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 autoradiography. I. Methods.

    PubMed

    CARO, L G; VAN TUBERGEN, R P; KOLB, J A

    1962-11-01

    Methods used in obtaining high resolution in autoradiography, with special emphasis on the technique of electron microscopic autoradiography, are described, together with control experiments designed to establish the optimum conditions or procedures. On the basis of these experiments the emulsion selected was Ilford L-4, with a crystal size slightly larger than 0.1 micron. It is applied to the specimen in the form of a gelled film consisting of a monolayer of silver halide crystals. Background, when present, can be eradicated by a simple method. The preparations can be stored, in presence of a drying agent, at room temperature or in a refrigerator. Photographic development is done in Microdol, or in a special fine grain "physical" developer. For examination in the electron microscope the sections are stained with uranyl or lead stains. These methods give a good localization of the label, at the subcellular level, and good reproducibility in relative grain counts. PMID:14018772

  3. Autoradiography: high-resolution molecular imaging in pharmaceutical discovery anddevelopment.

    PubMed

    Solon, Eric G

    2007-04-01

    Autoradiography (ARG) is a powerful, high resolution, quantitative molecular imaging technique used to study the tissue distribution of radiolabeled xenobiotics in biologic models. ARG involves the close apposition of solid specimens containing a radiolabeled substance to a detector layer, such as photographic emulsions, film, phosphor imaging plates and direct nuclear imagers/counters. The two basic types include: macroautoradiography, which is imaging of organs, organ systems and/or whole-body sections (WBA) and microautoradiography (MARG), which provides the localization of radioactivity at the cellular level. ARG has supported drug discovery and development efforts for many years and has provided pivotal decision making information for pharmaceutical research. This paper presents a review of the techniques, study designs and present considerations for use of WBA and MARG to support today's drug discovery and development efforts. In addition, this review comments on the integration of the exvivo ARG and invivo molecular imaging techniques to serve pharmaceutical discovery and development in the future. PMID:23484758

  4. Mapping of odor-related neuronal activity in the olfactory bulb by high-resolution 2-deoxyglucose autoradiography

    SciTech Connect

    Lancet, D.; Greer, C.A.; Kauer, J.S.; Shepherd, G.M.

    1982-01-01

    The spatial distribution of odor-induced neuronal activity in the olfactory bulb, the first relay station of the olfactory pathway, is believed to reflect important aspects of chemosensory coding. We report here the application of high-resolution 2-deoxyglucose autoradiography to the mapping of spatial patterns of metabolic activity at the level of single neurons in the olfactory bulb. It was found that glomeruli, which are synaptic complexes containing the first synaptic relay, tend to be uniformly active or inactive during odor exposure. Differential 2-deoxyglucose uptake was also observed in the somata of projection neurons (mitral cells) and interneurons (periglomerular and granule cells). This confirms and extends our previous studies in which odor-specific laminar and focal uptake patterns were revealed by the conventional x-ray film 2-deoxyglucose method due to Sokoloff and colleagues (Sokoloff, L., Reivich, M., Kennedy, C., DesRosiers, M. H., Patlak, C. S., Pettigrew, K. D., Sakurada, O. and Shinohara, M. (1977) J. Neurochem. 28, 897-916). Based on results obtained by the two methods, it is suggested that the glomerulus as a whole serves as a functional unit of activity. The high-resolution results are interpreted in terms of the well-characterized synaptic organization of the olfactory bulb and also serve to illustrate the capability of the 2-deoxyglucose autoradiographic technique to map metabolic activity in single neurons of the vertebrate central nervous system.

  5. High resolution autoradiography at the regional topographic level with [14C]2-deoxyglucose and [3H]2-deoxyglucose.

    PubMed

    Duncan, G E; Stumpf, W E; Pilgrim, C; Breese, G R

    1987-06-01

    After injection of 2-deoxyglucose (2-DG) labeled with tritium or carbon-14, autoradiograms were produced by thaw-mounting 4 micron frozen sections of rat brains on nuclear emulsion-coated slides. The results show that the distribution of radioactivity among different brain regions was similar and that the resolution at the regional topographical level was virtually identical for both compounds. The resolution obtained with the thaw-mounting of thin frozen sections onto nuclear emulsion was considerably greater than the resolution demonstrated in published results in the literature, when carbon-14 or tritium-labeled 2-deoxyglucose were used with 20 micron frozen sections and X-ray film or tritium-sensitive film. The results indicate that section thickness, detection medium and intimacy of contact between section and photographic emulsion influence resolution. At the regional level, the detection medium apparently influences resolution to a greater extent than the energy differences of the beta particles emitted from 14C or 3H. Although diffusion of radiolabeled 2-deoxyglucose and metabolites during the thaw-mounting process precludes single cell resolution of these autoradiograms, the improvement of visualizing regional topographic detail demonstrates that the described technique is a valuable approach with which to study regional 2-DG uptake. PMID:3600030

  6. 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.

  7. 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.

  8. Feasibility of In Situ, High-Resolution Correlation of Tracer Uptake with Histopathology by Quantitative Autoradiography of Biopsy Specimens Obtained Under 18F-FDG PET/CT Guidance

    PubMed Central

    Fanchon, Louise M.; Dogan, Snjezana; Moreira, Andre L.; Carlin, Sean A.; Schmidtlein, C. Ross; Yorke, Ellen; Apte, Aditya P.; Burger, Irene A.; Durack, Jeremy C.; Erinjeri, Joseph P.; Maybody, Majid; Schöder, Heiko; Siegelbaum, Robert H.; Sofocleous, Constantinos T.; Deasy, Joseph O.; Solomon, Stephen B.; Humm, John L.; Kirov, Assen S.

    2016-01-01

    Core biopsies obtained using PET/CT guidance contain bound radiotracer and therefore provide information about tracer uptake in situ. Our goal was to develop a method for quantitative autoradiography of biopsy specimens (QABS), to use this method to correlate 18F-FDG tracer uptake in situ with histopathology findings, and to briefly discuss its potential application. Methods Twenty-seven patients referred for a PET/CT-guided biopsy of 18F-FDG–avid primary or metastatic lesions in different locations consented to participate in this institutional review board–approved study, which complied with the Health Insurance Portability and Accountability Act. Autoradiography of biopsy specimens obtained using 5 types of needles was performed immediately after extraction. The response of autoradiography imaging plates was calibrated using dummy specimens with known activity obtained using 2 core-biopsy needle sizes. The calibration curves were used to quantify the activity along biopsy specimens obtained with these 2 needles and to calculate the standardized uptake value, SUVARG. Autoradiography images were correlated with histopathologic findings and fused with PET/CT images demonstrating the position of the biopsy needle within the lesion. Logistic regression analysis was performed to search for an SUVARG threshold distinguishing benign from malignant tissue in liver biopsy specimens. Pearson correlation between SUVARG of the whole biopsy specimen and average SUVPET over the voxels intersected by the needle in the fused PET/CT image was calculated. Results Activity concentrations were obtained using autoradiography for 20 specimens extracted with 18- and 20-gauge needles. The probability of finding malignancy in a specimen is greater than 50% (95% confidence) if SUVARG is greater than 7.3. For core specimens with preserved shape and orientation and in the absence of motion, one can achieve autoradiography, CT, and PET image registration with spatial accuracy better than 2 mm. The correlation coefficient between the mean specimen SUVARG and SUVPET was 0.66. Conclusion Performing QABS on core-biopsy specimens obtained using PET/CT guidance enables in situ correlation of 18F-FDG tracer uptake and histopathology on a millimeter scale. QABS promises to provide useful information for guiding interventional radiology procedures and localized therapies and for in situ high-spatial-resolution validation of radiopharmaceutical uptake. PMID:25722446

  9. Whole-body and microscopic autoradiography to determine tissue distribution of biopharmaceuticals -- target discoveries with receptor micro-autoradiography engendered new concepts and therapies for vitamin D.

    PubMed

    Stumpf, Walter E

    2013-07-01

    Information about the distribution of biopharmaceuticals is basic for understanding their actions. Tissue and cellular localization is a key to function. Autoradiography with radiolabeled compounds has provided valuable information with both low resolution whole-body macro-autoradiography and high resolution microscopic autoradiography (micro-autoradiography). Whole-body macro-autoradiography is a uniform and expedient single method approach, providing convenient dose- and time-related overviews with data similar to those obtained with conventional bioassays - and therefore widely used. However, whole-body macro-autoradiography, like common bioassays, has limitations. High specificity-low capacity sites of binding and deposition frequently remain unrecognized. Lack of cellular resolution can cause false negatives and provide misleading results (e.g., false blood-brain barrier). For micro-autoradiography, different methods are advertised in the literature. Most of them are, however, unsuited for drug localization because of inadequate resolution and frequent artifacts. Most drugs interact with their receptors non-covalently by weak electrostatic forces. Therefore, translocation and loss can occur during tissue preparation. This has complicated the use of micro-autoradiography. Receptor micro-autoradiography has overcome these complications and is a method of choice. It has been validated through several diffusible compounds with known localization, extensively applied. It has contributed numerous discoveries, followed by new concepts and therapies. Pictorial evidence in this review indicates that cellular information is essential, a 'sine qua non' for meaningful drug distribution studies. High resolution cellular microscopic information obtained from autoradiography requires tissue dissection and the necessary precautions for preserving pristine in vivo drug deposition. Receptor micro-autoradiography fulfils these requirements. It reveals crucial information at the subcellular level that cannot currently be obtained with any other type of autoradiography or spectrometric imaging. PMID:23391491

  10. Resolution in EM autoradiography V: /sup 45/Ca (and /sup 33/P)

    SciTech Connect

    Salpeter, M.M.; Nelson, R.; Harris, R.; Salpeter, E.E.

    1987-10-01

    We devised a specimen to test EM autoradiographic resolution for calcium-45 (and phosphorous-33). A dry emulsion film was used for soluble compounds. We obtained a resolution (HD) value of 2300 +/- 500 A. This value is no larger than that previously obtained for Carbon -14, whose emission is about 1.6-fold lower. This result is as expected on theoretical grounds.

  11. 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.

  12. 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.

  13. Soluble compound electron microscope (EM) autoradiography: a resolution source to test redistribution of soluble tritiated compounds during processing

    SciTech Connect

    Harris, W.V.; Salpeter, M.M.

    1983-04-01

    The development of a resolution source that can be labeled with either a soluble or insoluble tritiated compound, and of a method for applying a dry, uniform monolayer of emulsion is reported. Influences due to redistribution of the soluble isotope during emulsion coating were measured by comparing the grain density distributions around the resolution source for soluble tritiated proline (3H-PRO) with that obtained for cross-linked tritiated bovine serum albumin (3H-BSA). The grain density distributions resulting from a standard method of emulsion application (partly gelled/loop method) are compared to that obtained from a dry stripping film. It was found that only the dry stripping film gave a grain distribution which was statistically not different for the soluble and insoluble specimens.

  14. High-resolution echocardiography

    NASA Technical Reports Server (NTRS)

    Nathan, R.

    1979-01-01

    High resolution computer aided ultrasound system provides two-and three-dimensional images of beating heart from many angles. System provides means for determining whether small blood vessels around the heart are blocked or if heart wall is moving normally without interference of dead and noncontracting muscle tissue.

  15. High resolution drift chambers

    SciTech Connect

    Va'vra, J.

    1985-07-01

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

  16. 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.

  17. 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.

  18. High resolution SNOM probes

    NASA Astrophysics Data System (ADS)

    Antosiewicz, Tomasz J.; Wrbel, Piotr; Szoplik, Tomasz

    2008-12-01

    Development of nanotechnologies demands optical characterization and measurement techniques that yield information with resolutions well below the diffraction limit. This requires an increase of the resolution of scanning near-field optical microscopes (SNOMs) from 50-70 nm commercially available nowadays in the visible range, to beneficial 30 nm, where ? is the wavelength of light in free space. High resolution SNOM probes would be crucial in measurements of point spread functions of superlenses based on negative refraction and characterization of plasmonic circuitry. The resolution of SNOMs is ?r = d + 2a, where d is the diameter of a radiating aperture of a tapered-fiber metal-coated probe and a is a skin depth, that is the distance the electromagnetic field penetrates the metal coating. The size of the radiated field does not exceed the diameter ?r when the aperture-sample distance h is kept constant by the shear-force tuning fork method. One of the resolution parameters, the skin depth a, depends on the metal that coats the dielectric probe and the shape of the metal rim. For Ag and Al, the values of a are on the level of 10nm, when measured on a flat metal surface illuminated with a plane wave. Thus, the other resolution parameter which we intend to decrease is a probe diameter d. The probe should radiate enough energy to be detected in a reasonable scanning measurement time. Recently, we proved that probe emission depends on the charge density induced on the probe rim. To increase this density we propose enhancement of the photon-plasmon coupling on the interface between the dielectric core and the metal coating. To this end we corrugate the interface. In this paper we analyze the role of parameters of the corrugations and report on attempts to fabricate them.

  19. 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.

  20. Very high resolution radiometer

    NASA Technical Reports Server (NTRS)

    Aronson, A. I.

    1974-01-01

    A primary sensor used in environmental and earth-resource observation, the Very High Resolution Radiometer (VHRR) was designed for use on the ITOS D series spacecraft. The VHRR provides a 0.47 mile resolution made possible with a mercury-cadmium-telluride detector cooled to approximately 105 K by a passive radiator cooler. The components of this system are described. The optical subsystem of the VHRR consists of a scanning mirror, a Dall-Kirkham telescope, a dichroic beam splitter, relay lenses, spectral filters, and an IR detector. Signal electronics amplify and condition the signals from the infrared and visible light detector. Sync generator electronics provides the necessary time signals. Scan-drive electronics is used for commutation of the motor winding, velocity, and phase control. A table lists the performance parameters of the VHRR.

  1. Autoradiography techniques and quantification of drug distribution.

    PubMed

    Solon, Eric G

    2015-04-01

    The use of radiolabeled drug compounds offers the most efficient way to quantify the amount of drug and/or drug-derived metabolites in biological samples. Autoradiography is a technique using X- ray film, phosphor imaging plates, beta imaging systems, or photo-nuclear emulsion to visualize molecules or fragments of molecules that have been radioactively labeled, and it has been used to quantify and localize drugs in tissues and cells for decades. Quantitative whole-body autoradiography or autoradioluminography (QWBA) using phosphor imaging technology has revolutionized the conduct of drug distribution studies by providing high resolution images of the spatial distribution and matching tissue concentrations of drug-related radioactivity throughout the body of laboratory animals. This provides tissue-specific pharmacokinetic (PK) compartmental analysis which has been useful in toxicology, pharmacology, and drug disposition/patterns, and to predict human exposure to drugs and metabolites, and also radioactivity, when a human radiolabeled drug study is necessary. Microautoradiography (MARG) is another autoradiographic technique that qualitatively resolves the localization of radiolabeled compounds to the cellular level in a histological preparation. There are several examples in the literature of investigators attempting to obtain drug concentration data from MARG samples; however, there are technical issues which make that problematic. These issues will be discussed. This review will present a synopsis of both techniques and examples of how they have been used for drug research in recent years. PMID:25604842

  2. 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 Energys National Nuclear Security Administrations Office of Dismantlement and Transparency (DOE/NNSA/NA-241).

  3. Kinetics and autoradiography of high affinity uptake of serotonin by primary astrocyte cultures

    SciTech Connect

    Katz, D.M.; Kimelberg, H.K.

    1985-07-01

    Primary astrocyte cultures prepared from the cerebral cortices of neonatal rats showed significant accumulation of serotonin (5-hydroxytryptamine; (/sup 3/H)-5-HT). At concentrations in the range of 0.01 to 0.7 microM (/sup 3/H)-5-HT, this uptake was 50 to 85% Na+ dependent and gave a Km of 0.40 +/- 0.11 microM (/sup 3/H)-5-HT and a Vmax of 6.42 +/- 0.85 (+/- SEM) pmol of (/sup 3/H)-5-HT/mg of protein/4 min for the Na+-dependent component. In the absence of Na+ the uptake was nonsaturable. Omission of the monoamine oxidase inhibitor pargyline markedly reduced the Na+-dependent component of (/sup 3/H)-5-HT uptake but had a negligible effect on the Na+-independent component. This suggest significant oxidative deamination of serotonin after it has been taken up by the high affinity system, followed by release of its metabolite. The authors estimated that this system enabled the cells to concentrate (/sup 3/H)-5-HT up to 44-fold at an external (/sup 3/H)-5-HT concentration of 10(-7) M. Inhibition of (/sup 3/H)-5-HT uptake by a number of clinically effective antidepressants was also consistent with a specific high affinity uptake mechanism for 5-HT, the order of effectiveness of inhibition being chlorimipramine greater than fluoxetine greater than imipramine = amitriptyline greater than desmethylimipramine greater than iprindole greater than mianserin. Uptake of (/sup 3/H)-5-HT was dependent on the presence of Cl- as well as Na+ in the medium, and the effect of omission of both ions was nonadditive. Varying the concentration of K+ in the media from 1 to 50 mM had a limited effect on (/sup 3/H)-5-HT uptake.

  4. High resolution ultrasonic densitometer

    SciTech Connect

    Dress, W.B.

    1983-01-01

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

  5. High resolution ultrasonic densitometer

    SciTech Connect

    Dress, W.B.

    1983-01-01

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

  6. 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

  7. 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

  8. High Resolution Doppler Imager

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.

    1999-01-01

    This report summarizes the accomplishments of the High Resolution Doppler Imager (HRDI) on UARS spacecraft during the period 4/l/96 - 3/31/99. During this period, HRDI operation, data processing, and data analysis continued, and there was a high level of vitality in the HRDI project. The HRDI has been collecting data from the stratosphere, mesosphere, and lower thermosphere since instrument activation on October 1, 1991. The HRDI team has stressed three areas since operations commenced: 1) operation of the instrument in a manner which maximizes the quality and versatility of the collected data; 2) algorithm development and validation to produce a high-quality data product; and 3) scientific studies, primarily of the dynamics of the middle atmosphere. There has been no significant degradation in the HRDI instrument since operations began nearly 8 years ago. HRDI operations are fairly routine, although we have continued to look for ways to improve the quality of the scientific product, either by improving existing modes, or by designing new ones. The HRDI instrument has been programmed to collect data for new scientific studies, such as measurements of fluorescence from plants, measuring cloud top heights, and lower atmosphere H2O.

  9. 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.

  10. High Resolution Formaldehyde Photochemistry

    NASA Astrophysics Data System (ADS)

    Ernest, C. T.; Bauer, D.; Hynes, A. J.

    2010-12-01

    Formaldehyde (HCHO) is the most abundant and most important organic carbonyl compound in the atmosphere. The sources of formaldehyde are the oxidation of methane, isoprene, acetone, and other volatile organic compounds (VOCs); fossil fuel combustion; and biomass burning. The dominant loss mechanism for formaldehyde is photolysis which occurs via two pathways: (R1) HCHO + hv ? HCO + H (R2) HCHO + hv ? H2 + CO The first pathway (R1) is referred to as the radical channel, while the second pathway (R2) is referred to as the molecular channel. The products of both pathways play a significant role in atmospheric chemistry. The CO that is produced in the molecular channel undergoes further oxidation to produce CO2. Under atmospheric conditions, the H atom and formyl radical that are produced in the radical channel undergo rapid reactions with O2 to produce the hydroperoxyl radical (HO2) via (R3) and (R4). (R3) HCO + O2 ? HO2 + CO (R4) H + O2 ? HO2 Thus, for every photon absorbed, the photolysis of formaldehyde can contribute one CO2 molecule to the global greenhouse budget or two HO2 radicals to the tropospheric HOx (OH + HO2) cycle. The HO2 radicals produced during formaldehyde photolysis have also been implicated in the formation of photochemical smog. The HO2 radicals act as radical chain carriers and convert NO to NO2, which ultimately results in the catalytic production of O3. Constraining the yield of HO2 produced via HCHO photolysis is essential for improving tropospheric chemistry models. In this study, both the absorption cross section and the quantum yield of the radical channel (R1) were measured at high resolution over the tropospherically relevant wavelength range 304-330 nm. For the cross section measurements a narrow linewidth Nd:YAG pumped dye laser was used with a multi-pass cell. Partial pressures of HCHO were kept below 0.3 torr. Simultaneous measurement of OH LIF in a flame allowed absolute calibration of the wavelength scale. Pressure broadening in He, O2, N2, and H2O bath gas was also examined. Measurements of the radical yield of HCHO photolysis were conducted by converting the H atom to OH through reaction with NO2 via (R5) and then detecting OH LIF using a Pulsed Laser Photolysis-Pulsed Laser Induced Fluorescence (PLP-PLIF) technique. (R5) H + NO2 ? NO + OH The resulting relative quantum yield was converted to an absolute yield by using Cl2 photolysis (and the subsequent reaction of the Cl atom with HCHO) coupled with a photofragment-LIF variation of the PLP-PLIF technique.

  11. 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.

  12. 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.

  13. High resolution telescope

    DOEpatents

    Massie, Norbert A.; Oster, Yale

    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.

  14. High resolution bubble chambers

    SciTech Connect

    Bizzarri, R.

    1984-01-01

    This chapter discusses the performances obtained or to be expected from small bubble chambers with ''classical'' optics (i.e. no holography). LEBC and HOLEBC, two hydrogen chambers, are used. The limits on the accessible cross sections, the limits on the accessible life times, the limits on the resolution, and bubble density are considered. In the experiment with the bubble chamber LEBC, two lenses were used of focal length f=180 mm, open at f/11 and with a space to film demagnification m=3.2. In the experiment with HOLBEC, lenses of f=300 mm at f/17 are used with a demagnification m=.9.

  15. 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.

  16. 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.

  17. Autoradiography of phosphatidyl choline

    SciTech Connect

    Saffitz, J.E.; Gross, R.W.; Williamson, J.R.; Sobel, B.E.

    1981-03-01

    Saturated choline phosphatides are extracted during conventional tissue processing for electron microscopy. To facilitate autoradiographic subcellular localization of arrhythmogenic myocardial phospholipids, we evaluated tissue processing procedures for preservation of saturated phosphatidyl choline (PC). Suspensions, of a murine plasmacytoma were incubated with negative, unilamellar liposomes containing 14C-choline-labeled PC or 14C-1-palmitate dipalmitoyl PC. Extraction of radioactivity was monitored at each processing step by liquid scintillation spectrometry. Conventional fixation with glutaraldehyde and osmium tetroxide followed by acetone dehydration and Spurr's plastic embedding led to extraction of nearly all radioactivity. However, treatment of cells with 1.5% tannic acid after glutaraldehyde but before osmium tetroxide fixation preserved 93.1 +/- .6% of 14C-choline-labeled PC. Virtually identical results were obtained with dipalmitoyl PC. Autoradiography demonstrated no significant translocation of labeled PC from plasmacytoma cells to unlabeled avian erythrocytes, mixed in equal proportions after fixation but before dehydration and embedding.

  18. 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.

  19. 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).

  20. 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

  1. High Resolution Black Hole Simulations

    NASA Astrophysics Data System (ADS)

    Walter, Paul; Matzner, Richard; Allen, Jon; Nerozzi, Andrea; Anderson, Matt

    2008-04-01

    Developed at the University of Texas, openGR is an open framework for numerical simulations. We discuss results of high resolution binary black hole merger simulations and the resulting gravitational radiation. Fixed Mesh Refinement (FMR) simulations using openGR were carried out on Ranger, the new supercomputer at TACC (Texas Advanced Computing Center). Convergence results are also discussed.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. High Resolution Thermometry for EXACT

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  13. 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.

  14. 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.

  15. Global high resolution climate reconstructions

    NASA Astrophysics Data System (ADS)

    Schubert-Frisius, Martina; Feser, Frauke; Zahn, Matthias; von Storch, Hans; Rast, Sebastian

    2014-05-01

    Long-term reanalysis products represent an important data source for numerous climate studies. However, their coarse spatial resolution for data sets spanning the last more than 50 years and well known inhomogeneities in space and time make it difficult to derive changes in meteorological variables over time. We therefore use spectral nudging technique to down-scale the global reanalysis data to a finer resolution with a general global circulation model. With this technique the new calculated higher resolved global model fields are attracted to the large-scale state of the coarse resolution reanalysis. Besides the conservation of large-scale atmospheric information and the resulting finer topography, a surplus in contents of information in meteorological phenomena of small spatial extensions is expected. Following this strategy a simulation with the global high-resolution atmospheric model ECHAM6 (T255L95), developed by MPI-M Hamburg, will be started by spectrally nudging NCEP1 reanalysis for the time period from 1948 until 2013. Selected wavelengths of more than 1000 km of vorticity, divergence, temperature and the logarithm of the surface pressure will be imposed onto the simulated GCM counterparts at levels above 750 hPa. SST and sea ice distribution are taken from the NCEP1 data set. These simulations enable the investigation of long-term changes in meteorological phenomena; the focus is put here on intense storms. Various horizontal wavelength selections and associated vertical profiles in the strength of nudging were tested. The temporarily best configuration resulted in large time correlations for 2m-temperature and 10m wind speed at several selected locations in Germany in comparison to observations. Correlations were highest for extra-tropical regions, while over the western part of the Pacific and Indian Ocean relative low time correlations were found. In a continuing study meteorological quantities at different levels and the influences of the nudging configuration on the detection and tracking of intense storms will be investigated.

  16. High Resolution Scanning Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  17. High-resolution immersion viewer

    NASA Astrophysics Data System (ADS)

    Lipton, Lenny

    1994-04-01

    This paper is about a field-sequential electro-stereoscopic virtual reality (VR) viewing device which incorporates electro-optical shutters, and lenses that aid accommodation and convergence. Each eye looks through a combination of prismatic and positive-diopter lenses, and the same shutters used in CrystalEyesR eyewear are used for image selection. This is the first lenticular stereoscope to employ the time-multiplexing technique with superimposed images and shutters functioning as a kind of electronic septum. The result is a product with relatively low cost, high resolution, and a wide field of view.

  18. High-Resolution Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff; Goetz, Alexander F. H.

    1990-01-01

    Earth resources observed in greater detail. High-Resolution Imaging Spectrometer, undergoing development for use in NASA's Earth Observing System, measures reflectance of Earth's surface in visible and near-infrared wavelengths. From an orbit around Earth, instrument scans surface of Earth in 200 wavelength bands simultaneously. Produces images enabling identification of minerals in rocks and soils, important algal pigments in oceans and inland waters, changes in spectra associated with biochemistry of plant canopies, compositions of atmospheric aerosols, sizes of grains in snow, and contamination of snow by impurities that absorb visible light.

  19. 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.

  20. 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)…

  1. 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)

  2. 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.

  3. 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

  4. Solar corona at high resolution

    NASA Astrophysics Data System (ADS)

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

    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.

  5. 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.

  6. 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.

  7. 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

  8. 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

  9. Practising high-resolution anoscopy.

    PubMed

    Palefsky, Joel M

    2012-12-01

    The incidence of anal cancer is increasing in the general population among both men and women. The incidence is particularly high among men who have sex with men and HIV-infected men and women. Anal cancer is similar to cervical cancer and is associated with human papillomavirus (HPV). Anal cancer is potentially preventable through primary prevention with HPV vaccination or secondary prevention. Secondary prevention is modelled after cervical cancer, where cytology is used as a screening tool to identify women who need colposcopy. Colposcopy includes magnification of the cervix, which, along with acetic acid and Lugol's solution, is used to visualise and biopsy potentially precancerous lesions, enabling treatment before progression to cervical cancer. Anal cancer is likely preceded by high-grade anal intraepithelial neoplasia (HGAIN), and a colposcope with acetic acid and Lugol's solution may similarly be used to visualise HGAIN to permit biopsy and treatment in an effort to prevent anal cancer. To distinguish it from cervical colposcopy, this technique is called high-resolution anoscopy (HRA). Many of the features that distinguish low-grade AIN from HGAIN are similar to those of the cervix, but HRA poses several additional challenges compared with cervical colposcopy. These include uneven topography; obscuring of lesions due to haemorrhoids, folds, stool or mucus; or lesions being located at the base of folds and anal glands. Consequently, a long learning curve is typically required before becoming fully competent in this technique. The technique of HRA, its uses and challenges in prevention of anal cancer are described in this article. PMID:23380236

  10. High resolution auditory perception system

    NASA Astrophysics Data System (ADS)

    Alam, Iftekhar; Ghatol, Ashok

    2005-04-01

    Blindness is a sensory disability which is difficult to treat but can to some extent be helped by artificial aids. The paper describes the design aspects of a high resolution auditory perception system, which is designed on the principle of air sonar with binaural perception. This system is a vision substitution aid for enabling blind persons. The blind person wears ultrasonic eyeglasses which has ultrasonic sensor array embedded on it. The system has been designed to operate in multiresolution modes. The ultrasonic sound from the transmitter array is reflected back by the objects, falling in the beam of the array and is received. The received signal is converted to a sound signal, which is presented stereophonically for auditory perception. A detailed study has been done as the background work required for the system implementation; the appropriate range analysis procedure, analysis of space-time signals, the acoustic sensors study, amplification methods and study of the removal of noise using filters. Finally the system implementation including both the hardware and the software part of it has been described. Experimental results on actual blind subjects and inferences obtained during the study have also been included.

  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, 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.

  13. 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.

  14. Publications | High Resolution Electron Microscopy

    Cancer.gov

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

  15. 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.

  16. High resolution amorphous silicon radiation detectors

    DOEpatents

    Street, Robert A.; Kaplan, Selig N.; Perez-Mendez, Victor

    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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. New methods in high resolution neutron spectroscopy

    NASA Astrophysics Data System (ADS)

    Heidemann, A.

    1994-10-01

    A review is given on the state of the art of high resolution neutron spectroscopy techniques including backscattering and neutron spin echo. New methods in high resolution neutron spectroscopy such as double focusing, gradient, ultrasound excited, active, multiplexing, offset and other complex monochromators will be discussed. Sub-neV tunneling spectroscopy with NSE might become feasible soon. Projects on future neutron sources are mentioned. On these powerful sources new concepts for instruments will emerge from the symbiosis of ultra high flux, sharp time structure and modern neutron optics. These developments will lead high resolution neutron spectroscopy into exciting new applications in the 21st century.

  3. 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.

  4. 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

  5. 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)

  6. High-resolution spectrometer at PEP

    SciTech Connect

    Weiss, J.M.; HRS Collaboration

    1982-01-01

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

  7. High Resolution MOS Forecasts Based on a Low Resolution Model

    NASA Astrophysics Data System (ADS)

    Knpffer, K.

    2009-09-01

    MOS (Model Output Statistics) reduces approximately 50% of the error variance of the Direct Model Output forecasts of a numerical model - no matter whether high or low resolution - for standard weather elements like temperatures, wind and cloud cover. However, MOS forecasts are usually only provided at the very places where the observation locations are situated. In the presentation, a technology will be outlined which allows MOS forecasts for any location between the observation locations. Meteo Service has introduced a technology which relies on the interpolation of MOS coefficients (not MOS forecasts). This technology based on orographic descriptors has already been in use with the German National Weather Service (DWD) since 1996. These orographic descriptors refer to latitude, longitude, elevation and the difference between the elevation of the smoothed model orography, and the real elevation. This difference is used in order to distinguish between mountain and valley. In addition, an attribute such as land, sea, coast and mountain summits has been used as binary orographic descriptor. Nowadays high resolution grid information is available, and more complex orographic descriptors can be used. NOAA/NGDC orographic data is available in a resolution of approximately 0,5 x 0,5 km and allows for the definition of the following orographic descriptors with different spatial smoothing: - elevation - slope (= first derivative of elevation) - valley/hill (= second derivative of elevation). A difference between the weighted orographic desriptors is used to define the representativeness between interpolation points and observation locations. This representativeness is the norm of a multi-dimensional vector with the number of dimensions being equal to the number of orographic descriptors. A procedure to search for the most informative set of representative observation locations for a given interpolation point is applied. Finally interpolation weights are calculated for the selected observation locations. Results of the application of the concept of coefficient interpolation outlined above are presented using MOS forecasts for homogeneous, alpine and coastal orography. The results are convincing in particular, in areas where there is sufficient density of observation locations. Problems remain in areas with lower density of observation locations and complex orography. Interpolated Direct Model Output in the last resort is to be used in order to achieve complete fields of high resolution MOS forecasts based on a low resolution model.

