Science.gov

Sample records for high resolution autoradiography

  1. High-Resolution Autoradiography

    NASA Technical Reports Server (NTRS)

    Towe, George C; Gomberg, Henry J; Freemen, J W

    1955-01-01

    This investigation was made to adapt wet-process autoradiography to metallurgical samples to obtain high resolution of segregated radioactive elements in microstructures. Results are confined to development of the technique, which was perfected to a resolution of less than 10 microns. The radioactive samples included carbon-14 carburized iron and steel, nickel-63 electroplated samples, a powder product containing nickel-63, and tungsten-185 in N-155 alloy.

  2. High Resolution Quantitative Auto-Radiography to determine microscopic distributions of B-10 in neutron capture therapy

    E-print Network

    Harris, Thomas C. (Thomas Cameron)

    2006-01-01

    The success of Boron Neutron Capture Therapy (BNCT) is heavily dependent on the microscopic distribution of B-10 in tissue. High Resolution Quantitative Auto-Radiography (HRQAR) is a potentially valuable analytical tool ...

  3. Study of cell wall growth in Bacillus megaterium by high-resolution autoradiography.

    PubMed Central

    de Chastellier, C; Hellio, R; Ryter, A

    1975-01-01

    Growth of the cell wall of Bacillus megaterium was studied by pulse-labeling the cell wall of a DAP- Lys- mutant for a very short time with tritium-labeled diaminopimelic acid. The distribution of radioactivity along the cell wall was examined by high-resolution autoradiography on isolated cell walls and thin sections of bacteria. The results indicate that cell wall elongation occurs by diffuse intercalation of newly synthesized murein into the expanding cell wall during exponential growth, as well as during germination, and that the only zone of highly localized diaminopimelic acid incorporation is found at the cross wall during its synthesis. This zone contains about 30% of the radioactivity incorporated into the cell wall. Analysis of autoradiographs of thin sections of bacteria shows that the total radioactivity incorporated per bacterium doubles during the life cycle. This doubling occurs in the cylindrical part of the cell wall but not in the polar caps. This seems to indicate that elongation of the bacterium is not constant during the life cycle but increases with the length of the cell. Images PMID:808532

  4. High resolution track etch autoradiography

    DOEpatents

    Solares, G.; Zamenhof, R.G.

    1994-12-27

    A detector assembly is disclosed for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns. 13 figures.

  5. High resolution track etch autoradiography

    DOEpatents

    Solares, Guido (Arlington, MA); Zamenhof, Robert G. (Brookline, MA)

    1994-01-01

    A detector assembly for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns.

  6. The spatial resolution of silicon-based electron detectors in ?-autoradiography

    NASA Astrophysics Data System (ADS)

    Cabello, Jorge; Wells, Kevin

    2010-03-01

    Thin tissue autoradiography is an imaging modality where ex-vivo tissue sections are placed in direct contact with autoradiographic film. These tissue sections contain a radiolabelled ligand bound to a specific biomolecule under study. This radioligand emits ? - or ?+ particles ionizing silver halide crystals in the film. High spatial resolution autoradiograms are obtained using low energy radioisotopes, such as 3H where an intrinsic 0.1-1 µm spatial resolution can be achieved. Several digital alternatives have been presented over the past few years to replace conventional film but their spatial resolution has yet to equal film, although silicon-based imaging technologies have demonstrated higher sensitivity compared to conventional film. It will be shown in this work how pixel size is a critical parameter for achieving high spatial resolution for low energy uncollimated beta imaging. In this work we also examine the confounding factors impeding silicon-based technologies with respect to spatial resolution. The study considers charge diffusion in silicon and detector noise, and this is applied to a range of radioisotopes typically used in autoradiography. Finally an optimal detector geometry to obtain the best possible spatial resolution for a specific technology and a specific radioisotope is suggested.

  7. Analytical autoradiography

    NASA Astrophysics Data System (ADS)

    Babikova, Iu. F.; Gusakov, A. A.; Minaev, V. M.; Riabova, G. G.

    Autoradiography techniques applied in the field of material technology are discussed. Consideration is given to the choice of radionuclides introduced into or induced in the analyzed materials as well as the methods involved, the nuclear reactions taking place, and the methods for the detection of ionizing particles. Examples are presented of the application of the method, including studies of the distribution of impurities and alloying elements in an alloy, the redistribution of elements during soldering and welding of structural materials, corrosion kinetics, and diffusion and implantation processes in solids.

  8. Quantitative receptor autoradiography

    SciTech Connect

    Boast, C.A.; Snowhill, E.W.; Altar, C.A.

    1986-01-01

    Quantitative receptor autoradiography addresses the topic of technical and scientific advances in the sphere of quantitative autoradiography. The volume opens with a overview of the field from a historical and critical perspective. Following is a detailed discussion of in vitro data obtained from a variety of neurotransmitter systems. The next section explores applications of autoradiography, and the final two chapters consider experimental models. Methodological considerations are emphasized, including the use of computers for image analysis.

  9. Effects of high-dose fenfluramine treatment on monoamine uptake sites in rat brain: Assessment using quantitative autoradiography

    SciTech Connect

    Appel, N.M.; Mitchell, W.M.; Contrera, J.F.; De Souza, E.B. )

    1990-01-01

    Fenfluramine is an amphetamine derivative that in humans is used primarily as an anorectic agent in the treatment of obesity. In rats, subchronic high-dose d,l-fenfluramine treatment (24 mg/kg subcutaneously, twice daily for 4 days) causes long-lasting decreases in brain serotonin (5HT), its metabolite 5-hydroxyindoleacetic acid, and high-affinity 5HT uptake sites. Moreover, this high-dose treatment regimen causes both selective long-lasting decreases in fine-caliber 5HT-immunoreactive axons and appearance of other 5HT-immunoreactive axons with morphology characteristic of degenerating axons. Determination of the potential neurotoxic effects of fenfluramine treatment using immunohistochemistry is limited from the perspectives that staining is difficult to quantify and that it relies on presence of the antigen (in this case 5HT), and the 5HT-depleting effects of fenfluramine are well known. In the present study, we used quantitative in vitro autoradiography to assess, in detail, the density and regional distribution of (3H)paroxetine-labeled 5HT and (3H)mazindol-labeled catecholamine uptake sites in response to the high-dose fenfluramine treatment described above. Because monoamine uptake sites are concentrated on monoamine-containing nerve terminals, decreases in uptake site density would provide a quantitative assessment of potential neurotoxicity resulting from this fenfluramine treatment regimen. Marked decreases in densities of (3H)paroxetine-labeled 5HT uptake sites occurred in brain regions in which fenfluramine treatment decreased the density of 5HT-like immunostaining when compared to saline-treated control rats. These included cerebral cortex, caudate putamen, hippocampus, thalamus, and medial hypothalamus.

  10. Autoradiography Using OSL for Monitoring Warhead Dismantlement

    SciTech Connect

    Tanner, Jennifer E.; Miller, Steven D.; Conrady, Matthew M.; Benz, Jacob M.

    2010-08-11

    The use of radiation imaging techniques to provide increased confidence in a dismantlement verification regime is still under investigation. Currently, radiation measurements can be used to confirm attributes such as the presence, quality, and mass of containerized nuclear material. However, imaging techniques can be used to confirm the shape, size, and/or symmetry of the object being interrogated. Imaging can be used as a complementary technique to radiation measurements to confirm a declaration or as a chain of custody measure to confirm that an item has not been tampered with. As with other attribute measurements, the image data must be protected behind an information barrier and analyzed to give an unclassified result when compared to an agreed upon threshold. This paper will discuss the use of Optically Stimulated Luminescence to perform autoradiography of sources using coded apertures to differentiate between point sources and various distributed sources. The coded aperture chosen for this application is based on modified uniform redundant arrays (mURAs) which resulted in the design and manufacture of an efficient, high-resolution mURA mask/antimask system. The potential use of the autoradiography technique with the coded aperture as an intrinsic information barrier and the required protection of the mask and unfolding algorithm will also be discussed. This project has been supported by the US Department of Energy’s National Nuclear Security Administration’s Office of Dismantlement and Transparency (DOE/NNSA/NA-241).

  11. High resolution data acquisition

    DOEpatents

    Thornton, Glenn W. (Los Alamos, NM); Fuller, Kenneth R. (Los Alamos, NM)

    1993-01-01

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

  12. High resolution data acquisition

    DOEpatents

    Thornton, G.W.; Fuller, K.R.

    1993-04-06

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

  13. High Resolution Transforms

    NASA Astrophysics Data System (ADS)

    Volker, A. W. F.; Bloom, J. G. P.

    2009-03-01

    The introduction of phased arrays opens-up a range of new possibilities for ultrasonic inspections. Arrays come in various shapes ranging from linear arrays for weld inspection to circular arrays emitting guided waves for permanent monitoring applications. For this kind of applications, the data is best displayed as angle versus time to locate the position a defects. However, the data is normally measured as function of a certain spatial coordinate and time. A transformation is then applied to convert data from the spatial domain into the angle domain. The simplest example is a spatial Fourier transform. Unfortunately the resolution obtained by this kind of transforms is determined by the size of the array compared to the wavelength. The longer the array is compared to the wavelength, the higher is the resolution. The reason for this is the increased phase rotation along the aperture. A new iterative approach is proposed to overcome the shortcomings of the traditional plane wave decomposition. This is a so-called high resolution transform. The new approach yields at least a five times higher resolution and can deal easily with irregular sampling or missing data. The approach will be illustrated on numerically modeled.

  14. High resolution infrared measurements

    NASA Technical Reports Server (NTRS)

    Kessler, B.; Cawley, Robert

    1990-01-01

    Sample ground based cloud radiance data from a high resolution infrared sensor are shown and the sensor characteristics are presented in detail. The purpose of the Infrared Analysis Measurement and Modeling Program (IRAMMP) is to establish a deterministic radiometric data base of cloud, sea, and littoral terrain clutter to be used to advance the design and development of Infrared Search and Track (IRST) systems as well as other infrared devices. The sensor is a dual band radiometric sensor and its description, together with that of the Data Acquisition System (DAS), are given. A schematic diagram of the sensor optics is shown.

  15. Gallery | High Resolution Electron Microscopy

    Cancer.gov

    Skip to main content High Resolution Electron Microscopy High Resolution Electron Microscopy Center for Cancer Research at the National Institutes of Health Main menu Home Research 3D Correlative Imaging Methods Development Protein Complexes Viral Entry Publications Image

  16. Publications | High Resolution Electron Microscopy

    Cancer.gov

    Skip to main content High Resolution Electron Microscopy High Resolution Electron Microscopy Center for Cancer Research at the National Institutes of Health Main menu Home Research 3D Correlative Imaging Methods Development Protein Complexes Viral Entry Publications Image

  17. High resolution time interval meter

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.

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

    SciTech Connect

    Kanai Shah, M.S.

    2007-03-06

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

  19. Double label autoradiography--an improvement

    SciTech Connect

    Wynford-Thomas, D.; LaMontagne, A.; Prescott, D.M.

    1986-10-01

    A convenient method for double-label autoradiography is described that uses an aqueous mountant, Gelutol (polyvinyl alcohol), which keeps the gelatin spacer in the final autoradiograph permanently swollen to a thickness of around 18 microns in contrast to its 5 microns thickness during exposure of the autoradiograph. This greatly improves optical discrimination between upper and lower layers without the loss of sensitivity or resolution that would result if a 18 microns spacer were used during exposure.

  20. High resolution telescope

    SciTech Connect

    Massie, N.A.; Oster, Y.

    1990-12-31

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1m in a circle-of-nine configuration. The telescope array has an effective aperture of 12m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activities. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes. 9 figs., 1 tab.

  1. High resolution telescope

    SciTech Connect

    Massie, N.A.; Oster, Y.

    1990-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1m in a circle-of-nine configuration. The telescope array has an effective aperture of 12m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activities. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes. 9 figs., 1 tab.

  2. High resolution telescope

    DOEpatents

    Massie, Norbert A. (San Ramon, CA); Oster, Yale (Danville, CA)

    1992-01-01

    A large effective-aperture, low-cost optical telescope with diffraction-limited resolution enables ground-based observation of near-earth space objects. The telescope has a non-redundant, thinned-aperture array in a center-mount, single-structure space frame. It employs speckle interferometric imaging to achieve diffraction-limited resolution. The signal-to-noise ratio problem is mitigated by moving the wavelength of operation to the near-IR, and the image is sensed by a Silicon CCD. The steerable, single-structure array presents a constant pupil. The center-mount, radar-like mount enables low-earth orbit space objects to be tracked as well as increases stiffness of the space frame. In the preferred embodiment, the array has elemental telescopes with subaperture of 2.1 m in a circle-of-nine configuration. The telescope array has an effective aperture of 12 m which provides a diffraction-limited resolution of 0.02 arc seconds. Pathlength matching of the telescope array is maintained by an electro-optical system employing laser metrology. Speckle imaging relaxes pathlength matching tolerance by one order of magnitude as compared to phased arrays. Many features of the telescope contribute to substantial reduction in costs. These include eliminating the conventional protective dome and reducing on-site construction activites. The cost of the telescope scales with the first power of the aperture rather than its third power as in conventional telescopes.

  3. Database management in autoradiography.

    PubMed

    Shivaramakrishnan, K; Tretiak, O J

    1989-01-01

    Experiments in autoradiography involve the use of radiotracers to achieve a "functional mapping" between structures of the central nervous system and observed behavior in animals. A typical experiment produces 100-300 sections per animal. Computer systems such as DUMAS (Drexel's Unix based iMage Analysis System) are used to analyze these sections. Each section has two images associated with it--an autoradiographic image and a histological image. The latter is used to establish a correlation between anatomical structures and areas on the autoradiogram. User drawn outlines on the histological image are transferred to the autoradiographic image to obtain quantitative measures (such as average gray level). Existing systems do not take advantage of the fact that consecutive sections obtained from a brain are often similar. As a result, much of the effort involved with region outlining is repetitive. Also, the criteria for region selection varies not only across experiments, but also between users. This paper presents an approach to design an integrated database management system to manage both pictorial and quantitative data in autoradiography. Briefly, such a system is used to (a) store sets of reference outlines and images for use during the analysis of sections, (b) provide a bank of information to the user from across experiments, (c) provide an on-line help facility to the novice, and a reference guide to the expert. Based on specific requirements, we chose the relational model for data management. We developed a preliminary version of the database using INFORMIX-ESQL/C, which is a commercially available relational system. We also developed a graphics editor that is actively linked to the database. The results of our efforts have established the feasibility of using a commercially available relational system for autoradiographic data management. PMID:2924282

  4. Research | High Resolution Electron Microscopy

    Cancer.gov

    Our research program primarily focuses on the development of technologies for 3D imaging using electron microscopy techniques, and on the use of these technologies to image cells, viruses and proteins at high resolution.

  5. High resolution digital delay timer

    DOEpatents

    Martin, Albert D. (Los Alamos, NM)

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  6. Enhanced High Resolution RBS System

    SciTech Connect

    Pollock, Thomas J.; Hass, James A.; Klody, George M.

    2011-06-01

    Improvements in full spectrum resolution with the second NEC high resolution RBS system are summarized. Results for 50 A ring TiN/HfO films on Si yielding energy resolution on the order of 1 keV are also presented. Detector enhancements include improved pulse processing electronics, upgraded shielding for the MCP/RAE detector, and reduced noise generated from pumping. Energy resolution measurements on spectra front edge coupled with calculations using 0.4mStr solid angle show that beam energy spread at 400 KeV from the Pelletron registered accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic data collection. Depth profiles derived from experimental data are discussed. For the thin films profiled, depth resolutions were on the Angstrom level with the non-linear energy/channel conversions ranging from 100 to 200 eV.

  7. High Resolution Doppler Lidar

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This Grant supported the development of an incoherent lidar system to measure winds and aerosols in the lower atmosphere. During this period the following activities occurred: (1) an active feedback system was developed to improve the laser frequency stability; (2) a detailed forward model of the instrument was developed to take into account many subtle effects, such as detector non-linearity; (3) a non-linear least squares inversion method was developed to recover the Doppler shift and aerosol backscatter without requiring assumptions about the molecular component of the signal; (4) a study was done of the effects of systematic errors due to multiple etalon misalignment. It was discovered that even for small offsets and high aerosol loadings, the wind determination can be biased by as much as 1 m/s. The forward model and inversion process were modified to account for this effect; and (5) the lidar measurements were validated using rawinsonde balloon measurements. The measurements were found to be in agreement within 1-2 m/s.

  8. High resolution AMS imaging of radiocarbon in biomedical applications

    NASA Astrophysics Data System (ADS)

    Jiang, Z. X.; Bronk Ramsey, C.; Hedges, R. E. M.; Somogyi, P.; Roberts, J. D. B.; Cowey, A.

    1997-03-01

    Radiocarbon has been an important labelling element in biological metabolism studies. By interfacing an accelerator mass spectrometer (AMS) with a scanning microprobe secondary ion source, we have imaged the uptake of radiocarbon labelled metabolic or neurotransmitter amino acids by neurons and glial cells of rats and gerbils at high resolution (1 micron), high sensitivity and in a short time. The biological samples are prepared and sectioned serially at 0.5 ?m thickness using standard histological procedures. The adjacent sections to those used for AMS imaging were either immunolabelled with antibodies to GABA to reveal GABA-containing cells, or stained with toluidine blue to visualise every cell. Therefore, the distribution of radiocarbon revealed by AMS could be matched to that of the cells. By simultaneously measuring the 14C, 13C and 12C signals, we can demonstrate that the localised peaks of radiocarbon could be readily identified and matched to GABA-immunopositive neurons and glial cells by aligning the radiocarbon deficient blood vessels with the vessels in the adjacent histologically stained section. The results revealed the selective uptake of the neurotransmitter, GABA and that of metabolic amino acid, leucine. The technique compares favourably with high resolution autoradiography and provides great potential for improving the analysis of molecular interactions in and between cells.

  9. High-resolution electron microscope

    NASA Technical Reports Server (NTRS)

    Nathan, R.

    1977-01-01

    Employing scanning transmission electron microscope as interferometer, relative phases of diffraction maximums can be determined by analysis of dark field images. Synthetic aperture technique and Fourier-transform computer processing of amplitude and phase information provide high resolution images at approximately one angstrom.

  10. Advanced very high resolution radiometer

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The advanced very high resolution radiometer development program is considered. The program covered the design, construction, and test of a breadboard model, engineering model, protoflight model, mechanical structural model, and a life test model. Special bench test and calibration equipment was also developed for use on the program.

  11. High Resolution Quantitative Lorentz Microscopy

    NASA Astrophysics Data System (ADS)

    McVitie, S.; McGrouther, D.; Krajnak, M.

    2015-10-01

    The advent of aberration corrected transmission electron microscopy has led to considerable improvements in the field of high resolution electron microscopy imaging. In this paper we show how these developments are applied to imaging of magnetic structure in field free or low field conditions. Whilst the capability of increased spatial resolution is demonstrated on magnetic layers with a width of < 20nm we also consider how a pixelated detector can be used to dramatically increase the efficiency of the detection of the magnetic signal variation in the presence of strong diffraction contrast.

  12. High resolution optical DNA mapping

    NASA Astrophysics Data System (ADS)

    Baday, Murat

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

  13. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-08-01

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

  14. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-01-01

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

  15. HRSC: High resolution stereo camera

    USGS Publications Warehouse

    Neukum, G.; Jaumann, R.; Basilevsky, A.T.; Dumke, A.; Van Gasselt, S.; Giese, B.; Hauber, E.; Head, J. W., III; Heipke, C.; Hoekzema, N.; Hoffmann, H.; Greeley, R.; Gwinner, K.; Kirk, R.; Markiewicz, W.; McCord, T.B.; Michael, G.; Muller, Jan-Peter; Murray, J.B.; Oberst, J.; Pinet, P.; Pischel, R.; Roatsch, T.; Scholten, F.; Willner, K.

    2009-01-01

    The High Resolution Stereo Camera (HRSC) on Mars Express has delivered a wealth of image data, amounting to over 2.5 TB from the start of the mapping phase in January 2004 to September 2008. In that time, more than a third of Mars was covered at a resolution of 10-20 m/pixel in stereo and colour. After five years in orbit, HRSC is still in excellent shape, and it could continue to operate for many more years. HRSC has proven its ability to close the gap between the low-resolution Viking image data and the high-resolution Mars Orbiter Camera images, leading to a global picture of the geological evolution of Mars that is now much clearer than ever before. Derived highest-resolution terrain model data have closed major gaps and provided an unprecedented insight into the shape of the surface, which is paramount not only for surface analysis and geological interpretation, but also for combination with and analysis of data from other instruments, as well as in planning for future missions. This chapter presents the scientific output from data analysis and highlevel data processing, complemented by a summary of how the experiment is conducted by the HRSC team members working in geoscience, atmospheric science, photogrammetry and spectrophotometry. Many of these contributions have been or will be published in peer-reviewed journals and special issues. They form a cross-section of the scientific output, either by summarising the new geoscientific picture of Mars provided by HRSC or by detailing some of the topics of data analysis concerning photogrammetry, cartography and spectral data analysis.

  16. High resolution tomographic instrument development

    NASA Astrophysics Data System (ADS)

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

  17. Welcome | High Resolution Electron Microscopy

    Cancer.gov

    For many years, electron microscopy has been used to image cells and tissues at high resolution. This technology, invented in the early 20th century, provided breakthrough information in the virology and cell biology fields. Over the last 15 to 20 years, however, rapid advances in imaging and computation technologies have expanded the usefulness of electron microscopy into new realms. Electron microscopy is now poised to close a critical "gap" in the structural biology field.

  18. Autoradiography and the Cell Cycle.

    ERIC Educational Resources Information Center

    Jones, C. Weldon

    1992-01-01

    Outlines the stages of a cell biology "pulse-chase" experiment in which the students apply autoradiography techniques to learn about the concept of the cell cycle. Includes (1) seed germination and plant growth; (2) radioactive labeling and fixation of root tips; (3) feulgen staining of root tips; (4) preparation of autoradiograms; and (5)…

  19. High resolution time interval counter

    DOEpatents

    Condreva, Kenneth J. (Livermore, CA)

    1994-01-01

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.

  20. High resolution time interval counter

    DOEpatents

    Condreva, K.J.

    1994-07-26

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured. 3 figs.

  1. A simple, high efficiency, high resolution spectropolarimeter

    NASA Astrophysics Data System (ADS)

    Barden, Samuel C.

    2012-09-01

    A simple concept is described that uses volume phase holographic gratings as polarizing dispersers for a high efficiency, high resolution spectropolarimeter. Although the idea has previously been mentioned in the literature as possible, such a concept has not been explored in detail. Performance analysis is presented for a VPHG spectropolarimeter concept that could be utilized for both solar and night-time astronomy. Instrumental peak efficiency can approach 100% with spectral dispersions permitting R~200,000 spectral resolution with diffraction limited telescopes. The instrument has 3-channels: two dispersed image planes with orthogonal polarization and an undispersed image plane. The concept has a range of versatility where it could be configured (with appropriate half-wave plates) for slit-fed spectroscopy or without slits for snapshot/hyperspectral/tomographic spectroscopic imaging. Multiplex gratings could also be used for the simultaneous recording of two separate spectral bands or multiple instruments could be daisy chained with beam splitters for further spectral coverage.

  2. High Resolution Timing with Low Resolution Clocks A Microsecond Resolution Timer for Sun Workstations

    E-print Network

    Melvin, Stephen

    High Resolution Timing with Low Resolution Clocks and A Microsecond Resolution Timer for Sun for Sun 3 and Sun 4 workstations1. One can measure average service times without a high resolution clock?" 1. Introduction - Who Needs a Microsecond Clock Beginning with its Sun 3 workstations, Sun

  3. Former Lab Members | High Resolution Electron Microscopy

    Cancer.gov

    Skip to main content High Resolution Electron Microscopy High Resolution Electron Microscopy Center for Cancer Research at the National Institutes of Health Main menu Home Research 3D Correlative Imaging Methods Development Protein Complexes Viral Entry Publications Image

  4. Journal Covers | High Resolution Electron Microscopy

    Cancer.gov

    Skip to main content High Resolution Electron Microscopy High Resolution Electron Microscopy Center for Cancer Research at the National Institutes of Health Main menu Home Research 3D Correlative Imaging Methods Development Protein Complexes Viral Entry Publications Image

  5. Ultra-high resolution AMOLED

    NASA Astrophysics Data System (ADS)

    Wacyk, Ihor; Prache, Olivier; Ghosh, Amal

    2011-06-01

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

  6. High-resolution slug testing.

    PubMed

    Zemansky, G M; McElwee, C D

    2005-01-01

    The hydraulic conductivity (K) variation has important ramifications for ground water flow and the transport of contaminants in ground water. The delineation of the nature of that variation can be critical to complete characterization of a site and the planning of effective and efficient remedial measures. Site-specific features (such as high-conductivity zones) need to be quantified. Our alluvial field site in the Kansas River valley exhibits spatial variability, very high conductivities, and nonlinear behavior for slug tests in the sand and gravel aquifer. High-resolution, multilevel slug tests have been performed in a number of wells that are fully screened. A general nonlinear model based on the Navier-Stokes equation, nonlinear frictional loss, non-Darcian flow, acceleration effects, radius changes in the wellbore, and a Hvorslev model for the aquifer has been used to analyze the data, employing an automated processing system that runs within the Excel spreadsheet program. It is concluded that slug tests can provide the necessary data to identify the nature of both horizontal and vertical K variation in an aquifer and that improved delineation or higher resolution of K structure is possible with shorter test intervals. The gradation into zones of higher conductivity is sharper than seen previously, and the maximum conductivity observed is greater than previously measured. However, data from this project indicate that well development, the presence of fines, and the antecedent history of the well are important interrelated factors in regard to slug-test response and can prevent obtaining consistent results in some cases. PMID:15819943

  7. High resolution imaging at Palomar

    NASA Technical Reports Server (NTRS)

    Kulkarni, Shrinivas R.

    1992-01-01

    For the last two years we have embarked on a program of understanding the ultimate limits of ground-based optical imaging. We have designed and fabricated a camera specifically for high resolution imaging. This camera has now been pressed into service at the prime focus of the Hale 5 m telescope. We have concentrated on two techniques: the Non-Redundant Masking (NRM) and Weigelt's Fully Filled Aperture (FFA) method. The former is the optical analog of radio interferometry and the latter is a higher order extension of the Labeyrie autocorrelation method. As in radio Very Long Baseline Interferometry (VLBI), both these techniques essentially measure the closure phase and, hence, true image construction is possible. We have successfully imaged binary stars and asteroids with angular resolution approaching the diffraction limit of the telescope and image quality approaching that of a typical radio VLBI map. In addition, we have carried out analytical and simulation studies to determine the ultimate limits of ground-based optical imaging, the limits of space-based interferometric imaging, and investigated the details of imaging tradeoffs of beam combination in optical interferometers.

  8. Solar corona at high resolution

    NASA Technical Reports Server (NTRS)

    Golub, L.; Rosner, R.; Zombeck, M. V. Z.; Vaiana, G. S.

    1982-01-01

    The earth's surface is shielded from solar X rays almost completely by the atmosphere. It is, therefore, necessary to place X-ray detectors on rockets or orbiting satellites. Solar rays were detected for the first time in the late 1940's, using V-2 rockets. In 1960, the first true X-ray images of the sun were obtained with the aid of a simple pinhole camera. The spatial resolution of the X-ray images could be considerably improved by making use of reflective optics, operating at grazing incidence. Aspects of X-ray mirror developments are discussed along with the results obtained in coronal studies utilizing the new devices for the observation of solar X-ray emission. It is pointed out that the major achievements of the Skylab missions were due primarily to the unique opportunity to obtain data over an extended period of time. Attention is given to normal incidence X-ray optics, achievements possible by making use of high spatial resolution optics, and details of improved mirror design.

  9. A study of Cs-137 spatial distribution in soil thin sections by digital autoradiography

    NASA Astrophysics Data System (ADS)

    Korobova, Elena; Dogadkin, Nikolay; Shiryaev, Andrey; Kolotov, Vladimir; Turkov, Victor

    2013-04-01

    Recent studies have proved autoradiography to have high potential in detection of radiation in particles including geological objects [1-3]. We applied digital autoradiography based on usage of image plates to study Cs-137 microdistribution in thin sections of the podzolic sandy soil typical for the Chernobyl remote impact zone 25 years after the accident. The zone is noted for contamination of the so-called condensation type where the contribution of the "hot" fuel particles has been comparatively low. The initial 137Cs contamination level of the study plot approximated 40 Ci/km2. According to the soil core data twenty five years after the accident the main portion of cesium radioisotopes is still concentrated in the 10-20 cm thick surface layer. Thin sections have been prepared from the top 0-10 cm soil layer of the soil profile located on the shoulder of the relatively steep northern slope of the forested hill formed on the Iput river terrace ca 20 km to the east of the town of Novozybkov, Bryansk region. Undisturbed soil sample was impregnated with epoxy resin, then dissected in vertical triplicates and polished to obtain open surface. Autoradiography of the thin sections has clearly shown different patterns of Cs-137 distribution related to its concentration in organic material and on the surface of soil particles. High sensitivity and resolution of the applied technique enables to reveal concentration and dispersion zones on microscale level. Soil micro-morphology has shown to be helpful in deciphering soil components and properties responsible for Cs-137 retention in the soil top layer. References 1. Mihoko Hareyama, Noriyoshi Tsuchiya, Masahiro Takebe and Tadashi Chida. Two-dimensional measurement of natural radioactivity of granitic rocks by photostimulated luminescence technique Geochemical Journal, 2000, 34, 1- 9. 2. Zeissler C. J., R. M. Lindstrom, J. P. McKinley. Radioactive particle analysis by digital autoradiography. Journal of Radioanalytical and Nuclear Chemistry, 2001, 248, 2, 407-412. 3. Daniel Rufer and Frank Preusser. Potential of autoradiography to detect spatially resolved radiation patterns in the context of trapped charge dating. Geochronometria, 2009, 34, 1-13.

  10. High Resolution, High Frame Rate Video Technology

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Papers and working group summaries presented at the High Resolution, High Frame Rate Video (HHV) Workshop are compiled. HHV system is intended for future use on the Space Shuttle and Space Station Freedom. The Workshop was held for the dual purpose of: (1) allowing potential scientific users to assess the utility of the proposed system for monitoring microgravity science experiments; and (2) letting technical experts from industry recommend improvements to the proposed near-term HHV system. The following topics are covered: (1) State of the art in the video system performance; (2) Development plan for the HHV system; (3) Advanced technology for image gathering, coding, and processing; (4) Data compression applied to HHV; (5) Data transmission networks; and (6) Results of the users' requirements survey conducted by NASA.

  11. High resolution optoelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, Jim; Dinyari, Rostam; Huie, Phil; Butterwick, Alex; Peumans, Peter; Palanker, Daniel

    2009-02-01

    Electronic retinal prostheses seek to restore sight in patients with retinal degeneration by delivering pulsed electric currents to retinal neurons via an array of microelectrodes. Most implants use inductive or optical transmission of information and power to an intraocular receiver, with decoded signals subsequently distributed to retinal electrodes through an intraocular cable. Surgical complexity could be minimized by an "integrated" prosthesis, in which both power and data are delivered directly to the stimulating array without any discrete components or cables. We present here an integrated retinal prosthesis system based on a photodiode array implant. Video frames are processed and imaged onto the retinal implant by a video goggle projection system operating at near-infrared wavelengths (~ 900 nm). Photodiodes convert light into pulsed electric current, with charge injection maximized by specially optimized series photodiode circuits. Prostheses of three different pixel densities (16 pix/mm2, 64 pix/mm2, and 256 pix/mm2) have been designed, simulated, and prototyped. Retinal tissue response to subretinal implants made of various materials has been investigated in RCS rats. The resulting prosthesis can provide sufficient charge injection for high resolution retinal stimulation without the need for implantation of any bulky discrete elements such as coils or tethers. In addition, since every pixel functions independently, pixel arrays may be placed separately in the subretinal space, providing visual stimulation to a larger field of view.

  12. High-resolution infrared imaging

    NASA Astrophysics Data System (ADS)

    Falco, Charles M.

    2010-08-01

    The hands and mind of an artist are intimately involved in the creative process of image formation, intrinsically making paintings significantly more complex than photographs to analyze. In spite of this difficulty, several years ago the artist David Hockney and I identified optical evidence within a number of paintings that demonstrated artists began using optical projections as early as c1425 - nearly 175 years before Galileo - as aids for producing portions of their images. In the course of our work, Hockney and I developed insights that I have been applying to a new approach to computerized image analysis. Recently I developed and characterized a portable high resolution infrared for capturing additional information from paintings. Because many pigments are semi-transparent in the IR, in a number of cases IR photographs ("reflectograms") have revealed marks made by the artists that had been hidden under paint ever since they were made. I have used this IR camera to capture photographs ("reflectograms") of hundreds of paintings in over a dozen museums on three continents and, in some cases, these reflectograms have provided new insights into decisions the artists made in creating the final images that we see in the visible.

  13. A densitometer for quantitative autoradiography.

    PubMed

    Dauth, G W; Frey, K A; Gilman, S

    1983-11-01

    A low cost spot densitometer system is described. This system is useful for quantitative autoradiography of local cerebral glucose utilization, blood flow, receptor binding and other applications requiring densitometry on films. The densitometer can be used alone or interfaced to a microcomputer. The densitometer consists of a photographic enlarger, a digital multimeter, and the densitometer electronics. We have described how to construct, test and use the densitometer and how to interface the densitometer to a microcomputer. The advantages of this system are: (1) the ability to enlarge the image for accurate measurements from 'small' areas; (2) a completely unobscured image during measurement; (3) low cost and (4) ease of use. PMID:6319831

  14. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, R.A.; Kaplan, S.N.; Perez-Mendez, V.

    1992-05-26

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n-type, intrinsic, p-type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography. 18 figs.

  15. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A. (Palo Alto, CA); Kaplan, Selig N. (El Cerrito, CA); Perez-Mendez, Victor (Berkeley, CA)

    1992-01-01

    A radiation detector employing amorphous Si:H cells in an array with each detector cell having at least three contiguous layers (n type, intrinsic, p type), positioned between two electrodes to which a bias voltage is applied. An energy conversion layer atop the silicon cells intercepts incident radiation and converts radiation energy to light energy of a wavelength to which the silicon cells are responsive. A read-out device, positioned proximate to each detector element in an array allows each such element to be interrogated independently to determine whether radiation has been detected in that cell. The energy conversion material may be a layer of luminescent material having a columnar structure. In one embodiment a column of luminescent material detects the passage therethrough of radiation to be detected and directs a light beam signal to an adjacent a-Si:H film so that detection may be confined to one or more such cells in the array. One or both electrodes may have a comb structure, and the teeth of each electrode comb may be interdigitated for capacitance reduction. The amorphous Si:H film may be replaced by an amorphous Si:Ge:H film in which up to 40 percent of the amorphous material is Ge. Two dimensional arrays may be used in X-ray imaging, CT scanning, crystallography, high energy physics beam tracking, nuclear medicine cameras and autoradiography.

  16. Direct beta autoradiography using microchannel plate (MCP) detectors

    NASA Astrophysics Data System (ADS)

    Lees, J. E.; Fraser, G. W.; Dinsdale, D.

    1997-02-01

    We describe a new form of detector for digital autoradiography which combines high sensitivity and good spatial resolution (< 100 ?m). The detector is based on proximity registration of betas by radioisotope-free "low noise" microchannel plates (MCPs) developed for photon counting X-ray astronomy. Low dark count rates (<0.1 cm -2s -1) are combined with the high (>50%) electron detection efficiency of small pore MCPs for common beta emitting isotopes ( 3H, 14C, 35S…). In particular, the MCP detector is highly sensitive to the biologically important but previously difficult to detect low energy (average 6 keV, endpoint 18.6 keV) beta emission from tritium. We report 3H sensitivities and linearity derived from images of a 3H standard, together with images of 3H-Putrescine doped semi-thin-tissue sections of rat lung and isolated single cells from rabbit lung. We compare these results with those of previous attempts to digitally image tritium.

  17. Contact | High Resolution Electron Microscopy

    Cancer.gov

    The long-term mission of our research program is to obtain an integrated, quantitative understanding of cells and viruses at molecular resolution. We take an interdisciplinary approach to this problem by combining novel technologies for 3D imaging with computational and cell biological tools.

  18. Publications | High Resolution Electron Microscopy

    Cancer.gov

    Bartesaghi A, Merk A, Banerjee S, Matthies D, Wu X, Milne JLS, and Subramaniam S. 2.2 Å resolution cryo-EM structure of ?-galactosidase in complex with a cell-permeant inhibitor. Science. 2015 May 7; Epub ahead of print.

  19. High resolution scanning of DNA autoradiographs.

    PubMed

    Russell, J R

    1991-09-01

    The sizes of DNA fragments (alleles) on autoradiographs are measured by means of a computerised video scanner developed in this laboratory. This report investigates the advantages of using higher resolution equipment for this purpose. High resolution is simulated by using existing equipment and moving the video camera closer to the autoradiograph. Test autoradiographs, used to validate the original scanner, have been rescanned to determine the degree of improvement that could be obtained using expensive high resolution equipment. PMID:1752251

  20. High resolution scintillation detector with semiconductor readout

    DOEpatents

    Levin, Craig S. (Santa Monica, CA); Hoffman, Edward J. (Los Angeles, CA)

    2000-01-01

    A novel high resolution scintillation detector array for use in radiation imaging such as high resolution Positron Emission Tomography (PET) which comprises one or more parallelepiped crystals with at least one long surface of each crystal being in intimate contact with a semiconductor photodetector such that photons generated within each crystal by gamma radiation passing therethrough is detected by the photodetector paired therewith.

  1. High Resolution PDF Measurements on Ag Nanoparticles

    SciTech Connect

    Rocha, Tulio C. R.; Martin, Chris; Kycia, Stefan; Zanchet, Daniela

    2009-01-29

    The quantitative analysis of structural defects in Ag nanoparticles was addressed in this work. We performed atomic scale structural characterization by a combination of x-ray diffraction (XRD) using the Pair Distribution Function analysis (PDF) and High Resolution Transmission Electron Microscopy (HRTEM). The XRD measurements were performed using an innovative instrumentation setup to provide high resolution PDF patterns.

  2. High spectral resolution in the solar spectrum

    NASA Technical Reports Server (NTRS)

    Baret, F.; Green, R. O.

    1994-01-01

    A session dedicated to high spectral resolution in the solar spectrum, covering topics of calibration, atmospheric correction, geology/pedology, inland water, and vegetation, is reported. The session showed a high degree of diversity in the topics and the approaches used. It was highlighted that high spectral resolution data could provide atmospherically corrected ground level calibrated reflectance values. Important advances were shown in the use of radiative transfer models applied either on water bodies or vegetation. Several studies highlighted the high degree of redundancy contained in high spectral resolution data.

  3. Publications | High Resolution Electron Microscopy

    Cancer.gov

    Imaging biological objects with electrons involves principles similar to those used in light microscopy, except that electrons are used for illumination instead of photons and the lenses are magnetic instead of being optical. In the last five decades, electron microscopy (EM) helped to reveal basic cell structures in great detail, allowing researchers to visualize internal structure at resolutions that were about 100 times better than that obtained by optical microscopy.

  4. Identifying chromatin interactions at high spatial resolution

    E-print Network

    Reeder, Christopher Campbell

    2014-01-01

    This thesis presents two computational approaches for identifying chromatin interactions at high spatial resolution from ChIA-PET data. We introduce SPROUT which is a hierarchical probabilistic model that discovers high ...

  5. High-Resolution Gaming 1 High-Resolution Gaming: Interfaces, Notifications, and the User Experience

    E-print Network

    , the quality and detail of video game graphics have steadily #12;High-Resolution Gaming 3 improved with each of monitors--and video games--to incrementally improve over the past three decades. However, little researchHigh-Resolution Gaming 1 High-Resolution Gaming: Interfaces, Notifications, and the User Experience

  6. Characterization of a double-sided silicon strip detector autoradiography system

    SciTech Connect

    Örbom, Anders Ahlstedt, Jonas; Östlund, Karl; Strand, Sven-Erik; Serén, Tom; Auterinen, Iiro; Kotiluoto, Petri; Hauge, Håvard; Olafsen, Tove; Wu, Anna M.; Dahlbom, Magnus

    2015-02-15

    Purpose: The most commonly used technology currently used for autoradiography is storage phosphor screens, which has many benefits such as a large field of view but lacks particle-counting detection of the time and energy of each detected radionuclide decay. A number of alternative designs, using either solid state or scintillator detectors, have been developed to address these issues. The aim of this study is to characterize the imaging performance of one such instrument, a double-sided silicon strip detector (DSSD) system for digital autoradiography. A novel aspect of this work is that the instrument, in contrast to previous prototype systems using the same detector type, provides the ability for user accessible imaging with higher throughput. Studies were performed to compare its spatial resolution to that of storage phosphor screens and test the implementation of multiradionuclide ex vivo imaging in a mouse preclinical animal study. Methods: Detector background counts were determined by measuring a nonradioactive sample slide for 52 h. Energy spectra and detection efficiency were measured for seven commonly used radionuclides under representative conditions for tissue imaging. System dead time was measured by imaging {sup 18}F samples of at least 5 kBq and studying the changes in count rate over time. A line source of {sup 58}Co was manufactured by irradiating a 10 ?m nickel wire with fast neutrons in a research reactor. Samples of this wire were imaged in both the DSSD and storage phosphor screen systems and the full width at half maximum (FWHM) measured for the line profiles. Multiradionuclide imaging was employed in a two animal study to examine the intratumoral distribution of a {sup 125}I-labeled monoclonal antibody and a {sup 131}I-labeled engineered fragment (diabody) injected in the same mouse, both targeting carcinoembryonic antigen. Results: Detector background was 1.81 × 10{sup ?6} counts per second per 50 × 50 ?m pixel. Energy spectra and detection efficiency were successfully measured for seven radionuclides. The system dead time was measured to be 59 ?s, and FWHM for a {sup 58}Co line source was 154 ± 14 ?m for the DSSD system and 343 ± 15 ?m for the storage phosphor system. Separation of the contributions from {sup 125}I and {sup 131}I was performed on autoradiography images of tumor sections. Conclusions: This study has shown that a DSSD system can be beneficially applied for digital autoradiography with simultaneous multiradionuclide imaging capability. The system has a low background signal, ability to image both low and high activity samples, and a good energy resolution.

  7. Progress on LAMOST High Resolution Spectrograph Project

    NASA Astrophysics Data System (ADS)

    Zhang, KaI

    2015-08-01

    To explore more science case, LAMOST doesn't only has strong power on celestial spectral survey but also reserves an access to high resolution spectrograph with a few optional fibers. This commissioned spectrograph gets high resolution of R=30,000 - 60,000 at a broad visible band from 370nm to 760nm. With the consideration about site seeing variation in future, single science fiber covers wider field on sky of 4.5arcsec instead of the present 3.3arcsec. An oversize Echelle R4 grating and a pre-slit image slicer are adopted to relieve the spectrograph resolution pressure. High resolution observation will parallel to the low resolution spectral survey at a small cost of losing a few fibers (10 - 20) on telescope focal plane. These science fibers will locate at the different sky areas for more approciate choice. The presentation will give the detailed design introduction and the current project status.

  8. High-resolution finite volume methods

    E-print Network

    Frolkovic, Peter

    -resolution finite volume methods preserving physical properties, ... robust for rough data, ... (1st order scheme limiting to the 1st order scheme if necessary ("limiters") R. LeVeque: Finite Volume Methods for HyperbolicHigh-resolution finite volume methods for problems of reactive transport in porous media Peter

  9. High-resolution digital teleradiology: a perspective.

    PubMed

    Kuduvalli, G R; Rangayyan, R M; Desautels, J E

    1991-11-01

    Teleradiology has come a long way, from analog transmission systems using slow-scan television over standard telephone lines, to present-day, commercially available, microcomputer-based, low-resolution teleradiology systems. However, there exists a need to address the high-resolution end of the medical imaging categories, namely chest radiographs and mammograms, to firmly establish teleradiology. The availability of high-resolution image digitizers, display units, and digital hard copiers has made high-resolution digital teleradiology a feasible concept. Although the use of satellite channels can speed up the transmission of radiographic image data, with widespread acceptance of high-resolution teleradiology systems in the foreseeable future, the sheer amount of data involved in this field will give rise to problems of data transmission and storage. Data compression schemes can bring down the amount of data handled and can have a great economic impact on future teleradiology systems. We have developed a number of compression techniques for reversible compression of medical images. Our experiments have shown that lossless compression of the order of 4:1 is possible for a class of high-resolution medical images. Use of pattern recognition techniques offers the potential to bring down these data rates even further. We plan to use these techniques in a prototype high-resolution teleradiology system being developed. In this paper, we trace some of the developments in teleradiology and image data compression, and present a perspective for teleradiology in the 1990s. PMID:1772919

  10. High-Resolution Plots of Trigonometric Functions.

    ERIC Educational Resources Information Center

    Stick, Marvin E.; Stick, Michael J.

    1985-01-01

    Provides computer programs (for Apple microcomputers) for drawing (in high resolution graphics) a three-leaved rose, concentric circles, circumscribed and inscribed astroids. Sample output and discussions of the mathematics involved in the programs are included. (JN)

  11. High-Resolution X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    ODell, Stephen L.; Brissenden, Roger J.; Davis, William; Elsner, Ronald F.; Elvis, Martin; Freeman, Mark; Gaetz, Terry; Gorenstein, Paul; Gubarev, Mikhail V.

    2010-01-01

    Fundamental needs for future x-ray telescopes: a) Sharp images => excellent angular resolution. b) High throughput => large aperture areas. Generation-X optics technical challenges: a) High resolution => precision mirrors & alignment. b) Large apertures => lots of lightweight mirrors. Innovation needed for technical readiness: a) 4 top-level error terms contribute to image size. b) There are approaches to controlling those errors. Innovation needed for manufacturing readiness. Programmatic issues are comparably challenging.

  12. High resolution SAR applications and instrument design

    NASA Technical Reports Server (NTRS)

    Dionisio, C.; Torre, A.

    1993-01-01

    The Synthetic Aperture Radar (SAR) has viewed, in the last two years, a huge increment of interest from many preset and potential users. The good spatial resolution associated to the all weather capability lead to considering SAR not only a scientific instrument but a tool for verifying and controlling the daily human relationships with the Earth Environment. New missions were identified for SAR as spatial resolution became lower than three meters: disasters, pollution, ships traffic, volcanic eruptions, earthquake effect are only a few of the possible objects which can be effectively detected, controlled and monitored by SAR mounted on satellites. High resolution radar design constraints and dimensioning are discussed.

  13. High-Resolution PET Detector. Final report

    SciTech Connect

    Karp, Joel

    2014-03-26

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

  14. High spectral resolution reflectance spectroscopy of minerals

    USGS Publications Warehouse

    Clark, R.N.; King, T.V.V.; Klejwa, M.; Swayze, G.A.; Vergo, N.

    1990-01-01

    The reflectance spectra of minerals are studied as a function of spectral resolution in the range from 0.2 to 3.0 ??m. Selected absorption bands were studied at resolving powers (??/????) as high as 2240. At resolving powers of approximately 1000, many OH-bearing minerals show diagnostic sharp absorptions at the resolution limit. At low resolution, some minerals may not be distinguishable, but as the resolution is increased, most can be easily identified. As the resolution is increased, many minerals show fine structure, particularly in the OH-stretching overtone region near 1.4 ??m. The fine structure can enhance the ability to discriminate between minerals, and in some cases the fine structure can be used to determine elemental composition. The study shows that high-resolution reflectance spectroscopy of minerals may prove to be a very important tool in the laboratory, in the field using field-portable spectrometers, from aircraft, and from satellites looking at Earth or other planetary surfaces. -from Authors

  15. High Spatial Resolution Thermal Satellite Technologies

    NASA Technical Reports Server (NTRS)

    Ryan, Robert

    2003-01-01

    This document in the form of viewslides, reviews various low-cost alternatives to high spatial resolution thermal satellite technologies. There exists no follow-on to Landsat 7 or ASTER high spatial resolution thermal systems. This document reviews the results of the investigation in to the use of new technologies to create a low-cost useful alternative. Three suggested technologies are examined. 1. Conventional microbolometer pushbroom modes offers potential for low cost Landsat Data Continuity Mission (LDCM) thermal or ASTER capability with at least 60-120 ground sampling distance (GSD). 2. Backscanning could produce MultiSpectral Thermal Imager performance without cooled detectors. 3. Cooled detector could produce hyperspectral thermal class system or extremely high spatial resolution class instrument.

  16. High resolution solar X-ray studies

    NASA Technical Reports Server (NTRS)

    Blake, R. L.

    1974-01-01

    Two high resolution solar X-ray payloads and their launches on Aerobee rockets with pointing system are described. The payloads included 5 to 25A X-ray spectrometers, multiaperture X-ray cameras, and command box attitude control inflight by means of a television image radioed to ground. Spatial resolution ranged from five arc minutes to ten arc seconds and spectral resolution ranged from 500 to 3000. Several laboratory tasks were completed in order to achieve the desired resolution. These included (1) development of techniques to align grid collimators, (2) studies of the spectrometric properties of crystals, (3) measurements of the absorption coefficients of various materials used in X-ray spectrometers, (4) evaluation of the performance of multiaperture cameras, and (5) development of facilities.

  17. Solar system events at high spatial resolution

    SciTech Connect

    Baines, K H; Gavel, D T; Getz, A M; Gibbartd, S G; MacIntosh, B; Max, C E; McKay, C P; Young, E F; de Pater, I

    1999-02-19

    Until relatively recent advances in technology, astronomical observations from the ground were limited in image resolution by the blurring effects of earth's atmosphere. The blur extent, ranging typically from 0.5 to 2 seconds of arc at the best astronomical sights, precluded ground-based observations of the details of the solar system's moons, asteroids, and outermost planets. With the maturing of a high resolution image processing technique called speckle imaging the resolution limitation of the atmosphere can now be largely overcome. Over the past three years they have used speckle imaging to observe Titan, a moon of Saturn with an atmospheric density comparable to Earth's, Io, the volcanically active innermost moon of Jupiter, and Neptune, a gas giant outer planet which has continually changing planet-encircling storms. These observations were made at the world's largest telescope, the Keck telescope in Hawaii and represent the highest resolution infrared images of these objects ever taken.

  18. ELECTRONICS UPGRADE OF HIGH RESOLUTION MASS SPECTROMETERS

    SciTech Connect

    Mcintosh, J; Joe Cordaro, J

    2008-03-10

    High resolution mass spectrometers are specialized systems that allow researchers to determine the exact mass of samples to four significant digits by using magnetic and electronic sector mass analyzers. Many of the systems in use today at research laboratories and universities were designed and built more than two decades ago. The manufacturers of these systems have abandoned the support for some of the mass spectrometers and parts to power and control them have become scarce or obsolete. The Savannah River National Laboratory has been involved in the upgrade of the electronics and software for these legacy machines. The Electronics Upgrade of High Resolution Mass Spectrometers consists of assembling high-end commercial instrumentation from reputable manufacturers with a minimal amount of customization to replace the electronics for the older systems. By taking advantage of advances in instrumentation, precise magnet control can be achieved using high resolution current sources and continuous feedback from a high resolution hall-effect probe. The custom equipment include a precision voltage divider/summing amplifier chassis, high voltage power supply chassis and a chassis for controlling the voltage emission for the mass spectrometer source tube. The upgrade package is versatile enough to interface with valve control, vacuum and other instrumentation. Instrument communication is via a combination of Ethernet and traditional IEEE-488 GPIB protocols. The system software upgrades include precision control, feedback and spectral waveform analysis tools.

  19. RAPID DAMAGE ASSESSMENT FROM HIGH RESOLUTION IMAGERY

    SciTech Connect

    Vijayaraj, Veeraraghavan; Bright, Eddie A; Bhaduri, Budhendra L

    2008-01-01

    Disaster impact modeling and analysis uses huge volumes of image data that are produced immediately following a natural or an anthropogenic disaster event. Rapid damage assessment is the key to time critical decision support in disaster management to better utilize available response resources and accelerate recovery and relief efforts. But exploiting huge volumes of high resolution image data for identifying damaged areas with robust consistency in near real time is a challenging task. In this paper, we present an automated image analysis technique to identify areas of structural damage from high resolution optical satellite data using features based on image content.

  20. High-resolution Sidescan Sonar Towfish

    USGS Multimedia Gallery

    Mikhail Malin, visiting IBIW scientist, prepares to deploy a high-resolution sidescan sonar towfish below Bagnell Dam on the Osage River.  The CERC and IBIW collaborated with the Missouri Cooperative Fish and Wildlife Research Unit at the University of Missouri to assess the distribution of pad...

  1. Venus 2012 transit: spectroscopy and high resolution

    E-print Network

    Widemann, Thomas

    Venus 2012 transit: spectroscopy and high resolution observations proposals by Cyril Bazin, Serge the structuration of Venus upper atmosphere ? 2012 Venus transit : Better understanding these upper layers the Venus thick atmosphere >>> -tentative spectroscopic exp-t prepared at the 1m diam. Solar Tel

  2. A High-Resolution Stopwatch for Cents

    ERIC Educational Resources Information Center

    Gingl, Z.; Kopasz, K.

    2011-01-01

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

  3. High-resolution display system for mammograms

    NASA Astrophysics Data System (ADS)

    Moskowitz, Michael J.; Huang, H. K.; Wang, Jun; Allen, Jeffrey; Sickles, Edward A.; Giles, Anthony

    1995-04-01

    A high resolution mammographic display station is implemented for clinical diagnosis and for a digital teaching file. The display consists of a specially designed, high resolution mammographic station which contains a connection to a 50 micron (variable spot size) laser film digitizer, two 2 K X 2.5 K display monitors, an image processor, a host computer, and a disk array for high speed image transfer to the display monitors. After digitization on a separate host computer, the files are immediately transferred to the display station and post- processed for viewing. The algorithm for post-processing of the digitized image applies a non- linear LUT to mimic the original film characteristics while taking into account the luminosity of the display monitors in an attempt to produce the highest digital image quality possible. Image processing functions for enhancing calcification and soft tissue are also available to assist the human observer in classification of objects within the image. Windowing and level controls are seamlessly integrated for each monitor, as well as magnification capabilities. For an image display at its full resolution (e.g., digitized at 100 microns), the magnification is accomplished with a roaming window utilizing simple 2X pixel replication. This has been found to be acceptable in preliminary tests with clinicians. Measurements of features on the 2 k displays are possible, as well. The display format accurately simulates mammographic viewing arrangements with automatic side-by-side historical, current, left and right craniocaudal, mediolateral, etc., view comparisons. This high resolution mammographic display is found to be essential for fast and accurate display of high resolution digitized mammograms. A digital mammographic teaching file has been designed and tested using this display architecture. The teaching file presents the case questions on the host display monitor, and the related images for each question are presented on the high resolution displays. The full functionality of the aforementioned high resolution mammogram display is held intact, so that the images can be examined with the full range of tools available: image processing, magnification, window/level control, and feature measurement.

  4. High Resolution Melting Analysis for Gene Scanning

    PubMed Central

    Erali, Maria; Wittwer, Carl T.

    2010-01-01

    High resolution melting is a new method of genotyping and variant scanning that can be seamlessly appended to PCR amplification. Limitations of genotyping by amplicon melting can be addressed by unlabeled probe or snapback primer analysis, all performed without labeled probes. High resolution melting can also be used to scan for rare sequence variants in large genes with multiple exons and is the focus of this article. With the simple addition of a heteroduplex-detecting dye before PCR, high resolution melting is performed without any additions, processing or separation steps. Heterozygous variants are identified by atypical melting curves of a different shape compared to wild type homozygotes. Homozygous or hemizygous variants are detected by prior mixing with wild type DNA. Design, optimization, and performance considerations for high resolution scanning assays are presented for rapid turnaround of gene scanning. Design concerns include primer selection and predicting melting profiles in silico. Optimization includes temperature gradient selection of the annealing temperature, random population screening for common variants, and batch preparation of primer plates with robotically deposited and dried primer pairs. Performance includes rapid DNA preparation, PCR, and scanning by high resolution melting that require, in total, only 3 hours when no variants are present. When variants are detected, they can be identified in an additional 3 hours by rapid cycle sequencing and capillary electrophoresis. For each step in the protocol, a general overview of principles is provided, followed by an in depth analysis of one example, scanning of CYBB, the gene that is mutated in X-linked chronic granulomatous disease. PMID:20085814

  5. A Portable, High Resolution, Surface Measurement Device

    NASA Technical Reports Server (NTRS)

    Ihlefeld, Curtis M.; Burns, Bradley M.; Youngquist, Robert C.

    2012-01-01

    A high resolution, portable, surface measurement device has been demonstrated to provide micron-resolution topographical plots. This device was specifically developed to allow in-situ measurements of defects on the Space Shuttle Orbiter windows, but is versatile enough to be used on a wide variety of surfaces. This paper discusses the choice of an optical sensor and then the decisions required to convert a lab bench optical measurement device into an ergonomic portable system. The necessary trade-offs between performance and portability are presented along with a description of the device developed to measure Orbiter window defects.

  6. Scanning Transmission Electron Microscopy at High Resolution

    PubMed Central

    Wall, J.; Langmore, J.; Isaacson, M.; Crewe, A. V.

    1974-01-01

    We have shown that a scanning transmission electron microscope with a high brightness field emission source is capable of obtaining better than 3 Å resolution using 30 to 40 keV electrons. Elastic dark field images of single atoms of uranium and mercury are shown which demonstrate this fact as determined by a modified Rayleigh criterion. Point-to-point micrograph resolution between 2.5 and 3.0 Å is found in dark field images of micro-crystallites of uranium and thorium compounds. Furthermore, adequate contrast is available to observe single atoms as light as silver. Images PMID:4521050

  7. High-Resolution, Two-Wavelength Pyrometer

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.; Henry, Paul K.; Logiurato, D. Daniel

    1989-01-01

    Modified two-color pyrometer measures temperatures of objects with high spatial resolution. Image focused on hole 0.002 in. (0.05 mm) in diameter in brass sheet near end of bundle, causing image to be distributed so fibers covered by defocused radiation from target. Pinhole ensures radiation from only small part of target scene reaches detector, thus providing required spatial resolution. By spreading radiation over bundle, pinhole ensures entire active area of detectors utilized. Produces signal as quiet as conventional instruments but with only 1/64 input radiation.

  8. High resolution schemes for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Harten, A.

    1983-01-01

    A class of new explicit second order accurate finite difference schemes for the computation of weak solutions of hyperbolic conservation laws is presented. These highly nonlinear schemes are obtained by applying a nonoscillatory first order accurate scheme to an appropriately modified flux function. The so-derived second order accurate schemes achieve high resolution while preserving the robustness of the original nonoscillatory first order accurate scheme. Numerical experiments are presented to demonstrate the performance of these new schemes.

  9. High-Resolution Traction Force Microscopy

    PubMed Central

    Plotnikov, Sergey V.; Sabass, Benedikt; Schwarz, Ulrich S.; Waterman, Clare M.

    2015-01-01

    Cellular forces generated by the actomyosin cytoskeleton and transmitted to the extracellular matrix (ECM) through discrete, integrin-based protein assemblies, that is, focal adhesions, are critical to developmental morphogenesis and tissue homeostasis, as well as disease progression in cancer. However, quantitative mapping of these forces has been difficult since there has been no experimental technique to visualize nanonewton forces at submicrometer spatial resolution. Here, we provide detailed protocols for measuring cellular forces exerted on two-dimensional elastic substrates with a high-resolution traction force microscopy (TFM) method. We describe fabrication of polyacrylamide substrates labeled with multiple colors of fiducial markers, functionalization of the substrates with ECM proteins, setting up the experiment, and imaging procedures. In addition, we provide the theoretical background of traction reconstruction and experimental considerations important to design a high-resolution TFM experiment. We describe the implementation of a new algorithm for processing of images of fiducial markers that are taken below the surface of the substrate, which significantly improves data quality. We demonstrate the application of the algorithm and explain how to choose a regularization parameter for suppression of the measurement error. A brief discussion of different ways to visualize and analyze the results serves to illustrate possible uses of high-resolution TFM in biomedical research. PMID:24974038

  10. Constructing a WISE High Resolution Galaxy Atlas

    NASA Technical Reports Server (NTRS)

    Jarrett, T. H.; Masci, F.; Tsai, C. W.; Petty, S.; Cluver, M.; Assef, Roberto J.; Benford, D.; Blain, A.; Bridge, C.; Donoso, E.; Eisenhardt, P.; Fowler, J.; Koribalski, B.; Lake, S.; Neill, James D.; Seibert, M.; Stanford, S.; Wright, E.

