanning fiber-optic catheter is demonstrated that avoids the rotary optical junction that is required in circumferential scanning systems. These advancements have permitted the clinical implementation of OCT imaging in the human gastrointestinal tract.

  2. New radiolucent head fixation made of engineering plastics for intraoperative CT scanning.

    PubMed

    Okudera, H; Kobayashi, S; Kyoshima, K; Tokushige, K; Sugita, K

    1994-01-01

    A newly developed head fixation for intraoperative computerized tomographic (IOCT) scanning is presented. The system is developed based on the head holder of multipurpose head frame and is made of two kinds of advanced engineering material; carbon fiber reinforced plastic for head holder and frames, polyamide-imide polymer for joints, screws, and head pin. Clinical tests including autoclaving and sterilization were performed and revealed all materials had sufficient strength for clinical use. This fixation system enables us to increase the efficacy of IOCT scanning during open-field neurosurgery.

  3. Factors Affecting Cirrus-HD OCT Optic Disc Scan Quality: A Review with Case Examples

    PubMed Central

    Hardin, Joshua S.; Taibbi, Giovanni; Nelson, Seth C.; Chao, Diana; Vizzeri, Gianmarco

    2015-01-01

    Spectral-domain OCT is an established tool to assist clinicians in detecting glaucoma and monitor disease progression. The widespread use of this imaging modality is due, at least in part, to continuous hardware and software advancements. However, recent evidence indicates that OCT scan artifacts are frequently encountered in clinical practice. Poor image quality invariably challenges the interpretation of test results, with potential implications for the care of glaucoma patients. Therefore, adequate knowledge of various imaging artifacts is necessary. In this work, we describe several factors affecting Cirrus HD-OCT optic disc scan quality and their effects on measurement variability. PMID:26351574

  4. Factors Affecting Cirrus-HD OCT Optic Disc Scan Quality: A Review with Case Examples.

    PubMed

    Hardin, Joshua S; Taibbi, Giovanni; Nelson, Seth C; Chao, Diana; Vizzeri, Gianmarco

    2015-01-01

    Spectral-domain OCT is an established tool to assist clinicians in detecting glaucoma and monitor disease progression. The widespread use of this imaging modality is due, at least in part, to continuous hardware and software advancements. However, recent evidence indicates that OCT scan artifacts are frequently encountered in clinical practice. Poor image quality invariably challenges the interpretation of test results, with potential implications for the care of glaucoma patients. Therefore, adequate knowledge of various imaging artifacts is necessary. In this work, we describe several factors affecting Cirrus HD-OCT optic disc scan quality and their effects on measurement variability.

  5. Scan path entropy and arrow plots: capturing scanning behavior of multiple observers

    PubMed Central

    Hooge, Ignace; Camps, Guido

    2013-01-01

    Designers of visual communication material want their material to attract and retain attention. In marketing research, heat maps, dwell time, and time to AOI first hit are often used as evaluation parameters. Here we present two additional measures (1) “scan path entropy” to quantify gaze guidance and (2) the “arrow plot” to visualize the average scan path. Both are based on string representations of scan paths. The latter also incorporates transition matrices and time required for 50% of the observers to first hit AOIs (T50). The new measures were tested in an eye tracking study (48 observers, 39 advertisements). Scan path entropy is a sensible measure for gaze guidance and the new visualization method reveals aspects of the average scan path and gives a better indication in what order global scanning takes place. PMID:24399993

  6. Geodetic Laser Scanning: Refractive Optics Offer Wide Variety of Scan Patterns

    NASA Astrophysics Data System (ADS)

    Carter, W. E.; Shrestha, R. L.; Slatton, C. K.; Shrestha, K. Y.; Cossio, T.

    2005-12-01

    Most commercial geodetic laser mapping instruments use reflective element scanners, often a single nutating or oscillating mirror, and sometimes dual axis units, to create a specific pattern of laser spots on the surface being mapped. The user may be able to set the scanning speed (scan lines per second) and field of coverage (range of scan angles), but the basic pattern of points sampled is fixed. Engineers developing scanners for a surprisingly diverse set of applications, ranging from bar code scanning, to compensating for image motion in astronomical telescopes, to scanning spectrometers, have increasingly turned to refractive scanners-most particularly to scanners that utilize "Risley prisms." Samuel Doty Risley (1845-1920), an ophthalmologist, invented an optometer that contained a pair of thin prisms that rotated in opposite directions about their optical axes to change the convergence of light rays from a single source. He used his optometer measure the visual acuity of patients eyes, as a function of distance. In this original application, both prisms were driven by a common gear assembly, which resulted in a nearly linear scan line. But if the prisms are driven independently in both direction and angular speed, a wide variety of scan patterns can be generated. The University of Florida is developing, a photon counting geodetic laser scanning instrument that will use a Risley prism scanner. The scanner, being built by Sigma Space Inc., will be capable of producing nearly linear scan lines (saw tooth pattern from moving platform), circular scans lines (helical pattern from a moving platform) and any number of rosette scan patterns that are particularly interesting for fixed ground based work. The flexibility provided by the scanner offers the possibility of using the same sensor for airborne and ground based geodetic laser scanning. Examples of the scanner patterns and the initial results from laboratory and early field tests will be presented.

  7. Low Complexity Compression and Speed Enhancement for Optical Scanning Holography

    PubMed Central

    Tsang, P. W. M.; Poon, T.-C.; Liu, J.-P.; Kim, T.; Kim, Y. S.

    2016-01-01

    In this paper we report a low complexity compression method that is suitable for compact optical scanning holography (OSH) systems with different optical settings. Our proposed method can be divided into 2 major parts. First, an automatic decision maker is applied to select the rows of holographic pixels to be scanned. This process enhances the speed of acquiring a hologram, and also lowers the data rate. Second, each row of down-sampled pixels is converted into a one-bit representation with delta modulation (DM). Existing DM-based hologram compression techniques suffers from the disadvantage that a core parameter, commonly known as the step size, has to be determined in advance. However, the correct value of the step size for compressing each row of hologram is dependent on the dynamic range of the pixels, which could deviate significantly with the object scene, as well as OSH systems with different opical settings. We have overcome this problem by incorporating a dynamic step-size adjustment scheme. The proposed method is applied in the compression of holograms that are acquired with 2 different OSH systems, demonstrating a compression ratio of over two orders of magnitude, while preserving favorable fidelity on the reconstructed images. PMID:27708410

  8. Deep convolutional neural networks for classifying GPR B-scans

    NASA Astrophysics Data System (ADS)

    Besaw, Lance E.; Stimac, Philip J.

    2015-05-01

    Symmetric and asymmetric buried explosive hazards (BEHs) present real, persistent, deadly threats on the modern battlefield. Current approaches to mitigate these threats rely on highly trained operatives to reliably detect BEHs with reasonable false alarm rates using handheld Ground Penetrating Radar (GPR) and metal detectors. As computers become smaller, faster and more efficient, there exists greater potential for automated threat detection based on state-of-the-art machine learning approaches, reducing the burden on the field operatives. Recent advancements in machine learning, specifically deep learning artificial neural networks, have led to significantly improved performance in pattern recognition tasks, such as object classification in digital images. Deep convolutional neural networks (CNNs) are used in this work to extract meaningful signatures from 2-dimensional (2-D) GPR B-scans and classify threats. The CNNs skip the traditional "feature engineering" step often associated with machine learning, and instead learn the feature representations directly from the 2-D data. A multi-antennae, handheld GPR with centimeter-accurate positioning data was used to collect shallow subsurface data over prepared lanes containing a wide range of BEHs. Several heuristics were used to prevent over-training, including cross validation, network weight regularization, and "dropout." Our results show that CNNs can extract meaningful features and accurately classify complex signatures contained in GPR B-scans, complementing existing GPR feature extraction and classification techniques.

  9. Low Complexity Compression and Speed Enhancement for Optical Scanning Holography

    NASA Astrophysics Data System (ADS)

    Tsang, P. W. M.; Poon, T.-C.; Liu, J.-P.; Kim, T.; Kim, Y. S.

    2016-10-01

    In this paper we report a low complexity compression method that is suitable for compact optical scanning holography (OSH) systems with different optical settings. Our proposed method can be divided into 2 major parts. First, an automatic decision maker is applied to select the rows of holographic pixels to be scanned. This process enhances the speed of acquiring a hologram, and also lowers the data rate. Second, each row of down-sampled pixels is converted into a one-bit representation with delta modulation (DM). Existing DM-based hologram compression techniques suffers from the disadvantage that a core parameter, commonly known as the step size, has to be determined in advance. However, the correct value of the step size for compressing each row of hologram is dependent on the dynamic range of the pixels, which could deviate significantly with the object scene, as well as OSH systems with different opical settings. We have overcome this problem by incorporating a dynamic step-size adjustment scheme. The proposed method is applied in the compression of holograms that are acquired with 2 different OSH systems, demonstrating a compression ratio of over two orders of magnitude, while preserving favorable fidelity on the reconstructed images.

  10. Simulation and Characterization of a Miniaturized Scanning Electron Microscope

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica A.; Jerman, Gregory A.; Medley, Stephanie; Gregory, Don; Abbott, Terry O.; Sampson, Allen R.

    2011-01-01

    A miniaturized Scanning Electron Microscope (mSEM) for in-situ lunar investigations is being developed at NASA Marshall Space Flight Center with colleagues from the University of Alabama in Huntsville (UAH), Advanced Research Systems (ARS), the University of Tennessee in Knoxville (UTK) and Case Western Reserve University (CWRU). This effort focuses on the characterization of individual components of the mSEM and simulation of the complete system. SEMs can provide information on the size, shape, morphology and chemical composition of lunar regolith. Understanding these basic properties will allow us to better estimate the challenges associated with In-Situ Resource Utilization and to improve our basic science knowledge of the lunar surface (either precluding the need for sample return or allowing differentiation of unique samples to be returned to Earth.) The main components of the mSEM prototype includes: a cold field emission electron gun (CFEG), focusing lens, deflection/scanning system and backscatter electron detector. Of these, the electron gun development is of particular importance as it dictates much of the design of the remaining components. A CFEG was chosen for use with the lunar mSEM as its emission does not depend on heating of the tungsten emitter (lower power), it offers a long operation lifetime, is orders of magnitude brighter than tungsten hairpin guns, has a small source size and exhibits low beam energy spread.

  11. High resolution helium ion scanning microscopy of the rat kidney.

    PubMed

    Rice, William L; Van Hoek, Alfred N; Păunescu, Teodor G; Huynh, Chuong; Goetze, Bernhard; Singh, Bipin; Scipioni, Larry; Stern, Lewis A; Brown, Dennis

    2013-01-01

    Helium ion scanning microscopy is a novel imaging technology with the potential to provide sub-nanometer resolution images of uncoated biological tissues. So far, however, it has been used mainly in materials science applications. Here, we took advantage of helium ion microscopy to explore the epithelium of the rat kidney with unsurpassed image quality and detail. In addition, we evaluated different tissue preparation methods for their ability to preserve tissue architecture. We found that high contrast, high resolution imaging of the renal tubule surface is possible with a relatively simple processing procedure that consists of transcardial perfusion with aldehyde fixatives, vibratome tissue sectioning, tissue dehydration with graded methanol solutions and careful critical point drying. Coupled with the helium ion system, fine details such as membrane texture and membranous nanoprojections on the glomerular podocytes were visualized, and pores within the filtration slit diaphragm could be seen in much greater detail than in previous scanning EM studies. In the collecting duct, the extensive and striking apical microplicae of the intercalated cells were imaged without the shrunken or distorted appearance that is typical with conventional sample processing and scanning electron microscopy. Membrane depressions visible on principal cells suggest possible endo- or exocytotic events, and central cilia on these cells were imaged with remarkable preservation and clarity. We also demonstrate the use of colloidal gold probes for highlighting specific cell-surface proteins and find that 15 nm gold labels are practical and easily distinguishable, indicating that external labels of various sizes can be used to detect multiple targets in the same tissue. We conclude that this technology represents a technical breakthrough in imaging the topographical ultrastructure of animal tissues. Its use in future studies should allow the study of fine cellular details and provide

  12. Miniaturized Environmental Scanning Electron Microscope for In Situ Planetary Studies

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica; Abbott, Terry; Medley, Stephanie; Gregory, Don; Thaisen, Kevin; Taylor , Lawrence; Ramsey, Brian; Jerman, Gregory; Sampson, Allen; Harvey, Ralph

    2010-01-01

    The exploration of remote planetary surfaces calls for the advancement of low power, highly-miniaturized instrumentation. Instruments of this nature that are capable of multiple types of analyses will prove to be particularly useful as we prepare for human return to the moon, and as we continue to explore increasingly remote locations in our Solar System. To this end, our group has been developing a miniaturized Environmental-Scanning Electron Microscope (mESEM) capable of remote investigations of mineralogical samples through in-situ topographical and chemical analysis on a fine scale. The functioning of an SEM is well known: an electron beam is focused to nanometer-scale onto a given sample where resulting emissions such as backscattered and secondary electrons, X-rays, and visible light are registered. Raster scanning the primary electron beam across the sample then gives a fine-scale image of the surface topography (texture), crystalline structure and orientation, with accompanying elemental composition. The flexibility in the types of measurements the mESEM is capable of, makes it ideally suited for a variety of applications. The mESEM is appropriate for use on multiple planetary surfaces, and for a variety of mission goals (from science to non-destructive analysis to ISRU). We will identify potential applications and range of potential uses related to planetary exploration. Over the past few of years we have initiated fabrication and testing of a proof-of-concept assembly, consisting of a cold-field-emission electron gun and custom high-voltage power supply, electrostatic electron-beam focusing column, and scanning-imaging electronics plus backscatter detector. Current project status will be discussed. This effort is funded through the NASA Research Opportunities in Space and Earth Sciences - Planetary Instrument Definition and Development Program.

  13. Effects of scanning orientation on outlier formation in 3D laser scanning of reflective surfaces

    NASA Astrophysics Data System (ADS)

    Wang, Yutao; Feng, Hsi-Yung

    2016-06-01

    Inspecting objects with reflective surfaces using 3D laser scanning is a demanded but challenging part inspection task due to undesirable specular reflections, which produce extensive outliers in the scanned point cloud. These outliers need to be removed in order to alleviate subsequent data processing issues. Many existing automatic outlier removal methods do not detect outliers according to the outlier formation properties. As a result, these methods only offer limited capabilities in removing extensive and complex outliers from scanning objects with reflective surfaces. This paper reports an empirical study which experimentally investigates the outlier formation characteristics in relation to the scanning orientation of the laser probe. The objective is to characterize the scanning orientation effects on outlier formation in order to facilitate the development of an effective outlier detection and removal method. Such an experimental investigation was hardly done before. It has been found in this work that scanning orientation can directly affect outlier extensity and occurrence in 3D laser scanning. A general guidance on proper scan path planning can then be provided with an aim to reduce the occurrence of outliers. Further, the observed dependency of outlier formation on scanning orientation can be exploited to facilitate effective and automatic outlier detection and removal.

  14. Contact-Free Scanning and Imaging with the Scanning Ion Conductance Microscope

    PubMed Central

    2014-01-01

    Scanning ion conductance microscopy (SICM) offers the ability to obtain very high-resolution topographical images of living cells. One of the great advantages of SICM lies in its ability to perform contact-free scanning. However, it is not yet clear when the requirements for this scan mode are met. We have used finite element modeling (FEM) to examine the conditions for contact-free scanning. Our findings provide a framework for understanding the contact-free mode of SICM and also extend previous findings with regard to SICM resolution. Finally, we demonstrate the importance of our findings for accurate biological imaging. PMID:24521282

  15. Applying RANSAC Algorithm for Fitting Scanning Strips from Airborne Laser Scanning

    NASA Astrophysics Data System (ADS)

    Błaszczak-Bąk, Wioleta; Janicka, Joanna; Sobieraj-Żłobińska, Anna

    2016-12-01

    During the development of the data acquired by airborne laser scanning the important issue is the fitting and georeferencing of ALS point clouds by means of the tie surfaces and the reference planes. The process of scanning strips adjustment is based on mutual integration of point clouds (scanning strips) and their adaptation to the reference planes. In simultaneous adjustment all strips are combined into one geometrically coherent block, to which the coordinates are given. In the process of determining discrepancies between scanning strips it is important to determine the correct size of the shifts (offsets). Authors propose to do this by using RANSAC algorithm.