  8. Two-dimensional protein analysis at high resolution on a microscale.

    PubMed

    Neukirchen, R O; Schlosshauer, B; Baars, S; Jckle, H; Schwarz, U

    1982-12-25

    Proteins from small amounts of biological material are separated at high resolution by micro two-dimensional gel electrophoresis. Under nonequilibrium conditions, proteins are focused in 10-microliters capillaries and separated on ultrathin slab gels. Our device allows simultaneous focusing of up to 10 samples which can be processed in the second dimension on a single gel. Several hundred protein spots from less than a total of 300 ng of protein are resolved on an area the size of a postage stamp. A single spot containing less than 10 pg of protein or 1 cpm can be detected by silver staining or autoradiography, respectively. Our system allows inexpensive, simultaneous, rapid analysis of proteins when only a limited amount of biological material is available for investigation. A detailed description of the equipment, the methods, and the characteristics of this microanalysis are presented. PMID:7174694

  9. 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.

  10. HIS - A high resolution atmospheric sounder

    NASA Technical Reports Server (NTRS)

    Smith, W. L.; Revercomb, H. E.; Huang, H.-L.; Woolf, H. M.; Howell, H. B.

    1987-01-01

    This paper describes the High-Resolution Interferometer Sounder (HIS), which is the first of a new generation of passive remote sensors for achieving high vertical resolution sounding information, with special attention given to the sounding retrieval procedure. Examples of mesoscale temperature and moisture profiles obtained with airborne HIS during field programs held in 1986 are presented. A spacecraft version of the instrument, to be used in advanced global weather analysis and forecasting, is under development.

  11. 14C autoradiography with a novel wafer scale CMOS Active Pixel Sensor

    NASA Astrophysics Data System (ADS)

    Esposito, M.; Anaxagoras, T.; Larner, J.; Allinson, N. M.; Wells, K.

    2013-01-01

    14C autoradiography is a well established technique for structural and metabolic analysis of cells and tissues. The most common detection medium for this application is film emulsion, which offers unbeatable spatial resolution due to its fine granularity but at the same time has some limiting drawbacks such as poor linearity and rapid saturation. In recent years several digital detectors have been developed, following the technological transition from analog to digital-based detection systems in the medical and biological field. Even so such digital systems have been greatly limited by the size of their active area (a few square centimeters), which have made them unsuitable for routine use in many biological applications where sample areas are typically ~ 10-100 cm2. The Multidimensional Integrated Intelligent Imaging (MI3-Plus) consortium has recently developed a new large area CMOS Active Pixel Sensor (12.8 cm 13.1 cm). This detector, based on the use of two different pixel resolutions, is capable of providing simultaneously low noise and high dynamic range on a wafer scale. In this paper we will demonstrate the suitability of this detector for routine beta autoradiography in a comparative approach with widely used film emulsion.

  12. X-ray holography with high resolution

    SciTech Connect

    Chen Jianwen; Zhu Peiping; Xiao Tiqiao; Xu Zhizhan

    1995-05-01

    Some primary factors having effects on the resolution in x-ray holography are discussed. The factors in recording x-ray holograms are the x-ray coherent scattering by the specimen, the recording method and the coherence of the x-ray beam. There are two factors in reconstruction of the hologram. One is that the resolution of the detector may be lower than the spatial frequencies of fringes in x-ray holograms. The other is aberrations. Consequently, some conditions of x-ray holography with high resolution are given.

  13. Creation of high resolution pattern by nanoscratching

    NASA Astrophysics Data System (ADS)

    Rami?czek-Krasowska, Maria; Pra?mowska, Joanna; Los, Kornelia; Stafiniak, Andrzej; Szyszka, Adam; Paszkiewicz, Regina; Orski, Wojciech; Tarnowski, Karol; T?acza?a, Marek

    2011-04-01

    The lithography is a basic microelectronic process which determines properties of fabricated device. The resolution of optical lithography applied nowadays is insufficient for creating high resolution patterns such as gate electrode in transistors. The scaling ability is the major motivation for undertaking experiments to elaborate high resolution lithography techniques. The atomic force microscope (AFM) is commonly used as tool for creation patterns in sub-micrometers resolution. In this paper, the results of simulations of electromagnetic field behavior during passing the gap with a size smaller than the wavelength of the optical lithography light source are presented. Also results of the nanoscratching lithography prepared for various parameters of force that are applied to the tip are summarized.

  14. 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 μm 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 μm pixel. Energy spectra and detection efficiency were successfully measured for seven radionuclides. The system dead time was measured to be 59 μs, and FWHM for a {sup 58}Co line source was 154 ± 14 μm for the DSSD system and 343 ± 15 μm 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Superconducting high resolution fast-neutron spectrometers

    NASA Astrophysics Data System (ADS)

    Hau, Ionel Dragos

    Superconducting high resolution fast-neutron calorimetric spectrometers based on 6LiF and TiB2 absorbers have been developed. These novel cryogenic spectrometers measure the temperature rise produced in exothermal (n, alpha) reactions with fast neutrons in 6Li and 10B-loaded materials with heat capacity C operating at temperatures T close to 0.1 K. Temperature variations on the order of 0.5 mK are measured with a Mo/Cu thin film multilayer operated in the transition region between its superconducting and its normal state. The advantage of calorimetry for high resolution spectroscopy is due to the small phonon excitation energies kBT on the order of mueV that serve as signal carriers, resulting in an energy resolution DeltaE ? (k BT2C)1/2, which can be well below 10 keV. An energy resolution of 5.5 keV has been obtained with a Mo/Cu superconducting sensor and a TiB2 absorber using thermal neutrons from a 252Cf neutron source. This resolution is sufficient to observe the effect of recoil nuclei broadening in neutron spectra, which has been related to the lifetime of the first excited state in 7Li. Fast-neutron spectra obtained with a 6Li-enriched LiF absorber show an energy resolution of 16 keV FWHM, and a response in agreement with the 6Li(n, alpha) 3H reaction cross section and Monte Carlo simulations for energies up to several MeV. The energy resolution of order of a few keV makes this novel instrument applicable to fast-neutron transmission spectroscopy based on the unique elemental signature provided by the neutron absorption and scattering resonances. The optimization of the energy resolution based on analytical and numerical models of the detector response is discussed in the context of these applications.

  1. A High Resolution Scale-of-four

    DOE R&D Accomplishments Database

    Fitch, V.

    1949-08-25

    A high resolution scale-of-four has been developed to be used in conjunction with the nuclear particle detection devices in applications where the counting rate is unusually high. Specifically, it is intended to precede the commercially available medium resolution scaling circuits and so decrease the resolving time of the counting system. The circuit will function reliably on continuously recurring pulses separated by less than 0.1 microseconds. It will resolve two pulses (occurring at a moderate repetition rate) which are spaced at 0.04 microseconds. A five-volt input signal is sufficient to actuate the device.

  2. 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.

  3. 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.

  4. High-resolution electrohydrodynamic jet printing

    NASA Astrophysics Data System (ADS)

    Park, Jang-Ung; Hardy, Matt; Kang, Seong Jun; Barton, Kira; Adair, Kurt; Mukhopadhyay, Deep Kishore; Lee, Chang Young; Strano, Michael S.; Alleyne, Andrew G.; Georgiadis, John G.; Ferreira, Placid M.; Rogers, John A.

    2007-10-01

    Efforts to adapt and extend graphic arts printing techniques for demanding device applications in electronics, biotechnology and microelectromechanical systems have grown rapidly in recent years. Here, we describe the use of electrohydrodynamically induced fluid flows through fine microcapillary nozzles for jet printing of patterns and functional devices with submicrometre resolution. Key aspects of the physics of this approach, which has some features in common with related but comparatively low-resolution techniques for graphic arts, are revealed through direct high-speed imaging of the droplet formation processes. Printing of complex patterns of inks, ranging from insulating and conducting polymers, to solution suspensions of silicon nanoparticles and rods, to single-walled carbon nanotubes, using integrated computer-controlled printer systems illustrates some of the capabilities. High-resolution printed metal interconnects, electrodes and probing pads for representative circuit patterns and functional transistors with critical dimensions as small as 1?m demonstrate potential applications in printed electronics.

  5. 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

  6. 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...

  7. High resolution electronic spectroscopy on deuterated anisole

    NASA Astrophysics Data System (ADS)

    Pasquini, M.; Schiccheri, N.; Becucci, M.; Pietraperzia, G.

    2009-04-01

    New experimental data on the properties of different anisole deuterated species has been obtained using high resolution electronic spectroscopy methods on a molecular beam. The experimental information have been compared with ab initio calculations at different level of theory leading to a more clear understanding on the S 1 properties of anisole.

  8. 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…

  9. Sparse and accurate high resolution SAR imaging

    NASA Astrophysics Data System (ADS)

    Vu, Duc; Zhao, Kexin; Rowe, William; Li, Jian

    2012-05-01

    We investigate the usage of an adaptive method, the Iterative Adaptive Approach (IAA), in combination with a maximum a posteriori (MAP) estimate to reconstruct high resolution SAR images that are both sparse and accurate. IAA is a nonparametric weighted least squares algorithm that is robust and user parameter-free. IAA has been shown to reconstruct SAR images with excellent side lobes suppression and high resolution enhancement. We first reconstruct the SAR images using IAA, and then we enforce sparsity by using MAP with a sparsity inducing prior. By coupling these two methods, we can produce a sparse and accurate high resolution image that are conducive for feature extractions and target classification applications. In addition, we show how IAA can be made computationally efficient without sacrificing accuracies, a desirable property for SAR applications where the size of the problems is quite large. We demonstrate the success of our approach using the Air Force Research Lab's "Gotcha Volumetric SAR Data Set Version 1.0" challenge dataset. Via the widely used FFT, individual vehicles contained in the scene are barely recognizable due to the poor resolution and high side lobe nature of FFT. However with our approach clear edges, boundaries, and textures of the vehicles are obtained.

  10. 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.

  11. 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 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 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

  12. 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

  13. 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.

  14. 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

  15. High-resolution traction force microscopy.

    PubMed

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

    2014-01-01

    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

  16. High resolution electron crystallography of protein molecules

    SciTech Connect

    Glaeser, R.M. |; Downing, K.H.

    1993-06-01

    Electron diffraction data and high resolution images can now be used to obtain accurate, three-dimensional density maps of biological macromolecules. These density maps can be interpreted by building an atomic-resolution model of the structure into the experimental density. The Cowley-Moodie formalism of dynamical diffraction theory has been used to validate the use of kinematic diffraction theory, strictly the weak phase object approximation, in producing such 3-D density maps. Further improvements in the preparation of very flat specimens and in the retention of diffraction to a resolution of 0.2 nm or better could result in electron crystallography becoming as important a technique as x-ray crystallography currently is for the field of structural molecular biology.

  17. 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.

  18. HIRIS - The High Resolution Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Dozier, Jeff

    1988-01-01

    The High-Resolution Imaging Spectrometer (HIRIS) is a JPL facility instrument designed for NASA's Earth Observing System (Eos).It will have 10-nm wide spectral bands from 0.4-2.5 microns at 30 m spatial resolution over a 30 km swath. The spectral resolution allows identification of many minerals in rocks and soils, important algal pigments in oceans and inland waters, spectral changes associated with plant canopy biochemistry, composition of atmospheric aerosols, and grain size of snow and its contamination by absorbing impurities. The bands wil have 12-bit quantization over a dynamic range suitable for bright targets, such as snow. For targets of low brightness, such as water bodies, image-motion compensation will allow gains up to a factor of eight to increase signal-to-noise ratios. In the 824-km orbit altitude proposed for Eos, the crosstrack pointing capability will allow 4-5 views during a 16-day revisit cycle.

  19. 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.

  20. High-Resolution Photoelectron and Photoionization Spectroscopy

    NASA Astrophysics Data System (ADS)

    Merkt, F.

    2012-06-01

    Since its development in the late 1950s and early 1960s, photoelectron spectroscopy has established itself as an important method to study the electronic structure of molecules, their photoionization dynamics, and the structure and dynamics of molecular cations. In recent years, and particularly since the development of pulsed-field-ionization zero-kinetic-energy (PFI-ZEKE) photoelectron spectroscopy, considerable progress has been made in the resolution that can be achieved by photoelectron spectroscopy. This progress relies on the systematic exploitation of the unusual physical properties of high Rydberg states and enables one today to resolve the rotational structure in the photoelectron spectra of even large molecules and the hyperfine structure in the photoelectron spectra of small molecules. This talk will begin with a brief historical review of photoelectron spectroscopy. Then, the relationship between photoelectron spectroscopy, photoionization spectroscopy and the spectroscopy of high Rydberg states will be discussed. It will be explained how this relationship is currently exploited to improve the resolution achievable by PFI-ZEKE photoelectron spectroscopy. Then, the physical principles that are at the heart of the latest methods related to high-resolution photoelectron spectroscopy will be described together with their fundamental limitations. Depending on the resolution and the spectral range needed to address a specific scientific problem, a choice can be made between several different methods with spectral resolutions ranging from 30 GHz to better than 1 MHz. The talk will summarize the current state of the art in gas-phase photoelectron spectroscopy and be illustrated by several examples, primarily taken from the research in my group, in which photoelectron spectroscopy has contributed to answer questions concerning the structure and dynamics of small-sized molecular cations. F. I. Vilesov, B. C. Kurbatov, and N. Terrenin, Soviet Phys. (Doklady) 6, 490 (1961) D. W. Turner and M. I. Al-Jobory, J. Chem. Phys. 37, 3007 (1962) G. Reiser, W. Habenicht, K. Mller-Dethlefs and E. W. Schlag, Chem. Phys. Lett. 152, 119 (1988) F. Merkt, S. Willitsch and U. Hollenstein, High-resolution photoelectron spectroscopy, in: Handbook of high-resolution spectroscopy, eds. M. Quack and F. Merkt (Wiley, Chichester, 2011), Vol. III, pp 1617-1654

  1. 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-Prot 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.

  2. 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

  3. 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.

  4. High resolution light microscopy in renal pathology.

    PubMed

    Hoffmann, E O; Flores, T R

    1981-11-01

    Seven hundred renal specimens embedded in epoxy resins and stained with polychromatic stains were compared with paraffin sections stained with Hematoxylin and Eosin (H & E), Perodic and Schiff, (PAS), silver, and trichrome stains. High resolution of light microscopy, never in wax histopathology, may be obtained by the use of plastic embedding and polychromatic stains. Cell boundaries, intracellular organelles, basement membranes, different cellular types, apposition of different substances, and other pathologic changes were readily recognized in a single P + P (Plastic section stained with Polychromatic stains) section, whereas paraffin sections usually needed special stains. The same plastic block may be used for transmission electron microscopy. Slightly elevated cost, special training of the technician and pathologist, and some few remaining technical difficulties are the disadvantages of this method. High resolution light microscopy methods are recommended for routine renal biopsies. PMID:7027785

  5. High spatial resolution passive microwave sounding systems

    NASA Technical Reports Server (NTRS)

    Staelin, D. H.; Rosenkranz, P. W.; Bonanni, P. G.; Gasiewski, A. W.

    1986-01-01

    Two extensive series of flights aboard the ER-2 aircraft were conducted with the MIT 118 GHz imaging spectrometer together with a 53.6 GHz nadir channel and a TV camera record of the mission. Other microwave sensors, including a 183 GHz imaging spectrometer were flown simultaneously by other research groups. Work also continued on evaluating the impact of high-resolution passive microwave soundings upon numerical weather prediction models.

  6. 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.

  7. Obtaining high resolution XUV coronal images

    NASA Technical Reports Server (NTRS)

    Golub, L.; Spiller, E.

    1992-01-01

    Photographs obtained during three flights of an 11 inch diameter normal incident soft X-ray (wavelength 63.5 A) telescope are analyzed and the data are compared to the results expected from tests of the mirror surfaces. Multilayer coated X ray telescopes have the potential for 0.01 arcsec resolution, and there is optimism that such high quality mirrors can be built. Some of the factors which enter into the performance actually achieved in practice are as follows: quality of the mirror substrate, quality of the multilayer coating, and number of photons collected. Measurements of multilayer mirrors show that the actual performance achieved in the solar X-ray images demonstrates a reduction in the scattering compared to that calculated from the topography of the top surface of the multilayer. In the brief duration of a rocket flight, the resolution is also limited by counting statistics from the number of photons collected. At X-ray Ultraviolet (XUV) wavelengths from 171 to 335 A the photon flux should be greater than 10(exp 10) ph/sec, so that a resolution better than 0.1 arcsec might be achieved, if mirror quality does not provide a limit first. In a satellite, a large collecting area will be needed for the highest resolution.

  8. CrIS High Resolution Hyperspectral Radiances

    NASA Astrophysics Data System (ADS)

    Hepplewhite, C. L.; Strow, L. L.; Motteler, H.; Desouza-Machado, S. G.; Tobin, D. C.; Martin, G.; Gumley, L.

    2014-12-01

    The CrIS hyperspectral sounder flying on Suomi-NPPpresently has reduced spectral resolution in the mid-wave andshort-wave spectral bands due to truncation of the interferograms inorbit. CrIS has occasionally downlinked full interferograms for thesebands (0.8 cm max path, or 0.625 cm-1 point spacing) for a feworbits up to a full day. Starting Oct.1, 2014 CrIS will be commandedto download full interferograms continuously for the remainder of themission, although NOAA will not immediately produce high-spectralresolution Sensor Data Records (SDRs). Although the originalmotivation for operating in high-resolution mode was improved spectralcalibration, these new data will also improve (1) vertical sensitivityto water vapor, and (2) greatly increase the CrIS sensitivity tocarbon monoxide. This should improve (1) NWP data assimilation ofwater vapor and (2) provide long-term continuity of carbon monoxideretrievals begun with MOPITT on EOS-TERRA and AIRS on EOS-AQUA. Wehave developed a SDR algorithm to produce calibrated high-spectralresolution radiances which includes several improvements to theexisting CrIS SDR algorithm, and will present validation of thesehigh-spectral resolution radiances using a variety of techniques,including bias evaluation versus NWP model data and inter-comparisonsto AIRS and IASI using simultaneous nadir overpasses (SNOs). Theauthors are presently working to implement this algorithm for NASASuomi NPP Program production of Earth System Data Records.

  9. Binary Cepheids From High-Angular Resolution

    NASA Astrophysics Data System (ADS)

    Gallenne, A.; Mrand, 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

  10. Moderate resolution spectrophotometry of high redshift quasars

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  11. 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.

  12. High-Resolution Camera on AXAF

    NASA Astrophysics Data System (ADS)

    Kenter, Almus T.; Chappell, J. H.; Kraft, Ralph P.; Meehan, G. R.; Murray, Stephen S.; Zombeck, Martin V.; Fraser, George W.

    1996-10-01

    The high resolution camera (HRC) will be one of the two focal plane instruments on the Advanced X-ray Astrophysics Facility, (AXAF). AXAF is a major NASA space observatory and is scheduled for launch in 1998. AXAF will perform high resolution spectrometry and imaging in the x-ray band of 0.1 to 10 keV. The HRC instrument consists of two detectors, the HRC-I for imaging and the HRC-S for spectroscopy. Each HRC detector consists of chevron pairs of microchannel plates (MCPs) and a crossed grid charge readout. Spatial resolutions of the HRC detectors are less than 25 micrometer (less than 0.5'). The HRC-I is a 100 by 100 mm detector primarily for imaging, the HRC-S is an approximately 30 by 300 mm detector which is optimized to function as the readout for the low energy transmission grating spectrometer (LETGS). The development of the HRC is a collaborative effort between the Smithsonian Astrophysical Observatory, University of Leicester UK and the Osservatorio Astronomico, G.S. Vaiana, Palermo Italy. In this paper we present the most recent design, development and testing of the HRC instrument.

  13. 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.

  14. Microresonator array for high-resolution spectroscopy.

    PubMed

    Schweiger, Gustav; Nett, Ralf; Weigel, Thomas

    2007-09-15

    We investigated the properties of an array of spherical microresonators used as a miniaturized high-resolution spectroscopic device. Sixteen spherical microspheres made from polymethyl methacrylate were placed on a microscope slide serving as an optical wave guide. Light of a tunable narrowband laser source was coupled into this slide so that an evanescent wave was excited on the topside of the slide, where the resonators were placed. This evanescent field generated a particular intensity pattern in the array that depended sensitively on the wavelength. After calibration, that pattern was recorded by a CCD camera and used to identify the wavelength with a resolution of R ~ lambda/Deltalambda = 7 x 10(4). PMID:17873921

  15. High resolution patterning of silica aerogels

    SciTech Connect

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

    2008-10-30

    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{sup +} 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 {micro}m, 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 by Ag clusters with a size of several {micro}m, separated by thin layers of silica.

  16. Stellar population models at high spectral resolution

    NASA Astrophysics Data System (ADS)

    Maraston, C.; Strmbck, 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 , 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.

  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 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.

  19. High-resolution through-wall imaging

    NASA Astrophysics Data System (ADS)

    Beeri, Amir; Daisy, Ron

    2006-05-01

    A new technical approach for 'Through Wall Imaging', implemented with in the Xaver 800 system is introduced in this paper. The system is a portable Ultra-wideband (UWB) micro power radar that offers a comprehensive solution for field operational use. The Xaver 800 gives the user fast and reliable 3D visual information, the system shows objects situated behind walls with sufficient resolution such that a person can be observed including his different body parts. Enabling rich imaging capabilities and ease of use, the Xaver 800 gives the user the ability to make the right decisions and to run more efficient 'life saving' operations. One of the main problems with the current available through wall technologies is their low resolution, "Blob" like results limits their ability to be an effective tool in the field. Higher resolution can theoretically be achieved by widening the bandwidth of the UWB signals used in these systems. However, working with high bandwidth signals creates other challenges such as the un-alignment problem. Multi channels unaligned system can result in unfocused and distorted images. This paper deals with the un-alignment problem and suggests a few methods to solve it by coherent registration. Experimental results are given to prove the effectiveness of the different methods proposed.

  20. The EUV dayglow at high spectral resolution

    SciTech Connect

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

    1990-04-01

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

  1. High-resolution phylogenetic microbial community profiling

    SciTech Connect

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

    2014-03-17

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

  2. The Jimsonde - A high resolution temperature sensor.

    NASA Technical Reports Server (NTRS)

    Camp, D. W.

    1971-01-01

    The Jimsonde, a high-resolution lightweight temperature sensor developed for use with the FPS-16 Radar/Jimsphere wind system, and its related systems are discussed; and an error analysis that shows the sonde to have an rms error of 0.41 C at sea level and 0.56 C at 18 km is presented. Five flight tests, a sequence of four tests and one individual test, of the Jimsonde were made. For comparative purposes, radiosonde temperature data are presented along with the Jimsonde data.

  3. 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.

  4. Efficient Compression of High Resolution Climate Data

    NASA Astrophysics Data System (ADS)

    Yin, J.; Schuchardt, K. L.

    2011-12-01

    resolution climate data can be massive. Those data can consume a huge amount of disk space for storage, incur significant overhead for outputting data during simulation, introduce high latency for visualization and analysis, and may even make interactive visualization and analysis impossible given the limit of the data that a conventional cluster can handle. These problems can be alleviated by with effective and efficient data compression techniques. Even though HDF5 format supports compression, previous work has mainly focused on employ traditional general purpose compression schemes such as dictionary coder and block sorting based compression scheme. Those compression schemes mainly focus on encoding repeated byte sequences efficiently and are not well suitable for compressing climate data consist mainly of distinguished float point numbers. We plan to select and customize our compression schemes according to the characteristics of high-resolution climate data. One observation on high resolution climate data is that as the resolution become higher, values of various climate variables such as temperature and pressure, become closer in nearby cells. This provides excellent opportunities for predication-based compression schemes. We have performed a preliminary estimation of compression ratios of a very simple minded predication-based compression ratio in which we compute the difference between current float point number with previous float point number and then encoding the exponent and significance part of the float point number with entropy-based compression scheme. Our results show that we can achieve higher compression ratios between 2 and 3 in lossless compression, which is significantly higher than traditional compression algorithms. We have also developed lossy compression with our techniques. We can achive orders of magnitude data reduction while ensure error bounds. Moreover, our compression scheme is much more efficient and introduces much less overhead compared to traditaion compression algorithms. Our compression algorithms can also be parallelized easily. We have intergrated our compression algorithms to several simple climate analysis applications. We have carefully pipelined the applications so that the overhead introduced by compression does not undermine the advantage of reducing I/O overhead from compression. Our experimental results show that we improve end-to-end application performance as well as reduce storage requirements with compression.

  5. High Resolution Powder Diffraction and Structure Determination

    SciTech Connect

    Cox, D. E.

    1999-04-23

    It is clear that high-resolution synchrotrons X-ray powder diffraction is a very powerful and convenient tool for material characterization and structure determination. Most investigations to date have been carried out under ambient conditions and have focused on structure solution and refinement. The application of high-resolution techniques to increasingly complex structures will certainly represent an important part of future studies, and it has been seen how ab initio solution of structures with perhaps 100 atoms in the asymmetric unit is within the realms of possibility. However, the ease with which temperature-dependence measurements can be made combined with improvements in the technology of position-sensitive detectors will undoubtedly stimulate precise in situ structural studies of phase transitions and related phenomena. One challenge in this area will be to develop high-resolution techniques for ultra-high pressure investigations in diamond anvil cells. This will require highly focused beams and very precise collimation in front of the cell down to dimensions of 50 {micro}m or less. Anomalous scattering offers many interesting possibilities as well. As a means of enhancing scattering contrast it has applications not only to the determination of cation distribution in mixed systems such as the superconducting oxides discussed in Section 9.5.3, but also to the location of specific cations in partially occupied sites, such as the extra-framework positions in zeolites, for example. Another possible application is to provide phasing information for ab initio structure solution. Finally, the precise determination of f as a function of energy through an absorption edge can provide useful information about cation oxidation states, particularly in conjunction with XANES data. In contrast to many experiments at a synchrotron facility, powder diffraction is a relatively simple and user-friendly technique, and most of the procedures and software for data analysis are familiar to laboratory diffractionists. This is reflected in the fact that there are already dedicated instruments for powder diffraction at a number of synchrotrons sources, including the NSLS, the Synchrotrons Radiation Source, Daresbury, the Photon Factory, Tsukuba and HASYLAB. In addition, most general purpose beamlines can be adapted for powder diffraction experiments fairly easily. Dedicated beamlines are also planned or under consideration at the next generation of synchrotrons sources, the European Synchrotron Radiation Facility, Grenoble, the Advanced Photon Source, Argonne, and the SPring-8 machine at Harima. These will be high brilliance sources with a much harder radiation spectrum that will offer many new possibilities for powder diffraction experiments, especially at energies above 10 keV.

  6. High resolution multimodal clinical ophthalmic imaging system.

    PubMed

    Mujat, Mircea; Ferguson, R Daniel; Patel, Ankit H; Iftimia, Nicusor; Lue, Niyom; Hammer, Daniel X

    2010-05-24

    We developed a multimodal adaptive optics (AO) retinal imager which is the first to combine high performance AO-corrected scanning laser ophthalmoscopy (SLO) and swept source Fourier domain optical coherence tomography (SSOCT) imaging modes in a single compact clinical prototype platform. Such systems are becoming ever more essential to vision research and are expected to prove their clinical value for diagnosis of retinal diseases, including glaucoma, diabetic retinopathy (DR), age-related macular degeneration (AMD), and retinitis pigmentosa. The SSOCT channel operates at a wavelength of 1 microm for increased penetration and visualization of the choriocapillaris and choroid, sites of major disease activity for DR and wet AMD. This AO system is designed for use in clinical populations; a dual deformable mirror (DM) configuration allows simultaneous low- and high-order aberration correction over a large range of refractions and ocular media quality. The system also includes a wide field (33 deg.) line scanning ophthalmoscope (LSO) for initial screening, target identification, and global orientation, an integrated retinal tracker (RT) to stabilize the SLO, OCT, and LSO imaging fields in the presence of lateral eye motion, and a high-resolution LCD-based fixation target for presentation of visual cues. The system was tested in human subjects without retinal disease for performance optimization and validation. We were able to resolve and quantify cone photoreceptors across the macula to within approximately 0.5 deg (approximately 100-150 microm) of the fovea, image and delineate ten retinal layers, and penetrate to resolve features deep into the choroid. The prototype presented here is the first of a new class of powerful flexible imaging platforms that will provide clinicians and researchers with high-resolution, high performance adaptive optics imaging to help guide therapies, develop new drugs, and improve patient outcomes. PMID:20589021

  7. SHARPI: Solar High Angular Resolution Photometric Imager

    NASA Technical Reports Server (NTRS)

    Rabin, D.; Davila, J.; Content, D.; Keski-Kuha, R.; Oegerle, William (Technical Monitor)

    2002-01-01

    Observing the lower solar atmosphere with enough linear resolution (< 100 km) to study individual magnetic flux tubes and other features on scales comparable to the photon mean free path has proven to be a challenging and elusive goal. Space-borne instruments based on conventional heavy optics turned out to be too expensive, and adaptive optics on the ground made slow progress for many years. Nevertheless, the scientific case for high-resolution imaging and magnetography has only become more compelling over the last ten years. Today, ground-based adaptive optics is a promising approach for small fields of view at visible wavelengths. Space experiments will need to employ lightweight optics and low cost platforms. The Sunrise balloon experiment is one example. We describe a concept for a sounding rocket experiment that will achieve 0.1-arcsecond imaging using a lightweight, ultraprecise 55-cm mirror in the far ultraviolet (160 nm continuum, Lyman alpha, and possibly C IV 155 nm). The f/1.2 parabolic primary mirror is entering the final stages of production. The mirror is a ULE honeycomb design with front and back face sheets. The front sheet will be figured to 6.3 nm rms with microroughness 1 nm or better. For the initial proof of concept, we describe a no-frills, high-cadence imager aboard a Black Brant sounding rocket. Development of lightweight UV/EUV optics at Goddard Space Flight Center has been supported by the Internal Research and Development program.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. High Resolution BPM for Linear Colliders

    SciTech Connect

    Simon, C.; Chel, S.; Luong, M.; Napoly, O.; Novo, J.; Roudier, D.; Rouviere, N.

    2006-11-20

    A high resolution Beam Position Monitor (BPM) is necessary for the beam-based alignment systems of high energy and low emittance electron linacs. Such a monitor is developed in the framework of the European CARE/SRF programme, in a close collaboration between DESY and CEA/DSM/DAPNIA. This monitor is a radiofrequency re-entrant cavity, which can be used either at room or cryogenic temperature, in an environment where dust particle contamination has to be avoided, such as superconducting cavities in a cryomodule. A first prototype of a re-entrant BPM has already delivered measurements at 2K. inside the first cryomodule (ACC1) on the TESLA Test Facility 2 (TTF2). The performances of this BPM are analyzed both experimentally and theoretically, and the limitations of this existing system clearly identified. A new cavity and new electronics have been designed in order to improve the position resolution down to 1 {mu}m and the damping time down to 10 ns.