    2012-01-01

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

  11. CONSTRUCTING A WISE HIGH RESOLUTION GALAXY ATLAS

    SciTech Connect

    Jarrett, T. H.; Masci, F.; Tsai, C. W.; Fowler, J.; Petty, S.; Lake, S.; Wright, E.; Cluver, M.; Assef, Roberto J.; Eisenhardt, P.; Benford, D.; Blain, A.; Bridge, C.; Neill, James D.; Donoso, E.; Koribalski, B.; Seibert, M.; Sheth, K.; Stanford, S.

    2012-08-15

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

  12. Constructing a WISE High Resolution Galaxy Atlas

    E-print Network

    Jarrett, T H; Tsai, C W; Petty, S; Cluver, M; Assef, Roberto J; Benford, D; Blain, A; Bridge, C; Donoso, E; Eisenhardt, P; Fowler, J; Koribalski, B; Lake, S; Neill, James D; Seibert, M; Sheth, K; Stanford, S; Wright, E

    2012-01-01

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

  13. High resolution 3D nonlinear integrated inversion

    NASA Astrophysics Data System (ADS)

    Li, Yong; Wang, Xuben; Li, Zhirong; Li, Qiong; Li, Zhengwen

    2009-06-01

    The high resolution 3D nonlinear integrated inversion method is based on nonlinear theory. Under layer control, the log data from several wells (or all wells) in the study area and seismic trace data adjacent to the wells are input to a network with multiple inputs and outputs and are integratedly trained to obtain an adaptive weight function of the entire study area. Integrated nonlinear mapping relationships are built and updated by the lateral and vertical geologic variations of the reservoirs. Therefore, the inversion process and its inversion results can be constrained and controlled and a stable seismic inversion section with high resolution with velocity inversion, impedance inversion, and density inversion sections, can be gained. Good geologic effects have been obtained in model computation tests and real data processing, which verified that this method has high precision, good practicality, and can be used for quantitative reservoir analysis.

  14. DKIST: Observing the Sun at High Resolution

    NASA Astrophysics Data System (ADS)

    Tritschler, A.; Rimmele, T. R.; Berukoff, S.; Casini, R.; Craig, S. C.; Elmore, D. F.; Hubbard, R. P.; Kuhn, J. R.; Lin, H.; McMullin, J. P.; Reardon, K. P.; Schmidt, W.; Warner, M.; Woger, F.

    2015-01-01

    The 4-m aperture Daniel K. Inouye Solar Telescope (DKIST) formerly known as the Advanced Technology Solar Telescope (ATST) and currently under construction on Haleakal? (Maui, Hawai'i) will be the largest solar ground-based telescope and leading resource for studying the dynamic Sun and its phenomena at high spatial, spectral and temporal resolution. Accurate and sensitive polarimetric observations at high-spatial resolution throughout the solar atmosphere including the corona is a high priority and a major science driver. As such the DKIST will offer a combination of state-of-the-art instruments with imaging and/or spectropolarimetric capabilities covering a broad wavelength range. This first-light instrumentation suite will include: a Visible Broadband Imager (VBI) for high-spatial and -temporal resolution imaging of the solar atmosphere; a Visible Spectro-Polarimeter (ViSP) for sensitive and accurate multi-line spectropolarimetry; a double Fabry-Pérot based Visible Tunable Filter (VTF) for high-spatial resolution spectropolarimetry; a fiber-fed 2D Diffraction-Limited Near Infra-Red Spectro-Polarimeter (DL-NIRSP); and a Cryogenic Near Infra-Red Spectro-Polarimeter (Cryo-NIRSP) for coronal magnetic field measurements and on-disk observations of e.g. the CO lines at 4.7 microns. We will provide a brief overview of the DKIST's unique capabilities to perform spectroscopic and spectropolarimetric measurements of the solar atmosphere using its first-light instrumentation suite, the status of the construction project, and how facility and data access is provided to the US and international community.

  15. High-Resolution US of Rheumatologic Diseases.

    PubMed

    Taljanovic, Mihra S; Melville, David M; Gimber, Lana H; Scalcione, Luke R; Miller, Margaret D; Kwoh, C Kent; Klauser, Andrea S

    2015-01-01

    For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis. (©)RSNA, 2015. PMID:26562235

  16. High-resolution flurescence spectroscopy in immunoanalysis

    SciTech Connect

    Grubor, Nenad M.

    2005-05-01

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

  17. Transmitter sensitivity of neurons assayed by autoradiography

    SciTech Connect

    Yoshikami, D.

    1981-05-22

    Ionic conductance channels that are opened by activating nicotinic acetylcholine receptors at synapses of sympathetic neurons are permeable to small organic amines. Uptake of a tritium-labeled amine through these channels can be measured by autoradiography. This provides a simple and direct way to assess the sensitivity of individual neurons to acetylcholine without using microelectrodes.

  18. High time resolution studies of giant pulses

    NASA Astrophysics Data System (ADS)

    Bhat, Ramesh; van Straten, Willem; Jameson, Andrew; Carbone, Adam

    2013-04-01

    We propose to exploit the advanced pulsar instrumentation at the Parkes Observatory and employ novel methods of polarimetric calibration and statistical analysis to provide new insights into the rich variety of phenomena displayed by the Crab Nebula pulsar. Specifically, we will undertake baseband observations using the CASPSR system at 20 cm and 10 cm bands for the scientific objectives of (i) investigating the microstructure, and (ii) high time resolution polarimetry. With the ultra-high time resolution (2.5 ns) capabilities of CASPSR and its ability to sustain continuous recording for up to 4 hr, these observations will yield data of unprecedented quality, which will facilitate an in-depth, unbiased and accurate characterisation of giant pulses and microbursts. This will place novel constraints on pulsar emission mechanism.

  19. Conversational high resolution mass spectrographic data reduction

    NASA Technical Reports Server (NTRS)

    Romiez, M. P.

    1973-01-01

    A FORTRAN 4 program is described which reduces the data obtained from a high resolution mass spectrograph. The program (1) calculates an accurate mass for each line on the photoplate, and (2) assigns elemental compositions to each accurate mass. The program is intended for use in a time-shared computing environment and makes use of the conversational aspects of time-sharing operating systems.

  20. Binary Cepheids From High-Angular Resolution

    NASA Astrophysics Data System (ADS)

    Gallenne, A.; Mérand, A.; Kervella, P.

    2015-12-01

    Optical interferometry is the only technique giving access to milli-arcsecond (mas) spatial resolution. This is a powerful and unique tool to detect the close orbiting companions of Cepheids, and offers an unique opportunity to make progress in resolving the Cepheid mass discrepancy. Our goal in studying binary Cepheids is to measure the astrometric position of the high-contrast companion, and then combine them with spectroscopic measurements to derive the orbital elements, distances, and dynamical masses. In the course of this program, we developed a new tool, CANDID, to search for high-contrast companions and set detection limits from interferometric observations

  1. High resolution GLAS on the MCIDAS

    NASA Technical Reports Server (NTRS)

    Susskind, J.; Atlas, R.; Pursch, A.

    1984-01-01

    The GLAS physical inversion method for analysis of HIRS2/MSU data was implemented on the McIDAS. The method of analysis is identical to that used in processing global retrievals for six months of 1979, with the exception that the McIDAS retrievals are done on a higher spatial resolution, with one sounding attempted in every 4 x 4 array of HIRS2 spots, corresponding to roughly 80 x 80 km at nadir. This 4 x 4 array is further subdivided in 4 2 x 2 arrays with the sounding being performed utilizing all the spots in the single warmest 2 x 2 quadrant as sensed by the 11 micrometer window channel. Whether accurate retrievals can be performed on the high resolution grid without editing was determined. Different retrievals for a synoptic situation was compared and the guess dependence of the high resolution GLAS retrievals were examined. The orbit crossing the central United States at 1/21/79 09257 was studied. Radiosondes at 1200Z were used for comparison.

  2. Stellar population models at high spectral resolution

    NASA Astrophysics Data System (ADS)

    Maraston, C.; Strömbäck, G.

    2011-12-01

    We present new, high-to-intermediate spectral resolution stellar population models, based on four popular libraries of empirical stellar spectra, namely Pickles, ELODIE, STELIB and MILES. These new models are the same as our previous models, but with higher resolution and based on empirical stellar spectra, while keeping other ingredients the same including the stellar energetics, the atmospheric parameters and the treatment of the thermally pulsating asymptotic giant branch and the horizontal branch morphology. We further compute very high resolution (R= 20 000) models based on the theoretical stellar library MARCS which extends to the near-infrared. We therefore provide merged high-resolution stellar population models, extending from ˜1000 to 25 000 Å, using our previously published high-resolution theoretical models which extended to the ultraviolet. We compare how these libraries perform in stellar population models and highlight spectral regions where discrepancies are found. We confirm our previous findings that the flux around the V band is lower (in a normalized sense) in models based on empirical libraries than in those based on the BaSeL-Kurucz library, which results in a bluer B-V colour. Most noticeably the theoretical library MARCS gives results fully consistent with the empirical libraries. This same effect is also found in other models using MILES, namely Vazdekis et al. and Conroy & Gunn, even though the latter authors reach the opposite conclusion. The bluer predicted B-V colour (by 0.05 mag in our models) is in better agreement with both the colours of luminous red galaxies and globular cluster data. We test the models on their ability to reproduce, through full spectral fitting, the ages and metallicities of Galactic globular clusters as derived from colour-magnitude diagram (CMD) fitting and find overall good agreement. We also discuss extensively the Lick indices calculated directly on the integrated MILES-based spectral energy distributions (SEDs) and compare them with element ratio-sensitive index models. We find a good agreement between the two models, if the metallicity-dependent chemical pattern of the Milky Way stars is properly taken into account in this comparison. As a consequence, the ages and metallicities of Galactic globular clusters are not well reproduced when one uses straight the MILES-based indices, because subtle chemical effects on individual lines dominate the age derivation. The best agreement with the ages of the calibrating globular clusters is found with either element ratio-sensitive absorption-line models or the full SED fitting, for which no particular weight is given to selected lines.

  3. Computer synthesis of high resolution electron micrographs

    NASA Technical Reports Server (NTRS)

    Nathan, R.

    1976-01-01

    Specimen damage, spherical aberration, low contrast and noisy sensors combine to prevent direct atomic viewing in a conventional electron microscope. The paper describes two methods for obtaining ultra-high resolution in biological specimens under the electron microscope. The first method assumes the physical limits of the electron objective lens and uses a series of dark field images of biological crystals to obtain direct information on the phases of the Fourier diffraction maxima; this information is used in an appropriate computer to synthesize a large aperture lens for a 1-A resolution. The second method assumes there is sufficient amplitude scatter from images recorded in focus which can be utilized with a sensitive densitometer and computer contrast stretching to yield fine structure image details. Cancer virus characterization is discussed as an illustrative example. Numerous photographs supplement the text.

  4. Development of a high resolution and high dispersion Thomson parabola.

    PubMed

    Jung, D; Hörlein, R; Kiefer, D; Letzring, S; Gautier, D C; Schramm, U; Hübsch, C; Öhm, R; Albright, B J; Fernandez, J C; Habs, D; Hegelich, B M

    2011-01-01

    Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ?E?E < 5% at 100 MeV/nucleon and impede premature merging of different ion species at low energies on the detector plane. First results from laser driven ion acceleration experiments performed at the Trident Laser Facility demonstrate high resolution and superior species and charge state separation of this novel Thomson parabola for ion energies of more than 30 MeV/nucleon. PMID:21280824

  5. Development of a high resolution and high dispersion Thomson parabola

    NASA Astrophysics Data System (ADS)

    Jung, D.; Hörlein, R.; Kiefer, D.; Letzring, S.; Gautier, D. C.; Schramm, U.; Hübsch, C.; Öhm, R.; Albright, B. J.; Fernandez, J. C.; Habs, D.; Hegelich, B. M.

    2011-01-01

    Here, we report on the development of a novel high resolution and high dispersion Thomson parabola for simultaneously resolving protons and low-Z ions of more than 100 MeV/nucleon necessary to explore novel laser ion acceleration schemes. High electric and magnetic fields enable energy resolutions of ?E/E < 5% at 100 MeV/nucleon and impede premature merging of different ion species at low energies on the detector plane. First results from laser driven ion acceleration experiments performed at the Trident Laser Facility demonstrate high resolution and superior species and charge state separation of this novel Thomson parabola for ion energies of more than 30 MeV/nucleon.

  6. Applied high resolution digital control for universal precision systems

    E-print Network

    Gawlik, Aaron John

    2008-01-01

    This thesis describes the design and characterization of a high-resolution analog interface for dSPACE digital control systems and a high-resolution, high-speed data acquisition and control system. These designs are intended ...

  7. High Volume Rate, High Resolution 3D Plane Wave Imaging

    E-print Network

    Wenisch, Thomas F.

    High Volume Rate, High Resolution 3D Plane Wave Imaging Ming Yang, Richard Sampson, Siyuan Wei Department of Radiology, University of Michigan, Ann Arbor, MI 48109 Abstract--3D plane-wave imaging systems the image quality of plane-wave systems at the expense of significant increase in beamforming computational

  8. High Spectral Resolution Lidar: System Calibration

    NASA Astrophysics Data System (ADS)

    Vivek Vivekanandan, J.; Morley, Bruce; Spuler, Scott; Eloranta, Edwin

    2015-04-01

    One of the unique features of the high spectral resolution lidar (HSRL) is simultaneous measurements of backscatter and extinction of atmosphere. It separates molecular scattering from aerosol and cloud particle backscatter based on their Doppler spectrum width. Scattering from aerosol and cloud particle are referred as Mie scattering. Molecular or Rayleigh scattering is used as a reference for estimating aerosol extinction and backscatter cross-section. Absolute accuracy of the backscattered signals and their separation into Rayleigh and Mie scattering depends on spectral purity of the transmitted signals, accurate measurement of transmit power, and precise performance of filters. Internal calibration is used to characterize optical subsystems Descriptions of high spectral resolution lidar system and its measurement technique can be found in Eloronta (2005) and Hair et al.(2001). Four photon counting detectors are used to measure the backscatter from the combined Rayleigh and molecular scattering (high and low gain), molecular scattering and cross-polarized signal. All of the detectors are sensitive to crosstalk or leakage through the optical filters used to separate the received signals and special data files are used to remove these effects as much as possible. Received signals are normalized with respect to the combined channel response to Mie and Rayleigh scattering. The laser transmit frequency is continually monitored and tuned to the 1109 Iodine absorption line. Aerosol backscatter cross-section is measured by referencing the aerosol return signal to the molecular return signal. Extinction measurements are calculated based on the differences between the expected (theoretical) and actual change in the molecular return. In this paper an overview of calibration of the HSRL is presented. References: Eloranta, E. W., High Spectral Resolution Lidar in Lidar: Range-Resolved Optical Remote Sensing of the Atmosphere, Klaus Weitkamp editor, Springer Series in Optical Sciences, Springer-Verlag, New York, 2005. Hair, JW; Caldwell, LM; Krueger, D. A.Krueger, and C.Y. She 2001: High-spectral-resolution lidar with iodine-vapor filters: measurement of atmospheric-state and aerosol profiles. Appl. Optics, 40, 5280-5294.

  9. High Resolution ? Hypernuclear Spectroscopy with Electron Beams

    NASA Astrophysics Data System (ADS)

    Gogami, T.; Achenbach, P.; Ahmidouch, A.; Albayrak, I.; Androic, D.; Asaturyan, A.; Asaturyan, R.; Ates, O.; Baturin, P.; Badui, R.; Boeglin, W.; Bono, J.; Brash, E.; Carter, P.; Chen, C.; Chiba, A.; Christy, E.; Danagoulian, S.; De Leo, R.; Doi, D.; Elaasar, M.; Ent, R.; Fujii, Y.; Fujita, M.; Furic, M.; Gabrielyan, M.; Gan, L.; Garibaldi, F.; Gaskell, D.; Gasparian, A.; Hashimoto, O.; Horn, T.; Hu, B.; Hungerford, Ed. V.; Jones, M.; Kanda, H.; Kaneta, M.; Kato, S.; Kawai, M.; Kawama, D.; Khanal, H.; Kohl, M.; Liyanage, A.; Luo, W.; Maeda, K.; Margaryan, A.; Markowitz, P.; Maruta, T.; Matsumura, A.; Maxwell, V.; Mkrtchyan, A.; Mkrtchyan, H.; Nagao, S.; Nakamura, S. N.; Narayan, A.; Neville, C.; Niculescu, G.; Niculescu, M. I.; Nunez, A.; Nuruzzaman; Okayasu, Y.; Petkovic, T.; Pochodzalla, J.; Qiu, X.; Reinhold, J.; Rodriguez, V. M.; Samanta, C.; Sawatzky, B.; Seva, T.; Shichijo, A.; Tadevosyan, V.; Tang, L.; Taniya, N.; Tsukada, K.; Veilleux, M.; Vulcan, W.; Wesselmann, F. R.; Wood, S. A.; Yamamoto, T.; Ya, L.; Ye, Z.; Yokota, K.; Yuan, L.; Zhamkochyan, S.; Zhu, L.

    JLab E05-115 which is an experiment for ? hypernuclear spectroscopy with electron beams was carried out at Jefferson Lab (JLab) in 2009. In the experiment, ? 7He, ? 9Li, ? 10Be, ? 12B and ? 52V were measured by new magnetic spectrometer systems (SPL+HES+HKS) which were necessary for spectroscopy with high energy resolution of sub-MeV (FWHM). This is the first attempt to measure a ? hypernucleus with up to medium-heavy mass region by the (e,e' K + ) reaction, overcoming high rate and high multiplicity conditions due to electromagnetic background particles. An overview of the hypernuclear experiments at JLab Hall-C and preliminary binding energy spectrum of ? 10Be are shown.

  10. Biological organization: Macromolecular interactions at high resolution

    SciTech Connect

    Burnett, R.M.; Vogel, H.J.

    1987-01-01

    The main thrust of this book is to feature important current information on interactions of macromolecules themselves (rather than, say, enzyme-substrate interactions). Viruses, as paradigms of small biological systems, are covered as are the pivotal areas of DNA-protein and of antibody interactions. The treatment of the comparatively new field of membrane structure at high resolution includes the latest results on the photosynthetic reaction center, placed in perspective by contributions on light sensitivity of proteins. Finally, chapters on signal receptors highlight the importance of mechanisms for the control of the other systems presented.

  11. Sequential High-Resolution Wind Profile Measurements

    NASA Technical Reports Server (NTRS)

    Johnson, D. L.; Vaughan, W. W.

    1978-01-01

    Tropospheric flow and lower stratospheric flow as measured by 94 sequences of high-resolution Jimsphere balloon data are presented and discussed. The 70 and 24 sequential series are presented for the Kennedy Space Center, Florida, and Point Mugu, California, areas, respectively. Supplemental data, consisting of the associative temperature profiles and surface and 200 mb synoptic maps, are also presented. The measurements are discussed relative to both the engineering and disciplinary areas. An initial subjective analysis of mesoscale features observed on some sequences is presented.

  12. High resolution extremity CT for biomechanics modeling

    SciTech Connect

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

    1995-09-23

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

  13. 18F-FDG positron autoradiography with a particle counting silicon pixel detector

    NASA Astrophysics Data System (ADS)

    Russo, P.; Lauria, A.; Mettivier, G.; Montesi, M. C.; Marotta, M.; Aloj, L.; Lastoria, S.

    2008-11-01

    We report on tests of a room-temperature particle counting silicon pixel detector of the Medipix2 series as the detector unit of a positron autoradiography (AR) system, for samples labelled with 18F-FDG radiopharmaceutical used in PET studies. The silicon detector (1.98 cm2 sensitive area, 300 µm thick) has high intrinsic resolution (55 µm pitch) and works by counting all hits in a pixel above a certain energy threshold. The present work extends the detector characterization with 18F-FDG of a previous paper. We analysed the system's linearity, dynamic range, sensitivity, background count rate, noise, and its imaging performance on biological samples. Tests have been performed in the laboratory with 18F-FDG drops (37-37 000 Bq initial activity) and ex vivo in a rat injected with 88.8 MBq of 18F-FDG. Particles interacting in the detector volume produced a hit in a cluster of pixels whose mean size was 4.3 pixels/event at 11 keV threshold and 2.2 pixels/event at 37 keV threshold. Results show a sensitivity for ?+ of 0.377 cps Bq-1, a dynamic range of at least five orders of magnitude and a lower detection limit of 0.0015 Bq mm-2. Real-time 18F-FDG positron AR images have been obtained in 500-1000 s exposure time of thin (10-20 µm) slices of a rat brain and compared with 20 h film autoradiography of adjacent slices. The analysis of the image contrast and signal-to-noise ratio in a rat brain slice indicated that Poisson noise-limited imaging can be approached in short (e.g. 100 s) exposures, with ~100 Bq slice activity, and that the silicon pixel detector produced a higher image quality than film-based AR.

  14. Localization of beta-adrenergic receptors in transmural slices of myocardium with quantitative autoradiography

    SciTech Connect

    Murphree, S.S.; Saffitz, J.E.

    1986-03-01

    Alterations in the density of myocardial ..beta..-adrenergic receptors (..beta..AR) induced by ischemia may be important in the pathophysiology of acute ischemic heart disease. Conventional binding assays in tissue homogenates lack the anatomic resolution required for cell-specific analysis of early alterations in receptor density induced by ischemia. Accordingly, the authors have developed methods for localization of ..beta..AR in transmural slices of feline left ventricle with quantitative autoradiography. Frozen sections were incubated with /sup 125/I-iodocyanopindolol (ICYP) +/- Z-propranolol for 60 min at 37/sup 0/. Non-specifically bound radioactivity was removed by rinsing the sections for 60 min at 22/sup 0/. At saturating concentrations of ICYP, > 90% specific binding was achieved. Specific binding was rapid, saturable, of high affinity and proportional to section thickness (B/sub max/ = 26.5 +/- 6.4 fmol/mg tissue protein; K/sub d/ = 10.0 +/- 2.1 pM; N = 14). Agonist binding showed the rank order of potency expected for ..beta..AR (IC/sub 50/ = 0.12 ..mu..M, isoproterenol; .18 ..mu..M, norepinephrine; .54 ..mu..M, epinephrine) and demonstrated stereo-selectivity (IC/sub 50/ = .013 ..mu..M, Z-isoproterenol; 9.5 ..mu..M, d-isoproterenol). Quantitative autoradiography with both film and emulsion methods will permit regional analysis of ..beta..AR density in large transmural sections as well as cell-specific analysis at the microscopic level.

  15. Crusta: Visualizing High-resolution Global Data

    NASA Astrophysics Data System (ADS)

    Bernardin, T. S.; Kreylos, O.; Bowles, C. J.; Cowgill, E.; Hamann, B.; Kellogg, L. H.

    2009-12-01

    Virtual globes have become indispensable tools for visualizing, understanding and presenting data from Earth and other planetary bodies. The scientific community has invested much effort into exploiting existing globes to their fullest potential by refining and adapting their capabilities to better satisfy specific needs. For example, Google Earth provides users with the ability to view hillshade images derived from airborne LiDAR data such as the 2007 Northern California GeoEarthScope data. However, because most available globes were not designed with the specific needs of geoscientists in mind, shortcomings are becoming increasingly evident in geoscience applications such as terrain visualization. In particular, earth scientists struggle to visualize digital elevation models with both high spatial resolution (0.5 - 1 square meters per sample) and large extent (>2000 square kilometers), such as those obtained with airborne LiDAR. To address the specific earth science need of real-time terrain visualization of LiDAR data, we are developing Crusta as part of a close collaboration involving earth and computer scientists. Crusta is a new virtual globe that differs from widely used globes by both providing accurate global data representation and the ability to easily visualize custom topographic and image data. As a result, Crusta enables real-time, interactive visualization of high resolution digital elevation data spanning thousands of square kilometers, such as the complete 2007 Northern California GeoEarthScope airborne LiDAR data set. To implement an accurate data representation and avoid distortion of the display at the poles, where other projections have singularities, Crusta represents the globe as a thirty-sided polyhedron. Each side of this polyhedron can be subdivided to an arbitrarily fine grid on the surface of the globe, which allows Crusta to accommodate input data of arbitrary resolution ranging from global (e.g., Blue Marble) to local (e.g., a tripod LiDAR survey). Use of the GDAL library facilitates importing a number of data formats into the Crusta-specific, multi-scale hierarchies that enable interactive visualization on platforms ranging from laptops to immersive geowalls and caves. In addition to the underlying data representation, we also designed Crusta to be dynamic. The shading of the terrain surface is computed in real-time and on the fly when a user manipulates the viewpoint. Likewise, Crusta allows dynamic adjustment of the vertical exaggeration for the display of the globe's surface over an unlimited range of scales. The combination of these two effects greatly improves the perception of shape in high-resolution digital elevation data, critically enhancing the observation of minute details within the context of larger areas

  16. Limiting liability via high resolution image processing

    SciTech Connect

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

    1996-12-31

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

  17. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Benner, D. Chris; Venkataraman, Malathy Devi

    2000-01-01

    The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as carbon dioxide, water vapor, ozone, methane, and carbon monoxide, to name a few. Measurements were made using the NASA Langley Tunable Diode Laser Spectrometer System (TDL) and several Fourier Transform Spectrometer Systems (FTS) around the globe. The results from these studies made remarkable improvements in the line positions and intensities for several molecules, particularly ozone and carbon dioxide in the 2 to 17-micrometer spectral region. Measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced line shift coefficients for infrared transitions of ozone, methane, and water vapor were also performed. Results from these studies have been used for retrievals of stratospheric gas concentration profiles from data collected by several Upper Atmospheric Research satellite (UARS) infrared instruments as well as in the analysis of high resolution atmospheric spectra such as those acquired by space-based, ground-based, and various balloon-and aircraft-borne experiments. Our results made significant contributions in several updates of the HITRAN (HIgh resolution TRANsmission) spectral line parameters database. This database enjoys worldwide recognition in research involving diversified scientific fields.

  18. Common high-resolution MMW scene generator

    NASA Astrophysics Data System (ADS)

    Saylor, Annie V.; McPherson, Dwight A.; Satterfield, H. DeWayne; Sholes, William J.; Mobley, Scott B.

    2001-08-01

    The development of a modularized millimeter wave (MMW) target and background high resolution scene generator is reported. The scene generator's underlying algorithms are applicable to both digital and real-time hardware-in-the-loop (HWIL) simulations. The scene generator will be configurable for a variety of MMW and multi-mode sensors employing state of the art signal processing techniques. At present, digital simulations for MMW and multi-mode sensor development and testing are custom-designed by the seeker vendor and are verified, validated, and operated by both the vendor and government in simulation-based acquisition. A typical competition may involve several vendors, each requiring high resolution target and background models for proper exercise of seeker algorithms. There is a need and desire by both the government and sensor vendors to eliminate costly re-design and re-development of digital simulations. Additional efficiencies are realized by assuring commonality between digital and HWIL simulation MMW scene generators, eliminating duplication of verification and validation efforts.

  19. High Resolution Camera for Mapping Titan Surface

    NASA Technical Reports Server (NTRS)

    Reinhardt, Bianca

    2011-01-01

    Titan, Saturn's largest moon, has a dense atmosphere and is the only object besides Earth to have stable liquids at its surface. The Cassini/Huygens mission has revealed the extraordinary breadth of geological processes shaping its surface. Further study requires high resolution imaging of the surface, which is restrained by light absorption by methane and scattering from aerosols. The Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft has demonstrated that Titan's surface can be observed within several windows in the near infrared, allowing us to process several regions in order to create a geological map and to determine the morphology. Specular reflections monitored on the lakes of the North Pole show little scattering at 5 microns, which, combined with the present study of Titan's northern pole area, refutes the paradigm that only radar can achieve high resolution mapping of the surface. The present data allowed us to monitor the evolution of lakes, to identify additional lakes at the Northern Pole, to examine Titan's hypothesis of non-synchronous rotation and to analyze the albedo of the North Pole surface. Future missions to Titan could carry a camera with 5 micron detectors and a carbon fiber radiator for weight reduction.

  20. High-Resolution Scintimammography: A Pilot Study

    SciTech Connect

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

    2002-07-01

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

  1. Ultra-high resolution computed tomography imaging

    DOEpatents

    Paulus, Michael J. (Knoxville, TN); Sari-Sarraf, Hamed (Knoxville, TN); Tobin, Jr., Kenneth William (Harriman, TN); Gleason, Shaun S. (Knoxville, TN); Thomas, Jr., Clarence E. (Knoxville, TN)

    2002-01-01

    A method for ultra-high resolution computed tomography imaging, comprising the steps of: focusing a high energy particle beam, for example x-rays or gamma-rays, onto a target object; acquiring a 2-dimensional projection data set representative of the target object; generating a corrected projection data set by applying a deconvolution algorithm, having an experimentally determined a transfer function, to the 2-dimensional data set; storing the corrected projection data set; incrementally rotating the target object through an angle of approximately 180.degree., and after each the incremental rotation, repeating the radiating, acquiring, generating and storing steps; and, after the rotating step, applying a cone-beam algorithm, for example a modified tomographic reconstruction algorithm, to the corrected projection data sets to generate a 3-dimensional image. The size of the spot focus of the beam is reduced to not greater than approximately 1 micron, and even to not greater than approximately 0.5 microns.

  2. HIV: The Initial Invasion | High Resolution Electron Microscopy

    Cancer.gov

    Skip to main content High Resolution Electron Microscopy High Resolution Electron Microscopy Center for Cancer Research at the National Institutes of Health Main menu Home Research 3D Correlative Imaging Methods Development Protein Complexes Viral Entry Publications Image

  3. High-Resolution Radar Imagery of Mars

    NASA Astrophysics Data System (ADS)

    Harmon, John K.; Nolan, M. C.

    2009-09-01

    We present high-resolution radar images of Mars obtained during the 2005 and 2007 oppositions. The images were constructed from long-code delay-Doppler observations made with the Arecibo S-band (13-cm) radar. The average image resolution of 3 km represented a better than order-of-magnitude improvement over pre-upgrade Arecibo imagery of the planet. Images of depolarized reflectivity (an indicator primarily of wavelength-scale surface roughness) show the same bright volcanic flow features seen in earlier imagery, but with much finer detail. A new image of the Elysium region shows fine detail in the radar-bright channels of Athabasca Vallis, Marte Vallis, and Grjota Vallis. The new images of Tharsis and Olympus Mons also show a complex array of radar-bright and radar-dark features. Southern Amazonis exhibits some of the most complex and puzzling radar-bright structure on the planet. Another curiosity is the Chryse/Xanthe/Channels region, where we find some radar-bright features in or adjacent to fluvial chaos structures. Chryse/Xanthe is also the only region of Mars showing radar-bright craters (which are rare on Mars but common on the Moon and Mercury). We also obtained the first delay-Doppler image showing the enhanced backscatter from the residual south polar ice cap. In addition to the depolarized imagery, we were able to make the first delay-Doppler images of the circular polarization ratio (an important diagnostic for surface roughness texture). We find that vast areas of the radar-bright volcanic regions have polarization ratios close to unity. Such high ratios are rare for terrestrial lava flows and only seen for extremely blocky surfaces giving high levels of multiple scattering.

  4. The CIBA high resolution RBS facility

    NASA Astrophysics Data System (ADS)

    Osipowicz, T.; Seng, H. L.; Chan, T. K.; Ho, B.

    2006-08-01

    Recently, a high resolution RBS facility was installed at the Centre for Ion Beam Applications (CIBA) at the National University of Singapore (NUS). The magnetic spectrometer comprises of a 90° double focusing sector magnet and a 2D-MCP focal plane detector. The UHV scattering chamber is equipped with a five axis goniometer for channeling applications, the setup is similar to that used by the Kyoto group [K. Kimura, M. Kimura, Y. Mori, M. Maehara, H. Fukuyama, AIP Conf. Proc. 475 (1999) 500]. State of the art performance characteristics were expected, because the system operates in conjunction with the NUS Singletron accelerator, which provides ion beams with very favorable phase space characteristics. Well resolved spectra of 10 nm SiO2/Si are shown, and an energy resolution of 0.9 keV FWHM was measured at the leading Si edge of a SiO2 sample at 300 keV and 80° scattering angle, which is close to the value expected from kinematic broadening alone in this case (?0.7 keV).

  5. High Resolution Spectroscopic Study of $^{10}_?$Be

    E-print Network

    T. Gogami; C. Chen; D. Kawama; P. Achenbach; A. Ahmidouch; I. Albayrak; D. Androic; A. Asaturyan; R. Asaturyan; O. Ates; P. Baturin; R. Badui; W. Boeglin; J. Bono; E. Brash; P. Carter; A. Chiba; E. Christy; S. Danagoulian; R. De Leo; D. Doi; M. Elaasar; R. Ent; Y. Fujii; M. Fujita; M. Furic; M. Gabrielyan; L. Gan; F. Garibaldi; D. Gaskell; A. Gasparian; Y. Han; O. Hashimoto; T. Horn; B. Hu; Ed. V. Hungerford; M. Jones; H. Kanda; M. Kaneta; S. Kato; M. Kawai; H. Khanal; M. Kohl; A. Liyanage; W. Luo; K. Maeda; A. Margaryan; P. Markowitz; T. Maruta; A. Matsumura; V. Maxwell; A. Mkrtchyan; H. Mkrtchyan; S. Nagao; S. N. Nakamura; A. Narayan; C. Neville; G. Niculescu; M. I. Niculescu; A. Nunez; Nuruzzaman; Y. Okayasu; T. Petkovic; J. Pochodzalla; X. Qiu; J. Reinhold; V. M. Rodriguez; C. Samanta; B. Sawatzky; T. Seva; A. Shichijo; V. Tadevosyan; L. Tang; N. Taniya; K. Tsukada; M. Veilleux; W. Vulcan; F. R. Wesselmann; S. A. Wood; T. Yamamoto; L. Ya; Z. Ye; K. Yokota; L. Yuan; S. Zhamkochyan; L. Zhu

    2015-11-16

    A spectroscopy of a $^{10}_{\\Lambda}$Be hypernucleus was carried out at JLab Hall C using the $(e,e^{\\prime}K^{+})$ reaction. A new magnetic spectrometer system (SPL+HES+HKS), specifically designed for high resolution hypernuclear spectroscopy, was used to obtain an energy spectrum with a resolution of 0.78 MeV (FWHM). The well-calibrated spectrometer system of the present experiment using the $p(e,e^{\\prime}K^{+})\\Lambda,\\Sigma^{0}$ reactions allowed us to determine the energy levels, and the binding energy of the ground state peak (mixture of 1$^{-}$ and 2$^{-}$ states) was obtained to be B$_{\\Lambda}$=8.55$\\pm$0.07(stat.)$\\pm$0.11(sys.) MeV. The result indicates that the ground state energy is shallower than that of an emulsion study by about 0.5 MeV which provides valuable experimental information on Charge Symmetry Breaking (CSB) effect in the $\\Lambda N$ interaction.

  6. A high-resolution microchip optomechanical accelerometer

    NASA Astrophysics Data System (ADS)

    Krause, Alexander G.; Winger, Martin; Blasius, Tim D.; Lin, Qiang; Painter, Oskar

    2012-11-01

    The monitoring of acceleration is essential for a variety of applications ranging from inertial navigation to consumer electronics. Typical accelerometer operation involves the sensitive displacement measurement of a flexibly mounted test mass, which can be realized using capacitive, piezo-electric, tunnel-current or optical methods. Although optical detection provides superior displacement resolution, resilience to electromagnetic interference and long-range readout, current optical accelerometers either do not allow for chip-scale integration or utilize relatively bulky test mass sensors of low bandwidth. Here, we demonstrate an optomechanical accelerometer that makes use of ultrasensitive displacement readout using a photonic-crystal nanocavity monolithically integrated with a nanotethered test mass of high mechanical Q-factor. This device achieves an acceleration resolution of 10 µg Hz-1/2 with submilliwatt optical power, bandwidth greater than 20 kHz and a dynamic range of greater than 40 dB. Moreover, the nanogram test masses used here allow for strong optomechanical backaction, setting the stage for a new class of motional sensors.

  7. High Resolution Far-Infrared Studies

    NASA Technical Reports Server (NTRS)

    Mundy, Lee G.

    1997-01-01

    We have been obtained high-resolution data (20 ft at 50 microns and 30 ft at 100 microns) on the KAO using Paul Harvey's 2 x 10 element photometer in both scanning and nodding modes. The practical flux limit for scanning is about 100 Jy. For fainter sources, a nodding (beam-switching) mode, which spend more time on the source, is used. This technique has been used successfully on objects as faint as 10 Jy; the 1 sigma noise for a 1 hour integration is about 1 Jy. Although not as sensitive as space-based instruments, the higher spatial resolution afforded by the KAO is essential in studying the far-infrared emission associated with young stars; in several cases we have been able to distinguish emission from multiple sources which were blended in the IRAS beam. In addition, comparison of fluxes in the KAO beam to those in the much larger IRAS beam provides information on the extended low-level emission arising from the surrounding region. We have developed a number of codes for producing model intensity distributions.

  8. High Resolution Radar Measurements of Snow Avalanches

    NASA Astrophysics Data System (ADS)

    McElwaine, J. N.; Vriend, N. M.; Sovilla, B.; Keylock, C. J.; Brennan, P.; Ash, M.

    2012-12-01

    Geophysical mass flows, such as snow avalanches, are a major hazard in mountainous areas and have a significant impact on the infrastructure, economy and tourism of such regions. Obtaining a thorough understanding of the dynamics of snow avalanches is crucial for risk assessment and the design of defensive structures. However, because the underlying physics is poorly understood there are significant uncertainties concerning current models, which are poorly validated due to a lack of high resolution data. Direct observations of the denser core of a large avalanche are particularly difficult, since it is frequently obscured by the dilute powder cloud. We have developed and installed a phased array FMCW radar system that penetrates the powder cloud and directly images the dense core with a resolution of around 1 m at 50 Hz over the entire slope. We present data from recent avalanches at Vallée de la Sionne that show a wealth of internal structure and allow the tracking of individual fronts, roll waves and surges down the slope for the first time. We also show good agreement between the radar results and existing measurement systems that record data at particular points on the avalanche track.

  9. High Resolution Radar Measurements of Snow Avalanches

    NASA Astrophysics Data System (ADS)

    McElwaine, Jim; Sovilla, Betty; Vriend, Nathalie; Brennan, Paul; Ash, Matt; Keylock, Chris

    2013-04-01

    Geophysical mass flows, such as snow avalanches, are a major hazard in mountainous areas and have a significant impact on the infrastructure, economy and tourism of such regions. Obtaining a thorough understanding of the dynamics of snow avalanches is crucial for risk assessment and the design of defensive structures. However, because the underlying physics is poorly understood there are significant uncertainties concerning current models, which are poorly validated due to a lack of high resolution data. Direct observations of the denser core of a large avalanche are particularly difficult, since it is frequently obscured by the dilute powder cloud. We have developed and installed a phased array FMCW radar system that penetrates the powder cloud and directly images the dense core with a resolution of around 1 m at 50 Hz over the entire slope. We present data from recent avalanches at Vallee de la Sionne that show a wealth of internal structure and allow the tracking of individual fronts, roll waves and surges down the slope for the first time. We also show good agreement between the radar results and existing measurement systems that record data at particular points on the avalanche track.

  10. Clementine High Resolution Camera Mosaicking Project

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This report constitutes the final report for NASA Contract NASW-5054. This project processed Clementine I high resolution images of the Moon, mosaicked these images together, and created a 22-disk set of compact disk read-only memory (CD-ROM) volumes. The mosaics were produced through semi-automated registration and calibration of the high resolution (HiRes) camera's data against the geometrically and photometrically controlled Ultraviolet/Visible (UV/Vis) Basemap Mosaic produced by the US Geological Survey (USGS). The HiRes mosaics were compiled from non-uniformity corrected, 750 nanometer ("D") filter high resolution nadir-looking observations. The images were spatially warped using the sinusoidal equal-area projection at a scale of 20 m/pixel for sub-polar mosaics (below 80 deg. latitude) and using the stereographic projection at a scale of 30 m/pixel for polar mosaics. Only images with emission angles less than approximately 50 were used. Images from non-mapping cross-track slews, which tended to have large SPICE errors, were generally omitted. The locations of the resulting image population were found to be offset from the UV/Vis basemap by up to 13 km (0.4 deg.). Geometric control was taken from the 100 m/pixel global and 150 m/pixel polar USGS Clementine Basemap Mosaics compiled from the 750 nm Ultraviolet/Visible Clementine imaging system. Radiometric calibration was achieved by removing the image nonuniformity dominated by the HiRes system's light intensifier. Also provided are offset and scale factors, achieved by a fit of the HiRes data to the corresponding photometrically calibrated UV/Vis basemap, that approximately transform the 8-bit HiRes data to photometric units. The sub-polar mosaics are divided into tiles that cover approximately 1.75 deg. of latitude and span the longitude range of the mosaicked frames. Images from a given orbit are map projected using the orbit's nominal central latitude. Polar mosaics are tiled into squares 2250 pixels on a side, which spans approximately 2.2 deg. Two mosaics are provided for each pole: one corresponding to data acquired while periapsis was in the south, the other while periapsis was in the north. The CD-ROMs also contain ancillary data files that support the HiRes mosaic. These files include browse images with UV/Vis context stored in a Joint Photographic Experts Group (JPEG) format, index files ('imgindx.tab' and 'srcindx.tab') that tabulate the contents of the CD, and documentation files.

  11. ALMA Debuts High-Resolution Results

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2015-07-01

    The exciting results of the highest-resolution test campaign yet attempted by the Atacama Large Millimeter/submillimeter Array (ALMA) are detailed in a recent set of four papers. Animation (click to watch) of the asteroid Juno as seen in mm wavelengths by ALMA's Long Baseline Campaign. Image credit: ALMA (NRAO/ESO/NAOJ) ALMA's array of antennas can be configured so that the baseline of the simulated telescope is as small as 150 m or as large as 15 km across. In its smaller configurations, ALMA studies the large-scale structure of cold objects in the Universe — and this is how the array has been used since it began its first operations in 2011. But now ALMA has begun to test its long-baseline configuration, in which it is able to make its highest-resolution observations and study the small-scale structure of objects in detail. The Targets ALMA's Long Baseline Campaign, run in late 2014, observed five science targets using 22-36 antennas arranged with a baseline of up to the full 15 km. The targets were selected to push the limits of ALMA's capabilities: each target has a small angular size (less than two arcseconds) with fine-scale structure that is largely unresolved in previous observations. Two of the targets, the variable star Mira and the active galaxy 3C138, were primarily used for calibration and comparisons of ALMA data to those of other telescopes. The remaining three targets not only demonstrated ALMA's capabilities, but also resulted in new science discoveries. ALMA's highest resolution observation yet, of the gravitationally lensed galaxy SDP.81. The maximum resolution of this image is 23 milliarcseconds. Image credit: ALMA (NRAO/ESO/NAOJ); B. Saxton NRAO/AUI/NSF Juno is one of the largest asteroids in our solar system's main asteroid belt. ALMA's observations of Juno were made when the asteroid was approximately 295 million km from Earth, and the ten images ALMA took have been stitched together into a brief animation that show the asteroid tumbling through space as it orbits the Sun. The resolution of these images — enough to study the shape and even some surface features of the asteroid! — are unprecedented for this wavelength. HL Tau is a young star surrounded by a protoplanetary disk. ALMA's detailed observations of this region revealed remarkable structure within the disk: a series of light and dark concentric rings indicative of planets caught in the act of forming. Studying this system will help us understand how multi-planet solar systems like our own form and evolve. The star-forming galaxy SDP.81 — located so far away that the light we see was emitted when the Universe was only 15% of its current age — is gravitationally-lensed into a cosmic arc, due to the convenient placement of a nearby foreground galaxy. The combination of the lucky alignment and ALMA's high resolution grant us a spectacularly detailed view of this distant galaxy, allowing us to study its actual shape and the motion within it. The observations from ALMA's first test of its long baseline demonstrate that ALMA is capable of doing the transformational science it promised. As we gear up for the next cycle of observations, it's clear that exciting times are ahead! Citation: ALMA ship et al. 2015 ApJ 808 L1, L2, L3 and L4. Focus on the ALMA Long Baseline Campaign

  12. ALMA Debuts High-Resolution Results

    NASA Astrophysics Data System (ADS)

    Kohler, Susanna

    2016-01-01

    The exciting results of the highest-resolution test campaign yet attempted by the Atacama Large Millimeter/submillimeter Array (ALMA) are detailed in a recent set of four papers.Animation (click to watch) of the asteroid Juno as seen in mm wavelengths by ALMAs Long Baseline Campaign. Image credit: ALMA (NRAO/ESO/NAOJ)ALMAs array of antennas can be configured so that the baseline of the simulated telescope is as small as 150 m or as large as 15 km across. In its smaller configurations, ALMA studies the large-scale structure of cold objects in the Universe and this is how the array has been used since it began its first operations in 2011. But now ALMA has begun to test its long-baseline configuration, in which it is able to make its highest-resolution observations and study the small-scale structure of objects in detail.The TargetsALMAs Long Baseline Campaign, run in late 2014, observed five science targets using 2236 antennas arranged with a baseline of up to the full 15 km. The targets were selected to push the limits of ALMAs capabilities: each target has a small angular size (less than two arcseconds) with fine-scale structure that is largely unresolved in previous observations. Two of the targets, the variable star Mira and the active galaxy 3C138, were primarily used for calibration and comparisons of ALMA data to those of other telescopes. The remaining three targets not only demonstrated ALMAs capabilities, but also resulted in new science discoveries.ALMAs highest resolution observation yet, of the gravitationally lensed galaxy SDP.81. The maximum resolution of this image is 23 milliarcseconds. Image credit: ALMA (NRAO/ESO/NAOJ); B. Saxton NRAO/AUI/NSFJuno is one of the largest asteroids in our solar systems main asteroid belt. ALMAs observations of Juno were made when the asteroid was approximately 295 million km from Earth, and the ten images ALMA took have been stitched together into a brief animation that show the asteroid tumbling through space as it orbits the Sun. The resolution of these images enough to study the shape and even some surface features of the asteroid! are unprecedented for this wavelength.HL Tau is a young star surrounded by a protoplanetary disk. ALMAs detailed observations of this region revealed remarkable structure within the disk: a series of light and dark concentric rings indicative of planets caught in the act of forming. Studying this system will help us understand how multi-planet solar systems like our own form and evolve.The star-forming galaxy SDP.81 located so far away that the light we see was emitted when the Universe was only 15% of its current age is gravitationally-lensed into a cosmic arc, due to the convenient placement of a nearby foreground galaxy. The combination of the lucky alignment and ALMAs high resolution grant us a spectacularly detailed view of this distant galaxy, allowing us to study its actual shape and the motion within it.The observations from ALMAs first test of its long baseline demonstrate that ALMA is capable of doing the transformational science it promised. As we gear up for the next cycle of observations, its clear that exciting times are ahead!Citation:ALMA Partnership et al.2015 ApJ 808 L1, L2, L3 and L4. Focus on the ALMA Long Baseline Campaign

  13. High resolution color band pyrometer ratioing

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B. (Inventor); Henry, Paul K. (Inventor); LoGiurato, D. Daniel (Inventor)

    1989-01-01

    The sensing head of a two-color band ratioing pyrometer of a known type using a fiber optic cable to couple radiation to dual detector photodiodes is improved to have high spatial resolution by focusing the radiation received through an objective lens (i.e., by focusing the image of a target area) onto an opaque sheet spaced in front of the input end of the fiber optic cable. A two-mil hole in that sheet then passes radiation to the input end of the cable. The detector has two channels, one for each color band, with an electronic-chopper stabilized current amplifier as the input stage followed by an electronic-chopper stabilized voltage amplifier.

  14. A high spatial resolution infrared scene projector

    NASA Astrophysics Data System (ADS)

    Yang, Yang; Nuo, Shi; Zhou, Lang; Xu, Chang; Zhang, Li; Li, Yanghong; Wang, Xin; Li, Zhuo

    2015-08-01

    An infrared scene projector with high spatial resolution using the visible to infrared transducer is described in this paper. The film transducer is fabricated by MEMS technology. The single pixel with 25×25?m in sizes and 35um at intervals in a transducer which is 76.2mm (3 inch) diameter is realized. So, the array size of the film transducer is more than 1024×1024. Illuminated by a visible light projector with different intensities, the equivalent black body temperature of the transducer could be varied in the range of 293K to 573K. The emission spectrum is similar with the blackbody and the gray scale is more than 200.

  15. Multilinear interactions in high-resolution spectra

    PubMed

    Corio

    1998-09-01

    The most general interaction of a collection of nuclear magnetic moments, invariant under the operations of the pure rotation group in three dimensions, is shown to be a linear combination of basic invariants that are multilinear in the components of the nuclear spin vectors. For an even number of spins each basic invariant is proportional to a product of scalar products, whereas for an odd number of spins each basic invariant is proportional to a scalar triple product multiplied by a product of scalar products. Representation theory for the group of proper rotations is used to determine the exact number of independent basic invariants for a given number of spins. The implications of time-reversal invariance and the consequences of including multilinear interactions in the Hamiltonian are investigated. In particular, the high-resolution spectrum of the AA'XX' system when quadrilinear interactions are included is examined. Copyright 1998 Academic Press. PMID:9740738

  16. Internal reflection sensors with high angular resolution.

    PubMed

    Shavirin, I; Strelkov, O; Vetskous, A; Norton-Wayne, L; Harwood, R

    1996-07-20

    We discuss the use of total internal reflection for the production of sensors with high angular resolution. These sensors are intended for measurement of the angle between a sensor's axis and the direction to a source of radiation or reflecting object. Sensors of this type are used in controlling the position of machine parts in robotics and industry, orienting space vehicles and astronomic devices in relation to the Sun, and as autocollimators for checking angles of deviation. This kind of sensor was used in the Apollo space vehicle some 20 years ago. Using photodetectors with linear and area CCD arrays has opened up new application possibilities for appropriately designed sensors. A generalized methodology is presented applicable to a wide range of tasks. Some modifications that can improve the performance of the basic design are described. PMID:21102820

  17. High-resolution inversion of ultrasonic traces.

    PubMed

    Zala, C A

    1992-01-01

    An algorithm for estimating the acoustic reflection coefficient profile from ultrasonic traces obtained during inspection of layered materials is described. Given the measured trace and the incident wavelet, the inversion proceeds by means of a layer stripping approach combined with high-resolution deconvolution. The inversion algorithm is stable to noise and is suitable for use with bandlimited data. It is particularly suitable for use with materials that exhibit a few large discontinuities in impedance and in which multiple reflections in the data are evident. The performance of the algorithm is illustrated in tests with synthetic and real data. An implementation of the algorithm on a TMS 320C30 signal processing board allowed the inversion of an entire set of 256 traces, each of 256 elements, in 15 s. PMID:18267656

  18. High resolution analysis of satellite gradiometry

    NASA Technical Reports Server (NTRS)

    Colombo, O. L.

    1989-01-01

    Satellite gravity gradiometry is a technique now under development which, by the middle of the next decade, may be used for the high resolution charting from space of the gravity field of the earth and, afterwards, of other planets. Some data analysis schemes are reviewed for getting detailed gravity maps from gradiometry on both a global and a local basis. It also presents estimates of the likely accuracies of such maps, in terms of normalized spherical harmonics expansions, both using gradiometry alone and in combination with data from a Global Positioning System (GPS) receiver carried on the same spacecraft. It compares these accuracies with those of current and future maps obtained from other data (conventional tracking, satellite-satellite tracking, etc.), and also with the spectra of various signals of geophysical interest.

  19. Improved methods for high resolution electron microscopy

    SciTech Connect

    Taylor, J.R.

    1987-04-01

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

  20. High-Resolution Anamorphic SPECT Imaging

    PubMed Central

    Durko, Heather L.; Barrett, Harrison H.; Furenlid, Lars R.

    2015-01-01

    We have developed a gamma-ray imaging system that combines a high-resolution silicon detector with two sets of movable, half-keel-edged copper-tungsten blades configured as crossed slits. These apertures can be positioned independently between the object and detector, producing an anamorphic image in which the axial and transaxial magnifications are not constrained to be equal. The detector is a 60 mm × 60 mm, one-millimeter-thick, one-megapixel silicon double-sided strip detector with a strip pitch of 59 ?m. The flexible nature of this system allows the application of adaptive imaging techniques. We present system details; calibration, acquisition, and reconstruction methods; and imaging results. PMID:26160983

  1. Ecological applications of high resolution spectrometry

    NASA Technical Reports Server (NTRS)

    Lawrence, William T.

    1989-01-01

    Future directions of NASA's space program plans include a significant effort at studying the Earth as a system of interrelated ecosystems. As part of NASA's Earth Observing System (Eos) Program a series of space platforms will be launched and operated to study the Earth with a variety of active and passive instruments. Several of the Eos instruments will be capable of imaging the planet's surface reflectance on a large number of very narrow portions of the solar spectrum. After the development of appropriate algorithms, this reflectance information will be used to determine key parameters about the structure and function of terrestrial and aquatic ecosystems and the pattern and processes of those systems across large areas of the globe. Algorithm development applicable to terrestrial systems will permit the inference of ecological processes from high resolution spectrometry data, similar to that to be forthcoming from the Eos mission. The first summer was spent working with tropical soils and relating their reflectance characteristics to particle size, iron content, and color. This summer the emphasis is on vegetation and work was begun with the Forest Ecosystems Dynamics Project in the Earth Resources Branch where both optical and radar characteristics of a mixed conifer/hardwood forest in Maine are being studied for use in a ecological modeling effort. A major series of aircraft overflights will take place throughout the summer. Laboratory and field spectrometers are used to measure the spectral reflectance of a hierarchy of vegetation from individual leaves to whole canopies for eventual modeling of their nutrient content using reflectance data. Key leaf/canopy parameters are being approximated including chlorophyll, nitrogen, phosphorus, water content, and leaf specific weight using high resolution spectrometry alone. Measurements are made of carbon exchange across the landscape for input to a spatial modeling effort to gauge production within the forest. A Geographic Information System approach is used to associate these data, images, and other collateral information for the forest into a database with a common projection suitable for spatial modeling.

  2. Minimally invasive diagnostic imaging using high resolution Optical Coherence Tomography

    E-print Network

    Herz, Paul Richard, 1972-

    2004-01-01

    Advances in medical imaging have given researchers unprecedented capabilities to visualize, characterize and understand biological systems. Optical Coherence Tomography (OCT) is a high speed, high resolution imaging technique ...

  3. Toward high-resolution optoelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

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

    2005-04-01

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

  4. Stapes model using high-resolution ?CT

    NASA Astrophysics Data System (ADS)

    Baek, Jong Dae; Puria, Sunil

    2008-02-01

    Understanding the biomechanics of the middle ear is important for surgical reconstructions. As the output of the middle ear, the stapes plays a key role in transferring acoustic vibrations to the cochlea. In order to develop anatomically-based mathematical models, which are needed to improve our understanding of stapes dynamics, detailed morphometry of the stapes is required. High-resolution micro-CT imaging techniques were used to generate three-dimensional reconstructions of cadaveric temporal bones from 5 species commonly used in experimental middle ear research: the chinchilla, human (relatively mid-frequency hearing limit), cat, guinea pig, and gerbil (relatively high-frequency hearing limit). From the standard discretizations of micro-CT images and corresponding 3-D volume reconstructions, the centers of mass, principle axes, stapes head areas and stapes footplate areas were calculated. Mechanical relationships were estimated between the capitulum area and the footplate area and inter-species comparisons were performed between the cross-sectional shapes of the anterior and posterior crura. Quantitative dynamic properties were estimated from the rigid body motion calculations. The parameters estimated in this study will be useful for building biocomputational models of the stapes for a variety of species.

  5. High-Resolution Three-Dimensional Mapping of Semiconductor Dopant

    E-print Network

    Dunin-Borkowski, Rafal E.

    High-Resolution Three-Dimensional Mapping of Semiconductor Dopant Potentials Alison C. Twitchett April 12, 2007 ABSTRACT Semiconductor device structures are becoming increasingly three-dimensional electrostatic potential in an electrically biased semiconductor device with nanometer spatial resolution

  6. USING THE HIGH RESOLUTION AND DYNAMICS LIMB SOUNDER (HIRDLS)

    E-print Network

    Oxford, University of

    Experiment (GOME) . . . . . . . . . . . . . . . . . . . . . 22 B.2.4 Moderate-resolution Imaging Spectroradiometer (MODIS) . . . . . . . . . . . . . . . 22 B.2.5 Operational Linescan System (OLSUSING THE HIGH RESOLUTION AND DYNAMICS LIMB SOUNDER (HIRDLS) TO WARN AVIATION OF VOLCANIC ASH R. G

  7. High power, high resolution terahertz spectroscopy technologies and its applications

    NASA Astrophysics Data System (ADS)

    Wu, Dong Ho; Graber, Benjamin; Kim, Christopher

    2015-03-01

    Since a large number of molecules' resonance frequencies lie within terahertz frequencies, terahertz spectroscopy is a highly useful tool for scientific investigation of various materials. At the same time one can use the same technology for the identification of hidden materials. Despite these potential applications presently terahertz spectroscopy is largely underutilized, and it is mostly being used in the laboratory environment. This is in part largely due to the fact that no portable, high power, high resolution spectrometer is currently available. So we have been developing a high power, wideband terahertz source. The terahertz source is capable to produce a relatively high power (>2 mW), wideband (0.1 - 3 THz) terahertz beam. In addition to the source we have optimized and calibrated an electro-optic (EO) detector, of which sensitivity is 10-13 W/(Hz)1/2. Recently, by utilizing these terahertz source and detector, we have constructed a high power, high resolution terahertz spectrometer, and carried out various experiments to understand resonance spectra of water vapor, chemicals and ionized air. Also we constructed a modified terahertz spectrometer for a stand-off detection applications. In this presentation I will discuss our experimental achievements and progresses. Supported by DTRA.

  8. Comparison of 3D Maximum A Posteriori and Filtered Backprojection algorithms for high resolution animal imaging in microPET

    SciTech Connect

    Chatziioannou, A.; Qi, J.; Moore, A.; Annala, A.; Nguyen, K.; Leahy, R.M.; Cherry, S.R.

    2000-01-01

    We have evaluated the performance of two three dimensional reconstruction algorithms with data acquired from microPET, a high resolution tomograph dedicated to small animal imaging. The first was a linear filtered-backprojection algorithm (FBP) with reprojection of the missing data and the second was a statistical maximum-aposteriori probability algorithm (MAP). The two algorithms were evaluated in terms of their resolution performance, both in phantoms and in vivo. Sixty independent realizations of a phantom simulating the brain of a baby monkey were acquired, each containing 3 million counts. Each of these realizations was reconstructed independently with both algorithms. The ensemble of the sixty reconstructed realizations was used to estimate the standard deviation as a measure of the noise for each reconstruction algorithm. More detail was recovered in the MAP reconstruction without an increase in noise relative to FBP. Studies in a simple cylindrical compartment phantom demonstrated improved recovery of known activity ratios with MAP. Finally in vivo studies also demonstrated a clear improvement in spatial resolution using the MAP algorithm. The quantitative accuracy of the MAP reconstruction was also evaluated by comparison with autoradiography and direct well counting of tissue samples and was shown to be superior.

  9. Single sensor processing to obtain high resolution color component signals

    NASA Technical Reports Server (NTRS)

    Glenn, William E. (Inventor)

    2010-01-01

    A method for generating color video signals representative of color images of a scene includes the following steps: focusing light from the scene on an electronic image sensor via a filter having a tri-color filter pattern; producing, from outputs of the sensor, first and second relatively low resolution luminance signals; producing, from outputs of the sensor, a relatively high resolution luminance signal; producing, from a ratio of the relatively high resolution luminance signal to the first relatively low resolution luminance signal, a high band luminance component signal; producing, from outputs of the sensor, relatively low resolution color component signals; and combining each of the relatively low resolution color component signals with the high band luminance component signal to obtain relatively high resolution color component signals.

  10. High-resolution imaging using endoscopic holography

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.