  16. The need for environmental horizon scanning.

    PubMed

    Sutherland, William J; Woodroof, Harry J

    2009-10-01

    Policymakers and practitioners in most fields, including conservation and the environment, often make decisions based on insufficient evidence. One reason for this is that issues appear unexpectedly, when with hindsight, many of them were foreseeable. A solution to the problem of being insufficiently prepared is routine horizon scanning, which we describe as the systematic search for potential threats and opportunities that are currently poorly recognized. Researchers can then decide which issues might be most worthwhile to study. Practitioners can also use horizon scanning to ensure timely policy development and research procurement. Here, we suggest that horizon scanning is an underused tool that should become a standard element of environmental and conservation practice. We make recommendations for its incorporation into research, policy and practice. We argue that, as an ecological and conservation community, we are failing to provide timely advice owing to a weakness in identifying forthcoming issues. We outline possible horizon-scanning methods, and also make recommendations as to how horizon scanning could have a more central role in environmental and conservation practice.

  17. Simple Cassegrain scanning system for infrared astronomy

    NASA Technical Reports Server (NTRS)

    Apt, J.; Goody, R.; Mertz, L.

    1980-01-01

    To meet the need for a reliable, fast imaging system capable of being taken rapidly on and off the telescope, a simple, inexpensive, and compact Cassegrain reimaging system for scanning IR images was constructed. Using commercially available components without requiring close mechanical tolerances, the design solves the problem of beam stability pointed out by Koornneef and van Overbeeke (1976). For the moving-iron galvanometer scanner, it is noted that at the imaging frequency of 0.5 Hz, hysteresis in image plane motion was found to be less than 0.2 arc sec for a 64-arc sec scan, and the deviation from linearity with a triangular wave input was found to be less than 0.3 arc sec. This system and a scanning secondary were used to image Venus at 11.5 microns, and compared with the scanning secondary, the reimaging system did not appear to contribute any additional noise, considerably improved mechanical reliability, and eliminated cross-scan motion

  18. Negative appendectomy rate: influence of CT scans.

    PubMed

    McGory, Marcia L; Zingmond, David S; Nanayakkara, Darshani; Maggard, Melinda A; Ko, Clifford Y

    2005-10-01

    Negative appendectomy rate varies significantly depending on patient age and sex. However, the impact of computed tomography (CT) scans on the diagnosis of appendicitis is unknown. The goal of this study was to examine the negative appendectomy rate using a statewide database and analyze the association of receipt of CT scan. Using the California Inpatient File, all patients undergoing appendectomy in 1999-2000 were identified (n = 75,452). Demographic and clinical data were analyzed, including procedure approach (open vs laparoscopic) and appendicitis type (negative, simple, abscess, peritonitis). Patients with CT scans performed were identified to compare the negative appendectomy rate. For the entire cohort, appendicitis type was 59 per cent simple, 10 per cent with abscess, 18.7 per cent with peritonitis, and 9.3 per cent negative. Males had a lower rate of negative appendicitis than females (6.0% vs 13.4%, P < 0.0001). The use of CT scans was associated with an overall lower negative appendectomy rate for females, especially in the < 5 years and > 45 years age categories. Use of CT scans in males does not appear to be efficacious, as the negative appendectomy rates were similar across all age categories. In conclusion, use of CT was associated with lower rate of negative appendectomy, depending on patient age and sex.

  19. CT Scan of NASA Booster Nozzle

    SciTech Connect

    Schneberk, D; Perry, R; Thompson, R

    2004-07-27

    We scanned a Booster Nozzle for NASA with our 9 meV LINAC, AmSi panel scanner. Three scans were performed using different filtering schemes and different positions of the nozzle. The results of the scan presented here are taken from the scan which provided the best contrast and lowest noise of the three. Our inspection data shows a number of indications of voids in the outer coating of rubber/carbon. The voids are mostly on the side of the nozzle, but a few small voids are present at the ends of the nozzle. We saw no large voids in the adhesive layer between the Aluminum and the inner layer of carbon. This 3D inspection data did show some variation in the size of the adhesive layer, but none of the indications were larger than 3 pixels in extent (21 mils). We have developed a variety of contour estimation and extraction techniques for inspecting small spaces between layers. These tools might work directly on un-sectioned nozzles since the circular contours will fit with our tools a little better. Consequently, it would be useful to scan a full nozzle to ensure there are no untoward degradations in data quality, and to see if our tools would work to extract the adhesive layer.

  20. Scanning and focusing mechanisms of METEOSAT radiometer

    NASA Technical Reports Server (NTRS)

    Jouan, J.

    1977-01-01

    The scanning and focusing mechanisms settled onboard the METEOSAT Radiometer are described. A large camera which will take line by line pictures of the earth from a geostationary satellite in the same manner as a TV picture using both the spin of the spacecraft and the tilt of a telescope is included. The scanning mechanism provides the + or - 9 degrees tilt angle of the telescope through 2,500 elementary steps of 1.256 0.0001 radian. As the radiometer image quality is closely dependent on the characteristics of the scanning law, the mechanism is required to fulfill functional performances specifications particularly severe in terms of linearity of the scan curve, accuracy of each step as well as repeatability of the short-term scanning. The focusing mechanism allows + or - 12 millimeters shift of the telescope focus by step increments of 0.140 mm. The focus adjustment is achieved by moving a dihedral reflector according to a pure straight-line motion. The main requirements of each mechanism are summarized and their design and performances are described in detail.

  1. About infrared scanning of photovoltaic solar plant

    NASA Astrophysics Data System (ADS)

    Kauppinen, T.; Panouillot, P.-E.; Siikanen, S.; Athanasakou, E.; Baltas, P.; Nikopoulous, B.

    2015-05-01

    The paper is discussing about infrared scanning of PV solar plants. It is important that the performance of each solar panel and cell is verified. One new possibility compared to traditional ground-based scanning (handheld camera) is the utilization of UAV (Unmanned Aerial Vehicle). In this paper results from a PV solar Plant in Western Greece are introduced. The nominal power of the solar plants were 0, 9 MW and 2 MW and they were scanned both by a ground-controlled drone and by handheld equipment. It is essential to know all the factors effecting to results and also the time of scanning is important. The results done from the drone and from ground-based scanning are compared; also results from various altitudes and time of day are discussed. The UAV (Unmanned Aerial Vehicle/RPAS (Remote Piloted Aircraft Systems) will give an excellent opportunity to monitor various targets which are impossible or difficult to access from the ground. Compared to fixed-wing and helicopter-based platforms it will give advantages but also this technology has limitations. One limitation is the weight of the equipment and the short operational range and short flight time. Also valid procedures must be created for different solutions in the future. The most important thing, as in all infrared thermography applications, is the proper interpretation of results.

  2. Scanning-time evaluation of Digimarc Barcode

    NASA Astrophysics Data System (ADS)

    Gerlach, Rebecca; Pinard, Dan; Weaver, Matt; Alattar, Adnan

    2015-03-01

    This paper presents a speed comparison between the use of Digimarc® Barcodes and the Universal Product Code (UPC) for customer checkout at point of sale (POS). The recently introduced Digimarc Barcode promises to increase the speed of scanning packaged goods at POS. When this increase is exploited by workforce optimization systems, the retail industry could potentially save billions of dollars. The Digimarc Barcode is based on Digimarc's watermarking technology, and it is imperceptible, very robust, and does not require any special ink, material, or printing processes. Using an image-based scanner, a checker can quickly scan consumer packaged goods (CPG) embedded with the Digimarc Barcode without the need to reorient the packages with respect to the scanner. Faster scanning of packages saves money and enhances customer satisfaction. It reduces the length of the queues at checkout, reduces the cost of cashier labor, and makes self-checkout more convenient. This paper quantifies the increase in POS scanning rates resulting from the use of the Digimarc Barcode versus the traditional UPC. It explains the testing methodology, describes the experimental setup, and analyzes the obtained results. It concludes that the Digimarc Barcode increases number of items per minute (IPM) scanned at least 50% over traditional UPC.

  3. Spatially-Varying Calibration of Along-Track Monopulse Synthetic Aperture Radar Imagery for Ground Moving Target Indication and Tracking

    DTIC Science & Technology

    2010-05-01

    nonlinear subaperture-based coherent processing of dual receiver channels of the Gotcha platform to detect the moving targets [4]. This approach...maximum speed of the ground moving targets. In the case of the Gotcha platform, a suitable subaperture size is about 1,204 PRIs. In our...for estimating the motion track and parameters of the detected moving targets. The results presented here were generated using Gotcha radar data

  4. A novel approach to surveying sturgeon using side-scan sonar and occupancy modeling

    USGS Publications Warehouse

    Flowers, H. Jared; Hightower, Joseph E.

    2013-01-01

    Technological advances represent opportunities to enhance and supplement traditional fisheries sampling approaches. One example with growing importance for fisheries research is hydroacoustic technologies such as side-scan sonar. Advantages of side-scan sonar over traditional techniques include the ability to sample large areas efficiently and the potential to survey fish without physical handling-important for species of conservation concern, such as endangered sturgeons. Our objectives were to design an efficient survey methodology for sampling Atlantic Sturgeon Acipenser oxyrinchus by using side-scan sonar and to developmethods for analyzing these data. In North Carolina and South Carolina, we surveyed six rivers thought to contain varying abundances of sturgeon by using a combination of side-scan sonar, telemetry, and video cameras (i.e., to sample jumping sturgeon). Lower reaches of each river near the saltwater-freshwater interface were surveyed on three occasions (generally successive days), and we used occupancy modeling to analyze these data.We were able to detect sturgeon in five of six rivers by using these methods. Side-scan sonar was effective in detecting sturgeon, with estimated gear-specific detection probabilities ranging from 0.2 to 0.5 and river-specific occupancy estimates (per 2-km river segment) ranging from 0.0 to 0.8. Future extensions of this occupancy modeling framework will involve the use of side-scan sonar data to assess sturgeon habitat and abundance in different river systems.

  5. A radiographic scanning technique for cores

    USGS Publications Warehouse

    Hill, G.W.; Dorsey, M.E.; Woods, J.C.; Miller, R.J.

    1979-01-01

    A radiographic scanning technique (RST) can produce single continuous radiographs of cores or core sections up to 1.5 m long and up to 30 cm wide. Changing a portable industrial X-ray unit from the normal still-shot mode to a scanning mode requires simple, inexpensive, easily constructed, and highly durable equipment. Additional components include a conveyor system, antiscatter cylinder-diaphragm, adjustable sample platform, developing tanks, and a contact printer. Complete cores, half cores, sample slabs or peels may be scanned. Converting the X-ray unit from one mode to another is easy and can be accomplished without the use of special tools. RST provides the investigator with a convenient, continuous, high quality radiograph, saves time and money, and decreases the number of times cores have to be handled. ?? 1979.

  6. Rotary-scanning optical resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Qi, Weizhi; Xi, Lei

    2016-10-01

    Optical resolution photoacoustic microscopy (ORPAM) is currently one of the fastest evolving photoacoustic imaging modalities. It has a comparable spatial resolution to pure optical microscopic techniques such as epifluorescence microscopy, confocal microscopy, and two-photon microscopy, but also owns a deeper penetration depth. In this paper, we report a rotary-scanning (RS)-ORPAM that utilizes a galvanometer scanner integrated with objective to achieve rotary laser scanning. A 15 MHz cylindrically focused ultrasonic transducer is mounted onto a motorized rotation stage to follow optical scanning traces synchronously. To minimize the loss of signal to noise ratio, the acoustic focus is precisely adjusted to reach confocal with optical focus. Black tapes and carbon fibers are firstly imaged to evaluate the performance of the system, and then in vivo imaging of vasculature networks inside the ears and brains of mice is demonstrated using this system.

  7. Quantification of pilot workload via instrument scan

    NASA Technical Reports Server (NTRS)

    Tole, J. R.; Stephens, A. T.; Harris, R. L., Sr.; Ephrath, A.

    1982-01-01

    The use of visual scanning behavior as an indicator of pilot workload is described. The relationship between level of performance on a constant piloting task under simulated IFR conditions, the skill of the pilot the level of mental workload induced by an additional verbal task imposed on the basic control task, and visual scanning behavior is investigated. An increase in fixation dwell times, especially on the primary instrument with increased mental loading is indicated. Skilled subjects 'stared' less under increased loading than did novice pilots. Sequences of instrument fixations were also examined. The percentage occurrence of the subject's most used sequences decreased with increased task difficulty for novice subjects but not for highly skilled subjects. Entropy rate (bits/sec) of the sequence of fixations was also used to quantify the scan pattern. It consistently decreased for most subjects as the four loading levels used increased.

  8. Dynamic CT scanning of spinal column trauma

    SciTech Connect

    Brown, B.M.; Brant-Zawadzki, M.; Cann, C.E.

    1982-12-01

    Dynamic sequential computed tomographic scanning with automatic table incrementation uses low milliampere-second technique to eliminate tube cooling delays between scanning slices and, thus, markedly shortens examination times. A total of 25 patients with spinal column trauma involving 28 levels were studied with dynamic scans and retrospectively reviewed. Dynamic studies were considerably faster than conventional spine examinations and yielded reliable diagnosis. Bone disruption and subluxation was accurately evaluated, and the use of intrathecal metrizamide in low doses allowed direct visualization of spinal cord or radicular compromise. Multiplanar image reformation was aided by the dynamic incrementation technique, since motion between slices (and the resulting misregistration artifact on image reformation) was minimized. A phantom was devised to test spatial resolution of computed tomography for objects 1-3 mm in size and disclosed minimal differences for dynamic and conventional computed tomographic techniques in resolving medium-to-high-contrast objects.

  9. A Student-Built Scanning Tunneling Microscope

    NASA Astrophysics Data System (ADS)

    Ekkens, Tom

    2015-12-01

    Many introductory and nanotechnology textbooks discuss the operation of various microscopes including atomic force (AFM), scanning tunneling (STM), and scanning electron microscopes (SEM). In a nanotechnology laboratory class, students frequently utilize microscopes to obtain data without a thought about the detailed operation of the tool itself. I wanted to give my students a deeper appreciation for the physics by having them build a simple scanning tunneling microscope. Initially, 15 hours of an upper-division laboratory class were devoted to building and operating the STM. As the build process was refined, the time commitment for this project has shrunk to nine hours. Using the method described in this paper, the project is now simple enough that it can be built and operated by students in the introductory class.

  10. Effects of beam irregularity on uniform scanning

    NASA Astrophysics Data System (ADS)

    Kim, Chang Hyeuk; Jang, Sea duk; Yang, Tae-Keun

    2016-09-01

    An active scanning beam delivery method has many advantages in particle beam applications. For the beam is to be successfully delivered to the target volume by using the active scanning technique, the dose uniformity must be considered and should be at least 2.5% in the case of therapy application. During beam irradiation, many beam parameters affect the 2-dimensional uniformity at the target layer. A basic assumption in the beam irradiation planning stage is that the shape of the beam is symmetric and follows a Gaussian distribution. In this study, a pure Gaussian-shaped beam distribution was distorted by adding parasitic Gaussian distribution. An appropriate uniform scanning condition was deduced by using a quantitative analysis based on the gamma value of the distorted beam and 2-dimensional uniformities.

  11. Holographic optical elements as scanning lidar telescopes

    NASA Astrophysics Data System (ADS)

    Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.