  13. Low noise and high resolution microchannel plate

    NASA Astrophysics Data System (ADS)

    Liu, Shulin; Pan, Jingsheng; Deng, Guangxu; Su, Detan; Xu, Zhiqing; Zhang, Yanyun

    2008-02-01

    To improve the Figure of Merit (FOM) and reduce the Equivalent Background Input (EBI) and Fixed-Pattern-Noise (FPN) in image intensifier, NVT (North Night Vision Technology Co., Ltd) has been researching and developing a low noise and high resolution Micro Channel Plate (MCP). The density of dark current of this new MCP is less than 0.5PA/cm2 (when MCP voltage at 1000V). The FPN and scintillation noise are reduced remarkably. Channel diameter is 6 ?m and open area ratio is 60%~70%. The vacuum bakeout temperature could be as high as 500C. This new kind of MCP will be extensively used in the supper generation and the third generation image intensifiers.

  14. 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.

  15. High resolution colonoscopy in live mice.

    PubMed

    Becker, C; Fantini, M C; Neurath, M F

    2006-01-01

    Endoscopy in humans is a powerful method for physicians to examine the gut for inflammatory or neoplastic changes. In medical and immunological research, animal models of intestinal diseases are established key tools to investigate the mucosal immune system, colitis and cancer development in the gut. Moreover, such models represent valid systems for testing of novel drugs. In the past, mice had to be killed in order to analyze colitis activity and tumor development. The following protocol describes a method to perform high resolution endoscopic monitoring of live mice. Mice developing colitis or colonic tumors are anesthetized and examined with a miniendoscope. The endoscope is introduced via the anus and the colon is carefully insufflated with an air pump. Endoscopic pictures obtained are of high quality and allow the monitoring and grading of tumors and inflammation. In addition, colonic biopsies can be taken. This protocol can be completed within 1 h. PMID:17406549

  16. Infrared spectroscopic imaging with high spatial resolution and high sensitivity

    NASA Astrophysics Data System (ADS)

    Sablinskas, Valdas; Steiner, Gerald; Ceponkus, Justinas; Salzer, Reiner

    2008-02-01

    Polarization Modulation Infrared Reflection Absorption Spectroscopy (PM-IRRAS) is a very sensitive imaging technique for the characterization of molecular films. In order to achieve a spatial resolution close to the diffraction limit a very small pinhole which acts as a point-source has to be used. However, such a small pinhole, the typical diameter would be app. 100 ?m, may reduces dramatically the intensity of the infrared beam. Using a common FTIR spectrometer the spatial resolution is mainly limited by the brilliance of the globar infrared source. Therefore, an improvement in lateral resolution requires a more brilliant light source. The free electron laser (FEL) is such a high brilliant infrared source. The combination of the FEL with the PM-IRRAS imaging system is a new approach to capture spectroscopic images with an excellent spatial resolution close to the diffraction limit. PM-IRRAS images of a self assembly monolayer of phosphonic acid molecules onto a microstructures gold / aluminum oxide surface where characterized. The spectroscopic image exhibits a spatial resolution of app. 5 ?m. An evaluation of characteristic absorbance bands of the phosphate group reveals that phosphonic acid molecules bound with a high degree of orientation but differently at the gold and aluminum oxide surfaces. However, the spectroscopic image reveals also several domains of disordering across the surface. Such domains have a dimension of only few micrometers and can be identified in a high resolved PM-IRRAS image.

  17. High Resolution Observations of Solar Flares [Invited

    NASA Astrophysics Data System (ADS)

    Sylwester, B.

    2002-01-01

    The most suitable data set available for investigation of flares has been accumulated by the Yohkoh instruments. The SXT collected a wealth of solar X-ray images including thousands of flare sequences. Over several past years, our team in Space Research Center (SRC) of Polish Academy of Sciences in Wroclaw has been interested in developing the numerical image enhancement techniques with the aim of increasing the resolution on SXT flare images. The algorithm has been worked out which allows for the image deblurring with oversampling. The code (ANDRIL) is available in the public domain (SolarSoft). The application of this algorithm allows to increase the resolution on the SXT images to the level of 1 arc sec. We performed the deconvolution of large number of flare sequences using ANDRIL algorithm. The analysis of these data allowed to study the morphology of million degree flaring plasma with the resolution comparable to TRACE. The main results will be presented in the review. In order to infer the thermodynamic parameters of the plasma from the analysis of deconvolved images their precise coalignment is required. Techniques which have been developed at SRC to achieve high accuracy of image coalignment will be presented. The application of filter ratio (Al12/Be119) technique to the deconvolved and coaligned images allows to study temperature and emission measure distributions in great details. These maps better resolve flare kernels located both at the summits and foot points of flaring loop structures. We have studied the thermodynamic properties of kernels and related them with the corresponding characteristics derived from the analysis of BCS and HXT data. Performed analysis improved considerably our understanding of solar flares. Many of the results and theoretical ideas presented in this review have been obtained in cooperation with the team from the Astronomical Institute of Wroclaw University.

  18. 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.

  19. High resolution Fourier interferometer-spectrophotopolarimeter

    NASA Technical Reports Server (NTRS)

    Fymat, A. L. (Inventor)

    1976-01-01

    A high-resolution Fourier interferometer-spectrophotopolarimeter is provided using a single linear polarizer-analyzer the transmission axis azimuth of which is positioned successively in the three orientations of 0 deg, 45 deg, and 90 deg, in front of a detector; four flat mirrors, three of which are switchable to either of two positions to direct an incoming beam from an interferometer to the polarizer-analyzer around a sample cell transmitted through a medium in a cell and reflected by medium in the cell; and four fixed focussing lenses, all located in a sample chamber attached at the exit side of the interferometer. This arrangement can provide the distribution of energy and complete polarization state across the spectrum of the reference light entering from the interferometer; the same light after a fixed-angle reflection from the sample cell containing a medium to be analyzed; and the same light after direct transmission through the same sample cell, with the spectral resolution provided by the interferometer.

  20. 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.

  1. 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 g 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.

  2. 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.

  3. 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 Valle 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.

  4. 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.

  5. 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

  6. 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

  7. High resolution NMR of rubidium doped fullerenes

    SciTech Connect

    Zahab, A.; Bernier, P.; Firlej, L.

    1992-12-01

    The authors have used High Resolution {sup 13}C NMR (50.3 MHz) to study the structural and electronic properties of Rubidium doped Fullerenes. An anisotropic Knight shift is generally observed whose extend ({approximately} 40 ppm) and isotropic part value ({approximately} 42 ppm) do not depend on the stoichiometry of the compound. The resonance linewidth drastically increases by a factor of 10 between room temperature and 150 K, showing that the rotational motion of the individual C{sub 60} is severely hindered at low temperature. The relaxational time T{sub 1}({approximately} 70 ms at room temperature) roughly follows a law T{sub 1}T = constant, usual in the case of normal metal. All the results are discussed on the light of existing structural and electronic models for these compounds.

  8. Optical High Resolution Spectra of APOGEE Stars

    NASA Astrophysics Data System (ADS)

    Feuillet, Diane; Holtzman, J. A.; Cunha, K. M.; Garcia Perez, A.; Ghezzi, L.; Hayden, M. R.; Meszaros, Sz.; Allende Prieto, C.; Shetrone, M. D.; Smith, V. V.; Zasowski, G.

    2013-01-01

    The Apache Point Observatory Galactic Evolution Experiment (APOGEE) is an SDSS-III survey that is obtaining high resolution near-IR (H band) spectra of 100,000 Milky Way stars in an effort to chemically trace formation and evolution of Galactic stellar populations. Optical echelle spectra of a small subset of survey targets have been obtained with the ARC 3.5m telescope for the purpose of 1) helping to understand and calibrate the abundance analysis of the APOGEE IR spectra, and 2) measuring abundances of elements that do not have spectral features in the APOGEE wavelength region, which will ideally include neutron capture elements. We present our current sample of ~130 (out of a projected 500) stars, which is drawn from the brightest APOGEE targets and covers a range of stellar parameters (temperature, metallicity, and surface gravity), and compare some optically derived quantities with those from the APOGEE abundance pipeline.

  9. Potential High Resolution Dosimeters For MRT

    SciTech Connect

    Braeuer-Krisch, E.; Brochard, T.; Prezado, Y.; Bravin, A.; Berkvens, P.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Kamlowski, A.; Cellere, G.

    2010-07-23

    Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow ({approx}25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 {mu}m microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy/s, micron resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic registered films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al{sub 2}O{sub 3}:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 1x1 cm{sup 5} field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.

  10. 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 2525?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 10241024. 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.

  11. Rapid mapping of high resolution SAR scenes

    NASA Astrophysics Data System (ADS)

    Dell'Acqua, F.; Gamba, P.; Lisini, G.

    This paper describes a semi-automatic procedure for cartographic mapping using high resolution SAR and interferometric SAR data. Various two-dimensional features are extracted and combined in order to achieve a basic yet effective recognition of the elements in the scene. Many relevant elements of the landscape are automatically extracted without requiring any deep interaction with the operator. Being based on geometric models assuming regularity of shapes and patterns, the procedure is well suited for detecting man-made features, such as the road network (outside and inside human settlements) and built-up areas. It can be used, however, to extract natural features, focusing on different geometric models. Moreover, extracted elements of the scene can be grouped into higher level ones, such as crossroads, bridges and overpasses, through data fusion at the feature level, because the procedure is characterized by a multi-scale, object-based approach.

  12. 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.

  13. 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

  14. High-resolution Martian atmosphere modeling

    NASA Technical Reports Server (NTRS)

    Egan, W. G.; Fischbein, W. L.; Smith, L. L.; Hilgeman, T.

    1980-01-01

    A multilayer radiative transfer, high-spectral-resolution infrared model of the lower atmosphere of Mars has been constructed to assess the effect of scattering on line profiles. The model takes into accout aerosol scattering and absorption and includes a line-by-line treatment of scattering and absorption by CO2 and H2O. The aerosol complex indices of refraction used were those measured on montmorillonite and basalt chosen on the basis of Mars ir data from the NASA Lear Airborne Observatory. The particle sizes and distribution were estimated using Viking data. The molecular line treatment employs the AFGL line parameters and Voigt profiles. The modeling results indicate that the line profiles are only slightly affected by normal aerosol scattering and absorption, but the effect could be appreciable for heavy loading. The technique described permits a quantitative approach to assessing and correcting for the effect of aerosols on lineshapes in planetary atmospheres.

  15. High-resolution MRI: in vivo histology?

    PubMed Central

    Bridge, Holly; Clare, Stuart

    2005-01-01

    For centuries scientists have been fascinated with the question of how the brain works. Investigators have looked at both where different functions are localized and how the anatomical microstructure varies across the brain surface. Here we discuss how advances in magnetic resonance imaging (MRI) have allowed in vivo visualization of the fine structure of the brain that was previously only visible in post-mortem brains. We present data showing the correspondence between definitions of the primary visual cortex defined anatomically using very high-resolution MRI and functionally using functional MRI. We consider how this technology can be applied to allow the investigation of brains that differ from normal, and what this ever-evolving technology may be able to reveal about in vivo brain structure in the next few years. PMID:16553313

  16. 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.

  17. 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

  18. Potential High Resolution Dosimeters For MRT

    NASA Astrophysics Data System (ADS)

    Bruer-Krisch, E.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Brochard, T.; Kamlowski, A.; Cellere, G.; Paccagnella, A.; Siegbahn, E. A.; Prezado, Y.; Martinez-Rovira, I.; Bravin, A.; Dusseau, L.; Berkvens, P.

    2010-07-01

    Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow (25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 ?m microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy/s, micron resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al2O3:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 11 cm5 field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.

  19. 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.

  20. High-resolution transcriptome of human macrophages.

    PubMed

    Beyer, Marc; Mallmann, Michael R; Xue, Jia; Staratschek-Jox, Andrea; Vorholt, Daniela; Krebs, Wolfgang; Sommer, Daniel; Sander, Jil; Mertens, Christina; Nino-Castro, Andrea; Schmidt, Susanne V; Schultze, Joachim L

    2012-01-01

    Macrophages are dynamic cells integrating signals from their microenvironment to develop specific functional responses. Although, microarray-based transcriptional profiling has established transcriptional reprogramming as an important mechanism for signal integration and cell function of macrophages, current knowledge on transcriptional regulation of human macrophages is far from complete. To discover novel marker genes, an area of great need particularly in human macrophage biology but also to generate a much more thorough transcriptome of human M1- and M1-like macrophages, we performed RNA sequencing (RNA-seq) of human macrophages. Using this approach we can now provide a high-resolution transcriptome profile of human macrophages under classical (M1-like) and alternative (M2-like) polarization conditions and demonstrate a dynamic range exceeding observations obtained by previous technologies, resulting in a more comprehensive understanding of the transcriptome of human macrophages. Using this approach, we identify important gene clusters so far not appreciated by standard microarray techniques. In addition, we were able to detect differential promoter usage, alternative transcription start sites, and different coding sequences for 57 gene loci in human macrophages. Moreover, this approach led to the identification of novel M1-associated (CD120b, TLR2, SLAMF7) as well as M2-associated (CD1a, CD1b, CD93, CD226) cell surface markers. Taken together, these data support that high-resolution transcriptome profiling of human macrophages by RNA-seq leads to a better understanding of macrophage function and will form the basis for a better characterization of macrophages in human health and disease. PMID:23029029

  1. High Resolution Spectroscopy to Support Atmospheric Measurements

    NASA Technical Reports Server (NTRS)

    Venkataraman, Malathy Devi

    2006-01-01

    The major research activities performed during the cooperative agreement enhanced our spectroscopic knowledge of molecules of atmospheric interest such as H2O (water vapor), O3 (ozone), HCN (hydrogen cyanide), CH4 (methane), NO2 (nitrogen dioxide) and CO (carbon monoxide). The data required for the analyses were obtained from two different Fourier Transform Spectrometers (FTS); one of which is located at the National Solar Observatory (NSO) on Kitt Peak, Arizona and the other instrument is located at the Pacific Northwest National Laboratories (PNNL) at Richland, Washington. The data were analyzed using a modified multispectrum nonlinear least squares fitting algorithm developed by Dr. D. Chris Benner of the College of William and Mary. The results from these studies made significant improvements in the line positons and intensities for these molecules. The measurements of pressure broadening and pressure induced line shift coefficients and the temperature dependence of pressure broadening and pressure induced shift coefficients for hundreds of infrared transitions of HCN, CO3 CH4 and H2O were also performed during this period. 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. The research conducted during the period 2003-2006 has resulted in publications given in this paper. In addition to Journal publications, several oral and poster presentations were given at various Scientific conferences within the United States and abroad.

  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. The HFIP High Resolution Hurricane Forecast Test

    NASA Astrophysics Data System (ADS)

    Nance, L. B.; Bernardet, L.; Bao, S.; Brown, B.; Carson, L.; Fowler, T.; Halley Gotway, J.; Harrop, C.; Szoke, E.; Tollerud, E. I.; Wolff, J.; Yuan, H.

    2010-12-01

    Tropical cyclones are a serious concern for the nation, causing significant risk to life, property and economic vitality. The National Oceanic and Atmospheric Administration (NOAA) National Weather Service has a mission of issuing tropical cyclone forecasts and warnings, aimed at protecting life and property and enhancing the national economy. In the last 10 years, the errors in hurricane track forecasts have been reduced by about 50% through improved model guidance, enhanced observations, and forecaster expertise. However, little progress has been made during this period toward reducing forecasted intensity errors. To address this shortcoming, NOAA established the Hurricane Forecast Improvement Project (HFIP) in 2007. HFIP is a 10-year plan to improve one to five day tropical cyclone forecasts, with a focus on rapid intensity change. Recent research suggests that prediction models with grid spacing less than 1 km in the inner core of the hurricane may provide a substantial improvement in intensity forecasts. The 2008-09 staging of the High Resolution Hurricane (HRH) Test focused on quantifying the impact of increased horizontal resolution in numerical models on hurricane intensity forecasts. The primary goal of this test was an evaluation of the effect of increasing horizontal resolution within a given model across a variety of storms with different intensity, location and structure. The test focused on 69 retrospectives cases from the 2005 and 2007 hurricane seasons. Six modeling groups participated in the HRH test utilizing a variety of models, including three configurations of the Weather Research and Forecasting (WRF) model, the operational GFDL model, the Navys tropical cyclone model, and a model developed at the University of Wisconsin-Madison (UWM). The Development Testbed Center (DTC) was tasked with providing objective verification statistics for a variety of metrics. This presentation provides an overview of the HRH Test and a summary of the standard verification results, as well as results obtained by applying new verification tools developed at the DTC that assess changes in forecast skill for Rapid Intensification (RI) and Rapid Weakening (RW) events and forecast consistency.

  4. 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.

  5. High Resolution Airborne Shallow Water Mapping

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

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

  6. High resolution DNA separations using microchip electrophoresis.

    PubMed

    Sinville, Rondedrick; Soper, Steven A

    2007-07-01

    Planar microfluidic devices have emerged as effective tools for the electrophoretic separation of a variety of different DNA inputs. The advancement of this miniaturized platform was inspired initially by demands placed on electrophoretic performance metrics by the human genome project and has provided a viable alternative to slab gel and even capillary formats due to its ability to offer high resolution separations of nucleic acid materials in a fraction of the time associated with its predecessors, consumption of substantially less sample and reagents while maintaining the ability to perform many separations in parallel for realizing ultra-high throughputs. Another compelling advantage of this separation platform is that it offers the potential for integrating front-end sample preprocessing steps onto the separation device eliminating the need for manual sample handling. This review aims to compile a recent survey of various electrophoretic separations using either glass or polymer-based microchips in the areas of genotyping and DNA sequencing as well as those involving the growing field of DNA-based forensics. PMID:17623451

  7. 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.

  8. Advances in high-resolution image simulation

    SciTech Connect

    O'Keefe, M.A.; Kilaas, R.

    1988-09-01

    Continuing advances in hardware and software have improved both the speed and the range of computations that can be made to simulate high resolution electron microscope (HREM) images from various structures. Use of image display systems and array processors have made the image simulation procedure much more interactive while laser printers provide a fast high-quality hard copy output. Use of array processors has enabled the rewriting of electron scattering algorithms to include convergence effects (previously only considered after the scattered electron beams had emerged from the specimen) and upper-layer-line effects. With an array processor it is faster to compute effects of spatial and temporal coherence in real space, rather than use approximation solutions derived from series expansion in reciprocal space. With a frame buffer and suitable software the use has the facility to change parameters and view the results of the change almost immediately. Selected images can then be directed to hard copy output, in contrast with batch methods where series of hard copy images are produced and then selected from. Given a microdensitometer for input of experimental images from plates, or a video camera attached to the electron microscope and a frame buffer, split screen comparisons between experimental and computed images are possible, including independent control of image contrast, magnification and orientation. 23 refs., 19 figs., 2 tabs.

  9. 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.

  10. The High Time Resolution Radio Sky

    NASA Astrophysics Data System (ADS)

    Thornton, D.

    2013-11-01

    Pulsars are laboratories for extreme physics unachievable on Earth. As individual sources and possible orbital companions can be used to study magnetospheric, emission, and superfluid physics, general relativistic effects, and stellar and binary evolution. As populations they exhibit a wide range of sub-types, with parameters varying by many orders of magnitude signifying fundamental differences in their evolutionary history and potential uses. There are currently around 2200 known pulsars in the Milky Way, the Magellanic clouds, and globular clusters, most of which have been discovered with radio survey observations. These observations, as well as being suitable for detecting the repeating signals from pulsars, are well suited for identifying other transient astronomical radio bursts that last just a few milliseconds that either singular in nature, or rarely repeating. Prior to the work of this thesis non-repeating radio transients at extragalactic distances had possibly been discovered, however with just one example status a real astronomical sources was in doubt. Finding more of these sources was a vital to proving they were real and to open up the universe for millisecond-duration radio astronomy. The High Time Resolution Universe survey uses the multibeam receiver on the 64-m Parkes radio telescope to search the whole visible sky for pulsars and transients. The temporal and spectral resolution of the receiver and the digital back-end enable the detection of relatively faint, and distant radio sources. From the Parkes telescope a large portion of the Galactic plane can be seen, a rich hunting ground for radio pulsars of all types, while previously poorly surveyed regions away from the Galactic plane are also covered. I have made a number of pulsar discoveries in the survey, including some rare systems. These include PSR J1226-6208, a possible double neutron star system in a remarkably circular orbit, PSR J1431-471 which is being eclipsed by its companion with each orbit, PSR J1729-2117 which is an unusual isolated recycled pulsar, and PSR J2322-2650 which has a companion of very low mass - just 7 10^{-4} {M}_{?}, amongst others. I begin this thesis with the study of these pulsars and discuss their histories. In addition, I demonstrate that optical observations of the companions to some of the newly discovered pulsars in the High Time Resolution Universe survey may result in a measurement of their age and that of the pulsar. I have discovered five new extragalactic single radio bursts, confirming them as an astronomical population. These appear to occur frequently, with a rate of 1.0^{+0.6}_{-0.5} 10^4 sky^{-1} day^{-1}. The sources are likely at cosmological distances - with redshifts between 0.45 and 1.45, making them more than half way to the Big Bang in the most distant case. This implies their luminosities must be enormous, 10^{31} to 10^{33} J emitted in just a few milliseconds. Their source is unknown but I present an analysis of the options. I also perform a population simulation of the bursts which demonstrates how their intrinsic spectrum could be measured, even for unlocalised FRBs: early indications are that the spectral index of FRBs < 0.

  11. High-speed segmentation-driven high-resolution matching

    NASA Astrophysics Data System (ADS)

    Ekstrand, Fredrik; Ahlberg, Carl; Ekstrm, Mikael; Spampinato, Giacomo

    2015-02-01

    This paper proposes a segmentation-based approach for matching of high-resolution stereo images in real time. The approach employs direct region matching in a raster scan fashion influenced by scanline approaches, but with pixel decoupling. To enable real-time performance it is implemented as a heterogeneous system of an FPGA and a sequential processor. Additionally, the approach is designed for low resource usage in order to qualify as part of unified image processing in an embedded system.

  12. 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

  13. High resolution interferometric metrology for patterned wafers

    NASA Astrophysics Data System (ADS)

    Tang, Shouhong; Freischlad, Klaus; Yam, Petrie

    2007-09-01

    The precision metrology of patterned wafer is increasingly demanded by the semiconductor device manufacturers. The most common methods include scanning probe microscopy (SPM) techniques such as stylus profilometry and Atomic Force Microscopy (AFM). These methods acquire data by contacting the surface over a sequence of one-dimensional scans. While high lateral resolution can be achieved in this way, such processes are time-consuming and can have the potential to deform the surface under test. An alternative non-contact interferometric method is presented here. The method uses the white-light interferometry (WLI) to provide wafer topography quickly in a direct three-dimensional format. The improved measurement throughput suggests that it is feasible to use this method for production monitoring. Most commercial interferometers with WLI are capable of measuring opaque surfaces with sub-nanometer precision. The described method extends this capability to determine the top surface topography of structured surfaces in the presence of varying phase shifts on reflection. The phase shift on reflection may be due to the material properties of bulk surfaces, single or multi-layer film stacks on a substrate, or other micro-structures on the wafer. Furthermore, this method simultaneously or separately provides additional parameters of the test piece e.g. layer thickness and/or material refractive index for film stacks, or line width and structure depth of micro-structures. The measurement results on various types of the wafer surfaces will be presented in this paper.

  14. 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.

  15. High Resolution Images of Young Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Dyer, K. K.; Reynolds, S. P.

    1999-05-01

    3C 396 provides a morphological middle ground between young remnants whose morphology is obviously shaped by density variations in the circumstellar material, such as 3C 397 and remnants expanding into a relatively empty or smoothly varying regions such as 3C 391 or SN 1006 AD. The small scale "arcs" superimposed upon nearly perfect spherical morphology of 3C 396 can be seen in new high resolution VLA images at 20 and 6 cm. We discuss polarization and its spatial distribution across the remnant. We will examine archival X-ray observations and address the correlations between radio and X-ray images in terms of the dynamical evolution of the remnant and its interaction with the circumstellar medium. We also discuss radio images of 3C 397 and SN 1006 AD in comparison with 3C 396. We will examine possible spectral index variations across the remnant. This research is supported by NASA grant NAG5-7153 and NGT5-65 through the Graduate Student Researchers Program.

  16. 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.

  17. High-resolution microwave images of Saturn

    NASA Astrophysics Data System (ADS)

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

    1989-09-01

    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 midlatitudes. The data are consistent with a radiative transfer model of the atmosphere that constrains the well-mixed, fully saturated, NH3 mixing ratio to be 0.00012 in a region just below the NH3 clouds, while the observed bright band indicates a 25 percent relative decrease of NH3 in northern midlatitudes. 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.

  18. High resolution EUV monochromator/spectrometer

    DOEpatents

    Koike, Masako (Moraga, CA)

    1996-01-01

    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.

  19. 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

  20. 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.

  1. 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.

  2. High-resolution ion mobility measurements

    NASA Astrophysics Data System (ADS)

    Dugourd, Ph.; Hudgins, R. R.; Clemmer, D. E.; Jarrold, M. F.

    1997-02-01

    Gas phase ion mobility measurements can resolve structural isomers for polyatomic ions and provide information about their geometries. A new experimental apparatus for performing high-resolution ion mobility measurements is described. The apparatus consists of a pulsed laser vaporization/desorption source coupled through an ion gate to a 63-cm-long drift tube. The ion gate is a critical component that prevents the diffusion of neutral species from the source into the drift tube. Ions travel along the drift tube under the influence of a uniform electric field. At the end of the drift tube some of the ions exit through a small aperture. They are focused into a quadrupole mass spectrometer, where they are mass analyzed, and then detected by an off-axis collision dynode and by dual microchannel plates. The apparatus is operated with a drift voltage of up to 14 000 V and a helium buffer gas pressure of around 500 Torr. The resolving power for ion mobility measurements is over an order of magnitude higher than has been achieved using conventional injected-ion drift tube techniques. Examples of the application of the new apparatus in resolving isomers of laser desorbed metallofullerenes, in studying silicon clusters generated by laser vaporization, and in following the isomerization of small nanocrystalline (NaCl)nCl- clusters as a function of temperature, are presented.

  3. 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

  4. High Resolution Spectra of Solar Flares

    NASA Astrophysics Data System (ADS)

    Doschek, G. A.

    I discuss high-resolution solar flare spectra from the soft X-ray region through the extreme ultraviolet (EUV) wavelength regions. Spectra of solar flares at these wavelengths have been recorded since the late 1960s, beginning primarily with the NASA Orbiting Solar Observatory (OSO) series of spacecraft. Knowledge of EUV flare spectra took a quantum leap with the NASA Skylab Apollo Telescope Mount spectrographs in the early 1970s. Knowledge of the X-ray spectrum took a similar leap in the 1980s with the US Department of Defense P78-1 spacecraft, the NASA Solar Maximum Mission spacecraft (SMM), and the Japanese Hinotori spacecraft. Investigations of flare X-ray spectra continued with the BCS X-ray spectrometer experiment on the Japanese Yohkoh mission. Recently, EUV solar flare spectroscopy has been extended with the SUMER spectrometer on the ESA SOHO spacecraft. In addition to the above missions, significant contributions were made with instrumentation on a number of other spacecraft, e.g., the Soviet Intercosmos X-ray spectrometers. Our knowledge of the physical conditions in solar flares has been greatly expanded from analyses of X-ray and EUV flare spectra. I will discuss the general characteristics of the flare emission line and continuum spectra, and the physical processes that produce them. I will discuss what we have learned about solar flares from the spectra, and discuss solar flare spectra in terms of spectra expected from other astrophysical sources.

  5. 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.

  6. 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.

  7. High-resolution ophthalmic imaging system

    DOEpatents

    Olivier, Scot S. (Livermore, CA); Carrano, Carmen J. (Livermore, CA)

    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.

  8. 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 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.

  9. High resolution fire risk mapping in Italy

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    The high topographic and vegetation heterogeneity makes Italy vulnerable to forest fires both in the summer and in winter. In particular, northern regions are predominantly characterized by a winter fire regime, mainly due to frequent extremely dry winds from the north, while southern and central regions and the large islands are characterized by a severe summer fire regime, because of the higher temperatures and prolonged lack of precipitation. The threat of wildfires in Italy is not confined to wooded areas as they extend to agricultural areas and urban-forest interface areas. The agricultural and rural areas, in the last century, have been gradually abandoned, especially in areas with complex topography. Many of these areas were subject to reforestation, leading to the spread of pioneer species mainly represented by Mediterranean conifer, which are highly vulnerable to fire. Because of the frequent spread of fire, these areas are limited to the early successional stages, consisting mainly of shrub vegetation; its survival in the competition with the climax species being ensured by the spread of fire itself. Due to the frequency of fire ignition — almost entirely man caused — the time between fires on the same area is at least an order of magnitude less than the time that would allow the establishment of forest climax species far less vulnerable to fire. In view of the limited availability of fire risk management resources, most of which are used in the management of national and regional air services, it is necessary to precisely identify the areas most vulnerable to fire risk. The few resources available can thus be used on a yearly basis to mitigate problems in the areas at highest risk by defining a program of forest management interventions, which is expected to make a significant contribution to the problem in a few years' time. The goal of such detailed planning is to dramatically reduce the costs associated with water bombers fleet management and fire extinguishing actions, leaving more resources to improve safety in areas at risk. With the availability of fire perimeters mapped over a period spanning from 5 to 10 years, depending by the region, a procedure was defined in order to assess areas at risk with high spatial resolution (900 m2) based on objective criteria by observing past fire events. The availability of fire perimeters combined with a detailed knowledge of topography and land cover allowed to understand which are the main features involved in forest fire occurrences and their behaviour. The seasonality of the fire regime was also considered, partitioning the analysis in two macro season (November- April and May- October). In addition, the total precipitation obtained from the interpolation of 30 years-long time series from 460 raingauges and the average air temperature obtained downscaling 30 years ERA-INTERIM data series were considered. About 48000 fire perimeters which burnt about 5500 km2 were considered in the analysis. The analysis has been carried out at 30 m spatial resolution. Some important considerations relating to climate and the territorial features that characterize the fire regime at national level contribute to better understand the forest fire phenomena. These results allow to define new strategies for forest fire prevention and management extensible to other geographical areas.

  10. The High-Resolution IRAS Galaxy Atlas

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  11. In vivo measurement of glucose utilization in rats using a beta-microprobe: direct comparison with autoradiography.

    PubMed

    Millet, Philippe; Sallanon, Marcelle Moulin; Petit, Jean-Marie; Charnay, Yves; Vallet, Philippe; Morel, Christian; Cespuglio, Raymond; Magistretti, Pierre J; Ibez, Vicente

    2004-09-01

    A new beta-microprobe (betaP) has been used to locally measure the time-concentration curve of a radiolabeled substance. The betaP, analogous to positron emission tomography methodology, is useful for in vivo animal studies because it can acquire time-concentration curves with high temporal and spatial resolution. Using [18F]fluoro-2-deoxy-D-glucose and betaP, we evaluated the reliability of the biologic parameters and we compared this method with the [14C]2-deoxy-D-glucose autoradiography. BetaP time-concentration curves in three regions of the brain were obtained from 24 rats. Four kinetic parameters (K1-k4) were estimated from 60-minute experimental periods using a three-compartment model. Best fits were obtained when the vascular fraction (Fv) was estimated simultaneously with the four kinetic parameters (K1-k4). The mean estimated Fv values were about 5.5% for the frontal cortex regions and 8.0% for the cerebellum. Correlation coefficients higher than 0.830 were observed between regional cerebral metabolic rates for glucose (rCMRglc) values obtained by betaP and autoradiography. In addition, the betaP-derived input function was similar to that obtained by manual sampling. Our findings show that reliable rCMRglc values can be obtained using betaP. PMID:15356422

  12. 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.

  13. Middle Atmosphere High Resolution Spectrograph Investigation

    NASA Astrophysics Data System (ADS)

    Conway, Robert R.; Stevens, Michael H.; Brown, Charles M.; Cardon, Joel G.; Zasadil, Scott E.; Mount, George H.