    1990-08-01

    Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help to their control. 1.

  11. Holographic high-resolution endoscopic image recording

    NASA Astrophysics Data System (ADS)

    Bjelkhagen, Hans I.

    1991-03-01

    Endoscopic holography or endoholography combines the features of endoscopy and holography. The purpose of endoholographic imaging is to provide the physician with a unique means of extending diagnosis by providing a life-like record of tissue. Endoholographic recording will provide means for microscopic examination of tissue and in some cases may obviate the need to excise specimens for biopsy. In this method holograms which have the unique properties of three-dimensionality large focal depth and high resolution are made with a newly designed endoscope. The endoscope uses a single-mode optical fiber for illumination and single-beam reflection holograms are recorded in close contact with the tissue at the distal end of the endoscope. The holograms are viewed under a microscope. By using the proper combinations of dyes for staining specific tissue types with various wavelengths of laser illumination increased contrast on the cellular level can be obtained. Using dyes such as rose bengal in combination with the 514. 5 nm line of an argon ion laser and trypan blue or methylene blue with the 647. 1 nm line of a krypton ion laser holograms of the stained colon of a dog showed the architecture of the colon''s columnar epithelial cells. It is hoped through chronological study using this method in-vivo an increased understanding of the etiology and pathology of diseases such as Crohn''s diseases colitis proctitis and several different forms of cancer will help

  12. The High Resolution Tropospheric Ozone Residual

    NASA Technical Reports Server (NTRS)

    Schoeberl, Mark R.

    2006-01-01

    The co-flight of the MLS stratospheric limb sounder and the Ozone Monitoring Instrument (OMI) provides the capability of computing the Tropospheric Ozone Residual (TOR) in much greater detail [Ziemke et al., 2006]. Using forward trajectory calculations of MLS ozone measurements combined with OMI column ozone we have developed a high horizontal resolution tropospheric ozone residual (HTOR) which can provide even more detail than the standard TOR product. HTOR is especially useful for extra-tropical studies of tropospheric ozone transport. We find that both the Pacific pollution corridor (East Asia to Alaska) and the Atlantic pollution corridor (North America east coast to Europe) are also preferred locations for strat-trop folds leading to systematic overestimates of pollution amounts. In fact, fold events appear to dominate extra-tropical Northern Hemisphere day-to-day maps of HTOR. Model estimates of the tropospheric column are in reasonable agreement with the HTOR amounts when offsets due to different tropopause height calculations are taken into consideration.

  13. High Resolution Laboratory Studies for Astronomical Spectroscopy

    NASA Astrophysics Data System (ADS)

    Gupta, Harshal; Brown, L. R.; Drouin, B. J.; Miller, C. E.; Pearson, J. C.; Sung, K.; Yu, S.

    2012-05-01

    Understanding astronomical observations of molecules requires detailed spectroscopic data that can only be derived from laboratory studies. These data, including accurate transition frequencies, intensities, broadening coefficients, and collisional rates are essential for the proper characterization of the physics, chemistry, and dynamics of astronomical sources. Equally important is the comprehensive spectroscopic characterization of astronomical molecules in multiple wavelength regions. A strong effort is in place in the JPL Molecular Spectroscopy Group to provide fundamental knowledge to support ground-, aircraft-, and space-based astronomical spectroscopy. A synopsis of the high-resolution laboratory spectroscopy of astronomical molecules at JPL is presented, highlighting benchmark studies that span wavelengths from the radio to the optical. The systems under study include molecules that are ubiquitous in the interstellar medium and/or exoplanetary atmospheres (CH4, CO2, H2O, and NH3), as well as ones that have recently been shown to be important constituents of the interstellar gas (O2, CH3OH, H3O+, and HCl+).

  14. High spatial resolution probes for neurobiology applications

    NASA Astrophysics Data System (ADS)

    Gunning, D. E.; Kenney, C. J.; Litke, A. M.; Mathieson, K.

    2009-06-01

    Position-sensitive biological neural networks, such as the brain and the retina, require position-sensitive detection methods to identify, map and study their behavior. Traditionally, planar microelectrodes have been employed to record the cell's electrical activity with device limitations arising from the electrode's 2-D nature. Described here is the development and characterization of an array of electrically conductive micro-needles aimed at addressing the limitations of planar electrodes. The capability of this array to penetrate neural tissue improves the electrode-cell electrical interface and allows more complicated 3-D networks of neurons, such as those found in brain slices, to be studied. State-of-the-art semiconductor fabrication techniques were used to etch and passivate conformally the metal coat and fill high aspect ratio holes in silicon. These are subsequently transformed into needles with conductive tips. This process has enabled the fabrication of arrays of unprecedented dimensions: 61 hexagonally close-packed electrodes, ˜200 ?m tall with 60 ?m spacing. Electroplating the tungsten tips with platinum ensure suitable impedance values (˜600 k? at 1 kHz) for the recording of neuronal signals. Without compromising spatial resolution of the neuronal recordings, this array adds a new and exciting dimension to the study of biological neural networks.

  15. Europa Ice Cliffs-High Resolution

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This view of the Conamara Chaos region on Jupiter's moon Europa shows cliffs along the edges of high-standing ice plates. The washboard texture of the older terrain has been broken into plates which are separated by material with a jumbled texture. The cliffs themselves are rough and broadly scalloped, and smooth debris shed from the cliff faces is piled along the base. For scale, the height of the cliffs and size of the scalloped indentations are comparable to the famous cliff face of Mount Rushmore in South Dakota.

    This image was taken on December 16, 1997 at a range of 900 kilometers (540 miles) by the solid state imaging system (camera) on NASA's Galileo spacecraft. North is to the top right of the picture, and the sun illuminates the surface from the east. This image, centered at approximately 8 degrees north latitude and 273 degrees west longitude, covers an area approximately 1.5 kilometers by 4 kilometers (0.9 miles by 2.4 miles). The resolution is 9 meters (30 feet) per picture element.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  16. High-resolution microwave images of saturn.

    PubMed

    Grossman, A W; Muhleman, D O; Berge, G L

    1989-09-15

    An analysis of high-resolution microwave images of Saturn and Saturn's individual rings is presented. Radio interferometric observations of Saturn taken at the Very Large Array in New Mexico at wavelengths of 2 and 6 centimeters reveal interesting new features in both the atmosphere and rings. The resulting maps show an increase in brightness temperature of about 3 K from equator to pole at both wavelengths, while the 6-centimeter map shows a bright band at northern mid-latitudes. The data are consistent with a radiative transfer model of the atmosphere that constrains the well-mixed, fully saturated, NH(3) mixing ratio to be 1.2 x 10(-4) in a region just below the NH(3) clouds, while the observed bright band indicates a 25 percent relative decrease of NH(3) in northern mid-latitudes. Brightness temperatures for the classical rings are presented. Ring brightness shows a variation with azimuth and is linearly polarized at an average value of about 5 percent. The variations in ring polarization suggest that at least 20 percent of the ring brightness is the result of a single scattering process. PMID:17747882

  17. High vertical resolution crosswell seismic imaging

    DOEpatents

    Lazaratos, Spyridon K. (Houston, TX)

    1999-12-07

    A method for producing high vertical resolution seismic images from crosswell data is disclosed. In accordance with one aspect of the disclosure, a set of vertically spaced, generally horizontally extending continuous layers and associated nodes are defined within a region between two boreholes. The specific number of nodes is selected such that the value of a particular characteristic of the subterranean region at each of the nodes is one which can be determined from the seismic data. Once values are established at the nodes, values of the particular characteristic are assigned to positions between the node points of each layer based on the values at node within that layer and without regard to the values at node points within any other layer. A seismic map is produced using the node values and the assigned values therebetween. In accordance with another aspect of the disclosure, an approximate model of the region is established using direct arrival traveltime data. Thereafter, the approximate model is adjusted using reflected arrival data. In accordance with still another aspect of the disclosure, correction is provided for well deviation. An associated technique which provides improvements in ray tracing is also disclosed.

  18. Intracellular membrane traffic at high resolution.

    PubMed

    van Weering, Jan R T; Brown, Edward; Sharp, Thomas H; Mantell, Judith; Cullen, Peter J; Verkade, Paul

    2010-01-01

    Membrane traffic between organelles is essential for a multitude of processes that maintain cell homeostasis. Many steps in these tightly regulated trafficking pathways take place in microdomains on the membranes of organelles, which require analysis at nanometer resolution. Electron microscopy (EM) can visualize these processes in detail and is mainly responsible for our current view of morphology on the subcellular level. This review discusses how EM can be applied to solve many questions of intracellular membrane traffic, with a focus on the endosomal system. We describe the expansion of the technique from purely morphological analysis to cryo-immuno-EM, correlative light electron microscopy (CLEM), and 3D electron tomography. In this review we go into some technical details of these various techniques. Furthermore, we provide a full protocol for immunolabeling on Lowicryl sections of high-pressure frozen cells as well as a detailed description of a simple CLEM method that can be applied to answer many membrane trafficking questions. We believe that these EM-based techniques are important tools to expand our understanding of the molecular details of endosomal sorting and intracellular membrane traffic in general. PMID:20869541

  19. Investigation into High Spectral Resolution Lidar technologies

    NASA Astrophysics Data System (ADS)

    Dawsey, Martha Wallis

    The Intergovernmental Panel on Climate Change (IPCC) found in their 2007 report that aerosol radiative forcing contributed larger uncertainties to estimates affecting future climate change than any other radiative forcing factor. Lidar is a tool with which this uncertainty can be reduced, increasing our understanding of the impact of aerosols on climate change. Lidar, or laser radar, is a monostatic active remote sensing technique used to measure aerosols and particulates in the atmosphere, with accuracies comparable to in-situ measurements (Russell 2002). High Spectral Resolution Lidar (HSRL) systems use a narrow band filter to spectrally separate Doppler broadened aerosol and molecular back-scattered return signals, which allows for range resolved profiles of aerosol extinction and backscatter. The narrow band filter is a key component, for which two novel approaches are currently being used: NASA Langley Research Center has implemented a wide-angle Michelson interferometer in the second version of their airborne HSRL, and Montana State University is using a spherical Fabry-Perot interferometer in a ground based HSRL. In this research, a comprehensive comparative analysis of these two interferometric filters is performed, the result of which is a methodology for the design of narrow band filters for HSRL systems. The techniques presented identify the critical components and analyze the performance of each filter based on the spectral and angular properties, as well as the efficiency.

  20. High resolution EUV monochromator/spectrometer

    DOEpatents

    Koike, Masako

    1996-06-18

    This invention is related to a monochromator which employs a spherical mirror, a traveling plane mirror with simultaneous rotation, and a varied spacing plane grating. The divergent beam from the entrance slit is converged by the spherical mirror located at the various positions in the monochromator depending of the inventive system. To provide the meaningful diffraction efficiencies and to reduce unwanted higher order lights, the deviation angle subtending the incidence and diffraction beams for the plane grating is varied with the position of the traveling plane mirror with simultaneous rotation located in the front or back of the plane grating with wavelength scanning. The outgoing beam from the monochromator goes through the fixed exit slit and has same beam direction regardless of the scanning wavelength. The combination of properly designed motions of the plane mirror and novel varied-spacing parameters of the inventive plane grating corrects the aberrations and focuses the monochromatic spectral image on the exit slit, enabling measurements at high spectral resolution. 10 figs.

  1. Climate Simulations with a Variable-Resolution GCM: Stretched Cubed-Sphere High Resolution Atmospheric Model

    NASA Astrophysics Data System (ADS)

    Tu, C. Y.; Harris, L.; Lin, S. J.

    2014-12-01

    Variable-resolution GCM with enhanced resolution over the region of interest is an adaptive approach to self-consistent interactions between global and regional phenomena. A stretched cubed-sphere High Resolution Atmosphere Model (HiRAM) is constructed using the Geophysical Fluid Dynamics Laboratory (GFDL) finite-volume dynamical core. The horizontal grid spacing in the stretched cubed-sphere is smoothly transformed from the center of highest-resolution region to the center of coarsest-resolution region. Three 30-yr AMIP type simulations were performed in this study; one C384 uniformed cubed-sphere grid, and two stretched cubed-sphere grid with stretching factor 2.5. Two stretched-grid experiments further set the center of highest-resolution region in Taiwan (C384R2.5TW) and Oklahoma City (C384R2.5OKC), respectively. The horizontal resolution in this C384R2.5 stretched grid ranges from 10km to 65km. Three climate simulations were compared against re-analysis data to understand the effect of horizontal resolution on both the simulated global climate and regional features. The global mean climatology in stretched-grid AMIP simulations shows no unrealistic drift comparing to the uniform-grid simulation and observation. Regional orographic precipitation is better simulated in the high-resolution region. High resolution also shows improvement in typhoon/hurricane simulation. In western Pacific basin, high resolution improves simulated typhoon intensity. For weak and moderate typhoons, there is no strong trend with enhancing resolution. But for strong typhoon, there is high correlation between enhancing resolution with typhoon intensity. By comparing simulations with IBTrACS ?International Best Track Archieve for Climate Stewardship? in different basins, HiRAM demonstrates the reduction of simulated typhoon/hurricane numbers with enhancement of horizontal resolution.

  2. High-resolution ophthalmic imaging system

    SciTech Connect

    Olivier, Scot S.; Carrano, Carmen J.

    2007-12-04

    A system for providing an improved resolution retina image comprising an imaging camera for capturing a retina image and a computer system operatively connected to the imaging camera, the computer producing short exposures of the retina image and providing speckle processing of the short exposures to provide the improved resolution retina image. The system comprises the steps of capturing a retina image, producing short exposures of the retina image, and speckle processing the short exposures of the retina image to provide the improved resolution retina image.

  3. Fundamental constants and high-resolution spectroscopy

    NASA Astrophysics Data System (ADS)

    Bonifacio, P.; Rahmani, H.; Whitmore, J. B.; Wendt, M.; Centurion, M.; Molaro, P.; Srianand, R.; Murphy, M. T.; Petitjean, P.; Agafonova, I. I.; D'Odorico, S.; Evans, T. M.; Levshakov, S. A.; Lopez, S.; Martins, C. J. A. P.; Reimers, D.; Vladilo, G.

    2014-01-01

    Absorption-line systems detected in high resolution quasar spectra can be used to compare the value of dimensionless fundamental constants such as the fine-structure constant, ?, and the proton-to-electron mass ratio, ? = m_p/m_e, as measured in remote regions of the Universe to their value today on Earth. In recent years, some evidence has emerged of small temporal and also spatial variations in ? on cosmological scales which may reach a fractional level of ? 10 ppm (parts per million). We are conducting a Large Programme of observations with the Very Large Telescope's Ultraviolet and Visual Echelle Spectrograph (UVES), and are obtaining high-resolution ({R ? 60 000}) and high signal-to-noise ratio (S/N ? 100) spectra calibrated specifically to study the variations of the fundamental constants. We here provide a general overview of the Large Programme and report on the first results for these two constants, discussed in detail in Molaro et al. (2013) and Rahmani et al. (2013). A stringent bound for ??/? is obtained for the absorber at z_abs = 1.6919 towards HE 2217-2818. The absorption profile is complex with several very narrow features, and is modeled with 32 velocity components. The relative variation in ? in this system is +1.3± 2.4_stat ± 1.0_sys ppm if Al II ? 1670 Å and three Fe II transitions are used, and +1.1 ± 2.6_stat ppm in a slightly different analysis with only Fe II transitions used. This is one of the tightest bounds on ?-variation from an individual absorber and reveals no evidence for variation in ? at the 3-ppm precision level (1? confidence). The expectation at this sky position of the recently-reported dipolar variation of ? is (3.2-5.4)±1.7 ppm depending on dipole model used and this constraint of ??/? at face value is not supporting this expectation but not inconsistent with it at the 3? level. For the proton-to-electron mass ratio the analysis of the H_2 absorption lines of the z_abs ? 2.4018 damped Ly? system towards HE 0027-1836 provides ??/? = (-7.6 ± 8.1_stat ± 6.3_sys) ppm which is also consistent with a null variation. The cross-correlation analysis between individual exposures taken over three years and comparison with almost simultaneous asteroid observations revealed the presence of a possible wavelength dependent velocity drift as well as of inter-order distortions which probably dominate the systematic error and are a significant obstacle to achieve more accurate measurements. Based on observations obtained with UVES at the the 8.2 m Kueyen ESO telescope programme L185.A-0745.

  4. MULTIPULSE - high resolution and high power in one TDEM system

    NASA Astrophysics Data System (ADS)

    Chen, Tianyou; Hodges, Greg; Miles, Philip

    2015-09-01

    An airborne time domain electromagnetic (TEM) system with high resolution and great depth of exploration is desired for geological mapping as well as for mineral exploration. The MULTIPULSE technology enables an airborne TEM system to transmit a high power pulse (a half-sine, for instance) and one or multiple low power pulse(s) (trapezoid or square) within a half-cycle. The high power pulse ensures good depth of exploration and the low power pulse allows a fast transmitter current turn off and earlier off-time measurement thus providing higher frequency signals, which allows higher near-surface resolution and better sensitivity to weak conductors. The power spectrum of the MULTIPULSE waveform comprising a half-sine and a trapezoid pulse clearly shows increased power in the higher frequency range (> ~2.3 kHz) compared to that of a single half-sine waveform. The addition of the low power trapezoid pulse extends the range of the sensitivity 10-fold towards the weak conductors, expanding the geological conductivity range of a system and increasing the scope of its applications. The MULTIPULSE technology can be applied to standard single-pulse airborne TEM systems on both helicopter and fixed-wing. We field tested the HELITEM MULTIPULSE system over a wire-loop in Iroquois Falls, demonstrating the different sensitivity of the high and low power pulses to the overburden and the wire-loop. We also tested both HELITEM and GEOTEM MULTIPULSE systems over a layered oil sand geologic setting in Fort McMurray, Alberta, Canada. The results show comparable shallow geologic resolution of the MULTIPULSE to that of the RESOLVE system while maintaining superior depth of exploration, confirming the increased geological conductivity range of a system employing MULTIPULSE compared to the standard single-pulse systems.

  5. Ultra High Resolution Rain Retrieval from QuikSCAT Data

    E-print Network

    Long, David G.

    Ultra High Resolution Rain Retrieval from QuikSCAT Data David G. Long Brigham Young University, 459 can be used to simultaneously estimate wind and rain. By applying resolution enhancement algorithms, the wind and rain can be estimated at significantly improved resolution, though with higher noise. Initial

  6. High Spatial Resolution Commercial Satellite Imaging Product Characterization

    NASA Technical Reports Server (NTRS)

    Ryan, Robert E.; Pagnutti, Mary; Blonski, Slawomir; Ross, Kenton W.; Stnaley, Thomas

    2005-01-01

    NASA Stennis Space Center's Remote Sensing group has been characterizing privately owned high spatial resolution multispectral imaging systems, such as IKONOS, QuickBird, and OrbView-3. Natural and man made targets were used for spatial resolution, radiometric, and geopositional characterizations. Higher spatial resolution also presents significant adjacency effects for accurate reliable radiometry.

  7. High Resolution Sensor for Nuclear Waste Characterization

    SciTech Connect

    Mr. Kanai Shah; Mr. William Higgins; Dr. Edgar V. Van Loef

    2006-01-23

    Gamma ray spectrometers are an important tool in the characterization of radioactive waste. Important requirements for gamma ray spectrometers used in this application include good energy resolution, high detection efficiency, compact size, light weight, portability, and low power requirements. None of the available spectrometers satisfy all of these requirements. The goal of the Phase I research was to investigate lanthanum halide and related scintillators for nuclear waste clean-up. LaBr3:Ce remains a very promising scintillator with high light yield and fast response. CeBr3 is attractive because it is very similar to LaBr3:Ce in terms of scintillation properties and also has the advantage of much lower self-radioactivity, which may be important in some applications. CeBr3 also shows slightly higher light yield at higher temperatures than LaBr3 and may be easier to produce with high uniformity in large volume since it does not require any dopants. Among the mixed lanthanum halides, the light yield of LaBrxI3-x:Ce is lower and the difference in crystal structure of the binaries (LaBr3 and LaI3) makes it difficult to grow high quality crystals of the ternary as the iodine concentration is increased. On the other hand, LaBrxCl3-x:Ce provides excellent performance. Its light output is high and it provides fast response. The crystal structures of the two binaries (LaBr3 and LaCl3) are very similar. Overall, its scintillation properties are very similar to those for LaBr3:Ce. While the gamma-ray stopping efficiency of LaBrxCl3-x:Ce is lower than that for LaBr3:Ce (primarily because the density of LaCl3 is lower than that of LaBr3), it may be easier to grow large crystals of LaBrxCl3-x:Ce than LaBr3:Ce since in some instances (for example, CdxZn1-xTe), the ternary compounds provide increased flexibility in the crystal lattice. Among the new dopants, Eu2+ and Pr3+, tried in LaBr3 host crystals, the Eu2+ doped samples exhibited low light output. This was mostly because a large fraction of light was emitted via very slow decay components (>50 �¯��­s) and as a result was not included in the light estimation performed using gamma-ray spectroscopy where the typical amplifier integration time used is <12 �¯��­s. The origin of these slow component(s) is most likely related to the presence of defects caused by charge imbalance in the crystals. The charge imbalance occurs when the Eu2+ ions replace the La3+ ions in crystal lattice. This charge neutrality can be restored by codoping the Eu2+ doped LaBr3 crystals with ions such as Hf4+. The Pr3+ doped LaBr3 crystals provided exciting results. They exhibited very high light yield (85,000 photons/MeV) and good energy resolution. While the decay time of LaBr3:Pr is much slower than that for LaBr3:Ce, it is fast enough for many nuclear waste cleanup applications. Furthermore, it should be possible to increase the speed of LaBr3:Pr by adjusting its Pr3+ concentration. The most exciting feature of LaBr3:Pr is that it emits in red-region and is therefore, well suited for silicon photodiode readout. In fact, LaBr3:Pr is the brightest scintillator in the red-region and its light yield is ~15% higher than the light yield of LaBr3 doped with Ce. Overall, the Phase I research has been very successful and has lead to better understanding of the lanthanum halide and related scintillators. It has also opened up some promising avenues to optimize the performance of these exciting scintillators. Based on the Phase I results, we have clearly demonstrated the feasibility of the proposed approach.

  8. High-Resolution Spatial Light Modulation for Holographic Video

    E-print Network

    Bove Jr., V. Michael

    with holography as a middle-school student living in rural Utah. After high school he began a correspondence by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dr. Deb Roy Chairman, Media Arts and Sciences Committee #12;2 #12;High-Resolution Spatial LightHigh-Resolution Spatial Light Modulation for Holographic Video by Daniel E. Smalley Submitted

  9. High resolution, high rate x-ray spectrometer

    DOEpatents

    Goulding, F.S.; Landis, D.A.

    1983-07-14

    It is an object of the invention to provide a pulse processing system for use with detected signals of a wide dynamic range which is capable of very high counting rates, with high throughput, with excellent energy resolution and a high signal-to-noise ratio. It is a further object to provide a pulse processing system wherein the fast channel resolving time is quite short and substantially independent of the energy of the detected signals. Another object is to provide a pulse processing system having a pile-up rejector circuit which will allow the maximum number of non-interfering pulses to be passed to the output. It is also an object of the invention to provide new methods for generating substantially symmetrically triangular pulses for use in both the main and fast channels of a pulse processing system.

  10. High-energy resolution, high-angular acceptance crystal monochromator

    SciTech Connect

    Toellner, T.S.; Mooney, T.; Alp, E.E.; Shastri, S.

    1992-06-01

    The design principles, construction and characterization of a 4- bounce dispersive crystal monochromator is discussed. This monochromator is designed to reduce the bandpass of synchrotron radiation to 10--50 meV level, without sacrificing angular acceptance. This is achieved by combining an asymmetrically-cut, low order reflection with a symmetrically-cut, high order reflection in a nested configuration. This monochromator is being used as a beam conditioner for nuclear resonant scattering of synchrotron radiation to produce x-rays with {mu}eV{minus}neV resolution in the hard x-ray regime.

  11. High-energy resolution, high-angular acceptance crystal monochromator

    SciTech Connect

    Toellner, T.S.; Mooney, T.; Alp, E.E. ); Shastri, S. . Dept. of Applied Physics)

    1992-06-01

    The design principles, construction and characterization of a 4- bounce dispersive crystal monochromator is discussed. This monochromator is designed to reduce the bandpass of synchrotron radiation to 10--50 meV level, without sacrificing angular acceptance. This is achieved by combining an asymmetrically-cut, low order reflection with a symmetrically-cut, high order reflection in a nested configuration. This monochromator is being used as a beam conditioner for nuclear resonant scattering of synchrotron radiation to produce x-rays with [mu]eV[minus]neV resolution in the hard x-ray regime.

  12. High resolution optics combined with high spatial reproducibility in flow

    SciTech Connect

    Eisert, W.G.

    1981-01-01

    Accurate sizing in flow using optical methods generally requires high resolution optics and specially designed flow systems. Flow systems developed by this group have following features: (a) double sheath configuration for optical index match, (b) no curved optical surface in the sensing area, (c) gradual hydrodynamic focusing over a long distance to minimize mechanical shearing, (d) precision spatial positioning of cells by reducing suspension fluid diameter to a cell diameter or less, (e) total thickness between outer surfaces of the flow chamber at the viewing area of 1.5 mm or less. Cells intersect a laser light beam focussed go circular as well as elliptical cross-sections or 1 micron or less in diameter. Cellular extinction is monitored during transit through the beam. Cell length is derived from the time for flight measurement and corrected for absolute values by continuous velocity reference using a second laser beam intersecting the cell stream at a predetermined distance. This second spot may be circular or elliptical, of a different polarization and/or frequency. Simultaneous fluorescence intensity and diameter measurements were performed on test particles using different optical geometries. The influence of the particle structure on fluorescence measurements is demonstrated where high resolution sizing is required at the same time.

  13. High Resolution Velocity Structure in Eastern Turkey

    SciTech Connect

    Pasyanos, M; Gok, R; Zor, E; Walter, W

    2004-09-03

    We investigate the crustal and upper mantle structure of eastern Turkey where the Anatolian, Arabian and Eurasian Plates meet and form a complex tectonic structure. The Bitlis suture is a continental collision zone between the Anatolian plateau and the Arabian plate. Broadband data available through the Eastern Turkey Seismic Experiment (ETSE) provided a unique opportunity for studying the high resolution velocity structure. Zor et al. found an average 46 km thick crust in Anatolian plateau using six-layered grid search inversion of the ETSE receiver functions. Receiver functions are sensitive to the velocity contrast of interfaces and the relative travel time of converted and reverberated waves between those interfaces. The interpretation of receiver function alone with many-layered parameterization may result in an apparent depth-velocity tradeoff. In order to improve previous velocity model, we employed the joint inversion method with many layered parameterization of Julia et al. (2000) to the ETSE receiver functions. In this technique, the receiver function and surface-wave observations are combined into a single algebraic equation and each data set is weighted by an estimate of the uncertainty in the observations. We consider azimuthal changes of receiver functions and have stacked them into different groups. We calculated the receiver functions using iterative time-domain deconvolution technique and surface wave group velocity dispersion curves between 10-100 sec. We are making surface wave dispersion measurements at the ETSE stations and have incorporated them into a regional group velocity model. Preliminary results indicate a strong trend in the long period group velocity in the northeast. This indicates slow upper mantle velocities in the region consistent with Pn, Sn and receiver function results. We started with both the 1-D model that is obtained with the 12 tones dam explosion shot data recorded by ETSE network and the existing receiver function inversion results. In fact, we observe that the inversion results are independent at the starting model and converges well to the same final model. We don't observe a significant change at the first order discontinuities of model (e.g. Moho depth), but we obtain better defined depths to low velocity layers.

  14. High Resolution Surface Science at Mars

    NASA Technical Reports Server (NTRS)

    Bailey, Zachary J.; Tamppari, Leslie K.; Lock, Robert E.; Sturm, Erick J.

    2013-01-01

    The proposed mission would place a 2.4 m telescope in orbit around Mars with two focal plane instruments to obtain the highest resolution images and spectral maps of the surface to date (3-10x better than current). This investigation would make major contributions to all of the Mars Program Goals: life, climate, geology and preparation for human presence.

  15. Using high-resolution displays for high-resolution cardiac data.

    PubMed

    Goodyer, Christopher; Hodrien, John; Wood, Jason; Kohl, Peter; Brodlie, Ken

    2009-07-13

    The ability to perform fast, accurate, high-resolution visualization is fundamental to improving our understanding of anatomical data. As the volumes of data increase from improvements in scanning technology, the methods applied to visualization must evolve. In this paper, we address the interactive display of data from high-resolution magnetic resonance imaging scanning of a rabbit heart and subsequent histological imaging. We describe a visualization environment involving a tiled liquid crystal display panel display wall and associated software, which provides an interactive and intuitive user interface. The oView software is an OpenGL application that is written for the VR Juggler environment. This environment abstracts displays and devices away from the application itself, aiding portability between different systems, from desktop PCs to multi-tiled display walls. Portability between display walls has been demonstrated through its use on walls at the universities of both Leeds and Oxford. We discuss important factors to be considered for interactive two-dimensional display of large three-dimensional datasets, including the use of intuitive input devices and level of detail aspects. PMID:19487203

  16. Correlating ribosome function with high-resolution structures

    E-print Network

    Yonath, Ada E.

    Correlating ribosome function with high-resolution structures Anat Bashan and Ada Yonath Department;Correlating ribosome function with high-resolution structures Anat Bashan and Ada Yonath Department of Structural Biology, Weizmann Institute, Rehovot, 76100, Israel Ribosome research has undergone astonishing

  17. OBJECTIVE SYNOPTIC CLASSIFICATION COMBINED WITH HIGH RESOLUTION METEOROLOGICAL MODELS FOR

    E-print Network

    Politècnica de Catalunya, Universitat

    1 OBJECTIVE SYNOPTIC CLASSIFICATION COMBINED WITH HIGH RESOLUTION METEOROLOGICAL MODELS FOR WIND for publication (in final form 10th January 2005) Meteorology and Atmospheric Physics Corresponding author: Dr obtained, a mesoscale meteorological model (TAPM) has been run at high resolution for the region

  18. A sledge microtome for high resolution subsampling of freeze cores

    E-print Network

    Patterson, Timothy

    NOTES A sledge microtome for high resolution subsampling of freeze cores Andrew L. Macumber · R microtome designed for the high-resolution subsampling of freeze cores. This inexpensive freeze events even in systems with low sedimentation rates. The freeze-core micro- tome is particularly useful

  19. Equatorial waves in High Resolution Dynamics Limb Sounder (HIRDLS) data

    E-print Network

    Alexander, M. Joan

    Equatorial waves in High Resolution Dynamics Limb Sounder (HIRDLS) data M. J. Alexander1 and D. A December 2010. [1] We examine equatorial wave structure in temperature measurements from the High Resolution Dynamics Limb Sounder (HIRDLS) on the Aura satellite. Waves with periods longer than 1 day

  20. High-resolution reconstruction of the beating zebrafish heart.

    PubMed

    Mickoleit, Michaela; Schmid, Benjamin; Weber, Michael; Fahrbach, Florian O; Hombach, Sonja; Reischauer, Sven; Huisken, Jan

    2014-09-01

    The heart's continuous motion makes it difficult to capture high-resolution images of this organ in vivo. We developed tools based on high-speed selective plane illumination microscopy (SPIM), offering pristine views into the beating zebrafish heart. We captured three-dimensional cardiac dynamics with postacquisition synchronization of multiview movie stacks, obtained static high-resolution reconstructions by briefly stopping the heart with optogenetics and resolved nonperiodic phenomena by high-speed volume scanning with a liquid lens. PMID:25042787

  1. High-resolution studies of atmospheric IR emission spectra

    NASA Technical Reports Server (NTRS)

    Murcray, F. J.; Murcray, F. H.; Goldman, A.; Blatherwick, R. D.; Murcray, D. G.

    1991-01-01

    Atmospheric emission spectra obtained with two different spectrometer systems are presented. The first system (the BOMEM Michelson interferometer) is designed for emission work. Spectra were obtained under adverse conditions in the Antarctic, and are still of good absolute accuracy. The second system (a modified Bruker Instruments IFS120 very high spectral resolution interferometer) demonstrates the sensitivity that can be achieved even at higher spectral resolution. This system shows that mid-IR atmospheric emission spectra can be obtained with a good SNR in a reasonable length of time at a relatively high resolution. A properly designed high resolution system should achieve high accuracy, sensitivity, and resolution, thereby permitting measurements of many atmospheric constituents when solar spectra cannot be obtained.

  2. A high-resolution vehicle emission inventory for China

    NASA Astrophysics Data System (ADS)

    Zheng, B.; Zhang, Q.; He, K.; Huo, H.; Yao, Z.; Wang, X.

    2012-12-01

    Developing high resolution emission inventory is an essential task for air quality modeling and management. However, current vehicle emission inventories in China are usually developed at provincial level and then allocated to grids based on various spatial surrogates, which is difficult to get high spatial resolution. In this work, we developed a new approach to construct a high-resolution vehicle emission inventory for China. First, vehicle population at county level were estimated by using the relationship between per-capita GDP and vehicle ownership. Then the Weather Research and Forecasting (WRF) model were used to drive the International Vehicle Emission (IVE) model to get monthly emission factors for each county. Finally, vehicle emissions by county were allocated to grids with 5-km horizon resolution by using high-resolution road network data. This work provides a better understanding of spatial representation of vehicle emissions in China and can benefit both air quality modeling and management with improved spatial accuracy.

  3. Medusae Fossae Formation - High Resolution Image

    NASA Technical Reports Server (NTRS)

    1998-01-01

    An exotic terrain of wind-eroded ridges and residual smooth surfaces are seen in one of the highest resolution images ever taken of Mars from orbit. The Medusae Fossae formation is believed to be formed of the fragmental ejecta of huge explosive volcanic eruptions. When subjected to intense wind-blasting over hundreds of millions of years, this material erodes easily once the uppermost tougher crust is breached. The crust, or cap rock, can be seen in the upper right part of the picture. The finely-spaced ridges are similar to features on Earth called yardangs, which are formed by intense winds plucking individual grains from, and by wind-driven sand blasting particles off, sedimentary deposits.

    The image was taken on October 30, 1997 at 11:05 AM PST, shortly after the Mars Global Surveyor spacecraft's 31st closest approach to Mars. The image covers an area 3.6 X 21.5 km (2.2 X 13.4 miles) at 3.6 m (12 feet) per picture element--craters only 11 m (36 feet, about the size of a swimming pool) across can be seen. The best Viking view of the area (VO 1 387S34) has a resolution of 240 m/pixel, or 67 times lower resolution than the MOC frame.

    Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

  4. HIGH RESOLUTION PHOTOEMISSION STUDIES OF COMPLEX MATERIALS.

    SciTech Connect

    JOHNSON,P.D.

    1999-10-13

    Recent instrumentation developments in photoemission are providing new insights into the physics of complex materials. With increased energy and momentum resolution, it has become possible to examine in detail different contributions to the self-energy or inverse lifetime of the photohole created in the photoexcitation process, Employing momentum distribution and energy distribution curves, a detailed study of the optimally doped cuprate, Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub g+{delta}}, shows that the material behaves like a non-Fermi liquid with no evidence for the quasi-particles characteristic of a Fermi liquid.

  5. DSCOVR High Time Resolution Solar Wind Measurements

    NASA Technical Reports Server (NTRS)

    Szabo, Adam

    2012-01-01

    The Deep Space Climate Observatory (DSCOVR), previously known as Triana, spacecraft is expected to be launched in late 2014. It will carry a fluxgate magnetometer, Faraday Cup solar wind detector and a top-hat electron electrostatic analyzer. The Faraday Cup will provide an unprecedented 10 vectors/sec time resolution measurement of the solar wind proton and alpha reduced distribution functions. Coupled with the 40 vector/sec vector magnetometer measurements, the identification of specific wave modes in the solar wind will be possible for the first time. The science objectives and data products of the mission will be discussed.

  6. 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.

  7. High resolution radar map of the Moon

    NASA Technical Reports Server (NTRS)

    Thompson, T. W.

    1987-01-01

    Previous radar mappings of the Moon at 70 cm wavelength in the late 1960's by Thompson have been replaced with a new set of observations using the 430 MHz radar at the Arecibo Observatory, Puerto Rico. Radar resolution was reduced to 2 to 5 km radar cell size and a beam-sweep, limb-to-limb calibration was conducted. Advances in computer technology provided the principle means of improving lunar radar mapping at this wavelength. Observation techniques and data processing are described and scattering differences found in the orthographic projection of the radar data are discussed.

  8. High resolution IVEM tomography of biological specimens

    SciTech Connect

    Sedat, J.W.; Agard, D.A.

    1997-02-01

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

  9. High-resolution View of Gullies

    NASA Technical Reports Server (NTRS)

    2004-01-01

    12 January 2004 One goal of the Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) extended mission is to examine middle- and polar-latitude gullies at the highest resolutions available to MOC. This image, at 1.5 meters (5 feet) per pixel, shows several gullies carved into the material covering the wall of an old meteor impact crater near 46.7oS, 162.3oW. Large boulders that have come down the slopes are present among the gullies and their aprons. The image covers an area 3 km (1.9 mi) wide; sunlight illuminates the scene from the upper left.

  10. High-resolution imaging of compact high-velocity clouds

    NASA Astrophysics Data System (ADS)

    de Heij, V.; Braun, R.; Burton, W. B.

    2002-08-01

    We have imaged five compact high-velocity clouds in H I with arcmin angular resolution and km s-1 spectral resolution using the Westerbork Synthesis Radio Telescope. These CHVCs have a characteristic morphology, consisting of one or more quiescent, low-dispersion compact cores embedded in a diffuse warm halo. The compact cores can be unambiguously identified with the cool neutral medium of condensed atomic hydrogen, since their linewidths are significantly narrower than the thermal linewidth of the warm neutral medium. Because of the limited sensitivity to diffuse emission inherent to interferometric data, the warm medium is not directly detected in the WSRT observations. Supplementary total-power data, which is fully sensitive to both the cool and warm components of H I, is available for comparison for all the sources, albeit with angular resolutions that vary from 3' to 36'. The fractional H I flux in compact CNM components varies from 4% to 16% in our sample. All objects have at least one local peak in the CNM column density which exceeds about 1019;cm-2 when observed with arcmin resolution. It is plausible that a peak column density of 1-2 x 1019;cm-2 is a prerequisite for the long-term survival of these sources. One object in our sample, CHVC 120-20-443 (Davies' cloud), lies in close projected proximity to the disk of M 31. This object is characterized by exceptionally broad linewidths in its CNM concentrations, more than 5 times greater than the median value found in the 13 CHVCs studied to date at comparable resolution. These CNM concentrations lie in an arc on the edge of the source facing the M 31 disk. The diffuse H I component of this source, seen in total-power data from the NRAO 140-foot telescope, has a positional offset in the direction of the M 31 disk. All of these attributes suggest that CHVC 120-20-443 is in a different evolutionary state than most of the other CHVCs which have been studied. Similarly broad CNM linewidths have only been detected in one other cloud, CHVC 110.6-07.0-466 (Wakker & Schwarz \\cite{wakker91b}) which also lies in the Local Group barycenter direction and has the most extreme radial velocity known. A distinct possibility for Davies' cloud seems to be physical interaction of some type with M 31. The most likely form of this interaction might be the ram-pressure or tidal-stripping by either one of M 31's visible dwarf companions, M 32 or NGC 205, or else by a dark companion with an associated H I condensation. The compact objects located in the direction of the Local Group barycenter have an important role to play in constraining the Local Group hypothesis for the deployment of CHVCs.

  11. [Imaging properties of a high-resolution CT system].

    PubMed

    Schultz, E

    1989-12-01

    This paper provides an overview of the most important imaging properties of a high-resolution computed tomography system. Spatial and contrast resolution (inplane as well as crossplane) are described, while the trade-off between those two characteristics is pointed out. Furthermore, it is shown that extremely small structures are imaged, but not with realistic Hounsfield units. Finally, the noise is set into relation to the contrast resolution. PMID:2630153

  12. High-resolution interference with programmable classical incoherent light.

    PubMed

    Zhang, Er-Feng; Liu, Wei-Tao; Chen, Ping-Xing

    2015-07-01

    A scheme of high-resolution interference with classical incoherent light is proposed. In this scheme, the classical incoherent light is programmable in the amplitude distribution and wavefront, and with the programmable classical incoherent light we improve the resolution of the interference pattern by a factor of 2 compared with the scheme by Erkmen [J. Opt. Soc. Am. A29, 782 (2012)JOAOD60740-323210.1364/JOSAA.29.000782]. Compared with other schemes for observing interference patterns, only single-pixel detection is needed in our proposal. Moreover, the high-resolution interference pattern can be inverted to obtain an image with better resolution compared with that of the scheme proposed by Erkmen. Furthermore, this scheme of high-resolution interference is verified in detail by theoretical analysis and numerical simulations. PMID:26367153

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

    NASA Astrophysics Data System (ADS)

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

    2008-10-01

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

  14. High Spectral Resolution With Multilayer Gratings

    SciTech Connect

    Andre, J.-M.; Le Guen, K.; Jonnard, P.

    2010-04-06

    The improvement of spectral resolution brought about by the use of multilayer grating (MG) instead of multilayer mirror (MM) is analyzed. The spectrum of a complex sample containing various elements excited under electron irradiation is studied. This sample is a pellet made by pressing powders of Cu and compounds with Fe and F atoms. The MM is a Mo/B{sub 4}C periodic multilayer with a period of about 6 nm; for the MG a grating of 1 {mu}m period has been etched in the MM. It is shown that the MG can easily resolve the F Kalpha and Fe Lalpha emissions, separated by about 30 eV, whereas the MM is unable to give such a performance. A comparison with an EDS (SDD) detector is also given. It is also shown that the MG can improve the detection limit. Finally the role of the slit placed in front of the detector is discussed.

  15. A high resolution global scale groundwater model

    NASA Astrophysics Data System (ADS)

    de Graaf, I. E.; Sutanudjaja, E.; Van Beek, L. P.; Bierkens, M. F.

    2013-12-01

    As the world's largest accessible source of freshwater, groundwater plays a vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and also supplies water for agricultural and industrial activities. During times of drought, the large natural groundwater storage provides a buffer against water shortage and sustains flows to rivers and wetlands, supporting ecosystem habitats and biodiversity. Yet, the current generation of global scale hydrological models (GHMs) do not include a groundwater flow component, although it is a crucial part of the hydrological cycle. Thus, a realistic physical representation of the groundwater system that allows for the simulation of groundwater head dynamics and lateral flows is essential for GHMs that increasingly run at finer resolution. In this study we present a transient global groundwater model with a resolution of 5 arc-minutes (approximately 10 km at the equator) using MODFLOW (McDonald and Harbaugh, 1988). Aquifer schematization and properties of this groundwater model were developed from available global lithological maps and datasets (Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013) combined with information about e.g. aquifer thickness and presence of less permeable, impermeable, and semi-impermeable layers. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. We validated simulated groundwater heads with observations, from North America and Australia, resulting in a coefficient of determination of 0.8 and 0.7 respectively. This shows that it is feasible to build a global groundwater model using best available global information, and estimated water table depths are within acceptable accuracy in many parts of the world.

  16. High-resolution structure prediction and the crystallographic phase problem

    E-print Network

    Das, Rhiju

    The energy-based refinement of low-resolution protein structure models to atomic-level accuracy is a major structure to relax in a physically realistic all-atom force field. In applications to models produced usingARTICLES High-resolution structure prediction and the crystallographic phase problem Bin Qian1

  17. Experiments on High Resolution Images Towards Outdoor Scene Classification

    E-print Network

    Mirmehdi, Majid

    Experiments on High Resolution Images Towards Outdoor Scene Classification A. Monadjemi, B. T resolution images to increase texture classification accuracy when used in combination with lower frequency information in images can be commonly associated with edges and noise [12]. We are not concerned, at least

  18. High Resolution Aerosol Modeling: Decadal Changes in Radiative Forcing

    SciTech Connect

    Bergmann, D J; Chuang, C C; Govindasamy, B; Cameron-Smith, P J; Rotman, D A

    2005-02-01

    The Atmospheric Science Division of LLNL has performed high-resolution calculations of direct sulfate forcing using a DOE-provided computer resource at NERSC. We integrated our global chemistry-aerosol model (IMPACT) with the LLNL high-resolution global climate model (horizontal resolution as high as 100 km) to examine the temporal evolution of sulfate forcing since 1950. We note that all previous assessments of sulfate forcing reported in IPCC (2001) were based on global models with coarse spatial resolutions ({approx} 300 km or even coarser). However, the short lifetime of aerosols ({approx} days) results in large spatial and temporal variations of radiative forcing by sulfate. As a result, global climate models with coarse resolutions do not accurately simulate sulfate forcing on regional scales. It requires much finer spatial resolutions in order to address the effects of regional anthropogenic SO{sub 2} emissions on the global atmosphere as well as the effects of long-range transport of sulfate aerosols on the regional climate forcing. By taking advantage of the tera-scale computer resources at NERSC, we simulated the historic direct sulfate forcing at much finer spatial resolutions than ever attempted before. Furthermore, we performed high-resolution chemistry simulations and saved monthly averaged oxidant fields, which will be used in subsequent simulations of sulfate aerosol formation and their radiative impact.

  19. High resolution data base for use with MAP

    SciTech Connect

    Tapley, W.C.; Harris, D.B.

    1987-05-05

    A high resolution cartographic data base of thw World is available from the CIA. We obtained this data, extracted portions of the data, and produced cartographic files of varying resolutions. The resulting data files are of the proper format for use with MAP (2), our in-house cartographic plotting program.

  20. Reproducible high-resolution multispectral image acquisition in dermatology

    NASA Astrophysics Data System (ADS)

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

    2015-07-01

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

  1. Resolution analysis of high-resolution marine seismic data acquired off Yeosu, Korea

    NASA Astrophysics Data System (ADS)

    Lee, Ho-Young; Kim, Wonsik; Koo, Nam-Hyung; Park, Keun-Pil; Yoo, Dong-Geun; Kang, Dong-Hyo; Kim, Young-Gun; Seo, Gab-Seok; Hwang, Kyu-Duk

    2014-05-01

    High-resolution marine seismic surveys have been conducted for the mineral exploration and engineering purpose survey. To improve the quality of high-resolution seismic data, small-scaled multi-channel seismic techniques are used. In this study, we designed high-resolution marine seismic survey using a small airgun and an 8-channel streamer cable and analyzed the resolution of the seismic data related to acquisition and processing parameters. The field survey was conducted off Yeosu, Korea where the stratified thin sedimentary layers are deposited. We used a 30 in3 airgun and an 8-channel streamer cable with a 5 m group interval. We shoot the airgun with a 5 m shot interval and recorded digital data with a 0.1 ms sample interval and 1 s record length. The offset between the source and the first channel was 20 m. We processed the acquired data with simple procedure such as gain recovery, deconvolution, digital filtering, CMP sorting, NMO correction, static correction and stacking. To understand the effect of the acquisition parameters on the vertical and horizontal resolution, we resampled the acquired data using various sample intervals and CMP intervals and produced seismic sections. The analysis results show that the detailed subsurface structures can be imaged with good resolution and continuity using acquisition parameters with a sample interval shorter than 0.2 ms and a CMP interval shorter than 2.5 m. A high-resolution marine 8-channel airgun seismic survey using appropriate acquisition and processing parameters can be effective in imaging marine subsurface structure with a high resolution. This study is a part of a National Research Laboratory (NRL) project and a part of an Energy Technology Innovation (ETI) Project of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), funded by the Ministry of Trade, Industry and Energy (MOTIE). The authors thank the officers and crew of the R/V Tamhae II for their efforts in the field survey.

  2. Ultra-high resolution and high-brightness AMOLED

    NASA Astrophysics Data System (ADS)

    Wacyk, Ihor; Ghosh, Amal; Prache, Olivier; Draper, Russ; Fellowes, Dave

    2012-06-01

    As part of its continuing effort to improve both the resolution and optical performance of AMOLED microdisplays, eMagin has recently developed an SXGA (1280×3×1024) microdisplay under a US Army RDECOM CERDEC NVESD contract that combines the world's smallest OLED pixel pitch with an ultra-high brightness green OLED emitter. This development is aimed at next-generation HMD systems with "see-through" and daylight imaging requirements. The OLED pixel array is built on a 0.18-micron CMOS backplane and contains over 4 million individually addressable pixels with a pixel pitch of 2.7 × 8.1 microns, resulting in an active area of 0.52 inches diagonal. Using both spatial and temporal enhancement, the display can provide over 10-bits of gray-level control for high dynamic range applications. The new pixel design also enables the future implementation of a full-color QSXGA (2560 × RGB × 2048) microdisplay in an active area of only 1.05 inch diagonal. A low-power serialized low-voltage-differential-signaling (LVDS) interface is integrated into the display for use as a remote video link for tethered systems. The new SXGA backplane has been combined with the high-brightness green OLED device developed by eMagin under an NVESD contract. This OLED device has produced an output brightness of more than 8000fL with all pixels on; lifetime measurements are currently underway and will presented at the meeting. This paper will describe the operational features and first optical and electrical test results of the new SXGA demonstrator microdisplay.

  3. Road Extraction from High Resolution Satellite Images

    NASA Astrophysics Data System (ADS)

    Özkaya, M.

    2012-07-01

    Roads are significant objects of an infrastructure and the extraction of roads from aerial and satellite images are important for different applications such as automated map generation and change detection. Roads are also important to detect other structures such as buildings and urban areas. In this paper, the road extraction approach is based on Active Contour Models for 1-meter resolution gray level images. Active Contour Models contains Snake Approach. During applications, the road structure was separated as salient-roads, non-salient roads and crossings and extraction of these is provided by using Ribbon Snake and Ziplock Snake methods. These methods are derived from traditional snake model. Finally, various experimental results were presented. Ribbon and Ziplock Snake methods were compared for both salient and non-salient roads. Also these methods were used to extract roads in an image. While Ribbon snake is described for extraction of salient roads in an image, Ziplock snake is applied for extraction of non-salient roads. Beside these, some constant variables in literature were redefined and expressed in a formula as depending on snake approach and a new approach for extraction of crossroads were described and tried.

  4. High-resolution tomographic imaging of microvessels

    NASA Astrophysics Data System (ADS)

    Müller, Bert; Lang, Sabrina; Dominietto, Marco; Rudin, Markus; Schulz, Georg; Deyhle, Hans; Germann, Marco; Pfeiffer, Franz; David, Christian; Weitkamp, Timm

    2008-08-01

    Cancer belongs to the primary diseases these days. Although different successful treatments including surgery, chemical, pharmacological, and radiation therapies are established, the aggressive proliferation of cancerous cells and the related formation of blood vessels has to be better understood to develop more powerful strategies against the different kinds of cancer. Angiogenesis is one of the crucial steps for the survival and metastasis formation of malignant tumors. Although therapeutic strategies attempting to inhibit these processes are being developed, the biological regulation is still unclear. This study concentrates on the three-dimensional morphology of vessels formed in a mouse tumor xenograft model post mortem. Synchrotron radiation-based micro computed tomography (SR?CT) could provide the necessary information that is essential for validating the simulations. Using mouse and human brain tissue, the different approaches to extract the vessel tree from SR?CT data are discussed. These approaches include corrosion casting, the application of contrast agents such as barium sulfate, tissue embedding, all of them regarded as materials science based. Alternatively, phase contrast tomography was used, which gave rise to promising results but still not reaches the spatial resolution to uncover the smallest capillaries.

  5. GLASS CERAMICS FOR HIGH RESOLUTION IMAGING

    SciTech Connect

    Johnson, Jackie A.; Weber, Rick; Kolesnikov, Alexander I; SCHWEIZER, Stefan

    2008-01-01

    Glass-ceramic materials are being developed for use in digital mammography systems. The materials are transparent x-ray storage phosphors, which are potentially less expensive than competing materials with superior performance. The materials do not suffer from loss of resolution and increased noise due to light scattering from grain boundaries, as do the currently available polycrystalline materials. The glass ceramics are based on Eu2+ -doped fluorochlorozirconate glasses. These can be heat treated to nucleate Eudoped barium chloride nanocrystals. The glass ceramic converts ionizing radiation (typically x-rays) into stable electronhole pairs that can be read by scanning a stimulating light beam across the glass to cause photostimulated luminescence (PSL) emission. Measurements on the materials are ongoing to elucidate structure-property relationships developed as a result of introducing rare-earth ions and modifying process conditions. Image quality measurements indicate that the current material competes with state-of-the-art x-ray imaging plates. The paper presents results on structure, properties and future directions of the materials described above.

  6. Quantitative single-particle digital autoradiography with ?-particle emitters for targeted radionuclide therapy using the iQID camera

    SciTech Connect

    Miller, Brian W.; Frost, Sofia H. L.; Frayo, Shani L.; Kenoyer, Aimee L.; Santos, Erlinda; Jones, Jon C.; Orozco, Johnnie J.; Green, Damian J.; Press, Oliver W.; Pagel, John M.; Sandmaier, Brenda M.; Hamlin, Donald K.; Wilbur, D. Scott; Fisher, Darrell R.

    2015-07-15

    Purpose: Alpha-emitting radionuclides exhibit a potential advantage for cancer treatments because they release large amounts of ionizing energy over a few cell diameters (50–80 ?m), causing localized, irreparable double-strand DNA breaks that lead to cell death. Radioimmunotherapy (RIT) approaches using monoclonal antibodies labeled with ? emitters may thus inactivate targeted cells with minimal radiation damage to surrounding tissues. Tools are needed to visualize and quantify the radioactivity distribution and absorbed doses to targeted and nontargeted cells for accurate dosimetry of all treatment regimens utilizing ? particles, including RIT and others (e.g., Ra-223), especially for organs and tumors with heterogeneous radionuclide distributions. The aim of this study was to evaluate and characterize a novel single-particle digital autoradiography imager, the ionizing-radiation quantum imaging detector (iQID) camera, for use in ?-RIT experiments. Methods: The iQID camera is a scintillator-based radiation detection system that images and identifies charged-particle and gamma-ray/x-ray emissions spatially and temporally on an event-by-event basis. It employs CCD-CMOS cameras and high-performance computing hardware for real-time imaging and activity quantification of tissue sections, approaching cellular resolutions. In this work, the authors evaluated its characteristics for ?-particle imaging, including measurements of intrinsic detector spatial resolutions and background count rates at various detector configurations and quantification of activity distributions. The technique was assessed for quantitative imaging of astatine-211 ({sup 211}At) activity distributions in cryosections of murine and canine tissue samples. Results: The highest spatial resolution was measured at ?20 ?m full width at half maximum and the ?-particle background was measured at a rate as low as (2.6 ± 0.5) × 10{sup ?4} cpm/cm{sup 2} (40 mm diameter detector area). Simultaneous imaging of multiple tissue sections was performed using a large-area iQID configuration (ø 11.5 cm). Estimation of the {sup 211}At activity distribution was demonstrated at mBq/?g-levels. Conclusions: Single-particle digital autoradiography of ? emitters has advantages over traditional film-based autoradiographic techniques that use phosphor screens, in terms of spatial resolution, sensitivity, and activity quantification capability. The system features and characterization results presented in this study show that the iQID is a promising technology for microdosimetry, because it provides necessary information for interpreting alpha-RIT outcomes and for predicting the therapeutic efficacy of cell-targeted approaches using ? emitters.

  7. Sensitivity study of reliable, high-throughput resolution metricsfor photoresists

    SciTech Connect

    Anderson, Christopher N.; Naulleau, Patrick P.

    2007-07-30

    The resolution of chemically amplified resists is becoming an increasing concern, especially for lithography in the extreme ultraviolet (EUV) regime. Large-scale screening and performance-based down-selection is currently underway to identify resist platforms that can support shrinking feature sizes. Resist screening efforts, however, are hampered by the absence of reliable resolution metrics that can objectively quantify resist resolution in a high-throughput fashion. Here we examine two high-throughput metrics for resist resolution determination. After summarizing their details and justifying their utility, we characterize the sensitivity of both metrics to two of the main experimental uncertainties associated with lithographic exposure tools, namely: limited focus control and limited knowledge of optical aberrations. For an implementation at EUV wavelengths, we report aberration and focus limited error bars in extracted resolution of {approx} 1.25 nm RMS for both metrics making them attractive candidates for future screening and down-selection efforts.

  8. High Resolution CryoFESEM of Microbial Surfaces

    NASA Astrophysics Data System (ADS)

    Erlandsen, Stanley; Lei, Ming; Martin-Lacave, Ines; Dunny, Gary; Wells, Carol

    2003-08-01

    The outer surfaces of three microorganisms, Giardia lamblia, Enterococcus faecalis, and Proteus mirabilis, were investigated by cryo-immobilization followed by sublimation of extracellular ice and cryocoating with either Pt alone or Pt plus carbon. Cryocoated samples were examined at [minus sign]125°C in either an in-lens field emission SEM or a below-the-lens field emission SEM. Cryocoating with Pt alone was sufficient for low magnification observation, but attempts to do high-resolution imaging resulted in radiolysis and cracking of the specimen surface. Double coating with Pt and carbon, in combination with high resolution backscatter electron detectors, enabled high-resolution imaging of the glycocalyx of bacteria, revealing a sponge-like network over the surface. High resolution examination of bacterial flagella also revealed a periodic substructure. Common artifacts included radiolysis leading to “cracking” of the surface, and insufficient deposition of Pt resulting in the absence of detectable surface topography.

  9. Green-winged macaws Click here for a high resolution

    E-print Network

    McGraw, Kevin J.

    Green-winged macaws Click here for a high resolution photograph. Public release date: 16-Feb-2005 the colors of the birds possible, and then focused on "deconstructing the color into its #12;Military macaws

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

    NASA Astrophysics Data System (ADS)

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

    2015-08-01

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

  11. Holographic deconvolution microscopy for high-resolution particle tracking

    E-print Network

    Grier, David

    Holographic deconvolution microscopy for high-resolution particle tracking Lisa Dixon, Fook Chiong.-W. Fink, "Depth-resolved holographic reconstructions by three-dimensional deconvolution," Opt. Express 21

  12. Overshooting Convection from High-resolution NEXRAD Observations 

    E-print Network

    Solomon, David

    2014-01-09

    , magnitude, and location of overshooting convection events. A new method that combines radar reflectivities from individual radars into a three-dimensional composite with high vertical resolution is used to obtain storm top altitudes. These altitudes...

  13. AVHRR/1-FM Advanced Very High Resolution Radiometer

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The advanced very high resolution radiometer is discussed. The program covers design, construction, and test of a breadboard model, engineering model, protoflight model, mechanical/structural model, and a life test model. Special bench test and calibration equipment was developed for use on the program. The flight model program objectives were to fabricate, assemble and test four of the advanced very high resolution radiometers along with a bench cooler and collimator.