    2006-09-01

    We have developed and investigated the use of holographic optical elements (HOEs) and holographic transmission gratings for scanning lidar telescopes. Rotating a flat HOE in its own plane with the focal spot on the rotation axis makes a very simple and compact conical scanning telescope. We developed transmission and reflection HOEs for use at the first three harmonic wavelengths of Nd:YAG lasers. The diffraction efficiency, diffraction angle, focal length, focal spot size and optical losses were measured for several HOEs and holographic gratings, and found to be suitable for use as lidar receiver telescopes, and in many cases could also serve as the final collimating and beam steering optic for the laser transmitter. Two lidar systems based on this technology have been designed, built, and successfully tested in atmospheric science applications. This technology will enable future spaceborne lidar missions by significantly lowering the size, weight, power requirement and cost of a large aperture, narrow field of view scanning telescope.

  12. Conductivity map from scanning tunneling potentiometry

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Li, Xianqi; Chen, Yunmei; Durand, Corentin; Li, An-Ping; Zhang, X.-G.

    2016-08-01

    We present a novel method for extracting two-dimensional (2D) conductivity profiles from large electrochemical potential datasets acquired by scanning tunneling potentiometry of a 2D conductor. The method consists of a data preprocessing procedure to reduce/eliminate noise and a numerical conductivity reconstruction. The preprocessing procedure employs an inverse consistent image registration method to align the forward and backward scans of the same line for each image line followed by a total variation (TV) based image restoration method to obtain a (nearly) noise-free potential from the aligned scans. The preprocessed potential is then used for numerical conductivity reconstruction, based on a TV model solved by accelerated alternating direction method of multiplier. The method is demonstrated on a measurement of the grain boundary of a monolayer graphene, yielding a nearly 10:1 ratio for the grain boundary resistivity over bulk resistivity.

  13. Enter Words and Pictures the Easy Way--Scan Them.

    ERIC Educational Resources Information Center

    Olivas, Jerry

    1989-01-01

    Discusses image scanning and optical character recognition. Describes how computer scanners work. Summarizes scan quality, scanning speed requirements, and hardware requirements for scanners. Surveys the range of scanners currently available. (MVL)

  14. Scanning and storage of electrophoretic records

    DOEpatents

    McKean, Ronald A.; Stiegman, Jeff

    1990-01-01

    An electrophoretic record that includes at least one gel separation is mounted for motion laterally of the separation record. A light source is positioned to illuminate at least a portion of the record, and a linear array camera is positioned to have a field of view of the illuminated portion of the record and orthogonal to the direction of record motion. The elements of the linear array are scanned at increments of motion of the record across the field of view to develop a series of signals corresponding to intensity of light at each element at each scan increment.

  15. Scanning evanescent electro-magnetic microscope

    DOEpatents

    Xiang, Xiao-Dong; Gao, Chen

    2001-01-01

    A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

  16. Scanning evanescent electro-magnetic microscope

    DOEpatents

    Xiang, Xiao-Dong; Gao, Chen; Schultz, Peter G.; Wei, Tao

    2003-01-01

    A novel scanning microscope is described that uses near-field evanescent electromagnetic waves to probe sample properties. The novel microscope is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The inventive scanning evanescent wave electromagnetic microscope (SEMM) can map dielectric constant, tangent loss, conductivity, complex electrical impedance, and other electrical parameters of materials. The quantitative map corresponds to the imaged detail. The novel microscope can be used to measure electrical properties of both dielectric and electrically conducting materials.

  17. Lens based adaptive optics scanning laser ophthalmoscope.

    PubMed

    Felberer, Franz; Kroisamer, Julia-Sophie; Hitzenberger, Christoph K; Pircher, Michael

    2012-07-30

    We present an alternative approach for an adaptive optics scanning laser ophthalmoscope (AO-SLO). In contrast to other commonly used AO-SLO instruments, the imaging optics consist of lenses. Images of the fovea region of 5 healthy volunteers are recorded. The system is capable to resolve human foveal cones in 3 out of 5 healthy volunteers. Additionally, we investigated the capability of the system to support larger scanning angles (up to 5°) on the retina. Finally, in order to demonstrate the performance of the instrument images of rod photoreceptors are presented.

  18. The near-field scanning thermal microscope

    NASA Astrophysics Data System (ADS)

    Wischnath, Uli F.; Welker, Joachim; Munzel, Marco; Kittel, Achim

    2008-07-01

    We report on the design, characterization, and performance of a near-field scanning thermal microscope capable to detect thermal heat currents mediated by evanescent thermal electromagnetic fields close to the surface of a sample. The instrument operates in ultrahigh vacuum and retains its scanning tunneling microscope functionality, so that its miniature, micropipette-based thermocouple sensor can be positioned with high accuracy. Heat currents on the order of 10-7W are registered in z spectroscopy at distances from the sample ranging from 1 to about 30nm. In addition, the device provides detailed thermographic images of a sample's surface.

  19. The Scanning Optical Microscope: An Overview

    NASA Astrophysics Data System (ADS)

    Kino, G. S.; Corte, T. R.; Xiao, G. Q.

    1988-07-01

    In the last few years there has been a resurgence in research on optical microscopes. One reason stems from the invention of the acoustic microscope by Quate and Lemons,1 and the realization that some of the same principles could be applied to the optical microscope. The acoustic microscope has better transverse definition for the same wavelength than the standard optical microscope and at the same time has far better range definition. Consequently, Kompfner, who was involved with the work on the early acoustic microscope, decided to try out similar scanning microscope principles with optics, and started a group with Wilson and Sheppard to carry out such research at Oxford.2 Sometime earlier, Petran et a13 had invented the tandem scanning microscope which used many of the same principles. Now, in our laboratory at Stanford, these ideas on the tandem scanning microscope and the scanning optical microscope are converging. Another aspect of this work, which stems from the earlier experience with the acoustic microscope, involves measurement of both phase and amplitude of the optical beam. It is also possible to use scanned optical microscopy for other purposes. For instance, an optical beam can be used to excite electrons and holes in semiconductors, and the generated current can be measured. By scanning the optical beam over the semiconductor, an image can be obtained of the regions where there is strong or weak electron hole generation. This type of microscope is called OBIC (Optical Beam Induced Current). A second application involves fluorescent imaging of biological materials. Here we have the excellent range definition of a scanning optical microscope which eliminates unwanted glare from regions of the material where the beam is unfocused.3 A third application is focused on the heating effect of the light beam. With such a system, images can be obtained which are associated with changes in the thermal properties of a material, changes in recombination rates in

  20. Design Rules For Holographic Optical Scanning Elements

    NASA Astrophysics Data System (ADS)

    Herzig, H. P.; Dandliker, R.

    1987-10-01

    An analytical method for the design of holographic optical elements (HOE) for focussing laser scanners with minimum aberrations and optimum scan line definition is reported. It can be shown analytically, using second order (paraxial) approximation, that a circular motion of the HOE cannot generate a straight line in space without astigmatism of the focal spot. Accepting a slightly curved scan line, the astigmatism can be compensated. Experimental results for HOE with a wavelength shift between recording and reconstruction are demonstrated. The required aspherical wavefronts for the recording are realized with the help of computer generated holograms (CGH).

  1. Frequency scanning microstrip antenna (S-band)

    NASA Astrophysics Data System (ADS)

    Jayachandran, M.; Gupta, S. C.

    1983-10-01

    A frequency-scanning microstrip antenna using microstrip radiating resonators is described. The resonators are cascade-coupled. The experimental results in the S-band are in good agreement with the theory, showing that it is possible to scan the main lobe at an angle of + or - 30 deg by variation of frequency of + or - 125 MHz, where 3-dB beam width is less than 30 deg. Directivity of 12.8 dB and gain of 8.5 dB were observed.

  2. Tip-modulation scanned gate microscopy.

    PubMed

    Wilson, Neil R; Cobden, David H

    2008-08-01

    We introduce a technique that improves the sensitivity and resolution and eliminates the nonlocal background of scanned gate microscopy (SGM). In conventional SGM, a voltage bias is applied to the atomic force microscope tip and the sample conductance is measured as the tip is scanned. In the new technique, which we call tip-modulation SGM (tmSGM), the biased tip is oscillated and the induced oscillation of the sample conductance is measured. Applied to single-walled carbon nanotube network devices, tmSGM gives sharp, low-noise and background-free images.

  3. Trajectories of Multi-lined Spatial Scans

    NASA Astrophysics Data System (ADS)

    McCullough, P.

    2017-03-01

    We compare multi-lined (a.k.a. boustrophedonic) spatial scans with numerical simulations of the trajectories using a simple physical model for HST's motions. For scan rates less than or equal to 0.5 arc sec s-1, the simulated trajectories match the observed ones within 0.5 arc sec, i.e. sufficiently well for planning purposes. We provide IDL procedures for the simulator in the Appendix. We identify an overall unexplained drift, primarily in the UVIS detector X direction, throughout the one HST orbit during visit 1 of program 14878.

  4. High resolution obtained by photoelectric scanning techniques.

    NASA Technical Reports Server (NTRS)

    Hall, J. S.

    1972-01-01

    Several applications of linear scanning of different types of objects are described; examples include double stars, satellites, the Red Spot of Jupiter and a landing site on the moon. This technique allows one to achieve a gain of about an order of magnitude in resolution over conventional photoelectric techniques; it is also effective in providing sufficient data for removing background effects and for the application of deconvolution procedures. Brief consideration is given to two-dimensional scanning, either at the telescope or of electronographic images in the laboratory. It is suggested that some of the techniques described should be given serious consideration for space applications.

  5. A pressure scanning Fabry-Perot magnetometer.

    NASA Technical Reports Server (NTRS)

    Fay, T. D.; Wyller, A. A.

    1971-01-01

    Description of an oscillating magnetic analyzer (KDP crystal plus Glan-Thompson prism) coupled to an echelle-interferometer spectrograph, and of single-slit magnetometer which by pressure variations can be made to scan the entire profiles of the circularly and linearly polarized Zeeman components. Freon gas is used as the scanner gas with wavelength displacements of 0.02 A per 0.1 in. Hg pressure change at the NaD lines. The available scan range is 15 A in the visual spectral region.

  6. Ultrasonic and radiographic evaluation of advanced aerospace materials: Ceramic composites

    NASA Technical Reports Server (NTRS)

    Generazio, Edward R.

    1990-01-01

    Two conventional nondestructive evaluation techniques were used to evaluate advanced ceramic composite materials. It was shown that neither ultrasonic C-scan nor radiographic imaging can individually provide sufficient data for an accurate nondestructive evaluation. Both ultrasonic C-scan and conventional radiographic imaging are required for preliminary evaluation of these complex systems. The material variations that were identified by these two techniques are porosity, delaminations, bond quality between laminae, fiber alignment, fiber registration, fiber parallelism, and processing density flaws. The degree of bonding between fiber and matrix cannot be determined by either of these methods. An alternative ultrasonic technique, angular power spectrum scanning (APSS) is recommended for quantification of this interfacial bond.

  7. State-of-the-art in CT hardware and scan modes for cardiovascular CT

    PubMed Central

    Halliburton, Sandra; Arbab-Zadeh, Armin; Dey, Damini; Einstein, Andrew J.; Gentry, Ralph; George, Richard T.; Gerber, Thomas; Mahesh, Mahadevappa; Weigold, Wm. Guy

    2013-01-01

    Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and the coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography (SCCT) Basic and Emerging Sciences and Technology (BEST) Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging. PMID:22551595

  8. State-of-the-art in CT hardware and scan modes for cardiovascular CT.

    PubMed

    Halliburton, Sandra; Arbab-Zadeh, Armin; Dey, Damini; Einstein, Andrew J; Gentry, Ralph; George, Richard T; Gerber, Thomas; Mahesh, Mahadevappa; Weigold, Wm Guy

    2012-01-01

    Multidetector row computed tomography (CT) allows noninvasive anatomic and functional imaging of the heart, great vessels, and coronary arteries. In recent years, there have been several advances in CT hardware, which have expanded the clinical utility of CT for cardiovascular imaging; such advances are ongoing. This review article from the Society of Cardiovascular Computed Tomography Basic and Emerging Sciences and Technology Working Group summarizes the technical aspects of current state-of-the-art CT hardware and describes the scan modes this hardware supports for cardiovascular CT imaging.

  9. Radiographic Differentiation of Advanced Fibrocystic Lung Diseases.

    PubMed

    Akira, Masanori

    2017-03-01

    The concept of end-stage lung disease suggests a final common pathway for most diffuse parenchymal lung diseases. In accordance with this concept, end-stage disease is characterized radiographically and pathologically by the presence of extensive honeycombing. However, sequential computed tomographic (CT) scans obtained from patients with chronic diffuse lung disease evolve over time to show various advanced lung disease patterns other than honeycombing. In addition, several radiographically distinct honeycomb patterns, including microcystic, macrocystic, mixed, and combined emphysema and honeycombing, differentiate one advanced lung disease from another. For example, usual interstitial pneumonia (IP) usually shows mixed microcystic and macrocystic honeycombing. In contrast, CT images of long-standing fibrotic nonspecific IP typically show only small, scattered foci of honeycombing; instead, most enlarged airspaces observed in the advanced stage of this disease represent dilatation of bronchioles. In desquamative IP and pulmonary Langerhans cell histiocytosis, focal opacities typically evolve into emphysema-like lesions seen on CT imaging. In combined pulmonary fibrosis and emphysema and sarcoidosis, the cysts tend to be larger than those observed in usual IP. Sequential CT scans in other chronic, diffuse lung diseases also show various distinctive changes. This article highlights radiographic patterns of lung destruction that belie a single common pathway to end-stage lung disease. Recognition of distinct radiographic patterns of lung destruction can help differentiate diffuse parenchymal lung diseases, even in advanced stages of disease evolution.

  10. Scan posture definition and hip girth measurement: the impact on clothing design and body scanning.

    PubMed

    Gill, Simeon; Parker, Christopher J

    2016-11-15

    Ergonomic measurement is central to product design and development; especially for body worn products and clothing. However, there is a large variation in measurement definitions, complicated by new body scanning technology that captures measurements in a posture different to traditional manual methods. Investigations of hip measurement definitions in current clothing measurement practices supports analysis of the effect of scan posture and hip measurement definition on the circumferences of the hip. Here, the hip girth is a key clothing measurement that is not defined in current body scanning measurement standards. Sixty-four participants were scanned in the standard scan posture of a [TC](2) body scanner, and also in a natural posture similar to that of traditional manual measurement collection. Results indicate that scan posture affects hip girth circumferences, and that some current clothing measurement practices may not define the largest lower body circumference. Recommendations are made concerning how the hip is defined in measurement practice and within body scanning for clothing product development. Practitioner Summary: The hip girth is an important measurement in garment design, yet its measurement protocol is not currently defined. We demonstrate that body posture during body scanning affects hip circumferences, and that current clothing measurement practices may not define the largest lower body circumference. This paper also provides future measurement practice recommendations.

  11. The Scanning Theremin Microscope: A Model Scanning Probe Instrument for Hands-On Activities

    ERIC Educational Resources Information Center

    Quardokus, Rebecca C.; Wasio, Natalie A.; Kandel, S. Alex

    2014-01-01

    A model scanning probe microscope, designed using similar principles of operation to research instruments, is described. Proximity sensing is done using a capacitance probe, and a mechanical linkage is used to scan this probe across surfaces. The signal is transduced as an audio tone using a heterodyne detection circuit analogous to that used in…

  12. High-speed Lissajous-scan atomic force microscopy: Scan pattern planning and control design issues

    NASA Astrophysics Data System (ADS)

    Bazaei, A.; Yong, Yuen K.; Moheimani, S. O. Reza

    2012-06-01

    Tracking of triangular or sawtooth waveforms is a major difficulty for achieving high-speed operation in many scanning applications such as scanning probe microscopy. Such non-smooth waveforms contain high order harmonics of the scan frequency that can excite mechanical resonant modes of the positioning system, limiting the scan range and bandwidth. Hence, fast raster scanning often leads to image distortion. This paper proposes analysis and design methodologies for a nonlinear and smooth closed curve, known as Lissajous pattern, which allows much faster operations compared to the ordinary scan patterns. A simple closed-form measure is formulated for the image resolution of the Lissajous pattern. This enables us to systematically determine the scan parameters. Using internal model controllers (IMC), this non-raster scan method is implemented on a commercial atomic force microscope driven by a low resonance frequency positioning stage. To reduce the tracking errors due to actuator nonlinearities, higher order harmonic oscillators are included in the IMC controllers. This results in significant improvement compared to the traditional IMC method. It is shown that the proposed IMC controller achieves much better tracking performances compared to integral controllers when the noise rejection performances is a concern.