    1999-07-01

    The Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) was developed specifically to measure the vertical density profiles of hydroxyl (OH) and nitric oxide (NO) in the middle atmosphere from space. MAHRSI was launched on its first flight in November 1994 on the CRISTA-SPAS satellite that was deployed and retrieved by the space shuttle. The instrument measured the radiance profiles of ultraviolet solar resonance fluorescence on the Earth's limb with a spectral resolving power of 15,600 at a wavelength of 308 nm and 7200 at 215 nm. The instantaneous height of the field of view projected to the tangent point was about 300 m. OH limb radiance measurements were made between altitudes of 90 and 30 km, and each limb scan extended over a horizontal distance of 1200 km. For NO a limb scan extended between altitudes of 140 and 76 km and over a horizontal distance 700 km. Observations were made from 52S latitude to 62N latitude. The OH measurements have been inverted to provide the first global maps of the vertical distribution of OH between 90 and 50 km. The data show a detailed history of the morning formation of a strongly peaked layer of OH at an altitude of 68 km. This layer was produced by solar photodissociation of a thin layer of water vapor peaked at 65 km extending between 30S and 35N observed contemporaneously by the Halogen Occultation Experiment (HALOE) on the Upper Atmosphere Research Satellite. MAHRSI was successfully flown for a second time in August 1997 under conditions that extended the geographical coverage to 72N latitude and local solar time coverage through the afternoon hours. This paper provides a detailed description of the experiment and instrumentation, of the algorithms used to reduce the spectral data and perform the inversions, and presents examples of key results from the 1994 flight.

  14. High-resolution human cytomegalovirus transcriptome.

    PubMed

    Gatherer, Derek; Seirafian, Sepehr; Cunningham, Charles; Holton, Mary; Dargan, Derrick J; Baluchova, Katarina; Hector, Ralph D; Galbraith, Julie; Herzyk, Pawel; Wilkinson, Gavin W G; Davison, Andrew J

    2011-12-01

    Deep sequencing was used to bring high resolution to the human cytomegalovirus (HCMV) transcriptome at the stage when infectious virion production is under way, and major findings were confirmed by extensive experimentation using conventional techniques. The majority (65.1%) of polyadenylated viral RNA transcription is committed to producing four noncoding transcripts (RNA2.7, RNA1.2, RNA4.9, and RNA5.0) that do not substantially overlap designated protein-coding regions. Additional noncoding RNAs that are transcribed antisense to protein-coding regions map throughout the genome and account for 8.7% of transcription from these regions. RNA splicing is more common than recognized previously, which was evidenced by the identification of 229 potential donor and 132 acceptor sites, and it affects 58 protein-coding genes. The great majority (94) of 96 splice junctions most abundantly represented in the deep-sequencing data was confirmed by RT-PCR or RACE or supported by involvement in alternative splicing. Alternative splicing is frequent and particularly evident in four genes (RL8A, UL74A, UL124, and UL150A) that are transcribed by splicing from any one of many upstream exons. The analysis also resulted in the annotation of four previously unrecognized protein-coding regions (RL8A, RL9A, UL150A, and US33A), and expression of the UL150A protein was shown in the context of HCMV infection. The overall conclusion, that HCMV transcription is complex and multifaceted, has implications for the potential sophistication of virus functionality during infection. The study also illustrates the key contribution that deep sequencing can make to the genomics of nuclear DNA viruses. PMID:22109557

  15. 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.

  16. High Resolution Sensor for Nuclear Waste Characterization

    SciTech Connect

    Shah, Kanai; Higgins, William; Van Loef, Edgar V

    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.

  17. 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.

  18. High spatial resolution restoration of IRAS images

    NASA Technical Reports Server (NTRS)

    Grasdalen, Gary L.; Inguva, R.; Dyck, H. Melvin; Canterna, R.; Hackwell, John A.

    1990-01-01

    A general technique to improve the spatial resolution of the IRAS AO data was developed at The Aerospace Corporation using the Maximum Entropy algorithm of Skilling and Gull. The technique has been applied to a variety of fields and several individual AO MACROS. With this general technique, resolutions of 15 arcsec were achieved in 12 and 25 micron images and 30 arcsec in 60 and 100 micron images. Results on galactic plane fields show that both photometric and positional accuracy achieved in the general IRAS survey are also achieved in the reconstructed images.

  19. A High Resolution Electron Beam Profile Monitor

    SciTech Connect

    Graves, W.S.; Johnson, E.D.; O`Shea, P.G.

    1997-12-31

    A new beam diagnostic to measure transverse profiles of electron beams is described. This profile monitor uses a Yttrium:Aluminum:Garnet (YAG) crystal doped with a visible light scintillator to produce an image of the transverse beam distribution. The advantage of this material over traditional fluorescent screens is that it is formed from a single crystal, and therefore has improved spatial resolution. The current system is limited to a resolution of about 10 microns. Improvements in the optical transport will enable measurements of RMS beam sizes of less than 1 micron. The total cost of the system is modest.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. High spatial resolution LWIR hyperspectral sensor

    NASA Astrophysics Data System (ADS)

    Roberts, Carson B.; Bodkin, Andrew; Daly, James T.; Meola, Joseph

    2015-06-01

    Presented is a new hyperspectral imager design based on multiple slit scanning. This represents an innovation in the classic trade-off between speed and resolution. This LWIR design has been able to produce data-cubes at 3 times the rate of conventional single slit scan devices. The instrument has a built-in radiometric and spectral calibrator.

  6. 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.

  7. 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.

  8. Identifying network communities with a high resolution

    NASA Astrophysics Data System (ADS)

    Ruan, Jianhua; Zhang, Weixiong

    2008-01-01

    Community structure is an important property of complex networks. The automatic discovery of such structure is a fundamental task in many disciplines, including sociology, biology, engineering, and computer science. Recently, several community discovery algorithms have been proposed based on the optimization of a modularity function (Q) . However, the problem of modularity optimization is NP-hard and the existing approaches often suffer from a prohibitively long running time or poor quality. Furthermore, it has been recently pointed out that algorithms based on optimizing Q will have a resolution limit; i.e., communities below a certain scale may not be detected. In this research, we first propose an efficient heuristic algorithm QCUT, which combines spectral graph partitioning and local search to optimize Q . Using both synthetic and real networks, we show that QCUT can find higher modularities and is more scalable than the existing algorithms. Furthermore, using QCUT as an essential component, we propose a recursive algorithm HQCUT to solve the resolution limit problem. We show that HQCUT can successfully detect communities at a much finer scale or with a higher accuracy than the existing algorithms. We also discuss two possible reasons that can cause the resolution limit problem and provide a method to distinguish them. Finally, we apply QCUT and HQCUT to study a protein-protein interaction network and show that the combination of the two algorithms can reveal interesting biological results that may be otherwise undetected.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. HIGH RESOLUTION PHOTOEMISSION STUDIES OF COMPLEX MATERIALS.

    SciTech Connect

    JOHNSON,P.D.; VALLA,T.; FEDOROV,A.; REISFELD,G.; HULBERT,S.L.

    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 8+{delta}}, shows that the material behaves like a non-Fermi liquid with no evidence for the quasi-particles characteristic of a Fermi liquid.

  15. 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.

  16. DSCOVR High Time Resolution Solar Wind Measurements

    NASA Astrophysics Data System (ADS)

    Szabo, A.

    2012-12-01

    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.

  17. 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.

  18. High Resolution Chemical Study of ALH84001

    NASA Technical Reports Server (NTRS)

    Conrad, Pamela G.; Douglas, Susanne; Kuhlman, Kimberly R.

    2001-01-01

    We have studied the chemistry of a sample of the SNC meteorite ALH84001 using an environmental scanning electron microscope (ESEM) with an energy dispersive chemical analytical detector and a focused ion beam secondary ion mass spectrometer (FIB-SIMS). Here we present the chemical data, both spectra and images, from two techniques that do not require sample preparation with a conductive coating, thus eliminating the possibility of preparation-induced textural artifacts. The FIB-SIMS instrument includes a column optimized for SEM with a quadrupole type mass spectrometer. Its spatial and spectral resolution are 20 nm and 0.4 AMU, respectively. The spatial resolution of the ESEM for chemical analysis is about 100 nm. Limits of detection for both instruments are mass dependent. Both the ESEM and the FIB-SIMS instrument revealed contrasting surficial features; crumbled, weathered appearance of the matrix in some regions as well as a rather ubiquitous presence of euhedral halite crystals, often associated with cracks or holes in the surface of the rock. Other halogen elements present in the vicinity of the NaCl crystals include K and Br. In this report, elemental inventories are shown as mass spectra and as X-ray maps.

  19. Guided wave arrays for high resolution inspection.

    PubMed

    Velichko, Alexander; Wilcox, Paul D

    2008-01-01

    The paper describes a general approach for processing data from a guided wave transducer array on a plate-like structure. The raw data set from such an array contains time-domain signals from each transmitter-receiver combination. The technique is based on linear superposition of signals in the frequency domain with some amplitude and phase factors and can be applied to any array geometry and any types of array elements. The problem of finding optimal coefficients, which allow the best resolution to be achieved with the minimum number of array elements, is investigated. It is shown that improvements in resolution are obtained at the expense of sensitivity to noise. A method of quantifying this sensitivity is presented. Results are shown that illustrate the application of the technique to a linear array and an array of circular geometry (containing a single ring of elements). Experimental data obtained from a guided wave array containing electromagnetic acoustic transducer elements for exciting and detecting the S0 Lamb wave mode in a 5-mm-thick aluminum plate are processed with different algorithms and the results are discussed. Generalization of the technique for the case of multimode media is suggested. PMID:18177150

  20. High Resolution X-ray Imaging

    NASA Technical Reports Server (NTRS)

    Cash, Webster

    2002-01-01

    NAG5-5020 covered a period of 7.5 years during which a great deal of progress was made in x-ray optical techniques under this grant. We survived peer review numerous times during the effort to keep the grant going. In 1994, when the grant started we were actively pursuing the application of spherical mirrors to improving x-ray telescopes. We had found that x-ray detectors were becoming rapidly more sophisticated and affordable, but that x-ray telescopes were only being improved through the intense application of money within the AXAF program. Clearly new techniques for the future were needed. We were successful in developing and testing at the HELSTF facility in New Mexico a four reflection coma-corrected telescope made from spheres. We were able to demonstrate 0.3 arcsecond resolution, almost to the diffraction limit of the system. The community as a whole was, at that time, not particularly interested in looking past AXAF (Chandra) and the effort needed to evolve. Since we had reached the diffraction limit using non-Wolter optics we then decided to see if we could build an x-ray interferometer in the laboratory. In the lab the potential for improved resolution was substantial. If synthetic aperture telescopes could be built in space, then orders of magnitude improvement would become feasible. In 1998 NASA, under the direction of Dr Nick White of Goddard, started a study to assess the potential and feasibility of x-ray interferometry in space. My work became of central interest to the committee because it indicated that such was possible. In early 1999 we had the breakthrough that allowed us build a practical interferometer. By using flats and hooking up with the Marshall Space Flight Center facilities we were able to demonstrate fringes at 1.25keV on a one millimeter baseline. This actual laboratory demonstration provided the solid proof of concept that NASA needed. As the year progressed the future of x-ray astronomy jelled around the Maxim program. Maxim is a set of two major x-ray astronomy missions based on the concepts I developed and demonstrated under this SR&T grant. The first Maxim is to image the sky at 100 micro-arcsecond resolution. That is one thousand times higher resolution than Hubble. The full Maxim has the ultimate goal of imaging the event horizon of a black hole in an active galactic nucleus (ALAN). This will require 0.1 micro-arcsecond resolution - one million times higher than Hubble! Nonetheless, using the techniques developed under this grant, it has become possible. Maxim Pathfinder is now in the NASA planning for a new start in approximately 20 10. The full Maxim is carried as a vision mission for the post 2015 timeframe. Finally, this grant is the evolved version of the SR&T grant we carried during the 1980s and up to 1994. At that point in time this grant was also working on x-ray optics, but concentrating on x-ray spectroscopy. The techniques developed by 1990 were not chosen for use on Chandra or XMM-Newton because they were too new. During the last year, however, the Constellation-X mission recognized the need for better spectroscopy techniques and tapped our expertise. We were able to support the initial work on Con-X through this program. It now appears that the off-plane mount will be used in Con-X, increasing performance and decreasing cost and risk.

  1. High harmonic frequency combs for high resolution spectroscopy.

    PubMed

    Ozawa, A; Rauschenberger, J; Gohle, Ch; Herrmann, M; Walker, D R; Pervak, V; Fernandez, A; Graf, R; Apolonski, A; Holzwarth, R; Krausz, F; Hänsch, T W; Udem, Th

    2008-06-27

    We generated a series of harmonics in a xenon gas jet inside a cavity seeded by pulses from a Ti:sapphire mode-locked laser with a repetition rate of 10.8 MHz. Harmonics up to 19th order at 43 nm were observed with plateau harmonics at the microW power level. An elaborate dispersion compensation scheme and the use of a moderate repetition rate allowed for this significant improvement in output power of the plateau harmonics of 4 orders of magnitude over previous results. With this power level and repetition rate, high-resolution spectroscopy in the extreme ultraviolet region becomes conceivable. An interesting target would be the 1S-2S transition in hydrogenlike He+ at 60 nm. PMID:18643661

  2. Towards Improving Segmentation of Very High Resolution Satellite Imagery

    NASA Astrophysics Data System (ADS)

    Wuest, Ben A.

    High resolution satellite sensors, like QuickBird, have increased the dynamic grey-value variety and spatial detail in satellite imagery. New features can be distinguished that could not be discriminated in lower resolution imagery, such as that of Landsat TM. Object-oriented classification has shown significant promise as a method for the analysis and classification of objects in very high resolution imagery. This approach allows researchers to analyze pixel groups rather than individual pixels. Consequently, other features, such as texture and shape, can be applied to analysis. Object-oriented classification, however, is highly dependent upon successful image segmentation. This research proposes to investigate segmentation methods -- through algorithmic approaches -- for the purpose of reducing operator dependency, fragmentation, parameter complexity and improving other segmentation problems and restrictions. This research is conducted over a variety of high resolution satellite image scenes. The focus of this research will be region-based, unsupervised segmentation methods on very high resolution satellite imagery.

  3. 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.

  4. High resolution self-mixing laser rangefinder.

    PubMed

    Norgia, M; Magnani, A; Pesatori, A

    2012-04-01

    This work describes the development of a novel laser instrument for non-contact absolute distance measurements, working in safety class I. The physical principle of operation is based on the self-mixing effect in a laser diode: the laser diode wavelength is modulated through a change of the supply current, inducing a self-mixing signal. The frequency of the produced fringes depends on the target distance, therefore a particular algorithm is applied, in real-time, to extract the frequency tone of the fringes, even in the case of very low signal-to-noise ratio. The final low-cost instrument is realized with an embedded digital signal processor and works in real-time over diffusive targets, with resolution better than 100 ?m for distances up to 2 m. PMID:22559582

  5. High resolution spectral imagery of comets

    NASA Technical Reports Server (NTRS)

    Smith, W. H.

    1986-01-01

    C-13/C-12 data at a spectral resolution of 75,000, resolving the background interferences was obtained. Some data was obtained for N-15/N-14. In April, observations were obtained for the D/H ratio. The model analysis of these observations is beginning with the goal of presentation at the Heidelberg Halley meeting. A very large quantity of observations were obtained of both features with variations on the time scale of an hour being measured. At times, the 5577 feature dominates, and at times it is nearly absent. To date, a large body of data have been obtained for C2, NH2, (O I), and probably H2O+, CN, and from the MKO data, OH. These features can all be correlated with respect to their relative velocities and distribution at the time of observation. The Greenstein effect will be used to measure similar results for CN, OH, and few other selected molecular features.

  6. High Resolution X-ray Imaging

    NASA Technical Reports Server (NTRS)

    Cash, Webster

    2002-01-01

    NAG5-5020 covered a period of 7.5 years during which a great deal of progress was made in x-ray optical techniques under this grant. We survived peer review numerous times during the effort to keep the grant going. In 1994, when the grant started we were actively pursuing the application of spherical mirrors to improving x-ray telescopes. We had found that x-ray detectors were becoming rapidly more sophisticated and affordable, but that x-ray telescopes were only being improved through the intense application of money within the AXAF program. Clearly new techniques for the future were needed. We were successful in developing and testing at the HELSTF facility in New Mexico a four reflection coma-corrected telescope made from spheres. We were able to demonstrate 0.3 arcsecond resolution, almost to the diffraction limit of the system. The community as a whole was, at that time, not particularly interested in looking past AXAF (Chandra) and the effort needed to evolve. Since we had reached the diffraction limit using non-Wolter optics we then decided to see if we could build an x-ray interferometer in the laboratory. In the lab the potential for improved resolution was substantial. If synthetic aperture telescopes could be built in space, then orders of magnitude improvement would become feasible. In 1998 NASA, under the direction of Dr. Nick White of Goddard, started a study to assess the potential and feasibility of x-ray interferometry in space. My work became of central interest to the committee because it indicated that such was possible. In early 1999 we had the breakthrough that allowed us build a practical interferometer. By using flats and hooking up with the Marshall Space Flight Center facilities we were able to demonstrate fringes at 1.25keV on a one millimeter baseline. This actual laboratory demonstration provided the solid proof of concept that NASA needed.

  7. Modified Noise Power Ratio testing of high resolution digitizers

    SciTech Connect

    McDonald, T.S.

    1994-05-01

    A broadband, full signal range, side-by-side (tandem) test method for estimating the internal noise performance of high resolution digitizers is described and illustrated. The technique involves a re-definition of the traditional Noise Power Ratio (NPR) test, a change that not only makes this test applicable to higher resolution systems than was previously practical, but also enhances its value and flexibility. Since coherence analysis is the basis of this new definition, and since the application of coherence procedures to high resolution data poses several problems, this report discusses these problems and their resolution.

  8. Design of a high resolution scintillator based SPECT detector (SPECTatress)

    NASA Astrophysics Data System (ADS)

    Deprez, Karel; van Holen, Roel; Vandenberghe, Stefaan; Staelens, Steven

    2011-08-01

    SPECT scanners using multi-pinhole collimators benefit from compact detectors having a high spatial resolution. Such detectors can be placed closer to the collimator and perpendicular to the pinhole axis (thereby limiting DOI spatial resolution degradation). Current clinical gamma ray cameras have a large area and a poor spatial resolution.This proceeding describes the architecture of SPECTatress, a compact high resolution gamma camera. The main components (PMT and scintillator) are presented, a brief overview of the read-out electronics is given and a first measurement using the center-of-gravity (COG) event-positioning algorithm is shown.The result of this measurement indicates a good spatial resolution (1.75 mm FWHM) in the center of the detector. Further research has to be done on the event-positioning algorithm to extend the usable detector area and to enhance the spatial resolution.

  9. Analysis of the size, shape, and spatial distribution of microinclusions by neutron-activation autoradiography

    SciTech Connect

    Flitsiyan, E.S.; Romanovskii, A.V.; Gurvich, L.G.; Kist, A.A.

    1987-02-01

    The local concentration and spatial distribution of some elements in minerals, rocks, and ores can be determined by means of neutron-activation autoradiography. The local element concentration is measured in this method by placing an activated section of the rock to be analyzed, together with an irradiated standard, against a photographic emulsion which acts as a radiation detector. The photographic density of the exposed emulsion varies as a function of the tested element content in the part of the sample next to the detector. In order to assess the value of neutron-activation autoradiography in the analysis of element distribution, we considered the main factors affecting the production of selective autoradiographs, viz., resolution, detection limit, and optimal irradiation conditions, holding time, and exposure.

  10. 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.

  11. 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.

  12. MO-G-17A-09: Quantitative Autoradiography of Biopsy Specimens Extracted Under PET/CT Guidance

    SciTech Connect

    Fanchon, L; Carlin, S; Schmidtlein, C; Humm, J; Yorke, E; Solomon, S; Deasy, J; Kirov, A; Burger, I

    2014-06-15

    Purpose: To develop a procedure for accurate determination of PET tracer concentration with high spatial accuracy in situ by performing Quantitative Autoradiography of Biopsy Specimens (QABS) extracted under PET/CT guidance. Methods: Autoradiography (ARG) standards were produced from a gel loaded with a known concentration of FDG biopsied with 18G and 20G biopsy needles. Specimens obtained with these needles are generally cylindrical: up to 18 mm in length and about 0.8 and 0.6 mm in diameter respectively. These standards, with similar shape and density as biopsy specimens were used to generate ARG calibration curves.Quantitative ARG was performed to measure the activity concentration in biopsy specimens extracted from ten patients. The biopsy sites were determined according to PET/CT's obtained in the operating room. Additional CT scans were acquired with the needles in place to confirm correct needle placements. The ARG images were aligned with the needle tip in the PET/CT images using the open source CERR software. The mean SUV calculated from the specimen activities (SUVarg) were compared to that from PET (SUVpet) at the needle locations. Results: Calibration curves show that the relation between ARG signal and activity concentration in those standards is linear for the investigated range (up to 150 kBq/ml). The correlation coefficient of SUVarg with SUVpet is 0.74. Discrepancies between SUVarg and SUVpet can be attributed to the small size of the biopsy specimens compared to PET resolution. Conclusion: The calibration procedure using surrogate biopsy specimens provided a method for quantifying the activity within the biopsy cores obtained under FDG-PET guidance. QABS allows mapping the activity concentration in such biopsy specimens with a resolution of about 1mm. QABS is a promising tool for verification of biopsy adequacy by comparing specimen activity to that expected from the PET image. A portion of this research was funded by a research grant from Biospace Lab, 13 rue Georges Auric 75019 Paris, FRANCE.

  13. Eigenvector pruning method for high resolution beamforming.

    PubMed

    Quijano, Jorge E; Zurk, Lisa M

    2015-10-01

    This paper introduces an eigenvector pruning algorithm for the estimation of the signal-plus-interference eigenspace, required as a preliminary step to subspace beamforming. The proposed method considers large-aperture passive array configurations operating in environments with multiple maneuvering targets in background noise, in which the available data for estimation of sample covariances and eigenvectors are limited. Based on statistical properties of scalar products between deterministic and complex random vectors, this work defines a statistically justified threshold to identify target-related features embedded in the sample eigenvectors, leading to an estimator for the signal-bearing eigenspace. It is shown that data projection into this signal subspace results in sharpening of beamforming outputs corresponding to closely spaced targets and provides better target separation compared to current subspace beamformers. In addition, the proposed threshold gives the user control over the worst-case scenario for the number of false detections by the beamformer. Simulated data are used to quantify the performance of the subspace estimator according to the distance between estimated and true signal subspaces. Beamforming resolution using the proposed method is analyzed with simulated data corresponding to a horizontal line array, as well as experimental data from the Shallow Water Array Performance experiment. PMID:26520298

  14. Road Extraction from High Resolution Satellite Images

    NASA Astrophysics Data System (ADS)

    zkaya, 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.

  15. A High Resolution Southern Ocean Cyclone Climatology

    NASA Astrophysics Data System (ADS)

    Uotila, P. J.; Lynch, A. H.; D'Amico, M.; Abramson, R.; Egan, A.; Pezza, A. B.; Keay, K.; Cassano, J. J.

    2008-12-01

    Cyclones over the Southern Ocean represent an important element in the global circulation of heat and moisture and the maintenance of Southern Hemisphere climate. We seek to advance the understanding of atmospheric processes responsible for the development and decay of Southern Ocean mesocyclones and to explore the interactions between these cyclones and the underlying surface conditions, including sea ice extent, thickness, concentration, motion, and temperature. In this presentation, we will describe a Southern Ocean climatology, created based on the Antarctic Mesoscale Prediction System (AMPS) output and satellite observations. Intercomparison of cyclonicity between three re-analysis products and AMPS output reveals significant differences close to Antarctica especially during winter. Differences arise due to resolution of data and different surface parametrization schemes. The method applied to construct the climatology utilizes the Self-Organizing Map (SOM) technique to derive large-scale circulation patterns and a cyclone detection algorithm. The seasonal variability between large- scale circulation patterns and their association to the cyclone formation over the Southern Ocean is of particular interest. In addition, variables that influence the formation of a cyclogenetic environment, such as sea surface temperatures and the sea-ice extent, are analyzed.

  16. High-Resolution MOC Image of Phobos

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This image of Phobos, the inner and larger of the two moons of Mars, was taken by the Mars Global Surveyor on August 19, 1998. This image shows a close-up of the largest crater on Phobos, Stickney, 10 kilometers (6 miles) in diameter. Individual boulders are visible on the near rim of the crater, and are presumed to be ejecta blocks from the impact that formed Stickney. Some of these boulders are enormous - more than 50 meters (160 feet) across. Also crossing at and near the rim of Stickney are shallow, elongated depressions called grooves. This crater is nearly half the size of Phobos and these grooves may be fractures caused by its formation. Phobos was observed by both the Mars Orbiter Camera (MOC) and Thermal Emission Spectrometer (TES). This image is one of the highest resolution images (4 meters or 13 feet per picture element or pixel) ever obtained of the Martian satellite.

    Malin Space Science Systems, Inc. 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 Thermal Emission Spectrometer is operated by Arizona State University and was built by Raytheon Santa Barbara Remote Sensing. 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.

  17. High-resolution tomographic imaging of microvessels

    NASA Astrophysics Data System (ADS)

    Mller, 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.

  18. 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.

  19. High resolution airborne geophysics at hazardous waste disposal sites

    SciTech Connect

    Beard, L.P.; Nyquist, J.E.; Doll, W.E.; Chong Foo, M.; Gamey, T.J.

    1995-06-01

    In 1994, a high resolution helicopter geophysical survey was conducted over portions of the Oak Ridge Reservation, Tennessee. The 1800 line kilometer survey included multi-frequency electromagnetic and magnetic sensors. The areas covered by the high resolution portion of the survey were selected on the basis of their importance to the environmental restoration effort and on data obtained from the reconnaissance phase of the airborne survey in which electromagnetic, magnetic, and radiometric data were collected over the entire Oak Ridge Reservation in 1992--1993. The high resolution phase had lower sensor heights, more and higher EM frequencies, and tighter line spacings than did the reconnaissance survey. When flying over exceptionally clear areas, the high resolution bird came within a few meters of the ground surface. Unfortunately, even sparse trees and power or phone lines could prevent the bird from being towed safely at low altitude, and over such areas it was more usual for it to be flown at about the same altitude as the bird in the reconnaissance survey, about 30m. Even so, the magnetometers used in the high resolution phase were 20m closer to the ground than in the reconnaissance phase because they were mounted on the tail of the bird rather than on the tow cable above the bird. The EM frequencies used in the high resolution survey ranged from 7400Hz to 67000Hz. Only the horizontal coplanar loop configuration was used in the high resolution flyovers.

  20. High-resolution NMR spectroscopy in inhomogeneous fields.

    PubMed

    Chen, Zhong; Cai, Shuhui; Huang, Yuqing; Lin, Yulan

    2015-11-01

    High-resolution NMR spectroscopy, providing information on chemical shifts, J coupling constants, multiplet patterns, and relative peak areas, is a mainstream tool for analysis of molecular structures, conformations, compositions, and dynamics. Generally, a homogeneous magnetic field is a prerequisite for obtaining high-resolution NMR information. Magnetic field inhomogeneity, whether from non-ideal experimental conditions or from intrinsic magnetic susceptibility discontinuities in samples, represents a hurdle for applications of high-resolution NMR. Numerous techniques have been proposed for measuring high-resolution NMR spectra free from the influence of inhomogeneous magnetic fields. Besides developments and improvements in NMR instrumentation, various types of experimental approaches have been established for recovering NMR information in inhomogeneous magnetic fields. Three main types are systematically described in this review. In addition, other high-resolution NMR approaches or data processing methods are also briefly described. All high-resolution NMR approaches covered in this review have individual advantages and disadvantages in practical applications, and no one technique is applicable to all practical circumstances. Hence, they are complementary for high-resolution NMR applications in inhomogeneous fields. The underlying mechanisms of these approaches are presented, together with analyses of their applicability and efficiency. PMID:26592943

  1. High Resolution X-Ray Explorer (HIREX)

    NASA Technical Reports Server (NTRS)

    Golub, Leon

    1999-01-01

    SAO has carried out 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 image stability. The telescope design concept is based on a 0.6m Cassegrain-style telescope with a 240 meter effective focal length. This is achieved with 2 mirrors supported at opposite ends of a 27 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 a,rcsec level is achieved by active control of the secondary mirror. The primary mirror is held unadjustably to the spacecraft, its pointing set by the space- craft 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.

  2. A high resolution global scale groundwater model

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Groundwater is the world's largest accessible source of fresh water. It plays a vital role in satisfying needs for drinking water, agriculture and industrial activities. During times of drought groundwater sustains baseflow to rivers and wetlands, thereby supporting ecosystems. Most global scale hydrological models (GHMs) do not include a groundwater flow component, mainly due to lack of geohydrological data at the global scale. For the simulation of lateral flow and groundwater head dynamics a realistic physical representation of the groundwater system is needed, especially for GHMs that run at finer resolution. In this study we present a global scale groundwater model (run at 6' as dynamic steady state) using MODFLOW to construct an equilibrium water table at its natural state as the result of long-term climatic forcing. The aquifer schematization and properties were based on available global datasets of lithology and transmissivities combined with estimated aquifer thickness of an upper unconfined aquifer. The model is forced with outputs from the land-surface model PCR-GLOBWB, specifically with net recharge and surface water levels. A sensitivity analysis, in which the model was run with various parameter settings, showed variation in saturated conductivity causes most of the groundwater level variations. Simulated groundwater heads were validated against reported piezometer observations. The validation showed that groundwater depths are reasonably well simulated for many regions of the world, especially for sediment basins (R2 = 0.95). The simulated regional scale groundwater patterns and flowpaths confirm the relevance of taking lateral groundwater flow into account in GHMs. Flowpaths show inter-basin groundwater flow that can be a significant part of a basins water budget and helps to sustain river baseflow, explicitly during times of droughts. Also important aquifer systems are recharged by inter-basin groundwater flows that positively affect water availability.

  3. 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

  4. Reproducible high-resolution multispectral image acquisition in dermatology

    NASA Astrophysics Data System (ADS)

    Duliu, Alexandru; Gardiazabal, Jos; 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. High resolution shadowing for electron microscopy by sputter deposition.

    PubMed

    Adachi, K; Hojou, K; Katoh, M; Kanaya, K

    1976-12-01

    The sputtering process by an ion beam well collimated and highly accelerated provides a valuable means of high resolution shadowing, replication of a fine object by a combination of pre-shadowing and deposition as well as a preparation of supporting films. High resolution shadowing and films with grains smaller than 1 nm can be obtained by argon ion-sputtering targets of tungsten and tungsten/tantalum alloy. The resolution of carbon replicas pre-shadowed with tungsten/tantalum is determined from the radius of curvature of replicated magnesium oxide crystal corners. PMID:1028206

  10. High resolution extreme ultraviolet (EUV) studies of the sun

    NASA Astrophysics Data System (ADS)

    Jain, Surendra K.

    1992-01-01

    We briefly discuss some of the currently unanswered problems in solar astronomy which lend themselves to investigations particularly in the Extreme Ultra Violet (EUV) region of the spectrum. In this context, need of high spatial, spectral and temporal resolution is emphasized for such studies. Finally, after a brief discussion of the EUV instrumentation, a high resolution stigmatic EUV spectroheliometer is described which is currently under development for high resolution studies of the solar chromosphere, transition region and corona. The spectroheliometer will be flown aboard a sounding rocket.

  11. Applications of high resolution inverse Raman spectroscopy

    SciTech Connect

    Owyoung, A.; Esherick, P.