  14. A high resolution SPECT detector based on thin continuous LYSO.

    PubMed

    Deprez, Karel; Van Holen, Roel; Vandenberghe, Stefaan

    2014-01-01

    Single-photon emission computed tomography (SPECT) detectors with improved spatial resolution can be used to build multi-pinhole SPECT systems that have a higher sensitivity or a higher spatial resolution. In order to improve the spatial resolution we investigate the performance of a 2 mm thick continuous Lutetium Yttrium Orthosilicate (LYSO) scintillator and compare it to the performance of a 5 mm thick continuous NaI(Tl) scintillator. The advantages of LYSO are its high stopping power and its non-hygroscopicity. Drawbacks are the lower light output and the intrinsic radioactivity. The hypothesis of this study is that such a thin LYSO scintillator will have a small light spread and, as a consequence, will also have an improved spatial resolution when coupled to a Hamamatsu H8500 position sensitive photomultiplier tube. To optimize the spatial resolution and the useful detector area we used a mean nearest neighbor event-positioning method. Beam source measurements ((99m)Tc, 140 keV) were done to investigate the energy resolution and the spatial resolution of both detectors. The effect of the intrinsic radioactivity of the LYSO scintillator in the energy window was quantified. The mean energy resolution is 9.3% for the NaI(Tl) scintillator and 21.3% for the LYSO scintillator. The LYSO spectrum shows an X-ray escape peak which decreases the detection efficiency with 9.1%. The spatial resolution of the LYSO detector (0.93 mm full width at half maximum (FWHM)) is superior to the spatial resolution of the NaI(Tl) detector (1.37 mm FWHM). The intrinsic radioactivity in the energy window (42% window centered at 140 keV) is low (125.6 cps, 0.024 cps?mm(-3)). LYSO is a promising scintillator for small-animal SPECT imaging, where spatial resolution is more important than energy resolution. PMID:24334315

  15. Neurotechnique High-Resolution Intracellular Recordings Using

    E-print Network

    Bal, Thierry

    contribu- tion. Tests performed in vitro and in vivo demonstrate that AEC enables high-frequency recordings of resistances and capacitances depending on the age and species of the animal (rather low values could biases the measurement because of the voltage drop through the electrode. This elec- trode bias imposes

  16. High Resolution X-Ray Explorer (HIREX)

    NASA Technical Reports Server (NTRS)

    Goulb, Leon

    1997-01-01

    SAO is involved in a study to determine the feasibility of building an orbiting telescope capable of resolving 7 km structure on the Sun. In order to achieve the required imaging the telescope must have a resolution 0.01 arcsec. This fact challenges the state of the art of orbiting telescopes in several areas: Mirror Figuring; Optical Metrology; Optical Mounting; Mirror Figure Control; System Alignment; Optical Stability; Observatory Pointing; and Image Stability. The telescope design concept is based on a 0.6 m Gregorian-style telescope with a 240 meter effective focal length. This is achieved with 2 mirrors supported at opposite ends of a 35 m space-deployable boom. The telescope mirrors are coated with multilayers designed to reflect a broad XUV passband. A third, small mirror, near the focal plane performs the function of selecting the narrow band that is finally imaged. Image stabilization to the 0.005 arcsec level is achieved by active control of the secondary mirror. The primary mirror is held unadjustably to the spacecraft, its pointing set by the spacecraft orientation. The secondary mirror is mounted on a 6-axis stage that permits its position to be changed to align the telescope in space. The stage is intended for intermittent adjustment, both because of its speed of travel, and the TBD alignment procedure. The third mirror is called the TXI (Tuneable X-ray Imager). It is mounted on a gimbal that permits it to be tipped over a 60 degree range, selecting between the individual wavelengths in the initial bandpass. It can also rotated completely out of the way to allow the full, broadband EUV flux to strike the focal plane. Finally, the focal plane assembly is designed to rotate on the outer edge of a circle centered on the TXI mirror rotation axis. This permits the focal plane to move to the location that the TXI redirects the light once it has been set to a given wavelength response. The Engineering Study is divided into the following areas: Mirror Fabrication and Metrology; Optical Layout-Trade Study between On-axis and Off-axis; Overall System Design; and Pointing Control/Image Stabilization. The observational goals of the mission are described in the Mission Requirements document. The work is being performed to the requirements called out in the Science Requirements document.

  17. High resolution simulation of the South Asian monsoon using a variable resolution global climate model

    NASA Astrophysics Data System (ADS)

    P Sabin, T.; Krishnan, R.; Ghattas, Josefine; Denvil, Sebastien; Dufresne, Jean-Louis; Hourdin, Frederic; Pascal, Terray

    2013-07-01

    This study examines the feasibility of using a variable resolution global general circulation model (GCM), with telescopic zooming and enhanced resolution (~35 km) over South Asia, to better understand regional aspects of the South Asian monsoon rainfall distribution and the interactions between monsoon circulation and precipitation. For this purpose, two sets of ten member realizations are produced with and without zooming using the LMDZ (Laboratoire Meteorologie Dynamique and Z stands for zoom) GCM. The simulations without zoom correspond to a uniform 1° × 1° grid with the same total number of grid points as in the zoom version. So the grid of the zoomed simulations is finer inside the region of interest but coarser outside. The use of these finer and coarser resolution ensemble members allows us to examine the impact of resolution on the overall quality of the simulated regional monsoon fields. It is found that the monsoon simulation with high-resolution zooming greatly improves the representation of the southwesterly monsoon flow and the heavy precipitation along the narrow orography of the Western Ghats, the northeastern mountain slopes and northern Bay of Bengal (BOB). A realistic Monsoon Trough (MT) is also noticed in the zoomed simulation, together with remarkable improvements in representing the associated precipitation and circulation features, as well as the large-scale organization of meso-scale convective systems over the MT region. Additionally, a more reasonable simulation of the monsoon synoptic disturbances (lows and disturbances) along the MT is noted in the high-resolution zoomed simulation. On the other hand, the no-zoom version has limitations in capturing the depressions and their movement, so that the MT zone is relatively dry in this case. Overall, the results from this work demonstrate the usefulness of the high-resolution variable resolution LMDZ model in realistically capturing the interactions among the monsoon large-scale dynamics, the synoptic systems and the meso-scale convective systems, which are essential elements of the South Asian monsoon system.

  18. High-resolution Urban Image Classification Using Extended Features

    SciTech Connect

    Vatsavai, Raju

    2011-01-01

    High-resolution image classification poses several challenges because the typical object size is much larger than the pixel resolution. Any given pixel (spectral features at that location) by itself is not a good indicator of the object it belongs to without looking at the broader spatial footprint. Therefore most modern machine learning approaches that are based on per-pixel spectral features are not very effective in high- resolution urban image classification. One way to overcome this problem is to extract features that exploit spatial contextual information. In this study, we evaluated several features in- cluding edge density, texture, and morphology. Several machine learning schemes were tested on the features extracted from a very high-resolution remote sensing image and results were presented.

  19. High-resolution quantitative imaging of mammalian and bacterial cells using stable isotope mass spectrometry

    PubMed Central

    Lechene, Claude; Hillion, Francois; McMahon, Greg; Benson, Douglas; Kleinfeld, Alan M; Kampf, J Patrick; Distel, Daniel; Luyten, Yvette; Bonventre, Joseph; Hentschel, Dirk; Park, Kwon Moo; Ito, Susumu; Schwartz, Martin; Benichou, Gilles; Slodzian, Georges

    2006-01-01

    Background Secondary-ion mass spectrometry (SIMS) is an important tool for investigating isotopic composition in the chemical and materials sciences, but its use in biology has been limited by technical considerations. Multi-isotope imaging mass spectrometry (MIMS), which combines a new generation of SIMS instrument with sophisticated ion optics, labeling with stable isotopes, and quantitative image-analysis software, was developed to study biological materials. Results The new instrument allows the production of mass images of high lateral resolution (down to 33 nm), as well as the counting or imaging of several isotopes simultaneously. As MIMS can distinguish between ions of very similar mass, such as 12C15N- and 13C14N-, it enables the precise and reproducible measurement of isotope ratios, and thus of the levels of enrichment in specific isotopic labels, within volumes of less than a cubic micrometer. The sensitivity of MIMS is at least 1,000 times that of 14C autoradiography. The depth resolution can be smaller than 1 nm because only a few atomic layers are needed to create an atomic mass image. We illustrate the use of MIMS to image unlabeled mammalian cultured cells and tissue sections; to analyze fatty-acid transport in adipocyte lipid droplets using 13C-oleic acid; to examine nitrogen fixation in bacteria using 15N gaseous nitrogen; to measure levels of protein renewal in the cochlea and in post-ischemic kidney cells using 15N-leucine; to study DNA and RNA co-distribution and uridine incorporation in the nucleolus using 15N-uridine and 81Br of bromodeoxyuridine or 14C-thymidine; to reveal domains in cultured endothelial cells using the native isotopes 12C, 16O, 14N and 31P; and to track a few 15N-labeled donor spleen cells in the lymph nodes of the host mouse. Conclusion MIMS makes it possible for the first time to both image and quantify molecules labeled with stable or radioactive isotopes within subcellular compartments. PMID:17010211

  20. Event reconstruction in high resolution Compton telescopes

    E-print Network

    S. E. Boggs; P. Jean

    2000-05-11

    The development of germanium Compton telescopes for nuclear gamma-ray astrophysics (~0.2-20 MeV) requires new event reconstruction techniques to accurately determine the initial direction and energy of photon events, as well as to consistently reject background events. This paper describes techniques for event reconstruction, accounting for realistic instrument/detector performance and uncertainties. An especially important technique is Compton Kinematic Discrimination, which allows proper interaction ordering and background rejection with high probabilities. The use of these techniques are crucial for the realistic evaluation of the performance and sensitivity of any germanium Compton telescope configuration.

  1. High-resolution retinal imaging: enhancement techniques

    NASA Astrophysics Data System (ADS)

    Mujat, Mircea; Patel, Ankit; Iftimia, Nicusor; Akula, James D.; Fulton, Anne B.; Ferguson, R. Daniel

    2015-03-01

    AO has achieved success in a range of applications in ophthalmology where microstructures need to be identified, counted, and mapped. Multiple images are averaged to improve the SNR or analyzed for temporal dynamics. For small patches, image registration by cross-correlation is straightforward. Larger images require more sophisticated registration techniques. Strip-based registration has been used successfully for photoreceptor mosaic alignment in small patches; however, if the deformations along long strips are not simple displacements, averaging will actually degrade the images. We have applied non-rigid registration that significantly improves the quality of processed images for mapping cones and rods, and microvasculature in dark-field imaging. Local grid deformations account for local image stretching and compression due to a number of causes. Individual blood cells can be traced along capillaries in high-speed imaging (130 fps) and flow dynamics can be analyzed.

  2. [Extracting municipal solid waste dumps based on high resolution images].

    PubMed

    Zhang, Fang-Li; Du, Shi-Hong; Guo, Zhou

    2013-08-01

    The dramatically increasing informal MSW dumps are endangering the urban environment. Remote sensing (RS) technologies are more efficient to monitor and manage municipal solid wastes (MSW) than traditional survey-based methods. In high spatial resolution remotely sensed images, these irregularly distributed dumps have complex compositions and strong heterogeneities, thus it is still hard to extract them automatically no matter the pixel-or object-based image analysis method is used. Therefore, based on the analysis of MSW characteristics, the present study develops a multiresolution strategy to extract MSW dumps by combining image features at both high resolution and resampled low heterogeneity images, while the high resolution images can provide detailed information and the low resolution images can suppress the strong heterogeneities of informal MSW dumps. Taking the QuickBird image covering part of Beijing as an example, this multi-resolution strategy produced a high accuracy (75%), indicating that this multi-resolution strategy is quite effective for extracting the open-air informal MSW dumps. PMID:24159838

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

    E-print Network

    Véronique Delouille; Pierre Chainais; Jean-François Hochedez

    2008-08-22

    Future missions such as Solar Orbiter (SO), InterHelioprobe, or Solar Probe aim at approaching the Sun closer than ever before, with on board some high resolution imagers (HRI) having a subsecond cadence and a pixel area of about $(80km)^2$ at the Sun during perihelion. In order to guarantee their scientific success, it is necessary to evaluate if the photon counts available at these resolution and cadence will provide a sufficient signal-to-noise ratio (SNR). We perform a first step in this direction by analyzing and characterizing the spatial intermittency of Quiet Sun images thanks to a multifractal analysis. We identify the parameters that specify the scale-invariance behavior. This identification allows next to select a family of multifractal processes, namely the Compound Poisson Cascades, that can synthesize artificial images having some of the scale-invariance properties observed on the recorded images. The prevalence of self-similarity in Quiet Sun coronal images makes it relevant to study the ratio between the SNR present at SoHO/EIT images and in coarsened images. SoHO/EIT images thus play the role of 'high resolution' images, whereas the 'low-resolution' coarsened images are rebinned so as to simulate a smaller angular resolution and/or a larger distance to the Sun. For a fixed difference in angular resolution and in Spacecraft-Sun distance, we determine the proportion of pixels having a SNR preserved at high resolution given a particular increase in effective area. If scale-invariance continues to prevail at smaller scales, the conclusion reached with SoHO/EIT images can be transposed to the situation where the resolution is increased from SoHO/EIT to SO/HRI resolution at perihelion.

  4. High-resolution climate simulation of the last glacial maximum

    NASA Astrophysics Data System (ADS)

    Kim, Seong-Joong; Crowley, Thomas J.; Erickson, David J.; Govindasamy, Bala; Duffy, Phillip B.; Lee, Bang Yong

    2008-07-01

    The climate of the last glacial maximum (LGM) is simulated with a high-resolution atmospheric general circulation model, the NCAR CCM3 at spectral truncation of T170, corresponding to a grid cell size of roughly 75 km. The purpose of the study is to assess whether there are significant benefits from the higher resolution simulation compared to the lower resolution simulation associated with the role of topography. The LGM simulations were forced with modified CLIMAP sea ice distribution and sea surface temperatures (SST) reduced by 1°C, ice sheet topography, reduced CO2, and 21,000 BP orbital parameters. The high-resolution model captures modern climate reasonably well, in particular the distribution of heavy precipitation in the tropical Pacific. For the ice age case, surface temperature simulated by the high-resolution model agrees better with those of proxy estimates than does the low-resolution model. Despite the fact that tropical SSTs were only 2.1°C less than the control run, there are many lowland tropical land areas 4 6°C colder than present. Comparison of T170 model results with the best constrained proxy temperature estimates (noble gas concentrations in groundwater) now yield no significant differences between model and observations. There are also significant upland temperature changes in the best resolved tropical mountain belt (the Andes). We provisionally attribute this result in part as resulting from decreased lateral mixing between ocean and land in a model with more model grid cells. A longstanding model-data discrepancy therefore appears to be resolved without invoking any unusual model physics. The response of the Asian summer monsoon can also be more clearly linked to local geography in the high-resolution model than in the low-resolution model; this distinction should enable more confident validation of climate proxy data with the high-resolution model. Elsewhere, an inferred salinity increase in the subtropical North Atlantic may have significant implications for ocean circulation changes during the LGM. A large part of the Amazon and Congo Basins are simulated to be substantially drier in the ice age—consistent with many (but not all) paleo data. These results suggest that there are considerable benefits derived from high-resolution model regarding regional climate responses, and that observationalists can now compare their results with models that resolve geography at a resolution comparable to that which the proxy data represent.

  5. High-resolution climate simulation of the last glacial maximum

    SciTech Connect

    Erickson III, David J

    2008-01-01

    The climate of the last glacial maximum (LGM) is simulated with a high-resolution atmospheric general circulation model, the NCAR CCM3 at spectral truncation of T170, corresponding to a grid cell size of roughly 75 km. The purpose of the study is to assess whether there are significant benefits from the higher resolution simulation compared to the lower resolution simulation associated with the role of topography. The LGM simulations were forced with modified CLIMAP sea ice distribution and sea surface temperatures (SST) reduced by 1 C, ice sheet topography, reduced CO{sub 2}, and 21,000 BP orbital parameters. The high-resolution model captures modern climate reasonably well, in particular the distribution of heavy precipitation in the tropical Pacific. For the ice age case, surface temperature simulated by the high-resolution model agrees better with those of proxy estimates than does the low-resolution model. Despite the fact that tropical SSTs were only 2.1 C less than the control run, there are many lowland tropical land areas 4-6 C colder than present. Comparison of T170 model results with the best constrained proxy temperature estimates (noble gas concentrations in groundwater) now yield no significant differences between model and observations. There are also significant upland temperature changes in the best resolved tropical mountain belt (the Andes). We provisionally attribute this result in part as resulting from decreased lateral mixing between ocean and land in a model with more model grid cells. A longstanding model-data discrepancy therefore appears to be resolved without invoking any unusual model physics. The response of the Asian summer monsoon can also be more clearly linked to local geography in the high-resolution model than in the low-resolution model; this distinction should enable more confident validation of climate proxy data with the high-resolution model. Elsewhere, an inferred salinity increase in the subtropical North Atlantic may have significant implications for ocean circulation changes during the LGM. A large part of the Amazon and Congo Basins are simulated to be substantially drier in the ice age - consistent with many (but not all) paleo data. These results suggest that there are considerable benefits derived from high-resolution model regarding regional climate responses, and that observationalists can now compare their results with models that resolve geography at a resolution comparable to that which the proxy data represent.

  6. THz holography in reflection using a high resolution microbolometer array.

    PubMed

    Zolliker, Peter; Hack, Erwin

    2015-05-01

    We demonstrate a digital holographic setup for Terahertz imaging of surfaces in reflection. The set-up is based on a high-power continuous wave (CW) THz laser and a high-resolution (640 × 480 pixel) bolometer detector array. Wave propagation to non-parallel planes is used to reconstruct the object surface that is rotated relative to the detector plane. In addition we implement synthetic aperture methods for resolution enhancement and compare Fourier transform phase retrieval to phase stepping methods. A lateral resolution of 200 ?m and a relative phase sensitivity of about 0.4 rad corresponding to a depth resolution of 6 ?m are estimated from reconstructed images of two specially prepared test targets, respectively. We highlight the use of digital THz holography for surface profilometry as well as its potential for video-rate imaging. PMID:25969190

  7. Performance of a High Resolution Cavity Beam Position Monitor System

    SciTech Connect

    Walston, S; Boogert, S; Chung, C; Fitsos, P; Frisch, J; Gronberg, J; Hayano, H; Honda, Y; Kolomensky, Y; Lyapin, A; Malton, S; May, J; McCormick, D; Meller, R; Miller, D; Orimoto, T; Ross, M; Slater, M; Smith, S; Smith, T; Terunuma, N; Thomson, M; Urakawa, J; Vogel, V; Ward, D; White, G

    2006-12-18

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

  8. Performance of a High Resolution Cavity Beam Position Monitor System

    SciTech Connect

    Walston, Sean; Boogert, Stewart; Chung, Carl; Fitsos, Joe; Frisch, Joe; Gronberg, Jeff; Hayano, Hitoshi; Honda, Yosuke; Kolomensky, Yury; Lyapin, Alexey; Malton, Stephen; May, Justin; McCormick, Douglas; Meller, Robert; Miller, David John; Orimoto, Toyoko; Ross, Marc; Slater, Mark; Smith, Steve; Smith, Tonee; Terunuma, Nobuhiro; /Fermilab /UC, Berkeley /LBL, Berkeley /Cambridge U. /Royal Holloway, U. of London /Cornell U., LNS /LLNL, Livermore /University Coll. London /SLAC /Caltech /KEK, Tsukuba

    2007-06-08

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

  9. The high resolution actuator based on giant magnetostriction

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Tan, Jiu-bin; Zhang, Shan

    2008-09-01

    The giant magnetostrictive actuator has some unique characteristic, such as high displacement resolution, big output torque etc, so is suitable for the field of ultra precise measurement and fine machining. The principle of the giant magnetostrictive actuator is based on magnetostriction, and Tb0.27Dy0.73Fe1.9 is drove by magnetic field. So the high resolution of the giant magnetostrictive actuator is relate to uniformity of magnetic field. Furthermore, the resolution of actuator is effect by output setup. Because of magnetic field asymmetry, the giant magnetostrictive actuator based on the principle of electromagnetism transforming can be easily causes of displacement nonlinearity. For this problem, the structure and principle of magnetic field is analyzed based on FEA. For improving the resolution farther, the flexible hinge is used to replace to the traditional output setup. At last, the principle of this type of actuator is validated through experiments.

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

    PubMed

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

    2014-11-01

    The small-animal High-Resolution SPECT (HiReSPECT) is a dedicated dual-head gamma camera recently designed and developed in our laboratory for imaging of murine models. Each detector is composed of an array of 1.2 × 1.2 mm(2) (pitch) pixelated CsI(Na) crystals. Two position-sensitive photomultiplier tubes (H8500) are coupled to each head's crystal. In this paper, we report on a resolution-recovery-embedded image reconstruction code applicable to the system and present the experimental results achieved using different phantoms and mouse scans. Collimator-detector response functions (CDRFs) were measured via a pixel-driven method using capillary sources at finite distances from the head within the field of view (FOV). CDRFs were then fitted by independent Gaussian functions. Thereafter, linear interpolations were applied to the standard deviation (?) values of the fitted Gaussians, yielding a continuous map of CDRF at varying distances from the head. A rotation-based maximum-likelihood expectation maximization (MLEM) method was used for reconstruction. A fast rotation algorithm was developed to rotate the image matrix according to the desired angle by means of pre-generated rotation maps. The experiments demonstrated improved resolution utilizing our resolution-recovery-embedded image reconstruction. While the full-width at half-maximum (FWHM) radial and tangential resolution measurements of the system were over 2 mm in nearly all positions within the FOV without resolution recovery, reaching around 2.5 mm in some locations, they fell below 1.8 mm everywhere within the FOV using the resolution-recovery algorithm. The noise performance of the system was also acceptable; the standard deviation of the average counts per voxel in the reconstructed images was 6.6% and 8.3% without and with resolution recovery, respectively. PMID:24986422

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

    SciTech Connect

    Kotasidis, Fotis A.; Angelis, Georgios I.; Anton-Rodriguez, Jose; Matthews, Julian C.; Reader, Andrew J.; Zaidi, Habib; Geneva Neuroscience Centre, Geneva University, CH-1205 Geneva; Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, PO Box 30 001, Groningen 9700 RB

    2014-05-15

    Purpose: Measuring and incorporating a scanner-specific point spread function (PSF) within image reconstruction has been shown to improve spatial resolution in PET. However, due to the short half-life of clinically used isotopes, other long-lived isotopes not used in clinical practice are used to perform the PSF measurements. As such, non-optimal PSF models that do not correspond to those needed for the data to be reconstructed are used within resolution modeling (RM) image reconstruction, usually underestimating the true PSF owing to the difference in positron range. In high resolution brain and preclinical imaging, this effect is of particular importance since the PSFs become more positron range limited and isotope-specific PSFs can help maximize the performance benefit from using resolution recovery image reconstruction algorithms. Methods: In this work, the authors used a printing technique to simultaneously measure multiple point sources on the High Resolution Research Tomograph (HRRT), and the authors demonstrated the feasibility of deriving isotope-dependent system matrices from fluorine-18 and carbon-11 point sources. Furthermore, the authors evaluated the impact of incorporating them within RM image reconstruction, using carbon-11 phantom and clinical datasets on the HRRT. Results: The results obtained using these two isotopes illustrate that even small differences in positron range can result in different PSF maps, leading to further improvements in contrast recovery when used in image reconstruction. The difference is more pronounced in the centre of the field-of-view where the full width at half maximum (FWHM) from the positron range has a larger contribution to the overall FWHM compared to the edge where the parallax error dominates the overall FWHM. Conclusions: Based on the proposed methodology, measured isotope-specific and spatially variant PSFs can be reliably derived and used for improved spatial resolution and variance performance in resolution recovery image reconstruction. The benefits are expected to be more substantial for more energetic positron emitting isotopes such as Oxygen-15 and Rubidium-82.

  12. Design and implementation of spaceborne high resolution infrared touch screen

    NASA Astrophysics Data System (ADS)

    Li, Tai-guo; Li, Wen-xin; Dong, Yi-peng; Ma, Wen; Xia, Jia-gao

    2015-10-01

    For the consideration of the special application environment of the electronic products used in aerospace and to further more improve the human-computer interaction of the manned aerospace area. The research is based on the design and implementation way of the high resolution spaceborne infrared touch screen on the basis of FPGA and DSP frame structure. Beside the introduction of the whole structure for the high resolution spaceborne infrared touch screen system, this essay also gives the detail information about design of hardware for the high resolution spaceborne infrared touch screen system, FPGA design, GUI design and DSP algorithm design based on Lagrange interpolation. What is more, the easy makes a comprehensive research of the reliability design for the high resolution spaceborne infrared touch screen for the special purpose of it. Besides, the system test is done after installation of spaceborne infrared touch screen. The test result shows that the system is simple and reliable enough, which has a stable running environment and high resolution, which certainly can meet the special requirement of the manned aerospace instrument products.

  13. Evacuee Compliance Behavior Analysis using High Resolution Demographic Information

    SciTech Connect

    Lu, Wei; Han, Lee; Liu, Cheng; Tuttle, Mark A; Bhaduri, Budhendra L

    2014-01-01

    The purpose of this study is to examine whether evacuee compliance behavior with route assignments from different resolutions of demographic data would impact the evacuation performance. Most existing evacuation strategies assume that travelers will follow evacuation instructions, while in reality a certain percent of evacuees do not comply with prescribed instructions. In this paper, a comparison study of evacuation assignment based on Traffic Analysis Zones (TAZ) and high resolution LandScan USA Population Cells (LPC) were conducted for the detailed road network representing Alexandria, Virginia. A revised platform for evacuation modeling built on high resolution demographic data and activity-based microscopic traffic simulation is proposed. The results indicate that evacuee compliance behavior affects evacuation efficiency with traditional TAZ assignment, but it does not significantly compromise the efficiency with high resolution LPC assignment. The TAZ assignment also underestimates the real travel time during evacuation, especially for high compliance simulations. This suggests that conventional evacuation studies based on TAZ assignment might not be effective at providing efficient guidance to evacuees. From the high resolution data perspective, traveler compliance behavior is an important factor but it does not impact the system performance significantly. The highlight of evacuee compliance behavior analysis should be emphasized on individual evacuee level route/shelter assignments, rather than the whole system performance.

  14. High-resolution land cover classification using low resolution global data

    NASA Astrophysics Data System (ADS)

    Carlotto, Mark J.

    2013-05-01

    A fusion approach is described that combines texture features from high-resolution panchromatic imagery with land cover statistics derived from co-registered low-resolution global databases to obtain high-resolution land cover maps. The method does not require training data or any human intervention. We use an MxN Gabor filter bank consisting of M=16 oriented bandpass filters (0-180°) at N resolutions (3-24 meters/pixel). The size range of these spatial filters is consistent with the typical scale of manmade objects and patterns of cultural activity in imagery. Clustering reduces the complexity of the data by combining pixels that have similar texture into clusters (regions). Texture classification assigns a vector of class likelihoods to each cluster based on its textural properties. Classification is unsupervised and accomplished using a bank of texture anomaly detectors. Class likelihoods are modulated by land cover statistics derived from lower resolution global data over the scene. Preliminary results from a number of Quickbird scenes show our approach is able to classify general land cover features such as roads, built up area, forests, open areas, and bodies of water over a wide range of scenes.

  15. HIGH RESOLUTION FORWARD AND INVERSE EARTHQUAKE MODELING ON TERASCALE COMPUTERS

    E-print Network

    O'Hallaron, David R.

    , JULIO L ´OPEZ¶, DAVID O'HALLARON , TIANKAI TU, AND JOHN URBANIC Abstract. For earthquake simulations and high fidelity. We have developed algorithms and tools for earthquake simulation basedHIGH RESOLUTION FORWARD AND INVERSE EARTHQUAKE MODELING ON TERASCALE COMPUTERS VOLKAN AKC¸ ELIK

  16. Inverse scattering for high-resolution interferometric microscopy

    E-print Network

    Boppart, Stephen

    Inverse scattering for high-resolution interferometric microscopy Tyler S. Ralston, Daniel L. Marks of inverse scattering for optical coherence tomography (OCT) to the case of high numerical aperture focusing to the diag- nostic utility of OCT. Inverse scattering and com- puted imaging provide a means to obtain

  17. HIGH RESOLUTION STUDIES OF COMPLEX SOLAR ACTIVE REGIONS

    E-print Network

    and are the principal source of space weather. Most of them originate in solar active regions. The most violent eventsABSTRACT HIGH RESOLUTION STUDIES OF COMPLEX SOLAR ACTIVE REGIONS by Na Deng Flares and Coronal Mass are intriguing problems in solar physics. The study of complex active regions is based on high

  18. Lynx: A High-Resolution Synthetic Aperture Radar

    SciTech Connect

    Doerry, A.W.; Hensley, W.H.; Pace, F.; Stence, J.; Tsunoda, S.I.; Walker, B.C.; Woodring, M.

    1999-03-08

    Lynx is a high resolution, synthetic aperture radar (SAR) that has been designed and built by Sandia National Laboratories in collaboration with General Atomics (GA). Although Lynx may be operated on a wide variety of manned and unmanned platforms, it is primarily intended to be fielded on unmanned aerial vehicles. In particular, it may be operated on the Predator, I-GNAT, or Prowler II platforms manufactured by GA Aeronautical Systems, Inc. The Lynx production weight is less than 120 lb. and has a slant range of 30 km (in 4 mm/hr rain). It has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode. In ground moving target indicator mode, the minimum detectable velocity is 6 knots with a minimum target cross-section of 10 dBsm. In coherent change detection mode, Lynx makes registered, complex image comparisons either of 0.1 m resolution (minimum) spotlight images or of 0.3 m resolution (minimum) strip images. The Lynx user interface features a view manager that allows it to pan and zoom like a video camera. Lynx was developed under corporate finding from GA and will be manufactured by GA for both military and commercial applications. The Lynx system architecture will be presented and some of its unique features will be described. Imagery at the finest resolutions in both spotlight and strip modes have been obtained and will also be presented.

  19. High spectral resolution measurements for the ARM Program

    SciTech Connect

    Revercomb, H.E.

    1992-05-22

    This report focuses on the design and fabrication of high spectral resolution FTIR (Fourier Transform Infrared) instrumentation for the CART sites of the Atmospheric Radiation Measurement (ARM) Program. The ultimate objective of this grant is to develop three different types of instruments, named the AERI, AERI-X, and SORT. The Atmospheric Emitted Radiance Interferometer (AERI) is the simplest. It will be available for early deployment at the first ARM site and will be deployable at several locations in the extended network to give horizontal coverage. The AERI will be an 0.5 cm{sup {minus}1} resolution instrument, which measures accurately calibrated radiance spectra for radiation studies and for remote sensing of atmospheric state variables. The AERI-X and the SORTI are higher spectral resolution instruments for obtaining the highest practical resolution for spectroscopy at the ARM central sites. The AERI-X, like the AERI will measure atmospheric emitted radiance, but with resolutions as high as 0.1 cm{sup {minus}1}. The Solar Radiance Transmission Interferometer will measure the total transmission of the atmosphere by tracking the sun through changes in atmospheric air mass. The large solar signal makes it practical for this instrument to offer the ultimate in spectral resolution, about 0.002 cm{sup {minus}1}.

  20. The High Resolution Telescope Cluster. I - Overview and technical status

    NASA Technical Reports Server (NTRS)

    Walker, Arthur B. C., Jr.; Hoover, Richard B.; Roberts, William; Wu, Shi T.

    1992-01-01

    A major component of the Advanced Solar Observatory is the High Resolution Telescope Cluster (HRTC) for investigations of the solar atmosphere at soft X-ray, XUV, EUV, and VUV wavelengths, via high resolution spectroheliograms in lines and continuum emitted over the full, (4500 to 100,000,000 K) range of temperatures of the outer solar atmosphere; angular resolution may be as high as 0.03 arcsec. An analysis is conducted of a model HRTC instrument complement encompassing a 60-90 cm aperture VUV telescope, a 40-50 cm aperture EUV telescope, three 40-50 cm aperture XUV telescopes, and a 40-cm aperture soft X-ray telescope, as well as flare spectrometers and polarimeters and four coronagraph/spectrographs.

  1. The theory and practice of high resolution scanning electron microscopy

    SciTech Connect

    Joy, D.C. Oak Ridge National Lab., TN )

    1990-01-01

    Recent advances in instrumentation have produced the first commercial examples of what can justifiably be called High Resolution Scanning Electron Microscopes. The key components of such instruments are a cold field emission gun, a small-gap immersion probe-forming lens, and a clean dry-pumped vacuum. The performance of these microscopes is characterized by several major features including a spatial resolution, in secondary electron mode on solid specimens, which can exceed 1nm on a routine basis; an incident probe current density of the order of 10{sup 6} amps/cm{sup 2}; and the ability to maintain these levels of performance over an accelerating voltage range of from 1 to 30keV. This combination of high resolution, high probe current, low contamination and flexible electron-optical conditions provides many new opportunitites for the application of the SEM to materials science, physics, and the life sciences. 27 refs., 14 figs.

  2. Fifteen Years of High Angular Resolution Studies of Mira's Atmosphere

    NASA Astrophysics Data System (ADS)

    Karovska, M.

    I describe here results from high-angular resolution imaging studies of o Ceti (Mira). In 1983, we discovered that the atmosphere of the prototype of Mira-type variables is not symmetric. Since then, a number of multiwavelength high-angular resolution observations have confirmed the presence of asymmetries in Mira's atmosphere, and detected asymmetries in the atmospheres of other Mira-type variables. The high-angular resolution images of Mira obtained over the past fifteen years, including recent HST observations, show that the strength and shape of the asymmetries change as a function of wavelength and time. Plausible mechanisms for these asymmetries include hot spots, nonspherical pulsations, interaction with the companion and bipolar outflow. The presence of asymmetries in Miras could have serious impact on evolutionary models, and on the development of model atmospheres.

  3. High-Resolution Urban Monitoring of Greenhouse Gases and Pollutants

    NASA Astrophysics Data System (ADS)

    Baer, D. S.; Leen, J.; Gupta, M.; Graves, L.

    2012-12-01

    Accurate measurements of greenhouse gases and pollutants in urban areas with high spatial and temporal resolution allow scientists and policy makers determine source contributions, monitor pollution migration, and validate air quality models. Currently, these applications are limited by the poor spatial resolution of fixed air monitoring stations. We present very high-resolution measurements of CO, CO2, CH4, H2O, NH3 and NO2 taken throughout the San Francisco Bay Area, California using a flexible mobile monitoring platform. These measurements cover several highly urban and coastal regions that were repeatedly monitored over the course of several months. The data clearly shows the presence of several discrete sources and the migration of pollution through adjacent neighborhoods. Moreover, this validation study demonstrates the ease of mobile monitoring and the possibility of extending this platform to several other gas species (H2S, HF, HCl, NO, and others).

  4. Achieving High Resolution Timer Events in Virtualized Environment.

    PubMed

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events. PMID:26177366

  5. High-resolution structure of viruses from random diffraction snapshots.

    PubMed

    Hosseinizadeh, A; Schwander, P; Dashti, A; Fung, R; D'Souza, R M; Ourmazd, A

    2014-07-17

    The advent of the X-ray free-electron laser (XFEL) has made it possible to record diffraction snapshots of biological entities injected into the X-ray beam before the onset of radiation damage. Algorithmic means must then be used to determine the snapshot orientations and thence the three-dimensional structure of the object. Existing Bayesian approaches are limited in reconstruction resolution typically to 1/10 of the object diameter, with the computational expense increasing as the eighth power of the ratio of diameter to resolution. We present an approach capable of exploiting object symmetries to recover three-dimensional structure to high resolution, and thus reconstruct the structure of the satellite tobacco necrosis virus to atomic level. Our approach offers the highest reconstruction resolution for XFEL snapshots to date and provides a potentially powerful alternative route for analysis of data from crystalline and nano-crystalline objects. PMID:24914154

  6. Achieving High Resolution Timer Events in Virtualized Environment

    PubMed Central

    Adamczyk, Blazej; Chydzinski, Andrzej

    2015-01-01

    Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs—Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events. PMID:26177366

  7. High-resolution structure of viruses from random diffraction snapshots

    PubMed Central

    Hosseinizadeh, A.; Schwander, P.; Dashti, A.; Fung, R.; D'Souza, R. M.; Ourmazd, A.

    2014-01-01

    The advent of the X-ray free-electron laser (XFEL) has made it possible to record diffraction snapshots of biological entities injected into the X-ray beam before the onset of radiation damage. Algorithmic means must then be used to determine the snapshot orientations and thence the three-dimensional structure of the object. Existing Bayesian approaches are limited in reconstruction resolution typically to 1/10 of the object diameter, with the computational expense increasing as the eighth power of the ratio of diameter to resolution. We present an approach capable of exploiting object symmetries to recover three-dimensional structure to high resolution, and thus reconstruct the structure of the satellite tobacco necrosis virus to atomic level. Our approach offers the highest reconstruction resolution for XFEL snapshots to date and provides a potentially powerful alternative route for analysis of data from crystalline and nano-crystalline objects. PMID:24914154

  8. High resolution collimator system for X-ray detector

    DOEpatents

    Eberhard, Jeffrey W. (Schenectady, NY); Cain, Dallas E. (Scotia, NY)

    1987-01-01

    High resolution in an X-ray computerized tomography (CT) inspection system is achieved by using a collimator/detector combination to limit the beam width of the X-ray beam incident on a detector element to the desired resolution width. In a detector such as a high pressure Xenon detector array, a narrow tapered collimator is provided above a wide detector element. The collimator slits have any desired width, as small as a few mils at the top, the slit width is easily controlled, and they are fabricated on standard machines. The slit length determines the slice thickness of the CT image.

  9. Design and test of a High-Resolution EUV Spectroheliometer

    NASA Technical Reports Server (NTRS)

    Berger, Thomas E.; Timothy, J. G.; Walker, Arthur B. C., Jr.; Kirby, Helen; Morgan, Jeffrey S.; Jain, Surendra K.; Saxena, Ajay K.; Bhattacharyya, Jagadish C.; Huber, Martin C. E.; Tondello, Giuseppe

    1992-01-01

    The HiRES High-Resolution EUV Spectroheliometer is a sounding rocket instrument yielding very high spatial, spectral, and temporal resolution images of the solar outer atmosphere, on the basis of a 45-cm Gregorian telescope feeding a normal-incidence stigmatic EUV spectrometer with imaging multianode microchannel-array detector system, as well as an IR spectrometer with imaging CCD detector system. Attention is given to the expected performance of this system, including the effects of vibrational misalignments due to the sounding rocket flight environment.

  10. Production of high-resolution small-sized holographic stereograms

    NASA Astrophysics Data System (ADS)

    Osanlou, Ardeshir

    2011-09-01

    Color reflection multiplex holography is an obvious target for display applications. The aim of this project is to revisit the technique of multiplex holography using modern recording and developing methods and materials. In particular, exploiting techniques of color holography that have been developed in recent years and it should be possible to extend these to high resolution multiplex holography for small and creditcard sized holograms. The current generation of holographic laser printers is not suitable for such applications as they typically employ a pixel size of around 1 mm. This report outlines progress on the production of high- resolution small-sized holographic stereograms.

  11. Theoretical Problems in High Resolution Solar Physics, 2

    NASA Technical Reports Server (NTRS)

    Athay, G. (editor); Spicer, D. S. (editor)

    1987-01-01

    The Science Working Group for the High Resolution Solar Observatory (HRSO) laid plans beginning in 1984 for a series of workshops designed to stimulate a broadbased input from the scientific community to the HRSO mission. These workshops have the dual objectives of encouraging an early start on the difficult theoretical problems in radiative transfer, magnetohydrodynamics, and plasma physics that will be posed by the HRSO data, and maintaining current discussions of results in high resolution solar studies. This workshop was the second in the series. The workshop format presented invited review papers during the formal sessions and contributed poster papers for discussions during open periods. Both are presented.

  12. 3D Correlative Imaging | High Resolution Electron Microscopy

    Cancer.gov

    One key area of interest for the lab has been to close the 3D imaging gap, finding ways to image whole cells and tissues at high resolution. Focused ion beam scanning electron microscopy (FIB-SEM, or otherwise known as ion abrasion scanning electron microscopy, IA-SEM) uses a scanning electron beam to image the face of a fixed, resin-embedded sample, and an ion beam to remove “slices” of the sample, resulting in a sequential stack of high resolution images.

  13. Design of high-resolution grazing-incidence echelle monochromators

    SciTech Connect

    Poletto, Luca; Frassetto, Fabio

    2009-10-01

    A grazing-incidence configuration to achieve high spectral resolution in the extreme ultraviolet and soft x-ray regions is presented. It adopts a grating in the off-plane mount operated at high diffracted orders. Resolutions in the 10{sup 5} range can be achieved in a relatively compact size. The monochromator can be tuned in a complete octave by using different diffracted orders without changing the geometrical parameters of the configuration. The optical design of the configuration and the application to a beamline for free-electron-laser radiation centered at 120 eV are discussed.

  14. On the application and extension of Harten's high resolution scheme

    NASA Technical Reports Server (NTRS)

    Yee, H. C.; Warming, R. F.; Harten, A.

    1982-01-01

    Extensions of a second order high resolution explicit method for the numerical computation of weak solutions of one dimensonal hyperbolic conservation laws are discussed. The main objectives were (1) to examine the shock resoluton of Harten's method for a two dimensional shock reflection problem, (2) to study the use of a high resolution scheme as a post-processor to an approximate steady state solution, and (3) to construct an implicit in the delta-form using Harten's scheme for the explicit operator and a simplified iteration matrix for the implicit operator.

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

    SciTech Connect

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

    1987-07-01

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

  16. Simulation of imaging effects of very high resolution SAR systems

    NASA Astrophysics Data System (ADS)

    Anglberger, H.; Speck, R.; Suess, H.

    2013-10-01

    Current space borne synthetic aperture radar (SAR) systems are able to provide users with high resolution image data of around one meter. Focusing on systems operating in the X-band, this value is not the end of possible improvements in resolution. There still lies a great potential in an increase of bandwidth of the radar signal itself and also in a significant enlargement of the synthetic aperture. From the technical point of view this certainly is a challenge, but could be possible for future space borne SAR missions already with current state of the art hardware. As a matter of proof TerraSAR-X introduces a new staring spotlight image product that significantly improves the azimuthal resolution to around a quarter of a meter. The technical realization of the very high resolution SAR system is not the only obstacle to overcome. Especially the increase of Doppler bandwidth along the synthetic aperture requests special treatment and considerations in system design from a signal processing's point of view. Challenges like orbital accuracy, tropospheric effects, approximations in SAR processing methods and depth-of-focus issues have to be addressed. In this paper, most of these challenges are studied separately by performing parametric simulations for single point targets and also for complex signatures of an airplane. A comparable SAR parameter set as used by the high resolution sliding spotlight mode and the new staring spotlight mode of TerraSAR-X are used for simulation.

  17. Performance of the high-resolution SX700/II monochromator

    NASA Astrophysics Data System (ADS)

    Domke, M.; Mandel, T.; Puschmann, A.; Xue, C.; Shirley, D. A.; Kaindl, G.; Petersen, H.; Kuske, P.

    1992-01-01

    This article reports on the high-resolution performance of the grazing-incidence plane grating monochromator SX700/II, installed at BESSY by the Freie Universität Berlin, in the photon energy range from about 40 to 900 eV. The high resolving power up to 10 000 achieved with this monochromator is based on improving the figure error of the ellipsoidal focusing mirror, on reducing the vertical dimension of the beam source, and on employing a 5-?m exit slit. We report on high-resolution gas-phase studies in the double-excitation region of He, as well as at core-excitation thresholds of Ne, Ar, Kr, and Xe in the photon-energy range from ?45 eV to ?900 eV. In addition, high-resolution core-excitation spectra at the K thresholds of C, N, and O are presented for gas-phase CO, N2, and O2. In all cases, high-n Rydberg states and/or vibrational sidebands of the electronic excitations were resolved. The various contributions to the present instrumental linewidths are discussed as well as the prospects for further improvements in resolution with this monochromator.

  18. Unsupervised Feature Learning for High-Resolution Satellite Image Classification

    SciTech Connect

    Cheriyadat, Anil M

    2013-01-01

    The rich data provided by high-resolution satellite imagery allow us to directly model geospatial neighborhoods by understanding their spatial and structural patterns. In this paper we explore an unsupervised feature learning approach to model geospatial neighborhoods for classification purposes. While pixel and object based classification approaches are widely used for satellite image analysis, often these approaches exploit the high-fidelity image data in a limited way. In this paper we extract low-level features to characterize the local neighborhood patterns. We exploit the unlabeled feature measurements in a novel way to learn a set of basis functions to derive new features. The derived sparse feature representation obtained by encoding the measured features in terms of the learned basis function set yields superior classification performance. We applied our technique on two challenging image datasets: ORNL dataset representing one-meter spatial resolution satellite imagery representing five land-use categories and, UCMERCED dataset consisting of 21 different categories representing sub-meter resolution overhead imagery. Our results are highly promising and, in the case of UCMERCED dataset we outperform the best results obtained for this dataset. We show that our feature extraction and learning methods are highly effective in developing a detection system that can be used to automatically scan large-scale high-resolution satellite imagery for detecting large-facility.

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

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

  1. Science with High Spatial Resolution Far-Infrared Data

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  2. Portable electro-mechanically cooled high-resolution germanium detector

    SciTech Connect

    Neufeld, K.W.; Ruhter, W.D.

    1995-05-01

    We have integrated a small, highly-reliable, electro-mechanical cryo-cooler with a high-resolution germanium detector for portable/field applications. The system weighs 6.8 kg and requires 40 watts of power to operate once the detector is cooled to its operating temperature. the detector is a 500 mm{sup 2} by 20-mm thick low-energy configuration that gives a full-width at half maximum (FWHM) energy resolution of 523 eV at 122 keV, when cooled with liquid nitrogen. The energy resolution of the detector, when cooled with the electro-mechanical cooler, is 570 eV at 122 keV. We have field tested this system in measurements of plutonium and uranium for isotopic and enrichment information using the MGA and MGAU analysis programs without any noticeable effects on the results.

  3. Parallelization and Algorithmic Enhancements of High Resolution IRAS Image Construction

    NASA Technical Reports Server (NTRS)

    Cao, Yu; Prince, Thomas A.; Tereby, Susan; Beichman, Charles A.

    1996-01-01

    The Infrared Astronomical Satellite caried out a nearly complete survey of the infrared sky, and the survey data are important for the study of many astrophysical phenomena. However, many data sets at other wavelengths have higher resolutions than that of the co-added IRAS maps, and high resolution IRAS images are strongly desired both for their own information content and their usefulness in correlation. The HIRES program was developed by the Infrared Processing and Analysis Center (IPAC) to produce high resolution (approx. 1') images from IRAS data using the Maximum Correlation Method (MCM). We describe the port of HIRES to the Intel Paragon, a massively parallel supercomputer, other software developments for mass production of HIRES images, and the IRAS Galaxy Atlas, a project to map the Galactic plane at 60 and 100(micro)m.

  4. High-resolution High-Sensitivity Electron Imager Schematic diagram of the electron

    E-print Network

    Arizona, University of

    and various large-aperture imaging lenses. When using optics at unit magnification, the system has resolvedHigh-resolution High-Sensitivity Electron Imager Schematic diagram of the electron imaging system to directly image the distribution of electron-emitting isotopes at very high resolution and sensitivity

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  6. A compact high-resolution X-ray powder diffractometer

    PubMed Central

    Fewster, Paul F.; Trout, David R. D.

    2013-01-01

    A new powder diffractometer operating in transmission mode is described. It can work as a rapid very compact instrument or as a high-resolution instrument, and the sample preparation is simplified. The incident beam optics create pure Cu K?1 radiation, giving rise to peak widths of ?0.1° in 2? in compact form with a sample-to-detector minimum radius of 55?mm, reducing to peak widths of <0.05° in high-resolution mode by increasing the detector radius to 240?mm. The resolution of the diffractometer is shown to be governed by a complex mixture of angular divergence, sample size, diffraction effects and the dimensions of the detector pixels. The data can be collected instantaneously, which combined with trivial sample preparation and no sample alignment, makes it a suitable method for very rapid phase identification. As the detector is moved further from the sample, the angular step from the pixel dimension is reduced and the resolution improves significantly for very detailed studies, including structure determination and analysis of the microstructure. The advantage of this geometry is that the resolution of the diffractometer can be calculated precisely and the instrumental artefacts can be analysed easily without a sample present. The performance is demonstrated with LaB6 and paracetamol, and a critical appraisal of the uncertainties in the measurements is presented. The instantaneous data collection offers possibilities in dynamic experiments. PMID:24282331

  7. Workshop on high-resolution, large-acceptance spectrometers

    SciTech Connect

    Zeidman, B.

    1981-01-01

    The purpose of the Workshop on High-Resolution, Large-Acceptance Spectrometers was to provide a means for exchange of information among those actively engaged in the design and construction of these new spectrometers. Thirty-seven papers were prepared for the data base.

  8. High resolution bone mineral densitometry with a gamma camera

    NASA Technical Reports Server (NTRS)

    Leblanc, A.; Evans, H.; Jhingran, S.; Johnson, P.

    1983-01-01

    A technique by which the regional distribution of bone mineral can be determined in bone samples from small animals is described. The technique employs an Anger camera interfaced to a medical computer. High resolution imaging is possible by producing magnified images of the bone samples. Regional densitometry of femurs from oophorectomised and bone mineral loss.

  9. High-Resolution Computed Tomography of Lobster (Panulirus interruptus) Stomach

    E-print Network

    Hooper, Scott

    High-Resolution Computed Tomography of Lobster (Panulirus interruptus) Stomach Kevin H. Hobbs (Panulirus interruptus) stomach and identified on this image the previously defined stomach ossicles. These data are the first coordinate-based, three-dimensional description of the stomach and are a necessary

  10. RESEARCH ARTICLE Using High-Resolution Future Climate

    E-print Network

    Anderson, Charles W.

    and how this space may shift given future climate change. Modeling climate change at a small extent (1RESEARCH ARTICLE Using High-Resolution Future Climate Scenarios to Forecast Bromus tectorum, decreased soil nitrogen, altered nutrient and hydrologic regimes, and increased fire intensity. We estimated

  11. High-Resolution Nuclear Magnetic Resonance of Solids.

    ERIC Educational Resources Information Center

    Maciel, Gary E.

    1984-01-01

    Examines recent developments in techniques for obtaining high-resolution nuclear magnetic resonance (NMR) spectra on solid samples, discussing the kinds of applications for which these techniques are well suited. Also discusses the characteristics of NMR of solids and generating magnetization for NMR in solids. (JN)

  12. Feature Extraction from High-Resolution Remotely Sensed Imagery using

    E-print Network

    Ding, Wandi

    of America 1. Introduction Feature extraction, in the context of remote sensing, can be defined as image extraction differs from traditional pixel-based remote sensing image classification algorithms in which each22 Feature Extraction from High-Resolution Remotely Sensed Imagery using Evolutionary Computation

  13. Development of high accuracy and resolution geoid and gravity maps

    NASA Technical Reports Server (NTRS)

    Gaposchkin, E. M.

    1986-01-01

    Precision satellite to satellite tracking can be used to obtain high precision and resolution maps of the geoid. A method is demonstrated to use data in a limited region to map the geopotential at the satellite altitude. An inverse method is used to downward continue the potential to the Earth surface. The method is designed for both satellites in the same low orbit.

  14. MAPPING HIGH-RESOLUTION LAND SURFACE RADIATIVE FLUXES FROM MODIS

    E-print Network

    Liang, Shunlin

    pollution (Wang K. et al. 2009), and land cover and land use changes (Wang et al. 2007b). The SRB is alsoChapter 6 MAPPING HIGH-RESOLUTION LAND SURFACE RADIATIVE FLUXES FROM MODIS: ALGORITHMS-Chee Tsay, Robert Wolf, Crystal Schaaf, Alan Strahler 6.1 Introduction Land surface radiative fluxes

  15. High-Resolution Simulations of Coal Injection in A Gasifier

    SciTech Connect

    Li, Tingwen; Gel, Aytekin; Syamlal, M; Guenther, Chris; Pannala, Sreekanth

    2010-01-01

    This study demonstrates an approach to effectively combine high- and low-resolution simulations for design studies of industrial coal gasifier. The flow-field data from a 10 million cell full-scale simulation of a commercial-scale gasifier were used to construct a reduced configuration to economically study the coal injection in detail. High-resolution numerical simulations of the coal injection were performed using the open-source code MFIX running on a high performance computing system. Effects of grid resolution and numerical discretization scheme on the predicted behavior of coal injection and gasification kinetics were analyzed. Pronounced differences were predicted in the devolatilization and steam gasification rates because of different discretization schemes, implying that a high-order numerical scheme is required to predict well the unsteady gasification process on an adequately resolved grid. Computational costs for simulations of varying resolutions are presented to illustrate the trade-off between the accuracy of solution and the time-to-solution, an important consideration when engineering simulations are used for the design of commercial-scale units.

  16. RESEARCH ARTICLE High Resolution Cell Lineage Tracing Reveals

    E-print Network

    Weisblat, David A.

    RESEARCH ARTICLE High Resolution Cell Lineage Tracing Reveals Developmental Variability in Leech zone (PGZ) comprising five bilateral pairs of line- age-restricted stem cells (M, N, O/P, O/P, and Q teloblasts), and the initial divisions of the teloblast progeny (the m, n, o, p, and q blast cell clones

  17. HIGH RESOLUTION RESISTIVITY LEAK DETECTION DATA PROCESSING & EVALUATION MEHTODS & REQUIREMENTS

    SciTech Connect

    SCHOFIELD JS

    2007-10-04

    This document has two purposes: {sm_bullet} Describe how data generated by High Resolution REsistivity (HRR) leak detection (LD) systems deployed during single-shell tank (SST) waste retrieval operations are processed and evaluated. {sm_bullet} Provide the basic review requirements for HRR data when Hrr is deployed as a leak detection method during SST waste retrievals.

  18. HIGH RESOLUTION G-BANDED CHROMOSOMES OF THE MOUSE

    EPA Science Inventory

    High resolution G-banded mouse chromosomes were prepared using an actinomycin D and acridine orange pretreatment protocol, resulting in late prophase mouse chromosomes which reveal over twice the number of bands as compared to mid-metaphase. These elongated chromosomes, described...

  19. Human enamel structure studied by high resolution electron microscopy

    SciTech Connect

    Wen, S.L. )

    1989-01-01

    Human enamel structural features are characterized by high resolution electron microscopy. The human enamel consists of polycrystals with a structure similar to Ca10(PO4)6(OH)2. This article describes the structural features of human enamel crystal at atomic and nanometer level. Besides the structural description, a great number of high resolution images are included. Research into the carious process in human enamel is very important for human beings. This article firstly describes the initiation of caries in enamel crystal at atomic and unit-cell level and secondly describes the further steps of caries with structural and chemical demineralization. The demineralization in fact, is the origin of caries in human enamel. The remineralization of carious areas in human enamel has drawn more and more attention as its potential application is realized. This process has been revealed by high resolution electron microscopy in detail in this article. On the other hand, the radiation effects on the structure of human enamel are also characterized by high resolution electron microscopy. In order to reveal this phenomenon clearly, a great number of electron micrographs have been shown, and a physical mechanism is proposed. 26 references.

  20. Resolution of high order WENO schemes for complicated flow structures

    E-print Network

    Zhang, Yong-Tao

    Resolution of high order WENO schemes for complicated flow structures Jing Shi a , Yong-Tao Zhang b essentially non- oscillatory (WENO) schemes for computing solutions containing both discontinuities discontinuities and complex solution features, it is more economical in CPU time to use higher order WENO schemes

  1. HIGH RESOLUTION VERTICLE PROFILES OF PH IN RECENT SEDIMENTS

    EPA Science Inventory

    High resolution (0.1 cm sampling interval) profiles of pH were obtained from some recent estuarine (Long Island Sound, Chesapeake Bay) and freshwater (Lake Erie) sediments and from laboratory microcosms containing homogenized Lake Erie sediment (both with and without tubificid ol...

  2. Adaptive optics with pupil tracking for high resolution retinal imaging

    E-print Network

    Dainty, Chris

    for high resolution retinal imaging because eye movements constitute an important part of the ocular, "Wavefront sensorless adaptive optics ophthalmoscopy in the human eye," Opt. Express 19(21), 14160). 6. T. Nirmaier, G. Pudasaini, and J. Bille, "Very fast wave­front measurements at the human eye

  3. High-sensitivity diamond magnetometer with nanoscale resolution

    E-print Network

    Walsworth, Ronald L.

    ARTICLES High-sensitivity diamond magnetometer with nanoscale resolution J. M. TAYLOR1 *, P magnetometer that could potentially detect precession of single nuclear spins and an optical magnetic approach are closely related to those of magnetometers based on spin precession in atomic vapours

  4. ATS-6 - The Geosynchronous Very High Resolution Radiometer

    NASA Technical Reports Server (NTRS)

    Shenk, W. E.; Stephanides, C. C.; Sonnek, G. E.; Howell, L. D.

    1975-01-01

    The Geosynchronous Very High Resolution Radiometer (GVHRR), flown on the three-axis stabilized geosynchronous satellite, Applications Technology Satellite-6 (ATS-6), collected meteorological data for two months during the summer of 1974. Several hundred images were successfully taken. Data collection terminated when the instrument chopper motor failed. The instrument, its supporting ground equipment, and the data collected in orbit are described.

  5. High-resolution imaging by multiple-image deconvolution

    E-print Network

    Boccacci, Patrizia

    High-resolution imaging by multiple-image deconvolution M. Bertero, P.Boccacci, G. Desiderà, and G deconvolution is a powerful tool for improving the quality of images corrupted by blurring and noise. However on the direction in the imaging plane or volume. Such a distortion cannot be corrected by image deconvolution. One

  6. Decoding Rich Spatial Information with High Temporal Resolution.

    PubMed

    Stokes, Mark G; Wolff, Michael J; Spaak, Eelke

    2015-11-01

    New research suggests that magnetoencephalography (MEG) contains rich spatial information for decoding neural states. Even small differences in the angle of neighbouring dipoles generate subtle, but statistically separable field patterns. This implies MEG (and electroencephalography: EEG) is ideal for decoding neural states with high-temporal resolution in the human brain. PMID:26440122

  7. High Resolution Frequency Measurements of Far-Infrared Laser Lines

    E-print Network

    Massachusetts at Lowell, University of

    1 High Resolution Frequency Measurements of Far-Infrared Laser Lines Elizabeth J. Ehasz, Thomas M- infrared laser lines have been measured to an accuracy of 100 kHz. These laser lines were measured using a heterodyne system which allowed for more accurate measurement. The four far-infrared laser lines which

  8. The high resolution photo will be addedonce the

    E-print Network

    Dawson, Jeff W.

    The high resolution photo will be addedonce the brochure is approved. "Gaining competencies Professional Accountant (CPA). Carleton's Sprott School of Business is leading the way with a Master a 4-month internship placement, the MAcc goes beyond the requirements of CPA Canada, providing you

  9. Earthquake Damage Identification using High-Resolution Satellite

    E-print Network

    Shinozuka, Masanobu

    Algeria Earthquake Ellen M. Rathje Melba M. Crawford University of Texas at Austin Workshop on Application & evaluation · High-resolution satellite imagery · Images from Boumerdes, Algeria · Semi-automated damage · LIDAR (airborne laser altimetry) ­ 3D model of the surface #12;Northern Algeria Earthquake · 21 May 2003

  10. PROCEEDINGS Open Access High-resolution genetic mapping with pooled

    E-print Network

    Williams, Brian C.

    . A robust method for determining the genetic ele- ments that underlie a phenotype is to gather and group progeny with extreme phenotypes should elucidate the genetic basis of the trait. The main ideaPROCEEDINGS Open Access High-resolution genetic mapping with pooled sequencing Matthew D Edwards1

  11. High-Resolution Stimulated Raman Gain Spectroscopy of Parahydrogen Crystals

    E-print Network

    Oka, Takeshi

    High-Resolution Stimulated Raman Gain Spectroscopy of Parahydrogen Crystals Takamasa Momose1-H2 crystals with varying ortho-H2 concentrations is reported. A crys- tal containing 0.06% of ortho in a para-H2 crystal.5 The sharpness of infrared transition stems from the weak intermolecular interaction

  12. High-Resolution, Parallel Visualization of Turbomachinery Flowelds

    E-print Network

    Cincinnati, University of

    High-Resolution, Parallel Visualization of Turbomachinery Flowelds Michael G. List , Mark G Turbomachinery post- and co-processing and visualization tools are under development. The result has been in the analysis of turbomachinery. It has always been the way of the CFD analyst to expand and resolve simulations

  13. Acceleration Statistics of Inertial Particles from High Resolution DNS Turbulence

    E-print Network

    Cencini, Massimo

    Acceleration Statistics of Inertial Particles from High Resolution DNS Turbulence Federico Toschi1 the statistics of particle acceleration. We focus on the probability density function of the normalised acceleration. 2 Heavy Particle Dynamics and Numerical Simulations The equations of motion of a small, rigid

  14. Nanoparticle delivery Nanofountain-Probe-Based High-Resolution Patterning

    E-print Network

    Espinosa, Horacio D.