  13. Apparatus for controlling the scan width of a scanning laser beam

    DOEpatents

    Johnson, Gary W.

    1996-01-01

    Swept-wavelength lasers are often used in absorption spectroscopy applications. In experiments where high accuracy is required, it is desirable to continuously monitor and control the range of wavelengths scanned (the scan width). A system has been demonstrated whereby the scan width of a swept ring-dye laser, or semiconductor diode laser, can be measured and controlled in real-time with a resolution better than 0.1%. Scan linearity, or conformity to a nonlinear scan waveform, can be measured and controlled. The system of the invention consists of a Fabry-Perot interferometer, three CAMAC interface modules, and a microcomputer running a simple analysis and proportional-integral control algorithm. With additional modules, multiple lasers can be simultaneously controlled. The invention also includes an embodiment implemented on an ordinary PC with a multifunction plug-in board.

  14. Apparatus for controlling the scan width of a scanning laser beam

    DOEpatents

    Johnson, G.W.

    1996-10-22

    Swept-wavelength lasers are often used in absorption spectroscopy applications. In experiments where high accuracy is required, it is desirable to continuously monitor and control the range of wavelengths scanned (the scan width). A system has been demonstrated whereby the scan width of a swept ring-dye laser, or semiconductor diode laser, can be measured and controlled in real-time with a resolution better than 0.1%. Scan linearity, or conformity to a nonlinear scan waveform, can be measured and controlled. The system of the invention consists of a Fabry-Perot interferometer, three CAMAC interface modules, and a microcomputer running a simple analysis and proportional-integral control algorithm. With additional modules, multiple lasers can be simultaneously controlled. The invention also includes an embodiment implemented on an ordinary PC with a multifunction plug-in board. 8 figs.

  15. Scanning Transmission X-ray microscopy Imaging of Aerosol Particles

    NASA Astrophysics Data System (ADS)

    Gilles, M. K.; Kilcoyne, A.; Tyliszczak, T.; Shuh, D. K.; Fakra, S.; Robinson, M.; Chase, K.

    2003-12-01

    Scanning transmission x-ray microscopes (STXM) are used to image a diversity of carbon and metal containing items such as biofilms in soils, magnetic materials, polymers and meteorites. Studies on particles collected on SiO2 filters from biomass burns in Flagstaff, Arizona and individual aerosols collected in South Africa on TEM grids are underway at beamlines 5.3.2 and 11.0.2 at the Advanced Light Source of Lawrence Berkeley National Laboratory. Sub micron particles are imaged in the transmission mode over the energy range of 280 - 1900 eV. Spectromicroscopic studies on individual particles using near edge x-ray absorption fine structure (NEXAFS) probe multiple species within or on the same particle. In (STXM) an X-ray beam is focused with a zone plate onto a sample and the transmitted radiation is detected. Since the signal is obtained in the transmission mode, optically thin samples are required. Hence, atmospheric aerosols with submicron thickness and diameter are well suited for this method. Near edge spectra of various elements were scanned in step sizes from 0.1-0.5 eV around characteristic absorption edges, creating 2 dimensional images at each energy. While STXM images are taken with a lower spatial resolution (currently 40 nm) than microscopies such as scanning electron microscopy, transmission electron microscopy, and atomic force microscopy, detailed chemical information with spatial distributions, and oxidation states is obtained. A particular focus of this work is to obtain more detailed information on the type of carbons, multiply, or singly bonded and whether or not carbon is bonded to oxygen. The ultimate goal is discrimination between organic and black carbon within individual aerosol particles and determining if organic carbon, black carbon, and metal species are distributed homogeneously throughout aerosol particles. Initial scans of the samples from Flagstaff show spectral evidence of aromatic carbon, without distinct C=O signatures. NEXAFS

  16. Controlling air toxics through advanced coal preparation

    SciTech Connect

    Straszheim, W.E.; Buttermore, W.H.; Pollard, J.L.

    1995-11-01

    This project involves the assessment of advanced coal preparation methods for removing trace elements from coal to reduce the potential for air toxic emissions upon combustion. Scanning electron microscopy-based automated image analysis (SEM-AIA) and advanced washability analyses are being applied with state-of-the-art analytical procedures to predict the removal of elements of concern by advanced column flotation and to confirm the effectiveness of preparation on the quality of quantity of clean coal produced. Specific objectives are to maintain an acceptable recovery of combustible product, while improving the rejection of mineral-associated trace elements. Current work has focused on determining conditions for controlling column flotation system across its operating range and on selection and analysis of samples for determining trace element cleanability.

  17. Advanced magnetic resonance imaging of neurodegenerative diseases.

    PubMed

    Agosta, Federica; Galantucci, Sebastiano; Filippi, Massimo

    2017-01-01

    Magnetic resonance imaging (MRI) is playing an increasingly important role in the study of neurodegenerative diseases, delineating the structural and functional alterations determined by these conditions. Advanced MRI techniques are of special interest for their potential to characterize the signature of each neurodegenerative condition and aid both the diagnostic process and the monitoring of disease progression. This aspect will become crucial when disease-modifying (personalized) therapies will be established. MRI techniques are very diverse and go from the visual inspection of MRI scans to more complex approaches, such as manual and automatic volume measurements, diffusion tensor MRI, and functional MRI. All these techniques allow us to investigate the different features of neurodegeneration. In this review, we summarize the most recent advances concerning the use of MRI in some of the most important neurodegenerative conditions, putting an emphasis on the advanced techniques.

  18. A novel approach for fast scanning of nuclear emulsions with continuous motion of the microscope stage

    NASA Astrophysics Data System (ADS)

    Aleksandrov, A.; Tioukov, V.

    2013-08-01

    Nuclear emulsions have been used in particle physics experiments for many decades because of their unique spatial resolution. The use of nuclear emulsions as precise tracking detectors in large experiments has recently been made possible due to advances in the production of emulsion films and to the development of very fast automatic scanning devices. The present scanning speed of the European Scanning System (ESS), which has been developed within the OPERA Collaboration, is about 20 cm2/h. In addition to the scanning of OPERA films, the ESS is used for other applications with ever-growing demands for scanning speed, such as the muon radiography of volcanoes. In order to further increase the scanning speed of the ESS, we are testing a novel approach different from the standard stop-and-go motion of the microscope stage in the horizontal plane. Indeed we perform data acquisition with the stage moving at constant speed, using an objective lens with wide field of view. Unlike the implementation realized in Japan where the movement of objective lens and stage are synchronized to pile up images of the same view in a vertical stack, in this approach only the stage is moving horizontally. Thus images at different depths are not fully overlapped and special care is needed in the reconstruction. This approach can give a substantial increase in the scanning speed, especially for thin emulsion layers and wide field of view. In this paper we demonstrate that, after applying special corrections, the emulsion data quality can be as good as with the standard stop-and-go approach. This technique allows to double the scanning speed of the ESS, bringing it to 40 cm2/h without any hardware modification.

  19. Radar Scan Strategies for the Patrick Air Force Base Weather Surveillance Radar, Model-74C, Replacement

    NASA Technical Reports Server (NTRS)

    Short, David

    2008-01-01

    The 45th Weather Squadron (45 WS) is replacing the Weather Surveillance Radar, Model 74C (WSR-74C) at Patrick Air Force Base (PAFB), with a Doppler, dual polarization radar, the Radtec 43/250. A new scan strategy is needed for the Radtec 43/250, to provide high vertical resolution data over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) launch pads, while taking advantage of the new radar's advanced capabilities for detecting severe weather phenomena associated with convection within the 45 WS area of responsibility. The Applied Meteorology Unit (AMU) developed several scan strategies customized for the operational needs of the 45 WS. The AMU also developed a plan for evaluating the scan strategies in the period prior to operational acceptance, currently scheduled for November 2008.

  20. The LandScan Global Population Distribution Project: Current State of the Art and Prospective Innovation

    SciTech Connect

    Rose, Amy N; Bright, Eddie A

    2014-01-01

    Advances in remote sensing, dasymetric mapping techniques, and the ever-increasing availability of spatial datasets have enhanced global human population distribution databases. These datasets demonstrate an enormous improvement over the conventional use of choropleth maps to represent population distribution and are vital for analysis and planning purposes including humanitarian response, disease mapping, risk analysis, and evacuation modeling. Dasymetric mapping techniques have been employed to address spatial mismatch, but also to develop finer resolution population distributions in areas of the world where subnational census data are coarse or non-existent. One such implementation is the LandScan Global model which provides a 30 arc-second global population distribution based on ancillary datasets such as land cover, slope, proximity to roads, and settlement locations. This work will review the current state of the LandScan model, future innovations aimed at increasing spatial and demographic resolution, and situate LandScan within the landscape of other global population distribution datasets.

  1. (Gene sequencing by scanning molecular exciton microscopy)

    SciTech Connect

    Not Available

    1991-01-01

    This report details progress made in setting up a laboratory for optical microscopy of genes. The apparatus including a fluorescence microscope, a scanning optical microscope, various spectrometers, and supporting computers is described. Results in developing photon and exciton tips, and in preparing samples are presented. (GHH)

  2. Scanning and rotating micromirrors using thermal actuators

    NASA Astrophysics Data System (ADS)

    Butler, Jeffrey T.; Bright, Victor M.; Reid, J. Robert

    1997-07-01

    This paper reports on micromachined polysilicon scanning and rotating micromirrors and the development of a CMOS drive system. The micromirrors described in this research were developed at the Air Force Institute of Technology and fabricated using the DARPA-sponsored multi-user MEMS processes (MUMPs). The scanning micromirror is connected to the substrate using micro-hinges. This allows the mirror plate to rotate off the substrate surface and lock into a support mechanism. The angle between the scanning mirror and the substrate is modulated by driving the mirror with a thermal actuator array through a range of 20 degrees. For the rotating mirror, the mirror plate is attached to the substrate by three floating substrate hinges connected to a rotating base. Actuator arrays are also used to position the rotating mirror. A computer controlled electrical interface was developed which automates the positioning of both the scanning and rotating mirrors. The low operating voltages of the micromirror positioning mechanism makes the use of CMOS technology attractive; and the development of a digital interface allows for flexible operation of the devices. These designs are well suited for micro-optical applications such as optical scanners, corner cube reflectors, and optical couplers where electrical positioning of a mirror is desired.

  3. Scanning Gamma Ray Densitometer System for Detonations.

    DTIC Science & Technology

    in loaded detonators and delays. The 317 KEV gamma rays from an Ir192 source were collimated into a beam of 0.002 by 0.100 inch. A scanning system...minus 3%. With Ir192 , density measurements on NOL-130 were reproduced to plus or minus 5%, and on RDX to plus or minus 16%. Based on gamma ray

  4. Scanning electron microscopy study of Trichomonas gallinae.

    PubMed

    Tasca, Tiana; De Carli, Geraldo A

    2003-12-01

    A scanning electron microscopy (SEM) study of Trichomonas gallinae (Rivolta, 1878), provided more information about the morphology of this flagellated protozoan. SEM showed the morphological features of the trophozoites; the emergence of the anterior flagella, the structure of the undulating membrane, the position and shape of the pelta, axostyle and posterior flagellum. Of special interest were the pseudocyst forms.

  5. Vertically aligned nanostructure scanning probe microscope tips

    DOEpatents

    Guillorn, Michael A.; Ilic, Bojan; Melechko, Anatoli V.; Merkulov, Vladimir I.; Lowndes, Douglas H.; Simpson, Michael L.

    2006-12-19

    Methods and apparatus are described for cantilever structures that include a vertically aligned nanostructure, especially vertically aligned carbon nanofiber scanning probe microscope tips. An apparatus includes a cantilever structure including a substrate including a cantilever body, that optionally includes a doped layer, and a vertically aligned nanostructure coupled to the cantilever body.

  6. Chelsea Bank: SCANS and Workplace Knowledge.

    ERIC Educational Resources Information Center

    Mikulecky, Larry; And Others

    This study of student groups working with the Chelsea Bank computer simulation concentrates on the extent to which students are involved in activities related to the Secretary's Commission on Achieving Necessary Skills (SCANS) categories and to knowledge about work place practices. Studying students using the Chelsea Bank simulations offers the…

  7. Pulmonary nodule, solitary - CT scan (image)

    MedlinePlus

    ... a single lesion (pulmonary nodule) in the right lung. This nodule is seen as the light circle in the upper portion of the dark area on the left side of the picture. A normal lung would look completely black in a CT scan.

  8. 2006 Environmental Scan. ACAATO Archive Document

    ERIC Educational Resources Information Center

    Colleges Ontario, 2006

    2006-01-01

    The Association of Colleges of Applied Arts and Technology of Ontario (ACAATO) is pleased to present this report. The 2006 Environmental Scan provides an aggregate synopsis of the key trends which will impact on Ontario's Colleges of Applied Arts and Technology in the future and will assist colleges in their advocacy and strategic planning…

  9. 2005 Environmental Scan. ACAATO Archive Document

    ERIC Educational Resources Information Center

    Colleges Ontario, 2005

    2005-01-01

    The Association of Colleges of Applied Arts and Technology of Ontario (ACAATO) is pleased to present this report. The 2005 Environmental Scan provides an aggregate synopsis of the key trends which will impact on Ontario's Colleges of Applied Arts and Technology in the future and will assist colleges in their advocacy and strategic planning…

  10. Projections of scan patterns on human retina

    NASA Technical Reports Server (NTRS)

    Kelly, D. H.; Crane, H. D.

    1972-01-01

    Fundus camera tracks eye movements by using camera optics with the aid of an inverted system. Camera provides a flying-spot circular scanning light source in the normal film plane and a broadband photodetector in position normally occupied by light source.

  11. Radant - New method of electronic scanning

    NASA Astrophysics Data System (ADS)

    Chekroun, C.; Herrick, D.; Michel, Y. M.; Pauchard, R.; Vidal, P.

    1981-02-01

    The paper describes a novel electronic scanning process that differs from the conventional phased array process. Called Radant (from radome antennas), the process uses an electromagnetic lens such that the direction of the optical axis can be changed electronically. The principle of this process and a working model are described.

  12. Rapid 2-axis scanning lidar prototype

    NASA Astrophysics Data System (ADS)

    Hartsell, Daryl; LaRocque, Paul E.; Tripp, Jeffrey

    2016-10-01

    The rapid 2-axis scanning lidar prototype was developed to demonstrate high-precision single-pixel linear-mode lidar performance. The lidar system is a combined integration of components from various commercial products allowing for future customization and performance enhancements. The intent of the prototype scanner is to demonstrate current stateof- the-art high-speed linear scanning technologies. The system consists of two pieces: the sensor head and control unit. The senor head can be installed up to 4 m from the control box and houses the lidar scanning components and a small RGB camera. The control unit houses the power supplies and ranging electronics necessary for operating the electronics housed inside the sensor head. This paper will discuss the benefits of a 2-axis scanning linear-mode lidar system, such as range performance and a userselectable FOV. Other features include real-time processing of 3D image frames consisting of up to 200,000 points per frame.

  13. CT scan of the brain (image)

    MedlinePlus

    ... CAT scan (computed tomography) is a much more sensitive imaging technique than x-ray, allowing high definition not only of the bony structures, but of the soft tissues. Clear images of organs such as the brain, muscles, joint structures, veins ...

  14. Interval scanning photomicrography of microbial cell populations.

    NASA Technical Reports Server (NTRS)

    Casida, L. E., Jr.

    1972-01-01

    A single reproducible area of the preparation in a fixed focal plane is photographically scanned at intervals during incubation. The procedure can be used for evaluating the aerobic or anaerobic growth of many microbial cells simultaneously within a population. In addition, the microscope is not restricted to the viewing of any one microculture preparation, since the slide cultures are incubated separately from the microscope.