    1980-01-01

    The use of high-power, narrow-band lasers has significantly improved the resolving power and sensitivity of inverse Raman spectroscopy of gases. In this paper we shall describe this technique, illustrate its capabilities by showing some Q-branch spectra of heavy spherical tops, and survey some possible future applications.

  12. Spatially adaptive regularized iterative high-resolution image reconstruction algorithm

    NASA Astrophysics Data System (ADS)

    Lim, Won Bae; Park, Min K.; Kang, Moon Gi

    2000-12-01

    High resolution images are often required in applications such as remote sensing, frame freeze in video, military and medical imaging. Digital image sensor arrays, which are used for image acquisition in many imaging systems, are not dense enough to prevent aliasing, so the acquired images will be degraded by aliasing effects. To prevent aliasing without loss of resolution, a dense detector array is required. But it may be very costly or unavailable, thus, many imaging systems are designed to allow some level of aliasing during image acquisition. The purpose of our work is to reconstruct an unaliased high resolution image from the acquired aliased image sequence. In this paper, we propose a spatially adaptive regularized iterative high resolution image reconstruction algorithm for blurred, noisy and down-sampled image sequences. The proposed approach is based on a Constrained Least Squares (CLS) high resolution reconstruction algorithm, with spatially adaptive regularization operators and parameters. These regularization terms are shown to improve the reconstructed image quality by forcing smoothness, while preserving edges in the reconstructed high resolution image. Accurate sub-pixel motion registration is the key of the success of the high resolution image reconstruction algorithm. However, sub-pixel motion registration may have some level of registration error. Therefore, a reconstruction algorithm which is robust against the registration error is required. The registration algorithm uses a gradient based sub-pixel motion estimator which provides shift information for each of the recorded frames. The proposed algorithm is based on a technique of high resolution image reconstruction, and it solves spatially adaptive regularized constrained least square minimization functionals. In this paper, we show that the reconstruction algorithm gives dramatic improvements in the resolution of the reconstructed image and is effective in handling the aliased information. The proposed algorithm is also shown to be robust in the presence of severe registration error. Experimental results are provided to illustrate the performance of the proposed reconstruction algorithm. Comparative analyses with other reconstruction methods are also provided.

  13. High resolution survey for topographic surveying

    NASA Astrophysics Data System (ADS)

    Luh, L. C.; Setan, H.; Majid, Z.; Chong, A. K.; Tan, Z.

    2014-02-01

    In this decade, terrestrial laser scanner (TLS) is getting popular in many fields such as reconstruction, monitoring, surveying, as-built of facilities, archaeology, and topographic surveying. This is due the high speed in data collection which is about 50,000 to 1,000,000 three-dimensional (3D) points per second at high accuracy. The main advantage of 3D representation for the data is that it is more approximate to the real world. Therefore, the aim of this paper is to show the use of High-Definition Surveying (HDS), also known as 3D laser scanning for topographic survey. This research investigates the effectiveness of using terrestrial laser scanning system for topographic survey by carrying out field test in Universiti Teknologi Malaysia (UTM), Skudai, Johor. The 3D laser scanner used in this study is a Leica ScanStation C10. Data acquisition was carried out by applying the traversing method. In this study, the result for the topographic survey is under 1st class survey. At the completion of this study, a standard of procedure was proposed for topographic data acquisition using laser scanning systems. This proposed procedure serves as a guideline for users who wish to utilize laser scanning system in topographic survey fully.

  14. 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.

  15. Update on High-Resolution Geodetically Controlled LROC Polar Mosaics

    NASA Astrophysics Data System (ADS)

    Archinal, B.; Lee, E.; Weller, L.; Richie, J.; Edmundson, K.; Laura, J.; Robinson, M.; Speyerer, E.; Boyd, A.; Bowman-Cisneros, E.; Wagner, R.; Nefian, A.

    2015-10-01

    We describe progress on high-resolution (1 m/pixel) geodetically controlled LROC mosaics of the lunar poles, which can be used for locating illumination resources (for solar power or cold traps) or landing site and surface operations planning.

  16. 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.

  17. 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 zml church in Cappadocia, Turkey. This method enables us to achieve a high-resolution image database with low costs, short time, and limited human resources.

  18. High resolution CryoFESEM of microbial surfaces.

    PubMed

    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 -125 degrees 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. PMID:12901761

  19. Single-Molecule High-Resolution Colocalization of Single Probes

    PubMed Central

    Churchman, L. Stirling; Spudich, James A.

    2016-01-01

    Colocalization of fluorescent probes is commonly used in cell biology to discern the proximity of two proteins in the cell. Considering that the resolution limit of optical microscopy is on the order of 250 nm, there has not been a need for high-resolution colocalization techniques. However, with the advent of higher resolution techniques for cell biology and single-molecule biophysics, colocalization must also improve. For diffraction-limited applications, a geometric transformation (i.e., translation, scaling, and rotation) is typically applied to one color channel to align it with the other; however, to achieve high-resolution colocalization, this is not sufficient. Single-molecule high-resolution colocalization (SHREC) of single probes uses the local weighted mean transformation to achieve a colocalization resolution of at least 10 nm. This protocol describes the acquisition of registration data and the analysis required to obtain a high-resolution mapping between imaging channels. The total internal reflection fluorescence microscope (TIRFM) system described is designed to excite and image the fluorescent probes Cy3 and Cy5. Modifications may be required depending on the requirements of the individual study. PMID:22301661

  20. High Resolution Recombination Measurements of Stored Ions

    SciTech Connect

    Fogle, M.; Ekloew, N.; Lindroth, E.; Madzunkov, S.; Mohamed, T.; Schuch, R.; Tokman, M.; Badnell, N.

    2003-08-26

    The accuracy obtained in electron-ion recombination experiments at storage rings has reached a level which allows strenuous tests of theoretical models and the ability to derive accurate, and useful, information for applications such as plasma modeling and diagnostics. Here we present two such recombination experiments performed at the heavy ion storage ring CRYRING. First, we investigated the possibility to derive a temperature dependent plasma rate coefficient for Na-like Ni, which has been observed in emission lines from active solar regions and laboratory plasmas. Second, we determined the 2s1/2-2p1/2 energy splitting in Li-like Kr. Such a highly charged ion exhibits large QED contributions ({approx}1.5 eV) which are difficult to represent in theoretically calculations. The experimental value for the splitting was determined to within 8 meV while the theoretically determined value is only accurate to within 19 meV.

  1. 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 2mm thick continuous Lutetium Yttrium Orthosilicate (LYSO) scintillator and compare it to the performance of a 5mm thick continuous NaI(Tl) scintillator. The advantages of LYSO are its high stopping power and its non-hygroscopicity. Drawbacksare 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, 140keV) 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 (0.93mm full width at half maximum (FWHM)) is superior to the spatial resolution of the NaI(Tl) detector (1.37mm FWHM). The intrinsic radioactivity in the energy window (42% window centered at 140keV) 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

  2. 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.

  3. Quantitative 45Ca autoradiography of human bone

    PubMed Central

    Riggs, B. Lawrence; Marshall, John H.; Jowsey, Jenifer; Heaney, Robert P.; Bassingthwaighte, James B.

    2010-01-01

    Bone from 7 terminally ill men who received 45Ca to 23 days before death was studied by quantitative autoradiography. Short-term exchangeable calcium was located on bone surfaces, and had an apparent mass of 3.4 Gm. The time of maximal surface 45Ca activity was 2.5 days. Diffuse activity of low intensity from long-term exchange accounted for 16.9 3.3 per cent (mean S.E.) of total uptake; in the 2 patients having plasma 45Ca measurements; the rate of diffuse uptake ranged from 10 to 25 per cent of the normal accretion rate. However, focal activity of intermediate intensity accounted for 49.8 to 68.4 per cent of uptake and was believed to be due to both long-term exchange and secondary mineralization. An unexpected finding was that 7.5 1.6 per cent of activity was associated with bone resorption surfaces. Because of the terminal illness, bone formation was suppressed, and only 5.9 2.4 per cent of activity was associated with hot spots. PMID:5286527

  4. Organosilicate Materials for High Resolution Patterning

    NASA Astrophysics Data System (ADS)

    Christopher, Soles

    2010-03-01

    Organosilicate glasses (OSGs) of the form [RSiO1.5], where R is an organic functional group, have significant potential for nanoimprint lithography (NIL). We present and quantify two methods for fabricating NIL molds from OSG materials. The first utilizes conventional NIL templates, with patterns as small as 10 nm being directly imprinted into as-cast OSG films. The imprinted patterns are vitrified into hard ceramic-like materials that can then be used to imprint subsequent replica patterns with high fidelity. The second uses monomers where the R group is chosen to selectively render the OSG soluble in the polyethylene oxide (PEO) domains of a PEO-PS (PS being polystyrene) diblock copolymer. At elevated temperatures the BCP burns off while the OSG converts into a hard pattern. The resulting OSG patterns are templates of the PEO domains and can be used directly as a NIL molds to replicate the former BCP morphology into a range of materials. This approach offers incredible latitude in tuning the BCP morphology. The surface patterns can be driven through most of the morphologies of the BCP phase diagram by changing the ratio of the OSG to the BCP in the spin casting solution. These physics of these surprising results are discussed in detail.

  5. High pressure injection piping waterhammer and resolution

    SciTech Connect

    Lin, W.C.; Lee, H.H.; Cheng, Y.H.

    1995-12-01

    High Pressure Coolant Injection (HPCI) system is the major safeguard of a GE BWR/4 Reactor. However, it doesn`t have a specific injection nozzle on the Reactor. In order to inject coolant into the Reactor, it must use a connection on the FeedWater (FW) System. The FW system is a hot running system, but HPCI is a cold standby system. The connection of the two (2) systems with different fluid temperatures can cause trouble. NRC Information Notice No. 89-80 recognized this fact. Unfortunately, just like, the events described in NRC Notice No. 89-80, their Chin-Shan Nuclear Power Station (GE BWR/4) HPCI system had experienced several waterhammers during system Scheduled Surveillance testing and Cold Quick Start testing. The waterhammers had damaged several valves, some pipe supports and damaged some concrete surfaces near the support attachment points. The trigger of all issues are two (2) malfunctioning valves: injection valve (F006) and the test return valve (F008). Some practical measures are taken to alleviate the situation, and they have resulted in satisfactory success. This paper is going to review the how-and-why of the above issues. Suggestions for design rules are provided.

  6. High spectral resolution image of Barnacle Bill

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The rover Sojourner's first target for measurement by the Alpha-Proton-Xray Spectrometer (APXS) was the rock named Barnacle Bill, located close to the ramp down which the rover made its egress from the lander. The full spectral capability of the Imager for Mars Pathfinder (IMP), consisting of 13 wavelength filters, was used to characterize the rock's surface. The measured area is relatively dark, and is shown in blue. Nearby on the rock surface, soil material is trapped in pits (shown in red).

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

  7. High Resolution Infrared Spectra of Triacetylene

    NASA Astrophysics Data System (ADS)

    Doney, Kirstin D.; Zhao, Dongfeng; Linnartz, Harold

    2015-06-01

    Triacetylene, HC6H, is the longest poly-acetylene chain found in space, and is believed to be involved in the formation of longer chain molecules and polycyclic aromatic hydrocarbons (PAHs). However, abundances are expected to be low, and observational confirmation requires knowledge of the gas-phase spectra, which up to now has been incomplete with only the weak, low lying bending modes being known. We present new infrared (IR) spectra in the C-H stretch region obtained using ultra-sensitive and highly precise IR continuous wave cavity ring-down spectroscopy (cw-CRDS), combined with supersonic plasma expansions The talk reviews the accurate determination of the rotational constants of the asymmetric fundamental mode, νb{5}, including discussion on the perturber state, and associated hot bands. The determined molecular parameters are accurate enough to aid astronomical searches with such facilities as ALMA (Atacama Large Millimeter Array) or the upcoming JWST (James Webb Space Telecscope), which can now probe even trace molecules (abundances of ˜ 10-6 - 10-10 with respect to H2). D. Zhao, J. Guss, A. Walsh, H. Linnartz, Chem. Phys. Lett., 565, 132 (2013) K.D. Doney, D. Zhao, H. Linnartz, in preparation

  8. High-resolution signal synthesis for time-frequency distributions

    SciTech Connect

    Cunningham, G.S. ); Williams, W.J. . Dept. of Electrical Engineering and Computer Science)

    1993-01-01

    Bilinear time-frequency distributions (TFDs) offer improved resolution over linear nine-frequency representations (TFRs), but many TFDs are costly to evaluate and are not associated with signal synthesis algorithms. Recently, the spectrogram (SP) decomposition and weighted reversal correlator decomposition have been used to define low-cost, high-resolution TFDs. In this paper, we show that the vector-valued square-root'' of a TFD (VVTFR) provides a representational underpinning for the TFD. By synthesizing signals from modified VVTFRs, we define high-resolution signal synthesis algorithms associated with TFDs. The signal analysis and synthesis packages can be implemented as weighted sums of SP/short-time Fourier Transform signal analysis and synthesis packages, which are widely available, allowing the interested non-specialist easy access to high-resolution methods.

  9. 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.

  10. Potential For High Resolution Microscintigraphy using Polycapillary Optics

    NASA Astrophysics Data System (ADS)

    Conlon, Patrick

    Scintigraphy, also known as nuclear imaging, is the process of imaging an object that has been labeled with a radioactive material. A novel technique employing polycapillary optics for very high - resolution scintigraphy is presented. The small channel size and angular selectivity of polycapillary optics allow them to act as multiple-hole collimators and be used with high - resolution detectors. The ability of the optics to work with high resolution detectors allow the system to discriminate against scatter, thus negating the need for energy sensitive detectors, which are known to have poor resolution. Therefore the use of polycapillary optics presents the opportunity to both reject scatter and increase resolution. Measurements were performed to determine the effects of increasing source - to - detector distances and optic - to - detector distances compared to those used in previous works, as well as increasing the length of the optics. The images exhibited promising signal - to -background rations while still displaying sub - millimeter resolutions, even with large amounts of tissue - equivalent material in place. Lastly, a Markov Chain Monte Carlo algorithm was developed to estimate the resolution of images, determine parameters of the brachytherapy seeds employed to simulate patient dose, and determine theoretical signal - to - background ratios, all of which showed fair agreement with experimental results.

  11. [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

  12. 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 1.2נ1.2mm(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 2mm in nearly all positions within the FOV without resolution recovery, reaching around 2.5mm in some locations, they fell below 1.8mm 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

  13. A miniature high-resolution accelerometer utilizing electron tunneling

    NASA Astrophysics Data System (ADS)

    Rockstad, Howard K.; Kenny, T. W.; Reynolds, J. K.; Kaiser, W. J.; Vanzandt, T. R.; Gabrielson, Thomas B.

    New methods have been developed to implement high-resolution position sensors based on electron tunneling. These methods allow miniaturization while utilizing the position sensitivity of electron tunneling to give high resolution. A single-element tunneling accelerometer giving a displacement resolution of 0.002 A/sq rt Hz at 10 Hz, corresponding to an acceleration resolution of 5 x 10 exp -8 g/sq rt Hz, is described. A new dual-element tunneling structure which overcomes the narrow bandwidth limitations of a single-element structure is described. A sensor with an operating range of 5 Hz to 10 kHz, which can have applications as an acoustic sensor, is discussed. Noise is analyzed for fundamental thermal vibration of the suspended masses and is compared to electronic noise. It is shown that miniature tunnel accelerometers can achieve resolution such that thermal noise in the suspended masses is the dominant cause of the resolution limit. With a proof mass of order 100 mg, noise analysis predicts limiting resolutions approaching 10 exp -9 g/sq rt Hz in a 300 Hz band and 10 exp -8 g/sq rt Hz at 1 kHz.

  14. A miniature high-resolution accelerometer utilizing electron tunneling

    NASA Technical Reports Server (NTRS)

    Rockstad, Howard K.; Kenny, T. W.; Reynolds, J. K.; Kaiser, W. J.; Vanzandt, T. R.; Gabrielson, Thomas B.

    1992-01-01

    New methods have been developed to implement high-resolution position sensors based on electron tunneling. These methods allow miniaturization while utilizing the position sensitivity of electron tunneling to give high resolution. A single-element tunneling accelerometer giving a displacement resolution of 0.002 A/sq rt Hz at 10 Hz, corresponding to an acceleration resolution of 5 x 10 exp -8 g/sq rt Hz, is described. A new dual-element tunneling structure which overcomes the narrow bandwidth limitations of a single-element structure is described. A sensor with an operating range of 5 Hz to 10 kHz, which can have applications as an acoustic sensor, is discussed. Noise is analyzed for fundamental thermal vibration of the suspended masses and is compared to electronic noise. It is shown that miniature tunnel accelerometers can achieve resolution such that thermal noise in the suspended masses is the dominant cause of the resolution limit. With a proof mass of order 100 mg, noise analysis predicts limiting resolutions approaching 10 exp -9 g/sq rt Hz in a 300 Hz band and 10 exp -8 g/sq rt Hz at 1 kHz.

  15. Solar Observation with high spectral resolution and image restoration.

    NASA Astrophysics Data System (ADS)

    Koschinsky, M.; Kneer, F.; Wunnenberg, M.; Krieg, J.; Ritter, C.

    Observations of the Sun with both, high spectral and high spatial resolution are needed for an understanding of the structure, the dynamics and the temporal evolution of small scale features in the solar photosphere. To achieve this, high technical requirements on the optical setup have to be satisfied, and also extensive methods of data reduction and image restoration are needed. We present our approach to obtain high resolution observational data by using a double Fabry-Perot interferometer at the Vacuum Tower Telescope (VTT) on Tenerife. The spectral resolution is about 30 m. Different methods of image reconstruction to remove distortions by seeing and telescopic aberrations to a high extent are presented as well.

  16. 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.

  17. A new parallel subaperture algorithm for high resolution SAR imaging

    NASA Astrophysics Data System (ADS)

    Liu, Xiao; Pi, Yi-ming; Leng, Chuan-hang

    2007-10-01

    Both real-time rate and resolution both are key indexes of Synthetic Aperture Radar(SAR)imaging, but there is a conflict between them. Real-time imaging becomes difficult because of the large computational requirement posed by high-resolution processing. Parallel computing is an effective approach for real-time processing. In previous research, coarse and medium grained parallel algorithms for SAR imaging have been presented. Although they can significantly improve the processing speed, the quality of image has been ignored. Subaperture is widely used in high-resolution SAR. Compared with full aperture processing, it can compensate the motion errors more accurately and get better images. Whereas, subaperture processing can't be applied in existing parallel imaging algorithms because of they are all based on full aperture processing, which restricts the application of existing algorithms in high-resolution SAR parallel imaging. This paper presents a parallel imaging algorithm for high-resolution SAR, through which we can obtain high-resolution SAR image while achieving good computation efficiency. It combines chirp-scaling algorithm with subaperture processing. The new algorithm can highly effectively run on parallel computer, in which each node has the same load. It reduces the large communication requirement posed by three transposes through designing CS processing for subaperture data, and it has better parallel scalability, which means that it can be used on larger parallel computer without deducing the image quality. The experiments on SGI Origin2000 have proved that, compared with medium grained parallel CS algorithm, the algorithm presented in this paper is more suitable for high-resolution SAR parallel imaging.

  18. 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.

  19. 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.

  20. 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 μm and a relative phase sensitivity of about 0.4 rad corresponding to a depth resolution of 6 μm 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

  1. A procedure for high resolution satellite imagery quality assessment.

    PubMed

    Crespi, Mattia; De Vendictis, Laura

    2009-01-01

    Data products generated from High Resolution Satellite Imagery (HRSI) are routinely evaluated during the so-called in-orbit test period, in order to verify if their quality fits the desired features and, if necessary, to obtain the image correction parameters to be used at the ground processing center. Nevertheless, it is often useful to have tools to evaluate image quality also at the final user level. Image quality is defined by some parameters, such as the radiometric resolution and its accuracy, represented by the noise level, and the geometric resolution and sharpness, described by the Modulation Transfer Function (MTF). This paper proposes a procedure to evaluate these image quality parameters; the procedure was implemented in a suitable software and tested on high resolution imagery acquired by the QuickBird, WorldView-1 and Cartosat-1 satellites. PMID:22412312

  2. A Procedure for High Resolution Satellite Imagery Quality Assessment

    PubMed Central

    Crespi, Mattia; De Vendictis, Laura

    2009-01-01

    Data products generated from High Resolution Satellite Imagery (HRSI) are routinely evaluated during the so-called in-orbit test period, in order to verify if their quality fits the desired features and, if necessary, to obtain the image correction parameters to be used at the ground processing center. Nevertheless, it is often useful to have tools to evaluate image quality also at the final user level. Image quality is defined by some parameters, such as the radiometric resolution and its accuracy, represented by the noise level, and the geometric resolution and sharpness, described by the Modulation Transfer Function (MTF). This paper proposes a procedure to evaluate these image quality parameters; the procedure was implemented in a suitable software and tested on high resolution imagery acquired by the QuickBird, WorldView-1 and Cartosat-1 satellites. PMID:22412312

  3. 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.

  4. 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

  5. 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.

  6. High spectral resolution imager for solar induced fluorescence observation

    NASA Astrophysics Data System (ADS)

    Barducci, A.; Guzzi, D.; Lastri, C.; Marcoionni, P.; Nardino, V.; Pippi, I.; Raimondi, V.; Sandri, P.

    2011-11-01

    The use of high-resolution imagers for determination of solar-induced fluorescence of natural bodies by observing the infilling of Fraunhofer lines has been frequently adopted as a tool for vegetation characterization. The option to perform those measurements from airborne platforms was addressed in the past. In-field observations gave evidence of the main requirements for an imaging spectrometer to be used for Sun-induced fluorescence measurements such as high spectral resolution and fine radiometric accuracy needed to resolve the shape of observed Fraunhofer lines with a high level of accuracy. In this paper, some solutions for the design of a high spectral resolution push-broom imaging spectrometer for Sun-induced fluorescence measurements are analysed. The main constraints for the optical design are a spectral resolution better than 0.01 nm and a wide field of view. Due to the fine instrumental spectral resolution, bidimensional focal plane arrays characterized by high quantum efficiency, low read-out noise, and high sensitivity are requested. The development of a lightweight instrument is a benefit for aerospace implementations of this technology. First results coming from laboratory measurements and optical simulations are presented and discussed taking into account their feasibility.

  7. The Goddard High Resolution Spectrograph: Instrument, goals, and science results

    NASA Technical Reports Server (NTRS)

    Brandt, J. C.; Heap, S. R.; Beaver, E. A.; Boggess, A.; Carpenter, K. G.; Ebbets, D. C.; Hutchings, J. B.; Jura, M.; Leckrone, D. S.; Linsky, J. L.

    1994-01-01

    The Goddard High Resolution Spectrograph (GHRS), currently in Earth orbit on the Hubble Space Telescope (HST), operates in the wavelength range 1150-3200 A with spectral resolutions (lambda/delta lambda) of approximately 2 x 10(exp 3), 2 x 10(exp 4), and 1 x 10(exp 3). The instrument and its development from inception, its current status, the approach to operations, representative results in the major areas of the scientific goals, and prospects for the future are described.

  8. Placement of Accelerometers for High Sensing Resolution in Micromanipulation

    PubMed Central

    Latt, W. T.; Tan, U-X.; Riviere, C. N.; Ang, W. T.

    2012-01-01

    High sensing resolution is required in sensing of surgical instrument motion in micromanipulation tasks. Accelerometers can be employed to sense physiological motion of the instrument during micromanipulation. Various configurations of accelerometer placement had been introduced in the past to sense motion of a rigid-body such as a surgical instrument. Placement (location and orientation) of accelerometers fixed in the instrument plays a significant role in achieving high sensing resolution. However, there is no literature or work on the effect of placement of accelerometers on sensing resolution. In this paper, an approach of placement of accelerometers within an available space to obtain highest possible sensing resolution in sensing of rigid-body motion in micromanipulation tasks is proposed. Superiority of the proposed placement approach is shown in sensing of a microsurgical instrument angular motion by comparing sensing resolutions achieved as a result of employing the configuration following the proposed approach and the existing configurations. Apart from achieving high sensing resolution, and design simplicity, the proposed placement approach also provides flexibility in placing accelerometers; hence it is especially useful in applications with limited available space to mount accelerometers. PMID:22423176

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

    PubMed

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

    2016-03-31

    Lipidomics, which focuses on the global study of molecular lipids in biological systems, has been driven tremendously by technical advances in mass spectrometry (MS) instrumentation, particularly high-resolution MS. This requires powerful computational tools that handle the high-throughput lipidomics data analysis. To address this issue, a novel computational tool has been developed for the analysis of high-resolution MS data, including the data pretreatment, visualization, automated identification, deconvolution and quantification of lipid species. The algorithm features the customized generation of a lipid compound library and mass spectral library, which covers the major lipid classes such as glycerolipids, glycerophospholipids and sphingolipids. Next, the algorithm performs least squares resolution of spectra and chromatograms based on the theoretical isotope distribution of molecular ions, which enables automated identification and quantification of molecular lipid species. Currently, this methodology supports analysis of both high and low resolution MS as well as liquid chromatography-MS (LC-MS) lipidomics data. The flexibility of the methodology allows it to be expanded to support more lipid classes and more data interpretation functions, making it a promising tool in lipidomic data analysis. PMID:26965325

  10. High resolution BPMS with integrated gain correction system

    SciTech Connect

    Wendt, M.; Briegel, C.; Eddy, N.; Fellenz, B.; Gianfelice, E.; Prieto, P.; Rechenmacher, R.; Voy, D.; Terunuma, N.; Urakawa, J.; /KEK, Tsukuba

    2009-08-01

    High resolution beam position monitors (BPM) are an essential tool to achieve and reproduce a low vertical beam emittance at the KEK Accelerator Test Facility (ATF) damping ring. The ATF damping ring (DR) BPMs are currently upgraded with new high resolution read-out electronics. Based on analog and digital down-conversion techniques, the upgrade includes an automatic gain calibration system to correct for slow drift effects and ensure high reproducible beam position readings. The concept and its technical realization, as well as preliminary results of beam studies are presented.

  11. 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.

  12. 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.

  13. High-Resolution Cassini RADAR Scatterometer Images of Titan's Surface

    NASA Astrophysics Data System (ADS)

    Wye, Lauren C.; Zebker, H. A.; Cassini RADAR Team

    2006-09-01

    The Cassini RADAR scatterometer has acquired observations to date of about 40% of Titan's surface at resolutions averaging just under 100 km, where the resolution cell size is set by the real aperture of the radar antenna. Finer resolution (0.3-1 km) images have been acquired by RADAR in synthetic-aperture (SAR) mode of about 10% of the surface. Additional techniques have been developed to use the SAR processor at larger distances (denoted High-SAR) for increased high-resolution (2-3 km) coverage, though with very narrow swath sizes (see West et al., this conference). In this paper, we demonstrate that complex processing methods, specifically range compression and unfocused SAR processing, can also be applied to the data collected in rastered scatterometer mode, achieving resolutions near 15 km and maintaining 10 or more radar "looks. Despite poorer resolution, rastered scatterometry has two advantages over SAR and High-SAR: 1) greater surface coverage is possible with less data volume, and 2) the surface is sampled over a wider range of incidence angles, so that important characteristics like dielectric constant and surface slope may be estimated. Improving the resolution of the scatterometer's near-global backscatter maps will significantly enhance the unique knowledge that RADAR contributes to the understanding of Titan and its fascinating surface. Here, we present examples of scatterometer coverage of Titan at its highest resolution. This work was carried out at Stanford University, under contract with the Cassini Project of the Jet Propulsion Laboratory (JPL) / National Aeronautics and Space Administration (NASA).

  14. 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.

  15. How Far can we Push Ultra High Resolution Gamma Spectroscopy

    NASA Astrophysics Data System (ADS)

    Jentschel, M.; Brner, H.; Mutti, P.

    2003-06-01

    The ultra high resolution crystal spectrometers GAMS4/5 are available at both sides of a tangential beam tube at the high flux reactor of the Institut Laue-Langevin. They permit to investigate gamma radiation by double Laue diffraction using perfect Si/Ge crystals. Recent significant improvements of the instrument characteristics and their impact on the scientific program will be discussed

  16. 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}.

  17. High-resolution DEM Effects on Geophysical Flow Models

    NASA Astrophysics Data System (ADS)

    Williams, M. R.; Bursik, M. I.; Stefanescu, R. E. R.; Patra, A. K.

    2014-12-01

    Geophysical mass flow models are numerical models that approximate pyroclastic flow events and can be used to assess the volcanic hazards certain areas may face. One such model, TITAN2D, approximates granular-flow physics based on a depth-averaged analytical model using inputs of basal and internal friction, material volume at a coordinate point, and a GIS in the form of a digital elevation model (DEM). The volume of modeled material propagates over the DEM in a way that is governed by the slope and curvature of the DEM surface and the basal and internal friction angles. Results from TITAN2D are highly dependent upon the inputs to the model. Here we focus on a single input: the DEM, which can vary in resolution. High resolution DEMs are advantageous in that they contain more surface details than lower-resolution models, presumably allowing modeled flows to propagate in a way more true to the real surface. However, very high resolution DEMs can create undesirable artifacts in the slope and curvature that corrupt flow calculations. With high-resolution DEMs becoming more widely available and preferable for use, determining the point at which high resolution data is less advantageous compared to lower resolution data becomes important. We find that in cases of high resolution, integer-valued DEMs, very high-resolution is detrimental to good model outputs when moderate-to-low (<10-15) slope angles are involved. At these slope angles, multiple adjacent DEM cell elevation values are equal due to the need for the DEM to approximate the low slope with a limited set of integer values for elevation. The first derivative of the elevation surface thus becomes zero. In these cases, flow propagation is inhibited by these spurious zero-slope conditions. Here we present evidence for this "terracing effect" from 1) a mathematically defined simulated elevation model, to demonstrate the terracing effects of integer valued data, and 2) a real-world DEM where terracing must be addressed. We discuss the effect on the flow model output and present possible solutions for rectification of the problem.

  18. 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

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

    NASA Astrophysics Data System (ADS)

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

    1993-05-01

    The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates over a wide dynamic range (> 10 10), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 ?m for a field of view of 1 mm has been reported [R.W. Odom, M.D. Strathman, S.E. Buttrill, Jr., and S.M. Bauman, Nucl. Instr. and Meth. B44 (1990) 465]. A higher resolution detector for imaging small beams (< 50 ?m) with an image resolution of better than 0.5 ?m has since been developed and its design is presented.

  20. 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 VMMsXen, 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

  1. 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

  2. Adaptive optics high resolution spectroscopy: present status and future direction

    SciTech Connect

    Alcock, C; Angel, R; Ciarlo, D; Fugate, R O; Ge, J; Kuzmenko, P; Lloyd-Hart, M; Macintosh, B; Najita, J; Woolf, N

    1999-07-27

    High resolution spectroscopy experiments with visible adaptive optics (AO) telescopes at Starfire Optical Range and Mt. Wilson have demonstrated that spectral resolution can be routinely improved by a factor of - 10 over the seeing-limited case with no extra light losses at visible wavelengths. With large CCDs now available, a very wide wavelength range can be covered in a single exposure. In the near future, most large ground-based telescopes will be equipped with powerful A0 systems. Most of these systems are aimed primarily at diffraction-limited operation in the near IR. An exciting new opportunity will thus open up for high resolution IR spectroscopy. Immersion echelle gratings with much coarser grooves being developed by us at LLNL will play a critical role in achieving high spectral resolution with a compact and low cost IR cryogenically cooled spectrograph and simultaneous large wavelength coverage on relatively small IR detectors. We have constructed a new A0 optimized spectrograph at Steward Observatory to provide R = 200,000 in the optical, which is being commissioned at the Starfire Optical Range 3.5m telescope. We have completed the optical design of the LLNL IR Immersion Spectrograph (LISPEC) to take advantage of improved silicon etching technology. Key words: adaptive optics, spectroscopy, high resolution, immersion gratings

  3. Vehicle Detection and Classification from High Resolution Satellite Images

    NASA Astrophysics Data System (ADS)

    Abraham, L.; Sasikumar, M.