    Nanoparticle delivery Nanofountain-Probe-Based High-Resolution Patterning and Single-Cell Injection therapeutics and drug delivery. However, developing future nanoscale devices and arrays that harness and continuous delivery via microfluidic components. To address this, two modes of controlled delivery

  15. Decoding Rich Spatial Information with High Temporal Resolution

    PubMed Central

    Stokes, Mark G.; Wolff, Michael J.; Spaak, Eelke

    2015-01-01

    New research suggests that magnetoencephalography (MEG) contains rich spatial information for decoding neural states. Even small differences in the angle of neighbouring dipoles generate subtle, but statistically separable field patterns. This implies MEG (and electroencephalography: EEG) is ideal for decoding neural states with high-temporal resolution in the human brain. PMID:26440122

  16. A SIMPLE APPROACH TO HIGH RESOLUTION SEISMIC PROFILING FOR COAL *

    E-print Network

    A SIMPLE APPROACH TO HIGH RESOLUTION SEISMIC PROFILING FOR COAL * BY A. ZIOLKOWSKI ** and W. E Seismic Profiling for Coal, Geophysical Prospecting 27, 360-393, Seismic exploration techniques which have been developed for oil prospecting contrib- ute a valuable means for surveying coal measures. Since

  17. Amorphous Silicon as Semiconductor Material for High Resolution LAPS

    E-print Network

    Moritz, Werner

    Amorphous Silicon as Semiconductor Material for High Resolution LAPS Werner Moritz1 , Tatsuo-insulator- semiconductor (MIS) structures based on amorphous silicon (a-Si) prepared as a thin layer on transparent glass Adressable Potentimetric sensors electrode metal solution thin film under investigation SiO2 silicon metal

  18. Application of Classification Models to Pharyngeal High-Resolution Manometry

    ERIC Educational Resources Information Center

    Mielens, Jason D.; Hoffman, Matthew R.; Ciucci, Michelle R.; McCulloch, Timothy M.; Jiang, Jack J.

    2012-01-01

    Purpose: The authors present 3 methods of performing pattern recognition on spatiotemporal plots produced by pharyngeal high-resolution manometry (HRM). Method: Classification models, including the artificial neural networks (ANNs) multilayer perceptron (MLP) and learning vector quantization (LVQ), as well as support vector machines (SVM), were…

  19. HIGH-RESOLUTION SOIL MOISTURE MAPPING IN AFGHANISTAN

    E-print Network

    Borchers, Brian

    1 HIGH-RESOLUTION SOIL MOISTURE MAPPING IN AFGHANISTAN Jan M.H. Hendrickx1 , J. Bruce J. Harrison, Vicksburg, MS 39180-6199 ABSTRACT Soil moisture conditions have an impact upon virtually all aspects of Army activities and are increasingly affecting its systems and operations. Soil moisture conditions affect

  20. Letters to ESEX High resolution transmission electron microscopy

    E-print Network

    Dorn, Ron

    Letters to ESEX High resolution transmission electron microscopy evaluation of silica glaze reveals electron microscopy of a rock coating from the Ashikule Basin, Tibetan Plateau, reveals the presence dispersive electron microprobe analyses of silica glaze reveals six general types (Dorn, 1998): Type 1

  1. High-resolution extended source optical coherence tomography.

    PubMed

    Yu, Xiaojun; Liu, Xinyu; Chen, Si; Luo, Yuemei; Wang, Xianghong; Liu, Linbo

    2015-10-01

    High resolution optical coherence tomography (OCT) is capable of providing detailed tissue microstructures that are critical for disease diagnosis, yet its sensitivity is usually degraded since the system key components are typically not working at their respective center wavelengths. We developed a novel imaging system that achieves enhanced sensitivity without axial resolution degradation by the use of a spectrally encoded extended source (SEES) technique; it allows larger sample power without exceeding the maximum permissible exposure (MPE). In this study, we demonstrate a high-resolution extended source (HRES) OCT system, which is capable of providing a transverse resolution of 4.4 µm and an axial resolution of 2.1 µm in air with the SEES technique. We first theoretically show a sensitivity advantage of 6-dB of the HRES-OCT over that of its point source counterpart using numerical simulations, and then experimentally validate the applicability of the SEES technique to high-resolution OCT (HR-OCT) by comparing the HRES-OCT with an equivalent point-source system. In the HRES-OCT system, a dispersive prism was placed in the infinity space of the sample arm optics to spectrally extend the visual angle (angular subtense) of the light source to 10.3 mrad. This extended source allowed ~4 times larger MPE than its point source counterpart, which results in an enhancement of ~6 dB in sensitivity. Specifically, to solve the unbalanced dispersion between the sample and the reference arm optics, we proposed easy and efficient methods for system calibration and dispersion correction, respectively. With a maximum scanning speed reaching up to 60K A-lines/s, we further conducted imaging experiments with HRES-OCT using the human fingertip in vivo and the swine eye tissues ex vivo. Results demonstrate that the HRES-OCT is able to achieve significantly larger penetration depth than its conventional point source OCT counterpart. PMID:26480153

  2. High-resolution subsurface imaging and neural network recognition

    SciTech Connect

    Sternberg, B.K.; Poulton, M.M.

    1994-04-01

    A high-frequency, high-resolution electromagnetic (EM) imaging system is being developed for environmental geophysics surveys. Some key features of this system include: (1) rapid surveying to allow dense spatial sampling over a large area, (2) high-accuracy measurements which will be used to produce a high-resolution image of the subsurface, (3) measurements which have excellent signal-to-noise ratio over a wide bandwidth (32 kHz to 32 MHz), (4) large-scale physical modeling to produce accurate theoretical responses over targets of interest in environmental geophysics surveys, (5) rapid neural network interpretation at the field site, and (6) visualization of complex structures during the survey.

  3. Advances in DNA sequencing technologies for high resolution HLA typing.

    PubMed

    Cereb, Nezih; Kim, Hwa Ran; Ryu, Jaejun; Yang, Soo Young

    2015-12-01

    This communication describes our experience in large-scale G group-level high resolution HLA typing using three different DNA sequencing platforms - ABI 3730 xl, Illumina MiSeq and PacBio RS II. Recent advances in DNA sequencing technologies, so-called next generation sequencing (NGS), have brought breakthroughs in deciphering the genetic information in all living species at a large scale and at an affordable level. The NGS DNA indexing system allows sequencing multiple genes for large number of individuals in a single run. Our laboratory has adopted and used these technologies for HLA molecular testing services. We found that each sequencing technology has its own strengths and weaknesses, and their sequencing performances complement each other. HLA genes are highly complex and genotyping them is quite challenging. Using these three sequencing platforms, we were able to meet all requirements for G group-level high resolution and high volume HLA typing. PMID:26423536

  4. A High-resolution Reanalysis for the European CORDEX Region

    NASA Astrophysics Data System (ADS)

    Bentzien, Sabrina; Bollmeyer, Christoph; Crewell, Susanne; Friederichs, Petra; Hense, Andreas; Keller, Jan; Keune, Jessica; Kneifel, Stefan; Ohlwein, Christian; Pscheidt, Ieda; Redl, Stephanie; Steinke, Sandra

    2014-05-01

    A High-resolution Reanalysis for the European CORDEX Region Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. The work presented here focuses on the regional reanalysis for Europe with a domain matching the CORDEX-EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km). The COSMO reanalysis system comprises the assimilation of observational data using the existing nudging scheme of COSMO and is complemented by a special soil moisture analysis and boundary conditions given by ERA-interim data. The reanalysis data set currently covers 6 years (2007-2012). The evaluation of the reanalyses is done using independent observations with special emphasis on precipitation and high-impact weather situations. The development and evaluation of the COSMO-based reanalysis for the CORDEX-Euro domain can be seen as a preparation for joint European activities on the development of an ensemble system of regional reanalyses for Europe.

  5. Evaluation of a High-Resolution Regional Reanalysis for Europe

    NASA Astrophysics Data System (ADS)

    Ohlwein, C.; Wahl, S.; Keller, J. D.; Bollmeyer, C.

    2014-12-01

    Reanalyses gain more and more importance as a source of meteorological information for many purposes and applications. Several global reanalyses projects (e.g., ERA, MERRA, CSFR, JMA9) produce and verify these data sets to provide time series as long as possible combined with a high data quality. Due to a spatial resolution down to 50-70km and 3-hourly temporal output, they are not suitable for small scale problems (e.g., regional climate assessment, meso-scale NWP verification, input for subsequent models such as river runoff simulations). The implementation of regional reanalyses based on a limited area model along with a data assimilation scheme is able to generate reanalysis data sets with high spatio-temporal resolution. Within the Hans-Ertel-Centre for Weather Research (HErZ), the climate monitoring branch concentrates efforts on the assessment and analysis of regional climate in Germany and Europe. In joint cooperation with DWD (German Meteorological Service), a high-resolution reanalysis system based on the COSMO model has been developed. The regional reanalysis for Europe matches the domain of the CORDEX EURO-11 specifications, albeit at a higher spatial resolution, i.e., 0.055° (6km) instead of 0.11° (12km) and comprises the assimilation of observational data using the existing nudging scheme of COSMO complemented by a special soil moisture analysis with boundary conditions provided by ERA-Interim data. The reanalysis data set covers 6 years (2007-2012) and is currently extended to 16 years. Extensive evaluation of the reanalysis is performed using independent observations with special emphasis on precipitation and high-impact weather situations indicating a better representation of small scale variability. Further, the evaluation shows an added value of the regional reanalysis with respect to the forcing ERA Interim reanalysis and compared to a pure high-resolution dynamical downscaling approach without data assimilation.

  6. High-resolution Brillouin analysis of composite materials beams

    NASA Astrophysics Data System (ADS)

    London, Yosef; Antman, Yair; Silbiger, Maayan; Efraim, Liel; Froochzad, Avihay; Adler, Gadi; Levenberg, Eyal; Zadok, Avi

    2015-09-01

    High-resolution Brillouin optical correlation domain analysis of fibers embedded within beams of composite materials is performed with 4 cm resolution and 0.5 MHz sensitivity. Two new contributions are presented. First, analysis was carried out continuously over 30 hours following the production of a beam, observing heating during exothermal curing and buildup of residual strains. Second, the bending stiffness and Young's modulus of the composite beam were extracted based on distributed strain measurements, taken during a static three-point bending experiment. The calculated parameters were used to forecast the beam deflections. The latter were favorably compared against external displacement measurements.

  7. High-resolution schemes for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Harten, A.

    1982-01-01

    A class of new explicit second order accurate finite difference schemes for the computation of weak solutions of hyperbolic conservation laws is presented. These highly nonlinear schemes are obtained by applying a nonoscillatory first order accurae scheme to an appropriately modified flux function. The so derived second order accurate schemes achieve high resolution while preserving the robustness of the original nonoscillatory first order accurate scheme.

  8. High resolution dissociative electron attachment to gas phase adenine

    SciTech Connect

    Huber, D.; Beikircher, M.; Denifl, S.; Zappa, F.; Matejcik, S.; Bacher, A.; Grill, V.; Maerk, T. D.; Scheier, P.

    2006-08-28

    The dissociative electron attachment to the gas phase nucleobase adenine is studied using two different experiments. A double focusing sector field mass spectrometer is utilized for measurements requiring high mass resolution, high sensitivity, and relative ion yields for all the fragment anions and a hemispherical electron monochromator instrument for high electron energy resolution. The negative ion mass spectra are discussed at two different electron energies of 2 and 6 eV. In contrast to previous gas phase studies a number of new negative ions are discovered in the mass spectra. The ion efficiency curves for the negative ions of adenine are measured for the electron energy range from about 0 to 15 eV with an electron energy resolution of about 100 meV. The total anion yield derived via the summation of all measured fragment anions is compared with the total cross section for negative ion formation measured recently without mass spectrometry. For adenine the shape of the two cross section curves agrees well, taking into account the different electron energy resolutions; however, for thymine some peculiar differences are observed.

  9. Photoacoustic lymphatic imaging with high spatial-temporal resolution

    NASA Astrophysics Data System (ADS)

    Martel, Catherine; Yao, Junjie; Huang, Chih-Hsien; Zou, Jun; Randolph, Gwendalyn J.; Wang, Lihong V.

    2014-11-01

    Despite its critical function in coordinating the egress of inflammatory and immune cells out of tissues and maintaining fluid balance, the causative role of lymphatic network dysfunction in pathological settings is still understudied. Engineered-animal models and better noninvasive high spatial-temporal resolution imaging techniques in both preclinical and clinical studies will help to improve our understanding of different lymphatic-related pathologic disorders. Our aim was to take advantage of our newly optimized noninvasive wide-field fast-scanning photoacoustic (PA) microcopy system to coordinately image the lymphatic vasculature and its flow dynamics, while maintaining high resolution and detection sensitivity. Here, by combining the optical-resolution PA microscopy with a fast-scanning water-immersible microelectromechanical system scanning mirror, we have imaged the lymph dynamics over a large field-of-view, with high spatial resolution and advanced detection sensitivity. Depending on the application, lymphatic vessels (LV) were spectrally or temporally differentiated from blood vessels. Validation experiments were performed on phantoms and in vivo to identify the LV. Lymphatic flow dynamics in nonpathological and pathological conditions were also visualized. These results indicate that our newly developed PA microscopy is a promising tool for lymphatic-related biological research.

  10. High resolution three-dimensional prostate ultrasound imaging

    NASA Astrophysics Data System (ADS)

    Li, Yinbo; Patil, Abhay; Hossack, John A.

    2006-03-01

    This work reports on the application of ultrasound elastography to prostate cancer detection using a high resolution three-dimensional (3D) ultrasound imaging system. The imaging was performed at a relatively high frequency (14 MHz), yielding very fine resolution that is optimal for prostate ultrasound imaging. The fine resolution achieved aids in locating smaller lesions than are normally detectable. Elasticity was measured with a quantitative and automatically controlled "Synthetic Digital Rectal Examination (SDRE)" wherein a smoothly increasing force was applied by injecting water, controlled by an electronic syringe pump, into a latex cover over the transrectal transducer. The lesion identified as stiffened tissue was visually enhanced by colorizing and superimposing it over the conventional B-mode image. Experimental results using a tissue-mimicking phantom demonstrated that the reconstruction accuracy of the I-Beam transducer resulted in less than 15% volumetric error. Thus, this high resolution 3D prostate elastography is possible and may provide reliable and accurate determination of the size and the location of cancers, which may result in improved specificity and sensitivity of cancer detection.

  11. Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry

    PubMed Central

    Zhang, Jianqiu; Zhou, Xiaobo; Wang, Honghui; Suffredini, Anthony; Zhang, Lin; Huang, Yufei; Wong, Stephen

    2011-01-01

    In this paper, we address the issue of peptide ion peak detection for high resolution time-of-flight (TOF) mass spectrometry (MS) data. A novel Bayesian peptide ion peak detection method is proposed for TOF data with resolution of 10 000–15 000 full width at half-maximum (FWHW). MS spectra exhibit distinct characteristics at this resolution, which are captured in a novel parametric model. Based on the proposed parametric model, a Bayesian peak detection algorithm based on Markov chain Monte Carlo (MCMC) sampling is developed. The proposed algorithm is tested on both simulated and real datasets. The results show a significant improvement in detection performance over a commonly employed method. The results also agree with expert’s visual inspection. Moreover, better detection consistency is achieved across MS datasets from patients with identical pathological condition. PMID:21544266

  12. Advances toward high spectral resolution quantum X-ray calorimetry

    NASA Technical Reports Server (NTRS)

    Moseley, S. H.; Kelley, R. L.; Schoelkopf, R. J.; Szymkowiak, A. E.; Mccammon, D.

    1988-01-01

    Thermal detectors for X-ray spectroscopy combining high spectral resolution and quantum efficiency have been developed. These microcalorimeters measure the energy released in the absorption of a single photon by sensing the rise in temperature of a small absorbing structure. The ultimate energy resolution of such a device is limited by the thermodynamic power fluctuations in the thermal link between the calorimeter and isothermal bath and can in principle be made as low as 1 eV. The performance of a real device is degraded due to noise contributions such as excess 1/f noise in the thermistor and incomplete conversion of energy into phonons. The authors report some recent advances in thermometry, X-ray absorption and thermalization, fabrication techniques, and detector optimization in the presence of noise. These improvements have resulted in a device with a spectral resolution of 17 eV FWHM, measured at 6 keV.

  13. Very High Resolution Climate Modelling in Northern Russia

    NASA Astrophysics Data System (ADS)

    Stendel, M.; Christensen, J. H.

    2009-04-01

    Simulations with global climate models (GCMs) clearly indicate that major climate changes for the Arctic can be expected during the 21st century. Already now, there are substantial changes in sea-ice extent and thickness and a considerable increase in air temperature in several regions. Contemporary GCMs are unable to give a realistic representation of the climate and climate change in regions with steep orography, due to their coarse resolution. But even relatively high resolution regional climate models (RCMs) fail in this respect. We have therefore conducted a transient simulation with the newest version of the HIRHAM RCM, covering the period 1958-2001 over a region in northeast European Russia, including the Ural Mountains, with the unprecedented horizontal resolution of 4 km. For this simulation, a double downscaling procedure was applied. Average and extreme values will be discussed, and a comparison of subsurface temperatures to a set of observations from the region will be presented.

  14. Broadband high resolution X-ray spectral analyzer

    DOEpatents

    Silver, Eric H. (Berkeley, CA); Legros, Mark (Berkeley, CA); Madden, Norm W. (Livermore, CA); Goulding, Fred (Lafayette, CA); Landis, Don (Pinole, CA)

    1998-01-01

    A broad bandwidth high resolution x-ray fluorescence spectrometer has a performance that is superior in many ways to those currently available. It consists of an array of 4 large area microcalorimeters with 95% quantum efficiency at 6 keV and it produces x-ray spectra between 0.2 keV and 7 keV with an energy resolution of 7 to 10 eV. The resolution is obtained at input count rates per array element of 10 to 50 Hz in real-time, with analog pulse processing and thermal pile-up rejection. This performance cannot be matched by currently available x-ray spectrometers. The detectors are incorporated into a compact and portable cryogenic refrigerator system that is ready for use in many analytical spectroscopy applications as a tool for x-ray microanalysis or in research applications such as laboratory and astrophysical x-ray and particle spectroscopy.

  15. Bendable X-ray Optics for High Resolution Imaging

    NASA Technical Reports Server (NTRS)

    Gubarev, M.; Ramsey, B.; Kilaru, K.; Atkins, C.; Broadway, D.

    2014-01-01

    Current state-of the-art for x-ray optics fabrication calls for either the polishing of massive substrates into high-angular-resolution mirrors or the replication of thin, lower-resolution, mirrors from perfectly figured mandrels. Future X-ray Missions will require a change in this optics fabrication paradigm in order to achieve sub-arcsecond resolution in light-weight optics. One possible approach to this is to start with perfectly flat, light-weight surface, bend it into a perfect cone, form the desired mirror figure by material deposition, and insert the resulting mirror into a telescope structure. Such an approach is currently being investigated at MSFC, and a status report will be presented detailing the results of finite element analyses, bending tests and differential deposition experiments.

  16. SPRED spectrograph upgrade: high resolution grating and improved absolute calibrations

    SciTech Connect

    Stratton, B.C.; Fonck, R.J.; Ida, K.; Jaehnig, K.P.; Ramsey, A.T.

    1986-05-01

    Two improvements to the SPRED multichannel VUV spectrographs used on the TFTR and PBX tokamaks have been made: (1) A new 2100-g/mm grating covering the 100 to 320 A region with 0.4 A resolution (FWHM) has been added to the existing 450 g/mm grating (100 to 1100 A with 2 A resolution), and (2) the TFTR SPRED has been absolutely calibrated using synchrotron radiation from the NBS SURF II facility, while the PBX system has been calibrated using conventional branching ratios along with line ratios from charge-exchange-recombination-excited lines. The availability of high resolution spectra in the 100 to 320 A range provides improved measurements of metallic ion emissions and, when the instrument views across a neutral beam as in PBX, allows carbon and oxygen densities to be measured via charge exchange recombination spectroscopy.

  17. High throughput screening of ligand binding to macromolecules using high resolution powder diffraction

    DOEpatents

    Von Dreele, Robert B.; D'Amico, Kevin

    2006-10-31

    A process is provided for the high throughput screening of binding of ligands to macromolecules using high resolution powder diffraction data including producing a first sample slurry of a selected polycrystalline macromolecule material and a solvent, producing a second sample slurry of a selected polycrystalline macromolecule material, one or more ligands and the solvent, obtaining a high resolution powder diffraction pattern on each of said first sample slurry and the second sample slurry, and, comparing the high resolution powder diffraction pattern of the first sample slurry and the high resolution powder diffraction pattern of the second sample slurry whereby a difference in the high resolution powder diffraction patterns of the first sample slurry and the second sample slurry provides a positive indication for the formation of a complex between the selected polycrystalline macromolecule material and at least one of the one or more ligands.

  18. Performance characterization of a new high resolution PET scintillation detector.

    PubMed

    Vandenbroucke, A; Foudray, A M K; Olcott, P D; Levin, C S

    2010-10-01

    Performance of a new high resolution PET detection concept is presented. In this new concept, annihilation radiation enters the scintillator detectors edge-on. Each detector module comprises two 8 × 8 LYSO scintillator arrays of 0.91 × 0.91 × 1 mm(3) crystals coupled to two position-sensitive avalanche photodiodes (PSAPDs) mounted on a flex circuit. Appropriate crystal segmentation allows the recording of all three spatial coordinates of the interaction(s) simultaneously with submillimeter resolution. We report an average energy resolution of 14.6 ± 1.7% for 511 keV photons at FWHM. Coincident time resolution was determined to be 2.98 ± 0.13 ns FWHM on average. The coincidence point spread function (PSF) has an average FWHM of 0.837 ± 0.049 mm (using a 500 ?m spherical source) and is uniform across the arrays. Both PSF and coincident time resolution degrade when Compton interactions are included in the data. Different blurring factors were evaluated theoretically, resulting in a calculated PSF of 0.793 mm, in good agreement with the measured value. PMID:20844332

  19. Accelerated High-Resolution Differential Ion Mobility Separations Using Hydrogen

    PubMed Central

    Shvartsburg, Alexandre A.; Smith, Richard D.

    2011-01-01

    The resolving power of differential ion mobility spectrometry (FAIMS) was dramatically increased recently by carrier gases comprising up to 75% He or various vapors, enabling many new applications. However, the need for resolution of complex mixtures is virtually open-ended and many topical analyses demand yet finer separations. Also, the resolving power gains are often at the expense of speed, in particular making high-resolution FAIMS incompatible with online liquid-phase separations. Here, we report FAIMS employing hydrogen, specifically in mixtures with N2 containing up to 90% H2. Such compositions raise the mobilities of all ions and thus the resolving power beyond that previously feasible, while avoiding the electrical breakdown inevitable in He-rich mixtures. The increases in resolving power and ensuing peak resolution are especially significant at H2 fractions above ~50%. Higher resolution can be exchanged for acceleration of the analyses by up to ~4 times, at least. For more mobile species such as multiply-charged peptides, this exchange is presently forced by the constraints of existing FAIMS devices, but future designs optimized for H2 should consistently improve resolution for all analytes. PMID:22074292

  20. Spatial resolution effects on the assessment of evapotranspiration in olive orchards using high resolution thermal imagery

    NASA Astrophysics Data System (ADS)

    Santos, Cristina; Zarco-Tejada, Pablo J.; Lorite, Ignacio J.; Allen, Richard G.

    2013-04-01

    The use of remote sensing techniques for estimating surface energy balance and water consumption has significantly improved the characterization of the agricultural systems by determining accurate information about crop evapotranspiration and stress, mainly for extensive crops. However the use of these methodologies for woody crops has been low due to the difficulty in the accurate characterization of these crops, mainly caused by a coarse resolution of the imagery provided by the most widely used satellites (such as Landsat 5 and 7). The coarse spatial resolution provided by these satellite sensors aggregates into a single pixel the tree crown, sunlit and shaded soil components. These surfaces can each exhibit huge differences in temperature, albedo and vegetation indexes calculated in the visible, near infrared and short-wave infrared regions. Recent studies have found that the use of energy balance approaches can provide useful results for non-homogeneous crops (Santos et al., 2012) but detailed analysis is required to determine the effect of the spatial resolution and the aggregation of the scene components in these heterogeneous canopies. In this study a comparison between different spatial resolutions has been conducted using images from Landsat 7 (with thermal resolution of 60m) and from an airborne thermal (with resolution of 80 cm) flown over olive orchards at different dates coincident with the Landsat overpass. The high resolution thermal imagery was resampled at different scales to generate images with spatial resolution ranging from 0.8 m up to 120m (thermal resolution for Landsat 5 images). The selection of the study area was made to avoid those areas with missing Landsat 7 data caused by SLC-off gaps. The selected area has a total area of around 2500 ha and is located in Southern Spain, in the province of Malaga. The selected area is mainly cultivated with olive orchards with different crop practices (rainfed, irrigated, high density, young and adult olive, etc.). The METRIC surface energy balance approach (Allen et al., 2007) was applied for evapotranspiration assessment using the data provided by Landsat 7 and using the images from the airborne flights for three days during the summer of 2012. The flights and the Landsat 7 dates were coincident in order to avoid any difference in temperature or crop characteristic. The application of METRIC was made using detailed information from the olive orchards (mainly evapotranspiration and stress indexes) at different spatial resolutions to determine the errors generated by the aggregation process required when satellite images are considered in these studies. Recommendations are given on how to decompose the bulk surface temperature of Landsat into the component crown and soil (shaded and sunlit) components. References Allen RG, Tasumi M, Trezza R (2007) Satellite-based energy balance for mapping evapotranspiration with internalized calibration (METRIC) - Model. Journal of Irrigation and Drainage Engineering ASCE 133(4):380-394 Santos C, Lorite IJ, Allen RG, Tasumi M (2012) Aerodynamic Parameterization of the Satellite-Based Energy Balance (METRIC) Model for ET Estimation in Rainfed Olive Orchards of Andalusia, Spain. Water Resources Management 26:3267-3283

  1. High resolution imaging with multilayer telescopes: resolution performance of the MSSTA II telescopes

    SciTech Connect

    Martinez-Galarce, Dennis S.; Walker, Arthur B. C. II; Gore, David B.; Kankelborg, Charles C.; Hoover, Richard B.; Barbee, T. W. Jr.; Boerner, P. F. X.

    2000-04-01

    The Multi-Spectral Solar Telescope Array (MSSTA) is a sounding rocket-borne observatory composed of a set of normal-incidence multilayer-coated telescopes that obtained selected bandpass spectroheliograms (44 to 1550 Aa) of the solar atmosphere. These spectroheliograms were recorded on specially fabricated XUV and FUV 70-mm Kodak film. Rocket launches of this instrument payload took place in 1991 (MSSTA I) and 1994 (MSSTA II) at the White Sands Missile Test Range in New Mexico, sponsored by the National Aeronautics and Space Administration (NASA) sounding rocket experiment program. Immediately prior to the 1994 launch, visible light focusing tests of each telescope were performed in situ using a 1951 standard Air Force high-resolution test target, to measure optical resolution performance. We determined that the MSSTA II telescopes performed at diffraction-limited resolutions down to 0.70 arcsec at visible wavelengths. Based on these measurements, we calculate an upper bound to the focusing errors that incorporate the sum of all uncorrelated system focus errors that affect resolution performance. Coupling these upper bound estimates with the in-band diffraction limits, surface scattering errors and payload pointing jitter, we demonstrate that 11 of 19 MSSTA II telescopes--having negligible figures of focus errors in comparison to the corresponding visible diffraction limits--performed at sub arcsecond resolution at their operational FUV/EUV/XUV wavelengths during flight. We estimate the in-band performance down to 0.14{+-}0.08 arcsec. (c) 2000 Society of Photo-Optical Instrumentation Engineers.

  2. Mid-infrared high resolution spectrometer for SOFIA

    NASA Astrophysics Data System (ADS)

    Kutyrev, Alexander; Moseley, Samuel H.; Bergin, Edwin A.; Bjoraker, Gordon; Melnick, Gary J.; Neufeld, David A.; Pontoppidan, Klaus; Roberge, Aki; Stacey, Gordon J.; Watson, Dan M.; Wollack, Edward

    2016-01-01

    Mid-infrared spectral range between 20 µm and 120 µm has a number of diagnostic atomic and molecular lines that can probe physical conditions in a variety of objects. In particular, protoplanetary disk clouds, YSO, planetary atmospheres would benefit from a high resolution spectroscopy in that wavelength range. Through its high spectral resolution the instrument would allow to obtain both physical and dynamical information on the clouds. Comprehensive observations of the various phases of gas in the protoplanetary disks with the instrument would allow to advance the knowledge of the processes leading to the formation of planetary systems. Such an instrument with high spectral resolving power and sensitivity would be a powerful addition to the current SOFIA instruments.

  3. Calibration of sampling clock skew in high-speed, high-resolution time-interleaved ADCs

    E-print Network

    Kumar, Daniel Prashanth

    2015-01-01

    There is an ever-increasing demand for high-resolution and high-resolution ADCs. In order to raise the sampling rates of ADCs in a power efficient manner, time-interleaving is an essential technique, whereby N ADC channels, ...

  4. High-resolution ionization detector and array of such detectors

    DOEpatents

    McGregor, Douglas S. (Ypsilanti, MI); Rojeski, Ronald A. (Pleasanton, CA)

    2001-01-16

    A high-resolution ionization detector and an array of such detectors are described which utilize a reference pattern of conductive or semiconductive material to form interaction, pervious and measurement regions in an ionization substrate of, for example, CdZnTe material. The ionization detector is a room temperature semiconductor radiation detector. Various geometries of such a detector and an array of such detectors produce room temperature operated gamma ray spectrometers with relatively high resolution. For example, a 1 cm.sup.3 detector is capable of measuring .sup.137 Cs 662 keV gamma rays with room temperature energy resolution approaching 2% at FWHM. Two major types of such detectors include a parallel strip semiconductor Frisch grid detector and the geometrically weighted trapezoid prism semiconductor Frisch grid detector. The geometrically weighted detector records room temperature (24.degree. C.) energy resolutions of 2.68% FWHM for .sup.137 Cs 662 keV gamma rays and 2.45% FWHM for .sup.60 Co 1.332 MeV gamma rays. The detectors perform well without any electronic pulse rejection, correction or compensation techniques. The devices operate at room temperature with simple commercially available NIM bin electronics and do not require special preamplifiers or cooling stages for good spectroscopic results.

  5. High resolution experimental parameter space of a chaotic circuit

    E-print Network

    Francisco F. G. de Sousa; Rero M. Rubinger; José C. Sartorelli; Holokx A. Albuquerque; Murilo S. Baptista

    2015-10-26

    We have obtained a high resolution parameter space of an experimental Chua's circuit and shown that the topology of the chaotic and periodic regions present not only expected features previously observed from high resolution numerical simulations of idealised Chua's circuit, but also novel unexpected features. Unmatched feedback resistances cause the formation of at least two competing spirals with consequent disrupted or malformed shrimps. We have also confirmed experimentally that the period-adding bifurcation route is formed by periodic regions whose size decrease exponentially with their period, and consequently, periodic behaviour with higher period is unlikely to be observed. The higher-resolution span of parameters was possible by the use of a newly designed potentiometer that could be potentially used in other electronic equipments to reveal hidden behaviours. To have such resistances we developed in series arrays of resistors short-circuited by relays as discrete potentiometers with 1024 steps, and resolutions of 0.100 $\\Omega$ for $r_L$ in series with the inductor, and 0.200 $\\Omega$ for R connecting the two capacitors.

  6. High-resolution teleradiology applications within the hospital

    NASA Astrophysics Data System (ADS)

    Jost, R. Gilbert; Blaine, G. James; Kocher, Thomas E.; Muka, Edward; Whiting, Bruce R.

    1991-07-01

    Many of the commercial applications for teleradiology have involved the transmission of reduced resolution x-ray images over modest bandwidth telecommunications lines for the purpose of making a preliminary diagnosis. In order to study the technical and operational requirements for future teleradiology applications, the authors have focused on the demanding requirements for teleradiology within the hospital and medical center. Applications within the hospital often require x-ray images of primary diagnostic quality transmitted with a minimum of delay. An experimental, high-resolution film scan/print system designed by Health Sciences Division, Eastman Kodak Company, has been developed for installation in a working clinical environment. Images scanned at a spatial resolution of 4K X 5K can be delivered over a fiber optic link to a laser film printer at a rate of two films per minute. Preliminary plans to install this device in a variety of clinical settings have led to rethinking the requirements for automatic film loading, film and patient identification, throughput requirements, and image display formats. As an initial implementation, and application is being developed which allows chest radiographs taken in the admission area to be interpreted at a remote site within the hospital. Images can be viewed on high resolution monitors, or film replicates can be produced on a nearby laser printer. Tight coupling with a radiology information system provides access to relevant diagnostic information including prior radiology reports, and prompt electronic reporting and signature can be accomplished.

  7. High resolution 3D fluorescence tomography using ballistic photons

    NASA Astrophysics Data System (ADS)

    Zheng, Jie; Nouizi, Farouk; Cho, Jaedu; Kwong, Jessica; Gulsen, Gultekin

    2015-03-01

    We are developing a ballistic-photon based approach for improving the spatial resolution of fluorescence tomography using time-domain measurements. This approach uses early photon information contained in measured time-of-fight distributions originating from fluorescence emission. The time point spread functions (TPSF) from both excitation light and emission light are acquired with gated single photon Avalanche detector (SPAD) and time-correlated single photon counting after a short laser pulse. To determine the ballistic photons for reconstruction, the lifetime of the fluorophore and the time gate from the excitation profiles will be used for calibration, and then the time gate of the fluorescence profile can be defined by a simple time convolution. By mimicking first generation CT data acquisition, the sourcedetector pair will translate across and also rotate around the subject. The measurement from each source-detector position will be reshaped into a histogram that can be used by a simple back-projection algorithm in order to reconstruct high resolution fluorescence images. Finally, from these 2D sectioning slides, a 3D inclusion can be reconstructed accurately. To validate the approach, simulation of light transport is performed for biological tissue-like media with embedded fluorescent inclusion by solving the diffusion equation with Finite Element Method using COMSOL Multiphysics simulation. The reconstruction results from simulation studies have confirmed that this approach drastically improves the spatial resolution of fluorescence tomography. Moreover, all the results have shown the feasibility of this technique for high resolution small animal imaging up to several centimeters.

  8. Parameterizing convection in high-resolution global atmospheric models (Invited)

    NASA Astrophysics Data System (ADS)

    Bacmeister, J. T.; Tao, W.; Lee, M.; Skamarock, W. C.; Mittal, R.

    2009-12-01

    Representing the effects of atmospheric convection in global models has been, and remains, one of the major obstacles facing climate researchers. As the horizontal resolution used in global climate simulations increases to scales much finer than 100 km, problems related to convection show no signs of diminishing. This talk will present results from high resolution global atmospheric models, as well as cloud resolving model results, and satellite measurements from the CloudSat and TRMM instruments. These results suggest that climate simulations at high horizontal resolutions may in fact present new challenges to convection parameterization. Tropical cyclone simulations conducted at ¼o (or ~25 km) resolution show that standard climate-style convection parameterizations may interfere with the organization and strengthening of tropical systems. A three-way comparison of cloud resolving model (CRM) results, satellite data, and global simulations, suggests that assumptions about scale-separation and statistical equilibrium between convection and the resolved flow begin to break down for spatial scales smaller than 100 km. Quantities such as convective cloud height exhibit large variance when sorted into regimes with similar background meteorology. Simply put, a one-to-one relationship between convective parameters and resolved model fields may not exist, even approximately, for scales smaller than 100km. Possible remedies, including a stochastic component for parameterized convection, based on CRM results and satellite measurements, are discussed

  9. The spatially heterodyned spectrometer: A for high resolution Raman spectroscopy?

    NASA Astrophysics Data System (ADS)

    Pannell, Christopher N.; Zhang, Bill G.; Reed, Murray K.

    2015-03-01

    The spatially heterodyned spectrometer (SHS) is one of a class of interesting Static Fourier Transform Spectrometers (FSTS) which offers particular advantages when high spectral resolution is required over a relatively narrow design wavelength range, and high light throughput is needed. The technique was invented by Harlander and Roesler in 1990, and have been under development in various embodiments since; the original applications were astronomical but other application areas are continually appearing. We have investigated a field-widened SHS in terms of its fundamental spectral resolution and its sensitivity. The light grasp of the SHS is very large compared to "standard" dispersive spectrometer hoverer one must be careful to distinguish between light grasp and sensitivity; our prototype device used a 3mm liquid light guide as the input optic, operating at f/1.4, and was constructed with off-the-shelf optical components, apart from the field widening prisms which were custom made. It demonstrated a S/N ratio of unity with an input power of tens of femto-Watts in a sub-resolution spectral feature, and a spectral resolution of 2.9 wave numbers, operating between 790nm and 940nm. The exposure time was of the order of 60 seconds or greater. We conclude that this arrangement would be an excellent tool for analysis of Raman spectra.

  10. High-resolution electron microscopy of advanced materials

    SciTech Connect

    Mitchell, T.E.; Kung, H.H.; Sickafus, K.E.; Gray, G.T. III; Field, R.D.; Smith, J.F.

    1997-11-01

    This final report chronicles a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The High-Resolution Electron Microscopy Facility has doubled in size and tripled in quality since the beginning of the three-year period. The facility now includes a field-emission scanning electron microscope, a 100 kV field-emission scanning transmission electron microscope (FE-STEM), a 300 kV field-emission high-resolution transmission electron microscope (FE-HRTEM), and a 300 kV analytical transmission electron microscope. A new orientation imaging microscope is being installed. X-ray energy dispersive spectrometers for chemical analysis are available on all four microscopes; parallel electron energy loss spectrometers are operational on the FE-STEM and FE-HRTEM. These systems enable evaluation of local atomic bonding, as well as chemical composition in nanometer-scale regions. The FE-HRTEM has a point-to-point resolution of 1.6 {angstrom}, but the resolution can be pushed to its information limit of 1 {angstrom} by computer reconstruction of a focal series of images. HRTEM has been used to image the atomic structure of defects such as dislocations, grain boundaries, and interfaces in a variety of materials from superconductors and ferroelectrics to structural ceramics and intermetallics.

  11. Microfabrication of High Resolution X-ray Magnetic Calorimeters

    SciTech Connect

    Hsieh, W.-T.; Stevenson, Thomas R.; Bandler, Simon R.; Kelly, Daniel P.; Porst, Jan P.; Rotzinger, Hannes; Seidel, George M.

    2009-12-16

    Metallic magnetic calorimeter (MMC) is one of the most promising x-ray detector technologies for providing the very high energy resolution needed for future astronomical x-ray imaging spectroscopy. For this purpose, we have developed micro-fabricated 5x5 arrays of MMC of which each individual pixel has excellent energy resolution as good as 3.4 eV at 6 keV x-ray. Here we report on the fabrication techniques developed to achieve good resolution and high efficiency. These include: processing of a thin insulation layer for strong magnetic coupling between the AuEr sensor film and the niobium pick-up coil; production of overhanging absorbers for enhanced efficiency of x-ray absorption; fabrication on SiN membranes to minimize the effects on energy resolution from athermal phonon loss. We have also improved the deposition of the magnetic sensor film such that the film magnetization is nearly completely that is expected from the AuEr sputter target bulk material. In addition, we have included a study of a positional sensitive design, the Hydra design, which allows thermal coupling of four absorbers to a common MMC sensor and circuit.

  12. Temporal analysis of all high-resolution Mars imaging products

    NASA Astrophysics Data System (ADS)

    Sidiropoulos, P.; Muller, J.-P.

    2014-04-01

    A meta-data analysis has been performed of high-resolution imagery that have been acquired over the last four decades from Mars. More specifically, we are interested in two independent image parameters, the time that each image was acquired and the spatial resolution with which the planetary region is mapped in the image. We are only interested in mapping changes in high-resolution images. We use two different upper thresholds to discriminate them from low-resolution images, twenty metres and a hundred metres per pixel. In order to be able to extract semantic information about the temporal and spatial distribution of high-resolution Martian imagery we adopt two grouping strategies. In the first, images are clustered according to the time period (counted in Martian Years) that they were acquired, so as to examine whether sporadic Martian phenomena can be identified (e.g. a new crater) from imagery that depict the same area in different time periods. In the second grouping, images are clustered according to the Martian season that they were acquired, so as to examine whether seasonal Martian phenomena can be identified from imagery that depict the same area during the same season. This analysis supports the hypothesis that there is sufficient coverage for both tasks, since the Martian surface has been mapped at least once in each epoch and more than twice since 2002 and for each season at least 10 % of Martian surface has been mapped at least three times. The resulting maps and graphical plots will be presented will provide additional detail to this report.

  13. Coregistration of high-resolution Mars orbital images

    NASA Astrophysics Data System (ADS)

    Sidiropoulos, Panagiotis; Muller, Jan-Peter

    2015-04-01

    The systematic orbital imaging of the Martian surface started 4 decades ago from NASA's Viking Orbiter 1 & 2 missions, which were launched in August 1975, and acquired orbital images of the planet between 1976 and 1980. The result of this reconnaissance was the first medium-resolution (i.e. ? 300m/pixel) global map of Mars, as well as a variety of high-resolution images (reaching up to 8m/pixel) of special regions of interest. Over the last two decades NASA has sent 3 more spacecraft with onboard instruments for high-resolution orbital imaging: Mars Global Surveyor (MGS) having onboard the Mars Orbital Camera - Narrow Angle (MOC-NA), Mars Odyssey having onboard the Thermal Emission Imaging System - Visual (THEMIS-VIS) and the Mars Reconnaissance Orbiter (MRO) having on board two distinct high-resolution cameras, Context Camera (CTX) and High-Resolution Imaging Science Experiment (HiRISE). Moreover, ESA has the multispectral High resolution Stereo Camera (HRSC) onboard ESA's Mars Express with resolution up to 12.5m since 2004. Overall, this set of cameras have acquired more than 400,000 high-resolution images, i.e. with resolution better than 100m and as fine as 25 cm/pixel. Notwithstanding the high spatial resolution of the available NASA orbital products, their accuracy of areo-referencing is often very poor. As a matter of fact, due to pointing inconsistencies, usually form errors in roll attitude, the acquired products may actually image areas tens of kilometers far away from the point that they are supposed to be looking at. On the other hand, since 2004, the ESA Mars Express has been acquiring stereo images through the High Resolution Stereo Camera (HRSC), with resolution that is usually 12.5-25 metres per pixel. The achieved coverage is more than 64% for images with resolution finer than 20 m/pixel, while for ~40% of Mars, Digital Terrain Models (DTMs) have been produced with are co-registered with MOLA [Gwinner et al., 2010]. The HRSC images and DTMs represent the best available 3D reference frame for Mars showing co-registration with MOLA<25m (loc.cit.). In our work, the reference generated by HRSC terrain corrected orthorectified images is used as a common reference frame to co-register all available high-resolution orbital NASA products into a common 3D coordinate system, thus allowing the examination of the changes that happen on the surface of Mars over time (such as seasonal flows [McEwen et al., 2011] or new impact craters [Byrne, et al., 2009]). In order to accomplish such a tedious manual task, we have developed an automatic co-registration pipeline that produces orthorectified versions of the NASA images in realistic time (i.e. from ~15 minutes to 10 hours per image depending on size). In the first step of this pipeline, tie-points are extracted from the target NASA image and the reference HRSC image or image mosaic. Subsequently, the HRSC areo-reference information is used to transform the HRSC tie-points pixel coordinates into 3D "world" coordinates. This way, a correspondence between the pixel coordinates of the target NASA image and the 3D "world" coordinates is established for each tie-point. This set of correspondences is used to estimate a non-rigid, 3D to 2D transformation model, which transforms the target image into the HRSC reference coordinate system. Finally, correlation of the transformed target image and the HRSC image is employed to fine-tune the orthorectification results, thus generating results with sub-pixel accuracy. This method, which has been proven to be accurate, robust to resolution differences and reliable when dealing with partially degraded data and fast, will be presented, along with some example co-registration results that have been achieved by using it. Acknowledgements: The research leading to these results has received partial funding from the STFC "MSSL Consolidated Grant" ST/K000977/1 and partial support from the European Union's Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement n° 607379. References: [1]

  14. 14C autoradiography with an energy-sensitive silicon pixel detector

    NASA Astrophysics Data System (ADS)

    Esposito, M.; Mettivier, G.; Russo, P.

    2011-04-01

    The first performance tests are presented of a carbon-14 (14C) beta-particle digital autoradiography system with an energy-sensitive hybrid silicon pixel detector based on the Timepix readout circuit. Timepix was developed by the Medipix2 Collaboration and it is similar to the photon-counting Medipix2 circuit, except for an added time-based synchronization logic which allows derivation of energy information from the time-over-threshold signal. This feature permits direct energy measurements in each pixel of the detector array. Timepix is bump-bonded to a 300 µm thick silicon detector with 256 × 256 pixels of 55 µm pitch. Since an energetic beta-particle could release its kinetic energy in more than one detector pixel as it slows down in the semiconductor detector, an off-line image analysis procedure was adopted in which the single-particle cluster of hit pixels is recognized; its total energy is calculated and the position of interaction on the detector surface is attributed to the centre of the charge cluster. Measurements reported are detector sensitivity, (4.11 ± 0.03) × 10-3 cps mm-2 kBq-1 g, background level, (3.59 ± 0.01) × 10-5 cps mm-2, and minimum detectable activity, 0.0077 Bq. The spatial resolution is 76.9 µm full-width at half-maximum. These figures are compared with several digital imaging detectors for 14C beta-particle digital autoradiography.

  15. High Resolution Measurements and Electronic Structure Calculations of a Diazanaphthalene

    NASA Astrophysics Data System (ADS)

    Gruet, Sébastien; Goubet, Manuel; Pirali, Olivier

    2014-06-01

    Polycyclic Aromatic Hydrocarbons (PAHs) have long been suspected to be the carriers of so called Unidentified Infrared Bands (UIBs). Most of the results published in the literature report rotationally unresolved spectra of pure carbon as well as heteroatom-containing PAHs species. To date for this class of molecules, the principal source of rotational informations is ruled by microwave (MW) spectroscopy while high resolution measurements reporting rotational structure of the infrared (IR) vibrational bands are very scarce. Recently, some high resolution techniques provided interesting new results to rotationally resolve the IR and far-IR bands of these large carbonated molecules of astrophysical interest. One of them is to use the bright synchrotron radiation as IR continuum source of a high resolution Fourier transform (FTIR) spectrometer. We report the very complementary analysis of the [1,6] naphthyridine (a N-bearing PAH) for which we recorded the microwave spectrum at the PhLAM laboratory (Lille) and the high resolution far-infrared spectrum on the AILES beamline at synchrotron facility SOLEIL. MW spectroscopy provided highly accurate rotational constants in the ground state to perform Ground State Combinations Differences (GSCD) allowing the analysis of the two most intense FT-FIR bands in the 50-900 wn range. Moreover, during this presentation the negative value of the inertial defect in the GS of the molecule will be discussed. A. Leger, J. L. Puget, Astron. Astrophys. 137, L5-L8 (1984) L. J. Allamandola et al. Astrophys. J. 290, L25-L28 (1985). Z. Kisiel et al. J. Mol. Spectrosc. 217, 115 (2003) S. Thorwirth et al. Astrophys. J. 662, 1309 (2007) D. McNaughton et al. J. Chem. Phys. 124, 154305 (2011). S. Albert et al. Faraday Discuss. 150, 71-99 (2011) B. E. Brumfield et al. Phys. Chem. Lett. 3, 1985-1988 (2012) O. Pirali et al. Phys. Chem. Chem. Phys. 15, 10141 (2013).

  16. Glacial lake mapping with very high resolution satellite SAR data

    NASA Astrophysics Data System (ADS)

    Strozzi, T.; Wiesmann, A.; Kääb, A.; Joshi, S.; Mool, P.

    2012-08-01

    Floods resulting from the outbursts of glacial lakes are among the most far-reaching disasters in high mountain regions. Glacial lakes are typically located in remote areas and space-borne remote sensing data are an important source of information about the occurrence and development of such lakes. Here we show that very high resolution satellite Synthetic Aperture Radar (SAR) data can be employed for reliably mapping glacial lakes. Results in the Alps, Pamir and Himalaya using TerraSAR-X and Radarsat-2 data are discussed in comparison to in-situ information, and high-resolution satellite optical and radar imagery. The performance of the satellite SAR data is best during the snow- and ice-free season. In the broader perspective of hazard management, the detection of glacial lakes and the monitoring of their changes from very high-resolution satellite SAR intensity images contributes to the initial assessment of hazards related to glacial lakes, but a more integrated, multi-level approach needs also to include other relevant information such as glacier outlines and outline changes or the identification of unstable slopes above the lake and the surrounding area, information types to which SAR analysis techniques can also contribute.

  17. Towards Ultra-High Resolution Models of Climate and Weather

    SciTech Connect

    Wehner, Michael; Oliker, Leonid; Shalf, John

    2007-01-01

    We present a speculative extrapolation of the performance aspects of an atmospheric general circulation model to ultra-high resolution and describe alternative technological paths to realize integration of such a model in the relatively near future. Due to a superlinear scaling of the computational burden dictated by stability criterion, the solution of the equations of motion dominate the calculation at ultra-high resolutions. From this extrapolation, it is estimated that a credible kilometer scale atmospheric model would require at least a sustained ten petaflop computer to provide scientifically useful climate simulations. Our design study portends an alternate strategy for practical power-efficient implementations of petaflop scale systems. Embedded processor technology could be exploited to tailor a custom machine designed to ultra-high climate model specifications at relatively affordable cost and power considerations. The major conceptual changes required by a kilometer scale climate model are certain to be difficult to implement. Although the hardware, software, and algorithms are all equally critical in conducting ultra-high climate resolution studies, it is likely that the necessary petaflop computing technology will be available in advance of a credible kilometer scale climate model.

  18. Proceedings of the 2004 High Spatial Resolution Commercial Imagery Workshop

    NASA Technical Reports Server (NTRS)

    2006-01-01

    Topics covered include: NASA Applied Sciences Program; USGS Land Remote Sensing: Overview; QuickBird System Status and Product Overview; ORBIMAGE Overview; IKONOS 2004 Calibration and Validation Status; OrbView-3 Spatial Characterization; On-Orbit Modulation Transfer Function (MTF) Measurement of QuickBird; Spatial Resolution Characterization for QuickBird Image Products 2003-2004 Season; Image Quality Evaluation of QuickBird Super Resolution and Revisit of IKONOS: Civil and Commercial Application Project (CCAP); On-Orbit System MTF Measurement; QuickBird Post Launch Geopositional Characterization Update; OrbView-3 Geometric Calibration and Geopositional Accuracy; Geopositional Statistical Methods; QuickBird and OrbView-3 Geopositional Accuracy Assessment; Initial On-Orbit Spatial Resolution Characterization of OrbView-3 Panchromatic Images; Laboratory Measurement of Bidirectional Reflectance of Radiometric Tarps; Stennis Space Center Verification and Validation Capabilities; Joint Agency Commercial Imagery Evaluation (JACIE) Team; Adjacency Effects in High Resolution Imagery; Effect of Pulse Width vs. GSD on MTF Estimation; Camera and Sensor Calibration at the USGS; QuickBird Geometric Verification; Comparison of MODTRAN to Heritage-based Results in Vicarious Calibration at University of Arizona; Using Remotely Sensed Imagery to Determine Impervious Surface in Sioux Falls, South Dakota; Estimating Sub-Pixel Proportions of Sagebrush with a Regression Tree; How Do YOU Use the National Land Cover Dataset?; The National Map Hazards Data Distribution System; Recording a Troubled World; What Does This-Have to Do with This?; When Can a Picture Save a Thousand Homes?; InSAR Studies of Alaska Volcanoes; Earth Observing-1 (EO-1) Data Products; Improving Access to the USGS Aerial Film Collections: High Resolution Scanners; Improving Access to the USGS Aerial Film Collections: Phoenix Digitizing System Product Distribution; System and Product Characterization: Issues Approach; Innovative Approaches to Analysis of Lidar Data for the National Map; Changes in Imperviousness near Military Installations; Geopositional Accuracy Evaluations of QuickBird and OrbView-3: Civil and Commercial Applications Project (CCAP); Geometric Accuracy Assessment: OrbView ORTHO Products; QuickBird Radiometric Calibration Update; OrbView-3 Radiometric Calibration; QuickBird Radiometric Characterization; NASA Radiometric Characterization; Establishing and Verifying the Traceability of Remote-Sensing Measurements to International Standards; QuickBird Applications; Airport Mapping and Perpetual Monitoring Using IKONOS; OrbView-3 Relative Accuracy Results and Impacts on Exploitation and Accuracy Improvement; Using Remotely Sensed Imagery to Determine Impervious Surface in Sioux Falls, South Dakota; Applying High-Resolution Satellite Imagery and Remotely Sensed Data to Local Government Applications: Sioux Falls, South Dakota; Automatic Co-Registration of QuickBird Data for Change Detection Applications; Developing Coastal Surface Roughness Maps Using ASTER and QuickBird Data Sources; Automated, Near-Real Time Cloud and Cloud Shadow Detection in High Resolution VNIR Imagery; Science Applications of High Resolution Imagery at the USGS EROS Data Center; Draft Plan for Characterizing Commercial Data Products in Support of Earth Science Research; Atmospheric Correction Prototype Algorithm for High Spatial Resolution Multispectral Earth Observing Imaging Systems; Determining Regional Arctic Tundra Carbon Exchange: A Bottom-Up Approach; Using IKONOS Imagery to Assess Impervious Surface Area, Riparian Buffers and Stream Health in the Mid-Atlantic Region; Commercial Remote Sensing Space Policy Civil Implementation Update; USGS Commercial Remote Sensing Data Contracts (CRSDC); and Commercial Remote Sensing Space Policy (CRSSP): Civil Near-Term Requirements Collection Update.

  19. Fabricating High-Resolution X-Ray Collimators

    NASA Technical Reports Server (NTRS)

    Appleby, Michael; Atkinson, James E.; Fraser, Iain; Klinger, Jill

    2008-01-01

    A process and method for fabricating multi-grid, high-resolution rotating modulation collimators for arcsecond and sub-arcsecond x-ray and gamma-ray imaging involves photochemical machining and precision stack lamination. The special fixturing and etching techniques that have been developed are used for the fabrication of multiple high-resolution grids on a single array substrate. This technology has application in solar and astrophysics and in a number of medical imaging applications including mammography, computed tomography (CT), single photon emission computed tomography (SPECT), and gamma cameras used in nuclear medicine. This collimator improvement can also be used in non-destructive testing, hydrodynamic weapons testing, and microbeam radiation therapy.

  20. Analysis of Complex Steel Microstructures by High-Resolution EBSD

    NASA Astrophysics Data System (ADS)

    Isasti, Nerea; Jorge-Badiola, Denis; Alkorta, Jon; Uranga, Pello

    2015-10-01

    High-resolution electron backscattered diffraction (HR-EBSD) is a powerful tool to describe microstructures at the sub-micrometric scale that achieves a higher degree of angular accuracy compared with conventional EBSD. However, such an EBSD technique is time-consuming and requires data-intensive computing to save and postprocess the results obtained after each scan. In the current work, a simple strategy to transform conventional results into high-resolution results is put forward in an averaging statistical layout. This makes it possible to measure the misorientations more precisely and, subsequently, the geometrically necessary dislocations by lowering the typical noise generated from Hough transformation-based conventional EBSD. Different steel microstructures are analyzed in light of this strategy. The calculated dislocation densities for those microstructures are used as input values for evaluating the initial dislocation density contribution to the yield strength in a newly developed mechanical model.

  1. High resolution 4-dimension imaging of metanephric embryonic kidney morphogenesis.

    PubMed

    Clendenon, Sherry G; Ward, Heather H; Dunn, Kenneth W; Bacallao, Robert

    2013-04-01

    High-resolution three-dimensional imaging of fixed embryonic kidney tissues has advanced considerably in the past decade. Here we developed a new process for imaging whole metanephric organ culture at cell resolution in three dimensions over time. This technique combines the use of the newly available generation of infrared-optimized long working distance, high numerical aperture objectives and multiphoton fluorescence microscopy with a new system for vital staining of metanephric organ cultures with bodipy ceramide. This allows all cells in the organ culture to be visualized over time, enabling detailed observation of tissue morphogenesis. Thus, our method offers a powerful new approach for visualizing and understanding early events in renal development and for extending observations made in genetically manipulated models. PMID:23325081

  2. Measuring Large-Scale Social Networks with High Resolution

    PubMed Central

    Stopczynski, Arkadiusz; Sekara, Vedran; Sapiezynski, Piotr; Cuttone, Andrea; Madsen, Mette My; Larsen, Jakob Eg; Lehmann, Sune

    2014-01-01

    This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years—the Copenhagen Networks Study. Specifically, we collect data on face-to-face interactions, telecommunication, social networks, location, and background information (personality, demographics, health, politics) for a densely connected population of 1 000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation and research agenda driving the study. Additionally, the paper details the data-types measured, and the technical infrastructure in terms of both backend and phone software, as well as an outline of the deployment procedures. We document the participant privacy procedures and their underlying principles. The paper is concluded with early results from data analysis, illustrating the importance of multi-channel high-resolution approach to data collection. PMID:24770359

  3. A novel high resolution ion wide angle spectrometer

    NASA Astrophysics Data System (ADS)

    Jung, D.; Hörlein, R.; Gautier, D. C.; Letzring, S.; Kiefer, D.; Allinger, K.; Albright, B. J.; Shah, R.; Palaniyappan, S.; Yin, L.; Fernández, J. C.; Habs, D.; Hegelich, B. M.

    2011-04-01

    A novel ion wide angle spectrometer (iWASP) has been developed, which is capable of measuring angularly resolved energy distributions of protons and a second ion species, such as carbon C6 +, simultaneously. The energy resolution for protons and carbon ions is better than 10% at ˜50 MeV/nucleon and thus suitable for the study of novel laser-ion acceleration schemes aiming for ultrahigh particle energies. A wedged magnet design enables an acceptance angle of 30°(˜524 mrad) and high angular accuracy in the ?rad range. First, results obtained at the LANL Trident laser facility are presented demonstrating high energy and angular resolution of this novel iWASP.

  4. A novel high resolution ion wide angle spectrometer.

    PubMed

    Jung, D; Hörlein, R; Gautier, D C; Letzring, S; Kiefer, D; Allinger, K; Albright, B J; Shah, R; Palaniyappan, S; Yin, L; Fernández, J C; Habs, D; Hegelich, B M

    2011-04-01

    A novel ion wide angle spectrometer (iWASP) has been developed, which is capable of measuring angularly resolved energy distributions of protons and a second ion species, such as carbon C(6 +), simultaneously. The energy resolution for protons and carbon ions is better than 10% at ?50 MeV/nucleon and thus suitable for the study of novel laser-ion acceleration schemes aiming for ultrahigh particle energies. A wedged magnet design enables an acceptance angle of 30°(?524 mrad) and high angular accuracy in the ?rad range. First, results obtained at the LANL Trident laser facility are presented demonstrating high energy and angular resolution of this novel iWASP. PMID:21528999

  5. [Techniques and applications of noninvasive high-resolution ultrasound imaging].

    PubMed

    Grégoire, J-M; Serrière, S; Georgesco, G; Jamet, F; Bleuzen, A; Ossant, F; Levassort, F; Tranquart, F; Patat, F

    2006-12-01

    Today manufacturers propose echographic systems with a resolution ranging from 100 microm down to 30 microm. This requires ultrasonic frequencies ranging from 20 to 60 MHz. However, when associated with an increase in the attenuation of the wave in the media this limits the applications to superficial exploration. High frequencies also bring special technological limitations mainly in the fields of transducers, electronics, and acoustic coupling. Although high-resolution echography has long remained marginal and been used for the exploration of the skin or the anterior chamber of the eye, new powerful and easy-to-use devices have recently appeared on the market. With these new products, new applications have also appeared such as the exploration of the oral cavity or small laboratory animals (mice). PMID:17211307

  6. Space to Think: Large, High-Resolution Displays for Sensemaking

    SciTech Connect

    Andrews, Christopher P.; Endert, Alexander; North, Chris

    2010-05-05

    Space supports human cognitive abilities in a myriad of ways. The note attached to the side of the monitor, the papers spread out on the desk, diagrams scrawled on a whiteboard, and even the keys left out on the counter are all examples of using space to recall, reveal relationships, and think. Technological advances have made it possible to construct large display environments in which space has real meaning. This paper examines how increased space affects the way displays are regarded and used within the context of the cognitively demanding task of sensemaking. A study was conducted observing analysts using a prototype large, high-resolution display to solve an analytic problem. This paper reports on the results of this study and suggests a number of potential design criteria for future sensemaking tools developed for large, high-resolution displays.