  15. Near Field Scanning Optical Microscopy (NSOM)

    PubMed Central

    Betzig, E.; Lewis, A.; Harootunian, A.; Isaacson, M.; Kratschmer, E.

    1986-01-01

    A new method for high-resolution imaging, near-field scanning optical microscopy (NSOM), has been developed. The concepts governing this method are discussed, and the technical challenges encountered in constructing a working NSOM instrument are described. Two distinct methods are presented for the fabrication of well-characterized, highly reproducible, subwavelength apertures. A sample one-dimensional scan is provided and compared to the scanning electron micrograph of a test pattern. From this comparison, a resolution of > 1,500 Å (i.e., ≃λ/3.6) is determined, which represents a significant step towards our eventual goal of 500 Å resolution. Fluorescence has been observed through apertures smaller than 600 Å and signal-to-noise calculations show that fluorescent imaging should be feasible. The application of such imaging is then discussed in reference to specific biological problems. The NSOM method employs nonionizing visible radiation and can be used in air or aqueous environments for nondestructive visualization of functioning biological systems with a resolution comparable to that of scanning electron microscopy. ImagesFIGURE 4FIGURE 7FIGURE 9FIGURE 10 PMID:19431633

  16. The Scanning Electron Microscope and the Archaeologist

    ERIC Educational Resources Information Center

    Ponting, Matthew

    2004-01-01

    Images from scanning electron microscopy are now quite common and they can be of great value in archaeology. Techniques such as secondary electron imaging, backscattered electron imaging and energy-dispersive x-ray analysis can reveal information such as the presence of weevils in grain in Roman Britain, the composition of Roman coins and the…

  17. Atypical Saccadic Scanning in Autistic Spectrum Disorder

    ERIC Educational Resources Information Center

    Benson, Valerie; Piper, Jenna; Fletcher-Watson, Sue

    2009-01-01

    Saccadic scanning was examined for typically developing (TD) adults and those with autistic spectrum disorder (ASD) during inspection of the "Repin" picture (Yarbus, A. (1967). "Eye movements and vision". New York: Plenum) under two different viewing instructions: (A) material instructions ("Estimate the material circumstances of the family"); and…

  18. Autofocus method for scanning remote sensing cameras.

    PubMed

    Lv, Hengyi; Han, Chengshan; Xue, Xucheng; Hu, Changhong; Yao, Cheng

    2015-07-10

    Autofocus methods are conventionally based on capturing the same scene from a series of positions of the focal plane. As a result, it has been difficult to apply this technique to scanning remote sensing cameras where the scenes change continuously. In order to realize autofocus in scanning remote sensing cameras, a novel autofocus method is investigated in this paper. Instead of introducing additional mechanisms or optics, the overlapped pixels of the adjacent CCD sensors on the focal plane are employed. Two images, corresponding to the same scene on the ground, can be captured at different times. Further, one step of focusing is done during the time interval, so that the two images can be obtained at different focal plane positions. Subsequently, the direction of the next step of focusing is calculated based on the two images. The analysis shows that the method investigated operates without restriction of the time consumption of the algorithm and realizes a total projection for general focus measures and algorithms from digital still cameras to scanning remote sensing cameras. The experiment results show that the proposed method is applicable to the entire focus measure family, and the error ratio is, on average, no more than 0.2% and drops to 0% by reliability improvement, which is lower than that of prevalent approaches (12%). The proposed method is demonstrated to be effective and has potential in other scanning imaging applications.

  19. Energy conservation, using remote thermal scanning

    NASA Technical Reports Server (NTRS)

    Bowman, R. L.; Jack, J. R.

    1978-01-01

    Airborne thermal infrared scans and thermal maps utilized in NASA's energy conservation program have proven to be efficient cost-effective method for identifying heat losses from building roofs and heating system distribution lines. Method employs commercially available equipment in highly developed way.

  20. Visual scanning behavior and pilot workload

    NASA Technical Reports Server (NTRS)

    Tole, J. R.; Stephens, A. T.; Vivaudou, M.; Ephrath, A. R.; Young, L. R.

    1983-01-01

    Sophisticated man machine interaction often requires the human operator to perform a stereotyped scan of various instruments in order to monitor and/or control a system. For situations in which this type of stereotyped behavior exists, such as certain phases of instrument flight, scan pattern was shown to be altered by the imposition of simultaneous verbal tasks. A study designed to examine the relationship between pilot visual scan of instruments and mental workload is described. It was found that a verbal loading task of varying difficulty causes pilots to stare at the primary instrument as the difficulty increases and to shed looks at instruments of less importance. The verbal loading task also affected the rank ordering of scanning sequences. By examining the behavior of pilots with widely varying skill levels, it was suggested that these effects occur most strongly at lower skill levels and are less apparent at high skill levels. A graphical interpretation of the hypothetical relationship between skill, workload, and performance is introduced and modelling results are presented to support this interpretation.

  1. Response function and optimum configuration of semiconductor backscattered-electron detectors for scanning electron microscopes

    SciTech Connect

    Rau, E. I.; Orlikovskiy, N. A.; Ivanova, E. S.

    2012-06-15

    A new highly efficient design for semiconductor detectors of intermediate-energy electrons (1-50 keV) for application in scanning electron microscopes is proposed. Calculations of the response function of advanced detectors and control experiments show that the efficiency of the developed devices increases on average twofold, which is a significant positive factor in the operation of modern electron microscopes in the mode of low currents and at low primary electron energies.

  2. Solid-state electrochemistry on the nanometer and atomic scales: the scanning probe microscopy approach

    DOE PAGES

    Strelcov, Evgheni; Yang, Sang Mo; Jesse, Stephen; ...

    2016-04-21

    Energy technologies of the 21st century require an understanding and precise control over ion transport and electrochemistry at all length scales – from single atoms to macroscopic devices. Our short review provides a summary of recent studies dedicated to methods of advanced scanning probe microscopy for probing electrochemical transformations in solids at the meso-, nano- and atomic scales. In this discussion we present the advantages and limitations of several techniques and a wealth of examples highlighting peculiarities of nanoscale electrochemistry.

  3. Multi-channel scanning SQUID microscopy

    NASA Astrophysics Data System (ADS)

    Lee, Su-Young

    I designed, fabricated, assembled, and tested an 8-channel high- Tc scanning SQUID system. I started by modifying an existing single-channel 77 K high-Tc scanning SQUID microscope into a multi-channel system with the goal of reducing the scanning time and improving the spatial resolution by increasing the signal-to-noise ratio S/N. I modified the window assembly, SQUID chip assembly, cold-finger, and vacuum connector. The main concerns for the multi-channel system design were to reduce interaction between channels, to optimize the use of the inside space of the dewar for more than 50 shielded wires, and to achieve good spatial resolution. In the completed system, I obtained the transfer function and the dynamic range (phimax ˜ 11phi0) for each SQUID. At 1kHz, the slew rate is about 3000 phi0/s. I also found that the white noise level varies from 5 muphi0/Hz1/2 to 20 muphi 0/Hz1/2 depending on the SQUID. A new data acquisition program was written that triggered on position and collects data from up to eight SQUIDS. To generate a single image from the multichannel system, I calibrated the tilt of the xy-stage and z-stage manually, rearranged the scanned data by cutting overlapping parts, and determined the applied field by multiplying by the mutual inductance matrix. I found that I could reduce scanning time and improve the image quality by doing so. In addition, I have analyzed and observed the effect of position noise on magnetic field images and used these results to find the position noise in my scanning SQUID microscope. My analysis reveals the relationship between spatial resolution and position noise and that my system was dominated by position noise under typical operating conditions. I found that the smaller the sensor-sample separation, the greater the effect of position noise is on the total effective magnetic field noise and on spatial resolution. By averaging several scans, I found that I could reduce position noise and that the spatial resolution can

  4. Scanning Ion Conductance Microscopy of Live Keratinocytes

    NASA Astrophysics Data System (ADS)

    Hegde, V.; Mason, A.; Saliev, T.; Smith, F. J. D.; McLean, W. H. I.; Campbell, P. A.

    2012-07-01

    Scanning ion conductance microscopy (SICM) is perhaps the least well known technique from the scanning probe microscopy (SPM) family of instruments. As with its more familiar counterpart, atomic force microscopy (AFM), the technique provides high-resolution topographic imaging, with the caveat that target structures must be immersed in a conducting solution so that a controllable ion current may be utilised as the basis for feedback. In operation, this non-contact characteristic of SICM makes it ideal for the study of delicate structures, such as live cells. Moreover, the intrinsic architecture of the instrument, incorporating as it does, a scanned micropipette, lends itself to combination approaches with complementary techniques such as patch-clamp electrophysiology: SICM therefore boasts the capability for both structural and functional imaging. For the present observations, an ICnano S system (Ionscope Ltd., Melbourn, UK) operating in 'hopping mode' was used, with the objective of assessing the instrument's utility for imaging live keratinocytes under physiological buffers. In scans employing cultured HaCaT cells (spontaneously immortalised, human keratinocytes), we compared the qualitative differences of live cells imaged with SICM and AFM, and also with their respective counterparts after chemical fixation in 4% paraformaldehyde. Characteristic surface microvilli were particularly prominent in live cell imaging by SICM. Moreover, time lapse SICM imaging on live cells revealed that changes in the pattern of microvilli could be tracked over time. By comparison, AFM imaging on live cells, even at very low contact forces (scanning speed, however, the intrinsic non-obtrusive nature of

  5. An implementation of dual energy CT scanning.

    PubMed

    Marshall, W; Hall, E; Doost-Hoseini, A; Alvarez, R; Macovski, A; Cassel, D

    1984-08-01

    We have described a prereconstruction method for dual energy (PREDECT) analysis of CT scans. In theory, this method can (a) eliminate beam hardening and produce an accuracy comparable with monoenergetic scans and (b) provide the effective atomic number and electron density of any voxel scanned. Our implementation proves these statements and eliminates some of the objectionable noise. We constructed a phantom with a cylindrical sleeve-like compartment containing known amounts of high atomic number material simulating a removable skull. Conventional scans, with and without this beam hardener, were done of a water bath containing tubes of high electron and high atomic number material. Dual energy scans were then done for PREDECT. To increase the effective separation of the low and high energy beams by using more appropriate tube filtration, we fabricated a beam filter changer containing erbium, tungsten, aluminum, and steel. We used erbium, tungsten, and steel at high energy and aluminum, steel, and erbium at low energy for data acquisition. The reconstructions were compared visually and numerically for noise levels with the original steel only filtration. We found a decrease in noise down to approximately one-half the prior level when erbium/aluminum or tungsten/aluminum replaced the steel/steel filter. Erbium and tungsten were equally effective. Steel/erbium and steel/aluminum also significantly reduced image noise. The noise in the photoelectric (P) and Compton (C) images is negatively correlated. At any pixel, if the noise is positive in the P image, it is most probably negative in the C. Using this fact, the noise was reduced by postreconstruction processing.

  6. Challenges of microtome-based serial block-face scanning electron microscopy in neuroscience.

    PubMed

    Wanner, A A; Kirschmann, M A; Genoud, C

    2015-08-01

    Serial block-face scanning electron microscopy (SBEM) is becoming increasingly popular for a wide range of applications in many disciplines from biology to material sciences. This review focuses on applications for circuit reconstruction in neuroscience, which is one of the major driving forces advancing SBEM. Neuronal circuit reconstruction poses exceptional challenges to volume EM in terms of resolution, field of view, acquisition time and sample preparation. Mapping the connections between neurons in the brain is crucial for understanding information flow and information processing in the brain. However, information on the connectivity between hundreds or even thousands of neurons densely packed in neuronal microcircuits is still largely missing. Volume EM techniques such as serial section TEM, automated tape-collecting ultramicrotome, focused ion-beam scanning electron microscopy and SBEM (microtome serial block-face scanning electron microscopy) are the techniques that provide sufficient resolution to resolve ultrastructural details such as synapses and provides sufficient field of view for dense reconstruction of neuronal circuits. While volume EM techniques are advancing, they are generating large data sets on the terabyte scale that require new image processing workflows and analysis tools. In this review, we present the recent advances in SBEM for circuit reconstruction in neuroscience and an overview of existing image processing and analysis pipelines.

  7. A two-axis water-immersible MEMS scanning mirror for scanning optical and acoustic microscopy

    NASA Astrophysics Data System (ADS)

    Xu, Song; Huang, Chih-Hsien; Zou, Jun

    2016-03-01

    Fast scanning is highly desired for both ultrasound and photoacoustic microscopic imaging. Limited by water environment required for acoustic propagation, traditional mircoelectromechanical system (MEMS) scanning mirrors could not be widely used. In this paper, a new water-immersible scanning mirror microsystem has been designed, fabricated and tested. Polymer hinges were employed to achieve reliable under water performance. Two pairs of high strength neodymium magnet disc and three compact RF choke inductor were used to actuate mirror module. Experimental results show that the fast axis can reach a mechanical scanning angle of +/-15° at the resonance frequency of 350 Hz in air, and +/-12.5° at the resonance frequency of 240 Hz in water, respectively. The slow axis can reach a mechanical scanning angle of +/-15° at the resonance frequency of 20 Hz in air, and +/-12.5° at the resonance frequency of 13 Hz in water, respectively. The two scanning axes have very different resonance frequencies, which are suitable for raster scanning.

  8. Martian CAT scan: Three-dimensional imaging of Planum Boreum with Shallow Radar data

    NASA Astrophysics Data System (ADS)

    Putzig, N. E.; Foss, F. J., II; Campbell, B. A.; Phillips, R. J.

    2012-12-01

    and promoted to signal in its source location. Such 3-D imaging techniques are well developed not only in the medical field but also in terrestrial subsurface radar and seismic studies, where they are commonly referred to as "migration." Available 3-D imaging software requires that the data first be binned into a 3-D grid and co-registered to a common datum. For SHARAD, the Martian ionosphere introduces a complication in that it significantly distorts and delays the radar signals on the sunlit side of the planet. To address phase distortion, we apply an autofocus technique (Campbell et al., 2011, IEEE Geosci. Remote Sens. Lett. 8, No. 5) that relies on an empirically derived phase correction of the SHARAD signal and optimization of an image-quality metric over 100-km segments of each affected radargram. This method also allows us to estimate the along-track variable delays introduced by the ionosphere. We remove any residual delays using a correlation technique applied to the data subsequent to the 3-D binning step. At that point, we proceed to migration of the data, yielding a geometrically corrected 3-D volume of SHARAD data.

  9. Correcting scan-to-scan response variability for a radiochromic film-based reference dosimetry system

    SciTech Connect

    Lewis, David; Devic, Slobodan

    2015-10-15

    Purpose: In radiochromic film dosimetry systems, measurements are usually obtained from film images acquired on a CCD-based flatbed scanner. The authors investigated factors affecting scan-to-scan response variability leading to increased dose measurement uncertainty. Methods: The authors used flatbed document scanners to repetitively scan EBT3 radiochromic films exposed to doses 0–1000 cGy, together with three neutral density filters and three blue optical filters. Scanning was performed under two conditions: scanner lid closed and scanner lid opened/closed between scans. The authors also placed a scanner in a cold room at 9 °C and later in a room at 22 °C and scanned EBT3 films to explore temperature effects. Finally, the authors investigated the effect of altering the distance between the film and the scanner’s light source. Results: Using a measurement protocol to isolate the contribution of the CCD and electronic circuitry of the scanners, the authors found that the standard deviation of response measurements for the EBT3 film model was about 0.17% for one scanner and 0.09% for the second. When the lid of the first scanner was opened and closed between scans, the average scan-to-scan difference of responses increased from 0.12% to 0.27%. Increasing the sample temperature during scanning changed the RGB response values by about −0.17, −0.14, and −0.05%/°C, respectively. Reducing the film-to-light source distance increased the RBG response values about 1.1, 1.3, and 1.4%/mm, respectively. The authors observed that films and film samples were often not flat with some areas up to 8 mm away from the scanner’s glass window. Conclusions: In the absence of measures to deal with the response irregularities, each factor the authors investigated could lead to dose uncertainty >2%. Those factors related to the film-to-light source distance could be particularly impactful since the authors observed many instances where the curl of film samples had the

  10. An optical scan-calibration system in scanning near-field optical microscopy

    NASA Astrophysics Data System (ADS)

    Wu, Yunliang; Zhang, Hao; Wang, Keyi

    2009-11-01

    Scanning Probe Microscopes(SPM) use piezoelectric actuators to generate the scans. But the nonlinearities inherent in the piezoelectric actuators limit the usefulness of the instruments in precision metrology. This paper describes a simple optical beam displacement sensor that is used to accurately measure the (x,y) position of a piezoelectric tube scanner used in Scanning Near-field Optical Microscope(SNOM). As the nonlinearities is too complex to make up a simple math model, this paper use the Artificial neural network to Calibrate the nonlinearities.