    2014-11-01

    In the past decades satellite imagery has been used successfully for weather forecasting, geographical and geological applications. Low resolution satellite images are sufficient for these sorts of applications. But the technological developments in the field of satellite imaging provide high resolution sensors which expands its field of application. Thus the High Resolution Satellite Imagery (HRSI) proved to be a suitable alternative to aerial photogrammetric data to provide a new data source for object detection. Since the traffic rates in developing countries are enormously increasing, vehicle detection from satellite data will be a better choice for automating such systems. In this work, a novel technique for vehicle detection from the images obtained from high resolution sensors is proposed. Though we are using high resolution images, vehicles are seen only as tiny spots, difficult to distinguish from the background. But we are able to obtain a detection rate not less than 0.9. Thereafter we classify the detected vehicles into cars and trucks and find the count of them.

  4. Radioimagers as an alternative to film autoradiography for in situ quantitative analysis of 125I-ligand receptor binding and pharmacological studies.

    PubMed

    Crumeyrolle-Arias, M; Jafarian-Tehrani, M; Cardona, A; Edelman, L; Roux, P; Lanice, P; Charon, Y; Haour, F

    1996-11-01

    Three radioimagers, the mu-imager, the beta-imager and the phosphorimager, were tested as alternatives to quantitative autoradiography on film, for receptor imaging and pharmacological in situ quantitative analysis. Two iodinated ligands 125I-interleukin-1 alpha and 125I-gonadotropin releasing hormone agonist were used for receptor characterization in mouse brain and pituitary sections. Due to the high number of the agonist receptors in rat pituitary gland, this tissue was used to compare measurements obtained from digital autoradiograms with classical gamma detector determination. This permits the evaluation of radioimager efficiency and absolute quantification. Radioimagers represent an improvement in terms of time of image acquisition. All the radioimagers are more sensitive than film for the detection of low levels of radioactivity. The spatial resolution provided by the mu-imager compares favourably with that obtained on film autoradiograms while digital autoradiograms from the phosphorimager and beta-imager did not show precise definition under our experimental conditions. Superimposition of histological structures from the stained sections with radiolabelled areas in the autoradiograms remains, at this time, the unique advantage of film. In conclusion, radioimagers represent an alternative to autoradiography on film or emulsion for in situ quantitative studies on tissue sections. They combine precise imaging for in situ binding studies with easy and direct access to counts in cpm. The improvement in radioimaging technology has, therefore, brought in situ analysis of iodinated ligand binding to the level of accuracy that is obtained with classical detectors of radioactivity. PMID:8968732

  5. High-Resolution Room Temperature Spectroscopy with Lanthanum Halides

    SciTech Connect

    Mukhopadhyay, Sanjoy

    2005-11-15

    The most desirable features in a spectroscopic material are high sensitivity and high resolution. Cerium-activated crystals of lanthanum bromide (LaBr{sub 3}:Ce) have higher sensitivity and better spectroscopic resolution than sodium/cesium iodide (NaI/CsI) crystals because of higher density (5.29 g/cm{sup 3}), faster decay time (35 ns), minimal afterglow, and larger (63 000 photons/MeV) and more linear light output (6% nonlinearity over the energy range between 60 and 1332 keV). Of all the recent scintillator materials manufactured to date, LaBr{sub 3}, with cerium activators, is one of the most promising for high-resolution, fast timing techniques as applied to medical image reconstructions or associated particle imaging.

  6. Masers: High Resolution Probes of Massive Star Formation

    NASA Astrophysics Data System (ADS)

    Ellingsen, S. P.

    2004-09-01

    Astrophysical masers are one of the most readily detected signposts of high-mass star formation. Their presence indicates special conditions, probably indicative of a specific evolutionary phase. Masers also represent the ultimate high-resolution probe of star formation with the potential to reveal information on the kinematics and physical conditions within the region at milli-arcsecond resolution. To date this potential has largely remained unfulfilled, however, recent advances suggest that this will soon change. The key to unlocking the potential of masers lies in identifying where they fit within the star formation jigsaw puzzle. I will review recent high resolution observations of OH, water and methanol maser transitions and what they reveal. I also briefly discuss how multi-transition observations of OH and methanol masers are being used to constrain maser pumping models and through this estimate the physical conditions in the masing region.

  7. High-resolution streaming video integrated with UGS systems

    NASA Astrophysics Data System (ADS)

    Rohrer, Matthew

    2010-04-01

    Imagery has proven to be a valuable complement to Unattended Ground Sensor (UGS) systems. It provides ultimate verification of the nature of detected targets. However, due to the power, bandwidth, and technological limitations inherent to UGS, sacrifices have been made to the imagery portion of such systems. The result is that these systems produce lower resolution images in small quantities. Currently, a high resolution, wireless imaging system is being developed to bring megapixel, streaming video to remote locations to operate in concert with UGS. This paper will provide an overview of how using Wifi radios, new image based Digital Signal Processors (DSP) running advanced target detection algorithms, and high resolution cameras gives the user an opportunity to take high-powered video imagers to areas where power conservation is a necessity.

  8. High spatial resolution measurements of ram accelerator gas dynamic phenomena

    NASA Technical Reports Server (NTRS)

    Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

    1992-01-01

    High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Data obtained by using a special highly instrumented section of tube has allowed the recording of gas dynamic phenomena with a spatial resolution on the order of one tenth the projectile length. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) are presented and reveal the 3D character of the flowfield induced by projectile fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, 3D CFD code.

  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. 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.

  11. High resolution observations: The state of the art and beyond

    NASA Technical Reports Server (NTRS)

    Title, A.; Tarbell, T.; Shine, R.; Topka, K.; Frank, Z.

    1992-01-01

    The meaning of high resolution and its scientific importance with regard to solar observations is discussed. The state of the art is reviewed, looking into Solar Optical Universal Polarimeter (SOUP) observations, image selection techniques, and adaptive optics. It is concluded that until there are observations in space, complete understanding of processes in the solar photosphere, chromosphere, transition region, and corona will be impossible. The importance of high resolution is considered with regard to solar surface and convection, solar photosphere inside and outside magnetic fields, and sunspot geometry.

  12. 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.

  13. High-resolution seismic studies applied to injected geothermal fluids

    SciTech Connect

    Smith, A.T.; Kasameyer, P.

    1985-01-01

    The application of high-resolution microseismicity studies to the problem of monitoring injected fluids is one component of the Geothermal Injection Monitoring Project at LLNL. The evaluation of microseismicity includes the development of field techniques, and the acquisition and processing of events during the initial development of a geothermal field. To achieve a specific detection threshold and location precision, design criteria are presented for seismic networks. An analysis of a small swarm near Mammoth Lakes, California, demonstrates these relationships and the usefulness of high-resolution seismic studies. A small network is currently monitoring the Mammoth-Pacific geothermal power plant at Casa Diablo as it begins production.

  14. 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.

  15. High Resolution 3d Modeling of the Behaim Globe

    NASA Astrophysics Data System (ADS)

    Menna, F.; Rizzi, A.; Nocerino, E.; Remondino, F.; Gruen, A.

    2012-07-01

    The article describes the 3D surveying and modeling of the Behaim globe, the oldest still existing and intact globe of the earth, preserved at the German National Museum of Nuremberg, Germany. The work is primarily performed using high-resolution digital images and automatic photogrammetric techniques. Triangulation-based laser scanning is also employed to fill some gaps in the derived image-based 3D geometry and perform geometric comparisons. Major problems are encountered in texture mapping. The 3D modeling project and the creation of high-resolution map-projections is performed for scientific, conservation, visualization and education purposes.

  16. 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.

  17. Future X-ray Missions for High Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ohashi, Takaya

    2010-12-01

    The future X-ray missions for high resolution spectroscopy are briefly reviewed. ASTRO-H, planned for launch in 2014, will introduce microcalorimeters for the first time and reveal dynamical motions of hot gas in extended objects. High resolution spectroscopy will also be used for the search of missing baryons with oxygen lines in the local universe. Dedicated X-ray missions are also planned. A very large X-ray observatory IXO, under joint study of NASA, ESA and JAXA, will explore the evolution of the universe using X-ray spectroscopy as a very powerful tool.

  18. 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.

  19. Wide-field, high-resolution Fourier ptychographic microscopy

    PubMed Central

    Zheng, Guoan; Horstmeyer, Roarke; Yang, Changhuei

    2014-01-01

    In this article, we report an imaging method, termed Fourier ptychographic microscopy (FPM), which iteratively stitches together a number of variably illuminated, low-resolution intensity images in Fourier space to produce a wide-field, high-resolution complex sample image. By adopting a wavefront correction strategy, the FPM method can also correct for aberrations and digitally extend a microscopes depth-of-focus beyond the physical limitations of its optics. As a demonstration, we built a microscope prototype with a resolution of 0.78 ?m, a field-of-view of ~120 mm2, and a resolution-invariant depth-of-focus of 0.3 mm (characterized at 632 nm). Gigapixel colour images of histology slides verify FPMs successful operation. The reported imaging procedure transforms the general challenge of high-throughput, high-resolution microscopy from one that is coupled to the physical limitations of the systems optics to one that is solvable through computation. PMID:25243016

  20. 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.

  1. 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 variable-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.

  2. 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.

  3. 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.

  4. Performance of high-resolution monitors for digital chest imaging.

    PubMed

    Suddarth, S A; Johnson, G A; Sherrier, R H; Ravin, C E

    1987-01-01

    High-resolution cathode-ray tubes (CRT's) are currently the most viable soft-copy display for digital radiography. We present here methods for measuring large-area contrast ratio and detail contrast ratio. A two-dimensional charge coupled device (ccd) array signal-averaged with a video frame buffer permits linear microradiometric measure of individual beam lines. Results from three different 1000-line monitors demonstrate the shift variance of resolution. The detail contrast ratio (or modulation depth) was found to vary from 100% to less than 10% across the face of one CRT. Dynamic focus in both the horizontal and vertical deflection circuitry proved effective in reducing this shift variance. Comparisons of three phosphors demonstrate the utility of long persistence phosphors (P164) for static display in producing brighter images with less flicker. Recommendations for CRT design and selection for high-resolution digital radiography are included. PMID:3587149

  5. 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.

  6. High-resolution CCD camera family with a PC host

    NASA Astrophysics Data System (ADS)

    Raanes, Chris A.; Bottenberg, Les

    1993-05-01

    EG&G Reticon and Adaptive Optics Associates have developed a family of high resolution CCD cameras with a PC/AT host to fulfill imaging applications from medical science to industrial inspection. The MC4000 family of CCD cameras encompasses resolutions of 512 X 512, 1024 X 1024, and 2048 X 2048 pixels. All three of these high performance cameras interface to the SB4000, PC/AT controller, which serves as a frame buffer with up to 64 MBytes of storage, as well as providing all the required control, and setup parameters while the camera head is remotely located at distances of up to 100 ft. All of the MC4000 high resolution cameras employ MPP clocking to achieve high dynamic range without cooling the CCD sensor. The use of this low power clocking technique, surface mount components, electronic shutter and clever packaging have allowed Reticon to deliver the MC4000 cameras in convenient, rugged small housings. The MC4000 family provides users with a total imaging solution from leading edge sensors and electronics in ruggedized housings, to cables, power supplies, and a PC/AT frame buffer and controller card. All the components are designed to function together as a turn-key, self-contained system, or individual components can become part of a user's larger system. The MC4000 CCD camera family makes high resolution, electronic imaging an accessible tool for a wide range of applications.

  7. 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, Jess

    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.

  8. Attempts to combine 2-deoxyglucose autoradiography and tyrosine hydroxylase immunohistochemistry.

    PubMed

    Hkfelt, T; Smith, C B; Norell, G; Peters, A; Crane, A; Goldstein, M; Brownstein, M; Sokoloff, L

    1984-10-01

    The possibilities were analysed to combine the 2-deoxyglucose technique and indirect immunofluorescence histochemistry using tyrosine hydroxylase antiserum, with the aim to study functional activity in immunohistochemically characterized single neurons. Since the product measured with the 2-deoxyglucose method is water soluble and since immunohistochemistry requires that sections repeatedly run through aqueous media, the 2-deoxyglucose method was carried out before fixation and immunohistochemistry. The routine rapid thaw-mounting at + 60 degrees C of sections for 2-deoxyglucose autoradiography was found not to be compatible with immunohistochemistry. Instead a new mounting technique based on "gluing" the sections on to the object slide with a mixture of a standard mounting medium (Permount) and xylene was used to avoid diffusion at this stage. Two procedures were outlined, both starting with unfixed brains cut on a cryostat. In Method I autoradiographic sheet film was used. After autoradiographic exposure, the section was immersion-fixed in formalin, processed for immunohistochemistry, analysed and photographed in a fluorescence microscope and the results compared with the autoradiographic distribution patterns on the film. However, only the low resolution of the routine 2-deoxyglucose technique was obtained, which did not allow analysis of activity in single cells. In Method II, liquid emulsion applied by the loop technique was used. After exposure, autoradiographic developing and fixation, dehydration, mounting, analysis and photography of autoradiographs in the light microscope, the cover-slip was removed, the sections rehydrated and processed for indirect immunofluorescence histochemistry. With this procedure single autoradiographically labeled cells were observed, some of which contained tyrosine hydroxylase. Thus, with Method II it may in the future be possible to monitor functional activity in single immunohistochemically identified neuronal cell bodies. In order to obtain a useful and reliable method for this purpose, however, further extensive work with regard to, for example, quantification will be required. PMID:6151149

  9. High Resolution Urban Feature Extraction for Global Population Mapping using High Performance Computing

    SciTech Connect

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

    2007-01-01

    The advent of high spatial resolution satellite imagery like Quick Bird (0.6 meter) and IKONOS (1 meter) has provided a new data source for high resolution urban land cover mapping. Extracting accurate urban regions from high resolution images has many applications and is essential to the population mapping efforts of Oak Ridge National Laboratory's (ORNL) LandScan population distribution program. This paper discusses an automated parallel algorithm that has been implemented on a high performance computing environment to extract urban regions from high resolution images using texture and spectral features

  10. 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

  11. Sparse deconvolution of high-density super-resolution images

    PubMed Central

    Hugelier, Siewert; de Rooi, Johan J.; Bernex, Romain; Duwé, Sam; Devos, Olivier; Sliwa, Michel; Dedecker, Peter; Eilers, Paul H. C.; Ruckebusch, Cyril

    2016-01-01

    In wide-field super-resolution microscopy, investigating the nanoscale structure of cellular processes, and resolving fast dynamics and morphological changes in cells requires algorithms capable of working with a high-density of emissive fluorophores. Current deconvolution algorithms estimate fluorophore density by using representations of the signal that promote sparsity of the super-resolution images via an L1-norm penalty. This penalty imposes a restriction on the sum of absolute values of the estimates of emitter brightness. By implementing an L0-norm penalty – on the number of fluorophores rather than on their overall brightness – we present a penalized regression approach that can work at high-density and allows fast super-resolution imaging. We validated our approach on simulated images with densities up to 15 emitters per μm-2 and investigated total internal reflection fluorescence (TIRF) data of mitochondria in a HEK293-T cell labeled with DAKAP-Dronpa. We demonstrated super-resolution imaging of the dynamics with a resolution down to 55 nm and a 0.5 s time sampling. PMID:26912448

  12. Sparse deconvolution of high-density super-resolution images.

    PubMed

    Hugelier, Siewert; de Rooi, Johan J; Bernex, Romain; Duw, Sam; Devos, Olivier; Sliwa, Michel; Dedecker, Peter; Eilers, Paul H C; Ruckebusch, Cyril

    2016-01-01

    In wide-field super-resolution microscopy, investigating the nanoscale structure of cellular processes, and resolving fast dynamics and morphological changes in cells requires algorithms capable of working with a high-density of emissive fluorophores. Current deconvolution algorithms estimate fluorophore density by using representations of the signal that promote sparsity of the super-resolution images via an L1-norm penalty. This penalty imposes a restriction on the sum of absolute values of the estimates of emitter brightness. By implementing an L0-norm penalty - on the number of fluorophores rather than on their overall brightness - we present a penalized regression approach that can work at high-density and allows fast super-resolution imaging. We validated our approach on simulated images with densities up to 15 emitters per ?m(-2) and investigated total internal reflection fluorescence (TIRF) data of mitochondria in a HEK293-T cell labeled with DAKAP-Dronpa. We demonstrated super-resolution imaging of the dynamics with a resolution down to 55?nm and a 0.5?s time sampling. PMID:26912448

  13. High Resolution Wavenumber Standards for the Infrared. (IUPAC Recommendations 1995)

    NASA Technical Reports Server (NTRS)

    Guelachvili, G.; Birk, M.; Borde, C. J.; Brault, J. W.; Brown, L. R.; Carli, B.; Cole, A. R. H.; Evenson, K. M.; Fayt, A.; Hausamann, D.; Johns, J. W. C.; Kauppinen, J.; Kou, Q.; Maki, A. G.; Rao, K. N.; Toth, R. A.; Urban, W.; Valentin, A.; Verges, J.; Wagner, G.; Wappelhorst, M. H.; Wells, J. S.; Winnewisser, B. P.; Winnewisser, M.

    1995-01-01

    The calibration of high resolution infrared spectra is generally more precise than accurate. This is the case even when they are recorded with Fourier transform interferometers. This presentation aims at improving the accuracy of wavenumber measurements in the infrared by recommending a selection of spectral lines as wavenumber standards for absolute calibration.

  14. 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

  15. Lunar Orbiter Revived: Very High Resolution Views of the Moon

    NASA Astrophysics Data System (ADS)

    Weller, L.; Redding, B.; Becker, T. L.; Gaddis, L.; Sucharski, R.; Soltesz, D.; Cook, D. A.; Archinal, B. A.; Bennett, A.; McDaniel, T.

    2006-03-01

    U.S. Geological Survey Astrogeology Program report on the progress of the Lunar Orbiter filmstrip scanning, archiving and processing efforts. We describe the status of the global mosaic and describe additional work on very high resolution data of the Moon's near side acquired at low altitude.

  16. A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope

    ERIC Educational Resources Information Center

    Wakabayashi, Fumitaka; Hamada, Kiyohito

    2006-01-01

    Digital versatile disks (DVDs) have successfully made up an inexpensive but high-resolution spectroscope suitable for classroom experiments that can easily be made with common material and gives clear and fine spectra of various light sources and colored material. The observed spectra can be photographed with a digital camera, and such images can

  17. Gemini high-resolution optical spectrograph conceptual design

    NASA Astrophysics Data System (ADS)

    Szeto, Kei; McConnachie, Alan; Anthony, André; Bohlender, David; Crampton, David; Desaulniers, Pierre; Dunn, Jennifer; Hardy, Tim; Hill, Alexis; Monin, Dmitry; Pazder, John; Schwab, Christian; Spano, Paola; Starkenburg, Else; Thibault, Simon; Walker, Gordon; Venn, Kim; Zhang, Hu

    2012-09-01

    A multiplexed moderate resolution (R = 34,000) and a single object high resolution (R = 90,000) spectroscopic facility for the entire 340 - 950nm wavelength region has been designed for Gemini. The result is a high throughput, versatile instrument that will enable precision spectroscopy for decades to come. The extended wavelength coverage for these relatively high spectral resolutions is achieved by use of an Echelle grating with VPH cross-dispersers and for the R = 90,000 mode utilization of an image slicer. The design incorporates a fast, efficient, reliable system for acquiring targets over the7 arcmin field of Gemini. This paper outlines the science case development and requirements flow-down process that leads to the configuration of the HIA instrument and describes the overall GHOS conceptual design. In addition, this paper discusses design trades examined during the conceptual design study instrument group of the Herzberg Institute of Astrophysics has been commissioned by the Gemini Observatory as one of the three competing organizations to conduct a conceptual design study for a new Gemini High-Resolution Optical Spectrograph (GHOS). This paper outlines the science case development and requirements flow-down process that leads to the configuration of the HIA instrument and describes the overall GHOS conceptual design. In addition, this paper discusses design trades examined during the conceptual design study.

  18. High-Resolution Studies of Diffuse Interstellar Gas

    NASA Astrophysics Data System (ADS)

    Federman, Steven R.; Knauth, David C.; Lambert, David L.; Pan, Kaike

    We describe two recent projects undertaken at McDonald Observatory whose success required high-resolution measurements. First high-resolution spectra revealed a 7Li/6Li ratio of about 2 in gas toward o Persei a value consistent with expectations of Galactic cosmic ray spallation but much lower than the meteoritic value (12.3). In order to probe the extent in the variation of this ratio we performed an ultra-high-resolution survey. The line of sight toward o Per remains the only one with an isotope ratio different from the meteoritic value but this sight line shows no other indication of an enhanced Li abundance. Second through a high-resolution study of gas seen toward stars in rho Oph Cep OB2 and Cep OB3 we gleaned information about the structure of the diffuse material along the line of sight. Line widths (b-values) and column densities yielded the various distributions among species for individual velocity components. For instance CN resides in the densest central portion of a diffuse cloud while Ca+ is much more widely distributed. Moreover gas containing CH arises from two sources: CH associated with dense gas containing CN and CH arising from the synthesis of CH+ in less dense material.

  19. Using High Resolution SPOT 5 Multispectral Imagery for Crop Identification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High resolution satellite imagery offers new opportunities for crop monitoring and assessment. A SPOT 5 image with four spectral bands (green, red, near-infrared, and mid-infrared) and 10-m pixel size covering intensively cropped areas in south Texas was evaluated for crop identification. Two images...

  20. 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

  1. 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.

  2. 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)

  3. High-Resolution Projection Microstereolithography for Patterning of Neovasculature.

    PubMed

    Raman, Ritu; Bhaduri, Basanta; Mir, Mustafa; Shkumatov, Artem; Lee, Min Kyung; Popescu, Gabriel; Kong, Hyunjoon; Bashir, Rashid

    2016-03-01

    To gain a quantitative understanding of the way cells sense, process, and respond to dynamic environmental signals in real-time requires developing in vitro model systems that accurately replicate the 3D structure and function of native tissue. A high-resolution projection stereolithography apparatus (μSLA) capable of multimaterial and grayscale 3D patterning of cells and biomaterials at <5 μm resolution is presented. Murine cells (fibroblasts, myoblasts, endothelial, and bone marrow stromal cells) encapsulated within photosensitive hydrogels using the μSLA remain viable up to two weeks after fabrication. Harnessing the high-resolution fabrication capabilities of this machine, sub-millimeter scale angiogenic cell-encapsulating patches designed to promote targeted growth of neovasculature are printed, as assessed in vitro via enzyme-linked immunosorbent assay (ELISA) and in ovo via a chick chorioallantoic membrane assay (CAM). This application establishes the μSLA as an enabling technology that is widely adaptable to any application that requires high-resolution patterning of cells and cells signals. By providing an efficient and robust method of engineering microscale tissues with encapsulated cells, this apparatus has a range of applications including fundamental studies of extracellular matrix interactions, high throughput drug testing of physiologically relevant substitutes for native tissue, and programmable tissue engineering for applications in regenerative medicine. PMID:26696464

  4. A High-resolution Study of Local Interstellar Sodium

    NASA Technical Reports Server (NTRS)

    Ardeberg, A.; Lindgren, H.; Maurice, E.

    1984-01-01

    A high-resolution spectroscopic investigation was made of interstellar lines of sodium. From identifications of D1 and D2 line components concentrations of interstellar sodium gas were studied. Some preliminary data are provided on the spatial distribution of stronger sodium concentrations.

  5. High energy resolution off-resonant X-ray spectroscopy

    SciTech Connect

    Wojciech, Blachucki

    2015-01-01

    This work treats of the high energy resolution off-resonant X-ray spectroscopy (HEROS) method of determining the density of unoccupied electronic states in the vicinity of the absorption edge. HEROS is an alternative to the existing X-ray absorption spectroscopy (XAS) methods and opens the way for new studies not achievable before.

  6. 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...

  7. Plant respirometer enables high resolution of oxygen consumption rates

    NASA Technical Reports Server (NTRS)

    Foster, D. L.

    1966-01-01

    Plant respirometer permits high resolution of relatively small changes in the rate of oxygen consumed by plant organisms undergoing oxidative metabolism in a nonphotosynthetic state. The two stage supply and monitoring system operates by a differential pressure transducer and provides a calibrated output by digital or analog signals.

  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 airway morphometry from polyurethane casts

    NASA Astrophysics Data System (ADS)

    Neufeld, Gordon R.; Vargas, John; Hoford, John D.; Craft, Jeanne; Shroff, Sunil; McRae, Karen M.

    1995-05-01

    An airway cast was made and imbedded in a solid polyurethane block of a contrasting color. The block was sequentially milled and photographed. The sequential photographs were scanned to create an image database which was analyzed on VIDA; a multidimensional image analysis software package. The technique shows promise as a semi-automated process for generating a high resolution morphometric database from airway casts.

  10. Evaluating high resolution SPOT 5 satellite imagery for crop identification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High resolution satellite imagery offers new opportunities for crop monitoring and assessment. A SPOT 5 image with four spectral bands (green, red, near-infrared, and mid-infrared) and 10-m pixel size covering intensively cropped areas in south Texas was evaluated for crop identification. Two images...

  11. 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.

  12. 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.

  13. 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...

  14. 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…

  15. A DVD Spectroscope: A Simple, High-Resolution Classroom Spectroscope

    ERIC Educational Resources Information Center

    Wakabayashi, Fumitaka; Hamada, Kiyohito

    2006-01-01

    Digital versatile disks (DVDs) have successfully made up an inexpensive but high-resolution spectroscope suitable for classroom experiments that can easily be made with common material and gives clear and fine spectra of various light sources and colored material. The observed spectra can be photographed with a digital camera, and such images can…

  16. 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.

  17. 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.

  18. Precipitation Sensing in GEO Orbit with High Resolution

    NASA Astrophysics Data System (ADS)

    You, Rui

    2012-07-01

    Now casting of precipitation in geostationary orbit is a strongly requirements , two of difficults are antenna and radiometer receiver,it should satisfies high spatial and time resolution, this paper present two satellites with large scale feed array cofiguration get over 600 spot beams cove 3.5% China area, work in 118GHz for atmospheric temperature vertical profille and 183GHz for humidity vertical profille, two satellites consists of interferometric synthetic aperture it can satisfies weather nowcasting both spatial and time resolution in suspect zone for now casting requirements.

  19. 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

  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. 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.

  2. High Resolution Rapid Revisits Insar Monitoring of Surface Deformation

    NASA Astrophysics Data System (ADS)

    Singhroy, V.; Li, J.; Charbonneau, F.

    2014-12-01

    Monitoring surface deformation on strategic energy and transportation corridors requires high resolution spatial and temporal InSAR images for mitigation and safety purposes. High resolution air photos, lidar and other satellite images are very useful in areas where the landslides can be fatal. Recently, radar interferometry (InSAR) techniques using more rapid revisit images from several radar satellites are increasingly being used in active deformation monitoring. The Canadian RADARSAT Constellation (RCM) is a three-satellite mission that will provide rapid revisits of four days interferometric (InSAR) capabilities that will be very useful for complex deformation monitoring. For instance, the monitoring of surface deformation due to permafrost activity, complex rock slide motion and steam assisted oil extraction will benefit from this new rapid revisit capability. This paper provide examples of how the high resolution (1-3 m) rapid revisit InSAR capabilities will improve our monitoring of surface deformation and provide insights in understanding triggering mechanisms. We analysed over a hundred high resolution InSAR images over a two year period on three geologically different sites with various configurations of topography, geomorphology, and geology conditions. We show from our analysis that the more frequent InSAR acquisitions are providing more information in understanding the rates of movement and failure process of permafrost triggered retrogressive thaw flows; the complex motion of an asymmetrical wedge failure of an active rock slide and the identification of over pressure zones related to oil extraction using steam injection. Keywords: High resolution, InSAR, rapid revisits, triggering mechanisms, oil extraction.

  3. High-Resolution MRI of Intracranial Atherosclerotic Disease

    PubMed Central

    Kwak, Hyo-Sung; Jahng, Geon-Ho; Lee, Han Na

    2014-01-01

    Intracranial atherosclerotic disease (ICAD) causes up to 10% of all ischemic strokes, and the rate of recurrent vascular ischemic events is very high. Important predictors of vulnerability in atherosclerotic plaques include the degree of stenosis and the underlying plaque morphology. Vascular wall MRI can provide information about wall structures and atherosclerotic plaque components. High-resolution (HR)-MRI in ICAD poses a greater challenge in the neurologic fields, because a high in-plane resolution and a high signal-to-noise ratio are required for vessel wall imaging of ICAD. Until now, plaque imaging of ICAD has focused on assessing the presence of a plaque and evaluating the plaque load. Going forward, evaluation of plaque vulnerability through analysis of imaging characteristics will be a critical area of research. This review introduces the acquisition protocol for HR-MRI in ICAD and the current issues associated with imaging. PMID:24644529

  4. High-resolution nuclear magnetic resonance studies of proteins.

    PubMed

    Jonas, Jiri

    2002-03-25

    The combination of advanced high-resolution nuclear magnetic resonance (NMR) techniques with high-pressure capability represents a powerful experimental tool in studies of protein folding. This review is organized as follows: after a general introduction of high-pressure, high-resolution NMR spectroscopy of proteins, the experimental part deals with instrumentation. The main section of the review is devoted to NMR studies of reversible pressure unfolding of proteins with special emphasis on pressure-assisted cold denaturation and the detection of folding intermediates. Recent studies investigating local perturbations in proteins and the experiments following the effects of point mutations on pressure stability of proteins are also discussed. Ribonuclease A, lysozyme, ubiquitin, apomyoglobin, alpha-lactalbumin and troponin C were the model proteins investigated. PMID:11983393

  5. Colorado High-resolution Echelle Stellar Spectrograph (CHESS)

    NASA Astrophysics Data System (ADS)

    Beasley, Matthew; Burgh, Eric; France, Kevin

    2010-07-01

    We discuss the design of a new high-efficiency, high-resolution far ultraviolet echelle spectrograph. Our project concentrates on utilizing new technologies for gratings and detectors to reduce the impact of scattered light and maximize quantum efficiency over a large bandpass. This program will enable advances in a vast number of astrophysical subjects. Topics ranging from protoplanetary disks to the intergalactic medium can be addressed by incorporating such a spectrograph into a future, long-duration mission.

  6. High Resolution-Resonance Ionization Spectroscopy on uranium

    NASA Astrophysics Data System (ADS)

    Hakimi, Amin; Fischbach, Thomas; Raeder, Sebastian; Trautmann, Norbert; Wendt, Klaus

    2013-04-01

    High Resolution-Resonance Ionization Spectroscopy (HR-RIS) allows for sensitive probing of atomic structures and energy level schemes even for highly complex systems. This work explores the applicability of commercial diode lasers for isotope selective spectroscopy of uranium. Using narrow bandwidth continuous-wave (cw) diode lasers, multi step excitation processes were investigated involving levels which could be populated with the radiation of 405 nm BluRay laser diodes as a first step for ultra trace analysis of uranium.

  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. 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.

  9. 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.

  10. SPI: A high resolution imaging spectrometer for INTEGRAL

    SciTech Connect

    Teegarden, B. J.; Naya, J.; Seifert, H.; Sturner, S.; Schonfelder, V.; Lichti, G. G.; Diehl, R.; Georgii, R.; Durouchoux, P.; Cordier, B.; Diallo, N.; Lin, R.