  7. High-resolution ultrasound imaging of cutaneous lesions

    PubMed Central

    Mandava, Anitha; Ravuri, Prabhakar Rao; Konathan, Rajyalaxmi

    2013-01-01

    High-resolution variable frequency ultrasound imaging is increasingly being used in the noninvasive evaluation of various cutaneous diseases. It plays a complimentary role to physical examination in the assessment of cutaneous lesions. It is the only imaging modality useful in the evaluation of superficial cutaneous lesions that are too small to be evaluated on computed tomography (CT) or magnetic resonance imaging (MRI) and is helpful in reducing invasive procedures like biopsies and fine needle aspirations. In this article, we seek to describe the relevance and basic principles of cutaneous ultrasound, imaging findings of normal skin, current applications of high-resolution ultrasound in the diagnosis and management of various dermatological conditions, along with the features of some commonly encountered lesions. PMID:24347861

  8. Protein-DNA binding in high-resolution

    PubMed Central

    Mahony, Shaun; Pugh, B. Franklin

    2015-01-01

    Recent advances in experimental and computational methodologies are enabling ultra-high resolution genome-wide profiles of protein-DNA binding events. For example, the ChIP-exo protocol precisely characterizes protein-DNA crosslinking patterns by combining chromatin immunoprecipitation (ChIP) with 5? ? 3? exonuclease digestion. Similarly, deeply sequenced chromatin accessibility assays (e.g. DNase-seq and ATACseq) enable the detection of protected footprints at protein-DNA binding sites. With these techniques and others, we have the potential to characterize the individual nucleotides that interact with transcription factors, nucleosomes, RNA polymerases, and other regulatory proteins in a particular cellular context. In this review, we explain the experimental assays and computational analysis methods that enable high-resolution profiling of protein-DNA binding events. We discuss the challenges and opportunities associated with such approaches. PMID:26038153

  9. High resolution computed tomography of advanced composite and ceramic materials

    NASA Technical Reports Server (NTRS)

    Yancey, R. N.; Klima, S. J.

    1991-01-01

    Advanced composite and ceramic materials are being developed for use in many new defense and commercial applications. In order to achieve the desired mechanical properties of these materials, the structural elements must be carefully analyzed and engineered. A study was conducted to evaluate the use of high resolution computed tomography (CT) as a macrostructural analysis tool for advanced composite and ceramic materials. Several samples were scanned using a laboratory high resolution CT scanner. Samples were also destructively analyzed at the locations of the scans and the nondestructive and destructive results were compared. The study provides useful information outlining the strengths and limitations of this technique and the prospects for further research in this area.

  10. High resolution reservoir geological modelling using outcrop information

    SciTech Connect

    Zhang Changmin; Lin Kexiang; Liu Huaibo

    1997-08-01

    This is China`s first case study of high resolution reservoir geological modelling using outcrop information. The key of the modelling process is to build a prototype model and using the model as a geological knowledge bank. Outcrop information used in geological modelling including seven aspects: (1) Determining the reservoir framework pattern by sedimentary depositional system and facies analysis; (2) Horizontal correlation based on the lower and higher stand duration of the paleo-lake level; (3) Determining the model`s direction based on the paleocurrent statistics; (4) Estimating the sandbody communication by photomosaic and profiles; (6) Estimating reservoir properties distribution within sandbody by lithofacies analysis; and (7) Building the reservoir model in sandbody scale by architectural element analysis and 3-D sampling. A high resolution reservoir geological model of Youshashan oil field has been built by using this method.

  11. Turbine component casting core with high resolution region

    DOEpatents

    Kamel, Ahmed; Merrill, Gary B.

    2014-08-26

    A hollow turbine engine component with complex internal features can include a first region and a second, high resolution region. The first region can be defined by a first ceramic core piece formed by any conventional process, such as by injection molding or transfer molding. The second region can be defined by a second ceramic core piece formed separately by a method effective to produce high resolution features, such as tomo lithographic molding. The first core piece and the second core piece can be joined by interlocking engagement that once subjected to an intermediate thermal heat treatment process thermally deform to form a three dimensional interlocking joint between the first and second core pieces by allowing thermal creep to irreversibly interlock the first and second core pieces together such that the joint becomes physically locked together providing joint stability through thermal processing.

  12. High Resolution Radio Observations of Southern Galactic Star Forming Regions

    NASA Astrophysics Data System (ADS)

    Verma, Ram Prakash; Ghosh, S. K.; Kulkarni, V. K.; Ojha, D. K.; Tej, A.; Vig, S.

    2005-07-01

    As part a programme of high resolution radio mapping of Galactic star forming regions, many Galactic star forming regions have been observed at 1280, 610 and 325 MHz using Giant Metrewave Radio Telescope (GMRT), India. GMRT is a synthesis telescope consisting of thirty 45 m diameter parabolic dishes spread in a 'Y' shape configuration. Baselines range from 100 m to 25 km providing high angular resolution (about 3" at 1280 MHz, 6" at 610 MHz and 9" at 325 MHz) as well as sensitivity to diffuse structures. In this paper some of the maps of southern sources will be presented. All the sources are resolved and many show extended diffuse emission. These maps will be compared with available maps at other wavelengths (e.g. millimeter, infrared) to have an understanding of these regions. Radiation transfer modeling of the observed spectral energy distribution from dust continuum, constrained by the radio emission and angular sizes will be presented.

  13. High speed inverted optical-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Rao, Bin; Maslov, Konstantin; Danielli, Amos; Chen, Ruiming; Shung, K. Kirk; Zhou, Qifa; Wang, Lihong V.

    2011-03-01

    Photoacoustic microscopy (PAM) offers label-free, optical absorption contrast. A high-speed, high-resolution PAM system in an inverted microscope configuration with a laser pulse repetition rate of 100,000 Hz and a stationary ultrasonic transducer was built. Four-dimensional in vivo imaging of microcirculation in mouse skin was achieved at 18 three-dimensional volumes per second with repeated two-dimensional raster scans of 100 by 50 points. The corresponding twodimensional B-scan (50 A-lines) frame rate was 1800 Hz, and the one-dimensional A-scan rate was 90,000 Hz. The lateral resolution is 0.23+/-0.03 ?m for Au nano-wire imaging, which is 2.0 times below the diffraction limit.

  14. High resolution 4-dimension imaging of metanephric embryonic kidney morphogenesis

    PubMed Central

    Clendenon, Sherry G.; Ward, Heather H.; Dunn, Kenneth W.; Bacallao, Robert

    2013-01-01

    High resolution three-dimensional imaging of fixed embryonic kidney tissues has advanced considerably in the past decade. Here we developed a new process for imaging whole metanephric organ culture at cell resolution in three dimensions over time. This technique combines the use of the newly available generation of infrared optimized long working distance high numerical aperture objectives and multiphoton fluorescence microscopy with a new system for vital staining of metanephric organ cultures with bodipy ceramide. This allows all cells in the organ culture to be visualized over time, enabling detailed observation of tissue morphogenesis. Thus, our method offers a powerful new approach for visualizing and understanding early events in renal development and for extending observations made in genetically manipulated models. PMID:23325081

  15. HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

    SciTech Connect

    Brooks, David H.; Ugarte-Urra, Ignacio; Warren, Harry P.; Winebarger, Amy R.

    2013-08-01

    Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

  16. High Resolution Scanning Electron Microscopy of Cells Using Dielectrophoresis

    PubMed Central

    Tang, Shi-Yang; Zhang, Wei; Soffe, Rebecca; Nahavandi, Sofia; Shukla, Ravi; Khoshmanesh, Khashayar

    2014-01-01

    Ultrastructural analysis of cells can reveal valuable information about their morphological, physiological, and biochemical characteristics. Scanning electron microscopy (SEM) has been widely used to provide high-resolution images from the surface of biological samples. However, samples need to be dehydrated and coated with conductive materials for SEM imaging. Besides, immobilizing non-adherent cells during processing and analysis is challenging and requires complex fixation protocols. In this work, we developed a novel dielectrophoresis based microfluidic platform for interfacing non-adherent cells with high-resolution SEM at low vacuum mode. The system enables rapid immobilization and dehydration of samples without deposition of chemical residues over the cell surface. Moreover, it enables the on-chip chemical stimulation and fixation of immobilized cells with minimum dislodgement. These advantages were demonstrated for comparing the morphological changes of non-budding and budding yeast cells following Lyticase treatment. PMID:25089528

  17. Effective Area of the AXAF High Resolution Camera (HRC)

    NASA Technical Reports Server (NTRS)

    Patnaude, Daniel; Pease, Deron; Donnelly, Hank; Juda, Mike; Jones, Christine; Murray, Steve; Zombeck, Martin; Kraft, Ralph; Kenter, Almus; Meehan, Gary; Meehan, Gary; Swartz, Doug; Elsner, Ron

    1998-01-01

    The AXAF High-Resolution Camera (HRC) was calibrated at NASA MSFC's X-Ray Calibration Facility (XRCF) during 1997 March and April. We have undertaken an analysis of the HRC effective area using all data presently available from the XRCF. We discuss our spectral fitting of the beam-normalization detectors (BNDs), our method of removing higher order contamination lines present in the spectra, and corrections for beam non-uniformities. We apply a model of photon absorption depth in order to fit a smooth curve to the quantum efficiency of the detector. This is then combined with the most recent model of the AXAF High-Resolution Mirror Assembly (HRMA) to determine the ensemble effective area versus energy for the HRC. We also address future goals and concerns.

  18. Airborne laser scanning for high-resolution mapping of Antarctica

    NASA Astrophysics Data System (ADS)

    Csatho, Bea; Schenk, Toni; Krabill, William; Wilson, Terry; Lyons, William; McKenzie, Garry; Hallam, Cheryl; Manizade, Serdar; Paulsen, Timothy

    In order to evaluate the potential of airborne laser scanning for topographic mapping in Antarctica and to establish calibration/validation sites for NASA's Ice, Cloud and land Elevation Satellite (ICESat) altimeter mission, NASA, the U.S. National Science Foundation (NSF), and the U.S. Geological Survey (USGS) joined forces to collect high-resolution airborne laser scanning data.In a two-week campaign during the 2001-2002 austral summer, NASA's Airborne Topographic Mapper (ATM) system was used to collect data over several sites in the McMurdo Sound area of Antarctica (Figure 1a). From the recorded signals, NASA computed laser points and The Ohio State University (OSU) completed the elaborate computation/verification of high-resolution Digital Elevation Models (DEMs) in 2003. This article reports about the DEM generation and some exemplary results from scientists using the geomorphologic information from the DEMs during the 2003-2004 field season.

  19. Measuring large-scale social networks with high resolution.

    PubMed

    Stopczynski, Arkadiusz; Sekara, Vedran; Sapiezynski, Piotr; Cuttone, Andrea; Madsen, Mette My; Larsen, Jakob Eg; Lehmann, Sune

    2014-01-01

    This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years-the Copenhagen Networks Study. Specifically, we collect data on face-to-face interactions, telecommunication, social networks, location, and background information (personality, demographics, health, politics) for a densely connected population of 1000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation and research agenda driving the study. Additionally, the paper details the data-types measured, and the technical infrastructure in terms of both backend and phone software, as well as an outline of the deployment procedures. We document the participant privacy procedures and their underlying principles. The paper is concluded with early results from data analysis, illustrating the importance of multi-channel high-resolution approach to data collection. PMID:24770359

  20. Precision cosmology with time delay lenses: high resolution imaging requirements

    E-print Network

    Meng, Xiao-Lei; Agnello, Adriano; Auger, Matthew W; Liao, Kai; Marshall, Philip J

    2015-01-01

    Lens time delays are a powerful probe of cosmology, provided that the gravitational potential of the main deflector can be modeled with sufficient precision. Recent work has shown that this can be achieved by detailed modeling of the host galaxies of lensed quasars, which appear as "Einstein Rings" in high resolution images. We carry out a systematic exploration of the high resolution imaging required to exploit the thousands of lensed quasars that will be discovered by current and upcoming surveys with the next decade. Specifically, we simulate realistic lens systems as imaged by the Hubble Space Telescope (HST), James Webb Space Telescope (JWST), and ground based adaptive optics images taken with Keck or the Thirty Meter Telescope (TMT). We compare the performance of these pointed observations with that of images taken by the Euclid (VIS), Wide-Field Infrared Survey Telescope (WFIRST) and Large Synoptic Survey Telescope (LSST) surveys. We use as our metric the precision with which the slope $\\gamma'$ of the...

  1. LandScan 2013 High Resolution Global Population Data Set

    SciTech Connect

    2014-07-01

    The LandScan data set is a worldwide population database compiled on a 30"x30" latitude/longitude grid. Census counts (at sub-national level) were apportioned to each grid cell based on likelihood coefficients, which are based on land cover, slope, road proximity, high-resolution imagery, and other data sets. The LandScan data set was developed as part of Oak Ridge National Laboratory (ORNL) Global Population Project for estimating ambient populations at risk.

  2. High resolution microwave spectrometer sounder (HIMSS), volume 1, book 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The following topics are presented with respect to the high resolution microwave spectrometer sounder (HIMSS) that is to be used as an instrument for NASA's Earth Observing System (EOS): (1) preliminary program plans; (2) contract end item (CEI) specification; and (3) the instrument interface description document. Under the preliminary program plans section, plans dealing with the following subject areas are discussed: spares, performance assurance, configuration management, software implementation, contamination, calibration management, and verification.

  3. High spectral resolution remote sensing of canopy chemistry

    NASA Technical Reports Server (NTRS)

    Aber, John D.; Martin, Mary E.

    1995-01-01

    Near infrared laboratory spectra have been used for many years to determine nitrogen and lignin concentrations in plant materials. In recent years, similar high spectral resolution visible and infrared data have been available via airborne remote sensing instruments. Using data from NASA's Airborne visible/Infrared Imaging Spectrometer (AVIRIS) we attempt to identify spectral regions correlated with foliar chemistry at the canopy level in temperate forests.

  4. Conference Summary High Resolution Soft X-Ray Optics

    NASA Astrophysics Data System (ADS)

    Franks, A.

    1982-03-01

    The main topics discussed at the Conference were multilayer mirror optics and their applications, the manufacture and metrology of X-ray optical components, and microfabrication, particularly of zone plates for X-ray microscopy. The attainment of high resolution and the full potential of multilayer mirrors will require advances to be made in manufacturing technology, metrology and in the selection of suitable substrate materials.

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

    NASA Technical Reports Server (NTRS)

    Nghiem, Son V.; Neumann, Gregory

    2011-01-01

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

  6. High resolution microwave spectrometer sounder (HIMSS), volume 1, book 1

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The following topics are presented with respect to the high resolution microwave spectrometer sounder (HIMSS) that is to be used as an instrument for NASA's Earth Observing System (EOS): (1) an instrument overview; (2) an instrument description; (3) the instrument's conceptual design; (4) technical risks and offsets; (5) instrument reliability; (6) commands and telemetry; (7) mass and power budgets; (8) integration and test program; (9) program implementation; and (10) phase CD schedule.

  7. ALOS-2 science program and high resolution SAR applications

    NASA Astrophysics Data System (ADS)

    Shimada, M.; Osawa, Yuji

    2012-11-01

    Advanced Land Observation Satellite-2 (ALOS-2) will be launched in Nov. 2013 carrying the L-band Synthetic Aperture Radar (PALSAR-2) to the low polar orbit of 628km height with 14-day revisit time. To the four mission objectives, i.e., disaster mitigation, environmental monitoring represented by the forest monitoring and cryospheric monitoring, land monitoring, and technology development, PALSAR-2 and ALOS-2 will provide the 1~3m high resolution Spotlight and Strip with multi polarization with an imaging swath of 50km, ScanSAR imaging with 350~490km swath with dual polarizations, shorter temporal baseline of 14 days and spatial baseline of within 1km, shorter time delay of less than 72 hours (74 hours in worst case) for emergency observation request to the disaster area, and almost all of global beam synchronization for ScanSAR Interferometry. ALOS-2 science program initiates the JAXA's Calibration, Validation, Application researches of the PALSAR-2/ALOS-2 and Pi-SAR-L2. As the application research, the disaster mitigation and the urban area monitoring using the high resolution data should contribute significantly to the human society since the disasters occur frequently and globally. High resolution and multi polarimetric SAR with the shorter revisit time reserves the quicker detection of the land changes. In this presentation, we will summarize the contents of the ALOS-2 science program, its expected outcomes, and comparative study results with PALSAR. Some application examples of the disaster mitigation using the recent high resolution SARs, i.e., Pi-SAR-L2 and PALSAR will be also introduced.

  8. Large-field high-resolution mosaic movies

    NASA Astrophysics Data System (ADS)

    Hammerschlag, Robert H.; Sliepen, Guus; Bettonvil, Felix C. M.; Jägers, Aswin P. L.; Sütterlin, Peter; Martin, Sara F.

    2012-09-01

    Movies with fields-of-view larger than normal for high-resolution telescopes will give a better understanding of processes on the Sun, such as filament and active region developments and their possible interactions. New active regions can influence, by their emergence, their environment to the extent of possibly serving as an igniter of the eruption of a nearby filament. A method to create a large field-of-view is to join several fields-of-view into a mosaic. Fields are imaged quickly one after another using fast telescope-pointing. Such a pointing cycle has been automated at the Dutch Open Telescope (DOT), a high-resolution solar telescope located on the Canary Island La Palma. The observer can draw with the computer mouse the desired total field in the guider-telescope image of the whole Sun. The guider telescope is equipped with an H-alpha filter and electronic enhancement of contrast in the image for good visibility of filaments and prominences. The number and positions of the subfields are calculated automatically and represented by an array of bright points indicating the subfield centers inside the drawn rectangle of the total field on the computer screen with the whole-sun image. When the exposures start the telescope repeats automatically the sequence of subfields. Automatic production of flats is also programmed including defocusing and fast motion over the solar disk of the image field. For the first time mosaic movies were programmed from stored information on automated telescope motions from one field to the next. The mosaic movies fill the gap between whole-sun images with limited resolution of synoptic telescopes including space instruments and small-field high-cadence movies of high-resolution solar telescopes.

  9. High energy resolution, high angular acceptance crystal monochromator

    DOEpatents

    Alp, E.E.; Mooney, T.M.; Toellner, T.

    1996-06-04

    A 4-bounce dispersive crystal monochromator reduces the bandpass of synchrotron radiation to a 10-50 meV range without sacrificing angular acceptance. The monochromator includes the combination of an asymmetrical channel-cut single crystal of lower order reflection and a symmetrical channel-cut single crystal of higher order reflection in a nested geometric configuration. In the disclosed embodiment, a highly asymmetrically cut ({alpha}=20) outer silicon crystal (4 2 2) with low order reflection is combined with a symmetrically cut inner silicon crystal (10 6 4) with high order reflection to condition a hard x-ray component (5--30 keV) of synchrotron radiation down to the {micro}eV-neV level. Each of the crystals is coupled to the combination of a positioning inchworm and angle encoder via a respective rotation stage for accurate relative positioning of the crystals and precise energy tuning of the monochromator. 7 figs.

  10. High energy resolution, high angular acceptance crystal monochromator

    DOEpatents

    Alp, Ercan E. (Bolingbrook, IL); Mooney, Timothy M. (Westmont, IL); Toellner, Thomas (Green Bay, WI)

    1996-06-04

    A 4-bounce dispersive crystal monochromator reduces the bandpass of synchrotron radiation to a 10-50 meV range without sacrificing angular acceptance. The monochromator includes the combination of an asymmetrical channel-cut single crystal of lower order reflection and a symmetrical channel-cut single crystal of higher order reflection in a nested geometric configuration. In the disclosed embodiment, a highly asymmetrically cut (.alpha.=20) outer silicon crystal (4 2 2) with low order reflection is combined with a symmetrically cut inner silicon crystal (10 6 4) with high order reflection to condition a hard x-ray component (5-30 keV) of synchrotron radiation down to the .mu.eV-neV level. Each of the crystals is coupled to the combination of a positioning inchworm and angle encoder via a respective rotation stage for accurate relative positioning of the crystals and precise energy tuning of the monochromator.

  11. Thin polymer etalon arrays for high-resolution photoacoustic imaging

    PubMed Central

    Hou, Yang; Huang, Sheng-Wen; Ashkenazi, Shai; Witte, Russell; O’Donnell, Matthew

    2009-01-01

    Thin polymer etalons are demonstrated as high-frequency ultrasound sensors for three-dimensional (3-D) high-resolution photoacoustic imaging. The etalon, a Fabry-Perot optical resonator, consists of a thin polymer slab sandwiched between two gold layers. It is probed with a scanning continuous-wave (CW) laser for ultrasound array detection. Detection bandwidth of a 20-?m-diam array element exceeds 50 MHz, and the ultrasound sensitivity is comparable to polyvinylidene fluoride (PVDF) equivalents of similar size. In a typical photoacoustic imaging setup, a pulsed laser beam illuminates the imaging target, where optical energy is absorbed and acoustic waves are generated through the thermoelastic effect. An ultrasound detection array is formed by scanning the probing laser beam on the etalon surface in either a 1-D or a 2-D configuration, which produces 2-D or 3-D images, respectively. Axial and lateral resolutions have been demonstrated to be better than 20 ?m. Detailed characterizations of the optical and acoustical properties of the etalon, as well as photoacoustic imaging results, suggest that thin polymer etalon arrays can be used as ultrasound detectors for 3-D high-resolution photoacoustic imaging applications. PMID:19123679

  12. High-resolution multielement solid-state detectors

    SciTech Connect

    Pullia, A.; Furenlid, L.; Kraner, H.; Pietraski, P.; Siddons, D.

    1996-09-01

    Recent advances in multielement solid-state detector systems for high rate, high resolution x-ray spectroscopy at noncryogenic temperatures will be described in this paper. A 16-channel silicon detector system, designed and built at BNL, has been recently operated in the NSLS machine beam {number_sign}X19A, showing an average energy resolution of less than 250 eV FWHM, which is adequate to discriminate the fluorescence trace element against the background of elastically scattered photons in a typical EXAFS application. A larger, 128 channel system, will soon permit a higher overall count rate: {approx_gt}10{sup 6} counts per second. It is shown that, in order to achieve high resolution with a solid-state detector, special care must be spent in the detector-preamplifier assembly. A low noise detectorpreamplifier may be obtained integrating the front-end devices (an FET and/or a feedback capacitor) with the detector itself. {copyright} {ital 1996 American Institute of Physics.}

  13. Quantification of Murine Pancreatic Tumors by High Resolution Ultrasound

    PubMed Central

    Sastra, Stephen A.; Olive, Kenneth P.

    2013-01-01

    Summary Ultrasonography is a powerful imaging modality that enables non-invasive, real time visualization of abdominal organs and tissues. This technology may be adapted for use in mice through the utilization of higher frequency transducers, allowing for extremely high resolution imaging of the mouse pancreas. This technique is particularly well-suited to pancreas imaging due to the ultrasonographic properties of the normal mouse pancreas, easily accessible imaging planes for the head and tail of the mouse pancreas, and the comparative difficulty in imaging the mouse pancreas with other technologies. A suite of measurements tools is available to characterize the normal and diseased states of tissues. Of particular utility for cancer applications is the ability to use tomography to construct a 3D tumor volume, enabling longitudinal imaging studies to track tumor development, or response to therapies. Here, we describe a detailed method for performing high resolution ultrasound to detect and measure pancreatic lesions in a genetically engineered mouse model of pancreatic ductal using the VisualSonics Vevo2100 High Resolution Ultrasound System. The method includes preparation of the animal for imaging, 2D and 3D image acquisition, and post-acquisition analysis of tumors volumes. The combined procedure has been utilized extensively by our group and others for the preclinical evaluation of novel therapeutic agents in the treatment of pancreatic ductal adenocarcinoma (1–4). PMID:23359158

  14. High resolution ultrasonic spectroscopy system for nondestructive evaluation

    NASA Technical Reports Server (NTRS)

    Chen, C. H.

    1991-01-01

    With increased demand for high resolution ultrasonic evaluation, computer based systems or work stations become essential. The ultrasonic spectroscopy method of nondestructive evaluation (NDE) was used to develop a high resolution ultrasonic inspection system supported by modern signal processing, pattern recognition, and neural network technologies. The basic system which was completed consists of a 386/20 MHz PC (IBM AT compatible), a pulser/receiver, a digital oscilloscope with serial and parallel communications to the computer, an immersion tank with motor control of X-Y axis movement, and the supporting software package, IUNDE, for interactive ultrasonic evaluation. Although the hardware components are commercially available, the software development is entirely original. By integrating signal processing, pattern recognition, maximum entropy spectral analysis, and artificial neural network functions into the system, many NDE tasks can be performed. The high resolution graphics capability provides visualization of complex NDE problems. The phase 3 efforts involve intensive marketing of the software package and collaborative work with industrial sectors.

  15. First results from the Goddard High-Resolution Spectrograph - A demonstration of spectral resolution and experiments with deconvolution

    NASA Technical Reports Server (NTRS)

    Wahlgren, Glenn M.; Leckrone, David S.; Shore, Steven N.; Lindler, Don J.; Gilliland, Ronald L.; Ebbets, Dennis C.

    1991-01-01

    High-quality spectra of the sharp-lined star Chi Lupi were obtained with the Goddard High Resolution Spectrograph (GHRS). Spectra for the various resolving powers achievable with the echelle and G160M gratings are displayed. The effect of spherical aberration upon the spectral resolution is found to be negligible when using the small science aperture. The resolution of the large science aperture spectra is degraded by less than a factor of two. Efforts with spectral deconvolution using several techniques show that it is possible to regain much of the spectral resolution lost in the large science aperture if high signal-to-noise spectra are obtained.

  16. The Impact of Horizontal and Temporal Resolution on Convection and Precipitation with High-Resolution GEOS-5

    NASA Technical Reports Server (NTRS)

    Putman, William P.

    2012-01-01

    Using a high-resolution non-hydrostatic version of GEOS-5 with the cubed-sphere finite-volume dynamical core, the impact of spatial and temporal resolution on cloud properties will be evaluated. There are indications from examining convective cluster development in high resolution GEOS-5 forecasts that the temporal resolution within the model may playas significant a role as horizontal resolution. Comparing modeled convective cloud clusters versus satellite observations of brightness temperature, we have found that improved. temporal resolution in GEOS-S accounts for a significant portion of the improvements in the statistical distribution of convective cloud clusters. Using satellite simulators in GEOS-S we will compare the cloud optical properties of GEOS-S at various spatial and temporal resolutions with those observed from MODIS. The potential impact of these results on tropical cyclone formation and intensity will be examined as well.

  17. Identification of mosquito larval habitats in high resolution satellite data

    NASA Astrophysics Data System (ADS)

    Kiang, Richard K.; Hulina, Stephanie M.; Masuoka, Penny M.; Claborn, David M.

    2003-09-01

    Mosquito-born infectious diseases are a serious public health concern, not only for the less developed countries, but also for developed countries like the U.S. Larviciding is an effective method for vector control and adverse effects to non-target species are minimized when mosquito larval habitats are properly surveyed and treated. Remote sensing has proven to be a useful technique for large-area ground cover mapping, and hence, is an ideal tool for identifying potential larval habitats. Locating small larval habitats, however, requires data with very high spatial resolution. Textural and contextual characteristics become increasingly evident at higher spatial resolution. Per-pixel classification often leads to suboptimal results. In this study, we use pan-sharpened Ikonos data, with a spatial resolution approaching 1 meter, to classify potential mosquito larval habitats for a test site in South Korea. The test site is in a predominantly agricultural region. When spatial characteristics were used in conjunction with spectral data, reasonably good classification accuracy was obtained for the test site. In particular, irrigation and drainage ditches are important larval habitats but their footprints are too small to be detected with the original spectral data at 4-meter resolution. We show that the ditches are detectable using automated classification on pan-sharpened data.

  18. High Resolution Aircraft Scanner Mapping of Geothermal and Volcanic Areas

    SciTech Connect

    Mongillo, M.A.; Cochrane, G.R.; Wood, C.P.; Shibata, Y.

    1995-01-01

    High spectral resolution GEOSCAN Mkll multispectral aircraft scanner imagery has been acquired, at 3-6 m spatial resolutions, over much of the Taupo Volcanic Zone as part of continuing investigations aimed at developing remote sensing techniques for exploring and mapping geothermal and volcanic areas. This study examined the 24-band: visible, near-IR (NIR), mid-IR (MIR) and thermal-IR (TIR) imagery acquired over Waiotapu geothermal area (3 m spatial resolution) and White Island volcano (6 m resolution). Results show that color composite images composed of visible and NIR wavelengths that correspond to color infrared (CIR) photographic wavelengths can be useful for distinguishing among bare ground, water and vegetation features and, in certain cases, for mapping various vegetation types. However, combinations which include an MIR band ({approx} 2.2 {micro}m) with either visible and NIR bands, or two NIR bands, are the most powerful for mapping vegetation types, water bodies, and bare and hydrothermally altered ground. Combinations incorporating a daytime TIR band with NIR and MIR bands are also valuable for locating anomalously hot features and distinguishing among different types of surface hydrothermal alteration.

  19. High temporal resolution ocular aberrometry with pupil tracking

    NASA Astrophysics Data System (ADS)

    Jarosz, Jessica; Meimon, Serge; Conan, Jean-Marc; Paques, Michel

    2014-02-01

    More cost effective and robust designs of ocular adaptive optics systems could probably be derived from a thorough knowledge of ocular time-varying aberrations. This would in particular benefit to therapeutic systems where the problem of robustness is critical. Unfortunately, high frequency temporal statistical behavior of ocular aberrations remains poorly characterized. We set up an original high resolution custom-built Shack-Hartmann aberrometer running at a frequency of 236Hz additionally featuring pupil tracking and performedmeasurements on a 50-eye population. First analyses are carried out over 20 eyes. Qualitative correlation between dynamic aberrations and saccadic pupil movements is highlighted.

  20. High-Resolution and Animal Imaging Instrumentation and Techniques

    NASA Astrophysics Data System (ADS)

    Belcari, Nicola; Guerra, AlbertoDel

    During the last decade we have observed a growing interest in "in vivo" imaging techniques for small animals. This is due to the necessity of studying biochemical processes at a molecular level for pharmacology, genetic, and pathology investigations. This field of research is usually called "molecular imaging."Advances in biological understanding have been accompanied by technological advances in instrumentation and techniques and image-reconstruction software, resulting in improved image quality, visibility, and interpretation. The main technological challenge is then the design of systems with high spatial resolution and high sensitivity.

  1. Computing with high-resolution upwind schemes for hyperbolic equations

    NASA Technical Reports Server (NTRS)

    Chakravarthy, S. R.; Osher, S.

    1985-01-01

    Computational aspects of modern high-resolution upwind finite-difference schemes for hyperbolic systems of conservation laws are examined. An operational unification is demonstrated for constructing a wide class of flux-difference-split and flux-split schemes based on the design principles underlying total variation diminishing (TVD) schemes. Consideration is also given to TVD scheme design by preprocessing, the extension of preprocessing and postprocessing approaches to general control volumes, the removal of expansion shocks and 'glitches', relaxation methods for implicit TVD schemes, and a new family of high-accuracy TVD schemes.

  2. High Resolution Continuous Flow Analysis System for Polar Ice Cores

    NASA Astrophysics Data System (ADS)

    Dallmayr, Remi; Azuma, Kumiko; Yamada, Hironobu; Kjær, Helle Astrid; Vallelonga, Paul; Azuma, Nobuhiko; Takata, Morimasa

    2014-05-01

    In the last decades, Continuous Flow Analysis (CFA) technology for ice core analyses has been developed to reconstruct the past changes of the climate system 1), 2). Compared with traditional analyses of discrete samples, a CFA system offers much faster and higher depth resolution analyses. It also generates a decontaminated sample stream without time-consuming sample processing procedure by using the inner area of an ice-core sample.. The CFA system that we have been developing is currently able to continuously measure stable water isotopes 3) and electrolytic conductivity, as well as to collect discrete samples for the both inner and outer areas with variable depth resolutions. Chemistry analyses4) and methane-gas analysis 5) are planned to be added using the continuous water stream system 5). In order to optimize the resolution of the current system with minimal sample volumes necessary for different analyses, our CFA system typically melts an ice core at 1.6 cm/min. Instead of using a wire position encoder with typical 1mm positioning resolution 6), we decided to use a high-accuracy CCD Laser displacement sensor (LKG-G505, Keyence). At the 1.6 cm/min melt rate, the positioning resolution was increased to 0.27mm. Also, the mixing volume that occurs in our open split debubbler is regulated using its weight. The overflow pumping rate is smoothly PID controlled to maintain the weight as low as possible, while keeping a safety buffer of water to avoid air bubbles downstream. To evaluate the system's depth-resolution, we will present the preliminary data of electrolytic conductivity obtained by melting 12 bags of the North Greenland Eemian Ice Drilling (NEEM) ice core. The samples correspond to different climate intervals (Greenland Stadial 21, 22, Greenland Stadial 5, Greenland Interstadial 5, Greenland Interstadial 7, Greenland Stadial 8). We will present results for the Greenland Stadial -8, whose depths and ages are between 1723.7 and 1724.8 meters, and 35.520 to 35.636 kyr b2k 7), respectively. The results show the conductivity measured upstream and downstream of the debubbler. We will calculate the depth resolution of our system and compare it with earlier studies. 1) Bigler at al, "Optimization of High-Resolution Continuous Flow Analysis For Transient Climate Signals in Ice Cores". Environ. Sci. Technol. 2011, 45, 4483-4489 2) Kaufmann et al, "An Improved Continuous Flow Analysis System for High Resolution Field Measurements on Ice Cores". Environmental Environ. Sci. Technol. 2008, 42, 8044-8050 3) Gkinis, V., T. J. Popp, S. J. Johnsen and T, Blunier, 2010: A continuous stream flash evaporator for the calibration of an IR cavity ring down spectrometer for the isotopic analysis of water. Isotopes in Environmental and Health Studies, 46(4), 463-475. 4) McConnell et al, "Continuous ice-core chemical analyses using inductively coupled plasma mass spectrometry. Environ. Sci. Technol. 2002, 36, 7-11 5) Rhodes et al, "Continuous methane measurements from a late Holocene Greenland ice core : Atmospheric and in-situ signals" Earth and Planetary Science Letters. 2013, 368, 9-19 6) Breton et al, "Quantifying Signal Dispersion in a Hybrid Ice Core Melting System". Environ. Sci. Technol. 2012, 46, 11922-11928 7) Rasmussen et al, " A first chronology for the NEEM ice core". Climate of the Past. 2013, 9, 2967--3013

  3. High-resolution multimodal clinical multiphoton tomography of skin

    NASA Astrophysics Data System (ADS)

    König, Karsten

    2011-03-01

    This review focuses on multimodal multiphoton tomography based on near infrared femtosecond lasers. Clinical multiphoton tomographs for 3D high-resolution in vivo imaging have been placed into the market several years ago. The second generation of this Prism-Award winning High-Tech skin imaging tool (MPTflex) was introduced in 2010. The same year, the world's first clinical CARS studies have been performed with a hybrid multimodal multiphoton tomograph. In particular, non-fluorescent lipids and water as well as mitochondrial fluorescent NAD(P)H, fluorescent elastin, keratin, and melanin as well as SHG-active collagen has been imaged with submicron resolution in patients suffering from psoriasis. Further multimodal approaches include the combination of multiphoton tomographs with low-resolution wide-field systems such as ultrasound, optoacoustical, OCT, and dermoscopy systems. Multiphoton tomographs are currently employed in Australia, Japan, the US, and in several European countries for early diagnosis of skin cancer, optimization of treatment strategies, and cosmetic research including long-term testing of sunscreen nanoparticles as well as anti-aging products.

  4. Invariance Techniques And High-Resolution Null Steering

    NASA Astrophysics Data System (ADS)

    Roy, R.; Kailath, T.

    1988-02-01

    Over the past several decades, a significant amount of research has been performed in the area of high-resolution signal parameter estimation. It is a problem of significance in many signal processing applications including direction-of-arrival estimation in which the locations of multiple sources whose radiation is received by an array of sensors are sought. Much of the research has focussed on approaches based on the formation of optimal weight or copy vectors, procedures derived from the conventional practice of beamforming. This class of approached to parameter estimation problems has come to be known as high-resolution spectral analysis/beamforming since the introduction of the maximum entropy (MEM) method by Burg in 1967, and the maximum-likelihood (ML) method by Capon in 1969. These techniques provide increased resolution and accuracy over their predecessors (including conventional beamforming, but suffer from model mismatch. MUSIC and ESPRIT are recently developed geometric techniques that exploit the underlying model and thereby achieve significant improvements in performance. In this paper, these techniques are summarized. From basic physical principles, it is shown that ESPRIT is actually a multidimensional null steering algorithm, an interpretation with significant intuitive appeal. Finally, optimal signal copy vectors that naturally arise from the algorithm are presented, and their properties as beamforming vectors for this class of problems are discussed.

  5. Photoswitchable Nanoparticles Enable High-Resolution Cell Imaging: PULSAR Microscopy

    SciTech Connect

    Hu, Dehong; Tian, Z.; Wu, Wuwei; Wan, Wei; Li, Alexander D.

    2008-10-22

    Fluorescence imaging has transformed biological sciences and opened a window to reveal biological mechanisms in real time despite Abbe’s diffraction limit restricts current microscope resolution to 300 nm?.HDH2 Recently, two high-resolution fluorescence microscopic techniques emerged: one uses a special photoactivatable green fluorescent proteinHDH3 and the other employs a pair of cy3/cy5 dyes.HDH4 Both avoid Abbe’s diffraction limit by photoswitching nearby fluorophores off. Thus, photoswitching fluorescence between a bright and a dark state promises to deliver a wealth of information regarding biological phenomena at the nanoscale. The ideal probe is a key-enabling single molecule that can be photoswitched on and off. Such wonderful properties, albeit implausible to imagine at first, were realized in spiropyran derivatives. While being photoswitched, one molecule alternates red-fluorescence on-and-off. Using such photo-actuated unimolecular logical switching attained reconstruction (PULSAR) microscopy, we achieved high-resolution fluorescence imaging down to 80 nm? in nanostructures and cellular organelles.

  6. High-Resolution, Wide-Field-of-View Scanning Telescope

    NASA Technical Reports Server (NTRS)

    Sepulveda, Cesar; Wilson, Robert; Seshadri, Suresh

    2007-01-01

    A proposed telescope would afford high resolution over a narrow field of view (<0.10 ) while scanning over a total field of view nominally 16 wide without need to slew the entire massive telescope structure. The telescope design enables resolution of a 1-m-wide object in a 50- km-wide area of the surface of the Earth as part of a 200-km-wide area field of view monitored from an orbit at an altitude of 700 km. The conceptual design of this telescope could also be adapted to other applications both terrestrial and extraterrestrial in which there are requirements for telescopes that afford both wide- and narrow-field capabilities. In the proposed telescope, the scanning would be effected according to a principle similar to that of the Arecibo radio telescope, in which the primary mirror is stationary with respect to the ground and a receiver is moved across the focal surface of the primary mirror. The proposed telescope would comprise (1) a large spherical primary mirror that would afford high resolution over a narrow field of view and (2) a small displaceable optical relay segment that would be pivoted about the center of an aperture stop to effect the required scanning (see figure). Taken together, both comprise a scanning narrow-angle telescope that does not require slewing the telescope structure. In normal operation, the massive telescope structure would stare at a fixed location on the ground. The inner moveable relay optic would be pivoted to scan the narrower field of view over the wider one, making it possible to retain a fixed telescope orientation, while obtaining high-resolution images over multiple target areas during an interval of 3 to 4 minutes in the intended orbit. The pivoting relay segment of the narrow-angle telescope would include refractive and reflective optical elements, including two aspherical mirrors, to counteract the spherical aberration of the primary mirror. Overall, the combination of the primary mirror and the smaller relay optic would provide narrow-angle, diffraction-limited high resolution at a wavelength of 500 nm.

  7. High Resolution, Single-Step Patterning of Silica Aerogels

    NASA Technical Reports Server (NTRS)

    Bertino, M. F.; Hund, J. F.; Sosa, J.; Zhang, G.; Sotiriou-Leventis, C.; Leventis, N.; Tokuhiro, A. T.; Terry, J.

    2003-01-01

    Three-dimensional metallic structures are fabricated with high spatial resolution in silica aerogels. In our method, silica hydrogels are prepared with a standard base-catalyzed route, and exchanged with an aqueous solution typically containing Ag' ions (1 M) and 2-propanol (0.2 M). The metal ions are reduced photolytically with a table-top ultraviolet lamp, or radiolytically, with a focused X-ray beam. We fabricated dots and lines as small as 30 x 70 km, protruding for several mm into the bulk of the materials. The hydrogels are eventually supercritically dried to yield aerogels, without any measurable change in the shape and spatial resolution of the lithographed structures. Transmission electron microscopy shows that illuminated regions are composed of Ag clusters with a size of several pm, separated by thin layers of silica.

  8. High-resolution microendoscope for the detection of cervical neoplasia.

    PubMed

    Grant, Benjamin D; Schwarz, Richard A; Quang, Timothy; Schmeler, Kathleen M; Richards-Kortum, Rebecca

    2015-01-01

    Cervical cancer causes 275,000 deaths each year with 85 % of these deaths occurring in the developing world. One of the primary reasons for the concentration of deaths in developing countries is a lack of effective screening methods suited for the infrastructure of these countries. In order to address this need, we have developed a high-resolution microendoscope (HRME). The HRME is a fiber-based fluorescence microscope with subcellular resolution. Using the vital stain proflavine, we are able to image cell nuclei in vivo and evaluate metrics such as nuclear-to-cytoplasmic ratio, critical to identifying precancerous epithelial regions. In this chapter, we detail the materials and methods necessary to build this system from commercially available parts. PMID:25626555

  9. High-Resolution Mass Spectrometry for Untargeted Drug Screening.

    PubMed

    Wu, Alan H B; Colby, Jennifer

    2016-01-01

    While gas chromatography-mass spectrometry (GC/MS) continues to be the forensic standard for toxicology, liquid chromatography coupled to tandem MS offers significant operational advantages for targeted confirmatory analysis. LC-high-resolution (HR)-MS has recently been available that offers advantages for untargeted analysis. HR-MS analyzers include the Orbitrap and time-of-flight MS. These instruments are capable of detecting 1 ppm mass resolution. Following soft ionization, this enables the assignment of exact molecular formula, limiting the number of candidate compounds. With this technique, presumptive identification of unknowns can be conducted without the need to match MS library spectra or comparison against known standards. For clinical toxicology, this can greatly expand on the number of drugs and metabolites that can be detected and reported on a presumptive basis. Definitive assignments of the compound's identity can be retrospectively determined with acquisition of the appropriate reference standard. PMID:26660184

  10. High-resolution chalcogenide fiber bundles for infrared imaging.

    PubMed

    Zhang, Bin; Zhai, Chengcheng; Qi, Sisheng; Guo, Wei; Yang, Zhiyong; Yang, Anping; Gai, Xin; Yu, Yi; Wang, Rongping; Tang, Dingyuan; Tao, Guangming; Luther-Davies, Barry

    2015-10-01

    An ordered chalcogenide fiber bundle with a high resolution for infrared imaging was fabricated using a stack-and-draw approach. The fiber bundle consisted of about 810,000 single fibers with an As2S3 glass core of 9 ?m in diameter and a polyetherimide (PEI) polymer cladding of 10 ?m in diameter. The As2S3/PEI fibers showed good transparency in the 1.5-6.5 ?m spectral region. It presented a resolution of ?45??lp/mm and a crosstalk of ?2.5%. Fine thermal images of a hot soldering iron tip were delivered through the fiber bundle. PMID:26421537

  11. High-resolution computed tomography of the normal larynx

    SciTech Connect

    Silverman, P.M.; Korobkin, M.

    1983-05-01

    Computed tomography (CT) provides a unique method of evaluating abnormalities of the larynx by virture of its cross-sectional images. Several reports have demonstrated its utility in staging laryngeal carcinoma and defining the extent of injury in cases of laryngeal trauma. In order to appreciate subtle abnormalities of the larynx, a thorough understanding of the normal structures in this small anatomic area is crucial. Although previous studies have defined the normal CT anatomy of the larynx, many of the CT-anatomic correlations of the normal larynx used earlier-generation CT scanners with relatively poor resolution or were limited to transaxial images. High-resolution transaxial, coronal, and sagittal CT in vivo images are correlated with line drawings displaying normal laryngeal anatomy. The exquisite anatomic detail apparent in these images provides a sound basis for understanding subtle abnormalities in pathologic cases. (JMT)

  12. Towards high-resolution ptychographic x-ray diffraction microscopy

    SciTech Connect

    Takahashi, Yukio; Suzuki, Akihiro; Yamauchi, Kazuto; Zettsu, Nobuyuki; Kohmura, Yoshiki; Ishikawa, Tetsuya; Senba, Yasunori; Ohashi, Haruhiko

    2011-06-01

    Ptychographic x-ray diffraction microscopy is a lensless imaging technique with a large field of view and high spatial resolution, which is also useful for characterizing the wavefront of an x-ray probe. The performance of this technique is degraded by positioning errors due to the drift between the sample and illumination optics. We propose an experimental approach for correcting the positioning errors and demonstrate success by two-dimensionally reconstructing both the wavefront of the focused x-ray beam and the complex transmissivity of the weakly scattering objects at the pixel resolution of better than 10 nm in the field of view larger than 5 {mu}m. This method is applicable to not only the observation of organelles inside cells or nano-mesoscale structures buried within bulk materials but also the characterization of probe for single-shot imaging with x-ray free electron lasers.

  13. High-resolution infrared observations of active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Pott, Jörg-Uwe

    2012-07-01

    Interferometric resolution at IR wavelengths offers for the first time the possibility to zoom into the nuclei of galaxies beyond the circumnuclear stellar structures and spatially resolve gas and dust in the innermost regions (0.05-5pc), dominated by the central black hole. Ultimate goal is to reveal new aspects of AGN feeding, and interaction with its host galaxy. After first successes of resolving AGN with infrared interferometry (VLTI, Keck-IF), the second generation of high-resolution interferometric imagers behind 8m class telescopes is currently being built. I will summarize current aspects and successes of the field, and present our activities to provide extended capabilities for VLTI-Midi and -Matisse, LBT-Linc-Nirvana and Keck-Astra to study a larger sample of AGN in greater detail.

  14. Higher throughput high resolution multi-worm tracker

    NASA Astrophysics Data System (ADS)

    Javer, Avelino; Li, Kezhi; Gyenes, Bertalan; Brown, Andre; Behavioural Genomics Team

    2015-03-01

    We have developed a high throughput imaging system for tracking multiple nematode worms at high resolution. The tracker consists of 6 cameras mounted on a motorized gantry so that up to 48 plates (each with approximately 30 worms) can be imaged without user intervention. To deal with the high data rate of the cameras we use real time processing to find worms and only save the immediately surrounding pixels. The system is also equipped with automatic oxygen and carbon dioxide control for observing stimulus response behaviour. We will describe the design and performance of the new system, some of the challenges of truly high throughput behaviour recording, and report preliminary results on inter-individual variation in behaviour as well as a quantitative analysis of C. elegans response to hypoxia, oxygen reperfusion, and carbon dioxide. Funding provided by the Medical Research Council.

  15. High-resolution, high-throughput SNP mapping in Drosophila melanogaster

    E-print Network

    Cai, Long

    High-resolution, high-throughput SNP mapping in Drosophila melanogaster Doris Chen1,5, Annika for genetic mapping experiments in model organisms. Here we report the establishment of a high-density SNP map. For flexible, high-throughput SNP genotyping, we used fluorescent tag-array mini-sequencing (TAMS) assays. We

  16. High-resolution electromagnetic imaging of subsurface contaminant plumes

    SciTech Connect

    Sternberg, B.K.; Thomas, S.J.; Bax, N.H.; Poulton, M.M. . Lab. for Advanced Subsurface Imaging)

    1991-09-01

    A high-resolution electromagnetic (EM) system has been assembled to image subsurface contaminant plumes. The system consists of a transmitter which emits electromagnetic energy in the frequency range 30 Hz to 30 KHz. A receiver records 3 components of the magnetic field. From these 3 components the ellipticity of the magnetic field vector is determined. Ellipticity is a particularly diagnostic characteristic for detecting variations in subsurface resistivity. A unique feature of this system involves a high-accuracy calibration method. In this method a signal is fed to the receiver system at the same time that data are being collected. Our goal is to exploit the very-high-accuracy data collected with this system to obtain a high-resolution image of the surface. We are experimenting with several data interpretation methods. One method involves conventional modeling of the data. Another method treats the data set as an image. A particularly promising image processing technique involves recognizing the patterns in the data, specifically, the earth model pattern which corresponds to the observed EM data pattern. This is accomplished by training neural networks to recognize the patterns. 40 refs., 21 figs., 1 tab.

  17. SPIDER Progress Towards High Resolution Correlated Fission Product Data

    NASA Astrophysics Data System (ADS)

    Shields, Dan; Meierbachtol, Krista; Tovesson, Fredrik; Arnold, Charles; Blackeley, Rick; Bredeweg, Todd; Devlin, Matt; Hecht, Adam; Jandel, Marian; Jorgenson, Justin; Nelson, Ron; White, Morgan; Spider Team

    2014-09-01

    The SPIDER detector (SPectrometer for Ion DEtermination in fission Research) is under development with the goal of obtaining high-resolution, high-efficiency, correlated fission product data needed for many applications including the modeling of next generation nuclear reactors, stockpile stewardship, and the fundamental understanding of the fission process. SPIDER simultaneously measures velocity and energy of both fission products to calculate fission product yields (FPYs), neutron multiplicity (?), and total kinetic energy (TKE). A detailed description of the prototype SPIDER detector components will be presented. Characterization measurements with alpha and spontaneous fission sources will also be discussed. LA-UR-14-24875. The SPIDER detector (SPectrometer for Ion DEtermination in fission Research) is under development with the goal of obtaining high-resolution, high-efficiency, correlated fission product data needed for many applications including the modeling of next generation nuclear reactors, stockpile stewardship, and the fundamental understanding of the fission process. SPIDER simultaneously measures velocity and energy of both fission products to calculate fission product yields (FPYs), neutron multiplicity (?), and total kinetic energy (TKE). A detailed description of the prototype SPIDER detector components will be presented. Characterization measurements with alpha and spontaneous fission sources will also be discussed. LA-UR-14-24875. This work is in part supported by LANL Laboratory Directed Research and Development Projects 20110037DR and 20120077DR.

  18. High Resolution Energetic X-ray Imager (HREXI)

    NASA Astrophysics Data System (ADS)

    Grindlay, Jonathan

    We propose to design and build the first imaging hard X-ray detector system that incorporates 3D stacking of closely packed detector readouts in finely-spaced imaging arrays with their required data processing and control electronics. In virtually all imaging astronomical detectors, detector readout is done with flex connectors or connections that are not vertical but rather horizontal , requiring loss of focal plane area. For high resolution pixel detectors needed for high speed event-based X-ray imaging, from low energy applications (CMOS) with focusing X-ray telescopes, to hard X-ray applications with pixelated CZT for large area coded aperture telescopes, this new detector development offers great promise. We propose to extend our previous and current APRA supported ProtoEXIST program that has developed the first large area imaging CZT detectors and demonstrated their astrophysical capabilities on two successful balloon flight to a next generation High Resolution Energetic X-ray Imager (HREXI), which would incorporate microvia technology for the first time to connect the readout ASIC on each CZT crystal directly to its control and data processing system. This 3-dimensional stacking of detector and readout/control system means that large area (>2m2) imaging detector planes for a High Resolution Wide-field hard X-ray telescope can be built with initially greatly reduced detector gaps and ultimately with no gaps. This increases detector area, efficiency, and simplicity of detector integration. Thus higher sensitivity wide-field imagers will be possible at lower cost. HREXI will enable a post-Swift NASA mission such as the EREXS concept proposed to PCOS to be conducted as a future MIDEX mission. This mission would conduct a high resolution (<2 arcmin) , broad band (5 200 keV) hard X-ray survey of black holes on all scales with ~10X higher sensitivity than Swift. In the current era of Time Domain Astrophysics, such a survey capability, in conjunction with a nIR telescope in spece, will enable GRBs to be used as probes of the formation of the first stars and structure in the Universe. HREXI on its own, with broad bandwidth and high spectral and spatial resolution, will extend both Galactic surveys for obscured young supernova remnants (44Ti sources) and for transients, black holes and flaring AGN and TDEs well at greatly increased sensitivity and spatial/spectral resolution than has been done with Swift or INTEGRAL. If the HREXI-1 technology is developed in the first year of this proposed effort, it could be used on the upcoming Brazil-US MIRAX telescope on the Lattes satellite, scheduled for a 2018 launch with imaging detector planes to be provided (under contract) by our group. Finally, the 3D stacking technology development proposed here for imaging detector arrays has broad application to Wide Field soft X-ray imaging, to CMB polarization mode (B mode) imaging detectors with very high detector-pixel count, and to Homeland Security.

  19. ON THE IMPACT OF SUPER RESOLUTION WSR-88D DOPPLER RADAR DATA ASSIMILATION ON HIGH RESOLUTION NUMERICAL MODEL FORECASTS

    SciTech Connect

    Chiswell, S

    2009-01-11

    Assimilation of radar velocity and precipitation fields into high-resolution model simulations can improve precipitation forecasts with decreased 'spin-up' time and improve short-term simulation of boundary layer winds (Benjamin, 2004 & 2007; Xiao, 2008) which is critical to improving plume transport forecasts. Accurate description of wind and turbulence fields is essential to useful atmospheric transport and dispersion results, and any improvement in the accuracy of these fields will make consequence assessment more valuable during both routine operation as well as potential emergency situations. During 2008, the United States National Weather Service (NWS) radars implemented a significant upgrade which increased the real-time level II data resolution to 8 times their previous 'legacy' resolution, from 1 km range gate and 1.0 degree azimuthal resolution to 'super resolution' 250 m range gate and 0.5 degree azimuthal resolution (Fig 1). These radar observations provide reflectivity, velocity and returned power spectra measurements at a range of up to 300 km (460 km for reflectivity) at a frequency of 4-5 minutes and yield up to 13.5 million point observations per level in super-resolution mode. The migration of National Weather Service (NWS) WSR-88D radars to super resolution is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current operational mesoscale model domains utilize grid spacing several times larger than the legacy data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of super resolution reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution is investigated here to determine the impact of the improved data resolution on model predictions.

  20. High energy resolution with transparent ceramic garnet scintillators

    NASA Astrophysics Data System (ADS)

    Cherepy, N. J.; Seeley, Z. M.; Payne, S. A.; Beck, P. R.; Swanberg, E. L.; Hunter, S.; Ahle, L.; Fisher, S. E.; Melcher, C.; Wei, H.; Stefanik, T.; Chung, Y.-S.; Kindem, J.

    2014-09-01

    Breakthrough energy resolution, R(662keV) < 4%, has been achieved with an oxide scintillator, Cerium-doped Gadolinium Yttrium Gallium Aluminum Garnet, or GYGAG(Ce). Transparent ceramic GYGAG(Ce), has a peak emission wavelength of 550 nm that is better matched to Silicon photodetectors than to standard PMTs. We are therefore developing a spectrometer based on pixelated GYGAG(Ce) on a Silicon photodiode array that can provide R(662 keV) = 3.6%. In comparison, with large 1-2 in3 size GYGAG(Ce) ceramics we obtain R(662 keV) = 4.6% with PMT readout. We find that ceramic GYGAG(Ce) of a given stoichiometric chemical composition can exhibit very different scintillation properties, depending on sintering conditions and post-anneal treatments. Among the characteristics of transparent ceramic garnet scintillators that can be controlled by fabrication conditions are: scintillation decay components and their amplitudes, intensity and duration of afterglow, thermoluminescence glow curve peak positions and amplitudes, integrated light yield, light yield non-proportionality - as measured in the Scintillator Light Yield Non-Proportionality Characterization Instrument (SLYNCI), and energy resolution for gamma spectroscopy. Garnet samples exhibiting a significant fraction of Cerium dopant in the tetravalent valence also exhibit: faster overall scintillation decay, very low afterglow, high light yield, but poor light yield proportionality and degraded energy resolution.

  1. Extraction and labeling high-resolution images from PDF documents

    NASA Astrophysics Data System (ADS)

    Chachra, Suchet K.; Xue, Zhiyun; Antani, Sameer; Demner-Fushman, Dina; Thoma, George R.

    2013-12-01

    Accuracy of content-based image retrieval is affected by image resolution among other factors. Higher resolution images enable extraction of image features that more accurately represent the image content. In order to improve the relevance of search results for our biomedical image search engine, Open-I, we have developed techniques to extract and label high-resolution versions of figures from biomedical articles supplied in the PDF format. Open-I uses the open-access subset of biomedical articles from the PubMed Central repository hosted by the National Library of Medicine. Articles are available in XML and in publisher supplied PDF formats. As these PDF documents contain little or no meta-data to identify the embedded images, the task includes labeling images according to their figure number in the article after they have been successfully extracted. For this purpose we use the labeled small size images provided with the XML web version of the article. This paper describes the image extraction process and two alternative approaches to perform image labeling that measure the similarity between two images based upon the image intensity projection on the coordinate axes and similarity based upon the normalized cross-correlation between the intensities of two images. Using image identification based on image intensity projection, we were able to achieve a precision of 92.84% and a recall of 82.18% in labeling of the extracted images.

  2. Designing arrays for modern high-resolution methods

    SciTech Connect

    Dowla, F.U.

    1987-10-01

    A bearing estimation study of seismic wavefields propagating from a strongly heterogeneous media shows that with the high-resolution MUSIC algorithm the bias of the direction estimate can be reduced by adopting a smaller aperture sub-array. Further, on this sub-array, the bias of the MUSIC algorithm is less than those of the MLM and Bartlett methods. On the full array, the performance for the three different methods are comparable. Improvement in bearing estimation in MUSIC with a reduced aperture might be attributed to increased signal coherency in the array. For methods with less resolution, the improved signal coherency in the smaller array is possible being offset by severe loss of resolution and the presence of weak secondary sources. Building upon the characteristics of real seismic wavefields, a design language has been developed to generate, modify, and test other arrays. Eigenstructures of wavefields and arrays have been studied empirically by simulation of a variety of realistic signals. 6 refs., 5 figs.

  3. Computational analysis of high resolution unsteady airloads for rotor aeroacoustics

    NASA Technical Reports Server (NTRS)

    Quackenbush, Todd R.; Lam, C.-M. Gordon; Wachspress, Daniel A.; Bliss, Donald B.

    1994-01-01

    The study of helicopter aerodynamic loading for acoustics applications requires the application of efficient yet accurate simulations of the velocity field induced by the rotor's vortex wake. This report summarizes work to date on the development of such an analysis, which builds on the Constant Vorticity Contour (CVC) free wake model, previously implemented for the study of vibratory loading in the RotorCRAFT computer code. The present effort has focused on implementation of an airload reconstruction approach that computes high resolution airload solutions of rotor/rotor-wake interactions required for acoustics computations. Supplementary efforts on the development of improved vortex core modeling, unsteady aerodynamic effects, higher spatial resolution of rotor loading, and fast vortex wake implementations have substantially enhanced the capabilities of the resulting software, denoted RotorCRAFT/AA (AeroAcoustics). Results of validation calculations using recently acquired model rotor data show that by employing airload reconstruction it is possible to apply the CVC wake analysis with temporal and spatial resolution suitable for acoustics applications while reducing the computation time required by one to two orders of magnitude relative to that required by direct calculations. Promising correlation with this body of airload and noise data has been obtained for a variety of rotor configurations and operating conditions.