  11. Advanced planetary studies

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Results of planetary advanced studies and planning support are summarized. The scope of analyses includes cost estimation research, planetary mission performance, penetrator advanced studies, Mercury mission transport requirements, definition of super solar electric propulsion/solar sail mission discriminators, and advanced planning activities.

  12. Advances in forefoot trauma.

    PubMed

    Clements, J Randolph; Schopf, Robert

    2013-07-01

    Forefoot traumas, particularly involving the metatarsals, are commonly occurring injuries. There have been several advances in management of these injuries. These advances include updates in operative technique, internal fixation options, plating constructs, and external fixation. In addition, the advances of soft tissue management have improved outcomes. This article outlines these injuries and provides an update on techniques, principles, and understanding of managing forefoot trauma.

  13. Comparison of dimensional accuracy of digital dental models produced from scanned impressions and scanned stone casts

    NASA Astrophysics Data System (ADS)

    Subeihi, Haitham

    Introduction: Digital models of dental arches play a more and more important role in dentistry. A digital dental model can be generated by directly scanning intraoral structures, by scanning a conventional impression of oral structures or by scanning a stone cast poured from the conventional impression. An accurate digital scan model is a fundamental part for the fabrication of dental restorations. Aims: 1. To compare the dimensional accuracy of digital dental models produced by scanning of impressions versus scanning of stone casts. 2. To compare the dimensional accuracy of digital dental models produced by scanning of impressions made of three different materials (polyvinyl siloxane, polyether or vinyl polyether silicone). Methods and Materials: This laboratory study included taking addition silicone, polyether and vinyl polyether silicone impressions from an epoxy reference model that was created from an original typodont. Teeth number 28 and 30 on the typodont with a missing tooth number 29 were prepared for a metal-ceramic three-unit fixed dental prosthesis with tooth #29 being a pontic. After tooth preparation, an epoxy resin reference model was fabricated by duplicating the typodont quadrant that included the tooth preparations. From this reference model 12 polyvinyl siloxane impressions, 12 polyether impressions and 12 vinyl polyether silicone impressions were made. All 36 impressions were scanned before pouring them with dental stone. The 36 dental stone casts were, in turn, scanned to produce digital models. A reference digital model was made by scanning the reference model. Six groups of digital models were produced. Three groups were made by scanning of the impressions obtained with the three different materials, the other three groups involved the scanning of the dental casts that resulted from pouring the impressions made with the three different materials. Groups of digital models were compared using Root Mean

  14. Session: CSP Advanced Systems -- Advanced Overview (Presentation)

    SciTech Connect

    Mehos, M.

    2008-04-01

    The project description is: (1) it supports crosscutting activities, e.g. advanced optical materials, that aren't tied to a single CSP technology and (2) it supports the 'incubation' of new concepts in preliminary stages of investigation.

  15. Kinematic analysis of conically scanned environmental properties

    NASA Technical Reports Server (NTRS)

    Wilkerson, Thomas D. (Inventor); Sanders, Jason A. (Inventor); Andrus, Ionio Q. (Inventor)

    2003-01-01

    A method for determining the velocity of features such as wind. The method preferably includes producing sensor signals and projecting the sensor signals sequentially along lines lying on the surface of a cone. The sensor signals may be in the form of lidar, radar or sonar for example. As the sensor signals are transmitted, the signals contact objects and are backscattered. The backscattered sensor signals are received to determine the location of objects as they pass through the transmission path. The speed and direction the object is moving may be calculated using the backscattered data. The data may be plotted in a two dimensional array with a scan angle on one axis and a scan time on the other axis. The prominent curves that appear in the plot may be analyzed to determine the speed and direction the object is traveling.

  16. Development of Scanning Ultrafast Electron Microscope Capability.

    SciTech Connect

    Collins, Kimberlee Chiyoko; Talin, Albert Alec; Chandler, David W.; Michael, Joseph R.

    2016-11-01

    Modern semiconductor devices rely on the transport of minority charge carriers. Direct examination of minority carrier lifetimes in real devices with nanometer-scale features requires a measurement method with simultaneously high spatial and temporal resolutions. Achieving nanometer spatial resolutions at sub-nanosecond temporal resolution is possible with pump-probe methods that utilize electrons as probes. Recently, a stroboscopic scanning electron microscope was developed at Caltech, and used to study carrier transport across a Si p-n junction [ 1 , 2 , 3 ] . In this report, we detail our development of a prototype scanning ultrafast electron microscope system at Sandia National Laboratories based on the original Caltech design. This effort represents Sandia's first exploration into ultrafast electron microscopy.

  17. Scanning probe microscopy of biomedical interfaces

    NASA Astrophysics Data System (ADS)

    Vansteenkiste, S. O.; Davies, M. C.; Roberts, C. J.; Tendler, S. J. B.; Williams, P. M.

    1998-02-01

    The development of the scanning probe microscopes over the past decade has provided a number of exciting new surface analytical techniques making a significant progress in the characterisation of biomedical interfaces. In this review, several examples are presented to illustrate that SPM is a powerful and promising tool for surface investigations including biomolecules, cell membranes, polymers and even living cells. The ability of the SPM instrument to monitor adhesion phenomena and provide quantitative information about intermolecular interactions is also described. Moreover, the huge potential of the scanning probe microscopes to study dynamic processes at interfaces under nearly physiological conditions is highlighted. Novel applications in the field of biochemistry, microbiology, biomaterial engineering, drug delivery and even medicine are discussed.

  18. Performance evaluation of mail-scanning cameras

    NASA Astrophysics Data System (ADS)

    Rajashekar, Umesh; Vu, Tony Tuan; Hooning, John E.; Bovik, Alan Conrad

    2010-04-01

    Letter-scanning cameras (LSCs) form the front- end imaging systems for virtually all mail-scanning systems that are currently used to automatically sort mail products. As with any vision-dependent technology, the quality of the images generated by the camera is fundamental to the overall performance of the system. We present novel techniques for objective evaluation of LSCs using comparative imaging-a technique that involves measuring the fidelity of target images produced by a camera with reference to an image of the same target captured at very high quality. Such a framework provides a unique opportunity to directly quantify the camera's ability to capture real-world targets, such as handwritten and printed text. Noncomparative techniques were also used to measure properties such as the camera's modulation transfer function, dynamic range, and signal-to-noise ratio. To simulate real-world imaging conditions, application-specific test samples were designed using actual mail product materials.

  19. Optical advantages in retinal scanning displays

    NASA Astrophysics Data System (ADS)

    Urey, Hakan

    2000-06-01

    Virtual Retinal DisplayTM technology is a retinal scanning display (RSD) technology being developed at Microvision, Inc., for a variety of applications including microdisplays. An RSD scans a modulated light beam onto a viewer's retina to produce a perceived image. Red, green and blue light sources, such as lasers, laser diodes or LEDs combine with Microvision's proprietary miniaturized scanner designs to make the RSD very well suited for head-worn and helmet-mounted displays (HMD). This paper compares the features of RSD technology to other display technologies such as the cathode ray tubes or matrix-based displays for HMD and other wearable display applications, and notes important performance advantages due to the number of pixel- generating elements. Also discussed are some fundamental optical limitations for virtual displays used in the HMD applications.

  20. Scanning electron microscopy studies of bacterial cultures

    NASA Astrophysics Data System (ADS)

    Swinger, Tracy; Blust, Brittni; Calabrese, Joseph; Tzolov, Marian

    2012-02-01

    Scanning electron microscopy is a powerful tool to study the morphology of bacteria. We have used conventional scanning electron microscope to follow the modification of the bacterial morphology over the course of the bacterial growth cycle. The bacteria were fixed in vapors of Glutaraldehyde and ruthenium oxide applied in sequence. A gold film of about 5 nm was deposited on top of the samples to avoid charging and to enhance the contrast. We have selected two types of bacteria Alcaligenes faecalis and Kocuria rhizophila. Their development was carefully monitored and samples were taken for imaging in equal time intervals during their cultivation. These studies are supporting our efforts to develop an optical method for identification of the Gram-type of bacterial cultures.

  1. CS-Studio Scan System Parallelization

    SciTech Connect

    Kasemir, Kay; Pearson, Matthew R

    2015-01-01

    For several years, the Control System Studio (CS-Studio) Scan System has successfully automated the operation of beam lines at the Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) and Spallation Neutron Source (SNS). As it is applied to additional beam lines, we need to support simultaneous adjustments of temperatures or motor positions. While this can be implemented via virtual motors or similar logic inside the Experimental Physics and Industrial Control System (EPICS) Input/Output Controllers (IOCs), doing so requires a priori knowledge of experimenters requirements. By adding support for the parallel control of multiple process variables (PVs) to the Scan System, we can better support ad hoc automation of experiments that benefit from such simultaneous PV adjustments.

  2. Laser scanning system for object monitoring

    DOEpatents

    McIntyre, Timothy James [Knoxville, TN; Maxey, Lonnie Curtis [Powell, TN; Chiaro, Jr; John, Peter [Clinton, TN

    2008-04-22

    A laser scanner is located in a fixed position to have line-of-sight access to key features of monitored objects. The scanner rapidly scans pre-programmed points corresponding to the positions of retroreflecting targets affixed to the key features of the objects. The scanner is capable of making highly detailed scans of any portion of the field of view, permitting the exact location and identity of targets to be confirmed. The security of an object is verified by determining that the cooperative target is still present and that its position has not changed. The retroreflecting targets also modulate the reflected light for purposes of returning additional information back to the location of the scanner.

  3. A spatial scan statistic for multinomial data.

    PubMed

    Jung, Inkyung; Kulldorff, Martin; Richard, Otukei John

    2010-08-15

    As a geographical cluster detection analysis tool, the spatial scan statistic has been developed for different types of data such as Bernoulli, Poisson, ordinal, exponential and normal. Another interesting data type is multinomial. For example, one may want to find clusters where the disease-type distribution is statistically significantly different from the rest of the study region when there are different types of disease. In this paper, we propose a spatial scan statistic for such data, which is useful for geographical cluster detection analysis for categorical data without any intrinsic order information. The proposed method is applied to meningitis data consisting of five different disease categories to identify areas with distinct disease-type patterns in two counties in the U.K. The performance of the method is evaluated through a simulation study.

  4. Macroscopic model of scanning force microscope

    DOEpatents

    Guerra-Vela, Claudio; Zypman, Fredy R.

    2004-10-05

    A macroscopic version of the Scanning Force Microscope is described. It consists of a cantilever under the influence of external forces, which mimic the tip-sample interactions. The use of this piece of equipment is threefold. First, it serves as direct way to understand the parts and functions of the Scanning Force Microscope, and thus it is effectively used as an instructional tool. Second, due to its large size, it allows for simple measurements of applied forces and parameters that define the state of motion of the system. This information, in turn, serves to compare the interaction forces with the reconstructed ones, which cannot be done directly with the standard microscopic set up. Third, it provides a kinematics method to non-destructively measure elastic constants of materials, such as Young's and shear modules, with special application for brittle materials.

  5. Preliminary design study. Shuttle modular scanning spectroradiometer

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Fundamental concepts on which to base a detailed design for a Shuttle Modular Scanning Spectroradiometer were developed, and a preliminary design is presented. The recommended design features modularity and flexibility. It includes a 75-cm f/1.7-telescope assembly in an all-reflective Schmidt configuration, a solid state scan system (pushbroom) with high resolution over a 15 deg field of view, and ten detector channels covering the spectral range from 0.45 to 12.5 micrometers. It uses charge transfer device techniques to accommodate a large number of detector elements for earth observation measurements. Methods for in-flight radiometric calibration, for image motion compensation, and for data processing are described. Recommendations for ground support equipment are included, and interfaces with the shuttle orbiter vehicle are illustrated.

  6. Renal scans in pregnant transplant patients

    SciTech Connect

    Goldstein, H.A.; Ziessman, H.A.; Fahey, F.H.; Collea, J.V.; Alijani, M.R.; Helfrich, G.B.

    1988-08-01

    This study demonstrates the normal technetium-99m diethylenetriaminepentaacetic acid ((/sup 99m/Tc)DTPA) renal scan in pregnant patients with transplanted kidneys. Five pregnant renal transplant patients had seven (/sup 99m/Tc)DTPA renal studies to assess allograft perfusion and function. All scans showed the uteroplacental complex. The bladder was always compressed and distorted. The transplanted kidney was frequently rotated to a more vertical position. In all patients allograft flow and function were maintained. There was calyceal retention on all studies and ureteral retention activity in three of five patients. Using the MIRD formalism, the total radiation absorbed dose to the fetus was calculated to be 271 mrad. This radiation exposure is well within NRCP limits for the fetus of radiation workers and an acceptable low risk in the management of these high risk obstetric patients.

  7. Environmental scanning electron microscopy in cell biology.

    PubMed

    McGregor, J E; Staniewicz, L T L; Guthrie Neé Kirk, S E; Donald, A M

    2013-01-01

    Environmental scanning electron microscopy (ESEM) (1) is an imaging technique which allows hydrated, insulating samples to be imaged under an electron beam. The resolution afforded by this technique is higher than conventional optical microscopy but lower than conventional scanning electron microscopy (CSEM). The major advantage of the technique is the minimal sample preparation needed, making ESEM quick to use and the images less susceptible to the artifacts that the extensive sample preparation usually required for CSEM may introduce. Careful manipulation of both the humidity in the microscope chamber and the beam energy are nevertheless essential to prevent dehydration and beam damage artifacts. In some circumstances it is possible to image live cells in the ESEM (2).In the following sections we introduce the fundamental principles of ESEM imaging before presenting imaging protocols for plant epidermis, mammalian cells, and bacteria. In the first two cases samples are imaged using the secondary electron (topographic) signal, whereas a transmission technique is employed to image bacteria.

  8. Command profile for Galileo scan platform control

    NASA Astrophysics Data System (ADS)

    Man, G. K.; Breckenridge, W. G.

    1981-08-01

    A recursive command profile is developed for the control of a two-degree-of-freedom scan platform mounted on a flexible structure. Perfect sensors and actuators are assumed for development and testing, and structural vibrations are minimized by actuator torque commands following a smooth torque-time profile. The integral of the smooth torque profile, the rate profile, is recursively generated by a piecewise constant second derivation, and the torque applied by the closk actuator is divided into three components. Results show that the smooth platform motion in response to the command profiles is what the Galileo control systems needs to avoid stator structural vibrations. Position, rate and acceleration profiles are also presented, and the resulting motion of the scan platform in response to command profiles is illustrated.

  9. Damage detection using scanning laser vibrometer

    NASA Astrophysics Data System (ADS)

    Chen, Shen-En; Venkatappa, Suhas; Petro, Samer H.; Gangarao, Hota V.

    1998-06-01

    A damage detection algorithm based on the principle of curvature changes has been developed at CFC-WVU. However, the algorithm requires accurate mode shapes with adequate spatial density. Existing contact sensors can not provide adequate spatial density without adding excessive mass. Hence, non-contact scanning techniques, such as scanning laser vibrometer (SLV) has adequate sensitivity and accuracy is yet to be proven. The applicability of SLV on large structures is also questionable. To assess the suitability of using SLV for damage detection, a beam specimen has been tested using an existing system. The results confirm that damage detection using vibration measurements from SLV is successful. Due to more spatial density, the SLV data is shown to be more sensitive than the contact sensor test.