    1997-05-10

    SPI (Spectrometer for INTEGRAL) is a high spectral resolution gamma-ray telescope using cooled germanium detectors that will be flown on board the INTEGRAL mission in 2001. It consists of an array of 19 closely-packed germanium detectors surrounded by an active bismuth germanate (BGO) anti-coincidence shield. The instrument operates over the energy range 20 keV to 8 MeV with an energy resolution of 1-5 keV. A tungsten coded-aperture mask located 1.7 m from the detector array provides imaging over a 15 deg. fully-coded field-of-view with an angular resolution of {approx}3 deg. The point source narrow-line sensitivity is estimated to be 3-7x10{sup -6} ph cm{sup -2} s{sup -1} over most of the range of the instrument (E>200 keV) for a 10{sup 6} s observation. With its combination of high sensitivity, high spectral resolution and imaging, SPI will improve significantly over the performance of previous instruments such as HEAO-3, OSSE, and Comptel. It can be expected to take a major step forward in experimental studies in nuclear astrophysics. The SPI instrument is being developed under the auspices of the European Space Agency by a large international team of scientists and engineers in both Europe and the United States.

  11. High-resolution hand-held gamma camera

    NASA Astrophysics Data System (ADS)

    MacDonald, Lawrence R.; Patt, Bradley E.; Iwanczyk, Jan S.; Yamaguchi, Yuko; McElroy, David P.; Hoffman, Edward J.; Aarsvold, John N.; Mintzer, Robert A.; Alazraki, Naomi P.

    2000-12-01

    A high resolution, hand-held scintillation camera has been designed and built for specific Nuclear Medicine applications. Primary intended applications are pre-surgical and intra-operative lymphoscintigraphy. The detector head is highly compact with a 1-inch by 1-inch physical field of view. A variety of easily interchangeable collimators including parallel hole, diverging hole, and pinhole allow several choices of image parameters including variable spatial resolution, sensitivity and field of view. The camera can be operated in imaging mode or as a probe in a non-imaging mode. Surgeons performing sentinel node surgeries have the option of using the device asa standard audio-guided counting probe or as an imaging device to improve surgical management. The 20 mm FOV camera has 1 mm intrinsic spatial resolution. System FWHM in air is 2.1 mm and 2.6 mm at 0 cm from a high-resolution parallel hole collimator, respectively. FWHM of 3.8 mm is measured 2 cm from a 3 mm pinhole. Pinhole sensitivity is 600 cps/MBq above a 125 cps/MBq background for a 1 cm lesion 1 cm below a water surface. Nodes are identified in images even when overall count rate is not above the background from a nearby injection site.

  12. High Resolution Modeling of Tropical Cyclones Using Rare Event Simulation

    NASA Astrophysics Data System (ADS)

    Plotkin, D. A.; Abbot, D. S.; Weare, J.

    2014-12-01

    Tropical cyclones (TCs) present a challenge to modeling using general circulation models (GCMs) because they involve processes and structures that are too fine for GCMs to resolve. TCs have fine structures - e.g. the eye, eyewall, and rain bands - with length scales on the order of 10 km, while GCMs have typical resolutions on the order of 50-100 km. High resolution GCM runs that are sufficiently long to exhibit multiple TCs can be prohibitively computationally expensive. Thus, while GCMs exhibit TC-like vortices with similar spatial and temporal frequencies to observed TCs, the ability of GCMs to reproduce fine TC structures remains largely untested. In this study, we use recently developed rare event analysis and simulation methods to selectively simulate TCs under GCMs at very high resolution. These rare event simulation methods have been developed mostly in the context of computational chemistry, but are broadly applicable. They allow (either by careful manipulation of the model or by selection of trajectories) direct and detailed interrogation of the event of interest without introducing error and without the need to simulated for long periods of time to see the event. By creating targeted, high resolution GCM simulations with many TCs, we hope to determine whether or not GCMs can capture fine TC structures such as eyewalls and individual rain bands.

  13. High-Resolution Angioscopic Imaging During Endovascular Neurosurgery

    PubMed Central

    McVeigh, Patrick Z.; Sacho, Raphael; Weersink, Robert A.; Pereira, Vitor M.; Kucharczyk, Walter; Seibel, Eric J.; Wilson, Brian C.

    2014-01-01

    BACKGROUND: Endoluminal optical imaging, or angioscopy, has not seen widespread application during neurointerventional procedures, largely as a result of the poor imaging resolution of existing angioscopes. Scanning fiber endoscopes (SFEs) are a novel endoscopic platform that allows high-resolution video imaging in an ultraminiature form factor that is compatible with currently used distal access endoluminal catheters. OBJECTIVE: To test the feasibility and potential utility of high-resolution angioscopy with an SFE during common endovascular neurosurgical procedures. METHODS: A 3.7-French SFE was used in a porcine model system to image endothelial disruption, ischemic stroke and mechanical thrombectomy, aneurysm coiling, and flow-diverting stent placement. RESULTS: High-resolution, video-rate imaging was shown to be possible during all of the common procedures tested and provided information that was complementary to standard fluoroscopic imaging. SFE angioscopy was able to assess novel factors such as aneurysm base coverage fraction and side branch patency, which have previously not been possible to determine with conventional angiography. CONCLUSION: Endovascular imaging with an SFE provides important information on factors that cannot be assessed fluoroscopically and is a novel platform on which future neurointerventional techniques may be based because it allows for periprocedural inspection of the integrity of the vascular system and the deployed devices. In addition, it may be of diagnostic use for inspecting the vascular wall and postprocedure device evaluation. ABBREVIATIONS: CFB, coherent fiber bundle F, French SFE, scanning fiber endoscope PMID:24762703

  14. High-resolution Imaging Techniques for the Assessment of Osteoporosis

    PubMed Central

    Krug, Roland; Burghardt, Andrew J.; Majumdar, Sharmila; Link, Thomas M.

    2010-01-01

    Synopsis The importance of assessing the bones microarchitectural make-up in addition to its mineral density in the context of osteoporosis has been emphasized in a number of publications. The high spatial resolution required to resolve the bones microstructure in a clinically feasible scan time is challenging. Currently, the best suited modalities meeting these requirements in vivo are high-resolution peripheral quantitative imaging (HR-pQCT) and magnetic resonance imaging (MRI). Whereas HR-pQCT is limited to peripheral skeleton regions like the wrist and ankle, MRI can also image other sites like the proximal femur but usually with lower spatial resolution. In addition Multidetector-CT has been used for high-resolution imaging of trabecular bone structure, however, the radiation dose is a limiting factor. This article provides an overview of the different modalities, technical requirements and recent developments in this emerging field. Details regarding imaging protocols as well as image post-processing methods for bone structure quantification are discussed. PMID:20609895

  15. High resolution imaging with impulse based thermoacoustic tomography

    NASA Astrophysics Data System (ADS)

    Kellnberger, Stephan; Hajiaboli, Amir; Sergiadis, George; Razansky, Daniel; Ntziachristos, Vasilis

    2011-07-01

    Existing imaging modalities like microwave- or radiofrequency (RF) induced thermoacoustic tomography systems show the potential for resolving structures deep inside tissue due to the high penetration properties of RF. However, one of the major drawbacks of existing thermoacoustic tomography systems with pulse modulated carrier frequency excitation is the compromise between efficient signal generation and attainable spatial resolution. In order to overcome limitations of conventional thermoacoustic imaging methods, we herein present and experimentally validate our novel approach towards high resolution thermoacoustic tomography. Instead of carrier-frequency amplification, we utilize ultrahigh-energy electromagnetic impulses at nanosecond duration with near-field energy coupling, thus maintaining thermoacoustic signal strength without compromising spatial resolution. Preliminary experiments on highly absorbing objects, consisting of copper wires with characteristic sizes of ~100 μm, reveal the resolution performance which yields 160 μm. Furthermore, benefits like its cost effectiveness, simplicity and compactness with the potential application in small animal imaging as well as human body imaging show that thermoacoustic tomography with impulse excitation is a promising imaging modality which has a broad range of applications.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. Tuning and scanning control system for high resolution alexandrite lasers

    NASA Technical Reports Server (NTRS)

    Smith, James C.; Schwemmer, Geary K.

    1988-01-01

    An alexandrite laser is spectrally narrowed and tuned by the use of three optical elements. Each element provides a successively higher degree of spectral resolution. The digitally controlled tuning and scanning control servo system simultaneously positions all three optical elements to provide continuous high resolution laser spectral tuning. The user may select manual, single, or continuous modes of automated scanning of ranges up to 3.00/cm and at scan rates up to 3.85/cm/min. Scanning over an extended range of up to 9.999/cm may be achieved if the highest resolution optic is removed from the system. The control system is also capable of being remotely operated by another computer or controller via standard RS-232 serial data link.

  1. Broadband high resolution X-ray spectral analyzer

    DOEpatents

    Silver, E.H.; Legros, M.; Madden, N.W.; Goulding, F.; Landis, D.

    1998-07-07

    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. 6 figs.

  2. 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.

  3. High Resolution Absorption Spectroscopy using Externally Dispersed Interferometry

    SciTech Connect

    Edelstein, J; Erskine, D J

    2005-07-06

    We describe the use of Externally Dispersed Interferometry (EDI) for high-resolution absorption spectroscopy. By adding a small fixed-delay interferometer to a dispersive spectrograph, a precise fiducial grid in wavelength is created over the entire spectrograph bandwidth. The fiducial grid interacts with narrow spectral features in the input spectrum to create a moire pattern. EDI uses the moire pattern to obtain new information about the spectra that is otherwise unavailable, thereby improving spectrograph performance. We describe the theory and practice of EDI instruments and demonstrate improvements in the spectral resolution of conventional spectrographs by a factor of 2 to 6. The improvement of spectral resolution offered by EDI can benefit space instruments by reducing spectrograph size or increasing instantaneous bandwidth.

  4. 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.

  5. 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.

  6. Ultra high resolution soft x-ray tomography

    SciTech Connect

    Haddad, W.S.; Trebes, J.E.; Goodman, D.M.

    1995-07-19

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by {approximately}5{mu}m. A series of nine 2-D images of the object were recorded at angles between {minus}50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of {approximately}1000 {Angstrom} was observed. Artifacts in the reconstruction limited the overall depth resolution to {approximately}6000 {Angstrom}, however some features were clearly reconstructed with a depth resolution of {approximately}1000 {Angstrom}. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to {approximately}1200 {Angstrom} overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range.

  7. Development of High Resolution Scintillator Systems Based on Photocell Technology

    SciTech Connect

    W.J. Kernan; L.A. Franks; M. Groza; A. Burger

    2006-01-01

    Inorganic scintillator/photomultiplier-based spectrometers are the systems of choice for a multitude of X-ray and gamma radiation measurement applications. Despite widespread use, they have numerous shortcomings. The most serious shortcoming is the relatively poor energy resolution that makes isotope identification problematic, particularly in the case of trace quantities. Energy resolution in scintillator/photomultiplier tube (PMT) spectrometers is governed by a combination of the crystal intrinsic resolution that includes non-linearity effects, photomultiplier statistics, and the variability in the probability of a scintillation photon generating a photoelectron at the photocathode. It is evident that energy resolution in these systems is linked to both the physics of light generation in the scintillator and the characteristics of the PMT. PMTs also present design problems, especially in the case of handheld and portable instruments, due to their considerable weight and volume. Additionally, PMTs require well-regulated high voltage, and are vulnerable to magnetic fields. The objective of this work is to provide instrument designers of scintillation-based gamma-ray spectrometers with superior energy resolution and greatly reduced weight and volume. It is planned to achieve this advancement by optimizing the performance of a new class of inorganic scintillators by matching their emission spectra with the enhanced quantum efficiency of certain photocells.

  8. 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

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

    PubMed Central

    Foudray, A M K; Olcott, P D

    2013-01-01

    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 mm3 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

  10. Ultra-high resolution mass spectroscopy of boron cluster ions

    NASA Astrophysics Data System (ADS)

    Jacobson, Dale; Horsky, Thomas; Krull, Wade; Milgate, Bob

    2005-08-01

    Boron clusters have recently received considerable attention as a possible solution to the throughput dilemma associated with ultra-low energy (sub keV) p-type source drain extension implants required by cutting edge complimentary metal-oxide semiconductor (CMOS) technology. Boron cluster ion beams contain many masses due to the binomial distribution of the two naturally occurring isotopes (masses 10 and 11) of boron. The broadness of the mass distribution peak in the dispersive plane is further complicated by a plurality of ion states, due to the varying number of hydrogen atoms remaining attached to the borohydride molecule when it is ionized. The B18 Hx+ cluster ion mass spectrum from an electron impact ionization source will be analyzed in detail. An ultra-high resolution mass spectrum, exhibiting 1 AMU resolution of a mass 220 cluster ion will be shown. It will be compared to high-resolution spectra of decaborane (B10H14) cluster ions obtained from natural abundance decaborane and from isotopically enriched material. The deconvolution of the binominal distribution from ion states present in the cluster ion beam reveals the hydrogen distribution function. The hydrogen distribution functions as well as the binomial distributions will be presented and discussed. Physical models will be presented that explain the origin of hydrogen distribution function for these high mass borohydride cluster ions. This ultra-high mass resolution is usually unavailable to the ion implant community, however our 120 mass analyzing magnet and the extremely low emittance of the ion beam extracted from the ClusterIon source coupled with a variable width beam defining aperture and variable width mass defining slits allow for superior mass resolution.

  11. 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] K. F. Gwinner, et al. (2010) Topography of Mars from global mapping by HRSC high-resolution digital terrain models and orthoimages: characteristics and performance. Earth and Planetary Science Letters 294, 506-519, doi:10.1016/j.epsl.2009.11.007. [2] A. McEwen, et al. (2011) Seasonal flows on warm martian slopes. Science , 333 (6043): 740-743. [3] S. Byrne, et al. (2009) Distribution of mid-latitude ground ice on mars from new impact craters. Science, 325(5948):1674-1676.

  12. Radiometric Calibration of High Resolution UAVSAR Data Using Low Resolution SRTM DEMs

    NASA Astrophysics Data System (ADS)

    Riel, B. V.; Simard, M.

    2010-12-01

    Airborne and spaceborne Synthetic Aperture Radar (SAR) backscatter data have the potential to retrieve information on forest structure, above-ground biomass, and moisture content. However, SAR backscatter data contain both geometric and radiometric distortions due to underlying topography and the radar viewing geometry. These distortions can significantly affect the estimation of various scientific quantities. For example, a backscatter error of 1 dB can result in a biomass estimation error on the order of 10-15 Mg/ha. Thus, science applications based on SAR backscatter require accurate absolute radiometric calibration. The calibration process for topography involves estimation of the local radar scattering area through knowledge of the imaged terrain, which is often obtained through digital elevation models (DEMs). For this study, we radiometrically calibrate high resolution UAVSAR L-band radar data over a temperate forest site in New Hampshire using a low resolution (30m) SRTM DEM. Different calibration methods were tested and compared. We found that homomorphic methods based on the local incidence or projection angle do not estimate the scattering area as well as heteromorphic methods utilizing DEM integration techniques. Errors in the area estimation resulted in calibration differences less than 0.5 dB. The impact of low DEM resolution on calibration performance was assessed using a Fourier analysis of a large range of topographic classes. Power spectra were computed for high-resolution, bare-earth airborne lidar DEMs acquired over steep, moderate, and flat terrain. Similar power spectra were computed for oversampled SRTM DEMs over the same terrain. Errors for an SRTM DEM associated with a particular topographic class could be quantified through a comparison of its power spectrum with that from the lidar. We present a Fourier based method to systematically propagate errors in slope and aspect estimations to radiometric calibration accuracy. The methodology was validated by comparing slope and aspect derived from SRTM and lidar DEMs.

  13. High-resolution Surface Correlation Maps for Improved Resolution and Retrieval of Aerosols Over Urban Scenes

    NASA Astrophysics Data System (ADS)

    Oo, M. M.; Hernandez, E.; Jerg, M.; Gross, B. M.; Moshary, F.; Ahmed, S. A.

    2008-12-01

    Determination of Aerosol Optical Depth (AOD) by satellite remote sensing measurements over land is complicated by the fact that the Top of Atmosphere (TOA) reflectance is a combination of the desired atmospheric path reflectance as well as the ground reflectance. In this paper, we focus on the use of simultaneous MODIS and AERONET sky radiometer data to refine the surface albedo models regionally and improve on the current AOD operational retrieval. In particular, over New York City, we show that the correlation coefficient assumption used in the MODIS Collection (5) model between the VIS and MIR channels used for surface reflection parameterization are still severely underestimated in comparison with high spatial imagery data from Hyperion thereby leading to an underestimate in the VIS ground albedos and explaining the subsequent overestimate of the VIS optical depth. Furthermore, we find that the VIS/MIR ratios depend only weakly on the scattering geometry allowing us to generate a regional VIS/MIR surface reflectance correlation coefficient map at spatial resolutions down to 1.5km. When applying the new VIS/MIR surface reflectance ratio model, we show the MODIS and AERONET derived optical thickness agreement is significantly improved for the operational 10km resolution product. Moreover, we also show the high resolution surface model allows us to improve the resolution of the retrieved AOD to 3km. Although direct comparisons for a given day can only be made at the AERONET site, we find the AOD spatial variability from the improved MODIS retrievals is in far better agreement with temporal statistics seen in the AERONET time series retrievals. In addition to that, we also process and validate with another urban area, Mexico City, and the result is also significantly improved by using refined regional VIS/MIR surface reflectance ratio model.

  14. Sparse Recovery Analysis of High-Resolution Climate Data

    NASA Astrophysics Data System (ADS)

    Archibald, R.

    2013-12-01

    The field of compressed sensing is vast and currently very active, with new results, methods, and algorithms appearing almost daily. The first notions of compressed sensing began with Prony's method, which was designed by the French mathematician Gaspard Riche de Prony to extract signal information from a limited number of measurements. Since then, sparsity has been used empirically in a variety of applications, including geology and geophysics, spectroscopy, signal processing, radio astronomy, and medical ultrasound. High-resolution climate studies performed on large scale high performance computing have been producing large amounts of data that can benefit from unique mathematical methods for analysis. This work demonstrates how sparse recovery and L1 regularization can be used effectively on large datasets from high-resolution climate studies.

  15. 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 m and 120 m 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.

  16. High Resolution Optical Spectra of HBC 722 After Outburst

    NASA Astrophysics Data System (ADS)

    Lee, Jeong-Eun; Kang, Wonseok; Lee, Sang-Gak; Sung, Hyun-Il; Lee, Byeong-Cheol; Sung, Hwankyung Sung; Green, Joel D.; Jeon, Young-Beom

    2011-04-01

    We report the results of our high resolution optical spectroscopic monitoring campaign (? = 3800 - 8800 , R = 30000 - 45000) of the new FU Orionis-type object HBC 722. We observed HBC 722 with the BOES 1.8-m telescope between November 26 and December 29, 2010, and FU Orionis itself on January 26, 2011. We detect a number of previously unreported high-resolution K I and Ca II lines beyond 7500 . We resolve the H? and Ca II line profiles into three velocity components, which we attribute to both disk and outflow. The increased accretion during outburst can heat the disk to produce the relatively narrow absorption feature and launch outflows appearing as high velocity blue and red-shifted broad features.

  17. 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.

  18. Microfabrication of High Resolution X-ray Magnetic Calorimeters

    NASA Astrophysics Data System (ADS)

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

    2009-12-01

    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 55 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.

  19. Decadal climate predictions with an high resolution coupled model

    NASA Astrophysics Data System (ADS)

    Monerie, P. A.; Valcke, S.; Moine, M. P.; Maisonnave, E.; Coquart, L.; Cassou, C.; Terray, L.

    2014-12-01

    We analyze the decadal prediction skill of sea surface temperature variability with a high resolution coupled Ocean-Atmosphere General Circulation Model (OAGCM). The HR CERFACS was developed at the CERFACS (Centre Europen de Recherche et de Formation Avance en Calcul Scientifique) laboratory in the framework of the EU-FP7 SPECS (Seasonal-to-decadal climate Predictions for the improvement of European Climate Services) project in order to address the question of decadal predictability with the use of a high spatial resolution. The atmospheric model is ARPEGE/IFS with a T359 spectral truncature and the oceanic model is NEMO at 0.25 resolution including the LIM2 sea ice model. Each hindcasts consist of a 10-members ensemble integrated over a 10-years period. These hindcasts are full-field initialized every year from 1993 to 2009 and initial oceanic state is given by the GLORYS2V1 (0.25 resolution) sea-surface temperatures. Members of a given ensemble (one initialization date) are generated by perturbations of the atmospheric initial conditions. We study the predictability of the global sea-surface temperature focusing on the Atlantic Multidecadal Oscillation (AMO), the Pacific Decadal Oscillation (PDO), the North Atlantic Subpolar Gyre (SPG) and the El-Nino Southern Oscillation (ENSO). We also investigate the prediction skill of the Atlantic Meridional Overturning Circulation (AMOC).

  20. 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.

  1. Very high resolution scanner and image processing system

    NASA Astrophysics Data System (ADS)

    Gibbon, David C.; Kollarits, Richard V.

    1992-08-01

    A high-resolution imaging system employing a CCD line scan camera has been constructed with a resolution of 6000 x 6000 x 12 bits per pixel per color component with a variable pixel aspect ratio. The raw image data is processed in real time to correct for one dimensional artifacts arising from the sensor dark current signal as well as gain and integration control nonuniformities. The gain nonuniformity correction includes second order effects. Two dimensional artifacts attributable to sensor window defects are also removed. The system''s noise performance is found to be limited primarily by sensor shot noise and uncorrected sensor nonuniformities. For most images the system noise is below the visible threshold. This still imaging system has been used to digitize color transparencies up to 6 X 6cm including 35 and 70mm motion picture film for HDTV motion test sequences. 1. OVERVIEW AND DESIGN CONSIDERATIONS The CCD line scan camera described in this paper was designed as a laboratory system to be used as a source of high quality image data for visual communications research. A block diagram of the system is shown in Figure 1. The intent was to produce digital images of sufficient resolution and quality to meet the needs of HDTV researchers for the foreseeable future in fact the scanner''s resolution far exceeds that of present display technology. Output image quality was the primary design consideration and attention

  2. 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.

  3. 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 o (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

  4. 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.

  5. 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.

  6. High-Resolution Light Field Capture With Coded Aperture.

    PubMed

    Wang, Yu-Ping; Wang, Li-Chun; Kong, De-Hui; Yin, Bao-Cai

    2015-12-01

    Acquiring light field with larger angular resolution and higher spatial resolution in low cost is the goal of light field capture. Combining or modifying traditional optical cameras is a usual method for designing light field capture equipment, among which most models should deliberate trade-off between angular and spatial resolution, but augmenting coded aperture avoids this consideration by multiplexing information from different views. On the basis of coded aperture, this paper suggests an improved light field camera model that has double measurements and one mask. The two compressive measurements are respectively realized by a coded aperture and a random convolution CMOS imager, the latter is used as imaging sensor of the camera. The single mask design permits high light efficiency, which enables the sampling images to have high clarity. The double measurement design keeps more correlation information, which is conductive to enhancing the reconstructed light field. The higher clarity and more correlation of samplings mean higher quality of rebuilt light field, which also means higher resolution under condition of a lower PSNR requirement for rebuilt light field. Experimental results have verified advantage of the proposed design: compared with the representative mask-based light field camera models, the proposed model has the highest reconstruction quality and a higher light efficiency. PMID:26285152

  7. High energy resolution scintillators for nuclear nonproliferation applications

    NASA Astrophysics Data System (ADS)

    Zhuravleva, M.; Melcher, C. L.; Stand, L.; Lindsey, A.; Wei, H.; Hobbs, C.; Koschan, M.

    2014-09-01

    The detection of ionizing radiation is important in numerous applications related to national security ranging from the detection and identification of fissile materials to the imaging of cargo containers. A key performance criterion is the ability to reliably identify the specific gamma-ray signatures of radioactive elements, and energy resolution approaching 2% at 662 keV is required for this task. In this work, we present discovery and development of new high energy resolution scintillators for gamma-ray detection. The new ternary halide scintillators belong to the following compositional families: AM2X5:Eu, AMX3, and A2MX4:Eu (A = Cs, K; M = Ca, Sr, Ba; X = Br, I) as well as mixed elpasolites Cs2NaREBr3I3:Ce (RE = La, Y). Using thermal analysis, we confirmed their congruent melting and determined crystallization and melting points. Using the Bridgman technique, we grew 6, 12 and 22 mm diameter single crystals and optimized the Eu concentration to obtain the best scintillation performance. Pulse-height spectra under gamma-ray excitation were recorded in order to measure scintillation light output, energy resolution and light output nonproportionality. The KSr2I5:Eu 4% showed the best combination of excellent crystal quality obtained at fast pulling rates and high light output of ~95,000 photons/MeV with energy resolution of 2.4% at 662 keV.

  8. High Resolution Thz and FIR Spectroscopy of SOCl_2

    NASA Astrophysics Data System (ADS)

    Martin-Drumel, M. A.; Cuisset, A.; Sadovskii, D. A.; Mouret, G.; Hindle, F.; Pirali, O.

    2013-06-01

    Thionyl chloride (SOCl_2) is an extremely powerful oxidant widely used in industrial processes and playing a role in the chemistry of the atmosphere. In addition, it has a molecular configuration similar to that of phosgene (COCl_2), and is therefore of particular interest for security and defense applications. Low resolution vibrational spectra of gas phase SOCl_2 as well as high resolution pure rotational transitions up to 25 GHz have previously been investigated. To date no high resolution data are reported at frequencies higher than 25 GHz. We have investigated the THz absorption spectrum of SOCl_2 in the spectral region 70-650 GHz using a frequency multiplier chain coupled to a 1 m long single path cell containing a pressure of about 15 μbar. At the time of the writing, about 8000 pure rotational transitions of SO^{35}Cl_2 with highest J and K_a values of 110 and 50 respectively have been assigned on the spectrum. We have also recorded the high resolution FIR spectra of SOCl_2 in the spectral range 50-700 wn using synchrotron radiation at the AILES beamline of SOLEIL facility. A White-type cell aligned with an absorption path length of 150 m has been used to record, at a resolution of 0.001 wn, two spectra at pressures of 5 and 56 μbar of SOCl_2. On these spectra all FIR modes of SOCl_2 are observed (ν_2 to ν_6) and present a resolved rotational structure. Their analysis is in progress. T. J. Johnson et al., J. Phys. Chem. A 107, 6183 (2003) D. E. Martz and R. T. Lagemann, J. Chem. Phys. 22,1193 (1954) H. S. P. Müller and M. C. L. Gerry, J. Chem. Soc. Faraday Trans. 90, 3473 (1994)

  9. 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.

  10. 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).

  11. 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.

  12. High-resolution Interferometer Sounder (HIS), phase 2

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The High-resolution Interferometer Sounder (HIS) was successfully built, tested, and flight proven on the NASA U-2/ER-2 high altitude aircraft. The HIS demonstration has shown that, by using the technology of Fourier Transform Spectroscopy (FTS), it is possible to measure the spectrum of upwelling infrared radiance needed for temperature and humidity sounding with high spectral resolution and high radiometric precision. By resolving individual carbon dioxide lines, the retrieved temperature profiles have vertical resolutions of 1 to 2 km and RMS errors less than 1 C, about 2 to 4 times better than possible with current sounders. Implementing this capability on satellite sounders will greatly enhance the dynamical information content of temperature measurements from space. The aircraft model HIS is now a resource which should be used to support field experiments in mesoscale meteorology, to monitor trace gas concentrations and to better understand their effects on climate, to monitor the surface radiation budget and the radiative effects of clouds, and to collect data for research into retrieval techniques, especially under partially cloudy conditions.

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

    NASA Astrophysics Data System (ADS)

    Strozzi, T.; Wiesmann, A.; Kb, 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.

  14. High Resolution, Real-Time Interferometer for Coherent Beam Combination

    NASA Astrophysics Data System (ADS)

    Simion, Sandel; Blanaru, Constantin; Ursescu, Daniel

    2010-04-01

    Piston errors introduced during the pumping of high energy amplifiers in the laser chains are estimated to produce significant distortion and dramatically reduce the intensity of the combined beam resulted from the Coherent Beam Combination (CBC) of ultra intense short pulses. For monitoring the phase and optical path shift, we developed a high resolution real time interferometer. Based on the code counting method, the device is suitable for high speed/real time measurements and is immune to vibrations which might appear in the laser system. The device consists of an analog stage which generates the counting code, later processed by the microprocessor unit (CPU). The analog stage ensures 20 nm resolution, 2 m/s optical path variation speed measurements and has low sensitivity to variations of quadrature signals amplitude. The CPU is based on a complex programmable logic device (CPLD), with 8 ns processing time of the signals. The algorithm provides simultaneously measurements with increasing speed for lower resolution (20 nm at 2 m/s, 40 nm at 4 m/s and 80 nm at 8 m/s), making the system fault tolerant at high speed fluctuations of the optical path. The device contains also a digital-to-analog converter stage, making the instrument suitable for implementation of closed loop control.

  15. High spatial resolution measurements in a single stage ram accelerator

    NASA Technical Reports Server (NTRS)

    Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

    1992-01-01

    High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented in this paper. The ram accelerator is a ramjet-in-tube device which operates in a manner similar to that of a conventional ramjet. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Utilization of special highly instrumented sections of tube has allowed the recording of gas dynamic phenomena with high resolution. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) in a single stage gas mixture are presented and reveal the three-dimensional character of the flow field induced by projectile fins and the canting of the fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, three-dimensional CFD code. The knowledge gained from these experiments and simulations is useful in understanding the underlying nature of ram accelerator propulsive regimes, as well as assisting in the validation of three-dimensional CFD coded which model unsteady, chemically reactive flows.

  16. 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.

  17. 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.

  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. High-Resolution Multisensor Infrastructure Inspection with Unmanned Aircraft Systems

    NASA Astrophysics Data System (ADS)

    Eschmann, C.; Kuo, C.-M.; Kuo, C.-H.; Boller, C.

    2013-08-01

    This paper reports on the investigations made at Fraunhofer Institute for Non-Destructive Testing (IZFP) where different rotary wing micro UAS have been used to scan infrastructures including bridges and monuments at high resolutions for remote damage assessment and monitoring purposes. The aerial pictures taken at high speed and frequency have then been stitched together to obtain full 2D and 3D building reconstructions at a resolution allowing damages and cracking to be observed still in the millimeter range. With these ultra hi-res building reconstruction models a specific data base could be created for each object in order to provide extensive information for long term evaluation and life cycle management. The UAS also have been equipped with sensors for damage size estimation, which combined with an image processing software developed to allow automatic cracking pattern recognition could be used for further analysis.

  20. 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.

  1. High-resolution dot-matrix hologram generation

    NASA Astrophysics Data System (ADS)

    Zarkov, Boban; Gruji?, Duan; Panteli?, Dejan

    2012-05-01

    Holography is a technique that enables us to permanently record three-dimensional (3D) colour pictures. Owing to their sub-micron structure, holograms are remarkable safety devices that are very difficult to counterfeit. Dot-matrix technology, which is one of the commonly used methods, is a substantial obstacle to all types of fraudulent activities. This kind of hologram is mainly used for the purpose of protection against forgery of cheques, cards, passports, etc. Such a high-resolution technique also enables the engineering of 2D and 3D structures, potentially leading to the construction of metamaterials. In this paper, we describe high-resolution holographic structures obtained by dot-matrix devices of novel construction.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. High-resolution alpha-particle spectrometry of ?U.