  4. Convex optimization of coincidence time resolution for a high-resolution PET system.

    PubMed

    Reynolds, Paul D; Olcott, Peter D; Pratx, Guillem; Lau, Frances W Y; Levin, Craig S

    2011-02-01

    We are developing a dual panel breast-dedicated positron emission tomography (PET) system using LSO scintillators coupled to position sensitive avalanche photodiodes (PSAPD). The charge output is amplified and read using NOVA RENA-3 ASICs. This paper shows that the coincidence timing resolution of the RENA-3 ASIC can be improved using certain list-mode calibrations. We treat the calibration problem as a convex optimization problem and use the RENA-3's analog-based timing system to correct the measured data for time dispersion effects from correlated noise, PSAPD signal delays and varying signal amplitudes. The direct solution to the optimization problem involves a matrix inversion that grows order (n(3)) with the number of parameters. An iterative method using single-coordinate descent to approximate the inversion grows order (n). The inversion does not need to run to convergence, since any gains at high iteration number will be low compared to noise amplification. The system calibration method is demonstrated with measured pulser data as well as with two LSO-PSAPD detectors in electronic coincidence. After applying the algorithm, the 511 keV photopeak paired coincidence time resolution from the LSO-PSAPD detectors under study improved by 57%, from the raw value of 16.3 ±0.07 ns full-width at half-maximum (FWHM) to 6.92 ±0.02 ns FWHM ( 11.52 ±0.05 ns to 4.89 ±0.02 ns for unpaired photons). PMID:20876008

  5. Theoretical performance analysis for CMOS based high resolution detectors.

    PubMed

    Jain, Amit; Bednarek, Daniel R; Rudin, Stephen

    2013-03-01

    High resolution imaging capabilities are essential for accurately guiding successful endovascular interventional procedures. Present x-ray imaging detectors are not always adequate due to their inherent limitations. The newly-developed high-resolution micro-angiographic fluoroscope (MAF-CCD) detector has demonstrated excellent clinical image quality; however, further improvement in performance and physical design may be possible using CMOS sensors. We have thus calculated the theoretical performance of two proposed CMOS detectors which may be used as a successor to the MAF. The proposed detectors have a 300 ?m thick HL-type CsI phosphor, a 50 ?m-pixel CMOS sensor with and without a variable gain light image intensifier (LII), and are designated MAF-CMOS-LII and MAF-CMOS, respectively. For the performance evaluation, linear cascade modeling was used. The detector imaging chains were divided into individual stages characterized by one of the basic processes (quantum gain, binomial selection, stochastic and deterministic blurring, additive noise). Ranges of readout noise and exposure were used to calculate the detectors' MTF and DQE. The MAF-CMOS showed slightly better MTF than the MAF-CMOS-LII, but the MAF-CMOS-LII showed far better DQE, especially for lower exposures. The proposed detectors can have improved MTF and DQE compared with the present high resolution MAF detector. The performance of the MAF-CMOS is excellent for the angiography exposure range; however it is limited at fluoroscopic levels due to additive instrumentation noise. The MAF-CMOS-LII, having the advantage of the variable LII gain, can overcome the noise limitation and hence may perform exceptionally for the full range of required exposures; however, it is more complex and hence more expensive. PMID:24353390

  6. Wide-Field-of-View, High-Resolution, Stereoscopic Imager

    NASA Technical Reports Server (NTRS)

    Prechtl, Eric F.; Sedwick, Raymond J.

    2010-01-01

    A device combines video feeds from multiple cameras to provide wide-field-of-view, high-resolution, stereoscopic video to the user. The prototype under development consists of two camera assemblies, one for each eye. One of these assemblies incorporates a mounting structure with multiple cameras attached at offset angles. The video signals from the cameras are fed to a central processing platform where each frame is color processed and mapped into a single contiguous wide-field-of-view image. Because the resolution of most display devices is typically smaller than the processed map, a cropped portion of the video feed is output to the display device. The positioning of the cropped window will likely be controlled through the use of a head tracking device, allowing the user to turn his or her head side-to-side or up and down to view different portions of the captured image. There are multiple options for the display of the stereoscopic image. The use of head mounted displays is one likely implementation. However, the use of 3D projection technologies is another potential technology under consideration, The technology can be adapted in a multitude of ways. The computing platform is scalable, such that the number, resolution, and sensitivity of the cameras can be leveraged to improve image resolution and field of view. Miniaturization efforts can be pursued to shrink the package down for better mobility. Power savings studies can be performed to enable unattended, remote sensing packages. Image compression and transmission technologies can be incorporated to enable an improved telepresence experience.

  7. High-resolution SIMS depth profiling of nanolayers.

    SciTech Connect

    Baryshev, S. V.; Zinovev, A. V.; Tripa, C. E.; Pellin, M. J.; Peng, Q.; Elam, J. W.; Veryovkin, I. V.

    2012-10-15

    Although the fundamental physical limits for depth resolution of secondary ion mass spectrometry are well understood in theory, the experimental work to achieve and demonstrate them is still ongoing. We report results of high-resolution TOF SIMS (time-of-flight secondary ion mass spectrometry) depth profiling experiments on a nanolayered structure, a stack of 16 alternating MgO and ZnO {approx}5.5 nm layers grown on a Si substrate by atomic layer deposition. The measurements were performed using a newly developed approach implementing a low-energy direct current normally incident Ar{sup +} ion beam for ion milling (250 eV and 500 eV energy), in combination with a pulsed 5 keV Ar{sup +} ion beam at 60{sup o} incidence for TOF SIMS analysis. By this optimized arrangement, a noticeably improved version of the dual-beam (DB) approach to TOF SIMS depth profiling is introduced, which can be dubbed gentleDB. The mixing-roughness-information model was applied to detailed analysis of experimental results. It revealed that the gentleDB approach allows ultimate depth resolution by confining the ion beam mixing length to about two monolayers. This corresponds to the escape depth of secondary ions, the fundamental depth resolution limitation in SIMS. Other parameters deduced from the measured depth profiles indicated that a single layer thickness is equal to 6 nm so that the 'flat' layer thickness d is 3 nm and the interfacial roughness {sigma} is 1.5 nm, thus yielding d + 2{sigma} = 6 nm. We have demonstrated that gentleDB TOF SIMS depth profiling with noble gas ion beams is capable of revealing the structural features of a stack of nanolayers, resolving its original surface and estimating the roughness of interlayer interfaces, information which is difficult to obtain by traditional approaches.

  8. Towards high resolution soil property maps for Austria

    NASA Astrophysics Data System (ADS)

    Schürz, Christoph; Klotz, Daniel; Herrnegger, Mathew; Schulz, Karsten

    2015-04-01

    Soil hydraulic properties, such as soil texture, soil water retention characteristics, hydraulic conductivity, or soil depth are important inputs for hydrologic catchment modelling. However, the availability of such data in Austria is often insufficient to fulfill requirements of well-established hydrological models. Either, soil data is available in sufficient spatial resolution but only covers a small extent of the considered area, or the data is comprehensive but rather coarse in its spatial resolution. Furthermore, the level of detail and quality of the data differs between the available data sets. In order to generate a comprehensive soil data set for whole Austria that includes main soil physical properties, as well as soil depth and organic carbon content in a high spatial resolution (10x10 to 100x100m²) several available soil data bases are merged and harmonized. Starting point is a high resolution soil texture map that only covers agricultural areas and is available due to Austrian land appraisal. Soil physical properties for those areas are derived by applying pedotransfer functions (e.g. Saxton and Rawls, 2006) resulting in expectation values and quantiles of the respective property for each soil texture class. For agricultural areas where no texture information is available, the most likely soil texture is assigned applying a Bayesian network approach incorporating information such as elevation, soil slope, soil type, or hydro-geology at different spatial scales. Soil data for forested areas, that cover a large extent of the state territory, are rather sparse in Austria. For such areas a similar approach as for agricultural areas is applied by using a Bayesian network for prediction of the soil texture. Additionally, information to various soil parameters taken from literature is incorporated. For areas that are covered by land use different to agriculture or forestry, such as bare rock surfaces, or wetland areas, solely literature information is used to assign soil physical parameters to the soil data set. Soil depth is only available in a very coarse spatial resolution. By correlating this information with altitude and slope steepness, soil depth data is refined. An evaluation of the Bayesian network predictions will be performed within a cross-validation framework.

  9. Providing Internet Access to High-Resolution Mars Images

    NASA Technical Reports Server (NTRS)

    Plesea, Lucian

    2008-01-01

    The OnMars server is a computer program that provides Internet access to high-resolution Mars images, maps, and elevation data, all suitable for use in geographical information system (GIS) software for generating images, maps, and computational models of Mars. The OnMars server is an implementation of the Open Geospatial Consortium (OGC) Web Map Service (WMS) server. Unlike other Mars Internet map servers that provide Martian data using an Earth coordinate system, the OnMars WMS server supports encoding of data in Mars-specific coordinate systems. The OnMars server offers access to most of the available high-resolution Martian image and elevation data, including an 8-meter-per-pixel uncontrolled mosaic of most of the Mars Global Surveyor (MGS) Mars Observer Camera Narrow Angle (MOCNA) image collection, which is not available elsewhere. This server can generate image and map files in the tagged image file format (TIFF), Joint Photographic Experts Group (JPEG), 8- or 16-bit Portable Network Graphics (PNG), or Keyhole Markup Language (KML) format. Image control is provided by use of the OGC Style Layer Descriptor (SLD) protocol. The OnMars server also implements tiled WMS protocol and super-overlay KML for high-performance client application programs.

  10. Providing Internet Access to High-Resolution Lunar Images

    NASA Technical Reports Server (NTRS)

    Plesea, Lucian

    2008-01-01

    The OnMoon server is a computer program that provides Internet access to high-resolution Lunar images, maps, and elevation data, all suitable for use in geographical information system (GIS) software for generating images, maps, and computational models of the Moon. The OnMoon server implements the Open Geospatial Consortium (OGC) Web Map Service (WMS) server protocol and supports Moon-specific extensions. Unlike other Internet map servers that provide Lunar data using an Earth coordinate system, the OnMoon server supports encoding of data in Moon-specific coordinate systems. The OnMoon server offers access to most of the available high-resolution Lunar image and elevation data. This server can generate image and map files in the tagged image file format (TIFF) or the Joint Photographic Experts Group (JPEG), 8- or 16-bit Portable Network Graphics (PNG), or Keyhole Markup Language (KML) format. Image control is provided by use of the OGC Style Layer Descriptor (SLD) protocol. Full-precision spectral arithmetic processing is also available, by use of a custom SLD extension. This server can dynamically add shaded relief based on the Lunar elevation to any image layer. This server also implements tiled WMS protocol and super-overlay KML for high-performance client application programs.

  11. NEFER: a high resolution scanning Fabry-Perot spectrograph

    NASA Astrophysics Data System (ADS)

    Rosado, Margarita; Bernal, Abel; Cepa, Jordi; Martínez, Luis A.; Iriarte, Arturo

    2008-07-01

    The scanning Fabry-Perot spectrograph could give highly accurate, kinematical information of star forming regions (HH objects, protoplanetary disks and large scale flows) and the dynamics of isolated and interacting galaxies (resonances, galaxy pairs, compact groups). In this project we are developing a high spectral resolution scanning Fabry-Perot interferometer for the GTC 10 m telescope and the OSIRIS instrument. The system will provide the following characteristics: high spectral resolution data (R up to 20000) over a whole field of view of approximate 8 × 8 arcmin, 0.125 arcsec pixel size in two spectral ranges; 6300 to 7000 Å (galactic projects) and 8000 to 9500 Å (OTELO objects kinematics). ICOS ET100 Fabry-Perot will be used and installed within the OSIRIS collimated beam in the filter wheel hosting the tunable filters. Several acquisition software features have been defined like: synchronizing Fabry-Perot scanning with image acquisition, data cube assembly; single frame or data cube files would be provided according to the observer data reduction process. Fabry-Perot plates parallelism is extremely important to improve Finesse. Our team has developed an algorithm to accomplish this task.

  12. High resolution micro ultrasonic machining for trimming 3D microstructures

    NASA Astrophysics Data System (ADS)

    Viswanath, Anupam; Li, Tao; Gianchandani, Yogesh

    2014-06-01

    This paper reports on the evaluation of a high resolution micro ultrasonic machining (HR-µUSM) process suitable for post fabrication trimming of complex 3D microstructures made from fused silica. Unlike conventional USM, the HR-µUSM process aims for low machining rates, providing high resolution and high surface quality. The machining rate is reduced by keeping the micro-tool tip at a fixed distance from the workpiece and vibrating it at a small amplitude. The surface roughness is improved by an appropriate selection of abrasive particles. Fluidic modeling is performed to study interaction among the vibrating micro-tool tip, workpiece, and the slurry. Using 304 stainless steel (SS304) tool tips of 50 µm diameter, the machining performance of the HR-µUSM process is characterized on flat fused silica substrates. The depths and surface finish of machined features are evaluated as functions of slurry concentrations, separation between the micro-tool and workpiece, and machining time. Under the selected conditions, the HR-µUSM process achieves machining rates as low as 10 nm s-1 averaged over the first minute of machining of a flat virgin sample. This corresponds to a mass removal rate of ?20 ng min-1. The average surface roughness, Sa, achieved is as low as 30 nm. Analytical and numerical modeling are used to explain the typical profile of the machined features as well as machining rates. The process is used to demonstrate trimming of hemispherical 3D shells made of fused silica.

  13. High-resolution wide-range dynamic neutron monochromators

    NASA Astrophysics Data System (ADS)

    Girolami, M.; Pietropaolo, A.; Bellucci, A.; Calvani, P.; Trucchi, D. M.

    2015-03-01

    This work proposes the concept of a high-resolution wide-range dynamic neutron monochromator able to operate up to a few eV, thus significantly extending the reliable operating neutron energy range of the state-of-the-art crystal-based devices, and to improve energy resolution in the epithermal range if compared to mechanical choppers. The proposed device is based on a radiation-hard aluminium nitride (AlN)/diamond heterostructure, operating as a super-high-frequency (> 3 GHz) high-speed (> 10000 m/s) acoustic resonator. The resulting surface acoustic wave (SAW) acts as a dynamic grating for the incoming neutrons: as long as neutron speed is lower than (or at least comparable to) SAW speed, diffraction angles are significantly enhanced, thus allowing for neutron beam monochromatization to be effective up to the eV energy range. SAW amplitude can be electrically tuned to increase first-order reflectivity, leading to an enhanced intensity of the monochromatized beam.

  14. High Resolution Optical Filters for Space-borne Lidar Receivers

    NASA Astrophysics Data System (ADS)

    Rees, D.; Foster, M. J.; Bond, R.; Bakalski, I. V.; Pereira Do Carmo, J.

    Lidar techniques are now very well established as a means for probing the physical chemical and dynamical properties of the atmosphere from ground-based observatories Recently NASA e g LITE GLAS and ESA in particular have undertaken the development of a series of Space-borne Lidar Missions to measure atmospheric dynamics e g AEOLUS Atmospheric Aerosol and Cloud Properties e g ATLID -- EarthCARE Carbon Dioxide FACTS and Water Vapour WALES These future Missions promise major advances in data quality and in global coverage with a significant impact in Meteorological Prediction and in the study of Climate and Climate Change Future missions exploiting powerful and robust laser transmitter receiver systems none-the-less have the challenge of detecting and recording weak back-scattered lidar signals against the background of the sunlit earth including snow and cloud scenes We report on the development of High Resolution Optical Filters intended to assure that the full performance of these Space Lidar systems can be exploited on the dayside of the earth as well as the night-side The filters exploit stable and robust Capacitance-Stabilised Fabry-Perot etalons of very high finesse Additionally the high resolution optical filters are fully programmable to meet all the complex requirements of the space missions including calibration the tracking of variations of laser wavelength and the Doppler shifts induced by atmospheric winds and orbital variations

  15. High Resolution Optical Filters for Space Lidar Receivers

    NASA Astrophysics Data System (ADS)

    Rees, D.; Foster, M. J.; Bond, R.; Twaite, C. J.; Bakalski, I. V.; Pereira Do Carmo, J.

    Lidar techniques are now very well established as a means for probing the physical chemical and dynamical properties of the atmosphere from ground-based observatories Recently NASA e g LITE GLAS and ESA in particular have undertaken the development of a series of Space-borne Lidar Missions to measure atmospheric dynamics e g AEOLUS Atmospheric Aerosol and Cloud Properties e g ATLID -- EarthCARE Carbon Dioxide FACTS and Water Vapour WALES These future Missions promise major advances in data quality and in global coverage with a significant impact in Meteorological Prediction and in the study of Climate and Climate Change Future missions exploiting powerful and robust laser transmitter receiver systems none-the-less have the challenge of detecting and recording weak back-scattered lidar signals against the background of the sunlit earth including snow and cloud scenes We report on the development of High Resolution Optical Filters intended to assure that the full performance of these Space Lidar systems can be exploited on the dayside of the earth as well as the night-side The filters exploit stable and robust Capacitance-Stabilised Fabry-Perot etalons of very high finesse Additionally the high resolution optical filters are fully programmable to meet all the complex requirements of the space missions including calibration the tracking of variations of laser wavelength and the Doppler shifts induced by atmospheric winds and orbital variations

  16. High-Resolution Polarimetry of Supernova Remnant Kesteven 69

    NASA Astrophysics Data System (ADS)

    Wood, C. A.; Mufson, S. L.; Dickel, J. R.

    2008-06-01

    Reported here are high-resolution 6 cm measurements of the adolescent supernova remnant (SNR) Kesteven 69 made with the hybrid BnC configuration of the Very Large Array. Several three-field mosaics of the polarized and total intensity have been used to study this SNR. These investigations lead to a coherent picture of this region. The expanding shock defines an outer rim of high total intensity, suggesting the front is running into large dense clouds with random magnetic field directions. The SNR consists of predominantly of two types of regions, those with high total and relatively weak polarized emission and those with relatively weak total and strong polarized emission. This morphology can be generally explained by the number of clouds with organized magnetic field along the line of sight. Within this SNR there are regions where the field is varying from radial to tangential. As the SN shock encounters clouds, magnetic fields within clouds will strongly affect cloud dynamics.

  17. Quantitative high resolution electron microscopy of grain boundaries

    SciTech Connect

    Campbell, G.H., King, W.E., Cohen, D., Carter, C.B.

    1996-12-12

    The {Sigma}11 (113)/[1{bar 1}0] symmetric tilt grain boundary has been characterized by high resolution transmission electron microscopy. The method by which the images are prepared for analysis is described. The statistics of the image data have been found to follow a normal distribution. The electron-optical imaging parameters used to acquire the image have been determined by nonlinear least-square image simulation optimization within the perfect crystal region of the micrograph. A similar image simulation optimization procedure is used to determine the atom positions which provide the best match between the experimental image and the image simulation.

  18. High-resolution tomographic diffractive microscopy of biological samples.

    PubMed

    Simon, Bertrand; Debailleul, Matthieu; Beghin, Anne; Tourneur, Yves; Haeberlé, Olivier

    2010-07-01

    The authors have developed a tomographic diffractive microscope that combines microholography with illumination from an angular synthetic aperture. It images specimens relative to their complex index of refraction distribution (index and absorption) and permits imaging of unlabelled specimens, with high lateral resolution. The authors now study its use for biological applications, and imaged several preparations with fluorescence confocal microscopy and tomographic diffractive microscopy. The results highlight some interesting features of this instrument, which should attract the interest of biologists for this new technique. PMID:20209580

  19. NASA Langley Airborne High Spectral Resolution Lidar Instrument Description

    NASA Technical Reports Server (NTRS)

    Harper, David B.; Cook, Anthony; Hostetler, Chris; Hair, John W.; Mack, Terry L.

    2006-01-01

    NASA Langley Research Center (LaRC) recently developed the LaRC Airborne High Spectral Resolution Lidar (HSRL) to make measurements of aerosol and cloud distribution and optical properties. The Airborne HSRL has undergone as series of test flights and was successfully deployed on the Megacity Initiative: Local and Global Research Observations (MILAGRO) field mission in March 2006 (see Hair et al. in these proceedings). This paper provides an overview of the design of the Airborne HSRL and descriptions of some key subsystems unique to this instrument.

  20. High resolution subsurface imaging with geophysical diffraction tomography

    SciTech Connect

    King, W.C.; Witten, A.J.

    1989-01-01

    This paper describes the evolution of a promising new technique for subsurface remote sensing, geophysical diffraction tomography, from its theoretical formalism to its current state as a proven field technique capable of high resolution imaging of natural and buried subsurface features. The paper begins with a brief introduction of the concept of diffraction tomography and a review of the theoretical development of a scheme for implementing diffraction tomography in a geophysical imaging technique. Next, the field procedure is described. The final topic for this paper, and its primary objective, is to present results of three recent field tests of the system. 9 refs., 12 figs.

  1. High-Resolution Atom Interferometers with Suppressed Diffraction Phases

    NASA Astrophysics Data System (ADS)

    Estey, Brian; Yu, Chenghui; Müller, Holger; Kuan, Pei-Chen; Lan, Shau-Yu

    2015-08-01

    We experimentally and theoretically study the diffraction phase of large-momentum transfer beam splitters in atom interferometers based on Bragg diffraction. We null the diffraction phase and increase the sensitivity of the interferometer by combining Bragg diffraction with Bloch oscillations. We demonstrate agreement between experiment and theory, and a 1500-fold reduction of the diffraction phase, limited by measurement noise. In addition to reduced systematic effects, our interferometer has high contrast with up to 4.4 ×106 radians of phase difference, and a resolution in the fine structure constant of ? ? /? =0.25 ppb in 25 h of integration time.

  2. High-resolution continuum observations of the Sun

    NASA Technical Reports Server (NTRS)

    Zirin, Harold

    1987-01-01

    The aim of the PFI or photometric filtergraph instrument is to observe the Sun in the continuum with as high resolution as possible and utilizing the widest range of wavelengths. Because of financial and political problems the CCD was eliminated so that the highest photometric accuracy is only obtainable by comparison with the CFS images. Presently there is a limitation to wavelengths above 2200 A due to the lack of sensitivity of untreated film below 2200 A. Therefore the experiment at present consists of a film camera with 1000 feet of film and 12 filters. The PFI experiments are outlined using only two cameras. Some further problems of the experiment are addressed.

  3. Clickstream data yields high-resolution maps of science

    SciTech Connect

    Bollen, Johan; Van De Sompel, Herbert; Hagberg, Aric; Bettencourt, Luis; Chute, Ryan; Rodriguez, Marko A; Balakireva, Lyudmila

    2009-01-01

    Intricate maps of science have been created from citation data to visualize the structure of scientific activity. However, most scientific publications are now accessed online. Scholarly web portals record detailed log data at a scale that exceeds the number of all existing citations combined. Such log data is recorded immediately upon publication and keeps track of the sequences of user requests (clickstreams) that are issued by a variety of users across many different domains. Given these advantagees of log datasets over citation data, we investigate whether they can produce high-resolution, more current maps of science.

  4. Applied high resolution geophysical methods: Offshore geoengineering hazards

    SciTech Connect

    Trabant, P.K.

    1984-01-01

    This book is an examination of the purpose, methodology, equipment, and data interpretation of high-resolution geophysical methods, which are used to assess geological and manmade engineering hazards at offshore construction locations. It is a state-of-the-art review. Contents: 1. Introduction. 2. Maring geophysics, an overview. 3. Marine geotechnique, an overview. 4. Echo sounders. 5. Side scan sonar. 6. Subbottom profilers. 7. Seismic sources. 8. Single-channel seismic reflection systems. 9. Multifold acquisition and digital processing. 10. Marine magnetometers. 11. Marine geoengineering hazards. 12. Survey organization, navigation, and future developments. Appendix. Glossary. References. Index.

  5. A high resolution spectrum reconstruction algorithm using compressive sensing theory

    NASA Astrophysics Data System (ADS)

    Zheng, Zhaoyu; Liang, Dakai; Liu, Shulin; Feng, Shuqing

    2015-07-01

    This paper proposes a quick spectrum scanning and reconstruction method using compressive sensing in composite structure. The strain field of corrugated structure is simulated by finite element analysis. Then the reflect spectrum is calculated using an improved transfer matrix algorithm. The K-means singular value decomposition sparse dictionary is trained . In the test the spectrum with limited sample points can be obtained and the high resolution spectrum is reconstructed by solving sparse representation equation. Compared with the other conventional basis, the effect of this method is better. The match rate of the recovered spectrum and the original spectrum is over 95%.

  6. High Resolution Spectra of Novae and the Quadratic Zeeman Effect

    E-print Network

    Robert Williams; Elena Mason

    2006-02-27

    High resolution spectra of novae after outburst reveal distinctive characteristics in the line profiles and intensities. The higher Balmer lines are often broader than the lower members of the series, and the relative profiles and intensities of the [O I] \\lambda\\lambda6300, 6364 doublet differ from normal values. We suggest these features may be caused by the Quadratic Zeeman Effect from magnetic fields exceeding B=10^6 gauss. Taken together the emission and absorption lines point to multiple origins for the ejecta on both the erupting white dwarf and the cool secondary star.

  7. Design of a High Resolution Hexapod Positioning Mechanism

    NASA Technical Reports Server (NTRS)

    Britt, Jamie; Brodeur, Stephen J. (Technical Monitor)

    2001-01-01

    This paper describes the development of a high resolution, six-degree of freedom positioning mechanism. This mechanism, based on the Stewart platform concept, was designed for use with the Developmental Comparative Active Optics Telescope Testbed (DCATT), a ground-based technology testbed for the Next Generation Space Telescope (NGST). The mechanism provides active control to the DCATT telescope's segmented primary mirror. Emphasis is on design decisions and technical challenges. Significant issues include undesirable motion properties of PZT-inchworm actuators, testing difficulties, dimensional stability and use of advanced composite materials. Supporting test data from prototype mechanisms is presented.

  8. POWERWALL: International Workshop on Interactive, Ultra-High-Resolution Displays

    SciTech Connect

    Rooney, Chris; Endert, Alexander; Fekete, Jean-Daniel; Hornbaek, Kasper; North, Chris

    2013-04-27

    Ultra-high-resolution (Powerwall) displays are becoming increasingly popular due to the ever decreasing cost of hardware. As a result they are appearing more frequently in research institutes, and making the jump out of the lab and into industry. Due to the amount of work in this research area that has been published in CHI over the last few years, we felt that this confernece would be the ideal host for the first opportunity for both academics and practitioners in this field to get together.

  9. High-resolution television observations of black aurora

    NASA Astrophysics Data System (ADS)

    Trondsen, T. S.; Cogger, L. L.

    1997-01-01

    In view of a recent revival of interest in the black aurora and related phenomena, and a striking lack of information on the phenomenon in the literature, we present high spatial and temporal resolution optical observations of the black aurora made by the University of Calgary portable auroral imager. A variety of black auroral phenomena, such as black vortices, arcs, and eastward drifting black auroral patches and arc segments, were observed in the evening and midnight sector diffuse auroral oval during a field trip to Rabbit Lake, Saskatchewan, from February 25 to March 7, 1995. Observed spatial and temporal characteristics are reviewed, with statistical data presented in the form of histograms.

  10. High-resolution line-scanning optical coherence microscopy

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Huang, Shu-Wei; Aguirre, Aaron D.; Fujimoto, James G.

    2007-07-01

    An optical coherence microscopy system based on line illumination and detection is demonstrated. The system uses a Linnik-type interferometer illuminated by a broadband Ti:sapphire laser and detected by a high-speed, line-scan CCD camera. This approach is less sensitive to incoherent scattering and sample motion than full-field imaging. Spatial resolutions of ˜2 ?mט3 ?m(transverse×axial) are achieved. The sensitivity of the system is 93 dB with averaging over 30 line scans. En face real time, cellular-level imaging of biological tissues is demonstrated at ˜2 frames/s.

  11. A methodology for high resolution digital image correlation in high temperature experiments

    NASA Astrophysics Data System (ADS)

    Blaber, Justin; Adair, Benjamin S.; Antoniou, Antonia

    2015-03-01

    We propose a methodology for performing high resolution Digital Image Correlation (DIC) analysis during high-temperature mechanical tests. Specifically, we describe a technique for producing a stable, high-quality pattern on metal surfaces along with a simple optical system that uses a visible-range camera and a long-range microscope. The results are analyzed with a high-quality open-source DIC software developed by us. Using the proposed technique, we successfully acquired high-resolution strain maps of the crack tip field in a nickel superalloy sample at 1000 °C.

  12. Spinning glass cell for high-pressure high-resolution NMR measurements

    NASA Astrophysics Data System (ADS)

    Yamada, H.; Nakatsuka, M.; Yamochi, H.; Sawamura, M.; Sera, A.

    1991-03-01

    A full description of the rotatable high-pressure glass cell method for the NMR measurements is presented. This simple device eliminates the use of massive high-pressure apparatus such as the oil pump, the Bourdon gauge, and the high-pressure tubing and valves in performing the high-pressure experiments. This system also demonstrates capability of realizing an extremely high-resolution level in the NMR measurements at high pressure otherwise not easily attainable.

  13. ALMA: Millimeter/submillimeter Astronomy at high sensitivity and resolution

    NASA Astrophysics Data System (ADS)

    Wootten, Alwyn; Corder, Stuartt Alan; Iono, Daisuke; Testi, Leonardo

    2015-08-01

    Vigorous and transformative investigation of the millimeter/submillimeter sky at high sensitivity and high resolution has benefitted from the recent completion of the Atacama Large Millimeter/submillimeter Array (ALMA), an effort of 22 countries. ALMA, a versatile interferometric telescope at 5000m elevation in the Atacama Desert of northern Chile, is comprised of sixty-six precision telescopes which may be arrayed over a 16 km extent on the high Chajnantor plain. Owing to its large collecting area of over 6600m^2 and its commodious spectral grasp of 8 GHz of spectrum in dual polarizations within an 84-950 GHz range, ALMA provides astronomers with vastly improved spectroscopic sensitivity. Spatial resolutions of 30 milliarcsec were demonstrated recently, revealing rings within the HL Tau protoplanetary disk, the rotating structure of the asteroid Juno and the molecular structure of the z~3 lensed galaxy SDP.81. The astrometric accuracy even at this early stage of deployment is better than 3 milliarcsec, providing improved ephemerides for the encounter of the New Horizons spacecraft with the Pluto-Charon system. Very long baseline capability is expected to bring microarcsecond imaging to a worldwide array anchored by ALMA with potential for imaging nearby Black Holes on the scales of their Event Horizons.ALMA's huge collecting area has enabled detection of lines of C, N and CO and continuum for characterization of massive complexes near the Era of Recombination. ALMA's sensitivity and resolution have enabledmeasurement of molecular emission through cosmic time from numerous molecules characterizing galactic star-forming regions and tracing their kinematics near active nuclei, starbursts, interacting clouds and quiescent disks. ALMA's sensitivity, resolution and spectral grasp have enabled it to image molecules and dust characterizing circumstellar disks and embedded bodies in protostellar, transition and debris stages of development.ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ.

  14. High resolution remote sensing of water surface patterns

    NASA Astrophysics Data System (ADS)

    Woodget, A.; Visser, F.; Maddock, I.; Carbonneau, P.

    2012-12-01

    The assessment of in-stream habitat availability within fluvial environments in the UK traditionally includes the mapping of patterns which appear on the surface of the water, known as 'surface flow types' (SFTs). The UK's River Habitat Survey identifies ten key SFTs, including categories such as rippled flow, upwelling, broken standing waves and smooth flow. SFTs result from the interaction between the underlying channel morphology, water depth and velocity and reflect the local flow hydraulics. It has been shown that SFTs can be both biologically and hydraulically distinct. SFT mapping is usually conducted from the river banks where estimates of spatial coverage are made by eye. This approach is affected by user subjectivity and inaccuracies in the spatial extent of mapped units. Remote sensing and specifically the recent developments in unmanned aerial systems (UAS) may now offer an alternative approach for SFT mapping, with the capability for rapid and repeatable collection of very high resolution imagery from low altitudes, under bespoke flight conditions. This PhD research is aimed at investigating the mapping of SFTs using high resolution optical imagery (less than 10cm) collected from a helicopter-based UAS flown at low altitudes (less than 100m). This paper presents the initial findings from a series of structured experiments on the River Arrow, a small lowland river in Warwickshire, UK. These experiments investigate the potential for mapping SFTs from still and video imagery of different spatial resolutions collected at different flying altitudes and from different viewing angles (i.e. vertical and oblique). Imagery is processed using 3D mosaicking software to create orthophotos and digital elevation models (DEM). The types of image analysis which are tested include a simple, manual visual assessment undertaken in a GIS environment, based on the high resolution optical imagery. In addition, an object-based image analysis approach which makes use of the spectral and textural images properties is tested using Definiens eCognition software. Where possible, the DEM of the water surface topography is also analysed for identifying SFTs. The site is revisited in order to assess the temporal variability of SFTs as relating to changes in flow level, and the potential for variability in identifying SFTs from imagery as relating to changes in lighting and weather conditions.

  15. High Resolution Digital Elevation Models of Pristine Explosion Craters

    NASA Technical Reports Server (NTRS)

    Farr, T. G.; Krabill, W.; Garvin, J. B.

    2004-01-01

    In order to effectively capture a realistic terrain applicable to studies of cratering processes and landing hazards on Mars, we have obtained high resolution digital elevation models of several pristine explosion craters at the Nevada Test Site. We used the Airborne Terrain Mapper (ATM), operated by NASA's Wallops Flight Facility to obtain DEMs with 1 m spacing and 10 cm vertical errors of 4 main craters and many other craters and collapse pits. The main craters that were mapped are Sedan, Scooter, Schooner, and Danny Boy. The 370 m diameter Sedan crater, located on Yucca Flat, is the largest and freshest explosion crater on Earth that was formed under conditions similar to hypervelocity impact cratering. As such, it is effectively pristine, having been formed in 1962 as a result of a controlled detonation of a 100 kiloton thermonuclear device, buried at the appropriate equivalent depth of burst required to make a simple crater. Sedan was formed in alluvium of mixed lithology and subsequently studied using a variety of field-based methods. Nearby secondary craters were also formed at the time and were also mapped by ATM. Adjacent to Sedan and also in alluvium is Scooter, about 90 m in diameter and formed by a high-explosive event. Schooner (240 m) and Danny Boy (80 m) craters were also important targets for ATM as they were excavated in hard basalt and therefore have much rougher ejecta. This will allow study of ejecta patterns in hard rock as well as engineering tests of crater and rock avoidance and rover trafficability. In addition to the high resolution DEMs, crater geometric characteristics, RMS roughness maps, and other higher-order derived data products will be generated using these data. These will provide constraints for models of landing hazards on Mars and for rover trafficability. Other planned studies will include ejecta size-frequency distribution at the resolution of the DEM and at finer resolution through air photography and field measurements, correlation of ejecta size and composition with radar and visible-thermal IR remote sensing signatures, and comparison of these results with similar measurements of Mars. The final DEMs, ancillary data sets, and derived data products will be made available to the community.

  16. Synthesis of rainfall time series in a high temporal resolution

    NASA Astrophysics Data System (ADS)

    Callau Poduje, Ana Claudia; Haberlandt, Uwe

    2014-05-01

    In order to optimize the design and operation of urban drainage systems, long and continuous rain series in a high temporal resolution are essential. As the length of the rainfall records is often short, particularly the data available with the temporal and regional resolutions required for urban hydrology, it is necessary to find some numerical representation of the precipitation phenomenon to generate long synthetic rainfall series. An Alternating Renewal Model (ARM) is applied for this purpose, which consists of two structures: external and internal. The former is the sequence of wet and dry spells, described by their durations which are simulated stochastically. The internal structure is characterized by the amount of rain corresponding to each wet spell and its distribution within the spell. A multivariate frequency analysis is applied to analyze the internal structure of the wet spells and to generate synthetic events. The stochastic time series must reproduce the statistical characteristics of observed high resolution precipitation measurements used to generate them. The spatio-temporal interdependencies between stations are addressed by resampling the continuous synthetic series based on the Simulated Annealing (SA) procedure. The state of Lower-Saxony and surrounding areas, located in the north-west of Germany is used to develop the ARM. A total of 26 rainfall stations with high temporal resolution records, i.e. rainfall data every 5 minutes, are used to define the events, find the most suitable probability distributions, calibrate the corresponding parameters, simulate long synthetic series and evaluate the results. The length of the available data ranges from 10 to 20 years. The rainfall series involved in the different steps of calculation are compared using a rainfall-runoff model to simulate the runoff behavior in urban areas. The EPA Storm Water Management Model (SWMM) is applied for this evaluation. The results show a good representation of the seasonal variability, good performance in reproducing the sample statistics of the rainfall characteristics, whereas the extreme value statistics show some inconsistencies in some of the analyzed cases. The model presented here can be used in ungauged regions through regionalization of the model parameters. Key words: stochastic rainfall model, rainfall characteristics, copula, continuous simulation

  17. Special issue on high-resolution optical imaging

    NASA Astrophysics Data System (ADS)

    Smith, Peter J. S.; Davis, Ilan; Galbraith, Catherine G.; Stemmer, Andreas

    2013-09-01

    The pace of development in the field of advanced microscopy is truly breath-taking, and is leading to major breakthroughs in our understanding of molecular machines and cell function. This special issue of Journal of Optics draws attention to a number of interesting approaches, ranging from fluorescence and imaging of unlabelled cells, to computational methods, all of which are describing the ever increasing detail of the dynamic behaviour of molecules in the living cell. This is a field which traditionally, and currently, demonstrates a marvellous interplay between the disciplines of physics, chemistry and biology, where apparent boundaries to resolution dissolve and living cells are viewed in ever more clarity. It is fertile ground for those interested in optics and non-conventional imaging to contribute high-impact outputs in the fields of cell biology and biomedicine. The series of articles presented here has been selected to demonstrate this interdisciplinarity and to encourage all those with a background in the physical sciences to 'dip their toes' into the exciting and dynamic discoveries surrounding cell function. Although single molecule super-resolution microscopy is commercially available, specimen preparation and interpretation of single molecule data remain a major challenge for scientists wanting to adopt the techniques. The paper by Allen and Davidson [1] provides a much needed detailed introduction to the practical aspects of stochastic optical reconstruction microscopy, including sample preparation, image acquisition and image analysis, as well as a brief description of the different variants of single molecule localization microscopy. Since super-resolution microscopy is no longer restricted to three-dimensional imaging of fixed samples, the review by Fiolka [2] is a timely introduction to techniques that have been successfully applied to four-dimensional live cell super-resolution microscopy. The combination of multiple high-resolution techniques, such as the combination of light sheet and structured illumination microscopy (SIM), which efficiently utilize photon budget and avoid illuminating regions of the specimen not currently being imaged, hold the greatest promise for future biological applications. Therefore, the combined setup for SIM and single molecule localization microscopy (SMLM) described by Rossberger et al [3] will be very helpful and stimulating to advanced microscopists in further modifying their setups. The SIM image helps in identifying artefacts in SMLM reconstruction, e.g. when two active fluorophores are close together and get rejected as 'out-of-focus'. This combined setup is another way to facilitate imaging live samples. The article by Thomas et al [4] presents another advance for biological super-resolution imaging with a new approach to reconstruct optically sectioned images using structured illumination. The method produces images with higher spatial resolution and greater signal to noise compared to existing approaches. This algorithm demonstrates great promise for reconstructing biological images where the signal intensities are inherently lower. Shevchuk et al [5] present a non-optic near field approach to imaging with a review of scanning ion-conductance microscopy. This is a powerful alternative approach for examining the surface dynamics of living cells including exo and endocytosis, unlabelled, and at the level of the single event. Here they present the first data on combining this approach with fluorescence confocal microscopy—adding that extra dimension. Different approaches to label-free live cell imaging are presented in the papers by Patel et al [6], Mehta and Oldenbourg [7], as well as Rogers and Zheludev [8]. All three papers bring home the excitement of looking at live cell dynamics without reporters—Patel et al [6] review both the potential of coherent anti-Stokes Raman scattering and biological applications, where specific biomolecules are detected on the basis of their biophysical properties. Polarized light microscopy as presented by Mehta and Oldenbou

  18. Theme issue "High Resolution Earth Imaging for Geospatial Information"

    NASA Astrophysics Data System (ADS)

    Heipke, Christian; Soergel, Uwe; Rottensteiner, Franz; Jutzi, Boris

    2015-02-01

    Earth imaging from air and space has undergone major changes over the last decade. Examples of new and significant developments comprise the development and constant improvement of digital aerial cameras, multiple-echo and full-waveform laser scanners and the appearance of geosensor networks and unconventional platforms, most notably unmanned aircraft systems (UAS), sometimes called unmanned aerial vehicles (UAV) or remotely piloted aircraft systems (RPAS), and the ever increasing number of high-resolution and hyperspectral optical and SAR satellite sensors, small satellites and satellite constellations, which allow for both, a continued availability of satellite data over long periods of time, and a very short revisit time for any location on the globe. To give few examples: the latest Landsat satellite, appropriately called the Landsat data continuity mission or LDCM was launched on February 2013, continuing the Landsat mission which began back in 1972; during 2013 and 2014 France has put the SPOT 6 and 7 twin satellites into orbit, extending the history of high resolution space images, which started in 1986; and in April 2014 the European Space Agency (ESA) successfully launched the Sentinel 1A satellite with a synthetic aperture radar (SAR) sensor, the first of a fleet of different sensors that will be sent into space in the coming years. Sentinel 1A together with its twin system Sentinel 1B, to be launched in 2016, will continue the tremendous success story of ESA's C band SAR satellite activities dating back to 1991. Like the predecessors ERS 1, ERS 2, and Envisat ASAR, the Sentinel 1 systems are designed to cover the entire land mass with medium resolution, the repeat cycle is 12 days for Sentinel 1A alone and will even drop to six days as soon as both satellites are operational.

  19. High Resolution Atmospheric Modeling for Wind Energy Applications

    SciTech Connect

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

    2010-03-18

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

  20. The high-resolution time-of-flight spectrometer TOFTOF

    NASA Astrophysics Data System (ADS)

    Unruh, Tobias; Neuhaus, Jürgen; Petry, Winfried

    2007-10-01

    The TOFTOF spectrometer is a multi-disc chopper time-of-flight spectrometer for cold neutrons at the research neutron source Heinz Maier-Leibnitz (FRM II). After five reactor cycles of routine operation the characteristics of the instrument are reported in this article. The spectrometer features an excellent signal to background ratio due to its remote position in the neutron guide hall, an elaborated shielding concept and an s-shaped curved primary neutron guide which acts i.a. as a neutron velocity filter. The spectrometer is fed with neutrons from the undermoderated cold neutron source of the FRM II leading to a total neutron flux of ˜1010n/cm2/s in the continuous white beam at the sample position distributed over a continuous and particularly broad wavelength spectrum. A high energy resolution is achieved by the use of high speed chopper discs made of carbon-fiber-reinforced plastic. In the combination of intensity, resolution and signal to background ratio the spectrometer offers new scientific prospects in the fields of inelastic and quasielastic neutron scattering.

  1. Modeling Spatial Dependencies in High-Resolution Overhead Imagery

    SciTech Connect

    Cheriyadat, Anil M; Bright, Eddie A; Vatsavai, Raju

    2011-01-01

    Human settlement regions with different physical and socio-economic attributes exhibit unique spatial characteristics that are often illustrated in high-resolution overhead imageries. For example- size, shape and spatial arrangements of man-made structures are key attributes that vary with respect to the socioeconomic profile of the neighborhood. Successfully modeling these attributes is crucial in developing advanced image understanding systems for interpreting complex aerial scenes. In this paper we present three different approaches to model the spatial context in the overhead imagery. First, we show that the frequency domain of the image can be used to model the spatial context [1]. The shape of the spectral energy contours characterize the scene context and can be exploited as global features. Secondly, we explore a discriminative framework based on the Conditional Random Fields (CRF) [2] to model the spatial context in the overhead imagery. The features derived from the edge orientation distribution calculated for a neighborhood and the associated class labels are used as input features to model the spatial context. Our third approach is based on grouping spatially connected pixels based on the low-level edge primitives to form support-regions [3]. The statistical parameters generated from the support-region feature distributions characterize different geospatial neighborhoods. We apply our approaches on high-resolution overhead imageries. We show that proposed approaches characterize the spatial context in overhead imageries.

  2. High-Resolution Displacement Sensor Using a SQUID Array Amplifier

    NASA Technical Reports Server (NTRS)

    Chui, Talso; Penanen, Konstantin; Barmatz, M.; Paik, Ho Jung

    2004-01-01

    Improvement in the measurement of displacement has profound implications for both exploration technologies and fundamental physics. For planetary exploration, the new SQUID-based capacitive displacement sensor will enable a more sensitive gravity gradiometer for mapping the interior of planets and moons. A new concept of a superfluid clock to be reported by Penanen and Chui at this workshop is also based on a high-resolution displacement sensor. Examples of high-impact physics projects that can benefit from a better displacement sensor are: detection of gravitational waves, test of the equivalence principle, search for the postulated "axion" particle, and test of the inverse square law of gravity. We describe the concept of a new displacement sensor that makes use of a recent development in the Superconducting Quantum Interference Device (SQUID) technology. The SQUID array amplifier, invented by Welty and Martinis (IEEE Trans. Appl. Superconductivity 3, 2605, 1993), has about the same noise as a conventional SQUID; however, it can work at a much higher frequency of up to 5 MHz. We explain how the higher bandwidth can be translated into higher resolution using a bridge-balancing scheme that can simultaneously balance out both the carrier signal at the bridge output and the electrostatic force acting on the test mass.

  3. High resolution multi-temperature sensors for biomedical application.

    PubMed

    Urban, G; Jachimowicz, A; Kohl, F; Kuttner, H; Olcaytug, F; Goiser, P; Lindner, K; Pockberger, H; Prohaska, O; Schönauer, M

    1990-01-01

    A temperature sensor array was designed in order to study local temperature variations and temperature gradients in biological samples. The sensor probe was inserted in the optical cortex of rabbits in order to study temperature changes during normal brain activity as well as under artificial ventilation conditions. Temperature sensitive areas of 0.14 mm x 0.1 mm are arranged in a row with interdistances of 0.4 mm yielding high spatial resolution. A temperature resolution of 0.1 mK and a 90% response time of maximum 3 milliseconds was obtained utilizing the high temperature dependence of 2%/K of the conductivity of vacuum evaporated germanium films. The sensor is passivated by a 1 micron thick PECVD-silicon nitride layer and can be placed on glass-, alumina- and polymer substrates. For brain tissue studies, in order to minimize tissue damage the temperature sensors were placed on a 0.1 mm thick needle-shaped glass substrate. A sensor element mounted on a glass substrate and immersed in water showed a self heating of less than 5 mK due to the applied measurement current of 2.1 microA. PMID:2146481

  4. High Resolution Visualizations of Lake Floor Structures in Lake Superior.

    NASA Astrophysics Data System (ADS)

    Wattrus, N. J.; Cartwright, J.; Rausch, D.

    2004-12-01

    High resolution visualizations of acoustic data collected in Lake Superior reveals that the lake floor is not a featureless basin, rather that it possesses fine-scale features. These are the "fingerprints" of processes that have shaped the development of the basin. Some of these are no longer active while others continue today. Some of the most interesting lake floor features observed in Lake Superior are the ring shaped depressions that are widely developed in areas below wave-base, where fine-grained sediments are preserved. These features are typically 100-300m across, 25-50m wide and up to 5m deep. They occur both as interconnected clusters and also as isolated structures. Multibeam imagery reveals that rings are composed of chains of pockmarks. They are believed to be the product of dewatering of the Holocene glacio-lacustrine clays that compose the lake floor. High resolution seismic reflection data, collected with a 28 kHz echosounder, shows evidence of a layer bound system of small extensional faults that is widely developed in the very fine grained glacio-lacustrine clays. They exhibit a polygonal plan form geometry with a large range of strikes and oblique to orthogonal intersection geometries. They have been interpreted to be an immature polygonal fault system. Discrete horizons exhibiting lateral variations in thickness and zones of acoustic blanking are interpreted to be evidence of post-depositional remobilization of the lake floor sediments.

  5. High-resolution computed tomography reconstructions of invertebrate burrow systems

    PubMed Central

    Hale, Rachel; Boardman, Richard; Mavrogordato, Mark N.; Sinclair, Ian; Tolhurst, Trevor J.; Solan, Martin

    2015-01-01

    The architecture of biogenic structures can be highly influential in determining species contributions to major soil and sediment processes, but detailed 3-D characterisations are rare and descriptors of form and complexity are lacking. Here we provide replicate high-resolution micro-focus computed tomography (?-CT) data for the complete burrow systems of three co-occurring, but functionally contrasting, sediment-dwelling inter-tidal invertebrates assembled alone, and in combination, in representative model aquaria. These data (?2,000 raw image slices aquarium?1, isotropic voxel resolution, 81??m) provide reference models that can be used for the development of novel structural analysis routines that will be of value within the fields of ecology, pedology, geomorphology, palaeobiology, ichnology and mechanical engineering. We also envisage opportunity for those investigating transport networks, vascular systems, plant rooting systems, neuron connectivity patterns, or those developing image analysis or statistics related to pattern or shape recognition. The dataset will allow investigators to develop or test novel methodology and ideas without the need to generate a complete three-dimensional computation of exemplar architecture. PMID:26396743

  6. Compressed sensing technique for high-resolution radar imaging

    NASA Astrophysics Data System (ADS)

    Yoon, Yeo-Sun; Amin, Moeness G.

    2008-04-01

    Compressed sensing (CS) has recently attracted much interest because of its important offerings and versatility. High-resolution radar imaging applications such as through-the-wall radar (TWR) imaging or inverse synthetic aperture radar (ISAR) are two key application areas that can greatly benefit from CS. Both applications require probing targets using radar signals with large bandwidth for collecting, and then processing, a large number of data samples for achieving high resolution imaging. These applications are also characterized by sparse imaging where targets of interest are few and have larger cross-section than clutter objects. Reducing the number of samples without compromising the imaging quality reduces the acquisition time and saves signal bandwidth. This reduction is important when surveillance is performed within small time window and when targets are required to remain stationary without translation or rotation motions, to avoid blurring and smearing of images. In this paper, we discuss applicability of compressed sensing to indoor radar imaging, using synthesized TWR data.

  7. Optimized generation of high resolution breast anthropomorphic software phantoms

    SciTech Connect

    Pokrajac, David D.; Maidment, Andrew D. A.; Bakic, Predrag R.

    2012-04-15

    Purpose: The authors present an efficient method for generating anthropomorphic software breast phantoms with high spatial resolution. Employing the same region growing principles as in their previous algorithm for breast anatomy simulation, the present method has been optimized for computational complexity to allow for fast generation of the large number of phantoms required in virtual clinical trials of breast imaging. Methods: The new breast anatomy simulation method performs a direct calculation of the Cooper's ligaments (i.e., the borders between simulated adipose compartments). The calculation corresponds to quadratic decision boundaries of a maximum a posteriori classifier. The method is multiscale due to the use of octree-based recursive partitioning of the phantom volume. The method also provides user-control of the thickness of the simulated Cooper's ligaments and skin. Results: Using the proposed method, the authors have generated phantoms with voxel size in the range of (25-1000 {mu}m){sup 3}/voxel. The power regression of the simulation time as a function of the reciprocal voxel size yielded a log-log slope of 1.95 (compared to a slope of 4.53 of our previous region growing algorithm). Conclusions: A new algorithm for computer simulation of breast anatomy has been proposed that allows for fast generation of high resolution anthropomorphic software phantoms.

  8. High-resolution time-frequency distributions for fall detection

    NASA Astrophysics Data System (ADS)

    Amin, Moeness G.; Zhang, Yimin D.; Boashash, Boualem

    2015-05-01

    In this paper, we examine the role of high-resolution time-frequency distributions (TFDs) of radar micro-Doppler signatures for fall detection. The work supports the recent and rising interest in using emerging radar technology for elderly care and assisted living. Spectrograms have been the de facto joint-variable signal representation, depicting the signal power in both time and frequency. Although there have been major advances in designing quadratic TFDs which are superior to spectrograms in terms of detailing the local signal behavior, the contributions of these distributions in the area of human motion classifications and their offerings in enhanced feature extractions have not yet been properly evaluated. The main purpose of this paper is to show the effect of using high-resolution TFD kernels, in lieu of spectrogram, on fall detection. We focus on the extended modified B-distribution (EMBD) and exploit the level of details it provides as compared with the coarse and smoothed time-frequency signatures offered by spectrograms.

  9. A High Resolution Survey of the Disk of M31

    NASA Technical Reports Server (NTRS)

    Primini, Francis A.

    2000-01-01

    This report describes research activities funded for SAO Proposal P3481-5-95, "Monitoring the Center of M31". Related activities for SAO Proposal P3486- 5-95, "A High-Resolution Survey of the Disk of M31" are also described. The research involved the data analysis and interpretation of eleven separate ROSAT (Roentgen Satellite) HRI (High Resolution Imager) observations of the center and inner disk of M31, obtained between July, 1990 and January, 1997. A log of the individual data sets is given. All proposed observations were successfully carried out by the ROSAT Observatory, and standard data products were successfully generated for each observation. There were two basic thrusts to the research. First, we wished to monitor the x-ray source nearest the nucleus of M31, to search for anti-correlated radio/x-ray variability predicted by theoretical models for the source. We would also be able to assess the degree and range of variability of other x-ray sources in the central bulge of M31 and to estimate rates of transients. Secondly, we wished to survey the entire inner disk of M31, and in particular the region covered by the recent MIT wide-band and narrow-band surveys to identify x-ray counterparts to supernova remnants, OB associations, and young blue stars, in areas in which the ROSAT PSPC survey was confused. Results of each research project are summarized. Papers describing the results in more detail are in preparation.

  10. Very High Resolution Image of Icy Cliffs on Europa

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This image, taken by the camera onboard NASA's Galileo spacecraft, is a very high resolution view of the Conamara Chaos region on Jupiter's moon Europa. It shows an area where icy plates have been broken apart and moved around laterally. The top of this image is dominated by corrugated plateaus ending in icy cliffs over a hundred meters (a few hundred feet) high. Debris piled at the base of the cliffs can be resolved down to blocks the size of a house. A fracture that runs horizontally across and just below the center of the Europa image is about the width of a freeway.

    North is to the top right of the image, and the sun illuminates the surface from the east. The image is centered at approximately 9 degrees north latitude and 274 degrees west longitude. The image covers an area approximately 1.7 kilometers by 4 kilometers (1 mile by 2.5 miles). The resolution is 9 meters (30 feet) per picture element. This image was taken on December 16, 1997 at a range of 900 kilometers (540 miles) by Galileo's solid state imaging system.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  11. High resolution energy loss research: Si compounds and ceramics

    SciTech Connect

    Carpenter, R.W.; Lin, S.H.

    1992-01-01

    Our current investigation of the structure and chemistry of whisker/matrix interfaces and matrix grain boundaries in SiC whisker reinforced Si{sub 3}N{sub 4} composites has been completed. We examined these interfaces and boundaries in four composites whose starting materials and processing were identical except for the SiC whiskers themselves, which were from four different sources: American matrix, Nikkei, Huber and Tokai. Thus, differences in interfaces among the composites are attributable to differences in the whiskers. The results showed that oxygen-rich amorphous interfacial layers were discontinuous in all whisker/matrix interfaces and continuous in all matrix grain boundaries. Further, we used position-resolved high spatial resolution electron energy loss spectroscopy to show that the chemical interface width'' is much wider than the geometric or structural interface width'' at both types of interfaces in all four composites. The geometric interface widths were determined from high resolution transmission electron microscope images of edge-on interfaces.

  12. Limiting liability via high-resolution image processing

    NASA Astrophysics Data System (ADS)

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

    1997-01-01

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

  13. Detecting Climate Signatures with High Spectral Resolution Infrared Satellite Measurements

    NASA Astrophysics Data System (ADS)

    Deslover, D. H.; Tobin, D.; Knuteson, R. O.; Revercomb, H. E.

    2013-12-01

    Upwelling atmospheric infrared radiances can be accurately monitored from high spectral resolution satellite observations. The high spectral resolution nature of these measurements affords the ability to track various climate relevant parameters such as window channels sensitive to surface temperature and clouds, channels with higher sensitivity to trace gases including CO2, CH4, SO2, HNO3, as well as channels sensitive only to upper tropospheric or lower stratospheric temperature. NASA's Atmospheric Infrared Sounder (AIRS) provides a data record that extends from its 2002 launch to the present. The Infrared Atmospheric Sounding Interferometer (IASI) onboard Metop- (A launched in 2006, B in 2012), as well as the Joint Polar Satellite System (JPSS) Cross-track Infrared Sounder (CrIS) launched in 2011, complement this data record. Future infrared sounders with similar capabilities will augment these measurements into the distant future. We have created a global data set from the aforementioned satellite observations. Our analysis yields a channel dependent approach that can be further constrained in terms of diurnal, seasonal and geographic limits, with measurement accuracies of better than a few tenths of degree Kelvin. In this study, we have applied this concept to obtain a better understanding of long-term stratospheric temperature trends. We will present a survey of temperature trends for spectral channels that were chosen to be sensitive to stratospheric emission. Results will be shown for tropical, mid-latitude and polar stratospheric observations.

  14. Evaluation of a high resolution silicon PET insert module

    NASA Astrophysics Data System (ADS)

    Grkovski, Milan; Brzezinski, Karol; Cindro, Vladimir; Clinthorne, Neal H.; Kagan, Harris; Lacasta, Carlos; Mikuž, Marko; Solaz, Carles; Studen, Andrej; Weilhammer, Peter; Žontar, Dejan

    2015-07-01

    Conventional PET systems can be augmented with additional detectors placed in close proximity of the region of interest. We developed a high resolution PET insert module to evaluate the added benefit of such a combination. The insert module consists of two back-to-back 1 mm thick silicon sensors, each segmented into 1040 1 mm2 pads arranged in a 40 by 26 array. A set of 16 VATAGP7.1 ASICs and a custom assembled data acquisition board were used to read out the signal from the insert module. Data were acquired in slice (2D) geometry with a Jaszczak phantom (rod diameters of 1.2-4.8 mm) filled with 18F-FDG and the images were reconstructed with ML-EM method. Both data with full and limited angular coverage from the insert module were considered and three types of coincidence events were combined. The ratio of high-resolution data that substantially improves quality of the reconstructed image for the region near the surface of the insert module was estimated to be about 4%. Results from our previous studies suggest that such ratio could be achieved at a moderate technological expense by using an equivalent of two insert modules (an effective sensor thickness of 4 mm).

  15. High-resolution computed tomography reconstructions of invertebrate burrow systems.

    PubMed

    Hale, Rachel; Boardman, Richard; Mavrogordato, Mark N; Sinclair, Ian; Tolhurst, Trevor J; Solan, Martin

    2015-01-01

    The architecture of biogenic structures can be highly influential in determining species contributions to major soil and sediment processes, but detailed 3-D characterisations are rare and descriptors of form and complexity are lacking. Here we provide replicate high-resolution micro-focus computed tomography (?-CT) data for the complete burrow systems of three co-occurring, but functionally contrasting, sediment-dwelling inter-tidal invertebrates assembled alone, and in combination, in representative model aquaria. These data (? 2,000 raw image slices aquarium(-1), isotropic voxel resolution, 81 ?m) provide reference models that can be used for the development of novel structural analysis routines that will be of value within the fields of ecology, pedology, geomorphology, palaeobiology, ichnology and mechanical engineering. We also envisage opportunity for those investigating transport networks, vascular systems, plant rooting systems, neuron connectivity patterns, or those developing image analysis or statistics related to pattern or shape recognition. The dataset will allow investigators to develop or test novel methodology and ideas without the need to generate a complete three-dimensional computation of exemplar architecture. PMID:26396743

  16. Low-dose high-resolution CT of lung parenchyma

    SciTech Connect

    Zwirewich, C.V.; Mayo, J.R.; Mueller, N.L. )

    1991-08-01

    To evaluate the efficacy of low-dose high-resolution computed tomography (HRCT) in the assessment of lung parenchyma, three observers reviewed the scans of 31 patients. The 1.5-mm-collimation, 2-second, 120-kVp scans were obtained at 20 and 200 mA at selected identical levels in the chest. The observers evaluated the visualization of normal pulmonary anatomy, various parenchymal abnormalities and their distribution, and artifacts. The low-dose and conventional scans were equivalent in the evaluation of vessels, lobar and segmental bronchi, and anatomy of secondary pulmonary lobules, and in characterizing the extent and distribution of reticulation, honeycomb cysts, and thickened interlobular septa. The low-dose technique failed to demonstrate ground-glass opacity in two of 10 cases (20%) and emphysema in one of nine cases (11%), in which they were evident but subtle on the high-dose scans. These differences were not statistically significant. Linear streak artifact was more prominent on images acquired with the low-dose technique, but the two techniques were judged equally diagnostic in 97% of cases. The authors conclude that HRCT images acquired at 20 mA yield anatomic information equivalent to that obtained with 200-mA scans in the majority of patients, without significant loss of spatial resolution or image degradation due to linear streak artifact.