  10. High-speed massively parallel scanning

    DOEpatents

    Decker, Derek E.

    2010-07-06

    A new technique for recording a series of images of a high-speed event (such as, but not limited to: ballistics, explosives, laser induced changes in materials, etc.) is presented. Such technique(s) makes use of a lenslet array to take image picture elements (pixels) and concentrate light from each pixel into a spot that is much smaller than the pixel. This array of spots illuminates a detector region (e.g., film, as one embodiment) which is scanned transverse to the light, creating tracks of exposed regions. Each track is a time history of the light intensity for a single pixel. By appropriately configuring the array of concentrated spots with respect to the scanning direction of the detection material, different tracks fit between pixels and sufficient lengths are possible which can be of interest in several high-speed imaging applications.

  11. Scanning thermal plumes. [from power plant condensers

    NASA Technical Reports Server (NTRS)

    Scarpace, F. L.; Madding, R. P.; Green, T., III

    1974-01-01

    In order to study the behavior and effects of thermal plumes associated with the condenser cooling of power plants, thermal line scans are periodically made from aircraft over all power plants along the Wisconsin shore of Lake Michigan. Simultaneous ground truth is also gathered with a radiometer. Some sequential imagery has been obtained for periods up to two hours to study short term variations in the surface temperature of the plume. The article concentrates on the techniques used to analyze thermal scanner data for a single power plant which was studied intensively. The calibration methods, temperature dependence of the thermal scanner, and calculation of the modulation transfer function for the scanner are treated. It is concluded that obtaining quantitative surface-temperature data from thermal scanning is a nontrivial task. Accuracies up to plus or minus 0.1 C are attainable.

  12. Two-dimensional thermography image retrieval from zig-zag scanned data with TZ-SCAN

    NASA Astrophysics Data System (ADS)

    Okumura, Hiroshi; Yamasaki, Ryohei; Arai, Kohei

    2008-10-01

    TZ-SCAN is a simple and low cost thermal imaging device which consists of a single point radiation thermometer on a tripod with a pan-tilt rotator, a DC motor controller board with a USB interface, and a laptop computer for rotator control, data acquisition, and data processing. TZ-SCAN acquires a series of zig-zag scanned data and stores the data as CSV file. A 2-D thermal distribution image can be retrieved by using the second quefrency peak calculated from TZ-SCAN data. An experiment is conducted to confirm the validity of the thermal retrieval algorithm. The experimental result shows efficient accuracy for 2-D thermal distribution image retrieval.

  13. The scanning model for translation: an update

    PubMed Central

    1989-01-01

    The small (40S) subunit of eukaryotic ribosomes is believed to bind initially at the capped 5'-end of messenger RNA and then migrate, stopping at the first AUG codon in a favorable context for initiating translation. The first-AUG rule is not absolute, but there are rules for breaking the rule. Some anomalous observations that seemed to contradict the scanning mechanism now appear to be artifacts. A few genuine anomalies remain unexplained. PMID:2645293

  14. High-speed scanning: an improved algorithm

    NASA Astrophysics Data System (ADS)

    Nachimuthu, A.; Hoang, Khoi

    1995-10-01

    In using machine vision for assessing an object's surface quality, many images are required to be processed in order to separate the good areas from the defective ones. Examples can be found in the leather hide grading process; in the inspection of garments/canvas on the production line; in the nesting of irregular shapes into a given surface... . The most common method of subtracting the total area from the sum of defective areas does not give an acceptable indication of how much of the `good' area can be used, particularly if the findings are to be used for the nesting of irregular shapes. This paper presents an image scanning technique which enables the estimation of useable areas within an inspected surface in terms of the user's definition, not the supplier's claims. That is, how much useable area the user can use, not the total good area as the supplier estimated. An important application of the developed technique is in the leather industry where the tanner (the supplier) and the footwear manufacturer (the user) are constantly locked in argument due to disputed quality standards of finished leather hide, which disrupts production schedules and wasted costs in re-grading, re- sorting... . The developed basic algorithm for area scanning of a digital image will be presented. The implementation of an improved scanning algorithm will be discussed in detail. The improved features include Boolean OR operations and many other innovative functions which aim at optimizing the scanning process in terms of computing time and the accurate estimation of useable areas.

  15. Mapping with side-scan sonar

    SciTech Connect

    Prior, D.B.; Coleman, J.M.; Roberts, H.H.

    1981-04-01

    The use of sideways scanning sonar as a technique for detailed sea-floor mapping is described in this article. Sea-floor mapping of the continental shelf is becoming increasingly necessary for the development of oil and gas resources. More recently attempts are being made to extend the survey capabilities to deeper water shelf margins, slopes, and basins. Conventional systems, digital systems, survey ranges, data processing, mosaics, and applications are discussed. (DMC)

  16. Cryogenic Multichannel Pressure Sensor With Electronic Scanning

    NASA Technical Reports Server (NTRS)

    Hopson, Purnell, Jr.; Chapman, John J.; Kruse, Nancy M. H.

    1994-01-01

    Array of pressure sensors operates reliably and repeatably over wide temperature range, extending from normal boiling point of water down to boiling point of nitrogen. Sensors accurate and repeat to within 0.1 percent. Operate for 12 months without need for recalibration. Array scanned electronically, sensor readings multiplexed and sent to desktop computer for processing and storage. Used to measure distributions of pressure in research on boundary layers at high Reynolds numbers, achieved by low temperatures.

  17. Scanning electron microscope view of iron crystal

    NASA Technical Reports Server (NTRS)

    1972-01-01

    A scanning electron microscope photograph of iron crystals which grow in a small vug or cavity in a recrystallized breccia (fragmented rock) from the Apollo 15 Hadley-Apennino lunar landing site. The largest crystal is three microns across. Perfectly developed crystals such as these indicate slow formation from a hot vapor as the rock was cooling. The crystals are resting on an interlocking lattice of pyroxene (calsium-magnesium-iron silicate).

  18. Circular zig-zag scan video format

    DOEpatents

    Peterson, C. Glen; Simmons, Charles M.

    1992-01-01

    A circular, ziz-zag scan for use with vidicon tubes. A sine wave is generated, rectified and its fourth root extracted. The fourth root, and its inverse, are used to generate horizontal ramp and sync signals. The fourth root is also used to generate a vertical sync signal, and the vertical sync signal, along with the horizontal sync signal, are used to generate the vertical ramp signal. Cathode blanking and preamplifier clamp signals are also obtained from the vertical sync signal.

  19. High-performance reactionless scan mechanism

    NASA Technical Reports Server (NTRS)

    Williams, Ellen I.; Summers, Richard T.; Ostaszewski, Miroslaw A.

    1995-01-01

    A high-performance reactionless scan mirror mechanism was developed for space applications to provide thermal images of the Earth. The design incorporates a unique mechanical means of providing reactionless operation that also minimizes weight, mechanical resonance operation to minimize power, combined use of a single optical encoder to sense coarse and fine angular position, and a new kinematic mount of the mirror. A flex pivot hardware failure and current project status are discussed.

  20. Observation of Superlubricity by Scanning Tunneling Microscopy

    NASA Astrophysics Data System (ADS)

    Hirano, Motohisa; Shinjo, Kazumasa; Kaneko, Reizo; Murata, Yoshitada

    1997-02-01

    Experimental evidence of superlubricity, the state of vanishing friction, is obtained by examining systems of sliding atomically clean surfaces by using ultrahigh vacuum scanning tunneling microscopy. The experimental results agree with theoretical predictions: Friction is not observed in the superlubricity regime in measurements capable of resolving a friction force of 3×10-9 N, whereas friction of 8×10-8 N, which is comparable to theoretical values, is observed in the friction regime.

  1. First Experiences with the Trimble SX10 Scanning Total Station for Building Facade Survey

    NASA Astrophysics Data System (ADS)

    Lachat, E.; Landes, T.; Grussenmeyer, P.

    2017-02-01

    The use of Terrestrial Laser Scanner (TLS) tends to become a solution in many research areas related to large scale surveying. Meanwhile, the technological advances combined with the investigation of user needs have brought to the design of innovative devices known as scanning total stations. Such instruments merge in a unique hardware both scanning and surveying facilities. Even if their scanning rate is often reduced compared to conventional TLS, they make it possible to directly georeference laser scanning projects and to complete them with measurements of individual points of interest. The recent Trimble SX10 which was launched on the market in early October 2016 has been tested and some experiences carried out with it are reported in this paper. The analyses mainly focus on the survey of a building facade. Next to laser scanning survey, a photogrammetry campaign using an Unmanned Aerial Vehicle (UAV) has been carried out. These different datasets are used to assess the Trimble SX10 issued point clouds through a set of comparisons. Since georeferencing is possible either directly or indirectly using this device, data processed both ways are also compared to conclude about the more reliable method.

  2. Ultrasonography in the evaluation of renal scarring using DMSA scan as the gold standard.

    PubMed

    Moorthy, Ima; Wheat, Deirdre; Gordon, Isky

    2004-02-01

    Dimercaptosuccinic acid (DMSA) renal scan is presently the technique of choice for assessing renal scars. Recent advances suggest that ultrasonography could replace DMSA scan for this purpose. This paper describes the experience of a tertiary pediatric referral hospital performing ultrasonography and DMSA scans in the assessment of renal scarring. Investigations were conducted 3-6 months after patients presented with urinary tract infection (UTI). Results were extracted from the radiology information system and recorded for analysis. All children with a UTI who had undergone DMSA and ultrasound examination on the same day between January 1995 and December 1999 were included; 930 kidneys were compared. DMSA scan was utilized as the reference method. When used to detect focal renal scarring, ultrasonography had a sensitivity of 5.2%, specificity of 98.3%, a positive predictive value (PPV) of 50% and a negative predictive value (NPV) of 75.8%. When used to detect diffuse renal scarring, ultrasonography had a sensitivity of 47.2%, specificity of 91.8%, PPV of 60.8% and NPV of 86.6%. Our results demonstrate that although ultrasonography has a good specificity for the detection of renal scarring compared with DMSA, it has low sensitivity, PPV and NPV. Ultrasonography cannot be substituted for DMSA scan in the evaluation of focal renal scarring.

  3. Abnormal Visual Scanning of Emotionally Evocative Natural Scenes in Huntington’s Disease

    PubMed Central

    Kordsachia, Catarina C.; Labuschagne, Izelle; Stout, Julie C.

    2017-01-01

    Huntington’s disease (HD) is a neurodegenerative movement disorder associated with deficits in the processing of emotional stimuli, including alterations in the self-reported subjective experience of emotion when presented with pictures of emotional scenes. The aim of this study was to determine whether individuals with HD, compared to unaffected controls, display abnormal visual scanning of emotionally evocative natural scenes. Using eye-tracking, we recorded eye-movements of 25 HD participants (advanced pre-symptomatic and early symptomatic) and 25 age-matched unaffected control participants during a picture viewing task. Participants viewed pictures of natural scenes associated with different emotions: anger, fear, disgust, happiness, or neutral, and evaluated those pictures on a valence rating scale. Individuals with HD displayed abnormal visual scanning patterns, but did not differ from controls with respect to their valence ratings. Specifically, compared to controls, HD participants spent less time fixating on the pictures and made longer scan paths. This finding highlights the importance of taking visual scanning behavior into account when investigating emotion processing in HD. The visual scanning patterns displayed by HD participants could reflect a heightened, but possibly unfocussed, search for information, and might be linked to attentional deficits or to altered subjective emotional experiences in HD. Another possibility is that HD participants may have found it more difficult than controls to evaluate the emotional valence of the scenes, and the heightened search for information was employed as a compensatory strategy.

  4. Flexible polygon-mirror based laser scanning microscope platform for multiphoton in-vivo imaging.

    PubMed

    Li, Y X; Gautam, V; Brüstle, A; Cockburn, I A; Daria, V R; Gillespie, C; Gaus, K; Alt, C; Lee, W M

    2017-02-06

    Commercial microscopy systems make use of tandem scanning i.e. either slow or fast scanning. We constructed, for the first time, an advanced control system capable of delivering a dynamic line scanning speed ranging from 2.7 kHz to 27 kHz and achieve variable frame rates from 5 Hz to 50 Hz (512 × 512). The dynamic scanning ability is digitally controlled by a new customized open-source software named PScan1.0. This permits manipulation of scanning rates either to gain higher fluorescence signal at slow frame rate without increasing laser power or increase frame rates to capture high speed events. By adjusting imaging speed from 40 Hz to 160 Hz, we capture a range of calcium waves and transient peaks from soma and dendrite of single fluorescence neuron (CAL-520AM). Motion artifacts arising from respiratory and cardiac motion in small animal imaging reduce quality of real-time images of single cells in-vivo. An image registration algorithm, integrated with PScan1.0, was shown to perform both real time and post-processed motion correction. The improvement is verified by quantification of blood flow rates. This work describes all the steps necessary to develop a high performance and flexible polygon-mirror based multiphoton microscope system for in-vivo biological imaging.

  5. Advances in lung ultrasound.

    PubMed

    Francisco, Miguel José; Rahal, Antonio; Vieira, Fabio Augusto Cardillo; Silva, Paulo Savoia Dias da; Funari, Marcelo Buarque de Gusmão

    2016-01-01

    Ultrasound examination of the chest has advanced in recent decades. This imaging modality is currently used to diagnose several pathological conditions and provides qualitative and quantitative information. Acoustic barriers represented by the aerated lungs and the bony framework of the chest generate well-described sonographic artifacts that can be used as diagnostic aids. The normal pleural line and A, B, C, E and Z lines (also known as false B lines) are artifacts with specific characteristics. Lung consolidation and pneumothorax sonographic patterns are also well established. Some scanning protocols have been used in patient management. The Blue, FALLS and C.A.U.S.E. protocols are examples of algorithms using artifact combinations to achieve accurate diagnoses. Combined chest ultrasonography and radiography are often sufficient to diagnose and manage lung and chest wall conditions. Chest ultrasonography is a highly valuable diagnostic tool for radiologists, emergency and intensive care physicians. RESUMO O exame ultrassonográfico do tórax avançou nas últimas décadas, sendo utilizado para o diagnóstico de inúmeras condições patológicas, e fornecendo informações qualitativas e quantitativas. Os pulmões aerados e o arcabouço ósseo do tórax representam barreira sonora para o estudo ultrassonográfico, gerando artefatos que, bem conhecidos, são utilizados como ferramentas diagnósticas. Eco pleural normal, linhas A, linhas B, linhas C, linhas E e Z (conhecidas como falsas linhas B) são artefatos com características peculiares. Os padrões de consolidação e de pneumotórax também são bem estabelecidos. Alguns protocolos têm sido utilizados no manuseio dos pacientes: Blue Protocol, Protocolo FALLS e Protocolo C.A.U.S.E são exemplos de três propostas que, por meio da associação entre os artefatos, permitem sugerir diagnósticos precisos. A ultrassonografia de tórax, aliada à radiografia de tórax, muitas vezes é suficiente para o diagn

  6. CCD scanning for asteroids and comets

    NASA Technical Reports Server (NTRS)

    Gehrels, T.; Mcmillan, R. S.

    1986-01-01

    A change coupled device (CCD) is used in a scanning mode to find new asteroids and recover known asteroids and comet nuclei. Current scientific programs include recovery of asteroids and comet nuclei requested by the Minor Planet Center (MPC), discovery of new asteroids in the main belt and of unusual orbital types, and follow-up astrometry of selected new asteroids discovered. The routine six sigma limiting visual magnitude is 19.6 and slightly more than a square degree is scanned three times every 90 minutes of observing time during the fortnight centered on New Moon. Semiautomatic software for detection of moving objects is in routine use; angular speeds as low as 11.0 arcseconds per hour were distinguished from the effects of the Earth's atmosphere on the field of view. A typical set of three 29-minute scans near the opposition point along the ecliptic typically nets at least 5 new main-belt asteroids down to magnitude 19.6. In 18 observing runs (months) 43 asteroids were recovered, astrometric and photometric data on 59 new asteroids were reported, 10 new asteroids with orbital elements were consolidated, and photometry and positions of 22 comets were reported.