    PubMed

    Pomm, S; Garca-Torao, E; Marouli, M; Crespo, M T; Jobbgy, V; Van Ammel, R; Paepen, J; Stroh, H

    2014-05-01

    The alpha-particle emission probabilities associated with the three main alpha transitions of (238)U were measured by high-resolution alpha-particle spectrometry. Highly enriched (238)U material was used and its isotopic composition characterised by mass spectrometry. Source production through electrodeposition was optimised to reconcile conflicting demands for good spectral resolution and statistical precision. Measurements were performed at IRMM and CIEMAT for 1-2 years in three different set-ups. A new magnet system was put into use to largely eliminate true coincidence effects with low-energy conversion electrons. Finally the accuracy and precision of the relative emission probabilities for the three transitions - 77.01 (10)%, 22.92 (10)% and 0.068 (10)%, respectively - have been improved significantly. PMID:24355304

  7. 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

  8. 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

  9. 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

  10. High resolution irradiance tailoring using multiple freeform surfaces.

    PubMed

    Bruneton, Adrien; Buerle, Axel; Wester, Rolf; Stollenwerk, Jochen; Loosen, Peter

    2013-05-01

    More and more lighting applications require the design of dedicated optics to achieve a given radiant intensity or irradiance distribution. Freeform optics has the advantage of providing such a functionality with a compact design. It was previously demonstrated in [Buerle et al., Opt. Exp. 20, 14477-14485 (2012)] that the up-front computation of the light path through the optical system (ray mapping) provides a satisfactory approximation to the problem, and allows the design of multiple freeform surfaces in transmission or in reflection. This article presents one natural extension of this work by introducing an efficient optimization procedure based on the physics of the system. The procedure allows the design of multiple freeform surfaces and can render high resolution irradiance patterns, as demonstrated by several examples, in particular by a lens made of two freeform surfaces projecting a high resolution logo (530 160 pixels). PMID:23669912

  11. 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.

  12. High-resolution imaging through strong atmospheric turbulence

    NASA Astrophysics Data System (ADS)

    Jefferies, Stuart M.; Hope, Douglas A.; Hart, Michael; Nagy, James G.

    2013-10-01

    We propose the use of an aperture diverse imaging system for high-resolution imaging through strong atmospheric turbulence. The system has two channels. One channel partitions the aperture into a set of annular apertures that provide a set of images of the target at different spatial resolutions. The other channel feeds an imaging Shack-Hartmann wavefront sensor with a small number of sub-apertures. The combined imagery from this setup is processed using a blind restoration algorithm that captures the inherent temporal correlations in the observed atmospheric wave fronts. This approach shows significant promise for providing high-fidelity imagery for observations acquired through strong atmospheric turbulence. The approach also allows for the separation of the phase perturbations from different layers of the atmosphere. This characteristic offers potential for the accurate restoration of images with fields of view substantially larger than the isoplanatic angle.

  13. 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.

  14. 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

  15. 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.

  16. High Resolution Wavenumber Standards for the Infrared. (IUPAC Recommendations 1995)

    NASA Technical Reports Server (NTRS)

    Guelachvili, G.; Birk, M.; Bord, C.; Brault, J.; Brown, L.; Carli, B.; Cole, A.; Evenson, D.; Fayt, A.; Hausamann, D.; Johns, J.; Kauppinen, J.; Kou, Q.; Maki, A.; Narahari Rao, K.; Toth, R.; Urban, W.; Valentin, A.; Vergs, J.; Wagner, G.; Winnewisser, B.; Winnewisser, M.

    1995-01-01

    The calibration of high resolution infrared spectra is generally more precise than accurate even when they are recorded with Fourier interferometers. In order to improve the consistency of the spectral measurements, an IUPAC project has been undertaken. Its aim was to recommend a selection of spectral lines as wavenumber standards for absolute calibration in the infrared. This paper will report the final recommendations in the spectral range extending from about 4 to about 7000 cm(be).

  17. LandScan 2013 High Resolution Global Population Data Set

    Energy Science and Technology Software Center (ESTSC)

    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.

  18. 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.

  19. HIS analyses of mesoscale phenomena. [High resolution Interferometer Sounder

    NASA Technical Reports Server (NTRS)

    Bradshaw, John T.; Fuelberg, Henry E.

    1990-01-01

    Results are presented from two sets of measurements made by the High-resolution Interferometer Sounder (HIS) during two aircraft flights over the Cooperative-Huntsville-Meteorological-Experiment region on June 15 and 19, 1986. It is shown that the temperature and the dew-point field retrieved from HIS spectra contain distinct mesoscale structures. The features in the HIS dew-point fields agreed well with the cloud and moisture structures observed in visible and 6.7 micron GOES imagery.

  20. High-Resolution Water Vapor Mapping from Interferometric Radar Measurements.

    PubMed

    Hanssen; Weckwerth; Zebker; Klees

    1999-02-26

    Spaceborne radar interferometric delay measurements were used to infer high-resolution maps of integrated atmospheric water vapor, which can be readily related to meteorological phenomena. Maps of the water vapor distribution associated with a precipitating cloud, a partly precipitating cold front, and horizontal convective rolls reveal quantitative measures that are not observed with conventional methods, and suggest that such radar observations can be used for forecasting and to study atmospheric dynamics. PMID:10037594

  1. 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.

  2. 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.

  3. A high resolution cavity BPM for the CLIC Test Facility

    SciTech Connect

    Chritin, N.; Schmickler, H.; Soby, L.; Lunin, A.; Solyak, N.; Wendt, M.; Yakovlev, V.; /Fermilab

    2010-08-01

    In frame of the development of a high resolution BPM system for the CLIC Main Linac we present the design of a cavity BPM prototype. It consists of a waveguide loaded dipole mode resonator and a monopole mode reference cavity, both operating at 15 GHz, to be compatible with the bunch frequencies at the CLIC Test Facility. Requirements, design concept, numerical analysis, and practical considerations are discussed.

  4. High resolution studies of atoms and small molecules

    SciTech Connect

    Bushaw, B.A.; Tonkyn, R.G.; Miller, R.J.

    1992-10-01

    High resolution, continuous wave lasers have been utilized successfully in studies of small molecules. Examples of two-photon excitation schemes and of multiple resonance excitation sequences will be discussed within the framework of the spectroscopy and dynamics of selected Rydberg states of nitric oxide. Initial results on the circular dichroism of angular distributions in photoelectron spectra of individual hyperfine states of cesium will also be discussed, but no data given.

  5. Monitoring SiO Maser Emissions in High Time Resolution

    NASA Astrophysics Data System (ADS)

    Indermuehle, Balthasar; McIntosh, Gordon

    2014-04-01

    We propose high time resolution (weekly) observations of L2 Puppis and R Doradus in the v = 0, 1, 2 and 3; J=1-0 and J=2-1 SiO maser transitions. These observations will permit us to continue studying the interaction of the non-radial stellar pulsation with the circumstellar material. These observations are of short duration and require minimal time of order 30 minutes per week.

  6. 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.

  7. High-resolution climatology of lightning in Central Europe

    NASA Astrophysics Data System (ADS)

    Wapler, Kathrin

    2013-04-01

    Lightning pose a significant threat to life, property and economy. Hence, the detailed knowledge of the occurrence of lightning is important. A high-resolution climatology allows assessing the local risk of lightning. A 5-year analysis (including data of >30 million strokes measured by the LIghtning detection NETwork LINET) of the spatial and temporal occurrence of lightning in Germany and neighbouring areas is presented. The analysis on a high-resolution grid with spatial resolution of 1 km enables identifying local features, e.g. this resolution is high enough to identify TV towers which trigger lightning. The data set allows studying local effects, e.g. the influence of orography on the occurrence of thunderstorms. The analysis reveals spatial and temporal patterns. The highest numbers of lightning strokes occur in the pre-alpine region of southern Germany; further local maxima exist in low mountain ranges. The lowest number of lightning is present in areas of the North Sea and Baltic Sea. Despite a high year-to-year variability of lightning rates, on average a clear annual cycle (maximum June to August) and diurnal cycle (maximum in the afternoon) is present. Additionally to this well-known annual and diurnal pattern, the data show that those are intertwined: the diurnal cycle has an annual cycle, visible in the time of daily maximum which occurs later in the afternoon in summer compared to spring and autumn. Furthermore an annual cycle of mean IC height, i.e. rising IC height during the year with a maximum in late summer, is shown.

  8. High-resolution solid-state NMR of quadrupolar nuclei

    PubMed Central

    Meadows, Michael D.; Smith, Karen A.; Kinsey, Robert A.; Rothgeb, T. Michael; Skarjune, Robert P.; Oldfield, Eric

    1982-01-01

    We report the observation of high-resolution solid-state NMR spectra of 23Na (I = [unk]), 27Al (I = [unk]) and 51V (I = [unk]) in various inorganic systems. We show that, contrary to popular belief, relatively high-resolution (?10 ppm linewidth) spectra may be obtained from quadrupolar systems, in which electric quadrupole coupling constants (e2qQ/h) are in the range ?1-5 MHz, by means of observation of the (, -) spin transition. The (, -) transition for all nonintegral spin quadrupolar nuclei (I = [unk], [unk], [unk], or [unk]) is only normally broadened by dipolar, chemical shift (or Knight shift) anisotropy or second-order quadrupolar effects, all of which are to a greater or lesser extent averaged under fast magic-angle sample rotation. In the case of 23Na and 27Al, high-resolution spectra of 23NaNO3 (e2qQ/h ?300 kHz) and ?-27Al2O3 (e2qQ/h ?2-3 MHz) are presented; in the case of 51V2O5 (e2qQ/h ?800 kHz), rotational echo decays are observed due to the presence of a ?103-ppm chemical shift anisotropy. The observation of high-resolution solid-state spectra of systems having spins I = [unk], [unk], and [unk] in asymmetric environments opens up the possibility of examining about two out of three nuclei by solid-state NMR that were previously thought of as inaccessible due to the presence of large (a few megahertz) quadrupole coupling constants. Preliminary results for an I = [unk] system, 93Nb, having e2qQ/h ?19.5 MHz, are also reported. PMID:16593165

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

    NASA Astrophysics Data System (ADS)

    1990-10-01

    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.

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

    NASA Astrophysics Data System (ADS)

    1990-10-01

    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.

  11. 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.

  12. 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.

  13. High-resolution absolute position detection using a multiple grating

    NASA Astrophysics Data System (ADS)

    Schilling, Ulrich; Drabarek, Pawel; Kuehnle, Goetz; Tiziani, Hans J.

    1996-08-01

    To control electro-mechanical engines, high-resolution linear and rotary encoders are needed. Interferometric methods (grating interferometers) promise a resolution of a few nanometers, but have an ambiguity range of some microns. Incremental encoders increase the absolute measurement range by counting the signal periods starting from a defined initial point. In many applications, however, it is not possible to move to this initial point, so that absolute encoders have to be used. Absolute encoders generally have a scale with two or more tracks placed next to each other. Therefore, they use a two-dimensional grating structure to measure a one-dimensional position. We present a new method, which uses a one-dimensional structure to determine the position in one dimension. It is based on a grating with a large grating period up to some millimeters, having the same diffraction efficiency in several predefined diffraction orders (multiple grating). By combining the phase signals of the different diffraction orders, it is possible to establish the position in an absolute range of the grating period with a resolution like incremental grating interferometers. The principal functionality was demonstrated by applying the multiple grating in a heterodyne grating interferometer. The heterodyne frequency was generated by a frequency modulated laser in an unbalanced interferometer. In experimental measurements an absolute range of 8 mm was obtained while achieving a resolution of 10 nm.

  14. Regional High Resolution Reanalysis Covered European North East Shelf

    NASA Astrophysics Data System (ADS)

    Bourdalle-Badie, R.; Benkiran, M.; Chanut, J.; Drillet, Y.; Reffray, G.

    2011-12-01

    Mercator-Ocean has developed a regional forecasting system at 1/12 resolution over the North East Atlantic (IBI: Iberia, Biscay and Irish), taking advantage of the recent developments in NEMO. This regional forecasting system uses boundary conditions from the Mercator-Ocean global reanalysis (GLORYS: Global Ocean ReanalYses and Simulations). The assimilation component of the Mercator Ocean system, is based on a reduced-order Kalman filter (the SEEK or Singular Extended Evolutive Kalman filter). An IAU method (Incremental Analysis Updates) is used to apply the increments in the system. The error statistics are represented in a sub-space spanned by a small number of dominant 3D error directions. The data assimilation system allows to constrain the model in a multivariate way with Sea Surface Temperature (AVHRR + Multi-satellite High resolution), together with all available satellite Sea Level Anomalies, and with in situ observations from the CORA-03 data base, including ARGO floats temperature and salinity measurements. This reanalysis covers the period from January 2002 to December 2009. In this presentation, the results obtained with this reanalysis system (1/12) are compared to the GLORYS ones. A special focus will be made on the gain thanks to the higher resolution of the model and higher resolution of the SST assimilated in this reanalysis.

  15. High Resolution Cluster Pressure Profile Measurements with MUSTANG and Bolocam

    NASA Astrophysics Data System (ADS)

    Romero, Charles; Mason, Brian S.; Sayers, Jack; Young, Alexander; Dicker, Simon; Mroczkowski, Tony; Reese, Erik D.; Sarazin, Craig L.; Czakon, Nicole G.; Devlin, Mark J.; Korngut, Phillip

    2015-01-01

    Accurate high-resolution intracluster medium (ICM) pressure profiles will help further constrain cosmological parameters as well as baryonic physics in the cores of clusters of galaxies. MUSTANG, a 90 GHz bolometer array on the Green Bank Telescope (GBT) is among the highest resolution (9' FWHM) instruments at 90 GHz, and is among the best instruments to observe the ICM given its sensitivity. We present results from a sub-sample of the Cluster Lensing And Supernova with Hubble (CLASH) clusters of galaxies observed with both MUSTANG and Bolocam. Bolocam, a 150 GHz bolometer array on the CSO with 58' FWHM, and MUSTANG data probe different, and highly complementary, angular (size) scales. We jointly fit spherical electron pressure profiles to the two datasets and find that the addition of the high resolution MUSTANG data can considerably improve constraints on the pressure profiles. A major asset of our fitting algorithm is the ability to uniquely fit for contaminants such as point sources, and thus allowing us to determine the signal from the underlying ICM. We compare our best fit profiles to X-ray determined pressure profiles (provided by ACCEPT), where we find good agreement. Finally we investigate the implications of our results and describe ongoing work to extend this analysis to the full set of CLASH clusters viewable by the GBT, and to obtain even better results with the MUSTANG-1.5 camera

  16. Very High Angular Resolution Diffractive-Refractive Telescopes

    NASA Astrophysics Data System (ADS)

    Gorenstein, P.

    2003-03-01

    Larger versions of diffractive and refractive X-ray devices currently in use at synchrotron facilities for X-ray microscopy are potentially an entire new class of X-ray optics for astronomy. These elements can be configured as either high angular resolution telescopes for imaging, or high throughput concentrators for X-ray timing and moderate resolution spectroscopy with cryogenic or solid state detectors. They are theoretically capable of providing very high angular resolution on a level than can either complement or be an alternative to X-ray interferometry for imaging a black hole during the Beyond Einstein era. They also themselves can be configured for X-ray interferometry. As they are normal incidence devices, which operate in transmission, compared to grazing incidence telescopes they are extremely lightweight per unit area and the surface smoothness is much less critical. However, two major impediments must be overcome before devices composed of diffractive-refractive elements can be applied. They are chromatic aberration and like X-ray interferometry the need to accommodate extremely long focal lengths and separations between components with precision formation flying between multiple spacecraft. The latter requires the development of new technology for mission operations. We describe methods for dealing with chromatic aberration including a technique described by Leon Van Speybroeck.

  17. High-fidelity spectroscopy at the highest resolutions

    NASA Astrophysics Data System (ADS)

    Dravins, D.

    2010-05-01

    High-fidelity spectroscopy presents challenges for both observations and in designing instruments. High-resolution and high-accuracy spectra are required for verifying hydrodynamic stellar atmospheres and for resolving intergalactic absorption-line structures in quasars. Even with great photon fluxes from large telescopes with matching spectrometers, precise measurements of line profiles and wavelength positions encounter various physical, observational, and instrumental limits. The analysis may be limited by astrophysical and telluric blends, lack of suitable lines, imprecise laboratory wavelengths, or instrumental imperfections. To some extent, such limits can be pushed by forming averages over many similar spectral lines, thus averaging away small random blends and wavelength errors. In situations where theoretical predictions of lineshapes and shifts can be accurately made (e.g., hydrodynamic models of solar-type stars), the consistency between noisy observations and theoretical predictions may be verified; however this is not feasible for, e.g., the complex of intergalactic metal lines in spectra of distant quasars, where the primary data must come from observations. To more fully resolve lineshapes and interpret wavelength shifts in stars and quasars alike, spectral resolutions on order R=300 000 or more are required; a level that is becoming (but is not yet) available. A grand challenge remains to design efficient spectrometers with resolutions approaching R=1 000 000 for the forthcoming generation of extremely large telescopes.

  18. 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.

  19. Nucleotide Extension Genotyping by High-Resolution Melting

    PubMed Central

    Liew, Michael; Wittwer, Carl; Voelkerding, Karl V.

    2010-01-01

    One limitation of small amplicon melting is the inability to genotype certain nearest-neighbor symmetric variations without manipulating the sample. We have developed a method for these exceptions: a high-resolution melting single nucleotide extension assay. Single nucleotide extension was performed in a new instrument, the LightScanner 32 (LS32), which uses capillary reaction tubes and is capable of real-time PCR and sequential high-resolution melting of 32 samples. Asymmetric PCR used Platinum Taq and LC Green Plus in the master mix for target amplification. Dideoxynucleotides and extension oligonucleotides were sequestered in the tube cap and added post-PCR, maintaining a closed system. One dideoxynucleotides was used per capillary tube. Samples were cycled five times to incorporate dideoxynucleotides into the extension products using ThermoSequenase, followed by high-resolution melting. Single nucleotide polymorphisms from the RET proto-oncogene (n = 7), hemochromatosis (HFE, n = 30), coagulation factor 2 (F2, n = 29), coagulation factor 5 (F5, n = 30), and methylenetetrahydrofolate reductase (MTHFR, n = 60) genes were genotyped. The DNA melting profiles identified the target single nucleotide polymorphisms by the lowest melting temperature transition. All genotypes had a distinctive melting pattern. The method was 100% concordant with samples previously genotyped at HFE, MTHFR, and F2 and 90% concordant with F5. F5 discordants were genotyped correctly by redesigning the assay. Our results demonstrate that although single nucleotide polymorphisms can be successfully differentiated using this methodology, the method requires careful optimization. PMID:20847280

  20. Modeling high-resolution broadband discourse in complex adaptive systems.

    PubMed

    Dooley, Kevin J; Corman, Steven R; McPhee, Robert D; Kuhn, Timothy

    2003-01-01

    Numerous researchers and practitioners have turned to complexity science to better understand human systems. Simulation can be used to observe how the microlevel actions of many human agents create emergent structures and novel behavior in complex adaptive systems. In such simulations, communication between human agents is often modeled simply as message passing, where a message or text may transfer data, trigger action, or inform context. Human communication involves more than the transmission of texts and messages, however. Such a perspective is likely to limit the effectiveness and insight that we can gain from simulations, and complexity science itself. In this paper, we propose a model of how close analysis of discursive processes between individuals (high-resolution), which occur simultaneously across a human system (broadband), dynamically evolve. We propose six different processes that describe how evolutionary variation can occur in texts-recontextualization, pruning, chunking, merging, appropriation, and mutation. These process models can facilitate the simulation of high-resolution, broadband discourse processes, and can aid in the analysis of data from such processes. Examples are used to illustrate each process. We make the tentative suggestion that discourse may evolve to the "edge of chaos." We conclude with a discussion concerning how high-resolution, broadband discourse data could actually be collected. PMID:12876447

  1. 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.

  2. Distributed Modeling with Parflow using High Resolution LIDAR Data

    NASA Astrophysics Data System (ADS)

    Barnes, M.; Welty, C.; Miller, A. J.

    2012-12-01

    Urban landscapes provide a challenging domain for the application of distributed surface-subsurface hydrologic models. Engineered water infrastructure and altered topography influence surface and subsurface flow paths, yet these effects are difficult to quantify. In this work, a parallel, distributed watershed model (ParFlow) is used to simulate urban watersheds using spatial data at the meter and sub-meter scale. An approach using GRASS GIS (Geographic Resources Analysis Support System) is presented that incorporates these data to construct inputs for the ParFlow simulation. LIDAR topography provides the basis for the fully coupled overland flow simulation. Methods to address real discontinuities in the urban land-surface for use with the grid-based kinematic wave approximation used in ParFlow are presented. The spatial distribution of impervious surface is delineated accurately from high-resolution land cover data; hydrogeological properties are specified from literature values. An application is presented for part of the Dead Run subwatershed of the Gwynns Falls in Baltimore County, MD. The domain is approximately 3 square kilometers, and includes a highly impacted urban stream, a major freeway, and heterogeneous urban development represented at a 10-m horizontal resolution and 1-m vertical resolution. This resolution captures urban features such as building footprints and highways at an appropriate scale. The Dead Run domain provides an effective test case for ParFlow application at the fine scale in an urban environment. Preliminary model runs employ a homogeneous subsurface domain with no-flow boundaries. Initial results reflect the highly articulated topography of the road network and the combined influence of surface runoff from impervious surfaces and subsurface flux toward the channel network. Subsequent model runs will include comparisons of the coupled surface-subsurface response of alternative versions of the Dead Run domain with and without impervious surfaces. Following this we will compare the homogeneous domain with a version incorporating the spatial pattern of surficial soil properties and three-dimensional heterogeneity in the subsurface.

  3. High-resolution microscopy with low-resolution objectives: correcting phase aberrations in Fourier ptychography

    NASA Astrophysics Data System (ADS)

    Konda, Pavan Chandra; Taylor, Jonathan M.; Harvey, Andrew R.

    2015-09-01

    The spatial resolution of a microscope is inversely proportionate to the sum of the objective numerical aperture (NA) and the illumination NA. Fourier Ptychography (FP) microscopy achieves high-resolution, wide-field imaging by the use of a low-NA, wide-field objective combined with time-sequential synthesis of high NA illumination using an array of LEDs. We describe reconstruction algorithms based on Fresnel propagation, rather than the traditional Fraunhofer propagation, which enables more accurate representation of LED illumination and hence reduced aberration in the image reconstruction. This also enables the new technique of Multi-Aperture Fourier Ptychography in the near-field. In this work the implementation of this algorithm is described together with some experimental results. The performance of this algorithm is validated by comparing to Fraunhofer based algorithm. More sophisticated update functions in the reconstruction procedures developed for FP are implemented with this algorithm and their performance is validated. The pupil phase can also be reconstructed during the reconstruction procedure hence allowing us to correct for the aberrations in the optical system without the need of any additional measurements.

  4. 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

  5. Demonstrating the Power of Chandra High Resolution Spectroscopy Plasma Diagnostics

    NASA Technical Reports Server (NTRS)

    Drake, Jeremy

    2000-01-01

    The Chandra spectrometers can resolve spectroscopic features that can be used to diagnose the state of emitting plasma. Based on high resolution Chandra High Energy Transmission Grating (HETG) calibration observations of the active RS CVn-type Binary V711 Tau (HR1099), we determine for the first time the plasma density at a range of coronal temperatures for this type of object. The results are used to constrain coronal structural models and build a picture of the change in coronal structure from stars of solar-like activity to the most active RS CVn-type binaries.

  6. Compressive Fresnel holography approach for high-resolution viewpoint inference.

    PubMed

    Rivenson, Yair; Shalev, Maya Aviv; Zalevsky, Zeev

    2015-12-01

    Holography provides a means for indirect acquirement and reconstruction of 3-D object features. Here, we demonstrate high-resolution viewpoint object inference by formulating the object's reconstruction in the framework of compressive sensing. Further, when the object is dominated by speckle noise and cannot be considered to be sparse, we propose a digital resampling diversity compressive sensing approach to reconstruct a high-quality viewpoint inferred object. The results can be used in all types of holography for display and research purposes. PMID:26625062

  7. On a large time-step high resolution scheme

    NASA Technical Reports Server (NTRS)

    Harten, A.

    1986-01-01

    This paper presents a class of new second-order accurate (2K + 3)-point explicit schemes for the computation of weak solutions of hyperbolic conservation laws, that are total-variation-diminishing under a Courant-Friedrichs-Lewy restriction of K. These highly nonlinear schemes are obtained by applying a nonoscillatory first-order accurate (2K + 1)-point scheme to a modified flux. The derived second-order accurate schemes achieve high resolutions, while retaining the robustness of the original first-order accurate scheme.

  8. High resolution upgrade of the ATF damping ring BPM system

    SciTech Connect

    Terunuma, N.; Urakawa, J.; Frisch, J.; May, J.; McCormick, D.; Nelson, J.; Seryi, A.; Smith, T.; Woodley, M.; Briegel, C.; Dysert, R.; /Fermilab

    2008-05-01

    A beam position monitor (BPM) upgrade at the KEK Accelerator Test Facility (ATF) damping ring has been accomplished in its first stage, carried out by a KEK/FNAL/SLAC collaboration under the umbrella of the global ILC R&D effort. The upgrade consists of a high resolution, high reproducibility read-out system, based on analog and digital downconversion techniques, digital signal processing, and also tests a new automatic gain error correction schema. The technical concept and realization, as well as preliminary results of beam studies are presented.

  9. 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.

  10. 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.

  11. 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.

  12. A New Thermal Method for High-resolution Aquifer Characterization

    NASA Astrophysics Data System (ADS)

    Liu, G.; Knobbe, S.; Butler, J. J.; Reboulet, E. C.

    2011-12-01

    Spatial variations in flow and transport properties play an important role in solute movement in aquifer systems. A major challenge has been to develop field methods that allow information about these variations to be obtained at the resolution needed to characterize transport in heterogeneous formations. Recently, we have developed a new thermal method that holds considerable promise for obtaining high-resolution information about aquifer structure and, potentially, groundwater flux in an efficient fashion. This new approach, which is based on Raman scattering distributed temperature sensing along fiber optic cables deployed below the water table, was applied to a field site located in the floodplain of the Kansas River in the central United States. Results indicate that the temperature profiles obtained using this method are remarkably consistent with hydraulic conductivity (K) estimates obtained through other means at the same location and provide new insights into the factors controlling the relatively large K variations observed within the sand and gravel aquifer at this site. The temperature profiles were significantly changed when a nearby pump was turned on, particularly in the vicinity of the vertical interval of the pump intake, demonstrating the convergence of groundwater flow on the pump intake. The high resolution possible with distributed temperature sensing enables this new method to provide a more detailed representation of aquifer dynamics and structure than previous approaches.

  13. High resolution near-infrared deep fields with MCAO

    NASA Astrophysics Data System (ADS)

    Lacy, Mark; Ridgway, Susan; Jaggannathan, Preshanth; Pforr, Janine; Maraston, Claudia; Servs Team

    2014-07-01

    We have used the SERVS warm Spitzer survey to identify five rare 3-star asterisms suitable for extragalactic observations with the current multi-conjugate adaptive optics GeMS/GSAOI instrument on Gemini-South, and have been awarded time to observe them. Initial observations of one of the fields show that high image quality (better than HST in K-band) can be obtained across the entire field of view. We use lower-resolution surveys from Herschel, Spitzer and ground-based near-infrared observations to characterize the galaxies in the fields and estimate photo-zs. We discuss the use of high resolution multi-wavelength data can be used in conjunction with these images to characterize the morphologies of starforming galaxy population in these fields, concentrating on deep, 0.2" resolution 8GHz VLA data we have for three of the fields. Finally, we describe how pilot surveys such as these can be extended into the TMT era, and discuss the additional science goals that could be achieved using data from TMT instruments.

  14. 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 Abbes 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 Abbes 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.

  15. The sun and nearby stars: microwave observations at high resolution.

    PubMed

    Kundu, M R; Lang, K R

    1985-04-01

    High-resolution microwave observations are providing new insights into the nature of active regions and eruptions on the sun and nearby stars. The strength, evolution, and structure of magnetic fields in coronal loops can be determined by multiple-wavelength observations with the Very Large Array. Flare models can be tested with Very Large Array snapshot maps, which have angular resolutions of better than 1 second of arc in time periods as short as 10 seconds. Magnetic changes that precede solar eruptions on time scales of tens of minutes involve primarily emerging coronal loops and the interactions of two or more loops. Magnetic reconnection at the interface of two closed loops may accelerate electrons and trigger the release of microwave energy in the coronal parts of the magnetic loops. Nearby main-sequence stars of late spectral type emit slowly varying microwave radiation and stellar microwave bursts that show striking similarities to those of the sun. PMID:17811548

  16. 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)

  17. High-Resolution Multiphoton Imaging of Tumors In Vivo

    PubMed Central

    Wyckoff, Jeffrey; Gligorijevic, Bojana; Entenberg, David; Segall, Jeffrey; Condeelis, John

    2014-01-01

    Analysis of the individual steps in metastasis is crucial if insights at the molecular level are to be linked to the cell biology of cancer. A technical hurdle to achieving the analysis of the individual steps of metastasis is the fact that, at the gross level, tumors are heterogeneous in both animal models and patients. Human primary tumors show extensive variation in all properties ranging from growth and morphology of the tumor through tumor-cell density in the blood and formation and growth of metastases. Methods capable of the direct visualization and analysis of tumor-cell behavior at single-cell resolution in vivo have become crucial in advancing the understanding of mechanisms of metastasis, the definition of microenvironment, and the markers related to both. This article discusses the use of high-resolution multiphoton imaging of tumors (specifically breast tumors in mice) in vivo. PMID:21969629

  18. The sun and nearby stars - Microwave observations at high resolution

    NASA Technical Reports Server (NTRS)

    Kundu, M. R.; Lang, K. R.

    1985-01-01

    High-resolution microwave observations are providing new insights into the nature of active regions and eruptions on the sun and nearby stars. The strength, evolution, and structure of magnetic fields in coronal loops can be determined by multiple-wavelength observations with the Very Large Array. Flare models ccan be tested with Very Large Array snapshot maps, which have angular resolutions of better than 1 second of arc in time periods as short as 10 seconds. Magnetic changes that precede solar eruptions on time scales of tens of minutes involve primarily emerging coronal loops and the interactions of two or more loops. Magnetic reconnection at the interface of two closed loops may accelerate electrons and trigger the release of microwave energy in the coronal parts of the magnetic loops. Nearby main-sequence stars of late spectral type emit slowly varying microwave radiation and stellar microwave bursts that show striking similarities to those of the sun.

  19. High-resolution phosphor screen beam profile monitor

    SciTech Connect

    Yencho, S.; Walz, D.R.

    1985-05-01

    A high-resolution luminescent screen beam profile monitor was developed to allow viewing of both conventional large diameter SLAC e/sup +//e/sup -/ beams, and also collider rf-bunches having small transverse spatial extent, with one instrument. The principal features of the monitor are described. They include the two-power magnification system offering magnifications of 12 and 78X, respectively; the reticle grid which is optically superimposed on the screen image by a cube beam splitter; selection of a suitable camera; and the Al/sub 2/O/sub 3/(Cr) phosphor screen. A simplified version of the monitor for viewing of only micron-sized beams for applications in the collider arcs and final focus regions and achieving a magnification of approx. 40X, coupled with a resolution of approx. 20..mu..m is also presented. 4 refs., 4 figs.

  20. High resolution flat crystal spectrometer for the Shanghai EBIT.

    PubMed

    Xiao, J; Gao, Y; Zhang, X; Lu, D; Hu, W; Gao, M; Chen, W; Zou, Y

    2008-09-01

    We report on a high resolution flat crystal spectrometer designed for the Shanghai EBIT. Its energy range is from 0.5 to 10 keV. Three crystals can be installed in the vacuum chamber simultaneously, and its effective Bragg angle can be covered from 15 degrees to 75 degrees . A vacuum version charge-coupled device detector is used for detection of photons. An energy resolution under 1 eV was reached in measurements of the 4.5 keV Kalpha(1) line by using an x-ray generator with a titanium anode. The spectrometer was also tested to operate well on the Shanghai EBIT by observing the lines of tungsten at around 3.2 keV. PMID:19044398