  17. High-resolution mid-infrared imaging for disease diagnosis

    NASA Astrophysics Data System (ADS)

    Walsh, Michael J.; Mayerich, David; Kajdacsy-Balla, Andre; Bhargava, Rohit

    2012-01-01

    Histopathology is the gold standard for disease diagnosis; however it is subject to a number of limitations. Fourier Transform infrared (FT-IR) spectroscopic imaging can be used to derive chemical images from tissues based on their inherent molecular composition, thereby eliminating the use of dyes and stains. FT-IR imaging represents a novel, emerging approach that can allow for accurate cell type identification which is competitive with conventional histopathological approaches and may alleviate a number of the limitations associated with current techniques. Traditionally, this approach has involved in a loss of image detail due to the sub-optimal and, compared to optical microscopy, coarse pixel size in instruments. Recent advances in high-resolution FT-IR imaging have allowed for the identification and chemical characterization of cell types and tissue structures which were previously not discernible. Here we report on the visualization of several histologic details using high-resolution IR imaging that may be critical for tissue histology and disease diagnosis.

  18. High-Resolution Mars Camera Test Image of Moon (Infrared)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This crescent view of Earth's Moon in infrared wavelengths comes from a camera test by NASA's Mars Reconnaissance Orbiter spacecraft on its way to Mars. The mission's High Resolution Imaging Science Experiment camera took the image on Sept. 8, 2005, while at a distance of about 10 million kilometers (6 million miles) from the Moon. The dark feature on the right is Mare Crisium. From that distance, the Moon would appear as a star-like point of light to the unaided eye. The test verified the camera's focusing capability and provided an opportunity for calibration. The spacecraft's Context Camera and Optical Navigation Camera also performed as expected during the test.

    The Mars Reconnaissance Orbiter, launched on Aug. 12, 2005, is on course to reach Mars on March 10, 2006. After gradually adjusting the shape of its orbit for half a year, it will begin its primary science phase in November 2006. From the mission's planned science orbit about 300 kilometers (186 miles) above the surface of Mars, the high resolution camera will be able to discern features as small as one meter or yard across.

  19. A GUINIER CAMERA FOR SR POWDER DIFFRACTION: HIGH RESOLUTION AND HIGH THROUGHPUT.

    SciTech Connect

    SIDDONS,D.P.; HULBERT, S.L.; STEPHENS, P.W.

    2006-05-28

    The paper describe a new powder diffraction instrument for synchrotron radiation sources which combines the high throughput of a position-sensitive detector system with the high resolution normally only provided by a crystal analyzer. It uses the Guinier geometry which is traditionally used with an x-ray tube source. This geometry adapts well to the synchrotron source, provided proper beam conditioning is applied. The high brightness of the SR source allows a high resolution to be achieved. When combined with a photon-counting silicon microstrip detector array, the system becomes a powerful instrument for radiation-sensitive samples or time-dependent phase transition studies.

  20. High Resolution Ionospheric Mapping Using Spaceborne Synthetic Aperture Radars

    NASA Astrophysics Data System (ADS)

    Meyer, F. J.; Chotoo, K.; Roth, A. P.

    2012-12-01

    Spaceborne Synthetic Aperture Radars (SARs) are imaging radar systems that utilize the Doppler history of signals acquired during satellite flyby to produce high resolution images of the Earth. With modern sensors, operating at frequencies between about 1 GHz (L-band) and 10 GHz (X-band), radar images with resolutions in the meter to sub-meter range can be produced. The presence of the ionosphere is significantly affecting the propagation properties of the microwave signals transmitted by these systems, causing distortions of signal polarization and phase. These distortions can lead to a wide range of imaging artifacts including image range shifts, interferometric phase biases, loss of image focus, change of image geometry, and Faraday rotation. While these artifacts are particularly pronounced at L-band, they are still observable in data acquired at C- or even X-band. In recent years, a wealth of methods for measuring and correcting ionospheric influence were developed. These methods are self-calibration procedures that measure ionosphere-induced distortions to infer the two-dimensional TEC maps that affected the data. These TEC maps are then removed from the data to produce high performance SAR images. Besides being effective in correcting SAR observations, these self-calibration methods are producing high quality TEC information with sub-TECU sensitivity and sub-kilometer spatial resolution. The intent of this paper is to utilize SAR-derived ionospheric information and make the case for SAR as a data source for ionospheric research. After a short summary of ionosphere-induced distortions, the concept of TEC estimation from SAR is introduced. Here, the current state-of-the-art of ionospheric TEC estimation is presented, including Faraday rotation-based, interferometric, correlation-based, and autofocus-based techniques. For every approach, performance numbers are given that quantify the achievable TEC estimation accuracy as a function of system parameters, scene properties, and (if applicable) geographic location. Three case studies will be presented to highlight the type and quality of ionospheric information that can be retrieved: (1) The high spatial resolution of SAR-derived TEC maps is emphasized in a case study that focuses on high resolution mapping of aurora arcs in central Alaska. Here, TEC enhancements associated with aurora activity are mapped and compared to reference observations from sky cameras and GPS; (2) observations of mid-latitudal traveling ionospheric disturbances are shown to showcase the accuracy of SAR-derived TEC maps. Several SAR-based TEC mapping methods are compared to highlight their respective advantages and disadvantages regarding processing complexity and estimation accuracy; (3) a third example focuses on analyzing post-sunset scintillation phenomena in equatorial regions. SAR is used to assess the frequency of occurrence of scintillation and analyze their associated power spectra. To conclude the paper, the temporal and spatial sampling of the ionosphere provided by the fleet of current and future spaceborne SAR sensors is analyzed to provide an assessment of the global ionospheric mapping capabilities of SAR.

  1. Automated electrostatic probe device of high resolution and accuracy

    SciTech Connect

    Aleiferis, S.

    2014-12-15

    In this work, an automated apparatus for driving single electrostatic probes and acquiring the plasma-related data has been designed and fabricated. The voltage range of the present system is ±110 V with an adjustable voltage step as low as 3 mV. Voltage and current measurements are carried out with high resolution and high accuracy circuits, both based on 16 bit analog-to-digital converters. The code embedded in a micro-controller, schedules the operation of the device and transfers the experimental data to a personal computer. The modular design of the system makes possible its modification and thus increases its adaptability to different plasma setups. Finally, the reliable operation of the entire device is confirmed by tests in Electron Cyclotron Resonance plasma.

  2. High-resolution eye tracking using V1 neuron activity

    PubMed Central

    McFarland, James M.; Bondy, Adrian G.; Cumming, Bruce G.; Butts, Daniel A.

    2014-01-01

    Studies of high-acuity visual cortical processing have been limited by the inability to track eye position with sufficient accuracy to precisely reconstruct the visual stimulus on the retina. As a result, studies on primary visual cortex (V1) have been performed almost entirely on neurons outside the high-resolution central portion of the visual field (the fovea). Here we describe a procedure for inferring eye position using multi-electrode array recordings from V1 coupled with nonlinear stimulus processing models. We show that this method can be used to infer eye position with one arc-minute accuracy – significantly better than conventional techniques. This allows for analysis of foveal stimulus processing, and provides a means to correct for eye-movement induced biases present even outside the fovea. This method could thus reveal critical insights into the role of eye movements in cortical coding, as well as their contribution to measures of cortical variability. PMID:25197783

  3. High resolution ship hydrodynamics simulations in open source environment

    NASA Astrophysics Data System (ADS)

    Del Puppo, Norman

    2014-12-01

    The numerical simulation of wake and free-surface flow around ships is a complex topic that involves multiple tasks: the generation of an optimal computational grid and the development of numerical algorithms capable to predict the flow field around a hull. In this paper, a numerical framework is developed aimed at high-resolution CFD simulations of turbulent, free-surface flows around ship hulls. The framework consists in the concatenation of "tools", partly available in the open-source finite volume library OpenFOAM®. A novel, flexible mesh-generation algorithm is presented, capable of producing high-quality computational grids for free-surface ship hydrodynamics. The numerical frame work is used to solve some benchmark problems, providing results that are in excellent agreement with the experimental measures.

  4. Airborne high spectral resolution lidar for profiling aerosol optical properties.

    PubMed

    Hair, Johnathan W; Hostetler, Chris A; Cook, Anthony L; Harper, David B; Ferrare, Richard A; Mack, Terry L; Welch, Wayne; Isquierdo, Luis Ramos; Hovis, Floyd E

    2008-12-20

    A compact, highly robust airborne High Spectral Resolution Lidar (HSRL) that provides measurements of aerosol backscatter and extinction coefficients and aerosol depolarization at two wavelengths has been developed, tested, and deployed on nine field experiments (over 650 flight hours). A unique and advantageous design element of the HSRL system is the ability to radiometrically calibrate the instrument internally, eliminating any reliance on vicarious calibration from atmospheric targets for which aerosol loading must be estimated. This paper discusses the design of the airborne HSRL, the internal calibration and accuracy of the instrument, data products produced, and observations and calibration data from the first two field missions: the Joint Intercontinental Chemical Transport Experiment--Phase B (INTEX-B)/Megacity Aerosol Experiment--Mexico City (MAX-Mex)/Megacities Impacts on Regional and Global Environment (MILAGRO) field mission (hereafter MILAGRO) and the Gulf of Mexico Atmospheric Composition and Climate Study/Texas Air Quality Study II (hereafter GoMACCS/TexAQS II). PMID:19104525

  5. High Resolution Seismic Reflection Survey for Coal Mine: fault detection

    NASA Astrophysics Data System (ADS)

    Khukhuudei, M.; Khukhuudei, U.

    2014-12-01

    High Resolution Seismic Reflection (HRSR) methods will become a more important tool to help unravel structures hosting mineral deposits at great depth for mine planning and exploration. Modern coal mining requires certainly about geological faults and structural features. This paper focuses on 2D Seismic section mapping results from an "Zeegt" lignite coal mine in the "Mongol Altai" coal basin, which required the establishment of major structure for faults and basement. HRSR method was able to detect subsurface faults associated with the major fault system. We have used numerical modeling in an ideal, noise free environment with homogenous layering to detect of faults. In a coal mining setting where the seismic velocity of the high ranges from 3000m/s to 3600m/s and the dominant seismic frequency is 100Hz, available to locate faults with a throw of 4-5m. Faults with displacements as seam thickness detected down to several hundred meter beneath the surface.

  6. Thermal design concept for a high resolution UV spectrometer

    NASA Technical Reports Server (NTRS)

    Caruso, P.; Stipandic, E.

    1979-01-01

    The thermal design concept described has been developed for the High Resolution UV Spectrometer/Polarimeter to be flown on the Solar Maximum Mission. Based on experience gained from a similar Orbiting Solar Observatory mission payload, it has been recognized that initial protection of the optical elements, contamination control, reduction of scattered light, tight bulk temperature, and gradient constraints are key elements that must be accommodated in any thermal control concept for this class of instrument. Salient features of the design include: (1) a telescope door providing contamination protection of an aplanatic Gregorian telescope; (2) a rastering system for the secondary mirror; (3) a unique solar heat absorbing device; (4) heat pipes and special radiators; (5) heaters for active temperature control and optics contamination protection; and (6) high precision platinum resistance thermometers. Viability of the design concept has been established by extensive thermal analysis and some subsystem testing. A summary of analytical and test results is included.

  7. High Resolution Numerical Simulation of Detonation Diffraction of Condensed Explosives

    NASA Astrophysics Data System (ADS)

    Wang, Cheng

    2015-06-01

    In this paper, A high resolution large scale parallel computation software is developed based on positivity preserving for finite difference WENO method, high order boundary treatment method, multi-medium interface treatment. A new method for deriving the partial derivative of pressure in respect of every conserved quantity is proposed. The software can simulate detonation diffraction problems for two-dimensional condensed explosives. The numerical simulation results revealed the forming reasons of the low-pressure region, the low-density region, the ``vortex'' region and the ``dead zone'' in the vicinity of the corner. Furthermore, it demonstrated that the retonation will generate along the inner wall, and it plays an important role in the process of detonation diffraction. Finally, we obtain that the propagating state of detonation wave around the corner is generally determined by two factors: the transverse shock wave along the inner wall downwards and the extending curved detonation wave.

  8. High-Resolution Spectroscopy of some very Active Southern Stars

    NASA Technical Reports Server (NTRS)

    Soderblom, David R.; King, Jeremy R.; Henry, Todd J.

    1998-01-01

    We have obtained high-resolution echelle spectra of 18 solar-type stars that an earlier survey showed to have very high levels of Ca II H and K emission. Most of these stars belong to close binary systems, but five remain as probable single stars or well-separated binaries that are younger than the Pleiades on the basis of their lithium abundances and H.alpha emission. Three of these probable single stars also lie more than 1 mag above the main sequence in a color-magnitude diagram, and appear to have ages of 10 to 15 Myr. Two of them, HD 202917 and HD 222259, also appear to have a kinematic association with the pre-main-sequence multiple system HD 98800.

  9. Controllable printing droplets for high-resolution patterns.

    PubMed

    Kuang, Minxuan; Wang, Libin; Song, Yanlin

    2014-10-29

    Inkjet printing has attracted wide attention due to the important applications in fabricating biological, optical, and electrical devices. During the inkjet printing process, the solutes prefer to deposit along the droplet periphery and form an inhomogeneous morphology, known as the coffee-ring effect. Besides, the feature size of printed dots or lines of conventional inkjet printing is usually limited to tens or even hundreds of micrometers. The above two issues greatly restrict the extensive application of printed patterns in high-performance devices. This paper reviews the recent advances in precisely controlling the printing droplets for high-resolution patterns and three-dimensional structures, with a focus on the development to suppress the coffee-ring effect and minimize the feature size of printed dots or lines. A perspective on the remaining challenges of the research is also proposed. PMID:24687946

  10. Spontaneous Raman scattering as a high resolution XUV radiation source

    NASA Technical Reports Server (NTRS)

    Rothenberg, J. E.; Young, J. F.; Harris, S. E.

    1983-01-01

    A type of high resolution XUV radiation source is described which is based upon spontaneous anti-Stokes scattering of tunable incident laser radiation from atoms excited to metastable levels. The theory of the source is summarized and two sets of experiments using He (1s2s)(1)S atoms, produced in a cw hollow cathode and in a pulsed high power microwave discharge, are discussed. The radiation source is used to examine transitions originating from the 3p(6) shell of potassium. The observed features include four previously unreported absorption lines and several sharp interferences of closely spaced autoionizing lines. A source linewidth of about 1.9 cm(-1) at 185,000 cm(-1) is demonstrated.

  11. High-resolution three-dimensional imaging radar

    NASA Technical Reports Server (NTRS)

    Cooper, Ken B. (Inventor); Chattopadhyay, Goutam (Inventor); Siegel, Peter H. (Inventor); Dengler, Robert J. (Inventor); Schlecht, Erich T. (Inventor); Mehdi, Imran (Inventor); Skalare, Anders J. (Inventor)

    2010-01-01

    A three-dimensional imaging radar operating at high frequency e.g., 670 GHz, is disclosed. The active target illumination inherent in radar solves the problem of low signal power and narrow-band detection by using submillimeter heterodyne mixer receivers. A submillimeter imaging radar may use low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform. Three-dimensional images are generated through range information derived for each pixel scanned over a target. A peak finding algorithm may be used in processing for each pixel to differentiate material layers of the target. Improved focusing is achieved through a compensation signal sampled from a point source calibration target and applied to received signals from active targets prior to FFT-based range compression to extract and display high-resolution target images. Such an imaging radar has particular application in detecting concealed weapons or contraband.

  12. Calibration of a High Resolution Soft X-ray Spectrometer

    SciTech Connect

    Dunn, J; Beiersdorfer, P; Brown, G V; Magee, E W

    2010-01-26

    A high resolution grating spectrometer (HRGS) with 2400 line/mm variable line spacing grating for the 10-50 {angstrom} wavelength range has been designed for laser-produced plasma experiments at the Lawrence Livermore National Laboratory (LLNL). The spectrometer has a large radius of curvature, R=44.3 m, is operated at a 2{sup o} grazing angle and can record high signal-to-noise spectra when used with a low-noise, cooled, charge-coupled device detector. The instrument can be operated with a 10-25 {micro}m wide slit to achieve the best spectral resolving power on laser plasma sources, approaching 2000, or in slitless mode with a small symmetrical emission source. Results will be presented for the spectral response of the spectrometer cross-calibrated at the LLNL Electron Beam Ion Trap facility using the broadband x-ray energy EBIT Calorimeter Spectrometer (ECS).

  13. Network Design for CO2 Observation With High Resolution Inversions

    NASA Astrophysics Data System (ADS)

    Patra, P. K.; Maksyutov, S.; Inoue, G.; Nakazawa, T.

    2002-12-01

    The atmospheric data inversion and flux data assimilation of trace gases are two potential ways to determine their sources near the surface. A simple approach to the network optimization of CO2 observation is used in this study (Patra and Maksyutov, Geophys. Res. Lett., 29, 28 May 2002). We have started with the well tested TransCom-3 inverse model setup for 22 land/ocean regions (Gurney et al., Nature, 415, 7 February 2002). In a high resolution (HiRes) inverse model setup at subcontinental scale, the 11 land regions are divided into 42 regions to study the impact of spatial resolution on network design. We also have constructed region specific networks, where the new stations are placed to constrain the flux uncertainty of a target region (e.g. North America or Boreal Asia). We have found that more observations (by a few times) are needed to equally constrain the \\it a posteriori flux uncertainty at HiRes setup, since impact of a single station in restricting the flux uncertainty gets reduced in HiRes case compared to the TransCom-3 case. In higher resolution inversion, the optimal station locations are distributed more evenly over the space. For instance, to better estimate the North American CO2 flux in TransCom-3 setup most of the suggested stations are located in the eastern part of United States and north-west part of Canada, where as in the HiRes case many new stations could be found in the south-eastern part of Canada and north-west United States. During similar test for Boreal Asia (BA) region, it is seen that most of the optimal stations were located in the downwind region of Eurasian emission, in the eastern and far-east of BA, while the TransCom-3 set up is used. In the HiRes case, we observed about half of 25 new stations are moved to the western part of BA region and its vicinity. The results with two inverse model setups suggest that high resolution inverse model based measurement network design would be required if the NACP observations are to be utilised most effectively in regional surface source estimations within North America.

  14. Error and Uncertainty in High-resolution Quantitative Sediment Budgets

    NASA Astrophysics Data System (ADS)

    Grams, P. E.; Schmidt, J. C.; Topping, D. J.; Yackulic, C. B.

    2012-12-01

    Sediment budgets are a fundamental tool in fluvial geomorphology. The power of the sediment budget is in the explicit coupling of sediment flux and sediment storage through the Exner equation for bed sediment conservation. Thus, sediment budgets may be calculated either from the divergence of the sediment flux or from measurements of morphologic change. Until recently, sediment budgets were typically calculated using just one of these methods, and often with sparse data. Recent advances in measurement methods for sediment transport have made it possible to measure sediment flux at much higher temporal resolution, while advanced methods for high-resolution topographic and bathymetric mapping have made it possible to measure morphologic change with much greater spatial resolution. Thus, it is now possible to measure all terms of a sediment budget and more thoroughly evaluate uncertainties in measurement methods and sampling strategies. However, measurements of sediment flux and morphologic change involve different types of uncertainty that are encountered over different time and space scales. Three major factors contribute uncertainty to sediment budgets computed from measurements of sediment flux. These are measurement error, the accumulation of error over time, and physical processes that cause systematic bias. In the absence of bias, uncertainty is proportional to measurement error and the ratio of fluxes at the two measurement stations. For example, if the ratio between measured sediment fluxes is more than 0.8, measurement uncertainty must be less than 10 percent in order to calculate a meaningful sediment budget. Systematic bias in measurements of flux can introduce much larger uncertainty. The uncertainties in sediment budgets computed from morphologic measurements fall into three similar categories. These are measurement error, the spatial and temporal propagation of error, and physical processes that cause bias when measurements are interpolated or extrapolated. Unlike measurements of sediment flux, measurements of topographic change are independent of the total flux. In the absence of bias, uncertainty in a morphologic sediment budget is proportional only to the measurement error and the change in average elevation over the budget area. The greatest potential source of uncertainty is introduced by sampling design and the extrapolation of a budget from short to longer reaches. We illustrate these sources of uncertainty and their effect on sediment budget computations with examples from the Colorado River in Grand Canyon, where we have high-resolution measurements of both sediment flux and morphologic change.

  15. PANGU: A High Resolution Gamma-Ray Space Telescope

    NASA Astrophysics Data System (ADS)

    Su, Meng

    2014-08-01

    We propose a high angular resolution telescope dedicated to the sub-GeV gamma-ray astronomy as a candidate for the CAS-ESA joint small mission. This mission, called PANGU (PAir-productioN Gamma-ray Unit), will open up a unique window of electromagnetic spectrum that has never been explored with great precision. A wide range of topics of both astronomy and fundamental physics can be attacked with a telescope that has an angular resolution about one order of magnitude better than the currently operating Fermi Gamma-ray Space Telescope (Fermi) in the sub-GeV range, covering galactic and extragalactic cosmic-ray physics, extreme physics of a variety of extended (e.g. supernova remnants, galaxies, galaxy clusters) and compact (e.g. black holes, pulsars, gamma-ray bursts) objects, solar and terrestrial gamma-ray phenomena, and searching for Dark Matter (DM) decay and/or annihilation signature etc. The unprecedented resolution can be achieved with a pair-production telescope that, instead of the high-Z converter commonly used, relies on a large number of thin active tracking layers to increase the photon conversion probability, and to precisely reconstruct the pair-produced electron and positron tracks. Scintillating fibers or thin silicon micro-strip detectors are suitable technology for such a tracker. The energy measurement is achieved by measuring the momentum of the electrons and positrons through a magnetic field. The innovated spectrometer approach provides superior photon conversion identification and photon pointing resolution, and is particular suitable in the sub-GeV range, where the opening angle between the electron and positron is relatively large. The level of tracking precision makes it possible to measure the polarization of gamma rays, which would open up a new frontier in gamma-ray astronomy. The sub-GeV full sky survey by PANGU would provides crucial link with GeV to TeV maps from current/future missions including Fermi, DAMPE, HERD, and CTA.

  16. High resolution NMR imaging using a high field yokeless permanent magnet.

    PubMed

    Kose, Katsumi; Haishi, Tomoyuki

    2011-01-01

    We measured the homogeneity and stability of the magnetic field of a high field (about 1.04 tesla) yokeless permanent magnet with 40-mm gap for high resolution nuclear magnetic resonance (NMR) imaging. Homogeneity was evaluated using a 3-dimensional (3D) lattice phantom and 3D spin-echo imaging sequences. In the central sphere (20-mm diameter), peak-to-peak magnetic field inhomogeneity was about 60 ppm, and the root-mean-square was 8 ppm. We measured room temperature, magnet temperature, and NMR frequency of the magnet simultaneously every minute for about 68 hours with and without the thermal insulator of the magnet. A simple mathematical model described the magnet's thermal property. Based on magnet performance, we performed high resolution (up to [20 µm](2)) imaging with internal NMR lock sequences of several biological samples. Our results demonstrated the usefulness of the high field small yokeless permanent magnet for high resolution NMR imaging. PMID:21959998

  17. Development and Characterization of a High Resolution Portable Gamma Spectrometer

    NASA Astrophysics Data System (ADS)

    Ali, Muhammad

    The recent disaster of Fukushima in Japan combined with the high demand to enhance nuclear safety and to minimize personal exposure to radioactive materials has a significant impact on research and development of radiation detection instrumentation. Currently, there is ample effort worldwide in the pursuit of radiation detection to maximize the accuracy and meet international standards in terms of size and specifications to enable radiation protection decision making. Among the requirements is the development of a portable, light-weight gamma-ray isotope identifier to be used by first responders in nuclear accidents as well as for radiation security and identification of illicit material isotopes. From nuclear security perspective, research into advanced screening technologies has become a high priority in all aspects, while for occupational safety, and environmental radiation protection, the regulatory authorities are requiring specific performance of radiation detection and measuring devices. At the applied radiation laboratory of the University of Ontario Institute of Technology, UOIT, the development of a high resolution spectrometer for medium and high energy gamma ray has been conducted. The spectrometer used a newly developed scintillator based on a LaBr3(Ce) crystal. The detector has been modeled using advanced Monte Carlo code (MCNP/X code) for the response function simulation and parameter characterization. The simulation results have been validated by experimental investigations using a wide range of gamma radiation energies. The developed spectrometer has been characterized in terms of resolution and response in different fields. It has also been compared with other crystals such as NaI(TI) and LiI(Eu).

  18. High-resolution Geostatistical Inversion of the Transient Richards Equation

    NASA Astrophysics Data System (ADS)

    Klein, Ole; Bastian, Peter; Ippisch, Olaf

    2015-04-01

    The vadose zone and the complex physical processes in it play a vital role in our understanding of the environment. The production of most food is directly or indirectly linked to the growth of organic matter sustained by subsurface flow. For a reliable assessment of the influence of natural and anthropogenic changes to such a coupled system detailed knowledge about the flow patterns and dynamics is important, but the high spatial variability of subsurface hydraulic parameters makes reliable predictions about flow patterns difficult. Direct measurement of these properties is not possible, making indirect observations through dependent quantities and parameter estimation a necessity. The geostatistical approach characterizes these hydraulic parameters without predetermined zonation. The parameter fields are treated as stochastic processes, optionally incorporating a priori information in the probability distribution. Maximizing the likelihood of the parameters with regard to the given observations yields a parameter estimate with high spatial resolution. This approach naturally leads to non-linear least squares optimization problems that may theoretically be solved using standard techniques. However, the accurate numerical representation of the Richards equation necessitates high spatio-temporal resolution and therefore a large number of parameters, while time series of observed physical quantities typically lead to many data points to invert. This high dimensionality in both the parameter and observation space makes standard techniques infeasible. We present an extension of one of these existing inversion methods, developed for stationary flow in confined aquifers, to instationary flow regimes in partially saturated porous media. Our approach uses a Conjugate Gradients scheme preconditioned with the prior covariance matrix to avoid both multiplications with its inverse and the explicit assembly of the sensitivity matrix. Instead, one combined adjoint model run is used for all observations at once. As the computing time of our approach is largely independent of the number of measurements used for inversion, the presented method can be applied to large data sets.

  19. Analysis of the impact of spatial resolution on land/water classifications using high-resolution aerial imagery

    USGS Publications Warehouse

    Enwright, Nicholas M.; Jones, William R.; Garber, Adrienne L.; Keller, Matthew J.

    2014-01-01

    Long-term monitoring efforts often use remote sensing to track trends in habitat or landscape conditions over time. To most appropriately compare observations over time, long-term monitoring efforts strive for consistency in methods. Thus, advances and changes in technology over time can present a challenge. For instance, modern camera technology has led to an increasing availability of very high-resolution imagery (i.e. submetre and metre) and a shift from analogue to digital photography. While numerous studies have shown that image resolution can impact the accuracy of classifications, most of these studies have focused on the impacts of comparing spatial resolution changes greater than 2 m. Thus, a knowledge gap exists on the impacts of minor changes in spatial resolution (i.e. submetre to about 1.5 m) in very high-resolution aerial imagery (i.e. 2 m resolution or less). This study compared the impact of spatial resolution on land/water classifications of an area dominated by coastal marsh vegetation in Louisiana, USA, using 1:12,000 scale colour-infrared analogue aerial photography (AAP) scanned at four different dot-per-inch resolutions simulating ground sample distances (GSDs) of 0.33, 0.54, 1, and 2 m. Analysis of the impact of spatial resolution on land/water classifications was conducted by exploring various spatial aspects of the classifications including density of waterbodies and frequency distributions in waterbody sizes. This study found that a small-magnitude change (1–1.5 m) in spatial resolution had little to no impact on the amount of water classified (i.e. percentage mapped was less than 1.5%), but had a significant impact on the mapping of very small waterbodies (i.e. waterbodies ? 250 m2). These findings should interest those using temporal image classifications derived from very high-resolution aerial photography as a component of long-term monitoring programs.

  20. High resolution multi-scalar drought indices for Iberia

    NASA Astrophysics Data System (ADS)

    Russo, Ana; Gouveia, Célia; Trigo, Ricardo; Jerez, Sonia

    2014-05-01

    The Iberian Peninsula has been recurrently affected by drought episodes and by adverse associated effects (Gouveia et al., 2009), ranging from severe water shortages to losses of hydroelectricity production, increasing risk of forest fires, forest decline and triggering processes of land degradation and desertification. Moreover, Iberia corresponds to one of the most sensitive areas to current and future climate change and is nowadays considered a hot spot of climate change with high probability for the increase of extreme events (Giorgi and Lionello, 2008). The spatial and temporal behavior of climatic droughts at different time scales was analyzed using spatially distributed time series of multi-scalar drought indicators, such as the Standardized Precipitation Evapotranspiration Index (SPEI) (Vicente-Serrano et al., 2010). This new climatic drought index is based on the simultaneous use of precipitation and temperature fields with the advantage of combining a multi-scalar character with the capacity to include the effects of temperature variability on drought assessment. Moreover, reanalysis data and the higher resolution hindcasted databases obtained from them are valuable surrogates of the sparse observations and widely used for in-depth characterizations of the present-day climate. Accordingly, this work aims to enhance the knowledge on high resolution drought patterns in Iberian Peninsula, taking advantage of high-resolution (10km) regional MM5 simulations of the recent past (1959-2007) over Iberia. It should be stressed that these high resolution meteorological fields (e.g. temperature, precipitation) have been validated for various purposes (Jerez et al., 2013). A detailed characterization of droughts since the 1960s using the 10 km resolution hidncasted simulation was performed with the aim to explore the conditions favoring drought onset, duration and ending, as well as the subsequent short, medium and long-term impacts affecting the environment and the human resources. The understanding of the present-day underlying mechanisms together with the necessary contextualization within a wider past, is essential to understand future projections, and should lastly rebound on the adequacy of the management decision making. Acknowledgments: This work was partially supported by national funds through FCT (Fundação para a Ciência e a Tecnologia, Portugal) under project QSECA (PTDC/AAG-GLO/4155/2012) Gouveia C., Trigo R.M., DaCamara C.C. (2009) Drought and Vegetation Stress Monitoring in Portugal using Satellite Data, Natural Hazards and Earth System Sciences, 9, 1-11. Giorgi, F. and Lionello, P.; Climate change projections for the Mediterranean region. Global and Planetary Change, 63 (2-3): 90-104, 2008. Vicente-Serrano, Sergio M., Santiago Beguería, Juan I. López-Moreno, 2010: A Multiscalar Drought Index Sensitive to Global Warming: The Standardized Precipitation Evapotranspiration Index. J. Climate, 23, 1696-1718. Jerez, S., R.M. Trigo, S.M. Vicente-Serrano, D. Pozo-Vázquez, R. Lorente-Plazas, J. Lorenzo-Lacruz, F. Santos-Alamillos and J.P. Montávez (2013). The impact of the North Atlantic Oscillation on the renewable energy resources in south-western Europe. Journal of Applied Meteorology and Climatology, DOI 10.1175/JAMC-D-12-0257.1.

  1. High resolution modelling of extreme precipitation events in urban areas

    NASA Astrophysics Data System (ADS)

    Siemerink, Martijn; Volp, Nicolette; Schuurmans, Wytze; Deckers, Dave

    2015-04-01

    The present day society needs to adjust to the effects of climate change. More extreme weather conditions are expected, which can lead to longer periods of drought, but also to more extreme precipitation events. Urban water systems are not designed for such extreme events. Most sewer systems are not able to drain the excessive storm water, causing urban flooding. This leads to high economic damage. In order to take appropriate measures against extreme urban storms, detailed knowledge about the behaviour of the urban water system above and below the streets is required. To investigate the behaviour of urban water systems during extreme precipitation events new assessment tools are necessary. These tools should provide a detailed and integral description of the flow in the full domain of overland runoff, sewer flow, surface water flow and groundwater flow. We developed a new assessment tool, called 3Di, which provides detailed insight in the urban water system. This tool is based on a new numerical methodology that can accurately deal with the interaction between overland runoff, sewer flow and surface water flow. A one-dimensional model for the sewer system and open channel flow is fully coupled to a two-dimensional depth-averaged model that simulates the overland flow. The tool uses a subgrid-based approach in order to take high resolution information of the sewer system and of the terrain into account [1, 2]. The combination of using the high resolution information and the subgrid based approach results in an accurate and efficient modelling tool. It is now possible to simulate entire urban water systems using extreme high resolution (0.5m x 0.5m) terrain data in combination with a detailed sewer and surface water network representation. The new tool has been tested in several Dutch cities, such as Rotterdam, Amsterdam and The Hague. We will present the results of an extreme precipitation event in the city of Schiedam (The Netherlands). This city deals with significant soil consolidation and the low-lying areas are prone to urban flooding. The simulation results are compared with measurements in the sewer network. References [1] Guus S. Stelling G.S., 2012. Quadtree flood simulations with subgrid digital elevation models. Water Management 165 (WM1):1329-1354. [2] Vincenzo Cassuli and Guus S. Stelling, 2013. A semi-implicit numerical model for urban drainage systems. International Journal for Numerical Methods in Fluids. Vol. 73:600-614. DOI: 10.1002/fld.3817

  2. Optical Histology: High-Resolution Visualization of Tissue Microvasculature

    NASA Astrophysics Data System (ADS)

    Moy, Austin Jing-Ming

    Mammalian tissue requires the delivery of nutrients, growth factors, and the exchange of oxygen and carbon dioxide gases to maintain normal function. These elements are delivered by the blood, which travels through the connected network of blood vessels, known as the vascular system. The vascular system consists of large feeder blood vessels (arteries and veins) that are connected to the small blood vessels (arterioles and venules), which in turn are connected to the capillaries that are directly connected to the tissue and facilitate gas exchange and nutrient delivery. These small blood vessels and capillaries make up an intricate but organized network of blood vessels that exist in all mammalian tissues known as the microvasculature and are very important in maintaining the health and proper function of mammalian tissue. Due to the importance of the microvasculature in tissue survival, disruption of the microvasculature typically leads to tissue dysfunction and tissue death. The most prevalent method to study the microvasculature is visualization. Immunohistochemistry (IHC) is the gold-standard method to visualize tissue microvasculature. IHC is very well-suited for highly detailed interrogation of the tissue microvasculature at the cellular level but is unwieldy and impractical for wide-field visualization of the tissue microvasculature. The objective my dissertation research was to develop a method to enable wide-field visualization of the microvasculature, while still retaining the high-resolution afforded by optical microscopy. My efforts led to the development of a technique dubbed "optical histology" that combines chemical and optical methods to enable high-resolution visualization of the microvasculature. The development of the technique first involved preliminary studies to quantify optical property changes in optically cleared tissues, followed by development and demonstration of the methodology. Using optical histology, I successfully obtained high resolution, depth sectioned images of the microvasculature in mouse brain and the coronary microvasculature in mouse heart. Future directions of optical histology include the potential to facilitate visualization of the entire microvascular structure of an organ as well as visualization of other tissue molecular markers of interest.

  3. High Resolution Hydro-Climate Projections for Western Canada

    NASA Astrophysics Data System (ADS)

    Erler, A. R.; Peltier, W. R.

    2013-12-01

    Dynamical Downscaling is now a widely used method to obtain physically consistent high-resolution information from Global Climate Models. Here the Weather Research and Forecast model (WRFV3) is used to downscale IPCC scenario forecasts generated with the Community Earth System Model (CESM1).The domain of interest is Western Canada, which is simulated at 10km resolution using two nested domains and over a period of 15 years during a historical validation period and a mid-21st-century projection period. This region is particularly challenging, since it includes regions of complex terrain and high precipitation in the Coast Mountains, as well as largely arid regions in the lee of the Rocky Mountains; at the same time this makes it an interesting test bed for hydro-climatological modeling. The paper will focus on three major issues: namely, model configuration and validation, projections of future climate, and changes in the hydrological cycle. In order to quantify uncertainty and to estimate the impact of natural variability on projection skill, a suite of simulations with perturbed initial conditions and different physical parameterizations is presented. Over the validation period, the simulations are compared to several different observational datasets as well as reanalysis, but the validation of orographic precipitation relies largely on the high-resolution PRISM dataset. We show that the choice of physical parameterization schemes is critical to the accurate capture of important physical processes and for the reduction of model bias. Furthermore, the initial condition ensemble suggests a high degree of natural variability in the seasonal precipitation field. The results for the future projection period are characterized by a very consistent temperature increase, but no clear trend in precipitation: while winter precipitation increases somewhat in all ensemble members, natural variability may even lead to opposing trends in summer precipitation. A quantity of major interest for many climate projection and downscaling efforts is net-precipitation (precipitation - evapo-transpiration), an important indicator for fresh water availability. While the Rocky Mountains continue to receive excess precipitation, especially in winter, water availability in the more arid plains and forests in the lee of the mountains is more influenced by evapo-transpiration and precipitation in summer. At mid-century, under the RCP 8.5 scenario, the point where evaporation exceeds precipitation in the plains occurs up to one month earlier in the year. However, averaged over the annual cycle, evapo-transpiration and precipitation in the plains remain closely balanced in a warmer climate. The validity of these results is critically assessed in the light of limitations of currently available land models, and implications for climate and hydrological modeling are discussed.

  4. High resolution photoemission experiments on copper oxide superconductors

    NASA Astrophysics Data System (ADS)

    Rameau, Jonathan David

    The mechanism for achieving high transition temperatures (T c) in copper oxide superconductors and the nature of the mysterious "pseudogap" phase from which this phenomenon arises are two of the most pressing issues in solid state physics. High resolution angle resolved photoemission spectroscopy (ARPES), which can directly probe the momentum and energy dependence of the electronic structure of a crystal, is considered one of the foremost tools for unraveling these mysteries. In this thesis we present work on both the further development of the ARPES technique itself and the results of two experiments on the high temperature superconductor Bi2Sr2CaCu2O8+delta (BSCCO)---the drosophila of copper oxide superconductors---based upon these analytical and experimental advances. On the analytical side we have shown that the precision of any ARPES experiment can be radically enhanced by using the Lucy-Richardson method (LRM) of iterative deconvolution to remove the worst effects of experimental resolution broadening present in all ARPES spectra. On the experimental side we have constructed a deep ultraviolet laser system capable of increasing our data acquisition rate by more than an order of magnitude compared to what is possible using traditional synchrotron radiation sources at the same momentum and energy resolutions. Using the LRM, in conjunction with synchrotron radiation, spectroscopic evidence was found for the existence of incoherent Cooper pairs in underdoped BSCCO in the normal pseudogap state (above Tc). At the same time an asymmetry between the particle and hole states of BSCCO was found, implying that doped Mott insulators, of which BSCCO is a primordial example, are characterized by the presence of a Fermi-Luttinger surface, rather than a Fermi surface, as would be the case for a simple metal. This study provided the first spectroscopic evidence for either phenomenon. In our second experiment we were able to use the LRM on data acquired with the laser ARPES system to show the presence in optimally doped BSCCO, well below T c, of a previously unobserved electron-boson interaction. The momentum dependence of this interaction, which appears as a "kink" in ARPES spectra, shows that the responsible boson is an Einstein phonon. The ARPES data is well reproduced by a simple theoretical model based on these observations. After more than two decades of study this result represents the first unambiguous enumeration of an electron-boson interaction by ARPES in BSCCO. The identification of this interaction will require a theoretical reevaluation of the nature of several similar features long seen in BSCCO, the origins of which remain unknown and highly controversial to this day.

  5. High-resolution sea wind hindcasts over the Mediterranean area

    NASA Astrophysics Data System (ADS)

    Menendez, M.; García-Díez, M.; Fita, L.; Fernández, J.; Méndez, F. J.; Gutiérrez, J. M.

    2014-04-01

    The goal of this study is to develop a high-resolution atmospheric hindcast over the Mediterranean area using the WRF-ARW model, focusing on offshore surface wind fields. In order to choose the most adequate model configuration, the study provides details on the calibration of the experimental saet-up through a sensitivity test considering the October-December 2001 period (the 2001 super-storm event in the West Mediterranean). A daily forecast outperforms the spectral technique of previous products and the boundary data from ERA-Interim reanalysis produces the most accurate estimates in terms of wind variability and hour-to-hour correspondence. According to the sensitivity test, two data sets of wind hindcast are produced: the SeaWind I (30-km horizontal resolution for a period of 60 years) and the SeaWind II (15-km horizontal resolution for 20 years). The validation of the resulting surface winds is undertaken considering two offshore observational datasets. On the one hand, hourly surface buoy stations are used to validate wind time series at specific locations; on the other hand, wind altimeter satellite observations are considered for spatial validation in the whole Mediterranean Sea. The results obtained from this validation process show a very good agreement with observations for the southern Europe region. Finally, SeaWind I and II are used to characterize offshore wind fields in the Mediterranean Sea. The statistical structure of sea surface wind is analyzed and the agreement with Weibull probability distribution is discussed. In addition, wind persistence and extreme wind speed (50 year return period) are characterized and relevant areas of wind power generation are described by estimating wind energy quantities.

  6. High resolution studies of NGC 1275 and the galactic center

    NASA Astrophysics Data System (ADS)

    Marr, Jonathan Michael

    1990-02-01

    Radio studies of the parsec-scale structure in the centers of NGC 1275 and the Milky Way galaxy are presented. The nucleus of NGC 1275 was observed with Very Long Baseline Interferometry (VLBI) at 1.3 cm twice per year for three years, with a resolution of 0.3 milliarcseconds, corresponding to approximately 0.1 pc. The galactic center was observed in the J = 1 approaches 0 transition lines of H-13(CN) and HCO(+) with the Berkeley-Illinois-Maryland Array (BIMA) at the Hat Creek Radio Observatory, with a spatial resolution that corresponded to 0.2 pc, and spectral resolution of 4 km s-1. The H-13(CN) and HCO(+) data, which were seen in emission from the 2 pc galactocentric ring and in absorption from galactic line-of-sight features, were compared with published H-12(CN) observations. The VLBI maps of NGC 1275 reveal that intensity flares are associated with the ejection of knots of emission moving at velocities approximately 0.5 h-1 c, while a slowly evolving outburst is associated with the emergence of diffuse emission expanding in a cone at a velocity approximately 0.33 h-1 pc. The core emission has a roughly constant and complex morphology with a number of ridges extending out radially from the emission peak and an inner jet at PA 210 deg. The galactic center observations are also used to study previously identified foreground features that appear in absorption by HCO(+) and HCN. Opacity maps suggest either that Sgr A* is at least 3 pc in front of the ionized gas bar or that 'the high velocity gas' is very clumpy and has a window at the position of Sgr A*.

  7. Positron autoradiography for intravascular imaging: feasibility evaluation

    NASA Astrophysics Data System (ADS)

    Shikhaliev, Polad M.; Xu, Tong; Ducote, Justin L.; Easwaramoorthy, Balasubramaniam; Mukherjee, Jogeshwar; Molloi, Sabee

    2006-02-01

    Approximately 70% of acute coronary artery disease is caused by unstable (vulnerable) plaques with an inflammation of the overlying cap and high lipid content. A rupturing of the inflamed cap of the plaque results in propagation of the thrombus into the lumen, blockage of the artery and acute ischaemic syndrome or sudden death. Morphological imaging such as angiography or intravascular ultrasound cannot determine inflammation status of the plaque. A radiotracer such as 18F-FDG is accumulated in vulnerable plaques due to higher metabolic activity of the inflamed cap and could be used to detect a vulnerable plaque. However, positron emission tomography (PET) cannot detect the FDG-labelled plaques because of respiratory and heart motions, small size and low activity of the plaques. Plaques can be detected using a miniature particle (positron) detector inserted into the artery. In this work, a new detector concept is investigated for intravascular imaging of the plaques. The detector consists of a storage phosphor tip bound to the end of an intravascular catheter. It can be inserted into an artery, absorb the 18F-FDG positrons from the plaques, withdrawn from the artery and read out. Length and diameter of the storage phosphor tip can be matched to the length and the diameter of the artery. Monte Carlo simulations and experimental evaluations of coronary plaque imaging with the proposed detector were performed. It was shown that the sensitivity of the storage phosphor detector to the positrons of 18F-FDG is sufficient to detect coronary plaques with 1 mm and 2 mm sizes and 590 Bq and 1180 Bq activities in the arteries with 2 mm and 3 mm diameters, respectively. An experimental study was performed using plastic tubes with 2 mm diameter filled with an FDG solution, which simulates blood. FDG spots simulating plaques were placed over the surface of the tube. A phosphor tip was inserted into the tube and imaged the plaques. Exposure time was 1 min in all simulations and experiments. Experiments showed that detecting the coronary plaques using the proposed technique is possible. The proposed technique has the potential for fast and accurate detection of vulnerable coronary and other intravascular plaques.

  8. The Singapore high resolution single cell imaging facility

    NASA Astrophysics Data System (ADS)

    Watt, Frank; Chen, Xiao; Vera, Armin Baysic De; Udalagama, Chammika N. B.; Ren, M.; Kan, Jeroen A. van; Bettiol, Andrew A.

    2011-10-01

    The Centre for Ion Beam Applications, National University of Singapore has recently expanded from three state-of-the-art beam lines to five. Two new beam lines have been constructed: A second generation proton beam writing line, and a high resolution single cell imaging facility. Both systems feature high demagnification lens systems based on compact Oxford Microbeams OM52 lenses, coupled with reduced lens/image distances. The single cell imaging facility is designed around OM52 compact lenses capable of operating in a variety of high demagnification configurations including the spaced Oxford triplet and the double crossover Russian quadruplet. The new facility has design specifications aimed at spatial resolutions below 50 nm, with a variety of techniques including STIM, secondary electron and fluorescence imaging, and an in-built optical and fluorescence microscope for sample imaging, identification and positioning. Preliminary tests using the single space Oxford triplet configuration have indicated a beam spot size of 31 × 39 nm in the horizontal and vertical directions respectively, at beam currents of ?10,000 protons per second. However, a weakness in the specifications of the electrostatic scanning system has been identified, and a more stable scanning system needs to be implemented before we can fully realize the optimum performance. A single whole fibroblast cell has been scanned using 1.5 MeV protons, and a median fit to the proton transmission energy loss data has shown that proton STIM gives excellent details of the cell structure despite the relatively poor contrast of proton STIM compared with alpha STIM.

  9. MEMS phase former kit for high-resolution wavefront control

    NASA Astrophysics Data System (ADS)

    Gehner, Andreas; Wildenhain, Michael; Neumann, Hannes; Elgner, Andreas; Schenk, Harald

    2005-08-01

    The MEMS Phase Former Kit developed by the Fraunhofer IPMS is a complete Spatial Light Modulator system based on a piston-type Micro Mirror Array (MMA) for the use in high-resolution, high-speed optical phase control. It has been designed for an easy system integration into an user-specific environment to offer a platform for first practical investigations to open up new applications in Adaptive Optics. The key component is a fine segmented 240 x 200 array of 40 ?m piston-type mirror elements capable of 400 nm analog deflection for a 2pi phase modulation in the visible. Each mirror can be addressed and deflected independently by means of an integrated CMOS backplane address circuitry at an 8bit height resolution. Full user programmability and control is provided by a newly developed comfortable driver software for Windows XP based PCs supporting both a Graphical User Interface (GUI) for stand-alone operation with pre-defined data patterns as well as an open ActiveX programming interface for a closed-loop operation with real-time data from an external source. An IEEE1394a FireWire interface is used for high-speed data communication with an electronic driving board performing the actual MMA programming and control allowing for an overall frame rate of up to 500 Hz. Successful proof-of-concept demonstrations already have been given for eye aberration correction in ophthalmology, for error compensation of leightweight primary mirrors of future space telescopes and for ultra-short laser pulse shaping. Besides a presentation of the basic device concept and system architecture the paper will give an overview of the obtained results from these applications.

  10. High-resolution X-ray spectroscopy of Theta Car

    E-print Network

    Yael Naze; Gregor Rauw

    2008-08-25

    Context : The peculiar hot star Theta Car in the open cluster IC2602 is a blue straggler as well as a single-line binary of short period (2.2d). Aims : Its high-energy properties are not well known, though X-rays can provide useful constraints on the energetic processes at work in binaries as well as in peculiar, single objects. Methods : We present the analysis of a 50ks exposure taken with the XMM-Newton observatory. It provides medium as well as high-resolution spectroscopy. Results : Our high-resolution spectroscopy analysis reveals a very soft spectrum with multiple temperature components (1--6MK) and an X-ray flux slightly below the `canonical' value (log[L_X(0.1-10.)/L_{BOL}] ~ -7). The X-ray lines appear surprisingly narrow and unshifted, reminiscent of those of beta Cru and tau Sco. Their relative intensities confirm the anomalous abundances detected in the optical domain (C strongly depleted, N strongly enriched, O slightly depleted). In addition, the X-ray data favor a slight depletion in neon and iron, but they are less conclusive for the magnesium abundance (solar-like?). While no significant changes occur during the XMM-Newton observation, variability in the X-ray domain is detected on the long-term range. The formation radius of the X-ray emission is loosely constrained to <5 R_sol, which allows for a range of models (wind-shock, corona, magnetic confinement,...) though not all of them can be reconciled with the softness of the spectrum and the narrowness of the lines.

  11. High resolution distributed hydrological modeling for river flood forecasting

    NASA Astrophysics Data System (ADS)

    Chen, Y.

    2014-12-01

    High resolution distributed hydrological model can finely describe the river basin hydrological processes, thus having the potential to improve the flood forecasting capabilities, and is regarded as the next generation flood forecast model. But there are great challenges in deploying it in real-time river flood forecasting, such as the awesome computation resources requirement, parameter determination, high resolution precipitation assimilation and uncertainty controls. Liuxihe Model is a physically-based distributed hydrological model proposed mainly for catchment flood forecasting, which is a process-based hydrological model. In this study, based on Liuxihe Model, a parallel computation algorithm for Liuxihe model flood forecasting is proposed, and a cloudy computation system is developed on a high performance computer, this largely improves the applicability of Liuxihe Model in large river. Without the parallel computation, the Liuxihe Model is computationally incapable in application to rivers with drainage area bigger than 10,000km2 at the grid size of 100m. With the parallel computation, the Liuxihe Model is used in a river with a drainage area of 60,000km2, and could be expended indefinitely. Based on this achievement, a model parameter calibration method by using Particle Swale Optimization is proposed and tested in several rivers in southern China with drainage areas ranging from several hundreds to tens thousands km2, and with the model parameter optimization, the model performance has been approved largely. The modeling approach is also tested for coupling radar-based precipitation estimation/prediction for small catchment flash forecasting and for coupling quantitative precipitation estimation/prediction from meteorological model for large river flood forecasting.

  12. High Resolution Optical Imaging for Deep Water Archaeology Hanumant Singh1

    E-print Network

    Eustice, Ryan

    the goal of precise and repeatable high resolution mapping of archaeological sites of interest underwaterHigh Resolution Optical Imaging for Deep Water Archaeology Hanumant Singh1 , Christopher Roman1 Abstract High resolution imaging in the context of deep water archaeology presents some unique challenges

  13. Very high resolution rainfall patterns measured by TRMM precipitation radar: seasonal and diurnal cycles

    E-print Network

    Sobel, Adam

    Very high resolution rainfall patterns measured by TRMM precipitation radar: seasonal and diurnal Precipitation Radar is used to construct a high resolution (0.05° 9 0.05°) climatology of rainfall over of rainfall frequency and intensity at high spatial resolution, with special focus on the seasonal and diurnal

  14. High-Resolution Observations of a Binary Black Hole Candidate

    NASA Astrophysics Data System (ADS)

    Tsai, Chao-Wei; Phillips, Chris; Norris, Ray; Jarrett, Thomas; Emonts, Bjorn; Cluver, Michelle; Eisenhardt, Peter; Stern, Daniel; Assef, Roberto

    2012-10-01

    We propose a 12-hour 2.3 GHz continuum Long Baseline Array (LBA) observation of WISE J2332-5056, a newly discovered supermassive black hole (SMBH) merger candidate that is located in the nearby universe (z = 0.3447). Our recently acquired 9 GHz ATCA map shows unusual radio morphology: a one-sided, smaller (and likely younger) FR-I jet perpendicular to a larger, Doppler-boosted FR-II jet. Follow-up Gemini-S/GMOS spectroscopy of this WISE-selected radio galaxy reveals broad emission lines blue-shifted by > 3,500 km/s with respect to the narrow lines and host galaxy, hallmarks of a dual AGN system. Combined, the optical spectroscopy and radio morphology of this object are strongly suggestive of a black hole merger system. Even in the local universe these systems are extremely difficult to identify; yet the process of supermassive blackhole growth is vital toward understanding galaxy evolution from the early to the current universe. Moreover, nearby merging SMBHs may serve as outstanding targets for gravitational wave studies. The proposed high resolution LBA map, reaching 50 pc resolution at the source redshift will allow us to investigate the SMBH merger scenario hypothesis.

  15. Large Field, High Resolution Full-Field Optical Coherence Tomography

    PubMed Central

    Assayag, Osnath; Antoine, Martine; Sigal-Zafrani, Brigitte; Riben, Michael; Harms, Fabrice; Burcheri, Adriano; Grieve, Kate; Dalimier, Eugénie; Le Conte de Poly, Bertrand; Boccara, Claude

    2014-01-01

    We present a benchmark pilot study in which high-resolution Full-Field Optical Coherence Tomography (FF-OCT) was used to image human breast tissue and is evaluated to assess its ability to aid the pathologist’s management of intra-operative diagnoses. FF-OCT imaging safety was investigated and agreement between FF-OCT and routinely prepared histopathological images was evaluated. The compact setup used for this study provides 1 µm3 resolution and 200 µm imaging depth, and a 2.25 cm2 specimen is scanned in about 7 minutes. 75 breast specimens were imaged from 22 patients (21 women, 1 man) with a mean age of 58 (range: 25-83). Pathologists blind diagnosed normal/benign or malignant tissue based on FF-OCT images alone, diagnosis from histopathology followed for comparison. The contrast in the FF-OCT images is generated by intrinsic tissue scattering properties, meaning that no tissue staining or preparation is required. Major architectural features and tissue structures of benign breast tissue, including adipocytes, fibrous stroma, lobules and ducts were characterized. Subsequently, features resulting from pathological modification were characterized and a diagnosis decision tree was developed. Using FF-OCT images, two breast pathologists were able to distinguish normal/benign tissue from lesional with a sensitivity of 94% and 90%, and specificity of 75% and 79% respectively. PMID:24000981

  16. High-Resolution Imaging of Asteroids/Satellites

    NASA Astrophysics Data System (ADS)

    Merline, William J.; Tamblyn, Peter M.; Carry, Benoit; Drummond, Jack; Conrad, Al; Howell, Steve B.; Christou, Julian; Chapman, Clark R.; Dumas, Christophe

    2013-08-01

    We propose to make high-resolution observations of asteroids using two separate observational paths. We request LGS AO on Keck, as part of our ongoing program to measure size, 3D shape, and pole position, and to search for satellites. Second, we wish to make use of the new capability for speckle imaging on Gemini-N. We have demonstrated that AO imaging allows determination of the pole/dimensions in 1 or 2 nights, rather than the years of observations with lightcurve inversion techniques that only yield poles and axial ratios, not true dimensions. Detection of new satellites allows an accurate mass determination. Accurately determining the volume from the often-irregular shape allows us to derive densities to greater precision in cases where the mass is known. Satellites also provide a real-life lab for testing collisional models. We have demonstrated the tremendous fidelity of our shape/sizes of asteroids, and have pioneered asteroid satellite detection. The new DSSI instrument provides a potentially game-changing opportunity by pushing diffraction-limited imaging into the visible region, where the resolution will be roughly twice what we can get at Keck in the NIR. We will apply both techniques to determination of sizes of asteroids and search for binaries, particularly among understudied populations such as the NEOs and Trojans.

  17. High resolution muon tracking with resistive plate chambers

    NASA Astrophysics Data System (ADS)

    Baesso, P.; Cussans, D.; Davies, J.; Glaysher, P.; Thomay, C.; Vassallo, C.; Velthuis, J.; Quillin, S.; Robertson, S.; Steer, C.

    2012-11-01

    Following their introduction in the physics community in the early '80s the use of Resistive Plate Chambers (RPCs) as charged particles detectors has constantly increased. Low cost per unit area, good time resolution and easy of operation are some of the features that contributed to such large adoption and that make RPCs interesting for several applications not necessarily related to physics. We built a prototype detector to track cosmic muons and exploit the information provided by estimating the multiple coulomb scattering angle to determine the type of materials they traversed. Simulations show that the technique could be used to inspect a cargo container in a time of the order of minutes. The detector we built consists of six planes, each one providing X-Y readout over a 50 cm × 50 cm area. The readout scheme we adopted, based on multiplexing chips used in high energy physics, allowed us to use a limited amount of electronic output channels while still obtaining a spatial resolution lower than 1 mm. An overview of the detector and of the analysis performed on the data is provided.

  18. High-resolution adaptive imaging with a single photodiode.

    PubMed

    Soldevila, F; Salvador-Balaguer, E; Clemente, P; Tajahuerce, E; Lancis, J

    2015-01-01

    During the past few years, the emergence of spatial light modulators operating at the tens of kHz has enabled new imaging modalities based on single-pixel photodetectors. The nature of single-pixel imaging enforces a reciprocal relationship between frame rate and image size. Compressive imaging methods allow images to be reconstructed from a number of projections that is only a fraction of the number of pixels. In microscopy, single-pixel imaging is capable of producing images with a moderate size of 128?×?128 pixels at frame rates under one Hz. Recently, there has been considerable interest in the development of advanced techniques for high-resolution real-time operation in applications such as biological microscopy. Here, we introduce an adaptive compressive technique based on wavelet trees within this framework. In our adaptive approach, the resolution of the projecting patterns remains deliberately small, which is crucial to avoid the demanding memory requirements of compressive sensing algorithms. At pattern projection rates of 22.7?kHz, our technique would enable to obtain 128?×?128 pixel images at frame rates around 3?Hz. In our experiments, we have demonstrated a cost-effective solution employing a commercial projection display. PMID:26382114

  19. High-resolution oxygen-17 NMR of solid silicates

    SciTech Connect

    Mueller, K.T.; Wu, Y.; Chmelka, B.F. ); Stebbins, J. ); Pines, A. )

    1991-01-02

    Several{sup 17}O-enriched silicates were studied by use of dynamic angle spinning (DAS) and double rotation (DOR) nuclear magnetic resonance spectroscopy. These methods average away second-order quadrupolar interactions by reorienting a sample about a time-dependent axis, thereby yielding high-resolution spectra of oxygen-17 nuclei. A narrow spectral line is observed for each distinct oxygen site at the sum of the isotropic chemical shift and the field-dependent isotropic second-order quadrupolar shift. Resolution is increased by up to 2 orders of magnitude compared to conventional magic angle spinning (MAS) spectra. Crystallographically inequivalent oxygen are now observable as distinct resonances in spectra of polycrystalline silicates such as diopside (CaMgSi{sub 2}{sup 17}O{sub 6}), wollastonite (CaSi{sup 17}O{sub 3}), larnite (Ca{sub 2}Si{sup 17}O{sub 4}), and forsterite (Mg{sub 2}Si{sup 17}O{sub 4}).

  20. A Unitary Anesthetic Binding Site at High Resolution

    SciTech Connect

    L Vedula; G Brannigan; N Economou; J Xi; M Hall; R Liu; M Rossi; W Dailey; K Grasty; et. al.

    2011-12-31

    Propofol is the most widely used injectable general anesthetic. Its targets include ligand-gated ion channels such as the GABA{sub A} receptor, but such receptor-channel complexes remain challenging to study at atomic resolution. Until structural biology methods advance to the point of being able to deal with systems such as the GABA{sub A} receptor, it will be necessary to use more tractable surrogates to probe the molecular details of anesthetic recognition. We have previously shown that recognition of inhalational general anesthetics by the model protein apoferritin closely mirrors recognition by more complex and clinically relevant protein targets; here we show that apoferritin also binds propofol and related GABAergic anesthetics, and that the same binding site mediates recognition of both inhalational and injectable anesthetics. Apoferritin binding affinities for a series of propofol analogs were found to be strongly correlated with the ability to potentiate GABA responses at GABA{sub A} receptors, validating this model system for injectable anesthetics. High resolution x-ray crystal structures reveal that, despite the presence of hydrogen bond donors and acceptors, anesthetic recognition is mediated largely by van der Waals forces and the hydrophobic effect. Molecular dynamics simulations indicate that the ligands undergo considerable fluctuations about their equilibrium positions. Finally, apoferritin displays both structural and dynamic responses to anesthetic binding, which may mimic changes elicited by anesthetics in physiologic targets like ion channels.