  7. Impact echo scanning of concrete and wood

    NASA Astrophysics Data System (ADS)

    Sack, Dennis A.; Olson, Larry D.; Aouad, Marwan F.

    1995-05-01

    This paper presents an overview of a new nondestructive testing (NDT) system that allows rapid nondestructive assessment of many types of structural materials. The new system is based on scanning impact echo (IE), using a rolling receiver, digitally controlled impact source, and a distance measurement wheel integrated into a system that is capable of performing over 3000 IE tests per hour. The system has been successfully used on both concrete and wood for condition assessment. Previously, impact echo testing has been limited to point-by-point testing at rates of typically 30 - 60 points per hour. The new system is usable on any flat, relatively smooth surface such as floor slabs, pavements, walls, columns, beams, etc. In addition to IE scanning, the new system has recently been expanded to allow the performance of spectral analysis of surface waves (SASW) scanning on concrete and wood. The SASW method allows the measurement of material stiffness (modulus) versus depth, and therefore can give a profile of the material condition versus depth. Included in this paper are brief discussions of the IE and SASW methods, the scanner system hardware, and the software which was developed to enable efficient processing, analysis, and display of the test data and results. Also included are sample data plots and a case history presentation of the use of the system in the field, including one in which 23,000 IE tests were performed on an elevated floor slab in approximately 16 hours of testing time.

  8. Holographic Optical Elements as Scanning Lidar Telescopes

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.; Rallison, Richard D.; Wilkerson, Thomas D.; Guerra, David V.

    2005-01-01

    We have developed and investigated the use of holographic optical elements (HOEs) and holographic transmission gratings for scanning lidar telescopes. For example, rotating a flat HOE in its own plane with the focal spot on the rotation axis makes a very simple and compact conical scanning telescope. We developed and tested transmission and reflection HOEs for use at the first three harmonic wavelengths of Nd:YAG lasers. The diffraction efficiency, diffraction angle, focal length, focal spot size and optical losses were measured for several HOEs and holographic gratings, and found to be suitable for use as lidar receiver telescopes, and in many cases could also serve as the final collimating and beam steering optic for the laser transmitter. Two lidar systems based on this technology have been designed, built, and successfully tested in atmospheric science applications. This technology will enable future spaceborne lidar missions by significantly lowering the size, weight, power requirement and cost of a large aperture, narrow field of view scanning telescope.

  9. Synthetic holography based on scanning microcavity

    NASA Astrophysics Data System (ADS)

    Di Donato, A.; Farina, M.

    2015-11-01

    Synthetic optical holography (SOH) is an imaging technique, introduced in scanning microscopy to record amplitude and phase of a scattered field from a sample. In this paper, it is described a novel implementation of SOH through a lens-free low-coherence system, based on a scanning optical microcavity. This technique combines the low-coherence properties of the source with the mutual interference of scattered waves and the resonant behavior of a micro-cavity, in order to realize a high sensitive imaging system. Micro-cavity is compact and realized by approaching a cleaved optical fiber to the sample. The scanning system works in an open-loop configuration without the need for a reference wave, usually required in interferometric systems. Measurements were performed over calibration samples and a lateral resolution of about 1 μm is achieved by means of an optical fiber with a Numerical Aperture (NA) equal to 0.1 and a Mode Field Diameter (MDF) of 5.6 μm.

  10. The relaxed confocal scanning laser ophthalmoscope.

    PubMed

    Van de Velde, F J

    2006-01-01

    The development of the Scanning Laser Ophthalmoscope is reviewed from a historical perspective. Since a flying-spot scanning principle for an electro-optical ophthalmoscope was first disclosed in 1950, enabling milestones have included the introduction of the laser and inversion of the usual Gullstrand's configuration of optical pupils in 1977, and the application of the optical principle of confocality by means of double or de-scanning in 1983. As a result, high resolution and high contrast confocal infra-red ophthalmoscopy with a 790 nm diode laser, at video rates, is a major novel imaging modality when compared to traditional optical techniques. This imaging mode is ideal to provide the necessary fiducial landmarks for microperimetry, therapeutic laser and SD-OCT based optical sectioning of the retina. DPSS or He-Ne lasers emitting at 532, 543, 561 or 575 nm are used for complimentary red-free fundus imaging. The diode 790 nm and DPSS 490 nm lasers are also used for fluorescence excitation.

  11. A mini-rapid-scan-spectrophotometer.

    PubMed

    Schmidt, Werner

    2004-02-27

    The mini-rapid-scan-spectrophotometer (Mini-RSS) is a scanning single-beam spectrophotometer that has been patented. It is based on a minimum of reflections and involves exclusively mirrors as beam-deflecting components. This way stray light is minimized, which results in an excellent light-throughput, high dynamics, low cost, compactness and rigidity. The Mini-RSS has been designed as a multi-purpose instrument that allows absorption, transmission, reflection, fluorescence and luminescence measurements in a single-beam mode. Its spectral range extends from the UV and visible spectrum to the IR. This provides for the possibility to measure even optically unfavorable, highly turbid or scattering samples that would be otherwise inaccessible to investigations with commercial spectrophotometers. A miniaturized and very sensitive photomultiplier-module (PM) of high dynamics allows in the visible spectral range absorbance measurements that cover up to four OD units. The Mini-RSS is capable of scanning up to 100 spectra per second with a resolution of 12 bit and 500 points. The linear dispersion is currently 5 nm and the stray light level <0.01%.

  12. ISIS-II Scanning Auroral Photometer.

    PubMed

    Anger, C D; Fancott, T; McNally, J; Kerr, H S

    1973-08-01

    The ISIS-II dual wavelength scanning auroral photometer is designed to map the distribution of auroral emissions at 5577 A and 3914 A over the portion of the dark earth visible to the spacecraft. A combination of internal electronic scanning and the natural orbital and rotational motions of the spacecraft causes a dual wavelength photometer to be scanned systematically across the earth. The data will be reproduced directly in the form of separate pictures representing emissions at each wavelength, which will be used to study the large-scale distribution and morphology of auroras, to study the ratio of 3914-A and 5577-A emissions thought to depend upon the energies of exciting particles), and to compare with results from other instruments on board the spacecraft and on the ground. The Red Line Photometer experiment on the same spacecraft is described in an accompanying paper by Shepherd et al. [Appl. Opt. 12, 1767 (1973)]. The instrument can be thought of as the photometric equivalent of an all-sky color camera which will view the aurora from above instead of below and with a much wider vantage point unobstructed by cloud and haze. In one satellite pass, the instrument will be capable of surveying (in one hemisphere) the entire polar region in which auroras normally occur.

  13. Scanning scene tunnel for city traversing.

    PubMed

    Zheng, Jiang Yu; Zhou, Yu; Milli, Panayiotis

    2006-01-01

    This paper proposes a visual representation named scene tunnel for capturing urban scenes along routes and visualizing them on the Internet. We scan scenes with multiple cameras or a fish-eye camera on a moving vehicle, which generates a real scene archive along streets that is more complete than previously proposed route panoramas. Using a translating spherical eye, properly set planes of scanning, and unique parallel-central projection, we explore the image acquisition of the scene tunnel from camera selection and alignment, slit calculation, scene scanning, to image integration. The scene tunnels cover high buildings, ground, and various viewing directions and have uniformed resolutions along the street. The sequentially organized scene tunnel benefits texture mapping onto the urban models. We analyze the shape characteristics in the scene tunnels for designing visualization algorithms. After combining this with a global panorama and forward image caps, the capped scene tunnels can provide continuous views directly for virtual or real navigation in a city. We render scene tunnel dynamically by view warping, fast transmission, and flexible interaction. The compact and continuous scene tunnel facilitates model construction, data streaming, and seamless route traversing on the Internet and mobile devices.

  14. Clever imaging with SmartScan

    NASA Astrophysics Data System (ADS)

    Tchernykh, Valerij; Dyblenko, Sergej; Janschek, Klaus; Seifart, Klaus; Harnisch, Bernd

    2005-08-01

    The cameras commonly used for Earth observation from satellites require high attitude stability during the image acquisition. For some types of cameras (high-resolution "pushbroom" scanners in particular), instantaneous attitude changes of even less than one arcsecond result in significant image distortion and blurring. Especially problematic are the effects of high-frequency attitude variations originating from micro-shocks and vibrations produced by the momentum and reaction wheels, mechanically activated coolers, and steering and deployment mechanisms on board. The resulting high attitude-stability requirements for Earth-observation satellites are one of the main reasons for their complexity and high cost. The novel SmartScan imaging concept, based on an opto-electronic system with no moving parts, offers the promise of high-quality imaging with only moderate satellite attitude stability. SmartScan uses real-time recording of the actual image motion in the focal plane of the camera during frame acquisition to correct the distortions in the image. Exceptional real-time performances with subpixel-accuracy image-motion measurement are provided by an innovative high-speed onboard opto-electronic correlation processor. SmartScan will therefore allow pushbroom scanners to be used for hyper-spectral imaging from satellites and other space platforms not primarily intended for imaging missions, such as micro- and nano-satellites with simplified attitude control, low-orbiting communications satellites, and manned space stations.

  15. Development and application of multiple-probe scanning probe microscopes.

    PubMed

    Nakayama, Tomonobu; Kubo, Osamu; Shingaya, Yoshitaka; Higuchi, Seiji; Hasegawa, Tsuyoshi; Jiang, Chun-Sheng; Okuda, Taichi; Kuwahara, Yuji; Takami, Kazuhiro; Aono, Masakazu

    2012-04-03

    In the research of advanced materials based on nanoscience and nanotechnology, it is often desirable to measure nanoscale local electrical conductivity at a designated position of a given sample. For this purpose, multiple-probe scanning probe microscopes (MP-SPMs), in which two, three or four scanning tunneling microscope (STM) or atomic force microscope (AFM) probes are operated independently, have been developed. Each probe in an MP-SPM is used not only for observing high-resolution STM or AFM images but also for forming an electrical contact enabling nanoscale local electrical conductivity measurement. The world's first double-probe STM (DP-STM) developed by the authors, which was subsequently modified to a triple-probe STM (TP-STM), has been used to measure the conductivities of one-dimensional metal nanowires and carbon nanotubes and also two-dimensional molecular films. A quadruple-probe STM (QP-STM) has also been developed and used to measure the conductivity of two-dimensional molecular films without the ambiguity of contact resistance between the probe and sample. Moreover, a quadruple-probe AFM (QP-AFM) with four conductive tuning-fork-type self-detection force sensing probes has been developed to measure the conductivity of a nanostructure on an insulating substrate. A general-purpose computer software to control four probes at the same time has also been developed and used in the operation of the QP-AFM. These developments and applications of MP-SPMs are reviewed in this paper.

  16. Probing Individual Ice Nucleation Events with Environmental Scanning Electron Microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Bingbing; China, Swarup; Knopf, Daniel; Gilles, Mary; Laskin, Alexander

    2016-04-01

    Heterogeneous ice nucleation is one of the processes of critical relevance to a range of topics in the fundamental and the applied science and technologies. Heterogeneous ice nucleation initiated by particles proceeds where microscopic properties of particle surfaces essentially control nucleation mechanisms. Ice nucleation in the atmosphere on particles governs the formation of ice and mixed phase clouds, which in turn influence the Earth's radiative budget and climate. Heterogeneous ice nucleation is still insufficiently understood and poses significant challenges in predictive understanding of climate change. We present a novel microscopy platform allowing observation of individual ice nucleation events at temperature range of 193-273 K and relative humidity relevant for ice formation in the atmospheric clouds. The approach utilizes a home built novel ice nucleation cell interfaced with Environmental Scanning Electron Microscope (IN-ESEM system). The IN-ESEM system is applied for direct observation of individual ice formation events, determining ice nucleation mechanisms, freezing temperatures, and relative humidity onsets. Reported microanalysis of the ice nucleating particles (INP) include elemental composition detected by the energy dispersed analysis of X-rays (EDX), and advanced speciation of the organic content in particles using scanning transmission x-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS). The performance of the IN-ESEM system is validated through a set of experiments with kaolinite particles with known ice nucleation propensity. We demonstrate an application of the IN-ESEM system to identify and characterize individual INP within a complex mixture of ambient particles.

  17. 3D scanning and printing skeletal tissues for anatomy education.

    PubMed

    Thomas, Daniel B; Hiscox, Jessica D; Dixon, Blair J; Potgieter, Johan

    2016-09-01

    Detailed anatomical models can be produced with consumer-level 3D scanning and printing systems. 3D replication techniques are significant advances for anatomical education as they allow practitioners to more easily introduce diverse or numerous specimens into classrooms. Here we present a methodology for producing anatomical models in-house, with the chondrocranium cartilage from a spiny dogfish (Squalus acanthias) and the skeleton of a cane toad (Rhinella marina) as case studies. 3D digital replicas were produced using two consumer-level scanners and specimens were 3D-printed with selective laser sintering. The fidelity of the two case study models was determined with respect to key anatomical features. Larger-scale features of the dogfish chondrocranium and frog skeleton were all well-resolved and distinct in the 3D digital models, and many finer-scale features were also well-resolved, but some more subtle features were absent from the digital models (e.g. endolymphatic foramina in chondrocranium). All characters identified in the digital chondrocranium could be identified in the subsequent 3D print; however, three characters in the 3D-printed frog skeleton could not be clearly delimited (palatines, parasphenoid and pubis). Characters that were absent in the digital models or 3D prints had low-relief in the original scanned specimen and represent a minor loss of fidelity. Our method description and case studies show that minimal equipment and training is needed to produce durable skeletal specimens. These technologies support the tailored production of models for specific classes or research aims.

  18. Development and Application of Multiple-Probe Scanning Probe Microscopes

    SciTech Connect

    Nakayama, T.; Kubo, O.; Shingaya, Y.; Higuchi, S.; Hasegawa, T.; Jiang, C. S.; Okuda, T.; Kuwahara, Y.; Takami, K.; Aono, M.

    2012-04-03

    the research of advanced materials based on nanoscience and nanotechnology, it is often desirable to measure nanoscale local electrical conductivity at a designated position of a given sample. For this purpose, multiple-probe scanning probe microscopes (MP-SPMs), in which two, three or four scanning tunneling microscope (STM) or atomic force microscope (AFM) probes are operated independently, have been developed. Each probe in an MP-SPM is used not only for observing high-resolution STM or AFM images but also for forming an electrical contact enabling nanoscale local electrical conductivity measurement. The world's first double-probe STM (DP-STM) developed by the authors, which was subsequently modified to a triple-probe STM (TP-STM), has been used to measure the conductivities of one-dimensional metal nanowires and carbon nanotubes and also two-dimensional molecular films. A quadruple-probe STM (QP-STM) has also been developed and used to measure the conductivity of two-dimensional molecular films without the ambiguity of contact resistance between the probe and sample. Moreover, a quadruple-probe AFM (QP-AFM) with four conductive tuning-fork-type self-detection force sensing probes has been developed to measure the conductivity of a nanostructure on an insulating substrate. A general-purpose computer software to control four probes at the same time has also been developed and used in the operation of the QP-AFM. These developments and applications of MP-SPMs are reviewed in this paper.

  19. The effects of phase advances between interaction points

    SciTech Connect

    Luo, Y.; Tepekian, S.; Fischer, W.; Gu, X.; Trbojevic, D.

    2011-03-01

    In this note we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used. We also scan the phase advances between IP8 and the electron lens for the proposed Blue ring lattice with head-on beam-beam compensation.

  20. Continental-Scale Evaluation of Assimilated Soil Moisture Retrievals From the Advanced Microwave Scanning Radiometer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil moisture is a fundamental data source used in crop growth stage and crop stress models developed by the USDA Foreign Agriculture Service for global crop estimation. USDA’s International Production Assessment Division (IPAD) of the Office of Global Analysis (OGA). Currently, the PECAD DSS utiliz...